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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.
51

Vylepšení analýzy živých proměnných pomocí points-to analýzy / Improvement of Live Variable Analysis Using Points-to Analysis

Raiskup, Pavel January 2012 (has links)
Languages such as C use pointers very heavily. Implementation of operations on dynamically linked structures is, however, quite difficult. This can cause the programmer to make more mistakes than usual. One method for dealing with this situation is to use the static analysis tools. This thesis elaborates on the extension to the Code Listener architecture which is an interface for building static analysis tools. Code Listener is able to construct a call-graph or a control flow graph for a given source code and send it to the analyzing tool. One ability of the architecture is that it can conduct the live variable analysis internally. It detects places in the control flow graph where some subset of variables may be killed. The problem was that every variable for which a pointer address was assigned could not been killed, before. This decision had been made because there was no assurance that the variable could never been used through the pointer. So the goal of this work was to design and incorporate a points-to analysis which is able to exclude some references from the set of considered pointers to improve the live variable analysis.
52

Generation of Application Specific Hardware Extensions for Hybrid Architectures: The Development of PIRANHA - A GCC Plugin for High-Level-Synthesis

Hempel, Gerald 11 November 2019 (has links)
Architectures combining a field programmable gate array (FPGA) and a general-purpose processor on a single chip became increasingly popular in recent years. On the one hand, such hybrid architectures facilitate the use of application specific hardware accelerators that improve the performance of the software on the host processor. On the other hand, it obliges system designers to handle the whole process of hardware/software co-design. The complexity of this process is still one of the main reasons, that hinders the widespread use of hybrid architectures. Thus, an automated process that aids programmers with the hardware/software partitioning and the generation of application specific accelerators is an important issue. The method presented in this thesis neither requires restrictions of the used high-level-language nor special source code annotations. Usually, this is an entry barrier for programmers without deeper understanding of the underlying hardware platform. This thesis introduces a seamless programming flow that allows generating hardware accelerators for unrestricted, legacy C code. The implementation consists of a GCC plugin that automatically identifies application hot-spots and generates hardware accelerators accordingly. Apart from the accelerator implementation in a hardware description language, the compiler plugin provides the generation of a host processor interfaces and, if necessary, a prototypical integration with the host operating system. An evaluation with typical embedded applications shows general benefits of the approach, but also reveals limiting factors that hamper possible performance improvements.
53

Foreign direct investments : An antidote for hydrocarbon dependency in the Gulf Cooperation Council?

Mekidiche, Youssef January 2017 (has links)
The most essential questions in economics is what determines economic growth? In theory FDI led to economic growth (Mello 1997), but empirical evidences indicate that the relationship is ambiguous (Masahiro & Iwasaki 2014). This thesis uses contemporary growth theories and econometric methods to empirically test for the association between foreign direct investment and economic growth in the six countries that form the Gulf Cooperation Council (GCC). The analysis indicates a positive relationship concerning FDI and GDP growth in the panel of GCC. The result furthermore supports the endogenous growth theory and provide insights on the regions progress towards income diversification whit respect to hydrocarbons.
54

Investigation into using Stand-Alone Building Integrated Photovoltaic System (SABIPV) as a fundamental solution for Saudi rural areas and studying the expected impacts

Albaz, Abdulkarim January 2015 (has links)
A number of natural resources can be exploited for providing energy, such as the sun, wind, water flow, tides, waves and deep heat generated within the earth. Recently, renewable resources especially that extracted from solar have been significantly encouraged mainly for environmental worries, such as climate change mitigation and global warming, coupled with high oil cost and security and economic matters. The crucial need of energy in human development has also been another important drive pushing the rapid progresses in renewable technologies, which results in both large-scale strategic projects for covering wide urban and rural areas and simple systems suitable for individual buildings. Solar energy has become a widely desired option, especially in high solar radiation areas. The Middle East, especially Gulf region is an ideal geographical area for solar power where it has one of the highest solar irradiation rates across the world. The population in Gulf Cooperation Council (GCC) countries is significantly small compared to the geographical areas and populations are distributed mostly throughout huge areas forming small villages and rural communities on substantial distances from the main power networks. In Saudi Arabia, there is a crisis in supplying enough electricity to the large cities and domestic remote area in various parts in the country and a wide range of remote areas still suffer from a severe shortage of power supply. In this project, the opportunity of using small-scale solar energy technologies, such as Stand-Alone Building-Integrated PV (SABIPV) systems has been investigated as an optimal solution for providing solar energy to a great deal of off-grid areas in Kingdom of Saudi Arabia and the expected short and long-term impacts of such solution have been studied. The study showed that the main reasons behind the crisis in supplying electricity to domestic remote and rural off-grid areas in Saudi Arabia are the weakness of the financial returns compared to the cost of providing the service, the difficulty of the natural topography of areas, high cost of maintenance works, and the regulations of providing electric services in Saudi Arabia. This is in addition to the expected environmental impacts, such as raising the pollution rates in the area and the safety influences of extending the high voltage lines over huge areas. On the other hand, the lack of the necessary infrastructure services, particularly electricity and the looking forward for better level of prosperity lead people who live in countryside and remote areas usually to immigrate to in-grid areas which has several short and long-term negative impacts on economic, social and security sides. This study shows that SABIPV system is a cost-Impactive, powerful, and fundamental solution for all off-grid areas in Saudi Arabia including remote villages and rural communities and providing the same level of electricity services that can be achieved in urban on-grid areas. The system is expected to have positive impacts including reducing pollution and greenhouse gas emissions, the expansion of agricultural land and reduce desertification, reducing the influence of high-voltage electrical lines on living organisms, providing adequate electricity service at lower cost, offering more job opportunities for people in remote areas, increasing agricultural and handicraft products, developing the tourism sector in rural areas, reducing the rate of migration from rural areas to the cities, and reducing the slum areas in cities which helps to reduce the rate of crimes, ignorance, the low level of morality, and health and environmental problem.
55

Compilation optimisée des modèles UML

Charfi Smaoui, Asma 12 December 2011 (has links) (PDF)
Cette thèse s'inscrit dans le cadre de la mise en œuvre de l'ingénierie dirigée par les modèles (IDM) pour le développement des systèmes embarquées. Ces systèmes ayant généralement des ressources limitées (mémoire et/ou calculs), exigent que le code généré soit le plus optimisé possible. L'objectif de cette thèse est de produire à partir d'un modèle spécifié dans le langage UML, un code assembleur plus compact que le code assembleur produit par les compilateurs de code. Malgré l'évolution croissante des compilateurs optimisés, les compilateurs les plus répandus comme le GCC (Gnu Compiler Collection) sont incapables d'effectuer certains types d'optimisations qu'il est possible d'effectuer à un plus haut niveau d'abstraction dans une phase de pré-génération de code. En effet, certaines informations (liées à la sémantique d'exécution du langage UML) sont perdues lors de la génération de code. Ces informations, utiles pour les optimisations de haut niveau, sont invisibles par le compilateur de code vue qu'il prend toutes les informations liées au système modélisé à partir du code généré. Nous proposons ainsi une nouvelle approche dirigée par les modèles pour le développement des systèmes à ressources limitées, qui élimine l'étape de la génération de code en remplaçant cette étape par une compilation directe des modèles. Nous avons développé le premier compilateur de modèles UML (GUML : le front-end UML pour le compilateur GCC) qui génère directement de l'assembleur (sans passer par un langage de programmation) à partir des modèles UML. GUML permet de compiler les classes, les activités et les machines à états UML. Il permet de générer, en compilant certaines machines à états, un code assembleur plus compact que le code assembleur produit par GCC. Deux optimisations de GCC sont améliorées : l'élimination de code mort et l'élimination des expressions redondantes.
56

Effects of Coating Formulations on Thermal Properties of Coating Layers

Liang, Chong 15 February 2010 (has links)
The effects of coating formulation on thermal characteristics of coating layers were systematically studied for xerographic toner fusion on coated papers. Model coatings were formulated using three types of ground calcium carbonate and one kaolin pigments, each mixed with 6, 10, 18, and 25 pph of styrene butadiene latex binder. Porosity was found to be a key parameter for coating thermal conductivity adjustment, and was determined by the latex concentration. The particle size distribution and morphology of pigments also affect the overall thermal characteristics of coating layers. Print qualities on model coated papers were evaluated by print gloss measurement, toner adhesion test, and pair-wise visual ranking, and it was proved that print gloss is reduced with increasing bulk thermal conductivity of coating layers. The coating layer consisted of Covercarb HP pigment and 10 pph of latex was found to have the best performance in the three print quality evaluation tests.
57

Effects of Coating Formulations on Thermal Properties of Coating Layers

Liang, Chong 15 February 2010 (has links)
The effects of coating formulation on thermal characteristics of coating layers were systematically studied for xerographic toner fusion on coated papers. Model coatings were formulated using three types of ground calcium carbonate and one kaolin pigments, each mixed with 6, 10, 18, and 25 pph of styrene butadiene latex binder. Porosity was found to be a key parameter for coating thermal conductivity adjustment, and was determined by the latex concentration. The particle size distribution and morphology of pigments also affect the overall thermal characteristics of coating layers. Print qualities on model coated papers were evaluated by print gloss measurement, toner adhesion test, and pair-wise visual ranking, and it was proved that print gloss is reduced with increasing bulk thermal conductivity of coating layers. The coating layer consisted of Covercarb HP pigment and 10 pph of latex was found to have the best performance in the three print quality evaluation tests.
58

Efficient Propagators for Global Constraints

Quimper, Claude-Guy January 2006 (has links)
We study in this thesis three well known global constraints. The All-Different constraint restricts a set of variables to be assigned to distinct values. The <em>global cardinality constraint</em> (GCC) ensures that a value <em>v</em> is assigned to at least <em>l<sub>v</sub></em> variables and to at most <em>u<sub>v</sub></em> variables among a set of given variables where <em>l<sub>v</sub></em> and <em>u<sub>v</sub></em> are non-negative integers such that <em>l<sub>v</sub></em> &le; <em>u<sub>v</sub></em>. The Inter-Distance constraint ensures that all variables, among a set of variables <em>x</em><sub>1</sub>, . . . , <em>x<sub>n</sub></em>, are pairwise distant from <em>p</em>, i. e. |<em>x<sub>i</sub></em> - <em>x<sub>j</sub></em>| &ge; <em>p</em> for all <em>i</em> &ne; <em>j</em>. The All-Different constraint, the GCC, and the Inter-Distance constraint are largely used in scheduling problems. For instance, in scheduling problems where tasks with unit processing time compete for a single resource, we have an All-Different constraint on the starting time variables. When there are <em>k</em> resources, we have a GCC with <em>l<sub>v</sub></em> = 0 and <em>u<sub>v</sub></em> = <em>k</em> over all starting time variables. Finally, if tasks have processing time <em>t</em> and compete for a single resource, we have an Inter-Distance constraint with <em>p</em> = <em>t</em> over all starting time variables. We present new propagators for the All-Different constraint, the GCC, and the Inter-Distance constraint i. e. , new filtering algorithms that reduce the search space according to these constraints. For a given consistency, our propagators outperform previous propagators both in practice and in theory. The gains in performance are achieved through judicious use of advanced data structures combined with novel results on the structural properties of the constraints.
59

Efficient Propagators for Global Constraints

Quimper, Claude-Guy January 2006 (has links)
We study in this thesis three well known global constraints. The All-Different constraint restricts a set of variables to be assigned to distinct values. The <em>global cardinality constraint</em> (GCC) ensures that a value <em>v</em> is assigned to at least <em>l<sub>v</sub></em> variables and to at most <em>u<sub>v</sub></em> variables among a set of given variables where <em>l<sub>v</sub></em> and <em>u<sub>v</sub></em> are non-negative integers such that <em>l<sub>v</sub></em> &le; <em>u<sub>v</sub></em>. The Inter-Distance constraint ensures that all variables, among a set of variables <em>x</em><sub>1</sub>, . . . , <em>x<sub>n</sub></em>, are pairwise distant from <em>p</em>, i. e. |<em>x<sub>i</sub></em> - <em>x<sub>j</sub></em>| &ge; <em>p</em> for all <em>i</em> &ne; <em>j</em>. The All-Different constraint, the GCC, and the Inter-Distance constraint are largely used in scheduling problems. For instance, in scheduling problems where tasks with unit processing time compete for a single resource, we have an All-Different constraint on the starting time variables. When there are <em>k</em> resources, we have a GCC with <em>l<sub>v</sub></em> = 0 and <em>u<sub>v</sub></em> = <em>k</em> over all starting time variables. Finally, if tasks have processing time <em>t</em> and compete for a single resource, we have an Inter-Distance constraint with <em>p</em> = <em>t</em> over all starting time variables. We present new propagators for the All-Different constraint, the GCC, and the Inter-Distance constraint i. e. , new filtering algorithms that reduce the search space according to these constraints. For a given consistency, our propagators outperform previous propagators both in practice and in theory. The gains in performance are achieved through judicious use of advanced data structures combined with novel results on the structural properties of the constraints.
60

Water Depth Estimation Using Ultrasound Pulses for Handheld Diving Equipment / Skattning av vattendjup med ultraljudspulser för mobil dykarutrustning

Mollén, Katarina January 2015 (has links)
This thesis studies the design and implementation of an ultra-sonic water depth sounder. The depth sounder is implemented in a hand-held smart console used by divers. Since the idea of echo sounding is to measure the flight time between transmitting the signal and receiving the echo, the main challenge of this task is to find a time-of-flight (ToF) estimation for a signal in noise. It should be suitable for this specific application and robust when implemented in the device. The thesis contains an investigation of suitable ToF methods. More detailed evaluations of the matched filter, also known as the correlation method, and the linear phase approach are done. Aspects like pulse frequency and duration, speed of sound in water and underwater noise are taken into account. The ToF-methods are evaluated through simulation and experiments. The matched filter approach is found suitable based on these simulations and tests with signals recorded by the console. This verification leads to the implementation of the algorithm on the device. The algorithm is tested in real time, the results are evaluated and improvements suggested. / Denna rapport behandlar skattning av vattendjup med hjälp av ultraljudspulser och implementation av detta. Djupmätaren implementeras i en handhållen dykarkonsoll. Eftersom grundidén i ekolodning är att mäta tiden mellan att pulsen skickas iväg och att ekot tas emot är en stor del av utmaningen att hitta en lämplig metod för att skatta flykttiden för en signal i brus. Metoden ska passa för detta användingsområde och vara robust. Rapporten tar upp tidigare forskning gjord inom flykttidsestimering. De metoder som utvärderas för implementation är det matchade filtret, också kallad korrelationsmetoden, och linjär fas-metoden. Andra aspekter som avvägs och utreds är pulsfrekvens och pulsvaraktighet, ljudets hastighet och brus under vattnet. Metoderna för att skatta flykttid utvärderas genom simuleringar. Det matchade filtret bedöms vara lämpligt baserat på dessa simuleringar och experiment med data inspelad med konsollen. Denna verifikation leder till att algoritmen implementeras på konsollen. Den implementerade algoritmen testas i realtid, resultaten utvärderas och förbättringar föreslås.

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