Theses and Dissertations
2002
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 2002.
They are all 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
[02_PhD_silva]
Adelailson Peixoto da SILVA. Extração de malhas adaptativas em multi-resolução a
partir de volumes, usando simplificação e refinamento. [Title in English:
Multiresolution adaptive mesh extraction from volumes, using simplification and
refinement] Ph.D.Thesis. Port.
Presentation: 04/10/02 104 p. Advisors: Marcelo Gattass and Luiz Velho.
Abstract: This work presents a method for extracting multiresolution adaptive
polygonal meshes, from volumetric
objects. Main applications of this work are related to medical area, fluid
dynamics, geosciences, metheorology and others. In these areas data may be
represented as volumetric objects. Volumetric datasets are implicit
representations of objects, so it's very difficult to apply directly any process
to these objects. Mesh extraction obtains an explicit representation of the
object, such that it's easier to process directly the objects. The presented
method extracts the mesh from two main processes: Simplification and Refinement.
The simplification step extracts a supersampled representation of the object (in
the same volume resolution), and simplifies it in such a way to obtain a base
mesh (or coarse mesh), in a low resolution, but containing the correct topology
of the object. Refinement step uses the distance transform to obtain a
multiresolution representation of the mesh, it means that at each instant it's
obtained an adaptive higher resolution mesh. The final mesh presents a set of
important properties, like good triangle aspect ratio, convergency to the object
surface, may be applied as to objects with boundary and as to objects with
multiple connected components, among others properties.
[02_MSc_pfeifer]*
Alésio Leoni PFEIFER. ALua: um sistema multi-canal baseado em eventos e
mobilidade de código. [Title in English: ALua: a multi-channel system based on
events and code mobility] M.Sc.Diss. Port. Presentation: 11/07/02 58 p. Advisor:
Noemi de La Rocque Rodriguez.
Abstract: Current interest in wide-area distributed computing has highlighted
the need for an adequate programming model for this environment. Because of its
asynchronous nature, event-driven programming provides a suitable model for
dealing with the failures and delays that are frequent in this context. Besides
that, new services and uses of computer networks often demand a high degree of
customizability and increasingly demand more flexibility and extensibility.
Recent research has explored the mobile code paradigm, investigating how dynamic
code exchange between processes can enhance the flexibility of services and
applications. In this work we propose an architecture for distributed multimedia
applications based on an event-driven programming model. To avoid the
synchronization problems that are inherent to multi-threaded programming, the
propose architecture is based on a single-threaded
structure. Instead of multithreading, we opted for the event-oriented approach
allied to multiple communication channels with user-defined handling procedures
to allow the application to deal concurrently with control and data streams. We
discuss this programming model, present the system we have implemented based on
this model, and
describe the experience we have had with this system.
[02_MSc_mele]
Alexandre MELE. Um framework para simulação de redes móveis ad-hoc. [Title in
English: A framework for simulation of mobile ad hoc networks] M.Sc.Diss.
Port. Presentation: 30/12/02 109 p. Advisor: Markus Endler.
Abstract: A mobile ad hoc network consists of a set of portable computational
devices, equipped with a wireless communication interface, that are randomly and
dynamically distributed in space, and where each host serves as a router for the
other hosts by discovering and maintaining multi-hop routes among the hosts. In
general, protocols for mobile ad hoc networks are more complex than equivalent
protocols for static networks, due to several properties of such networks, such
as its dynamic topology, the mutual interference, concurrent access and smaller
communication
bandwidth of the wireless links, as well as, operation with restricted amount of
energy, and scarce resources of the mobile devices. A main focus of research in
mobile ad hoc networks has been the development, analysis and comparison of
routing protocols for such networks. Therefore, there is some demand for
environments that facilitate the rapid prototyping, the simulation and the
debugging of protocols at the network and other layers for such
networks. These environments should preferably be flexible, easy to use, and
allow for the definition of different levels of abstractions for modeling the
main characteristics of the mobile network, such as the pattern of mobility, the
wireless links, the energy consumption, etc. This thesis describes the design
and implementation of a framework for the simulation of mobile ad hoc networks,
which aims at supporting the development of concrete simulation environments for
prototyping, testing and doing the complexity and performance analysis of
protocols for such
networks.
[02_MSc_azambuja]
Antonio Carlos Pereira de AZAMBUJA. Multi-resolução para a visualização de
reservatórios naturais de petróleo.[Title in English: Multi-resolution for
visualization of natural oil reservoirs] M.Sc.Diss. Port. Presentation: 06/05/02 138
p. Advisors: Marcelo Gattass and Waldemar Celes Filho.
Abstract: Current flow-simulation meshes of natural oil reservoirs (NOR) are
composed of hundreds of thousands of hexahedral cells. The visualization of the
geometry of these cells superimposed with color attributes to represent
properties and flow results requires the rendering of an unstructured mesh of
millions of triangles. Current graphics hardware does not allow for an
interactive visualization of such meshes. As computers and graphics boards
increase their processing capacity, simulation meshes also grow and the solution
to the rendering problem usually includes acceleration techniques, one of which
is multi-resolution (MR). However, currently known MR models are not applicable
to NOR simulation meshes due to this field's specific requirements, such as the
preservation of the hexahedral-cell model and discontinuities among cells. In
fact, MR techniques tend to focus on Realistic
Visualization, while the NOR problem is one of Scientific Visualization, for
which generic solutions still do not exist. The present work proposes a specific
MR model for the visualization problem concerning NOR simulation meshes, in
which discontinuous space partition, hexahedral-cell-based semantics and the
problem's visualization characteristics are taken into account. The proposed
model allows an efficient construction of a MR structure, from which, in real
time, adaptive meshes can be extracted that depend on: (a) the geometric error
approximation, (b) the view, and (c)
the polygon budget. This model can also be used combined with another
acceleration technique, frustum culling, which allows for the hierarchical
elimination of regions in the mesh that are out of the view volume. The proposed
model was implemented in a system on which extensive testing was performed,
providing results that allowed us to draw some conclusions and recommendations.
[02_MSc_barbosa]
Clarissa Maria de Almeida BARBOSA. MetaCom-G*: especificação da
comunicação entre membros de um grupo. [Title in English: MetaCom-G*:
specification of the communication among members of a group] M.Sc.Diss. Port.
Presentation: 27/03/02 111 p. Advisors: Clarisse Sieckenius de
Souza and Raquel Oliveira Prates.
Abstract: The complexity inherent in the design activity and the
challenges proper to the design of multi-user interfaces motivate
the development of models, methods, techniques and tools for the
support of the design process of multi-user interfaces. MetaCom-G is one of such models. Within the Semiotic Engineering
framework by De Souza, Prates proposes that the designer be
offered an environment which enables him to describe how members of
a group organize themselves in order to perform the group activity.
In addition, this environment should provide the designer with
qualitative indicators of his description, which will assist him
in making his design decisions. Nevertheless, MetaCom-G only allows
the designer to describe communication among group members at a high
level of abstraction. Consequently, the environment proposed in this
model holds little information about the group's communication
process to effectively help the designer make his future design
decisions. In order to expand MetaCom-G's support to the designer,
we extend this model and propose MetaCom-G*. With the extended
model, we enable the designer to describe more accurately the
communication process of a group. As the extension is based on the Speech Act
Theory and
Discourse Analysis, the information provided
by the environment for the support of the design process of
multi-user interfaces proposed in MetaCom-G* leads the designer
to reflect on the effect of communication on group members. By
doing so, it helps him make his future design decisions
regarding this communication.
[02_MSc_nehab]
Diego Fernandes NEHAB. A implementação da linguagem de programação
Sloth. [Title in English: The implementation of the Sloth programming language] M.Sc.Diss. Port. Presentation: 12/07/02 58 p. Advisor:
Roberto Ierusalimschy.
Abstract: This work describes a new functional programming language
and its implementation. Sloth is a non-strict purely functional
interpreted programming language, which supports high order functions
as first class values, structured data types and pattern-matching
based function definitions. Sloth was created for academical use in
activities related to the use and to the implementation of
functional programming languages. Therefore, there has been a great
concern with the simplicity of both the language specification and
its implementation. As a result, Sloth's syntax is modest, but
expressive enough for practical applications. Furthermore, the great
simplicity and portability of its implementation has no serious
impact on its performance. The main contributions of this work are
the design and implementation of Sloth, an optimization to combinator
graph reduction as an alternative to the use of Turner combinators,
a new architecture for the implementation of interpreted functional
programming languages, based on the cooperation between two
programming languages, and the performance comparison between Sloth
and similar languages.
[02_MSc_andrade]
Diogo Vieira ANDRADE. Um modelo para determinação de preços para
leilões. [Title in English: A model for determining prices in auctions] M.Sc.Diss. Port. Presentation: 14/08/02 69 p. Advisor:
Marcus V. S. Poggi de Aragao
Abstract: This work presents a linear programming model for virtual
markets. The main objective is to encourage sellers to offer lower
prices and buyers to pay more for products. This is done through a
system where the agents are awarded for acting this way. The basic
version of the model works as an auction where buyers and sellers
can make their bids. Some extensions were developed for this basic
model, to allow situations like: transportation cost between buyers
and sellers; scale economy for the buyer's price; multiples products
in the same auction. For the basic model and each of its extensions,
the system of awards has been developed based on Game Theory
principles. In each case, the model was reinterpreted as a game and
its core solutions were found. It was also verified how these
solutions determine market's behavior.
[02_MSc_poyart]
Eduardo Ribeiro POYART. IEngine - uma interface abstrata para
motores de jogos 3D. [Title in English: IEngine - an abstract interface for 3D
games engines] M.Sc.Diss. Port. Presentation: 26/04/02 64 p. Advisor:
Bruno Feijó
Abstract: 3D game engines are APIs that help the development of
games with real time 3D graphics. It is convenient to use a 3D game
engine when developing games, because all the low-level functionality
is already built. However, each 3D engine API is constructed in a
different way, causing engines to be incompatible. The learning
process is also difficult, because the APIs of some engines are not
well designed. This work analyzes this issue by doing a critic survey
of some existing 3D engines and proposes an abstraction layer over
them, called IEngine. The IEngine layer gives engines a standard API.
An application built over IEngine can be compiled with any of the 3D
engines adapted to IEngine, and that application could switch
engines without any code change. The adaptation of a new engine to
IEngine is also facilitated by IEngine's structure of abstract
classes (interfaces) and is done by inheritance. In this work, an
implementation of IEngine over the open-source and multiplatform
engine Crystal Space is presented. Also, it is presented a way to
implement IEngine over a second engine, Fly3D. Finally, the
possibility of IEngine receiving an interface layer with other
programming languages such as Java and Lua is studied, in such a way
to allow the quick development of good visual quality 3D games.
[02_MSc_rodrigues]
Elisette Maria Figueiredo de Almeida RODRIGUES. Aplicando o modelo
MOF e o XMI para a integração de bancos de dados heterogêneos.
[Title in English: Applying the MOF model and XMI for heterogeneous databases
integration] M.Sc.Diss. Port. Presentation: 25/03/02 77 p. Advisor: Rubens
Nascimento Melo
Abstract: The Information Technology Boom during the last decades,
consequence of technology maturation, resulted in a large diversity
of implementations technologies. The current software vendors'
strategies pass now, due to that variety of implementation
technologies used during the "IT rush", through an integration
path. The heterogeneity of systems to be integrated, allied to
the massive use of the Internet, specially for publishing
businesses information, providing the user with a simple and
complete assessment of the subjects, and also reducing the
information storm that has to be handled, while improving their
quality, asks for solutions that allow an easy and sound legacy
data integration to new applications implemented using modern
technologies. Heterogeneous Database Systems are viewed as a
good legacy systems' integration solution, since they can be
coupled "as is". However, the majority of newly developed
applications use object technology, usually not used in DBMS's.
From this, arises the need for integrating OO applications with
DBMS's using distinct technologies. This work aims at presenting
a model for systems integration, considering the characteristics
above, developing a framework to facilitate the construction of
specific solutions for integrating OO applications to legacy
systems. The framework is based on the MOF Model and XMI, both
OMG standards.
[02_MSc_santos]*
Fábio Marcos de Abreu SANTOS. Plataformas para jogos de guerra com
computação móvel. [Title in English: Warfare games platforms using mobile
computation] M.Sc.Diss. Port. Presentation: 10/05/02 117 p.
Advisors: Marco Antonio Casanova and Roberto de Beauclair Seixas.
Abstract: Mobile applications attracted great interest in the last
years. Several applications, based on totally new concepts have been
created by taking advantage of the ubiquitous computation. War games
traditionally have helped military training in many countries,
bringing to the classroom simulations of the operation theater.
Military field exercises are equally necessary to prepare the troop.
The use of war games with mobile equipment represents a new field
trainning facility for the Brazilian Marines. We believe that war
games can not be limited to classrooms, but be extended to the field,
where the realism of the operation theater helps the Brazilian
Marines to receive a fuller and better training, compatible with the
importance of its mission. The main goal of this work is to propose
some ways to use mobile devices on Brazilian Marines field exercises
integrating it with the war game, which runs in classrooms. Nowadays,
the field exercises use only wired workstations and the server needs
to be transported to the exercise's place. The data entry is manual
and data are received by radio communications. By developing a WAP
application and using techniques of data summarization and active
databases, we will receive the response of each requested message
by SMS.
[02_MSc_silva]*
Flávio Heleno Bevilacqüa e SILVA. Coordenação de sistemas
multiagentes via equilíbrio de mercado econômico. [Title in English: Multi-agent
systems coordination via balance of the economic market] M.Sc.Diss. Port. Presentation:
19/04/02 134 p. Advisor: Ruy Luiz Milidiú.
Abstract: Multiagent systems need efficient strategies of
coordination to achieve their objectives. When there is a task
distributed among agents, their interaction involves an exchange of
messages. This problem can be harmful depending on the volume. The
strategies of coordination must reduce the volume of messages
exchanged and the number of centralized elements without prejudice
the system efficacy. The objective here uses the balance of the
economic market to develop coordination techniques for multiagent
systems with the market-oriented modelling. These techniques reduce
the interaction of agents and don't need a central coordinator. We
explain this model by using two applications: a resource allocation
and a component realocation in consumer groups. Preliminary results
compared with another technique of coordination present advantages in
some aspects, essentially in the search for the best possible solution
and the measurement of the agents performance. We conclude that this
modeling is an efficient strategy of coordination, with easy
implementation that, depending on the kind of application, generates
better solutions than other existing coordination techniques.
[02_MSc_guimaraes]
Francisco José Zamith GUIMARÃES. Utilização de ontologias no domínio
B2C. [Title in English: Ontologies use in B2C domain] M.Sc.Diss. Port. Presentation: 19/12/02 195 p. Advisor:
Carlos José Pereira de Lucena.
Abstract: The main difficulty associated with the B2C domain is
increasing the usefulness of WWW for the electronic trade through
the improvement of the services provided to the consumer. Even
though the WWW allows the buyer to have access to a great amount of
information, to obtain the information from the right supplier that
sells the desired product by a reasonable price can be a very
expensive task. One of the ways of improving the web functionality
is through the use of intelligent agents for search of information,
that is, the introduction of purchase agents that aid the buyers to
find products of their interest. For that to happen we need to
overcome an inherent difficulty of the WWW: the mixture of natural
language, images and layout information in HTML is one of the
greatest barriers for the automation of the electronic trade, because
the semantics of the information is only comprehensible for human
beings. To solve this problem we hope to produce more efficient
purchase agents by associating them to the use of ontologies, and
virtual stores that have special annotations that follow ontologies.
In the present dissertation we make a study of the main technologies
related to ontologies development in Computer Science. We also
develop a case study about the ontologies application to the B2C
domain, seeking in this way to evaluate potential and existing
difficulties for the development of this type of application.
[02_MSc_pierre]
Gustavo Moreira PIERRE. Ambiente integrado para posicionamento em
operações militares. [Title in English: Positioning integrated environment for
military operations] M.Sc.Diss. Port. Presentation: 01/07/02 65 p.
Advisors: Marcelo Gattass and Roberto de Beauclair Seixas.
Abstract: With technological development, we have been witnessing a
growing popularization of satellite-location equipment (GPS receivers)
and pocket computers (PDA) in several areas: air, sea and earth
transports, mapping and geoprocessing, sports and entertainment. We
can see hikers, for example, acquiring their own GPS receivers. In
the military environment, this popularization is also occurring: the
Armed Forces in several countries are obtaining increasing numbers
of GPS receivers and are testing equipment to interact with them. The
purpose of this work is to integrate GPS receivers and PDAs, with the
intention of employing them in military operations in order to obtain
quick responses for a faster and more efficient use of fractions of
involved troops. This work involves the generation of files readable
by PDAs, the communication of GPS receivers with PDAs, and an easy
and fast visualization of the information provided by the receivers.
It also includes a comparison between the use of map in two different
representations, raster and vector, both allowing for zooming and
movement of the image, as well as the possibility of measuring
distances between points of the map in the PDA screen, and the
inclusion, exclusion and alteration of several observations. The
great advantage of using raster images instead of vector images in
PDAs for this purpose was verified, as well as some disadvantages
in the use of PDAs, common in military operations, with
general-purpose GPS receivers.
[02_PhD_mathiasfilho]
Ivan MATHIAS FILHO. A documentação e a instanciação de frameworks
orientados a objetos. [Title in English: Documenting and instantiating object
oriented frameworks] Ph.D.Thesis. Port. Presentation: 17/04/02
184 p. Advisor: Carlos José Pereira de Lucena.
Abstract: The extreme competitiveness of contemporary economy
generates a huge demand for cheaper, efficient and reliable software
products, which often are developed under great pressures of time and
budget. These premises suggests that software development must take
place in an environment where proved solutions can be modified,
combined and adapted to be used in the development of new products.
Therefore, the use o object oriented frameworks, or frameworks for
short, seems to be one of the most promising techniques for code and
design reuse. Nevertheless, one of the obstacles that have to be
removed before the widespread use of frameworks is the great amount
of time for study necessary to be proficient in the use of a specific
framework. This situation occurs due to the inherent complexity of
the design of the frameworks, which are conceived to fulfill the
requirements of an entire application family. In this context, this
work presents a detailed description of a high-level framework
instantiation process based on the Features Model. This model is
responsible for presenting to the application developers a simplified
view of the main functional and technological characteristics of a
framework. In a following step, the instantiation process modifies the
original design of the framework to produce a new design for a specific
member of an application family. All of the modification steps will be
based on choices available in the Features Model.
[02_MSc_magalhaes]
João Alfredo Pinto de MAGALHÃES. Um framework multi-agentes para busca
e flexibilização de algoritmos de classificação de documentos.
[Title in English: A multi-agent framework for search and flexibilization of
document classification algorithms] M.Sc.Diss. Port. Presentation: 27/09/02 103 p. Advisor: Carlos José Pereira de Lucena.
Abstract: We are living in the information age, where knowledge is
constantly being created in a rate that was never seen before. This
is mainly due to Internet, that changed all the information exchange
paradigms between people. Through the net, it is possible to publish
or exchange whole works, reaching an audience impossible to be reached
through other means. However, excess of information can be harmful:
having too much information can be equal to having no information at
all. Our work was to build a multi-agent framework for search and
flexibilization of textual document classification algorithms of a
specific domain. We have built an infra-structure that separates the
concerns of document search and selection (platform) from the
concerns of document classification (an application of the separation
of concerns concept). It is possible not only to use existing
algorithms, but also to generate new ones that consider domain-specific
characteristics of documents. We generated four instances of the
framework, a webclipping application, a knowledge management component,
a search engine for websites and an application for the semantic web.
[02_MSc_cunha]
Leonardo Magela CUNHA. Formação de grupos de trabalho utilizando
agentes de software. [Title in English: Working groups formation using software
agents] M.Sc.Diss. Port. Presentation: 17/04/02 104 p.
Advisor: Hugo Fuks.
Abstract: Nowadays, the complexity of work and the dissemination of
the information and communication technologies value and make group
work a potential allied for the organizations. The computer support
offered under the umbrella of groupware systems is based on the
research from Computer Supported Cooperative Work (CSCW). The support
for the workers should be given since the group formation until its
dissolution, going through the group work itself. In Software
Engineering, multi-agent systems provide a properly level of
abstraction for the treatment of complex and distributed problems.
One of these problems is characterized by environments for group work
and/or learning in groups. In this dissertation it is presented the
study and how a multi-agent system was implemented in AulaNet to help
group formation.
[02_MSc_lima]
Luciana dos Santos LIMA. Um framework para provisão de QoS em redes
móveis sem fio. [Title in English: A framework for QoS provisioning in wireless
mobile networks] M.Sc.Diss. Port. Presentation: 23/08/02 142 p.
Advisor: Luiz Fernando Gomes Soares.
Abstract: In the last decades, increasing interest has been observed
in technologies related to wireless mobile communication environments.
Great part of such interest follows the growth in the telecommunications
industry, more specifically of cellular mobile telephony systems. Users
are quickly absorbing these technologies and generating new necessities,
such as the use of services of multimedia data, which demand quality
assurance. In this context, one of the challenges is the efficient use
of the limited frequency spectrum available, providing users quality
services. This dissertation proposes an architecture for the provision of
end-to-end QoS in wireless mobile networks, taking into account
inherent characteristics of these environments. To reach this purpose,
modifications were proposed to the frameworks for QoS provisioning
in generic processing and communication environments, aiming to
fulfill the necessities brought by mobile networks, generating an
adaptable architecture to offer QoS in environments that support
mobile connections. In order to validate the proposal, an
instantiation of frameworks for QoS provisioning in wireless mobile
networks is described by means of a mobility scenario in which an
infrastructure network of integrated services is simulated working over
Mobile IP.
[02_MSc_martins]
Lucimar Candido MARTINS. Personalização de visões sobre documentos
hipermídia. [Title in English: Personalization of views over hipermedia
documents] M.Sc.Diss. Port. Presentation: 10/06/02 125 p. Advisors:
Marco Antonio Casanova and Carlos José Pereira de Lucena.
Abstract: One of the most difficult tasks in dealing with the large
amount of available data on the Web is to deliver the right data to
a specific user. Many applications related to e-learning, e-commerce
and information retrieval have been developed for this purpose. Some
examples are search engines, recommendation systems and
personalization systems. In spite of the great effort to develop
personalized presentation and filtering systems there are challenging
problems to be resolved. Some of them are directly related to
information filtering, packaging and formatting, wherever this
information needs to meet the user goals, interests and preferences.
The main purpose of this dissertation is to define a framework, using
the separation of concerns concepts, which contemplates personalization
issues such as filtering, packaging and formatting processes. The
framework facilitates the implementation and fine-tuning of algorithms
addressing these issues.
[02_PhD_seibel]
Luiz Fernando Bessa SEIBEL. Bio-AXS: uma arquitetura para integração
de fontes de dados e aplicações de biologia molecular. [Title in English:
Bio-AXS: an architecture for integration of molecular biology data sources and
their applications] Ph.D.Thesis.
Port. Presentation: 20/05/02 169 p. Advisor: Sergio Lifschitz.
Abstract: There are many molecular biology databases, also known as
genome databases, that need to be integrated with all related
applications and other data sources. This work proposes the use of an
object-oriented framework for genome data access and manipulations. It
is an innovative approach for an integration tool, which deals well
with these application domain requirements, such as flexibility,
reusability and extensibility. This works also presents a conceptual
schema for the central dogma of molecular biology, defining an
ontology which can be used within the data sources and compared to
previous approaches. The framework, called Bio-AXS, is presented in
details using class and sequence diagrams that explore both the
structural and dynamic parts of the architecture. The Bio-AXS
implementation issues are discussed, as well as some functionalities
of the implemented prototype. Indeed, many case studies were explored
in order to show the adequacy and applicability of the proposed
architecture.
[02_PhD_ribeiro]*
Marcelo Blois RIBEIRO. Web life - uma arquitetura para a implementação
de sistemas multi-agentes para a Web. [Title in English: Web Life - an
architecture for the implementation of multi-agent systems for the Web] Ph.D.Thesis. Port. Presentation:
19/12/02 203 p. Advisor: Carlos José Pereira de Lucena.
Abstract: The resolution of distributed problems by applying computer
systems composed by agents and organized towards a common objective is
attracting the scientific community's attention. This is shown by the
increasing number of initiatives for the development of methods and
platforms to help constructing multi-agent systems. Some platforms
concentrate efforts on supporting some multi-agent systems' aspects
while others try to offer a complete infrastructure for the agents and
organizations development. The Web Life architecture offers an
implementation platform for developing Web-based multi-agent systems.
The architecture is focused on the provision of a complete multi-agent
infrastructure with native support for communication, coordination,
decision-taking and task-oriented behavior. The incorporation of current
under development standards and tools for solving specific problems in
multi-agent systems is one of the main objectives of this work. These
standards and tools are integrated by the Web Life framework. The
architecture try to help the evolution of the Web into a Web with
semantic contents that may be automatically processed - the Semantic
Web.
[02_MSc_moreno]
Marcelo Ferreira MORENO. Um framework
para provisão de QoS em sistemas operacionais.
[Title in English: A framework for QoS provisioning in operating systems] M.Sc.
Diss. Port. Presentation: 16/08/02 105 p. Advisor: Luiz Fernando Gomes Soares.
Abstract: The progressive demand for distributed multimedia applications, which
are characterized by strong requirements over computational resources, makes
evident the need for quality of service (QoS) provisioning in each one of the
involved subsystems (e.g. communication networks and operating systems). At the
same time, these subsystems must be flexible enough that they can offer new
services to future applications, or in other words, they must be adaptable at
runtime. Specifically, general-purpose operating systems provide few or no
QoS/service adaptability support, what have motivated many isolated studies
about these topics. Observing some implemented technologies on specific
operating systems, it is noted that the provisioning mechanisms have certain
functional similarities. In this way, this work proposes an adaptable
architecture for QoS provisioning on networking and process scheduling
subsystems of operating systems, through the description of generic frameworks.
It is demonstrated how the framework hot-spots can be specialized in
order to implement some QoS models. Finally, it is proposed a scenario of use of
the architecture, where a bit modified generalpurpose operating system is used
as infrastructure for an instantiation of the QoS frameworks.
[02_PhD_carneiro]
Marcelo Medeiros CARNEIRO. Interfaces assistidas para deficientes
visuais utilizando dispositivos reativos e transformadas de distância.
[Title in English: Assistive interfaces for the visual impaired using force feedback
devices and distance transforms] Ph.D.Thesis. Port. Presentation: 30/10/02 162 p. Advisors: Luiz Velho
and Marcelo Gattass.
Abstract: The natural evolution of user interface models that occurred
in the last few decades ended up popularizing a standard model based
almost exclusively on visual metaphors. This process has left visually
impaired users unable to use computers and to access new technologies.
Some actions have been made to revert this scenario. Most of them were
based on adapting the existing models instead of creating specific
solutions for the visually impaired community. The development of
applications for such users requires the use of new technologies, tools
and communication media. This thesis proposes the use of force feedback
devices in the project and implementation of assistive user interfaces,
helping blind users in simple 2D interaction tasks. By exploring the
sense of touch, such devices can be used to improve the efficiency of
the communication between the user and the interface. Also, this work
investigates the use of distance transforms as a powerful mechanism to
support many 2D interaction tasks.
[02_MSc_gerosa]
Marco Aurélio GEROSA. Categorização e estruturação de mensagens
textuais em ambientes virtuais de colaboração. [Title in English: Categorizing
and structuring textual messages in virtual environments of collaboration] M.Sc.Diss. Port.
Presentation: 28/02/02 85 p. Advisor: Hugo Fuks.
Abstract: The telecommunications technologies are improving the way of
transmitting and generating information. But these technologies also
lead to a non-manageable growth of the quantity, nature and quality of
the available information. This is a critical problem in collaboration,
where group members have to intensively communicate in order to
resolve tasks. A way to minimize the information overload in textual
communication is to organize, structure and categorize messages. The
objective of this work is to analyze whether by structuring and
categorizing the messages, there is a reduction in the information
overload, and to figure out what other effects take place when the
communication and collaboration of a group is realized through textual
messages. The categorization of messages was implemented in the
asynchronous communication services of the learning environment
AulaNet and used during four semesters in a course.
[02_MSc_silva]
Marcos Aurélio Citeli da SILVA. Simulação do escoamento de água e óleo
em meios porosos. [Title in English: Computer simulation for a two-phase fluid
flow in porous media] M.Sc.Diss. Port. Presentation: 11/09/02 67 p.
Advisors: Marcus Vinicius Soledade Poggi de Aragão and Marcus Vinicius
Sarkis Martins.
Abstract: Many problems arising from real world can be represented by
systems of partial differential equations (PDE's). However, the
resulting discrete equations produce large and frequently bad
conditioned matrices. This work implements the mixed finite element
method to numerically solve a system of PDE's coming from a multiphase
flow in porous media model and improve its performance by
preconditioners and parallel processing.
[02_MSc_silva]
Maurício Hofmam da SILVA. Tratamento eficiente de visibilidade através
de árvores de volumes envolventes. [Title in English: A comparison among
diferent bounding volumes for view-frustum culling] M.Sc.Diss. Port. Presentation:
08/03/02 154 p. Advisors: Marcelo Gattass and Waldemar Celes.
Abstract: Rendering complex three-dimensional engineering models has
been a challenge for Computer Graphics ever since its origin, as
detailed models are often composed of millions of polygons while
current graphic stations are able to display, at interactive rates,
only dozens or hundreds of thousands of polygons. A way to increase
the performance of viewers of three-dimensional models is to reduce
the number of polygons passed to the rendering pipeline by eliminating
large groups of polygons classified as non-visible for being out of
the viewing frustum or hidden by other polygons. In this work, we
study the use of bounding volumes to determine sets of polygons which
are potentially visible, propose ways to automatically structure such
polygons in a hierarchy so as to restrict the necessary computations
for this purpose, and compile a series of results which allow us to
take some conclusions on the use of bounding volumes and model
structuring.
[02_PhD_silveira]
Milene Selbach SILVEIRA. Metacomunicação designer-usuário na interação
humano-computador: design e construção do sistema de ajuda. [Title in English:
Designer-to-user meta-communication in human-computer interaction: help system
design and development] Ph.D.Thesis.
Port. Presentation: 18/12/02 147 p. Advisor: Clarisse Sieckenius de
Souza.
Abstract: This work is based on the Semiotic Engineering theory of
Human-Computer Interaction. This theory views the application interface
as a meta-communication act, a message from designer to user,
representing the designers' view of the artifact he developed. Since the
designer cannot be present in the interface, he is represented by his
deputy, who is endowed with a communicative capacity that allows it to carry out a discourse that is complete and exclusively
regarding the
designers' final conclusions about the needs, preference, capacities
and opportunities that he understands the user has. Being impossible
to predict all the interpretations that each user can generate for the
application, the designer needs, through his deputy, to explain
everything that he did (and why he did it), and to give the users a
chance to clarify their doubts. The best alternative for
meta-communication is, certainly, the help system. In this way, the
work herein proposed extends the current theoretical model of Semiotic
Engineering, making explicit the presence of the help system and its
communicative role. The purpose of this extension is to provide
software designers with epistemic tools to support them when
constructing their application's help systems. These tools allow
designers to explore help systems' communicative power, supporting them
in the reflection about the materials available for its elaboration
(design models, design rationale, among others), thus supporting them
both in the construction of the discourse embedded in the help system,
and in the elaboration of the possible ways the user will be able to
express himself within this discourse.
[02_MSc_silva]
Otávio Rezende da SILVA. Uma arquitetura para sistemas multi-agentes
baseada em espacos de tuplas reflexivos. [Title in English: A reflective
tuplespace-based architecture for the development of multi-agent systems] M.Sc.Diss. Port. Presentation:
18/12/02 79 p. Advisor: Carlos José Pereira de Lucena.
Abstract: Software technology is undergoing a transition from
monolithic architectures, constructed according to a single overall
design, into open architectures composed of conglomerates of
collaborative, heterogeneous, and independently designed agents and
multi-agent systems (MAS). These architectures are driven by additional
system-wide properties, such as communication, coordination,
adaptability, mobility and persistence. However, controlling these
properties and managing different application agents is not an easy
task, requiring a more sophisticated software architectural approach.
In this context, we propose the Reflective Blackboard architectural
pattern, which is the result of the composition of two other well-known
architectural patterns: the Blackboard pattern and the Reflection
pattern. The pattern allows a better separation of concerns, supporting
the separate handling of control strategies, by means of the
computational reflection technique. An infrastructure, which implements
the proposed pattern and provides support to multiple system-level
properties, such as mobility, communication, coordination and
persistence, was also developed. The Reflective Blackboard pattern was
applied together with this infrastructure to the development of a
Marketplace application in order to validate de concepts proposed in
this work.
[02_PhD_vilain]*
Patrícia VILAIN. Modelagem da interação com o usuário em aplicações
hipermídia. [Title in English: Modeling user interactions in hypermedia
applications] Ph.D.Thesis. Port. Presentation: 30/01/02 221 p. Advisor:
Daniel Schwabe.
Abstract: Hypermedia applications are inherently interactive, with
which users interact in an intensive way. This work proposes a
technique dedicated exclusively to represent the information
exchanged in the interaction between users and applications. This
technique is called UID (User Interaction Diagram) and it can be used
to represent the exchange of information contained in textual
descriptions which express the requirements of given hypermedia
application, without considering specific aspects of user interface
and design. The proposal presented here is to use UIDs in several
phases of the development cycle of applications where an intensive
exchange of information with users takes place. In requirements
gathering, as UIDs present a simple notation and are comprehensible
by users, they are used to aid the specification and validation of
requirements. In conceptual design, as UIDs present data items
participate of the interaction, they are used for identifying the
classes, attributes and associations of a preliminary class diagram.
In navigation design, UIDs are used for identifying the indexes and
contexts through which users can navigate. A UID extension that
supports navigation aspects, called UND (User Navigation Diagram),
can also be used in this phase. This work proposes a method for
requirements gathering where UIDs are used to represent user tasks.
Further, guidelines to define a preliminary class diagram, indexes
and contexts, from UIDs, are presented. To test and improve the
proposed guidelines, three case studies were developed, on which the
examples used during the text are based. Besides being used in these
case studies, the proposals presented here have been currently applied
in the method OOHDM (Object-Oriented Hypermedia Design Method), thus
showing the viability of such proposals.
[02_MSc_lucena]
Paula Salgado LUCENA. Expressive talking heads: um estudo de fala e
expressão facial em personagens virtuais. [Title in English: Expressive talking
heads: a study on speech and facial expression in virtual characters] M.Sc.Diss. Port.
Presentation: 25/06/02 80 p. Advisors: Marcelo Gattass and
Luiz Velho.
Abstract: The human face is interesting and challenging mainly because
of its familiarity. Essentially, it is the part of the human body that
is used to recognize individuals. As well as the face, the speech is
an important instrument for human communication, allowing the
exteriorization of thoughts and the definition of emotions. Together,
speech and face are the main elements of interactivity among human
beings. However, the natural and faithful reproduction of the
peculiarities of these elements in the computational universe is not
a simple task, constituting topics of research in diverse areas,
particularly in facial animation. Among the diverse types of facial
animation systems developed, those that involve the facial animation
of the virtual character combined with speech synchronization are
distinguished as directly related to this work. These kinds of
systems are known as talking head or talking face. For the development
of a talking head system, it is necessary to identify the possible
approaches for the speech and face modeling. The models used will
influence not only the way that the animation is performed, but will
also affect the system's interactivity. An important contribution
of the present master thesis is the study of several possible
approaches for the main elements and the proposal of taxonomy for
the classification of the talking head systems. From the proposed
taxonomy and making use of one approach for each analyzed parameter,
an application was developed that receives as input a text composed
by the character's speech and genus, language and emotion parameters,
and it generates as output, in real time, the animation of a virtual
character uttering the input text with speech synchronization and
expressiveness. The system developed, called "Expressive Talking
Heads", explores the naturalness of facial animation and it seeks to
offer the user a real-time interactivity interface. The "Expressive
Talking Heads" system can run as a stand-alone application or
connected to web browsers. It was designed and developed to provide
a platform - and operating system-independent solution.
[02_PhD_aiex]
Renata Machado AIEX. Uma investigação experimental da distribuição
de probabilidade do tempo de solução em heurísticas GRASP e sua
aplicação na análise de implementações paralelas. [Title in English: An
experimental investigtion of probability distribution of solution time in GRASP
and its application on the analysis of parallel implementations] Ph.D.Thesis. Port.
Presentation: 05/08/02 243 p. Advisors: Celso Carneiro Ribeiro and
Mauricio G. C. Resende.
Abstract: GRASP (Greedy Randomized Adaptive Search Procedure) is a
multi-start metaheuristic for combinatorial optimization problems.
GRASP has been used to find quality solutions of several combinatorial
optimization problems. In this work we describe a methodology for
analysis of GRASP. Hybrid strategies of GRASP with path relinking are
also proposed. These strategies are studied for the 3-index assignment
problem (AP3) and for the job-shop scheduling problem (JSP) and are
analyzed according to the methodology proposed. The methodology for
analysis of GRASP is used to predict qualitatively how the quality of
the solution varies in a parallel independent GRASP, using the data
of the GRASP sequential version as input. The GRASPs for the AP3 and
for the JSP are parallelized and the computational results are
compared to the results obtained using the methodology proposed.
[02_PhD_noya]*
Ricardo Choren NOYA. Uma linguagem de modelagem para sistemas baseados
em agentes. [Title in English: A modeling language for agent based systems] Ph.D.Thesis. Port. Presentation: 20/12/02 121 p. Advisor:
Carlos José Pereira de Lucena.
Abstract: The agent technology is gaining acceptance, both in academy
and industry, with regards to distributed systems development. Modeling
languages and development processes were created to formalize the
development of agent based systems. Nevertheless, existing modeling
languages are either based on previous development methods (object
oriented) or they do not have artifacts (models) that show the agency
characteristics that exist in a system. This thesis proposes a
modeling language, for agent based systems, that generates artifacts
that model agency aspects, such as adaptation, learning, interaction
and autonomy. The language has artifacts that allow the modeling of
the non-agent part of an agent based system, using ontology.
[02_MSc_guimaraes]*
Robson Mattos GUIMARÃES. Considerando o usuário em aplicações
hipermidia. [Title in English: Considering the user in hypermedia applications] M.Sc.Diss. Port. Presentation: 25/04/02 224 p. Advisor:
Daniel Schwabe.
Abstract: This work aims at characterizing the problem in using the
user as part of the modeling of a hypermedia project and at extending
the OOHDM method to represent such problems. To illustrate the
motivation, several cases of Web site personalization and information
security applied to information systems based on Web are presented.
The OOHDM method is extended using new primitives, such as user and
role, that are also used in the definition of the main components of
this method: navigational classes, links, access structures and
contexts. The hypermedia application framework patterns raised to
customization are described. Besides that, it is presented how the
OOHDM-WEB 2.0 can be altered in order to contemplate the proposed
extensions.
[02_MSc_costa]*
Rogério Luís de Carvalho COSTA. Alocação de dados e distribuição de
carga para execução paralela da estratégia BLAST de comparação de
sequências. [Title in English: Data placement and workload distribution for the
parallel execution of BLAST sequence comparison strategy] M.Sc.Diss. Port. Presentation: 27/03/02 75 p.
Advisor: Sergio Lifschitz.
Abstract: The BLAST (Basic Local Alignment Search Tool) is the
sequence comparison strategy mostly used in computational biology.
While molecular biology databases are getting larger, performance has
become an important problem to be solved. Indeed, depending on the
processing environment, sequences complexity and the database size, a
BLAST execution for a given sequences input set may last for hours or
even days. Among all distinct solutions that aim at obtaining better
performances, we are interested here in the use of multiprocessor
machines and parallel techniques. In this dissertation we study the use
of distributed database design methods for executing BLAST in a
shared-nothing parallel architecture. We propose specific data
allocation approaches similar to conventional fragmentation and
replication techniques. We give some practical results obtained from
a PC cluster-based implementation with MPI and a WU-BLAST version,
which is kept unchanged. The main parameters evaluated include the
number and size of input sequences and also the database size. Besides
presenting detailed results for performance and speedup, we discuss
tasks distribution strategies to deal with load balancing issues.
[02_PhD_bergmann]
Ulf BERGMANN. Evolução de cenários através de um mecanismo de
rastreamento baseado em transformações. [Title in English: Scenario evolution
with a transformation based traceability approach] Ph.D.Thesis. Port.
Presentation: 18/12/02 224 p. Advisor: Julio Cesar Sampaio do
Prado Leite.
Abstract: The importance of traceability in software evolutions was
quite established, but despite the effort spent, they are many issues
that difficult they effective use. These issues are related to the
generating and validating of trace information about the relationships
and interdependencies between the real world, the requirements and the
software system. This information is often mistrusted since they may
have become obsolete due to separate evolution of models and systems.
This thesis study the use of the transformational technology in the
implementation of a traceability mechanism that automatically obtain
trace information by identifying the changes made in consecutive
artifact versions and store it as transformations. The main advantages
gained with its uses are the elimination of the problems of the lack of
trace information updating, the systematization of the trace process
and the decrease of the cost to obtain, update and validate trace
information. Besides these benefits, the storage of trace information
in the form of transformations incorporates a larger knowledge on the
accomplished modeling, unlike other mechanisms that only store the
artifacts and their static inter-relationships.
[02_MSc_braconi]*
Viviane Monteiro BRACONI. Heurísticas multifluxo para roteamento de
produtos em redes dutoviárias. [Title in English: Multiflow heuristics for
products routing in networks of pipes] M.Sc.Diss. Port. Presentation: 26/04/02 78 p.
Advisor: Ruy Luiz Milidiú.
Abstract: This master's dissertation deals with the Problem of
Petroleum Derived Products Transportation through Pipelines(PTDPO).
We focus on Petrobras nets located in the State of Sao Paulo. These
networks represent the most intense operations of Petrobras. Each
network is composed of a set of areas (bases) and segments. The bases
are responsible for the production and delivery of the products. The
areas are not self-sufficient in the supply of their consumers' markets
so it is necessary to transport products through pipes. Considering
that initial configuration and consumption values are already
available, the problem consists of determining how to operate the
network of pipes to satisfy the demand within a established time
interval without violating the technological restrictions.The PTDPO
is a problem of NP-Complete class. As this is a difficult problem and
because of the implementation difficulties and acquisition of data,
we decided to simplify the problem to obtain better results. In order
to find to solution to the problem, we propose a heuristic approach
separated in two phases: planning of the products to be pumped and
scheduling of the products to be pumped. In the first phase of the
proposed heuristic we adopted a relaxation of the problem that makes
possible the use of linear programming for definition of routes and
products necessary to satisfy the demand of the network . In this
phase the proposed model is derived from the network flows model with
multiperiods. Due to the difficulty in obtaining an integer result
in a reasonable execution time, we restricted the solution to the
continuous model. In the scheduling phase we defined for each segment
the order of pumping of the products. This order could be modified if
some restriction of tank's capacity were violated. If it is necessary,
we can accomplish interactions between the heuristic phases to find a
feasible solution for PTDPO. In our experiments using a Pentium III
850MHz and the XPRESS-MP application, version 1.2, we found feasible
solutions for 5 instances pertaining to two different network of
Petrobras, for programming intervals varying between 5 and 30
operational days. Most of these instances were built on the real data
of the Petrobras. As a whole, the processing time used for obtaining
these results did not exceed 20 minutes. In searching for a feasible
scheduling, this work promoted a detailed study of the PTDPO and its
intrinsic difficulties. Among other aspects, it made possible
development of more efficient linear formulation provided a better
understanding of the problem as a result of the performed experiments.