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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.
1

The provision of a Generic Application (GApp) Layer for the Parley/OSA architecture

Oni, Opeyemi 10 December 2008 (has links)
The OSA/Parlay architecture supports the development of applications that control network connections through an open API. This research presents a proposal on improving the rate at which applications are developed and deployed using the Parlay/OSA architecture. The work seeks to facilitate software reuse by providing logical groupings in the application layer of the Parlay/OSA architecture. This research presents a new layer to provide a higher level of abstraction for application developer using Parlay to provide telecommunication services. The layer introduced is referred to as the Generic Application Programming (GApp) interface. This document details the design and implementation of this interface.
2

Performance Analysis of Service in Heterogeneous Operational Environments

Tipirisetty, Venkat Sivendra January 2016 (has links)
In recent years there is a rapid increase in demand for cloud services, as cloud computing has become a flexible platform for hosting microservices over the Internet. Microservices are the core elements of service oriented architecture (SOA) that facilitate the deployment of distributed software systems. As the user requires good quality of service the response time of microservices is critical in assessing the performance of the application from the end user perspective.This thesis work aims at developing a typical service architecture to facilitate the deployment of compute and I/O intensive services. The work also aims at evaluating the service times of these service when their respective subservices are deployed in heterogeneous environments with various loads.The research work has been carried out using an experimental testbed in order to evaluate the performance. The transport level performance metric called Response time is measured. It is the time taken by the server to serve the request sent by the client. Experiments have been conducted based on the objectives that are to be achieved.The results obtained from the experimentation contain the average service times of a service when it is deployed on both virtual and non-virtual environment. The virtual environment is provided by Docker containers. They also include the variation in position of their subservices. From results it can be concluded that the total service times obtained are less in case of non-virtual environments when compared to container environment.
3

Architecture des services de communication dans un contexte de convergence / Towards a converged environment for communication services

Bertin, Emmanuel 11 December 2009 (has links)
Les services de communication de nouvelle génération doivent pouvoir coopérer pour répondre à des besoins spécifiques tout en gardant leur autonomie. Ceci nécessite de maîtriser leurs architectures et de partager ces architectures au sein de l'entreprise. Des cadres architecturaux communs sont alors indispensables. Après avoir fait le point des travaux sur ce sujet dans les domaines télécoms, web et IT, et après avoir discuté des enjeux de la convergence des services télécoms, nous introduisons ici quatre angles de vue (métier, fonctionnel, technique et applicatif), ainsi qu'une méthodologie pour construire des vues de référence partagées au sein d'une entreprise et des vues d'architecture propres à chaque service. Nous illustrons cette démarche à l'aide d'exemples et montrons ses applications pour construire des offres de service, pour rationnaliser les services existants et pour réaliser une convergence entre différents services. / Next-generation communication services should be able to cooperate in order to meet specific needs, while keeping their autonomy. This implies to master their architectures and to share these architectures within the enterprise. Architectural frameworks are therefore essential. After a review of the state of the art in the telecom, web and IT fields, and after having discussed the stakes of the telecom service convergence, we introduce here four viewpoints (business, functional, technical and applicative), as well as a methodology to build reference views that will be shared across the enterprise, and architectural views that are dedicated to each service. We illustrate this approach through case studies and we point out its applications to build service offers, to rationalize existing services and to realize a convergence between various services.
4

A Mobile Agent Based Service Architecture for Internet Telephony

Glitho, Roch H. January 2002 (has links)
Internet Telephony defined as real time voice or multimediacommunications over packet switched networks dates back to theearly days of the Internet. ARPA's Network SecureCommunications project had implemented, as early as December1973, an infrastructure for local and transnet real time voicecommunication. Two main sets of standards have emerged: H. 323from the ITU-T and the session initiation protocol (SIP) fromthe Internet Engineering Task Force (IETF). Both includespecifications for value added services. Value added services,or more simply services, are critical to service providers'survival and success. Unfortunately, the service architecturesthat come with the ITU-T and the IETF sets of standards arerather weak. Although they are constantly evolving,alternatives and complements need to be researched. This thesiswhich is made up of a formal dissertation and 6 appendices,proposes a novel mobile agent based service architecture forInternet Telephony. The architecture addresses the issues noneof the existing architectures solves in a satisfactory manner.Furthermore it adds mobile agents to the panoply of servicecreation tools. The appendices are reprints of articlespublished in refereed magazines/journals or under considerationfor publication. The formal dissertation is a summary of thepublications. A consistent and comprehensive set ofrequirements are derived. They are TINA-C flavored, but adaptedto Internet Telephony. They are used to critically reviewrelated work and also used to motivate the use of mobile agentsas the pillars of a novel architecture. The components of thisnovel architecture are identified. The key component is themobile service agent. It acts as a folder and carriesservice(s) to which the end-user has subscribed. Mobile serviceagents need to be upgraded when new versions of service logicare available and when end-users make changes to service data.This thesis proposes a novel upgrading framework. The currentInternet infrastructure comprises a wide range of hosts. Mobileagent platforms are now available for most of thesehosts/clients including memory/processing power constrainedPDAs. Our mobile service agents need to adapt to hostvariability when roaming. A novel adaptivity framework is alsoproposed. These two frameworks are general and can be appliedto any other mobile agent which meets a basic set ofassumptions. A key advantage of a mobile agent based servicearchitecture is that it enables the developement of mobileagent based services. The thesis proposes a novel mobile agentbased multi-party session scheduler. The feasibility and theadvantages of the architecture proposed by this thesis havebeen demonstrated by a prototype on which measurements havebeen made. Future work includes the addition of a securityframework to the architecture, and refinenements to theupgrading and adaptivity frameworks. More mobile agent basedservices, especially mobile multi agent based services willalso be developed. / <p>NR 20140805</p>
5

A Mobile Agent Based Service Architecture for Internet Telephony

Glitho, Roch H. January 2002 (has links)
<p>Internet Telephony defined as real time voice or multimediacommunications over packet switched networks dates back to theearly days of the Internet. ARPA's Network SecureCommunications project had implemented, as early as December1973, an infrastructure for local and transnet real time voicecommunication. Two main sets of standards have emerged: H. 323from the ITU-T and the session initiation protocol (SIP) fromthe Internet Engineering Task Force (IETF). Both includespecifications for value added services. Value added services,or more simply services, are critical to service providers'survival and success. Unfortunately, the service architecturesthat come with the ITU-T and the IETF sets of standards arerather weak. Although they are constantly evolving,alternatives and complements need to be researched. This thesiswhich is made up of a formal dissertation and 6 appendices,proposes a novel mobile agent based service architecture forInternet Telephony. The architecture addresses the issues noneof the existing architectures solves in a satisfactory manner.Furthermore it adds mobile agents to the panoply of servicecreation tools. The appendices are reprints of articlespublished in refereed magazines/journals or under considerationfor publication. The formal dissertation is a summary of thepublications. A consistent and comprehensive set ofrequirements are derived. They are TINA-C flavored, but adaptedto Internet Telephony. They are used to critically reviewrelated work and also used to motivate the use of mobile agentsas the pillars of a novel architecture. The components of thisnovel architecture are identified. The key component is themobile service agent. It acts as a folder and carriesservice(s) to which the end-user has subscribed. Mobile serviceagents need to be upgraded when new versions of service logicare available and when end-users make changes to service data.This thesis proposes a novel upgrading framework. The currentInternet infrastructure comprises a wide range of hosts. Mobileagent platforms are now available for most of thesehosts/clients including memory/processing power constrainedPDAs. Our mobile service agents need to adapt to hostvariability when roaming. A novel adaptivity framework is alsoproposed. These two frameworks are general and can be appliedto any other mobile agent which meets a basic set ofassumptions. A key advantage of a mobile agent based servicearchitecture is that it enables the developement of mobileagent based services. The thesis proposes a novel mobile agentbased multi-party session scheduler. The feasibility and theadvantages of the architecture proposed by this thesis havebeen demonstrated by a prototype on which measurements havebeen made. Future work includes the addition of a securityframework to the architecture, and refinenements to theupgrading and adaptivity frameworks. More mobile agent basedservices, especially mobile multi agent based services willalso be developed.</p>
6

Privacy trade-offs in web-based services

Boyens, Claus 13 January 2005 (has links)
Rapide Fortschritte in der Netzwerk- und Speichertechnologie haben dazu geführt, dass Informationen über viele verschiedene Quellen wie z.B. Personal Computer oder Datenbanken verstreut sind. Weil diese Informationen oft auch sehr heterogen sind, wurde gleichzeitig die Entwicklung effektiver Softwaretechniken zur Datensammlung und -integration vorangetrieben. Diese werden beispielsweise in Online-Katalogen von Bibliotheken oder in Internetsuchmaschinen eingesetzt und ermöglichen eine breitgefächerte Suche von Informationen unterschiedlichster Art und Herkunft. In sensiblen Anwendungsgebieten kann der Einsatz solcher Techniken aber zu einer Gefährdung der Privatsphäre der Datenhalter führen. Bei der Erforschung häufig auftretender Krankheiten beispielsweise sammeln und analysieren Wissenschaftler Patientendaten, um Muster mit hohem Erkrankungspotenzial zu erkennen. Dazu werden von den Forschern möglichst präzise und vollständige Daten benötigt. Der Patient hat dagegen großes Interesse am Schutz seiner persönlichen Daten. Dieser Interessenkonflikt zwischen Datenhaltern und Nutzern tritt auch in anderen Konstellationen wie beispielsweise in Internetdiensten auf, die die Eingabe von persönlichen Finanz- und Steuerdaten erfordern. Oft kann ein qualitativ höherwertiger Dienst angeboten werden, wenn persönliche Informationen preisgegeben werden. Über die hierzu notwendige Abwägung von Datenschutz und Dienstqualität sind sich nicht alle Datenhalter im Klaren und neigen zu Extremverhalten wie der Übermittlung aller persönlicher Daten oder gar keiner. Diese Dissertation erforscht den Grenzbereich zwischen den scheinbar konträren Interessen von Datenhaltern und Dienstnutzern. Dabei werden insbesondere die technischen Möglichkeiten zur Modellierung und Beschreibung dieses Bereiches betrachtet. Die erarbeiteten Techniken sollen den beteiligten Parteien ermöglichen, den bestehenden Konflikt unter Einbeziehung ihrer Präferenzen zur beiderseitigen Zufriedenheit zu lösen. Die Beiträge dieser Dissertation sind im Einzelnen: - Eine Klassifizierung von Dienstarchitekturen im Hinblick auf Datenschutzprobleme Verschiedene Dienstarchitekturen werden nach ihrer Datenschutzproblematik klassifiziert. Für jede Kategorie werden praktische Anwendungen erläutert. - Entwurf, Analyse und Implementierung einer verschlüsselungsbasierten Dienstarchitektur in einer nicht vertrauenswürdigen 2-Parteien-Umgebung Es werden Gründe für Vertrauen von Datenhaltern in Anbieter von netzbasierten Diensten dargestellt. Für Fälle, in denen dieses Vertrauen alleine nicht ausreicht, wird eine Datenschutz garantierende Dienstarchitektur abgeleitet, die auf einem modifizierten Verschlüsselungsalgorithmus basiert. Wichtige Datenbankoperationen und arithmetische Elemente werden auf die verschlüsselten Daten übertragen und in beispielhaften Diensten zum Einsatz gebracht. - Entwurf, Analyse und Implementierung einer aggregationsbasierten Dienstarchitektur in einer nicht vertrauenswürdigen 3-Parteien-Umgebung Am Beispiel eines den Datenschutz verletzenden Gesundheitsberichts wird gezeigt, wie Methoden des Operations Research dazu eingesetzt werden können, aus veröffentlichten Statistiken enge Intervalle für vertrauliche numerische Daten abzuleiten ("Intervallinferenz"). Zur Lösung des Interessenkonflikts zwischen Datenhaltern und Dienstnutzern wird die Verwendung eines sogenannten Datenschutzmediators vorgeschlagen. Dessen Kernkomponente ist die "Audit & Aggregate" Methodologie, die das Auftreten von Intervallinferenz aufdecken und verhindern kann. - Quantifizierung der Datenschutzabwägungen und Schlussfolgerungen für den elektronischen Handel Es werden verschiedene Ansätze zur Quantifizierung der Datenschutzabwägungen betrachtet und Schlussfolgerungen für den elektronischen Handel gezogen. Zusammengefasst versucht diese Arbeit, (a) die Wahrnehmung von Datenhaltern und Dienstnutzern für den bestehenden Interessenkonflikt zu erhöhen, (b) einen Rahmen zur Modellierung der Datenschutzabwägungen bereitzustellen und (c) Methoden zu entwickeln, die den Interessenkonflikt zur beiderseitigen Zufriedenheit beilegen können. / Recent developments in networking and storage technology have led to the dissemination of information over many different sources such as personal computers or corporate and public databases. As these information sources are often distributed and heterogeneous, effective tools for data collection and integration have been developed in parallel. These tools are employed e.g. in library search catalogues or in Internet search engines to facilitate information search over a wide range of different information sources. In more sensitive application areas however, the privacy of the data holders can be compromised. In medical disease research for example, scientists collect and analyze patient data for epidemiological characterizations and for the construction of predictive models. Whereas the medical researchers need patient data at the highest level of detail, patients are only willing to provide data when their privacy is guaranteed. This conflict of interest between the data holders and the users occurs in many different settings, for example in the use of web-based services that require confidential input data such as financial or tax data. The more accurate and rich the provided private information, the higher the quality of the provided service. Not all data holders are aware of this trade-off and for lack of knowledge tend to the extremes, i.e. provide no data or provide it all. This thesis explores the borderline between the competing interests of data holders and service users. In particular, we investigate the technical opportunities to model and describe this borderline. These techniques allow the two opposing parties to express their preferences and to settle the conflict with a solution that is satisfactory to both. The specific contributions of this thesis are the following: - Privacy classification of service architectures We present a privacy classification of different service architectures after the number of involved parties and the reactivity of the data provision. For each class, we provide examples of practical applications and explain their relevance by discussing preceding cases of real-world privacy violations. - Design, analysis and implementation of an encryption-based service architecture in an untrusted two-party environment We analyze the foundations of trust in web-based services and point out cases where trust in the service provider alone is not enough e.g. for legal requirements. For these cases, we derive a new privacy-preserving architecture that is based on an adapted homomorphic encryption algorithm. We map important database and arithmetic operations from plain data to encrypted data, and we present sample services that can be carried out within the framework. - Design, analysis and implementation of an aggregation-based service architecture in an untrusted three-party environment Using a privacy-compromising health report as a running example through the thesis, we show how mathematical programming can be used to derive tight intervals for confidential data fields from non-critical aggregated data. We propose a new class of privacy mediators that settle the conflict between data holders and service users. A core component is the "audit & aggregate" methodology that detects and limits this kind of disclosure called interval inference. - Quantification of the privacy trade-off and implications for electronic commerce and public policy We analyze several frameworks to quantify the trade-off between data holders and service users. We also discuss the implications of this trade-off for electronic commerce and public policy. To summarize, this thesis aims to (a) increase data holders'' and service users'' awareness of the privacy conflict, (b) to provide a framework to model the trade-off and (c) to develop methods that can settle the conflict to both parties'' satisfaction.
7

Ferramenta para mapear a qualidade percebida pelo usuário em requisitos de QoS em ambiente convergente e heterogêneo. / User perceived quality into convergent and heterogeneous environment QoS requirements mapping tool.

Vieira, Gabriel Mauricio Oswald 02 December 2010 (has links)
Uma das principais características dos sistemas de informação e de comunicação é permitir que os usuários finais utilizem e disponibilizem serviços interativos com conteúdo multimídia a qualquer hora, em qualquer lugar, com qualquer dispositivo e em movimento, independentemente da tecnologia de rede utilizada. Um desafio que surge face a essa nova característica dos serviços é como identificar os requisitos de QoS (Qualidade de Serviço) fim-a-fim sob a ótica do usuário final em um ambiente convergente e heterogêneo com o intuito de evoluir as relações entre o usuário final e o Provedor de Serviços para o estabelecimento de um contrato com níveis de serviço personalizado. Este trabalho apresenta uma pesquisa para a elaboração de uma ferramenta genérica e aberta para mapear a qualidade percebida pelo usuário em requisitos técnicos de QoS através da captura do fluxo de pacotes gerado entre as aplicações que compõem um serviço e simula atrasos, jitter, perdas e banda percebida com o objetivo de permitir ao usuário final identificar e expressar os valores desses parâmetros tornando transparente os aspectos tecnológicos que envolvem esta identificação. A definição de um ambiente de simulação que hospeda o serviço, o desenvolvimento de um simulador de QoS específico e uma nova relação entre o usuário e o Provedor de Serviços também são abordados. / One of the main characteristics of communication and information systems is to allow final users to use and make available multimedia content interactive services at any time, anywhere, in motion and using any device regardless of network technology. Under this perspective a challenge arises on how to identify the QoS (Quality of Service) requirements in a convergent and heterogeneous environment end-to-end user centric way, in order to evolve the relationship between users and service providers aiming the establishment of personalized demands through personalized agreements. This work presents a study for the development of an open and generic tool for mapping the user perceived quality in QoS requirements through the capture of the packet flow generated between the applications of a service and simulates delays, jitter, loss of packets and bandwidth in order to allow the end user to identify and express the values of these parameters making transparent all the technological aspects involved in this identification. The definition of a service simulation environment, the development of a QoS simulator and a new relationship between users and services providers are also addressed.
8

Ferramenta para mapear a qualidade percebida pelo usuário em requisitos de QoS em ambiente convergente e heterogêneo. / User perceived quality into convergent and heterogeneous environment QoS requirements mapping tool.

Gabriel Mauricio Oswald Vieira 02 December 2010 (has links)
Uma das principais características dos sistemas de informação e de comunicação é permitir que os usuários finais utilizem e disponibilizem serviços interativos com conteúdo multimídia a qualquer hora, em qualquer lugar, com qualquer dispositivo e em movimento, independentemente da tecnologia de rede utilizada. Um desafio que surge face a essa nova característica dos serviços é como identificar os requisitos de QoS (Qualidade de Serviço) fim-a-fim sob a ótica do usuário final em um ambiente convergente e heterogêneo com o intuito de evoluir as relações entre o usuário final e o Provedor de Serviços para o estabelecimento de um contrato com níveis de serviço personalizado. Este trabalho apresenta uma pesquisa para a elaboração de uma ferramenta genérica e aberta para mapear a qualidade percebida pelo usuário em requisitos técnicos de QoS através da captura do fluxo de pacotes gerado entre as aplicações que compõem um serviço e simula atrasos, jitter, perdas e banda percebida com o objetivo de permitir ao usuário final identificar e expressar os valores desses parâmetros tornando transparente os aspectos tecnológicos que envolvem esta identificação. A definição de um ambiente de simulação que hospeda o serviço, o desenvolvimento de um simulador de QoS específico e uma nova relação entre o usuário e o Provedor de Serviços também são abordados. / One of the main characteristics of communication and information systems is to allow final users to use and make available multimedia content interactive services at any time, anywhere, in motion and using any device regardless of network technology. Under this perspective a challenge arises on how to identify the QoS (Quality of Service) requirements in a convergent and heterogeneous environment end-to-end user centric way, in order to evolve the relationship between users and service providers aiming the establishment of personalized demands through personalized agreements. This work presents a study for the development of an open and generic tool for mapping the user perceived quality in QoS requirements through the capture of the packet flow generated between the applications of a service and simulates delays, jitter, loss of packets and bandwidth in order to allow the end user to identify and express the values of these parameters making transparent all the technological aspects involved in this identification. The definition of a service simulation environment, the development of a QoS simulator and a new relationship between users and services providers are also addressed.

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