Thesis and Dissertation Abstracs 1994-1998 For any information, please contact bib-di@inf.puc-rio.br 1994 94_MSc_mathias Adolfo Gil MATHIAS. O gerenciamento de conflitos na elicitacao de requisitos. M.Sc. Diss. Port. Presentation: 14/09/94 197 p. Advisor: Julio Cesar Sampaio do Prado Leite Abstract: The proposed work is a method that supports meetings of requirements elicitation. Each meeting has to be carefully planned, with its objectives well defined. The people directly related to the system must be convoked to the meeting. A leader will do the work of controlling and coordinating the activities during the meeting, aiming the elaboration of a list of requirements that the system has to reach. After each meeting, the participants answer a questionnaire that will be submitted to a system that will detect the main conflicts that have occurred at the meeting, as well the main causes of the conflicts, giving suggestions about the most adequate management techniques to each situation. The conflicts will point the main problems observed by the participants and by the leader during the meeting and that have prejudiced the requirements. New meetings will be done to manage the conflicts detected, aiming to augment the quality of the system requirements. The cycle of meetings will end when there won't exist any more conflicts that can prejudice the next stages of the process of system development. The most important result of the meetings is a list of requirements produced by refinements aiming the elimination of the main problems related to the requirements elicitation. 94_MSc_scuri Antonio Escano SCURI. Filtros interativos para imagens digitais no dominio da frequencia. M.Sc.Diss. Port. Presentation: 14/09/94 50 p. Advisor: Bruno Feijo Abstract: The widespread use of interactive environments as well as the development of powerful Graphical User Interfaces have made it possible to reach new solutions to old problems. In the field of Digital Image Processing this can be very useful, as for the technique of spatial filtering in the frequency domain. With this technique the Fast Fourier Transform (FFT) of an image is obtained and then edited to preserve or reject specific regions, and then the Inverse Fast Transform (IFFT) of the edited FFT provides the resulting filtered image. The present work studies the use of interface elements to create graphical masks that function as filters, and proposes the combination of these filters so as to provide great flexibility to the filtering technique. The creation of the filters and the implementation of the FFT algorithms were done in a prototype of a new image processing system, SPID, which is under development as a platform for Image Processing applications under the Microsoft Windows TM graphical environment. 94_MSc_oliveira Antonio de Padua Albuquerque OLIVEIRA. SERBAC - Suporte a engenharia de requisitos com bases em acoes concretas. M.Sc.Diss. Port. Presentation: 24/03/94 34 p. Advisor: Julio Cesar Sampaio do Prado Leite Abstract: SERBAC is the proposal for a Requirement Definition process. The process uses the Language Extended Lexicon as the main source of External Requirements of an Information System or of a Software System. The External System Requirements are proceeding from: the Concrete Actions realized by the system clients, the External Events answered, and also from Inputs and Outputs of the system. In this dissertation, we discuss the chief problems that the requirements engineer faces during the Elicitation and during the System Requirements Modeling. We also presented a taxonomy for requirements and a survey of the most frequent mistakes in the Systems Requirements. SERBAC was used in the External Requirements Elicitation of the AVP - Autorizacoes de Viagens no Pais, a real system for trip management. 94_MSc_gilvaz Ana Paula Pinho GILVAZ. FAES - Um assistente para entrevistas. M.Sc.Diss. Port. Presentation: 23/06/94 140 p. Advisor: Julio Cesar Sampaio do Prado Leite Abstract: Interviewing is the most common elicitation technique. We designed an automated tool - FAES, to support the software engineer during interviews. FAES implements an interview strategy derived from a conceptual model. The conceptual model was built from methodology approaches used on Information Systems. FAES is an three assistant tool that besides storing information from interview in a structured form, provides real-time information analysis and generates new questions to clarify some aspects and get new information. 94_MSc_ciarlini Angelo Ernani Maia CIARLINI. Sistema para gerencia de banco de dados orientados a objetos em ambiente Prolog (SIGBOP). M.Sc.Diss. Port. Presentation: 28/09/94 100 p. Advisor: Rosana de Saldanha da Gama Lanzelotte Abstract: Relational database management systems (DBMS') are now almost a standard, but they don't provide enough resources to develop non-conventional applications. Artificial Intelligence applications, need to manage knowledge (data and programs) uniformly, while other applications, like Computer Aided Design (CAD) systems, need to manage complex structures. To solve the needs of the former, deductive systems, using logic programming, were proposed and, to solve the needs of the later, the object oriented database model is currently adopted. Prolog is the main implementation of logic language. It provides a high abstraction level, specially suited to develop programs in a quick fashion. The object oriented paradigm provides also means to increment programmer's productivity. In this paper, we try to integrate the object oriented database model and Prolog into an environment based on a personal computer running Microsoft Windows. The main objective is to provide the means to develop quickly non-conventional database applications in such environment, specially applications that need both to manage complex structures and to manage uniformly data and programs. The prototype was validated through the development of a complex and non-trivial volume engineering application. 94_MSc_silva Bruno Costa da SILVA. Deformacao e metamorfose de imagens digitais. M.Sc.Diss. Port. Presentation: 07/06/94 57 p. Advisors: Jonas de Miranda Gomes (IMPA) and Bruno Feijo Abstract: Image metamorphosis is simply a transformation that maps one image into another, altering both its shape and intensities; images deformation is a transformation that changes the shape of an image. These types of transformation have a wide range of applications in remote sensing, medical imaging and, specially, in entertainment industry. This work attempts, through the use of adequate mathematical models, to conceptually describe and analyze digital image deformation and metamorphosis transformations. Moreover, the main techniques for obtaining these transformations are analyzed under this conceptual framework, and topics such as user interface, signal sampling and reconstruction, and two-pass transformations are discussed. Concluding, an implementation and some of its results and problems are presented. 94_MSc_laufer Carlos Cesar LAUFER. Representacoes de cliches de conversacao para cooperacao. M.Sc.Diss. Port. Presentation: 28/07/94 108 p. Advisor: Hugo Fuks Abstract: Cliches - conversation stereotypes - are state transition machines that control the sequencing of dialog events in a conversation between two participants. Cliches are represented in the language of ACCORD - a framework for dialog representation systems using commitment and dialog. The notion of contract - mapped to Winograd's Conversation for Action diagram - is presented as an example of the framework's ability for representation conversation cliches for cooperative work. 94_MSc_duarte Carlos Henrique Cabral DUARTE. O desenvolvimento de um compilador MIRANDA usando um metodo orientado a objetos. M.Sc.Diss. Port. Presentation: 29/07/94 [irr.] p. Advisor: Roberto Ierusalimschy Abstract: The development of functional languages compilers is a complex activity, which demands a careful design to avoid an inefficient final product and to allow it to be maintained and extended in a simple manner. In this paper we describe the development of a compiler for Miranda functional language, developed using a method which joins object orientation as a development process approach and formal specification of programming languages as a design technique, changing this activity into a more tractable and systematic one. 94_MSc_moutinho Claudia Marcia Pereira MOUTINHO. Gerencia de redes de computadores: as arquiteturas padronizadas e suas implementacoes. M.Sc.Diss. Port. Presentation: 25/04/94 226 p. Advisor: Michael Anthony Stanton Abstract: As the complexity of computer network increases, the network management activity becomes more important. An efficient management solution for heterogeneous networks is only possible through the adoption of a standard. Although some network management standards have been defined several years ago, the management tools available today show low levels of sophisticated and automation, and the network administrators have to interfere manually in most management tasks. This paper describes the ISO and the internet community management architectures standards. Some management products are described as examples of the implementation of these standards. This paper also discusses some advanced features that can be added to management tools, improving their "intelligence" and simplifying the network administrators' work. 94_MSc_galucio Eduardo Goncalves GALUCIO. O Sistema IMAGO/2 para processamento digital de imagens orientado a objetos. M.Sc.Diss. Port. Presentation: 29/04/94 132 p. Advisor: Sergio Eduardo Rodrigues de Carvalho Abstract: Imago-2 is a generic system to process digital images. The system has a graphical user interface which makes it easy to use. Various operating targeting image processing were implemented. These operations can classify among pontual, local, geometric and transforms. The images can be visualized with various qualities on different graphic hardware. Various image types can be processed: monochromatic or colored, having pixels as bytes, signed double bytes, IEEE floating point and complex of IEEE floating point. This system is different from similar ones because of its object oriented architecture, which allowed the handling of system's size without any increase in complexity, besides other advantages. Other important characteristic is the system's extensibility in many directions: the number of its operation may increase and other image types may be included. 94_MSc_uchoa Elvira Maria Antunes UCHOA. HEROS - um sistema de banco de dados heterogeneos: integrando esquemas. M.Sc.Diss. Port. Presentation: 11/02/94 202 p. Advisor: Rubens Nascimento Melo Abstract: The increase of the volume of information stored in different Databases Management Systems brings the need of accessing the information without changing it. Heterogeneous Databases Systems has been shown to be the best solution for this problem. The characteristics and abilities of the Heterogeneous databases Systems depends strongly on data model used to express its global schema. The data model must capture the meaning of all data stored in the component Database Systems. Thus, it should be able to capture the specific characteristic of the different integrated data models. Since the component Database Systems are designed and implemented independently, they are typically incompatibilities between the data stored in each of them. Since this heterogeneity has been identified, the data model should support a treatment to produce a single representation on the global schema and insure the data consistency and integrity. In this work, we propose an Object Model to support the global schema of HEROS - a Heterogeneous Databases System. A systematic for component Database Systems schema integration is shown, which is exemplified through the development of case study, with the proposed model. 94_MSc_ayres Fausto Veras Maranhao AYRES. Adicionando persistencia a linguagem PASCAL orientada a objetos. M.Sc.Diss. Port. Presentation: 29/08/94 92 p. Advisor: Rubens Nascimento Melo Abstract: This work presents the database programming language POP (Persistent Object-oriented Pascal) which is an extension of the object-oriented Pascal language. This extension improves the base language with the main feature of database systems - the persistence. The proposed persistence model allows an integration of the base language and a storing subsystem letting the programmer free of the movement of complex objects between volatile and persistent stores. The work does an overview of different persistence models that is used for the evaluation of the proposed one. Implementation issues is also presented. 94_MSc_pereira Florys Fabia Almeida PEREIRA. CDR-uma ferramenta de apoio a cooperação na definicao de requisitos. M.Sc.Diss. Port. Presentation: 08/03/94 115 p. Advisor: Julio Cesar Sampaio do Prado Leite Abstract: From the union of concepts of workgroups and discussion methods oriented to the requirements elicitation of a model and a tool called CDR - Requirements Definition Cooperation - which in its conception conjugates and adapts methods and procedures already used separately, providing an order and a framework to collect systems requirements. The model provides an environment for the study of the problem to be solved, requirements collect and definition, whereas different opinions and views points of the system user and projects customers. 94_MSc_cafezeiro Isabel Leite CAFEZEIRO. Prototipo para especificacao de processos baseado em CSP: um enfoque em orientacao a objetos. Port. M.Sc.Diss. Presentation: 24/03/94 155 p. Advisor: Edward Hermann Haeusler Abstract: Not provided. 94_MSc_nogueira Jose Helano Matos NOGUEIRA. Reconhecimento de planos: uma teoria formal hibrida e implementação de um sistema reconhecedor. M.Sc.Diss. Port. Presentation: 01/12/94 153 p. Advisor: Antonio Luz Furtado Abstract: The central part of intelligent reasoning resides in the agent (human or machine) capacity to realize plans and explain them. Plan recognition process consists in explain observed actions. In this way, plan recognition find out methods that explain this action in some plan instances. Plan recognition complexity appears when we try to infer reasonable plan of actions which are not explicitly observed, but actions which are implicit into agent's knowledge. This process is not purely deductive because it uses a powerful knowledge representation model, heuristics, and a typical library. So, we create a Hybrid Formal Theory (HFT), based in Kautz's formal theory where we include new concepts, rules, and improvements. We also create a Plan Recognition System (RPS) that implement our HFT. Furthermore, in our HFT and RPS we treat some important topics to plan recognition: priorities, exceptions, total and partial plans, and multiple observations. 94_MSc_darsa Lucia DARSA. Deformacao e metamorfose de objetos graficos. M.Sc.Diss. Port. Presentation: 14/07/94 59 p. Advisors: Jonas de Miranda Gomes (IMPA) and Bruno Feijo Abstract: Metamorphosis is defined as a complete change of shape, structure or substance of something. This common sense dictionary definition corresponds to the three main forms of information that must be represented in object models: geometry, topology and properties. This dissertation attempts to describe and analyze the metamorphosis problem in Rn , through the use of objects general enough to encompass, in essence, all classical forms of representation in R2 and R3 . Existing techniques are analyzed as subcases of the generalization, integrating the treatment given to the previously dissociated 2D and 3D metamorphosis problems, and allowing the sharing of some of the techniques. A new approach for 3D metamorphosis, based on a 2D technique, and an implementation are described. 94_MSc_magalhaes Luiz Claudio Schara MAGALHAES. Correio eletronico em portugues. M.Sc.Diss. Port. Presentation: 04/03/94 105 p. Advisor: Michael Anthony Stanton Abstract: The objective of this work is to present alternatives for the transmission of messages in Portuguese using electronic mail. It begins by describing some of the largest networks in operation. Then the concepts of electronic mail are presented, together with the standards that allow the use of a Portuguese-compatible set of characters. A simple coding that may be used in the transmission to these new standards is suggested. Finally, the software that permit the use of this codification and of different sets of characters are analyzed. 94_MSc_coutinho Luiz de Lacerda COUTINHO. Estruturas de dados para o ambiente orientado a objetos Tool. M.Sc.Diss. Port. Presentation: 17/03/94 141 p. Advisor: Sergio Eduardo Rodrigues de Carvalho Abstract: Tool is an object and event oriented programming environment that simplifies the task of building applications with graphical user interfaces. The current version of the programming language and libraries does not support basic data structures. Our objective is to study basic data structures and to include these structures in the context of the object oriented language TOOL. The classes that model data structures will be extended with a number of methods, increasing TOOL's flexibility. A special type of iterator is proposed, simplifying the task of navigating through data structures. Several existing implementations are analyzed, involving concepts, such as variance, levels of abstraction, generic data types and forms of inheritance. 94_MSc_estellita Marcelo Maranhao ESTELLITA. Estudo de criterios de escalonamento em ambiente multiprogramado sob restricoes de reparticao de recursos. M.Sc.Diss. Port. Presentation: 27/12/94 121 p. Advisor: Celso da Cruz Carneiro Ribeiro Abstract: The client of data processing center usually makes his job planning based on the elapsed time of the tasks. On the other hand there is optimization needs that must fulfilled when this kind of resources are used. The motivation is the proposal of new scheduling criteria that can deal with these conflicts, reducing the job average queue time, sharing the total execution time between the clients and keeping the good performance level of the machine. For the evaluation of these criteria, a scheduling simulator was developed which uses a sub-model that represents the system, with the CPU, disks and tape devices. 94_MSc_silva Margareth Prevot da SILVA. O2 ASSIST: uma interface interativa para evolucao de esquemas O2. M.Sc.Diss. Port. Presentation: 26/05/94 92 p. Advisor: Rosana de Saldanha da Gama Lanzelotte Abstract: Unlike relational Database Management Systems (DBMS's), which store only data, object-oriented DBMSs also store code, in the form of methods. Also, the classes of an object-oriented schema may be related, through composition or inheritance. Hence, support for schema evolution is much more complex than that of conventional DBMS's. Although dynamic evolution of schemas is a desirable feature, object-oriented DBMS's provide partial support to it. This work proposes a formalization of a mechanism for schema evolution applied to O2 object-oriented DBMS. This formalization acts as the basis of an interactive support tool to be used for dynamic schema evolution, called O2 Assist. Besides allowing the use of primitives for modification of schemas, keeping users from having to do this job through the use of the textual language provided by O2, O2Assist also provides interactive support for database updating. 94_MSc_sousa Mario Costa SOUSA. Visualizacao cientifica 3D - simulacao numerica de reservatorio de petroleo. M.Sc.Diss. Port. Presentation: 25/05/94 77 p. Advisor: Marcelo Gattass Abstract: This work describes and evaluates scientific visualization techniques applied to datasets resulting from petroleum reservoir numerical simulations. Volume visualization algorithms are implemented and a set of tools are developed and integrated in a 3D visualization system. The system offers an intuitive and ergonomic interface with an advanced functional environment to flexibilize and enhance the analysis of reservoir mechanisms. Applications to real reservoir models show the visualization results. 94_PhD_bigonha Mariza Andrade da Silva BIGONHA. Otimização de codigo em arquiteturas superescalares. Ph.D.Thesis. Port. Presentation: 29/04/94 530 p. Advisor: Jose Lucas Mourao Rangel Netto Abstract: Modern computer architectures led to research looking for better techniques for effective implementation of compilers which must be able to produce high-quality code. In the special case of superscalar architectures we have reduced instructions sets, and instructions must be combined to warrant efficient execution by the compilers, which have more complex back-ends than their CISC counterparts. Objectives of this thesis are: (1) the study of the problems of the code generation for more complex architectures, such as the superscalar ones; (2) the study of the characteristics of existing code generator, specially those intended for these architectures; (3) the study of the characteristics of formal languages for the description of architectures, meant for use with code generators. Among these problems are the interdependence of register allocation and instruction scheduling, and the design of more complex data structures, allowing the use of well-established algorithms reported in the literature. We also present the project of a generator system which produces code generator well-suited for the afore mentioned architectures, and the project and the semantic validation of an architecture description language for use with the generator system. 94_MSc_cerqueira Paulo Monteiro CERQUEIRA. Um Processo para recuperacao de requisitos a partir de especificacoes estruturadas. M.Sc.Diss. Presentation: 12/04/94 126 p. Advisor: Julio Cesar Sampaio do Prado Leite Abstract: Experimental activities in the engineering field are not very common. Our proposal is based on an evolution of a requirements recovery process, using a set of structured specifications. We try to show that a model of user requirements, based on restricted natural language and an auxiliary modeling tool (Language Extended Lexicon), is equivalent to a traditional structured specification, with the advantage of being more user friendly than former. In our experiment, the recovery process has been applied to a significant number of specifications, so several data could be compiled, such as, syntactical errors, semantical errors and vocabulary used in the specifications. The analysis of these data, allowed us to list several observations, that could be useful in the understanding of the domain construction problem. 94_MSc_prates Raquel Oliveira PRATES. Visual LED: uma ferramenta interativa para operacao de interfaces graficas. M.Sc.Diss. Port. Presentation: 15/08/94 58 p. Advisor: Marcelo Gattass Abstract: We described and analyzed the design and development of LED interface graphical editor: Visual LED. Visual LED presents to the user three views: a textual view, a graphical view and a resulting view. The textual and graphical views are editable representations of the same dialog and they are always consistent with each other. The textual view presents the abstract layout of the dialog, in which the user may direct manipulate the elements of the dialog. The user can edit in any of the two views, and is able to switch from one to another at any moment without requesting an explicit switch. The resulting view presents the look-and-feel of the dialog. To create Visual LED, we studied the interaction with other generic graphical editors and interfaces graphical editors. In the text we discuss these graphical editors and we compare them among themselves and with Visual LED. During the study of the graphical editors, we identified some interaction problems and we present some solutions for them. The major problem identified was the impossibility of editing the hierarchy of a group. For this problem we suggest the solution of the tree, for generic graphical editors and concrete layout interfaces graphical editors, and the hierarchical politics for the abstract layout interfaces graphical editors. 94_PhD_cabral Regina Helena Bastos CABRAL. Design ++: um modelo de design de software baseado em processo de desenvolvimento por prototipacao. Ph.D.Thesis. Port. Presentation: 10/06/94 260 p. Advisor: Carlos Jose Pereira de Lucena Abstract: The generalized use of interactive graphical user interfaces has trigged considerable progress in software development environments, particularly those aimed at user interface development. These changes have not been accompanied by results that coherently cover aspects of the design process. The lack of a common terminology about the activities involved in those processes decreases both process reutilization and comparison between different alternatives, thus slowing down results contributing to the characterization and development of environments t support them. Besides, design processes are dependent on the application domain of interest. In this work we define, as scope, application domains which are not concurrent, do not need high semantic feedback, and for which the use of interactive graphical user interfaces is appropriate, as for example in administrative, management, scientific and educational applications. Considering this scope, we present and justify a conceptua hierarchy of levels of abstraction which relates one design model, one approach that adheres to this model as well as emphasizes the separation between the phases of design of the interface and of the application kernel, one set of methods, in the object oriented paradigm, that are coherent with the approach, and the characteristic of a supporting environment. The distinct levels of the hierarchy are presented via a graphical formalism, termed ADVchart, which is adequate for the description of abstract data views and can be supported by an interactive environment. 94_MSc_castro Ricardo Gomes de CASTRO. SCRIPT: uma linguagem de representacao para modelagem de sistemas de informacoes. Port. M.Sc.Diss. Presentation: 28/02/94 175 p. Advisor: Julio Cesar Sampaio do Prado Leite Abstract: This work proposes a difference between the terms information system and software system in the context of organizations that use computational systems to support their activities. The importance of modeling information systems is presented by the demonstration that the great reasons of failure in develop software systems projects are in the social and organizational aspects and that investments in computational systems should give more return when they change the organization processes. We propose the representation language SCRIPT, oriented to Tasks, their Information Products and Roles played by the responsible for their execution, modeling in one systemic vision the software and the environment integration. The language was implemented in the meta-environment Talisman producing a support system for construction of information systems models. The proposal language and the support system were showed in a case study. 94_PhD_silva Sidney Dias da SILVA. Sistemas de banco de dados heterogeneos: modelo de execucao da gerencia de transacoes. Ph.D.Thesis. Port. Presentation: 10/10/94 150 p. Advisor: Rubens Nascimento Melo Abstract: Heterogeneous database systems resulted from the integration of multiple and pre-existing database systems, interconnected by communication networks. Each system is managed by an autonomous, and possibly different, database management system (DBMS). The software that incorporates the facilities to manage the resulting database is called heterogeneous database management system (HDBMS). The transaction management in this introduces challenges due to the composing DBMSs autonomy and heterogeneity. In this work, we present a transaction model for the HDBMS of HEROS Project - an heterogeneous object system being developed at the Departamento de Informatica of PUC-Rio. We also present an architecture proposal for a management system to process the transaction in the defined model and we specify the corresponding transaction management execution model. The transaction model defined is based on an already published proposal. It incorporates some characteristics suitable to the non-traditional requirements of the heterogeneous database systems environment. We specified the execution model using high-level Petri Nets. A prototype system was developed to validate some of the specified functions. 94_MSc_werlang Sonia Souza de Carvalho WERLANG. Metodologias de desenvolvimento de software: confronto entre suas metas e sua utilizacao em uma grande empresa. Port. M.Sc.Diss. Presentation: 14/07/94 66 p. Advisor: Roberto Ierusalimschy Abstract: This thesis intends to compare the theory and the practice of the Software Development Methodology usage in terms of the benefits, motivation factors and barriers verified in case studies. These case studies were conducted in a great Company, and represent the multiple ways to work with it. We hope that the results of this thesis will give some useful information that help us to grow the understanding about Software Development Methodology usage, the main features involved in it and the current actual level of usage. 94_MSc_batista Thais Vasconcelos BATISTA. Controle de versoes no modelo hipermidia de contextos aninhados. M.Sc.Diss. Port. Presentation: 18/03/94 109 p. Advisor: Luiz Fernando Gomes Soares Abstract: The development of Hypermedia Systems requires a conceptual model that offers structures to organize information and operations for their manipulations. In addition, the model must have a mechanism for version management in order to accommodate applications which consistently maintain more than one version of the data. The Nested Context Model is a hypermedia conceptual model designed to include abstractions for document organization and navigation, versions management and conformance with the MHEG proposal. This thesis has three basic objectives. First, it describes the structures proposed by the Nested Context Model and the mechanism for version control. Then, it proposes a notification strategy to maintain consistency. Finally, it discusses the development of a prototype with version control that implements the concepts introduced by the model in a library of classes. Using this library, an interface for authoring and navigation was constructed. ------------------------------------------- 1995 95_PhD_hemerly Andrea Silva HEMERLY. Fundamentos logicos para modelos de usuarios em ambientes cooperativos. Ph.D. Thesis. Port. Presentation: 23/11/95 125 p. Advisor: Marco Antonio Casanova Abstract: The first part revises the Logic background needed for the other parts. It starts by briefly recalling the concepts of normal program and SLD- and SLDNF-resolution. Then it presents major definitions of Default Logic and the concept of default proof for normal defaults. Finally, it discusses cooperative environments and, in particular, a cooperative environment called NICE, on which the development of the third part depends. The second part is based on an interpretation of normal programs into default logic, which uses non-normal defaults. It extends known results about stratified normal programs to programs that satisfy a weaker condition. Then, it presents a proof theory for generic defaults which is sound and complete. In particular, when used in conjunction with stratified normal programs and the given logic default interpretation, the proof theory simulates the behavior of the negation as finite failure rule of SLDNF- resolution. In addition to being interesting by themselves, the results introduced are fundamental for the development of the third part of the thesis. When interacting with a database, a user is typically tempted to infer further information from that explicitly obtained by precious queries. However, these inferences are frequently not valid, because his model of the world the user has often incomplete or even faulty. The third part describes two approaches for devising a cooperative interface, one based on SLDNF-resolution and another based on default logic. Adopting a user model, the interfaces alter the processing of users' requests to include additional information that will block faulty inferences. In both cases, it proved that the cooperative interfaces generate sufficient information to block all misconstrues. The techniques and results presented in this part are easily adaptable to the NICE cooperative environment. 95_MSc_carregal Andre Filipe Lessa CARREGAL. Tche: um ambiente visual Lua. M.Sc.Diss. Port. Presentation: 24/3/95 60 p. Advisor: Roberto Ierusalimschy Abstract: The goal of this work is to describe the Tche (Tiny Canvas-Hosted Environment) system, a visual environment that supports the direct manipulation of Lua visual objects. Tche was designed to be simple, portable and flexible, being also highly user customizable. Tche uses a workspace where the visual objects can be manipulated, modified and browsed. The system allow the use of text Lua commands, offering a real-time interactivity not available in conventional systems. To create the Tche system we analyzed other visual environments such as Visual Basic, ACE, Smalltalk, Oberon, SELF and Tcl/Tk. We discuss the solutions and characteristics of each system in the direct manipulation of visual objects, ease of use and portability. Tche tries to use the most interesting solutions offered, including the object manipulation maintaining its hierarchical position and the use of double buffering techniques in this manipulation. 95_PhD_buchsbaum Arthur Ronald de Vallauris BUCHSBAUM. Logicas da inconsistencia e da incompletude: semantica e axiomatica. Ph.D. Thesis. Port. Presentation: 16/10/95 167 p. Advisor: Tarcisio Haroldo Cavalcanti Pequeno. Abstract: A family of logics suitable for inconsistency and incompleteness are defined. This family is formed by paraconsistent logics (LI*1 e LI*2) paracomplete logics (PCL*) and non alethic logics (NALL*1 a NALL*2), besides the Logic for Epistemic Inconsistency (LEI) and the Logic for Skeptical Reasoning (LSR), elaborated for the formalization of reasoning in the presence of plausible knowledge, reflecting respectively credulous and skeptical attitudes, with respect to the knowledge. For each one of these logics is given a semantics and an axiomatics. Two alternatives of default rule-generated extensions are defined, forming non monotonic logics based respectively on LEI and LSR, suitable to some inductive reasoning forms. 95_MSc_castier Beatriz CASTIER. Visualizacao 3D de unidades geologicas representadas por subdivisoes espaciais. M.Sc. Diss. Port. Presentation: 27/04/95 82 p. Advisors: Luiz Fernando Martha (CIV) and Marcelo Gattass Abstract: In the search and development of oil and gas reservoirs, one of the tasks of subsurface petroleum geology is the mapping of unseen structures that may exist underneath the earth's surface. Earth scientists use 2D tools, contour maps and cross sections, to interpret geological data. However, spatial relationships presented in three dimensions are easier to interpret than if they are shown as a series of 2D representations. The aim of this work is to evaluate the use of spatial subdivision methodology in the representation and visualization of 3D geological models (called block diagrams). This methodology models heterogeneous objects (with different parts made of different materials), by decomposing the space into homogeneous parts, and then describing the way they are connected. To evaluate visualization and manipulation strategies of block diagrams, a prototype interactive-graphics system was developed. Block diagram visualization exploits, as much as possible, the underlying topological data structure characteristics and the rendering functions available in powerful workstations. The work describes a taxonomy for interactive manipulation of 3D objects using 2D input devices. The proposed classification is based on the type of movement control (Screen-based, Walk-through or Object-based), on the type of geometric transformation (translation or rotation), and on the control of viewing parameters (clipping plane positions with respect to the eye point and distance from eye to reference point). Basic Screen-based and Walk-through models are presented. It is proposed a model for Object-based manipulation, which is ideal for objects which present a natural bounding box, such as a block diagram. The suggested strategy for cutting the 3D model includes the design of an intuitive cutting-plane positioning and also exploits the spatial subdivision methodology. 95_PhD_pietrobon Carlos Alberto R. PIETROBON. Gerencia de configuracao em ambiente de trabalho cooperativo. Ph.D. Thesis. Port. Presentation: 20/03/95 360 p. Advisor: Arndt von Staa Abstract: To develop large software systems, software engineering environments are needed. Such environments must support cooperative work. Managing development data is one of the basic requirements of such environments. In this thesis we use Configuration Management to support collaboration between the several people involved in the development. Configuration management controls fine grained objects stored in the repository. These objects are in constant evolution and are shared. They are distributed logically and physically over a network of workstations. Design objects contain small pieces of information and both objects and attributes are versioned. These objects are explicitly linked. We discuss software development environment databases, which are private databases, shared databases and the delta database. The delta database contains all changes made by a specific developer on a shared database. To support multiuser work, we consider the partitioning and distribution of databases over shared platforms interconnected by means of a local network. Owing to these concepts, we show how several developers work in a cooperative way, sharing information, merging information, solving conflicts and propagating alterations. We also show how the developers can work disconnected from the other workstations (databases). 95_MSc_tocantins Claudia de Andrade TOCANTINS. Armazenamento e manipulacao de mapas vetoriais em arquiteturas paralelas. M.Sc. Diss. Port. Presentation: 30/08/95 114 p. Advisor: Marco Antonio Casanova Abstract: Motivated by the need to improve the performance of the execution of spatial operations is a geographical database, this dissertation proposes a method to store and manipulate vector maps in a parallel environment. First, a model for geographic objects and some concepts about vector maps are summarized. A general architecture for geographic objects management is then presented and some variations for a distributed environments are discussed. Then, the storage structure and its variations are explained in detail. Procedures to edit the structure and some heuristics to define an uniform load balancing are described. Finally, some geographic operations are defined and their parallel execution is discussed. 95_MSc_aquino Claudio Alcino dos Santos AQUINO. Visualizacao de movimentos e de interior em modelos solidos de elementos finitos. M.Sc. Diss. Port. Presentation: 07/03/95 75 p. Advisor: Marcelo Gattass Abstract: The present work discusses some techniques of scalar and vector data visualization in finite element solid model post-processors. Computer animation is used to visualize modes of vibration. An original algorithm for mesh simplification is described to enhance the efficiency of the animation process. The visualization of the results in the interior of finite element models is obtained with the use of iso-surfaces, transparency equations are applied. Finally, the verification of presented ideas is made based upon examples analyzed on the development post-processor prototype. 95_MSc_akerman Claudio Luiz AKERMAN. Coleta de lixo em sistemas distribuidos orientados a objetos. M.Sc.Diss. Port. Presentation: 03/04/95 187 p. Advisor: Michael Anthony Stanton Abstract: Many distributed systems are being built these years using the object oriented paradigm. Object oriented programming encourages building complex dynamic structures with a large number of connections among the components of these structures which makes it difficult to determine the nonreachable (garbage) objects manually. Storage recycling is an essential task for avoiding a system failure for lack of storage space. Garbage collection algorithms and techniques do this job automatically. The present work presents a survey of garbage collection algorithms and techniques, from the basic uniprocessor system sharing a single storage space to the most sophisticated collectors designed for multiprocessed distributed systems. Distributed garbage collection adds inherent distribution difficulties to traditional garbage collectors problems, bringing a new sort of challenges to the already existing ones. Some mathematical models are presented for helping to quantify processing and storage space costs of the main classes of algorithms. 95_MSc_barbosa Ellens BARBOSA. Modelagem de sistemas de tempo-real - estudo da caso de um sistema de controle para uma area de linhas de engarrafamento de um composto quimico. M.Sc.Diss. Port. Presentation: 10/10/95. 138 p. Advisor: Bruno Maffeo Abstract: This work constitutes an application of conceptual tools and modeling technique for the construction of the Essential Model and the Implementation Model (Design) for a real-time system which monitors and controls a chemical product bottling lines area. It employs extensions, proposed for the treatment of real-time systems, of tools and techniques used for the modeling of conventional socio-technical systems. Using an activity-oriented approach, it addresses aspects related to the representation of system dynamics with assuring an easily understandable conceptual model and the choice of viable implementation alternative. 95_PhD_poubel Haydee Werneck POUBEL. Estruturando e concretizando especificacoes para implementacoes. Ph.D. Thesis. Port. Presentation: 11/09/95. 83 p. Advisor: Paulo Augusto Silva Veloso Abstract: In this work we propose a formalization of some ideas obtained from the construction of a program, in the context of axiomatic specifications and the Canonical Step Paradigm . In this method, a specification A is implemented in a specification C by constructing D, a conservative extension of C, on which A is interpreted. Our main purpose is to make the Canonic Step process more concrete, or as we defined, effective. To do that, we obtain an implementation of A in C, where the last one expresses the behavior of a machine, by means of its set of axioms, and D expresses the behavior of a program using C. We show that the properties described for an effective canonic step of implementation are preserved by composition, which is based on the Modularization Theorem. We also provide a useful guideline to construct effective implementations. 95_PhD_zhu Jiang ZHU. Sobre a formulacao velocidade-vorticidade do sistema de Stokes e sua aproximacao via elementos finitos. Ph.D.Thesis. Port. Presentation: 12/12/95 78 p. Advisor: Vitoriano Ruas de Barros Santos. Abstract: In this work, we consider the two- and three-dimensional velocity-vorticity formulations of the Stokes equations with a rather handy set of boundary conditions. The equivalence between the standard velocity-pressure formulation and such velocity-vorticity formulation both in two and in three dimension spaces are proved. A corresponding rigorous variational framework also both in two and three dimension spaces are given. In two-dimensional case, two kinds of uncoupled solution and a class of efficient finite element schemes based on the first uncoupling technique by using discrete harmonic functions to approximate a harmonic component of the vorticity are proposed, with an optimal convergence analysis. Finally, some extensions to more general cases such as nonhomogeneous. Dirichlet boundary conditions and multiply connected domains are presented. 95_PhD_perezalcazar Jose de Jesus PEREZ ALCAZAR. Respostas cooperativas baseadas na geracao e reconhecimento de planos. Ph.D.Thesis. Port. Presentation:21/12/95 224 p. Advisor: Antonio Luz Furtado Abstract: When the user accesses a database, she/he frequently does not have a precise idea of the information contained in the database that could help her/him to solve a problem, in other words, to achieve a goal. Then, a flexible systems is necessary to provide the user additional information that allows her/him to find the actions to achieve her/his goal. Such actions, or precisely, operations, integrate the user's original plan. In order to provide this level of assistance, we suggest, in this thesis, that it is very advantageous to include in the Data Base Management Systems interfaces with tools to recognize and generate plans. This thesis describes a cooperative interface to Deductive Databases, based in the plan generation and recognition. We use two techniques that are the state of the art in the plan reasoning area: Abtweak and the Kautz' plan recognition system. The advantage of these techniques is their formal basis, which the great majority of the plan reasoning techniques lacks. Plan recognition allows the system to follow the user's focus of attention in the ongoing session, and plan generation complements it when the user's plan is not found in the typical plans library or the plan cannot be applied in the current state. Therefore, two modules are added to the system: a pre-processing module, which corrects the requests and finds implicit operations related to the request, and a clarification module, which generates a cooperative response when the user's plan is ambiguous. 95_MSc_militao Julio Guido Oliveira MILITAO. Uma metodologia para posicionamento de predios em terrenos acidentados. M.Sc.Diss. Port. Presentation: 06/11/95 88 p. Advisors: Paulo Cesar Pinto Carvalho (IMPA) and Marcelo Gattass Abstract: As a consequence of the widespread urban growth there is a considerable demand for tools that provide support for planning and monitoring urban conglomerates and their infrastructure. The use of Computer Graphics techniques has made it possible to develop tools capable of operating in low costs platforms with high degree of interactivity and precision. This dissertation presents a methodology for positioning buildings on terrain surfaces. As a result of this methodology, a computer system (SYSTER) was developed. SYSTER uses appropriate models for the terrain and the objects to be positioned and provides graphical tools for positioning these objects. The current version supports positioning buildings and roads. Distinct representations are adopted for each type of object. Buildings are solids which are represented, for simplicity, by prisms; roads are seen as thick polygonal lines; terrain surfaces are represented by poliedrical surfaces stored in a topological data structure. An algorithm for combining the different models is provided. Numerical data resulting from this combination - such as the area occupied by the buildings and the buried volume of each building - is produced. As auxiliary tools, we have provided an object editor and a 3-dimensional viewer. The editor allows defining and editing, within the system, the objects to be positioned. The viewer is necessary for better scene exploration. 95_PhD_garcia Laura Sanchez GARCIA. LINX: um ambiente integrado de interface para sistemas de informacao baseados em conhecimento. Ph.D.Thesis. Port. Presentation: 04/05/95 191 p. Advisor: Clarisse Sieckenius de Souza Abstract: Knowledge-based systems have, as one of its principal features, the kind of dialogue that takes place between user and system; it's all a conversation, an explanatory discourse, about abstractions and rationalizations of facts and objects of reality, and where the same dialogue is the crucial point of the application. Aiming at the attendance of these features, especially relating to the provision of adequate explanations, natural language emerges as the intuitively desirable communication code. The present work introduces an hybrid environment in which a pseudo-natural language that has discourse as its leading aspect goes together with direct manipulation resources in the search for an easy and efficient interaction. Integrating different linguistic and computational theories, a close subenvironment allows the exploitation, in a natural way, of the whole potentiality of the knowledge-based system, while the multimodal communication code provides some more insights to human-computer interfaces area. The contribution of this work is complemented by a demonstrative prototype of the environment. 95_MSc_ridolfi Lorenzo Francisco G.G. Maria RIDOLFI. Proposta de uma arquitetura transacional distribuida. M.Sc.Diss. Port. Presentation: 28/09/95 145 p. Advisor: Marco Antonio Casanova Abstract: This work presents an enhanced architecture for distributed transaction processing with additional mechanisms to assure reliability in information storage. It is based on the shared-nothing model, and divides server functions into two kinds of nodes, called transaction servers and storage servers, aiming flexibility in data allocation and tolerance. It also uses a central data communication structure which avoids occurrence of faults with complex fixing procedures. The reliability of this architecture is kept by a recovery and replication mechanism, using the primary-copy replication model, that supports transactions based on their reliability requirements. It offers higher confidence to critical data, while saving resources in ordinary transactions. Additionally, in replication and recovery mechanisms introduces a concept of pseudo-transactions, a transaction with low reliability requirements used to increase the utility of the backup copies, usually poorly used in the primary-copy model. By doing this, it offers a low cost alternative for applications that tolerate a slight data inconsistency. 95_PhD_guedes Luiz Carlos Castro GUEDES. Um modelo orientado a objetos para geracao automatica de compiladores. Ph.D. Thesis. Port. Presentation: 22/08/95 303 p. Advisor: Jose Lucas Mourao Rangel Netto. Abstract: This thesis proposes an object oriented model for semantics directed compiler generation based on the denotational description of the source language. The correctness of the code produced by the generated compilers is proven and the process is compared with Actions Semantics based systems. A precise meaning for reparability is given and it is shown that it can be achieved from denotational semantics with the object oriented model. Some code optimizations are presented and a prototype has been implemented. Performance tests have shown that our system outperforms similar systems and that it just is about one order of magnitude slower than hand-written compilers. This result strongly suggests the adequacy of the object oriented paradigm to the task of semantics directed compiler generation. 95_MSc_bunchaft Maria Elizabeth BUNCHAFT. Uma extensao do processo recursivo de Ortiz de construcao dos polinomios canonicos no metodo TAU de Lanczos. M.Sc.Diss. Port. Presentation: 28/03/95 69 p. Advisor: Therezinha Souza da Costa Abstract: Lanczos-Ortiz's theory of canonical polynomials (c.p.) is extended as regards the following aspects: a) the differential operators which lower the polynomial's degree are included in the theoretical construction; b) the c.p. and the associated indices, respectively, are classified and a formula is proved which gives the set of orders of the primary c.p.; c) the concept of multiplicity of indices is introduced, its general properties are proved and its relations with the structure of multiplicity of the primary c.p. and with the existence of non-primary c.p. are demonstrated; d) in the rather frequent case in with all c.p. are primary, a recurrency formula is proved which generates a basis of primary c.p. and also generates all their multiples arising from distinct indices. Some examples, solved by a software which implements the theoretical results here obtained, called GPC (Generates Canonical Polynomials), illustrate the new theoretical developments. 95_MSc_carneiro Marcelo Medeiros CARNEIRO. Interact- um modelo de interacao para editores graficos. M.Sc.Diss. Port. Presentation: 22/12/95 79 p. Advisor: Marcelo Gattass Abstract: With the current programming technology, the development and implementation of user interface code modules in graphical editors is complex and prone to errors. This work discusses interaction techniques in these systems based on direct manipulation of the objects in the canvases and proposes a model to manager such interactions. This model reduces the programming effort by providing an appropriate abstraction of the interaction tasks. The model defines four basic canvas interaction tasks: construction, selection, transformation and visualization. A class library that implements these abstractions is also presented. Finally, a graphical editor implemented using this model is presented and used to test and validate the ideas of this work. 95_PhD_guimaraes Mario Andre M. GUIMARAES. Um ambiente para ensino de algoritmos introdutorios. Ph.D.Thesis. Port. Presentation: 12/06/95 233 p. Advisor: Carlos Jose Pereira de Lucena Abstract: Introduction to Algorithms is a discipline that demonstrates a high level of difficulty throughout the learning process. Current tools available today help teach concepts through the use of animations or through offering students support in constructing their own algorithms. This work describes the conception and development process of an Environment for Animation and Simulation of Algorithms (ASA) whose strong points are the integration of these modules (teaching and construction), their capacity for generating test data, the offer of multiple representations of information and the introduction of code reusability. Besides this, it presents as its most original feature, a module called Analyzer, which allows teachers to follow-up (navigate) student responses, classifying their errors, generating statistics, emitting orientation and offering pertinent hypothesis. 95_MSc_mediano Mauricio Riguette MEDIANO. V-TREES um metodo de armazenamento para dados vetoriais longos. M.Sc.Diss. Port. Presentation: 19/01/95 80 p. Advisor: Marco Antonio Casanova Abstract: This dissertation introduces a new data structure, called V-tree, designed to store long sequences of points in 2D space and yet allow efficient access to their fragments. V-trees also optimize access to sequence of points when the query involves changes to a smaller scale. They operate in much the same way as positional B-trees do in the context of long fields and they can be viewed as a variant of R-trees. The design of V-trees was motivated by the problem of storing and retrieving geographical objects that are fairly long, such as river margins or political boundaries, and the fact that geographic queries typically access just fragments of such objects, frequently using a smaller scale. 95_MSc_albuquerque Neudson Cavalcante ALBUQUERQUE. Prova automatica de teoremas nas Fork Algebras. M.Sc.Diss. Port. Presentation: 10/11/95 87 p. Advisors: Armando Martins Haeberer and Edward Hermann Haeusler Abstract: The promising expectation of good results on the application of relational algebras on the automatic program development brings the necessity to create critical mass to this algebras, specially on this specific application. Heading this general goal, it is shown here a proof method which makes easier the automatization of the abstract relational algebras theorem proves. Specifically, it is shown a Sequent Calculus to the -Algebras which are an abstract relational algebras extension. Furthermore, it was developed an automatic theorem prover prototype using this method, a first step to a more efficient product. 95_PhD_trales Paulo Roberto TRALES. Resolucao das equacoes de Navier-Strokes pelo metodo das projecoes via elementos finitos com aceleracao pelas tecnicas multigrid. Ph.D. Thesis. Port. Presentation: 06/01/95 123 p. Advisor: Vitoriano Ruas de Barros Santos Abstract: This work deals with the numerical solution of the two-dimensional Navier-Strokes equations. A finite element for unstructured meshes provide an acceleration of the solution procedure. The resulting numerical scheme gave rise to a robust software whose implementation cost is rather low for this class of problems. Numerical tests for flows at Reynolds numbers up to a few thousands were performed both in the context of academic stationary problems and of classical time-dependent problems, with structured and unstructured meshes. The performance and the accuracy of the scheme in all cases allow us to assert that it is a promising one for use in Engineering or industrial applications which can be modeled by these equations. 95_MSc_pereira Paulo Roberto dos Santos PEREIRA. Analise de agrupamentos por mapas de Kohonen. M.Sc. Diss. Port. Presentation: 21/09/95 236 p. Advisor: Ruy Luiz Milidiu Abstract: Several research works have already tested and proved Neural Network applicability to the solution of classification problems. All are based on self-organizing networks developed by Kohonen. We investigate the applicability of Kohonen Maps to Clustering Analysis problems and exemplify with the concrete case of sample data analysis used on surface geochemical work applied to oil exploration. Aspects of project, difficulties and suggestions are discussed. 95_MSc_hubscher Pedro Jorge Eugenio HUBSCHER. Um processo de desenvolvimento de software utilizando TALISMAN e MFC. M.Sc. Diss. Port. Presentation: 11/10/95 55 p. Advisor: Arndt von Staa Abstract: The adoption of operating systems which use a graphical user interface, has greatly increased the difficulty in developing software. New tools have been developed in the effort to counterbalance this increase, however not being successful. The great deficiency of these tools is that they do not allow the specification of the systems being developed, restricting themselves to the automation of specific tasks. This text presents a software development process that integrates TALISMAN - an environment for specification and source code composition - the MFC (Microsoft Foundation Classes) library and other auxiliary tools. The development process focus on the interface specification, coding and module composition steps. Representation languages that permit the combination of specification with a high degree of abstraction and source code fragments are employed. This allows the automatic generation of source code directly from the specifications. Specification standards are defined for each object class used throughout the process. Automatic validators, special programs written in TALISMAN's internal language, allow the critics of specification contributing to increase in quality of the final software. 95_MSc_duarte Renato Carioca DUARTE. Derivacao semi-automatica de modelos entidade relacionamento a partir de descricao de sistemas de informacao. M.Sc.Diss. Port. Presentation: 25/04/95 170 p. Advisor: Julio Cesar Sampaio do Prado Leite Abstract: Not provided. 95_MSc_araujo Renato Goncalves de ARAUJO. Refinamento da cena com quantizacao de cores e tracado de raios. M.Sc. Diss. Port. Presentation: 14/12/95 45 p. Advisor: Marcelo Gattass Abstract: In the Image Synthesis discipline, Distributed Ray Tracing algorithms produce high quality realistic images but are not computationally efficient. This low performance makes the production process tedious and not productive. This work presents two optimizations of the Distributed Ray Tracing algorithm that improves the productivity. The first is a preview technique based on the progressive refinement of the scene. The second is a review of two color quantization algorithms presented in the literature. This work also presents the inclusion of special effects, like refraction, colored lights, anti-aliasing and depth of field in the proposed optimized method. Finally, the ideas presented here are implemented in a program, called RT. Several examples are presented to support some conclusions and suggestions for future work. 95_MSc_soares Ricardo de Assis Mesquita SOARES. Correio eletronico mulimidia/hipermidia. M.Sc.Diss. Port. Presentation: 29/05/95 140 p. Advisor: Luiz Fernando Gomes Soares Abstract: This work presents an experimental multimedia/hypermedia electronic mail system, SMHMS, dealing with issues related to network traffic generation and storage management, which are very important when multimedia messages are the transport objects. The basis for the creation and manipulation of these messages is an multimedia/hypermedia machine that supports objects interchange. The system is built on top of existing mail transport protocol for flexibility, portability and to easy the implementation, and should work on most systems which support the Simple Mail Transfer Protocol (SMTP). To transfer multimedia objects the system makes use of the File Transfer Protocol (FTP), by the same reasons of flexibility, portability and implementation facility, and should work on most systems that support such protocol. 95_MSc_uchoa Rodrigo Cardoso UCHOA. Suporte ao monitoramento e controle de carga em ambientes distribuidos. M.Sc.Diss. Port. Presentation: 31/08/95 127 p. Advisor: Noemi de La Roque Rodrigues Abstract: This thesis discusses the use of the network management framework and protocols as a support platform for load monitoring and controlling in a distributed system. An extension to the management information base (MIB) is proposed in order to deal specifically with system load information. Furthermore, we defined and implemented a SNMP (Simple Network Management Protocol) agent and an object oriented library which provides a high level, protocol independent interface for programming management applications. Finally, an overview of load balancing in distributed systems is presented and the utilization of the management framework as a support mechanism is discussed. 95_MSc_barbosa Simone Diniz Junqueira BARBOSA. Modelagem e especificacao da navegacao em aplicacoes hipermidia. M.Sc.Diss. Port. Presentation: 22/02/95 110 p. Advisor: Daniel Schwabe Abstract: An important feature of hypermedia applications is the freedom to navigate through the network nodes. This flexibility may cause user disorientation, the problem known as lost in hyperspace. This dissertation presents the concept of navigational contexts - defined in the framework of the Object-Oriented Hypermedia Design Methodology -, which offers a consistent way to specify the navigation structure of hypermedia applications, using a hybrid model that combines graph-oriented and set-oriented hypertexts. The navigational contexts attempts to reduce the cognitive load created when navigating in hyperdocuments by proposing paths with well-defined navigational strategies and contextual information that help the user traverse the nodes according to her interest, avoiding user disorientation. 95_MSc_fiorini Soeli T. FIORINI. Processos de negocio e hipertextos: uma proposta para elicitacao de requisitos. M.Sc.Diss. Port. Presentation: 02/05/95 161 p. Advisor: Julio Cesar Sampaio do Prado Leite Abstract: This dissertation is an attempt to integrate business engineering and requirements engineering. It uses business processes methodology and hypertext technology to support requirements elicitation. A Conceptual Model was created to represent the organizational context from the point of view of its business processes, in accordance with a total quality strategy. This model, which is a representation of the processes data structure and its elements, is redefined to ensure its implementation as a hypertext. This hypertext is made available to the software engineer - for reference and requirements elicitation - and to the business engineer - for reference and maintenance. In order to help the software engineer with the process and the requirements elicitation, a structured access to the hypertext information was created. This structured access was based upon a requirements representation (Serbac, Concrete Actions-Based Support to Requirements Engineering) and a business process analysis. In order to validate the structured access, some processes of a business unit within a large company - certified according to ISO 9001 standards - were used. 95_PhD_porto Stella Cavalcanti da Silva PORTO. Algoritmos sequenciais e paralelos para escalonamento de tarefas em processadores heterogeneos sob restricoes de precedencia. Ph.D.Thesis Port. Presentation: 14/11/95 96 p. Advisor: Celso da Cruz Carneiro Ribeiro Abstract: Parallel applications may be represented through task precedence graphs, which determine a partial execution order between tasks. The scheduling of tasks to processors is an essential factor in the reduction of the makespan of a parallel application. In a heterogeneous processor setting, this is even more important, as processors do not present the same processing capacity. In this work, we present different approaches to the solution of two cases of the task scheduling problem on heterogeneous processors under precedence constraints. In the first case, the communication costs between tasks was explicitly considered. Greedy heuristic algorithms are presented and their behavior is analyzed according to the variation of several parameters which characterize the parallel applications to be scheduled and the heterogeneous architecture of the parallel machine. In the second case, without communication delays, a sequential algorithm based on tabu search is proposed. This algorithm obtains significative better solutions with respect to the ones obtained by other greedy algorithms already published in the literature. This sequential tabu search algorithm was paralleled according to four different synchronous strategies, based essentially on the decomposition of the solution space (neighborhood). Computational results have proved that these parallelization strategies achieve almost linear speedup for most of the studied cases. 95_PhD_celesfilho Waldemar CELES Filho. Modelagem configuravel de subdivisoes planares hierarquicas. Ph.D.Thesis. Port. Presentation: 04/07/95 75 p. Advisor: Marcelo Gattass Abstract: Topological data structures have been used to support applications that work with planar subdivisions. Many of theses applications require a hierarchical representation, which is currently not supported by the usual data structures. This work proposes a topological data structure to represent hierarchical planar subdivisions. The proposed data structure answers all the relationships between the topological entities. A set of operators, needed to model such subdivisions, is presented and discussed. To allow the use of such representations over different domains, a strategy for adding a client model to characterize the semantic associated with the model entities is proposed. The development of customizable applications as a strategy of software reuse is also discussed. Customization tools that allow software development with high level of abstraction provide users an easy access to the technology implemented by the applications. For several classes of technical-scientific applications, attributes characterize the semantics of the underlying mathematical model. So, an embedded system for adding configuration mechanisms to applications, based on attributes, is proposed. A model for the communication between an application and the configuration environment, with clearly defined boundaries, is presented. An auxiliary tool for developing highly abstract, interactive graphical applications is also described. Simple, high level programmable access is provided to both conventional interface objects and active graphical objects that are specific to the application domain. This allows occasional programmers to quickly develop their own sophisticated interactive dialogs. The configuration system and the data structure proposed are integrated to provide a powerful hierarchical planar subdivisions modeling tool. 95_MSc_teixeira Wanda dos Santos TEIXEIRA. Uma linguagem de interacao sobre graficos quantitativos. M.Sc.Diss. Port. Presentation: 22/06/95 79 p. Advisor: Clarisse Sieckenius de Souza Abstract: This work proposes a visual interactive language, based on Cognitive Engineering and on Semiotic Engineering, for the communication with mathematical models in computer applications. The visualizations treated by the language are the pie, bar and line charts. Through the language the user can visualize, interpret and manipulate models data and results interactively, which helps him considerably in the decision process. The language pragmatic component provides hints to the user as to when to use which visualization. A case study is presented, along with a prototype, whose interface is based on the proposed language. 95_PhD_vervloet Werther Jacques da Silva VERVLOET. Objetos inteligentes: a convivencia entre diferentes paradigmas. Ph.D.Thesis. Port. Presentation: 17/03/95 89 p. Advisor: Sergio Eduardo Rodrigues de Carvalho Abstract: This work proposes the use of some First Order Logic mechanisms in the domain defined by Object Orientation. To accomplish that, it includes also the specification of some logic programming devices as an extension to an Object Oriented host language (TOOL). Investigates how different paradigms can share a same programming environment -------------------------------------------- 1996 96_PhD_oliveira Alcione de Paiva OLIVEIRA. Casamento de padroes em ambientes para processamento de conhecimento. Ph.D.Thesis. Port. Presentation: 10/07/96 130 p. Advisor: Roberto Lins de Carvalho. Abstract: The hybrid environments are arising as a promising proposal for modeling complex problems. In a hybrid environment the notation of the languages are kept in their original state, without extra symbols that try to avoid their expressiveness deficiency. Then, each language can be used to overcome the deficiencies of the others. The combination of the several types of representations build up the total representation. The pattern-matching languages have an important role in these environments, working in a cooperative way with the other paradigms. This combination has not been properly explored in the current knowledge processing environments. This thesis presents a pattern-matching language, inspired in the Post System notation, inserted in a hybrid environment for knowledge processing. We show that this combination can be very advantageous in many fields as, for example, the implementation of non-classical logics, software engineering and multilevel inference engines. 96_MSc_nigri Alexandre NIGRI. Estruturacao de conhecimento para logicas modais. M.Sc.Diss. Port. Presentation: 10/01/96 49 p. Advisor: Roberto Lins de Carvalho Abstract: This dissertation proposes a new method of theorem proving for the modal logic. In this method, each modality is represented by a knowledge base. A relation between the different knowledge bases is defined. With the use of the defined relation and the defined knowledge bases, a proof is constructed using classical logic methods. Correctness and completeness proofs are given. A brief comparison between this method and classical logic is presented. 96_MSc_santos Andre Luiz Soares Clinio dos SANTOS. VIX - um framework para suporte a objetos visuais interativos. M.Sc.Diss. Port. Presentation: 11/12/96 65 p. Advisor: Roberto Ierusalimschy Abstract: This work presents the modeling and the implementation of a framework which supports visual interactive objects. Its architecture defines an extensible protocol for constructing new objects and defining new operations. For the construction of this framework, some requirements were established: extensibility, reuse, portability and conceptual simplicity. These requirements were treated in this work. Moreover, the framework has a wide range of applicability for constructing several types of graphical and interactive systems. In order to validate the framework's flexibility, a modular system for object direct manipulation, a hierarchical object composer, a graphical editor, and an interface toolkit were constructed. The results obtained from the development of these systems indicate that the framework has accomplished its requirements. 96_MSc_campos Andre Mauricio Cunha CAMPOS. Active chart: uma ferramenta para apresentacao de edicao de graficos quantitativos. Port. M.Sc.Diss. Presentation: 09/02/96 68 p. Advisor: Marcelo Gattass Abstract: The study of design models to provide independence between user-interface elements and application data has been the subject of research for the last years. This work uses the ADV model (Abstract Data View) to specify and develop a new tool, called Active Chart (AC), for the presentation of quantitative 2D-graphs, which allow the user to interact with the numerical data being presented. The ADV model assures the visual consistency of the data and allows the re-use of elements from the interface library. The visual consistency refers to AC's ability to present multiple visions of the same data and also to provide user interfaces of the type WYSIWYG (What You See Is What You Get). The re-usability of software components, also assured by the ADV, allows the proposed library to be extensible. For this purpose, programmers just need to add new presentation layouts and ways of interaction, depending on the nature of the application. 96_MSc_sousajunior Anibal Jose de SOUSA JUNIOR. Modelagem espacial atraves de arvores BSP. M.Sc. Diss. Port. Presentation: 23/09/96 79 p. Advisors: Marcelo Andrade Dreux (MEC) and Bruno Feijo Abstract: In the last decades, many hierarchical structures for spatial modeling have been developed, like B-Tree, V-Tree, Octree, etc. One very powerful structure that has been largely used, specially for the development of games for microcomputers, are the BSP trees. In this research, its concepts are presented, the advantages and disadvantages of this structures are discussed, many applications are showed, and comparisons to other hierarchical structures are also presented. As an example of an application of this structure, BSP trees are used in a Ray Tracing program, which has been described in details and where many optimizations are suggested. 96_PhD_maia Antonio Carlos Pereira MAIA. Um ambiente de design cooperativo de software e documentacao ativa. Ph.D. Thesis. Port. Presentation: 09/07/96 199 p. Advisor: Carlos Jose Pereira de Lucena Abstract: In this thesis we present a descriptive study of cooperative software design activity. We propose an environment that addresses the communication, coordination, and documentation needs of this activity. By cooperative design we mean a design where all designers share a global and participate in a problem-solving activity based on collective decisions. The main contributions of this work are (1) methods for describing the activity and designer's communicative behavior, (2) a software design process model, and (3) an environment to support cooperative software design (CoopADD) which merges the acquired process model with the Active Design Document (ADD) approach. 96_MSc_cassino Carlos Roberto Serra Pinto CASSINO. Uma ferramenta para programacao literaria modular. M.Sc.Diss. Port. Presentation: 12/08/96 67 p. Advisor: Roberto Ierusalimschy Abstract: This thesis presents a support tool for literate programming. Its development was preceded by a research of the basic facilities usually required for programs of this class. After that, a framework has been developed to offer those facilities. The framework was developed in standard C++, in such a way that would guarantee its probability. Its efficiency is due to an optimized kernel which performs all character-level operations, and as well defined application program interface (API) assures its flexibility. On top of this framework an access layer has been created using a configuration language. This layer allows that, through small programs written in the configuration language, a user can adapt the tool for different literate programming styles, like modular or WWW-enable documentation. 96_MSc_baruque Cassia Blondet BARUQUE. Extensoes de banco de dados relacional para aplicacoes OLAP. M.Sc.Diss. Port. Presentation: 11/03/96 110 p. Advisor: Rubens Nascimento Melo Abstract: This work aims at contributing to the development of on-line analytical processing (OLAP) systems as Non-Conventional Database applications. Particularly, it is intended to establish DB relational extensions such as new types, functions and operators based on the facilities of POSTGRES (an extensible relational DBMS). These extensions will allow the DBMS to incorporate the semantics of such applications which now may be developed as a genuine DB application, where the full features of DBMS operational controls are preserved. After an initial presentation of the basic OLAP concepts, which are normally used by EIS and DSS systems, it will be explained how to extend the POSTGRES for OLAP. The proposed types, functions and operators are described and the application in a typical example is also shown. 96_MSc_oliveira Cesar Augusto Assis Mascarenhas de OLIVEIRA. Projeto de aplicacoes hipermidia com suporte de banco de dados relacionais. M.Sc.Diss. Port. Presentation: 14/11/96 151 p. Advisor: Daniel Schwabe Abstract: Information systems have undergone considerable evolution in recent years, aiming at being more natural to users. In particular, there has been an increase in the use of hypermedia technology, that, using the modern digital media, allows changing subjects in the same way the human brain does: associatively. In this paper, we show a systematic method for design hypermedia applications, supported by a relational data base. For that, we complement the Object Oriented Hypermedia Design Method (OOHDM), and show a design of an example application. 96_MSc_braga Christiano de Oliveira BRAGA. Uma ferramenta para geracao de documentacao de sistemas de software. M.Sc.Diss. Port. Presentation: 10/03/96 155 p. Advisor: Arndt von Staa Abstract: Documentu is a tool developed to help the software engineer with the documentation preparation problem. The input is C/C++ source code modules with special markups in the code comments. The tool analyzes the code and generates a hyperdocument system to be used by the development team, helping on the maintenance task and even reusing already built software components. 96_MSc_muchaluat Debora Christina MUCHALUAT. Browsers e trilhas para documentos hipermidia baseados em metodos com composicoes aninhadas. M.Sc.Diss. Port. Presentation: 01/03/96 132 p. Advisor: Luiz Fernando Gomes Soares Abstract: Navigating in complex hypermedia documents is not an easy task for users, specially when the number of nodes and links is large. In order to improve user orientation during the navigation process, it is necessary to give them global information about the hyperdocument structure and also details about their navigation possibilities at any point in time. These resources are offered by graphic browsers and trails in hypermedia systems. In this work, it is proposed an extension to the fisheye model to built browsers for hypermedia systems that allow nested compositions of nodes. To illustrate the expected results, these tools were implemented for the Nested Context Model in the HyperProp hypermedia system. 96_MSc_porto Fabio Andre Machado PORTO. Tipos de dados continuos em SGBDs relacional-objeto. M.Sc.Diss. Presentation: 23/08/96 120 p. Advisor: Rubens Nascimento Melo Abstract: Multimedia applications are characterized by the manipulation of different data types. In particular, the continuous data types, those in which the represented information varies as a function of time, present great challenges to various areas of the Computer Science. Our main concern in this arena are the aspects related to the storage and access of the continuous data types by a DataBase Management System. On these grounds, our objective is to integrate the Continuous Data Types to the Traditional Data Types using the Object-Relational Model and to propose a MMDBMS architecture as a extension of The Postgres95 DBMS supporting Video playout. 96_MSc_costa Fabio Rodrigues COSTA. Um editor grafico para definicao e exibicao do sincronismo de documentos multimidia/hipermidia. M.Sc.Diss. Port. Presentation: 23/08/96 92 p. Advisor: Luiz Fernando Gomes Soares Abstract: Synchronization is a important task in the presentation of hypermedia documents, for that reason hypermedia systems need tools for the definition of temporal and spatial synchronization relationships. This thesis presents a graphic Editor and Browser (EBS) for temporal and spatial Synchronization of multimedia/hypermedia objects in documents with nested compositions. EBS, part of the HySEE environment (HyperProp Show Editor and Executor), uses the Nested Context Model (NCM) as the structural and presentation model, in conformance with the MHEG standard proposal. The system provides a graphical interface that permits the definition of the temporal and spatial placement of objects, relative either to a time axis or to other objects. It also permits the visualization of the compositions in time and space. 96_PhD_rossi Gustavo Hector ROSSI. Um metodo orientado a objetos para o projeto de aplicacoes hipermidia. Ph.D.Thesis. Port. Presentation: 30/07/96 205 p. Advisor: Daniel Schwabe Abstract: This research is aimed at defining an integrated method for building large, complex hypermedia applications. The method, from now on Object-Oriented Hypermedia Design Method (OOHDM) will be built out of a set of design models and a process model, i.e. a set of abstract constructs for describing different aspects of a hypermedia applications and a suggested ordering of the steps involved during the whole process. In this document we present our view of the process of building hypermedia applications, discussing in detail the problems that must be faced during each step. We outline our solutions to those problems, illustrating them with concrete examples. We next analyze some further design problems such as achieving reuse of hypermedia component and design strategies and discuss several alternatives for supporting our method. Some additional aspects and proofs are presented in the appendix. 96_MSc_mathiasfilho Ivan MATHIAS FILHO. A modelagem interna de uma ferramenta para o desenvolvimento visual de sistemas orientados a objetos. M.Sc.Diss. Port. Presentation: 15/02/96 56 p. Advisor: Sergio Eduardo Rodrigues de Carvalho Abstract: A powerful CASE tool supporting a consistent object oriented methodology, is an important feature in the construction of reliable, reusable and lower cost software. This work discusses solutions to two fundamentals aspects in tools of this nature. Firstly, the construction of a data structure having a degree of flexibility adequate to the several construction activities (analysis, design, code generation). Secondly, the construction of a repository for system components allowing maximal reutilization. 96_MSc_oliveira Jauvane Cavalcante de OLIVEIRA. TVS: um sistema de videoconferencia. M.Sc.Diss. Port. Presentation: 15/08/96 104 p. Advisor: Luiz Fernando Gomes Soares Abstract: This dissertation describes the implementation of a videoconferencing system, the TVS (TeleMidia Videoconferencing System), result of the research done at the TeleMidia Laboratory, part of the Computer Networks and Mulitmidia Systems Team from the Computer Science Department of the Pontifical Catholic University of Rio de Janeiro, PUC-Rio. TVS is a system that allows the basic transmission of medias such as video and audio in a synchronized and standardized mode. In addition, TVS handles multimedia/hypermedia documents through the Nested Context Model (NCM), according to the MHEG standard proposal. The TVS system supports voting and message sending facilities among participants, in addition to allowing ample environment configuration. The floor control is done by silence detection, in order to improve the interaction among conferees. 96_MSc_milet Jose Renato Lepak MILET. Autoria de aplicacoes hipermidia utilizando banco de dados orientado a objetos. M.Sc.Diss. Port. Presentation: 30/04/96 61 p. Advisor: Rosana de Saldanha da Gama Lanzelotte Abstract: Hypermedia applications constitute the most natural means of access to heterogeneous data. However Database Management Systems (DBMSs) are the most adequate to store them, given the functionalities available in terms of safety and access efficiency. In this work, meta-schema is proposed which implements in a Object-Oriented DBMS (OODBMS) the basic concepts of OOHDM(Object Oriented Hypermedia Design Method) authoring method. OOHDM-designed hypermedia applications are implemented extending this meta-schema through specializations. The viability of this proposal is demonstrated by a real application in which OOHDM modeling is mapped and implemented in O2 OODBMS. 96_MSc_calvano Joao Alberto CALVANO. Um modelo para o controle de versoes e desenvolvimento em equipe em sistemas orientados a objetos. M.Sc.Diss. Port. Presentation: 31/10/96 102 p. Advisor: Sergio Eduardo Rodrigues de Carvalho Abstract: The development of object oriented systems depends heavily on class and relationship libraries, frequently updated. Besides, object oriented systems are amenable to team oriented development, who share resources and information create by lifecycle of software development. In this report, we present, for the ARTS environment, versions control and team development models. 96_MSc_moura Leonardo Mendonca de MOURA. Um sistema de programacao visual. M.Sc.Diss. Port. Presentation: 15/03/96 124 p. Advisor: Carlos Jose Pereira de Lucena Abstract: One of the greatest promises of object oriented technology has been to promote fast and cheaper software development, due to the possibility of software reuse. It failed to do so. The simple use of this technology does not either imply reusable software or reuse. In order to achieve an effective software reuse, this work proposes a system based on the following concepts: visual programming, componentware, design patterns, embedded languages, code and design generation wizards and reusable elements' archives. 96_MSc_riveraescriba Luis Antonio RIVERA ESCRIBA. Simulacao dinamica de corpos rigidos com restricoes de nao interpretacao. M.Sc.Diss. Port. Presentation: 28/02/96 153 p. Advisors: Paulo Cezar Pinto de Carvalho (IMPA) and Marcelo Gattass Abstract: Dynamic simulation based on physical laws has always been of interest to scientists and engineers for several purposes. Recently, these techniques have been used in Computer Graphic to improve the realism of computer animation. In the present work, the dynamic of rigid bodies is implemented using the laws of Newtonian mechanisms to model the movement of bodies and to handle collisions and contacts. The integration between the geometric representation of the body and its dynamic description is important for this purpose. The dynamic simulation system is modeled, in this work, in a three step process. The first step of the simulation is responsible for modeling the body movement. The mathematical formulation is resolved in a simple manner using numerical techniques. The second step of the simulation is oriented towards the detection of contact points between bodies. This work presents collision detection algorithms, based on interpenetrating principles for the dynamic simulation of bodies composed of polyhedral. A strategy based on using separating as witness of the separation of two bodies is employed to make collision detection more efficient. The third step of the simulation involves the solution of the contact problem, based on the computation of the contact forces for each contact point without considering friction. The forces are computed analytically, with the purpose of enforcing the non-interpenetrating constraints between the bodies. The computation of the contact forces is done in such a way as to yield a mathematical formulation that is computationally practical for use in a simulation. 96_MSc_medina Maira Tres MEDINA. Seguranca em correio eletronico - distribuicao de chaves publicas e caminhos de certificacao. M.Sc.Diss. Port. Presentation: 26/11/96 103 p. Advisor: Noemi de La Rocque Rodriguez Abstract: This work presents a survey of problems and techniques related to security in electronic communication, and more specifically in electronic mail. This survey deals mainly with cryptography, and with the issue of public key distribution, which is perhaps the main problem in the use of asymmetric cryptography. The study of these problems and techniques led to the development of a tool which minimizes the problems of public key distribution. This tool gives support to communication between partners served by different certification authorities. Two different algorithms are proposed for the construction of a certification path linking these authorities. 96_MSc_mendonca Marcilio Fernandes MENDONCA. Inclusao de padroes de design em uma ferramenta para o desenvolvimento visual de sistemas orientados a objetos. M.Sc.Diss. Port. Presentation: 15/02/96 81 p. Advisor: Sergio Eduardo Rodrigues de Carvalho Abstract: The search for systematic ways of improving the software construction process is a continuity activity in software engineering. Object oriented methodologies and CASE tools are being increasingly used to structure the software development process. In this work we describe a CASE tool being developed to facilitate the construction of real time object oriented software, which includes the use of design patterns. We explore the reuse of code and design, automatically generating data structures and texts describing such patterns. We hope to stimulate the use of design patterns, increasing overall system quality. 96_PhD_sanchez Maria Luiza d'Almeida SANCHEZ. Um metodo de design de sistemas de tempo-real fundamentado por experimentacao. Ph.D.Thesis. Port. Presentation: 05/01/96 225 p. Advisor: Bruno Maffeo Abstract: The present work discusses concepts, tools and techniques used as a basis for the development process of process-control real-time systems, particularly focusing on a design method associated to a deductive process from a conceptual model. It also presents a summary of results concerning a controlled experiment related to employing these techniques for the development of COMONLIFE - a system for Controlling and Monitoring Electrons Beam Lithography -, in future use by the Department of Materials Science and Metallurgy (DCMM) of Rio de Janeiro Catholic University (PUC-Rio). This work emphasizes an experimental approach to Software Engineering. It follows a model of research inspired on methods of empirical research used by traditional engineering disciplines and by the sciences of nature. Particularly aiming at the conceptual and implementation modeling of software systems, we elaborated on tools and techniques proposed for the development of software for process-control real-time systems as extensions of those in use by practitioners for developing conventional information systems. This choice reflects a concern related to reducing the costs associated with the transfer to practice of the proposed method. These tools and techniques were experimented and refined within the context of a controlled empirical process: the development of a realistic system, COMONLIFE, with size and intrinsic complexity seemingly adequate to the scope of the experiment. Specifically, the work focuses: - the phase of Requirements Analysis and Specification restricted to the construction of the Conceptual Model: - the design of COMONLIFE restricted to a method, introduced in this work, based on "Information Hiding and Exchange of Messages between Autonomous Subsystems". Four quality features were considered prerequisites to the definition of the design method: modularity, maintainability, portability and reusability. This method of software design employs the information hiding concept for partitioning complex system in more manageable subsystems. 96_PhD_silva Maria Teresa Mosella Pereira da SILVA. Navegacao adaptativa em hipermeios. Ph.D.Thesis. Port. Presentation: 28/10/96 277 p. Advisor: Daniel Schwabe Abstract: Navigation in hypermedia generates sequences composed by navigation units that may be treated as blocks of text, where signals are used in addition to words. These texts are associated with rhetorical structures based on the concepts of RST (Mann; Thompson 86). The construction of guided tours is considered as an important task in hypermedia authoring. This task is then supported by the rhetorical structure of the resulting text. The methodology used for authoring is OOHDM (Schwabe: Rossi 94) enriched with a suitable extension. A set of properties for authoring environments based on this methodology are described so that it facilitates the task of creation of guided tours with adaptive navigation. 96_PhD_cunha Marisa Ortegoza da CUNHA. Um modelo de indexacao automatica de sequencias de imagens baseado em uma sintaxe espacial 2D. Ph.D.Thesis. Port. Presentation: 27/05/96 143 p. Advisor: Clarisse Sieckenius de Souza Abstract: In this work we propose an indexing model for image sequences. The model is based on the syntactic analysis of image elements. We extended the concept of indexation in order to get closer to the content representation one, thus allowing to be done by structured sentences instead of descriptor sets. The model presupposes the existence of a preliminary stage. In this stage information is elicited to support the tasks of object and attribute detection and movement identification. During the main processing stage more detailed information describing pairs of objects in relative movement is gathered. The model specifies a representation language that generates a descriptive sentence about the image sequence. One contribution of this approach is that the language organizes the information structure of the image sequence. A user implementing a system based on the proposed model can easily access any constant item present in a descriptor sentence through the use of a image and image-sequence database. The proposed model also provides for user friendly interface development, offering a variety of facilities for user interaction design, thus making clear the availability of the information as well as the ways to get it. 96_MSc_rezende Neil Armstrong REZENDE. GLB: Uma ferramenta para manipulacao de objetos procedurais. MS.C.Diss. Port. Presentation: 28/03/96 60 p. Advisor: Marcelo Gattass Abstract: This dissertation describes and analyzes the development of a tool for the construction of graphic editors. This tool offers the general capabilities found in other systems, as well as new capabilities in construction of primitives, for example, via the description of these primitives in a programming language. As for other advantages of this system, we note: the reduction in time and effort in the construction of graphic systems. The construction of editors within specific areas, such as chemical element preprocessors, via the derivation of classes, adapting the terminology of the graphic system to that of the application, is possible principally thanks to the hierarchical structure of the tool developed around the paradigm of orientation to objects. This tool also offers the users a simple data structure, although the user can also generate his/her own structure, without the need for duplicating the information from the graphics primitives. Via a programming language it is possible to work with graphic objects in a procedural way, such that the final user of the application can define his/her graphic objects, utilizing basic primitives and creating new ones, via the resources of this language such as ties, conditions, etc. It is also possible for the editors constructed with this tool to obtain greater precision in the construction of primitives that may require a more precise scale, via the access to graphic elements which the programming language affords. 96_MSc_baptista Renan Martins BAPTISTA. Um estudo sobre processos certificaveis de desenvolvimento de software. M.Sc.Diss. Port. Presentation: 02/08/96 199 p. Advisor: Arndt von Staa Abstract: This work proposes a software development process which satisfies the requirements of the ISO-9000 standard, as well as the Carnegie Mellon Capability Maturity Model, at level 2. Software development, with acceptable quality level, built under limited resources (cost, term, personnel, etc.) depends on a software process, which is able enough to provide a managerial and/or technical mechanisms to ensure the best reachable quality level, within the imposed constraints. The software quality is important, due to market competition, which imposes high quality programs with low costs, as well as, due to the reliability imposed by the software application domain. Thus, the development process must fit to specific conditions established by the Software Process Qualifiers, which are organisms that establishes requirements to those who work in their domain. The next introduces and comments the imposed conditions by two internationally known Software Process Qualifiers: the ISO-9000 standard, and the Capability Maturity Model - CMM, a work ordered by US Department of Defense to the Carnegie Mellon University Software Engineering Institute. Compiling their requirements, it will be presented a software process proposal, in a qualitative and non-instanced way, which can be certified by them. 96_MSc_aiex Renata Machado AIEX. Estrategias paralelas assincronas de busca tabu aplicadas ao problema de particionamento de circulos. M.Sc. Diss. Port. Presentation: 09/08/96 117 p. Advisor: Celso da Cruz Carneiro Ribeiro Abstract: No English abstract provided. 96_MSc_borges Renato Ferreira BORGES. Uma implementacao para a linguagem School. M.Sc.Diss. Port. Presentation: 09/08/96 66 p. Advisor: Roberto Ierusalimschy Abstract: This thesis presents an implementation of a compiler for the School object oriented language. The work is focused on the specific compilation techniques employed on this kind of language like message passing, generic types and garbage collection. At first is introduced a study of many proposals for the implementation of different object oriented languages. Based on such study, the School compiler is described and evaluated. In this work, some aspects of modules in object oriented languages are investigated and a proposal is made of a module system for the programming language School. A formal method is used to describe the module system proposed. 96_MSc_cerqueira Renato de Gusmao CERQUEIRA. Um estudo sobre interoperabilidade entre linguagens orientadas a objetos. M.Sc.Diss. Port. Presentation: 10/04/96 85 p. Advisor: Roberto Ierusalimschy Abstract: This dissertation studies some issues related to interoperability of object-oriented languages. First it discusses some problems of object-oriented languages that make impossible or very difficult the interoperability among objects defined in different languages and also among distributed objects. This difficulty harms the goal so desired by object-oriented languages: to development software components for reuse. After a discussion about these obstacles, some proposals to solve the interoperability problem are studied, trying to identify their main features. Finally, for a better appreciation of some discussed issues, a case study about object model integration is done, where is proposed a mapping between the School language object model and the CORBA standard. 96_MSc_santos Selan Rodrigues dos SANTOS. Perseguicao automatica de sistemas de uvens. M.Sc.Diss. Port. Presentation: 06/03/96 89 p. Advisors: Marcelo Andrade Dreux (MEC) and Marcelo Gattass Abstract: This work presents Scientific Visualization (SV) techniques applied to Meteorology. Some SV aspects are discussed, such as methodology to select visualization techniques, interaction classical models between simulation and user and specific visualization techniques. It also presented the problem of cloud tracking and the manner the SV could be helpful to solve it. A prototype system which performs Automatic Tracking of Cloud Systems has been implemented. The system deals with two data types. The first is a set of digital images from the METEOSAT meteorological satellite. The images cover the Brazilian Northeastern region and define a specific period of time. The other data are information about the topography. The system generates a three-dimensional modeling by combining the satellite images with the topography. It is possible to generate an animated tracking of an interactively selected cloud from a set of input images. Meteorological parameters related to the clouds and its tracking are evaluated during the processing. Some of the key computational aspects are: a) development of a modified visualization model named Pseudo-Steering; b) a new algorithm for cloud segmentation, based on the thresholding classification technique; c) a new algorithm for cloud tracking , based on the methodology proposed by Arnaud et al. [Arnaud 92]. 96_MSc_gorham Tomas Guisasola GORHAM. Um sistema de depuracao para linguagem de extensao LUA. M.Sc.Diss. Port. Presentation: 27/03/96 58 p. Advisor: Roberto Ierusalimschy Abstract: The aim of this dissertation is a debugging system for the extension language Lua. It was designed to be small, efficient and flexible, as the language. To reach these goals, the system was built as a library of functions that can be embedded to the application being debugged. An extern monitoring interface has been defined to encapsulate all functions and mechanisms built for this aim. The interface is composed basically by mechanism to control the execution (based on hooks) and some functions that offer access to the names of the local variables, information of the stack, number of line of execution and other debugging information. The mechanism of hooks is the responsible of transferring the control of the execution between the debugger and the interpreter. Built this way, the library provides the developing of other tools that monitor the execution of the Lua code. To validate this idea, was built a simple profiler that uses the hooks to count the time of execution of the functions of a program. The debugger reached all the three goals determined at the beginning of the works in satisfactory way. The fact of being offered as a library activated by the mechanism of hooks required a small quantity of lines to be added to the interpreter. This characteristic also ensured the efficient of the Lua programs that aren't being debugged, because the library can be removed and the hooks will not be called again. The implementation of the debugging resources as Lua functions and the functions that deal with the hooks made possible all the language resources to be used during the debugging phase, inclusively the construction of new debugging commands based on those primitives. -------------------------------------------- 1997 97_MSc_silva Adelailson P. SILVA. Morphing de curvas poligonais usando evolucao convexa. M.Sc.Diss. Port. Presentation: 9/4/97 65p. Advisor: Marcelo Gattass Abstract: This work presents a conceptual framework and a technique of polygonal curves metamorphosis. The concept of polygonal curves metamorphosis is based on the concept of deformation and metamorphosis of graphical objects. Based on these concepts, this work studies the main techniques of polygonal curves metamorphosis, allowing to compare and classify them. It's also presented and implemented a technique of polygonal curves metamorphosis based on the curve evolution theory. 97_MSc_castro Adriane C.M. CASTRO. Agregando valor aos sistemas de informacao para executivos. M.Sc. Diss. Presentation: 6/11/97 137p. Port. Advisor: Julio Cesar Sampaio do Prado Leite Abstract: This work presents a study of Executive Information Systems (EIS) and Expert Systems (ES) and proposes an architecture for the integration of these two technologies aiming to add value to the EIS. We define a software strategy for the integration of off-the-shelf tools and develop a case study which integrates Microsoft Excel (executive database), Microsoft Excel's VBA (interface), Microsoft Word (display of recommendations) and Intelligent Rules Element (knowledge base). We conclude showing that the proposed architecture enhances the analytical ability of the executive and, therefore, improves the decision making process. 97_PhD_andrade Aline Maria S. ANDRADE. O processo de desenvolvimento de software a luz da visao estruturalista das teorias da ciencia natural. M.Sc. Diss. Presentation: 4/28/97 95p. Port. Advisor: Armando Martin Haeberer Abstract: This work compares the Software Development Process (SDP) with the process of scientific theories construction. It introduces the concept of Theory of Computation Engineering (TEC), based on the model of mathematical physics theories introduced by Sneed. The model of Sneed contains a large definition of theory in a structured way that permit to relate the theory with the empirical world and represents the dynamic of theories based on Kuhn's concept of normal progress of science. The model of Theory of computation Engineering takes as an important characteristic of the software development, an adequate structuring that permit generalizations and specialization of a concept. TEC represents the synthetic aspects of the SDP and propose a prescriptive model in a way that a concept of normal evolution of software can de introduced. 97_MSc_derraik Andre L. DERRAIK. Um estudo comparativo de representacoes de multi-resolucao para linhas poligonais. M.Sc. Diss. Presentation: 4/25/9 61p. Port. Advisor: Marcelo Gattass Abstract: This work presents a comparative study of some multiresolution representations for polygonal lines. We study the strip tree, the arc tree and the box tree data structures, comparing their performance for constructing, drawing, intersection and selection; and memory storage costs. The comparison uses actual databases available in the Internet. The goal of this study is to identify techniques and algorithms for interactive exploration of large cartographic data bases. 97_MSc_costa Andre O. COSTA. TkVIX - Um toolkit para construcao de interfaces graficas em Lua. M.Sc. Diss. Port. Presentation: 4/24/97 76p. Advisor: Roberto Ierusalimschy Abstract: This work presents yet another tool designed to support the creation of graphical user interfaces. These interfaces are described according to the syntax of Lua, an interpreted language that can be easily learned and used. The use of Lua allows the development of the interface apart of that of the application, therefore making it suitable for rapid prototyping. This tool, the TkVIX toolkit, was developed in C++ and Lua over a framework which hides the details of the graphical system underneath and implements the concepts of visual object and visual space; these concepts were used to implement the interface objects (widgets). TkVIX offers support to abstract layout, and allows the utilization of other toolkits' widgets (the so-called native widgets) in the same manner its own widgets are used. The modular architecture of TkVIX was conceived so that the incorporation of new widgets, be they native or not, does not imply in re-implementation of the toolkit itself. The layers that make up the toolkit were implemented aiming a high degree of portability. 97_MSc_montenegro Anselmo A. MONTENEGRO. Investigacao de novos criterios para insercao de pontos em metodos de simplificacao de modelos de terreno atraves de refinamento. M.Sc. Diss. Port. Presentation: 8/27/97 74p. Advisor: Marcelo Gattass Abstract: In this work we study algorithms for obtaining representations for terrain models. Terrain data is difficult to deal with, due to its complexity and dimension. Simplification methods are one of the techniques used to reduce the natural complexity of real terrain data. Among several simplification methods, greedy insertion with vertical local error measure is the one which has provided best results. In spite of its qualities, the method presents some shortcomings, specially when applied to terrain with different height regions. We investigate the existence of better measures to deal with such problem and propose the adoption of greedy insertion methods in which the local vertical error is modified according to the variability of the surface in a neighborhood of the point under consideration. 97_PhD_bastos Carlos A. M. BASTOS. Servico sem conexao para trafego garantido em inter-redes IP sobre ATM. Ph.D. Thesis. Port. Presentation: 10/24/97 163p. Advisor: Michael Anthony Stanton Abstract: A description is presented of several proposals, which have been the subject of discussion, within the IETF, for integrating IP internetworks over ATM subnetworks. These include Classical IP over ATM, the Next Hop Resolution Protocol (NHRP) and IP switching is not limited to ATM, and includes a number for proposals which are discussed and compared. Basic aspects of quality of service in internetworks are discussed, and a description is presented of the model for integrated services, which is being adopted for use in the Internet. Amongst other things, this model specifies a resource reservation protocol, called RSVP, and two packet delivery services with quality control: guaranteed service, which offers packet delivery with deterministic delay; and controlled load, which guarantees to user only that its packets will suffer delays similar to those encountered in an uncongested internetwork. A calculation is made of the network bandwidth which must be reserved for an application in order to guarantee a given maximum delay, when using the guaranteed service. This calculation takes into consideration different alternatives for IP/ATM implementation, and factors such as traffic profile, the number of intermediate nodes between origin and destination, packet transmission with or without fragmentation, and bandwidth reservation made for individual flows, or for groups of flows. The conclusion is reached that packet fragmentation, group reservation and the reduction in the number of intermediate nodes all reduce reserved bandwidth necessary to guarantee a given delay. Arguments are presented in defense of the use of switched virtual channels in large-scale internetworks, implemented using similarly large-scale ATM subnetworks. In such a context, the need for group reservations and fragmentation requires packet multiplexing with interleaved cells on a single virtual channel, and proposals are presented for the use of a segmentation and reassemble layer and a method for such cell interleaving. Virtual circuit management is also discussed, and a proposal is presented for a multilink procedure, in order to facilitate the inclusion of new flows into a group. Finally, the proposal is presented for a new device called a SIA - Server for IP/ATM Integration, which operates with switched virtual channels, which may act like an IP switch, and which permits packet multiplexing with cell interleaving on a virtual channel, and flow bandwidth reservation for groups, offering a Connectionless Service for Guaranteed Traffic. 97_MSc_cunha Cecilia K. V. da CUNHA. Planejador de respostas explicativas baseado em uma biblioteca de esquemas RST. M.Sc. Diss. Port. Presentation: 5/05/97 90p. Advisor: Clarisse Sieckenius de Souza Abstract: This work presents an Explanation Planner which objective is to disclose to an end-user the knowledge applied in a Knowledge Based System. This disclosure is possible specially due to the generation of natural language explanations, which provide rhetorical structure and organization to the information presented. Other forms of expression can also be planned, among which the use of graphic resources is currently available. One of the main contributions of this work is the application of knowledge in Semiotics and Computational Semiotics to the construction of a solution, bringing a new perspective to approach the usability challenge. The Planner here proposed has been developed for a real knowledge based system in a project of ADDLabs. 97_MSc_laber Eduardo Sany LABER. Um algoritmo eficiente para construcao de codigos de prefixos com restricao de comprimento. M.Sc. Diss. Port. Presentation: 3/17/97 78p. Advisor: Ruy Luiz Milidiu Abstract: In this work we present an algorithm to construct a length restricted Huffman code. The complexity of the algorithm is O (n log n+n log fn) where n is the number of symbols of the given alphabet and fn is the maximum frequency among all the symbols of the alphabet. The algorithm is divided into two parts: In the first part we build an approximated solution for the problem using a Lagrangean approach. In the second part we use a special representation of binary trees called Nodesets. These structure allows us to build an optimal solution through some changes in the solution achieved in the first part. 97_MSc_oliveira Eliane S. OLIVEIRA. Heros: A interoperabilidade de seus componentes usando CORBA. M.Sc. Diss. Presentation: 6/09/97 129p. Port. Advisor: Rubens Nascimento Melo Abstract: The current computational environments are characterized by autonomous and heterogeneous systems. The system integration and the heterogeneity resolution are treated by heterogeneous database systems. In this context, standardization is specified, based on client-server model and object technology, as strategy to better support interconnectivity and interoperability between components spread in the network. The standardization application in heterogeneous database systems architecture increases their portability and extensibility. This work purposes the use of a interoperability standardization (CORBA) in HEROS - HEteRogeneous Object System in developing in PUC-Rio, showing and comparing the most important standardization, and considering similar projects - MIND and Jupiter. 97_MSc_freitas Felipe Gouveia de FREITAS. Aplicando tecnicas de reuso de software na construcao de ferramentas de engenharia reversa. M.Sc. Diss. Port. Presentation: 7/10/97 199 p. Advisor: Julio Cesar Sampaio do Prado Leite Abstract: Reverse Engineering is an emerging area within software engineering. Reverse Engineering aims to recover the knowledge of software systems and represent it at a high level of abstraction. How to perform this recovery process and how to present the recovered information is the subject of ongoing research. The reverse engineering of software systems is a problem so complex that, in most cases, it demands human interference. On the other hand, it is very useful to have software tools that help the human to deal with the voluminous information and the tedious work related to the task of reverse engineering. Another important are within the software engineering field is software reuse. The Draco paradigm of software development is a paramount philosophy for software reuse, since it preaches reuse of requirements information, thus high level abstractions, that encompass the reuse of design and code. This work presents an application of the Draco paradigm in the construction of reverse engineering tools. Two architectures are presented in different levels, in the reverse engineering tool level a typical architecture is presented; and in the level of building the tools an architecture based on the Draco paradigm is presented. The work was partially validated by a case study, where software engineering design models were recovered from a complex software system, a HTML browser, which was unknown to the author. 97_MSc_szenberg Flavio SZENBERG. Um algoritmo para visualizacao de um terreno com objetos. MSc. Diss. Presentation: 8/27/97 57p. Port. Advisor: Marcelo Gattass Abstract: This work describes a method for the visualization of terrains and objects by means of combining two algorithms, one for terrains and one for objects. Our purpose is to generate, effectively and quickly, aerial images of a terrain with objects such as houses, vehicles and transmission lines and thus to allow a simulated flight. For the objects, described by lines and polygons, the Z-Buffer algorithm is used; for the terrain, described through height maps, the algorithm of improved ray-casting, called of algorithm of Flotation Horizon, is used. 97_PhD_souzafilho Guido L. de SOUZA FILHO. Sincronismo na modelagem e execucao de apresentacoes de documentos multimidia. Ph.D. Thesis Presentation: 9/29/97 221p. Port. Advisor: Luiz Fernando Gomes Soares Abstract: Logical, temporal and semantic complexity of multimedia and hypermedia documents claims for a conceptual model permitting its specification and manipulation. Expression of ideas through documents presupposes a logical ordering of information fragments represented through different media. This ordering defines the time and space occupied by the presentation of each component. This work proposes a multimedia document conceptual model called Nested Context Model (NCM). When this work started, NCM had been object of other studies focused on structured aspects of documents. So, the main contribution of this thesis was to propose entities allowing to capture specifications of temporal and spatial synchronism in order to define documents structured as nested compositions. The specification of the presentation's temporal synchronism is based in two entities: events and links. The occurrence of a collection of events aligned in time by links defines the semantic of document's presentations. Spatial synchronism specification is captured by an entity called descriptor, which keeps the specification of the presentation characteristics separated from the data to be presented. This facility allows the definition of alternative presentations for documents as well as for its components. In order to validate the proposed model, tools allowing the edition and execution of NCM documents presentations were developed. 97_MSc_COSTA Heitor Augustus Xavier COSTA. Modelagem conceitual de sistemas - prototipo de ambiente baseado em aplicativos comerciais. Port. M.Sc. Diss. Presentation: 3/25/97 112p. Port. Advisor: Bruno Maffeo Abstract: One serious problem in software engineering is the fact that a large amount of human resources is used in systems maintenance instead of systems development. The documentation of a system is a primary tool for a efficient system maintenance, and this reason it must always be up to date. In the present work, we have designed and implemented a prototype for a Conceptual Modeling Environment based on commercial applications (Microsoft Access 2.0 and Word 6.0) which provides the necessary tools to facilitate the elaboration and updating of system's documentation. This prototype employs the modeling instruments which constitute an Essential Model and its main goals were: easy of acquisition and fast learning, execution based on a platform of widespread use, a low cost environment and an efficient maintenance. 97_MSc_lima Iremar N. de LIMA. O ambiente Web banco de dados: funcionalidades e arquiteturas de integracao. M.Sc. Diss. Presentation: 8/29/97 153p. Port. Advisor: Sergio Lifschitz Abstract: This work presents the basic concepts related to the integration environment of the WWW (World Wide Web) with Database Management Systems (DBMS), particularly the development of Intranet/Internet applications. The advantages of this integration are described, as well as some of the main problems that will be studied in this new environment, focusing on some DBMS issues. The functional requirements that have to be satisfied by the gateways that integrates these technologies are also discussed, aiming at offering two important characteristics: the stateful nature of the systems based on databases and the extension of the ACID properties to the integration. A taxonomy for the current architectures of these Web Database gateways is proposed, concerning mainly database systems functionalities, such as transactions management, integrity constraints control, security and access, performance, development and portability. Finally, a case study is discussed, based on the most employed Web Databases integration architecture to develop Internet/Intranet applications, called CGI Executable Programs. 97_MSc_chaves Juliana G. CHAVES. Estudo da viabilidade do barramento de geometria em ambiente de CAD integrado. M.Sc. Diss. Presentation: 10/3/97 97p. Port. Advisor: Bruno Feijo Abstract: This dissertation is a feasibility study of ACIS as a Geometry Bus for integrated CAD systems. In order to establish a solid foundation, the concepts of integrated CAD systems and a proposal for an integrative architecture are also presented. The effectiveness of the proposed architecture is evaluated by two applications. The cornerstone of the present work is the exploration of the idea of Virtual Prototyping. The Virtual Prototype represents the structure of the real artifact and is made of data stored in a standard format compatible with the Geometry Bus. 97_MSc_fonseca Lucia T. S. FONSECA. Uma arquitetura para construcao de ferramentas da manipulacao para visualizacao interativa de dados volumetricos. M.Sc. Diss. Presentation: 9/23/97 77 p. Port. Advisors: Luiz Fernando Martha (CIV) and Marcelo Gattass Abstract: The use of three-dimensional visualization in the exploration and production area (E&P) of the petroleum industry represented a great improvement in the work of geoscientists. With this technology, precise 3D images of the subsurface formations can be created and the interpretation of exploration and production data can be done faster and more accurately. In Petrobras, geologists, geophysicists and reservoir engineers still use two-dimensional data representations in their work, like seismic sections, contour maps, cross sections and grids of properties. But the interest in working with data in a three-dimensional way is increasing and have motivated the development of an object-oriented toolkit to facilitate the construction of interactive 3D applications for exploration and production data visualization and interpretation. The integration of direct manipulation interfaces to the data representations implemented in the toolkit, to provide a more interactive data exploration, is the aim of this work. It proposes the use of widgets 3D, a combination of geometry and behavior to control application objects. An architecture for the construction of widgets 3D, in this work called manipulators, and a set of manipulators for interaction with volumetric seismic data visualization are implemented. The object-oriented methodology was used in the development of this architecture too. New manipulators can be incorporated as new data and visualization techniques extend the toolkit. 97_MSc_cysneiros Luiz Marcio CYSNEIROS. Integrando requisitos nao funcionais ao processo de desenvolvimento de software. M.Sc. Diss. Presentation: 4/7/97 125p. Port. Advisor: Julio Cesar Sampaio do Prado Leite Abstract: Complex information systems need conceptual models that can deal with aspects beyond the usual entity/activity framework. Recent research has pointed out that conceptual models do need to explicit deal with goals, in order to model complex situations that happen in the real world. Our work investigated the integration of non-functional aspects to the widely used ER conceptual model. We have designed and validated a prototype method to derive such models, as well as a prototype tool to implement the conceptual model. The tool is based on the Talisman software development environment. The method was used in a real case study and the results confirm possible impacts of non-functional aspects in the process of software construction. 97_MSc_nobrega Marcelo G. W. da NOBREGA. Gerencia de correio eletronico. M.Sc. Diss. Presentation: 4/14/97 115p. Port. Advisor: Noemi de La Rocque Rodriguez Abstract: This work proposes a model for the management of electronic mail servers based on SMTP over TCP/IP networks. Electronic mail is one of the most used network applications and it has been deployed as base for other applications. A MIB (Management Information Base) with the Information structure for the proposed model was created. This model is an agreement with SNMP reference model for network management. The proposed model was validated by an implementation of a mail manager tool, specific for the management of "sendmail", which is the most widely adopted UNIX MTA (Message Transfer Agent) on the Internet. The tool was developed in TCL (Tool Command Language) with the libraries TK for graphic interfaces and Scotty for SNMP network management functions. 97_PhD_correa Marcelo S. CORREA. Categorias e sequencialidade. Ph.D. Thesis. Presentation: 10/29/97 199p. Port. Advisor: Edward Hermann Haeusler Abstract: In this work, we present a categorical model for sequentiality, which focus on two central aspects of the sequencing operation: non-commutativity and partiality. The model is obtained by using basic categorical concepts. In fact, the sequencing operation is modeled by means of a variation of the (Cartesian) categorical product, which is given by a limit of a diagram consisting of a pair of arrows. This new product operator is non-commutative by construction. Such a "concrete" aspect joined together with the abstract treatment provided by the categorical approach determine the main novelty of our framework. We present a concrete categorical model for the Lambek Calculus, in which we just focus the non-commutative aspect. The intended model is obtained from that by considering the partial aspect. We also present an abstract characterization for another important feature of sequentiality: communication between process. We present a realization for our main category, by considering the information flow in the sequencing of computational processes. Finally, we point out some questions about the development of a logical system to capture the partial aspect of sequentiality, for instance, a refinement of the Lambek Calculus which could be obtained by adopting constraints on the formation process of its language. 97_MSc_fontoura Marcus Felipe M. C. FONTOURA. Um ambiente para modelagem e execucao de processos. M.Sc.Diss. Presentation: 3/24/97 81p. Port. Advisor: Carlos Jose Pereira de Lucena Abstract: This work proposes an environment for process modeling and analysis. The software and business processes are modeled through a process language based on Petri Nets. This language manipulates all the important objects for process definition such as artifacts, roles and tools. The design aspects to the environment modeling are discussed and case studies of its utilization are presented. 97_PhD_serrano Maria Amélia Braghirolli SERRANO. Analise de negocio aplicada a modelagem de meta ambientes automatizados. Ph.D. Thesis Presentation: 3/13/97 322 p. Port. Advisor: Arndt von Staa Abstract: It is recognized that both applications and software engineering environments evolve over time and must adequately integrate despite of this evolution. Using mission analysis, a model is created, integrating both the application environment and the software engineering environment. In order to facilitate the evolution of both environments, the use of a automated software engineering environment is proposed. This meta-environment is used to instanciate software engineering which are adequately integrated and geared towards developing and evolving applications in a given domain. The model is used to identify and justify properties of these three environments. The model is composed of three orthogonal domains: needs generation (people domain), problem solution (mission domain) and problem solution and implementation (technology domain). These domains are applied to the application mission and to the software engineering mission. The model uses several feedback cycles in order to support application and software engineering environment evolution. These feedback cycles allow learning and improvement of both the application and the software engineering environments, in close accordance to external changes and needs evolution. The model integrates business organization, available tools and roles played by the several participants in the application environment and in the software engineering environment. 97_MSc_amorim Mauro T. de AMORIM. O roteamento no dimensionamento para redes de alta velocidade. M.Sc. Diss. Presentation: 5/9/97 90p. Port. Advisors: Reinaldo Antonio Vallejos Campos (UTFSM, Chile) and Luiz Fernando Gomes Soares Abstract: The next challenge in the telecommunication world is related with the high speed WANs, in order to support the applications for the next century and as ATM - Assynchronous Transfer Mode - is now becoming more acceptable by the market as the platform to support then, it's now very important to plan these new networks. The routing problem is the key of this work and, in association with traffic modeling, will be discussed in order to show its importance by the time of planning the link capacities of the network. Also in this work, a new routing algorithm is presented and tested with other methods and the results will show that it is an interesting new solution for the routing problem. 97_PhD_costa Monica M. F. da COSTA. Animacao comportamental baseada em agentes. Ph.D. Thesis Presentation: 4/18/97 87p. Port. Advisor: Bruno Feijo Abstract: This work proposes a new paradigm for Behavioral Animation: Agent-Based Behavioral Animation. The developed agent model is based on results of cognitive science and considers issues related to real-time animation, reactivity, concurrence, and emotional responses. As far as agency is concerned, this work settles on an emergent computing model, where intelligent behavior on a system emerges from the interaction of it components. An architecture for a real-time Behavioral Animation system based on the developed agent model is presented. This architecture is organized in two different Views connected by an interface layer called Animation Bus. Furthermore, the proposed architecture leads to an agent-oriented programming methodology which is realized in this work by a tool designed for the definition of the agents in a character. 97_MSc_sant'anna Paulo H. M. SANT'ANNA. Modelos de extensao de agentes para gerenciamento de redes. M.Sc. Diss. Presentation: 4/25/97 66p. Port. Advisor: Noemi de La Rocque Rodriguez Abstract: This thesis discusses the use of extensible agents in network management. Several models are presented and two, in particular, are implemented. The work also introduces a MIB for access to system variables using the extension language Lua. The AgentX protocol model and a Scripting model are implemented. Besides that a brief explanation about the use of meta-variables is presented. 97_MSc_pontes Rita de Cassia A. PONTES. Ambiente para desenvolvimento de aplicacoes Web. M.Sc.Diss. Presentation: 10/31/97 144p. Port. Advisor: Daniel Schwabe Abstract: A major characteristic of Web Based Information Systems is the use of the hypertext paradigm. This paradigm affects the way designers must organize information during the design, making it harder for professionals who are used to design conventional information systems with traditional access to information. One of the difficulties lies in the lack of adequate methodologies which address the notion of hypertext and allow a simple and concise record of the design. Coupled with this problem is the lack of tools that support the implementation of such projects. This work intends to facilitate the elaboration of hypermedia project for the Web using the methodology OOHDM (Object Oriented Hypermedia Design Model), by the development of a support environment to the implementation of the systems. 97_MSc_cunha Roberto H. da CUNHA. Roteamento multiponto em redes ATM homogeneas. M.Sc.Diss. Presentation: 5/9/97 151p. Port. Advisors: Reinaldo Antonio Vallejos Campos (UTFSM, Chile) and Luiz Fernando Gomes Soares Abstract: The most common connections established in a network are those which involve a source and a destination nodes, known as point-to-point connections. Nevertheless, emerging multimedia applications are requiring faster networks, that assure the negotiated Quality of Service (QoS), and new kinds of communication services, in which a plenty of nodes may participate in a connection, known as multicasts connections. This means that Multicast Routing has become a key requirement for networks that will support multimedia applications, like audio/videoconferences and distributed computation. In this paper it is proposed three new multicast algorithms on ATM based networks. 97_PhD_seixas Roberto de B. SEIXAS. Visualizacao volumetrica com Ray-Casting num ambiente distribuido. Ph.D. Thesis Presentation: 4/9/97 70p. Port. Advisor: Marcelo Gattass Abstract: Ray-Casting is a useful volume visualization technique applied to medical images such as computer tomography (CT) and magnetic resonance image (MRI). It has, however, a high computational cost that results in a slow rendering process, which compromises the interactivity that is necessary for a good comprehension of the three-dimensional data set. This work proposes optimization strategies to the ray-casting algorithm to improve its efficiency. To enhance, even further, the thesis investigates the use of a distributed computer environment through a communication protocol between heterogeneous and non-dedicate LAN-connected workstations. The ideas proposed here were implemented in two versions of the algorithm, one sequential and one parallel. Test results, obtained with these implementations and real data sets, show that it is possible to obtain interactive time with the current available machines. 97_MSc_rodrigues Rogerio F. RODRIGUES. Formatacao temporal e espacial no sistema HyperProp. M. Sc. Diss. Presentation: 5/12/97 108p. Port. Advisor: Luiz Fernando Gomes Soares Abstract: Multimedia/hypermedia systems development requires an element responsible for receiving a document presentation specification and to execute its exhibition to the user. The main tasks of this element, called temporal and spatial formatter, are the generation and the maintenance of an execution plan, the control of the presentation of the document's components, and the allocation of resources for media presentation. This thesis presents the spatial and temporal formatting mechanisms implemented in the HyperProp system, besides the formatter's interfaces with other parts of the system. 97_MSc_pinheiro Sergio E. M. L. PINHEIRO. Deformacoes interativas por especificacao direta. M. Sc. Diss. Presentation: 9/17/97 70p. Port. Advisors: Jonas de Miranda Gomes (IMPA) and Marcelo Gattass Abstract: The work describes and implements a surface deformation system, through space transformations. These transformations are directly specified by surface points, chosen by the user. The method used in this work determines global transformations by coordinate system changing, therefore, it does not depend of the surface description or representation, and can be used for surfaces described implicitly or parametrically, and also for volumetric dates. 97_MSc_goldenstein Siome Klein GOLDENSTEIN. Metamorfose de sons. M. Sc. Diss. Port. Presentation: 7/10/97 66 p. Advisors: Jonas de Miranda Gomes (IMPA) and Marcelo Gattass Abstract: Not provided. 97_MSc_oliveira Toacy C. de OLIVEIRA. Um modelo de concorrencia para o projeto ARTS. [na tese: Um modelo de concorrencia para o ambiente 2GOOD/DDL] M.Sc. Diss. Presentation: 8/22/97 94p. Port. Advisor: Sergio Eduardo Rodrigues de Carvalho Abstract: The main goal of this work is to propose a solution for the concurrency problem that appears in a object oriented development environment like 2GOOD, so that the syntactic constructions do not decrease legibility. This is based on the fact that for 2GOOD/DDL, the most important phase in the development of a system is Design, where all knowledge for system construction should be extracted, including concurrency. -------------------------------------------- 1998 98_MSc_alvim Adriana de C. de F. ALVIM. Estrategias de paralelizacao da metaheuristica GRASP. M.Sc. Diss. Presentation: 4/13/98 95 p. Port. Advisor: Celso da Cruz Carneiro Ribeiro Abstract: We study different parallelization strategies for the GRASP (Greedy Randomized Adaptive Search Procedure) metaheuristic, considering an application to optimal traffic assignment in TDMA satellite systems. In the first strategy, parallelization is done through the uniform distribution of the GRASP iterations among the processors, which leads to linear speed-up. The second strategy is based on the parallelization by diversification of the main parameter of the algorithm, where the behavoir of the algorithm is investigated in terms of solution quality. We also compare the performance of two applications using different strategies for load balancing in parallel GRASP implementations. Their difference consists in the data partioning technique: pre-scheduled decomposition (static load balancing) or self-scheduling decomposition (dynamic load balancing). Dynamic load balancing is shown to be the most suitable strategy, with significant improvements in terms of elapsed times. 98_MSc_lerner Alberto LERNER. Uma proposta de arquitetura para o tratamento paralelo da juncao com equilibrio de carga em ambiente com memoria distribuida. M.Sc. Diss. Presentation: 3/30/98 55p. Port. Advisor: Sergio Lifschitz Abstract: The study of the most significant algorithms for the parallel execution of the join operation, particularly those towards a shared-nothing environment, opens this dissertation. The algorithms were chosen for their capability in handling load imbalances during the parallel execution of the join. Based on this study, a new taxonomy for the algorithms was developed and evidences have been found that the majority of the algorithms handle load imbalances in a corrective fashion. Indeed, they detect uneven data distributions at the time there are already overloaded processors and then try to redistribute workload among them. On the other hand, the VAST-PJ architecture, presented in this work, has the ability to handle their effects on the parallel execution of the join operation. The main techniques that support the architecture are twofolf: (a) the turning, as far as size goes, of the tasks assigned to each processor, so not to overload it, even in the presence of data skew (b) the assignment of such tasks in a demand-driven approach. The work also presents a software project implementing the VAST-PJ architecture into an existing SGBD. 98_PhD_andreatta Alexandre A. ANDREATTA. Uma arquitetura abstrata de dominio para o desenvolvimento de heuristicas de busca local com uma aplicacao ao problema da filogenia. Ph.D.Thesis. Presentation: 6/5/98 151p. Port. Advisor: Celso da Cruz Carneiro Ribeiro Abstract: In the study of heuristics for combinatorial problems, it is important to develop and compare, in a sistematic way, different algorithms, strategies, and parameters for the same problem. This comparison is often based not only by different implementation languages, but also by different architecture. In this thesis we propose a framework, described using design patterns, modeling different aspects involved in local search heuristics, such as algorithms for the construction of initial solutions, methods for neighborhood generation, and movement selection criteria. Using this framework we fix a basic architecture, increasing our ability to construct and compare heuristics. An implementation of the framework is performed for the phylogeny problem, one of the main problems in cladistics and systematics. The optimization criteria used was the parsimony criteria. The phylogeny problem is NP-hard and can be modeled as an Steiner tree problem in graphs. The implemented system has the following local search options: iterative improvement, GRASP, VNS, and tabu search. Several algorithms for the phylogeny problem are compared, extensively reusing the implemented code. The most promising strategies were tested on available benchmark instances. The use of tabu search and VNS metaheuristics for the phylogeny problem are original contributions of this thesis. The computational results suggest GRASP strategy as the best one to obtain phylogenies. The implementation of the framework for the phylogeny problem has shown the flexibility and expansibility of the model. With respect to the code reusability, it has an estimated potential of reuse by representation inheritance of almost 30%. 98_MSc_matos Andre M. de MATOS. Visualizacao de panoramas virtuais. M.Sc. Diss. Presentation: 7/9/98 90p. Port. Advisors: Luiz Carlos Pacheco Velho (IMPA) and Marcelo Gattass Abstract: Recently, a large number of systems were developed that allows the visualization of panorama-based virtual environments, like the Quicktime VR system for instance. However, these systems have several limitations in terms of the quality of the image generated and interativity. In this work, we present a few visualization techniques that solve these limitations. These techniques are currently being used as part of the Visorama System, which uses hardware and software components to provide a natural and immersive interaction with panoramas. The system we developed allows the visualization of very large panoramas at interative frame rates. Among the topics covered are real time visualization, image deformation, cache management and multiresolution images. 98_MSc_pizol Andrea Miranda PIZZOL. Um framework para implementacao na WWW de aplicacoes hipermidia modeladas com OOHDM. M.Sc. Diss. Presentation: 12/10/98 166 p. Port. Advisor: Daniel Schwabe. Abstract: The development of hypermedia applications in the WWW lacks higher-level tools that help the designer in the design task. This dissertation describes an object-oriented framework for the implementation in the WWW of complex hypermedia applications, designed using OOHDM. In addition, it examines tha various implementation approaches for web application development using Java, and specify and architecture for the implementation of applications developed using the proposed framework. 98_ MSc_ ferreira Carla C. F. FERREIRA. Um estudo sobre arquivos vetoriais para visualizacao de mapas na Web. M.Sc. Diss. Presentation: 5/11/98 85p. Port. Advisor: Marcelo Gattass Abstract: This paper presents a study on the transmission of maps in the World Wide Web. Maps are approximate representations of the Earth surface in which points of the globe are projected on a plane. An important feature of figures that represent maps is that they have polygonal lines with a large number of points. With current vectorformats these points generate archives that are too large to be transmitted through the web. The use of images formats, although common in the web today, only provide poor resolution figures that do not scale well. A review of current metafile formats is presented, followed by a study on compression algorithms. The thesis proposes strategies to reduce the size of the archives by restricting the precision of the points, eliminating repeated points and performing an efficient coding of the coordinates. Real examples are shown to evaluate the proposed strategies and recommendations are made based on these examples. 98_MSc_castro Carlos E. P. S. de CASTRO. Integracao de "Legacy Systems" a sistemas de banco de dados heterogeneos. M.Sc. Diss. Presentation: 5/11/98 117p. Port. Advisor: Rubens Nascimento Melo Abstract: The dynamism of the computer environment where equipments, programs and methodologies are always in evolution, makes that systems soon become obsolete. Some systems, due to its importance for the operation of the company, survive per decades, living together with new environment and systems developed under new paradigms. Such systems are known as Legacy Systems. Several alternatives are proposed to solve the following dilemma of the Legacy Systems: "What to do with the systems that are already obsolete but are of vital importance for the business of the organization"? The tecnology of heterogenous Databases Systems that allows that systems of models, makers and different products can be integrated in a way to offer an unique vision of the user. The database vision provides a higher abstraction level where detail of storage, recovery, integrity, concurrence and security, common to the systems with traditional files can be omitted. The use of Heterogenous Database Systems, for its capacity to integrate different architectures, comes as an interesting alternative for the solution of the integration problem of Legacy Systems. This work identifies some of the characteristics and problems of the Legacy Systems, it evaluates alternatives for its integration to the computer environment of the companies and it proposes as one of the solutions, its incorporation to Heterogenous Databases Systems, through the extension of HEROS -Heterogenous Databases Management Systems in development at PUC-Rio. 98_MSc_aguilar Carolina de L. AGUILAR. Tecnicas procedimentais de texturizacao. M.Sc.Diss. Presentation: 8/18/98 102 p. Port. Advisors: Marcelo Dreux (MEC) and Bruno Feijo Abstract: Several researches in the Computer Graphics area are focused on the obtention of more realistic images synthesized by computers. One way to increase the realism in image synthesis is through the use of texture. Whenever realistic images are generated by computers, natural phenomena cannot be forgotten. This work presents a study about the generation of procedural textures for the representation of these phenomena. The fundamental theoretical concepts of the main techniques for procedural modeling and texturing applied to a set of natural phenomena are described. A natural phenomena classification is proposed according to the main procedural techniques. As a case study, Particle System techniques using the 3D RenderWare graphics library have been implemented. 98_MSc_monteir Claudia de Castro Oliveira MONTEIRO. Mecanismos para o trabalho em grupo utilizando as ferramentas WWW e SGBD no processo de gestao de ambiental da Petrobras. M.Sc. Diss. Presentation: 8/7/98 Port. 143 [+68] p. Advisor: Hugo Fuks Abstract: The increasing amount of information that need to be managed nowadays by the corporations, and the geographical dispersion of their organizational units request comprehensive management systems capable of making the information flow through the entire corporation. Thus the need to analyze the behavior of groups that have to perform common activities, which led to the concept of CSCW (Computer Supported Cooperative Work). The purpose of the present work is to study this new concept and to introduce SGMA, an Intranet system based on groupware technology. SIGMA allows the monitoring of environmental licensing processes for enterprises that might impact on the environment, including their phases, activities, requirements, schedules, etc. in real time and in differentiated ways for each type of user. Thus the dissemination of data both from the projects and the people involved can be made more easily. 98_MSc_silva Claudio L.da SILVA. SPADD: Uma extensao do modelo ADD aplicada ao projeto de layout espacial. M.Sc. Diss. Presentation: 4/27/98 74p. Port. Advisors: Ana Cristina Bicharra Garcia (UFF) e Clarisse Sieckenius de Souza Abstract: ADD (Active Design Documentation) is a model that offers computational support to design development and documentation in engineering. This model has been sucessful used to support decisions originated from projects development in several engineering domains. However, the knowledge representation and reasoning of ADD don't treat fundamentals issues intrinsic to the spatial layout domain, such as: (a) multiple methods for alternative design generation, (b) cyclic dependencies, (c) a context dependent decision process. This research presents SpADD, an extension of the ADD model which guarentees the functions of the original model, applied also to the spatial layout domain. SpADD was implemented to the oil pipeline layout domain, showing the viability of the SpADD model. Initial tests show the feasibility of the model to the domain. 98_MSc_ururahy Cristina D. URURAHY. Agentes Lua: um mecanismo de comunicacao em Lua. M.Sc. Diss. Presentation: 9/25/98 60 p. Port. Advisor: Noemi de La Rocque Rodriguez Abstract: The object of this work is to evaluate the use of the Lua language [IFC96] as a tool for parallel programming in distributed environments. The communication mechanism adopts an eventdriven approach, that simplifies many aspects of concurrent programming, since processes never block in communication primitives. The goal of this work is to evaluate this mechanism through implementations of problems previously codified with other mechanisms. To study these problems in Lua, a layer over the original mechanism has been implemented, in order to make the processes configuration and the communication among them easier and more reliable. This work describes not only the original mechanism, but also this new layer. We also present the applications that are used for the mechanisms evaluation and the results of this evaluation. 98_MSc_ishikawa Edison ISHIKAWA. Gerenciamento de redes de computadores baseado em Web. M.Sc. Diss. Presentation: 4/13/98 66p. Port. Advisor: Noemi de La Roque Rodriguez Abstract: This thesis discusses computer network management using WWW's framework. It verifies the possibilities of this framework in network management and offers a management system prototype, the LuaWebMan. It's main feature is the ability to be an extensible application through the Web. 98_PhD_almeida Eliana S. de ALMEIDA. A logica dos recursos no formalismo de Redes de Petri. PH.D. Diss. Presentation: 12/10/98 152 p. Port. Advisor: Edward Hermann Haeusler Abstract: We propose a logical language of specification that has as its model the dynamic of resouces in Petri Net formalism. This language can be used to describe both the behavior and the properties on concurrent systems. We also extended this language in order to accomodate the time requirements on real time systems. The model of Place/Transition Petri Net is used and is restricted in order to simplify the definition of the calculus. We prove that this restriction is only syntactical and it allows the behavior of any system, modeled by the Place/Transition Petri Net, to be modeled considering this restriction. In order to model the dynamic of resources, net constructing operations are defined, which are identified by a binary tree called decomposition. From any decomposition a deduction in the sequent calculus presentation for this logic can be obtained. For this language, we present an operational semantic that interprets the behavior of the net in the absence of an initial stimulus (formula with dual). This stimulus might cause the realization of some action in the net. We also propose a semantics, based on the idea of possible words, in order to give meaning to the formulas, and the soundness of the system with respect to this proposed semantic is obtained. 98_PhD.pacitti Esther de C. PACITTI. Estrategias de atualizacao de dados para diversas configuracoes de replicacao assincrona. Ph.D. Diss. Presentation: 11/23/98 51 p. Port. Advisor: Rubens Nascimento Melo Abstract: Data replication is often used in distributed database applications to improve data availability and performance. Replicated data must be periodically refreshed using update propagation strategies. Most of the current strategies guarantee mutual consistency of replicated data but are inefficient. Lazy (or asynchronous) replication is an alternative, more efficient solution where mutual consistency is relaxed. It is needed in applications such as on-line financial transactions and telecomunication systems which require high freshness of replicated data. In this case, the concept of freshness is used to measure the deviation replica copies. One focus of thsi paper is to propose strategies for improving data freshness. Another focus is to specify correctness criterias for different replication configurations, and to propose solutions for correctness enforcement. In this paper, we give a state of the art of replicated databases and we propose a new framework for lazy replication. We introduce two strategies that improve data freshness and an algorithm that enforces correctness for different configurations. Finally, we propose a simulation environment and a performance model to evaluate our strategies. The performance results show that our strategies outperform significantly exisitng strategies. 98_MSc_lopes Flavio B. LOPES. Tecnologia de Workflow e World Wide Web aplicada a garantia de qualidade de produtos e servicos da Petrobras segundo a Norma ABNT NBR ISO 9002. M.Sc.Diss. Presentation: 6/9/98 281p. Port. Advisor: Hugo Fuks Abstract: Companies worldwide have sought the ISO 9000 certificate of compliance as a means of demonstrating to their customers that their respective meet a global quality standard. In Brazil, attaining ISO 9000 certification is a way for Petrobras to be eligible for The National Quality Award to improve its market share, to reduce operating problems and to become more competitive in the merging open oil markets currently operating in Brazil. We propose a corporate system for Petrobras that Membraces the ABNT NBR ISO 9002 standard, World Wide Web, groupware and workflow technology research. We suggest a strategy to implement an Intranet system developed on Lotus Notes Domino's environment. Finally, we report on results of applying this strategies proposal and of deploying this system for a pilot group. 98_PhD_azevedo Gilberto P. de AZEVEDO. Agentes reativos para centros de controle de energia eletrica. Ph.D. Thesis. Presentation: 8/28/98 Port. 139 p. Advisor: Bruno Feijo Abstract: This work proposes a new organization for Energy Management Systems based on Reactive Agents. It follows a modern trend in computing by proposing systems of agents based on behavioral decompositions, and whose "intelligence" emerges from the interactions among those agents and their environment. A framework is developed to apply this approach to Energy Management Systems. The framework aims at providing a structure capable of handling the ever increasing complexity and openess of power system control induced by the changes that are taking place on the power industry, while taking into account that human operators will remain a key element of control. This is performed by a set of agents specialized on helping the operators to accomplish their tasks. 98_MSc_piccinini Helena S. PICCININI. Integrando acervos da Internet/Intranet a banco de dados heterogeneos. M.Sc.Diss. Presentation: 5/19/98 272p. Port. Advisor: Rubens Nascimento Melo Abstract: Regarding the present companies environment for information management and handling, it has became usual the proliferation of distinct hardware and software platforms, as well as the need of accessing data stored in such different ways. In the Internets, WWW browsers play a role similar to an universal client, allowing the access to information kept not only in HTML formatted documents, but also in conventional files, databases and others kinds of sources. However, there still remains the difficulty of offering the user an integrated view of distinct data types, by using an information integrator system. This dissertation is about an extension of the HEROS system, an Heterogenous Database System with strong coupling, in order to integrate information other than those stored in databases. The present solution uses the Meta Content Framework (MCF), a meta-standard, which allows the definition of patterns of descriptors for each stored data type. In this HEROS context, MCF can be seen as a Data Model, and each metadata pattern (defined using MCF) as an schema describing any of the different information sources to be integrated. 98_PhD_martins Isa H. MARTINS. Um instrumento de analise semiotica para linguagens visuais de interfaces. Ph.D.Thesis. Presentation: 4/24/98 117p. Port. Advisor: Clarisse Sieckenius de Souza Abstract: Geometric Modeling Systems have changed from textual batch data entry styles to direct manipulation graphical interface data entry, as a consequence of advances in hardware technology. This has brought out several advantages to users. However, it has also raised several issues that remain to be resolved, with respect to the use of visual resources as expressive tools. One of the weakest points is the non-systematic use of the expressive resources in interactive language specification. This problem is particularly important in Geometric Modeling Systems, due to the complexity of such systems and the language constraints imposed by visual expression. These systems are representation/abstraction of physical world objects, so, they are intrinsically semiotic systems. Because they are signs generatin systems, they have to support users in the fundamental actions related to this task: (a) to select and to establish significant shapes (primary and secondary) and (b) to supply systematic procedures for the interpretation of such shapes when used in communication/representation acts. This work discusses the use of direct manipulation visual languages in Geometric Modeling Systems through the use of a semiotic paradigm. It proposes a systematic analysis to the use of visual expressive resources and shows the effect of this approach in interface specification environments. The work analyses the limits of the visual resource as an expressive medium and its structuring as a language. Based on the theoretical directives presented, it proposes an extension of TAG (Task-Action Grammars), including semiotic aspects of the language, named Semiotic TAG (STAG). The STAG reflects the systematization of expressive choices, in order to support designers in the specification of these particular visual languages. It acts together with orientation directives for coding the visual language (ODCVL) and with implementation of STAG together with the ODCVL and EHVL is proposed. 98_MSc_rosseti.ps.gz Isabel C. M. ROSSETI. Uma biblioteca para balanceamento de carga em ambientes distribuidos. M.Sc. Diss. Presentation: 3/5/98 100p. Port. Advisor: Noemi de La Roque Rodriguez Abstract: Many load balancing techniques have been proposed, in order to improve the performance of parallel applications. This dissertation presents some existing load balancing algorithms. These algorithms are presented according to an analytical model called Matrix Iterative Model. The application of some these algorithms to a specific problem, the N-body problem, is discussed. A load balancing library developed for a parallel implementation of this problem, based on Barnes-Hut algorithm, is also discussed. 98_DhD_leite Jair Cavalcanti LEITE. Modelos e formalismos para a engenharia semiotica de interfaces de usuario. Ph.D. Thesis. Presentation: 10/7/98 194p. Port. Advisor: Clarisse Sieckenius de Souza Abstract: Interactive sysems usability could be enhanced if users learn all the knowledge - the usability model - that enables them to apply the designer's potential solutions to their domain tasks. The Semiotic Engineering approach perceives interactive systems as metacommunication artifacts that send a message from designer to users, whose expression is the lower-level messages exchanged between user and system and whose content is the usability model. Starting from this perspective and based on semiotic theory concepts from Charles S. Peirce and Umberto Eco we present conceptual models to the interface as the expression and to the usability model as the content of the designer's message. We also develop a semiotic system to support user interface design. The system is composed of a specification language and rules that map specified messages to user interface widgets. Our emphasis here is not on aesthetics aspects of users interfaces, but on the interactive and performing nature of the interface message as it is carried throughout the computational medium. 98_MSc_huang Juli L. C. HUANG. Uma arquitetura para o desenvolvimento de interfaces graficas baseadas em grafos. M.Sc.Diss. Presentation: 8/21/98 54p. Port. Advisor: Marcelo Gattass Abstract: The development of graphical interfaces based on the direct manipulation of application objects on a canvas is a complex task that finds little support in nowaday's programming technology. Directed graphs in the form of schematic diagrams are used in programs for supervision, control and simulation of electric power systems, industrial plants, and many other similar systems in which the process flows through a net of components. Due to the large number of applications based on these types of objects, they have come to deserve specialized tools for their development. The present work proposes an architecture for the development of graphical interfaces based on graphs, it allows users to create and to instance equipments with attributes and behavior that depend on the application, with a high level of abstraction. As a tool for the development of applications based on the proposed architecture, a graphical object library with support for the underlying graph, was implemented. The goal of this architecture is to allow the programmar to focus on the application's development rather than on user interface issues. The proposed architecture was used in industrials prototypes in order to validate the ideas presented here. 98_PhD_coelho Luiz Cristovao G. COELHO. Modelagem de cascas com intersecao parametricas. Ph.D. Thesis. Presentation: 8/11/98 94p. Port. Advisor: Marcelo Gattass Abstract: We present a methodology for modeling finite-element mesches defined on parametrics surface patches. The idea is to build curves and generate meshes over the parametric patches built with these curves, which also connect adjacent meshes. The final model is a representation of all meshes combined into a single data structure. The basic tools to generate such meshes are the user interface to model space curves and the algorithms to construct the elementary domain mappings. The main problem in composite modeling is how to handle mesh surfaces that intersect each other. We present an algorithm that models the intersection curves precisely and adjusts both meshes to the newly formed borders. The algorithm is part of an interactive shell modeling program, which has been used in the design of large offshore oil structures. We avoid unacceptable interaction delays by using a variant of the DCEL data structure that stores topological entities in spatial indexing trees instead of linked lists. These tree speed up the intersection computations required to determine points of the trimming curves, and also allows mesh reconstruction using only local queries. 98_MSc_ribeiro Marcelo Blois RIBEIRO. CLEW- Uma proposta de ambiente de aprendizado cooperativo para a Web. M.Sc.Diss. Presentation: 3/17/98 118p. Port. Advisor: Hugo Fuks Abstract: The combination between entertainment and education is becoming a productive form of human knowledge transmission. This work presents a proposal of a cooperative learning environment for the Web. It combines constructivist educational concepts with the structure of the Multi-User Dungeon, the theory of workflows, the interactivity of the Web and the multimedia and three-dimensional presentation feature of the Virtual Reality. The learner becomes an active participant of the learning process, interacting with the elements of the virtual environment to construct his knowledge. The knowledge of each learner is shared with other learners who share the same virtual world, generating a proper set of social relations and originating a knowledge community. 98_PhD_frias Marcelo F. FRIAS. Fork algebras em algebra, logica e ciencia da computacao. Ph.D. Thesis. Presentation: 2/18/98 230p. Port. Advisor: Armando Martin Haeberer Abstract: This thesis is focused on the study of fork algebras (an extension of relation algebras with a new operator called fork) from three different points of view. From an algebraic point of view, emphasis will be made on providing a clear and concise definition of the classes of proper fork algebras (i.e. fork fork algebras whose domain is made of binary relations) and abstract fork algebras (defined by a finite set of equations), as well as on proving a representation theorem stating that every abstract fork algebra is isomorphic to a proper one. Also the completeness of the relational calculus MU2 (a relational calculus for program schemes) will be proved by using as an essential tool the representability of fork algebras. From a logical point of view, fork algebras will de used for algebraizing classical and non classical logics (among the latter, modal, dynamic, intuitionistic, and intermediate logics). Finally, from the point of view of computer science, fork algebras will be used as the foundation of a calculus for formal program construction. Because of the algebraic and logical properties of fork algebras the calculus also allows to reason about program design strategies. 98_MSc_felix Marcelo F. FELIX. LET: Uma linguagem para especificar traducoes e seu compilador. M.Sc.Diss. Presentation: 4/24/98 210p. Port. Advisor: Edward Hermann Hauesler Abstract: Code Transformation is a fundamental activity in Computer Science, and one of the most usually remembered tasks in this context is the language translation. The traditional methods for compiler construction evolved from manual and ad hoc construction techniques to the usage of tools for automatic generation. Another approach to the translation problem arise from the area of Transformations and, at present, its tools are being used for many purposes which have to do with this problem. TXL is one of this transformational tools. It consists in a transformational machine and a language for specification which was increased until become considered as a programming language. The experience with transformational implementation of a compiler,using TXL, motivated the creation of a tool which improves the programming, in view of the fact that a great part of the manual code generation could be automated. These are our purposes when proposing LET, a transformation specification language ("Linguagem para Especificar Transformacoes"), and a compiler prototype which generates code for TXL machine. Initially, we do an overview of the subject and, in this context, of the transformational language TXL as well. Subsequently, we present LET: the language and its compiler, detailing the project and the implementation. Finally, samples of specification and cases of study are given at the end of this work. 98_MSc_martins Marco Aurelio Catunda MARTINS. Extensao dinamica de agentes CORBA. M.Sc.Diss. Presentation: 29/09/98 76 p. Port. Advisor: Noemi de La Roque Rodriguez Abstract: The SNMP architecture of network management focus all of process in manager application, that is, the application manager collects raw data from agents and analyze it, showing the results to a local administrator. With the computer networks growth, more distributed management architectures has become more important. The use of the distributed objects technology CORBA have becomeing a strong candidate to build more distributed management architectures. In this architecture, the applications are organized in objects that are distributed through the network. When building a management tool, agents are replaced by server objects, while the management application acts as a CORBA client. With the goal of making more flexible the role of servers so they can be dinamically extended, this work proposes two ways of extending CORBA objects using the configuration language Lua. The first one is based on the meta-interface, where the methods exposed by the meta-interface can be used to access the data structures that describe the effective interface of the objects installed in the server. The second one is through DSI (Dynamic Skeleton Interface), where a Lua object can be installed in the server and begins to act as a regular CORBA object. 98_MSc_sobreiro Marcus V. R. SOBREIRO. Quantizacao de imagens. M.Sc.Diss. Presentation: 05/15/98 91p. Port. Advisors: Jonas de Miranda Gomes (IMPA) and Marcelo Gattass Abstract: In this master thesis we studied the image quantization problem. In the beginning of this work we presented an introduction about digital image and its attributes. The image quantization problem is presented showing the possible strategies for solving it. We presented several image quantization algorithms and proposed a new one called quantization by pairwise clustering. In the conclusion, we made a comparison between all algorithms presented. 98_MSc_vidal Maria Elisa F. VIDAL. Metodo para mapeamento e avaliacao de processos organizacionais. M.Sc.Diss. Presentation: 5/20/98 145 p. Port. Advisor: Bruno Maffeo Abstract: This dissertation presents a method to map and evaluate organizational processes, to be used during different phases of a reengineering program. According to this method, the definition of a new design for the process to be innovated begins with the creation of the model of the essence of the information system responsible for the process execution. This model, generally used during the phase of essencial requirements especification, is a conceptual tool of Software Engineering used to represent what the system is expected to do, regardless to how the system will be implemented using certain technologies. The conceptual tools of Software Engineering are also used to represent the actual and innovated process design. The latter must also be compared to the former in terms of quantity and quality, in order to evaluate the possibility, the oportunity and the relation between the costs and benefits associated to the reengineering. This evaluation was supported by a software tool used in project planning and management. The method was used in a case study of the process of receiving goods in a store. It was necessary to extend and adapt the languages used to model the essence and to specify the design of the processes to represent some features of the organizational process. 98_PhD_barbosa Maria Lucia S. BARBOSA. Uma extensao da abordagem operacional do metodo Tau de Lanczos. Ph.D.Thesis. Presentation: 8/31/98 82 p. Port. Advisor: Therezinha Souza da Costa Abstract: It is presented a formal extension of the operational approach for the Tau-Lanczos-Ortiz Method complementing the Bunchaft's work related to the recursive approach of Tau-Lanczos-Ortiz and that one by El-Daou of the equivalence of the two approaches. This method is applied to a numerical treatment of the atmospheric pollution concerns. The spliting method has been used, subdividing the problem according to the different phisics processes envolved. A comparation with the method of characteristics has been made. 98_MSc_michirefe Maria Stella Costa MICHIREFE. Un enfoque de banco de dados para workflow [na tese:Em busca de um sistema de gerencia de workflow baseado na tecnologia de sistemas de gerencia de banco de dados] M.Sc. Diss. Presentation: 12/17/98 132 p. Port. Advisor: Rubens Nascimento Melo. Abstract: Wokflow is the automation of processes that we daily use to do our business. A workflow application automates the sequence of activities used to execute a process, including the status of the execution of each process, as well as the tools needed to manage the process in itself. The workflow technology has problems just like the ones in the database technology that were not completely solved yet. Moreover, the workflow products are considered to be proprietary in term of their process and data models. The focus of the present work is to study the workflow technology in terms of database management. This text presents a model of workflow management as a non-conventional databse management, where the process management issue is stressed. The workflow technology characteristics are defined and it is presented some related works and some commercially available products. To study how the DBMS (Dta Base Management System) concepts helps to solve problems in the workflow technology, there is a comparative analysis between the database management and workflow management systems. 98_MSc_souza Mauricio C. de Souza. Tecnicas de aceleracao e reducao de vizinhanca em busca tabu para o problema de Steiner em grafos. M.Sc.Diss. Presentation: 5/11/98 66p. Port. Advisor: Celso da Cruz Carneiro Ribeiro Abstract: We propose a tabu search algorithm for the Steiner problem in graphs. We present the Steiner problems in graphs, its formulation and complexity. Variants and applications are also described. Exact methods and the most efficient heuristics for its approximate solution are reviewed. We also review the basic concepts of tabu search. The proposed tabu search algorithm for the Steiner problem in graphs makes use of neighbourhood reduction techniques and move value estimations. Feasible solutions are characterized by their Steiner nodes. The solution itself is a minimum spanning tree of the set of terminal nodes and Steiner nodes. The neighbourhood is based on insertions and eliminations of nodes to/from the current solution. A neighbourhood reduction technique is used to speed up the evaluation of insertion moves. Only the nodes that can be inserted in the current solution by an edge with a weight less than that of maximum weight in the current solution are evaluated. Move values associated with insertion moves are estimated by a greedy procedure. Two alternative procedures to find the initial solution and three diferent diversification strategies are used. Computational experiments on benchmark problems are reported. Comparative results are presented. We conclude that the search mechanisms developed are able to find high quality solutions in moderate computation times. We analyze the contributions and possible extensions of this work. 98_MSc_lima Michele M. de A. E. LIMA. LuaMan - Uma plataforma para desenvolvimento de aplicacoes de gerenciamento extensiveis. M.Sc.Diss. Presentation: 1/16/98 114p. Port. Advisor: Noemi de La Roque Rodriguez Abstract: The development of network management applications faces problems such as size, complexity and heterogeneity of devices, services, protocols and the communication medium, platform dependence, and differing management policies from institution to institution. This work presents a platform for the development of extensible management applications based on the programming language Lua, a configuration language developed at PUC-RIO. With this platform, management applications can be developed, and then new features can be dynamically added to the application if new needs appear. This work also presents some typical management applications that were developed to evaluate the platform. 98_MSc_guellbarroso Natacha GUELL BARROSO. Projeto da navegacao orientada ao usuario de aplicativos hipermidia. M.Sc.Diss. Presentation: 4/24/98 211p. Port. Advisor: Daniel Schwabe Abstract: This paper describes a user centered method for navigation design in hypermedia applications. The proposed approach extends the Navigational Design phase of OOHDM with the use of scenarios. This allows the reuse by less experienced designers of design knowledge, gathered by more experienced ones, resulting in a more systematic method. The method's effectiveness has been exercised in designing the navigation of real life hypermedia application in the WWW, which allowed a better characterization of such applications with respect to other hypermedia applications. A second consequence has been the enrichment of OOHDM, making it more suitable for representing solutions for the WWW. 98_PhD_prates Raquel O. PRATES. A engenharia semiotica de linguagens de interfaces multi-usuario. Ph.D. Thesis. Presentation: 10/09/98 117 p. Port. Advisor: Clarisse Sieckenius de Souza Abstract: Nowadays there are guidelines, frameworks, models and toolkits that support the development of multi-user interfaces. Toolkit assist designers in building the interface, whereas guidelines and frameworks direct the designer towards issues to be considered during interface design. Models, on their turn, allow for the description of the conceptual model of the group (or part of it) to be represented in the interface. Nevertheless, none of these provide the designer with an environment in which to plan and define the system's interface. We take a Semiotic Engineering approach, in which the interface is perceived as one-shot message being sent from the designer to hte users. In particular, interfaces can be viewed as meta-communication artifacts, since they can also exchange with the users. Furthermore, in multi-user environments, they are also communication embedding artifacts, since they allow for the communication among users. This approach focuses on the expression of the designer and requires the development of means to support this expression. In this work, we intend to provide support to multi-user interface designers, in a Semiotic Engineering framework. In order to meet our goal, we developed a meta-communication model from which models and techniques to support the development of multi-user interfaces can be developed. The meta-communication model proposes that designers should be provided not only with means to describe their messages, but also some qualitative indications on their description. Based on this model, we developed a model of an architecture to support the design of multi-user interfaces. This model assists designers that develop multi-user interfaces top-down. Therefore, this work is the first step in the direction of an environment to support the design of multi-user interfaces with quality. 98_MSc_noya Ricardo Choren NOYA. Quest - Um ambiente de avaliacao educacional para a Web. M.Sc.Diss. Presentation: 3/12/98 111p. Port. Advisor: Hugo Fuks Abstract: The Internet has a great potential for educational purposes. In 1997, the Software Engineering Laboratory at PUC-Rio implemented a first version of AulaNetTM, a web-based educational environment. This year, some of the teaching staff will be using this environment to offer regular term discipline through the Web. This work introduces Quest, the quiz generator and assessment tool incorporated into AulaNet TM to provide the means to support educational assessment through the Web. 98_MSc_bezerra Ricardo Flores Hilgenberg BEZERRA. Um modelo para integracao de funcionalidades de navegacao hipermidia em aplicacoes R-OLap de data warehose. M.SC. Diss. Presentation: 12/17/98 183 p. Port. Advisor: Rubens Nascimento Melo Abstract: We present a study of the Data Warehouse (DW) and hypermedia technologies and we propose a model to integrate the hypermedia navigation and visualization concepts to the concepts used on the dimensional modeling of Relational On-Line Analytical Processing (R-Olap) applications. R-Olap applications designers may use the proposed model, named integrator model, to incorporate more refined navigation functionality, adding semantics and access and interaction utilities. We made a case study to show the proposed model utilization implementing both the dimensional data structure and the integrator model through the Microsoft Access DBMS and developing an internet R-Olap application prototype through HTML and CGI-Lua. We conclude by comparing the proposed solution to the ones presently available on the market. 98_MSc_cruz Sylvia de O. CRUZ. Um catalogo de padroes para construcao de sistemas orientados a objetos. M.Sc.Diss. 212 p. Presentation: 4/27/98 Port. Advisor: Sergio Eduardo Rodrigues de Carvalho Abstract: Appearing like a proposal of solution to the problem of reuse of software, the patterns had been quickly accepted and incorporated by the community of object oriented. In a prime moment they were proposed in a extremely abstract way, not being, therefore, completely specified. The current necessity of incorporation of the patterns concepts by software development tools, with automatic code generation for these, require, although, complete specifications, what most of the times, reduces its generality. This tendency urged the creation of patterns specifics to certain applications domains. Among the techniques developed with this aim, there is one that deserves special attention. Called pattern mining, it consist in searching patterns in softwares already developed and tested to be, after words, used in the development of news softwares. This work uses this technique about a system that implements a tool in order to develop objects oriented systems that guarantee the correct application of the concepts existing in this paradigm. The set of patterns generated captures this guarantee of correction and could be used in the construction of a new tool of development or, being so, in a more generic way, in the construction of systems that follows the object oriented paradigm. 98_PhD_richa Thereza Regina Werneck RICHA. Convergencia de algoritmos tipo-Jacobi quaternionios. Ph.D. Thesis. Presentation: 8/27/98 166 (+42) p. Port. Advisors: Derek Douglas Jack (MAT) and Therezinha Souza da Costa Abstract: In this thesis we consider various aspects of the problem of calculating the eigenvalues of a real skew-symmetric matrix via the so-called qJ (quaternionic Jacobi) algorithm, with an eye to generalizing known algorithms to the skew-symmetric case. In particular, we shall be interested in the global and asymptotically quadratic convergence of the qJ algorithm for quasi-cyclic orderings, when the eigenvalues are distinct. After some considerations on Jacobi-type methods in the symmetric case and a description of the qJ algorithm following [H 93], we present a version of the algorithm in terms of the rotation angles which leads to a proof, in the skew-symmetric case, of global convergence for distinct eigenvalues. Using the method of [H 93] we prove a majorization result for the eigenvalues of a skew-symmetric matrix, analogous to Schur's theorem [Le 96] in the symmetric case. We also give a geometric proof of the skew-symmetric Schur-Horn theorem (following [LRT] ) based on the ideas of [Le 96], where the symmetric case is dealt with. 98_MSc_costa Veronica L. do H. COSTA. Browsers para sistemas de desenvolvimento orientados a objetos: uma aplicacao. M.Sc.Diss. Presentation: 9/14/98 114 p.Port. Advisor: Sergio Eduardo Rodrigues de Carvalho Abstract: Because of the huge amount of information available nowadays from computers all around the world, dealing with them with our bare hands is a difficult task. This situation turns browsers into indispensable tools for the handling of information in the World Wide Web or in Software Engineering. This work is about browsers for object oriented development systems, particularly CASES and programming environments. The study of the browsers of some of such tools available in the market leads to a proposition of the aspects of what should be the state of art for this kind of application. As a result, we obtain the framework of a browser for 2GOOD, a CASE tool which is part of the ARTS project from Laboratorio de Metodos Formais of the Computer Science Department of PUC-Rio.