Dissertations / Theses: 'Autonomic network management'

1

Bashar, Abul. "On the application of Bayesian networks for autonomic network management." Thesis, Ulster University, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.646023.

Full text

Abstract:

The quest for achieving an efficient, reliable and cost-effective network infrastructure in support of innovative and rich communication services has resulted in the advent and popularity of IP based converged Next Generation Networks (NGN). According to the ITU-T, the NGN has significant advantages such as support for end to end Quality of Service (QoS), generalised mobility, converged services between fixed & mobile networks and interworking with legacy networks. These networks require Network Management Systems (NMS), which play a key role in monitoring and administering them, to ensure smooth running of services and optimum utilisation of network resources. However, it has been observed that a disparity exists in the pace of development of the NGN and the existing NMSs. This thesis takes up the challenge of addressing this disparity by providing autonomic, intelligent and scalable NM solutions with focus on QoS Management, Distributed Monitoring & Control and Traffic Engineering. Traditional methods of network management do have shortcomings in providing the level of dependability and reliability which is required in the current NGN environment. Machine Learning (ML) approaches have gained popularity as the foundation of intelligent and automated systems, since they are capable of modelling the system behaviour through the process of learning, based on the observation of the system over a period of time. Once appropriately trained they can automatically estimate and predict future system behaviour with high accuracy and speed. Hence, the overall objective of this research is design, development and evaluation of ML based network management mechanisms for Admission Control , Distributed Monitoring & Control and Intelligent Traffic Engineering. In the pursuit of fulfilling the stated objective, the Bayesian Networks (BN) approach emerged as a viable and efficient solution to the identified specific problems.

APA, Harvard, Vancouver, ISO, and other styles

2

Varsha, Jain. "Enabling energy efficiency of the network management function using autonomic network element Intelligence." Thesis, Ulster University, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.667763.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Ljungdahl, Emil, and Erik Andersson. "Design of an autonomic system for IP-network environments." Thesis, Karlstad University, Faculty of Economic Sciences, Communication and IT, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-3331.

Full text

Abstract:

A2B Electronics AB is a company that develops and manufactures products and technology for digital cable television. A2B's new EXM-product family translates digital television channels from multiple source networks into a single destination network. Multiple EXM-units are connected in a system to provide a custom set of TV channels. To minimize the administrative effort, the units in a system should be able to interact and collaborate without manual intervention. The purpose of this thesis is to propose an underlying system that supports seamless interaction and collaboration between units.The autonomic system concept has served as a foundation for the proposed solution. The requirements for the EXM-system proved to be similar to many properties of an autonomic system. The proposed solution was elaborated by answering five reseach questions. The answers describe how an autonomic system can be implemented with the prerequisites of the EXM-system. Solutions for service availability, configuration preservation, system state changes and automatic addressing and communication are provided.The project has resulted in a proposal of a general autonomic system. The solution has also been implemented as prototype that runs both in a simulator and on the EXM-hardware. The simulator was also developed in the scope of this project as a side-effect of the limited access to EXM-hardware.The proposed solution together with the prototype can hopefully serve as a base for projects with prerequisites similar to the project described in this thesis.

APA, Harvard, Vancouver, ISO, and other styles

4

Luoto, M. (Markus). "Managing control information in autonomic wireless networking." Doctoral thesis, Oulun yliopisto, 2017. http://urn.fi/urn:isbn:9789526216454.

Full text

Abstract:

Abstract As mobile Internet access traffic continues to grow at an explosive rate and wireless networks continue to diverge into multiple access technologies with partly overlapping sets of features, new solutions for efficient use of these networks are vital. Cognitive network management provides tools to tackle this challenge by automatically learning from past experience the characteristics and usage patterns of the connected devices, thus enabling autonomic optimization of those connections. Cognitive network management requires a vast amount of information in order to function effectively, making collaboration of the networked devices essential as the best sources of information are scattered throughout the network. This makes efficient information dissemination one of the key enablers for autonomic networking. This dissertation studies managing control information related to autonomic selection of access networks and adapting services in a heterogeneous wireless network environment. It presents a solution to simple and efficient information dissemination in the form of Distributed Decision Engine— a CEP-like system enabling the building of a highly scalable and dynamic messaging system enabling dissemination, analysis and control of the complex series of interrelated events in the network. The dissertation also presents results showing a clear benefit in using cross-layer and cross-domain information in a modern wireless environment and validates the final prototype implementation of DDE with laboratory measurements. Effective use of disseminated cross-layer information is another key element in autonomic wireless networking. This dissertation also focuses on intelligent decision-making based on cross-layer information by presenting test results which attest that the performance of an autonomic wireless networking system can be improved by using cognitive techniques in its management algorithms, and that hierarchy and coordination can be utilized to minimize the effect of conflicting decisions of the system Tiivistelmä Mobiilin Internet-liikenteen räjähdysmäinen kasvu ja langattomien verkkojen jatkuva jakautuminen useisiin tekniikoihin vaativat uusia ratkaisuja näiden verkkojen tehokkaaseen käyttöön. Kognitiivinen verkon hallinta mahdollistaa oppimisen, minkä avulla laitteiden yhteyksiä voidaan optimoida autonomisesti aiemman kokemuksen perusteella. Tällainen optimointi vaatii kuitenkin valtavan määrän verkosta ja laitteista kerättyä tietoa, mikä tekee tehokkaasta tiedonjakelusta keskeisen elementin autonomisessa verkon hallinnassa. Tässä väitöskirjassa tutkitaan verkon valintaan ja palveluiden sopeuttamiseen vaadittavan tiedon välittämistä ja hallintaa autonomisissa langattomissa verkoissa. Ratkaisuna yksinkertaiseen ja tehokkaaseen tiedonvälitykseen esitellään hajautettu Distributed Decision Engine -komponentti, joka mahdollistaa skaalautuvan tiedon jakelu-, analysointi- ja hallintajärjestelmän rakentamisen. Lisäksi väitöskirjassa kuvataan myös tuloksia, jotka osoittavat, että verkkokerrosten välisen tiedon käyttämisellä voidaan saavuttaa selvää etua, sekä tuloksia, jotka vahvistavat DDE-prototyyppitoteutuksen toimivuuden laboratoriomittauksin. Verkkokerrosten välisen tiedon tehokas hyödyntäminen on toinen keskeinen tekijä autonomisessa langattomien verkkojen hallinnassa. Väitöskirjassa käsitellään myös älykästä päätöksentekoa kyseisen informaation pohjalta sekä esitellään tuloksia, jotka osoittavat, että päätöksentekoa autonomisessa langattomien verkkojen hallinnassa voidaan parantaa kognitiivisilla tekniikoilla. Lisäksi esitetyt tulokset osoittavat, että hierarkialla sekä koordinoinnilla voidaan minimoida ristiriitaisten päätösten vaikutukset järjestelmään

APA, Harvard, Vancouver, ISO, and other styles

5

Barrère, Cambrún Martín. "Vulnerability management for safe configurations in autonomic networks and systems." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0048/document.

Full text

Abstract:

Le déploiement d'équipements informatiques à large échelle, sur les multiples infrastructures interconnectées de l'Internet, a eu un impact considérable sur la complexité de la tâche de gestion. L'informatique autonome permet de faire face à cet enjeu en spécifiant des objectifs de haut niveau et en déléguant les activités de gestion aux réseaux et systèmes eux-mêmes. Cependant, lorsque des changements sont opérés par les administrateurs ou par les équipements autonomes, des configurations vulnérables peuvent être involontairement introduites. Ces vulnérabilités offrent un point d'entrée pour des attaques de sécurité. À cet égard, les mécanismes de gestion des vulnérabilités sont essentiels pour assurer une configuration sûre de ces environnements. Cette thèse porte sur la conception et le développement de nouvelles méthodes et techniques pour la gestion des vulnérabilités dans les réseaux et systèmes autonomes, afin de leur permettre de détecter et de corriger leurs propres expositions aux failles de sécurité. Nous présenterons tout d'abord un état de l'art sur l'informatique autonome et la gestion de vulnérabilités. Nous décrirons ensuite notre approche d'intégration du processus de gestion des vulnérabilités dans ces environnements, et en détaillerons les différentes facettes, notamment : extension de l'approche dans le cas de vulnérabilités distribuées, prise en compte du facteur temps en considérant une historisation des paramètres de configuration, et application en environnements contraints en utilisant des techniques probabilistes. Nous présenterons également les prototypes et les résultats expérimentaux qui ont permis d'évaluer ces différentes contributions Over the last years, the massive deployment of computing devices over disparate interconnected infrastructures has dramatically increased the complexity of network management. Autonomic computing has emerged as a novel paradigm to cope with this challenging reality. By specifying high-level objectives, autonomic computing aims at delegating management activities to the networks themselves. However, when changes are performed by administrators and self-governed entities, vulnerable configurations may be unknowingly introduced. Nowadays, vulnerabilities constitute the main entry point for security attacks. Therefore, vulnerability management mechanisms are vital to ensure safe configurations, and with them, the survivability of any autonomic environment. This thesis targets the design and development of novel autonomous mechanisms for dealing with vulnerabilities, in order to increase the security of autonomic networks and systems. We first present a comprehensive state of the art in autonomic computing and vulnerability management. Afterwards, we present our contributions which include autonomic assessment strategies for device-based vulnerabilities and extensions in several dimensions, namely, distributed vulnerabilities (spatial), past hidden vulnerable states (temporal), and mobile security assessment (technological). In addition, we present vulnerability remediation approaches able to autonomously bring networks and systems into secure states. The scientific approaches presented in this thesis have been largely validated by an extensive set of experiments which are also discussed in this manuscript

APA, Harvard, Vancouver, ISO, and other styles

6

Guardalben, Lucas. "Communication between nodes for autonomic and distributed management." Doctoral thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/12877.

Full text

Abstract:

Doutoramento conjunto MAPi em Informática Over the last decade, the most widespread approaches for traditional management were based on the Simple Network Management Protocol (SNMP) or Common Management Information Protocol (CMIP). However, they both have several problems in terms of scalability, due to their centralization characteristics. Although the distributed management approaches exhibit better performance in terms of scalability, they still underperform regarding communication costs, autonomy, extensibility, exibility, robustness, and cooperation between network nodes. The cooperation between network nodes normally requires excessive overheads for synchronization and dissemination of management information in the network. For emerging dynamic and large-scale networking environments, as envisioned in Next Generation Networks (NGNs), exponential growth in the number of network devices and mobile communications and application demands is expected. Thus, a high degree of management automation is an important requirement, along with new mechanisms that promote it optimally and e ciently, taking into account the need for high cooperation between the nodes. Current approaches for self and autonomic management allow the network administrator to manage large areas, performing fast reaction and e ciently facing unexpected problems. The management functionalities should be delegated to a self-organized plane operating within the network, that decrease the network complexity and the control information ow, as opposed to centralized or external servers. This Thesis aims to propose and develop a communication framework for distributed network management which integrates a set of mechanisms for initial communication, exchange of management information, network (re) organization and data dissemination, attempting to meet the autonomic and distributed management requirements posed by NGNs. The mechanisms are lightweight and portable, and they can operate in di erent hardware architectures and include all the requirements to maintain the basis for an e cient communication between nodes in order to ensure autonomic network management. Moreover, those mechanisms were explored in diverse network conditions and events, such as device and link errors, di erent tra c/network loads and requirements. The results obtained through simulation and real experimentation show that the proposed mechanisms provide a lower convergence time, smaller overhead impact in the network, faster dissemination of management information, increase stability and quality of the nodes associations, and enable the support for e cient data information delivery in comparison to the base mechanisms analyzed. Finally, all mechanisms for communication between nodes proposed in this Thesis, that support and distribute the management information and network control functionalities, were devised and developed to operate in completely decentralized scenarios. Durante a última década, protocolos como Simple Network Management Protocol (SNMP) ou Common Management Information Protocol (CMIP) foram as abordagens mais comuns para a gestão tradicional de redes. Essas abordagens têm vários problemas em termos de escalabilidade, devido às suas características de centralização. Apresentando um melhor desempenho em termos de escalabilidade, as abordagens de gestão distribuída, por sua vez, são vantajosas nesse sentido, mas também apresentam uma série de desvantagens acerca do custo elevado de comunicação, autonomia, extensibilidade, exibilidade, robustez e cooperação entre os nós da rede. A cooperação entre os nós presentes na rede é normalmente a principal causa de sobrecarga na rede, uma vez que necessita de colectar, sincronizar e disseminar as informações de gestão para todos os nós nela presentes. Em ambientes dinâmicos, como é o caso das redes atuais e futuras, espera-se um crescimento exponencial no número de dispositivos, associado a um grau elevado de mobilidade dos mesmos na rede. Assim, o grau elevado de funções de automatiza ção da gestão da rede é uma exigência primordial, bem como o desenvolvimento de novos mecanismos e técnicas que permitam essa comunicação de forma optimizada e e ciente. Tendo em conta a necessidade de elevada cooperação entre os elementos da rede, as abordagens atuais para a gestão autonómica permitem que o administrador possa gerir grandes áreas de forma rápida e e ciente frente a problemas inesperados, visando diminuir a complexidade da rede e o uxo de informações de controlo nela gerados. Nas gestões autonómicas a delegação de operações da rede é suportada por um plano auto-organizado e não dependente de servidores centralizados ou externos. Com base nos tipos de gestão e desa os acima apresentados, esta Tese tem como principal objetivo propor e desenvolver um conjunto de mecanismos necessários para a criação de uma infra-estrutura de comunicação entre nós, na tentativa de satisfazer as exigências da gestão auton ómica e distribuída apresentadas pelas redes de futura geração. Nesse sentido, mecanismos especí cos incluindo inicialização e descoberta dos elementos da rede, troca de informação de gestão, (re) organização da rede e disseminação de dados foram elaborados e explorados em diversas condições e eventos, tais como: falhas de ligação, diferentes cargas de tráfego e exigências de rede. Para além disso, os mecanismos desenvolvidos são leves e portáveis, ou seja, podem operar em diferentes arquitecturas de hardware e contemplam todos os requisitos necessários para manter a base de comunicação e ciente entre os elementos da rede. Os resultados obtidos através de simulações e experiências reais comprovam que os mecanismos propostos apresentam um tempo de convergência menor para descoberta e troca de informação, um menor impacto na sobrecarga da rede, disseminação mais rápida da informação de gestão, aumento da estabilidade e a qualidade das ligações entre os nós e entrega e ciente de informações de dados em comparação com os mecanismos base analisados. Finalmente, todos os mecanismos desenvolvidos que fazem parte da infrastrutura de comunicação proposta foram concebidos e desenvolvidos para operar em cenários completamente descentralizados.

APA, Harvard, Vancouver, ISO, and other styles

7

Franco, Theo Ferreira. "Uma arquitetura baseada em políticas para o provimento de QoS utilizando princípios de Autonomic Computing." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2008. http://hdl.handle.net/10183/14781.

Full text

Abstract:

Sistemas corporativos modernos cada vez mais dependentes da rede e a integração de serviços entorno do modelo TCP/IP elevam a exigência de Qualidade de Serviço da infraestrutura de TI. Neste cenário, o dinamismo das redes atuais em conjunto com os novos requisitos de QoS exigem que a infra-estrutura de TI seja mais autônoma e confiável. Para tratar esta questão, o modelo de Gerenciamento de Redes Baseado em Políticas, proposto pelo IETF, vem se consolidando como uma abordagem para controlar o comportamento da rede através do controle das configurações dos seus dispositivos. Porém, o foco deste modelo é o gerenciamento de políticas internas a um domínio administrativo. Esta característica faz com que o modelo possua algumas limitações, tais como a incapacidade de estabelecer qualquer tipo de coordenação entre diferentes PDPs e a impossibilidade de reagir a eventos externos. Visando agregar autonomia ao modelo de gerenciamento baseado em políticas, este trabalho propõe uma arquitetura em camadas que empregue os conceitos de Autonomic Computing relacionados a: i) adaptação dinâmica dos recursos gerenciados em resposta às mudanças no ambiente, ii) integração com sistemas de gerenciamento de outros domínios através do recebimento de notificações destes, iii) capacidade de planejar ações de gerenciamento e iv) promoção de ações de gerenciamento que envolvam mais de um domínio administrativo, estabelecendo uma espécie de coordenação entre PDPs. Para a implementação destes conceitos, a arquitetura prevê o uso de uma camada peerto- peer (P2P) sobre a plataforma de políticas. Desta forma, a partir de uma notificação recebida, a camada P2P planeja ações visando adaptar o comportamento da rede aos eventos ocorridos na infra-estrutura de TI. As ações planejadas traduzem-se em inclusões ou remoções de políticas da plataforma de políticas responsável por gerenciar a configuração dos dispositivos de rede. Para notificações que envolvam recursos de mais de um domínio administrativo, os peers de gerenciamento agem de forma coordenada para implantar as devidas ações em cada domínio. A arquitetura proposta foi projetada com foco em prover QoS em uma rede com suporte à DiffServ, embora acredite-se que a sua estrutura seja genérica o bastante para ser aplicada a outros contextos. Como estudo de caso, foi analisado o emprego da arquitetura em resposta a eventos gerados por uma grade computacional. Foi elaborado ainda um protótipo da arquitetura utilizando o Globus Toolkit 4 como fonte de eventos. Modern corporative systems becoming more dependent of the network and the integration of services around the TCP/IP model increase the requirement of Quality of Service (QoS) of the IT infrastructure. In this scene, the dynamism of current networks together with the new requirements of QoS demands a more autonomous and reliable IT infrastructure. To address this issue, the model of Police Based Network Management, proposed by IETF, has been consolidated as an approach to control the behavior of the network through the control of the configurations of its devices. However, the focus of this model is the management of the policies internal to an administrative domain. This feature brings some limitations to the model, such as the incapacity to establish any kind of coordination between different PDPs and the impossibility to react to external events. Aiming at to add autonomy to the model of Policy Based Network Management, this work proposes a layered architecture based on the concepts of Autonomic Computing related to: i) the dynamic adaptation of the managed resources in response to changes in the environment, ii) integration with management systems of other domains through the reception of notifications of these systems, iii) ability of planning the management actions and iv) execution of multi-domain management actions, establishing a kind of coordination between PDPs. To implement these concepts, the architecture was designed with a peer-to-peer layer above the policy platform. Thus, from a received notification, the P2P layer plans actions aiming to adapt the network behavior in response to the events occurred in the IT infrastructure. The planned actions are, actually, inclusions or removals of policies in the policy platform responsible for the management of the network devices configuration. For notifications related with resources of more than one administrative domain, the management peers act in a coordinated way in order to establish the suitable actions in each domain. The proposed architecture was designed with focus in providing QoS in a network with support to DiffServ, although we believe that its structure is generic enough to be applied to other contexts. As case study, it was analyzed the use of the architecture in response to events generated by a computational grid. Additionally, a prototype of the architecture was build making use of Globus Toolkit 4 as an event source.

APA, Harvard, Vancouver, ISO, and other styles

8

Elkotob, Muslim. "Efficient and systematic network resource management." Doctoral thesis, Luleå tekniska universitet, Datavetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-17190.

Full text

Abstract:

The demand for network resources (e.g. forwarding capacity, buffer space) by increasingly used real-time multimedia applications is growing. Moreover, their stringent performance requirements (e.g. delay and jitter bounds) pose challenges on network resource management (RM). RM determines how available resources are modeled and distributed to achieve a performance goal such as assuring forwarding quality to real-time multimedia applications. Improvements to existing RM mechanisms can avoid performance limitations of networks by facilitating more efficient use of scarce resources. For example, in a vehicular to infrastructure (V2I) communication scenario that uses IP Multimedia Subsystem (IMS) lacking RM support for multicast, the 3G downlink quickly becomes a bottleneck although some information is addressed to multiple receivers. The main goal of this thesis is to develop RM algorithms and protocols that improve forwarding capacity utilization and remove performance bottlenecks. An additional goal is to improve the scalability of existing RM mechanisms. Three architectural paradigms are covered to demonstrate the advantages of efficient and systematic network RM: open access networks (OAN), next generation networks (NGN), and heterogeneous access networks (HAN). For OAN, a cross-layer signaling technique called parameter injection was developed. It reduces the signaling overhead and update time for real-time multimedia sessions over Wi-Fi while autonomously selecting the format and CODEC that best match the current resource settings. Within NGN, a resource management protocol is proposed for extending unicast signaling in IMS with multicast capabilities. The contribution uses adaptive and dynamic group size selection to improve resource utilization on the 3G downlink for the signaling and data planes. For HAN, an algorithm is proposed that predicts the best access network for achieving the highest QoE of a real-time multimedia session with the available QoS resources based on regression and statistical learning. In all three paradigms, the provided core contributions serve the common goal of achieving a performance edge in terms of efficiency and systematic operation with a limited amount of network resources. Godkänd; 2011; 20110207 (ysko); DISPUTATION Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Muslim Elkotob Ämnesområde: Mobila system/Mobile Systems Avhandling: Efficient and Systematic Network Resource Management Opponent: Professor Anna Brunström, Institutionen för datavetenskap, Karlstads universitet Ordförande: Docent Christer Åhlund, Institutionen för system- och rymdteknik, Luleå tekniska universitet Tid: Fredag den 18 mars 2011, kl 10.00 Plats: A1514, Luleå tekniska universitet

APA, Harvard, Vancouver, ISO, and other styles

9

Nobre, Jéferson Campos. "Decentralized detection of violations f service level agreements using peer-to-peer technology." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/147771.

Full text

Abstract:

Critical networked services established between service provider and customers are expected to operate respecting Service Level Agreements (SLAs). An interesting possibility to monitor such SLAs is using active measurement mechanisms. However, these mechanisms are expensive in terms of network devices resource consumption and also increase the network load because of the injected traffic. In addition, if the number of SLA violations in a given time is higher than the number of available measurement sessions (common place in large and complex network infrastructures), certainly some violations will be missed. The current best practice, the observation of just a subset of network destinations driven by human administrators expertise, is error prone, does not scale well, and is ineffective on dynamic network conditions. This practice can lead to SLA violations being missed, which invariably affect the performance of several applications. In the present thesis, we advocated the use of Peer-to-Peer (P2P) technology to improve the detection of SLA violations. Such use is described using principles to control active measurement mechanisms. These principles are accomplished through strategies to activate measurement sessions. In this context, the major contributions of this thesis are: i) An approach to improve the detection of SLA violations through the steering of the activation of active measurement sessions using local and remote past service level measurement results and resource utilization constraints; ii) The concept of destination rank as an approach to autonomically prioritize destinations for the activation of active measurement sessions using destination scores; iii) The concept of correlated peers to enable the autonomic provisioning of a P2P measurement overlay for the exchange of relevant active measurement results; iv) The concept of virtual measurement sessions to enable the sharing of measurement results among correlated peers in order to save network devices resources and to improve SLA monitoring coverage; v) The definition of decentralized strategies to steer the activation of active measurement sessions using P2P principles. The method used on the investigation started with the execution of literature reviews on the networkwide control of measurement mechanisms and the employment of P2P technology on network management. After that, the proposed principles to control active measurement mechanisms and the strategies to activate measurement sessions were described. Finally, experiments were performed to evaluate the performance as well as to highlight properties of such principles and strategies. The findings showed properties which improve the detection of SLA violations in terms of the number of detected violations and the adaptivity to network dynamics. We expect that such findings can lead to better SLA monitoring tools and methods.

APA, Harvard, Vancouver, ISO, and other styles

10

Duarte, Pedro Arthur Pinheiro Rosa. "Um serviço de self-healing baseado em P2P para manutenção de redes de computadores." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/122507.

Full text

Abstract:

Observou-se nos últimos anos um grande aumetno na complexidade das redes. Surgiram também novos desa os para gerenciamento dessas redes. A dimensão atual e as tendências de crescimento das infraestruturas tem inviabilizado as técnicas de gerencimento de redes atuais, baseadas na intervenção humana. Por exemplo, a heterogeneidade dos elementos gerenciados obrigam que administradores e gerentes lidem com especi cidades de implanta ção que vão além dos objetivos gerenciais. Considerando as áreas funcionais da gerência de redes, a gerência de falhas apresenta impactos operacionais interessantes. Estima-se que 33% dos custos operacionais estão relacionados com a prevenção e recuperação de falhas e que aproximadamente 44% desse custo visa à resolução de problemas causados por erros humanos. Dentre as abordagens de gerência de falhas, o Self-Healing objetiva minimizar as interações humanas nas rotinas de gerenciamento de falhas, diminuindo dessa forma erros e demandas operacionais. Algumas propostas sugerem que o Self-Healing seja planejado no momento do projeto das aplicações. Tais propostas são inviáveis de aplicação em sistemas legados. Otras pesquisas sugerem à análise e instrumentação das aplicações em tempo de execução. Embora aplicáveis a sistemas legados, análise e instrumentação em tempo de execução estão fortemente acopladas as tecnologias e detalhes de implementação das aplicações. Por esse motivo, é difícil aplicar tais propostas, por exemplo, em um ambiente de rede que abrange muitas entidades gerenciadas implantadas através de diferentes tecnologias. Porém, parece plausível oferecer aos adminitradores e gerentes facilidades através das quais eles possam expressar seus conhecimentos sobre anoamlias e falhas de aplicações, bem como mecanismos através dos quais esses conhecimentos possam ser utilizado no gerenciamento de sistemas. Essa dissertação de mestrado tem como objetivo apresentar e avaliar uma solução comum que introduza nas redes capacidades de self-healing. A solu- ção apresentada utiliza-se de workplans para capturar o conhecimento dos administradores em como diagnosticar e recuperar anomalias e falhas em redes. Além disso, o projeto e implementação de um framework padrão para detecção e noti cação de falhas é discutido no âmbito de um sistema de gerenciamento baseado em P2P. Por último, uma avaliação experimental clari ca a viabilidade do ponto de vista operacional. In recent years, a huge raise in networks' complexity was witnessed. Along the raise in complexity, many management challenges also arose. For instance, managed entities' heterogeneity demands administrators and managers to deal with cumbersome implementation and deployment speci cities. Moreover, infrastructures' current size and growth-trends show that it is becoming infeasible to rely on human-in-the-loop management techniques. Inside the problem domain of network management, Fault Management is appealing because of its impact in operational costs. Researches estimate that more than 33% of operational costs are related to preventing and recovering faults, where about 40% of this investment is directed to solve human-caused operational errors. Hence, addressing human interaction is mostly unarguably a need. Among di erent approaches, Self-Healing, a property of Autonomic Network Management's proposal, targets to avoid humans' interactions and decisions on Fault Management loops, thereupon unburden administrators and managers from performing Fault Management-related tasks. Some researches on Self-Healing enabling approaches suppose that Fault Management capabilities should be planned in design-time. These approaches are impossible to apply on legacy systems. Other researches suggest runtime analysis and instrumentation of applications' bytecode. Albeit applicable to some legacy systems, these last proposals are tightly-coupled to implementation's issues of underlaying technologies. For this reason, it is hard to apply such proposals end-toend, for example, in a scenario encompassing many managed entities implemented through di erent technologies. However, it is possible to o er to administrators and managers facilities to express they knowledge about networks' anomalies and faults, and facilities to leverage this knowledge. This master dissertation has as objective to present and evaluate a solution to imbue network management systems with self-healing capabilities. The solution relies on workplans as a mean to gather administrators and managers' knowledge on how to diagnose and heal networks' anomalies and faults. Besides that, the design and implementation of a standard framework for fault detection and noti cation customization is discussed while considering a P2P-Based Network Management System as its foundations. At last, an experimental evaluation renders clear the proposal's feasibility from the operational point of view.

APA, Harvard, Vancouver, ISO, and other styles

11

Coelho, Josiane Ortolan. "Elemento autonômico para processos de monitoração adaptativa de redes." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2008. http://hdl.handle.net/10183/15744.

Full text

Abstract:

Estudos recentes sobre padrões de gerenciamento em redes de produção apontam que apenas um pequeno e estático conjunto de dados de gerenciamento tende a ser utilizado. Eles também revelam que o fluxo de dados de gerenciamento é relativamente constante e que as operações em uso para a comunicação agente-gerente são reduzidas a alguns, as vezes obsoletos, conjuntos. Essa realidade demonstra uma expressiva falta de progresso nos processos de monitoração, levando em consideração o seu papel estratégico e o potencial, por exemplo, para antecipar e prevenir falhas, perdas de desempenho e problemas de segurança em redes, serviços e aplicações. Uma das razões para tal limitação recai no fato de que o operador, ainda considerado um elemento fundamental no loop de controle, já não suporta o rápido crescimento tanto do tamanho quanto da heterogeneidade de ambos os componentes de software e de hardware, os quais constituem os modernos sistemas de computação em rede. Essa forma de "administrador no loop de gerenciamento" certamente dificulta a realização de adaptações oportunas nos processos de monitoração. Para resolver este problema, esse trabalho apresenta um modelo para monitoração adaptativa de redes, serviços e aplicações inspirado na abordagem de aprendizado por reforço. O modelo é analisado por meio da implementação de um protótipo de um elemento autonômico, o qual baseia-se em valores históricos, muitas vezes inesperados, obtidos de objetos gerenciados. Por meio do raciocínio sobre essas informações, o elemento autonômico dinamicamente amplia ou restringe o conjunto de objetos gerenciados a ser monitorado. Recent investigations of management patterns in production networks suggest that just a small and static set of management data tends to be used, the flow of management data is relatively constant, and the operations in use for manager-agent communication are reduced to a few, sometimes obsolete set. This reality demonstrates an impressive lack of progress of monitoring processes, taking into account their strategic role and potential, for example, to anticipate and prevent faults, performance bottlenecks, and security problems. One of the key reasons for such limitation relies on the fact that operators, who still are a fundamental element of the monitoring control loop, can no longer handle the rapidly increasing size and heterogeneity of both hardware and software components that comprise modern networked computing systems. This form of human-in-the-loop management certainly hampers timely adaptation of monitoring processes. To tackle this issue, this work presents a model, inspired by the reinforcement learning theory, for adaptive network, service and application monitoring. The model is analyzed through a prototypical implementation of an autonomic element, which, based on historical and even unexpected values retrieved for management objects, dynamically widens or restricts the set of management objects to be monitored.

APA, Harvard, Vancouver, ISO, and other styles

12

Sahay, Rishikesh. "Policy-driven autonomic cyberdefense using software-defined networking." Thesis, Evry, Institut national des télécommunications, 2017. http://www.theses.fr/2017TELE0022/document.

Full text

Abstract:

Les attaques cybernétiques causent une perte importante non seulement pour les utilisateurs finaux, mais aussi pour les fournisseurs de services Internet (FAI). Récemment, les clients des FAI ont été la cible numéro un de cyber-attaques telles que les attaques par déni de service distribué (DDoS). Ces attaques sont favorisées par la disponibilité généralisée outils pour lancer les attaques. Il y a donc un besoin crucial de contrer ces attaques par des mécanismes de défense efficaces. Les chercheurs ont consacré d’énormes efforts à la protection du réseau contre les cyber-attaques. Les méthodes de défense contiennent d’abord un processus de détection, complété par l’atténuation. Le manque d’automatisation dans tout le cycle de détection à l’atténuation augmente les dégâts causés par les cyber-attaques. Cela provoque des configurations manuelles de périphériques l’administrateur pour atténuer les attaques affectent la disponibilité du réseau. Par conséquent, il est nécessaire de compléter la boucle de sécurité avec un mécanisme efficace pour automatiser l’atténuation. Dans cette thèse, nous proposons un cadre d’atténuation autonome pour atténuer les attaques réseau qui visent les ressources du réseau, comme par les attaques exemple DDoS. Notre cadre fournit une atténuation collaborative entre le FAI et ses clients. Nous utilisons la technologie SDN (Software-Defined Networking) pour déployer le cadre d’atténuation. Le but de notre cadre peut se résumer comme suit : d’abord, les clients détectent les attaques et partagent les informations sur les menaces avec son fournisseur de services Internet pour effectuer l’atténuation à la demande. Nous développons davantage le système pour améliorer l’aspect gestion du cadre au niveau l’ISP. Ce système effectue l’extraction d’alertes, l’adaptation et les configurations d’appareils. Nous développons un langage de politique pour définir la politique de haut niveau qui se traduit par des règles OpenFlow. Enfin, nous montrons l’applicabilité du cadre par la simulation ainsi que la validation des tests. Nous avons évalué différentes métriques QoS et QoE (qualité de l’expérience utilisateur) dans les réseaux SDN. L’application du cadre démontre son efficacité non seulement en atténuant les attaques pour la victime, mais aussi en réduisant les dommages causés au trafic autres clients du FAI Cyber attacks cause significant loss not only to end-users, but also Internet Service Providers (ISP). Recently, customers of the ISP have been the number one target of the cyber attacks such as Distributed Denial of Service attacks (DDoS). These attacks are encouraged by the widespread availability of tools to launch the attacks. So, there is a crucial need to counter these attacks (DDoS, botnet attacks, etc.) by effective defense mechanisms. Researchers have devoted huge efforts on protecting the network from cyber attacks. Defense methodologies first contains a detection process, completed by mitigation. Lack of automation in the whole cycle of detection to mitigation increase the damage caused by cyber attacks. It requires manual configurations of devices by the administrator to mitigate the attacks which cause the network downtime. Therefore, it is necessary to close the security loop with an efficient mechanism to automate the mitigation process. In this thesis, we propose an autonomic mitigation framework to mitigate attacks that target the network resources. Our framework provides a collaborative mitigation strategy between the ISP and its customers. The implementation relies on Software-Defined Networking (SDN) technology to deploy the mitigation framework. The contribution of our framework can be summarized as follows: first the customers detect the attacks and share the threat information with its ISP to perform the on-demand mitigation. We further develop the system to improve the management aspect of the framework at the ISP side. This system performs the alert extraction, adaptation and device configurations. We develop a policy language to define the high level policy which is translated into OpenFlow rules. Finally, we show the applicability of the framework through simulation as well as testbed validation. We evaluate different QoS and QoE (quality of user experience) metrics in SDN networks. The application of the framework demonstrates its effectiveness in not only mitigating attacks for the victim, but also reducing the damage caused to traffic of other customers of the ISP

APA, Harvard, Vancouver, ISO, and other styles

13

Nobre, Jéferson Campos. "Manutenção da consistência do estado dos dados de gerenciamento em sistemas de gerenciamento autonômico baseados em infraestruturas peer-to-peer." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2010. http://hdl.handle.net/10183/29009.

Full text

Abstract:

O Gerenciamento Autonômico de Redes é uma visão que utiliza princípios da Computação Autonômica para o Gerenciamento de Redes. Além disso, algum grau de descentralização é necessário para habilitar capacidades autonômicas completas. Uma alternativa interessante de infraestrutura para essa união é a utilização de overlays Peer-to-Peer (P2P). No entanto, a consistência do estado dos dados de gerenciamento entre os peers é um desafio importante. Mecanismos tradicionais para manter a consistência desses estados são implementados por meio de centralização, o que desperdiça algumas propriedades desejáveis de abordagens P2P. Em contraste com esses mecanismos, é proposto um mecanismo distribuído, escalável e robusto para a manutenção da consistência do estado dos dados de gerenciamento pela introdução de funcionalidades de Manutenção da Verdade Multiagente. Além disso, são propostas estratégias de comunicação para prover suporte a essas funcionalidades. São apresentados também estudos de caso para ilustrar as possibilidades da proposta: o gerenciamento cooperativo de falhas em enlaces Ethernet em provedores de serviços e a ativação distribuída de políticas de gerenciamento de redes. Experimentos simulados são realizados a fim de verificar as propriedades de escalabilidade e robustez da presente proposta. Autonomic network management is a vision that brings Autonomic Computing principles to Network Management. Besides, it is necessary some level of decentralization to enable broad autonomic capabilities. An interesting alternative of infrastructure for this union is the utilization of Peer-to-Peer (P2P) overlays. However, the consistency of state of management data among peers is an important challenge. Traditional mechanisms to maintain consistency of these states are supported by some centralization which wastes some desirable properties of P2P approach. In contrast to these mechanisms, a distributed, scalable and robust mechanism to maintain the consistency of state of management data is proposed through the introduction of Multi-Agent Truth Maintenance features. Besides, communication strategies are proposed to support these features. Case studies are presented to show possibilities of this proposal: cooperative fault management of Ethernet links in service providers and distributed activation of network management policies. Simulated experiments are performed to verify the scalability and robustness properties of this proposal.

APA, Harvard, Vancouver, ISO, and other styles

14

Agarwala, Sandip. "System Support for End-to-End Performance Management." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/16171.

Full text

Abstract:

This dissertation introduces, implements, and evaluates the novel concept of "Service Paths", which are system-level abstractions that capture and describe the dynamic dependencies between the different components of a distributed enterprise application. Service paths are dynamic because they capture the natural interactions between application services dynamically composed to offer some desired end user functionality. Service paths are distributed because such sets of services run on networked machines in distributed enterprise data centers. Service paths cross multiple levels of abstraction because they link end user application components like web browsers with system services like http providing communications with embedded services like hardware-supported data encryption. Service paths are system-level abstractions that are created without end user, application, or middleware input, but despite these facts, they are able to capture application-relevant performance metrics, including end-to-end latencies for client requests and the contributions to these latencies from application-level processes and from software/hardware resources like protocol stacks or network devices. Beyond conceiving of service paths and demonstrating their utility, this thesis makes three concrete technical contributions. First, we propose a set of signal analysis techniques called ``E2Eprof' that identify the service paths taken by different request classes across a distributed IT infrastructure and the time spent in each such path. It uses a novel algorithm called ``pathmap' that computes the correlation between the message arrival and departure timestamps at each participating node and detect dependencies among them. A second contribution is a system-level monitoring toolkit called ``SysProf', which captures monitoring information at different levels of granularity, ranging from tracking the system-level activities triggered by a single system call, to capturing the client-server interactions associated with a service paths, to characterizing the server resources consumed by sets of clients or client behaviors. The third contribution of the thesis is a publish-subscribe based monitoring data delivery framework called ``QMON'. QMON offers high levels of predictability for service delivery and supports utility-aware monitoring while also able to differentiate between different levels of service for monitoring, corresponding to the different classes of SLAs maintained for applications.

APA, Harvard, Vancouver, ISO, and other styles

15

Jiang, Tao. "Distributed trust management in autonomic networks." College Park, Md.: University of Maryland, 2007. http://hdl.handle.net/1903/7769.

Full text

Abstract:

Thesis (Ph. D.) -- University of Maryland, College Park, 2007. Thesis research directed by: Dept. of Electrical and Computer Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

APA, Harvard, Vancouver, ISO, and other styles

16

Gomez, montalvo Jorge. "A Multimedia Ontology-Driven Architecture for Autonomic Quality of Service Management in Home Networks." Thesis, Toulouse, INSA, 2012. http://www.theses.fr/2012ISAT0017/document.

Full text

Abstract:

Dans le contexte actuel de l’Internet, un enjeu de recherche majeur est de permettre aux applications et à leurs utilisateurs de disposer de systèmes de communication offrant une qualité de service (QdS) optimale. Ceci en fonction des ressources machine et réseau disponibles, dont les capacités et les performances, hétérogènes et variables, ne sont pas connues à l’avance. Le provisionnement optimal de la QdS dans ces futurs systèmes de communication autonomes nécessite d’une part la caractérisation des services et des ressources de communication disponibles, et d’autre part la prise en compte des expressions des besoins et des préférences des différents acteurs du système (utilisateurs, fournisseurs des services, etc.). Le sujet de la thèse porte sur la définition d’un cadre sémantique de QdS basé sur les ontologies pour la caractérisation des ressources et des services de communication dans le but de fournir la meilleure QdS au regard des besoins et des préférences des utilisateurs. Ce cadre sera utilisé dans la définition des objectifs et des contraintes de QdS et dans l’élaboration de modèles de décision. L'ensemble sera utilisé pour la mise en œuvre de QdS dans les systèmes de communication autonomes situés dans un contexte de réseaux domestiques In the current context of the Internet, a major research challenge is to enable applications and users to have their communications systems with an optimal quality of service (QoS). Indeed, QoS provisioning should take into account the available machine and network resources, which capacities and performances are heterogeneous, variable, and not known in advance. The optimal QoS provisioning for the future autonomous communication systems requires the characterization of available services and communication resources and also taking into account the expressions of needs and preferences of different actors in the system (users, service providers, etc.). The subject of this thesis deals with the definition of a QoS ontology-based semantic framework for the characterization of network resources and communication services in order to provide better QoS according to the needs and preferences of users. This framewor! k will be used in the definition of objectives and QoS constraints as well as in the development of decision models in order to provide QoS for autonomous communication systems located in the context of home networks

APA, Harvard, Vancouver, ISO, and other styles

17

Elkotob, Muslim. "Autonomic resource management in IEEE 802.11 open access networks." Licentiate thesis, Luleå : Department of Computer Science and Electrical Engineering, Luleå University of Technology, 2008. http://epubl.ltu.se/1402-1757/2008/38/.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Maiden, Wendy Marie. "Dualtrust a trust management model for swarm-based autonomic computing systems /." Pullman, Wash. : Washington State University, 2010. http://www.dissertations.wsu.edu/Thesis/Spring2010/W_Maiden_6041310.pdf.

Full text

Abstract:

Thesis (M.A. in electrical engineering and computer science)--Washington State University, May 2010. Title from PDF title page (viewed on May 3, 2010). "Department of Electrical Engineering and Computer Science." Includes bibliographical references (p. 110-117).

APA, Harvard, Vancouver, ISO, and other styles

19

Tauber, Markus. "Autonomic management in a distributed storage system." Thesis, St Andrews, 2010. http://hdl.handle.net/10023/926.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Gomez, Montalvo Jorge Ricardo. "A multimedia ontology-driven architecture for autonomic quality of service management in home networks." Phd thesis, INSA de Toulouse, 2012. http://tel.archives-ouvertes.fr/tel-00752389.

Full text

Abstract:

Dans le contexte actuel de l'Internet, un enjeu de recherche majeur est de permettre aux applications et à leurs utilisateurs de disposer de systèmes de communication offrant une qualité de service (QdS) optimale. Ceci en fonction des ressources machine et réseau disponibles, dont les capacités et les performances, hétérogènes et variables, ne sont pas connues à l'avance. Le provisionnement optimal de la QdS dans ces futurs systèmes de communication autonomes nécessite d'une part la caractérisation des services et des ressources de communication disponibles, et d'autre part la prise en compte des expressions des besoins et des préférences des différents acteurs du système (utilisateurs, fournisseurs des services, etc.). Le sujet de la thèse porte sur la définition d'un cadre sémantique de QdS basé sur les ontologies pour la caractérisation des ressources et des services de communication dans le but de fournir la meilleure QdS au regard des besoins et des préférences des utilisateurs. Ce cadre sera utilisé dans la définition des objectifs et des contraintes de QdS et dans l'élaboration de modèles de décision. L'ensemble sera utilisé pour la mise en œuvre de QdS dans les systèmes de communication autonomes situés dans un contexte de réseaux domestiques.

APA, Harvard, Vancouver, ISO, and other styles

21

Mhiri, Fadoua. "Resource Management in femtocell networks." Paris 6, 2013. http://www.theses.fr/2013PA066136.

Full text

Abstract:

Dans cette thèse, nous proposons des solutions évolutives et entièrement distribuée appelés SOCS, ADAC, TRIPLET « algorithmes » dans une architecture autonome de femtocellules ; telle que réseau d'Entreprise, qui permettent de surmonter les problèmes fondamentales liés à la gestion des ressources dans les réseaux Femtocells: la gestion des interférences, la consommation d'énergie et le Handover. Basé sur l'approche cognitive, nous formulons des systèmes d'optimisation multi-objectifs tout en introduisant des variables entières et des paramètres de pondération pour le contrôle de la puissance transmise, la couverture de la femtocellule, la capacité des canaux, le débit moyen et éventuellement des paramètres pour la mesure de la QoS des utilisateurs. En outre, ces problèmes d’optimisation sont soumis à diverses circonstances atténuantes ainsi, les interférences considérées dans les scénarios simulés sont limitées. L’évaluation de ces systèmes et de ces techniques sont faite dans de telles conditions afin de s'assurer qu'elles sont évolutives et flexibles Grâce à ce travail, nous essayons non simplement d’améliorer le débit moyen des utilisateurs en fonction de leur niveau d’accès et leur QoS dans une Femtocellule, mais aussi de proposer une technique de Handover qui s’adapte aux critères imposés par le réseau d’une part, et celles par l’utilisateur d’autre part. De plus, nous visons dans cette thèse d’optimiser la consommation d’énergie dans le réseau d’Entreprise, assurer une couverture de réseau optimale dans l’Entreprise, améliorer l’efficacité spectrale et réduire l’interférence. Les systèmes et les techniques proposés dans cette thèse permettent d’assurer une efficacité énergétique et spectrale en ajustant et en optimisant la couverture globale des femtocellules tout en améliorant le débit moyen du système Through this work, we propose some scalable and fully distributed solutions called SOCS, Adac, TRIPLET Algorithms in Autonomic Architecture of Femtocells Network such Enterprise environment, which overcome the basic challenging issues as: interference management, handover and power consumption. Based on cognitive approach, we formulate some multi-objective optimization problems with mixed integer variables for the joint power control, base station assignment, and channel assignments according to user’s QoS. Further, these schemes are subjected to various mitigating circumstances and interference-limited scenarios. The performance evaluations of these schemes are done under such conditions to ensure that they are scalable, flexible and can be considered as a practically viable option. Through this work, we try not just to improve the average throughput experienced by users according to their access level and their QoS in a femtocell, but also to propose a Handover technique that responds to the criteria imposed by the network and by the user. Furthermore, we aim in this thesis; to optimize the energy consumption in the whole network, to ensure optimal network coverage in the Enterprise, to improve the spectral efficiency and to reduce interference. Systems and techniques proposed in this thesis are designed to provide energy and spectral efficiencies by adjusting and optimizing the overall coverage of femtocells while improving the average Throughput of the system

APA, Harvard, Vancouver, ISO, and other styles

22

Bouguera, Taoufik. "Capteur communicant autonome en énergie pour l'loT." Thesis, Nantes, 2019. http://www.theses.fr/2019NANT4007/document.

Full text

Abstract:

Une grande partie des nouvelles générations d'objets connectés ne pourra se développer que s'il est possible de les rendre entièrement autonomes sur le plan énergétique. Même si l'utilisation de batteries ou de piles résout une partie de ce problème en assurant une autonomie qui peut-être importante avec des coûts relativement faibles, elle introduit non seulement des contraintes de maintenance incompatibles avec certaines applications, mais aussi des problèmes de pollution. La récupération de l'énergie thermique, mécanique, électromagnétique, solaire ou éolienne est une solution très prometteuse. Dans ce cas, la vie de l'objet connecté peut-être prolongée. Cependant, l'énergie récupérée dépend fortement des conditions au voisinage du dispositif et peut donc varier de façon périodique ou aléatoire. Il parait alors important d'adapter le système (mesure et transmission de données) aux contraintes de la récupération d'énergie. L'objectif de la thèse est de proposer une solution de capteur autonome basée sur un système de récupération et de gestion multisources d'énergies (solaire et éolienne) et pouvant-être mis en oeuvre dans différentes classes d'applications IoT. On s'intéresse, dans un premier temps, à la modélisation de la consommation du noeud capteur. Ensuite, on modélise le système de récupération multisources. Puis, on se focalise sur le management de puissance du système autonome. Ce management est basé sur des prédictions de l'énergie disponible et de celle consommée. Enfin, le travail de modélisation et d'optimisation est validé par des expérimentations afin d’avoir un démonstrateur de Capteur Communicant Autonome en Énergie pour les applications IoT Researchers aim to develop entirely autonomous sensors. By ensuring an important autonomy, the use of batteries solves part of the energy problem with relatively low costs. However, batteries introduce different problems such as maintenance and environmental pollution. Harvesting thermal, mechanical, electromagnetic, solar or wind energy present in the environment is an attractive solution. Using harvested energy from their surroundings, wireless sensor nodes can significantly increase their typical lifetime. Nevertheless, the harvested energy depends on the surrounding conditions of the device and can vary periodically or randomly. It seems important to adapt the system (measurement and data transmission) to the harvesting energy constraints. The thesis objective is to provide an autonomous sensor solution based on a multisources energy harvesting and management system (solar and wind energies), which can be used in different IoT applications. First, we are interested in modeling and optimizing the sensor node energy consumption. Then, the multiple harvesting system is modeled according to the energy needs of the sensor node. Besides, we focus on the power management of the autonomous system. This management part is based on predictions of both available and consumed energies. Finally, the proposed modeling and optimization studies are validated with experimental works in order to develop an Autonomous Communicating Sensor platform for IoT applications

APA, Harvard, Vancouver, ISO, and other styles

23

Chen, Huoping. "Self-Configuration Framework for Networked Systems and Applications." Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/195456.

Full text

Abstract:

The increased complexity, heterogeneity and the dynamism of networked systems and applications make current configuration and management tools to be ineffective. A new paradigm to dynamically configure and manage large-scale complex and heterogeneous networked systems is critically needed. In this dissertation, we present a self configuration paradigm based on the principles of autonomic computing that can handle efficiently complexity, dynamism and uncertainty in configuring networked systems and their applications. Our approach is based on making any resource/application to operate as an Autonomic Component (that means, it can be self-configured, self-healed, self-optimized and self-protected) by using two software modules: Component Management Interface (CMI) to specify the configuration and operational policies associated with each component and Component Runtime Manager (CRM) that manages the component configurations and operations using the policies defined in CMI. We use several configuration metrics (adaptability, complexity, latency, scalability, overhead, and effectiveness) to evaluate the effectiveness of our self-configuration approach when compared to other configuration techniques. We have used our approach to dynamically configure four systems: Automatic IT system management, Dynamic security configuration of networked systems, Self-management of data backup and disaster recovery system and Automatic security patches download and installation on a large scale test bed. Our experimental results showed that by applying our self-configuration approach, the initial configuration time, the initial configuration complexity and the dynamic configuration complexity can be reduced significantly. For example, the configuration time for security patches download and installation on nine machines is reduced to 4399 seconds from 27193 seconds. Furthermore our system provides most adaptability (e.g., 100% for Snort rule set configuration) comparing to hard coded approach (e.g., 22% for Snort rule set configuration) and can improve the performance of managed system greatly. For example, in data backup and recovery system, our approach can reduce the total cost by 54.1% when network bandwidth decreases. In addition, our framework is scalable and imposes very small overhead (less than 1%) on the managed system.

APA, Harvard, Vancouver, ISO, and other styles

24

Nastasi, Kevin Michael. "Autonomous and Responsive Surveillance Network Management for Adaptive Space Situational Awareness." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/84931.

Full text

Abstract:

As resident space object populations grow, and satellite propulsion capabilities improve, it will become increasingly challenging for space-reliant nations to maintain space situational awareness using current human-in-the-loop methods. This dissertation develops several real-time adaptive approaches to autonomous sensor network management for tracking multiple maneuvering and non-maneuvering satellites with a diversely populated Space Object Surveillance and Identification network. The proposed methods integrate suboptimal Partially Observed Markov Decision Processes (POMDPs) with covariance inflation or multiple model adaptive estimation techniques to task sensors and maintain viable orbit estimates for all targets. The POMDPs developed in this dissertation use information-based and system-based metrics to determine the rewards and costs associated with tasking a specific sensor to track a particular satellite. Like in real-world situations, the population of target satellites vastly outnumbers the available set of sensors. Robust and adaptable tasking algorithms are needed in this scenario to determine how and when sensors should be tasked. The strategies developed in this dissertation successfully track 207 non-maneuvering and maneuvering spacecraft using only 24 ground and space-based sensors. The results show that multiple model adaptive estimation coupled with a multi-metric, suboptimal POMDP can effectively and efficiently task a diverse network of sensors to track multiple maneuvering spacecraft, while simultaneously monitoring a large number of non-maneuvering objects. Overall, this dissertation demonstrates the potential for autonomous and adaptable sensor network command and control for real-world space situational awareness. Ph. D.

APA, Harvard, Vancouver, ISO, and other styles

25

Abdeljaouad, Imad. "Self-Configuration and Monitoring of Service Specific Overlay Networks." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/23960.

Full text

Abstract:

The constant growth in network communications technologies and the emergence of Service Specific Overlay Networks (SSONs), coupled with the rapid development of multimedia applications make the management of such technologies a major challenge. This thesis investigates the SSONs management problem and proposes an autonomic architecture, a self-organizing and self-adapting algorithm, and a utility function for monitoring the Quality of Experience (QoE) of IPTV streams in SSONs. First, we examine the different issues stemming from the autonomic management of SSONs and identify the limitations of existing approaches. We then propose an architecture to ease the management of SSONs by incorporating autonomic computing principles to make SSONs acquire self-management capabilities. The proposed architecture introduces autonomic control loops that continuously monitor network components and analyze the gathered data. An Autonomic System (AS) is comprised of one or more Autonomic Managers (AM) which take control of managing other elements in the network. The proposed architecture highlights the different components of an AM and identifies its purpose. The distributed nature of the proposed architecture avoids limitations of centralized management solutions. We then propose a scheme to allow AMs to emerge among the set of nodes in the network as the most powerful ones in terms of different factors, including processing capabilities and stability. Using a self-organizing and self-adapting distributed protocol, each node in the overlay selects an appropriate AM to report to so that sensed data is delivered error-free, and in a timely manner, while the load is distributed over the AMs. Finally, we propose a utility function to monitor the quality of IPTV streams by predicting QoE based on statistical Quality of Service (QoS) information. The proposed function is simple and does not require high processing power. It allows the QoE of IPTV users to be monitored in real-time by the AMs, so that quality degradations are accurately identified and adaptation mechanisms are triggered at the right moment to correct issues causing degradations. Theoretical analysis and simulations studies are presented to demonstrate the performance of the proposed schemes.

APA, Harvard, Vancouver, ISO, and other styles

26

Bsaybes, Sahar. "Models and algorithms for fleet management of autonomous vehicles." Thesis, Université Clermont Auvergne‎ (2017-2020), 2017. http://www.theses.fr/2017CLFAC114/document.

Full text

Abstract:

Résumé indisponible The VIPAFLEET project aims at developing a framework to manage a fleet of IndividualPublic Autonomous Vehicles (VIPA). We consider a fleet of cars distributed at specifiedstations in an industrial area to supply internal transportation, where the cars can beused in different modes of circulation (tram mode, elevator mode, taxi mode). The goalis to develop and implement suitable algorithms for each mode in order to satisfy all therequests either under an economic point aspect or under a quality of service aspect, thisby varying the studied objective functions.We model the underlying online transportation system as a discrete event basedsystem and propose a corresponding fleet management framework, to handle modes,demands and commands. We consider three modes of circulation, tram, elevator andtaxi mode. We propose for each mode appropriate online algorithms and evaluate theirperformance, both in terms of competitive analysis and practical behavior by computationalresults. We treat in this work, the pickup and delivery problem related to theTram mode and the Elevator mode the pickup and delivery problem with time windowsrelated to the taxi mode by means of flows in time-expanded networks

APA, Harvard, Vancouver, ISO, and other styles

27

Peres, Martin. "A holistic approach to green networking in wireless networks : collaboration among autonomic systems as a mean towards efficient resource-sharing." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0433/document.

Full text

Abstract:

Les vingt dernières années ont vu l’émergence de systèmes sans fil dans la vie de tous les jours. Ils ont rendu possible la création de technologies telles que les téléphones portables, le WiFi ou l’internet mobile qui sont maintenant tenus pour acquis dans la société actuelle. L’impact environnemental des technologies de l’information et des communications connaît une croissance exponentielle et a atteint l’impact de l’industrie du transport aérien. L’initiative d’informatique verte a été lancée en réponse à cette observation pour réduire de 15 à 30% les émissions de gaz à effet de serre en 2020 comparé aux prédictions faites en 2002 afin de garder le réchauffement climatique inférieur à 2°C. Dans cette thèse, nous avons étudié des techniques d’économie d’énergie dans les réseaux sans fil et comment elles interagissent entre elles afin de donner une vue holistique des réseaux verts. Nous prenons également en compte l’usage du spectre radio fréquence qui est le moyen le plus utilisé pour les communications entre systèmes sans fil et qui devient une ressource rare à cause du besoin grandissant de notre société pour de la bande passante en mobilité. Cette thèse suit les couches réseaux avant de remonter les piles matérielleset logicielles. Des contributions ont été apportées à la plupart des couches afin de proposer un réseau sans fil autonome où les noeuds peuvent collaborer pour améliorer les performances du réseau, réduire de façon globale l’utilisation du spectre radio tout en limitant la consommation énergétique du réseau The last twenty years saw the emergence of wireless systems in everyday’s life. They made possible technologies such as mobile phones, WiFi or mobile Internet which are now taken for granted in today’s society. The environmental impact of Information and Communications Technology (ICT) has been raising exponentially to equate the impact of the airline industry. The green computing initiative has been created in response to this observation in order to meet the 15%-30% reduction in green-house gases by 2020 compared to estimations made in 2002 to keep the global temperature increasebelow 2°C. In this thesis, we studied power-saving techniques in wireless networks and how they interact with each others to provide a holistic view of green networking. We also take into account the radio frequency resource which is the most commonly usedcommunication medium for wireless systems and is becoming a scarce resource due to our society’s ever-increasing need for mobile bandwidth. This thesis goes down the network stacks before going up the hardware and software stack. Contributions have been madeat most layers in order to propose an autonomic wireless network where nodes can work collaboratively to improve the network’s performance, globally reduce the radio frequency spectrum usage while also increasing their battery life

APA, Harvard, Vancouver, ISO, and other styles

28

Wickliff, Tanya Verniece Dugat. "An empirical study of the relations between leadership, social support networks, task autonomy and emotions in a technical work environment." Texas A&M University, 2005. http://hdl.handle.net/1969.1/3074.

Full text

Abstract:

The world in which we live is hyper-dynamic with multiple inputs, outputs and expectations. As it relates to the fast pace of corporate America, customers want products and services within a tighter market window, with no defects and for lower costs. Stakeholders insist that managers do more with less human and financial resources yet more aggressive technological and sales goals. These realities translate into a more complex work environment in that the emotional toll of pending economic outcomes act to motivate or paralyze the very engine designed to produce the desired outcomes the employees. The body of work presented in this dissertation directly addresses the empirical relationship between the perceptions of the work context factors of leadership, task autonomy and social support networks with respect to the positive and negative emotions of the employees of the engineering firm that participated in this study. The empirical results from this research indicate that a positive and significant interrelationship does exist among the factors examined in this study. The employees studied included 249 middle to upper level managers of whom 78.7% were men and 21.3% were women. The range of years of experience for the participants varied from new hire to more than 20 years. Homogeneity of Variance tests confirms the validity of comparative analysis for the segmented data population. Multivariate statistics were used to address the four research questions. The strongest correlations occurred for the subgroups of women and non-managers with respect to the relationship of social support networks and positive emotions. Until now, there has been no empirical research linking the social support networks factor directly to emotions.

APA, Harvard, Vancouver, ISO, and other styles

29

Vidalenc, Bruno. "Méthodes d'autoréparation proactives pour les réseaux d'opérateurs." Phd thesis, Institut National des Télécommunications, 2012. http://tel.archives-ouvertes.fr/tel-00835924.

Full text

Abstract:

Les opérateurs de réseaux de télécommunications accordent une importance toute particulière à la gestion des pannes. L'implication de l'humain dans la prise de décision et l'analyse d'une quantité énorme d'alarmes et d'informations, ainsi que le caractère réactif des mécanismes de gestion des pannes, ne permettent pas la réactivité nécessaire à une gestion optimale des incidents. Pour pallier ce problème, cette thèse s'intéresse à des mécanismes proactifs qui anticipent les pannes afin d'améliorer l'efficacité de leur gestion. La mise en oeuvre, dans les équipements, de composants autonomes capables d'analyser en permanence l'état de santé du réseau permettrait de fournir une information en temps réel sur le risque de panne, nécessaire au déploiement de nouveaux mécanismes d'autoréparation proactifs. La première partie de cette thèse est donc consacrée à la définition des composants architecturaux indispensables à l'introduction de fonctions d'autoréparation proactives. Dans un deuxième temps, nous étudions et analysons en détail trois mécanismes d'autoréparation proactifs exploitant une information de risque de panne. Le premier mécanisme a pour objectif d'accélérer la convergence des protocoles de routage à état de lien en adaptant la fréquence d'envoi des messages de détection de pannes en fonction du risque de panne. Le deuxième mécanisme modifie dynamiquement les métriques de routage afin de détourner le trafic des équipements risqués et de minimiser l'impact d'une panne sur le trafic. Enfin, le dernier mécanisme s'attache aux dispositifs de protection et de restauration du protocole GMPLS afin d'adapter dynamiquement la consommation des ressources, aux risques encourus

APA, Harvard, Vancouver, ISO, and other styles

30

Ericeira, Júlio Augusto Mendes 1959. "Colegiado escolar : espaço democrático nas escolas do ensino médio da rede pública estadual em São Luís do Maranhão - 2007 a 2010." [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/253987.

Full text

Abstract:

Orientador: Pedro Ganzeli Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação Made available in DSpace on 2018-08-27T15:19:24Z (GMT). No. of bitstreams: 1 Ericeira_JulioAugustoMendes_M.pdf: 2048166 bytes, checksum: 23d3944929b3eadbdaf10cd5c6d748c8 (MD5) Previous issue date: 2015 Resumo: O presente trabalho resulta de um estudo sobre gestão democrática na escola pública, tendo como pano de fundo as reformas neoliberais implantadas na América Latina e no Brasil sob a orientação dos organismos internacionais de financiamento, motivadas pela necessidade do capitalismo de se reordenar para o enfrentamento de uma nova crise estrutural, levando o país a aderir a um projeto de sociabilidade baseada no mercado como regulador das relações econômicas e sociais viabilizadas através da reforma do estado brasileiro nos anos de 1990 e seus reflexos na máquina administrativa do estado do Maranhão. Trata das influencias das reformas do Estado no campo educacional, especialmente com a implantação da gestão democrática na escola pública brasileira e maranhense, face à análise dos efeitos do Decreto nº 14.558, de 22 de maio de 1995, na organização do processo participativo nas escolas do ensino médio da rede pública estadual em São Luís, no período de 2007 a 2010. Os procedimentos adotados foram: a revisão sobre a temática, análise de documentos oficiais, relacionados as políticas educacionais no Brasil e no Maranhão a partir de 1995, e entrevistas semiestruturadas com os membros dos Colegiados Escolares das escolas do ensino médio da Rede Pública Estadual de Ensino do Maranhão, localizadas na capital São Luís. Os resultados indicaram que no transcorrer dos anos as experiências dos Colegiados foram se consolidando com a ampliação da participação da comunidade escolar na definição dos propósitos das escolas, e a democratização do poder, anteriormente centralizada na figura do diretor de escola, a partir da alteração em 2008, do Decreto estadual que regulamentava o funcionamento dos Colegiados e retirou dos diretores a função nata de presidente desses órgãos, passando a ser exercida por um membro eleito entre seus integrantes. Palavras-Chave: Gestão escolar democrática. Participação. Autonomia. Reforma educacional. Rede Estadual de Educação do Maranhão Abstract: This paper results from a study of democratic management in the public school, with a backdrop of the neoliberal reforms implemented in Latin America and Brazil under the guidance of international financial institutions, motivated by capitalism need to reorder itself to face a new structural crisis, leading the country to join a sociability project based on the market as a regulator of economic and social relations made possible by reforming the Brazilian state in 1990 and its effects on the administrative organization of the state of Maranhão. It deals with the influence of state reforms in the educational field , especially with the implementation of democratic management in the Brazilian public school and Maranhão, given the analysis of the effects of Law No. 14558 of 22 May 1995, in the organization of the participatory process in schools high school of the public schools in São Lois from 2007 to 2010. The procedures were: a review of the subject, analysis of official documents , related educational policies in Brazil and Maranhão in 1995, and semi-structured interviews with members of the Collegiate School Board of the high schools of the State Public education Network of Maranhão, located in São Luis, capital state. The results indicated that through the years the experiences of Collegiate School Boards were consolidated with the expansion of the school community participation in definition of the purposes of schools , and the democratization of power, previously centered on the school principal figure, from the change in 2008 , the state Law that regulated the operation of Collegiate School Boards and removed the principals inate president function of these organs, passing to be exercised by a member elected from among its members. Keywords: Democratic School Management. Participation. Autonomy. Educational Reform. State of Maranhão Education Network Mestrado Politicas, Administração e Sistemas Educacionais Mestre em Educação

APA, Harvard, Vancouver, ISO, and other styles

31

Mifsud, Denise. "Raising the curtain on relations of power in a Maltese school network." Thesis, University of Stirling, 2014. http://hdl.handle.net/1893/21710.

Full text

Abstract:

This study concerns school reform in Malta. Under the policy framework ‘For All Children to Succeed’ (Ministry of Education, Youth & Employment, 2005) [henceforth referred to as FACT], Maltese state schools embarked on the process of being organized into networks called ‘colleges’. These consisted of primary and secondary schools according to geographical location, under the leadership of the Principal – a newly-designated role hierarchically above that of the individual Heads of School. The purpose of my research is to explore relations of power in a Maltese college. My study gives prominence to both theory and methodology. The theoretical research question investigates how networking unfolds among the various leadership hierarchies in school governance in a Maltese college. This is explored through the performance of policy-mandated collegiality; the circulating relations of power; and leadership distribution. My study is framed within a postmodern paradigm and adopts a Foucauldian theoretical framework, more specifically his concepts of power, discipline, governmentality, discourse, and subjectification. Data for my case study are collected through semi-structured, in-depth interviews; observation of a Council of Heads meeting; and a documentary analysis of FACT. Narrative is not only the phenomenon under exploration, but also the method of analysis, and mode of representation. Thus, I attempt to answer my methodological research question that investigates the ways a researcher negotiates the methodological tensions and contradictions in the conduct of qualitative inquiry in order to construct knowledge differently. The Maltese college is viewed as a surveillance mechanism by both the Principal and the Heads, with collegiality being regarded as a straitjacket imposed by the State through a policy mandate. However, there is unanimous agreement on conscription being the only way forward for Maltese state schools. Different degrees of ‘support’ and empowerment exist, according to the directives of the Principal and the State. College setup is problematized on geographical clustering and college streaming, due to which it may end up defying the primary aim of networking by clustering students from particular areas in isolation, resulting in social injustice and educational inequality. This study exposes a strong sense of sectoral isolation among the Heads – a situation being mirrored at macro-level with very few opportunities for inter-networking among colleges. There is an asymmetrical power flow among the college schools, both within the same level and across different levels. Despite the policy FACT mandating distributed leadership, hierarchical forms of accountability are still inherent within the system, bringing out a tension between autonomy and centralization.

APA, Harvard, Vancouver, ISO, and other styles

32

Zermani, Sara. "Implémentation sur SoC des réseaux Bayésiens pour l'état de santé et la décision dans le cadre de missions de véhicules autonomes." Thesis, Brest, 2017. http://www.theses.fr/2017BRES0101/document.

Full text

Abstract:

Les véhicules autonomes, tels que les drones, sont utilisés dans différents domaines d'application pour exécuter des missions simples ou complexes. D’un côté, ils opèrent généralement dans des conditions environnementales incertaines, pouvant conduire à des conséquences désastreuses pour l'humain et l'environnement. Il est donc nécessaire de surveiller continuellement l’état de santé du système afin de pouvoir détecter et localiser les défaillances, et prendre la décision en temps réel. Cette décision doit maximiser les capacités à répondre aux objectifs de la mission, tout en maintenant les exigences de sécurité. D’un autre côté, ils sont amenés à exécuter des tâches avec des demandes de calcul important sous contraintes de performance. Il est donc nécessaire de penser aux accélérateurs matériels dédiés pour décharger le processeur et répondre aux exigences de la rapidité de calcul.C’est ce que nous cherchons à démontrer dans cette thèse à double objectif. Le premier objectif consiste à définir un modèle pour l’état de santé et la décision. Pour cela, nous utilisons les réseaux Bayésiens, qui sont des modèles graphiques probabilistes efficaces pour le diagnostic et la décision sous incertitude. Nous avons proposé un modèle générique en nous basant sur une analyse de défaillance de type FMEA (Analyse des Modes de Défaillance et de leurs Effets). Cette analyse prend en compte les différentes observations sur les capteurs moniteurs et contextes d’apparition des erreurs. Le deuxième objectif était la conception et la réalisation d’accélérateurs matériels des réseaux Bayésiens d’une manière générale et plus particulièrement de nos modèles d’état de santé et de décision. N’ayant pas d’outil pour l’implémentation embarqué du calcul par réseaux Bayésiens, nous proposons tout un atelier logiciel, allant d’un réseau Bayésien graphique ou textuel jusqu’à la génération du bitstream prêt pour l’implémentation logicielle ou matérielle sur FPGA. Finalement, nous testons et validons nos implémentations sur la ZedBoard de Xilinx, incorporant un processeur ARM Cortex-A9 et un FPGA Autonomous vehicles, such as drones, are used in different application areas to perform simple or complex missions. On one hand, they generally operate in uncertain environmental conditions, which can lead to disastrous consequences for humans and the environment. Therefore, it is necessary to continuously monitor the health of the system in order to detect and locate failures and to be able to make the decision in real time. This decision must maximize the ability to meet the mission objectives while maintaining the security requirements. On the other hand, they are required to perform tasks with large computation demands and performance requirements. Therefore, it is necessary to think of dedicated hardware accelerators to unload the processor and to meet the requirements of a computational speed-up.This is what we tried to demonstrate in this dual objective thesis. The first objective is to define a model for the health management and decision making. To this end, we used Bayesian networks, which are efficient probabilistic graphical models for diagnosis and decision-making under uncertainty. We propose a generic model based on an FMEA (Failure Modes and Effects Analysis). This analysis takes into account the different observations on the monitors and the appearance contexts. The second objective is the design and realization of hardware accelerators for Bayesian networks in general and more particularly for our models of health management and decision-making. Having no tool for the embedded implementation of computation by Bayesian networks, we propose a software workbench covering graphical or textual Bayesian networks up to the generation of the bitstream ready for the software or hardware implementation on FPGA. Finally, we test and validate our implementations on the Xilinx ZedBoard, incorporating an ARM Cortex-A9 processor and an FPGA

APA, Harvard, Vancouver, ISO, and other styles

33

Gléonec, Philip-Dylan. "Design and implementation of power management strategies for long range radio module with energy harvesting." Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S017/document.

Full text

Abstract:

L'avènement de l'Internet des Objets a permis de déployer de nombreux réseaux de capteurs sans-fil. Ces réseaux sont utilisés dans des domaines aussi variés que l'agriculture, l'industrie ou la ville intelligente, où ils permettent d'optimiser finement les processus. Ces appareils sont le plus souvent alimentés par des piles ou batteries, ce qui limite leur autonomie. De plus, il n'est pas toujours possible ou financièrement viable de changer ou recharger les batteries. Une solution possible est d'alimenter ces capteurs en récupérant l'énergie présente dans l'environnement alentour. Ces sources d'énergie sont cependant peu fiables, et le capteur doit être capable d'éviter de vider complètement sa réserve d'énergie. Afin de moduler sa consommation d'énergie, le capteur peut adapter sa qualité de service à ses capacités énergétiques. L'appareil peut ainsi fonctionner en continu sans interruption de service. Cette thèse présente les méthodes utilisées pour la conception d'un capteur entièrement autonome alimenté par récupération d'énergie ambiante, communiquant sur un réseau longue portée LoRa. Afin d'assurer l'alimentation électrique, une carte permettant de récupérer de l'énergie depuis plusieurs sources d'énergie simultanément a été conçue. Un module logiciel de gestion d'énergie a ensuite été développé afin de calculer un budget énergétique que le capteur peut dépenser, et choisir la meilleure manière de dépenser ce budget pour exécuter une ou plusieurs tâches. Ce travail a ainsi permis le développement d'un prototype de produit industriel entièrement autonome en énergie The advent of the Internet of Things has enabled the roll-out of a multitude of Wireless Sensor Networks. These networks can be used in various fields, such as agriculture, industry or the smart city, where they facilitate fine optimization of processes. These devices are often powered by primary or rechargeable batteries, which limits their battery life. Moreover, it is sometimes not possible or financially viable to change and/or recharge these batteries. A possible solution is to harvest energy from the environment to power these sensors. But these energy sources are unreliable, and the sensor must be able to prevent the complete depletion of its energy storage. In order to adapt its energy consumption, the node can match its quality of service to its energetical capabilities. Thus, the device can continuously operate without any service interruption. This thesis presents the methods used for the conception of a completely autonomous sensor, powered by energy harvesting and communicating through a long range LoRa network. In order to ensure its power supply, a board has been designed to harvest energy from multiple energy sources simultaneously. A power management software module has then been developed to calculate an energy budget the sensor can use, and to choose the best way to spend this budget over one or multiple tasks. This work has enabled the development of an energy autonomous industrial sensor prototype

APA, Harvard, Vancouver, ISO, and other styles

34

Sánchez, Vílchez José Manuel. "Cross-layer self-diagnosis for services over programmable networks." Thesis, Evry, Institut national des télécommunications, 2016. http://www.theses.fr/2016TELE0012/document.

Full text

Abstract:

Les réseaux actuels servent millions de clients mobiles et ils se caractérisent par équipement hétérogène et protocoles de transport et de gestion hétérogènes, et des outils de gestion verticaux, qui sont très difficiles à intégrer dans leur infrastructure. La gestion de pannes est loin d’être automatisée et intelligent, ou un 40 % des alarmes sont redondantes et seulement un 1 ou 2% des alarmes sont corrélées au plus dans un centre opérationnel. Ça indique qu’il y a un débordement significatif des alarmes vers les adminis-trateurs humains, a comme conséquence un haut OPEX vue la nécessité d’embaucher de personnel expert pour accomplir les tâches de gestion de pannes. Comme conclusion, le niveau actuel d’automatisation dans les tâches de gestion de pannes dans réseaux télécoms n’est pas adéquat du tout pour adresser les réseaux programmables, lesquels promettent la programmation des ressources et la flexibilité afin de réduire le time-to-market des nouveaux services. L’automatisation de la gestion des pannes devient de plus en plus nécessaire avec l’arrivée des réseaux programmables, SDN (Software-Defined Networking), NFV (Network Functions Virtualization) et le Cloud. En effet, ces paradigmes accélèrent la convergence entre les domaines des réseaux et la IT, laquelle accélère de plus en plus la transformation des réseaux télécoms actuels en menant à repenser les opérations de gestion de réseau et des services, en particulier les opérations de gestion de fautes. Cette thèse envisage l’application des principes d’autoréparation en infrastructures basées sur SDN et NFV, en focalisant sur l’autodiagnostic comme facilitateur principal des principes d’autoréparation. Le coeur de cette thèse c’est la conception d’une approche de diagnostic qui soit capable de diagnostiquer de manière continuée les services dynamiques virtualisés et leurs dépendances des ressources virtuels (VNFs et liens virtuels) mais aussi les dépendances de ceux ressources virtuels de la infrastructure physique en-dessous, en prenant en compte la mobilité, la dynamicite, le partage de ressources à l’infrastructure en-dessous Current networks serve billions of mobile customer devices. They encompass heterogeneous equipment, transport and manage-ment protocols, and vertical management tools, which are very difficult and costly to integrate. Fault management operations are far from being automated and intelligent, where around 40% of alarms are redundant only around 1-2% of alarms are correlated at most in a medium-size operational center. This indicates that there is a significant alarm overflow for human administrators, which inherently derives in high OPEX due to the increasingly need to employ high-skilled people to perform fault management tasks. In conclusion, the current level of automation in fault management tasks in Telcos networks is not at all adequate for programmable networks, which promise a high degree of programmability and flexibility to reduce the time-to-market. Automation on fault management is more necessary with the advent of programmable networks, led by with SDN (Software-Defined Networking), NFV (Network Functions Virtualization) and the Cloud. Indeed, the arise of those paradigms accelerates the convergence between networks and IT realms, which as consequence, is accelerating faster and faster the transformation of cur-rent networks leading to rethink network and service management and operations, in particular fault management operations. This thesis envisages the application of self-healing principles in SDN and NFV combined infrastructures, by focusing on self-diagnosis tasks as main enabler of self-healing. The core of thesis is to devise a self-diagnosis approach able to diagnose at run-time the dynamic virtualized networking services and their dependencies from the virtualized resources (VNFs and virtual links) but also the dependencies of those virtualized resources from the underlying network infrastructure, taking into account the mobility, dynamicity, and sharing of resources in the underlying infrastructure

APA, Harvard, Vancouver, ISO, and other styles

35

Sharrock, Rémi. "Gestion autonomique de performance, d'énergie et de qualité de service : Application aux réseaux filaires, réseaux de capteurs et grilles de calcul." Phd thesis, Toulouse, INPT, 2010. http://oatao.univ-toulouse.fr/11717/1/sharrock.pdf.

Full text

Abstract:

La motivation principale de cette thèse est de faire face à l'accroissement de la complexité des systèmes informatiques, qui, dans un futur proche ( de l'ordre de quelques années) risque fort d'être le principal frein à leur évolution et à leur développement. Aujourd'hui la tendance s'inverse et le coût de gestion humaine dépasse le coût des infrastructures matérielles et logicielles. De plus, l'administration manuelle de grands systèmes (applications distribuées, réseaux de capteurs, équipements réseaux) est non seulement lente mais aussi sujette à de nombreuses erreurs humaines. Un des domaines de recherche émergent est celui de l'informatique autonomique qui a pour but de rendre ces systèmes auto-gérés. Nous proposons une approche qui permet de décrire des politiques de gestion autonomiques de haut niveau. Ces politiques permettent au système d'assurer quatre propriétés fondamentales de l'auto-gestion: l'auto-guérison, l'auto-configuration, l'auto-protection et l'auto-optimisation. Nos contributions portent sur la spécification de diagrammes de description de politiques de gestion autonomiques appelés (S)PDD "(Sensor) Policy Description Diagrams". Ces diagrammes sont implémentés dans le gestionnaire autonomique TUNe et l'approche a été validée sur de nombreux systèmes: simulation électromagnétique répartie sur grille de calcul, réseaux de capteurs SunSPOT, répartiteur de calcul DIET. Une deuxième partie présente une modélisation mathématique de l’auto-optimisation pour un « datacenter ». Nous introduisons un problème de minimisation d’un critère intégrant d’une part la consommation électrique des équipements du réseau du « datacenter » et d’autre part la qualité de service des applications déployées sur le « datacenter ». Une heuristique permet de prendre en compte les contraintes dues aux fonctions de routage utilisées.

APA, Harvard, Vancouver, ISO, and other styles

36

Liu, Bing. "Contrôle et optimisation des systèmes de transport intelligents dans le voisinage des intersections." Thesis, Ecole centrale de Lille, 2016. http://www.theses.fr/2016ECLI0008/document.

Full text

Abstract:

Cette thèse est consacrée à étudier les applications potentielles de véhicules autonomes et communications V2X pour construire les systèmes de transport intelligents. Premièrement, le comportement de caravane dans un environnement de véhicule connecté est étudié. Un algorithme de commande de caravane est conçu pour obtenir l'espacement sécuritaire ainsi que la conformité de la vitesse et de l'accélération. Deuxièmement, à plus grande échelle, les caravanes autour d'une intersection sont considérées. Le débit pendant une période de signal de trafic peut être amélioré en tirant profit de la capacité redondante de la route. Dans diverses contraintes, les véhicules peuvent choisir d'accélérer et rejoindre la caravane précédente ou à décélérer de déroger à l'actuel. Troisièmement, une intersection sans signalisation en VANET est considérée. Dans des conditions de faible trafic, les véhicules peuvent réguler leur vitesse avant d'arriver à l'intersection en fonction du temps d'occupation de la zone de conflit (TOZC) stocké au niveau du gestionnaire, afin qu'ils puissent traverser l'intersection sans collision ni arrêt. Le délai peut être réduit en conséquence. Enfin, un algorithme de gestion d'intersection autonome universelle, qui peut fonctionner même avec le trafic lourd, est développé. Le véhicule cherche à sécuriser les fenêtres entrant dans le TOZC. Ensuite, sur la base des fenêtres trouvées et le mouvement du véhicule qui précède, les trajectoires des véhicules peuvent être planifiées en utilisant une méthode de programmation dynamique segmentée. Tous les algorithmes conçus sont testés et vérifiés avec succès par des simulations dans scénarios différents This thesis is devoted to study the potential applications of autonomous vehicles and V2X communications to construct the intelligent transportation systems. Firstly, the behavior of platoon in connected vehicle environment is studied. A platoon control algorithm is designed to obtain safe spacing as well as accordance of velocity and acceleration for vehicles in the same lane. Secondly, in larger scale, the platoons around an intersection are considered. The throughput in a traffic signal period can be improved by taking advantage of the redundant road capacity. Within diverse constraints, vehicles can choose to accelerate to join in the preceding platoon or to decelerate to depart from the current one. Thirdly, an unsignalized intersection in VANET is considered. In light traffic conditions, vehicles can regulate their velocities before arriving at the intersection according to the conflict zone occupancy time (CZOT) stored at the manager, so that they could get through the intersection without collision or stop. The delay can be reduced accordingly. Finally, an universal autonomous intersection management algorithm, which can work even with heavy traffic, is developed. The vehicle searches for safe entering windows in the CZOT. Then based on the found windows and the motion of preceding vehicle, the trajectories of vehicles can be planned using a segmented dynamic programming method. All the designed algorithms are successfully tested and verified by simulations in various scenarios

APA, Harvard, Vancouver, ISO, and other styles

37

Tizghadam, Ali. "Autonomic Core Network Management System." Thesis, 2009. http://hdl.handle.net/1807/18070.

Full text

Abstract:

This thesis presents an approach to the design and management of core networks where the packet transport is the main service and the backbone should be able to respond to unforeseen changes in network parameters in order to provide smooth and reliable service for the customers. Inspired by Darwin's seminal work describing the long-term processes in life, and with the help of graph theoretic metrics, in particular the "random-walk betweenness", we assign a survival value, the network criticality, to a communication network to quantify its robustness. We show that the random-walk betweenness of a node (link) consists of the product of two terms, a global measure which is fixed for all the nodes (links) and a local graph measure which is in fact the weight of the node (link). The network criticality is defined as the global part of the betweenness of a node (link). We show that the network criticality is a monotone decreasing, and strictly convex function of the weight matrix of the network graph. We argue that any communication network can be modeled as a topology that evolves based on survivability and performance requirements. The evolution should be in the direction of decreasing the network criticality, which in turn increases the network robustness. We use network criticality as the main control parameter and we propose a network management system, AutoNet, to guide the network evolution in real time. AutoNet consists of two autonomic loops, the slow loop to control the long-term evolution of robustness throughout the whole network, and the fast loop to account for short-term performance and robustness issues. We investigate the dynamics of network criticality and we develop a convex optimization problem to minimize the network criticality. We propose a network design procedure based on the optimization problem which can be used to develop the long-term autonomic loop for AutoNet. Furthermore, we use the properties of the duality gap of the optimization problem to develop traffic engineering methods to manage the transport of packets in a network. This provides for the short-term autonomic loop of AutoNet architecture. Network criticality can also be used to rank alternative networks based on their robustness to the unpredicted changes in network conditions. This can help find the best network structure under some pre-specified constraint to deal with robustness issues.

APA, Harvard, Vancouver, ISO, and other styles

38

Fernandes, Vitor Celso de Pinho Leal. "“Autonomic Networking” – tendencies and evolution of network management technologies and computer communication protocols." Master's thesis, 2008. http://hdl.handle.net/10348/241.

Full text

Abstract:

Dissertação de Mestrado em Informática A computação autónoma tem sido proposta como uma abordagem para reduzir os custos e a complexidade de gestão da infra-estrutura de Tecnologias de Informação (TI). Um sistema autonómico deve ser considerado como um sistema que se auto-configura, auto-optimiza, auto-cura e se auto-defende. Para efeito desse comportamento autónomo, um sistema deve controlar o seu funcionamento e as interacções com outros sistemas externos. É necessário representar essas informações num modelo que permita a sua interpretação automatizada e controlo, agrupando conhecimento sobre como automatizar acções de gestão. Neste trabalho procurou-se abordar a evolução histórica das tecnologias de rede até á evolução natural do conceito de redes autónomas. Os projectos sobre redes autónomas adoptam várias abordagens descentralizadas (isto é, autónomas ou distribuídas) para novas arquitecturas e serviços de Internet com propriedades de auto-organização. Nesta dissertação são explicados os quatro maiores projectos (ANA, CASCADAS, BIONETS e HAGGLE). É também proposto um modelo, solução, ferramentas e uma implementação de monitorização para a infra-estrutura de Tecnologias de Informação e Comunicação da Universidade de Trás-os-Montes e Alto Douro gerida pelo Centro de Informática da UTAD. São por fim feitas as considerações necessárias para a integração da solução de monitorização proposta neste estudo no contexto de uma arquitectura de redes autonómicas. Autonomic computing has been proposed as an approach to reducing the cost and complexity of managing Information Technology (IT) infrastructure. An autonomic system is one that is self-configuring, self-optimizing, self-healing and self-protecting. To effect such autonomic behaviour, a system must instrument its operational behaviour and external interactions with other systems. It needs to represent this information in a model which admits automated interpretation and control, incorporating knowledge on how to automate management actions. This thesis addressed the networking technologies historical evolution up to the natural evolution of the Autonomic networks concept. The launched autonomic projects address several decentralised (i.e. autonomic or distributed) approaches for new Internet architectures and services, featuring self-organising properties. The four major projects in this area were presented (ANA, CASCADAS, BIONETS and HAGGLE). A monitoring model, solution, tools and implementation for the Information and Communication Technology infrastructure of University of Trás-os-Montes e Alto Douro managed by the CI-UTAD was proposed. Finally, the relevant considerations for the integration of the proposed monitoring model into an autonomic networking architecture are presented.

APA, Harvard, Vancouver, ISO, and other styles

39

Farha, Ramy. "Autonomic Service Architecture for Next Generation Networks." Thesis, 2008. http://hdl.handle.net/1807/11201.

Full text

Abstract:

Next generation networks will provide customers with a service mix placing variable demands for resources on the underlying infrastructure, motivating automated telecommunications services management approaches. This thesis proposes the Autonomic Service Architecture (ASA) for automated service delivery over next generation networks. First, we propose an architectural blueprint for ASA. We describe our view of the next generation network infrastructure, which will be application oriented. We elaborate on the layered design of ASA, the virtualization of resources, and the separation between manual and autonomic functions in the service delivery lifecycle. The autonomic functions are delivered by the interaction between Autonomic Resource Brokers (ARBs). The architecture of an ARB is then detailed, with a description of its different components and the message exchanges needed. Next, we discuss a Peer-to-Peer (P2P) naming and mobility management approach for next generation networks using ASA. This P2P approach will help ensure the scalability, robustness, and flexibility that ASA needs to ensure service delivery over next generation networks. The proposed P2P naming and mobility management infrastructure is then detailed, and its performance is evaluated. Finally, we suggest several autonomic resource management algorithms for ASA. The first algorithm is based on the Transportation Model, commonly used in the Operations Research community for cost minimization in delivering a commodity from sources to destinations, adapted to perform allocation of virtual resources. The second algorithm is based on the Assignment Model, commonly used in the Operations Research community for cost minimization in assigning several jobs to several workers, adapted to perform autonomic assignment of dedicated virtual resources. The third algorithm is based on Inventory Control, commonly used in the Operations Research community to analyze inventory systems, placing and receiving orders when needed for a given product, adapted to predict the demand on virtual resources. The fourth algorithm is based on Reinforcement Learning, commonly used in the Machine Learning community by agents to find a control policy that will maximize the observed rewards over their lifetime, adapted to adjust the prices of virtual resources.

APA, Harvard, Vancouver, ISO, and other styles

40

Liu, Fang. "Coordination Mechanism Design for Sustainable Global Supply Networks." Diss., 2011. http://hdl.handle.net/10161/5674.

Full text

Abstract:

This dissertation studies coordination mechanism design for sustainable supply networks in a globalized environment, with the goal of achieving long-term profitability, environmental friendliness and social responsibility. We examine three different types of supply networks in detail.The first network consists of one supplier and multiple retailers. The main issue is how to efficiently share a scarce resource, such as capacities for green technology, among all members with private information under dynamically changing environment. We design a shared surplus supply agreement among the members which can lead to both efficient private investments and efficient capacity allocation under unpredictable and unverifiable market conditions.The second network is a serial supply chain. The source node provides critical raw material (like coffee cherries) for the entire chain and is typically located in an underdeveloped economy, the end node is a retailer serving consumer at a developed economy (like Starbucks Co.). We construct a dynamic supply agreement that takes into account the changing market and production conditions to ensure fair compensations so that the partners have the right incentives to work together to develop sustainable quality supply.The third network is a stylized global production network of a multinational company consisting of a home plant and a foreign branch. The branch serves the foreign market but receives a key component from the home plant. The distinctive feature is that both facilities belong to the same company, governed by the headquarters, yet they each also have their own autonomies. We analyze the role of the headquarters in designing coordination mechanism to improve efficiency. We show the headquarters can delegate the coordination effort to the home plant, as long as it keeps veto power. Dissertation

APA, Harvard, Vancouver, ISO, and other styles

41

Mano, Luísa Maria Fernandes Duarte. "Modelo integrado de gestão das finanças públicas para Portugal." Master's thesis, 2014. http://hdl.handle.net/10071/8144.

Full text

Abstract:

Trabalho de projeto O presente trabalho de projeto pretende apresentar um Modelo integrado de Gestão das Finanças Públicas para Portugal que se constitua como uma alteração estrutural duradoura no âmbito das finanças públicas nacionais, permitindo contribuir para resolução dos seus problemas recorrentes, garantindo a sua transparência e a accountability de todos os envolvidos na sua gestão. Neste sentido, o presente trabalho estrutura-se em três capítulos. O primeiro capítulo apresenta uma perspetiva abrangente sobre o Estado e a Administração Pública ao longo tempo, desde o início da modernidade às mais recentes reformas. O segundo capítulo efetua o diagnóstico da situação atual da Gestão das Finanças Públicas (GFP) em Portugal através das redes que se podem observar e das fragilidades existentes. Por último, o terceiro capítulo apresenta uma proposta de melhoria que pela construção de um modelo integrado de GFP em Portugal, efetuando um enquadramento genérico do mesmo e desenvolvendo os aspetos de integração, atendendo ao aconselhado pelas boas práticas internacionais, e estabelecendo as diretrizes principais do funcionamento das redes identificadas no âmbito do modelo. O modelo apresentado pretende resolver as fragilidades identificadas através da integração das funções da GFP: Contabilidade, Orçamento e Tesouro. Para tal é necessária a utilização pela plenitude das administrações públicas da contabilidade com base de acréscimo assente num plano de contas adequado, a revisão dos classificadores do Orçamento do Estado (OE) e a adoção de uma boa governança do OE, o desenvolvimento de um sistema de conta única do Tesouro, no contexto de uma gestão de tesouraria moderna. This research project intends to present an integrated model of Public Financial Management for Portugal as a lasting structural change in national public finances, concurring to solve their recurring problems, ensuring the transparency and accountability of all involved in its management. In this sense, this paper is divided into three chapters. The first chapter presents a comprehensive perspective on the state and public administration over time, since the beginning of modernity to the latest reforms. The second chapter makes the diagnosis of the current situation of the Public Financial Management (PFM) in Portugal through the networks that can be observed and existing weaknesses. Finally, the third chapter presents a proposal to improve it by building an integrated model of PFM in Portugal, setting up a generic framework and developing aspects of integration, given the international good practices, and establishing the main guidelines for the operation of networks identified in the model. The proposed model aims to solve the weaknesses identified by integrating the functions of PFM: Accounting, Budget and Treasury. This means the use of accrual accounting based on a suitable chart of accounts by the fullness of government, the review of State Budget classifiers, the adoption of State Budget good governance and the development of a Treasury Single Account system, in the context of a modern cash management.

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'Autonomic network management'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles