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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Fusion multi-niveaux pour l'indexation et la recherche multimédia par le contenu sémantique

Benmokhtar, Rachid 09 June 2009 (has links) (PDF)
Aujourd'hui, l'accès aux documents dans les bases de données, d'archives et sur Internet s'effectue principalement grâce à des données textuelles : nom de l'image ou mots-clés. Cette recherche est non exempte de fautes plus ou moins graves : omission, orthographe, etc. Les progrès effectués dans le domaine de l'analyse d'images et de l'apprentissage automatique permettent d'apporter des solutions comme l'indexation et la recherche à base des caractéristiques telles que la couleur, la forme, la texture, le mouvement, le son et le texte. Ces caractéristiques sont riches en informations et notamment d'un point de vue sémantique. Cette thèse s'inscrit dans le cadre de l'indexation automatique par le contenu sémantique des documents multimédia: plans vidéo et images-clés. L'indexation consiste à extraire, représenter et organiser efficacement le contenu des documents d'une base de données. L'état de l'art du domaine est confronté au «fossé sémantique» qui sépare les représentations visuelles brutes (bas-niveau) et conceptuelles (haut-niveau). Pour limiter les conséquences de cette problématique, nous avons introduit dans le système plusieurs types de descripteurs, tout en prenant à notre avantage les avancées scientifiques dans le domaine de l'apprentissage automatique et de la ``fusion multi-niveaux''. En effet, la fusion est utilisée dans le but de combiner des informations hétérogènes issues de plusieurs sources afin d'obtenir une information globale, plus complète, de meilleure qualité, permettant de mieux décider et d'agir. Elle peut être appliquée sur plusieurs niveaux du processus de classification. Dans cette thèse, nous avons étudié la fusion bas-niveau (précoce), la fusion haut-niveau (tardive), ainsi qu'à un niveau décisionnel basé sur l'ontologie et la similarité inter-concepts dit de raisonnement. Les systèmes proposés ont été validés sur les données de TRECVid (projet NoE K-Space) et les vidéos de football issues d'Orange-France Télécom Labs (projet CRE-Fusion). Les résultats révèlent l'importance de la fusion sur chaque niveau du processus de classification, en particulier, l'usage de la théorie des évidences.
32

Autonomous Mapping and Exploration of Dynamic Indoor Environments / Autonom kartläggning och utforskning av dynamiska inomhusmiljöer

Fåk, Joel, Wilkinson, Tomas January 2013 (has links)
This thesis describes all the necessary parts needed to build a complete system for autonomous indoor mapping in 3D. The robotic platform used is a two-wheeled Segway, operating in a planar environment. This, together with wheel odometers, an Inertial Measurement Unit (IMU), two Microsoft Kinects and a laptop comprise the backbone of the system, which can be divided into three parts: The localization and mapping part, which fundamentally is a SLAM (simultaneous localization and mapping) algorithm implemented using the registration technique Iterative Closest Point (ICP). Along with the map being in 3D, it also designed to handle the mapping of dynamic scenes, something absent from the standard SLAM design. The planning used by the system is twofold. First, the path planning - finding a path from the current position to a destination - and second, the target planning - determining where to go next given the current state of the map and the robot. The third part of the system is the control and collision systems, which while they have not received much focus, are very necessary for a fully autonomous system. Contributions made by this thesis include: The 3D map framework Octomap is extended to handle the mapping of dynamic scenes; A new method for target planning, based on image processing is presented; A calibration procedure for the robot is derived that gives a full six degree of freedom pose for each Kinect. Results show that our calibration procedure produces an accurate pose for each Kinect, which is crucial for a functioning system. The dynamic mapping is shown to outperform the standard occupancy grid in fundamental situations that arise when mapping dynamic scenes. Additionally, the results indicate that the target planning algorithm provides a fast and easy way to plan new target destinations. Finally, the entire system’s autonomous mapping capabilities are evaluated together, producing promising results. However, it also highlights some problems that limit the system’s performance such as the inaccuracy and short range of the Kinects or noise added and reinforced by the multiple subsystems / Detta exjobb beskriver delarna som krävs för att för bygga ett komplett system som autonomt kartlägger inomhusmiljöer i tre dimensioner. Robotplattformen är en Segway, som är kapabel att röra sig i ett plan. Segwayn, tillsammans med en tröghetssensor, två Microsoft Kinects och en bärbar dator utgör grunden till systemet, som kan delas i tre delar: En lokaliserings- och karteringsdel, som i grunden är en SLAM-algoritm (simultan lokalisering och kartläggning)  baserad på registreringsmetoden Iterative Closest Point (ICP). Kartan som byggs upp är i tre dimensioner och ska dessutom hantera kartläggningen av dynamiska miljöer, något som orginalforumleringen av SLAM problemet inte klarar av. En automatisk planeringsdel, som består av två delar. Dels ruttplanering som går ut på att hitta en väg från sin nuvarande position till det valda målet och dels målplanering som innebär att välja ett mål att åka till givet den nuvarande kartan och robotens nuvarande position. Systemets tredje del är regler- och kollisionssystemen. Dessa system har inte varit i fokus i detta arbete, men de är ändå högst nödvändiga för att ett autonomt system skall fungera. Detta examensarbete bidrar med följande: Octomap, ett ramverk för kartläggningen i 3D, har utökats för att hantera kartläggningen av dynamiska miljöer; En ny metod för målplanering, baserad på bildbehandling läggs fram; En kalibreringsprocedur för roboten är framtagen som ger den fullständiga posen i förhållande till roboten för varje Kinect. Resultaten visar att vår kalibreringsprocedur ger en nogrann pose for för varje Kinect, vilket är avgörande för att systemet ska fungera. Metoden för kartläggningen av dynamiska miljöer visas prestera bra i grundläggande situationer som uppstår vid kartläggning av dynamiska miljöer. Vidare visas att målplaneringsalgoritmen ger ett snabbt och enkelt sätt att planera mål att åka till. Slutligen utvärderas hela systemets autonoma kartläggningsförmåga, som ger lovande resultat. Dock lyfter resultat även fram problem som begränsar systemets prestanda, till exempel Kinectens onoggranhet och korta räckvidd samt brus som läggs till och förstärks av de olika subsystemen.
33

Atividades caracter?sticas do turismo: uma an?lise da dimens?o do turismo na economia brasileira do ano de 2013 / Tourism characteristics activities: an anlysis of the tourism dimension in the brazilian economy in 2013

Souza, Ivanise Borges 10 August 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-09-05T19:39:01Z No. of bitstreams: 1 IvaniseBorgesSouza_DISSERT.pdf: 2800497 bytes, checksum: 50c24b5e23510fcd8e07cecda4fbee7c (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-09-15T20:52:51Z (GMT) No. of bitstreams: 1 IvaniseBorgesSouza_DISSERT.pdf: 2800497 bytes, checksum: 50c24b5e23510fcd8e07cecda4fbee7c (MD5) / Made available in DSpace on 2017-09-15T20:52:51Z (GMT). No. of bitstreams: 1 IvaniseBorgesSouza_DISSERT.pdf: 2800497 bytes, checksum: 50c24b5e23510fcd8e07cecda4fbee7c (MD5) Previous issue date: 2016-08-10 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A atividade tur?stica brasileira, ao longo dos ?ltimos anos, vem se desenvolvendo substancialmente. Por?m, n?o h? informa??es o bastante para dimensionar o desempenho do turismo na economia, pois as pesquisas que existem n?o s?o suficientes ou est?o com dados defasados. As pesquisas com abordagem estat?stica e econ?mica, como a Conta Sat?lite do Turismo (CST), configuram-se como importantes fontes de informa??es para o planejamento de pol?ticas, investimentos e expans?o do mercado, visando melhorias para a popula??o, para o trade tur?stico e para o turista. Com a mensura??o econ?mica do turismo, torna-se poss?vel identificar atividades em crescimento, que geram postos de trabalho, renda e melhorias da condi??o social da popula??o, assim como apontar atividades estagnadas. O presente trabalho tem por objetivo analisar a participa??o das Atividades Caracter?sticas do Turismo (ACT?s) na economia brasileira no ano de 2013. O intuito ? gerar informa??es para o dimensionamento e o desenvolvimento da atividade tur?stica no contexto brasileiro. A pesquisa caracteriza-se como explorat?rio-descritiva, transversal, de abordagem quantitativa. O estudo foi realizado a partir de dados secund?rios extra?dos principalmente da Pesquisa Anual de Servi?os desenvolvida pelo Instituto Brasileiro de Geografia e Estat?stica ? IBGE e do Sistema de Informa??es Sobre o Mercado de Trabalho no setor de turismo do Instituto de Pesquisa Econ?mica e Aplicada. A metodologia aplicada teve como base o modelo da CST-99 do Brasil e o relat?rio ?Economia do Turismo: uma perspectiva macroecon?mica 2003-2009?, ambas as publica??es fundamentadas nas diretrizes e metodologias recomendadas pela Organiza??o Mundial do Turismo (OMT) e pelo Sistema de Contas Nacionais -1993/2008. Para dimensionar a participa??o das ACT?s na economia, foram aplicados os conceitos das identidades cont?beis sobre os agregados macroecon?micos do turismo. Com isso, o trabalho teve com resultado a estimativa do valor bruto da produ??o, consumo intermedi?rio, valor agregado bruto, gastos com o pessoal, excedente operacional bruto, n?mero de postos de trabalho, rendimentos pagos e n?mero de empresas. Para tanto, esta pesquisa vem a contribuir para a literatura da economia do turismo com perspectiva de ampliar as discuss?es sobre os mecanismos de mensura??o do turismo para gera??o de informa??es econ?micas e estat?sticas para o Brasil. / Brazilian tourism has been developing, quickly over the last years. However, there is not enough information to measure the performance of tourism in the economy, because the existing research sufficiently specific or obsolete data. Statistical and economic research, such as the Tourism Satellite Account (TSA), in an important source of information for policy planning, investment and market expansion, enabling improvements for residents, businesses and tourists. With the economic measurement of tourism, it is possible to identify growing activities that generate jobs, income and welfare, also pointing stable activities. This study aims to analyze the participation of Tourism Characteristic Activities (TCAs) in the Brazilian economy in 2013.The objective is to generate information for the measurement and development of tourism in the Brazilian context. The research is characterized as exploratory, descriptive, cross-sectional, using quantitative approach. The study relied on secondary data sources drawn mainly from research the Annual Survey of Services developed by the Brazilian Institute of Geography and Statistics (IBGE) and the tourism Labor Market Information System of the Applied Economic Research Institute (IPEA). The applied methodology was based on Brazil?s TSA-99 and on the report ?Tourism Economics: a macroeconomic perspective 2003-2009?, both based on the guidelines and methodologies recommended by the World Tourism Organization (UNWTO) and National Accounts System-1993/2008.To measure the participation of TCAs in the economy, the concepts of accounting identities of the macroeconomic aggregates of tourism were applied. Thus, the study resulted in estimation of gross value of production, intermediate consumption, gross value added, expenses personnel, gross operating surplus, number of jobs, paid income and number of companies. Therefore, this research contributes to the tourism literature with perspective to expand discussions on tourism measurement mechanisms for the generation of economic and statistical information about Brazil.
34

Vliv pohybové intervence na fyzickou zdatnost a kvalitu života u pacientů po bariatrické operaci / The Effect of Exercise Intervention on Physical Fitness and Quality of Life in Patients after Bariatric Surgery

Pacholíková, Pavlína January 2020 (has links)
Title: The Effect of Exercise Intervention on Physical Fitness and Quality of Life in Patients after Bariatric Surgery Objectives: The aim of this thesis is to evaluate the effect of a three-month physical intervention on the physical fitness and quality of life in patients after bariatric surgery. Compare the measured values from six-minute walk test (6MWT) and the questionnaire survey of quality of life between the group undergoing exercise program and the group of non-exercise patients. Methods: The diploma thesis was constructed as a quasi-experiment. A six-minute walk test, a visual analogue pain scale, a Borg scale and a standardized IWQOL-Lite questionnaire were used to asses physical fitness and quality of life. The study involved 28 patients (8 undergoing an exercise program, 20 non-excercisers). The groups were measured before the planned bariatric surgery and about 3-4 months after the surgery. For the analysis of final values, the Microsoft Excel and its add-in Realstatistics was used. Results: In patients undergoing the exercise program, the VAS on average decreased of 2,04 cm, 6MWT improved on average of 42,75 m, and quality of life of 34 points. In non-exercise patients there was an average decrease in VAS of 0,08 cm, an increase in 6MWT of 41,45 m and an increase in quality of life...
35

Evaluation of AXI-Interfaces for Hardware Software Communication

Sharma, Ankit 01 February 2019 (has links)
A SoC design approach is implemented for the MERGE project which features Machine Learning (ML) interface for the hardware design. This setup deals with detection and localization of impact on a piezo metal composite. Development of the project is executed on Digilent ZYBO board. ZYBO incorporates Xilinx ZYNQ architecture. This architecture provides Processing System (PS) and Programmable Logic (PL) that communicate with each other via AMBA Standard AXI4 Interface. Communication cost have major inuence on the system performance. A optimized hardware software partitioning solution will reduce the communication costs. Therefore, best fitting interface for the provided design is needed to be evaluated to trade-off between cost and performance. High performance of AXI Interface will provide efficient localization of impact, especially for real-time scenario. In the thesis, the performance of three different AXI4 interface are evaluated. Evaluation is performed on the basis of the amount of data transferred and the time taken to process it. Evaluation of interfaces are done through implementation of test cases in Xilinx SDK. Hardware design for AXI4-Interfaces is implemented in Vivado and later tested on Digilent ZYBO board. To test the performance of interfaces, read and write operations are initiated by PS on interface design. Each operation is performed for multiple data lengths. Average execution time is calculated that highlights time taken to transfer the corresponding input data length. Through these tests, it is found that AXI4-Stream is the best choice for a continuous set of data. Preferably, it provides unlimited burst length which is useful for the current project. Among other two interfaces, AXI4-Full performed better in terms of execution time as compared to AXI4-Lite.
36

Perceptions of Women in the Far-Right : A Comparative Ideology Analysis of Far-Right Perceptions of Women.

Eriksson, Elin January 2021 (has links)
This bachelor’s thesis aspires to contribute to the field of research concerning women and far-right extremism. Scholars have during recent years called attention to the surge of far-right extremism and female participation in jihadi terrorism. However, when these fields of research meet, various knowledge gaps are distinguishable. The explicit research gap that this thesis aims to fill concerns a lack of comparative research on how men and women in the extreme-right perceive women. To fill this gap, this thesis aspires to describe how women are perceived, on a sex-disaggregated basis, in the far-right extremist movement by answering the research question: How do the female far-right extremists in Proud Girls and the male far-right extremists in Proud Boys' perception of women differ? Using the gender-separated US extreme-right group Proud Boys/Proud Girls as a typical case, the study performs an ideology analysis to distinguish how the groups perceive women. Thus, this study contributes to the field by presenting a comparative analysis of how extreme right perceives women. The results of the study suggest a difference in how Proud Boys and Proud Girls perceive women as the former conveys a more misogynist perception whereas the latter adheres to a more empowering view of women.
37

Analysis of different face detection andrecognition models for Android

Hettiarachchi, Salinda January 2021 (has links)
Human key point tracking such as face detection and recognition has become an increasingly popular research topic. It is a platform independent functionality and already being implemented on a wide range of platforms. Android is one such platform that runs on mobile phones and top of many edge devices such as car devices and smart home appliances. In the current times, AI and ML related applications are slightly moving into those edge devices due to various reasons such as security and low latency. The hardware enhancements are also backing this trend that happened over the last few years. Many solutions and algorithms have been proposed in this context, and various frameworks and models have also been developed. Even though there are different models available, they tend to deliver varying results in terms of performance. Evaluating these different alternatives to find an optimized solution is a problem worth addressing. In this thesis project, several selected face detection and recognition models have been implemented in an Android device, and their performance been evaluated. Google ML Kit showed the best results among the face detection methods since it took only around 68 milliseconds on average to detect a face. Out of the three face recognition algorithms evaluated, FaceNet was the most accurate as it showed an accuracy above 95% for most cases. Meanwhile, MobileFaceNet was the fastest algorithm, and it took only around 90 milliseconds on average to produce and output. Eventually, a face recognition application was also developed using the best performing models selected from the experiment.
38

Dinaminių kelio paieškos algoritmų tyrimas / Analysis of dynamic path finding algorithms

Chabibulin, Linar 26 August 2013 (has links)
Dinaminiai kelio paieškos algoritmai apjungia euristinės ir plečiamos (angl. incremental) paieškos metodus, sprendžiant eiles panašių paieškos uždavinių tiek žinant visą informaciją apie aplinką, tiek neturint jokios informacijos. Yra trys plečiamą paiešką naudojančių algoritmų klasės. Šiame darbe pateikiama trumpa dinaminių kelio paieškos algoritmų, naudojančių plečiamos paieškos metodus analizė. Pagrindinis darbo tikslas – visų trijų plečiamos paieškos klasių algoritmų, kuriuos naudojant gaunamas optimalus kelio paieškos sprendinys aplinkose, kur perėjimų tarp viršūnių svoriai gali didėti ir mažėti, palyginimas. Algoritmai lyginami trijose skirtingose situacijose: stacionarioje, judėjimo link tikslo (angl. goal – directed) bei judančio taikinio (angl. moving – target). Tyrimo rezultatai parodė, jog A* ir FSA* nepasiekiamų viršūnių kiekiui esant ~16000 yra ~23,6% našesni už GAA* ir trečios plečiamos klasės algoritmus, o pasiekiamumą keičiančių viršūnių kiekiui esant ~8000 – 42,3%. Nepasiekiamų viršūnių kiekiui kintant nuo 1000 iki 16000 trečios plečiamos klasės algoritmai yra vidutiniškai ~58,7% našesni už GAA* ir ~54% našesni už A* ir FSA*. Pasiekiamumą keičiančių viršūnių kiekiui kintant nuo 500 iki 8000 trečios plečiamos klasės algoritmai yra vidutiniškai ~69,3% našesni už GAA* ir ~47,8% našesni už A* ir FSA*. / Dynamic path finding algorithms combine heuristic and incremental search methods to solve a series of similar search tasks in both known and unknown environments. There are three classes of incremental search algorithms. In this document we provide a brief summary of dynamic path finding algorithms, that uses incremental search methods, but its main focus is on comparing main algorithms of all three incremental classes, that are guaranteed to give optimal solution in environment where action costs can increase and decrease over time, and showing their strong and weak sides. The algorithms are compared in three different situations: stationary, goal – directed and moving – target. At the end of the document conclusions are given based on performed work. In this paper, research showed that A* and FSA* are ~23,6% more efficient than GAA* and third incremental class algorithms when the amount of untraversable cells is ~16000 and ~42,3% more efficient when the amount of traversability changing cells is ~8000. When the amount of untraversable cells is between 1000 and 16000, the third incremental class algorithms are ~58,7% more efficient than GAA* and ~54% – than A* and FSA*. When the amount of traversability changing cells is between 500 and 8000, the third incremental class algorithms are ~69,3% more efficient than GAA* and ~47,8% – than A* and FSA*.
39

Estudos e projetos de filtro interdigital em microfita para aplica??o pr?tica ao transponder do sat?lite ITASAT

Ara?jo, Tiago Costa de 07 May 2012 (has links)
Made available in DSpace on 2014-12-17T14:55:58Z (GMT). No. of bitstreams: 1 TiagoCA_DISSERT.pdf: 3801367 bytes, checksum: 9225a3c3c8dc4d02582f66bec6b853a7 (MD5) Previous issue date: 2012-05-07 / This work shows a theoretical analysis together with numerical and experimental results of transmission characteristics from the microstrip bandpass filters with different geometries. These filters are built over isotropic dielectric substrates. The numerical analysis is made by specifical commercial softwares, like Ansoft Designer and Agilent Advanced Design System (ADS). In addition to these tools, a Matlab Script was built to analyze the filters through the Finite-Difference Time-Domain (FDTD) method. The filters project focused the development of the first stage of filtering in the ITASAT s Transponder receptor, and its integration with the others systems. Some microstrip filters architectures have been studied, aiming the viability of implementation and suitable practical application for the purposes of the ITASAT Project due to its lowspace occupation in the lower UHF frequencies. The ITASAT project is a Universityexperimental project which will build a satellite to integrate the Brazilian Data Collect System s satellite constellation, with efforts of many Brazilian institutes, like for example AEB (Brazilian Spatial Agency), ITA (Technological Institute of Aeronautics), INPE/CRN (National Institute of Spatial Researches/Northeastern Regional Center) and UFRN (Federal University of Rio Grande do Norte). Comparisons were made between numerical and experimental results of all filters, where good agreements could be noticed, reaching the most of the objectives. Also, post-work improvements were suggested. / Esse trabalho apresenta uma an?lise te?rica e resultados num?ricos e experimentais das caracter?sticas de transmiss?o de filtros passa-faixa de microfita, que usam diferentes geometrias. Os filtros s?o constru?dos sobre substratos diel?tricos isotr?picos. A an?lise ? efetuada utilizando-se diferentes programas computacionais comerciais como o Ansoft Designer e o Advanced Design System (ADS). Al?m dessas ferramentas, foram desenvolvidas rotinas computacionais que analisam os filtros atrav?s do m?todo das diferen?as finitas no dom?nio do tempo (FDTD). O projeto dos filtros teve foco no desenvolvimento do primeiro est?gio de filtragem do sistema de recep??o do Transponder do Sat?lite ITASAT e sua integra??o com os demais sistemas. Foram estudadas algumas arquiteturas de filtro passa-faixa de microfita para viabilizar sua aplica??o no Transponder, por sua economia de espa?o na frequ?ncia de opera??o (faixa UHF inferior). O ITASAT ? um projeto que visa a constru??o de um sat?lite de car?ter experimental universit?rio para integrar a constela??o de sat?lites do Sistema Brasileiro de Coleta de Dados, reunindo esfor?os de diversas institui??es do Brasil, incluindo a AEB, o ITA, o INPE/CRN e a UFRN. Foram efetuadas compara??es entre os resultados num?ricos e experimentais para todos os filtros, onde observou-se uma boa concord?ncia, atingindo boa parte dos objetivos. Sugest?es de continuidade do trabalho s?o apresentadas.
40

Desenvolvimento de um protocolo de comunica??o para automa??o de subesta??es m?veis via sat?lite

Oliveira J?nior, Carlos Augusto de 19 December 2005 (has links)
Made available in DSpace on 2014-12-17T14:56:04Z (GMT). No. of bitstreams: 1 CarlosAOJ.pdf: 1085948 bytes, checksum: 14c962ba5a82f983a474383c27475bb0 (MD5) Previous issue date: 2005-12-19 / One of the most important decisions to turn a substation automatic and no attended it relates to the communication media between this substation and Operation Center. Generally energy companies uses radio or optic fiber, depending of distances and infrastructure of each situation. This rule applies to common substations. Mobile substations are a particular case, therefore they are conceived for use at provisional situations, emergencies, preventive or corrective maintenance. Thus the telecommunication solution used at common substations are not applied so easily to mobile substations, due absence of infrastructure (media) or difficulty to insert the mobile substation data in existing automation network not long. The ideal media must supply covering in a great geographic area to satisfy presented requirements. The implantation costs of this big infrastructure are expensive, however a existing operator may be used. Two services that fulfill that requirements are satellite and cellular telephony. This work presents a solution for automation of mobile substations through satellite. It was successfully implanted at a brazilian electric energy concessionaire named COSERN. The operation became transparent to operators. Other gotten benefits had been operational security, quality in the supply of electric energy and costs reduction. The project presented is a new solution, designed to substations and general applications where few data should be transmitted, but there is difficulties in relation to the media. Despite the satellite having been used, the same resulted can be gotten using celullar telephony, through Short Messages or packet networks as GPRS or EDGE. / Uma das decis?es t?cnicas mais importantes para se automatizar uma subesta??o e torn?-la desassistida refere-se ao meio de comunica??o entre esta subesta??o e o Centro de Opera??es. Normalmente as empresas do setor el?trico optam por usar r?dio ou fibra ?tica, dependendo das dist?ncias e infra-estrutura dispon?vel em cada situa??o. Essa regra se aplica a subesta??es comuns. Subesta??es m?veis s?o um caso particular, pois s?o concebidas para uso em situa??es sazonais, emerg?ncias, manuten??es preventivas ou corretivas. Dessa forma, as solu??es de telecomunica??es para subesta??es comuns n?o s?o facilmente aplic?veis ?s m?veis, seja devido ? inexist?ncia de infra-estrutura (meio de comunica??o), ou ? dificuldade de inserir, em um curto espa?o de tempo, as informa??es da subesta??o m?vel numa rede de automa??o existente. Considera-se, ent?o, que para atender aos requisitos de mobilidade apresentados, o meio de comunica??o ideal deve fornecer cobertura em uma grande ?rea geogr?fica. Os custos de implanta??o de uma infra-estrutura desse porte s?o muito elevados, por?m os servi?os de uma operadora existente podem ser usados. Dois servi?os que atendem bem a esses requisitos s?o o sat?lite e a telefonia celular. Neste trabalho, ? apresentada uma solu??o para automa??o de subesta??es m?veis atrav?s de enlace via sat?lite. O projeto foi implantado na concession?ria de energia COSERN, com sucesso. A opera??o tornou-se transparente aos operadores. Outros benef?cios obtidos foram seguran?a operacional, qualidade no fornecimento de energia el?trica e redu??o de custos. A solu??o apresentada ? um projeto piloto, voltado n?o s? para subesta??es, mas para aplica??es cujo volume de dados transmitidos seja pequeno, e h? dificuldades quanto ao meio de comunica??o. Apesar do sat?lite ter sido usado, pode-se obter o mesmo resultado usando-se a telefonia celular, atrav?s de Short Messages ou via rede de comuta??o de pacotes, como o GPRS ou o EDGE.

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