Theses and Dissertations

2001

ABSTRACTS

Departmento de Informática 
Pontifícia Universidade Católica do Rio de Janeiro - PUC-Rio
Rio de Janeiro - Brazil


This file contains the list of the MSc. Dissertations and PhD. Thesis presented to the Departmento de Informática, Pontifcia Universidade Católica do Janeiro - PUC-Rio, Brazil, in 2001. They all are available in print format and, according to the authors' preference, some of them are freely available for download, while others are freely available for download to the PUC-Rio community exclusively(*).
For any requests, questions, or suggestions, please contact:
Rosane Castilho bib-di@inf.puc-rio.br

Last update: 31/MARCH/2005
 

INDEX


[01_MSc_medeiros]
Adriana Pereira de MEDEIROS. Especificação declarativa e implementação de aplicações hipermídia na Web. M.Sc.Diss. Port. Presentation: 08/06/01 222 p. Advisor: Daniel Schwabe.

Abstract: Hypermedia application development is composed of two main steps: the application specification by a design method (such as OOHDM) and its implementation in a programming language (using a support environment). The design specification of a hypermedia application is generally composed of models whose information must be mapped onto the implementation environment primitives. In many environments this mapping is done through the manual translation of the models into application code. This paper presents the declarative language OOHDM-ML, allowing the specification of hypermedia applications designed with OOHDM, and the OOHDM-XWEB environment, created to support the implementation of these applications. The main objective of this environment is to automatically generate the OOHDM design description of a hypermedia application into the format required by the OOHDM-Web 2.0 environment, using its OOHDM-ML specification. This description is generated by the OOHDM-Translation stylesheet implemented in XSLT, a transformation language for XML documents.


[01_PhD_barbosa]
Álvaro Cesar Pereira BARBOSA. Middleware para integração de dados heterogêneos baseado em composição de frameworks. Ph.D.Thesis. Port. Presentation: 03/05/01 154 p. Advisor: Rubens Nascimento Melo.

Abstract: Developing heterogeneous data integration systems in the Internet is a current and complex problem. There are many users with different skills and interests, needing to access different data types and data models, and requiring different functionality from the integration systems. In literature, there are a large number of integration systems reported. However, such systems are either specifically developed according to one application, or extremely generic to cope with different situations. Both cases bring problems when it is necessary to customise them to a new application. In order to conciliate a great variety of existing data, it is necessary to research new models for data integration systems, which could be tailored to a specific context. This is the goal of the present work: the development of the CoDIMS (Configurable Data Integration Middleware System), a flexible and configurable environment for generating configured systems for the integration of distributed and heterogeneous data. The essence of the CoDIMS environment is the Control component, which implements mechanisms for physical and logical configuration.  The physical configuration is obtained through the selection and integration of an adequate set of components that implement Data Integration Middleware Services - DIMS. DIMS Components are based on typical data management services, like the existing ones in the DBMSs. In order to provide more flexibility and facility in the adaptation to a specific application, DIMS Components are modelled using the framework technique. The logical configuration is obtained using an original approach, where DIMS services execution schedule is abstracted in a representaion based on the workflow concept.


[01_MSc_leite]
Ângela Cristina Julião LEITE. Weblearning: um ambiente para autoria de aplicações de apoio ao aprendizado na Web. M.Sc.Diss. Port. Presentation: 26/10/01 131 p. Advisor: Daniel Schwabe.

Abstract: The objective of this work is the development of an environment for the authorship of applications to support learning on the Web, named WebLearning. The features of this environment are based on requirements culled from many Instructional Design theories, used by educators in traditional teaching. Consequently, WebLearning is 
able to support several pedagogical approaches, enabling authors to create content on WebLearning using different instructional styles. The navigational structure of the applications developed with WebLearning is easy to use. The environment also provides tools to make this navigation more efficient, such as annotations - to enable the student to add personalized annotations to the content -, and navigational sessions, structures that allow the student to keep up some navigation he/she made previously. These structures enable the authors to follow the progress of each student while navigating the content. WebLearning's model was built using the OOHDM methodology. 


[01_PhD_paiva]
Anselmo Cardoso de PAIVA. Um método para a compressão de dados volumétricos baseado na transformada do cosseno local. Ph.D.Thesis. Port. Presentation: 25/04/01 77 p. Advisor: Marcelo Gattass.

Abstract: The volume visualization techniques present two classical computer problems: long execution time and large memory requirements. The memory requirements becomes more investigated with the popularization of the distributed applications. This problem is important also, to make possible the access to volume visualization techniques from a personal computer or low end workstation with limited memory. In this thesis we propose a new lossy compression scheme for volumetric data based on the local cosine transform. This method is appropriated for further volume visualization application because it provides good compression rates, minimizes reconstruction errors, and allows local decompression of the volume. We analyze the compression results and estimate some scheme parameter variations, investigating the adaptivity properties and different space decomposition arrangements.


[01_MSc_sampaiojunior]
Antonio Benedito Coimbra SAMPAIO JUNIOR. Especificação de um protocolo de comunicação hipermídia com qualidade de serviço e modularidade funcional. M.Sc.Diss. Port. Presentation: 12/06/01 176 p. Advisor: Luiz Fernando Gomes Soares.

Abstract: In recent years, an increasing demand for the transmission of multimedia information with guaranteed Quality of Service (QoS) over the Internet has arisen. This has been driven mainly by the fact that since its conception, the world wide network offers only the best-effort service without guarantees of delivery of the data packages transmitted through Internet applications. On situations of congestion, the referred packages can be lost or suffer undetermined delays in their transmission what is not desirable in multimedia applications. Driven by the fact that the hypermedia protocol currently used on the WWW, the HTTP, does not offer adequate support for multimedia transmission with guaranteed QoS, this research was developed with the objective of presenting the complete specification of a new hypermedia communication protocol which offers Quality of Service (QoS) treatment, functional modularity and independence between the transport and resource reservation protocols. To develop the protocol here proposed, an analysis of the various hypermedia and multimedia protocols developed by IETF, ITU and WAPForum, was carried out in order to single out their core characteristics and limitations. Based on the findings of this analysis, a new hypermedia communication protocol which possesses the desirable characteristics of the other protocols but does not inherit their limitations was proposed. Various scenarios of use for the proposed protocol were presented, within these, particular emphasis was given to the scenario of document request with Quality of Service; this being the area where the main contribution of this research lies.


[01_MSc_alvarez]
Beatriz Silva Villa ALVAREZ. Edição tridimensional de fotografias arquitetônicas. M.Sc.Diss. Port. Presentation: 28/08/01 68 p. Advisors: Paulo Cesar Pinto Carvalho (INPA) and Marcelo Gattass.

Abstract: This work proposes an interactive system that allows modifying a 3D photograph depicting an architectural scene so that the user may evaluate the aesthetic effects and the impact the changes may cause. The proposed method is based on the existence of three main mutually orthogonal directions of interest in architectural photos. The identification of vanishing points for those directions allows the calibration of the camera used to take the pictures and the insertion of new elements to the scene. 


[01_PhD_barbosa]
Carlos Alberto Moreno BARBOSA. Modelagem dinâmica de produto baseada na história de design. Ph.D.Thesis. Port. Presentation: 02/05/01 165 p. Advisors: Marcelo Dreux (DEM/PUC) and Bruno Feijó.

Abstract: The distributed object approach is applied to many researches in different areas. However, few references can be found regarding its application to design studies. Even fewer are found related the collaborative aspect of design in strongly dynamic situations. The objective of this study is to propose new models and mechanisms to deal with design under a collaborative approach, based on the same stage of the artifact evolution and dynamic features of the processes. Firstly, a model for the artifact properties classification, properties of which are organized in generic and spatial groups, is described. All the model elements are objects. A primary element of information has a value and a measure unit to establish its order of magnitude, when necessary. The associations between objects are realized with flexible mechanisms, which keep information about its hierarchy within a tree and allow their organization according to the focus of interest. The artifact evolution is studied and represented through the design history, in which the reassessment of properties where more than one alternative can be followed. Besides object models, studies about paradigms relevant to this research are also developed: interpretive languages, geometric bus, database, and middleware for distributed objects. A tier model, elaborated as a basis for the design integrated environment, is proposed and the principles for such an environment are formulated. A model aiming at integrating design professionals in an organization structure, the activities plans to be developed and design specification are also described. The participation of each of these elements in a job can be observed in the object virtual tree. More than one object tree can be instantiated to the same client and a bi-directional mapping between this representation and the database in a remote server guarantees the consistency of the operations. In the proposed collaborative environment there is no central or local schema showing where the objects are stored in some of the machines. The generated messages can automatically find the addressed objects, which allows flexibility to the model in order to support the artifact specification dynamically proposed by the designer. A framework instance is implemented where the elements involved in the integration can be dynamically created to a specific client and stored in any remote machines connected to the network.


[01_PhD_baptista]
Carlos Eduardo dos Santos BAPTISTA. Dificuldades na quebra de código de prefixo. Ph.D.Thesis. Port. Presentation: 20/12/01 169 p. Advisor: Ruy Luiz Milidiu.

Abstract: Huffman's method is widely used for construction of prefix codes for data compression. Huffman's algorithm gives a binary tree of minimum cost among all binary trees whose leaves are the elements of a dictionary. In general, large files that need to be safe against the action of intruders, have to be submitted to two different and successive processes: data compression and encryption. However, data compression methods together with some strategy can also be used as encryption. Huffman's codes have minimum redundancy compared with other prefix free codes, which suggests the use of Huffaman's algorithms also for encryption. In this report, we examine and revise some of the main results available in the literature related to the difficulty in breaking encryptions based on prefix free codes of variable length, which includes Huffman's codes. During our analyses, we've found some mistakes in the proofs of the NP-Completeness of the problems Subsequence Prefix Code (SPC), Restricted Prefix Encoding (RPE) and Prefix Encoding (PE). In the case of the SPC, an argument used to prove the indutive step of the Claim that affirms that the partition of a plaintext contains only maximal meta-characters is wrong. We've decided to substitute the SPC for the Maximal Subsequence Prefix Code (MSPC) problem, in which we impose that the meta-characters of the elements of the partition have to be maximal. In the case of the RPE, the application of the technic of the proof by induction, used in the main Claim, is also wrong. But in the RPE case, the mistake was solved, because we could correct the proof of the mentioned Claim. The results confirming the NP-Completeness of the Maximal Subsequence Prefix Code (MSPC), Restricted Prefix Encoding (RPE) and Prefix Encoding (PE) show evidences that certain variants of Huffman's algorithm added to certain strategies can also be used for encryption of text files.


[01_PhD_cunha, anexo]
Cecilia Kremer Vieira da CUNHA. Um modelo semiótico dos processos de comunicação relacionados a atividade de extensão a aplicação por usuários finais. Ph.D.Thesis. Port. Presentation: 17/09/01 155 p. Advisor: Clarisse Sieckenius de Souza.

Abstract: Applications that are extensible by end-users represent a proposal to cope with the issue that it is improbable that a software will attend every specific need of each different user within a domain. One of the research areas approaching extensible applications is End-User Programming (EUP). EUP empirical investigations evidence the 
existence of collaborative practices related to the process of application extension. In these practices, people communicate with each other with various purposes: to help themselves deal with their problems regarding computing, to share ready-made extensions or to build extensions together. Our work complements these investigations by offering a deep and theoretically motivated treatment of the communication phenomena related to the observed collaborative practices. Based on Semiotics theory and Semiotic Engineering, we propose a model of these  phenomena, describing its structure and behavior thus supporting a better understanding of the issues related to them. According to the model, we designed a computable language for the representation of extensions in association with corresponding communicative discourse.


[01_PhD_braga]
Christiano de Oliveira BRAGA. Lógica de reescrita como um framework semantico para semantica operacional estrutural modular. Ph.D.Thesis. Port. Presentation: 28/09/01 116 p. Advisor: Edward Hermann Haeusler.

Abstract: The abstraction level provided by programming languages constructs in the past decade has increased substantially. We moved from low level machine programming in card processing systems to executable mathematical specifications using functions, logic specifications with inference rules, or algebraic specifications with abstract datatypes, all running on laptops. The motto is becoming more and more "what" instead of "how". A byproduct of this technology evolution is the transformation technology which moved from assembly to machine level code complication towards-level specification processing. This is accomplished by transformations from that high level language to another language following a refinement process, that is, a process that preserves semantic properties from the source language into the language, in a potential network of transformations. Among the high level frameworks that relate to the above mentioned process, are actions semantics (AS), modular structural operational semantics (MSOS), and rewriting logic (RWL). AS is a framework for specifying the semantics of programming languages in a very readable way without loosing its mathematical precision. MSOS is an extension to structural operational semantics framework, that manages the pragmatic issue of modularity in a simple and elegant way. RWL is a generic framework to which many logics and specification languages have been mapped to. This thesis applies state-of-the-art transformation technology to the scope of semantic-driven generation of programming languages interpreters. The main contribution of this work is a proven correct mapping from MSOS to RWL and the MSOS-SL Interpreter, an implementation of an interpreter for MSOS specifications. As a case study for the MSOS-SL Interpreter, we have implemented the Maude Action Tool (MAT), an executable environment for AS using the MSOS specification of action notation. We have coded our tools in Maude, an efficient implementation for rewriting logic, with a fairly intensive use of its meta-programming capabilities. 


[01_PhD_szwarcman]
Dilza de Mattos SZWARCMAN. Dead reckoning orientado a metas para personagens reativos. Ph.D.Thesis. Port. Presentation: 14/03/01 113 p. Advisor: Bruno Feijó.

Abstract: This work proposes a new type of dead reckoning for share state management of networked virtual environments. By exploring the idea of clone autonomy, the goal-oriented dead reckoning is particularly advantageous for the state management of reactive characters. In this new version, state predictions, typical of the dead reckoning technique, become a matter of goal fulfillment. The goal-oriented state management maintains physical and mental state consistency through mechanisms that favor scalability and visual soundness - a concept proposed in this work to better evaluate the quality of a network virtual environment. As a generalization, the new dead reckoning formulation includes previous versions as special cases.


[01_PhD_barboza]
Eduardo Uchoa BARBOZA. Algoritmos para problemas de Steiner com aplicações em projeto de circuito VLSI. Ph.D.Thesis. Port. Presentation: 04/05/01 100 p. Advisor: Marcus Vinicius Soledad Poggi de Aragão.

Abstract: The first part of this thesis addresses the Packing of Two Steiner Trees Problem, which is NP-hard and has applications on VLSI layout. We present a new formulation and a theoretical investigation on the corresponding polyhedra. New families of valid inequalities, including proven facets, are identified. We also discuss branch-and-cut
implementation issues. The resulting code has a good practical performance and can solve some instances with up to 10.000 vertices in minutes. The second part of the thesis addresses the Steiner Problem in Graphs, which is also NP-hard. VLSI layout applications yield Steiner instances considered hard to be solved by current methods. In particular, preprocessing techniques developed for Steiner problems over general graphs are not likely to reduce significantly such instances. We propose a new preprocessing procedure effective for VLSI problems. Testing this procedure on real-world instances available on the web, significant reductions were obtained within reasonable computational times. Finally, we study the exact solution of the Problem in Graphs. We analyze a well-known dual heuristic for this problem and propose three new dual heuristics to improve its performance. These heuristics lead to two exact algorithms, a branch-and-bound without linear programming and a branch-and-cut. The algorithms were tested over instances from the literature and obtained good results, solving several instances for the first time.


[01_PhD_porto]
Fábio André Machado PORTO. Estratégias para execução paralela de consultas em bancos de dados científicos distribuídos. Ph.D.Thesis. Port. Presentation: 16/04/01 152 p. Advisors: Rubens Nascimento Melo and Patrick Valduriez (INRIA).

Abstract: This work was conceived based on the data integration architecture proposed by the Le Select system which is an integration middleware developed to support scientific applications. The goal of this work is to propose an execution strategy for distributed scientific queries that minimize their elapsed-time and maximize resource utilization. As a result of this research, we propose an original strategy for the generation of parallel execution plans. 
Considering the assumption that the execution of scientific programs present a per tuple cost extremely higher than of traditional relational operations, we adopt a strategy that aims into reducing the number of programs invocation during the execution. To that end we conceive some special execution techniques. The result of applying such techniques are reflected in the query execution plan where the placement of the expensive program invocation is flexibilized, making it possible to adopt heuristics for parallel query plans generation, as well as the hybrid strategy for expensive predicates. This strategy combines pipelined and independent inter-operator parallelism providing
an execution profile that is adapted to variations of estimated parameters during query execution. As an alternative to the hybrid strategy, we propose the Picking Cherry approach for the execution of expensive predicates based on the analysis of input data dependency.


[01_PhD_szenberg]
Flávio SZENBERG. Acompanhamento de cenas com calibração automática de câmeras. Ph.D.Thesis. Port. Presentation: 19/12/01 159 p. Advisors: Marcelo Gattass and Paulo Cezar Pinto Carvalho (INPA).

Abstract: In the television casting of sports events, it has become very common to insert synthetic elements to the images in real time, such as adds, marks on the field, etc. Usually, this insertion is made using special cameras, previously calibrated and provided with features that record their movements and parameter changes. With such 
information, inserting new objects to the scene with the adequate projection is a simple task. In the present work, we will introduce an algorithm to retrieve, in real time and using no additional information, the position and parameters of the camera in a sequence of images containing the visualization of previously-known models. For such, the method explores the existence in these images of straight-line segments that compose the visualization of the model whose positions are known in the three-dimensional world. In the case of a soccer match, for example, the respective model is composed by the set of field lines determined by the rules that define their geometry and dimensions. Firstly, methods are developed to extract long straight-line segments from the first image. Then an image of the model is located in the set formed by such segments based on an interpretation tree. With such information, the segments that compose the visualization of the model are readjusted, resulting in the obtainment of interest points which are then passed to a proceeding able to locate the camera responsible for the model's visualization. For the second image on, only a part of the algorithm is used, taking into account the coherence between the frames, with the propose of 
improving performance to allow real-time processing. Among several applications that can be employed to evaluate the performance and quality of the proposed method, there is one that captures images with a camera to show the on-line functioning of the algorithm. By using image capture, we can test algorithm in a great variety of instances, including different models and environments.


[01_MSc_dahis]
Gilda DAHIS. Um modelo para a especificação de cenários de interação. M.Sc.Diss. Port. Presentation: 14/10/01 177 p. Advisors: Clarisse Sieckenius de Souza and Simone Diniz Junqueira Barbosa.

Abstract: Since there are many complementary approaches that aim to contribute to support human-computer interaction design, it is worth use the best of some of them to treat questions less explored. The lack of research about modeling in abstraction levels intermediary between task and interface levels in addition with the fact that despite of the constant development of new technologies the existing models privilege specific interface styles I-O devices make interesting the investigation of modeling in an abstraction level intermediary between task and 
interface, that focus on representations less dependent of implementation technologies. An abstraction level that represents the possible conversations between user system, which we call interaction level, seems to satisfy those requirements. We believe that the conversation can represent an interactive system execution, independently of the interface implementation technology, because, in fact, this execution always consists in the information exchange 
between this system and its user or group of users. By means of the recognized value of scenarios as design tools, in this work we present a scenario specification model in this abstraction level little explored. As the majority of the scenario specification models are more concerned with the use of scenarios on requirements elicitation activities, the design process part that focus on user/client to designer communication, we concentrate on exploring the use of 
scenarios on the other side of this communication. Following the Semiotic Engineering approach, which considers that software applications are messages, sent from designers to users, we propose a model for the specification of scenarios as part of the content of these messages. 


[01_MSc_sardinha]
José Alberto Rodrigues Pereira SARDINHA. VGROUPS: um framework para grupos virtuais de consumo. M.Sc.Diss. Port. Presentation: 20/02/01 107 p. Advisor: Ruy Luiz Milidiú.

Abstract: The main goal of this framework is to create instantiated applications that explore the power of the virtual consuming groups.  Many benefits can be obtained with the union of these consumers, such as: reduced prices; gifts; auto-financing; time-sharing; and much more. An online retailer is able to create marketing campaigns more 
efficiently with the framework VGroups. Nevertheless, we had to combine some theories in order to achieve these results. The theories we used were: network marketing; specialized offerings; segmentation; and product aggregation and desegregation. With this combination, we were able to create two group applications, LotOnline and Bundless.com. LotOnline is an online Brazilian lottery that allows the creation of two different consuming organizations called bolao. The results of some tests were able to show us how important the consuming organizations can influence the adhesions to the groups. The application Bundless.com used some data mining techniques and evolutionary software agents to build a tool that automatically generates offerings. This tool proved 
to be very useful, because it is able to select the best offerings to the future consuming groups. 


[01_MSc_fernandes]
José Rodrigues FERNANDES. O algoritmo homofônico canônico para cifragem e compressão simultâneas. M.Sc.Diss. Port. Presentation: 30/03/01 131 p. Advisor: Ruy Luiz Milidiú.

Abstract: In this work, we propose the HC algorithm that simultaneously compresses and encrypt. It aims at the transmission and storage of large textual files. It is based on variable length Homophonic Substitution. We use canonical Huffman coding to represent the homophonic symbol set. Furthermore, we adopt a secret key at the final permutation stage of the encryption scheme. We compare HC against a conventional file compressor. Our experiments indicate a compression loss smaller than 6%. The time performance of HC is close to the similar measure for the conventional compressor. These results indicate that HC provides a good balance of quality and efficiency.


[01_MSc_nogueira]
Letícia NOGUEIRA. Um ambiente de gerência de aplicações CORBA. M.Sc.Diss. Port. Presentation: 29/03/01 100 p. Advisors: Noemi de La Rocque Rodriguez and Renato Cerqueira.

Abstract: Component-based programming is nowadays an important trend for distributed systems development. Using component-based programming, we can substitute or add new components in applications and also reuse tested components. Among other component systems, CORBA has become the most popular. It's widely accepted because it's an open specification, supported by a large number of programming languages, available from a large number of vendors (academics and commercials). However, the success of CORBA distributed systems depends upon its reliability and so depends upon management support. Despite the large number of ORBs available, few of them are concerned with the growing necessity of administration tools to help systems development and maintenance. This work presents Cometa, a LuaCorba tool for managing CORBA applications that supports the administration and reconfiguration of dynamic systems. With Cometa, we can use, in a simple and integrated manner, CORBA services that are important to administrate systems: the Interface Repository, the Trading Service and the Implementation Repository.


[01_MSc_miceli]
Lúcia Aparecida MICELI. GROUPLORE: um ambiente de apoio ao compartilhamento de conhecimentos. M.Sc.Diss. Port. Presentation: 21/11/01 137 p. Advisor: Clarisse Sieckenius de Souza.

Abstract: Grouplore is a tool for interdisciplinary research groups. Grouplore supports the organization, storage, retrieval and maintenance of an annotation base spontaneously composed by group members, directly or indirectly, about the content of documents. One of the distinctive features of Grouplore is the annotation classification mechanism. Grouplore has two important characteristics aiming at specific needs of the kind of user it is aimed at. The first, the classification of the annotations is extracted from a group model. The second, since it deals with research groups, its features are neither fixed, nor definitive. Both the annotator's or the group profile can change. These characteristics point out at an important facet of Grouplore, the retrieval mechanism. As the purpose of the environment is to support the dynamic nature of a research group, Grouplore works with the notion of Eras. An Era is characterized by a period of time in which certain features are kept invariable.


[01_MSc_callado]
Luiz Fernando Martins CALLADO. WebBBD-XML - Uma arquitetura de um sistema de banco de dados baseada em XML para extração de conteúdo da Web. M.Sc.Diss. Port. Presentation: 21/12/01 127 p. Advisor: Rubens Nascimento Melo.

Abstract: The extraction of Web contents has been the target of investments made by the scientific community and by many software development companies, not only in Brazil but also abroad. The aim of Web pages content extraction is to identify relevant information in a subject domain. The extraction technique allows for building Web-oriented database systems targeting a specific subject domain. These databases are known as webbases. Building them is a hard job as long as those information retrieved from the Web must be stored in the database. As a consequence its maintenance is extremely difficult because the Web pages are changed frequently. As the volume of those information is extremely large and there is a lack of criteria to organize them, accessing those information in the webbase is not an easy task as well. This master thesis proposes the use of webBD-XML, a XML-based database system architecture that aims to allow Web contents extraction and storage in webbases. The architecture is totally XML-based and has two major components: the first one is responsible for building the webbase and is called Crawler Module, once it implements a semantic crawler to select the information needed; the second one analyses and selects the information stored in the webbase, in order to answer users search requirements. The information analysis in the webbase is made through the use of an Ontology Model wich reflects the concepts and their relationships pertaining to the domain. An Ontology Model, which is proposed for each domain, supports the extraction process by detecting interesting information. The architecture is flexibilized towards its support to different subject domains through the 
specification of a specific Ontology Model.


[01_PhD_cysneiros]
Luiz Márcio CYSNEIROS. Requisitos não funcionais: da elicitação ao modelo conceitual. Ph.D.Thesis. Port. Presentation: 08/02/01 224 p. Advisor: Julio Cesar Sampaio do Prado Leite.

Abstract: The development of complex information systems calls for conceptual models that model aspect beyond entities and activities. In particular, recent research has pointed out that conceptual models need to model goals, in order to capture the intentions which underline complex situations within an organizational context. One particular 
class of goals is named non-functional (NFR) which need to be captured and analyzed from the very early phases of the software development process. Errors caused by not conveniently dealing, not dealing at all with NFR are among the most difficult and expensive to correct. In spite of that, a few proposal are met on the literature to systematically deal with NFRs. This thesis broaches two aspects on dealing with NFR that were not covered in the literature: how to elicit NFR and how to integrate them to the conceptual models. To do that, we propose a strategy that deals with NFR during the early phases of software development and integrate these NFR to conceptual models. The thesis was validated by three case studies. The results of these case studies suggest that the use of the proposed strategy can lead to a final conceptual model with better quality as well as to a more productive software development process.


[01_MSc_moura]
Marcel Stanley Albuquerque de MOURA. Relações espaciais em documento hipermídia. M.Sc.Diss. Port. Presentation: 31/08/01 152 p. Advisor: Luiz Fernando Gomes Soares.

Abstract: Hypermedia Authoring is a very complex process. Along with the definition of the document's logic structure, the specification of its temporal and spatial synchronization plays a major role. Spatial synchronization deals with the document's objects visual placement within their presentation devices and the definition of the spatial dynamics that should take place on those objects throughout a presentation. This work presents a spatial synchronization model for 
hypermedia documents along with a definition of a set of spatial relationships. An instantiation of this model into NCM (Nested Context Model), and its extension through a definition of spatio-temporal relationships and animations are also presented. Finally, some features of a synchronization tool are showed. 


[01_MSc_amaral]
Marcelo Jaccoud AMARAL. Mantendo codigo-fonte em XML - rumo ao hiperfonte. M.Sc.Diss. Port. Presentation: 29/05/01 240 p. Advisor: Edward Hermann Haeusler.

Abstract: The file format used today to maintain source code hampers both manual and automatic edition. Using the Extensible Markup Language (XML) and an appropriate document model designed for the programming language, the source code can be turned into a hypersource which exhibits several advantages over the plain text version. We present methods for designing the XML document models, creating translation programs to import traditional source code (using TXL), and building other tools to work with the hypersource. Examples of document models for TXL, Fortran and C++ are given, together with the import programs, style sheets and several transformations written in XSLT, a language designed to transform XML files.


[01_MSc_bezerra]
Márcia Martyres BEZERRA. Um modelo hierárquico para detecção de regiões regulatórias em seqüências de DNA. M.Sc.Diss. Port. Presentation: 28/11/01 98 p. Advisor: Marcus Vinicius Poggi.

Abstract: The main purpose of this dissertation is to study methods for the detection of regulatory regions in DNA sequences. It presents a hierarchical method for this purpose, where mechanisms for introducing correlations between different components of these regions are available. This dissertation also presents a language for a precise description of the signs that characterize regulatory regions. The method proposed was implemented and tested on primate lentivirus DNA sequences. The results reported lead to the conclusion that the methodology proposed is 
adequate, moreover they indicate that it supports throughout analysis.


[01_PhD_lima]
Maria Júlia Dias de LIMA. ORFEO: programação distribuída orientada a eventos com funções e continuações como valores de primeira classe. Ph.D.Thesis. Port. Presentation: 20/07/01 108 p. Advisors: Noemi Rodriguez and Roberto Ierusalimschy.

Abstract: In this work, we support the thesis that functions and continuations as first-class values constitute a good basis for abstractions that benefit from the asynchronous behavior found in event-oriented distributed programming. We have proposed and implemented ORFEO, a system based on the Lua programming language, which assigns to
remote functions the same first-class status of local functions. ORFEO also has the property of manipulating continuations as first-class values, allowing the capture of what remains to be executed in the processing of an event. The union of these two properties - remote functions and continuations as first-class values - in an event-oriented 
communication context allows a developer to build new abstractions, such as distributed objects and synchronization mechanisms, without the need of any special primitive in the system. The result combines the expressive power of a procedural language that offers remote functions and continuations as first-class values with the flexibility of  functional techniques and extension mechanisms.


[01_MSc_jacyntho]
Mark Douglas de Azevedo JACYNTHO. Um framework e uma arquitetura para implementacao de aplicações hipermídia na Web. M.Sc.Diss. Port. Presentation: 20/09/01 341 p. Advisor: Daniel Schwabe. 

Abstract: In the competitive environment of the Information Economy, programming productivity is indispensable for success. In this context, the creation of tools that automate software development is crucial. This dissertation proposes an object (component) oriented framework and an architecture for the implementation of hypermedia applications in the World Wide Web, using the J2EE (Java 2 Enterprise Edition) platform. This framework is based on the OOHDM method and on the traditional Model-View-Controller architecture. In addition, this work brings important Software Engineering principles to Web application development, allowing the production of organized, maintainable, and reusable code.


[01_PhD_barria]
Marta Emilia BARRIA MARTINEZ. Algoritmos para QoS em redes de computadores. Ph.D.Thesis. Port. Presentation: 19/03/01 173 p. Advisor: Luiz Fernando Gomes Soares.

Abstract: One of the problems related to the evaluation of networks that provide guarantees of QoS is the lack of simple models that would generate a first approximation of QoS parameters for the different types of traffic transported by the network. The overall objective of this thesis is to suggest some improvements in the techniques used in the transmission of different types of traffic across a computer network in order to achieve a better QoS. To this end, various algorithms, models and performance analysis methodologies are proposed, and the latter are then applied to the performance analysis of the proposed algorithms, calculating the most relevant performance measures 
in each particular case. The algorithms analyzed include those of the type used in packet-switching networks, such as TCP/IP, as well as those used in label switching networks, exemplified by the ATM network. The QoS parameters of greatest interest were the probability of loss of cells and system delay. Other performance measures were also derived, including various probability distribution function. 


[01_MSc_mota]
Oscar Thyago José Duarte Dantas Lisboa MOTA. Uma arquitetura adaptável para provisão de QoS na Internet. M.Sc.Diss. Port. Presentation: 29/05/01 112 p. Advisor: Luiz Fernando Gomes Soares.

Abstract: The variety of intserv and diffserv possible configurations as well as the various QoS provision techniques used in subnetworks makes it difficult to identify which model and subnetwork technology should be used to accomplish a specific service. Additionally, the fast technological evolution suggests the development of flexible 
architectures that accommodate, in execution time, adaptations nowadays only possible by less dynamic procedures such as hardware or firmware updates. This paper proposes an adaptable architecture for Internet QoS provision that is independent of service models and provision mechanisms, besides the used provider subnetwork technology. Through a generic framework definition the paper shows how hot-spots can be specialized to implement the two mentioned models used for Internet QoS provision. Following this, the paper proposes a general architecture 
that allows the QoS provision representation, in host and routers, independent from service models and existing subnetworks.


[01_MSc_ribeiro]
Paula Clark RIBEIRO. Modelagem e implementação OO de sistemas multi-agentes. M.Sc.Diss. Port. Presentation: 26/10/01 106 p. Advisor: Carlos José Pereira de Lucena.

Abstract: This work proposes a mapping between agent-based software engineering elements and object oriented software engineering elements. The mappings are illustrated through the modelling of an Internet marketplace. During the analysis and design phases, the Gaia methodology for agent-oriented analysis and design is used. Gaia methodology views the system as an organization of roles that interact. Two mappings are proposed between the Gaia methodology elements and object oriented programming models. The first one is done to the MAS Framework, a 
framework to build multi-agent systems, and the other is done to a design pattern to construct multi-agent systems. MAS Framework is applicable to reactive agents and the design pattern is concerned with the development of cognitive agents. Both of them were developed at Teccomm labs. At the end, an analysis of the advantages and disadvantages of mapping Gaia methodology artifacts is presented based on two approaches of developing OO systems. The case studies involve the development of the Babilonia marketplace.


[01_MSc_gorini]
Renata Abrantes de Campos GORINI. Um ambiente de suporte a autoria cooperativa de documentos hipermídia. M.Sc.Diss. Port. Presentation: 11/09/01 132 p. [xiv p.] Advisor: Luis Fernando Gomes Soares

Abstract: This thesis describes how a cooperative work can be organized using a task structure. Based on this structure, some mechanisms will be defined in order to support a coordinated collaboration between participants of a work. In this context, a task will represent a cooperative work, while a set of tasks will represent a complex 
cooperative work. Based on tasks, an environment was proposed to support the cooperative authoring on hypermedia documents. This environment will allow definitions of a task structure, task relationships (to define rules for the execution of a work, represented by tasks) analogous to workflow systems, and the definition of collaboration, communication and coordination mechanisms, which are essentials during cooperative processes. The environment was specialized and implemented for a particular hypermedia system, called HyperProp, using some hypermedia concepts (nodes and links), more precisely some concepts defined by the NCM model (a hypermedia model). 


[01_MSc_werneck]
Renato Fonseca Furquim WERNECK. Problema de Steiner em grafos: algoritmos primais, duais e exatos. M.Sc.Diss. Port. Presentation: 00/08/01 142 p. Advisor: Marcus Vinicius Soledad Poggi de Aragão.

Abstract: The Steiner problem in graphs is one of the most important NP-hard problems in combinatorial optimization, with applications in VLSI design, networks, logistics and computational biology, among others. We present a computational assessment of several strategies to deal with this problem in practice. The methods are divided into a 
number of classes: constructive heuristics, local search procedures, metaheuristics, dual heuristics and exact algorithms. Each class has its own way of dealing with the problem: running times, solution qualities and guarantees provided differ among them. We discuss the most relevant algorithms described in the literature and propose new 
ones. The result is a collection of tools that represent the state-of-the-art in practical algorithms for the Steiner problem in graphs. Several open instances in the literature were solved or had their bounds improved by these methods.


[01_MSc_kostin]
Sérgio KOSTIN. Modelo para gerenciamento de dados em um ambiente de comando e controle. M.Sc.Diss. Port. Presentation: 27/04/01 148 p. Advisor: Marco Antonio Casanova.

Abstract: The development of Command and Control Information Systems is a trend in worldwide Armed Forced. Military Operations are very mobile, subject to interferences of the environment and of the enemy. In short,
the communications are not trustworthy. The organization of Military Operations is hierarchical and can change in time. The goal of this dissertation is the definition of a model of data management of mobile computing that meets the requirements of a command and control system for military application. Specifically, the main contributions of the 
dissertation are: a data replication model; the definition of techniques for treatment of the search and diffusion of the system's information, considering the mobility characteristics, the customer's profile and the location of the stations; and a framework for the implementation of proposed techniques.


[01_PhD_silva]
Sergio Roberto Pereira da SILVA. Um modelo semiótico para programação por usuários finais. Ph.D.Thesis. Port. Presentation: 30/05/01 208 p. Advisor: Clarisse Sieckenius de Souza.

Abstract: One of many noticeable trends in the software industry has been to create resources to configure or extend applications available to end-users, in an attempt to broaden the applications' usability, thus satisfying the real need of these users. Unfortunately, simply making such resources available does not enable end-users to extend their
applications, for they normally lack the knowledge of how to use them. Adler and Winograd propose that the criterion for the usability of software should be the extent to which it supports the understanding and learning of its working, adaptation and extension. The area of End-User Programming could be seen as an answer to such demand. However, to the best of our knowledge, there is no agreement regarding a theoretical model that reasonably supports the development of extensible applications. In this work we take the view of software as a meta-communication artifact, proposed by De Souza in the Semiotic Engineering, and cast its use as a communication process between the software designer and the end-user. Taking up this view, we make use of Jakobson's Verbal Communication Model to understand the effect of the functions of language on this process. Supported by this knowledge and by the Semiotic Continuum and Interpretive Abstraction Principles, proposed by De Souza Semiotic Engineering, we present a theoretical model for the end-user programming task that pursues Adler and Winograd's proposal. This model is composed by a process for the creation of software extensions; a type-language for end-user programming that uses communicative resources to maintain the textual cohesion and coherence, such as the use of anaphors, metaphors and metonymy; and a software architecture with specific mechanism to support the interpretation of instances of that type-language and to maintain the Semiotic Engineering principles previously cited.


[01_PhD_fiorini]
Soeli Teresinha FIORINI. Arquitetura para reutilização de processos de software. Ph.D.Thesis. Port. Presentation: /04/01 200 p. [42 p.] Advisor: Julio Cesar Sampaio do Prado Leite.

Abstract: This thesis present an architecture for the organization and description of software processes. Its main goal is to enable software process reuse. The architecture is organized by three different process types (standard, pattern and usual) and by the concept of process framework. Processes are described according to their process type and
by special languages, which are based on XML (Extensible Markup Language). In order to help the retrieval of process information, the architecture provides a facet classification schema, a 3C-based reuse guide, and a process pattern classification (community, family and individual). A prototype tool implements the architecture. A requirements engineering process framework was built in order to explore the architecture capabilities. A case study on the reuse of requirements engineering process was conducted. 


[01_PhD_oliveira]
Toacy Cavalcante de OLIVEIRA. Uma abordagem sistemática para a instanciação de frameworks orientados a objetos. Ph.D.Thesis. Port. Presentation: 05/10/01 166 p. Advisor: Carlos José Pereira de Lucena.

Abstract: The use of techniques that can improve quality and productivity in the software development process is a key point to Software Engineering. Among those techniques the reuse of well documented past experiences is one of the most efficient to reduce the resources, such as time and cost, used. In this scenario, object oriented frameworks represent a step ahead to reuse in the way that they represent knowledge to a certain application domain where reuse can be broadly obtained. The framework reuse process, called instantiation, is driven by a set of reuse activities that due to their complexity, should be systematically executed in order to produce a significant advantage to the software development process. The main goal of this work is to report a set of techniques such as, framework design documentation and reuse process description language that are integrated in a reuse environment that guide the reuser through the instantiation process.