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Waheed, Adnan. "Support for Modelica Action Code in ModelicaML Models." Thesis, Linköpings universitet, PELAB - Laboratoriet för programmeringsomgivningar, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-72164.
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ModelicaML is a UML/Modelica profile to support model-driven development of combined software/hardware UML/Modelica models. In order to support the development and maintenance of large ModelicaML models this thesis work has developed advanced enhancements to the ModelicaML profile, to enable users to more conveniently edit textual parts, i.e., action code, of ModelicaML models. This approach covers many of the concepts present in advanced language editors, i.e., code completion, error markers, as well as indentation and code template user support for developing and maintaining complex models. In large and complex models it is hard to remember all the parameters and values given in textual parts of UML diagrams. It is also very difficult to remember the complete set of components of a ModelicaML model. The ModelicaML enhancements developed in this work now supports features to facilitate advanced usage by showing all the components in just one key press. Two levels of Error Marker support have been developed to help user to find errors anywhere in a model without knowing the details. Moreover, ModelicaML has been extended with features like Modelica syntax highlighting and code completion. Furthermore, this work included upgrading and porting ModelicaML to run on the new Papyrus [13] on the new Eclipse versions. For example, by using the new features introduced in ModelicaML in this work the users do not have to remember all the variables from used base classes and derived classes.
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Akhlagi, Ali. "A Modelica-based framework for modeling and optimization of microgrids." Thesis, KTH, Energiteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-263037.
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Microgrids have lately drawn much attention due to their considerable financial benefits and the increasing concerns about environmental issues. A solution that can address different engineering problems - from design to operation - is desired for practical reasons and to ensure consistency of the analyses. In this thesis, the capabilities of a Modelicabased framework is investigated for various microgrid optimization problems. Various sizing and scheduling problems are successfully formulated and optimized using nonlinear and physical component models, covering both electrical and thermal domains. Another focus of the thesis is to test the optimization platform when varying the problem formulation; performance and robustness tests have been performed with different boundary conditions and system setups. The results show that the technology can effectively handle complex scheduling strategies such as Model Predictive Control and Demand Charge Management. In sizing problems, although the platform can efficiently size the components while simultaneously solving for the economical load dispatch for short horizons (weekly or monthly), the implemented approach would require adaptations to become efficient on longer horizons (yearly).
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Hakam, Imran. "ModelicaML Graphical Modeling Environment Based on Eclipse MDT Papyrus." Thesis, Linköpings universitet, PELAB - Laboratoriet för programmeringsomgivningar, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-72112.
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The ModelicaML graphicalModeling Language and Modelica/UML profile is a language for the description of continuous-time and discrete-time/event-based system dynamics. Modelica ML uses Papyrus as modelling tool implementation platform which is used for editing models. These models may be expressed in UML withoptional textual statements in Modelica as action language code. For the new version ModelicaML 2.0, the need for support in the new Papyrus M1 version was essential. In this master thesis project, new plug-in functionality was developed that has enhanced the existing functionality of the ModelicaML modelling environment within the Papyrus Eclipse plug-in. This includes handling Modelica modifiers as well as new views and component tree views which provides complete list of components for a selected class.
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Eriksson, Henrik. "Advanced OpenModelica plotting package for Modelica." Thesis, Linköping University, Linköping University, Department of Computer and Information Science, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-15075.
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<p>OpenModelica is an open-source based development environment for Modelica coordinated by the Programming Environments Laboratory (PELAB) at Linköpings Universitet. Previously an external tool, PtPlot, has been used to create graphics from simulation data. This tool is poorly integrated with OMNotebook, the OpenModelica Notebook, which is a tool for creating interactive documents where Modelica code can be edited and evaluated. This thesis develops and implements a plotting API accessible from Modelica algorithmic code and extends OMNotebook to allow creation of diagrams and other forms of graphics without an external application.These diagrams are more customizable than those generated by PtPlot and allow for example logarithmic scaling. The new Modelica API for graphic programming allows access of graphic functionality from within Modelica models and Modelica functions.</p>
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Hagernäs, Mikael. "Att lösa reglertekniska problem med Modelica." Thesis, Linköping University, Department of Electrical Engineering, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-54214.
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<p>The purpose of this thesis is to examine and present the oportunities of solving</p><p>control problems using Modelica. This is done by creating some demonstration</p><p>examples with exercises. These examples should cover as many types of control</p><p>problems as possible. The exercises are aimed for people with basic knowledge</p><p>in modeling and automatic control engineering but with little or no knowledge</p><p>in Modelica. There are different types of Modelica implementations and the ones</p><p>used in this thesis are OpenModelica and MathModelica.</p>
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Ali, Abdul-Amir Ahmed. "Att lösa reglertekniska problem med Modelica." Thesis, Linköpings universitet, Reglerteknik, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-60744.
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Modelica is a multi-domain and equation-based modeling language. Modelica is based on object-oriented principles and non-causal modeling. The language is constructed to facilitate reuse and decompose models. The models and the modellibrary can modified to design a new nonlinear components. Object-oriented modeling is an excellent way to analyze and study large complex heterogeneous physical systems. The object-oriented modeling approach build on reusing and decomposition of models and non-causal modeling. Modeling physical systems often leads to a DAE system with index 2 or 3. It is required to use automated symbolic manipulation of the DAE system to do the simulation. Modelica need a compiler tool to run the simulation. Dymola is the dominating tool on the market. Through a graphic editor the user can easily model and simulate the physical system.<br>Objektorienterad modellering är ett utmärkt sätt att analysera och modellera fysikaliska system. Den ger möjlighet att hantera stora, komplexa och blandade system. Modelica är ett exempel på ett multidomän modelleringsspråk som är ekvationsbaserat och hanterar modeller från olika fysikaliska domäner. Det är baserat på principer från objektorientering och hanterar icke-kausala problem. Modelicas struktur gör att befintliga modeller kan delas upp i delmodeller som kan designas och testas oberoende av de andra delmodellerna. Det ger överskådlig bild av fysikaliska systemet. Modellbibliotek i Modelica kan enkelt modifieras för att designa nya komponenter. Modellering av fysikaliska system, speciellt mekaniska eller mekatroniska system ger upphov till DAE system med index 2 eller 3. Det resulterar svårigheter vid simulering av modeller. En automatiserad symbolisk manipulering av DAE systemen behövs för att underlätta simuleringen. För att simulera modeller skrivna i Modelica, behövs en kompilator och ett simuleringsverktyg. Dymola är det dominerande verktyget för dessa ändamål. Man har tillgång till Modelicas standardbibliotek via ett grafiskt gränssnitt. Vid simulering kontrolleras modellen så att Modelicas syntax är uppfylld. Sedan kompileras och simuleras modellen.
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Andersson, Conny. "Design of the Modelica Library VehProLib with Non-ideal Gas Models in Engines." Thesis, Linköpings universitet, Fordonssystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-121817.
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This thesis covers the reconstruction and the redesign of the modeling library VehProLib,which is constructed in the modeling language Modelica with help of the modeling toolWolfram SystemModeler. The design choices are discussed and implemented. This thesisalso includes the implementation of a turbocharger package and an initial study of the justificationof the ideal gas law in vehicle modeling. The study is made with help of Van derWaals equation of states as a reference of non-ideal gas model. It will be shown that for themean-value-engine-model, the usage of ideal gas law is justified.
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Hemmati, Moghadam Afshin. "Modelica PARallel benchmark suite (MPAR) - a test suite for evaluating the performance of parallel simulations of Modelica models." Thesis, Linköpings universitet, PELAB - Laboratoriet för programmeringsomgivningar, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-72685.
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Using the object-oriented, equation-based modeling language Modelica, it is possible to model and simulate computationally intensive models. To reduce the simulation time, a desirable approach is to perform the simulations on parallel multi-core platforms. For this purpose, several works have been carried out so far, the most recent one includes language enhancements with explicit parallel programing language constructs in the algorithmic parts of the Modelica language. This extension automatically generates parallel simulation code for execution on OpenCL-enabled platforms, and it has been implemented in the open-source OpenModelica environment. However, to ensure that this extension as well as future developments regarding parallel simulations of Modelica models are feasible, performing a systematic benchmarking with respect to a set of appropriate Modelica models is essential, which is the main focus of study in this thesis. In this thesis a benchmark test suite containing computationally intensive Modelica models which are relevant for parallel simulations is presented. The suite is used in this thesis as a means for evaluating the feasibility and performance measurements of the generated OpenCL code when using the new Modelica language extension. In addition, several considerations and suggestions on how the modeler can efficiently parallelize sequential models to achieve better performance on OpenCL-enabled GPUs and multi-coreCPUs are also given. The measurements have been done for both sequential and parallel implementations of the benchmark suite using the generated code from the OpenModelica compiler on different hardware configurations including single and multi-core CPUs as well as GPUs. The gained results in this thesis show that simulating Modelica models using OpenCL as a target language is very feasible. In addition, it is concluded that for models with large data sizes and great level of parallelism, it is possible to achieve considerable speedup on GPUs compared to single and multi-core CPUs.
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Nouidui, Thierry Stephane. "Entwicklung einer objektorientierten Modellbibliothek zur Ermittlung und Optimierung des hygrothermischen und hygienischen Komforts in Räumen." [S.l. : s.n.], 2008. http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-37291.
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Magnusson, Henrik. "Integrated generic 3D visualization of Modelica models." Thesis, Linköping University, Department of Computer and Information Science, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-15453.
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<p>OpenModelica is a complete environment for developing and simulatingModelica models based on free software. It is promoted and developed bythe OpenModelica Consortium. This thesis details a method for describingand consequently displaying visualizations of Modelica models in OMNote-book, an application in the OpenModelica suite where models can be writtenand simulated in a document mixed with text, images and plots. Two dif-ferent approaches are discussed; one based on Modelica annotations and onebased on creating a simple object hierarchy which can be connected to exist-ing models. Trial implementations are done which make it possible to discardthe annotation approach, and show that an object based solution is the onebest suited for a complete implementation. It is expanded into a working 3Dvisualization solution, embedded in OMNotebook.</p>
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Mohammad, Jahanzeb. "Type Inferencing and MATLAB to Modelica Translation." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-111048.
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Matlab is a proprietary, interactive, dynamically-typed language for technical computing. It is widely used for prototyping algorithms and applications of scientific computations. Since it is a dynamically typed language, the execution of programs has to be analyzed and interpreted which results in lower computational performance. In order to increase the performance and integrate with Modelica applications it is useful to be able to translate Matlab programs to statically typed Modelica programs. This project presents the design and implementation of Matlab to Modelica translator. The Lexical and Syntax analysis is done with the help of the OMCCp (OpenModelica Compiler Compiler parser generator) tool which generates the Matlab AST, which is later used by the translator for generating readable and reusable Modelica code.
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Frenkel, Jens. "Entwicklung eines Modelica Compiler BackEnds für große Modelle." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-132032.
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Die symbolische Aufbereitung mathematischer Modelle ist eine wesentliche Voraussetzung, um die Dynamik komplexer physikalischer Systeme mit Hilfe numerischer Simulationen zu untersuchen. Deren Modellierung mit gleichungsbasierten objektorientierten Sprachen bietet gegenüber der signalflussbasierenden Modellierung den Vorteil, dass die sich aus der Mathematik und Physik ergebenden Gleichungen in ihrer ursprünglichen Form zur Modellbeschreibung verwendet werden können. Die akausale Beschreibung mit Gleichungen erhöht die Wiederverwendbarkeit der Modelle und reduziert den Aufwand bei der Modellierung. Die automatisierte Überführung der Gleichungen in Zuweisungen lässt sich theoretisch auf Modelle beliebiger Größe und Komplexität anwenden. In der praktischen Anwendung ergeben sich jedoch, insbesondere bei der automatisierten Überführung großer Modelle, mathematische Systeme mit sehr vielen Gleichungen und zeitabhängigen Variablen. Die daraus resultierenden langen Ausführungszeiten schränken die Anwendbarkeit der symbolischen Aufbereitung erheblich ein. Die vorliegende Arbeit beschreibt den Prozess der automatisierten Überführung eines Modells bis zur numerischen Simulation. Alle Teilschritte werden detailliert untersucht und bezüglich ihrer theoretischen Komplexität bewertet. Geeignete Algorithmen werden im OpenModelica Compiler umgesetzt und bezüglich ihrer Laufzeit anhand praxisrelevanter Modelle miteinander verglichen und für jeden Teilschritt die beste Implementierung ausgewählt. Dadurch konnte ein nahezu linearer Zusammenhang zwischen Modellgröße und benötigter Zeit zur Überführung erreicht werden. Zusätzlich bietet die Arbeit eine umfassende Dokumentation mit zahlreichen Empfehlungen für die Implementierung eines BackEnds eines Modelica Compilers. Dies erleichtert den Einstieg für neue Entwickler sowie die Weiterentwicklung bestehender Algorithmen. Letzteres wird durch ein modulares Konzept einer BackEnd-Pipeline unterstützt. Außerdem werden Methoden diskutiert, wie ein neues Modul innerhalb dieser Pipeline effizient getestet werden kann<br>The symbolic treatment of mathematical models is essential to study the dynamics of complex physical systems by means of numerical simulations. In contrast to signal flow based approaches, modeling with equation-based and object-oriented languages has the advantage that the original equations can be used directly. The acausal description of equations increases reusability and reduces the effort for the modeller. The automated transformation of equations into assignments can in theory be applied to models of any size and complexity. In practice, however, problems arise when large models, i.e. mathematical systems with many equations and time-dependent variables, shall be transformed. Long execution times that occur limit the applicability of symbolic processing considerably. The present work describes the process of automated transformation from a model to program code which can be simulated numerically. All steps are examined in detail and evaluated in terms of its theoretical complexity. Suitable algorithms are implemented in the OpenModelica Compiler. Their execution times are compared by looking at models which are relevant to engineering. The best implementations for each sub-step are selected and combined to a Modelica Compiler BackEnd. Thus a relationship between model size and the time needed for transformation has been achieved which is mostly linear. In addition, a comprehensive discussion with numerous recommendations for the implementation of a Modelica Compiler BackEnd is given. This is supposed to help new developers as well as to facilitate the development of existing algorithms. The latter is supported by a modular concept of a BackEnd pipeline. Moreover, methods are discussed how new modules can be tested efficiently using this pipeline
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Sjölund, Martin. "Tools and Methods for Analysis, Debugging, and Performance Improvement of Equation-Based Models." Doctoral thesis, Linköpings universitet, Programvara och system, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-116346.
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Equation-based object-oriented (EOO) modeling languages such as Modelica provide a convenient, declarative method for describing models of cyber-physical systems. Because of the ease of use of EOO languages, large and complex models can be built with limited effort. However, current state-of-the-art tools do not provide the user with enough information when errors appear or simulation results are wrong. It is of paramount importance that such tools should give the user enough information to correct errors or understand where the problems that lead to wrong simulation results are located. However, understanding the model translation process of an EOO compiler is a daunting task that not only requires knowledge of the numerical algorithms that the tool executes during simulation, but also the complex symbolic transformations being performed. As part of this work, methods have been developed and explored where the EOO tool, an enhanced Modelica compiler, records the transformations during the translation process in order to provide better diagnostics, explanations, and analysis. This information is used to generate better error-messages during translation. It is also used to provide better debugging for a simulation that produces unexpected results or where numerical methods fail. Meeting deadlines is particularly important for real-time applications. It is usually essential to identify possible bottlenecks and either simplify the model or give hints to the compiler that enable it to generate faster code. When profiling and measuring execution times of parts of the model the recorded information can also be used to find out why a particular system model executes slowly. Combined with debugging information, it is possible to find out why this system of equations is slow to solve, which helps understanding what can be done to simplify the model. A tool with a graphical user interface has been developed to make debugging and performance profiling easier. Both debugging and profiling have been combined into a single view so that performance metrics are mapped to equations, which are mapped to debugging information. The algorithmic part of Modelica was extended with meta-modeling constructs (MetaModelica) for language modeling. In this context a quite general approach to debugging and compilation from (extended) Modelica to C code was developed. That makes it possible to use the same executable format for simulation executables as for compiler bootstrapping when the compiler written in MetaModelica compiles itself. Finally, a method and tool prototype suitable for speeding up simulations has been developed. It works by partitioning the model at appropriate places and compiling a simulation executable for a suitable parallel platform.
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Bäck, Olof. "Modelling for diagnosis in Modelica : implementation and analysis." Thesis, Linköping University, Department of Electrical Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-12169.
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<p>Technical systems of today are often complex and integrated. To maintain operational functionality and security it is sometimes necessary to have a surveillance system which can detect a fault in an early stage. The device that detects and locates the faulty component is called a diagnosis system. There are several different approaches to fault diagnosis, this study focus on a part of technical diagnosis that uses a model of the system for assistance to make the diagnosis. In the creation of the model of the system computer tools can be used, in this thesis it is investigated if one such software tool is practical to use in the building of the model of the system.</p><p>One aspect of technical diagnosis based on models is the creation of a model of the process in question with support for faults, a fault model. In this thesis, Modelica is used to create fault models. The models produced from Modelica are then analyzed by some existing diagnosis algorithms.</p><p>The approach of designing fault models in Modelica and then exporting the corresponding system and perform diagnosis analysis on it in Matlab is considered feasible. But the process falls a bit short of the aim of a automatic model building and and diagnosis analysis procedure.</p><p>If the results from this thesis are to be used in the future will depend on if the freedom that Modelica gives in designing fault models are deemed worthwhile to accommodate so that the results from the modeling suits the diagnosis analysis. One way to do ease this transformation of data is to restrict the freedom of model designs in Modelica but then some of the benefit that Modelica brings is negated. It is shown here however that it it possible to design fault models in Modelica and then use the results to analyze the models regarding sensor placement and test design.</p>
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Östlund, Per. "Simulation of Modelica Models on the CUDA Architecture." Thesis, Linköping University, Department of Computer and Information Science, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-52060.
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<p>Simulations are very important for many reasons, and finding ways of accelerating simulations are therefore interesting. In this thesis the feasibility of automatically generating simulation code for a limited set of Modelica models that can be executed on NVIDIAs CUDA architecture is studied. The OpenModelica compiler, an open-source Modelica compiler, was for this purpose extended to generate CUDA code.</p><p>This thesis presents an overview of the CUDA architecture, and looks at the problems that need to be solved to generate efficient simulation code for this architecture. Methods of finding parallelism in models that can be used on the highly parallel CUDA architecture are shown, and methods of efficiently using the available memory spaces on the architecture are also presented.</p><p>This thesis shows that it is possible to generate CUDA simulation code for the set of Modelica models that were chosen. It also shows that for models with a large amount of parallelism it is possible to get significant speedups compared with simulation on a normal processor, and a speedup of 4.6 was reached for one of the models used in the thesis. Several suggestions on how the CUDA architecture can be used even more efficiently for Modelica simulations are also given.</p>
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Mengist, Alachew. "Template Based XML and Modelica Unparser in OpenModelica." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-81999.
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In many areas modeling and simulation plays an important role. Currently, an equation-based object oriented modeling and simulation languages, such as Modelica, are used for multi-domain modeling, and the OpenModelica Compiler (OMC) is Modelica-based platform for modeling, compilation and simulation. In this thesis, we address two issues relevant to OMC. The first issue deals with translation from the internal equation-based model representation in OpenModelica to an Extensible Markup Language (XML) form which can be imported in to the CasADi open source toolkit, in order to enable integrated dynamic modeling and optimization. To achieve this, we have implemented a new template based XML code generator module in OMC based on an XML standard defined in OPENPROD EU project for representation of flattened Modelica model. The second issue deals with transformation of OpenModelica Abstract Syntax Tree (AST) into Modelica text (Unparser). With regard to this issue, we have implemented a new template based Modelica Unparser from OpenModelica AST into Modelica text.
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Tinnerholm, John. "An LLVM backend for the Open Modelica Compiler." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-154291.
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This thesis presents the construction and evaluation of an LLVM based codegenerator, an LLVM backend. The introduction of an LLVM based backend into the OpenModelica compiler was done to examine the advantages and disadvantages of compiling Modelica and MetaModelica to LLVM IR instead of C. To answer this question, the LLVM backend was compared against the existing interpreter and C code generator using four different schemes with corresponding cases. This comparison was made both for both optimised and unoptimised code. From the experiments, it was concluded that an LLVM backend can be used to improve runtime and compile time performance in the OpenModelica Interactive environment.
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Schubert, Christian. "Algorithmen zur effizienten Simulation großer Mehrkörpersysteme für Modelica." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-158550.
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In der vorliegenden Arbeit werden mithilfe von Methoden zur numerischen Behandlung schwach besetzter Matrizen O(n³)- und O(n)-Berechnungsalgorithmen für Mehrkörpersysteme aus deren Bewegungsgleichungen abgeleitet. Durch Verwendung von Dualen Basen kann gezeigt werden, dass sich die bezüglich der Berechnungszeit effizienten Algorithmen sowohl auf Systeme mit explizit als auch implizit formulierten Bindungsgleichungen anwenden lassen. Mit diesen gewonnen Erkenntnissen wird die derzeitige Implementierung der vorgestellten Algorithmen im Sprachstandard Modelica untersucht. Es werden Ansatzmöglichkeiten aufgezeigt, mit denen ausgewählte Modelica Compiler große Mehrkörpersysteme effizienter lösen können. Zum einen wird durch eine graphentheoretische Verallgemeinerung des O(n)-Algorithmus dieser direkt in dem freien Modelica Werkzeug OpenModelica umgesetzt. Zum anderen wird die Methode der Subsysteme für den O(n)-Algorithmus vorgestellt. Sie ermöglicht es, beliebig komplexe Teilsysteme als eigenständige Modellelemente zu erstellen. Die Berechnung von kinematischen Schleifen kann auf diese Weise wesentlich beschleunigt werden. Ferner wird gezeigt, dass sich mit der Methode der Subsysteme Modellgleichungen eines idealen homokinetischen Gelenks ableiten lassen, die frei von Zwangsbedingungen sind. Dies führt ebenfalls zu einer schnelleren und robusteren Berechnung<br>Using methods from sparse matrice theory, O(n³)- and O(n)-algorithms for multibody systems are derived from the equations of motion. The concept of Dual Bases reveals that efficient algorithms for explicit joint descriptions, regarding calculation time, may also be applied to systems which use implicit joint constraints. Consequently, the feasibility of implementing these results in Modelica is examined. This leads to new approaches which enable selected Modelica compilers to solve large multibody systems more efficiently. On the one hand side a graph-theoretic generalization of the O(n)-algorithm has been implemented into the OpenModelica compiler. On the other hand, a method of subsystems for the O(n)-algorithm has been devised. It allows to derive the model equations for arbitrary complex sub-systems which can be implemented as new model elements for an O(n)-algorithm library. This has been carried out for recurring kinematic loops of Mobile Machinery improving simulation speed considerably. Furthermore, it is shown that a fast and robust model of an ideal constant velocity joint can be derived that way
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Liang, Feng. "Modeling in Modelica and SysML of System Engineering at Scania Applied to Fuel Level Display." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-84829.
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The main objective of this thesis is to introduce a four perspectives structure in order to provide one solution for traceability and dependability in the system design phase. The traceability between different perspectives help engineers have a clear picture of the whole system before goes to the real implementation. Fuel Level Display system from Scania Truck is used to undertake as a case study to offer insights of the approach. A four perspectives structure is made in the first place in order to analysis traceability between different viewpoints. After implementing the Fuel Level Display system in Modelica, a verification scenario is specified to perform a complete requirement verification process for system design against requirements.
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Berriche, Aroua. "Contribution à l’analyse de cohérence des modèles système, multi-physique et sûreté de fonctionnement." Thesis, CY Cergy Paris Université, 2020. http://www.theses.fr/2020CYUN1105.
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Le développement d'un système mécatronique implique la collaboration de différents concepteurs qui ont, normalement, des points de vue différents sur le système global pour gérer sa complexité. Par conséquent, de multiples modèles sont créés pour les divers domaines tels que le génie mécanique, l’électronique, le logiciel, etc. Ces modèles utilisent différents formalismes, différents langages de modélisation et divers outils pour répondre à des préoccupations spécifiques. Ceci pose le problème de la bonne collaboration entre les différentes équipes pluridisciplinaires pour pouvoir mener à terme l’opération de conception. Pour gérer ce problème, il est impératif d'identifier et de résoudre les incohérences potentielles entre les modèles afin de minimiser les coûts et le temps de développement avant les phases de vérification et de validation. Le présent travail de thèse propose une nouvelle méthodologie de collaboration qui aura pour objectif de maintenir la cohérence entre les différentes disciplines d'ingénierie tout au long du cycle de développement des systèmes mécatroniques. Nous proposons une approche de synchronisation pour vérifier la cohérence des modèles d’un même système de manière continue pendant le processus de conception multidisciplinaire. Notre contribution dans cette thèse consiste à démontrer comment les techniques de transformation des modèles peuvent être utilisées ; premièrement, pour abstraire divers modèles d'ingénierie dans un formalisme commun basé sur la théorie des graphes et, deuxièmement, pour mettre à jour les modèles avec les changements appropriés évalués par un chef de projet. Les méthodes développées permettent également de détecter automatiquement les différences et de proposer les séquences où la prise des décisions entre les différents choix possibles est essentielle pour résoudre les incohérences<br>The development of a mechatronic system involves different designers having various viewpoints on the overall system to handle its complexity. Consequently, multiple models are created from a variety of domains such as mechanical, electronic, and software engineering. These models use different formalisms, modeling languages, and tools to address specific concerns. The major challenge of this approach is to identify and solve any potential inconsistency between models in order to minimize costs and development time before the verification and validation phases. This paper proposes a new collaborative methodology to maintain consistency between different engineering disciplines at an early stage of the development cycle of mechatronic systems. We apply a model synchronization approach to actively check for model consistency in a continuous way during the multidisciplinary design process. As a novel contribution of this thesis, we demonstrate how model transformation techniques can be employed; firstly, to abstract various engineering models in a common formalism based on graph theory and, secondly, to update models with appropriate changes evaluated by a project manager. We also show how to detect the differences automatically, and we discuss where designer decisions are essential
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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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Höger, Christoph [Verfasser], Peter [Akademischer Betreuer] Pepper, Peter [Gutachter] Pepper, Stefan [Gutachter] Jähnichen, and David [Gutachter] Broman. "Compiling Modelica : about the separate translation of models from Modelica to OCaml and its impact on variable-structure modeling / Christoph Höger ; Gutachter: Peter Pepper, Stefan Jähnichen, David Broman ; Betreuer: Peter Pepper." Berlin : Technische Universität Berlin, 2019. http://d-nb.info/1185571582/34.
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Poudel, Sabin. "Modelling of a Generic Aircraft Environmental Control System in Modelica." Thesis, Linköpings universitet, Fluida och mekatroniska system, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-156675.
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This thesis documents the modelling of generic Environmental Control System(ECS) of an aircraft in Modelica by utilizing components from free version of theTTECCS (Technical Thermodynamic Environmental Control and Cooling Systems) library. In doing so, components used for developing ECS from the TTECCS library are mathematically verified with theoretical formula in MATLAB. Selected components are investigated with valid input data to initialize the simulation and verify its behaviors with corresponding available data. Hereinafter, the object-oriented modelling method is used to integrate ECS components to develop a functional system. The main function of ECS is to regulate the pressure and temperature inside the cabin to accepted physiology flight safetylevels. Different types of ECS architecture are presented in this document. An ECS developed here is based on the bootstrap system and consists only one cooling unit comprised with the source, pipes, two heat exchanger, compressor, turbine, temper-ature control valve, pressure control valve, and sinks. Dry air(Ideal gas) is used as a medium in the system. Temperature drop along each component corresponds to available A320 cruise flight data in order to calculate the top level parameter and to initialize the components, subsequently an ECS system. Several systematized methods for Object-oriented modelling and system design were studied and steps are extracted accordingly that suits to initiate the procedurefor this project, which is also presented. Time domain simulation is performed inModelica and Dymola. A simplified control system is built to regulate the system, therefore restrained it as a future work to develop real in-flight condition control system of an ECS.Top level parameters were selected within valid customized ranges for developing a performance map of the components. After generating the map, optimal data from the map were taken to initialize final ECS. The simulation results of the final model is then compared to A320 flight data which is comparable in behavior; this was expected. Above all, simulation environment Modelica and free version of TTECCS library components are reliable to develop ECS in order to investigate ECS components behavior and predict cabin conditions before developing a prototype.
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Sjölund, Martin. "Bidirectional External Function Interface Between Modelica/MetaModelica and Java." Thesis, Department of Computer and Information Science, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-20386.
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<p>A complete Java interface to OpenModelica has been created, supporting both standard Modelica and the metamodeling extensions in MetaModelica. It is bidirectional, and capable of passing both standard Modelica data types, as well as abstract syntax trees and list structures to and from Java and process them in either Java or the OpenModelica Compiler.It currently uses the existing CORBA interface as well as JNI for standard Modelica. It is also capable of automatically generating the Java classes corresponding to MetaModelica code.This interface opens up increased possibilities for tool integration between OpenModelica and Java-based tools, since for example models or model fragments can be extracted from OpenModelica, processed in a Java tool, and put back into the main model representation in OpenModelica.</p><p>A first version text generation template language for MetaModelica is also presented. The goal for such a language is the ability to create a more concise and readablecode when translating an abstract syntax tree (AST) to text.</p>
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Montell, Otto. "Advanced concepts in Modelica and their implementation in VehProLib." Thesis, Linköping University, Department of Electrical Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2348.
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<p>VehProLib is one of many libraries being developed for the object oriented multi-domain language Modelica. The layout and the current status of the library are shown. The aims of the library are to provide the user with a number of different components with different levels of complexity. The components included range from mean value engine components to in-cylinder models. An efficient way to handle parameters using records is provided. Different bus systems are implemented and discussed. Furthermore are replaceable fluid models introduced in the library. It will be shown that Modelica is a very efficient way to create an advanced modelling library.</p>
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Lopez-Rojas, Edgar Alonso. "OMCCp : A MetaModelica Based Parser Generator Applied to Modelica." Thesis, Linköpings universitet, PELAB - Laboratoriet för programmeringsomgivningar, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-68863.
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The OpenModelica Compiler-Compiler parser generator (OMCCp) is an LALR(1) parser generator implemented in the MetaModelica language with parsing tables generated by the tools Flex and GNU Bison. The code generated for the parser is in MetaModelica 2.0 language which is the OpenModelica compiler implementation language and is an extension of the Modelica 3.2 language. OMCCp uses as input an LALR(1) grammar that specifies the Modelica language. The generated Parser can be used inside the OpenModelica Compiler (OMC) as a replacement for the current parser generated by the tool ANTLR from an LL(k) Modelica grammar. This report explains the design and implementation of this novel Lexer and Parser Generator called OMCCp. Modelica and its extension MetaModelica are both languages used in the OpenModelica environment. Modelica is an Object-Oriented Equation-Based language for Modeling and Simulation.
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Xu, Weigao 1974. "The design and implementation of the [mu]Modelica compiler /." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=82452.
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Modelica is a recently developed object-oriented language for physical systems modeling. It is a modern language built on non-causal modeling with mathematical equations and object-oriented constructs.<br>An open source research prototype compiler for muModelica, a subset of Modelica, is presented. The compiler takes textual Modelica source as input, translates it into flat Modelica, then performs a series of symbolic transformations on the differential-algebraic equations, most notably, assigning causality, and generates input suitable for processing by a numerical simulator such as Octave.<br>Design and implementation issues of the muModelica compiler are discussed in some detail in this thesis. These issues include the general architecture of the compiler, semantic analysis, formula manipulation, and code generation. Some advanced formula manipulation techniques are also studied, and are proposed to be implemented as future work.
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Flieger, Björn [Verfasser]. "Innenraummodellierung einer Fahrzeugkabine in der Programmiersprache Modelica / Björn Flieger." Aachen : Hochschulbibliothek der Rheinisch-Westfälischen Technischen Hochschule Aachen, 2014. http://d-nb.info/1049573099/34.
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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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Glos, Jan. "Využití modelů v jazyce Modelica v prostředí Matlab-Simulink." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-221266.
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This thesis solves the use of Modelica models in Matlab/Simulink enviroment. The first part is focused on Modelica language and Functional Mock-up Interface, a standard way for model exchange and co-simulation of dynamic models, which is supported by most Modelica oriented tools. Based on this standard FMUtoolbox was created and it provides the ability to import and simulate models exported as Functional Mock-up Unit. The tool provides a Simulink block, graphical and command-line interface.
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Kara, Ibrahim Bumin. "Design and Implementation of the ModelicaML Code Generator Using Acceleo 3.X." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-117873.
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In today’s fast paced changing technology world, it is essential to adapt the new technologies and standards in order to stay compliant with the market. Software development is one of those key areas that have been growing highly fast and thus the need for staying up to date needs to be acknowledged by everyone in the area. The technology focused in this project is called ModelicaML[1] which is an integrated system modeling environment based on standardized languages such as UML[2] and Modelica[3]. Modelica Modeling Language (ModelicaML) is a graphical modeling language used for the description of time-continuous and time-discrete/event-based system dynamics. Currently, a ModelicaML code generator – that generates Modelica code from UML models – is implemented using the old Acceleo framework[4]. Within this thesis, the ModelicaML code generator was re-factored and implemented by using the latest Acceleo version 3.X[5]. The differences between the old and new Acceleo framework was also given an evaluation in the study in order to provide a hint of its future use for further improvements of the code generator.
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Stavåker, Kristian. "Contributions to Parallel Simulation of Equation-Based Models on Graphics Processing Units." Licentiate thesis, Linköpings universitet, PELAB - Laboratoriet för programmeringsomgivningar, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-71270.
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In this thesis we investigate techniques and methods for parallel simulation of equation-based, object-oriented (EOO) Modelica models on graphics processing units (GPUs). Modelica is being developed through an international effort via the Modelica Association. With Modelica it is possible to build computationally heavy models; simulating such models however might take a considerable amount of time. Therefor techniques of utilizing parallel multi-core architectures for simulation are desirable. The goal in this work is mainly automatic parallelization of equation-based models, that is, it is up to the compiler and not the end-user modeler to make sure that code is generated that can efficiently utilize parallel multi-core architectures. Not only the code generation process has to be altered but the accompanying run-time system has to be modified as well. Adding explicit parallel language constructs to Modelica is also discussed to some extent. GPUs can be used to do general purpose scientific and engineering computing. The theoretical processing power of GPUs has surpassed that of CPUs due to the highly parallel structure of GPUs. GPUs are, however, only good at solving certain problems of data-parallel nature. In this thesis we relate several contributions, by the author and co-workers, to each other. We conclude that the massively parallel GPU architectures are currently only suitable for a limited set of Modelica models. This might change with future GPU generations. CUDA for instance, the main software platform used in the thesis for general purpose computing on graphics processing units (GPGPU), is changing rapidly and more features are being added such as recursion, function pointers, C++ templates, etc.; however the underlying hardware architecture is still optimized for data-parallelism.
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Buqueras, Carbonell Carles. "Model-based predictive control using Modelica and open source components." Thesis, Norwegian University of Science and Technology, Department of Engineering Cybernetics, 2010. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-9120.
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<p>This thesis is about Model Predictive Control (MPC) method for process control. It describes how this method could be implemented using some different open source software components, describing functionalities of each one and showing how the implementation has been done. Finally the code is tested to demonstrate effectiveness of this software in front of this kind of problems and to demonstrate MPC main characteristics. The main goals of this thesis are these last ones, code development and tests, so all mathematical and theoretical background are described but not as in detail as development and tests. Globally describing, MPC is a process control method where a previous knowledge of the plant is needed, so the controller have a model to simulate and predict the behavior of the system to calculate the best command signal. It has an optimization algorithm determining the optimal trajectory to bring system from initial state to desired state. Optimization is done by iterative simulation and solved online periodically at each sample time, initializing values at each time with measured feedback.</p>
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Sievert, Nicke. "Modelica Models in a Distributed Environment Using FMI and HLA." Thesis, Linköpings universitet, Programvara och system, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-131385.
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Modelica is a domain independent modeling language allowing for componentbased modeling of complex systems. Functional Mock-up Interface (FMI) defines a standardized interface for complex computer simulations. High Level Architecture (HLA) is an interoperability standard of a general purpose architecture for distributed simulation. This thesis aims to show the possibilities of having Modelica models in a distributed environment by usage of FMI and HLA. An additional objective is to provide a base for a possible generic solution.
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Lundkvist, Herman, and Alexander Yngve. "Accelerated Simulation of Modelica Models Using an FPGA-Based Approach." Thesis, Linköpings universitet, Datorteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-145692.
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This thesis presents Monza, a system for accelerating the simulation of modelsof physical systems described by ordinary differential equations, using a generalpurpose computer with a PCIe FPGA expansion card. The system allows bothautomatic generation of an FPGA implementation from a model described in theModelica programming language, and simulation of said system.Monza accomplishes this by using a customizable hardware architecture forthe FPGA, consisting of a variable number of simple processing elements. A cus-tom compiler, also developed in this thesis, tailors and programs the architectureto run a specific model of a physical system.Testing was done on two test models, a water tank system and a Weibel-lung,with up to several thousand state variables. The resulting system is several timesfaster for smaller models and somewhat slower for larger models compared to aCPU. The conclusion is that the developed hardware architecture and softwaretoolchain is a feasible way of accelerating model execution, but more work isneeded to ensure faster execution at all times.
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Reichl, Gerald Puta Horst. "Optimierte Bewirtschaftung von Kläranlagen basierend auf der Modellierung mit Modelica /." Göttingen : Cuvillier, 2006. http://www.gbv.de/dms/ilmenau/toc/506555593.PDF.
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Li, James Jizhi. "Requirement Verification in Modelica For a Small Scale Network Simulation." Thesis, Linköpings universitet, Programvara och system, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-134026.
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The usage of computer networks has increased enormously recently due to many benefits; it facilitates data distribution speed, long distance communication and industrial system control. Due to these reasons, industry systems have started to use computer networks for system control and data transmission. Meanwhile, the limitations of network devices also raise many challenges for network system configuration. To have the best optimized network system, we need to study the network system by performing experiments. However, experiments on the real systems could be expensive and dangerous. Therefore, we need a model to represent the behaviours of the system. This thesis work uses object-oriented acasual modelling language Modelica to model a local area network system, and the development is performed in OpenModelica, an open source Modelica-based modelling and simulation environment. The simulation results are analysed and verified by using a separate requirement verification model.
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Edelfeldt, Stina. "Evaluation and Comparison of Ecological Models Simulating Nitrogen Processes in Treatment Wetlands,Implemented in Modelica." Thesis, Linköping University, Department of Science and Technology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2879.
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<p>Two ecological models of nitrogen processes in treatment wetlands have been evaluated and compared. These models have been implemented, simulated, and visualized in the Modelica language. The differences and similarities between the Modelica modeling environment used in this thesis and other environments or tools for ecological modeling have been evaluated. The modeling tools evaluated are PowerSim, Simile, Stella, the MathModelica Model Editor, and WEST. </p><p>The evaluation and the analysis have been performed using McCall’s factors for software quality (McCall et al, 1977), a correlation analysis and the Constant Comparative Method (Glaser&Strauss, 1999). The results show that the modeling tools and the models can both be separated into two categories: Simple Components and Complex Components for the modeling tools, and Simple Models and Complex Models for the models. The major difference between the Simple Components and the Complex Components is the higher possibility of the Complex Components to create and reuse separate components and the higher complexity in these components. The similarities between the categories are that they are consistent, easy to overview and use, if no new components are to be created. The major difference between the Simple Models and the Complex models lies in the number of functions and in the possibility of reuse and expansion. The similarities between all the models are that they are all consequent, logical, valid, specialized, and easy to use if the user has programming skill. </p><p>To conclude thisthesis, the nitrogen decrease in a constructed treatment wetland can well be simulated using the Nitrification/Denitrification model expressed in Modelica and the MathModelica Model Editor. However, some changes to the Model Editor are recommended to make the creation of the model easier. The most important of these changes are the addition of a tutorial, the ddition of useful error handling and messages, and the removal of unnecessary Visio features.</p>
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Shrestha, shilu. "Software Modeling in Cyber-Physical Systems." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-111435.
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A Cyber-Physical System (CPS) has a tight integration of computation, networking and physicalprocess. It is a heterogeneous system that combines multi-domain consisting of both hardware andsoftware systems. Cyber subsystems in the CPS implement the control strategy that affects the physicalprocess. Therefore, software systems in the CPS are more complex. Visualization of a complex system provides a method of understanding complex systems byaccumulating, grouping, and displaying components of systems in such a manner that they may beunderstood more efficiently just by viewing the model rather than understanding the code. Graphicalrepresentation of complex systems provides an intuitive and comprehensive way to understand thesystem. OpenModelica is the open source development environment based on Modelica modeling andsimulation language that consists of several interconnected subsystems. OMEdit is one of the subsystemintegrated into OpenModelica. It is a graphical user interface for graphical modeling. It consists of toolsthat allow the user to create their own shapes and icons for the model. This thesis presents a methodology that provides an easy way of understanding the structure andexecution of programs written in the imperative language like C through graphical Modelica model.
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Källdahl, Malin. "Separation Analysis with OpenModelica." Thesis, Linköping University, Department of Electrical Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-10399.
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<p>When launching a satellite a separation system is used to keep the satellite attached to a launch vehicle during ascent and to separate it from the launch vehicle while in space. In separation analysis the separation is studied by simulations to see if requirements on the system can be fulfilled. The purpose of this master’s thesis is to investigate if separation analysis can be done using the modeling program OpenModelica and to evaluate OpenModelica and compare it to other modeling programs.</p><p>OpenModelica is free software implementing the Modelica language, which is an object-oriented language for modeling and simulation of complex physical systems. Modelica uses equation-based modeling, this means that the physical behaviour of a model is described by differential, algebraic and discrete equations and no particular variable needs to be solved manually.</p><p>The work is divided into two parts. The main part is to implement a mathematical model of a separation system in OpenModelica, simulate it and study the behaviour of the system. A Monte Carlo method, which randomly generates values for uncertain model parameters, is used when simulating the model. The other part of the work is to evaluate OpenModelica and compare it with other modeling programs, such as Matlab/Simulink, C/C++ and JAVA to see advantages and disadvantages with OpenModelica.</p>
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Betshammar, Jan. "Improved Billet Shape Modeling in Optimization of the Hot Rod and Wire Rolling Process." Thesis, Linköping University, Department of Electrical Engineering, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-7914.
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<p>The hot rod and wire rolling process is widely used to produce rolled iron alloys in different shapes and dimensions. This industry has been under a constant development during the last decades. Today, complex geometries are produced at a high speed since it is possible to use several stands in each mill at the same time. A reason for the development is rising demands from customers. The most important demands are to save energy, to get better material properties and higher dimension accuracy. To meet these demands on speed and accuracy, a better control of how the material behaves in the process is needed. There is also a need to be able to quickly find a new setup of the mill in order to be able to produce other geometries.</p><p>The purpose with this Master Thesis is to model and simulate the hot rod and wire rolling process with the modeling language Modelica. The model is given the known inputs and the desired final result in order to compute the unknown inputs to the mill. To meet these goals, a model that depends on for example the gap between the rolls, the roll speeds and the tensions between different stands is needed. It should be possible to make simulations to find roll speeds or to calculate the tensions caused by known roll speeds.</p><p>With the help of models of the steps in the process, a model has been developed in Modelica. The model can be expanded to a mill with an arbitrary number of stands. In the search for the best way of modeling a hot rod and wire rolling mill, several algorithms have been simulated and analyzed in Modelica. The results from all simulations show that the billet and the groove should be described by different functions for the upper and the lower half. Furthermore, it is not a good solution to use only polynomials to describe the shapes in the process. A function with infinite derivative in the endpoints is needed to describe the billet in an acceptable way. The problem has also been solved using Matlab. In this work it is shown that the Modelica solution is preferred, compared to solving the optimization problems in Matlab. An advantage with the Modelica solution is that the model can be split into several easily connected sub models. Unfortunately it was even hard for Modelica to solve general problems. The describing functions made it hard to find the intersections and to keep the area constant during the rotation. The least square method could lead to bad approximations of the shapes.</p><br><p>Profilvalsning används idag globalt som en process för att tillverka metaller i olika former och har under de senaste årtiondena varit i en lång utvecklingsfas. Numera valsas komplicerade geometrier samtidigt som produktiviteten har ökat drastiskt tack vare möjligheten att valsa med flera valspar samtidigt. Under utvecklingsprocessen har även kraven från kunderna ökat, främst vad gäller energibesparing och noggrannhet på den slutgiltiga produktens dimensioner och materialegenskaper. För att kunna möta dessa krav på snabbhet och noggrannhet krävs större kontroll av hur materialet beter sig i valsningsprocessen och att det snabbt går att bestämma hur valsverket ska ställas in när en ny serie ska tillverkas.</p><p>Syftet med examensarbetet som redovisas i denna rapport är främst att modellera och simulera profilvalsningsprocessen med modelleringsspråket Modelica. Modellen ska sedan kunna användas för att utifrån givna indata till processen bestämma olika inparametrar till valsverket för att uppnå önskat slutresultat. För att nå dessa mål krävs en modell som bland annat beror på spelet mellan valsarna, valshastigheterna och dragen mellan olika valspar. Simuleringar ska kunna göras för att både bestämma önskade valshastigheter och för att beräkna vilka drag givna valshastigheter ger upphov till i valsverket.</p><p>Med hjälp av modeller och beskrivningar av de olika stegen i valsningsprocessen har en modell tagits fram i Modelica. Modellen har en given inprofil och kan sedan byggas ut till ett valsverk med önskat antal valspar. I Modelica har olika modeller och algoritmer simulerats och analyserats för att kunna svara på hur ett profilvalsverk modelleras på bästa sätt. Resultaten från de olika simuleringarna visar att heta och valsspår bör beskrivas med olika funktioner för den övre och för den undre delen av profilen. Det är ingen bra lösning att endast använda polynom för att beskriva de olika formerna. En basfunktion med oändlig derivata i ändpunkterna är nödvändig för att beskriva hetan på ett bra sätt. En fördel med Modelica är även att modellen enkelt kan delas upp i flera enkelt sammankopplade delmodeller. Tyvärr var det svårt även för Modelica att lösa generella problem. Funktionerna som användes för att beskriva de olika formerna gjorde det svårt att hitta skärningspunkter och att hålla arean konstant under rotationen. Minsta kvadratmetoden resulterade ibland i dåliga approximationer av de olika formerna.</p>
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Baloch, Adeel. "Graphical Web Interface for OpenModelica Platform." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-89858.
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“OPENMODELICA is an open-source Modelica-based modeling and simulation environment intended for industrial and academic usage. Its long-term development is supported by a non-profit organization – the Open Source Modelica Consortium (OSMC).” OpenModelica aims to provide an enhanced, Open Source Modelica modeling and simulation environment and this thesis is an addition in this direction. The purpose of this thesis is to create a web based graphical connection editor. There are other open-source connection editors available, but these editors were desktop applications. There is one web based editor but it is a textual editor. Desktop applications need installation and space on the local system. OMWeb connection editor is the first web based graphical connection editor that runs on a web browser. It’s a web platform for OpenModelica and provides the environment for modeling and simulation in the Modelica Modeling Language. The OMWeb connection editor can run on any system without the need for an OpenModelica installation. If a system is connected to the internet, and contains a web browser, it can run the OMWeb connection editor. The OMWeb connection editor uses Java Runtime Environment to run an applet in the browser. The user can create models graphically; but they can also be viewed in the textual format. The user can simulate and plot his models. The plot file generated for the model can be downloaded from the server. The OMWeb Connection Editor uses Servlet to handle requests from the client. The servlet is responsible for the communication with OpenModelica Compiler. It also gets the results from OMC and sends them back to the client. In our case the browser is the client.
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Larsson, Emil. "Modellering av ett bränslesystem i Modelica : tillämpat på ett obemannat flygplan." Thesis, Linköping University, Department of Electrical Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-10445.
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<p>Mathematical models possible to simulate are of great importance in order to make successful projects in the aircraft manufacturing industry. An aircraft fuel system is very complex, containing pipes, tanks, orifices, valves and pumps. The principal of this thesis is using the tool Easy5, which no longer is considered reliable enough in terms of development and support. This thesis tries to evaluate the Modelica language as a possible alternative to Easy5. To make this evaluation, the components concerned in the fuel library in Easy5 are implemented to the Modelica language. Small hydraulic systems are built up in Dymola, and verified against Easy5 through simulation with high accuracy.</p><p>A model of the fuel system of an unmanned aerial vehicle (UAV) is built from the implemented Modelica components to examine how Dymola manage a large model. The simulation made in Dymola was considerably more time efficient than the one made in Easy5, in the range of minutes instead of hours. Thus, much time can be saved if Dymola is used instead of Easy5.</p><p>Finally, the components in the fuel library handle a two phase flow of fuel and air. Modeling a two phase flow is not trivial and discontinuous mass flow and pressure values are also implemented and discussed.</p><br><p>För att driva framgångsrika projekt inom flygindustrin är det av stor vikt att ha matematiska modeller som kan simuleras. Ett bränslesystem till ett flygplan kan ses som ett komplext system bestående av bl.a. rör, tankar, ventiler och pumpar. För närvarande använder uppdragsgivaren till detta examensarbete modeller till dessa komponenter i verktyget Easy5, vars framtid anses osäker med avseende på nyutveckling och support. Syftet med detta examensarbete är därför att utvärdera modelleringsspråket Modelica som möjligt alternativ till Easy5. För att kunna göra en utvärdering implementeras berörda komponenter i Modelica med utgångspunkt från Easy5s bränslebibliotek. Mindre hydrauliska system skapas i verktyget Dymola, och dessa verifieras mot Easy5 genom simuleringar. Simuleringsresultaten visar på hög överensstämmelse mellan de båda verktygen.</p><p>För att undersöka hur verktyget Dymola hanterar en stor modell skapas bränslesystemet till ett obemannat flygplan (UAV) utifrån de implementerade Modelicakomponenterna. Resultat tyder på att simuleringstiden kan kortas betydligt om Dymola används gentemot Easy5; storleksordningen minuter istället för timmar.</p><p>Avslutningsvis hanterar komponenterna i bränslebiblioteket ett massflöde av både bränsle och luft. Att modellera ett 2-fasflöde stöter på vissa simuleringstekniska komplikationer i form av diskontinuerliga massflöden och tryck, vilket visas och diskuteras.</p>
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Lovaco, Jorge Luis. "Verication of a Modelica Helicopter Rotor Model Using Blade Element Theory." Thesis, Linköpings universitet, Fluida och mekatroniska system, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-142055.
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Helicopters have been valuable vehicles ever since their invention. Their capabilities for axial flight and hovering make them an outstanding resource. However, their complexity, directly related to their aerodynamics, makes them extremely hard to design. In today’s market competitivity resources must be optimized and accurate models are needed to obtain realizable designs. The well known Blade Element Theory was used to model helicopter rotors using the Modelica based software SystemModeler. However, it remained unverified due to the lack of experimental data available. The access to experimental data published by NASA motivated the comparison from the model to the measurements obtained during real testing to a scaled rotor. Some improvements were performed to the model obtaining unexpectedly accurate results for hover and axial flight. Two approaches based on the Blade Element Theory and related to Vortex Theory were followed: an infinite number of blades and a finite number of blades. Moreover, the model simulation speed was notice ably increased and prepared for the forward flight model development. Nonetheless, even though the model was ready for forward flight simulations, further research is needed due to, again, the lack of experimental data available. It is concluded from the present work that Wolfram’s SystemModeler can be used as a tool in early design phases of helicopters, even before CAD modeling and CFD due to its simplicity, speed, accuracy, and especially its capability for being used on simple desktop computers.
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Gallois, Thibaut-Hugues. "Amélioration de la rapidité d'exécution des systèmes EDO de grande taille issus de Modelica." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLC023/document.
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L'étude des systèmes aux équations différentielles ordinaires vise à prédire le futur des systèmes considérés. La connaissance de l'évolution dans le temps de toutes les variables d' état du modèle permet de prédire de possibles changements radicaux des variables ou des défaillances, par exemple, un moteur peut exploser, un pont peut s'écrouler, une voiture peut se mettre à consommer plus d'essence. De plus, les systèmes dynamiques peuvent contenir des dérivées spatiales et leur discrétisation peut ajouter un très grand nombre d'équations. La résolution des équations différentielles ordinaires est alors une étape essentielle dans la construction des systèmes physiques en terme de dimensionnement et de faisabilité. Le solveur de tels systèmes EDOs doit être rapide, précis et pertinent.En pratique, il n'est pas possible de trouver une fonction continue qui soit solution exacte du problème EDO. C'est pourquoi, des méthodes numériques sont utilisées afin de donner des solutions discrèes qui approchent la solution continue avec une erreur contrôlable. La gestion précise de ce contrôle est très importante afin d'obtenir une solution pertinente en un temps raisonnable.Cette thèse développe un nouveau solveur qui utilise plusieurs méthodes d'amélioration de la vitesse d'exécution des systèmes EDOs. La première méthode est l'utilisation d'un nouveau schéma numérique. Le but est de minimiser le coût de l'intégration en produisant une erreur qui soit le plus proche possible de la tolérance maximale permise par l'utilisateur du solveur. Une autre méthode pour améliorer la vitesse d'exécution est de paralléliser le solveur EDO en utilisant une architecture multicoeur et multiprocesseur. Enfin, le solveur a été testé avec différentes applications d'OpenModelica<br>The study of systems of Ordinary Differential Equations aims at predicting the future of the considered systems. The access to the evolution of all states of a system's model allows us to predict possible drastic shifts of the states or failures, e.g. an engine blowing up, a bridge collapsin, a car consuming more gasoline etc. Solving ordinary differential equations is then an essential step of building industrial physical systems in regard to dimensioning and reliability. The solver of such ODE systems needs to be fast, accurate and relevant.In practice, it is not possible to find a continuous function as the exact solution of the real ODE problem. Consequently numerical methods are used to give discrete solutions which approximates the continuous one with a controllable error. The correct handline of this control is very important to get a relevant solution within an acceptable recovery time. Starting from existing studies of local and global errors, this thesis work goes more deeply and adjusts the time step of the integration time algorithm and solves the problem in a very efficient manner.A new scheme is proposed is this thesis, to minimize the cost of integration. Another method to improve the execution speed is to parallelize the ODE solver by using a multicore and a multiprocessor architecture. Finally, the solver has been tested with different applications from OpenModelica
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Cao, Jun Verfasser], Christoph van [Akademischer Betreuer] [Treeck, and Vladimir [Akademischer Betreuer] Bazjanac. "Simmodel transformation middleware for modelica-based building energy modeling and simulation / Jun Cao ; Christoph Alban van Treeck, Vladimir Bazjanac." Aachen : Universitätsbibliothek der RWTH Aachen, 2018. http://d-nb.info/1169754953/34.
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Cao, Jun [Verfasser], Christoph van [Akademischer Betreuer] Treeck, and Vladimir [Akademischer Betreuer] Bazjanac. "Simmodel transformation middleware for modelica-based building energy modeling and simulation / Jun Cao ; Christoph Alban van Treeck, Vladimir Bazjanac." Aachen : Universitätsbibliothek der RWTH Aachen, 2018. http://d-nb.info/1169754953/34.
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Hamza, Ghazoi. "Contribution aux développements des modèles analytiques compacts pour l’analyse vibratoire des systèmes mécatroniques." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLC018/document.
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Cette thèse a pour objectif le développement d’une méthode de pré-dimensionnement des systèmes mécatroniques prenant en compte l’aspect vibratoire sans passer par des techniques de conception coûteuses en temps de calculs et de mise en œuvre, telles que la CAO 3D et la méthode des éléments finis.Dans la phase amont de choix d’architecture du processus de conception des systèmes mécatroniques, des modèles analytiques simples sont nécessaires à l’architecte du système mécatronique afin de lui permettre de faire des choix d‘architecture prenant en compte les contraintes multi-physiques, notamment les vibrations. Dans ce but, une bibliothèque de modèles analytiques d’éléments mécaniques flexibles simples a été développée dans cette thèse en utilisant le langage de modélisation Modelica.Pour démontrer les possibilités de cette approche, une étude des réponses vibratoires de certains systèmes mécatroniques a été réalisée. Cette approche de pré-dimensionnement a ainsi été appliquée dans un premier temps à un système mécatronique simple formé d’une plaque rectangulaire supportant des composants tels que des moteurs et des cartes électroniques, puis dans un second temps à une éolienne représentant un système mécatronique complet.Les résultats obtenus lors des simulations ont été comparés avec ceux obtenus par la méthode des éléments finis ainsi qu’avec les résultats d’études présentes dans la littérature scientifique. Ces simulations nous ont permis de prouver que les modèles compacts développés fournissent à l’architecte du système mécatronique des résultats très précis avec un besoin en ressources informatiques faibles<br>This thesis focuses on the development of a method for the preliminary design of mechatronic systems, taking into account the vibratory aspect, without going through costly design techniques, such as 3D CAD and finite element method.In an early stage of the design process of mechatronic systems, simple analytical models are necessary to the architect engineer in Mechatronics, for important conceptual decisions related to multi-physics coupling and vibration. For this purpose, a library of flexible elements, based on analytical models, was developed in this thesis, using the Modelica modeling language.To demonstrate the possibilities of this approach, we conducted a study of the vibration response of some mechatronic systems. Therefore, the pre-sizing approach was applied in a first phase to a simple mechatronic system, formed with a rectangular plate supporting electrical components such as electric motors and electronic cards, and in a second phase the approach was applied to a wind turbine, considered as a complete mechatronic system. Simulation results were compared with the finite elements method and other studies found in the scientific literature. Simulation results have enabled us to prove that the developed compact models assist the mechatronic architect to find results of simulation with an important accuracy and a low computational cost
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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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Lundvall, Håkan. "Automatic Parallelization using Pipelining for Equation-Based Simulation Languages." Licentiate thesis, Linköping University, Linköping University, PELAB - Programming Environment Laboratory, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-12504.
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<p>During the most recent decades modern equation-based object-oriented modeling and simulation languages, such as Modelica, have become available. This has made it easier to build complex and more detailed models for use in simulation. To be able to simulate such large and complex systems it is sometimes not enough to rely on the ability of a compiler to optimize the simulation code and reduce the size of the underlying set of equations to speed up the simulation on a single processor. Instead we must look for ways to utilize the increasing number of processing units available in modern computers. However to gain any increased performance from a parallel computer the simulation program must be expressed in a way that exposes the potential parallelism to the computer. Doing this manually is not a simple task and most modelers are not experts in parallel computing. Therefore it is very appealing to let the compiler parallelize the simulation code automatically. This thesis investigates techniques of using automatic translation of models in typical equation based languages, such as Modelica, into parallel simulation code that enable high utilization of available processors in a parallel computer. The two main ideas investigated here are the following: first, to apply parallelization simultaneously to both the system equations and the numerical solver, and secondly. to use software pipelining to further reduce the time processors are kept waiting for the results of other processors. Prototype implementations of the investigated techniques have been developed as a part of the OpenModelica open source compiler for Modelica. The prototype has been used to evaluate the parallelization techniques by measuring the execution time of test models on a few parallel archtectures and to compare the results to sequential code as well as to the results achieved in earlier work. A measured speedup of 6.1 on eight processors on a shared memory machine has been reached. It still remains to evaluate the methods for a wider range of test models and parallel architectures.</p>