liu.seSearch for publications in DiVA
Change search
Link to record
Permanent link

Direct link
BETA
Bunus, Peter
Publications (10 of 24) Show all publications
Mehrpouyan, H., Bunus, P. & Kurtoglu, T. (2012). Model-Based Hazard Analysis of Undesirable Environmental and Components Interaction. Paper presented at 2012 IEEE Aerospace Conference, 3-10 March 2012, Big Sky, Montana, USA. IEEE
Open this publication in new window or tab >>Model-Based Hazard Analysis of Undesirable Environmental and Components Interaction
2012 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Identifying the detrimental effect of environmental factors and subsystem interactions are historically one of the most challenging aspects of early hazard assessment in the design of complex avionic systems. Therefore, a complete understanding of potential failure effects before and even after a catastrophe happens is a very difficult task. This paper proposes a model-based hazard analysis procedure for early identification of potential safety issues caused by unexpected environmental factors and subsystem interactions within a complex avionic system. The proposed methodology maps hazard and vulnerability modes to specific components in the system and analyzes the hazard propagation paths for risk control and protection strategies. The main advantage of the proposed method is the ability to provide the designers with means to use low-fidelity, high level models to identify hazardous interactions. Using this technique, designers can examine the collective impacts of environmental and subsystem risks on overall system during early stages of design and develop a hazard mitigation strategy.

Place, publisher, year, edition, pages
IEEE, 2012
Keywords
Hazard and vulnerability analysis; Conceptual modeling; environmental and subsystem interaction risks; Fail-free component design; Risk-based design
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-87583 (URN)10.1109/AERO.2012.6187374 (DOI)000309105304003 ()978-1-4577-0556-4 (ISBN)
Conference
2012 IEEE Aerospace Conference, 3-10 March 2012, Big Sky, Montana, USA
Available from: 2013-01-18 Created: 2013-01-18 Last updated: 2013-02-21
Sandholm, A., Bunus, P. & Fritzson, P. (2006). A Numeric Library for Use in Modelica Simulations with Lapack, SuperLU, Interpolation, and MatrixIO. In: : . Paper presented at 5th International Modelica Conference (Modelica'2006), Vienna, Austria, September, 4-5, 2006.
Open this publication in new window or tab >>A Numeric Library for Use in Modelica Simulations with Lapack, SuperLU, Interpolation, and MatrixIO
2006 (English)Conference paper, Published paper (Refereed)
Abstract [en]

This paper introduces a numerical Modelica library that provides access to some of the most well-known powerful libraries for numerical methods. Our approach has been to develop wrappers that allow Modelica users easy access as functions both from textual and graphical Modelica environments . This library also includes additional external functions withcorresponding Modelica wrappers to interpolate data and to read/write matrix data from/to files.

Keywords
Matrix, Lapack, SuperLU, Matrix Market, File Format, Harwell-Boeing Matrix Format, Interpolation
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-110223 (URN)
Conference
5th International Modelica Conference (Modelica'2006), Vienna, Austria, September, 4-5, 2006
Available from: 2014-09-04 Created: 2014-09-04 Last updated: 2014-10-20Bibliographically approved
Chalabine, M., Kessler, C. & Bunus, P. (2006). Automated Round-trip Software Engineering in Aspect Weaving Systems. In: 21st IEEE/ACM International Conference on Automated Software Engineering, 2006. ASE '06.: . Paper presented at 21st IEEE/ACM International Conference on Automated Software Engineering, Tokyo Japan, 18-22 Sept. 2006 (pp. 305-308). Tokyo, Japan: IEEE/ACM
Open this publication in new window or tab >>Automated Round-trip Software Engineering in Aspect Weaving Systems
2006 (English)In: 21st IEEE/ACM International Conference on Automated Software Engineering, 2006. ASE '06., Tokyo, Japan: IEEE/ACM , 2006, p. 305-308Conference paper, Published paper (Refereed)
Abstract [en]

We suggest an approach to Automated Round-trip Software Engineering in source-level aspect weaving systems that allows for transparent mapping of manual edits in the woven program back to the appropriate source of origin, which is either the application core or the aspect space.

Place, publisher, year, edition, pages
Tokyo, Japan: IEEE/ACM, 2006
Series
IEEE / ACM International Conference on Automated Software Engineering, ISSN 1938-4300
National Category
Computer Sciences
Identifiers
urn:nbn:se:liu:diva-35760 (URN)10.1109/ASE.2006.20 (DOI)28490 (Local ID)0-7695-2579-2 (ISBN)28490 (Archive number)28490 (OAI)
Conference
21st IEEE/ACM International Conference on Automated Software Engineering, Tokyo Japan, 18-22 Sept. 2006
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2018-01-13Bibliographically approved
Bunus, P. (2005). An Empirical Study on Debugging Equation-based Simulation Models. In: 4th International Modelica Conference,2005 (pp. 281).
Open this publication in new window or tab >>An Empirical Study on Debugging Equation-based Simulation Models
2005 (English)In: 4th International Modelica Conference,2005, 2005, p. 281-Conference paper, Published paper (Refereed)
Keywords
modelica
National Category
Computer Sciences
Identifiers
urn:nbn:se:liu:diva-24650 (URN)6879 (Local ID)6879 (Archive number)6879 (OAI)
Available from: 2009-10-07 Created: 2009-10-07 Last updated: 2018-01-13
Bunus, P. & Fritzson, P. (2004). Automated static analysis of equation-based components. Simulation (San Diego, Calif.), 80(7-8), 321-345
Open this publication in new window or tab >>Automated static analysis of equation-based components
2004 (English)In: Simulation (San Diego, Calif.), ISSN 0037-5497, E-ISSN 1741-3133, Vol. 80, no 7-8, p. 321-345Article in journal (Refereed) Published
Abstract [en]

Mathematical modeling and the simulation of complex physical systems are emerging as key technologies in engineering. The availability of static analyzers and automatic debuggers for detecting structural and numerical inconsistencies in the simulation models is crucial. To address this need, the authors propose a methodology for detecting and repairing overconstrained and underconstrained situations based on graph-theoretical approaches. Components and equations that cause the irregularities are automatically isolated, and meaningful error messages for the user are elaborated. The authors have implemented the AMOEBA (Automatic Modelica Equation-Based Analyzer) environment to support the development and specification of correct equation-based simulation models by applying graph-theoretical approaches and semiautomatic debugging techniques. The implementation architecture and preliminary experiments with a prototype debugger integrated in the symbolic and numeric engine, ModSimPack, of the Modelica language compiler are presented and discussed.

Keywords
Bipartite graphs, Debugging, Modelica, Overconstrained system, Underconstrained system
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-45704 (URN)10.1177/0037549704046340 (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-13
Bunus, P. (2004). Debugging techniques for equation-based languages. (Doctoral dissertation). Linköping: Linköping University
Open this publication in new window or tab >>Debugging techniques for equation-based languages
2004 (English)Doctoral thesis, monograph (Other academic)
Abstract [en]

Mathematical modeling and simulation of complex physical systems is emerging as a key technology in engineering. Modern approaches to physical system simulation allow users to specify simulation models with the help of equation-based languages. Such languages have been designed to allow automatic generation of efficient simulation code from declarative specifications. Complex simulation models are created by combining available model components from user-defined libraries. The resulted models are compiled in a simulation environment for efficient execution.

The main objective of this thesis work is to develop significantly improved declarative debugging techniques for equation-based languages. Both static and dynamic debugging methods have been considered in this context.

A typical problem which often appears in physical system modeling and simulation is when too many/few equations are specified in a systems of equations. This leads to a situation where the simulation model is inconsistent and therefore cannot be compiled and executed. The user should deal with over- and under-constrained situation by identifying the minimal set of equations or variables that should be removed/added from the equation system in order to make the remaining set of equations solvable.

In this context, this thesis proposes new methods for debugging over- and under-constrained systems of equations. We propose a methodology for detecting and repairing over- and underconstrained situations based on graph theoretical methods. Components and equations that cause the irregularities are automatically isolated, and meaningful error messages for the user are presented. A major contribution of the thesis is our approach to reduce the potentially large number of error fixing alternatives by applying filtering rules extracted from the modeling language semantics.

The thesis illustrates that it is possible to localize and repair a significant number of errors during static analysis of an object-oriented equation-based model without having to execute the simulation model. In this way certain numerical failures can be avoided later during the execution process. The thesis proves that the result of structural static analysis performed on the underlying system of equations can effectively be used to statically debug real models.

A semi-automated algorithmic debugging framework is proposed for dynamic fault localization and behavior verification of simulation models. The run-time debugger is automatically invoked when an assertion generated from a formal specification of the simulation model behavior is violated. Analysis of the execution trace decorated with data dependency graph in the form of the Block Lower Triangular Dependency Graph (BLTDG) extracted from the language compiler is the basis of the debugging algorithm proposed in the thesis. We show how program slicing and dicing performed at the intermediate code level combined with assertion checking techniques to a large extent can automate the error finding process and behavior verification for physical system simulation models. Via an interactive session, the user is able to repair errors caused by incorrectly specified equations and incorrect parameter values.

The run-time algorithmic debugger described in the thesis represents the first major effort in adapting automated debugging techniques to equation-based languages. To our knowledge none of the existing simulation environments associated with such languages provides support for run-time declarative automatic debugging.

This thesis makes novel contributions to the structure and design of easy-to-use equation-based modeling and simulation environments and illustrates the role of structural static analysis and algorithmic automated debugging in this setting. The scope and feasibility of the approach is demonstrated by a prototype environment

Place, publisher, year, edition, pages
Linköping: Linköping University, 2004. p. 243
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 873
National Category
Computer Sciences
Identifiers
urn:nbn:se:liu:diva-35555 (URN)27536 (Local ID)91-7373-941-3 (ISBN)27536 (Archive number)27536 (OAI)
Public defence
2004-06-02, Visionen, Hus B, Linköpings Universitet, Linköping, 13:15 (Swedish)
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2018-01-13
Fritzson, P., Engelson, V., Idebrant, A., Aronsson, P., Lundvall, H., Bunus, P. & Nyström, K. (2004). Modelica - A Strongly Typed System Specification Language for Safe Engineering Practices. In: Proceedings of the SimSAFE Conference, Karlskoga, Sweden, June 15-17, 2004: . Paper presented at SIMSAFE 2004, June 17, Karlskoga, Sweden.
Open this publication in new window or tab >>Modelica - A Strongly Typed System Specification Language for Safe Engineering Practices
Show others...
2004 (English)In: Proceedings of the SimSAFE Conference, Karlskoga, Sweden, June 15-17, 2004, 2004Conference paper, Published paper (Other academic)
Abstract [en]

Recent years have witnessed a significant growth of interest in modeling and simulation of engineering application systems. A key factor in this growth has been the development of efficient equation-based simulation languages, with Modelica as one of the prime examples. Such languages have been designed to allow automatic generation of efficient simulation code from declarative specifications. A major objective is to facilitate reuse and exchange of models, model libraries, and simulation specifications.

The Modelica language and its associated support technologies have achieved considerable success through the development of domain libraries in a number of technical areas. By using domain-libraries complex simulation models can be built by aggregating and combining submodels and components from various physical domains.

The concept of safe engineering practices has been one of the most important guidelines when designing Modelica. This made it natural to make Modelica a statically strongly typed language, which allows the compiler to check the consistency of a design before it is executed, in contrast to dynamically typed languages such as Matlab.

The ability of static checking has also influenced the design of conditional equations and the ongoing the design of variant handling features in Modelica. Moreover, the language allows support for standardized physical units, thus enabling tools for unit checking of relationships and connections between interfaces. A third possible level of checking is through design rules within application-specific libraries, which can be enforced via assert statements. These properties taken together gives a good foundation for safe engineering practices, even though more work is needed to further increase the safety quality level.

National Category
Computer Sciences
Identifiers
urn:nbn:se:liu:diva-23103 (URN)2500 (Local ID)2500 (Archive number)2500 (OAI)
Conference
SIMSAFE 2004, June 17, Karlskoga, Sweden
Available from: 2009-10-07 Created: 2009-10-07 Last updated: 2018-01-13Bibliographically approved
Lundvall, H., Bunus, P. & Fritzson, P. (2004). Towards Automatic Generation of Model Checkable Code from Modelica. In: : . Paper presented at SIMS 2004, the 45th Conference on Simulation and Modelling. September 2004,2004.
Open this publication in new window or tab >>Towards Automatic Generation of Model Checkable Code from Modelica
2004 (English)Conference paper, Published paper (Other academic)
National Category
Computer Sciences
Identifiers
urn:nbn:se:liu:diva-23121 (URN)2518 (Local ID)2518 (Archive number)2518 (OAI)
Conference
SIMS 2004, the 45th Conference on Simulation and Modelling. September 2004,2004
Available from: 2009-10-07 Created: 2009-10-07 Last updated: 2018-01-13
Lengquist Sandelin, E.-L., Monemar, S., Fritzson, P. & Bunus, P. (2003). DrModelica - A Web-Based Teaching Environment for Modelica. In: Proceedings of the 44th Conference on Simulation and Modeling (SIMS). Paper presented at Conference on Simulation and Modeling - SIMS 2003. (Västerås, Sweden, September 18-19, 2003).. Malardalen University
Open this publication in new window or tab >>DrModelica - A Web-Based Teaching Environment for Modelica
2003 (English)In: Proceedings of the 44th Conference on Simulation and Modeling (SIMS), Malardalen University , 2003Conference paper, Published paper (Other academic)
Abstract [en]

This paper states the need for interactive teaching materials for programming languages within the area of modeling and simulation. We propose an interactive teaching material for the modeling language Modelica inspired by existing tutoring systems for Java and Scheme.

The purpose of this new teaching material, called DrModelica, is to facilitate the learning of Modelica in a modeling and simulation environment. We have developed two versions of DrModelica, one that is based on Mathematica and another that is intended for the web. With the web version of DrModelica we hope for an increased usage of Modelica.

Place, publisher, year, edition, pages
Malardalen University, 2003
National Category
Computer Sciences
Identifiers
urn:nbn:se:liu:diva-62125 (URN)91-631-4716-5 (ISBN)
Conference
Conference on Simulation and Modeling - SIMS 2003. (Västerås, Sweden, September 18-19, 2003).
Available from: 2010-11-19 Created: 2010-11-19 Last updated: 2018-01-12
Lengquist Sandelin, E.-L., Monemar, S., Fritzson, P. & Bunus, P. (2003). DrModelica - An Interactive Environment for Learning Modelica and Modeling using MathModelica. In: : . Paper presented at ISCS'2003, Cefalu, Sicily, Italy, Nov 28-29.
Open this publication in new window or tab >>DrModelica - An Interactive Environment for Learning Modelica and Modeling using MathModelica
2003 (English)Conference paper, Published paper (Refereed)
Abstract [en]

This paper states the need for interactive teaching materials for programming languages within the area of modeling and simulation. We propose an interactive teaching material for the modeling language Modelica inspired by existing tutoring systems for Java and Scheme. The purpose of this new teaching material, called DrModelica, is to facilitate the learning of Modelica through an environment that integrates programming, program documentation and visualization. The teaching material is intended to be used for modeling and simulation related courses at the undergraduate and graduate level.

National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-110197 (URN)
Conference
ISCS'2003, Cefalu, Sicily, Italy, Nov 28-29
Available from: 2014-09-04 Created: 2014-09-04 Last updated: 2014-10-20Bibliographically approved
Organisations

Search in DiVA

Show all publications