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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

The energy scale of the 3-flavour Lambda parameter

Bruno, Mattia 27 April 2016 (has links)
Alle dimensionsbehafteten Gitter-QCD-Observablen muessen in Einheiten einer Referenzskala ausgedrueckt werden und die Bestimmung dieser ist haeufig der erste Schritt in der Berechnung anderer Observablen. In dieser Arbeit beschreiben wir eine scale setting-Strategie fuer eine neue Satz an Ensembles mit großem Volumen, die von CLS generiert worden sind. Die Simulationen enthalten up, down und strange O(a)-verbesserte Wilson-Fermionenfelder. Die Eichfeld-dynamik ist mit Luescher-Weisz-Wirkung implementiert. Um das freezing der Topologie bei kleinen Gitterabstaenden zu ueberwinden, wurden offene Randbedingungen in Zeitrichtung verwendet. Außerdem wurde twisted mass reweighting eingesetzt, eine Technik, um die Fermionbeitraege in der Infrarotregion zu stabilisieren und zu regularisieren. In dieser Arbeit diskutieren wir deren Auswirkungen auf mesonische Spektralgroeßen. Wir berechnen die Gitterabstaende fuer unsere vier β Werte unter Verwendung der pseudoskalaren Zerfallskonstanten, die wir aus den Simulationen mit offenen Randbedingungen extrahieren. Außerdem bestimmen wir die Observable t0 und extrapolieren sie zum Kontinuum. / In lattice computations all dimensionful observables have to be expressed in units of a reference scale and its determination is often the first step before proceeding to other quantities. In this thesis we describe the scale setting strategy for a new set of large-volume ensembles generated within the CLS effort. The simulations have been carried out including up, down and strange quark fields, discretized a là Wilson and following the O(a)-improvement program. The gauge field dynamics is implemented with the improved Luescher-Weisz action. To overcome the freezing of topology in simulations at small lattice spacings, open boundary conditions in the time direction have been adopted, together with twisted-mass reweighting, a technique to regularize and stabilize the fermionic contributions in the infrared region. In this thesis we discuss their implications on mesonic spectral quantities. We compute the lattice spacings, for our four values of β, using the pseudo-scalar decay constants, extracted in the presence of open boundary conditions. In addition to that, we determine the observable t0 and extrapolate it to the continuum.
82

Spectral and Energy Efficiency in 5G Wireless Networks / Efficacité spectrale et énergétique dans les réseaux 5G

Lahsen-Cherif, Iyad 02 December 2016 (has links)
La pénurie d'énergie et le manque d'infrastructures dans les régions rurales représentent une barrière pour le déploiement et l'extension des réseaux cellulaires. Les approches et techniques pour relier les stations de base (BSs) entre elles à faible coût et d'une manière fiable et efficace énergiquement sont l'une des priorités des opérateurs. Ces réseaux peu denses actuellement, peuvent évoluer rapidement et affronter une croissance exponentielle due principalement à l'utilisation des téléphones mobiles, tablettes et applications gourmandes en bande passante. La densification des réseaux est l'une des solutions efficaces pour répondre à ce besoin en débit élevé. Certes, l'introduction de petites BSs apporte de nombreux avantages tels que l'amélioration du débit et de la qualité du signal, mais entraîne des contraintes opérationnelles telles que le choix de l'emplacement des noeuds dans ces réseaux de plus en plus denses ainsi que leur alimentation. Les problèmes où la contrainte spatiale est prépondérante sont bien appropriés à la modélisation par la géométrie stochastique qui permet une modélisation réaliste de distribution des BSs. Ainsi, l'enjeu est de trouver de nouvelles approches de gestions d'interférence et de réductions de consommation énergétique dans les réseaux sans fil. Le premier axe de cette thèse s'intéresse aux méthodes de gestion d'interférence dans les réseaux cellulaires se basant sur la coordination entre les BSs, plus précisément, la technique Coordinated MultiPoint Joint Transmission (CoMP-JT). En CoMP-JT, les utilisateurs en bordure de cellules qui subissent un niveau très élevé d'interférences reçoivent plusieurs copies du signal utile de la part des BSs qui forment l'ensemble de coordination. Ainsi, nous utilisons le modèle r-l Square Point Process (PP) à fin de modéliser la distribution des BSs dans le plan. Le processus r-l Square PP est le plus adapté pour modéliser le déploiement réel des BSs d'un réseau sans fil, en assurant une distance minimale, (r - l), entre les points du processus. Nous discutons l'impact de la taille de l'ensemble de coordination sur les performances évaluées. Ce travail est étendu pour les réseaux denses WiFi IEEE 802.11, où les contraintes de portées de transmission et de détection de porteuse ont été prises en compte. Dans le deuxième axe du travail, nous nous intéressons à l'efficacité énergétique des réseaux mesh. Nous proposons l'utilisation des antennes directionnelles (DAs) pour réduire la consommation énergétique et améliorer le débit de ces réseaux mesh. Les DAs ont la capacité de focaliser la transmission dans la direction du récepteur, assurant une portée plus importante et moins d'énergie dissipée dans toutes les directions. Pour différentes topologies, nous dérivons le nombre de liens et montrons que ce nombre dépend du nombre de secteurs de l'antenne. Ainsi, en utilisant les simulations, nous montrons que le gain, en énergie et en débit, apporté par les DAs peut atteindre 70% dans certains cas. De plus, on propose un modèle d'optimisation conjointe d'énergie et du débit adapté aux réseaux WMNs équipés de DAs. La résolution numérique de ce modèle conforte les résultats de simulation obtenus dans la première partie de cette étude sur l'impact des DAs sur les performances du réseau en termes de débit et d'énergie consommée. Ces travaux de thèse s'inscrivent dans le cadre du projet collaboratif (FUI16 LCI4D), qui consiste à concevoir et à valider une architecture radio ouverte pour renforcer l'accès aux services broadband dans des lieux ne disposant que d'une couverture minimale assurée par un réseau macro-cellulaire traditionnel. / Today's networks continue to evolve and grow resulting more dense, complex and heterogeneous networks.This leads to new challenges such as finding new models to characterize the nodes distribution in the wireless network and approaches to mitigate interference. On the other hand, the energy consumption of WMNs is a challenging issue mainly in rural areas lacking of default electrical grids. Finding alternative technologies and approaches to reduce the consumed energy of these networks is a interesting task. This thesis focuses on proposing and evaluating interference management models for next generation wireless networks (5G and Very Dense High WLANs), and providing tools and technologies to reduce energy consumption of Wireless Mesh Networks (WMNs). Two different problems are thus studied; naturally the thesis is divided into two parts along the following chapters.The contribution of the first part of the thesis is threefold. Firstly, we develop our interference management coordination (CoMP-JT) model. The main idea of CoMP-JT is to turn signals generating harmful interference into useful signals. We develop a new model where BSs inside the coordinated set send a copy of data to border's users experiencing high interference. We consider the r-l Square point process to model the BSs distribution in the network. We derive network performance in terms of coverage probability and throughput. Additionally, we study the impact of the size of coordination set on the network performance. Secondly, we extend these results and provide a new model adopted for Dense Very high throughput WLANs. We take into consideration constraints of WLANs in our model such as carrier sensing range. Thirdly, we tackle resource allocation strategies to limit the interference in LTE networks. We study three cyclic allocation strategies: (i) the independent allocation, (ii) the static allocation and (iii) the load-dependent strategy. We derive tractable analytical expression of the first and second mean of interference. We validate the model using extensive simulations. Reducing the energy consumption and improving the energy efficiency of WMNs is our concern in the second part of the thesis. Indeed, we aim at studying the impact of directional antennas technology on the performance of WMNs, using both analysis and simulations. Fisrt, We derive the Number of Links (NLs) for the chain and grid topologies for different antennas beams. These results are based on the routing tables of nodes in the network. We consider different scenarios such as 1Source-NDestinations to model the downlink communications, NSources-1Destination to model the uplink communications and the 1Source-1Destination as a baseline scenario. Using ns-3 simulator, we simulate network performance in terms of Mean Loss Ratio, throughput, energy consumption and energy efficiency. Then, we study the impact of number of beams, network topology and size, the placement of the gateway on the network performance. Next, we go beyond simulations and propose an optimization framework minimizing the consumed energy while maximizing the network throughput for DAs WMNs. We consider a weighted objective function combining the energy consumption and the throughput. We use power control to adapt transmission power depending on the location of the next hop. This model is a first step to approve the obtained simulation results. We use ILOG Cplex solver to find the optimal solution. Results show that DAs improves the network throughput while reduce the energy consumption and that power control allows saving more energy. In this direction, the LCI4D Project aims at providing low cost infrastructure to connect isolated rural and sub-urban areas to the Internet. In order to reduce the installation and maintenance costs, LCI4D proposes the usage of self-configured Wireless Mesh Networks (WMNs) to connect multimode outdoor femtocells to the remote Marco cell (gateway).
83

Um framework para coordenação do tratamento de exceções em sistemas tolerantes a falhas / A framework for exception handling coordination in fault-tolerant systems

Pereira, David Paulo 09 March 2007 (has links)
A adoção em larga escala de redes de computadores e gerenciadores de banco de dados contribuiu para o surgimento de sistemas de informação complexos. Atualmente, estes sistemas tornaram-se elementos essenciais na vida das pessoas, dando suporte a processos de negócio e serviços corporativos indispensáveis à sociedade, como automação bancária e telefonia. A utilização de componentes na estruturação destes sistemas promove maior qualidade e flexibilidade ao produto e agiliza o processo de desenvolvimento. Entretanto, para que estes benefícios sejam totalmente observados, é fundamental que os provedores de componentes de prateleira projetem especificações precisas, completas e consistentes. Geralmente, as especificações omitem ou negligenciam o comportamento dos componentes nas situações de falha. Desta forma, a utilização de componentes não confiáveis, cujos comportamentos não podem ser inteiramente previstos, compromete seriamente o projeto de sistemas tolerantes a falhas. Uma estratégia para a especificação de componentes tolerantes a falhas é informar a ocorrência de erros através de exceções e realizar a recuperação dos mesmos por rotinas de tratamento correspondentes. A especificação deve separar claramente o comportamento normal do excepcional, destinado à recuperação do erro. Entretanto, em sistemas concorrentes e distribuídos, a especificação apenas deste tratamento local não é suficiente. Uma exceção pode ser lançada em decorrência de erros sistêmicos (i.e. problemas de rede) que afetam todo o sistema. Assim, determinadas exceções devem ser tratadas em nível arquitetural, envolvendo os demais componentes no tratamento. O modelo conceitual de ações Atômicas Coordenadas (ações CA - Coordinated Atomic actions), bastante aplicado na estruturação de sistemas tolerantes a falhas, define um mecanismo geral para a coordenação do tratamento excepcional dos componentes, que cooperam na execução das atividades e competem por recursos compartilhados. Portanto, o modelo de ações CA oferece uma solução potencialmente viável para a especificação do tratamento de exceções em nível arquitetural. Este trabalho propõe um framework para a especificação do tratamento de exceções em nível arquitetural, baseando-se no modelo de aninhamento de ações CA e utilizando a linguagem orientada a eventos CSP (Communicating Sequential Processes). Sua principal característica é prover um protocolo padronizado para a coordenação do tratamento de exceções, que envolve a cooperação dos componentes do sistema. Além disso, é apresentada uma estratégia para a verificação formal dos sistemas na ferramenta FDR (Failure Divergence Refinement), com base no modelo de refinamento por rastros. / The widespread scale adoption of computer networks and database management systems has contributed to the arising of complex information systems. Nowadays, these systems have become essential aspects in the everyday life, supporting business processes and indispensable enterprise services to society such as banking automation and telephony. The usage of components in structuring of these systems promotes higher quality and flexibility to the product and accelerates the software development process. However, in order to fully observe the benefits it is essential that the suppliers of these COTS (commercial off-the-shelf) design precise, complete and consistent specifications. Generally, the specifications omit or neglect the behavior of these components in exceptional situations. Therefore, the usage of untrustworthy components whose behavior cannot be entirely foreseen seriously compromise the design of fault-tolerant systems. One of the strategies used for the specification of fault-tolerant components is to inform the occurrence of errors through exceptions and make its recovering by the correspondent exception handling routines. The specification should separate clearly the normal behavior from the exceptional one, specially designed for error recovery. However, in concurrent and distributed systems, specification of local exception handling is not enough. An exception could be raised as a result of systemic errors (i.e. network errors) which affect the entire system, thus specific types of exceptions should be treated at an architectural level involving all the other components in this handling activity. The conceptual model of Coordinated Atomic (CA) actions, often applied in the structuring of fault-tolerant systems, defines a general mechanism for coordination of exception handling with components that cooperate while executing activities and compete for shared resources. Therefore, the model of CA actions offers a perfectly viable solution for the specification of exception handling at an architectural level. This work proposes a framework for the specification of exception handling at an architectural level, based on the nesting model of CA actions and using the event-oriented language CSP (Communicating Sequential Processes). Its main characteristic is to provide a standardized protocol for coordination of exception handling that involves the cooperation of system components. Moreover, it is presented a formal strategy for system verification using the FDR (Failure Divergence Refinement) tool, based on the traces refinement model.
84

Self-Perceived Coordinated School Health Coordinator Leadership Styles and Practices

Ledbetter, Heather R 01 December 2016 (has links)
School-aged children’s health needs have changed over the last several decades to the present day population of many overweight and obese children with health complications (Centers for Disease Control & Prevention, 2015). Tennessee has implemented the Centers for Disease Control and Prevention’s (CDC) model for Coordinated School Health (CSH) in all public schools. Leading each school district’s program is a CSH Coordinator. The role of CSH Coordinators is to provide leadership to district and school administrators while effectively and efficiently implementing the CSH program (Wechsler, 2012). The purpose of this quantitative study was to explore the self-perceived leadership styles and practices of Tennessee CSH Coordinators. The focus of many public health initiatives in America is childhood health. Research conducted by the CDC has shown that school health interventions have been effective in improving physical activity, comprehensive health education, and nutrition. Good health is essential for academic success (McKenzie & Richmond, 1998). CSH Coordinators are the leaders of health for school systems (Wechsler, 2012). How these individuals implement the CDC model for CSH varies based on leadership style and practices. Many studies exist on the topic of CSH but few consider the people leading the program (Strickland, 2012). By obtaining information regarding the leadership style of current CSH Coordinators, this research provides insight into best practices and continuing education for current and future leaders. The study population consisted of all 137 Tennessee CSH Coordinators. Seventy (51.1%) CSH Coordinators participated in the demographic, best practices, and Multifactor Leadership Questionnaire (Appendix A). Findings indicated that all of the CSH Coordinators self-reported leadership style was transformational. There were no significant differences reported between the degree to which CSH Coordinator identified as transformational leaders compared by years of experience, gender, school district size, education level, and number of best practices implemented.
85

Att samverka med hjälp av Gemensamma Individuella Vårdplaner : en undersökning av ett samverkansprojekt i Sollentuna kommun hösten/vintern 2007

Blom, Robert, Sandström, Ulf January 2007 (has links)
<p>The purpose of this paper is to provide an overview of how cooperation functions between the health services and social services within Sollentuna County Municipal area regarding clients and simultaneous or double diagnoses. Focusing more specifically; the paper also aims to provide additionally, an inquiry as to how the implementation of the Gemensam Individuell Vårdplan (GIVP) (The Integrated Individual Service Care Programme or (GIVP) functions within the Sollentuna Municipal County Area. The questions asked in the paper are: How do the Municipal and County Council personnel experience how the (GIVP) system functions in Sollentuna? How do the Municipal Council and County Council personnel respectively describe their own and their cooperative sister services rolls in terms of the implementation of the GIVP system in practice? The projection activates a hypothesis and tries to explain how the cooperation functions and provides an assessment as to how it functions or not as may be the case in practise. The authors attempt to achieve this using a combination of methodologies. Partly through data based collection and collation through the use of a vignette-focus-study and partly through the use of a questionnaire. A combination of methods has been used to collate both quantitative and qualitative data. The analysis and interpretation of the data is managed through the use of Bengt Berggren’s (1982) cooperative model, incorporating both cognitive theory as well as meta-cognitive theory. The purpose and application of the theories is designed both to individually and collectively nuance interpretations of the relevant data. The investigations primary results show the existence of a strong willingness to cooperate. It shows that cooperation is widely regarded as being important, and that in addition, GIVP is regarded as a useful system for an improved integrated service. It additionally suggests that cooperation can be improved amongst the relevant services to an even greater extent.</p>
86

Samarbete ger samordnad behandling : För individer med samsjuklighet / Coordinated treatment : For individs with co-morbidity

Petersson, Malin, Perez, Chaly January 2010 (has links)
<p>Syftet med studien var att undersöka hur samarbetet för individer med samsjuklighet ser ut mellan kommun och landsting samt hur möjligheterna ser ut till samordnad vård och behandling. Frågeställningarna var att ta reda på hur samarbetet ser ut mellan kommun och landsting gällande individer med samsjuklighet samt vilka tillvägagångssätt som finns för att förbättra samordnad vård och behandling mellan kommun och landsting. Studien genomfördes med kvalitativa semistrukturerade intervjuer. Den teoretiska utgångspunkten var Fridolfs (2004) fyra motiv till ett bra samarbete. Utifrån det hermeneutiska synsättet tolkades intervjuerna inför resultatet med hjälp av innehållsanalys. Resultatet visar att det finns ett samarbete mellan kommun och landsting men för förbättring behövs det mer erfarenhet och kunskap om varandras arbetsuppgifter. Slutsatsen av resultatet är att mer forskning fordras om hur och på vilket sätt samarbete mellan kommun och landsting kan förbättras. Kan en gemensam huvudman vara ett alternativ?</p>
87

Coordinated Routing : applications in location and inventory management

Andersson, Henrik January 2006 (has links)
Almost everywhere, routing plays an important role in everyday life. This thesis consists of three parts, each studying different applications where routing decisions are coordinated with other decisions. A common denominator in all applications is that an intelligent utilization of a fleet of vehicles is crucial for the performance of the system. In the first part, routing and inventorymanagement decisions are coordinated, in the second part, routing decisions concerning different modes of transportation are coordinated with inventory management, and in the third part, location decision and routing are coordinated. In the first part, an application concerning waste management is presented. Many industries generate garbage, and instead of handling the waste disposal themselves, other companies, specialized in garbage collection, handle the disposal. Each industry rents containers from a company to be used for waste, and the garbage collection companies handle the collection. The industries buy a service including one or more containers at the industry and the garbage collection companies are obliged to make sure that the containers never become overfull. The idea is that the industries buy this service and in return, the garbage collection company can plan the collection so that the overall cost and the number of overfull containers is minimized. Two models for the problem facing the garbage collection company are proposed. The first is solved using a Lagrangean relaxation approach on a flow based model, and the second is solved using Benders decomposition on a column based model. The second part investigates a distribution chain management problem taken from the Swedish pulp industry. Given fixed production plans at the mills, and fixed customer demands, the problem is to minimize the distribution cost. Unlike many other models for marine distribution chains, the customers are not located at the harbors. This means that the model proposed also incorporates the distribution planning from the harbors to the customers. All customers are not served from the harbors; some are served directly from the mills using trucks and trains to distribute the pulp, and these decisions are also included. The problem is modeled as a mixed integer linear program and solved using a branch and price scheme. Due to the complexity of the problem, the solution strategy is divided into two phases, where the first emphasizes the generation of schedules for the vessels operated by the company, while the second deals with the chartering of vessels on the spot market. In the third part, routing is combined with location decisions in the location-routing problem. Special emphasis is given to strategic management where decision makers must make location, capacity and routing decisions over a long planning period. The studied application comes fromstrategic schoolmanagement, where the location and capacity of the schools as well as their catchment areas are under consideration. The problem is modeled as a mixed integer linear program. The computational study shows the importance of incorporating a routing component allowing multiple visits, as well as the danger of having a too short planning period.
88

Samarbete ger samordnad behandling : För individer med samsjuklighet / Coordinated treatment : For individs with co-morbidity

Petersson, Malin, Perez, Chaly January 2010 (has links)
Syftet med studien var att undersöka hur samarbetet för individer med samsjuklighet ser ut mellan kommun och landsting samt hur möjligheterna ser ut till samordnad vård och behandling. Frågeställningarna var att ta reda på hur samarbetet ser ut mellan kommun och landsting gällande individer med samsjuklighet samt vilka tillvägagångssätt som finns för att förbättra samordnad vård och behandling mellan kommun och landsting. Studien genomfördes med kvalitativa semistrukturerade intervjuer. Den teoretiska utgångspunkten var Fridolfs (2004) fyra motiv till ett bra samarbete. Utifrån det hermeneutiska synsättet tolkades intervjuerna inför resultatet med hjälp av innehållsanalys. Resultatet visar att det finns ett samarbete mellan kommun och landsting men för förbättring behövs det mer erfarenhet och kunskap om varandras arbetsuppgifter. Slutsatsen av resultatet är att mer forskning fordras om hur och på vilket sätt samarbete mellan kommun och landsting kan förbättras. Kan en gemensam huvudman vara ett alternativ?
89

Att samverka med hjälp av Gemensamma Individuella Vårdplaner : en undersökning av ett samverkansprojekt i Sollentuna kommun hösten/vintern 2007

Blom, Robert, Sandström, Ulf January 2007 (has links)
The purpose of this paper is to provide an overview of how cooperation functions between the health services and social services within Sollentuna County Municipal area regarding clients and simultaneous or double diagnoses. Focusing more specifically; the paper also aims to provide additionally, an inquiry as to how the implementation of the Gemensam Individuell Vårdplan (GIVP) (The Integrated Individual Service Care Programme or (GIVP) functions within the Sollentuna Municipal County Area. The questions asked in the paper are: How do the Municipal and County Council personnel experience how the (GIVP) system functions in Sollentuna? How do the Municipal Council and County Council personnel respectively describe their own and their cooperative sister services rolls in terms of the implementation of the GIVP system in practice? The projection activates a hypothesis and tries to explain how the cooperation functions and provides an assessment as to how it functions or not as may be the case in practise. The authors attempt to achieve this using a combination of methodologies. Partly through data based collection and collation through the use of a vignette-focus-study and partly through the use of a questionnaire. A combination of methods has been used to collate both quantitative and qualitative data. The analysis and interpretation of the data is managed through the use of Bengt Berggren’s (1982) cooperative model, incorporating both cognitive theory as well as meta-cognitive theory. The purpose and application of the theories is designed both to individually and collectively nuance interpretations of the relevant data. The investigations primary results show the existence of a strong willingness to cooperate. It shows that cooperation is widely regarded as being important, and that in addition, GIVP is regarded as a useful system for an improved integrated service. It additionally suggests that cooperation can be improved amongst the relevant services to an even greater extent.
90

Haptic Control of Hydraulic Machinery Using Proportional Valves

Kontz, Matthew Edward 30 July 2007 (has links)
Supplying haptic or force feedback to operators using hydraulic machinery such as excavators has the potential to increase operator capabilities. Haptic, robotic, human-machine interfaces enable several enhancing features including coordinated motion control and programmable haptic feedback. Coordinated or resolved motion control supplies a more intuitive means of specifying the equipment's motion. Haptic feedback is used to relay meaningful information back to the user in the form of force signals about digging force acting on the bucket, programmable virtual constraints and system limitations imposed by the mechanism, maximum pressure or maximum flow. In order to make this technology economically viable, the benefits must offset the additional cost associated with implementation. One way to minimize this cost is to not use high-end hydraulic components. For smaller backhoes and mini-excavators this means that the hydraulic systems are comprised of a constant displacement pump and proportional direction control valves. Hydraulic and haptic control techniques suitable for backhoes/excavators are developed and tested on a small backhoe test-bed. A virtual backhoe simulator is created for controller design and human evaluation. Not only is the virtual simulator modeled after the test-bed, but the control algorithm used in the simulator is the same as the actual backhoe test-bed. Data from human subject tests are presented that evaluate the control strategies on both the real and virtual backhoe. The end goal of this project is to incorporate coordinated haptic control algorithms that work with low-cost systems and maximize the enhancement of operator capabilities.

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