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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.
1

AN ALGORITHM TO SOLVE THE ASSOCIATIVE PARALLEL MACHINE SCHEDULING PROBLEM

Shuaib, Mohannad Abdelrahman 01 January 2009 (has links)
Effective production scheduling is essential for improved performance. Scheduling strategies for various shop configurations and performance criteria have been widely studied. Scheduling in parallel machines (PM) is one among the many scheduling problems that has received considerable attention in the literature. An even more complex scheduling problem arises when there are several PM families and jobs are capable of being processed in more than one such family. This research addresses such a situation, which is defined as an Associative Parallel Machine scheduling (APMS) problem. This research presents the SAPT-II algorithm that solves a highly constrained APMS problem with the objective to minimize average flow time. A case example from a make-to-order industrial product manufacturer is used to illustrate the complexity of the problem and evaluate the effectiveness of the scheduling algorithm.
2

Časová analýza sedání podloží vyztuženého štěrkovými pilíři / Time depending analysis of subsoil reinforced by stone columns

Vykoukal, Libor January 2012 (has links)
The thesis focuses on the time analysis of the subsoil which is reinforced with stone columns and without them. The subsoil is made of saturated clays. Main purpose is to introduce the improvement into the numerical models. For the purpose of the diploma thesis the software Plaxis has been chosen, which is normally used for geotechnical tasks. The influence of the stone columns have been introduce to the model using the drain elemnets, spare charakteristics and local elements.
3

Étude de fonctionnelles géométriques dépendant de la courbure par des méthodes d'optimisation de formes. Applications aux fonctionnelles de Willmore et Canham-Helfrich / Study of geometric functionals depending on curvature by shape optimization methods. Applications to the functionals of Willmore and Canham-Helfrich

Dalphin, Jérémy 05 December 2014 (has links)
En biologie, lorsqu'une quantité importante de phospholipides est insérée dans un milieu aqueux, ceux-Ci s'assemblent alors par paires pour former une bicouche, plus communément appelée vésicule. En 1973, Helfrich a proposé un modèle simple pour décrire la forme prise par une vésicule. Imposant la surface de la bicouche et le volume de fluide qu'elle contient, leur forme minimise une énergie élastique faisant intervenir des quantités géométriques comme la courbure, ainsi qu'une courbure spontanée mesurant l'asymétrie entre les deux couches. Les globules rouges sont des exemples de vésicules sur lesquels sont fixés un réseau de protéines jouant le rôle de squelette au sein de la membrane. Un des principaux travaux de la thèse fut d'introduire et étudier une condition de boule uniforme, notamment pour modéliser l'effet du squelette. Dans un premier temps, on cherche à minimiser l'énergie de Helfrich sans contrainte puis sous contrainte d'aire. Le cas d'une courbure spontanée nulle est connu sous le nom d'énergie de Willmore. Comme la sphère est un minimiseur global de l'énergie de Willmore, c'est un bon candidat pour être un minimiseur de l'énergie de Helfrich parmi les surfaces d'aire fixée. Notre première contribution dans cette thèse a été d'étudier son optimalité. On montre qu'en dehors d'un certain intervalle de paramètres, la sphère n'est plus un minimum global, ni même un minimum local. Par contre, elle est toujours un point critique. Ensuite, dans le cas de membranes à courbure spontanée négative, on se demande si la minimisation de l'énergie de Helfrich sous contrainte d'aire peut être effectuée en minimisant individuellement chaque terme. Cela nous conduit à minimiser la courbure moyenne totale sous contrainte d'aire et à déterminer si la sphère est la solution de ce problème. On montre que c'est le cas dans la classe des surfaces axisymétriques axiconvexes mais que ce n'est pas vrai en général.Enfin, lorsqu'une contrainte d'aire et de volume sont considérées simultanément, le minimiseur ne peut pas être une sphère qui n'est alors plus admissible. En utilisant le point de vue de l'optimisation de formes, la troisième et plus importante contribution de cette thèse est d'introduire une classe plus raisonnable de surfaces, pour laquelle l'existence d'un minimiseur suffisamment régulier est assurée pour des fonctionnelles et des contraintes générales faisant intervenir les propriétés d'ordre un et deux des surfaces. En s'inspirant de ce que fit Chenais en 1975 quand elle a considéré la propriété de cône uniforme, on considère les surfaces satisfaisant une condition de boule uniforme. On étudie d'abord des fonctionnelles purement géométriques puis nous autorisons la dépendance à travers la solution de problèmes aux limites elliptiques d'ordre deux posés sur le domaine intérieur à la surface / In biology, when a large amount of phospholipids is inserted in aqueous media, they immediatly gather in pairs to form bilayers also called vesicles. In 1973, Helfrich suggested a simple model to characterize the shapes of vesicles. Imposing the area of the bilayer and the volume of fluid it contains, their shape is minimizing a free-Bending energy involving geometric quantities like curvature, and also a spontanuous curvature measuring the asymmetry between the two layers. Red blood cells are typical examples of vesicles on which is fixed a network of proteins playing the role of a skeleton inside the membrane. One of the main work of this thesis is to introduce and study a uniform ball condition, in particular to model the effects of the skeleton. First, we minimize the Helfrich energy without constraint then with an area constraint. The case of zero spontaneous curvature is known as the Willmore energy. Since the sphere is the global minimizer of the Willmore energy, it is a good candidate to be a minimizer of the Helfrich energy among surfaces of prescribed area. Our first main contribution in this thesis was to study its optimality. We show that apart from a specific interval of parameters, the sphere is no more a global minimizer, neither a local minimizer. However, it is always a critical point. Then, in the specific case of membranes with negative spontaneous curvature, one can wonder whether the minimization of the Helfrich energy with an area constraint can be done by minimizing individually each term. This leads us to minimize total mean curvature with prescribed area and to determine if the sphere is a solution to this problem. We show that it is the case in the class of axisymmetric axiconvex surfaces but that it does not hold true in the general case. Finally, considering both area and volume constraints, the minimizer cannot be the sphere, which is no more admissible. Using the shape optimization point of view, the third main and most important contribution of this thesis is to introduce a more reasonable class of surfaces, in which the existence of an enough regular minimizer is ensured for general functionals and constraints involving the first- and second-Order geometric properties of surfaces. Inspired by what Chenais did in 1975 when she considered the uniform cone property, we consider surfaces satisfying a uniform ball condition. We first study purely geometric functionals then we allow a dependence through the solution of some second-Order elliptic boundary value problems posed on the inner domain enclosed by the shape
4

Semi-Automatic Mapping of Structured Data to Visual Variables / Halbautomatische Abbildung von strukturierten Daten auf Visuelle Variablen

Polowinski, Jan 09 April 2013 (has links) (PDF)
While semantic web data is machine-understandable and well suited for advanced filtering, in its raw representation it is not conveniently understandable to humans. Therefore, visualization is needed. A core challenge when visualizing the structured but heterogeneous data turned out to be a flexible mapping to Visual Variables. This work deals with a highly flexible, semi-automatic solution with a maximum support of the visualization process, reducing the mapping possibilities to a useful subset. The basis for this is knowledge, concerning metrics and structure of the data on the one hand and available visualization structures, platforms and common graphical facts on the other hand — provided by a novel basic visualization ontology. A declarative, platform-independent mapping vocabulary and a framework was developed, utilizing current standards from the semantic web and the Model-Driven Architecture (MDA). / Während Semantic-Web-Daten maschinenverstehbar und hervorragend filterbar sind, sind sie — in ihrer Rohform — nicht leicht von Menschen verstehbar. Eine Visualisierung der Daten ist deshalb notwendig. Die Kernherausforderung dabei ist eine flexible Abbildung der strukturierten aber heterogenen Daten auf Visuelle Variablen. Diese Arbeit beschreibt eine hochflexible halbautomatische Lösung bei maximaler Unterstützung des Visualisierungsprozesses, welcher die Abbildungsmöglichkeiten, aus denen der Nutzer zu wählen hat, auf eine sinnvolle Teilmenge reduziert. Die Grundlage dafür sind einerseits Metriken und das Wissen über die Struktur der Daten und andererseits das Wissen über verfügbare Visualisierungsstrukturen, -plattformen und bekannte grafische Fakten, welche durch eine neuentwickelte Visualisierungsontologie bereitgestellt werden. Basierend auf Standards des Semantic Webs und der Model-getriebenen Architektur, wurde desweiteren ein deklaratives, plattformunabhängiges Visualisierungsvokabular und -framework entwickelt.
5

Semi-Automatic Mapping of Structured Data to Visual Variables

Polowinski, Jan 11 October 2007 (has links)
While semantic web data is machine-understandable and well suited for advanced filtering, in its raw representation it is not conveniently understandable to humans. Therefore, visualization is needed. A core challenge when visualizing the structured but heterogeneous data turned out to be a flexible mapping to Visual Variables. This work deals with a highly flexible, semi-automatic solution with a maximum support of the visualization process, reducing the mapping possibilities to a useful subset. The basis for this is knowledge, concerning metrics and structure of the data on the one hand and available visualization structures, platforms and common graphical facts on the other hand — provided by a novel basic visualization ontology. A declarative, platform-independent mapping vocabulary and a framework was developed, utilizing current standards from the semantic web and the Model-Driven Architecture (MDA).:ABSTRACT S. x 1. INTRODUCTION S. 1 2. VISUALIZATION OF STRUCTURED DATA IN GENERAL S. 4 2.1. Global and Local Interfaces S. 4 2.2. Steps of the Visualization Process S. 4 2.3. Existing Visual Selection Mechanisms S. 6 2.4. Existing Visualizations of Structured Data S. 12 2.5. Categorizing SemVis S. 25 3. REQUIREMENTS FOR A FLEXIBLE VISUALIZATION S. 27 3.1. Actors S. 27 3.2. Use Cases S. 27 4. FRESNEL, A STANDARD DISPLAY VOCABULARY FOR RDF S. 31 4.1. Fresnel Lenses S. 31 4.2. Fresnel Formats S. 33 4.3. Fresnel Groups S. 33 4.4. Primaries (Starting Points) S. 33 4.5. Selectors and Inference S. 34 4.6. Application and Reusability S. 34 4.7. Implementation S. 35 5. A VISUALIZATION ONTOLOGY S. 37 5.1. Describing and Formalizing the Field of Visualization S. 37 5.2. Overview S. 37 5.3. VisualVariable S. 38 5.4. DiscreteVisualValue S. 39 5.5. VisualElement S. 41 5.6. VisualizationStructure S. 42 5.7. VisualizationPlatform S. 42 5.8. PresentationScenario S. 43 5.9. Facts S. 44 6. A NOVEL MAPPING VOCABULARY FOR SEMANTIC VISUALIZATION S. 45 6.1. Overview S. 45 6.2. Mapping S. 46 6.3. PropertyMapping S. 47 6.4. ImplicitMapping S. 48 6.5. ExplicitMapping S. 53 6.6. MixedMapping S. 54 6.7. ComplexMapping S. 55 6.8. Inference S. 58 6.9. Explicit Display of Relations S. 58 6.10. Limitations s. 59 7. A MODEL-DRIVEN ARCHITECTURE FOR FLEXIBLE VISUALIZATION S. 60 7.1. A Model-Driven Architecture S. 61 7.2. Applications of the MDA Pattern S. 62 7.3. Complete System Overview S. 71 7.4. Additional Knowledge of the System S. 72 7.5. Comparison to the Graphical Modelling Framework — GMF S. 77 8. VISUALIZATION PLATFORMS S. 80 8.1. Extensible 3D (X3D) S. 80 8.2. Scalable Vector Graphics (SVG) S. 81 8.3. XHTML + CSS S. 82 8.4. Text S. 82 9. OUTLOOK AND CONCLUSION S. 84 9.1. Advanced Mapping Vocabulary S. 84 9.2. Reusing Standardized Ontologies S. 84 9.3. Enabling Dynamic, Interaction and Animation S. 84 9.4. Implementation and Evaluation S. 85 9.5. Conclusion S. 85 GLOSSARY S. 86 BIBLIOGRAPHY S. 87 A. S. 90 A.1. Schemata S. 90 / Während Semantic-Web-Daten maschinenverstehbar und hervorragend filterbar sind, sind sie — in ihrer Rohform — nicht leicht von Menschen verstehbar. Eine Visualisierung der Daten ist deshalb notwendig. Die Kernherausforderung dabei ist eine flexible Abbildung der strukturierten aber heterogenen Daten auf Visuelle Variablen. Diese Arbeit beschreibt eine hochflexible halbautomatische Lösung bei maximaler Unterstützung des Visualisierungsprozesses, welcher die Abbildungsmöglichkeiten, aus denen der Nutzer zu wählen hat, auf eine sinnvolle Teilmenge reduziert. Die Grundlage dafür sind einerseits Metriken und das Wissen über die Struktur der Daten und andererseits das Wissen über verfügbare Visualisierungsstrukturen, -plattformen und bekannte grafische Fakten, welche durch eine neuentwickelte Visualisierungsontologie bereitgestellt werden. Basierend auf Standards des Semantic Webs und der Model-getriebenen Architektur, wurde desweiteren ein deklaratives, plattformunabhängiges Visualisierungsvokabular und -framework entwickelt.:ABSTRACT S. x 1. INTRODUCTION S. 1 2. VISUALIZATION OF STRUCTURED DATA IN GENERAL S. 4 2.1. Global and Local Interfaces S. 4 2.2. Steps of the Visualization Process S. 4 2.3. Existing Visual Selection Mechanisms S. 6 2.4. Existing Visualizations of Structured Data S. 12 2.5. Categorizing SemVis S. 25 3. REQUIREMENTS FOR A FLEXIBLE VISUALIZATION S. 27 3.1. Actors S. 27 3.2. Use Cases S. 27 4. FRESNEL, A STANDARD DISPLAY VOCABULARY FOR RDF S. 31 4.1. Fresnel Lenses S. 31 4.2. Fresnel Formats S. 33 4.3. Fresnel Groups S. 33 4.4. Primaries (Starting Points) S. 33 4.5. Selectors and Inference S. 34 4.6. Application and Reusability S. 34 4.7. Implementation S. 35 5. A VISUALIZATION ONTOLOGY S. 37 5.1. Describing and Formalizing the Field of Visualization S. 37 5.2. Overview S. 37 5.3. VisualVariable S. 38 5.4. DiscreteVisualValue S. 39 5.5. VisualElement S. 41 5.6. VisualizationStructure S. 42 5.7. VisualizationPlatform S. 42 5.8. PresentationScenario S. 43 5.9. Facts S. 44 6. A NOVEL MAPPING VOCABULARY FOR SEMANTIC VISUALIZATION S. 45 6.1. Overview S. 45 6.2. Mapping S. 46 6.3. PropertyMapping S. 47 6.4. ImplicitMapping S. 48 6.5. ExplicitMapping S. 53 6.6. MixedMapping S. 54 6.7. ComplexMapping S. 55 6.8. Inference S. 58 6.9. Explicit Display of Relations S. 58 6.10. Limitations s. 59 7. A MODEL-DRIVEN ARCHITECTURE FOR FLEXIBLE VISUALIZATION S. 60 7.1. A Model-Driven Architecture S. 61 7.2. Applications of the MDA Pattern S. 62 7.3. Complete System Overview S. 71 7.4. Additional Knowledge of the System S. 72 7.5. Comparison to the Graphical Modelling Framework — GMF S. 77 8. VISUALIZATION PLATFORMS S. 80 8.1. Extensible 3D (X3D) S. 80 8.2. Scalable Vector Graphics (SVG) S. 81 8.3. XHTML + CSS S. 82 8.4. Text S. 82 9. OUTLOOK AND CONCLUSION S. 84 9.1. Advanced Mapping Vocabulary S. 84 9.2. Reusing Standardized Ontologies S. 84 9.3. Enabling Dynamic, Interaction and Animation S. 84 9.4. Implementation and Evaluation S. 85 9.5. Conclusion S. 85 GLOSSARY S. 86 BIBLIOGRAPHY S. 87 A. S. 90 A.1. Schemata S. 90
6

Low-Power Policies Based on DVFS for the MUSEIC v2 System-on-Chip

Mallangi, Siva Sai Reddy January 2017 (has links)
Multi functional health monitoring wearable devices are quite prominent these days. Usually these devices are battery-operated and consequently are limited by their battery life (from few hours to a few weeks depending on the application). Of late, it was realized that these devices, which are currently being operated at fixed voltage and frequency, are capable of operating at multiple voltages and frequencies. By switching these voltages and frequencies to lower values based upon power requirements, these devices can achieve tremendous benefits in the form of energy savings. Dynamic Voltage and Frequency Scaling (DVFS) techniques have proven to be handy in this situation for an efficient trade-off between energy and timely behavior. Within imec, wearable devices make use of the indigenously developed MUSEIC v2 (Multi Sensor Integrated circuit version 2.0). This system is optimized for efficient and accurate collection, processing, and transfer of data from multiple (health) sensors. MUSEIC v2 has limited means in controlling the voltage and frequency dynamically. In this thesis we explore how traditional DVFS techniques can be applied to the MUSEIC v2. Experiments were conducted to find out the optimum power modes to efficiently operate and also to scale up-down the supply voltage and frequency. Considering the overhead caused when switching voltage and frequency, transition analysis was also done. Real-time and non real-time benchmarks were implemented based on these techniques and their performance results were obtained and analyzed. In this process, several state of the art scheduling algorithms and scaling techniques were reviewed in identifying a suitable technique. Using our proposed scaling technique implementation, we have achieved 86.95% power reduction in average, in contrast to the conventional way of the MUSEIC v2 chip’s processor operating at a fixed voltage and frequency. Techniques that include light sleep and deep sleep mode were also studied and implemented, which tested the system’s capability in accommodating Dynamic Power Management (DPM) techniques that can achieve greater benefits. A novel approach for implementing the deep sleep mechanism was also proposed and found that it can obtain up to 71.54% power savings, when compared to a traditional way of executing deep sleep mode. / Nuförtiden så har multifunktionella bärbara hälsoenheter fått en betydande roll. Dessa enheter drivs vanligtvis av batterier och är därför begränsade av batteritiden (från ett par timmar till ett par veckor beroende på tillämpningen). På senaste tiden har det framkommit att dessa enheter som används vid en fast spänning och frekvens kan användas vid flera spänningar och frekvenser. Genom att byta till lägre spänning och frekvens på grund av effektbehov så kan enheterna få enorma fördelar när det kommer till energibesparing. Dynamisk skalning av spänning och frekvens-tekniker (såkallad Dynamic Voltage and Frequency Scaling, DVFS) har visat sig vara användbara i detta sammanhang för en effektiv avvägning mellan energi och beteende. Hos Imec så använder sig bärbara enheter av den internt utvecklade MUSEIC v2 (Multi Sensor Integrated circuit version 2.0). Systemet är optimerat för effektiv och korrekt insamling, bearbetning och överföring av data från flera (hälso) sensorer. MUSEIC v2 har begränsad möjlighet att styra spänningen och frekvensen dynamiskt. I detta examensarbete undersöker vi hur traditionella DVFS-tekniker kan appliceras på MUSEIC v2. Experiment utfördes för att ta reda på de optimala effektlägena och för att effektivt kunna styra och även skala upp matningsspänningen och frekvensen. Eftersom att ”overhead” skapades vid växling av spänning och frekvens gjordes också en övergångsanalys. Realtidsoch icke-realtidskalkyler genomfördes baserat på dessa tekniker och resultaten sammanställdes och analyserades. I denna process granskades flera toppmoderna schemaläggningsalgoritmer och skalningstekniker för att hitta en lämplig teknik. Genom att använda vår föreslagna skalningsteknikimplementering har vi uppnått 86,95% effektreduktion i jämförelse med det konventionella sättet att MUSEIC v2-chipets processor arbetar med en fast spänning och frekvens. Tekniker som inkluderar lätt sömn och djupt sömnläge studerades och implementerades, vilket testade systemets förmåga att tillgodose DPM-tekniker (Dynamic Power Management) som kan uppnå ännu större fördelar. En ny metod för att genomföra den djupa sömnmekanismen föreslogs också och enligt erhållna resultat så kan den ge upp till 71,54% lägre energiförbrukning jämfört med det traditionella sättet att implementera djupt sömnläge.

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