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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.
41

Queue Streaming Model Theory, Algorithms, and Implementation

Zope, Anup D 03 May 2019 (has links)
In this work, a model of computation for shared memory parallelism is presented. To address fundamental constraints of modern memory systems, the presented model constrains how parallelism interacts with memory access patterns and in doing so provides a method for design and analysis of algorithms that estimates reliable execution time based on a few architectural parameters. This model is presented as an alternative to modern thread based models that focus on computational concurrency but rely on reactive hardware policies to hide and amortize memory latency. Since modern processors use reactive mechanisms and heuristics to deduce the data access requirement of computations, the memory access costs of these threaded programs may be difficult to predict reliably. This research presents the Queue Streaming Model (QSM) that aims to address these shortcomings by providing a prescriptive mechanism to achieve latency-amortized and predictable-cost data access. Further, the work presents application of the QSM to algorithms commonly used in a number of applications. These algorithms include structured regular computations represented by merge sort, unstructured irregular computations represented by sparse matrix dense vector multiplication, and dynamic computations represented by MapReduce. The analysis of these algorithms reveal architectural tradeoffs between memory system bottlenecks and algorithm design. The techniques described in this dissertation reveal a general software approach that could be used to construct more general irregular applications, provided they can be transformed into a relational query form. It demonstrates that the QSM can be used to design algorithms that enhance utilization of memory system resources by structuring concurrency and memory accesses such that system bandwidths are balanced and latency is amortized. Finally, the benefit of applying the QSM algorithm to the Euler inviscid flow solver is demonstrated through experiments on the Intel(R) Xeon(R) E5-2680 v2 processor using ten cores. The transformation produced a speed-up of 25% over an optimized OpenMP implementation having identical computational structure.
42

Automated Runtime Analysis and Adaptation for Scalable Heterogeneous Computing

Helal, Ahmed Elmohamadi Mohamed 29 January 2020 (has links)
In the last decade, there have been tectonic shifts in computer hardware because of reaching the physical limits of the sequential CPU performance. As a consequence, current high-performance computing (HPC) systems integrate a wide variety of compute resources with different capabilities and execution models, ranging from multi-core CPUs to many-core accelerators. While such heterogeneous systems can enable dramatic acceleration of user applications, extracting optimal performance via manual analysis and optimization is a complicated and time-consuming process. This dissertation presents graph-structured program representations to reason about the performance bottlenecks on modern HPC systems and to guide novel automation frameworks for performance analysis and modeling and runtime adaptation. The proposed program representations exploit domain knowledge and capture the inherent computation and communication patterns in user applications, at multiple levels of computational granularity, via compiler analysis and dynamic instrumentation. The empirical results demonstrate that the introduced modeling frameworks accurately estimate the realizable parallel performance and scalability of a given sequential code when ported to heterogeneous HPC systems. As a result, these frameworks enable efficient workload distribution schemes that utilize all the available compute resources in a performance-proportional way. In addition, the proposed runtime adaptation frameworks significantly improve the end-to-end performance of important real-world applications which suffer from limited parallelism and fine-grained data dependencies. Specifically, compared to the state-of-the-art methods, such an adaptive parallel execution achieves up to an order-of-magnitude speedup on the target HPC systems while preserving the inherent data dependencies of user applications. / Doctor of Philosophy / Current supercomputers integrate a massive number of heterogeneous compute units with varying speed, computational throughput, memory bandwidth, and memory access latency. This trend represents a major challenge to end users, as their applications have been designed from the ground up to primarily exploit homogeneous CPUs. While heterogeneous systems can deliver several orders of magnitude speedup compared to traditional CPU-based systems, end users need extensive software and hardware expertise as well as significant time and effort to efficiently utilize all the available compute resources. To streamline such a daunting process, this dissertation presents automated frameworks for analyzing and modeling the performance on parallel architectures and for transforming the execution of user applications at runtime. The proposed frameworks incorporate domain knowledge and adapt to the input data and the underlying hardware using novel static and dynamic analyses. The experimental results show the efficacy of the introduced frameworks across many important application domains, such as computational fluid dynamics (CFD), and computer-aided design (CAD). In particular, the adaptive execution approach on heterogeneous systems achieves up to an order-of-magnitude speedup over the optimized parallel implementations.
43

Vendor Lock-in in the transistion to a Cloud Computing platform

Fawzy Kamel, Menatalla Ashraf January 2015 (has links)
The thesis introduces a study about the vulnerabilities that a company as Scania IT faces towards vendor lock-in in the transition to a cloud computing platform. Cloud computing is a term that refers to anetwork of remote servers hosted on the internet to store, manage and process data, rather than on a local server or a personal computer. Vendor lock-in is an outcome that causes companies to pay a significant cost to move between cloud providers. The effects that cause vendor lock-in that will be described are portability, interoperability and federation are called the lock-in effects. The goal of the research is to help Scania IT understand the vendor lock-in and the vulnerabilities they can face in the transition to the cloud as well as to clarify the concern that they may have against falling in vendor lock-in. The main purpose of the research is to present the various lock-in effects that are related to the transition from one cloud provider to another and the vulnerabilities that cause companies to fall in vendor lock-in. The thesis presents the reasons that motivates why Scania IT would consider using the cloud and the concerns that they may have against usage of a cloud computing platform. The results will be based on a case study of a similar company that has moved to a cloud provider and specifically Microsoft Azure and an interview of Microsoft Azure point of view with the risk of vendor lock-in. Finally, a process of interviews with different people from Scania IT to extract the current bottleneck in the development process that caused the company to think of a cloud computing platform. The results show that companies should consider many risks and factors while moving to the cloud, as vendor lock-in, cloud maturity index and their IT strategies. As a result, the thesis gives recommendations of the steps needed to minimize the risks of the cloud while maintaining the positivity of the cloud. / Uppsatsen presenterar en studie om de sårbarheter som ett företag som Scania IT har mot inlåsning i övergången till molntjänster. Molntjänster är en term som hänvisar till ett nätverk av servrar som finns på internet för att lagra, hantera och processa data, istället för på en lokal server eller en persondator. Inlåsning är ett resultat i vilket orsakar att företagen behöver betala en betydande kostnad för att flytta mellan molnleverantörer. De effekter som orsakar inlåsning vilket kommer att beskrivas är portabilitet, interoperabilitet och federation, dessa kallas inlåsningseffekter. Målet med forskningen är att hjälpa Scania IT att förstå inlåsning och sårbarheter som de kan möta i övergången till molnet. Dessutom är målet att klarlägga riskerna som de kan ha mot att falla i inlåsning. Det huvudsakliga syftet med forskningen är att presentera de olika inlåsningseffekter som är relaterade till övergången från en molnleverantör till en annan samt de sårbarheter som orsakar företagen att falla i inlåsning. Uppsatsen presenterar skäl som motiverar varför Scania IT ska överväga att använda molnet samt den oro som de kan ha mot användning av en molnleverantör. Resultaten kommer att baseras på en fallstudie av ett liknande företag som har flyttat till en molnleverantör och specifikt Microsoft Azure samt en intervju av Microsoft Azure synvinkel med risken för inlåsning. Slutligen, en rad av intervjuer med olika personer från Scania IT för att extrahera den nuvarande flaskhalsen i utvecklingsprocessen som orsakade företaget att tänka på molntjänster. Resultaten visar att företagen bör överväga många risker och faktorer när de flyttar till molnet, som exempelvis inlåsning, cloud maturity index och deras IT-strategier. Som ett resultat ger examensarbetet nödvändiga rekommendationer för att minimera riskerna för molnet samtidigt som positivitet av molnet.
44

兩岸四地勞工退休保障可攜性之研究 / An analysis on Possibility of Pension Portability for Interregional Mobile Workers

潘智茵, Pun, Chi Ian Unknown Date (has links)
人口老化是全球趨勢,而此現象引起社會各界對退休保障的關注。此外,跨國勞工移動人數因全球化而急速上升。勞工跨國移動對於跨國界之退休保障帶來新的挑戰。作為社會的一份子,每人都應該享有社會保障的權利,但跨國移動勞工可能會面對與就業國本地勞工在社會保障上存在差別待遇之問題,甚至有機會同時失去家國及就業國的社會保障。勞工個人的流動量越大,對其退休保障所造成的影響就會越大。 會產生此類問題的原因是因為勞工跨國移動,但國家之間的退休保障制度卻沒有連接起來。此問題可以通過簽訂雙邊協議或多邊協議來解決。通過協議,就業國應提供外籍勞工與本地勞工平等待遇。協議亦可用於訂定移動勞工應該適用那一個國家的法規。同時亦可以解決投保年資中斷及分隔兩地、給付出口有設置限制等問題。雖然並非必須的,但協議可幫助協約國間之退休行政服務連結起來,為受益人帶來方便性。 保障移動勞工的權益不只單單是允許其參加退休保障制度,而且應該確保勞工受到與本地勞工同等之對待。通過訂定社會保障協議,勞工即使離國工作亦可以維持獲取退休保障之權利。社會保障可攜性,特別是退休保障,不止對勞工有利,對政府、對經濟發展亦是有益處的。 近年兩岸四地的經濟交流合作及勞工流動增加,四地之間的退休保障問題更值得關注。探討兩岸四地退休保障可攜性,可以幫助解決或至少減低四地間移動勞工之退休保障攜帶性損失。 / Aging population is a global phenomenon and this leads to the concern of social security issues. Besides, the number of international mobile workers is increasing rapidly due to globalization. International labour mobility is creating new challenges for cross national social security. Being a member of the society, everyone should have the right to social security, but international mobile workers may face the problem of having a deduction on pension benefits comparing with native workers, or even, lack of social security protection from both home and host countries. And the larger the mobility, the greater the influences are towards pension benefits. These problems occur because of workers working abroad, but there is no connection between the social security systems between home and host countries. This can be solved by concluding bilateral agreements or multilateral agreements. Through social security agreements, the host countries should provide equality of treatment towards expatriates. Besides, agreements can also be used for the determination of the applicable legislation, as well as solving the problems of separation of insured years and restrictions on the export of benefits etc. Although it is not a must, agreements can also help in providing administrative assistance for beneficiaries. Ensuring the right to social security of mobile workers is not only allowing them to join social security schemes, but also guaranteeing them to have equality of treatment comparing with native workers. Social security agreements can help in maintaining the right to social security for mobile workers. Portability of social security, especially on pension issue, benefits not only mobiles workers, but also government and the economic development. The economic cooperation and labour mobility between Taiwan, China, Hong Kong and Macau is increasing in recent years, and thus brings to the attention on the pension issue for mobile workers between places. Analyze on interregional pension portability can help in solving, or at least reducing the portability loss of mobile workers among these four places.
45

The SoftDecom Engine

Benitez, Jesus, Guadiana, Juan, Torres, Miguel, Creel, Larry 10 1900 (has links)
ITC/USA 2006 Conference Proceedings / The Forty-Second Annual International Telemetering Conference and Technical Exhibition / October 23-26, 2006 / Town and Country Resort & Convention Center, San Diego, California / The software decommutator was recently fielded at White Sands to address the requirements of a new missile test program. This software decommutator is rewritten as a simple C program Function or Class with a simple interface. The function and an Interface Control Definition (ICD) comprise the SoftDecom Engine (SDE). This paper addresses how an SDE can deliver Enterprise Wide Portability, not only that of the SDE, but more importantly a test program!s Verification & Validation (V&V). The crux of the portability issue is reduced to defining the interface of the SDE. In the simplest manifestation only two interfaces are needed and one is a given. The input structure is defined by the telemeter minor frame with time appended if desired. The output structure is no more than an array containing the parameters required. The ICD could be generalized into a standard for most applications, but that isn!t necessary, as the structures are simple, hence easy to adapt to anyway. This new paradigm!s importance will flourish on industries irreversible migration to faster and more complex telemeters. The paper reviews the relative ease that software exhibits when addressing very complex telemeters. With confidence it may be said “ if the telemeter format can be described in writing, it can be processed real time”. Also discussed are tasks that normally require specialized or customized and expensive equipment for example, merged streams, complex simulations and recording and reproducing PCM (sans recorder). Hopefully, your creativity will be engaged as ours has been.
46

Etude des architectures échantillonnées de réception radio en technologies CMOS submicroniques avancées

Mina, Rayan 18 December 2008 (has links) (PDF)
Avec l'arrivée des systèmes radio mobiles de troisième et de quatrième génération, les standards de communications ont tendance à occuper plus de bande pour pouvoir assurer des services de voix, de données et de multimédia. En parallèle, le terminal mobile doit être reconfigurable pour couvrir à la fois le service cellulaire et la connectivité de données. Dans ce contexte, la tendance est d'intégrer les fonctions radio et bandes de base sur le même substrat en utilisant la technologie CMOS afin de réduire la surface, le coût de fabrication et la consommation des terminaux sans fils. Récemment, de nouvelles architectures de réception radio dites " échantillonnées " sont apparues (TexasInstruments, STMicroelectronics, UCLA). Dans ce cas, l'échantillonnage est fait directement sur le signal RF et la majorité du traitement de signal se fait en temps-discret par des capacités commutées. L'évolution de la technologie CMOS et la miniaturisation des transistors rendent la conception analogique de plus en plus difficile (capacités parasites, bruit, linéarité, etc.). De nouveaux effets parasites apparaissent comme la fuite de grille qui inquiète désormais les technologues et les concepteurs de circuits. D'un autre côté, des contraintes de dynamique surgissent avec la diminution des tensions d'alimentation et le bruit des circuits numériques de plus en plus denses augmente considérablement. Le but de ce travail de thèse est de répondre à la question de la portabilité de la solution échantillonnée, en étudiant l'impact des différents effets parasites cités précédemment sur les performances radio de la solution. Ainsi, les critères de portabilité qui sont considérés sont la reconfigurabilité, l'immunité aux effets parasites, l'adaptation à la baisse des tensions d'alimentation, la surface, la consommation et la facilité de conception. Ce travail de thèse a été basé sur des études théoriques et sur des simulations d'une solution échantillonnée de réception radio. Afin d'affronter réellement les problématiques de portabilité, un portage d'une chaîne de réception échantillonnée Wi-Fi/WiMAX de CMOS 65nm à 45nm a été réalisé. Les résultats de mesures obtenus sur ce circuit donnent une grande confiance vis-à-vis des performances radio de la solution échantillonnée et constituent un premier élément de réponse concret à la question de portabilité étudiée.
47

A portable uniform random number generator well suited for the rejection method

Hörmann, Wolfgang, Derflinger, Gerhard January 1992 (has links) (PDF)
Up to now all known efficient portable implementations of linear congruential random number generators with modulus 2^(31)-1 are working only with multipliers which are small compared with the modulus. We show that for non-uniform distributions, the rejection method may generate random numbers of bad quality if combined with a linear congruential generator with small multiplier. Therefore a method is described that works for any multiplier smaller than 2^(30). It uses the decomposition of multiplier and seed in high order and low order bits to compute the upper and the lower half of the product. The sum of the two halfs gives the product of multiplier and seed modulo 2^(31)-1. Coded in ANSI-C and FORTRAN77 the method results in a portable implementation of the linear congruential generator that is as fast or faster than other portable methods. (author's abstract) / Series: Preprint Series / Department of Applied Statistics and Data Processing
48

CCS - Collect, Convert and Send : Designing and implementing a system for data portability and media migration to mobile devices

Gustafsson, Jonas, Alserin, Fredrik January 2006 (has links)
<p>In this thesis we will identify which are the desired features and functionalities for implementing a system capable of acting as an information bridge for content available in the “wired” Internet to be delivered to mobile devices. We will also explore how to design and build such a system based on the specifications within parts of the MUSIS project. The MUSIS’ system development is used as a base of the work described in this thesis and the experiences from those efforts are used in order to design a system with more focus on data portability and media migration.</p><p>During the development of the MUSIS platform, problems related to system upgrading, i.e. adding new ad-hoc functionalities were discovered. Due to the fact that a user-centred design approach was taken, this was essential in the project. To solve some of these issues, we propose a new component-based system with a high level of scalability and re-usability. We name this system Collect, Convert and Send, CCS. The system shall be seen as a base that can be used as a core system for different projects where interoperability of content between different platforms, devices or systems is important.</p><p>The implementation of the system is based on the use cases and those theoretical aspects and ideas related to component software, interoperability, media migration and metadata in a Web service context. The results of our efforts give some indications that the use of component software gives a foundation for a service-oriented architecture.</p>
49

Konfucianistinės - maoistinės pedagogikos vertybių ir principų hermeneutinė interpretacija / Hermeneutic interpretation of confucian - maoistic pedagogy values and principles

Savickis, Antanas 03 September 2010 (has links)
Šiame darbe nagrinėjamos pagrindinės konfucianizmo – maoizmo moralinės padegogikos idėjos bei vertybės. Konfucianistinės – maoistinės pedagogikos idėjos Vakaruose yra klaidingai traktuojamos ir privalo būti išverstos / perkeltos į mūsų suvokimui artimesnes formas. Pirmojoje darbo dalyje nuodugniai aprašomas hermeneutinio rato metodas bei intersubjektyvumo teorija, leidžianti tyrimo metu įgyjamą asmeninį suvokimą perkelti kitiems ugdymo sistemos dalyviams. Antrojoje dalyje aprašomos Kinijos idėjinių lyderių pamatinės idėjos, stengiamasi išskirti pagrindines jų, pateikti asmeniniu sovokimu grindžiamą interpretaciją. Trečioji dalis skirta konfucianizmą – maoizmą nagrinėjusių Vakarų autorių idėjų nagrinėjimui, pasitelkiant darbo metu įgytą suvokimą. Šiame darbe paaiškėjo, kad Vakarų mokslininkai neretai klaidingai interpretuoja Kinijos pamatines ugdymo idėjas; kad Kinijos idėjinių lyderių idėjos gali būti traktuojamos kaip vientisa, vieninga sistema. / In this work is analyzed basic ideas and values of confucianistic – maoistic moral pedagogy. Confucianistic – maoistic moral pedagogy ideas is wrongly perceived in Western countries and demands peculiar translation / transfer to forms, appropriate to our perception. In the first part of work is described in detail method of hermeneutic circle and theory of intersubjectivity, which allows personal knowing transfer to other members or certain educational system. In second part are presented main Chinese principled leaders educational ideas. Efforts were made to exclude main ideas, give personal interpretation for them. Third part is intended to analize Western authors, who were writing about confucianistic – maoistic theories, by using new gained perception. This work showed that often Western scientists quite skin-deep assess Chinese main educational ideas; the ideas of Chinese leaders can be understood in a way of united, integral system.
50

Televisão digital nos espaços públicos : promoção da hospitalidade social /

Souza, Thalita Maria Mancoso Mantovani e. January 2011 (has links)
Orientador: Maria Cristina Gobbi / Banca: João Baptista de Mattos Winck Filho / Banca: Jane Aparecida Marques / O "Programa de Pós-Graduação em Televisão Digital: informação e conhecimento" capacita profissionais para atuarem em televisão digital nas três áreas: comunicação, educação e tecnologia / Resumo: A televisão digital no Brasil objetiva promover interação entre as diversas áreas, tais como: gestão da informação, tecnologia, educação, comunicação, engenharia e, destancando-se a hospitalidade, para que, juntas, possam buscar resultados, contemplando os seres humanos, matéria prima desses diversificados saberes. Neste contexto, o presente estudo analisa a portabilidade e a mobilidade da televisão digital como possibilidades de promoção para o hospitabilidade social. São recentes as pesquisas sobre televisão digital e hospitabilidade no Brasil. As tecnologias digitais apresentam novos ingredientes aos conceitos da hospitabilidade, convergindo para a possibilidade do resgate do ser social, integrando e reforçando seus vínculos sociais no espaço tecnológico. A metodologia escolhida para este estudo consiste nas pesquisas exploratória, bibliográfica e qualitativa. Assim, com a televisão digital, é possível que tenhamos novas formas de sociabilidade, pois pode ser levada e assistida em e para qualquer lugar, em decorrência dos seus recursos de portabilidade e mobilidade, os quais permitem a construção de laços sociais ou em um conceito mais amplo, a hospitabilidade social nos espaços públicos. A implantação da televisão digital, além do progresso tecnológico, também permite uma sociedade mais comunicativa, com o receptor da mensagem mais ativo, participativo e interativo inclusive na construção de laços de hospitabilidade. Por estas considerações, acredita-se que a televisão digital e as ferramentas de portabilidade e mobilidade contribuem para tornarem os espaços públicos lugares de reconhecimento, de possibilidades de encontro, de proximidade com o outro, de hospitabilidade social / Abstract: Digital television in Brazil aims to promote interaction between many areas such as information management, technology, education, communications, engineering, and the hospitality, so that together they can get results, considering the human, material os these diverse knowledge. In this context, this study examines the portability and mobility of digital television as opportunities to promote social hospitality. The research on digital television and hospitality in Brazil are recent. Digital tecnhnologies ofter new ingredientes to the concepts of hospitality, converging to the possibility of redemption of the social being, integrating and strengthening their social ties in the technological space. The methodology chosen for this study consists of research, exploratory and qualitative literature. So, with digital television, we way have new forms of sociability, it can be taken and seen anywhere and, due to their portability and mobility capabilities, which allow the construction of social ties or a concept broader social hospitality in public spaces. The deployment of digital television in addition to technological progress, it also allows a more communicative society, with the receiver of the message more active, participatory and interactive including the construction of bonds of hospitality. For these considerations, it is believed that digital television and tools for portability and mobility contribute to public spaces become places of recognition, opportunities for encounters and proximity to the other the social hospitality / Mestre

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