DECOM - Trabalhos apresentados em eventos

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https://monog.ufop.br/handle/123456789/581

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Um algoritmo coevolutivo cooperativo para configuração de uma rede de sensores sem fio.
(2011) Ruela, André Siqueira; Aquino, André Luiz Lins de; Guimarães, Frederico Gadelha; Freitas, Alan Robert Resende de
This work proposes a cooperative coevolutionary algorithm for design of a wireless sensor network considering complex network metrics. It is proposed a heuristic to ﬁnd a network conﬁguration such that its communication structure presents a small value for the average shortest path length and a high cluster coefﬁcient. This conﬁguration considers a cluster based network, where the cluster heads have two communication radii. We describe how the problem can be partitioned and how the ﬁtness computation can be divided such that the cooperative coevolution model is feasible. The results reveal that our methodology allows the conﬁguration of networks with more than a hundred nodes with two speciﬁcs complex network measurements allowing the reduction of energy consumption and the data transmission delay.
Um algoritmo de amostragem multivariada para redes de sensores sem fio.
(2010) Silva Junior, Orlando; Aquino, André Luiz Lins de; Mini, Raquel Aparecida de Freitas
A wireless sensor network (WSN) is energy constrained, and the ex-tension of its lifetime is an important issue in its design. A WSN can be used to collect and process data of environment that can be, in some cases, multivariate. In this way, to help the data processing, this work proposes a multivariate sampling algorithm which uses component analysis techniques to rank the data and then to select only the data more relevant to the application. Simulation results show that our technique reduces the data keeping its representativeness. In addition, the energy consumption and delay on the network are reduced.
Analysis of selection and crossover methods used by genetic algorithm-based heuristic to solve the LSP allocation problem in MPLS Networks under capacity constraints
(2008) Andrade, Alessandro Vivas; Errico, Luciano de; Aquino, André Luiz Lins de; Assis, Luciana Pereira de; Barbosa, Carlos Henrique Nogueira de Resende
The Multiprotocol Label Switching (MPLS) is a popular routing technique for IP networks, where the core problem is to find a route (called LSP) that satisfy all the capacity constraints imposed by a specific traffic. Genetic algorithms come as a simple, appealing solution approach, but one that requires careful choices concerning initial population generation, crossover, mutation and selection. The present paper discusses the influence of different crossover and selection methods in achieving a fast and accurate convergence of the genetic algorithm, when solving the MPLS allocation problem. The experimental results, using different network topologies such as Carrier, Dora, and Mesh, have shown that uniform crossover and Stochastic Remainder Sampling selection are the most suitable combination to solve the problem.
Data stream based algorithms for wireless sensor network applications
(2007) Aquino, André Luiz Lins de; Figueiredo, Carlos Maurício Seródio; Nakamura, Eduardo Freire; Buriol, Luciana Salete; Loureiro, Antônio Alfredo Ferreira; Fernandes, Antônio Otávio; Coelho Júnior, Claudionor José Nunes
A wireless sensor network (WSN) is energy con-strained, and the extension of its lifetime is one of the most important issues in its design. Usually, a WSN collects a large amount of data from the environment. In contrast to the conventional remote sensing – based on satellites that collect large images, sound files, or specific scientific data – sensor networks tend to generate a large amount of sequential small and tuple-oriented data from several nodes, which constitutes data streams. In this work, we propose and evaluate two algorithms based on data stream, which use sampling and sketch techniques, to reduce data traffic in a WSN and, consequently, decrease the delay and energy consumption. Specifically, the sampling solution, provides a sample of only log n items to represent the original data of n elements. Despite of the reduction, the sampling solution keeps a good data quality. Simulation results reveal the efficiency of the proposed meth-ods by extending the network lifetime and reducing the delay without loosing data representativeness. Such a technique can be very useful to design energy-efficient and time-constrained sensor networks if the application is not so dependent on the data precision or the network operates in an exception situation (e.g., there are few resources remaining or there is an urgent situation)
Um esquema de gerenciamento para redes de sensores sem fio auto-organizáveis : atuando sobre regras locais.
(2007) Figueiredo, Carlos Maurício Seródio; Aquino, André Luiz Lins de; Loureiro, Antônio Alfredo Ferreira; Ruiz, Linnyer Beatrys
Auto organização e um importante conceito sendo aplicado em sistemas de rede modernos para obter funcionamento autônomo e robusto. Particularmente, as Redes de Sensores Sem Fio (RSSFs) foram concebidas sob esse paradigma. Basicamente, em uma rede auto organizável, os elementos interagem somente entre si, de forma completamente descentralizada, para executar uma função para o correto funcionamento da rede. No entanto, os objetivos determinados por uma entidade de gerência ou aplicação podem mudar ao longo do tempo, e um esquema para controlar as interações entre os elementos e ajustar ou mudar o comportamento global a ser obtido a um novo requisito n ˜ao foi explicitamente abordado na literatura. Neste trabalho, é apresentado um esquema geral para o gerenciamento de redes auto organizáveis. Sua ideia geral consiste em atuar sobre as regras de interação locais governando as interações entre os elementos e, consequentemente, adequando o comportamento da rede a diferentes objetivos e/ou métricas de QoS necessárias. Uma metodologia também é provida, e essa define um procedimento genérico e relaciona importantes aspectos para o projeto de soluções de gerenciamento. A aplicabilidade do esquema proposto é demonstrada através da apresentação de um estudo de caso.
Evolutionary design of wireless sensor networks based on complex networks.
(2009) Ruela, André Siqueira; Cabral, Raquel da Silva; Aquino, André Luiz Lins de; Guimarães, Frederico Gadelha
This work proposes a genetic algorithm for design-ing a wireless sensor network based on complex network theory. We develop an heuristic approach based on genetic algorithms for finding a network configuration such that its communication structure presents complex network characteristics, e.g. a small value for the average shortest path length and high cluster coefficient. The work begins with the mathematical model of the hub location problem, developed to determine the nodes which will be configured as hubs. This model was adopted within the genetic algorithm. The results reveal that our methodology allows the configuration of networks with more than a hundred nodes with complex network characteristics, thus reducing the energy consumption and the data transmission delay.
A framework for sensor stream reduction in wireless sensor networks.
(2011) Aquino, André Luiz Lins de
This work presents a general methodology to perform sensor stream reduction in wireless sensor networks. This methodology considers the application requirements, the reduction design, and the data reduce validation. Specifically, the reduction design, we present a architecture that can be applied to reduce the data when it is sensed or routed through to sink. The objective of this work is to show step-by-step how we can realize reduction applications in wireless sensor networks by using our methodology. The study cases show the usefulness of our methodology applied on a general sensing and a real time scenarios.
Multivariate reduction in wireless sensor networks.
(2009) Silva Junior, Orlando; Aquino, André Luiz Lins de; Mini, Raquel Aparecida de Freitas; Figueiredo, Carlos Maurício Seródio
In wireless sensor networks, energy consumption is generally associated with the amount of sent data once communication is the activity of the network that consumes more energy. This work proposes an algorithm based on "Principal Component Analysis "to perform multivariate data reduction. It is considered air quality monitoring scenario as case study. The results show that, using the proposed technique, we can reduce the data sent preserving its representativeness. Moreover, we show that the energy consumption and delay are reduced proportionally to the amount of reduced data
On the use data reduction algorithms for real-time Wireless Sensor Networks.
(2007) Aquino, André Luiz Lins de; Figueiredo, Carlos Maurício Seródio; Nakamura, Eduardo Freire; Loureiro, Antônio Alfredo Ferreira; Fernandes, Antônio Otávio; Coelho Júnior, Claudionor José Nunes
This work presents the design of real time applications for Wireless Sensor Networks (WSNs) by using analgorithm based on data stream to process the sensor data. The proposed algorithm is based on sampling techniques applied to data histograms created from original data stream sac quired by sensor nodes. As a result, the algorithm provides a sample of log n item store present the original data stream of n elements. In this work, we show how to use the data reduction algorithmin real-time WSN design.
Redes de sensores sem fio para monitoramento de anfíbios.
(2008) Aquino, André Luiz Lins de; Figueiredo, Carlos Maurício Seródio; Loureiro, Antônio Alfredo Ferreira; Mini, Raquel Aparecida de Freitas; Nakamura, Eduardo Freire; Oliveira, Horácio Antônio Braga Fernandes de; Ruiz, Linnyer Beatrys
Sistemas do tipo eixo-raio aplicados a redes de sensores sem fio mdeladas cmo Redes Small World.
(2007) Guidoni, Daniel Ludovico; Aquino, André Luiz Lins de; Cabral, Raquel da Silva; Loureiro, Antônio Alfredo Ferreira; Fernandes, Antônio Otávio
As redes de sensores sem fio possuem restrições de recursos, tais como baixo poder computacional, largura de banda reduzida e especialmente, fonte de energia limitada. O alto consumo de energia pode ser observado quando o fluxo de dados em cada n´o ´e alto e quando o numero de vizinhos e grande. Alem disso, essas redes podem ser modeladas como redes do tipos small world, onde o coeficiente de agrupamento é alto e o caminho médio mínimo entre cada par de nos na rede é pequeno. Através da utilização do conceito de sistemas do tipo eixo-raio, obtivemos uma configuração com um caminho médio mínimo pequeno entre qualquer par de n´os, obtendo assim, uma configuração ótima para a rede, onde alguns n´os são escolhidos como concentradores garantindo o menor consumo de energia
A wavelet-based sampling algorithm for wireless sensor networks applications.
(2010) Aquino, André Luiz Lins de; Oliveira, Ricardo Augusto Rabelo; Wanner, Elizabeth Fialho
This work proposes and evaluates a sampling algorithm based on wavelet transforms with Coiflets basis to reduce the data sensed in wireless sensor networks applications. The Coiflets basis is more computationally efficient when data are smooth, which means that, data are well approximated by a polynomial function. As expected, this algorithm reduces the data traffic in wireless sensor network and, consequently, decreases the energy consumption and the de-lay to delivery the sensed information. The main contribution of this algorithm is the capability to detect some event by adjusting the sampling dynamically. In order to evaluate the algorithm, we compare it with a static sampling strategy considering a real sens-ing data where an external event is simulated. The results reveal the efficiency of the proposed method by reducing the data with-out loosing its representativeness, including when some event oc-curs. This algorithm can be very useful to design energy-efficient and time-constrained sensor networks when it is necessary to detect some event.

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