| 1. |
- Garro, Alfredo, et al.
(författare)
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On formal cyber physical system properties modeling: a new temporal logic language and a Modelica-based solution
- 2016
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Ingår i: 2016 IEEE International Symposium on Systems Engineering (ISSE). - : IEEE. - 9781509007936 - 9781509007943 ; , s. 112-119
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Konferensbidrag (refereegranskat)abstract
- Modeling and Simulation methods, tools and techniques aim at supporting the different phases of the lifecycle of modern systems, going from requirements analysis to system design and operation. However, their effective application requires investigating several aspects such as the formal modeling of system requirements and the binding and automated composition between heterogeneous models (e.g. requirements models, architectural models, behavioral models). In this context, the paper presents a new formal requirement modeling language based on temporal logic, called FORM-L, and a software library, based on the Modelica language, that implements the constructs provided by FORM-L so as to enable the visual modeling of system properties as well as their verification through simulation. The effectiveness of the proposal is shown on a real case study concerning an Intermediate Cooling System.
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| 2. |
- Asghar, Adeel, et al.
(författare)
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Automatic Regression Testing of Simulation Models and Concept for Simulation of Connected FMUs in PySimulator
- 2015
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Ingår i: Proceedings of the 11th International Modelica Conference. - Linköping : Linköping University Electronic Press. - 9789176859551 ; , s. 671-679
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Konferensbidrag (refereegranskat)abstract
- The Modelica and FMI tool ecosystem is growing each year with new tools and methods becoming available. The open Modelica standard promises portability but it is important to ensure that a certain model behaves the same in different Modelica tools or in a different version of the same tool. It is also very important (for model evolution) to check that a new version of the same model produces comparable results. Finally, it is desirable to verify that a model exported in FMU form from a Modelica tool gives exactly the same results as the original model. This paper presents a framework for automatic regression testing as part of PySimulator which provides an efficient and concise way of testing if a model or a range of models behaves in the same way in several tools or versions of a tool by checking that the results produced are essentially identical. The FMI standard has been adopted by many tool vendors and is growing in popularity each year. This paper proposes a concept for building and simulating a system made from connected FMUs generated by different tools. The FMUs for Co-Simulation can be connected together using a GUI. The system model built graphically in this way can be saved for later use or simulated directly inside PySimulator. Active development is going on to support simulation of connected FMUs for Model Exchange.
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| 3. |
- Asghar, Adeel, et al.
(författare)
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Efficient Debugging of Large Algorithmic Modelica Applications
- 2012
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Konferensbidrag (refereegranskat)abstract
- Modelica models often contain functions with algorithmic code. The fraction of algorithmiccode is increasing in Modelica models since Modelica, in addition to equation-based modeling, is also used for embedded system control code and symbolic model transformations in compilers using the MetaModelica language extension. For these reasons, debugging of algorithmic Modelica code is becoming increasingly relevant.Our earlier work in debuggers for the algorithmic subset of Modelica used trace-based techniques. These have the advantages of being very portable, but turned out to have too much overhead for very large applications.The new debugger is the first Modelica debugger that can operate without trace information. Instead it communicates with a low-level C-language symbolic debugger, the Gnu debugger GDB, to directly extract information from a running executable, set and remove breakpoints, etc. This is made possible by the new bootstrapped OpenModelica compiler which keeps track of a detailed mapping from the high level Modelica code down to the generated C code compiled to machine code.The debugger is operational, supports browsing of both standard Modelica data structures and tree/list data structures, and operates efficiently on large applications such as the OpenModelica compiler with more than 100 000 lines of code.
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| 4. |
- Asghar, Syed Adeel, et al.
(författare)
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An Open Source Modelica Graphic Editor Integrated with Electronic Notebooks and Interactive Simulation
- 2011
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Ingår i: Proceedings of the 8th International Modelica Conference, March 20th-22nd, Technical Univeristy, Dresden, Germany. - Linköping : Linköping University Electronic Press. - 9789173930963 ; , s. 739-747
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Konferensbidrag (refereegranskat)abstract
- This paper describes the first open source Modelica graphic editor which is integrated with interactive electronic notebooks and online interactive simulation. The work is motivated by the need for easy-to-use graphic editing of Modelica models using OpenModelica, as well as needs in teaching where the student should be able to interactively modify and simulate models in an electronic book. Models can be both textual and graphical. The interactive online simulation makes the simulation respond in real-time to model changes, which is useful in a number of contexts including immediate feedback to students.
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| 5. |
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| 6. |
- Broda, Anja, et al.
(författare)
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Perspectives of policy and political decision makers on access to formal dementia care : expert interviews in eight European countries
- 2017
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Ingår i: BMC Health Services Research. - : Springer Science and Business Media LLC. - 1472-6963. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: As part of the ActifCare (ACcess to Timely Formal Care) project, we conducted expert interviews in eight European countries with policy and political decision makers, or representatives of relevant institutions, to determine their perspectives on access to formal care for people with dementia and their carers.METHODS: Each ActifCare country (Germany, Ireland, Italy, The Netherlands, Norway, Portugal, Sweden, United Kingdom) conducted semi-structured interviews with 4-7 experts (total N = 38). The interview guide addressed the topics "Complexity and Continuity of Care", "Formal Services", and "Public Awareness". Country-specific analysis of interview transcripts used an inductive qualitative content analysis. Cross-national synthesis focused on similarities in themes across the ActifCare countries.RESULTS: The analysis revealed ten common themes and two additional sub-themes across countries. Among others, the experts highlighted the need for a coordinating role and the necessity of information to address issues of complexity and continuity of care, demanded person-centred, tailored, and multidisciplinary formal services, and referred to education, mass media and campaigns as means to raise public awareness.CONCLUSIONS: Policy and political decision makers appear well acquainted with current discussions among both researchers and practitioners of possible approaches to improve access to dementia care. Experts described pragmatic, realistic strategies to influence dementia care. Suggested innovations concerned how to achieve improved dementia care, rather than transforming the nature of the services provided. Knowledge gained in these expert interviews may be useful to national decision makers when they consider reshaping the organisation of dementia care, and may thus help to develop best-practice strategies and recommendations.
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| 7. |
- Buffoni, Lena, et al.
(författare)
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Open source languages and methods for cyber-physical system development : Overview and case studies
- 2021
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Ingår i: Electronics (Switzerland). - Basel : MDPI AG. - 2079-9292. ; 10:8
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Tidskriftsartikel (refereegranskat)abstract
- Industrial cyber-physical system products interleave hardware, software, and communication components. System complexity is increasing simultaneously with increased demands on quality and shortened time-to-market. To effectively support the development of such systems, we present languages and tools for comprehensive integrated model-based development that cover major phases such as requirement analysis, design, implementation, and maintenance. The model-based approach raises the level of abstraction and allows to perform virtual prototyping by simulating and optimizing system models before building physical products. Moreover, open standards and open source implementations enable model portability, tool reuse and a broader deployment. In this paper we present a general overview of the available solutions with focus on Modelica/OpenModelica, Bloqqi, and Acumen. The paper presents contributions to these languages and environments, including symbolic-numeric modeling, requirement verification, code generation, model debugging, design optimization, graphical modeling, and variant handling with traceability, as well a general discussion and conclusions.
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| 8. |
- Frenkel, Jens, et al.
(författare)
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Towards a Benchmark Suite for Modelica Compilers: Large Models
- 2011
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Konferensbidrag (refereegranskat)abstract
- The paper presents a contribution to a Modelica benchmark suite. Basic ideas for a tool independent benchmark suite based on Python scripting along with models for testing the performance of Modelica compilers regarding large systems of equation are given. The automation of running the benchmark suite is demonstrated followed by a selection of benchmark results to determine the current limits of Modelica tools and how they scale for an increasing number of equations.
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| 9. |
- Frenkel, Jens, et al.
(författare)
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Towards a Modular and Accessible Modelica Compiler Backend
- 2011
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Konferensbidrag (refereegranskat)abstract
- Modelica is well suited for modelling complex physical systems due to the acausal description it is using. The causalisation of the model is carried out prior to each simulation. A significant part of the causalisation process is the symbolic manipulation and optimisation of the model. Despite the growing interest in Modelica, the capabilities of symbolic manipulation and optimisation are not fully utilized. This paper presents an approach to increase the customisability, access, and reuse of symbolic optimisation by a more modular and flexible design concept. An overview of the common symbolic manipulation and optimisation algorithms of a typical Modelica compiler is presented as well as a general modular design concept for a Modelica compiler backend. The modularisation concept will be implemented in a future version of the OpenModelica compiler.
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| 10. |
- Fritzson, Peter, 1952-, et al.
(författare)
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MetaModelica – A Symbolic-Numeric Modelica Language and Comparison to Julia
- 2019
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Ingår i: Proceedings of the 13th International Modelica Conference, Regensburg, Germany, March 4–6, 2019. - Linköping : Linköing University Electronic Press. - 9789176851227
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Konferensbidrag (refereegranskat)abstract
- The need for integrating system modeling with advanced tool capabilities is becoming increasingly pronounced. For example, a set of simulation experiments may give rise to new data that are used to systematically construct a series of new models, e.g. for further simulation and design optimization. Such combined symbolic-numeric capabilities have been pioneered by dynamically typed interpreted languages such as Lisp and Mathematica. Such capabilities are also relevant for advanced modeling and simulation applications but lacking in the standard Modelica language. Therefore, this is a topic of long-running design discussions in the Modelica Design group. One contribution in this direction is MetaModelica, that has been developed to extend Modelica with symbolic operations and advanced data structures, while preserving safe engineering practices through static type checking and a compilation-based efficient implementation. Another recent effort is Modia, implemented using the Julia macro mechanism, making it dynamically typed but also adding new capabilities. The Julia language has appeared rather recently and has expanded into a large and fast-growing ecosystem. It is dynamically typed, provides both symbolic and numeric operations, advanced data structures, and has a just-intime compilation-based efficient implementation. Despite independent developments there are surprisingly many similarities between Julia and MetaModelica. This paper presents MetaModelica and its environment as a large case study, together with a short comparison to Julia. Since Julia may be important for the future Modelica, some integration options between Modelica tools and Julia are also discussed, including a possible approach for implementing MetaModelica (and OpenModelica) in Julia.
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