Monografias em Ciência da Computação
Departmento de Informática
Pontifícia Universidade Católica do Rio de Janeiro - PUC-Rio
Rio de Janeiro - Brazil
This file contains a list of the technical reports of the Departmento de Informática, Pontífícia Universidade Católica do Janeiro - PUC-Rio, Brazil, which are published in our series Monografias em Ciência da Computação (ISSN 0103-9741), edited by Prof. Carlos Lucena. Please note that the reports not available for download are available in their print format and can be obtained via the e-mail below.
For any questions, requests or suggestions, please contact:
Rosane Castilho email@example.com
Last update: 18/DECEMBER/2003
ASSIS, R.L.; FUKS, H. Um framework conceitual de percepção para ambientes virtuais utilizando a tecnologia groupware. 38 p. Port. E-mail: firstname.lastname@example.org
Abstract: We believe that supporting awareness of other person's actions improves the performance of groupware environments. In this article, a theory of awareness is developed. A conceptual framework is presented to address some groupware design issues: what information to track, how to provide it and how to manage the control of it. The proposed framework extends exisiting research. It provides designers with a vocabulary and a set of ground rules for analysing working situations in order to improve coordination.
BARBOSA, A.C.P.; LUCENA, C.J.P. Integração de frameworks de software. 25 p. Port. E-mail: email@example.com
Abstract: Heterogeneous Database Management System (HDBMS) has been proposed as one of the solutions to the integration of autonomous, heterogeneous and distributed databases. The HDBMS needs flexibility to adapt itself to different environments and component systems. In the Computer Science Department at PUC-RIO, Brazil, it has been developed the HEROS project, an object oriented HDBMS whose architecture was defined using the frameworks techniques. In order to the advancement of this project, it is necessary a research about a better alternative to the components framework integration of the HEROS Framework. This work presents a study about some patterns to the components integration and also about software frameworks integration.
HANSEN, P.; CHAUNY, F.; ARAGÃO, M.P.; JAUMARD, B.; PERRON, S. Probabilistic satisfiability with imprecise probabilities. 9 p. Eng. E-mail: firstname.lastname@example.org
Abstract: Treatment of imprecise probabilities within the probabilistic satisfiability approach to uncertainty in knowledge-based systems is surveyedand discussed. Both probability intervals and qualitative probabilities are considered. Analytical and numerical methods to test coherence and bound theprobability of a conclusion are reviewed. They use polyhedral combinatorics and advanced methods of linear programming.
CUNHA, C.K.V.; QUENTAL, V.S.T.D.B.; de SOUZA, C.S.; SCHWABE, D. A Model for extensible Web based information intensive task oriented systems. 33 p. Eng. E-mail: email@example.com
Abstract: This paper proposes representation dimensions of models of eXtensible Web-based Information-intensive Task-orientated Systems (X-WITS). The proposal is expressed in a unifying language that acts as the base for the construction of extensions and generation of texts, which are descriptions or narratives of interaction flows between end-users and X-WITS. The general architecture of X-WITS is presented, as well as a walkthrough of an extension scenario which enlightens the main characteristics of the proposal. The proposal is then discussed in view of its theoretical underpinnings: Semiotic Engineering and End-User Programming.
LEMOS, M.; CASANOVA, M.A. Algoritmos para análises de sequências. 73 p. Port. E-mail: firstname.lastname@example.org
Abstract: Sequence comparison is one of the most important primitive operations in Computational Biology. It is the basis for more elaborated manipulations. The algorithm for comparing two sequences is based on dynamic programming. Both the basic algorithm and its extensions have quadratic time complexity, which makes them unsuitable for database searches. For this reason, families of heuristic algorithms were developed to improve the response time of database searches. The FAST and BLAST are the best known families. This work describes the basic algorithm, its extensions and the FAST and BLAST families.
MOURA, L.M.; LUCENA, C.J.P.; HAEUSLER, E.H. Analysis of parallel programs. 12 p. Eng. E-mail: email@example.com
Abstract: Parallel implementations are of growing interest, as they are more and more supported by modern hardware. However, despite its importance there is little work on classical data flow analysis for parallel languages. Probably, the reason for such dificiency is that a naive adaptation of classical data flow analysis fails and the straightforward correct adaptation needs an unacceptable effort, which is caused by considering all possible execution traces of a parallel program. Therefore, we propose an approach to implement program analyzers for parallel languages based on theories of Abstract Interpretation, Model Checking and Constraint Solving. We also consider features such as dynamic memory allocation (aliases) and dynamic process creation, which are often ignored by other approaches.
MOURA, L.M.; LUCENA, C.J.P.; HAEUSLER, E.H. A Modular implementation of action notation. 15 p. Eng. E-mail: firstname.lastname@example.org
Abstract: This paper describes the implementation of a modular interpreter for the new modular semantics of action notation, the formal notation used in action semantics. Our interpreter supports nondeterministic features of action semantics, and allows the user to explore different execution traces. The implementation is based on a new logic programming language called PAN. A brief and pragmatic introduction to modular structured operational semantics is also provided.
MOURA, L.M.; LUCENA, C.J.P.; HAEUSLER, E.H. Automating the generation of program analysis and verification tools. 39 p. Eng. E-mail: email@example.com
Abstract: The use of domain-specific languages (DSLs) is an interesting alternative for software development. DSLs increases productivity, reliability, and flexibility. However, implementing them is often difficult and costly. The problem is even worse if simulation, analysis and verification tools are desired. Presently, program analysis and verification is at best achieved by a hand-crafted tool specific to a programming/specification language. Since the manual construction of tools is expensive, they are hard to obtain and not often used, limiting the quality of the implemented software. We have proposed for the automated generation of simulation, analysis and verification tools for programs/specifications based on machine-processable formal definitions of the language's operational semantics. we also use a modular approach for language semantics that allows us to reuse semantic modules and fragments of already defined tools. In this article, the theoretical foundations and algorithms of our framework are described. Although the main motivation for our framework is to automate the development of program analysis and
verification tools for DSLs, it can also be used in the development of such tools for general-purpose languages.
SILVEIRA, M.S.; BARBOSA, S.D.J.; MONTEIRO, C.C.O.; SOUZA, C.S. The role of designer-generated scenarios in developing Web applications and their help systems. 13 p. Eng. E-mail: firstname.lastname@example.org
Abstract: Due to the increasing changes in the working practices of organizations brought about by Web technology, developers now face not only the new technological challenges, but also the communicative challenges involved in a multidisciplinary development team. Complex communication process involve human-computer interaction, human-human interaction mediated by computers, and human-human interaction about computer artifacts. In this paper, we present a communicative approach that makes use of scenarios produced by designers and developers throughout the development of web applications. We describe a case study, focusing on the communicative aspects involved both in the process of software development, and in the users' interactions with the final product. The use we made of the scenarios is best illustrated in the final product by the help system, whose architecture is also described.
LIMA, M.J.; RODRIGUEZ, N.; IERUSALIMSCHY, R. Funções remotas como valores de primeira classe em um sistema de objetos distribuídos. 11 p. Port. E-mail: email@example.com
Abstract: This paper describes a system for distributed programming based on the interpreted language Lua. Like functional languages, Lua supports functions as first-class values. The system proposed in this work extends this feature to remote functions. Processes communicate using remote procedure calls which accept functions as arguments or returned values. The solution combines expressive power with transparency in the manipulation of distributed resources. The paper also shows how distributed objects can be implemented using remote functions references and properties already provided by Lua, emphasizing the flexibility of the system.
FUKS, H. Aprendizagem e trabalho cooperativo no ambiente AulaNet. 20 p. Port. E-mail: firstname.lastname@example.org
Abstract: This paper presents AulaNet, an environment for the creation, participation and maintenance of Web-based courses. It differs from other Web-based instruction enviroments because it lacks the physical elements of the traditional school which are ever present in most of the other environments. AulaNet does not interfere in the developement of didactic contents. Those could be developed using regular tools like any word processor. That gives the teacher the opportunity to use the work that is already in its hard disk to create its online course. AulaNet relieves teachers from the Internet programming burden.
VILAIN, P.; SCHWABE, D.; de SOUZA, C.L. Use cases and scenarios in the conceptual design of Web applications. 12 p. Eng. E-mail: email@example.com
Abstract: In this work we describe a method for gathering requirements and synthesizing the conceptual design of Web applications. Our method emphasizes the importance of modeling user interaction and involving users in this process. It starts by capturing the requirements expressed in use cases and user are also useful as a requirement validation tool and as input for obtaining the conceptual schema. We show how to derive user interaction diagrams from use cases and how to obtain a conceptual schema from these diagrams. Conceptual design is followed by navigation design, which is a crucial phase for the success of web application developement. We finally describe how techniques used in this method can be extended to support specially the navigational design stage.
SILVEIRA, M.; LUCENA, C.J.P. Frameworks para as interfaces de busca e catalogação de conteúdo do ContentNet. 26 p. Port. E-mail: firstname.lastname@example.org
Abstract: The IMS standard for interoperability of educational contents meets the needs for information exchange in this area. Due to the standard's complexity, this study proposes frameworks for user interfaces mostly for people with little or no experience in IMS. These frameworks were built for the user interfaces of search and content cataloguing in ContentNet, as instantiated in the AulaNet environment.
CARNEIRO, M.M.; VELHO, L. Um estudo de algoritmos para visualização simultânea de dados volumétricos e superfícies poligonais. 54 p. Port. E-mail: email@example.com
Abstract: Some scientific visualization applications requires rendering not only of volume data but also of polygonal surfaces in the same scene. This work presents some basic direct volume rendering algorithms in addition to some changes in them so as to allow rendering of both representations at the same time. Hybrid Ray Casting and Shear-Warp algorithms are discussed and the main problems related to the integration of volume and surfaces are presented. This study allow us evaluate computational cost and image quality in these hybrid algorithms.
CARNEIRO, M.M.; MARTHA, L.F. Visualização interativa 3D de dados volumétricos. 47 p. Port. E-mail: firstname.lastname@example.org
Abstract: Volume rendering is a method of extracting useful information from a data set in the tridimensional space. However, this method requires the use of adequate tools that allows the exploration of the data in a flexible and interactive fashion. This work presents a set of techniques that helps the development of user interfaces for volumetric data manipulation. This study allows us to identify the most important aspects of the architecture of these interfaces.
CARNEIRO, M.M.; GATTASS, M. Métodos de aceleração de rendering de volumes. 35 p. Port. E-mail: email@example.com
Abstract: Volume rendering is a method of creating bidimensional images from a data set in the tridimensional space. However, when the 3D data set is too large, this method has several limitations, especially requiring too much computation time to generate good quality images. This work presents some volume rendering acceleration techniques in order to allow interactive volume visualization.
LUCENA, C.J.P.; FUKS, H.; BLOIS, M.; CHOREN, R.; ASSIS, R.L.; ROBICHEZ, G. Tecnologia de informação aplicada a Educação: um (meta) curso no ambiente AulaNet. 9 p. Port. E-mail: firstname.lastname@example.org
Abstract: This paper present a course developed at the Computer Science Department at the Catholic University of Rio de Janeiro (PUC-Rio). AulaNet is an environment for the creation, participation and maintenance of Web-based courses developed at the software Engineering Laboratory at PUC-Rio. The aim of the course is to show how to apply information technology to the teaching / learning process using distance learning environments like AulaNet. In this work is shown how to use groupware technolgy to give support, facilitate and manage cooperative learning.
OLIVEIRA, T.C.; CARVALHO, S.E.R.; LUCENA, C.J.P. DSSFrame - a decision support system framework with agents. 28 p. Eng. E-mail: email@example.com
Abstract: The decision making process is a cyclic process involving choice within a solution space. In the choice process, the data involved, the algorithm chosen and the path (sequence of steps) used to accomplish the solution are all very important. In this work we report the development of a software framework designed to put together the four main aspects of systems that aid the decision making process: the graphical interface, the database system, the mathematical support and an agent support. Composing those areas, we have developed a system that interacts with the end user through a mining and guiding process to improve the quality of the chosen solution.
MARKIEWICZ, M.E.; LUCENA, C.J.P.; COWAN, D. Taming access control security: extending capabilities using "views" relationship. 24 p. Eng. E-mail: firstname.lastname@example.org
Abstract: The "views" relationship indicates how an object-oriented design can be clearly separated into objects and their corresponding interface. This paper uses the concept of "views" in order to achieve full separation between the application and security policy in the design and implementation. The result is achieved by providing a model for capabilities using "views" that is richer than the traditional capability model. In addition, a distributed access control model is shown to be effective through the use of Secure Object Communication Channels (SOCCs) to allow for secure connections at the abstract object level. This security is applicable in the e-commerce application domain, bringing security directly to the application abstraction level.
BLOIS, M.; FUKS, H.; LUCENA, C.J.P. The e-society groupware approach. 12 p. Eng. E-mail: email@example.com
Abstract: New Economy, Knowledge Management, Knowledge Community, Intellectual Capital and .Com Enterprises are examples of terms currently used to illustrate the transformation of the social, economic, cultural and technological order. With this "new way of doing things" the work processes are completely reformulated and the vision of a single worker performing his own tasks apart from the task being performed by the others in the team is clearly being replaced by a more sinergistic group work approach. To support the demand for new technologies that enable a workgroup to perform tasks and to create a common process understanding, the Software Engineering Laboratory (LES) at the Catholic University of Rio de Janeiro (PUC-Rio) is developing groupware infrastructure for application in different domains like e-education, e-commerce and e-business. In this paper, we will briefly discuss the transformation of work relationships that are taking place in our society and detail two technologies developed at LES to foster the adoption of the Web as an arena for business and education. The first technology discussed is the AulaNet environment for creation, maintenance, administration and participation in Web based courses. Then we present the Scriba tool which facilitates the development of Java based Web applications showing its use in the AulaNet usage in PUC-Rio and the results of a initial analysis of the Scriba tool. Finaly, we present some general research directions taken at the laboratory for the development of new e-commerce, e-business and e-education technologies.
MAIA NETO, A.; LUCENA, C.J.P. CommercePipe: a framework for the creation of commerce channels on the Internet. 11 p. Eng. E-mail: firstname.lastname@example.org
Abstract: Based on the study of different electronic commerce software applications and mainly inspired by the research work and software evolution carried out in the Vmarket framework, this article presents the Commercepipe Object Oriented Framework as an alternative for the instatiation of Consumer to Business Virtual Markets on the Internet. Using Software Agents Technology combined with the WAP (Wireless Application Protocol) as a wireless interface to access Internet services, the framework proposes a new approach for C2B markets, bringing a new vision of how sellers and buyers can interact to perform commercial transactions through the Internet.
CHAVEZ, C.F.G.; CRUZ, S.O.; CARVALHO, S.E.R. An action semantics for the D2L design description language. 18 p. Eng. E-mail: email@example.com
Abstract: D2L is a language for expressing object-oriented designs. It provides mechanisms for the representation of classes and their relationships, object lifecycles, scenarios, state-dependent behavior and object communication in general, as well as some less conventional features, such as several new semantics for object behavior and some predefined automatic relationships between objects. This work reports our ongoing effort in developing a complete formal specification for D2L using Action Semantics. The first stage of this effort comprises the formal specification of D2L dynamic semantics. With the complete action-semantic specification for D2L, we hope to provide an executable model for designs expressed in D2L that can be simulated and also automatically translated to source code in some
WERNECK, R.F.; RIBEIRO, C.C. Sorting methods for small arrays. 14 p. Eng. E-mail: firstname.lastname@example.org
Abstract: We present and compare four efficient quadratic, comparison-based algorithms for small arrays and (for three of them) almost sorted inputs. In addition to the well-known insertion sort and selection sort, we analyze 2-insertion sort (a variation of insertion sort) and stacksort (based on selection sort). We show that the new algorithms perform fewer comparisons on average than their original versions. The theoretical analysis is confirmed by experimental data, which include promising results concerning the use of 2-insertion sort in conjunction with quicksort.
FRANCA, L.P.A.; STAA, A.v. A construction process for artifact generators using a CASE tool. 9 p. Eng. E-mail: email@example.com
Abstract: Artifact generators are a way to reduce production costs and time to market, and to increase reliability of artifacts within a given application domain. However, in order to achieve a more widespread usage of artifact generators, the difficulty and the cost of their development and maintenance must be reduced. This report presents a low-cost artifact generator development and maintenance process. The process departs from an example of a simple artifact within the target application domain. Given this example and considering all possible artifacts of the domain, all commonalties and variables are identified, as well as the properties that the specification of each specific target artifact must satisfy. The example is then modified in order to contain specific generator tags at all variable points. These tags establish the transformation rules that must be applied to the specification in oder to generate the application. We have used a CASE tool, which allows the programming of the specification editors and of the generators. By means of another tool, the tagged example artifact is transformed into a component, which is combined with the transformation library, yielding the generator code to be internalized by the CASE tool. The process has been sucessfully used to transform specifications into applications, components and documentation.
CHOREN, R.; FUKS, H.; LUCENA, C.J.P. Using a group support system to meet educational objectives. 11 p. Eng. E-mail: firstname.lastname@example.org
Abstract: This work presents a WWW-based Group Support System (GSS) to facilitate the teaching/learning process. This work also describes our experiences over four successive editions of a pilot course offered using the GSS. We show the methodologies used and draw some results, experiences and impressions from this experience. We further describe planned future research, including discussion of the possibility of using this method to support distance education.
SAUERBRONN, L.E., FEIJÓ, B., DREUX, M. Transparent video watermarking. 13 p. Eng. E-mail: email@example.com
Abstract: This paper describes the watermarking procedure to embed copyright protection into generic signals. A brief explanation concerning the Discrete Cossine Transform (DCT) is presented, showing how can it be obtained from a FFT (Fast Fourier Transform) algorithm. Finally, it applies its use into image and video sequences and presents two embeding methods. One intends to ilustrate what has been expalined herein and the other presents the state of the art in video watermarking.
VELOSO, P.A.S. Qualitative reasoning with "Generally": a logical approach - Part I. 25 p. Eng. E-mail: firstname.lastname@example.org
Abstract: Assertions and arguments involving qualitative notions occur often, not only in ordinary language, but also in some branches of science. The qualitative character may be apparent from "qualifiers" such as 'generally', 'many', 'almost all', etc., or objects termed 'representative', 'typical' or generic'. A precise treatment of such arguments has been a basic motivation for logics for qualitative reasoning. We will examine logical systems, with generalized quantifiers for them, also handling 'generic' objects. We also discuss some fundamental issues involved, such as the need for having, and comparing distinct qualitative notions relative to various universes, as well as some aparent misconceptions. These (monotonic) logics, with simple sound and complete deductive calculi, are proper conservative extensions of classical first-order logic, with which they share several properties. Other possible applications for these and related logics for qualitative reasoning are indicated, as are some connections with certain (philosophical) aspects of Mathematics, (Natural) Science and Artificial Intelligence.
PEIXOTO, A.; GATTASS, M. Reconstrução de superfícies a partir de seções bidimensionais. 25 p. Port. E-mail: email@example.com
Abstract: This work discusses the problem of reconstructing surfaces from cross-sectional contours. The contours are situated on parallel planes and are distributed along the direction of one axis of the coordinate system. The basic idea is to interpolate the contours, using a specific method, to recover the surface. The interpolation process depends on the applied reconstruction method. It will be discussed the main reconstruction techniques, how each approach treats the problems and which solution they've adopted.
VELOSO, P.A.S. Qualitative reasoning with "Generally": a logical approach - Part II. 33 p. Eng. E-mail: firstname.lastname@example.org
Abstract: Assertions and arguments involving qualitative notions occur often, not only in ordinary language, but also in some branches of Science. The qualitative character may be apparent from "qualifiers", such as 'generally', 'many', 'almost all', etc., or objects termed 'representative', 'typical' or 'generic'. A precise treatment of such arguments has been a basic motivation for logics for qualitative reasoning. We will examine logical systems, with generalized quantifiers, for expressing and reasoning about such notions. Here, we focus mainly on assertions involving 'generally', and present logical systems with generalized quantifiers for them, also handling 'generic' objects. We also discuss some fundamental issues involved, such as the need for having, and comparing, distinct qualitative notions relative to various universes, as well as some and complete deductive calculi, are proper conservative extensions of classical first-order logic, with which they share several properties. Other possible applications for these and related logics for qualitative reasoning are indicated, as are some connections with certain (philosophical) aspects of Mathematics, (Natural) Science and Artificial Intelligence.
URURAHY, C.; RODRIGUEZ, N.L.R.; IERUSALIMSCHY, R. ALua: a event-driven communication mechanism for parallel and distributed programming. 26 p. Eng. E-mail: email@example.com
Abstract: This paper presents ALua, an event-driven communication mechanism based on the interpreted language Lua. This mechanism takes advantage of the interpreted nature of Lua to define messages as chunks of code which are executed by the receiver. The event-driven distributed programming model is discussed and demonstrated with a set of examples. To illustrate the flexibility of the mechanism, the paper describes the implementation of an asynchronous agents team and a parallel programming paradigm. The applicability of ALua in real-sized parallel applications is studied by comparing the implementation of two parallel applications written in ALua with their compiled counterparts.
GARCIA, A.F.; CUNHA, L.M. Avaliação em instrução baseada na Web. 31 p. Port. E-mail: firstname.lastname@example.org
Abstract: The World Wide Web and related technologies propiciate adequate environments for the teaching/learning process, removing time and spatial barriers. Issues such as evaluation of the learning process and performance verification of students in Web courses are crucial for the success of online courses. The evaluation in distance learning has to be part of the whole process of learning, i.e., it should not be dealt as an isolated issue. Evaluation plays a very important role into the learning process since it helps to know the students and determine whether or not the goals of the courses have been achieved. It also provides feedback for the instructors and students. The main goals of this work are: (i) to review evaluation concepts from the literature; (ii) to identify open problems regarding evaluation in web-based courses; (iii) to show the methods and tools for evaluation in this context; (iv) to present some evaluation aspects of educational environments; and (v) to suggest future works.
GEROSA, M.A.; FUCKS, H.; LUCENA, C.J.P. Categorização de mensagens nos serviços de grupo de discussão e grupo de interesse do ambiente AulaNet. 13 p. Port. E-mail: email@example.com
Abstract: This paper presents a study about Web based textual asynchronous discussion, where software like gIBIS and AulaNet are analyzed. From this study and from the observation of the discussion that took place during one semester of the Information Technology Applied to Education course, we propose modifications to the course and a new structure for the discussion. The modifications and the structure will be tested in a new edition of the course. AulaNet is a software for the creation, participation and maintenance of Web-based courses.
VELOSO, P.A.S. Qualitative reasoning with 'generally': a logical approach (Part III). 38 p. Eng. E-mail: firstname.lastname@example.org
Abstract: Assertions and arguments involving qualitative notions occur often, not only in ordinary language, but also in some branches of science. The qualitative character may be apparent from "qualifiers", such as 'generally', 'many', 'almost all', etc., or objects termed 'representative', 'typical' or 'generic'. A precise treatment of such arguments has been a basic motivation for logics for qualitative reasoning. We will examine logical systems, with generalized quantifiers, for expressing and reasoning about such notions. Here, we focus mainly on assertions involving 'generally', and present logical systems with generalized quantifiers for them, also handling 'generic' objects. We also discuss some fundamental issues involved, such as the need for having, and comparing, distinct qualitative notions relative to various universes, as well as some apparent misconceptions. These (monotonic) logics, with simple sound and complete deductive calculi, are proper conservative extensions of classical first-order logic, with which they share several properties. Other possible applications for these and related logics for qualitative reasoning are indicated, as are some connections with certain (philosophical) aspects of Mathematics, (Natural) Science and Artificial Inteligence.
PEIXOTO, A.; CARVALHO, P.C.P. Esqueletos de objetos volumétricos. 26 p. Port. E-mail: email@example.com
Abstract: Skeltons of graphical objects are powerful tools that represent the object in a simple and efficient way. Volumetric objects are represented by a large quantity of information. Skeltons extraction, among other applications, can be used to calculate a compact representation of volumetric objects. This work presents a general framework of the main techniques used to compute skeltons of volumetric data. We will discuss the main problems and the different solution approaches.
PEIXOTO, A.; VELHO, L. Transformadas de distância. 30 p. Port. E-mail: firstname.lastname@example.org
Abstract: The computation of distance transforms has applications in several areas of Computer Graphics. One of the main difficulties in computing a distance function involves the transition between the continuous and discrete universes. When studied in the continuous universe, a method may present completely different properties than those exhibited in the discrete universe. This work presents a general framework about distance transforms, emphasizing mainly raster data (images and volumes). We will also discuss the interface propagation problem as an approach to distance transforms.
SILVEIRA, M.S.; BARBOSA, S.D.J.; de SOUZA, C.S. Getting users to understand via help systems. 13 p. Eng. E-mail: email@example.com
Abstract: Help systems are often underutilized, because they fail to clarify user's doubts. One of the reasons for this shortcoming is the fact that help systems are usually developed at the end of an application development process. This paper presents an approach to the development of help systems throughout applications' design and development processes, supported by both a model and an architecture of online help systems. This work is developed in the context of semiotic engineering, in which interactive applications are one-shot messages from designers to users, about how to exchange messages with the applications in order to achieve a range of goals.
MILIDIU, R.L.; PESSOA, A.A.; LABER, E.S. Pipeline transportation of petroleum products. 23 p. Eng. E-mail: firstname.lastname@example.org
Abstract: In this paper, we introduce a new model for pipeline transportation of petroleum products. We use a direct graph with arcs representing pipes and nodes representing locations. Moreover, we define an order as a requirement to transport an amount of a given product. Initially, we assume that all the ordered volumes are unitary. Orders are grouped into packages that are received on-line. A feasible solution is a pumping sequence for each new package such that all residual orders from the previous package are satisfied. The pumping restriction is required because products must be "pushed" by other products to move in pipelines. Our goal is to minimize the total pumping cost. Furthermore, we consider the problem of finding a strategy for the next order package, when the graph is acyclic. For that, we propose the Batch-to-Pipe Assignment (BPA) algorithm. This algorithm finds a minimum cost solution in (formula) time, for m pipelines, n locations and r unitary orders. Moreover, we observe that this solution is also optimal for on-line package sequences. Finally, we show that results can be extended to deal with general graph and
with non-unitary orders.
MARKIEWICZ, M.; LUCENA, C.J.P. Understanding object-oriented framework engineering. 11 p. Eng. E-mail: email@example.com
Abstract: Framework engineering is an emerging area within the Software Engineering discipline. The framework development approach must be considered when one must meet requirements that are prone to fast change as it occurs in new areas such as e-commerce and Web-based education applications. The present paper discusses the pros and cons of using the framework development approach as well as pitfalls and open problems associated with the framework technology.
BRAGA, C.O.; HAEUSLER, E.H.; MESEGUER, J.; MOSSES, P.D. Maude action tool: using reflection to map action semantics to rewriting logic (extended version). 29 p. Eng. E-mail: firstname.lastname@example.org
Abstract: Action semantics (AS) is a framework for specifying the semantics of programming languages, in a very modular and readable way. Recently, the operational semantics of action notation (action semantic's specification language) has been rewritten using Modular SOS (MSOS), a new modular approach for specifying operational semantics. The new modular specification of action notation facilitates the creation of extensions to action semantics, to deal with new concepts, such as components. The Maude Action Tool uses the reflective capabilities of rewritting logic, implemented on the Maude system, to create an executable environment for action semantics and its potential extensions. This is achieved by a mapping between the MSOS and rewriting logic formalisms which, when applied to the MSOS semantics of each facet of action notation, yields a corresponding rewrite theory. Such rewrite theories are executed on action programs, that is, on the action notation translation of a given program P in a language L, according to L's action semantics.
ZONENSCHEIN, R.; GOMES, J.; VELHO, L.; RODRIGUEZ, N. Towards interactivity on texturing implicit surfaces: a distributed approach. 6 p. Eng. E-mail: email@example.com
Abstract: We describe a distributed system for texture mapping implicit surfaces. The method uses a particle system associated with the gradient vector field of an implicit function to acquire texture coordinates at a support surface. As each particle trajectory is independent of each other, this method has a special suitability to run in parallel. Our results show good improvement as more processors are added to the system, with speedups of up to 13 with 32 processors, performance such as required by an interactive system.
CIARLINI, A.E.M.; FURTADO, A.L. Aiding the construction of libraries of typical plans. 32 p. Eng. E-mail: firstname.lastname@example.org
Abstract: Databases able to represent, not only facts, but also events in the mini-world of the underlying information system can be seen as repositories of narratives about the agents and objects involved. The events treated in our approach are those attributed to executions of predefined application-oriented operations. This work addresses the identification of typical plans adopted by agents, by analysing a Log registering the occurence of events, as represented by executions of such operations. The analysis is done by applying a previously formulated set of goal-inference rules to sequences of interrelated events, called plots, taken from the Log. The obtained Library of Typical Plans, together with the goal-inference rules, constitute the behavioural level of our proposed three-level conceptual schemas for the specification of information systems. A prototype Prolog implementation of the method for extracting typical plans is operational. A simple example is used to illustrate the discussion.
VELOSO, P.A.S. Ultrafilter logic has interpolation and related properties. 11 p. Eng. E-mail: email@example.com
Abstract: We show that ultrafilter logic has interpolation and some properties, such as joint consistency and modularity. By adapting a strategy used for classical first-order, we establish a joint model existence lemma, from which these properties, as well as Lowenheim-Skolem and completeness, follow.
TOSCANI, L.V.; VELOSO, P.A.S. On the time complexity of divide-and-conquer algorithms. 15 p. Eng. E-mail: firstname.lastname@example.org
Abstract: The time complexity of algorithms designed by divide and conquer is analyzed from a general formulation of the method. Typical cases are emphasized and illustrated with familiar algorithms. Some methodological aspects are also considered.
VELOSO, P.A.S. On a logical approach to qualitative reasoning with 'several'. 17 p. Eng. E-mail: email@example.com
Abstract: We examine logical systems, with generalized quantifiers, for expressing 'several' and reasoning about it. The primary motivation is a qualitative approach to assertions and arguments involving such vague notions, which occur often both in ordinary language and in some branches of science. Some intuitions underlying (a version of) 'several' are rendered precise by means of families of subsets. This gives a monotonic and conservative extension of classical first-order logic, with which it shares interesting metamathematical properties. Its sorted version captures notions with appropriate behavior. Our logic belongs to a family of closely connected systems with generalized quantifiers for reasoning about qualitative notions.
VELOSO, P.A.S. On a logic for qualitative reasoning with 'most' and 'typical'. 19 p. Eng. E-mail: firstname.lastname@example.org
Abstract: We examine a logical system, with generalised quantifiers, for expressing 'most' and 'typical' and reasoning about them. The intuition of 'most' as "all but for a 'negligible' set of exceptions" is rendered precise by means of filters. This gives a monotonic and conservative extension of classical first-order logic, with which it shares several properties. For typical reasoning, special individuals are introduced by means of 'most' and internalised as constants, thus producing conservative extensions where one can reason about them as intended. Our logic, though related to default logics, is quite different, belonging to a family of closely connected systems with generalised quantifiers for qualitative reasoning about vague notions.
MARKIEWICZ, M.E.; LUCENA, C.J.P.; COWAN, D.D. Abstract design views and design patterns. 28 p. Eng. E-mail: email@example.com
Abstract: Software reuse can be defined as the creation of new software systems using old artifacts. The Abstract Design Views model was created with reuse in mind, allowing the designer to apply separation of concerns from the design to the implementation. Using a reuse taxonomy, this model will be analyzed and categorized. Even further, using design patterns, it will be shown how Abstract Design Views can be realized and implemented.
ROSSETI, I.; ARAGÃO, M.P.; RIBEIRO, C.C., UCHOA, E.; WERNECK, R.F. Instâncias para o problema de Steiner em grafos. 18 p. Eng. E-mail: firstname.lastname@example.org
Abstract: In this work, 33 Steiner problems in graph's instances are proposed. They are based on otimization problems as set covering, code covering and Steiner triples systems. These instances are interesting because, in most of them, a good gap between linear relaxation and primal solution was obtained. Moreover, for some of these instances, the optimal solution was easily calculated.