| 1. |
- Grundberg, Johan, et al.
(författare)
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A coherent-state path-integral for anyons
- 1995
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Ingår i: Modern Physics Letters A. - UNIV STOCKHOLM,FYSIKUM,S-11385 STOCKHOLM,SWEDEN. : WORLD SCIENTIFIC PUBL CO PTE LTD. - 0217-7323 .- 1793-6632. ; 10:12, s. 985-989
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Tidskriftsartikel (refereegranskat)abstract
- We derive an su(1, 1) coherent state path integral formula for a system of two one-dimensional anyons in a harmonic potential. By a change of variables we transform this integral into a coherent states path integral for a harmonic oscillator with a shifted energy. The shift is the same as the one obtained for anyons by other methods. We justify the procedure by showing that the change of variables corresponds to an su(1, 1) version of the Holstein-Primakoff transformation.
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| 2. |
- Huselius, Joel, et al.
(författare)
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Automatic Generation and Validation of Models of Legacy Software
- 2006
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Ingår i: Proceedings of the 12:th IEEE International Conference on Embedded and Real-Time Computing Systems and Applications (RTCSA), Sydney, Australia. - 9780769526768 ; , s. 342-349
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Konferensbidrag (refereegranskat)abstract
- The modeling approach is not used to its full potential in maintenance of legacy systems. Often, models do not even exist. The main reasons being that the economic implications and practical hurdles in manually maintaining models of in-use legacy systems are considered too high by the industry. In this paper, we present a method for automated validation of models automatically generated from recordings of executing real-time embedded systems. This forms an essential constituent of a unified process for the automatic modeling of legacy software. We also present a study in which we automatically model a state-of-practice industrial robot control system, the results of which are clearly positive indicators of the viability of our approach.
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| 3. |
- Huselius, Joel, et al.
(författare)
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Evaluating the Quality of Models Extracted from Embedded Real-Time Software
- 2007
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Ingår i: Proceedings of the International Symposium and Workshop on Engineering of Computer Based Systems. - 9780769527727 ; , s. 577-585
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Konferensbidrag (refereegranskat)abstract
- Due to the high cost of modeling, model-based techniques are yet to make their impact in the embedded systems industry, which still persist on maintaining code-oriented legacy systems. Re-engineering existing code-oriented systems to fit model-based development is a risky endeavor due to the cost and efforts required to maintain correspondence between the code and model. We aim to reduce the cost of modeling and model maintenance by automating the process, thus facilitating model-based techniques. We have previously proposed the use of automatic model extraction from recordings of existing embedded real-time systems. To estimate the quality of the extracted models of timing behavior, we need a framework for objective evaluation. In this paper, we present such a framework to empirically test and compare extracted models, and hence obtain an implicit evaluation of methods for automatic model extraction. We present a set of synthetic benchmarks to be used as test cases for emulating timing behaviors of diverse systems with varying architectural styles, and extract automatic models out of them. We discuss the difficulties in comparing response time distributions, and present an intuitive and novel approach along with associated algorithms for performing such a comparison. Using our empirical framework, and the comparison algorithms, one could objectively determine the correspondence between the model and the system being modeled.
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| 4. |
- Kostela, Johan, 1975-, et al.
(författare)
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Electrochemical properties of an amphiphilic viologen in differently charged micelles
- 2002
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Ingår i: Journal of Electroanalytical Chemistry. - : Elsevier. - 0022-0728 .- 1873-2569. ; 536:1-2, s. 97-107
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Tidskriftsartikel (refereegranskat)abstract
- The electrochemical properties of N-tetradecyl-N′-methylviologen (TMV) in differently charged micelles were studied with a glassy carbon electrode using electrochemical techniques. The redox potential varied depending on the charge of the surrounding surfactants. When the viologen was situated in cationic micelles the redox potential for the 2+/1+ reaction was more positive than when situated in negatively charged micelles. The non-ionic micelles destabilised the 2+-state most showing the highest redox potentials. From studies of several different cationic micelles it was concluded that the most important parameter for the redox potential was the surface charge density. A calculation based on a simple model confirmed this. Other interactions also influenced the stability of the redox states. Adsorption, desorption and reorganisation of the surfactants at the electrode surface caused capacitive currents. To control the nonfaradaic current, differential pulse voltammetry (DPV) was used in addition to cyclic voltammetry.
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| 5. |
- Kraft, Johan, et al.
(författare)
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Software Maintenance Research in the PROGRESS Project for Predictable Embedded Software Systems
- 2011
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Ingår i: 15th European Conference on Software Maintenance and Reengineering (CSMR'11). - Los Alamitos : IEEE Computer Society. - 9780769543437 ; , s. 335-338
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Konferensbidrag (refereegranskat)abstract
- PROGRESS is a project and strategic research centre at Malardalen University in Sweden that is funded for 2006-2010 by the Swedish Foundation for Strategic Research (SSF). PROGRESS research targets embedded software in the vehicular, automation, and telecom domains, focusing on the areas of component technology, verification and analysis for predictability, predictable execution, as well as reuse and maintenance of legacy embedded software. We first describe the funding, organization and research areas of PROGRESS, and then give several examples of PROGRESS research that addresses maintenance of legacy embedded software with the goal to improve program comprehension, quality assurance, and debugging. Specifically, we describe research in tracing and trace visualization, impact analysis of temporal behavior, slicing, and system-specific static analyses.
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| 6. |
- Åkerholm, Mikael, et al.
(författare)
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Handling Subsystems using the SaveComp Component Technology
- 2006
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Ingår i: Workshop on Models and Analysis for Automotive Systems (WMAAS'06) in conjunction with the 27th IEEE Real-Time Systems Symposium (RTSS'06), Rio de Janeiro, Brazil.
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Konferensbidrag (refereegranskat)
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| 7. |
- Åkerholm, Mikael, et al.
(författare)
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The SAVE Approach to Component-Based Development of Vehicular Systems
- 2007
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Ingår i: Journal of Systems and Software. - : Elsevier BV. - 0164-1212 .- 1873-1228. ; 80:5, s. 655-667
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Tidskriftsartikel (refereegranskat)abstract
- The component-based strategy aims at managing complexity, shortening time-to-market, and reducing maintenance requirements by building systems with existing components. The full potential of this strategy has not yet been demonstrated for embedded software, mainly because of specific requirements in the domain, e.g., those related to timing, dependability, and resource consumption. We present SaveCCT – a component technology intended for vehicular systems, show the applicability of SaveCCT in the engineering process, and demonstrate its suitability for vehicular systems in an industrial case-study. Our experiments indicate that SaveCCT provides appropriate expressiveness, resource efficiency, analysis and verification support for component-based development of vehicular software.
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