DISSERTAÇÃO DE MESTRADO - PROGRAMA DE PÓS GRADUAÇÃO EM ENGENHARIA DE ELETRICIDADE

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ABIDS-WSN: UM FRAMEWORK DE DETECÇÃO DE INTRUSÃO EM REDES DE SENSORES SEM FIO ORIENTADO POR AGENTES INTELIGENTES.
(Universidade Federal do Maranhão, 2017-01-26) PIRES, Higo Fellipe Silva; LOPES, Denivaldo Cícero Pavão; 613643713-91; http://lattes.cnpq.br/7611180871627212
Lately, there has been a significant advance in several technologies directly or indirectly related to Ubiquitous Computing. Among them, the technology of Wireless Sensor Networks (WSNs) can be mentioned. Having its space in the current scenario, the use of wireless sensors extends into various branches of human activity: industrial monitoring, smart houses, medical and military applications. However, several shortcomings and limitations in wireless sensors can be noted: limited hardware, energy and computational capacity are points that are always treated by those who work with such devices. As for these devices, there is, besides the factors already mentioned, an important concern regarding their safety. As with other devices, for these threats to be at least mitigated, it is necessary to create layers of security. One of these layers may be formed by Intrusion Detection Systems (IDS). However, due to the aforementioned hardware restriction of the sensors, the development of IDSs - as well as any other application - for such devices should assume such characteristics. As for IDSs, there are some aspects that need to be taken into account, especially flexibility, efficiency and adaptability to new situations. A paradigm that facilitates the implementation of such capabilities is the Intelligent Agents. Therefore, this paper describes the proposition of a framework for intrusion detection in WSNs based on intelligent agents.
UMA ABORDAGEM BASEADA EM ENGENHARIA DIRIGIDA POR MODELOS PARA SUPORTAR O TESTE DE SISTEMAS DE SOFTWARE NA PLATAFORMA DE COMPUTAÇÃO EM NUVEM
(Universidade Federal do Maranhão, 2012-12-21) OLIVEIRA, Jéssica Bassani de; LOPES, Denivaldo Cícero Pavão; CPF:61364371391; http://lattes.cnpq.br/7611180871627212; ABDELOUAHAB, Zair; CPF:61438154372; http://lattes.cnpq.br/3277510464047127
We present an approach to support the creation of test cases for software systems in cloud computing environments. This approach is based on Model Driven Engineering (MDE). A framework, a methodology and metamodels are proposed to support the generation of test cases. Metamodels for cloud computing environments and transformation definitions are proposed. Two illustrative examples help to understand our approach and the steps to apply it. A prototype implementing the proposed framework is presented and it works together with MT4MDE and SAMT4MDE to generate semi-automatically transformation definitions and contribute to the semiautomatic creation of testing model and test code for cloud computing platforms. We present an evaluation of our approach and compare it with other approaches, detaching main differences, including advantages and disavantages.
ALGORITMO RECURSIVO BASEADO EM UMA FUNÇÃO NÃO QUADRÁTICA USANDO KERNEL
(Universidade Federal do Maranhão, 2014-02-28) Nogueira, Aleksandro Costa; Fonseca Neto, João Viana da; CPF:2199749048; http://lattes.cnpq.br/0029055473709795; SANTANA, Ewaldo Eder Carvalho; CPF:24267341320; http://lattes.cnpq.br/0660692009750374; Barros Filho, Allan Kardek Duailibe; CPF:34022589353; http://lattes.cnpq.br/0492330410079141
This work has the objective to develop an analytical model that makes prediction of the behavior of the algorithm as a function of the design parameters (step adaptation, kernel function and its parameters).We use a non-quadratic function based on kernel, performing a nonlinear transformation of the input space filtering applied on line. Was developed and implemented in the system for adaptive filtering based on Kernel, which provides an analysis of the behavior of KRLS algorithm as well as its properties of convergence. It applies a kernel function in the cost function from the non-recursive quadratic function of an even power, which minimizes the error, defined as the expectation of the cumulative cost of actions taken along a sequence of steps. It appears that this approach allows the determination of the parameters of the problem with greater reliability and robustness and lower cost compared with traditional algorithms (RLS, KRLS, RNQ) .
ALOCAÇÃO ÓTIMA DE CAPACITORES EM SISTEMAS DE DISTRIBUIÇÃO RADIAL, UTILIZANDO-SE ESTRATÉGIAS EVOLUTIVAS
(Universidade Federal do Maranhão, 2002-05-29) Petinelli, Airton Egydio; SAAVEDRA MENDEZ, Osvaldo Ronald; CPF:10813804892; http://lattes.cnpq.br/6400934417933768
Static reactive power sources, such as shunt capacitors, have been commonly used to provide reactive compensation in distribution systems, minimizing losses and keeping voltage levels within operational limits. Heuristic algorithms for capacitor placement have been proposed in several works. However, the majority of these approaches converge to a local solution. This dissertation presents a hierarchical evolution strategy-based approach for solving the optimal reactive sources placement in radial distribution systems. The approach is based on the (m+l)-EE paradigm, improved by mutations control and by two types of mutations: the classical Gaussian mutation and the Cauchy-based mutation. Discrete standard capacitor values with non-linear cost are considered. Constraints such as the maximum number of parallel banks and installations cost are included. Validation tests have been performed using a real industrial feeder.
Análise da Confiabilidade em Redes de Distribuição Radiais: Reconfiguração e Alocação de Geração Distribuída
(Universidade Federal do Maranhão, 2006-03-10) Coelho Neto, Agnelo; SILVA, Maria da Guia da; CPF:09837418400; http://lattes.cnpq.br/5175196133230969
The distribution utilities must satisfy two concurrent objectives during planning process of the electric network: minimization of the investment cost and the satisfaction of reliability targets. An alternative to satisfy these objectives is to include low cost alternatives in the planning process. One of these alternatives is the reconfiguration of the distribution network. The reconfiguration of the distribution network can reduce the loss and balance the loads in the system only with opening and closing of switches without additional investment cost. In addition to reconfiguration, another alternative of low cost is the Distributed Generation (DG) allocation. This alternative became feasible due to the recent technological advances in the building of turbines that reduced significantly the costs of energy generation. In this way, the DG is a attractive option to satisfy the demand growth and minimize the costs associated with: building of new substations, feeder reconductoring and transformer upgrading. Consequently, is opportune to develop methodologies that include the reconfiguration and the DG in the planning of the distribution network. This dissertation presents the development of two methodologies for the planning of distribution networks: reconfiguration and optimal allocation of DG. The first part of the dissertation presents the development of the methodology for the network reconfiguration. Usually, the reconfiguration is carried out with the following objectives: minimization of the electric losses, voltage profile correction and load balancing between feeders. In this dissertation, in addition to these objectives, reliability constraints have been included in the reconfiguration methodology. This methodology is based on the combination of the following techniques: power flow algorithm, based on the Power Summation Method, to estimate the state of the network; analytic techniques to estimate the reliability indices and Tabu Search to identify the optimal topology. The second part of the research work presents the development of the methodology for the allocation of DG. This methodology has as objective to attend a forecasted demand level without violating operational constraints of the network (feeders loading and voltage drops) and minimizing the interruption costs through the DG allocation. These objectives are satisfied minimizing the cost/worth ratio between the installation/operation costs of DG and the costs associated with: interruptions, noncommercialized, energy purchases and electric losses. The minimization of the cost/worth ratio described above has been carried out by combining the following techniques: analytic approaches to estimate the impact of DG in the reliability indices, load flow algorithm to estimate the losses and violations in the operational constraints and genetic algorithms to maximize the cost worth ratio. The impact of the DG in the reliability indices has been considered including network constraints (voltage drop and feeder loading) in the predictive reliability model. The models and techniques proposed in this dissertation for the reconfiguration and DG allocation have been validated and applied in two large scale substations belonging to distribution network of the Electricity Utility of Maranhão - CEMAR. The results obtained with the algorithm of reconfiguration demonstrated that the proposed methodology was capable of reducing the losses in the feeders without deteriorating the reliability. Furthermore, the application of the methodology of DG allocation in the test system resulted in a cost/worth ratio lower than one.
ANÁLISE DE MÉTODOS DE SIMILARIDADE EM TABELAS DE DECISÃO ADAPTATIVA COM APLICAÇÃO EM RECOMENDAÇÕES NUTRICIONAIS PARA DOENTES RENAIS CRÔNICOS
(Universidade Federal do Maranhão, 2014-02-07) Barroso Filho, Haroldo Gomes; LABIDI, Sofiane; CPF:61878782300; http://lattes.cnpq.br/3474810859116416; Abdelouahab, Zair; CPF:61438154372; http://lattes.cnpq.br/3277510464047127
The information retrieval have been shown to be a technique or great efficiency in decision making process and is used from beginning to end of a process of software development, directly impacting their usability and optimization. There is what one might consider paradigms in a information retrieval, the Classical Model and Retrieval by similarity. The Classical Model makes use of features of logical databases and their query languages, matched against the Information Retrieval by similarity, is based on cases where there are similar attributes for a decision, in this paper we used if this paradigm to analyze and evaluate which method of similarity has a better performance in a nutritional recommendation through a Adaptive Decisio
Aplicação de redes neurais para estimava da gordura corporal de adolescente utilizando variáveis clínicas.
(Universidade Federal do Maranhão, 2021-09-24) ARAÚJO, Claudyane da Silva; SOUSA, Nilviane Pires Silva; CARVALHO, Ewaldo Eder Santana; SANTANA, Ewaldo Eder Carvalho; SOUSA, Nilviane Pires Silva; BARROS FILHO, Allan Kardec Duailibe; ROSA, Claudia R. de Andrade A.
The prevalence of overweight in adolescence is a worldwide public health problem, as it is associated with several metabolic disorders, such as cardiovascular diseases and diabetes. Such problems if not evaluated and treated early can lead to negative outcomes such as premature death, so the importance of analyzing the body fat of this population. Thus, the objective of this study is to develop an artificial neural network (ANN) to predict the percentage of body fat (%GC) of adolescents. In this network are used, as input parameters, weight, height, age, gender, heart rate, waist circumference, hip circumference, arm circumference. For training and testing of ANN, we used 5-fold cross-validation in a set of data from 772 adolescents of both sexes, aged between 10 and 19 years. For data labeling, we used the (%GC) obtained by bioimpedance (BIA). The prediction given by our RNA was compared with the prediction of other anthropometric methods commonly used in the evaluation of nutritional status. When comparing the value obtained by the net, in the test phase, with the value of BIA a correlation R= 0.87 was obtained. Our method showed significantly better results than the usual anthropometric indicators such as Body Mass Index (BMI), Waist-Height Relationship (WHtR), as can be evaluated by the area over the ROC curve (AUROC):0.83 (RNA), 0.62 (BMI) and 0.56 (WHtR). Our proposal also obtained 85.3% accuracy, 73.2% specificity, the sensitivity of 93%, and a 59.09% rate of true positives. These results are much better than the BMI and CER methods that present low sensitivity (27.6% and 11.2%). The specificity of our method showed a high rate of true negatives (26.28%). Thus, it is concluded that the RNA model obtained a better performance to predict excess body fat in adolescents compared to the usual anthropometric indicators, presenting itself as a low cost alternative for the tracking of obesity in adolescents.
Circuito de Condicionamento de Sinais Analógicos Programável para Sistemas Integrados
(Universidade Federal do Maranhão, 2007-09-05) Belfort, Diomadson Rodrigues; CATUNDA, Sebastian Yuri Cavalcanti; CPF:76867668453; http://lattes.cnpq.br/0873496251879638
In digital measurement systems, signal conditioning circuits have the main functionality of adjusting analog signals for digital conversion. For maximizing the application of a measurement circuit or system, yet considering its integration in a single chip, these circuits must be programmable, in order to serve to different kinds of sensors with diverse output signal characteristics. The main functions of the signal conditioning circuit, in this case, are the amplification and dc level shift of the analog signal. In this master s thesis, an architecture of a signal conditioning integrated circuit with programmable gain and dc level shift, optimized in number of discrete components, using the switched capacitor technique is proposed. The proposed architecture allows the circuit use in differential and single-ended modes, with unipolar and bipolar signals. The design of an integrated circuit is carried out for implementing the proposed architecture using 0.35 mm TSMC CMOS technology, available in the ASIC design kit (ADK) of the Mentor Graphics, IC Nanometer software package.
Classificação de Fibrilação Atrial utilizando Curtose
(Universidade Federal do Maranhão, 2017-02-16) OLIVEIRA jÚNIOR, Alfredo Costa; BARROS FILHO, Allan Kardec Duailibe; 340225893-53; http://lattes.cnpq.br/0492330410079141
Atrial fibrilation(AF) is one of the most common cardiac arrhythmias worldwide. Thus, there are ample efforts to implement AF diagnosis systems. The main noninvasive way to assess cardiac health is through electrocardiogram (ECG) signal analysis, which represents the electrical activity of the cardiac muscle, and has characteristic temporal markings: P, Q, R, S and T waves. Some authors use filtering techniques, statistical analysis and even neural networks for detecting AF based on the RR interval, that is given by the temporal difference between the peaks of the R wave. However, analises of the RR interval allows for evaluating changes occurring only in the R wave of the ECG signal, not allowing to assess, for example, variations in the P wave provoked by the AF. In face of that, we propose characterize the ECG signal amplitude aiming at classifying both healthy and AF patients. The ECG signal was analyzed in the proposed methodology through the following statistics: variance, asymmetry, and kurtosis. Herein, we use the MIT-BIH Atrial Fibrillation and MIT-BIH Normal Sinus Rhythm database signals to evaluate AF and normal heartbeat intervals. Our study shown that kurtosis outperfomed variance and asymmetry with respect to sensibility (Se = 100%), specificity (Sp = 88.33%) and accuracy (Ac = 91.33%). The results were expected since kurtosis is a non-Gaussian measure and the ECG signal has sparse distribution. The proposed methodology also requires a lower number of pre-processing stages, and its simplicity allows for implementations in imbedded systems supporting the clinical diagnosis.
Classificação de Lesões em Mamografias Digitais Utilizando Análise de Componentes Independentes e Perceptron Multicamadas
(Universidade Federal do Maranhão, 2006-03-24) Campos, Lucio Flavio de Albuquerque; BARROS FILHO, Allan Kardec Duailibe; CPF:34022589353; http://lattes.cnpq.br/0492330410079141
We propose a method for discrimination and classification of mammograms with benign, malignant and normal tissues using independent component analysis and neural networks. The method was tested for a mammogram set from MIAS database, and multilayer perceptron. The method obtained a success rate of 97.83% , with 97.5% of specificity and 98% of sensitivity.
COMPOSIÇÃO DINÂMICA DE SERVIÇOS WEB SEMÂNTICOS UTILIZANDO ABORDAGENS DA ENGENHARIA DIRIGIDA POR MODELOS
(Universidade Federal do Maranhão, 2011-07-29) BEZERRA, Eduardo Devidson Costa; Lopes, Denivaldo Cícero Pavão; CPF:61364371391; http://lattes.cnpq.br/7611180871627212; ABDELOUAHAB, Zair; CPF:61438154372; http://lattes.cnpq.br/3277510464047127
The use of the Internet as a way to publish new applications and deliver new functionalities has consolidated the use of web services technology. Once web services technology enables a high degree of autonomy and interoperability, it provides a basic infrastructure for the development and composition of new services, which has benefited the business process management providing the agility required by enterprises to meet the need of rapidly changing business environment. Recently, new paradigms are being developed to deal with the increasing complexity in the development, maintenance and evolution of software systems. Among the new paradigms, Model Driven Engineering (MDE) and the Ontology stands out as the most promising for handling complex software systems. This work presents an approach to perform the dynamic composition of web services using techniques of match models (metamodels) that represent services. Models representing services must include semantic and structural aspects of the web service achieved through approaches to ontologies. Thus, we conjecture to establish matchings and measure the degree of similarity between models and investing in research about Ontologies and MDE in order to generate a tool that can assist in a Dynamic Composition of Web Services. A case study is presented to illustrate this approach.
Comunicação Segura e Confiável para Sistemas Multiagentes Adaptando Especificações XML
(Universidade Federal do Maranhão, 2006-12-01) OLIVEIRA, Emerson José Santos; ABDELOUAHAB, Zair; CPF:61438154372; http://lattes.cnpq.br/3277510464047127
Multi-agent systems are evolving to enterprise applications and they are more used in open environments, such as the Internet. Many issues should be considered with this evolution, like security and reliability of communication. In this work, we propose a solution for secure communication and a solution for a reliable communication; both solutions are for multi-agent systems. These solutions adapt XML technologies and consist of several XML Specifications and RDF standard. For secure communication, we adapt the XML-DSig specification to provide integrity and digital signature; the XMLEnc specification is used to provide confidentiality through encryption, and the XKMS specification is used to provide PKI support. For reliable communication, we adapt the WS-RM specification that guarantees the message delivery. The RDF standard enables agents for exchanging messages using XML syntax. In this work, the tests with prototypes of the proposed solutions and comparisons with other solutions are also presented.
Conservação de energia elétrica: um enfoque em consumidores residenciais
(Universidade Federal do Maranhão, 2008-04-25) Silva, Paulo Roberto Mendes da; PESSANHA, José Eduardo Onoda; CPF:80603190782; http://lattes.cnpq.br/8268655137736254
This work investigates the most used forms of electric energy conservation, especially in Brazil, without neglecting the power quality aspect, emphasizing residential loads. Among the investigated issues, the technological is a very important one since it comprises the application of efficient equipment. However, it is not forgotten the human actions, with great application in the residential point of view. Power quality practical studies involving lightning residential loads are also presented. These studies were carried out with a lab prototype capable of simulating power quality problems, such as momentary and long-term voltage sags. Electrical parameters were monitored trough a power quality analyzer equipment - DRANETZ 4300. The results show that the consumer may not acquire a product (compact efficiency light in this case) according to the manufacturer specifications, being very far from the label specifications. The main objective was, therefore, to study the efficiency energy concepts actions and energy savings, associating them to the cost reduction related to electrical energy and the continuous improvement in cost management taking into account the power quality aspect.
DEFINIÇÃO DE UMA ARQUITETURA P2P BASEADA EM REPUTAÇÃO E ORIENTADA A SERVIÇOS
(Universidade Federal do Maranhão, 2009-05-04) RAMOS, Flávio Marcílio Paiva; ABDELOUAHAB, Zair; CPF:61438154372; http://lattes.cnpq.br/3277510464047127
Nowadays, peer-to-peer networks are very popular mainly, when we wish to search or share a considerable amount of information and resources among various participants. One of the main difficulties of this technology is how to avoid that those participants maintain, at the same time, a considerable number of shared resources and to guarantee that those resources are not corrupted or polluted content. Another problem commonly found in P2P networks is the lack of interoperability among existing P2P solutions especially because the inconsistencies of metadata and operation interfaces used in node communication. This work describes P2PWSRep, a reputation management protocol that identifies non-cooperative nodes or that can hinder network performance by sharing corrupted, infected or non-existent files. P2PWSRep infrastructure was based on web services in order to tackle interoperability problems and to facilitate its extensibility, making it feasible to be accessed by several other P2P applications. The P2PWSRep protocol employs a distributed reputation computation using an exponentially weighted average that takes into account the current and previous node reputation and which is tuned by an adjustment parameter in order to obtain the final reputation, thus considering the node s behavior. The P2PWSRep protocol is validated by means of simulation and our results show that it is able to point out the more trustable nodes in the network as well as to insulate those which are not reliable or cooperative. Besides, the protocol does not unnecessarily impacts on the network load P2PWS.
Desenvolvimento de método de inteligência artificial baseado no comportamento de enxames do gafanhoto-do-deserto
(Universidade Federal do Maranhão, 2017-02-20) RIBEIRO, Tiago Martins; PAUCAR, Vicente Leonardo; 213445538-18; http://lattes.cnpq.br/1155686983267102
Complex optimization problems have been studied over the years by researchers seeking better solutions, these studies have encouraged the development of several algorithms of artificial intelligence, and a part of them are bio-inspired methods, based on the behavior of populations. These algorithms target to develop techniques based on nature in search of solutions to these problems. In this work, was introduced as a purpose, an algorithm based on the behavior of locust swarms, the Locust Swarm Optimizer (LSO). The behavior of the desert locust is introduced highlighting the formation of clouds of attacks caused by a synthesized neurotransmitter monoamine, present on the insect, known as serotonin. Observing this behavior, the LSO was developed. It was compared to other known artificial intelligence techniques through 23 benchmark functions and also tested on an power system economical dispatch problem. From the point of view of the results and the ease of implementation, it can be concluded that the LSO algorithm is very competitive as compared to existing methods
Desenvolvimento de um chaveador baseado em topologia spdt associado a sensores interdigitados para medicao de parametros de capacitancia e impedancia em misturas pseudobinarias diesel/biodiesel
(Universidade Federal do Maranhão, 2019-04-11) ANDRADE, Cassio Daniel Salomao Silva; MENDES, Francisco Savio; 008865174-60; http://lattes.cnpq.br/5984945942545807; BARROS FILHO, Allan Kardec Duailibe; 340225893-53; http://lattes.cnpq.br/0492330410079141; BARROS FILHO, Allan Kardec Duailibe; 927999733-53; http://lattes.cnpq.br/0492330410079141; MENDES, Francisco Savio; 008865174-60; http://lattes.cnpq.br/5984945942545807; RIBEIRO, Aurea Celeste da Costa; lattes.cnpq.br/7281004775553558; CASAS, Vicente Leonardo Paucar; http://lattes.cnpq.br/1155686983267102; NETO, Joao Viana da Fonseca; http://lattes.cnpq.br/0029055473709795
The increasing addition of biodiesel to diesel has reached significant market importance and methods for detecting these levels, in these blends, have been essential in the monitoring of their quality. In this context, it is proposed the design, construction and evaluation of an 8- channel microcontrolled switcher based on miniature electromechanical armature relays that, in association with an LCR meter, allows the measurement of capacitance and impedance parameters in multiple diesel/biodiesel blend samples, using, for this purpose, an interdigitated electrode to investigate the feasibility of multiple measurements of these parameters and to evaluate the applicability of this methodology in the detection of biodiesel contents in those samples. A functional test to determine the mean percentage errors and measurement uncertainties associated with each switcher channel, relatively to reference values – obtained with an ordinary capacitor directly connected to the LCR bridge terminals –, as well as a significance test to evaluate the differences between the the measured values with and without interposing switcher were performed. It is suggested, subsequently, an apparatus for detection of organoleptic patterns in substances (electronic tongue/nose), electrochemical and/or biochemical (electronic probing device).
Uma estratégia para transição suave de microrredes sem diferença de fase e de tensão
(Universidade Federal do Maranhão, 2022-09-22) ROCHA, Gabriel Silva; RIBEIRO, Luiz Antonio de Souza; http://lattes.cnpq.br/0347940613470051; MATOS, José Gomes de; http://lattes.cnpq.br/2748821360301364; OLIVEIRA, Alexandre Cunha; http://lattes.cnpq.br/6699829609793478; RIBEIRO, Luiz Antonio de Souza; http://lattes.cnpq.br/0347940613470051
In this work, Microgrid transition methods between grid-connected and isolated modes are presented and a transition method based on existing strategies, such as the cross product, is proposed to minimize the disadvantages of the traditional ones. The basic concepts about Microgrids and the main difference of a Critical Mission Microgrid regarding the others types is defined. Control structures are depicted at the primary, phase estimation, synchronism and secondary control level. The main proposal of the work is a modified control structure based on the estimation of the angle of the phase difference between the grid and the Microgrid, and on the use of a synchronism unit to provide smooth transitions of the Grid-Forming Converter control modes with no difference of phase and voltage. During synchronization, the synchronism unit varies the phase angle respecting the maximum frequency variation limits predefined for the Microgrid. While, during islanding, the estimated angle compensates the internal reference of the converter in order to eliminate transients related to sudden changes in phase reference. In the results, comparisons are carried out with methods from the literature and it was possible to prove that with the correct phase and voltage compensations, it is possible to practically eliminate the transients in the Microgrid voltage due to the switching of the control modes of the Grid-Forming Converter and the transition of the Microgrid operating mode.
Estudo da Utilização de Mecanismos de QoS em Redes com Enlaces de Banda Estreita
(Universidade Federal do Maranhão, 2005-03-14) MELO, José Coelho de; ABDELOUAHAB, Zair; CPF:61438154372; http://lattes.cnpq.br/3277510464047127
This work presents several ways of using mechanisms of Quality of Service (QoS) in networks hardwired for links of short band. It is demonstrated that the use of mechanisms of QoS brings profits of performance for priority applications and rationality in the use of band resources. The work is developed in a test platform of Previdência Social. Implementations of the PHBs EF, Afs and BE are tested. The work has evaluated the capacities to offer guaranteed band, traffic priority, conditioning of traffic and the impact of the competition between traffic classes. The experiments are mounted using the architecture of differentiated services (DiffServ) of platform Cisco, that is the standard in the network of the Previdência Social and are manipulated the mechanisms of classification, control of congestion, policing and conformation of traffic. The results give subsidy for implementation of some models of QoS in IP networks, mainly for those that serve short band.
EXTRAÇÃO CEGA DE SINAIS COM ESTRUTURAS TEMPORAIS UTILIZANDO ESPAÇOS DE HILBERT REPRODUZIDOS POR KERNEIS
(Universidade Federal do Maranhão, 2012-02-10) Santana Júnior, Ewaldo éder Carvalho; BARROS FILHO, Allan Kardec Duailibe; CPF:34022589353; http://lattes.cnpq.br/0492330410079141
This work derives and evaluates a nonlinear method for Blind Source Extraction (BSE) in a Reproducing Kernel Hilbert Space (RKHS) framework. For extracting the desired signal from a mixture a priori information about the autocorrelation function of that signal translated in a linear transformation of the Gram matrix of the nonlinearly transformed data to the Hilbert space. Our method proved to be more robust than methods presented in the literature of BSE with respect to ambiguities in the available a priori information of the signal to be extracted. The approach here introduced can also be seen as a generalization of Kernel Principal Component Analysis to analyze autocorrelation matrices at specific time lags. Henceforth, the method here presented is a kernelization of Dependent Component Analysis, it will be called Kernel Dependent Component Analysis (KDCA). Also in this dissertation it will be show a Information-Theoretic Learning perspective of the analysis, this will study the transformations in the extracted signals probability density functions while linear operations calculated in the RKHS.
Ferramenta de Auxílio na Formação de Estratégias de Oferta em Leilões de Longo Prazo de Energia Elétrica
(Universidade Federal do Maranhão, 2012-05-04) Santos, Sergio Augusto Trovão; SAAVEDRA MENDEZ, Osvaldo Ronald; CPF:10813804892; http://lattes.cnpq.br/6400934417933768; Casas, Vicente Leonardo Paucar; CPF:21344553818; http://lattes.cnpq.br/1155686983267102
This work provides a framework to obtain the optimal bidding strategy for a GENCO in long-term electricity auction. The tool is based on intelligent techniques for optimizing the proposed Utility Function. The goal is to find the optimal strategy that maximizes the expected payoff of GENCO and simultaneously minimize the risks. The risks are modeled by two classical metrics: the Variance (Portfolio Theory) and Value at Risk (VaR). The proposed methodology is applied to auctions for long-term forward contracts, such that used in the Brazilian power system for buying and selling energy in the regulated market. The Bidding Strategy is formed through a Supply Curve which relates the optimal amount of energy to different offer prices. Thus, it allows the GENCO define the best bid (offer) for a given offer price. The proposed approach is validated for three test cases: First, concerning the variation of generation and price of energy scenarios for evaluation of the bidding strategy and the GENCOS risk perception; The second, consider a cascade hydro-term system for evaluation of MRE; and The third, considers the northeastern Brazilian subsystem where the supply curve is formed for the CHESF company's power plants portfolio. The results show how the offer may be changed according the variation of the spot prices and physical generation and demonstrate the efficacy of meta-heuristics proposed to optimize the supply model.

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