DECOM - Trabalhos apresentados em eventos

URI permanente para esta coleçãohttp://www.hml.repositorio.ufop.br/handle/123456789/581

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Scatter search based approach for the quadratic assignment problem
(1997) Cung, Van Dat; Mautor, Thierry; Michelon, Philippe Yves Paul; Tavares, Andréa Iabrudi
Scatter search is an evolutionary heuristic, proposed two decades ago, that uses linear combinations of a population subset to create new solutions. A special operator is used to ensure their feasibility and to improve their quality. In this paper, we propose a scatter search approach to the QAP problem. The basic method is extended with intensification and diversification stages and we present a procedure to generate good scattered initial solutions
Projeto/Reprojeto de bancos de dados relacionais : a ferramenta DB-Tool.
(1997) Ferreira, Anderson Almeida; Laender, Alberto Henrique Frade; Silva, Altigran Soares da
This paper describes a tool that supp orts the design and redesign of relational databases The tool produces optimized relational representations of entity relationship ER schemas and is implemented using Informix as its target database management system DBMS The tool operates in two phases In the first phase it receives as input an ER schema and generates a list of commands to implement the corresponding Informix schema In the second phase it receives a list of redesign commands specifying changes to the ER schema and generates a redesign plan to reestructure the database accordingly An example illustrates the use of the tool.
Evolving visual features and detectors.
(1998) Guarda, Álvaro; Le Gal, Christophe; Lux, Augustin
This paper addresses the problemof automatic synthesis of visual detectors. We present a method using genetic techniques to learn visual features and a program which combines and integrates the features in non-linear ways. The method is integrated in a face tracking system to generate a variety of new visual perceptual processes.
System-level partitioning with uncertainty.
(1999) Albuquerque, Jones; Coelho Júnior, Claudionor José Nunes; Cavalcanti, Carlos Frederico Marcelo da Cunha; Silva Júnior, Diógenes Cecílio da; Fernandes, Antônio Otávio
Several models and algorithms have been proposed in the past to generate HW/SW components for system-level designs. However, they were focused on a single designer who had a throughout knowledge of the design. In other words, the decision trade-offs were simplified to a stand-alone developer who did not have to consider individual skills, concurrent development for portions of the design, risk analysis for time-to-market development, nor team load and assignment. In this paper, we propose a design management approach associated with a partitioning methodology to deal with the concurrent design problems of system-level specifications. This methodology allows one to incorporate the uncertainties related to development at the very early stages of the design, and to follow up during the development of a final product.
An architectural framework for providing QoS in IP differentiated services networks.
(2001) Trimintzios, Panos; Andrikopoulos, Ilias; Pavlou, George; Cavalcanti, Carlos Frederico Marcelo da Cunha; Georgatsos, Panos; Griffin, David; Jacquenet, C.; Goderis, D.; T'Joens, Y.; Georgiadis, Leonidas; Egan, R.; Memenios, G.
As the Internet evolves, a key consideration is support for services with guaranteed quality of service (QoS). The proposed differentiated services (DiffServ) framework, which supports aggregate traffic classes, is seen as the key technology to achieve this. DiffServ currently concentrates on control/data plane mechanisms to support QoS but also recognises the need for management plane aspects through the bandwidth broker (BB). In this paper we propose a model and architectural framework for supporting end-to-end QoS in the Internet through a combination of both management and control/data plane aspects. Within the network we consider control mechanisms for traffic engineering (TE) based both on explicitly routed paths and on pure node-by-node layer 3 routing. Management aspects include customer interfacing for service level specification (SLS) negotiation, network dimensioning, traffic forecasting and dynamic resource and routing management. All these are policy-driven in order to allow for the specification of high-level management directives. Many of the functional blocks of our architectural model are also features of BBs, the main difference being that a BB is seen as driven purely by customer requests whereas, in our approach, TE functions are continually aiming at optimising the network configuration and its performance. As such, we substantiate the notion of the BB and propose an integrated management and control architecture that will allow providers to offer both qualitative and quantitative QoS-based services while optimising the use of underlying network resources
Engineering the multi-service internet : MPLS and IP-based techniques.
(2001) Trimintzios, Panos; Georgiadis, Leonidas; Pavlou, George; Griffin, David; Cavalcanti, Carlos Frederico Marcelo da Cunha; Georgatsos, Panos; Jacquenet, C.
IP Differentiated Services (DiffServ) is seen as the framework to support quality of service (QoS) in the Internet in a scalable fashion, turning it to a global multiservice network. In this context, integrated service/network management and traffic control mechanisms are of paramount importance for service provisioning and network operation, aiming to satisfy the QoS requirements of contacted services while optimizing the use of underlying network resources. In this paper, after briefly introducing an architectural framework for integrated service/network management and control, we concentrate in its traffic engineering aspects comparing and contrasting two different approaches: MPLS-based explicit routed paths and IP-based hop-by-hop routing. We consider relatively longterm network dimensioning based on the requirements of contracted services and subsequent dynamic route and resource management that react in shorter time scales to statistical traffic fluctuations and varying network conditions.
A method for specification of collaborative interfaces through the use of scenarios.
(2001) Dumont, Anamaria Montandon; Pietrobon, Carlos Alberto Marques
The complexity and the extension of tasks in the world today demand an extensive interaction among people with different knowledge backgrounds, who need to work in cooperation, aiming at a common goal. In this paper, we present a method to model the tasks and actions that a group of users carries out when working cooperatively through a computational system integace. For this purpose, we use scenarios for requirements gathering for user-cooperative interfaces. Along with the method, we propose the use of a notation that was developed to support interaction characteristics of users in cooperative work.
An embedded converter from RS232 to universal serial bus.
(2001) Zuquim, Ana Luiza de Almeida Pereira; Coelho Júnior, Claudionor José Nunes; Fernandes, Antônio Otávio; Oliveira, Marcos Pêgo; Tavares, Andréa Iabrudi
Universal Serial Bus (USB) is a new personal computer interconnection protocol, developed to make the connection of peripheral devices to a computer easier and more efficient. It reduces the cost for the enduser, improves communication speed and supports simultaneous attachment of multiple devices (up to 127). RS232, in another hand, was designed to single device connection, but is one of the most used communication protocols. An embedded converter from RS232 to USB is very interesting, since it would allow serial-based devices to experience USB advantages without major changes. This work describes the specification and development of such converter and it is also a useful guide for implementing other USB devices. The converter specification was based on Engetron UPS’ serial communication requirements and its implementation uses a Cypress microcontroller with USB support.
Using XML to improve frameworks reuse.
(2002) Amaral, Juliana Alves; Pietrobon, Carlos Alberto Marques
This paper presents an approach to promote framework exchange through the use of XML standards. This exchange is quite important for developers’ teams who do not work at the same place neither the same environment, but need to collaborate in common projects. This paper combines the benefits of XML for defining, validating and sharing documents on the Web with the benefits of frameworks and object-oriented Unified Modeling Language (UML). UML-F-X, a extension of UML-F (an extension of UML for framework domain), is then proposed in this paper in order to take advantage of DTD concepts, reducing the semantic loss of framework-DTD mapping. By using standards for storing (UML) and sharing (XML) object-oriented frameworks, development teams using tools from multiple vendors can build and reuse applications in a distributed environment. The objective of this approach is to use the Web as a channel to exchange frameworks, stimulating then the use of this object-oriented technique among software engineers.
ABCTool - uma ferramenta para cooperação baseada na arquitetura do sistema.
(2002) Barros, Cynthia Maria Silva de; Pietrobon, Carlos Alberto Marques
O projeto de um sistema de software pode se tornar um trabalho bastante complexo em se tratando da construção de grandes sistemas. Assim, cada vez mais os projetistas têm reconhecido a importância do design da arquitetura no projeto do sistema com o propósito de facilitar o trabalho de desenvolvimento. Outro aspecto que também tem sido observado é o fato de que estes sistemas são desenvolvidos por grupos de pessoas que trabalham paralelamente e cooperativamente. A dificuldade de comunicação entre a equipe gera problemas na hora da integração das partes que cada um desenvolveu. Esse artigo propõe uma ferramenta de apoio ao desenvolvimento cooperativo de software baseado na arquitetura do sistema sendo desenvolvido.
Simulated annealing approach to solve the daily crew scheduling problem.
(2002) Silva, Gustavo Peixoto; Souza, Marcone Jamilson Freitas; Alves, José Maria do Carmo Bento
Syntactic similarity of web documents.
(2003) Pereira Junior, Álvaro Rodrigues; Ziviani, Nivio
This paper presents and compares two methods for evaluating the syntactic similarity between documents. The first method uses the Patricia tree, constructed from the original document, and the similarity is computed searching the text of each candidate document in the tree. The second method uses shingles concept to obtain the similarity measure for every document pairs, and each shingle from the original document is inserted in a hash table, where shingles of each candidate document are searched. Given an original doc-ument and some candidates, two methods find documents that have some similarity relationship with the original doc-ument. Experimental results were obtained by using a pla-giarized documents generator system, from 900 documents collected from the Web. Considering the arithmetic ave rage of the absolute differences between the expected and ob-tained similarity, the algorithm that uses shingles obtained a performance of 4,13 % and the algorithm that uses Patricia tree a performance 7.50%
An early warning system for space-time cluster detection.
(2003) Assunção, Renato Martins; Tavares, Andréa Iabrudi; Kulldorff, Martin
A new topic of great relevance and concern has been the design of efficient early warning systems to detect as soon as possible the emergence of spatial clusters. In particular, many applications involving spatial events recorded as they occur sequentially in time require this kind of analysis, such as fire spots in forest areas as in the Amazon, crimes occurring in urban centers, locations of new disease cases to prevent epidemics, etc. We propose a statistical method to test for the presence of space-time clusters in point processes data, when the goal is to identify and evaluate the statistical significance of localized clusters. It is based on scanning the three dimensional space with a score test statistic under the null hypothesis that the point process is an inhomogeneous Poisson point process with space and time separable first order intensity. We discuss an algorithm to carry out the test and we illustrate our method with space-time crime data from Belo Horizonte, a large Brazilian city.
Geração de impressão digital para recuperação de documentos similares na web
(2004) Pereira Junior, Álvaro Rodrigues; Ziviani, Nivio
This paper presents a mechanism for the generation of the “finger-print” of a Web document. This mechanism is part of a system for detecting and retrieving documents from the Web with a similarity relation to a suspicious do-cument. The process is composed of three stages: a) generation of a fingerprint of the suspicious document, b) gathering candidate documents from the Web and c) comparison of each candidate document and the suspicious document. In the first stage, the fingerprint of the suspicious document is used as its identifica-tion. The fingerprint is composed of representative sentences of the document. In the second stage, the sentences composing the fingerprint are used as queries submitted to a search engine. The documents identified by the URLs returned from the search engine are collected to form a set of similarity candidate do-cuments. In the third stage, the candidate documents are “in-place” compared to the suspicious document. The focus of this work is on the generation of the fingerprint of the suspicious document. Experiments were performed using a collection of plagiarized documents constructed specially for this work. For the best fingerprint evaluated, on average87.06%of the source documents used in the composition of the plagiarized document were retrieved from the Web.
Balancing coordination and synchronization cost in cooperative situated multi-agent systems with imperfect communication.
(2004) Tavares, Andréa Iabrudi; Campos, Mário Fernando Montenegro
We propose a new Markov team decision model to the decentralized control of cooperative multi-agent systems with imperfect communication. Informational classes capture system’s communication semantics and uncertainties about transmitted information and stochastic transmission models, including delayed and lost messages, summarize characteristics of communication devices and protocols. This model provides a quantitative solution to the problem of balancing coordination and synchronization cost in cooperative domains, but its exact solution is computationally infeasible.We propose a generic heuristic approach, based on a off-line centralized team plan. Decentralized decision-making relies on Bayesian dynamic system estimators and decision-theoretic policy generators. These generators use system estimators to express agent’s uncertaintyabout system state and also to quantify expected effects of communication on local and external knowledge. Probabilities of external team behavior, a byproduct of policy generators, are used into system estimators to infer state transition. Experimental results concerning two previously proposed multi-agent tasks are presented, including limited communication range and reliability.
Scheduling the brazilian soccer championship : a simulated annealing approach.
(2004) Biajoli, Fabrício Lacerda; Souza, Marcone Jamilson Freitas; Chaves, Antônio Augusto; Mine, Otávio Massashi; Cabral, Lucídio dos Anjos Formiga; Pontes, Roberto Carlos
Um método exato para otimizar a escala de motoristas e cobradores do sistema de transporte público.
(2004) Silva, Gustavo Peixoto; Souza, Marcone Jamilson Freitas; Reis, Jorge von Atzingen dos
Este trabalho te m com o objetivo implementa r um método de otimizaçã o para o problema de geração da Escala d e Motoristas e Cobradores do Sistema de Trans porte Público . Esse problema, denomina do na literatura Problema d a Programação d e Tripulações (Crew Scheduling Problem) , tem como objetivo determinar u m conjunto de jornadas de trabalho para as tripulações, de tal forma que a programação do s veículos seja realizada com o menor custo possível. Como restrições , cada jornada deve atende r à legislação e à convenção coletiva de trabalho do setor. Neste trabalho é apresentada uma metodologia que formula o problema com o um modelo de particionamento e utiliza o método Simplex para resolvê -lo . Para reduzir a dimensão do problema, tira -se proveito das característica s do problema real estuda do. Sã o apresentados também o s resulta dos obtidos, sinalizando a possibilidade de redução no s custos referentes à mão de obra operacional do setor.
Uma metodologia heurística baseada em grasp, VND e VNS para a resiolução do problema de dimensionamento em redes IP.
(2004) Cavalcanti, Carlos Frederico Marcelo da Cunha; Souza, Marcone Jamilson Freitas; Souza, Fernanda Sumika Hojo de; Coelho, Viviane de Souza
O presente trabalho apresenta uma proposta de formulação e implementação de algoritmos baseados nas técnicas de otimização GRASP (Greed Randomized Search Procedure), VND (Variable Neighborhood Descent) e VNS (Variable Neighborhood Search) para satisfazer a nova geração da Internet, que implementa Qualidade de Serviço e Engenharia de Tráfego. Este contexto surgiu da crescente expansão da Internet e da necessidade de satisfazer a novos requisitos impostos por aplicações mais complexas, tais como transmissões em tempo real, exigindo que caminhos explícitos entre um nó de entrada da rede e um ou mais nós de saída sejam computados. Esta tarefa é também chamada de dimensionamento da rede. Resultados computacionais são apresentados, comprovando que é possível prover uma melhora no dimensionamento da rede através das técnicas propostas.
Definição de um ambiente para apoiar a gerência do conhecimento para projeto de banco de dados utilizando um framework conceitual e padrões de análise.
(2004) Dias, Viviane Cristina; Pietrobon, Carlos Alberto Marques; Alves, Mário Fabiano
Uma das grandes dificuldades no desenvolvimento de software é que, muitas vezes, os desenvolvedores não estão familiarizados com o domínio para o qual o software está sendo desenvolvido. A necessidade de apoiar o desenvolvimento de software em domínio específicos tem sido endereçada tanto por Ambientes de Desenvolvimento de Software Orientados a Domínio (ADSODs), como pelo uso de gerência do conhecimento. Este artigo apresenta o uso de gerência do conhecimento para apoiar a orientação do domínio no Ambiente de Definição de um Banco de Dados para QEE(ADEBDQEE) utilizando um Framework Conceitual e Padrões de Análise.
Simulação de roteamento em redes IP com QoS.
(2004) Cavalcanti, Carlos Frederico Marcelo da Cunha; Nascimento, Ricardo Alonso dos Santos; Borges, Daniel Prata Leite
The costumer demands for multimedia and realtime applications are rising up the Internet into a new level of guarantees of QoS. This article explains the key steps to provide an effective schema of how to implement QoS routing based on Diffserv and MPLS and explains how to simulate it using the classical NS-2 simulator.