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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

Evaluation of Software Architectures in the Automotive Domain for Multicore Targets in regard to Architectural Estimation Decisions at Design Time

Roßbach, André Christian 05 November 2014 (has links)
In this decade the emerging multicore technology will hit the automotive industry. The increasing complexity of the multicore-systems will make a manual verification of the safety and realtime constraints impossible. For this reason, dedicated methods and tools are utterly necessary, in order to deal with the upcoming multicore issues. A lot of researchprojects for new hardware platforms and software frameworks for the automotive industry are running nowadays, because the paradigms of the “High-Performance Computing” and “Server/Desktop Domain” cannot be easily adapted for the embedded systems. One of the difficulties is the early suitability estimation of a hardware platform for a software architecture design, but hardly a research-work is tackling that. This thesis represents a procedure to evaluate the plausibility of software architecture estimations and decisions at design stage. This includes an analysis technique of multicore systems, an underlying graph-model – to represent the multicore system – and a simulation tool evaluation. This can guide the software architect, to design a multicore system, in full consideration of all relevant parameters and issues.:Contents List of Figures vii List of Tables viii List of Abbreviations ix 1. Introduction 1 1.1. Motivation 1 1.2. Scope 2 1.3. Goal and Tasks 2 1.4. Structure of the Thesis 3 I. Multicore Technology 4 2. Fundamentals 5 2.1. Automotive Domains 5 2.2. Embedded System 7 2.2.1. Realtime 7 2.2.2. Runtime Predictions 8 2.2.3. Multicore Processor Architectures 8 2.3. Development of Automotive Embedded Systems 9 2.3.1. Applied V-Model 9 2.3.2. System Description and System Implementation 10 2.4. Software Architecture 11 2.5. Model Description of Software Structures 13 2.5.1. Design Domains of Multicore Systems 13 2.5.2. Software Structure Components 13 3. Trend and State of the Art of Multicore Research, Technology and Market 17 3.1. The Importance of Multicore Technology 17 3.2. Multicore Technology for the Automotive Industry 19 3.2.1. High-Performance Computing versus Embedded Systems 19 3.2.2. The Trend for the Automotive Industry 20 3.2.3. Examples of Multicore Hardware Platforms 23 3.3. Approaches for Upcoming Multicore Problems 24 3.3.1. Migration from Single-Core to Multicore 24 3.3.2. Correctness-by-Construction 25 3.3.3. AUTOSAR Multicore System 26 3.4. Software Architecture Simulators 28 3.4.1. Justification for Simulation Tools 28 3.4.2. System Model Simulation Software 29 3.5. Current Software Architecture Research Projects 31 3.6. Portrait of the current Situation 32 3.7. Summary of the Multicore Trend 32 II. Identification of Multicore System Parameters 34 4. Project Analysis to Identify Crucial Parameters 35 4.1. Analysis Procedure 35 4.1.1. Question Catalogue 36 4.1.2. Three Domains of Investigation 37 4.2. Analysed Projects 41 4.2.1. Project 1: Online Camera Calibration 41 4.2.2. Project 2: Power Management 45 4.2.3. Project 3: Battery Management 46 4.3. Results of Project Analysis 51 4.3.1. Ratio of Parameter Influence 51 4.3.2. General Influences of Parameters 53 5. Abstract System Model 54 5.1. Requirements for the System-Model 54 5.2. Simulation Tool Model Evaluation 55 5.2.1. System Model of PRECISION PRO 55 5.2.2. System Model of INCHRON 57 5.2.3. System Model of SymTA/S 58 5.2.4. System Model of Timing Architects 59 5.2.5. System Model of AMALTHEA 60 5.3. Concept of Abstract System Model 62 5.3.1. Components of the System Model 63 5.3.2. Software Function-Graph 63 5.3.3. Hardware Architecture-Graph 64 5.3.4. Specification-Graph for Mapping 65 6. Testcase Implementation 67 6.1. Example Test-System 68 6.1.1. Simulated Test-System 70 6.1.2. Testcases 73 6.2. Result of Tests 74 6.2.1. Processor Core Runtime Execution 74 6.2.2. Communication 75 6.2.3. Memory Access 76 6.3. Summary of Multicore System Parameters Identification 78 III. Evaluation of Software Architectures 80 7. Estimation-Procedure 81 7.1. Estimation-Procedure in a Nutshell 81 7.2. Steps of Estimation-Procedure 82 7.2.1. Project Analysis 82 7.2.2. Timing and Memory Requirements 83 7.2.3. System Modelling 84 7.2.4. Software Architecture Simulation 85 7.2.5. Results of a Validated Software Architecture 86 7.2.6. Feedback of Partly Implemented System 88 8. Implementation and Simulation 89 8.1. Example Project Analysis – Online Camera Calibration 89 8.1.1. Example Project Choice 90 8.1.2. OCC Timing Requirements Analysis 90 8.2. OCC Modelling 94 8.2.1. OCC Software Function-Graph 95 8.2.2. OCC Hardware Architecture 96 8.2.3. OCC Mapping – Specification-Graph 101 8.3. Simulation of the OCC Model with Tool Support 102 8.3.1. Tasks for Tool Setup 103 8.3.2. PRECISION PRO 105 8.3.3. INCHRON 107 8.3.4. SymTA/S 108 8.3.5. Timing Architects 112 8.3.6. AMALTHEA 115 8.4. System Optimisation Possibilities 116 8.5. OCC Implementation Results 117 9. Results of the Estimation-Procedure Evaluation 119 9.1. Tool-Evaluation Results 119 9.2. Findings of Estimation, Simulation and ECU-Behavior. 123 9.2.1. System-Specific Issues 123 9.2.2. Communication Issues 123 9.2.3. Memory Issues 124 9.2.4. Timing Issues 124 9.3. Summary of the Software Architecture Evaluation 125 10.Summary and Outlook 127 10.1. Summary 127 10.2. Usability of the Estimation-Procedure 128 10.3. Outlook and Future Work 129 11. Bibliography xii IV. Appendices xxi A. Appendices xxii A.1. Embedded Multicore Technology Research Projects xxii A.1.1. Simulation Software xxii A.1.2. Multicore Software Research Projects xxiii A.2. Testcase Implementation Results xxvi A.2.1. Function Block Processor Core Executions xxvi A.2.2. Memory Access Mechanism xxvii A.2.3. Memory Access Timings of Different Datatypes xxviii A.2.4. Inter-Processor Communication xxix A.3. Further OCC System Description xxxii A.3.1. OCC Timing Requirements of the FB xxxii A.3.2. INCHRON Validation Results xxxiv A.4. Detailed System Optimisation xxxv A.4.1. Optimisation through Hardware Alternation xxxv A.4.2. Optimisation through Mapping Alternation xxxv A.4.3. Optimisation of Execution Timings xxxvii B. Estimation-Procedure Engineering Paper xl B.1. Components and Scope of Software Architecture xl B.2. Estimation-Procedure in a Nutshell xlii B.3. Project Analysis xliii B.3.1. System level analysis xliv B.3.2. Communication Domain xlv B.3.3. Processor Core Domain xlvi B.3.4. Memory Domain xlvii B.3.5. Timing and Memory Requirements xlviii B.4. System Modelling xlix B.4.1. Function Model xlix B.4.2. Function-Graph l B.4.3. Possible ECU Target l B.4.4. Architecture-Graph l B.4.5. Software Architecture Mapping li B.4.6. Domain Specific Decision Guide lii B.5. Software Architecture Simulation liii B.6. Results of a Simulated Software Architecture lv B.7. Feedback of Partly Implemented System for Software Architecture Improvement lvi B.8. Benefits of the Estimation-Procedure lvii / In den nächsten Jahren wird die aufkommende Multicore-Technologie auf die Automobil-Branche zukommen. Die wachsende Komplexität der Multicore-Systeme lässt es nicht mehr zu, die Verifikation von Sicherheits- und Echtzeit-Anforderungen manuell auszuführen. Daher sind spezielle Methoden und Werkzeuge zwingend notwendig, um gerade mit den bevorstehenden Multicore-Problemfällen richtig umzugehen. Heutzutage laufen viele Forschungsprojekte für neue Hardware-Plattformen und Software-Frameworks für die Automobil-Industrie, weil die Paradigmen des “High-Performance Computings” und der “Server/Desktop-Domäne” nicht einfach so für die Eingebetteten Systeme angewendet werden können. Einer der Problemfälle ist das frühe Erkennen, ob die Hardware-Plattform für die Software-Architektur ausreicht, aber nur wenige Forschungs-Arbeiten berücksichtigen das. Diese Arbeit zeigt ein Vorgehens-Model auf, welches ermöglicht, dass Software-Architektur Abschätzungen und Entscheidungen bereits zur Entwurfszeit bewertet werden können. Das beinhaltet eine Analyse Technik für Multicore-Systeme, ein grundsätzliches Graphen-Model, um ein Multicore-System darzustellen, und eine Simulatoren Evaluierung. Dies kann den Software-Architekten helfen, ein Multicore System zu entwerfen, welches alle wichtigen Parameter und Problemfälle berücksichtigt.:Contents List of Figures vii List of Tables viii List of Abbreviations ix 1. Introduction 1 1.1. Motivation 1 1.2. Scope 2 1.3. Goal and Tasks 2 1.4. Structure of the Thesis 3 I. Multicore Technology 4 2. Fundamentals 5 2.1. Automotive Domains 5 2.2. Embedded System 7 2.2.1. Realtime 7 2.2.2. Runtime Predictions 8 2.2.3. Multicore Processor Architectures 8 2.3. Development of Automotive Embedded Systems 9 2.3.1. Applied V-Model 9 2.3.2. System Description and System Implementation 10 2.4. Software Architecture 11 2.5. Model Description of Software Structures 13 2.5.1. Design Domains of Multicore Systems 13 2.5.2. Software Structure Components 13 3. Trend and State of the Art of Multicore Research, Technology and Market 17 3.1. The Importance of Multicore Technology 17 3.2. Multicore Technology for the Automotive Industry 19 3.2.1. High-Performance Computing versus Embedded Systems 19 3.2.2. The Trend for the Automotive Industry 20 3.2.3. Examples of Multicore Hardware Platforms 23 3.3. Approaches for Upcoming Multicore Problems 24 3.3.1. Migration from Single-Core to Multicore 24 3.3.2. Correctness-by-Construction 25 3.3.3. AUTOSAR Multicore System 26 3.4. Software Architecture Simulators 28 3.4.1. Justification for Simulation Tools 28 3.4.2. System Model Simulation Software 29 3.5. Current Software Architecture Research Projects 31 3.6. Portrait of the current Situation 32 3.7. Summary of the Multicore Trend 32 II. Identification of Multicore System Parameters 34 4. Project Analysis to Identify Crucial Parameters 35 4.1. Analysis Procedure 35 4.1.1. Question Catalogue 36 4.1.2. Three Domains of Investigation 37 4.2. Analysed Projects 41 4.2.1. Project 1: Online Camera Calibration 41 4.2.2. Project 2: Power Management 45 4.2.3. Project 3: Battery Management 46 4.3. Results of Project Analysis 51 4.3.1. Ratio of Parameter Influence 51 4.3.2. General Influences of Parameters 53 5. Abstract System Model 54 5.1. Requirements for the System-Model 54 5.2. Simulation Tool Model Evaluation 55 5.2.1. System Model of PRECISION PRO 55 5.2.2. System Model of INCHRON 57 5.2.3. System Model of SymTA/S 58 5.2.4. System Model of Timing Architects 59 5.2.5. System Model of AMALTHEA 60 5.3. Concept of Abstract System Model 62 5.3.1. Components of the System Model 63 5.3.2. Software Function-Graph 63 5.3.3. Hardware Architecture-Graph 64 5.3.4. Specification-Graph for Mapping 65 6. Testcase Implementation 67 6.1. Example Test-System 68 6.1.1. Simulated Test-System 70 6.1.2. Testcases 73 6.2. Result of Tests 74 6.2.1. Processor Core Runtime Execution 74 6.2.2. Communication 75 6.2.3. Memory Access 76 6.3. Summary of Multicore System Parameters Identification 78 III. Evaluation of Software Architectures 80 7. Estimation-Procedure 81 7.1. Estimation-Procedure in a Nutshell 81 7.2. Steps of Estimation-Procedure 82 7.2.1. Project Analysis 82 7.2.2. Timing and Memory Requirements 83 7.2.3. System Modelling 84 7.2.4. Software Architecture Simulation 85 7.2.5. Results of a Validated Software Architecture 86 7.2.6. Feedback of Partly Implemented System 88 8. Implementation and Simulation 89 8.1. Example Project Analysis – Online Camera Calibration 89 8.1.1. Example Project Choice 90 8.1.2. OCC Timing Requirements Analysis 90 8.2. OCC Modelling 94 8.2.1. OCC Software Function-Graph 95 8.2.2. OCC Hardware Architecture 96 8.2.3. OCC Mapping – Specification-Graph 101 8.3. Simulation of the OCC Model with Tool Support 102 8.3.1. Tasks for Tool Setup 103 8.3.2. PRECISION PRO 105 8.3.3. INCHRON 107 8.3.4. SymTA/S 108 8.3.5. Timing Architects 112 8.3.6. AMALTHEA 115 8.4. System Optimisation Possibilities 116 8.5. OCC Implementation Results 117 9. Results of the Estimation-Procedure Evaluation 119 9.1. Tool-Evaluation Results 119 9.2. Findings of Estimation, Simulation and ECU-Behavior. 123 9.2.1. System-Specific Issues 123 9.2.2. Communication Issues 123 9.2.3. Memory Issues 124 9.2.4. Timing Issues 124 9.3. Summary of the Software Architecture Evaluation 125 10.Summary and Outlook 127 10.1. Summary 127 10.2. Usability of the Estimation-Procedure 128 10.3. Outlook and Future Work 129 11. Bibliography xii IV. Appendices xxi A. Appendices xxii A.1. Embedded Multicore Technology Research Projects xxii A.1.1. Simulation Software xxii A.1.2. Multicore Software Research Projects xxiii A.2. Testcase Implementation Results xxvi A.2.1. Function Block Processor Core Executions xxvi A.2.2. Memory Access Mechanism xxvii A.2.3. Memory Access Timings of Different Datatypes xxviii A.2.4. Inter-Processor Communication xxix A.3. Further OCC System Description xxxii A.3.1. OCC Timing Requirements of the FB xxxii A.3.2. INCHRON Validation Results xxxiv A.4. Detailed System Optimisation xxxv A.4.1. Optimisation through Hardware Alternation xxxv A.4.2. Optimisation through Mapping Alternation xxxv A.4.3. Optimisation of Execution Timings xxxvii B. Estimation-Procedure Engineering Paper xl B.1. Components and Scope of Software Architecture xl B.2. Estimation-Procedure in a Nutshell xlii B.3. Project Analysis xliii B.3.1. System level analysis xliv B.3.2. Communication Domain xlv B.3.3. Processor Core Domain xlvi B.3.4. Memory Domain xlvii B.3.5. Timing and Memory Requirements xlviii B.4. System Modelling xlix B.4.1. Function Model xlix B.4.2. Function-Graph l B.4.3. Possible ECU Target l B.4.4. Architecture-Graph l B.4.5. Software Architecture Mapping li B.4.6. Domain Specific Decision Guide lii B.5. Software Architecture Simulation liii B.6. Results of a Simulated Software Architecture lv B.7. Feedback of Partly Implemented System for Software Architecture Improvement lvi B.8. Benefits of the Estimation-Procedure lvii
82

Control and optimization of energy flow in hybrid large scale systems - A microgrid for photovoltaic based PEV charging station

Tulpule, Pinak J. 20 October 2011 (has links)
No description available.
83

Techno-economic analysis of implementing energy-efficiency and alternative fuels in Indonesia using OSeMOSYS / Teknokonomisk analys av implementering av energieffektivitet och alternativa bränslen i Indonesien med OSeMOSYS

Gupta, Kushagra January 2020 (has links)
Indonesia’s energy demand has been growing rapidly driven by increasing population, urbanization, and rapid economic growth. With increasing energy demand, the emissions associated with the energy sector continue to increase. With the gradual increase in demand and dominant share of fossil fuels in the energy mix, implementing the energy efficiency measures is crucial for Indonesia to achieve its energy and climate goals. From the policy perspective, National Energy plan of Indonesia aims to achieve higher levels of energy efficiency to reduce the overall energy intensity. Indonesia also has commitments to reduce greenhouse gas emissions and achieve SDG targets. This report reviews the current status of energy demand and energy efficiency in Indonesia and evaluates the potential of implementing energy efficiency measures and fuel switching options to achieve future low carbon energy future. Long term energy model of Indonesia is modelled using the open-source modelling tool OSeMOSYS. Different scenarios have been developed to investigate the outcome of implementing energy efficiency and fuel switching measures in the Residential, Commercial, and Transportation sectors. The results are presented in terms of reduction in total final energy use, greenhouse gas emissions, and local air pollution. Cost-Benefit analysis of the applied measures present their financial feasibility. With the deployment of efficient appliances, up to 30% electricity savings can be achieved in the residential and commercial sector. Vehicle electrification can contribute towards reduction in annual energy use by 48% by the end of modelling period. Measures in the residential and commercial sector directly contribute towards emission reductions. Vehicle electrification does not show proportionate reduction in emissions compared to energy use reduction due to high carbon intensity of the electricity grid. However, significant reduction in local air pollutants can be achieved. Cost benefit analysis shows that deployment of efficient appliances is financially feasible with maximum 2 years of payback period. On the other hand, successful deployment of electric vehicles will require tangible support from government due to its high price premium compared to conventional vehicles. Energy efficiency measures and fuel switching also contribute substantially to achieving Sustainable Development Goal 7.3. In conclusion, this study presents a set of technically and economically feasible energy system development options for Indonesia. From the modelling perspective, this study identifies ways to implement demand side management measures in the energy supply modelling system OSeMOSYS. / Indonesiens energibehov har ökat snabbt drivet av ökande befolkning, urbanisering och snabbekonomisk tillväxt. Med ökande energibehov fortsätter utsläppen i energisektorn att öka. Medden gradvisa ökningen i efterfrågan och den dominerande andelen fossila bränslen ienergimixen är genomförandet av energieffektivitetsåtgärderna avgörande för att Indonesienska uppnå sina energi- och klimatmål. Ur politiskt perspektiv syftar Indonesiens nationella energiplan till att uppnå högre nivåer av energieffektivitet för att minska den totala energiintensiteten. Indonesien har också åtaganden att minska utsläppen av växthusgaser och uppnå SDG-mål. Denna rapport granskar den aktuella statusen för efterfrågan på energi och energieffektivitet i Indonesien och utvärderar potentialen för att genomföra energieffektivitetsåtgärder och alternativ för bränsleomkoppling för att uppnå framtida energiförbrukning med låg koldioxid. Indonesiens långsiktiga energimodell modelleras med hjälp av open-sourcemodelleringsverktyget OSeMOSYS. Olika scenarier har utvecklats för att undersöka resultatet av genomförande av energieffektivitet och bränsleomkopplingsåtgärder inom bostads-, kommersiellt och transportsektorn. Resultaten presenteras i termer av minskning av den totalaslutliga energiförbrukningen, växthusgasutsläpp och lokal luftföroreningar. Kostnadsnyttoanalys av de tillämpade åtgärderna utgör deras ekonomiska genomförbarhet. Med användning av effektiva apparater kan upp till 30% elbesparing uppnås i bostads- och affärssektorn. Fordonselektrifiering kan bidra till minskning av den årliga energiförbrukningen med 48% i slutet av modelleringsperioden. Åtgärder inom bostads- och kommersiell sektor bidrar direkt till utsläppsminskningar. Fordonselektrifiering visar inte proportionell minskning av utsläpp jämfört med energiförbrukningen på grund av hög kolintensitet i elnätet. Emellertid kan en betydande minskning av lokala luftföroreningar uppnås. Kostnads för delningsanalys visar att distribution av effektiva apparater är ekonomiskt möjlig med maximalt 2 års återbetalningsperiod. Å andra sidan kommer framgångsrik distribution av elfordon att kräva konkret stöd från regeringen på grund av dess höga prispremie jämfört med konventionella fordon. Energi effektivitetsåtgärder och bränsleomkoppling bidrar också väsentligt till att uppnå mål för hållbar utveckling 7.3. Sammanfattningsvis presenterar denna studie en uppsättning tekniska och ekonomiskt genomförbara energisystemutvecklingsalternativ för Indonesien. Från modelleringsperspektivet identifierar denna studie sätt att implementera hanteringsåtgärder på efterfrågesidan i modelleringssystemet för energiförsörjning OSeMOSYS.
84

What to plant and where to plant it; Modeling the biophysical effects of North America temperate forests on climate using the Community Earth System Model

Ahlswede, Benjamin James 21 July 2015 (has links)
Forests affect climate by absorbing CO₂ but also by altering albedo, latent heat flux, and sensible heat flux. In this study we used the Community Earth System Model to assess the biophysical effect of North American temperate forests on climate and how this effect changes with location, tree type, and forest management. We calculated the change in annual temperature and energy balance associated with afforestation with either needle leaf evergreen trees (NET) or broadleaf deciduous trees (BDT) and between forests with high and low leaf-area indices (LAI). Afforestation from crops to forests resulted in lower albedo and higher sensible heat flux but no consistent difference in latent heat flux. Forests were consistently warmer than crops at high latitudes and colder at lower latitudes. In North America, the temperature response from afforestation shifted from warming to cooling between 34° N and 40° N for ground temperature and between 21° N and 25° N for near surface air temperature. NET tended to have lower albedo, higher sensible heat flux and warmer temperatures than BDT. The effect of tree PFT was larger than the effect of afforestation in the south and in the mid-Atlantic. Increasing LAI, a proxy for increased management intensity, caused a cooling effect in both tree types, but NET responded more strongly and albedo decreased while albedo increased for BDT. Our results show that forests' location, tree type, and management intensity can have nearly equal biophysical effects on temperature. A forest will have maximum biophysical cooling effect if it is in the south, composed of broadleaf PFT, and is managed to maximize leaf area index. / Master of Science
85

Power Systems Model Developments for Power Qality Monitoring : Application to Fundamental Frequency and Unbalance Estimation / Contribution à la modélisation des systèmes électriques pour la surveillance de la qualité de l’énergie électrique : application à l’estimation de la fréquence fondamentale et du déséquilibre

Phan, Anh Tuan 16 September 2016 (has links)
Les énergies renouvelables, l’énergie sous la forme électrique et son transport à l’aide de réseaux électriques intelligents représentent aujourd’hui des enjeux majeurs car ils ont de grands impacts environnementaux et sociétaux. Ainsi, la production, le transport et la gestion de l’énergie électrique, continuent toujours à susciter un intérêt croissant. Pour atteindre ces objectifs, plusieurs verrous technologiques doivent être levés. Au-delà des questions liées aux architectures des réseaux électriques, aux modèles, aux outils de dimensionnement, à la formalisation de caractéristiques et d’indicateurs, aux contraintes et aux critères, à la gestion et à la production décentralisée, la qualité de la puissance électrique est centrale pour la fiabilité de l’ensemble du système de distribution. Les perturbations affectent la qualité des signaux électriques et peuvent provoquer des conséquences graves sur les autres équipements connectés au réseau. Les travaux de cette thèse s’inscrivent dans ce contexte et de fait ils sont orientés vers le développement de modèles, d’indicateurs et de méthodes de traitement des signaux dédiés à la surveillance en temps-réel des performances des réseaux de distribution électrique.Cette thèse analyse la qualité de la puissance électrique, en prenant en compte plusieurs caractéristiques bien connues ainsi que leur pertinence. Les modèles des systèmes électriques et les méthodes de traitement du signal pour estimer leurs paramètres sont étudiés pour des applications en temps-réel de surveillance, de diagnostic et de contrôle sous diverses conditions. Parmi tous, la fréquence fondamentale est l’un des paramètres les plus importants pour caractériser un système de distribution électrique. En effet, sa valeur qui est censée être une constante, varie en permanence et reflète la dynamique de l’énergie électrique disponible. La fréquence peut également être affectée par certaines productions d’énergie renouvelable et peut être influencée par des mauvaises synchronisations de certains équipements. En outre, la puissance absorbée par les charges ou produite par des sources est généralement différente d’une phase à l’autre. Évidemment, la plupart des installations électriques existantes avec plusieurs phases, qu’elles soient résidentielles ou industrielles, travaillent dans des conditions déséquilibrées. Identifier les composantes symétriques de tension est dans ce cas un moyen pertinent pour quantifier le déséquilibre entre les phases d’un système électrique.De nouvelles représentations de type espace d’état et modélisant des systèmes électriques sont proposées pour estimer la fréquence fondamentale et pour identifier les composantes symétriques de tension des systèmes électriques triphasés et déséquilibrés. Le premier modèle d’espace d’état proposé considère la fréquence fondamentale comme connue ou obtenue par un autre estimateur. En contrepartie, il fournit les autres paramètres caractérisant le système électrique. Un second modèle d’état-espace est introduit. Il est original dans le sens où il ne nécessite aucune connaissance de la fréquence fondamentale. Une de ses variables d’état est directement reliée à la fréquence et permet donc de la déduire. En outre, ce nouvel espace d’état est parfaitement capable de représenter des systèmes électriques à trois phases équilibrés et non équilibrés. [...] / Renewable energy, electricity and smart grids are core subjects as they have great environmental and societal impacts. Thus, generating, transporting and managing electric energy, i.e., power, still continue to drive a growing interest. In order to properly achieve these goals, several locks must be removed. Beyond issues related to the distribution architecture, the formalization of models, sizing tools, features and indicators, constraints and criteria, decentralized generation and energy management, power quality is central for the whole grid’s reliability. Disturbances affect the power quality and can cause serious impact on other equipment connected to the grid. The work of this thesis is part of this context and focuses on the development of models, indicators, and signal processing methods for power quality monitoring in time-varying power distribution systems.This thesis analyzes the power quality including several well-known features and their relevance. Power system models and signal processing methods for estimating their parameters are investigated for the purpose of real-time monitoring, diagnostic and control tasks under various operating conditions. Among all, the fundamental frequency is one of the most important parameters of a power distribution system. Indeed, its value which is supposed to be a constant varies continuously and reflects the dynamic availability of electric power. The fundamental frequency can also be affected by renewable energy generation and by nasty synchronization of some devices. Moreover, the power absorbed by loads or produced by sources is generally different from one phase to the other one. Obviously, most of the existing residential and industrial electrical installations with several phases work under unbalanced conditions. Identifying the symmetrical components is therefore an efficient way to quantify the imbalance between the phases of a grid. New state-space representations of power systems are proposed for estimating the fundamental frequency and for identifying the voltage symmetrical components of unbalanced three-phase power systems. A first state-space representation is developed by supposing the fundamental frequency to be known or to be calculated by another estimator. In return, it provides other parameters and characteristics from the power system. Another original state-space model is introduced which does not require the fundamental frequency. Here, one state variable is a function of the frequency which can thus be deduced. Furthermore this new state-space model is perfectly are able to represent a three-phase power system in both balanced and unbalanced conditions. This not the case of lots of existing models. The advantage of the proposed state-space representation is that it gives directly access to physical parameters of the system, like the frequency and the amplitude and phase values of the voltage symmetrical components. Power systems parameters can thus be estimated in real-time by using the new state-space with an online estimation process like an Extended Kalman Filter (EKF). The digital implementation of the proposed methods presents small computational requirement, elegant recursive properties, and optimal estimations with Gaussian error statistics.The methods have been implemented and validated through various tests respecting real technical constraints and operating conditions. The methods can be integrated in active power filtering schemes or load-frequency control strategies to monitor power systems and to compensate for electrical disturbances.
86

Generická analýza toků v počítačových sítích / Generic Flow Analysis in Computer Networks

Jančová, Markéta January 2020 (has links)
Tato práce se zabývá problematikou popisu síťového provozu pomocí automaticky vytvořeného modelu komunikace. Hlavním zaměřením jsou komunikace v řídicích systémech , které využívají speciální protokoly, jako je například IEC 60870-5-104 . V této práci představujeme metodu charakteristiky síťového provozu z pohledu obsahu komunikace i chování v čase. Tato metoda k popisu využívá deterministické konečné automaty , prefixové stromy  a analýzu opakovatelnosti. Ve druhé části této diplomové práce se zaměřujeme na implementaci programu, který je schopný na základě takového modelu komunikace verifikovat síťový provoz v reálném čase.
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Att förstå arbetssättet med identifiering av hållbarhetsmål : En studie i kvalitetsteknik utförd vid LKAB / Making sense of the methodology of identifying sustainability goals in a production company

Rydberg, William January 2021 (has links)
Syftet med denna studie är att lämna förslag till Luossavaara-Kiirunavaara aktiebolags (LKAB i fortsättningen) arbetssätt för framtagning av hållbarhetsmål på koncernnivå. Två frågeställningar har konstruerats för att kunna besvara studiens syfte. Frågeställningarna undersöker hur LKAB arbetar idag med att ta fram hållbarhetsmål på koncernnivå och hur ett optimerat arbetssätt med framtagning av hållbarhetsmål skulle kunna se ut. Datainsamlingen består av intervjuer med olika medarbetare som på ett eller annat sätt har varit involverade i framtagning av förslag till hållbara mål. Resultatet visar att LKAB har arbetet med identifieringen av hållbarhetsmål utifrån ett projektbaserat arbetssätt. Detta är studiens första slutsats. Analysen visar att arbetssättet med framtagning av koncernmål skulle kunna genomföras utifrån ett processbaserat arbetssätt. Analysen och diskussionen i den här studien visar att ett optimerat arbetssätt skulle kunna uppnås genom att dela huvudprocessen till två och utveckla ett processbaserat arbetssätt för varje huvudprocess. Detta är studiens andra slutsats. / The purpose of this study is to submit proposals to the company Luossavaara-Kiirunavaara (LKAB) and its mythology of identifying sustainability goals at group level. two questions have been created in order to be able to answer the study´s purpose. The questions examine LKAB´s mythology of identifying sustainability goals at group level and how an optimized mythology of identifying sustainability goals could look like. The data collection consists of interviews with various employees who have been involved in the identifying of sustainability goals. The results shows that LKAB´s mythology of identifying sustainability goals has formed on a project-based approach. This is the first conclusion of this study. The analysis shows that the mythology of identifying sustainability goals could be implemented with a process-based mythology. The analysis and the discussion in this study show that an optimized mythology could be achieved by dividing the main process into two main processes and developing a process-based mythology for each main process. This is the second conclusion of this study.
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Koncept rychlonabíjecí stanice pro elektromobily s akumulací / Concept of Fast Charging Station with Accumulation for Electric Vehicles

Miškovský, Ján January 2017 (has links)
Main purpose of the thesis is the creation of a concept a fast-charging station associated with accumulation that uses renewable source. The introduction of the thesis describes a standard that specifies the charge of electric vehicles using direct and alternating current as well. It depicts an overview of using charging connectors. The first part also deals with overview of the technology of renewable sources and exploitation energy storage system for charging station. The second part introduces the theoretical basement for mathematical model of the charging station in Matlab/Simulink. The function of model station is verified by a physical laboratory model. For options verification of the connection station to the distribution net is created simulation of voltage losses in Matlab/Simulink. The thesis shows four 24 hours’ scenarios that have been simulated. According to the assumptions of simulation, the technology of station and connecting component is suggested. Next is the designed energy and financial analysis of the project charging station until 2030.
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Changes in Cross-Equatorial Ocean Heat Transport Impact Regional Climate and Precipitation Sensitivity

Oghenechovwen, Oghenekevwe C. 01 December 2022 (has links)
Do changes in how cross-equatorial energy transport is partitioned between the ocean and atmosphere impact the hemispheric climate response to forcing? To find out, we alter the cross-equatorial ocean heat transport in a state-of-the-art GCM and ascertain how changes in energy transport and its partitioning impact hemispheric climate and precipitation sensitivity following abrupt CO2-doubling. We further evaluate the applicability our results in CMIP6-class ESMs, where AMOC facilitates the northward cross-equatorial ocean heat transport. In our experiments, changes in ocean cross-equatorial energy transport trigger compensating changes in atmospheric energy transport through changes in the Hadley cells and a shift in the Intertropical Convergence Zone. However, the climate sensitivity in each hemisphere is linearly related to the ocean heat transport convergence, not atmospheric energy transport convergence, due to the impact of ocean heating on evaporation and atmospheric specific humidity. Similarly, we also find that ocean heat transport convergence controls the hemispheric precipitation sensitivity through the impact of ocean heating on surface evaporation. This relationship is also evident in CMIP6 models, where we find differences in hemispheric precipitation sensitivity to be related to the Atlantic Meridional Overturning Circulation (AMOC). Changes in the AMOC control hemispheric differences in upper ocean heat content, which then affect how the hydrologic cycle responds to CO2 forcing in each hemisphere. These results suggest that ocean dynamics impact the hemispheric climate response to CO2 forcing, particularly how much regional precipitation changes with warming. / Graduate
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Exact Analysis of Exponential Two-Component System Failure Data

Zhang, Xuan 01 1900 (has links)
<p>A survival distribution is developed for exponential two-component systems that can survive as long as at least one of the two components in the system function. It is assumed that the two components are initially independent and non-identical. If one of the two components fail (repair is impossible), the surviving component is subject to a different failure rate due to the stress caused by the failure of the other.</p> <p>In this paper, we consider such an exponential two-component system failure model when the observed failure time data are (1) complete, (2) Type-I censored, (3) Type-I censored with partial information on component failures, (4) Type-II censored and (5) Type-II censored with partial information on component failures. In these situations, we discuss the maximum likelihood estimates (MLEs) of the parameters by assuming the lifetimes to be exponentially distributed. The exact distributions (whenever possible) of the MLEs of the parameters are then derived by using the conditional moment generating function approach. Construction of confidence intervals for the model parameters are discussed by using the exact conditional distributions (when available), asymptotic distributions, and two parametric bootstrap methods. The performance of these four confidence intervals, in terms of coverage probabilities are then assessed through Monte Carlo simulation studies. Finally, some examples are presented to illustrate all the methods of inference developed here.</p> <p>In the case of Type-I and Type-II censored data, since there are no closed-form expressions for the MLEs, we present an iterative maximum likelihood estimation procedure for the determination of the MLEs of all the model parameters. We also carry out a Monte Carlo simulation study to examine the bias and variance of the MLEs.</p> <p>In the case of Type-II censored data, since the exact distributions of the MLEs depend on the data, we discuss the exact conditional confidence intervals and asymptotic confidence intervals for the unknown parameters by conditioning on the data observed.</p> / Thesis / Doctor of Philosophy (PhD)

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