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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.
21

Transformations source-à-source pour l'optimisation de codes irréguliers et multithreads

Jaeger, Julien 02 July 2012 (has links) (PDF)
Dans cette thèse, nous montrons que les optimisations source-à-source sont un moyen efficace pour générer des programmes irréguliers ou parallèles performants à partir d'une implémentation. Après avoir présenté l'évolution des architectures des processeurs, nous proposons deux méthodes distinctes. La première pour extraire des codelets d'un programme irréguliers, les optimiser et prédire les performances du programme modifié. L'autre pour limiter l'impact des problèmes d'alignements dus à la vectorisation ou aux conflits de bancs. Nous présentons aussi différentes techniques de parallélisation, l'une générant des codelets parallèles, l'autre ordonnançant un graphe de taches sur un système hétérogène.
22

Projeto e desenvolvimento de uma fonte de potência CA trifásica a quatro fios / Design and development of a three-phase four-wire AC power source

Stefanello, Márcio 06 April 2006 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work presents a contribution to the study of AC Power Sources, where a prototype s development is presented. The stages that compose the system, including converter topology, filter, instrumentation and controller, are presented. The developed prototype is a three-phase four-wire source, which uses a four-leg voltage source inverter. This topology increases the flexibility for unbalanced waveforms generation or unbalanced load conditions, also simplifying the control problem of the process. This work first looks for justifying the use and the study of AC Power Sources, in this sense, some examples of tests and norms, whose tests demand its use, are given. The applications are in general related to electrical and electronic equipments and for driving electromechanical plants such as shakers. In this sense, AC Power Sources are equipment that can be used both in industry applications and didactic or research laboratories. In practically all applications, it is shown that good performance in waveforms generation is necessary. This performance is related to the ability for waveforms generation with low harmonic distortion even in conditions of variable frequency or amplitude and with nonlinear loads behavior. In this way, the use of an adequate converter topology is not enough, are too necessary controllers to guarantee performance for the system, even in adverse load conditions or in presence of unmodeled dynamics. The unmodeled dynamics are derived from some stages that compose the system, but they are generally related to the uncertainties on the model of the plant and load. Then, this work not only describes the implemented prototype and topological relative questions but also applies a Robust Model Reference Adaptive Control (RMRAC) for the plant control. This technique improves the robustness in the closed loop system even under presence of unmodeled dynamics and disturbances. The controller makes use of a Gradient type algorithm for parametric adaptation with four adapted parameters, which leads to a new error equation that is used for the controller s implementation / Este trabalho apresenta uma contribuição ao estudo de Fontes de Potência CA onde é apresentado o desenvolvimento de um protótipo. Os diversos estágios que compõem o sistema, desde a topologia do conversor, do filtro, da instrumentação e do controlador são apresentados e analisados. O protótipo desenvolvido é uma fonte trifásica a quatro fios, que utiliza um inversor de tensão de quatro braços. Esta topologia permite uma maior flexibilidade na geração de formas de onda desbalanceadas ou em condições de cargas desequilibradas, simplificando também o problema de controle do sistema. Este trabalho procura primeiramente justificar a utilização e o estudo de Fontes de Potência CA, neste sentido são dados alguns exemplos de ensaios e normas, cujos testes demandam a sua utilização. As aplicações são em geral relacionadas a equipamentos eletroeletrônicos e acionamento de outras plantas como vibradores eletromecânicos. Deste modo, as Fontes de Potência CA são equipamentos que podem ser utilizados tanto na indústria quanto em laboratórios didáticos e de pesquisa. Em praticamente todas as aplicações, é mostrado que um bom desempenho na geração de formas de onda é necessário. Este desempenho está relacionado à capacidade de geração de formas de onda com baixa distorção harmônica, não raro, em condições de freqüência e amplitude variáveis e com cargas de comportamento não-linear. Deste modo, a seleção de uma topologia de conversor adequado não basta, são também necessários controladores que garantam um bom desempenho do sistema, mesmo em condições adversas de carga e em presença de dinâmicas não-modeladas. As dinâmicas não-modeladas são oriundas das várias etapas que compõem o sistema, mas geralmente são relacionadas às incertezas sobre o modelo da planta e da carga. Neste sentido, este trabalho descreve não apenas o protótipo implementado e questões topológicas relativas a ele, mas também aplica um Controle Robusto por Modelo de Referência ou RMRAC (Robust Model Reference Adaptive Control) para o controle da planta. Esta técnica garante robustez do sistema em malha fechada mesmo na presença de dinâmicas não modeladas e distúrbios. O controlador utilizado faz uso de um algoritmo de adaptação paramétrica do tipo Gradiente, no qual quatro parâmetros são adaptados. Este fato leva a uma nova equação do erro, que é utilizada para a implementação do controlador.
23

Translation of CAN Bus XML Messages to C Source Code

Andersson, Gustav January 2020 (has links)
The concept of translating source code into other target programming languages is extensively used in a wide area of applications. Danfoss Power Solutions AB, a company located in Älmhult, strives to streamline their way of software development for microcontrollers by implementing this idea. Their proprietary software tool PLUS+1 GUIDE is based on the CAN bus communication network, which allows electronic control units to share data represented in the XML format. Due to compatibility problems, the application in the electronic control units requires this data to be translated into the source code in the low-level C programming language. This thesis project proposes an approach for facilitating this task by implementing a source-to-source compiler that performs the translation with a reduced level of manual user involvement. A literature review was conducted in order to find the existing solutions relevant to our project task. An analysis of the provided XML input files was thereafter performed to clarify a software design suitable for the problem. By using a general XML parser, a solution was then constructed. The implementation resulted in a fully functional source-to-source compiler, producing the generated C code within a time range of 73–85 milliseconds for the input test files of typical size. The feedback received from the domain experts at Danfoss confirms the usability of the proposed solution.
24

Context-aware automated refactoring for unified memory allocation in NVIDIA CUDA programs

Nejadfard, Kian 25 June 2021 (has links)
No description available.
25

Výkonový zesilovač pro pásmo 435MHz s vysokou účinností / Power amplifier for 435MHz Band with High Efficiency

Herceg, Erik January 2017 (has links)
This diploma thesis is focused on design of high frequency power amplifiers in UHF band, specifically at 435 MHz. Amplifiers are designed in different classes of operation. The thesis deals with the comparison of main parameters in each class of operation, the most important parameter is effeciency. The amplifying part is unipolar transistor which is working in Single-stage mode. The results were simulated in Advanced Design Systems Software.
26

Water quality of the Red River system in the period 2012 - 2013: Short communication

Le, Thi Phuong Quynh, Ho, Tu Cuong, Duong, Thi Thuy, Nguyen, Thi Bich Ngoc, Vu, Duy An, Pham, Quoc Long, Seidler, Christina 07 December 2015 (has links)
Few data are available on the quality of Red river water that is used for multi-purposes, including for domestic water demand in some rural areas. This paper presents the observation results of the Red River water quality in two years 2012 and 2013. The monitoring results showed that the average concentrations of nutrients (N, P) were still far lower than the allowed value of the Vietnamese standard limits for surface water quality (QCVN 08:2008/BTNMT, column A2). Due to the impoundment of two big dams in the Da tributary, the suspended solids contents in river water decreased remarkably. The dissolved heavy metal (DHM) concentrations varied in a high range: Cu: 10 – 80 μg.l-1; Zn: 2 – 88 μg.l-1; Cr: 0.2 – 5.1 μg.l-1; Pb: 2 - 107 μg.l-1; Cd: 2 – 12 μg.l-1; Mn: 2 - 35 μg.l-1; and Fe: 160 – 2370 μg.l-1. Most of the mean values of DHM were lower than the allowed values of the QCVN 08:2008/BTNMT, but at several points of time, several DHM (e.g. Fe, Cd, Pb) contents exceeded the allowed values. The Total Coliform (TC) and Fecal Coliform (FC) densities varied in a high range: TC: 23 to 13,000MPN.100ml-1 and FC: 0 to 1,600MPN.100ml-1 and they exceeded the allowed values QCVN 08:2008/BTNMT at several points observed. The dissolved organic carbon (DOC) contents were in low level and the particulate organic carbon (POC) content mainly derived from soil organic leaching and erosion in the basin. The results underlined the need for regularly monitoring the river water quality, and there should be some effective solutions to manage and treat the waste sources in order to provide safe water for different actual purposes use in the Red River basin. / Rất ít số liệu sẵn có về chất lượng nước sông Hồng, dòng sông được sử dụng cho nhiều mục đích, bao gồm cả cung cấp nước sinh hoạt ở một số vùng nông thôn. Bài báo trình bày các kết quả quan trắc chất lượng nước sông Hồng trong hai năm 2012 và 2013. Kết quả quan trắc cho thấy chất dinh dưỡng (N, P) thấp xa so với giới hạn cho phép của tiêu chuẩn Việt Nam về chất lượng nước mặt (QCVN 08: 2008/BTNMT cột A2). Do có hai hồ chứa trên sông Đà, hàm lượng chất rắn lơ lửng trong nước sông giảm đáng kể. Các kim loại nặng hòa tan (DHM) có hàm lượng dao động trong khoảng rộng: Cu: 10-80 μg.l-1; Zn: 2-88 μg.l-1; Cr: 0,2-5,1 μg.l-1; Pb: 2-107 μg.l-1; Cd: 2-12 μg.l-1; Mn: 2-35 μg.l-1; và Fe: 160 - 2370 μg.l-1. Hầu hết các giá trị trung bình của DHM thấp hơn giá trị cho phép của quy chuẩn QCVN 08: 2008/BTNMT, tuy nhiên, tại một số thời điểm, một số DHM (ví dụ Fe, Cd, Pb) có hàm lượng vượt quá giới hạn cho phép. Mật độ tổng coliform (TC) và coliform phân (FC) dao động trong khoảng rộng: TC: 23 đến 13,000MPN.100ml-1 và FC: 0 đến 1,600MPN.100ml-1 và tại một số thời điểm mật độ TC và FC vượt giá trị cho phép của Quy chuẩn QCVN 08:2008/BTNMT. Hàm lượng cabon hữu cơ hòa tan (DOC) ở mức thấp, và hàm lượng cacbon hữu cơ dạng không tan (POC) chủ yếu có nguồn gốc từ đất rửa trôi và xói mòn trong lưu vực. Kết quả quan trắc nhấn mạnh nhu cầu giám sát thường xuyên chất lượng nước sông, và nên có các giải pháp hiệu quả để quản lý và xử lý các nguồn gây ô nhiễm trong lưu vực nhằm cung cấp nước sạch cho các mục đích sử dụng nước sông Hồng như hiện nay.
27

SIMD-aware word length optimization for floating-point to fixed-point conversion targeting embedded processors / Optimisation SIMD de la largeur des mots pour la conversion de virgule flottante en virgule fixe pour des processeurs embarqués

El Moussawi, Ali Hassan 16 December 2016 (has links)
Afin de limiter leur coût et/ou leur consommation électrique, certains processeurs embarqués sacrifient le support matériel de l'arithmétique à virgule flottante. Pourtant, pour des raisons de simplicité, les applications sont généralement spécifiées en utilisant l'arithmétique à virgule flottante. Porter ces applications sur des processeurs embarqués de ce genre nécessite une émulation logicielle de l'arithmétique à virgule flottante, qui peut sévèrement dégrader la performance. Pour éviter cela, l'application est converti pour utiliser l'arithmétique à virgule fixe, qui a l'avantage d'être plus efficace à implémenter sur des unités de calcul entier. La conversion de virgule flottante en virgule fixe est une procédure délicate qui implique des compromis subtils entre performance et précision de calcul. Elle permet, entre autre, de réduire la taille des données pour le coût de dégrader la précision de calcul. Par ailleurs, la plupart de ces processeurs fournissent un support pour le calcul vectoriel de type SIMD (Single Instruction Multiple Data) afin d'améliorer la performance. En effet, cela permet l'exécution d'une opération sur plusieurs données en parallèle, réduisant ainsi le temps d'exécution. Cependant, il est généralement nécessaire de transformer l'application pour exploiter les unités de calcul vectoriel. Cette transformation de vectorisation est sensible à la taille des données ; plus leurs tailles diminuent, plus le taux de vectorisation augmente. Il apparaît donc un compromis entre vectorisation et précision de calcul. Plusieurs travaux ont proposé des méthodologies permettant, d'une part la conversion automatique de virgule flottante en virgule fixe, et d'autre part la vectorisation automatique. Dans l'état de l'art, ces deux transformations sont considérées indépendamment, pourtant elles sont fortement liées. Dans ce contexte, nous étudions la relation entre ces deux transformations, dans le but d'exploiter efficacement le compromis entre performance et précision de calcul. Ainsi, nous proposons d'abord un algorithme amélioré pour l'extraction de parallélisme SLP (Superword Level Parallelism ; une technique de vectorisation). Puis, nous proposons une nouvelle méthodologie permettant l'application conjointe de la conversion de virgule flottante en virgule fixe et de l'exploitation du SLP. Enfin, nous implémentons cette approche sous forme d'un flot de compilation source-à-source complètement automatisé, afin de valider ces travaux. Les résultats montrent l'efficacité de cette approche, dans l'exploitation du compromis entre performance et précision, vis-à-vis d'une approche classique considérant ces deux transformations indépendamment. / In order to cut-down their cost and/or their power consumption, many embedded processors do not provide hardware support for floating-point arithmetic. However, applications in many domains, such as signal processing, are generally specified using floating-point arithmetic for the sake of simplicity. Porting these applications on such embedded processors requires a software emulation of floating-point arithmetic, which can greatly degrade performance. To avoid this, the application is converted to use fixed-point arithmetic instead. Floating-point to fixed-point conversion involves a subtle tradeoff between performance and precision ; it enables the use of narrower data word lengths at the cost of degrading the computation accuracy. Besides, most embedded processors provide support for SIMD (Single Instruction Multiple Data) as a mean to improve performance. In fact, this allows the execution of one operation on multiple data in parallel, thus ultimately reducing the execution time. However, the application should usually be transformed in order to take advantage of the SIMD instruction set. This transformation, known as Simdization, is affected by the data word lengths ; narrower word lengths enable a higher SIMD parallelism rate. Hence the tradeoff between precision and Simdization. Many existing work aimed at provide/improving methodologies for automatic floating-point to fixed-point conversion on the one side, and Simdization on the other. In the state-of-the-art, both transformations are considered separately even though they are strongly related. In this context, we study the interactions between these transformations in order to better exploit the performance/accuracy tradeoff. First, we propose an improved SLP (Superword Level Parallelism) extraction (an Simdization technique) algorithm. Then, we propose a new methodology to jointly perform floating-point to fixed-point conversion and SLP extraction. Finally, we implement this work as a fully automated source-to-source compiler flow. Experimental results, targeting four different embedded processors, show the validity of our approach in efficiently exploiting the performance/accuracy tradeoff compared to a typical approach, which considers both transformations independently.
28

Změny spektra zářivého toku světelných zdrojů v závislosti na napětí / Spectram power distribution of radiant flux depending on supply voltage

Novotný, Tomáš January 2008 (has links)
The master’s thesis consists of two parts. The first part describes base quantities of lighting engineering, basics of the electrical energy transformation to the light energy, laws of the thermal radiation and characteristics of incandescence and discharge light sources used for general illumination. This part concludes with a theoretical analysis of influence of power supply on the parameters of light source’s luminous flux. The second part of the thesis deals with the draft and configuration of a workplace for measuring spectral radiation of light sources depending on power supply. The last part of the thesis is created by the evaluation of spectral radiation and other light parameters changes according to the light source’s power supply changes.
29

Composants multiplateformes pour la prise en compte de l'hétérogénéité des terminaux mobiles / Cross-platform components to manage the heterogenity of mobile devices

Perchat, Joachim 08 January 2015 (has links)
Ces travaux de thèse visent à diminuer le coût de développement des applications mobilespour smartphones Android, iOS, etc. Les applications mobiles sont de plus en plus complexes. Auparavant, une application mobile se contentait d’afficher des données provenant du web. Maintenant, en plus de cela, elles communiquent avec le monde extérieur. Par exemple, certaines applications communiquent avec des montres, avec des écrans de télévision etc. D’autres permettent le scan de codes barres ou encore l’interaction avec des objets réels à travers la réalité augmentée. Les serveurs peuvent envoyer des notifications aux applications, etc. Une application mobile est devenue un logiciel à part entière. Cependant, pour toucher un maximum d’utilisateurs de smartphones, les applications mobiles doivent être conçues, implémentées et déployées sur tous les smartphones possibles. Avec la multiplication des configurations matérielles différentes ainsi que la multiplication des systèmes d’exploitation mobiles, cette tâche devient de plus en plus ardue. En effet, une application mobile doit souvent être réalisée une fois pour chaque plate-forme cible (Android, iOS, Windows Phone 8, etc.). Le temps et le coût de réalisation d’applications mobiles est donc multiplié par le nombre de plates-formes ciblées. Dans ces travaux, nous proposons de combiner le développement natif avec la programmation par composants. Pour ce faire, nous introduisons la notion de composants multiplateformes. Ce sont des composants qui peuvent être exécutés sur plusieurs plates-formes mobiles. Pour la représentation des composants, nous avons introduit la notion d’interface indépendante à n’importe quelle plate-forme mobile. Ainsi, l’intégration et l’assemblage se font d’une façon unique, que l’on soit dans un environnement de développement Android, iOS ou autre. Pour ce faire, nous avons spécifié un nouveau langage de programmation basé sur les annotations. Cette approche a été validée à travers le développement d’une application mobile pour Android et iOS avec notre solution. L’application implémentée a été réalisée en concordance avec les problématiques que rencontrent les entreprises de développement mobile et plus particulièrement Keyneosoft. Ensuite, nous avons comparé ces versions de l’application avec les versions développées nativement. Nous avons montré qu’avec notre solution nous diminuons le temps de développement d’au moins 30% sans aucune limitation pour les développeurs d’applications (même expérience utilisateur, même performance). Nous avons aussi comparé notre solution avec des produits disponibles sur le marché Phonegap, Titanium mobile et Xamarin. Nous en avons conclu que notre solutiton offrait le plus de possibilités sans aucune limitation. / In this thesis, we aim to decrease the development cost of applications for smartphones running Android, iOS, etc. Mobile applications are more and more complex. A few year ago, a mobile application was only design to display web content. Today, in addition, they are connected with the external world. For example, some applications are connected with watches, TVs, etc. Mobile applications became real softwares. However, in order to be visible by all smartphones users, mobile applications are designed, developed and deployed on every kind of smartphone. With the increase of the multiplicity of hardware configurations and the diversity of mobile operating systems, this task is becoming more and more laborious. Indeed, a mobile application is often implemented one time for each target platform (Android, iOS, Windows Phone 8, etc.). Therefore, the time and the cost for a mobile application implementation is multiplied by the number of target platforms. In this thesis, we propose to combine native development with the advantages of component-based software engineering. To do that, we have introduced the concept of multiplatform components. Those components are capable to be executed on any mobile platform. In order to describe components, we have introduced interfaces that are independent of any mobile platform. Thus, component integration and assembly are common on Android, iOS and others systems. To achieve that, we have specified a new programming language based on Annotations. We have validated this approach with the implementation of a real mobile application for Android and iOS. We have compared this application with the same application developed natively. Results show that with our solution, developers implement a multiplatform application 30% faster than native development. Moreover, our solution does not show any limitation for developers (same user experience, same performances). Finally, we have compared our solution with real products available on the software market: Phonegap, Titanium mobile and Xamarin. This comparison illustrates that our solution provides the best features and does not limit developers possibilities.
30

En modernisering av källkritisk undervisning / A Modernization of Teaching Source Criticism

Hansson, Johan, Nilsson, Kevin January 2022 (has links)
Syftet med denna översikt har varit att presentera aktuella metoder för den källkritiska undervisningen i högstadiet. Vår frågeställning genom arbetet har varit, “vilka metoder kan lärare undervisa om inom källkritik för att lära ut ett källkritiskt förhållningssätt?” Genom systematiska sökningar i olika databaser valde vi ut tio artiklar som kunde hjälpa oss att besvara vår frågeställning. Dessa artiklar ligger till grund för vårt arbete och vi har strävat efter att hitta svensk, Nordisk och även internationell forskning. Artiklarna vi valt har behandlat källkritik som ett eget område inom skolan och samhället, men även i relation till ämnet svenska.  För att analysera resultatet av valda artiklar har vi använt oss av en tematiskt analys. Genom analysmetoden har vi kunnat urskilja utmärkande drag i forskningen och därefter kunnat benämna det som olika tema. Med våra tema fastställda kunde vi presentera de metoder som var mest framträdande i forskningen, men även visa på att det finns vissa begränsningar inom området. I resultatet lyfter vi bland annat fram tre viktiga nyckelfrågor i en digital sökprocess och presenterar även en metod som vi benämner lateral läsning. Den laterala läsningen syftar till att bredda digitala sökningar och undersöka information på flera olika hemsidor. Vidare presenterar vi vad forskningen förespråkar om undervisning gällande källkritik där vi också drar slutsatsen att forskarna inte är överens om undervisningen ska ske explicit, eller implementeras som en del av den ordinarie undervisningen.

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