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Idnani, Sunil Charan 1964. "An ACSL interface for DYMOLA." Thesis, The University of Arizona, 1991. http://hdl.handle.net/10150/291863.
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This MS thesis proposes the use of DYMOLA, an object-oriented language for modeling hierarchically structured systems, to generate ACSL simulation programs for continuous system analysis. An ACSL model described in terms of time dependent non-linear differential equations or transfer functions can be generated from a hierarchical model description of the system using DYMOLA. The model description in DYMOLA can be an equation description or a non-linear hierarchical bond graph abstraction to describe the system under investigation. The interface provides an automated method to generate ACSL simulation programs, hence eliminating the need for manual coding. The provision to specify an experiment description for run-time analysis and additional model statements is implemented. The implementation of the compiler's code generator includes parsing, error checking and system dependent file handling routines. Implementation techniques, model and control file specifications, and validation with examples in several application areas are described.
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Lannerhed, Petter. "Structural Diagnosis Implementation of Dymola Models using Matlab Fault Diagnosis Toolbox." Thesis, Linköpings universitet, Fordonssystem, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-138753.
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Models are of great interest in many fields of engineering as they enable prediction of a systems behaviour, given an initial mode of the system. However, in the field of model-based diagnosis the models are used in a reverse manner, as they are combined with the observations of the systems behaviour in order to estimate the system mode. This thesis describes computation of diagnostic systems based on models implemented in Dymola. Dymola is a program that uses the language Modelica. The Dymola models are translated to Matlab, where an application called Fault Diagnosis Toolbox, FDT is applied. The FDT has functionality for pinpointing minimal overdetermined sets of equations, MSOs, which is developed further in this thesis. It is shown that the implemented algorithm has exponential time complexity with regards to what level the system is overdetermined,also known as the degree of redundancy. The MSOs are used to generate residuals, which are functions that are equal to zero given that the system is fault-free. Residual generation in Dymola is added to the original methods of the FDT andthe results of the Dymola methods are compared to the original FDT methods, when given identical data. Based on these tests it is concluded that adding the Dymola methods to the FDT results in higher accuracy, as well as a new way tocompute optimal observer gain. The FDT methods are applied to 2 models, one model is based on a system ofJAS 39 Gripen; SECS, which stands for Secondary Enviromental Control System. Also, applications are made on a simpler model; a Two Tank System. It is validated that the computational properties of the developed methods in Dymolaand Matlab differs and that it therefore exists benefits of adding the Dymola implementations to the current FDT methods. Furthermore, the investigation of the potential isolability based on the current setup of sensors in SECS shows that full isolability is achievable by adding 2 mass flow sensors, and that the isolability is not limited by causality constraints. One of the found MSOs is solvable in Dymola when given data from a fault-free simulation. However, if the simulation is not fault-free, the same MSO results in a singular equation system. By utilizing MSOs that had no reaction to any modelled faults, certain non-monitored faults is isolated from the monitored ones and therefore the risk of false alarms is reduced. Some residuals are generated as observers, and a new method for constructing observers is found during the thesis by using Lannerheds theorem in combination with Pontryagin’s Minimum Priniple. This method enables evaluation of observer based residuals in Dymola without any selection of a specific operating point, as well as evaluation of observers based on high-index Differential Algebraic Equations, DAEs. The method also results in completely different behaviourof the estimation error compared to the method that is already implemented inthe FDT. For example, one of the new observer-implementations achieves both an estimation error that converges faster towards zero when no faults are implementedin the monitored system, and a sharper reaction to implemented faults.
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Ahmed, Umair. "Racing Driver Model in Dymola Vehicle Dynamics Library (VDL) : Steering Controller Design." Thesis, Karlstads universitet, Avdelningen för fysik och elektroteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-11858.
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Racing drivers always want to traverse path at vehicle’s maximum performance limits while keeping the vehicle at its ideal trajectory. The main objective of this report is to elaborate strategy for the path following problem in which driver has to follow the predefined 2D roads. New steering controller design for closed loop racing driver model in Dymola vehicle dynamics library is developed. The methodology proposed by Sharp et al. [2] is followed with the optimal velocity profile that tries to mimic the actions of the real drivers in real time scenarios. Vehicle handling limits i.e. longitudinal and lateral limits are defined before simulation. While travelling in the neighbourhood of optimal velocity on the straight road as well as during the curves, the performance of the steering controller is tested by conducting the test on J turn, Clothoid, Extended chicane and the closing curve path and also tested during the different environment effects e.g. when there is a side wind affecting the vehicle. Performance of existing and new steering controllers discussed and compared in result chapter. It is ensured that the drawbacks in the existing steering controller are eliminated by using the proposed methodology in new implemented steering controller. Key Words: Driver Model, Steering Controller, Path following, Velocity profile
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Karlén, Johan. "Uncertainty Quantification of a Large 1-D Dynamic Aircraft System Simulation Model." Thesis, Linköpings universitet, Reglerteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-120189.
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A 1-D dynamic simulation model of a new cooling system for the upcoming Gripen E aircraft has been developed in the Modelica-based tool Dymola in order to examine the cooling performance. These types of low-dimensioned simulation models, which generally are described by ordinary differential equations or differential-algebraic equations, are often used to describe entire fluid systems. These equations are easier to solve than partial differential equations, which are used in 2-D and 3-D simulation models. Some approximations and assumptions of the physical system have to be made when developing this type of 1-D dynamic simulation model. The impact from these approximations and assumptions can be examined with an uncertainty analysis in order to increase the understanding of the simulation results. Most uncertainty analysis methods are not practically feasible when analyzing large 1-D dynamic simulation models with many uncertainties, implying the importance to simplify these methods in order to make them practically feasible. This study was aimed at finding a method that is easy to realize with low computational expense and engineering workload. The evaluated simulation model consists of several sub-models that are linked together. These sub-models run much faster when simulated as standalone models, compared to running the total simulation model as a whole. It has been found that this feature of the sub-models can be utilized in an interval-based uncertainty analysis where the uncertainty parameter settings that give the minimum and maximum simulation model response can be derived. The number of simulations needed of the total simulation model, in order to perform an uncertainty analysis, is thereby significantly reduced. The interval-based method has been found to be enough for most simulations since the control software in the simulation model controls the liquid cooling temperature to a specific reference value. The control system might be able to keep this reference value, even for the worst case uncertainty combinations, implying no need to further analyze these simulations with a more refined uncertainty propagation, such as a probabilistic propagation approach, where different uncertainty combinations are examined. While the interval-based uncertainty analysis method lacks probability information it can still increase the understanding of the simulation results. It is also computationally inexpensive and does not rely on an accurate and time-consuming characterization of the probability distribution of the uncertainties. Uncertainties from all sub-models in the evaluated simulation model have not been included in the uncertainty analysis made in this thesis. These neglected sub-model uncertainties can be included using the interval-based method, as a future work. Also, a method for combining the interval-based method with aleatory uncertainties is proposed in the end of this thesis and can be examined.
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Capodaglio, Cristina. "Modellazione in ambiente Dymola di una sottostazione di scambio termico bidirezionale per reti di teleriscaldamento attive." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
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La commissione europea introduce i traguardi in ambito energetico da raggiungere entro il 2030, in particolare stabilisce la riduzione delle emissioni inquinanti, l’aumento della quota per le energie rinnovabili e il miglioramento dell'efficienza energetica. Inoltre, considerando che gli edifici rappresentano il più grande consumatore di energia in Europa, soprattutto per il riscaldamento degli ambienti e la produzione di ACS, si trovano a svolgere un ruolo determinante, in questo contesto energetico, le reti di teleriscaldamento. A tal proposito, è stato sviluppato, con l’ausilio del software Dymola, il modello dinamico di una sottostazione di scambio termico bidirezionale per reti di teleriscaldamento attive. I punti chiave per la realizzazione del modello sono: la bidirezionalità dei flussi termici, l’interazione tra gli scambiatori di calore e la gestione dei sistemi di controllo che regolano le logiche di funzionamento della sottostazione. La prima validazione del modello è stata eseguita con 7 simulazioni in regime stazionario che si distinguono per i livelli energetici di richiesta e produzione. Successivamente sono state svolte 8 prove in regime dinamico che rappresentano la transizione tra differenti scenari al variare nel tempo delle condizioni al contorno. Per ogni simulazione verrà riportato un confronto tra i risultati numerici e i dati sperimentali ottenuti dai test condotti da Eurac Research sul prototipo della sottostazione.
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Andreou, Spyros 1956. "Simulation of a solar-heated house using the bond graph modeling approach and the DYMOLA modeling software." Thesis, The University of Arizona, 1990. http://hdl.handle.net/10150/277286.
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This thesis discusses the application of the bond graph modeling technique directly coded into the Dynamic Modeling Language (DYMOLA) for simulating a solar-heated house. Scientists throughout the years have investigated the exploitation of solar radiation for space heating. In this thesis, the physical behavior of such a system is modeled and simulated in a convenient, robust and fast manner. The bond graph modeling methodology has found widespread use in a wide range of systems. DYMOLA is a modeling language well suited to represent bond graphs. DYMOLA is a program generator that can map a topological system description, such as a bond graph, into a state-space description expressed in the form of a DESIRE simulation program.
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Maaraoui, Samer. "Étude et conception d'une pompe à chaleur résidentielle intégrant un stockage par chaleur latente." Thesis, Paris, ENMP, 2013. http://www.theses.fr/2013ENMP0014/document.
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L'introduction des énergies renouvelables intermittentes, la mise en place d'une réglementation thermique qui baisse les besoins de chauffage d'un facteur 5 à 10, entraîne une re-conception des moyens de chauffage intégrant efficacité énergétique et effacement d'équipements domestiques lors des heures de pointe. Cette thèse comporte l'étude et la conception d'une PAC intégrant un stockage thermique par chaleur latente dans son condenseur. Ce stock permettra un effacement d'au moins deux heures. Les besoins d'une maison basse consommation (BBC) ont été évalués ainsi que la quantité de chaleur à stocker afin d'assurer cet effacement. Une étude sur le phénomène de changement de phase et les MCP a été menée afin de sélectionner un matériau adapté à cette application. Le phénomène de changement de phase a été modélisé en régime dynamique. Quatre matériaux candidats ont été sélectionnés et analysés par colorimétrie différentielle (DSC) avec ajustement par méthode inverse. Plusieurs structures de l'échangeur stockeur ont été proposées, simulées et optimisées et deux ont été choisies et réalisées. Les deux échangeurs réalisés ont été testés seuls et intégrés dans un système de PAC. La dernière génération a donné des résultats très encourageants pour le développement d'une PAC à stockage efficace. Finalement, l'apport de stockage a été évalué en termes d'efficacité énergétique et d'émissions de CO2. Cette PAC présente une amélioration potentielle du COP saisonnier de 20 à 30 % comparativement à des PAC air/eau et air/air du fait de la gestion intelligente du stockage/déstockage d'énergie en faisant fonctionner la PAC pendant les heures les plus favorables de la journée et en évitant les cycles courts de fonctionnement correspondant aux besoins thermiques faiblesThe introduction of intermittent renewable energies, the implementation of a thermal regulation, which decreases heating needs of a factor between 5 and 10, causes a redesign of heating systems integrating energy efficiency and the cut-off of domestic equipments during peak hours. This thesis involves the study and design of a heat pump incorporating a latent thermal storage in its condenser. This storage will allow a cut-off during at least two hours. The heating needs of a low-energy consumption house (BBC) have been estimated as well as the heat amount to be stored so as to ensure such a cut-off. A study on the phase-change phenomenon and the PCM has been carried out in order to select suitable materials for this application. A dynamic model of the phase change was also developed. Four candidate materials were selected and analyzed by tuned Differential Scaning Calorimetry (DSC) with adjustment by the inverse method. Several storing-exchanger structures have been proposed, simulated, and optimized; two of them have been realized. Both heat exchangers have been tested alone and then integrated into a heat pump system. The final generation gave very promising results for the development of an efficient heat pump with storage. Finally, the heat storage effect has been evaluated in terms of energy efficiency and CO2 emissions. This heat pump presents potential improvement of the seasonal COP between 20% and 30% compared to air-to-water and air-to-air heat pumps because of the smart monitoring of the energy storage/delivery due to the heat pump operation during the most favorable hours of the day and by avoiding short cycles operation corresponding to low heating needs
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Wendelius, Ludvig. "Development of a SimulationModel of an Automatic Gearbox." Thesis, Umeå universitet, Institutionen för fysik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-58488.
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A simulation model for an automatic gearbox with primary retarder has been constructedand implemented, in this thesis. Together with other modelled vehicle components, thismodel could for example be used for fuel consumption estimation or optimizing vehicleparameters.The mechanical components and the control system inside the automatic gearbox weremodelled separately and then assembled into the nal gearbox model, using the objectorientedprogramming language Modelica. Modelica ensures that each individual componentcan be reused in other models.The gearbox model was validated through a number of test cycles designed to capturedierent vehicle behaviours. The test cycles were recreated in the simulation environmentand the simulation results could be compared to a real vehicle performing the same tests.Validation showed that the model succeeded in its goal, that the implemented model isreproducing similar behaviour as the real gearbox. With gear shifts taking place in aboutthe same situations and converter locking/unlocking occurring the same time in the simulationsas in the real vehicle testing.I det här examensarbetet har en simuleringsmodell för en automatisk växellåda med primär retarder utvecklats och implementerats. Tillsammans med andra modeller från fordonoch drivlina skulle denna simuleringsmodell kunna användas för att uppskatta ett fordonsbränsleförbrukning eller till att optimera olika fordonsparametrar.De olika mekaniska komponenterna samt kontrollsystemet i växellådan modellerades separat.Dessa modeller kunde sedan sammanfogas för att bygga den slutliga växellådsmodellen.Alla modeller implementerades i det objektorienterade programmeringsspråket Modelica,som tillåter en stor återanvändningsbarhet till vardera enskild komponent.Den implementerade modellen verierades genom ett antal provcykler, utformade för attfånga olika beteenden hos växellådan. Dessa cykler har återskapats i simuleringsmiljön ochmed det kunde resultat från simuleringar jämföras mot data från ett verkligt fordon somutförde samma prov.Från verieringen har slutsatsen dragits att modellen uppfyllde målen med projektet. Målen var, att den slutliga simuleringsmodellen visar ett liknande beteende som en växellåda i ett verkligen fordon. Växlingar och låsning/upplåsning hos momentomvandlareninträande vid ungefär samma situationer i simuleringarna som i provningen med det verkligafordonet.
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Noguer, Nicolas. "Aide à l'analyse fiabiliste d'une pile à combustible par la simulation." Thesis, Belfort-Montbéliard, 2015. http://www.theses.fr/2015BELF0261/document.
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Le fonctionnement de la pile à combustible (PAC) de type PEM (à membrane polymère) est encore soumis à de nombreuses incertitudes, aux natures différentes, qui affectent ses performances électriques, sa fiabilité et sa durée de vie. L'objectif général de cette thèse est de proposer une méthode d'aide à l'évaluation de la fiabilité des PAC par la simulation ; la fiabilité étant vue ici comme la garantie d’accéder à un niveau de performance électrique donné dans les différentes conditions d’usage envisagées pour la PAC. La démarche proposée s’appuie sur un couplage physico-fiabiliste où la complexité des phénomènes physiques présents dans la pile est prise en compte par une modélisation de connaissance, dynamique, symbolique et acausale, développée dans l’environnement Modelica - Dymola. La modélisation retenue, monodimensionnelle, non isotherme inclut une représentation diphasique des écoulements fluidiques pour mieux retranscrire la complexité des échanges d’eau dans le coeur de la pile PEM. La modélisation permet aussi d’intégrer des incertitudes sur certains de ses paramètres physiques et semi-empiriques (classés en trois catégories : opératoires, intrinsèques et semi-empiriques) puis d’entreprendre, par des tirages de Monte-Carlo, la modélisation probabiliste des conséquences des incertitudes injectées sur la performance d’une PAC. Il est ainsi possible, par la suite, d’estimer la fiabilité d’une PAC par le calcul de la probabilité que la performance électrique reste supérieure à un seuil minimal à définir en fonction de l’application. Une analyse physico-fiabiliste détaillée a été menée en introduisant à titre d’exemple une incertitude sur la valeur de la porosité de la couche de diffusion cathodique d’une PAC de type PEM (coefficients de variation retenus : 1%, 5% et 10%). L’étude des conséquences de cette incertitude sur la tension et l’impédance d’une PAC a été menée en réalisant un plan d’expériences numériques et en mettant en oeuvre différents outils d’analyse statistique : graphes des effets, analyses de la variance, graphes des coefficients de variation des distributions en entrée et sortie du modèle déterministe. Dans cet exemple d’analyse et dans les conditions d’usages considérées, le taux de fiabilité prévisionnel (probabilité pour que la cellule de pile fournisse un minimum de tension de 0.68V) a été estimé à 91% avec un coefficient de variation d’entrée à 10%The Proton Exchange Membrane Fuel Cell (PEMFC) operation is subject to inherent uncertainty in various material, design and control parameters, which leads to performance variability and impacts the cell reliability. Some inaccuracies in the building process of the fuel cell (in the realization of the cell components and also during the assembly of the complete fuel cell stack), some fluctuations in the controls of the operating parameters (e.g. cell and gas temperatures, gas pressures, flows and relative humidity rates) affect the electrical performance of the cell (i.e. cell voltage) as well as its reliability and durability. For a given application, the selections of the different materials used in the various components of the electrochemical cell, the choices in the cell design (geometrical characteristics / sizes of the cell components) correspond to tradeoffs between maximal electrical performances, minimal fuel consumption, high lifespan and reliability targets, and minimal costs.In this PhD thesis, a novel method is proposed to help evaluating the reliability of a PEMFC stack. The aim is to guarantee a target level of electrical performance that can be considered as sufficient to meet any application requirements. The approach is based on the close coupling between physical modeling and statistical analysis of reliability. The complexity of the physical phenomena involved in the fuel cell is taken into account through the development of a dynamical, symbolic, acausal modeling tool including physical and semi-empirical parameters as well. The proposed knowledge PEMFC model is one-dimensional, non-isothermal and it includes a two-phase fluidic flow representation (each reactant is considered as a mix of gases and liquid water) in order to better take into account the complexity of the water management in the cell. The modeling is implemented using the MODELICA language and the DYMOLA software; one of the advantages of this simulation tool is that it allows an effective connection between multi-physical modeling and statistical treatments. In this perspective, the modeling is done with the aim of having as much relevant physical parameters as possible (classified in our work as operating, intrinsic, and semi-empirical parameters). The different effects of these parameters on the PEMFC electrical behavior can be observed and the performance sensitivity can be determined by considering some statistical distributions of input parameters, which is a step towards reliability analysis.A detailed physical and reliability analysis is conducted by introducing (as an example) an uncertainty rate in the porosity value of the cathodic Gas Diffusion Layer (coefficients of variance equal to 1%, 5% and 10%). The study of the uncertainty consequences on the cell voltage and electrical impedance is done through a design of numerical experiments and with the use of various statistical analysis tools, namely: graphs of the average effects, statistical sensitivity analyses (ANOVAs), graphs displaying the coefficients of variances linked with the statistical distributions observed in the inputs and outputs of the deterministic model. In this example of analysis and in the considered cell operating conditions, the provisional reliability rate (probability that the cell voltage is higher than 0.68V) is estimated to 91% with an input coefficient of variance equal to 10%
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Bengtsson, Sara. "Modelling of a Power System in a Combined Cycle Power Plant." Thesis, Uppsala universitet, Elektricitetslära, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-149318.
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Simulators for power plants can be used for many different purposes, like training for operators or for adjusting control systems, where the main objective is to perform a realistic behaviour for different operating conditions of the power plant. Due to an increased amount of variable energy sources in the power system, the role of the operators has become more important. It can therefore be very valuable for the operators to try different operating conditions like island operation. The aim of this thesis is to model the power system of a general combined-cycle power plant simulator. The model should contain certain components and have a realistic behaviour but on the same time be simple enough to perform simulations in real time. The main requirements are to simulate cold start, normal operation, trip of generator, a controlled change-over to island operation and then resynchronisation. The modelling and simulations are executed in the modelling software Dymola, version 6.1. The interface for the simulator is built in the program LabView, but that is beyond the scope of this thesis. The results show a reasonable performance of the power system with most of the objectives fulfilled. The simulator is able to perform a start-up, normal load changes, trip of a generator, change-over to island operation as well as resynchronisation of the power plant to the external power grid. However, the results from the changing-over to island operation, as well as large load losses during island operation, show an unreasonable behaviour of the system regarding the voltage magnitude at that point. This is probably due to limitations in calculation capacity of Dymola, and the problem has been left to further improvements due to lack of time. There has also been a problem during the development of a variable speed regulated induction motor and it has not been possible to make it work due to lack of enough knowledge about how Dymola is performing the calculations. Also this problem has been left to further improvements due to lack of time.
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Di, Donato Elena. "Analisi dinamica di una rete di teleriscaldamento reale." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/22440/.
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L’esigenza via via più stringente di mitigare il cambiamento climatico e di trovare fonti di energia alternative all’uso dei combustibili fossili ha determinato negli ultimi anni una sempre più ampia diffusione delle cosiddette smart cities. Le reti di teleriscaldamento si inseriscono pienamente in questo quadro come un sistema di trasporto intelligente dell’energia termica, che soddisfa gli obiettivi indicati di riduzione dei consumi energetici e di abbattimento delle emissioni di inquinanti. La sfida richiesta per la diffusione di questa tecnologia riguarda per lo più lo sviluppo dei sistemi di controllo e di analisi degli elementi di cui si compone. Risulta pertanto determinante l’attività di modellazione numerica delle reti mediante l’utilizzo di strumenti caratterizzati da un alto livello di interdisciplinarità. A tal proposito, il presente lavoro di tesi si inserisce in un’attività di ricerca che vede la modellazione di reti di teleriscaldamento mediante l’ausilio di softwares quali “OpenModelica” e “Dymola”, con lo scopo di fornire nuove metodologie di analisi finalizzate allo studio e all’ottimizzazione della gestione delle stesse. Nello specifico, attraverso una serie di step di modellazione, è stato realizzato per la rete denominata “Nuova Sud” a servizio del Campus Universitario di Parma un modello numerico dinamico che consente di effettuare alcune valutazioni energetiche dirette ad ottimizzare la logica di controllo dell’impianto. Grazie alla descrizione dettagliata dei metodi adottati è possibile utilizzare i risultati ottenuti come punto di partenza per ulteriori sviluppi della rete in esame e, allo stesso tempo, riprodurre i medesimi in attività di analisi dinamica di altre reti.
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M'Himdi, Ibrahim. "Analisi dinamica di una rete di teleriscaldamento reale." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
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La seguente tesi di laurea ha come obiettivo l'analisi dinamica di una rete di teleriscaldamento reale, sita nel quartiere di Corticella a Bologna. L'implementazione della suddetta rete è stata fatta in un ambiente di modellazione basato sul linguaggio di programmazione Modelica. La tesi è stata svolta con la collaborazione dell'Enea, sono state condotte delle simulazioni dinamiche con l'obiettivo di valutare il comportamento della centrale termica facente parte del sistema di teleriscaldamento.
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Lockowandt, Karin. "Parsing and Validation of Modelica Models Utilising Fault Diagnosis." Thesis, Linköpings universitet, Fordonssystem, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-137542.
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Models have become an indispensable tool within most industrial sectors and are used to reduce costs, enhance the performance of a system etc. The computer support within modelling is extensive, whereof the programming language Modelica is eminent, especially for multi-domain models. Dymola, a commercial program, is built on Modelica and is foremost used for simulation purposes, but many applications for which models are useful are not supported by Dymola. Instead other tools, e.g. Matlab, could be used to exploit the full potential of a model, which means that it first would be needed to be translated. This master's thesis examines one of the possible ways to accomplish this. Specifically the possibility to translate Modelica-models via an XML file, generated by Dymola, is examined. The structure and content of this file is explored, and based thereupon a software is implemented in Python, which successfully translates the models constituting the base for this thesis. Specifically the method was developed on a model of a sub-system of Saab 39 Gripen air-plane. Besides porting models between different languages, it is of great interest to determine how well a model describes the system on which it is based. Hence a new method for model validation is developed using the Matlab Fault Diagnosis Toolbox, which also determines the Matlab syntax of the Modelica translation. The novelty with the developed method, compared to traditional model validation methods, is that it is equation based. It is meant to point out specifically which equations are poorly fitted to validation data. On a simple example model the method was successfully used to isolate a poorly fitted equation. This is accomplished by introducing faults to the equations and generating residuals, based on sets of over-determined equations. As a measure of the modelling error the estimation error of the simulated residuals is used, which are weighted together depending on the fault properties of the residuals.
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Wikström, Jonas. "3D Model of Fuel Tank for System Simulation : A methodology for combining CAD models with simulation tools." Thesis, Linköpings universitet, Maskinkonstruktion, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-71370.
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Engineering aircraft systems is a complex task. Therefore models and computer simulations are needed to test functions and behaviors of non existing systems, reduce testing time and cost, reduce the risk involved and to detect problems early which reduce the amount of implementation errors. At the section Vehicle Simulation and Thermal Analysis at Saab Aeronautics in Linköping every basic aircraft system is designed and simulated, for example the fuel system. Currently 2-dimensional rectangular blocks are used in the simulation model to represent the fuel tanks. However, this is too simplistic to allow a more detailed analysis. The model needs to be extended with a more complex description of the tank geometry in order to get a more accurate model. This report explains the different steps in the developed methodology for combining 3-dimensional geometry models of any fuel tank created in CATIA with dynamic simulation of the fuel system in Dymola. The new 3-dimensional representation of the tank in Dymola should be able to calculate fuel surface location during simulation of a maneuvering aircraft. The first step of the methodology is to create a solid model of the fuel contents in the tank. Then the area of validity for the model has to be specified, in this step all possible orientations of the fuel acceleration vector within the area of validity is generated. All these orientations are used in the automated volume analysis in CATIA. For each orientation CATIA splits the fuel body in a specified number of volumes and records the volume, the location of the fuel surface and the location of the center of gravity. This recorded data is then approximated with the use of radial basis functions implemented in MATLAB. In MATLAB a surrogate model is created which are then implemented in Dymola. In this way any fuel surface location and center of gravity can be calculated in an efficient way based on the orientation of the fuel acceleration vector and the amount of fuel. The new 3-dimensional tank model is simulated in Dymola and the results are compared with measures from the model in CATIA and with the results from the simulation of the old 2-dimensional tank model. The results shows that the 3-dimensional tank gives a better approximation of reality and that there is a big improvement compared with the 2-dimensional tank model. The downside is that it takes approximately 24 hours to develop this model.Att utveckla ett nytt flygplanssystem är en väldigt komplicerad arbetsuppgift. Därför används modeller och simuleringar för att testa icke befintliga system, minska utvecklingstiden och kostnaderna, begränsa riskerna samt upptäcka problem tidigt och på så sätt minska andelen implementerade fel. Vid sektionen Vehicle Simulation and Thermal Analysis på Saab Aeronautics i Linköping designas och simuleras varje grundflygplanssystem, ett av dessa system är bränslesystemet. För närvarande används 2-dimensionella rätblock i simuleringsmodellen för att representera bränsletankarna, vilket är en väldigt grov approximation. För att kunna utföra mer detaljerade analyser behöver modellerna utökas med en bättre geometrisk beskrivning av bränsletankarna. Denna rapport går igenom de olika stegen i den framtagna metodiken för att kombinera 3- dimensionella tankmodeller skapade i CATIA med dynamisk simulering av bränslesystemet i Dymola. Den nya 3-dimensionella representationen av en tank i Dymola bör kunna beräkna bränsleytans läge under en simulering av ett manövrerande flygplan. Första steget i metodiken är att skapa en solid modell av bränslet som finns i tanken. Därefter specificeras modellens giltighetsområde och alla tänkbara riktningar hos accelerationsvektorn som påverkar bränslet genereras, dessa används sedan i den automatiserade volymanalysen i CATIA. För varje riktning delar CATIA upp bränslemodellen i ett bestämt antal delar och registrerar volymen, bränsleytans läge samt tyngdpunktens position för varje del. Med hjälp av radiala basfunktioner som har implementerats i MATLAB approximeras dessa data och en surrogatmodell tas fram, denna implementeras sedan i Dymola. På så sätt kan bränsleytans och tyngdpunktens läge beräknas på ett effektivt sätt, baserat på riktningen hos bränslets accelerationsvektor samt mängden bränsle i tanken. Den nya 3-dimensionella tankmodellen simuleras i Dymola och resultaten jämförs med mätningar utförda i CATIA samt med resultaten från den gamla simuleringsmodellen. Resultaten visar att den 3-dimensionella tankmodellen ger en mycket bättre representation av verkligheten och att det är en stor förbättring jämfört med den 2-dimensionella representationen. Nackdelen är att det tar ungefär 24 timmar att få fram denna 3-dimensionella representation.
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Divecha, Avinash S. "Modelling of Hybrid Electric Vehicle Components in Modelica And Comparison with Simulink." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1461244804.
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Mazloum, Youssef. "Modélisation dynamique et optimisation des systèmes de stockage d'énergie par air comprimé fonctionnant à pression fixe." Thesis, Paris Sciences et Lettres (ComUE), 2016. http://www.theses.fr/2016PSLEM076.
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La contribution des sources d'énergie renouvelables dans le mix de la production d'électricité augmente largement. De ce fait, l'intégration des technologies de stockage d'énergie dans le réseau électrique devient inévitable afin de remédier aux inconvénients des sources renouvelables. Ainsi, l'objectif de cette thèse est d'évaluer la rentabilité, d'optimiser et d'étudier le comportement dynamique d'un cycle adiabatique de stockage d'énergie par air comprimé fonctionnant à pression fixe (IA-CAES). Ce système est caractérisé d'une part par la récupération de la chaleur de compression et d'autre part par le stockage d'air comprimé sous pression fixe dans des réservoirs hydropneumatiques. Ceux-ci permettent d'améliorer l'efficacité et la densité énergétiques du système de stockage et d'éviter l'utilisation de sources d'énergie fossiles.Tout d'abord, un modèle statique est développé pour achever des analyses énergétiques et exergétique du système IA-CAES. Un modèle exergoéconomique est également réalisé dans le but d'optimiser la rentabilité du système de stockage en utilisant un algorithme génétique. Ainsi, une fonction objective, qui prend en compte le coût d'investissement et le coût d'exploitation, est définie pour être minimisée. L'efficacité du système est de 55,1% dans le cas de base, elle est améliorée à 56,6% après optimisation avec une diminution du capital investi de 5,6%.D'autre part, un modèle dynamique est développé pour étudier la flexibilité du système de stockage et sa capacité à répondre aux besoins du réseau électrique (réserves primaires et secondaires) en évaluant la durée des phases transitoires. Les résultats montrent que le système de stockage a besoin d’un temps supérieur à 2 min avant de pouvoir consommer tout l'excès d'énergie disponible sur le réseau électrique et supérieur à 5 min avant d'être capable de produire toute l'énergie requise par le réseau électrique. Des suggestions sont analysées dans l'objectif d'améliorer la flexibilité du système de stockage tel que le fonctionnement du système en mode de veille avec des vitesses réduites. Il permet de réduire les pertes d'énergie de 68% en mode de stockage et de 27% en mode de production par rapport au mode de veille en vitesses nominalesThe contribution of the renewable energy sources in the electricity generation mix is greatly increasing. Thereby, the integration of the energy storage technologies into the electrical grid is becoming crucial to reduce the drawbacks of the renewable energy sources. Then, the objective of this thesis is to evaluate the cost-effectiveness, to optimize and to study the transient behavior of a novel isobaric adiabatic compressed air energy storage (IA-CAES) system. This plant is characterized by the recovery of the compression heat and the storage of the compressed air under fixed pressure in hydro-pneumatic tanks. These allow improving the efficiency and the energy density of the storage system and avoiding the use of fossil fuel sources.Firstly, a steady state model is developed to perform energy and exergy analyses of the IA-CAES system. An exergoeconomic model is also carried out in order to optimize the cost-effectiveness of the storage system by using a genetic algorithm. So, an objective function, which includes the investment cost and the operating cost, is defined to be minimized. The system efficiency is 55.1% in the base case, it is improved to 56.6% after optimization with a decrease in the capital investment by 5.6%.Secondly, a dynamic model is developed to study the flexibility of the storage system and its ability to meet the electrical grid requirements (primary and secondary reserves) by evaluating the duration of the transient states. The results show that the storage system needs more than 2 min before being able to consume all the excess energy available on the electrical grid and more than 5 min before being able to produce all the energy required by the electrical grid. Suggestions are analyzed to improve the flexibility of the storage system such as the operation of the storage system in standby mode with low speeds. It allows reducing the energy losses by 68% during the storage mode and by 27% during the production mode compared to the standby mode in nominal speeds
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Osama, Hassan Eltayeb Khalid. "Development of the Simulation Model for the CoSES Laboratory Test Microgrid in Modelica." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
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Evolution of the traditional consumer in a power system to a prosumer has posed many problems in the traditional uni-directional grid. This evolution in the grid model has made it
important to study the behaviour of microgrids. This thesis deals with the laboratory microgrid setup at the Munich School of Engineering, built to assist researchers in studying microgrids.
The model is built in Dymola which is a tool for the OpenModelica language.
Models for the different components were derived, suiting the purpose of this study. The equivalent parameters were derived from data sheets and other simulation programs such as
PSCAD.
The parameters were entered into the model grid and tested at steady state, firstly. This yielded satisfactory results that were similar to the reference results from MATPOWER power flow.
Furthermore, fault conditions at several buses were simulated to observe the behaviour of the grid under these conditions.
Recommendations for further developing this model to include more detailed models for components, such as power electronic converters, were made at the end of the thesis.
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Bois, Jérémy. "Outil d’aide à la décision pour la conception de maisons solaires à énergie positive." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0679/document.
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Les enjeux énergétiques et environnementaux liés au réchauffement climatique amènent à généraliser la sobriété énergétique des bâtiments neufs ainsi que la production locale d’énergie à l’horizon 2020. Ce travail de thèse se concentre sur le secteur de la maison individuelle qui représente près de la moitié des logements neufs construits en France pour un volume d’environ 200000 unités par an.Le contexte de la maison individuelle à énergie positive 100 % solaire consiste à rechercher les compromis entre le niveau de performance du bâti qui détermine les besoins en énergie et la capacité des équipements à valoriser l’énergie solaire pour d’une part subvenir aux besoins en chaleur pour assurer le chauffage et la production d’eau chaude sanitaire, et d’autre part produire l’électricité nécessaire à l’éclairage et aux autres usages spécifiques (matériels électroménager, vidéo, etc.). Après un examen des différents concepts de bâtiments à énergie positive, une analyse a été menée pour identifier les solutions techniques de systèmes solaires combinés capables de fournir le double service de production d’eau chaude et de chauffage. Un modèle détaillé a été développé dans l’environnement Dymola et vérifié par inter-comparaison de modèles à l’échelle des composants. Un algorithme de contrôle original a été mis au point pour maximiser la performance globale du système.Une première étude paramétrique a montré que ce système est capable dans certaines conditions de couvrir près de 80 % des besoins en chaleur de la maison étudiée. Néanmoins, son dimensionnement demeure complexe et la recherche de compromis entre la sobriété de la maison et le dimensionnement des systèmes solaires thermiques et photovoltaïques doit s’appuyer sur un algorithme d’optimisation multi-objectifs adapté.Un chapitre est donc consacré à l’élaboration d’un algorithme d’optimisation multi- objectifs qui s’appuie sur la méthode des colonies d’abeilles virtuelles. Cette approche s’est avérée particulièrement pertinente vis à vis du problème (paramètres discrets, continus et qualitatifs) à caractère multiobjectifs(maximiser la valorisation du solaire thermique pour le chauffage d’une part et pour la production d’eau chaude d’autre part, minimiser la consommation d’énergie conventionnelle) et sous contrainte car seules les solutions à bilan d’énergie positif sur l’année seront retenues. L’algorithme d’optimisation développé ici a été confronté à une série de problèmes classiques et a démontré sa capacité à construire l’ensemble des solutions avec un nombre relativement faible d’évaluations du modèle.Le dernier chapitre présente deux applications de conception de maisons à énergie positive. La première se situe en région bordelaise alors que la seconde est située à proximité de Strasbourg. Ces deux conditions climatiques permettent de mettre en évidence la capacité de l’algorithme d’optimisation à proposer un éventail de solutions optimales présentant des compromis différents en termes de performance du bâti et de dimensionnement des équipements solaires. Enfin, un outil d’aide à la décision permet d’explorer les fronts optimaux pour dégager les solutions à retenirWith energy-related and environmental climate change challenges, energy sobriety and local energy production are yet to become a mainstream practice for new buildings construction by 2020. This works focuses on single-family houses which in France represent half of new buildings constructions with 200000 new units new units each year. Near zero energy single-family houses with 100 % solar energy consists on compromising between performance of building envelope which defines energy needs and the ability for equipments to value free solar energy. Hence solar energy must be able to cover space heating and domestic hot waterdemands but also provide enough energy for lightning and other specific uses such as domestic appliances.After a literature review of near zero energy house concepts, an analysis was undertaken to providea clear view of solar combi-systems technical solutions with the ability to provide enough energyfor both needs : space heating and domestic hot water. Using Dymola environment a detailed modelwas developed and its consistency was checked by inter-comparison at component scale. An innovative control algorithm has been worked out to maximize the solar system’s global performance. Afirst parametric study has shown that the system was able to cover close to 80 % of house heat requirement. However sizing of a solar combi-system is a complex task and requires to find compromises between building sobriety, solar thermal energy efficiency, and photovoltaics solar energy sizing. Because of the problem’s complexity, a decision aid tool with an appropriate multi-criteria optimizationalgorithm is required.To that end a chapter is dedicated to the development of a multi-criteria optimization algorithm based on artificial bee colony behavior. This approach has proved to be quite effective to solve the problem and to handle continuous, discrete and qualitative decision variables. Chosen solution was constrained to have a positive energy balance and must maximize solar space heating and domestic fraction in a view to reduce total energy consumption. A validation process has also been set up and the developed optimization algorithm has proved its ability to solve standard problems with a fairlyshort number of evaluations. Adopted methodology was illustrated by two applications of the design phase of a near zero energydetached house. First one is located at Bordeaux an second one in Strasbourg. Selected climate conditions emphasize the ability of the proposed approach to identify a wide range of optimal solutions showing differences within the building’s performance as well as the solar system sizing. Lastly a decision aid tool allows to explore optimal front in a convenient way to shape adapted solutions
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Horkeby, Kristofer. "Simulation of Heat Recovery Steam Generator in a Combined Cycle Power Plant." Thesis, Linköpings universitet, Institutionen för systemteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-75836.
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This thesis covers the modelling of a Heat Recovery Steam Generator (HRSG) in a Combined Cycle Power Plant(CCPP). This kind of power plant has become more and more utilized because of its high efficiency and low emissions. The HRSG plays a central role in the generation of steam using the exhaust heat from the gas turbine. The purpose of the thesis was to develop efficient dynamic models for the physical components in the HRSG using the modelling and simulation software Dymola. The models are then to be used for simulations of a complete CCPP.The main application is to use the complete model to introduce various disturbances and study their consequences inthe different components in the CCPP by analyzing the simulation results. The thesis is a part of an ongoingdevelopment process for the dynamic simulation capabilities offered by the Solution department at SIT AB. First, there is a theoretical explanation of the CCPP components and control system included in the scope of this thesis. Then the development method is described and the top-down approach that was used is explained. The structure and equations used are reported for each of the developed models and a functional description is given. Inorder to ensure that the HRSG model would function in a complete CCPP model, adaptations were made and tuning was performed on the existing surrounding component models in the CCPP. Static verifications of the models are performed by comparison to Siemens in-house software for static calculations. Dynamic verification was partially done, but work remains to guarantee the validity in a wide operating range. As a result of this thesis efficient models for the drum boiler and its control system have been developed. An operational model of a complete CCPP has been built. This was done integrating the developed models during the work with this thesis together with adaptations of already developed models. Steady state for the CCPP model is achieved during simulation and various disturbances can then be introduced and studied. Simulation time for a typical test case is longer than the time limit that has been set, mainly because of the gas turbine model. When using linear functions to approximate the gas turbine start-up curves instead, the simulation finishes within the set simulation time limit of 5 minutes for a typical test case.
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M, Venkata Raghu Chaitanya. "Model Based Aircraft Control System Design and Simulation." Thesis, Linköping University, Linköping University, Department of Management and Engineering, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-19264.
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Development of modern aircraft has become more and more expensive and time consuming. In order to minimize the development cost, an improvement of the conceptual design phase is needed. The desired goal of the project is to enhance the functionality of an in house produced framework conducted at the department of machine design, consisting of parametric models representing a large variety of aircraft concepts.
The first part of the work consists of the construction of geometric aircraft control surfaces such as flaps, aileron, rudder and elevator parametrically in CATIA V5.
The second part of the work involves designing and simulating an Inverse dynamic model in Dymola software.
An Excel interface has been developed between CATIA and Dymola. Parameters can be varied in the interface as per user specification; these values are sent to CATIA or Dymola and vice versa. The constructed concept model of control surfaces has been tested for different aircraft shapes and layout. The simulation has been done in Dymola for the control surfaces.
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Jung, Ylva. "Local Sensitivity Analysis of Nonlinear Models - Applied to Aircraft Vehicle Systems." Thesis, Linköping University, Fluid and Mechanical Engineering Systems, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-51212.
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As modeling and simulation becomes a more important part of the modeling process, the demand on a known accuracy of the results of a simulation has grown more important. Sensitivity analysis (SA) is the study of how the variation in the output of a model can be apportioned to different sources of variation. By performing SA on a system, it can be determined which input/inputs influence a certain output the most. The sensitivity measures examined in this thesis are the Effective Influence Matrix, EIM, and the Main Sensitivity Index, MSI.
To examine the sensitivity measures, two tests have been made. One on a laboratory equipment including a hydraulic servo, and one on the conceptual landing gear model of the Gripen aircraft. The purpose of the landing gear experiment is to examine the influence of different frictions on the unfolding of the landing gear during emergency unfolding. It is also a way to test the sensitivity analysis method on an industrial example and to evaluate the EIM and MSI methods.
The EIM and MSI have the advantage that no test data is necessary, which means the robustness of a model can be examined early in the modeling process. They are also implementable in the different stages of the modeling and simulation process. With the SA methods in this thesis, documentation can be produced at all stages of the modeling process. To be able to draw correct conclusions, it is essential that the information that is entered into the analysis at the beginning is well chosen, so some knowledge is required of the model developer in order to be able to define reasonable values to use.
Wishes from the model developers/users include: the method and model quality measure should be easy to understand, easy to use and the results should be easy to understand. The time spent on executing the analysis has also to be well spent, both in the time preparing the analysis and in analyzing the results.
The sensitivity analysis examined in this thesis display a good compromise between usefulness and computational cost. It does not demand knowledge in programming, nor does it demand any deeper understanding of statistics, making it available to both the model creators, model users and simulation result users.
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Bauersfeld, Sindy. "Dynamische Modellierung des Gaspfades eines Gesamt-IGCC-Kraftwerkes auf Basis des SFG-Verfahrens." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2014. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-148639.
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Im Rahmen der vorliegenden Arbeit werden dynamische Modelle eines IGCC-Kraftwerkes mit CO2-Abtrennung unter Verwendung des Modellierungstools Modelica/Dymola entwickelt. Dabei liegt der Schwerpunkt auf dem Gaspfad der Gasreinigung. Es ist vorteilhaft, für verschiedene Aufgaben, Modelle mit unterschiedlicher Tiefe zu verwenden. Mit den detaillierten Modellen werden Simulationen der Teilprozesse durchgeführt. Für den Aufbau eines Gesamtsystems werden vereinfachte Modelle verwendet. Anhand des Gesamtsystems werden drei Regelkonzepte (Gleitdruckregelung, Leistungsregelung der Gasturbine, Leistungsregelung des Vergasers) untersucht und bewertet. Des Weiteren werden drei Störfallszenarien (Ausfall des Sättigers im Brennstoffsystem, Betriebsstörung in der Vergaserinsel, Unterbrechung der Stickstoffzumischung im Brennstoffsystem) getestet.
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Ejjabraoui, Kamal. "Contribution à la conception de systèmes mécatroniques automobiles : méthodologie de pré-dimensionnement multi-niveau multi-physique de convertisseurs statiques." Paris 11, 2010. http://www.theses.fr/2010PA112381.
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Les travaux de cette thèse sont effectués dans le cadre du projet O2M (Outil de Modélisation Mécatronique), labellisé par les pôles de compétitivité Mov'eo et System@tic, dont l'objectif est de développer une nouvelle génération d'outils dédiés aux différentes phases de conception de systèmes mécatroniques automobiles. Nous avons montré à travers de cette thèse l'absence d'une plateforme logicielle permettant la conception de l'ensemble des éléments d'une chaine d'actionnement mécatronique avec la même finesse et d'une méthodologie globale capable de formaliser le choix d'architecture et de considérer plusieurs contraintes multi-physiques y compris des contraintes d'intégration 3D. Dans ce contexte et au sein du sous-projet "Pré-dimensionnement" dont lequel ces travaux sont principalement concentrés, nous nous sommes intéressé au développement d'une approche de prédimensionnement de systèmes mécatroniques réalisée en trois niveaux : choix d'architecture et de technologies des composants, optimisation sous contraintes multi-physiques et optimisation avec intégration de la simulation numérique 3D. Une évaluation sur des outils de simulation et de conception les plus répandus sur différents critères a permis de conclure qu'une plateforme logicielle mécatronique peut être une association de certains outils tels que MATLAB-SIMULINK, DYMOLA, AMESim pour les niveaux 1 et 2 de prédimensionnement et COMSOL pour le niveau 3. Une adaptation de la démarche proposée est réalisée sur un élément essentiel de la chaine mécatronique, le convertisseur DC-DC. Des bases de données technologiques de composants actifs et passifs sont mises en place afin d'alimenter la démarche de pré-dimensionnement. Des modèles nécessaires à la réalisation de chaque niveau de cette démarche sont développés. Ils permettent dans le premier niveau de réaliser le choix d'architecture, d'estimer rapidement le volume des composants et de faire le choix technologique des composants selon une contrainte majeure (volume dans notre cas). Ils assurent dans le deuxième niveau l'optimisation sous contraintes multiphysiques (volume, rendement, température, spectre électromagnétique et commande). Enfin, dans le troisième niveau une association de deux logiciels (COMSOL pour la simulation éléments finis et MATLAB comme environnement d'optimisation) a été mise en place en vue d'une optimisation du placement des composants de puissance sous contrainte thermique en utilisant un modèle thermique plus fin basé sur la méthode des éléments finis. La démarche est appliquée à trois cahier des charges : convertisseur Buck, convertisseur Boost et l'onduleur triphasé. Des optimisations mono-objectif (volume) et multi-objectif (volume et rendement, volume et temps de réponse) sous contraintes multi-physiques ont été réalisées. Nous avons montré à travers ces optimisations l'impact direct des contraintes liées à la commande (temps de réponse, stabilité) au même titre que celles classiquement utilisées lors de la conception des convertisseurs statiques. De plus, nous avons montré la possibilité de lever des risques d'intégration 3D très tôt dans la phase de conception de ces convertisseurs. Cette démarche de pré-dimensionnement multi-niveau, multi-physique proposée a permis de répondre à des besoins exprimés par les partenaires industriels du projet O2M en termes de méthodologie de conception de systèmes mécatroniques automobiles.
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Horáček, Tomáš. "Počítačová podpora výpočtů v energetice a nové trendy v simulacích." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217605.
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Computer aided calculations are booming nowadays and thanks to more powerfull computers and sofistikated simulators we are able to modelling more and more complex problems in much more engineering domains. Also in power engineering are are simulators used more frequntly. They are used for or checking transmission lines and in testing different kinds of working states including fails.
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Fjellstedt, Christoffer. "Methods for including stiffness parameters from reduced finite element models in simulations of multibody systems." Thesis, Uppsala universitet, Fasta tillståndets elektronik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-387499.
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Two methods using lumped element (lumped parameter) methods to model flexible bodies have been presented. The methods are based on the concept of using a Guyan reduced stiffness matrix to describe the elasticity of a body. The component to be modeled has been divided into two parts using FE software and the mass and inertia tensor for the respective part of the component have been retrieved. The first method has been based on including the elements from the stiffness matrix in compliant constraints. The compliant constraints have been derived and a prototype has been implemented in MATLAB. It has been shown that using compliant constraints and stiffness parameters from a Guyan reduced stiffness matrix it is possible, with highly accurate results, to describe the deformation of a flexible body in multibody simulations. The second method is based on springs and dampers and has been implemented in the simulation environment Dymola. The springs and dampers have been constructed to include coupling elements from a Guyan reduced stiffness matrix. It has been shown that using the proposed method it is possible, with highly accurate results, to describe the static deformation of a flexible body. Further, using dynamic simulations of a full robot manipulator model, it has been shown that it is possible to use the spring-damper model to capture the deformation of the links of a manipulator in dynamic simulations with large translations and rotations.
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Barczyk, Zygmunt. "Adolf Dymsza na ekranie - przykład aktorstwa autorskiego." Doctoral thesis, Katowice : Uniwersytet Śląski, 2008. http://hdl.handle.net/20.500.12128/5210.
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Celem piszącego o filmie, tj. o różnej „barwy” komediach Adolfa Dymszy, jest utrwalenie, a zarazem określenie, zapisanej przez aktora żywej niepowtarzalności kina. Ona wcale w tym opisie nie musi być definitywna czy jedyna. Byłby to wówczas jeszcze jeden komputerowy program ludzkiej kultury w polskiej wersji kina, gdyby go tak rozumieć tu, w „pogodnej komedii filmowej Adolfa Dymszy”. Ale przecież nie o tak wysublimowany rodzaj fałszu chodzi! Chodzi natomiast o inspirację tworzenia śladu filmu poprzez słowo. Ślad, który zostałby po tak rozumianej, żywej, niepowtarzalności filmu powinien natomiast mieć szansę bycia trwałym źródłem lub tylko źródełkiem historii ludzkiego zjawiska kulturowego jakim jest kino. A więc?
Warto czy nie warto? - to jest pytanie… Ano właśnie…
Adolf Dymsza był tym wielkim polskim komikiem, który dla współczesnego odbiorcy do tej pory istnieje tylko w unikalnych projekcjach telewizyjnych. Mając jednak możliwość dzięki współczesnej technice filmowego przekazu oraz idei przekazu komputerowego - unaocznienia ekranowych kreacji Dymszy, chciałbym podjąć ryzyko
odpowiedzi na podstawowe pytania dotyczące uzasadnienia wielkości tego aktora. Jednak odpowiedź będzie niełatwa, wymaga bowiem precyzji opisu jego poszczególnych kreacji, w żywym rytmie i specyfice plastyki zapisu kina tego filmowego twórcy komedii, z ryzykiem by zapamiętać - choć po części - żywą postać Dymszy dla dzisiejszego czytelnika - widza. Po co? Dla zachowania kulturowej pamięci naszej polskiej historii…Kreatywność komizmu tego artysty humoru jest cytatem z różnorodnej, a i pełnej wdzięku normalności życia dla widza. Jest cieniowana subtelnymi nutami parodii lub nieco mocniej kreską groteski. Stanowi przykład gamy zaskakujących spojrzeń ku odbiorcy, aby ten w chwili projekcji mógł chłonąć proces porównania fikcji obrazu
ze znaną rzeczywistością otoczenia lub historii. Te spojrzenia nie tylko drgają( film! ), kadr za kadrem, ujęcie za ujęciem, one w wykonaniu Dymszy są nie tylko „barwne”, nie tylko żywe – one są prawdziwe i sugestywne, a przez to niepowtarzalne. Tworzą swoistą pamięć kultury, choć jej ruch powstaje – by tak rzec - w odłamkach, ale o Napoleonie wszyscy wiedzą, nie tyle, że wygrał pod Wagram, lecz że był cesarzem Francji, mimo iż był nader niski…
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Wahlberg, Tobias. "Modeling of Heat Transfer." Thesis, Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-12217.
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Modeling of heat transfer using Dymola. In this report a evaporator, economizer and superheater where modeled. The report describes how the models where modeled and what input was most suitable for a accurate model.
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Šťastná, Hilda. "Simulace CMOS VLSI obvodů." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2017. http://www.nusl.cz/ntk/nusl-363732.
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This diploma thesis deals with processes of electrical circuits calculations in the last years' worldwide standards like Dymola, MATLAB, Maple or SPICE applications. Circuits calculations are linked with methods for solving linear differential equations, used in this work also by verification of functionality of designed models for CMOS inverter, CMOS NAND, CMOS NOR. Numerical integration method in combination with Taylor series is a suitable method also for parallel calculations of CMOS VLSI circuits. CMOS circuits simulation was implemented with this method in applications in MATLAB language, solving circuits, represented by differential equations. Functionality of the applications was verified by some real examples. Significant acceleration of calculations using Taylor series compared to other methods is an important factor in choosing methods used in circuit simulations.
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Minárik, Michal. "Modelování elektrických obvodů s využitím diferenciálního počtu." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2010. http://www.nusl.cz/ntk/nusl-237269.
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This master's thesis deals with modeling of linear electrical circuits through the differential algebraical equation systems. It describes methods of numerical solving, discusses the need of algebraical conversions and possibility of minimalization through the use of parasitic components. In addition, it involves the design and implementation of extension of available simulation tool.
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Nemtsov, Jascha. "Ein jüdischer Synagogenmusiker im Berlin der 1930er Jahre : Jakob Dymont und seine Freitagabendliturgie." Universität Potsdam, 2014. http://opus.kobv.de/ubp/volltexte/2014/7164/.
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Jakob Dymont (1880–1956) stammte aus Litauen und lebte seit seinem 15. Lebensjahr in Berlin. Von 1908 bis 1938 war er Chorleiter an der orthodoxen Berliner Gemeinde „Adass Jisroel“. 1936 wurde er außerdem Lehrer an dem neugegründeten „Beth- Hachasanim“ (Kantorenseminar) der Jüdischen Privaten Musikschule Hollaender. Zu diesem Zeitpunkt war er als begabter Komponist und einer der ersten Autoren von modernen deutsch-jüdischen liturgischen Kompositionen bekannt. Seine Freitagabendund Sabbatmorgenliturgien wurden 1934 bzw. 1936 in der Synagoge Rykestrasse uraufgeführt und fanden eine sehr positive Resonanz. Dymont konnte 1938 Deutschland verlassen. Er lebte dann in New York, wo er sich der Ausbildung jüdischer Kantoren widmete. Dymonts Schaffen der 1930er Jahre ist im Kontext einer Erneuerungsbewegung in der deutsch-jüdischen Synagogenmusik jener Zeit zu betrachten. Seine Werke präsentieren eine fruchtbare Synthese der osteuropäischen jüdischen Tradition mit modernen westeuropäischen Musikformen.Jacob Dymont (1880 – 1956) was born in Lithuania and lived in Berlin from the age of 15. From 1908 to 1938 he was choirmaster at the Orthodox Berlin congregation “Adass Yisroel”. In 1936, he also became a teacher at the newly founded “Beth-Hachasanim” (Cantorial School) of the Hollaender Jewish Private Music School. At that time he was well-known as a talented composer and one of the first authors of modern German- Jewish liturgical compositions. His Friday Evening and Sabbath Morning liturgies were premiered in 1934 and in 1936 in the Rykestrasse synagogue and found a very positive response. Dymont was able to leave Germany in 1938. He then lived in New York, where he devoted himself to the education of Jewish cantors. Dymont’s synagogal music is to be considered in the context of a renewal movement in the German-Jewish synagogue music of the time. His works present a fruitful synthesis of Eastern European Jewish tradition with modern Western European musical forms.
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Austrin, Lars. "On magnetic amplifiers in aircraft applications." Licentiate thesis, Stockholm : Elektrotekniska system, Kungliga Tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4439.
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Lundvall, Louise, and Linda Smetana. "DYnamisk Motorisk TAlbedömning (DYMTA) – en referensstudie : Åldersgrupperna 4:0–4:11 år och 7:0–8:11 år." Thesis, Uppsala universitet, Logopedi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-243240.
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Dynamisk motorisk talbedömning (DYMTA) är ett nyutvecklat test för diagnosticering av verbal dyspraxi. Verbal dyspraxi är termen för barn som har en nedsättning i förmågan att viljemässigt programmera motoriken vid talproduktion. Den här studien syftar till att stärka den kliniska användningen av DYMTA genom att bidra till insamlingen av referensdata från typiskt utvecklade barn. Studien tillhör ett större doktorandprojekt där sammanlagt tre magisteruppsatser kommer att bidra till insamlingen av referensdata av barn med typisk tal- och språkutveckling. I föreliggande studie undersöktes 16 barn i åldern 4:0–4:11 och 17 barn i åldern 7:0–8:11 med DYMTA och ett omfattande testbatteri. Resultatet av DYMTA ska sambedömmas med anamnes, hörsel, språkförmåga, fonologi, artikulation, samt oral struktur och funktion. DYMTA är ett verktyg vid bedömning av barnet när logopeden misstänker att någon motorisk komponent påverkar barnets talförmåga. Bakgrundsfaktorerna kön, hereditet, flerspråkighet undersöks om de har en inverkan på prestationen på DYMTA. Vidare undersöks det i studien om det finns ett samband mellan testresultat på DYMTA och övriga test i testbatteriet. Slutligen undersöks talmotoriska utvecklingstrender mellan åldersgrupperna 4:0–4:11 och 7:0–8:11. Inget signifikant samband avseende kön, hereditet, flerspråkighet framkom avseende prestation på DYMTA. Resultatet visade på ett starkt samband mellan fonologisk förmåga, artikulationsförmåga, grammatisk produktionsförmåga och prestation på DYMTA. Utvecklingstrender fanns och åldersgruppen 4:0–4:11 påvisade en större variabilitet i sin talmotorik och hade därför en större resultatspridning inom sin grupp än vad gruppen 7:0–8:11 hade. Resultatet visar även att det är märkbart att åldersgruppen 4:0–4:11 ännu inte har etablerat samtliga fonem. Åldersgruppen 7:0–8:11 har etablerat alla fonem men gruppen har ännu inte utvecklat en fullt vuxenlik talmotorik. Studien bidrar till med utökad kunskap om barns talmotoriska förmåga i de utvalda åldersgrupperna.DYMTA is a newly developed test for differential diagnostics of the speech disorder childhood apraxia of speech (CAS). Childhood apraxia of speech is a speech sound disorder involving deficits in planning and/or programming speech movements. This study contributes to the data collection of children with normal speech and language abilities. The aim is to create a reference sample for DYMTA. 16 children in the ages 4:0–4:11 and 17 children in the ages 7:0–8:11 were included in this study. The children were assessed with DYMTA along with several other relevant tests regarding their speech, language and oral motor skills. The test results of DYMTA should be interpreted along with anamnestic data, hearing, language, phonology, articulation and oral structure and function. DYMTA is an assessment tool when the clinician suspects a motor speech disorder. Apart from collecting reference data this study also examines if factors regarding abilities in language, articulation, oral motor control and heredity and bilingualism have an impact on the result of DYMTA. This study describes the development of motor speech skills in the selected age groups. The results in this study show a significant correlation between phonology, articulation, expressive grammar and DYMTA. No statistical significance was found regarding gender, heredity and bilingualism. Developmental motor speech trends were found. The age group 4:0-4:11 displayed a greater variability in motor speech skills than the age group 7:0–8:11 and did not show a fully developed phonology. The group 7:0–8:11 had not yet established an adult like motor speech ability. This study contributes to research in motor speech ability of the selected age groups.
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Silva, Jakson Raniel Florencio da. "DYMOS QOS: Uma Abordagem Para Seleção de Serviços em Tempo de Execução em Linhas de Produto de Software Dinâmicas." reponame:Repositório Institucional da UFPE, 2014. https://repositorio.ufpe.br/handle/123456789/13868.
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A produção industrial antes de Taylor era essencialmente manufatureira e focada em produtos únicos. O Taylorismo e seus estudos de tempos e movimentos levaram para a indústria a ideia de padronização dos produtos. Ford, tempos depois, inventou a linha de produtos, onde a partir de então foi possível produzir em massa reduzindo o tempo de entrega do produto e seus custos. No que tange a indústria de software, esta apresenta tanto uma produção manufatureira quanto em massa que gera produtos que são denotados segundo POHL; BöCKLE; LINDEN (2005) como software individual e software standard: uma clara influência do fordismo na concepção do paradigma de Linhas de Produto de Software (SPL). No entanto, este paradigma de desenvolvimento não foi concebido para suportar mudanças nos requisitos de usuários em tempo de execução. Diante deste problema, a academia tem desenvolvido e proposto maneiras de estender o paradigma de SPL de forma a permitir que essas reconfigurações dinâmicas do software sejam suportadas. Surgiram deste esforço as Linhas de Produto de Software Dinâmicas (DSPL) (HALLSTEINSEN et al., 2008). Levando em consideração este cenário, objetiva-se nesta pesquisa contribuir com a área de DSPL apresentando uma nova maneira de pensar quais características de uma DSPL devem ser ligadas em tempo de execução a um produto com base em uma análise que mensura e valida atributos de qualidade em níveis de serviços especificados pelo usuário. Para tanto foi necessária a revisão da literatura existente em busca de meios de analisar atributos de qualidade de serviços em tempo de execução em DSPL e o desenvolvimento exploratório de uma abordagem de reconfiguração da DSPL utilizando-se das características dinâmicas do OSGi como base em tal análise. Com a finalidade de validar a abordagem proposta, a mesma foi testada exploratoriamente em uma DSPL para o domínio de guia de visitas móveis e sensível ao contexto, onde pode-se verificar a assertividade desta. Ao final da validação exploratória pode-se observar a efetividade da abordagem proposta na DSPL na qual foi aplicada. No entanto, faz-se necessário a execução de testes estatísticos para comprovar a hipótese de que esta efetividade demonstrada é válida para outras DSPLs de outros domínios.
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Martins, Dhiego Abrantes de Oliveira. "DYMOS: Uma abordagem para suporte a variabilidades dinâmicas em Linhas de Produto de Software Orientado a Serviços e Sensível ao Contexto." Universidade Federal de Pernambuco, 2013. https://repositorio.ufpe.br/handle/123456789/11633.
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Submitted by Daniella Sodre (daniella.sodre@ufpe.br) on 2015-03-10T13:52:04Z
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Dissertaçao Dhiego Abrantes De Oliveira Martins..pdf: 2253205 bytes, checksum: ac6b5aaa983adfe88c8555520c237441 (MD5)Made available in DSpace on 2015-03-10T13:52:04Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertaçao Dhiego Abrantes De Oliveira Martins..pdf: 2253205 bytes, checksum: ac6b5aaa983adfe88c8555520c237441 (MD5) Previous issue date: 2013-08-30
É notório o surgimento de ambientes cada vez mais dinâmicos, exigindo sistemas mais flexíveis, de forma que componentes possam ser plugados ou desplugados durante o seu ciclo de vida, inclusive em tempo de execução. Para atender estes requisitos, é necessário que decisões sobre possíveis adaptações e variações do produto possam ser tomadas em tempo de execução. Sistemas Sensíveis ao Contexto atendem a esse propósito, sendo capazes de adaptar-se em tempo de execução de acordo com mudanças no ambiente, obedecendo um conjunto de regras. Quando técnicas de Linhas de Produto de Software (LPS) são aplicadas no desenvolvimento de sistemas adaptativos, tais decisões podem resultar na configuração de um novo produto. Em uma LPS tradicional, um produto é derivado de acordo com sua configuração, que ocorre na fase de design e consiste na seleção de features que irão compor o produto, remoção das features que não farão parte do produto e ligação dos pontos de variação. Linhas de Produto de Software Dinâmicas extendem o conceito convencional de LPS abordando aspectos dinâmicos, provendo uma abordagem para tratar variabilidades que precisam ser manipuladas em tempo de execução. Quando alinhamos paradigmas como Sistemas Sensíveis ao Contexto, Arquitetura Orientada a Serviços e LPS, podemos enfrentar alguns desafios. O sistema derivado de uma LPS é composto por features e pontos de variação. Considerando que o modelo de Arquitetura Orientada a Serviços segue o padrão arquitetural Cliente-Servidor, podemos ter um cenário em que as features que compõem o produto no lado cliente podem endereçar uma composição de serviços. Dessa forma, os pontos de variação podem sofrer variabilidades de acordo com mudanças no contexto, exigindo a execução de reconfigurações nos serviços de modo a atender tais variabilidades. As abordagens propostas atualmente não oferecem um suporte para esse tipo de problema ou são incipientes, estando em fases iniciais de pesquisa. Neste trabalho é apresentado um estudo sobre variabilidades dinâmicas em Linhas de Produto de Software Orientadas a Serviços e Sensíveis ao Contexto, investigando especificamente situações quando features que endereçam um ou mais serviços são reconfiguradas no lado cliente, requerendo reconfigurações nos serviços, no lado servidor.
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Liu, Haiying. "Interfacing comprehensive rotorcraft analysis with advanced aeromechanics and vortex wake models." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/22534.
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Thesis (Ph. D.)--Aerospace Engineering, Georgia Institute of Technology, 2008.Committee Chair: Bauchau, Olivier; Committee Member: Armanios, Erian; Committee Member: Hodges, Dewey; Committee Member: Ruzzene, Massimo; Committee Member: Stallybrass, Michael.
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Li, Wei-En. "Enhancement of roll maneuverability using post-reversal design." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29602.
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Thesis (Ph.D)--Aerospace Engineering, Georgia Institute of Technology, 2009.Committee Chair: Hodges, Dewey; Committee Member: Bauchau, Olivier; Committee Member: Goldsman, David; Committee Member: Prasad, J.V.R.; Committee Member: Smith, Marilyn. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Alash, Hayder Majid Abdulhameed. "Impact of Mobility Models on Routing Protocols for Various Traffic Classes in Mobile Ad Hoc Networks." Kent State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=kent1461022411.
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Johnson, David Lloyd. "Performance analysis of mesh networks in indoor and outdoor wireless testbeds." Diss., Pretoria : [s.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-01232009-170259/.
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Marinis, Artelaris Spyridon. "Performance evaluation of routing protocols for Wireless Mesh Networks." Thesis, Linnéuniversitetet, Institutionen för datavetenskap (DV), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-49745.
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Wireless Mesh Networks provide an organisation or a community with the means to extend or create a network independent of infrastructure. However, the network’s dynamic topology along with the fact that devices in the network might be mobile and move randomly, brings tolight various kind of problems on the network, with the most common being the routing. In this report, the problem of routing is examined in terms of throughput, routing overhead, end-to-end delay and packet delivery ratio on two chosen algorithms, namely the Dynamic MANET On-demand (DYMO) and the Better Approach To Mobile Adhoc Networking (B.A.T.M.A.N.). Furthermore, this thesis examines also a Transmission Control Protocol (TCP) connection and compares it against several TCP congestion control mechanisms, two of which, were implemented, namely TCP-Illinois and TCP-FIT, to address the effects that different TCP congestion mechanisms have on an ad-hoc network, when reliable connections are needed. The results show that DYMO is more stable, performs good overall and has the lowest routing overhead, however in a situation with limited mobility or no mobility (as in high mobility they perform poorly) proactive protocols like B.A.T.M.A.N. are worthy protocols, should the extra penalty of routing overhead in the network traffic is not causing any problems. Furthermore, regarding the TCP results, it was observed that TCP congestion algorithms designed specifically for Wireless networks, do offer better performance and should be considered, when designing an ad-hoc network.
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Quach, Minh thao. "Cross-layer framework for interference avoidance in cognitive radio ad-hoc networks." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0489/document.
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Le plan d’attribution du spectre présente un problème de déficit de ressources dans les réseaux sans fil. En 2002, la FCC (Federal Communication Commission) a rapporté que le spectre radioélectrique était de 20% à 85% sous-utilisé. L’utilisation inefficace du spectre est un problème majeur qui doit être résolu si l’on veut que les communications radio se développent. La FCC a ensuite changé la politique de gestion du spectre pour la rendre plus souple en s’interessant à l’approche radio cognitive (CR). La radio cognitive est un type de radio intelligente qui explore l’environnement de fréquences radio, apprend et décide d’utiliser la partie inutilisée du spectre. Les principales fonctions de la CR sont la détection, la prise de décision, et le partage. Cependant, ces radios doivent respecter les infrastructures sans fil standards en minimisant leur impact sur les appareils prioritaires, également appelés systèmes primaires. La coexistence entre les systèmes CR et les systèmes primaires nécessite des processus d’observation et de gestion des interférences dédiés. Dans cette thèse, nous nous sommes intéressés à la phase d’observation du point de vue CR. La zone de chevauchement entre un émetteur CR et l’émetteur primaire (PR) est analysée et prise en compte. L’impact de cette zone est appris par simulation et présenté dans le chapitre 4. En conséquence, des interférences potentielles sont envisagées. Durant la phase d’observation, nous étudions un mécanisme permettant de mieux prévenir la perturbation sur les dispositifs PR en utilisant le Grey Model et le filtre de Kalman comme modèle de prédiction de la densité des récepteurs primaires. En complément à cette observation, nous fournissons une stratégie visant à combiner les observations obtenues en une mesure qui pourra être utilisée par le routage dans le cadre de la coexistence entre réseaux radio cognitive (CRN) et réseaux primaires. La stratégie proposée utilise la logique floue et est présentée dans le chapitre 5. Dans ce chapitre, nous étudions comment la couche réseau réagit et prend les bonnes décisions pour maximiser l’utilisation des ressources du spectre, tout en évitant les interférences avec les récepteurs primaires. Par exemple, un noeud CR peut fonctionner dans une zone de recouvrement, si les récepteurs primaires sont inactifs dans cette zone. Ainsi, nous avons proposé un mécanisme de routage basé sur le protocole de routage DYMO qui prend en compte l’impact relatif observé. Dans ce même chapitre, nous avons également présenté des scénarios pratiques illustrant l’utilité de notre proposition. L’interconnexion des noeuds CR dans le CRN est aussi un problème crucial pour la mise en place du réseau. C’est pourquoi nous présentons un processus de diffusion par balises au chapitre 6. Dans ce chapitre, nous décrivons également un dispositif pratique conçu pour des expériences en radio cognitive. Même si notre travail se rapporte à différentes couches de la pile protocolaire, le cadre général que nous avons conçu est multicouches. En effet, les composants accèdent aux différentes couches pour récupérer l’information, la traiter et réagir en conséquence. Ainsi, notre travail constitue un environnement inter-couches pour un dispositif radio cognitive local visant à minimiser les interférences et à maximiser les ressources réseau dans les réseaux radio cognitiveA fixed spectrum assignment scheme has a problem with resource deficiency in a wireless network. In 2002, the US Federal Communication Commission (FCC) reported that the radio spectrum was 20% to 85% under-utilized. The insufficient use of the spectrum is a critical issue for radio communication; as communication grows, a fixed spectrum becomes more limiting. The FCC then changed its spectrum management policy to make it more flexible by investigating the cognitive radio (CR) approach. Cognitive radio is a type of intelligent radio that explores the radio frequency environment, learns, and decides to use the unused portion of the frequency. The main functions of a CR are sensing, decision making, and sharing. However, these radios have to respect the standard wireless infrastructures by ensuring the least impact with their devices, also known as primary radios. Coexistence between CR systems and primary systems requires dedicated observation processes and interference management. In this thesis, observation from a CR point of view is presented. The overlapping area between a CR transmitter and primary radio (PR) transmitter is analysed so that it can be taken into account. The impact of this area is learnt by simulation and presented in Chapter 4. As a consequence, potential interference is envisaged. Along with observation, we investigate a proper mechanism to better prevent perturbation on PR devices using the Grey model and Kalman filter as a prediction model for predicting the density of primary receivers. In addition, we provide a strategy to combine the obtained observations into a metric that can be used in routing design in the context of coexistence between Cognitive Radio Networks (CRNs) and primary networks. The proposed strategy, using fuzzy logic, is presented in Chapter 5. In this chapter, we investigate how the routing layer reacts and makes the right decisions to maximise the spectrum resources, while avoiding interference with the primary receivers. For instance, a CR node can operate in an overlap region if primary receivers are inactive within this area. Also, we propose a routing mechanism based on the DYMO routing protocol that takes into account the observed relative impact. In the same chapter, we provide some practical scenarios illustrating the usefulness of our proposal. Interconnecting the CR nodes in CRNs is also a critical problem for the establishment of the network. We therefore present a beacon-based dissemination process in Chapter 6. In this chapter, we also describe a practical device designed for cognitive radio experiments. Even though our work affects different protocol layers, the designed framework is cross-layered. Indeed, the different components of the proposed framework access the various layers to retrieve information, process it, and react accordingly. Thus, our work constitutes a cross-layer framework for a local cognitive radio that aims to minimise the interference and maximise the network resources in cognitive radio networks
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Bauersfeld, Sindy. "Dynamische Modellierung des Gaspfades eines Gesamt-IGCC-Kraftwerkes auf Basis des SFG-Verfahrens." Doctoral thesis, 2013. https://tubaf.qucosa.de/id/qucosa%3A22927.
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Im Rahmen der vorliegenden Arbeit werden dynamische Modelle eines IGCC-Kraftwerkes mit CO2-Abtrennung unter Verwendung des Modellierungstools Modelica/Dymola entwickelt. Dabei liegt der Schwerpunkt auf dem Gaspfad der Gasreinigung. Es ist vorteilhaft, für verschiedene Aufgaben, Modelle mit unterschiedlicher Tiefe zu verwenden. Mit den detaillierten Modellen werden Simulationen der Teilprozesse durchgeführt. Für den Aufbau eines Gesamtsystems werden vereinfachte Modelle verwendet. Anhand des Gesamtsystems werden drei Regelkonzepte (Gleitdruckregelung, Leistungsregelung der Gasturbine, Leistungsregelung des Vergasers) untersucht und bewertet. Des Weiteren werden drei Störfallszenarien (Ausfall des Sättigers im Brennstoffsystem, Betriebsstörung in der Vergaserinsel, Unterbrechung der Stickstoffzumischung im Brennstoffsystem) getestet.
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Zhou, Yuliang Leon. "Modeling and simulation of hybrid electric vehicles." Thesis, 2007. http://hdl.handle.net/1828/307.
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With increasing oil price and mounting environment concerns, cleaner and sustainable
energy solutions have been demanded. At present transportation constitutes a large
portion of the energy consumed and pollution created. In this work, two hybrid
vehicle powertrain technologies were studied, a fuel cell - battery hybrid and two
internal combustion engine - battery/ultracapacitor hybrids. Powertrain performance
models were built to simulate the performance of these new designs, and to assess the
feasibility of a fuel cell hybrid power backup system for a special type of vehicles,
elevators in high-rise buildings, using the ADvanced VehIcle SimulatOR (ADVISOR)
first. The model was then applied to evaluate the two-mode hybrid powertrain for
more common vehicles - commercial trucks, showing potential fuel consumption
reduction. To improve modeling accuracy, a new and more flexible tool for modeling
multi-physics systems, Modelica/Dymola, was used to carry out the modeling and
analysis of next generation hybrid electric vehicles, exploring the potentials of new
hybrid powertrain architectures and energy storage system designs. The study forms
the foundation for further research and developments.
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Pimentel, Tomás Pereira da Costa. "District heating systems: case study development using modelica." Master's thesis, 2015. http://hdl.handle.net/10451/22473.
Full textAbstract:
Tese de mestrado integrado em Engenharia da Energia e do Ambiente , apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2015Sistemas de aquecimento de distritos são actualmente considerados uma solução viável para atingir as metas de emissões de CO2 na Europa, devido à sua capacidade de recuperar calor que seria desperdiçado e à sua compatibilidade com fontes de energia renovável. Para dimensionar estes sistemas, programas de simulação de energia em edifícios são frequentemente usados, uma vez que possibilitam uma análise prática, em termos de tempo, das necessidades de consumo do distrito. No entanto, os programas convencionais foram inicialmente desenvolvidos para endereçar edifícios a uma escala individual, o que leva a uma necessidade de desenvolvimento de programas de nova geração que permitam a integração de sistemas de maior escala. Para este efeito, o anexo 60 da agência internacional do ambiente (AIA) visa o desenvolvimento de novas ferramentas computacionais para sistemas de edifícios e comunidades em Modelica, uma linguagem que permite a modelação de processos físicos extensos, complexos e de multi-domínio. Esta dissertação está inserida na Actividade 2.2 do Anexo 60 e avalia diferentes formas de endereçar as necessidades de aquecimento e arrefecimento, utilizando como caso de estudo um bairro com 24 edifícios. A implementação em Modelica é detalhadamente descrita e uma analise de sensibilidade foi conduzida relativamente a quatro parâmetros que influenciam as necessidades anuais: Número de zonas térmicas consideradas, ganhos internos, temperatura do solo e trocas de calor entre edifícios adjacentes. Concluiu-se que as necessidades de calor são particularmente sensíveis à forma como dividimos o interior dos edifícios e às trocas de calor entre os mesmos, enquanto as necessidades de arrefecimento revelaram maior sensibilidade à forma como são modelados os ganhos internos. Finalmente, o uso do Modelica para estas aplicações foi também avaliado.
As countries in Europe are focusing in reducing their CO2 emission levels, district heating systems (DHS) are considered to be a feasible solution due to their ability to re-use heat that would otherwise be wasted and their compatibility with renewable energy sources (RES). When sizing these systems, building energy simulation (BES) programs are often used as they allow a time-practical analysis of the district’s consumption needs. However, conventional BES programs were primarily designed to address buildings at an individual scale; hence the need for next-generation programs which can integrate larger scale building systems is clearly recognized. For this matter, Annex 60 (IEA EBC) is developing new computational tools for building and community energy systems using Modelica, an object-oriented modelling language for large, complex and multi-domain physical processes. This project is inserted in subtask 2.2 of Annex 60 and evaluates different ways to approach the heating and cooling needs of a neighbourhood case study. The implementation in Modelica is described in this dissertation and a sensitivity analysis was carried out regarding different levels of detail applied in four different fields that influence the annual demand: Number of thermal zones considered, internal gains, ground temperature and the heat transfer between adjacent buildings. It was concluded that the heat demand was more sensitive to the sub-zoning of the living space and the heat exchange between the buildings, while the cooling demand proved to be more sensitive to the way the internal gains are modelled. Ultimately, the use of Modelica for this application was also evaluated.
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Batista, Fábio Emanuel Lourenço. "Analysis of a district energy system containing thermal energy storage and heat pumps." Master's thesis, 2017. http://hdl.handle.net/10451/30761.
Full textAbstract:
Tese de mestrado integrado em Engenharia da Energia e do Ambiente, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2017No contexto de atingir as metas estabelecidas até 2050 para a redução da emissão de gases de efeito de estufa, as redes urbanas de energia são já consideradas uma solução provada. Isto deve-se essencialmente ao facto de estas possibilitarem recuperar energia que seria de outra forma desperdiçada. Para além disso, possibilitam a integração de diferentes fontes de energia renovável, ou outras tecnologias, como é o caso de armazenamento térmico de energia. Quando presente, armazenamento de energia térmica confere maior flexibilidade, bem como maior segurança energética e pode ser usado para otimizar o equipamento responsável pela produção de energia térmica, como por exemplo bombas de calor. O principal objetivo deste projeto é estudar a influência da introdução de armazenamento de energia térmica de curta duração numa rede urbana de energia, em que o abastecimento de calor é suprido por uma combinação de armazenamento de energia térmica sazonal e bombas de calor. Em particular, pretende-se analisar de que forma pode o armazenamento de curta duração, que consiste num tanque de água, ser usado para deslocar a produção de calor (carga térmica), de períodos de cheia ou ponta, para períodos de vazio, e quantificar as consequências desta estratégia (load shifting) na produção de energia térmica e consumo de eletricidade. Para que isto seja possível, o consumo de energia relacionado com aquecimento e arrefecimento de um grupo de edifícios é determinado usando um modelo implementado em Modelica, e a análise dos sistemas de energia é feita através de um modelo analítico, implementado em Matlab. Os resultados obtidos mostram que a introdução de armazenamento térmico de curto prazo, permitiu deslocar parte da carga térmica de períodos de pico, para períodos de vazio. Isto levou a uma redução significativa (11.5% a 37.5%) nos custos individuais de eletricidade para os consumidores de calor, que foram determinados com base nos preços de mercado de eletricidade holandês (EPEX), e em tarifas de distribuição e transmissão. Paralelamente, verificou-se um aumento na produção total de calor (~ 7%), principalmente devido a maiores perdas térmicas face ao sistema sem armazenamento de curta duração. No entanto, a eficiência global das bombas de calor (COP) também aumentou (~ 14%), o que resultou ainda assim num menor consumo global de eletricidade (~ -13%), apesar da maior produção de energia.
In the context of meeting the targets set by 2050 for reducing greenhouse gas emissions, District Energy (DE) systems are considered to be a proven solution. This is essentially due to their ability to re-use energy that would otherwise be wasted, and its compatibility with a variety of other technologies, such as Thermal Energy Storage (TES) and renewable energy sources. When available, thermal energy storage provides greater flexibility, reliability, as well as energy security and it can be used to optimize equipment responsible for thermal energy production, as for instance, heat pumps. The main objective of this project is to study the influence of the introduction of short-term thermal storage in a DE, where heat and cold requirements are supplied by a combination of seasonal TES and heat pumps. To be specific, the focus is to analyze to what extent can short-term TES be used to shift the heat pumps electrical heating loads, from peak to off-peak periods, and quantify the influence of this strategy on energy production and electricity consumption. In order to do this, space heating and cooling demand data regarding a group of buildings is determined in Dymola/Modelica, and the energy systems performance is evaluated by using an analytical MATLAB model. The results obtained show that the introduction of short-term storage allowed to shift some of the thermal load from peak to off-peak periods. This operation led to a significant reduction in the individual electricity costs for the heat consumers (11.5% to 37.5%), which were determined based on electricity prices from the Dutch EPEX day-ahead spot market. Regarding electricity consumption and total heat production, it was noticed that the introduction of short-term storage led to an increase in the total heat output from heat pumps (~7%), mainly due to higher thermal losses. However, the global heat pumps coefficient of performance (COP) also increased (~14%), which resulted in less electricity consumption (~-13%), despite of the higher heat production.
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Sy, Wei-Dih, and 思瑋玓. "Analysis of human Dynamin IV (Dymple) gene promoter." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/95094024753912977066.
Full textAbstract:
碩士國立中山大學
生物科學系研究所
91
We first identified the transcriptional regulatory element of the human dynamin IV gene (Hdyn IV; dymple). The Hdyn IV belongs to a large GTPase family. This protein has a N-terminal highly conserved tripartite GTP-binding domain, coiled-coil (CC) region, but it lacks the pleckstrin homology (PH) domain and a modestly conserved C-terminal proline rich domain (PRD). Hdyn IV gene is enriched in subcellular membrane fractions of cytoplasmic vesicles and endoplasmic reticulum, and the function of Hdyn IV gene is considered to be associated with the functions of mitochondria. The Hdyn IV is expressed as four alternative splicing variants in all eukaryotic organisms. Our question concerning why expressions of four alternative splicing variants in brain tumor tissues? To elucidate the regulatory mechanism and the transcription factors involved, we firstly determined the transcriptional start site by 5’ RACE. We next cloned the 5’-flanking region of the Hdyn IV gene and determined the nucleotide sequence of 999 bases upstream from the transcription start site. The promoter has several potential binding sites for AP2, Sp1 binding protein, but it lacks TATA and CAAT boxes. Transfection studies using a series of Hdyn IV promoter luciferase constructs in HeLa cell demonstrate that the 5’flanking region has a promoter activity. Functional promoter element of the Hdyn IV gene was located within the –140~ +29 region. Deletion analyses demonstrated that the minimal promoter activity for the transcriptional element of Hdyn IV was detected in the sequence between nucleotides –110 and –100. Electorphoretic mobility shift assay demonstrated that a putative transcriptional factor bound to the –119 to –90 region. Site-directed mutagenesis analysis of this region revealed that nucleotides at positions –108 to –100 were essential for transactivation mediated by this element. To summary, the data indicated that the ’’CTCCCAGCA’’ (-108~ -100) sequence is capable of regulating Hdyn IV gene expression. However, the protein involved in the binding of this novel sequence requires further study.
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Braziel, David Orion. "Dymore finite element analysis of the paired blade tiltrotor conceptual design and a comparable conventional tiltrotor design." 2009. http://hdl.handle.net/10106/1661.
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