1,721,066 research outputs found
Security, QoS and self-management within an end-to-end Cloud Computing environment
No full textDe nos jours, le Cloud Networking est considéré comme étant l'un des domaines de recherche innovants au sein de la communauté de recherche du Cloud Computing. Les principaux défis dans un environnement de Cloud Networking concernent non seulement la garantie de qualité de service (QoS) et de sécurité mais aussi sa gestion en conformité avec un accord de niveau de service (SLA) correspondant. Dans cette thèse, nous proposons un Framework pour l'allocation des ressources conformément à un SLA établi de bout en bout entre un utilisateur de services Cloud (CSU) et plusieurs fournisseurs de services Cloud (CSP) dans un environnement de Cloud Networking (architectures d’inter-Cloud Broker et Fédération). Nos travaux se concentrent sur les services Cloud de types NaaS et IaaS. Ainsi, nous proposons l'auto-établissement de plusieurs types de SLA ainsi que la gestion autonome des ressources de Cloud correspondantes en conformité avec ces SLA en utilisant des gestionnaires autonomes spécifiques de Cloud. De plus, nous étendons les architectures et les SLA proposés pour offrir un niveau de service intégrant une garantie de sécurité. Ainsi, nous permettons aux gestionnaires autonomes de Cloud d'élargir leurs objectifs de gestion autonome aux fonctions de sécurité (auto-protection) tout en étudiant l'impact de la sécurité proposée sur la garantie de QoS. Enfin, nous validons notre architecture avec différents scénarios de simulation. Nous considérons dans le cadre de ces simulations des applications de vidéoconférence et de calcul intensif afin de leur fournir une garantie de QoS et de sécurité dans un environnement de gestion autonome des ressources du Cloud. Les résultats obtenus montrent que nos contributions permettent de bonnes performances pour ce type d’applications. En particulier, nous observons que l'architecture de type Broker est la plus économique, tout en assurant les exigences de QoS et de sécurité. De plus, nous observons que la gestion autonome des ressources du Cloud permet la réduction des violations, des pénalités et limite l'impact de la sécurité sur la garantie de la QoS.Today, Cloud Networking is one of the recent research areas within the Cloud Computing research communities. The main challenges of Cloud Networking concern Quality of Service (QoS) and security guarantee as well as its management in conformance with a corresponding Service Level Agreement (SLA). In this thesis, we propose a framework for resource allocation according to an end-to-end SLA established between a Cloud Service User (CSU) and several Cloud Service Providers (CSPs) within a Cloud Networking environment (Inter-Cloud Broker and Federation architectures). We focus on NaaS and IaaS Cloud services. Then, we propose the self-establishing of several kinds of SLAs and the self-management of the corresponding Cloud resources in conformance with these SLAs using specific autonomic cloud managers. In addition, we extend the proposed architectures and the corresponding SLAs in order to deliver a service level taking into account security guarantee. Moreover, we allow autonomic cloud managers to expand the self-management objectives to security functions (self-protection) while studying the impact of the proposed security on QoS guarantee. Finally, our proposed architecture is validated by different simulation scenarios. We consider, within these simulations, videoconferencing and intensive computing applications in order to provide them with QoS and security guarantee in a Cloud self-management environment. The obtained results show that our contributions enable good performances for these applications. In particular, we observe that the Broker architecture is the most economical while ensuring QoS and security requirements. In addition, we observe that Cloud self-management enables violations and penalties’ reduction as well as limiting security impact on QoS guarantee
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Autonomous management of Quality of Service and security in an Internet of Things environment
No full textDe nos jours, les avancées technologiques font que l’Internet des Objets (IoT) est en train de s’imposer dans notre vie quotidienne afin d’en améliorer la qualité grâce à entre autres l’automatisation de certaines tâches. Un défi majeur dans le déploiement massif des applications et services IoT ainsi que leur utilisation dans différents domaines est l’amélioration du niveau de service correspondant. Ce niveau de service peut être caractérisé selon deux axes importants : la Qualité de Service (QoS) et la sécurité. De plus, ce niveau de service doit être géré d’une manière autonome au sein de l’IoT vu l’hétérogénéité et la taille des réseaux qui forment cet environnement rendant difficile, même impossible, leurs gestions d’une façon manuelle par les administrateurs. Dans le cadre de cette thèse, nous proposons un mécanisme de QoS, appelé QBAIoT (QoS Based Access for IoT environments) permettant d’assurer un traitement différencié des trafics existants dans l’environnement IoT afin de respecter les exigences de chacun des trafics selon différents paramètres de QoS (i.e., délai, gigue, taux de livraison de paquets, etc.). QBAIoT est ensuite amélioré afin d’être géré d’une manière autonome à travers deux fonctions importantes : l’auto-configuration et l’auto-optimisation. De plus, afin d’assurer la QoS au sein de l’environnement IoT, il faut optimiser la consommation énergétique des composants contraints en termes de ressources. Ainsi, nous proposons une adaptation de QBAIoT permettant de réduire sa consommation énergétique d’une manière autonome tout en respectant la précision des données remontées par les objets IoT. Notre contribution concernant le deuxième axe du niveau de service dans un environnement IoT, à savoir la sécurité, se traduit par un mécanisme permettant de contrôler l’accès des objets aux passerelles IoT. Nous appelons cette méthode de contrôle d’accès IoT-MAAC (IoT Multiple Attribute Access Control) car elle prend en compte différents paramètres spécifiques à l’environnement IoT (i.e., confiance des objets, identificateur de l’objet, empreinte digitale de l’objet, etc.). La prise de décision concernant le contrôle d’accès des objets IoT est gérée d’une façon autonome par les passerelles IoT et vise à respecter les exigences de cet environnement en termes de confiance.Nowadays, the Internet of Things (IoT) is becoming important in our daily lives thanks to technological advances. This paradigm aims to improve the quality of human life through automating several tasks. In this context, service level guarantee within IoT environments is a major challenge while considering a massive deployment of IoT applications and services as well as extending their usage to different domains. The IoT service level can be characterized in two parts: Quality of Service (QoS) and security. Moreover, this service level must be managed in an autonomic manner within the IoT environment given the heterogeneity and the size of its infrastructure making it difficult, even impossible, their management in a manual manner by the administrators. In this thesis, we propose a QoS based channel access control mechanism, called QBAIoT (QoS Based Access for IoT environments), to ensure a differentiated processing of existing traffics in the IoT environment. The differentiated processing allows satisfying the requirements of each traffic according to different QoS parameters (i.e., delay, jitter, packet delivery ratio, etc.). Then, QBAIoT is improved and upgraded to integrate self-management capabilities thanks to two important functions of the closed control loop: self-configuration and self-optimization. In addition, to offer a better QoS within the IoT environment, it is necessary to optimize the energy consumption of resources’ constrained components. Thus, we propose an adaptation of QBAIoT allowing to reduce its energy consumption in an autonomic manner while respecting the data accuracy. Our contribution concerning the second part of service level guarantee within an IoT environment, which is security, consists is a mechanism enabling IoT objects access control to IoT gateways, called IoT-MAAC (IoT Multiple Attribute Access Control). This mechanism takes into account different parameters that are specific to IoT environments (i.e., IoT object trust, IoT object identifier, IoT object fingerprint, etc.). Finally, the decision making process regarding IoT object access control is autonomously managed by IoT gateways and aims to meet the requirements of IoT environment in terms of trust
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Gestion du niveau de service dans les environnements émergents
No full textInternational audienceCet ouvrage présente différentes approches pour permettre la gestion d'un ou plusieurs composants du niveau de service dans différents environnements émergents tels que l'internet des objets, le Cloud, les smart grids, la e-santé, les réseaux radio maillés, le D2D, les villes intelligentes ou encore le green networking. Il permet ainsi une meilleure compréhension des défis et enjeux importants relatifs à la gestion de la qualité de service, la sécurité, et la mobilité dans ce type d'environnements. (site de l'éditeur
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