One of the major problems in applying automatic verification tools to industrial-size systems is ... more One of the major problems in applying automatic verification tools to industrial-size systems is the excessive amount of memory required during the state-space exploration of a model. In the setting of real-time, this problem of state-explosion requires extra attention as information must be kept not only on the discrete control structure but also on the values of continuous clock variables. In this paper, we exploit Clock Difference Diagrams, CDD's, a BDD-like data-structure for representing and effectively manipulating certain nonconvex subsets of the Euclidean space, notably those encountered during verification of timed automata. A version of the real-time verification tool Uppaal using CDD's as a compact data-structure for storing explored symbolic states has been implemented. Our experimental results demonstrate significant spacesavings: for eight industrial examples, the savings are in average 42% with moderate increase in runtime. We further report on how the symbolic state-space exploration itself may be carried out using CDD's.
See back inner page for a list of recent BRICS Report Series publications. Copies may be obtained... more See back inner page for a list of recent BRICS Report Series publications. Copies may be obtained by contacting:
Testing Continuous Systems Conformance Using Cross Correlation Jacob Palczynski, Carsten Weise, a... more Testing Continuous Systems Conformance Using Cross Correlation Jacob Palczynski, Carsten Weise, and Stefan Kowalewski Informatik 11, RWTH Aachen University, Ahornstr. 55, 52074 Aachen, Germany {palczynski, weise, kowalewski}@ embedded. rwth-aachen. de ...
One of the most successful techniques for automatic verification is that of model checking. For f... more One of the most successful techniques for automatic verification is that of model checking. For finite automata there exist since long extremely efficient model-checking algorithms, and in the last few years these algorithms have been made applicable to the verification of real-time automata using the region-techniques of Alur and Dill. In this paper, we continue this transfer of existing techniques from the setting of finite (untimed) automata to that of timed automata. In particular, a timed logic L ν is put forward, which is sufficiently expressive that we for any timed automaton may construct a single characteristic L ν formula uniquely characterizing the automaton up to timed bisimilarity. Also, we prove decidability of the satisfiability problem for L ν with respect to given bounds on the number of clocks and constants of the timed automata to be constructed. None of these results have as yet been succesfully accounted for in the presence of time 1. * This work has been supported by the European Communities under CONCUR2, BRA 7166 † Basic Research in Computer Science, Centre of the Danish National Research Foundation. 1 An exception occurs in Alur's thesis [Alu91] in which a decidability result is presented for a linear timed logic called MITL.
See back inner page for a list of recent BRICS Report Series publications. Copies may be obtained... more See back inner page for a list of recent BRICS Report Series publications. Copies may be obtained by contacting:
... tr Tuula Paakkonen Nokia Technology Platforms Tampere, Finland Yuri Gurevich Microsoft Resear... more ... tr Tuula Paakkonen Nokia Technology Platforms Tampere, Finland Yuri Gurevich Microsoft Research Redmond, WA, USA gurevich ... Railway Interlockings with TTCN-3 Stefan Blom, Natalia Ioustinova, Jaco van de Pol, Axel Rennoch, Natalia Sidorova..... ...
... tr Tuula Paakkonen Nokia Technology Platforms Tampere, Finland Yuri Gurevich Microsoft Resear... more ... tr Tuula Paakkonen Nokia Technology Platforms Tampere, Finland Yuri Gurevich Microsoft Research Redmond, WA, USA gurevich ... Railway Interlockings with TTCN-3 Stefan Blom, Natalia Ioustinova, Jaco van de Pol, Axel Rennoch, Natalia Sidorova..... ...
The use of general descriptive names, registered names, trademarks, service marks, etc. in this p... more The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
International Journal of Radiation Oncology*Biology*Physics, 2012
Conclusions: Hypofractionated VMAT-IGRT in prostate cancer patients is dosimetrically and clinica... more Conclusions: Hypofractionated VMAT-IGRT in prostate cancer patients is dosimetrically and clinically feasible. Acute toxicity and impairment of QLQ were acceptable and similar to other hypofractionated series. Further following is required to assess late toxicity and disease control.
In den vergangenen Jahren ist die Informationsmenge von frei verfügbaren Weltkarten wie OpenStree... more In den vergangenen Jahren ist die Informationsmenge von frei verfügbaren Weltkarten wie OpenStreetMap enorm gewachsen. Davon profitieren wiederum andere freie Dienste und Applikationen, wie der freie Routenplaner OpenRouteService und das mobile Smartphone-Navigationssystem AndNav. Neben einer großen Infrastruktur-Abdeckung findet man mittlerweile auch vermehrt detaillierte Streckeninformationen, z. B. Bodenbelag und Steigung. Diese Arbeit beschreibt ein Konzept, wie man diese verfügbaren Streckeninformationen dazu nutzen kann, ein Navigationssystem für Elektrofahrzeuge (z. B. Elektrorollstühle) zu entwickeln. Dieses Konzept basiert auf der Tatsache, dass der kürzeste oder schnellste Weg, den ein Routenplaner berechnet, nicht immer der effizienteste im Bezug auf den Energieverbrauch eines Elektromotors ist. Es wird ein Algorithmus vorgestellt, der mithilfe der Streckeninformation "Steigung" eine effizientere Route für ein Elektrofahrzeug berechnen kann. Als Fallstudie wird die Umsetzung des Algorithmus auf dem freien Routenplaner OpenRouteService, sowie die Erweiterung des auf dem OpenRouteService basierenden mobilen Open Source Navigationssystems AndNav beschrieben. Mit dem resultierenden erweiterten Navigationssystem kann ein Elektrofahrzeugführer leicht mit seinem Android-Mobiltelefon über den OpenRouteService und damit über die OpenStreetMap-Daten eine energieeffiziente Route für sein Elektrofahrzeug in Erfahrung bringen. 1 Einleitung Bei der Planung einer Route mit einem Elektrofahrzeug (z. B. Elektrorollstuhl) spielen unterschiedliche Faktoren eine wichtige Rolle. Zu diesen gehören zum Beispiel der Akkustand bei Beginn der Route, die Streckensteigung des Routenverlaufs und mögliche Ladestationen für das Elektrofahrzeug. Zurzeit gibt es sehr wenige Systeme, die einen der obigen Faktoren in ihre Routenplanung einbeziehen. Dabei ist ein solches System bei der heutzutage frei verfügbaren Informationsmenge gut denkbar. Die freie Weltkarte OSM (RAMM & TOPF 2008) bietet sowohl die Möglichkeit Stromtankstellen einzutragen, als auch Streckenabschnitte mit Steigungsinformationen zu versehen. So sind auf OSM bereits Steigungsinformationen von vielen Teilen Deutschlands verfügbar. Die vorliegende Arbeit stellt eine Möglichkeit vor, die frei verfügbaren Steigungsinformationen aus den OSM-Daten zu nutzen, um eine Routenplanung unter Einbeziehung von Steigungsinformationen zu erlauben. Für die Routenplanung wird der auf OSM basierende
Verifying architectural models of embedded systems is desirable, since architecture can impact th... more Verifying architectural models of embedded systems is desirable, since architecture can impact the performance and resource usage of the final system implementation. To fulfill this need, one could think of combining formal verification and testing to achieve proofs of system correctness with respect to functional and extra-functional requirements. Our first step to accomplish this goal has concretized in the development of a framework that integrates architectural models described in East-adl language with component-based model-checking techniques. The framework is supported by a tool called ViTAL, which captures the behavior of East-adl functions as timed automata models, which can be formally verified in the Uppaal Port model-checker that exploits the components-based semantics at the architectural level. Later, the same formal models will help generate test-suites to provide support for model-based testing.
Proceedings of the 9th ACM/IEEE International Conference on Information Processing in Sensor Networks - IPSN '10, 2010
Complex interactions and the distributed nature of wireless sensor networks make automated testin... more Complex interactions and the distributed nature of wireless sensor networks make automated testing and debugging before deployment a necessity. A main challenge is to detect bugs that occur due to non-deterministic events, such as node reboots or packet duplicates. Often, these events have the potential to drive a sensor network and its applications into corner-case situations, exhibiting bugs that are hard to detect using existing testing and debugging techniques. In this paper, we present KleeNet, a debugging environment that effectively discovers such bugs before deployment. KleeNet executes unmodified sensor network applications on symbolic input and automatically injects non-deterministic failures. As a result, KleeNet generates distributed execution paths at high-coverage, including low-probability cornercase situations. As a case study, we integrated KleeNet into the Contiki OS and show its effectiveness by detecting four insidious bugs in the µIP TCP/IP protocol stack. One of these bugs is critical and lead to refusal of further connections.
Verifying architectural models of embedded systems is desirable, since architecture can impact th... more Verifying architectural models of embedded systems is desirable, since architecture can impact the performance and resource usage of the final system implementation. To fulfill this need, one could think of combining formal verification and testing to achieve proofs of system correctness with respect to functional and extra-functional requirements. Our first step to accomplish this goal has concretized in the development of a framework that integrates architectural models described in East-adl language with component-based model-checking techniques. The framework is supported by a tool called ViTAL, which captures the behavior of East-adl functions as timed automata models, which can be formally verified in the Uppaal Port model-checker that exploits the components-based semantics at the architectural level. Later, the same formal models will help generate test-suites to provide support for model-based testing.
One of the major problems in applying automatic verification tools to industrial-size systems is ... more One of the major problems in applying automatic verification tools to industrial-size systems is the excessive amount of memory required during the state-space exploration of a model. In the setting of real-time, this problem of state-explosion requires extra attention as information must be kept not only on the discrete control structure but also on the values of continuous clock variables. In this paper, we exploit Clock Difference Diagrams, CDD's, a BDD-like data-structure for representing and effectively manipulating certain nonconvex subsets of the Euclidean space, notably those encountered during verification of timed automata. A version of the real-time verification tool Uppaal using CDD's as a compact data-structure for storing explored symbolic states has been implemented. Our experimental results demonstrate significant spacesavings: for eight industrial examples, the savings are in average 42% with moderate increase in runtime. We further report on how the symbolic state-space exploration itself may be carried out using CDD's.
See back inner page for a list of recent BRICS Report Series publications. Copies may be obtained... more See back inner page for a list of recent BRICS Report Series publications. Copies may be obtained by contacting:
Testing Continuous Systems Conformance Using Cross Correlation Jacob Palczynski, Carsten Weise, a... more Testing Continuous Systems Conformance Using Cross Correlation Jacob Palczynski, Carsten Weise, and Stefan Kowalewski Informatik 11, RWTH Aachen University, Ahornstr. 55, 52074 Aachen, Germany {palczynski, weise, kowalewski}@ embedded. rwth-aachen. de ...
One of the most successful techniques for automatic verification is that of model checking. For f... more One of the most successful techniques for automatic verification is that of model checking. For finite automata there exist since long extremely efficient model-checking algorithms, and in the last few years these algorithms have been made applicable to the verification of real-time automata using the region-techniques of Alur and Dill. In this paper, we continue this transfer of existing techniques from the setting of finite (untimed) automata to that of timed automata. In particular, a timed logic L ν is put forward, which is sufficiently expressive that we for any timed automaton may construct a single characteristic L ν formula uniquely characterizing the automaton up to timed bisimilarity. Also, we prove decidability of the satisfiability problem for L ν with respect to given bounds on the number of clocks and constants of the timed automata to be constructed. None of these results have as yet been succesfully accounted for in the presence of time 1. * This work has been supported by the European Communities under CONCUR2, BRA 7166 † Basic Research in Computer Science, Centre of the Danish National Research Foundation. 1 An exception occurs in Alur's thesis [Alu91] in which a decidability result is presented for a linear timed logic called MITL.
See back inner page for a list of recent BRICS Report Series publications. Copies may be obtained... more See back inner page for a list of recent BRICS Report Series publications. Copies may be obtained by contacting:
... tr Tuula Paakkonen Nokia Technology Platforms Tampere, Finland Yuri Gurevich Microsoft Resear... more ... tr Tuula Paakkonen Nokia Technology Platforms Tampere, Finland Yuri Gurevich Microsoft Research Redmond, WA, USA gurevich ... Railway Interlockings with TTCN-3 Stefan Blom, Natalia Ioustinova, Jaco van de Pol, Axel Rennoch, Natalia Sidorova..... ...
... tr Tuula Paakkonen Nokia Technology Platforms Tampere, Finland Yuri Gurevich Microsoft Resear... more ... tr Tuula Paakkonen Nokia Technology Platforms Tampere, Finland Yuri Gurevich Microsoft Research Redmond, WA, USA gurevich ... Railway Interlockings with TTCN-3 Stefan Blom, Natalia Ioustinova, Jaco van de Pol, Axel Rennoch, Natalia Sidorova..... ...
The use of general descriptive names, registered names, trademarks, service marks, etc. in this p... more The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
International Journal of Radiation Oncology*Biology*Physics, 2012
Conclusions: Hypofractionated VMAT-IGRT in prostate cancer patients is dosimetrically and clinica... more Conclusions: Hypofractionated VMAT-IGRT in prostate cancer patients is dosimetrically and clinically feasible. Acute toxicity and impairment of QLQ were acceptable and similar to other hypofractionated series. Further following is required to assess late toxicity and disease control.
In den vergangenen Jahren ist die Informationsmenge von frei verfügbaren Weltkarten wie OpenStree... more In den vergangenen Jahren ist die Informationsmenge von frei verfügbaren Weltkarten wie OpenStreetMap enorm gewachsen. Davon profitieren wiederum andere freie Dienste und Applikationen, wie der freie Routenplaner OpenRouteService und das mobile Smartphone-Navigationssystem AndNav. Neben einer großen Infrastruktur-Abdeckung findet man mittlerweile auch vermehrt detaillierte Streckeninformationen, z. B. Bodenbelag und Steigung. Diese Arbeit beschreibt ein Konzept, wie man diese verfügbaren Streckeninformationen dazu nutzen kann, ein Navigationssystem für Elektrofahrzeuge (z. B. Elektrorollstühle) zu entwickeln. Dieses Konzept basiert auf der Tatsache, dass der kürzeste oder schnellste Weg, den ein Routenplaner berechnet, nicht immer der effizienteste im Bezug auf den Energieverbrauch eines Elektromotors ist. Es wird ein Algorithmus vorgestellt, der mithilfe der Streckeninformation "Steigung" eine effizientere Route für ein Elektrofahrzeug berechnen kann. Als Fallstudie wird die Umsetzung des Algorithmus auf dem freien Routenplaner OpenRouteService, sowie die Erweiterung des auf dem OpenRouteService basierenden mobilen Open Source Navigationssystems AndNav beschrieben. Mit dem resultierenden erweiterten Navigationssystem kann ein Elektrofahrzeugführer leicht mit seinem Android-Mobiltelefon über den OpenRouteService und damit über die OpenStreetMap-Daten eine energieeffiziente Route für sein Elektrofahrzeug in Erfahrung bringen. 1 Einleitung Bei der Planung einer Route mit einem Elektrofahrzeug (z. B. Elektrorollstuhl) spielen unterschiedliche Faktoren eine wichtige Rolle. Zu diesen gehören zum Beispiel der Akkustand bei Beginn der Route, die Streckensteigung des Routenverlaufs und mögliche Ladestationen für das Elektrofahrzeug. Zurzeit gibt es sehr wenige Systeme, die einen der obigen Faktoren in ihre Routenplanung einbeziehen. Dabei ist ein solches System bei der heutzutage frei verfügbaren Informationsmenge gut denkbar. Die freie Weltkarte OSM (RAMM & TOPF 2008) bietet sowohl die Möglichkeit Stromtankstellen einzutragen, als auch Streckenabschnitte mit Steigungsinformationen zu versehen. So sind auf OSM bereits Steigungsinformationen von vielen Teilen Deutschlands verfügbar. Die vorliegende Arbeit stellt eine Möglichkeit vor, die frei verfügbaren Steigungsinformationen aus den OSM-Daten zu nutzen, um eine Routenplanung unter Einbeziehung von Steigungsinformationen zu erlauben. Für die Routenplanung wird der auf OSM basierende
Verifying architectural models of embedded systems is desirable, since architecture can impact th... more Verifying architectural models of embedded systems is desirable, since architecture can impact the performance and resource usage of the final system implementation. To fulfill this need, one could think of combining formal verification and testing to achieve proofs of system correctness with respect to functional and extra-functional requirements. Our first step to accomplish this goal has concretized in the development of a framework that integrates architectural models described in East-adl language with component-based model-checking techniques. The framework is supported by a tool called ViTAL, which captures the behavior of East-adl functions as timed automata models, which can be formally verified in the Uppaal Port model-checker that exploits the components-based semantics at the architectural level. Later, the same formal models will help generate test-suites to provide support for model-based testing.
Proceedings of the 9th ACM/IEEE International Conference on Information Processing in Sensor Networks - IPSN '10, 2010
Complex interactions and the distributed nature of wireless sensor networks make automated testin... more Complex interactions and the distributed nature of wireless sensor networks make automated testing and debugging before deployment a necessity. A main challenge is to detect bugs that occur due to non-deterministic events, such as node reboots or packet duplicates. Often, these events have the potential to drive a sensor network and its applications into corner-case situations, exhibiting bugs that are hard to detect using existing testing and debugging techniques. In this paper, we present KleeNet, a debugging environment that effectively discovers such bugs before deployment. KleeNet executes unmodified sensor network applications on symbolic input and automatically injects non-deterministic failures. As a result, KleeNet generates distributed execution paths at high-coverage, including low-probability cornercase situations. As a case study, we integrated KleeNet into the Contiki OS and show its effectiveness by detecting four insidious bugs in the µIP TCP/IP protocol stack. One of these bugs is critical and lead to refusal of further connections.
Verifying architectural models of embedded systems is desirable, since architecture can impact th... more Verifying architectural models of embedded systems is desirable, since architecture can impact the performance and resource usage of the final system implementation. To fulfill this need, one could think of combining formal verification and testing to achieve proofs of system correctness with respect to functional and extra-functional requirements. Our first step to accomplish this goal has concretized in the development of a framework that integrates architectural models described in East-adl language with component-based model-checking techniques. The framework is supported by a tool called ViTAL, which captures the behavior of East-adl functions as timed automata models, which can be formally verified in the Uppaal Port model-checker that exploits the components-based semantics at the architectural level. Later, the same formal models will help generate test-suites to provide support for model-based testing.
Uploads
Papers by Carsten Weise