119 resultados para Rede de sensores
Resumo:
Wireless Sensor and Actuator Networks (WSAN) are a key component in Ubiquitous Computing Systems and have many applications in different knowledge domains. Programming for such networks is very hard and requires developers to know the available sensor platforms specificities, increasing the learning curve for developing WSAN applications. In this work, an MDA (Model-Driven Architecture) approach for WSAN applications development called ArchWiSeN is proposed. The goal of such approach is to facilitate the development task by providing: (i) A WSAN domain-specific language, (ii) a methodology for WSAN application development; and (iii) an MDA infrastructure composed of several software artifacts (PIM, PSMs and transformations). ArchWiSeN allows the direct contribution of domain experts in the WSAN application development without the need of specialized knowledge on WSAN platforms and, at the same time, allows network experts to manage the application requirements without the need for specific knowledge of the application domain. Furthermore, this approach also aims to enable developers to express and validate functional and non-functional requirements of the application, incorporate services offered by WSAN middleware platforms and promote reuse of the developed software artifacts. In this sense, this Thesis proposes an approach that includes all WSAN development stages for current and emerging scenarios through the proposed MDA infrastructure. An evaluation of the proposal was performed by: (i) a proof of concept encompassing three different scenarios performed with the usage of the MDA infrastructure to describe the WSAN development process using the application engineering process, (ii) a controlled experiment to assess the use of the proposed approach compared to traditional method of WSAN application development, (iii) the analysis of ArchWiSeN support of middleware services to ensure that WSAN applications using such services can achieve their requirements ; and (iv) systematic analysis of ArchWiSeN in terms of desired characteristics for MDA tool when compared with other existing MDA tools for WSAN.
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Generation systems, using renewable sources, are becoming increasingly popular due to the need for increased use of electricity. Currently, renewables sources have a role to cooperate with conventional generation, due to the system limitation in delivering the required power, the need for reduction of unwanted effects from sources that use fossil fuels (pollution) and the difficulty of building new transmission and/or distribution lines. This cooperation takes place through distributed generation. Therefore, this work proposes a control strategy for the interconnection of a PV (Photovoltaic) system generation distributed with a three-phase power grid through a connection filter the type LCL. The compensation of power quality at point of common coupling (PCC) is performed ensuring that the mains supply or consume only active power and that his currents have low distorcion. Unlike traditional techniques which require schemes for harmonic detection, the technique performs the harmonic compensation without the use of this schemes, controlling the output currents of the system in an indirect way. So that there is effective control of the DC (Direct Current) bus voltage is used the robust controller mode dual DSMPI (Dual-Sliding Mode-Proportional Integral), that behaves as a sliding mode controller SM-PI (Sliding Mode-Proportional Integral) during the transition and like a conventional PI (Proportional Integral) in the steady-state. For control of current is used to repetitive control strategy, which are used double sequence controllers (DSC) tuned to the fundamental component, the fifth and seventh harmonic. The output phase current are aligned with the phase angle of the utility voltage vector obtained from the use of a SRF-PLL (Synchronous Reference Frame Phase-Locked-Loop). In order to obtain the maximum power from the PV array is used a MPPT (Maximum Power Point Tracking) algorithm without the need for adding sensors. Experimental results are presented to demonstrate the effectiveness of the proposed control system.
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Cryptography is the main form to obtain security in any network. Even in networks with great energy consumption restrictions, processing and memory limitations, as the Wireless Sensors Networks (WSN), this is no different. Aiming to improve the cryptography performance, security and the lifetime of these networks, we propose a new cryptographic algorithm developed through the Genetic Programming (GP) techniques. For the development of the cryptographic algorithm’s fitness criteria, established by the genetic GP, nine new cryptographic algorithms were tested: AES, Blowfish, DES, RC6, Skipjack, Twofish, T-DES, XTEA and XXTEA. Starting from these tests, fitness functions was build taking into account the execution time, occupied memory space, maximum deviation, irregular deviation and correlation coefficient. After obtaining the genetic GP, the CRYSEED and CRYSEED2 was created, algorithms for the 8-bits devices, optimized for WSNs, i.e., with low complexity, few memory consumption and good security for sensing and instrumentation applications.
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Cryptography is the main form to obtain security in any network. Even in networks with great energy consumption restrictions, processing and memory limitations, as the Wireless Sensors Networks (WSN), this is no different. Aiming to improve the cryptography performance, security and the lifetime of these networks, we propose a new cryptographic algorithm developed through the Genetic Programming (GP) techniques. For the development of the cryptographic algorithm’s fitness criteria, established by the genetic GP, nine new cryptographic algorithms were tested: AES, Blowfish, DES, RC6, Skipjack, Twofish, T-DES, XTEA and XXTEA. Starting from these tests, fitness functions was build taking into account the execution time, occupied memory space, maximum deviation, irregular deviation and correlation coefficient. After obtaining the genetic GP, the CRYSEED and CRYSEED2 was created, algorithms for the 8-bits devices, optimized for WSNs, i.e., with low complexity, few memory consumption and good security for sensing and instrumentation applications.
Resumo:
GUEDES, Clediane de Araújo; FARIAS, Gabriela Belmont de. Information literacy: uma análise nas bibliotecas escolares da rede privada em Natal / RN. Revista Digital de Biblioteconomia e Ciência da Informação, Campinas, v. 4, n. 2, p. 110-133, jan./jun. 2007
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VALENTIM, R. A. M. ; MORAIS, A. H. F. ; SOUZA, V. S. V ; ARAUJO JUNIOR, H. B. ; BRANDAO, G. B. ; GUERREIRO, A. M. G. . Rede de Controle em Ambiente Hospitalar: um protocolo multiciclos para automação hospitalar sobre IEEE 802.3 com IGMP Snooping. Revista Ciência e Tecnologia, v. 11, p. 19, 2009
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TORRES, Gilson de Vasconcelos; ENDERS, Bertha Cruz. Atividades educativas na prevencao da AIDS em uma rede basica municipal de saude: participacao do enfermeiro. Rev.latino-am.enfermagem, Ribeirao Preto, v.7, n.2, p.71-77, abril 1999. Disponivel em:
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BEZERRA, Gesiane Ferreira; CÂMARA, Rafael Silva da; SANTOS, Valdete Honorato dos et al. As bibliotecas escolares digitais contituídas através de uma rede de conhecimento digital. In: SEMINÁRIO DE PESQUISA DO CENTRO DE CIENCIAS SOCIAIS APLICADAS, 16, 2010. Natal. Anais eletrônicos... Natal: SEMINÁRIO CCSA, 2010. Trabalho oral. Disponível em:
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Este artigo analisa a organização da rede de saúde da Paraíba a partir do modelo de regionalização proposto pelo estado da Paraíba. Material e Métodos: Trata-se de um estudo documental que tomou por base, prioritariamente, o Plano Diretor de Regionalização da Paraíba e os documentos oficiais do Ministério da Saúde que orientam a construção dos mesmos pelos Estados. Resultados: A análise dos dados revelou alguns limites no processo de implantação do PDR/ PB, tais como a ausência de análise das características sociais, econômicas e culturais durante a escolha das sedes das regiões de saúde e a inexistente descrição da organização da assistência à saúde do território estadual. Conclusão: O processo de regionalização e a formulação do PDR da Paraíba não seguiram a Instrução Normativa do Ministério da Saúde em alguns aspectos, desconsiderando as especificidades de cada região de saúde, o que pode resultar em problemas no acesso e na articulação da rede de serviços com vistas à legitimação das regiões de saúde desse Estado
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This study approaches bureaucratic organizational structures with the aim to understand the adherence procedure to virtual technologies in the stricto sensu educational administrative process. Thus, the author navigates through the formation of these organizations in Brazil with the intent to demonstrate the bureaucratic organizational culture and the consequent form of domination of those who detain power. In this epistemological construction, the author explores the culture s bureaucratic environment and the organizational power. In the analyses, it was observed the technological phenomenon in the ODL s administrative environment, which can explain the adherence procedure to structures and technological instruments for stricto sensu courses that, hypothetically, dilutes the traditional inherited organizational axiom. Therefore, it was utilized as object of study the Professional Master s degree in National Scale Public Administration PROFIAP, hence analyzing the documental content and the legislation related to institutionalization as well as the positioning of professors/coordinators and of the director of CAPES/MEC. Considering this axioms, it was concluded that the bureaucratic structures can admit ODL in the stricto sensu s environment. However, this can only be done as long as the adherence does not imply in a dilution of the traditional forms of power and institutional bureaucratic inherited dominance, as well as the alleged hegemony of the governmental structure in the educational administration adopted in person by the stricto sensu courses in Brazil
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As peculiaridades presentes no ser humano são observadas a partir da manifestação de sua cultura. Estas manifestações podem ser influenciadas pelo contexto social do indivíduo. A cultura nacional é uma destas influências. A brasileira, por exemplo, possui alguns traços nacionais peculiares ao seu povo que amenizam a sua complexidade e pluralidade. Estes traços podem se tornar influentes na cultura organizacional, através da manifestação das práticas e dos valores utilizados pela organização. Diante disso, o presente trabalho teve como objetivo diagnosticar a cultura organizacional dos hospitais, enfatizando as práticas e os valores organizacionais e a percepção dos colaboradores sobre a cultura organizacional. A metodologia utilizada na pesquisa foi de caráter descritivo e explicativo. A pesquisa ocorreu através da aplicação do Instrumento Brasileiro para a Avaliação da Cultura Organizacional IBACO, com 283 sujeitos distribuídos em três hospitais da rede privada de Natal/RN. As evidências encontradas pelo estudo foram analisadas através do software estatístico SPSS, com as técnicas multivariadas de análise fatorial, análise de aglomerados e análise discriminante. A partir dessas análises, foram obtidos cinco fatores distribuídos entre práticas e valores apresentados pelo IBACO, que foram: as práticas de recompensa e treinamento; integração externa e promoção do relacionamento interpessoal; e, os valores de satisfação, bem-estar e cooperação dos empregados e profissionalismo competitivo. Os grupos encontrados na análise apresentaram divergências de opinião quanto às práticas e os valores utilizados nos hospitais. Concluiu-se, portanto, que o Hospital A apresentou uma cultura mais proativa e voltada mais para a satisfação e bem-estar dos funcionários. Já os outros dois hospitais apresentaram culturas semelhantes, com limitações quanto à valorização do bem-estar e da cooperação entre os colaboradores, porém com uma boa prática do relacionamento interpessoal
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The democratic management is a challenge for education, on the one hand for its actualization needs a link between the government and the educational institution. From that, research aims to understand the main challenges faced by the school administration to consolidate the management of public schools in Natal/RN. Against this context the methodology used was multiple cases, qualitative approach in which respondent were manager (director, deputy director and coordinator) of the four municipal schools and two representatives of the Democratic Management Commission of a Government departament of Education, Natal/RN. The analysis was made by peers, between schools that had grade superior IDEB that average stipulated by the federal government and two that had grade lower and between managers and representatives of the Secretary. Were used techniques of categorization and content analysis of the speeches of respondents. Was note that managers understand the importance of the participation about whole community in the democratic management, however only one school highlighted means of attracting the parents against to the difficulty of representing these. The lack of knowledge about the democratic management is evident mainly in the pair of schools with lower IDEB. That schools with a lower IDEB adhere to this management as a way to meet rules. So unanimous, the broad role of director hampers knowledge about the legislation. About relationship of the Government department with managers, there are some contradictions between the understanding of the role of the coordinator by managers and representatives of the Government department. It was perceptible the no uniformity about a good relationship between managers and Government department. It was notable features of democratic management in all school units, well as the efforts of the Government department in this scope. However there are also undemocratic features that deserve further study
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
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This study aimed to describe the spatial and temporal patterns of variation in trophic state and its relation with the structure and dynamics of planktonic community of a large reservoir located in semi-arid tropical region of Northeast Brazil. The reservoir Armando Ribeiro Gonçalves is the biggest reservoir of the Rio Grande do Norte State and is responsible for about 53% of all surface water accumulated in the State. The samples of water and plankton were taken monthly in 10 points distributed throughout the longitudinal axis of the reservoir and over a full hydrological cycle. The samples were collected to determine concentrations of total phosphorus, total nitrogen, chlorophyll a and suspended solids (fixed and volatile) and for determining the composition and abundance of phytoplanktonic and zooplanktonic species. During the study period, the reservoir was characterized as eutrophic and there was no trend of increasing the trophic state of the reservoir in the period of drought. The concentrations of total phosphorus and suspended fixed solids decreased towards the dam while the N:P ratios increased in the same direction due to the reduction in the phosphorus concentrations and relative constancy in the nitrogen concentrations. The N:P ratios observed were indicative of greater limitation by phosphorus than by nitrogen. However, as concentrations of both nutrients were high and the water transparency was very low, with secchi depth usually lower than one meter, it seems likely that the planktonic primary production of the reservoir is more limited by the availability of light than the availability of nutrients. High nutrient concentrations coupled with low availability of light may explain the continuing dominance of filamentous cyanobacteria such as Cylindrospermopsis raciborskii in the plankton of the reservoir.These cyanobacteria are potentially toxic and pose a serious environmental problem because it compromises the water quality for public supply, recreation and fishing when present in high densities as in this study. The mesozooplankton of the reservoir was dominated by the calanoid Notodiaptomus cearensis and the cladoceran Diaphanosoma spinulosum. In general, the structure of zooplankton community seems to be particularly influenced by the spatial variation of cyanobacteria. The results of the regression analyses show that both the chlorophyll a concentrations and the cyanobacteria biovolume were more strongly correlated with the nitrogen than with phosphorus and that the water transparency was more strongly correlated with algal biomass than with other sources of turbidity. The maximum load of phosphorus to attain the maximum permissible concentration of total P in the reservoir was estimated in 63.2 tonnes P/ year. The current external P load to the reservoir is estimated in 324 tonnes P / year and must be severely reduced to improve the water quality for water supply and allow the implementation of aquaculture projects that could contribute to the socio-economic development of the region
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The aims of this study were: i) assessing the trophic state of the Mendubim reservoir (semi-arid, Rio Grande do Norte, Brazil; 05° 38 99,0 S 36°55 98,0 W) based on chlorophyll-a, total phosphorus and nitrogen concentrations and water transparency; ii) relating the patterns of temporal variation of zooplankton and phytoplankton to the trophic state of the reservoir and iii) investigating the carrying capacity of the reservoir for cage fish farming. The samplingwas done monthly from July 2006 to July 2007 in three stations at the reservoir: next to the dam (barrage), in the central region and in the mouth of the main tributary. The abiotic and biotic variables analyzed were: Secchi depth, volatiles and fixed suspended solids, chlorophyll-a, total phosphorus and nitrogen, TN:TP ratio and mesozooplankton and phytoplankton composition and biomass. The results showed that the reservoir can be considered as mesotrophic with mean concentrations of total nitrogen, phosphorus and chlorophyll-a equal to 1711, 1 μg.L-1, 30,8 μg.L-1 and 5,62 μg.L-1 respectively. The Cyanophyceae class was the most representative in terms of density, with the presence of potentially toxic species such as Microcystis aeruginosa, Planktothrix planctonica, Cylindrospermopsis raciborskii, Aphanizomenon sp. ,Aphanocapsa delicatissima and Pseudanabaena acicularis. Among the zooplankton, the genus Notodiaptomus presented the largest biomass values. Overall, our results show that the light limitation should explain the weak relationship between chlorophyll-a and total phosphorus and nitrogen concentrations. We concluded that the water of Mendubim reservoir is suitable for intensive fish cage aquaculture. Based on the carrying capacity calculations for this reservoir, we found that the maximum sustainable yield of tilapias in cages in the reservoir is 126 ton per year assuming a factor of food conversion of 1.5: 1.0 and a phosphorus content in the fish food of 1%