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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.
411

A formulation for efficient adaptive metamodelling in engineering design

Makin, Thomas January 2014 (has links)
This thesis presents the research and development of robust metamodelling tools for engineering design. Metamodelling in engineering is typically used for reducing computational cost of highly expensive analyses or simulations. Metamodels have been shown to be effective in these problems where an approximation constructed from a limited set of true data points is used in support of optimisation. The inspiration for this work is drawn from the optimisation of aircraft wing structures, constructed using large numbers of rectangular stiffened panels. When optimising such structures to produce a minimum weight design, it is necessary to evaluate multiple design constraints such as buckling load, damage tolerance and repairability. The total computational cost for this aspect of the analysis can become considerable when a large number of evaluations is required and can creates a bottleneck in the optimisation workflow. In response to this industrial design problem, a specification is proposed for an efficient and adaptive metamodelling formulation. Following an extensive literature review the multilevel Radial Basis Function (mRBF) model is highlighted as a promising candidate for further investigation. The mRBF formulation is discussed in detail, and a comparative study is presented comparing mRBF to more established modelling techniques. mRBF is then put to work on a range of optimisation test problems, including an industrial scale multi-panel wing design scenario. Emphasis is placed on the adaptive acquisition of model data as the optimisation process progresses. Implementation details and software development processes are also presented in detail. The case is made for decoupled modelling workflows, and a RESTful web based mRBF modelling framework. Finally the performance of the proposed modelling scheme is compared to the original specification, and recommendations are made for further investigation.
412

Resource-oriented architecture based scientific workflow modelling

Duan, Kewei January 2016 (has links)
This thesis studies the feasibility and methodology of applying state-of-the-art computer technology in scientific workflow modelling, within a collaborative environment. The collaborative environment also indicates that the people involved include non-computer scientists or engineers from other disciplines. The objective of this research is to provide a systematic methodology based on a web environment for the purpose of lowering the barriers brought by the heterogeneous features of multi-institutions, multi-platforms and geographically distributed resources which are implied in the collaborative environment of scientific workflow.
413

SINS: um ambiente para geração de aplicações a partir de serviços

Larentis Júnior, Sérgio 10 January 2008 (has links)
Made available in DSpace on 2015-03-05T13:59:42Z (GMT). No. of bitstreams: 0 Previous issue date: 10 / Nenhuma / A arquitetura SOA (service oriented architecture) possibilita que serviços sejam desenvolvidos em linguagens diversas, orquestrados e combinados de modo a se obter aplicações, as chamadas Composite Applications. Apesar dos grandes avanços no que diz respeito à Web Services e IDEs de desenvolvimento, ainda não há um ambiente que permita a geração destas Composite Applications sem a necessidade de codificação e sem a necessidade de intervenção de um profissional da área de desenvolvimento de software. O SINS, apresentado por este trabalho, é um ambiente capaz de gerar Composite Applications em tempo real, consumindo serviços pré-existentes. Tendo a vantagem de não necessitar de codificação ou da intervenção de um profissional da área de software / SOA (service oriented architecture) makes possible that services developed in several languages be organized and combined to obtain applications (called Composite Applications). Despite the advances in Web Services and development IDEs, there is not an environment capable of generate Composite Application without the need of coding and without the need of a software development professional participation. SINS, showed in this work, is an environment capable of generate Composite Applications in real time, consuming the existent services with the advantage that it doesn’t need any coding to do this task
414

Aruba: uma arquitetura para geração de serviços a partir de sistemas legados de forma não intrusiva

Larentis, Andrêsa Vargas 10 January 2008 (has links)
Made available in DSpace on 2015-03-05T13:59:42Z (GMT). No. of bitstreams: 0 Previous issue date: 10 / Nenhuma / A abordagem tradicional de construção de softwares baseia-se num modelo voltado para atender um conjunto de requisitos de negócios (normalmente um modelo de objetos ou componentes), porém, precisa estar preparado para atender necessidades de negócios que podem surgir no decorrer do processo. Assim, um modelo baseado em serviços pode representar uma nova forma de tecnologia para atender estas necessidades. No cenário brasileiro e internacional, o parque de sistemas de computação legado é muito expressivo. Estes sistemas se encontram em produção utilizando tecnologias muitas vezes já ultrapassadas que permitem uma pequena taxa de reuso. Portar estes sistemas para uma tecnologia baseada em serviços, visando obter reuso em grande escala, requer uma análise criteriosa do código existente e algumas customizações para disponibilizar serviços sem comprometer seu funcionamento. Este trabalho propõe e implementa uma arquitetura denominada Aruba que permite a geração de serviços a partir de sistemas legados e o acesso a / The traditional software development is based on a model focused in answering a set of business requirements (generally an object or component model), but it needs to be prepared to deliver solutions to business needs that may occur during the process. This way, a service based model may represent a new technology approach to meet these needs. At the Brazilian and international scenario there are many legacy systems. These systems are being currently in use and often are built on old technologies that do not allow much reuse. Porting these systems to a service based technology, aiming large scale reuse, needs analysis of the existing code and some customizations to make services available without compromising its functions. This work explains an architecture called Aruba that allows service generation from legacy systems with no need of legacy code change. This solution uses the Web Services technology, which allows service description and use through WSDL and SOAP (all XML based), and uses a database as re
415

QoS management of web services. / Web服務質量管理 / Quality of service management of web services / CUHK electronic theses & dissertations collection / Web fu wu zhi liang guan li

January 2011 (has links)
In this thesis, we first propose a distributed QoS evaluation framework for Web services, named WS-DREAM. Inspired by the recent success of Web 2.0, our evaluation framework employs the concept of user-collaboration. In our framework, users in different geographic locations collaborative with each other to evaluate the target Web services and share their observed Web service QoS information. Based on our Web service evaluation framework, several large-scale distributed evaluations are conducted on 5,825 real-world Web services and the detailed evaluation results are publicly released for future research. / The predicted Web service QoS values can be employed to build fault-tolerant service-oriented systems. In the area of service computing, the cost for developing multiple redundant components is greatly reduced, since the functionally equivalent Web services are provided by different organizations and are accessible via Internet. Hence, based on the predicted QoS values, we propose two methods for building fault tolerance Web services. Firstly, we propose an adaptive fault tolerance strategy for Web services. Then, we present an optimal fault tolerance strategy selection framework for Web services. / Web service evaluation is time and resource consuming. Moreover, in some scenarios, Web service evaluation may not be possible (e.g., the Web service invocation is charged, too many service candidate, etc.). Therefore, Web service QoS prediction approaches are becoming more and more attractive. In order to prediction the Web service QoS as accurate as possible, we propose three prediction methods. The first prediction method employs the information of neighborhoods for making missing value prediction. The second method engages matrix factorization techniques to enhance the prediction accuracy. The third method predicts the ranking of the target Web services instead of QoS values. / Web service is becoming a major technique for building loosely-coupled distributed systems. Service-oriented architecture (SOA) has been widely employed in e-business, e-government, automotive systems, multimedia services, process control, finance, and a lot of other domains. Quality-of-Service (QoS) is usually employed for describing the non-functional characteristics of Web services and employed as an important differentiating point of different Web services. With the prevalence of Web services on the Internet, Web service QoS management is becoming more and more important. / Zheng, Zibin. / Adviser: Michael R. Lyu. / Source: Dissertation Abstracts International, Volume: 73-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 184-198). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
416

Disseminação de dados estatísticos georeferenciados através de WEB services e software livre. / Dissemination of statistical data GIS through WEB services and free software.

Paulo Cesar Rangel da Rocha 02 October 2009 (has links)
Diferentes organizações públicas e privadas coletam e disponibilizam uma massa de dados sobre a realidade sócio-econômica das diferentes nações. Há hoje, da parte do governo brasileiro, um interesse manifesto de divulgar uma gama diferenciada de informações para os mais diversos perfis de usuários. Persiste, contudo, uma série de limitações para uma divulgação mais massiva e democrática, entre elas, a heterogeneidade das fontes de dados, sua dispersão e formato de apresentação pouco amigável. Devido à complexidade inerente à informação geográfica envolvida, que produz incompatibilidade em vários níveis, o intercâmbio de dados em sistemas de informação geográfica não é problema trivial. Para aplicações desenvolvidas para a Web, uma solução são os Web Services que permitem que novas aplicações possam interagir com aquelas que já existem e que sistemas desenvolvidos em plataformas diferentes sejam compatíveis. Neste sentido, o objetivo do trabalho é mostrar as possibilidades de construção de portais usando software livre, a tecnologia dos Web Services e os padrões do Open Geospatial Consortium (OGC) para a disseminação de dados espaciais. Visando avaliar e testar as tecnologias selecionadas e comprovar sua efetividade foi desenvolvido um exemplo de portal de dados sócio-econômicos, compreendendo informações de um servidor local e de servidores remotos. As contribuições do trabalho são a disponibilização de mapas dinâmicos, a geração de mapas através da composição de mapas disponibilizados em servidores remotos e local e o uso do padrão OGC WMC. Analisando o protótipo de portal construído, verifica-se, contudo, que a localização e requisição de Web Services não são tarefas fáceis para um usuário típico da Internet. Nesta direção, os trabalhos futuros no domínio dos portais de informação geográfica poderiam adotar a tecnologia Representational State Transfer (REST). / Several public and private organizations collect and provide a large amount of data on the socio-economic realities of different countries. Governmental Brazilian agencies are showing today clear interest to disseminate a range of different information to several user profiles. However, many limitations to a more massive and democratic dissemination persist, including heterogeneity of data sources, data dispersion and not friendly format of presentation. Due to the inherent complexity involved in the spatial information, which produces conflict on many levels, the exchange of data in geographic information systems is not a trivial problem. For Web-based applications, Web services can be a useful solution, since they enable new applications to interact with those that already exist and also enable compatibility among systems developed in different platforms. This study aims to show the possibilities of developing thematic portals using free software, Web services technology and the Open Geospatial Consortium standards for the dissemination of spatial data. To evaluate and test the proposal, a portal that integrates data from statistical information servers was built. As example, a thematic portal of socio-economic data was developed, integrating data from a local server and data from remote servers. The main contributions of work is the availability of dynamic maps, the generation of maps by the composition of maps available at local and remote servers and use the standard OGC WMC. The portal shows however that the location and application of Web services are not an easy task for typical Internet users. In this direction, future work could adopt the technology REST (Representational State Transfer).
417

Trh web services v ČR / Web Services Market in the Czech Republic

Maleček, David January 2007 (has links)
Cílem této diplomové práce je popsat trh webových služeb v České republice a poskytnout přehled předních dodavatelů a jejich produktů. Práce je rozdělena na tři hlavní části, které jsou dále členěny do jednotlivých kapitol. První část je věnována vymezení pozice a úlohy webových služeb v rámci celého IS/ICT. Popisuji zde hlavní oblasti uplatnění této technologie. Zároveň se věnuji jejím výhodám a vlastnostem. Ve druhé části se zabývám dvěma pohledy na webové služby ? pohledem vývojáře a pohledem architekta IS. Zde také čtenáře seznamuji s jednotlivými standardy, na kterých jsou webové služby založeny (SOAP, WSDL, UDDI). Třetí část je zaměřena na přehled předních dodavatelů webových služeb a jejich produktů. Součástí je také přehled některých implementací webových služeb v ČR a softwarových firem, které tyto implementace zajišťují. Také zde popisuji úroveň podpory webových služeb v ERP systémech dostupných na současném českém trhu. Následuje zhodnocení situace na trhu webových služeb. Při psaní této práce jsem se opíral jednak o vlastní znalosti a jednak o odbornou literaturu a zdroje na Internetu.
418

Modelagem de contexto utilizando ontologias. / Context modeling using ontologies.

Edgardo Paúl Ponce Escobedo 05 May 2008 (has links)
Com os avanços dos processos da microeletrônica temos dispositivos menores e com maior poder de computação e comunicação. Um Ambiente Pervasivo contém diferentes dispositivos, tais como sensores, atuadores, eletroeletrônicos e dispositivos móveis que interagem com a pessoa de forma natural ao conhecer o contexto. A diversidade de dispositivos e informações do Ambiente Pervasivo introduz um problema de interoperabilidade. Um Ambiente Pervasivo é dinâmico devido à mobilidade do usuário, a variedade de dispositivos. Neste trabalho, é proposto um modelo semântico de contexto para permitir interoperabilidade e fornecer suporte ao dinamismo do Ambiente Pervasivo. O modelo proposto contém características da modelagem de contexto realizadas por trabalhos anteriores, assim como sua integração com a modelagem de preferências das pessoas, políticas de privacidade e serviços. Verificou-se que o modelo de contexto proposto é adequado mediante sua aplicação em um Estudo de Caso e mediante testes realizados. Mostra-se que a modelo de contexto utilizado ontologias e Serviços Web Semânticos permite tratar com informação incompleta e inconsistente, bem como fornece suporte na interoperabilidade e ao dinamismo do Ambiente Pervasivo. / Advances in microelectronic processes have allowed smaller devices with more computation and communication power. Pervasive environment contains different devices like electronic sensor, actuators and mobile devices which interact with the person naturally after the context is known. The device and information diversity introduce an interoperability problem. Pervasive environments are dynamics because of user\'s mobility and a variety of devices. In this work, we propose a context model to allow interoperability and to give support to pervasive environment dynamism. The proposed model contains features of context modeling developed in previous works, as well as, their integration with the modeling of the people\'s preferences, privacy policies and services. It was verified that the context model is appropriate by their application in a Case Study and by accomplished tests. It is shown that the model of context using ontologies and Semantic Web Services allow us to work with inconsistent and incomplete information, as well as gives support to interoperability and dynamism of the Pervasive Environment.
419

Identificação e tratamento dos problemas de desempenho de redes de sensores expostas por arquiteturas orientadas a serviço / Identification and treatment of performance problems in sensor network exposed by service oriented architectures

Thiago Caproni Tavares 11 June 2014 (has links)
Este trabalho de doutorado tem como objetivo principal mostrar que a abstração de redes de sensores, por meio de arquiteturas orientadas a serviço, pode impor alguma degradação do desempenho, mas não inviabiliza a maioria das aplicações. A metodologia utilizada na condução deste trabalho consta de experimentos que realizam avaliações de desempenho que analisam o comportamento de diferentes mecanismos de exposição de redes de sensores, bem como avalia três dos principais serviços do modelo de interfaces do Sensor Web Enablement (SWE). Os resultados obtidos mostram diferenças de desempenho significativas entre os métodos de acesso considerados. Esses resultados ainda mostram que a sobrecarga gerada não é significativa se comparada com a frequência de obtenção de observações da maioria das redes de sensores. Visando minimizar os problemas de desempenho impostos pelo framework SWE é proposta e implementada uma arquitetura de provisão de qualidade de serviço (QoS), denominada Sensor Web Architecture (SWARCH). Um estudo de caso da SWARCH demonstra que é possível reduzir os tempos de resposta no acesso aos serviços do SWE por meio de um Broker que monitora constantemente diferentes provedores de serviços / This PhD work aims to show that the abstraction of sensor networks, by means of service-oriented architectures, may impose some performance degradation, but it does not invalidate most applications. The methodology used to conduct this research consists of experiments that realize performance evaluations that analyze the behavior of different mechanisms of exposure of sensor networks, and evaluates the three major services of the Sensor Web Enablement (SWE) model interfaces. The results show significant differences in performance between the methods of considered access. The results also show that the generated overhead is not significant when compared with the frequency of obtaining observations of most wireless sensor networks. Aiming to minimize the performance issues imposed by the SWE framework, an architecture providing quality of service (QoS) called Sensor Web Architecture (SWARCH) is proposed and implemented. A case study of SWARCH demonstrates that it is possible to reduce response times when accessing the SWE services through a Broker that constantly monitors various service providers
420

Um Ambiente Virtual baseado em Nuvem para Simulação de Redes de Computadores com o NS-3

Martins, Arlison Wady Sousa 31 August 2016 (has links)
Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-05-30T18:55:47Z No. of bitstreams: 1 ArlisonMartins.pdf: 2421881 bytes, checksum: de6d96674a6a86949e4f717068dbe0e8 (MD5) / Made available in DSpace on 2017-05-30T18:55:47Z (GMT). No. of bitstreams: 1 ArlisonMartins.pdf: 2421881 bytes, checksum: de6d96674a6a86949e4f717068dbe0e8 (MD5) Previous issue date: 2016-08-31 / The breakthrough in the development of new technologies and network protocols contributed to the growth of computer networks, and consequently increased the need to use simulations to design and analyze these networks. Such simulations need to be evaluated and compared in different scenarios where there are not always available computing resources to execute them. The use of computing resources of cloud shows an interesting approach because of their intrinsic characteristics, elasticity and provisioning capabilities on demand. In this context, this work proposes an architectural model, service and network simulations repository in the Amazon cloud that uses web services technology. / O avanço no desenvolvimento de novas tecnologias e protocolos de redes contribuiu para o crescimento das redes de computadores, e consequentemente aumentou a necessidade de se utilizar simulações para projetar e analisar estas redes. Tais simulações precisam ser avaliadas e comparadas em diferentes cenários, em que nem sempre existem recursos computacionais disponíveis para executá-las. Em virtude disso, a utilização dos recursos computacionais da nuvem se mostra uma abordagem interessante devido às suas características intrínsecas, como a elasticidade e o provisionamento de recursos sob demanda. Nesse contexto, este trabalho propõe um modelo arquitetural, serviço e repositório de simulações de redes na nuvem da Amazon que utiliza a tecnologia de serviços web.

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