A high speed 3.3V current mode CMOS comparators with 10-b resolution

This paper presents a high speed current mode CMOS comparator. The comparator was optimized for allows wide range input current 1mA, ±0.5uA resolution and has fast response. This circuit was implemented with 0.8μm CMOS n-well process with area of 120μm × 105μm and operates with 3.3V(±1.65V).

HPF boost interleaved operating in discontinuous conduction mode for trolleybus application

This paper deals with results of a research and development (R&D) project in cooperation with Electric Power Distribution Company in São Paulo (Brazil) regarding the development and experimental analysis of a new concept of power drive system suitable for application in traction systems of electrical vehicles pulled by electrical motors, which can be powered by urban DC or AC distribution networks. The proposed front-end structure is composed by five boost power cells in interleaving connection, operating in discontinuous conduction mode as AC-DC converter, or as DC-DC converter, in order to provide the proper DC output voltage range required by DC or AC adjustable speed drivers. Therefore, when supplied by single-phase AC distribution networks, and operating as AC-DC converter, it is capable to provide high power factor, reduced harmonic distortion in the input current, complying with the restrictions imposed by the IEC 61000-3-4 standards resulting in significant improvements for the trolleybuses systems efficiency and for the urban distribution network costs. Considering the compliance with input current restrictions imposed by IEC 61000-3-4 standards, two digital control strategies were evaluated. The digital controller has been implemented using a low cost FPGA (XC3S200) and developed totally using a hardware description language VHDL and fixed point arithmetic. Experimental results from a 15 kW low power scale prototype operating in DC and AC conditions are presented, in order to verify the feasibility and performance of the proposed system. © 2009 IEEE.

A novel single-phase hpf hybrid rectifier suitable for front-end trolleybus systems

This paper proposal presents the development and the experimental analysis of a new single-phase hybrid rectifier structure with high power factor (PF) and low harmonic distortion of current (THDI), suitable for application in traction systems of electrical vehicles pulled by electrical motors (trolleybus), which are powered by urban distribution network. This front-end rectifier structure is capable of providing significant improvements in trolleybuses systems and in the urban distribution network costs, and efficiency. The proposed structure is composed by an ordinary single-phase diode rectifier with parallel connection of a switched converter. It is outlined that the switched converter is capable of composing the input line current waveform assuring high power factor (HPF) and low THDI, as well as ordinary front-end converter. However, the power rating of the switched converter is about 34% of the total output power, assuring robustness and reliability. Therefore, the proposed structure was named single-phase HPF hybrid rectifier. A prototype rated at 15kW was developed and analyzed in laboratory. It was found that the input line current harmonic spectrum is in accordance with the harmonic limits imposed by IEC61000-3-4. The principle of operation, the mathematical analysis, the PWM control strategy, and experimental results of a 15kW prototype are also presented in this paper. © 2009 IEEE.

Distributed generation impact evaluation using a multi-objective tabu search

Distribution networks paradigm is changing currently requiring improved methodologies and tools for network analysis and planning. A relevant issue is analyzing the impact of the Distributed Generation penetration in passive networks considering different operation scenarios. Studying DG optimal siting and sizing the planner can identify the network behavior in presence of DG. Many approaches for the optimal DG allocation problem successfully used multi-objective optimization techniques. So this paper contributes to the fundamental stage of multi-objective optimization of finding the Pareto optimal solutions set. It is proposed the application of a Multi-objective Tabu Search and it was verified a better performance comparing to the NSGA-II method. © 2009 IEEE.

A malware detection system inspired on the human immune system

Malicious programs (malware) can cause severe damage on computer systems and data. The mechanism that the human immune system uses to detect and protect from organisms that threaten the human body is efficient and can be adapted to detect malware attacks. In this paper we propose a system to perform malware distributed collection, analysis and detection, this last inspired by the human immune system. After collecting malware samples from Internet, they are dynamically analyzed so as to provide execution traces at the operating system level and network flows that are used to create a behavioral model and to generate a detection signature. Those signatures serve as input to a malware detector, acting as the antibodies in the antigen detection process. This allows us to understand the malware attack and aids in the infection removal procedures. © 2012 Springer-Verlag.

Análisis organizacional del Partido de la Democracia Social Brasileña en el Estado de San Pablo (1988-2006)

The article represents a theoretical and methodological approach to the analysis of organizational dynamics of political parties today, based on a study of the Party of Brazilian Social Democracy (PSDB) in the State of Sao Pãulo (period between 1988 to 2006). It is hypothesized that the structure and the institutional rules of a particular party, or even their election results, are insufficient to explain the inner workings, such as the role of party organization in the electoral system. An approach that articulates the relationship patterns, election results and posts held in the party, identified the factors that explain the political capital that circulated within the party and ensured its organizational dynamics over the period analyzed.

Intraspecific variation and emendation of Hannaella kunmingensis

In order to investigate the intraspecific variability in Hannaella kunmingensis, 11 isolates, including the type strain, were analyzed for their morphological and biochemical traits. The combined internal transcribed spacer region (ITS), D1/D2 domains of the large subunit rDNA (LSU), and cytochrome b gene were examined using phylogenetic and parsimony network analyses. Our investigations revealed differences in colony morphology as well as differences in 31 out of 64 phenotypic characteristics examined, including growth in lactose, vitamin free medium, xylitol, L-arabinitol, and nitrite. Growth in the presence of 0. 1 % cycloheximide was also highlighted in H. kunmingensis. All the 11 strains were conspecific in the LSU; however, variations of about 2. 5 % were found in the ITS while isolate CBS 8356 exhibited a 27. 3 % divergence from the other strains in the cytochrome b gene. Parsimony network analysis revealed the existence of three haplotypes among the H. kunmingensis strains studied but excluded CBS 8356 from the network connecting these haplotypes. This study contributes to the knowledge of the intraspecific diversity of H. kunmingensis. To accommodate such intraspecific variations, an emendation of the species diagnosis is proposed. © 2012 German Mycological Society and Springer.

Uma análise do embeddedness na formação de valor em redes de empresas: um exemplo de aplicação em uma rede do setor metal-mecânico

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A escola da escolha pública e o logrolling: um teste para o Senado Federal brasileiro, entre os anos de 2003 e 2006

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Proposta de Algoritmos Inteligentes para Localizar Faltas e Monitorar a Qualidade da Energia em Redes de Distribuição de Energia Elétrica

Pós-graduação em Engenharia Elétrica - FEIS

Sistema de informação geográfica e sensoriamento remoto na avaliação do processo de mudança de uso da terra para subsidiar o planejamento de bacias hidrográficas

Pós-graduação em Geociências e Meio Ambiente - IGCE

Análise da expressão gênica no músculo esquelético de bovinos das raças Nelore e Aberdeen Angus e sua relação com o desenvolvimento muscular e a maciez da carne

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterização das formas juvenis e adultas dos camarões-rosa Farfantepenaeus brasiliensis (Latrelle, 1917) e F. paulensis (Perez-Farfante, 1967) (Decapoda: Penaeidae) por meio de técnicas moleculares e morfologia comparativa

Pós-graduação em Ciências Biológicas (Zoologia) - IBB

El área de gestión de la información y del conocimiento como frente de investigación en la Ciencia de la Información brasileña: análisis de la producción científica en el período 2000-2009

The management of information and knowledge has been one of the areas of expertise of the fastest growing Brazilian information science. The purpose of this work is to observe how this research front structure from the point of view of the subjects that compose and intellectual frameworks which supports. For this we have analyzed the content of scientific production published in four majo r national journals of the discipline: Ciência da Informação, DataGramaZero, Perspectivas em Ciência da Informação and Transinformação over 2000-2009. The methodology is based on co-occurrence analysis of keywords of articles and co-citation analysis of authors. For the representation and interpretation of the results are used to social network analysis (SNA). We conclude that both information management and knowledge management are closely linked areas within topics including approaches but no consensus answer from the point of view of intellectual frameworks referenced.

Eficiência energética em uma indústria madeireira

In wood processing industries, which use electrical equipment in the production process, in most cases these are badly scaled or operate under inadequate conditions, resulting directly in industrial energy efficiency, which proves important because besides having technological innovation, also with practices and policies, aims to decrease power consumption. So in a wiring project should take into account the variables that influence energy efficiency. Thus this work has been reviewed and subsequently calculated some of these variables, such as active power, power factor and demand for the entire industry (global) and also for specific equipment, the chipper. The network analysis was performed in a wood processing industry in the city of Taquarivaí - SP, and evaluated these variables with a network analyzer and also by analysis on energy bills, which were found in both analysis levels below those found in literature. These factors are due to poor design, improper use, storage of equipment or even by characteristic of the production process, ie, the equipment running on empty because of the volatility of production