Anne Remke | Wwu Münster (original) (raw)

Papers by Anne Remke

Lecture Notes in Computer Science, 2005

In this paper algorithms for model checking CSL (continuous stochastic logic) against infinite-st... more In this paper algorithms for model checking CSL (continuous stochastic logic) against infinite-state continuous-time Markov chains of so-called quasi birth-death type are developed. In doing so we extend the applicability of CSL model checking beyond the recently proposed case for finite-state continuous-time Markov chains, to an important class of infinite-state Markov chains. We present syntax and semantics for CSL and develop efficient model checking algorithms for the steady-state operator and the time-bounded next and until operator. For the former, we rely on the so-called matrix-geometric solution of the steady-state probabilities of the infinite-state Markov chain. For the time-bounded until operator we develop a new algorithm for the transient analysis of infinite-state Markov chains, thereby exploiting the quasi birth-death structure. A case study shows the feasibility of our approach.

Two-hop ad-hoc networks, in which some nodes forward traffic for multiple sources, with which the... more Two-hop ad-hoc networks, in which some nodes forward traffic for multiple sources, with which they also compete for channel access suffer from large queues building up in bottleneck nodes. This problem can often be alleviated by using IEEE 802.11e to give preferential treatment to bottleneck nodes. Previous results have shown that differentiation parameters can be used to allocate capacity in a more efficient way in the two-hop scenario. However, the overall throughput of the bottleneck may differ considerably, depending on the differentiation method used. By applying a very fast and accurate analysis method, based on steady-state analysis of an QBD-type infinite Markov chain, we find the maximum throughput that is possible per differentiation parameter. All possible parameter settings are explored with respect to the maximum throughput conditioned on a maximum buffer occupancy. This design space exploration cannot be done with network simulators like NS2 or Opnet, as each simulation run simply takes to long. The results, which have been validated by detailed simulations, show that by differentiating TXOP it is possible to achieve a throughput that is about 50% larger than when differentiating AIFS and CWmin.

Among others, drinking water belongs to the socalled critical infrastructures. To ensure that the... more Among others, drinking water belongs to the socalled critical infrastructures. To ensure that the water production meets current and future societal needs, a systematic and rigorous analysis is needed. In this paper, we report our first experience with dependability analysis of the last phase of a water treatment facility, namely the water distribution. We use the architectural language Arcade to

In this paper algorithms for model checking CSL (continuous stochastic logic) against infinite-st... more In this paper algorithms for model checking CSL (continuous stochastic logic) against infinite-state continuous-time Markov chains of so-called quasi birth-death type are developed. In doing so we extend the applicability of CSL model checking beyond the recently proposed case for finite-state continuous-time Markov chains, to an important class of infinite-state Markov chains. We present syntax and semantics for CSL and

Optics Express, 2010

A hybrid Petri net formalism that is specifically tailored towards so-called fluid critical infra... more A hybrid Petri net formalism that is specifically tailored towards so-called fluid critical infrastructures is introduced, allowing for timed, generally distributed and fluid transitions. Such models are analyzed with Parametric Reachability Analysis, by separating the deterministic and the stochastic evolution of the system. Several performance metrics, such as the distribution of fluid over time, can be derived by deconditioning according

Mathematical Methods of Operations Research, 2012

Recently, many systems consisting of a large number of interacting objects were analysed using th... more Recently, many systems consisting of a large number of interacting objects were analysed using the mean-field method, which has only been used for performance evaluation. In this short paper, we apply it to model checking. We define logic, which allows to describe the overall properties of the large system.

Physics of Fluids, 2011

Peer-to-peer botnets, as exemplified by the Storm Worm and Stuxnet, are a relatively new threat t... more Peer-to-peer botnets, as exemplified by the Storm Worm and Stuxnet, are a relatively new threat to security on the internet: infected computers automatically search for other computers to be infected, thus spreading the infection rapidly. In a recent paper, such botnets have been modeled using Stochastic Activity Networks, allowing the use of discrete-event simulation to judge strategies for combating their

Lecture Notes in Computer Science, 2008

Recently, a quality-of-service (QoS) extension of the IEEE 802.11 standard (known as IEEE 802.11e... more Recently, a quality-of-service (QoS) extension of the IEEE 802.11 standard (known as IEEE 802.11e) for wireless LANs has been proposed. We present a versatile and accurate performance model to study how these new QoS enhancements can be used to improve the performance of wireless nodes competing for bandwidth in a multi-hop ad hoc network. The paper presents the QoS enhancements, and shows how they can be modeled using a simple, yet effective, parameterized quasi-birth-death model. The model is developed hierarchically, in that results at packet level (e.g., as developed by Bianchi and others) are used in our flow-level model, in which a single bottleneck station interacts with a time-varying number of traffic sources. Thus, we are able to study the impact of the QoS enhancements on the flow-level performance. This has not been done before. The results of our analyses are compared with extensive simulations (using Opnet), and show excellent agreement for throughput, mean number of active sources and mean buffer occupancy at the bottleneck station. An important asset of our model is that it allows for very quick evaluations: where simulations require up to an hour per scenario, our model is solved in seconds.

Lecture Notes in Computer Science, 2007

Jackson queueing networks (JQNs) are a very general class of queueing networks that find their ap... more Jackson queueing networks (JQNs) are a very general class of queueing networks that find their application in a variety of settings. The state space of the continuous-time Markov chain (CTMC) that underlies such a JQN, is highly structured, however, of infinite size in as many dimensions as there are queues. We present CSL model checking algo- rithms for labeled JQNs.

Lecture Notes in Computer Science, 2008

We present a model checking procedure for the CSL until operator on the CTMCs that underly Jackso... more We present a model checking procedure for the CSL until operator on the CTMCs that underly Jackson queueing networks. The key issue lies in the fact that the underlying CTMC is infinite in as many dimensions as there are queues in the JQN. We need to compute the transient state probabilities for all goal states and for all possible starting states. However, for these transient probabilities no computational procedures are readily available. The contribution of this paper is the proposal of a new uniformization-based approach to compute the transient state probabilities. Furthermore, we show how the highly structured state space of JQNs allows us to compute the possible infinite satisfaction set for until formulas. A case study on an e-business site shows the feasibility of our approach. ⋆ The work presented in this paper has been performed in the context of the MC=MC project (612.000.311), financed by the Netherlands Organization for Scientific Research (NWO). The authors thank Lucia Cloth for fruitful discussions on the topic.

Lecture Notes in Computer Science, 2005

In this paper algorithms for model checking CSL (continuous stochastic logic) against infinite-st... more In this paper algorithms for model checking CSL (continuous stochastic logic) against infinite-state continuous-time Markov chains of so-called quasi birth-death type are developed. In doing so we extend the applicability of CSL model checking beyond the recently proposed case for finite-state continuous-time Markov chains, to an important class of infinite-state Markov chains. We present syntax and semantics for CSL and develop efficient model checking algorithms for the steady-state operator and the time-bounded next and until operator. For the former, we rely on the so-called matrix-geometric solution of the steady-state probabilities of the infinite-state Markov chain. For the time-bounded until operator we develop a new algorithm for the transient analysis of infinite-state Markov chains, thereby exploiting the quasi birth-death structure. A case study shows the feasibility of our approach.

Proceeding from the 2006 workshop on Tools for solving sturctured Markov chains - SMCtools '06, 2006

A large variety of computer and communication systems can be modeled adequately as infinite-state... more A large variety of computer and communication systems can be modeled adequately as infinite-state continuoustime Markov chains (CTMCs). A highly-structured class of such infinite-state CTMCs is the class of Quasi-Birth-Death processes (QBDs), on which we focus in this paper. We present an efficient variant of uniformization for the comprehensive transient analysis of infinite-state QBDs, namely computing the transient probability of being in each state of the QBD for any possible initial state. Both, the set of starting states and the set of end states are infinite. The key idea of our algorithm is to split the infinite set of starting states into a finite part and an infinite part. The transient probabilities of the infinite part are then indicated using the new notion of representatives.

Lecture Notes in Computer Science, 2014

Resilience Assessment and Evaluation of Computing Systems, 2012

Lecture Notes in Computer Science, 2011

Peer-to-peer botnets, as exemplified by the Storm Worm and Stuxnet, are a relatively new threat t... more Peer-to-peer botnets, as exemplified by the Storm Worm and Stuxnet, are a relatively new threat to security on the internet: infected computers automatically search for other computers to be infected, thus spreading the infection rapidly. In a recent paper, such botnets have been modeled using Stochastic Activity Networks, allowing the use of discrete-event simulation to judge strategies for combating their

2013 43rd Annual IEEE/IFIP International Conference on Dependable Systems and Networks (DSN), 2013

This paper investigates the survivability of a water cleaning facility using Fluid Stochastic Pet... more This paper investigates the survivability of a water cleaning facility using Fluid Stochastic Petri Nets (FSPN). Water cleaning facilities are responsible for providing drinking water to a specific district. The provided service is very important and makes such facilities belong to a nation's critical infrastructures. Therefore, such a facility should be able to recover in a timely manner after the occurrence of disasters. The use of FSPNs in survivability research is new and promising due to its general applicability. In this paper we model and analyze the survivability of the last phases of the water cleaning process in a Dutch water company. Analysis results identify the weaknesses of the process and redundancy is suggested to improve the survivability.

The endorsement of information technologies for critical infrastructures control introduces new t... more The endorsement of information technologies for critical infrastructures control introduces new threats in their security and surveillance. Along with certain level of protection against attacks, it is desirable for critical processes to survive even if they succeed. A stochastic Petri Nets-based model of a SCADA control loop is presented in this paper, modelling both, the system functioning and attacks. Together

Nutsvoorzieningen, zoals water-, gas- en stroomfaciliteiten zijn dikwijls gebaseerd op Supervisor... more Nutsvoorzieningen, zoals water-, gas- en stroomfaciliteiten zijn dikwijls gebaseerd op Supervisory Control And Data Acquisition (Scada). Steeds vaker wordt dit soort systemen met de publieke netwerken verbonden en gebaseerd op Windows. Dat maakt ze gevoelig voor dezelfde dreigingen als op het publieke internet. Boudewijn Haverkort, Anne Remke en Pieter Hartel gaan in op deze gevaren en de maatregelen die we

Lecture Notes in Computer Science, 2005

In this paper algorithms for model checking CSL (continuous stochastic logic) against infinite-st... more In this paper algorithms for model checking CSL (continuous stochastic logic) against infinite-state continuous-time Markov chains of so-called quasi birth-death type are developed. In doing so we extend the applicability of CSL model checking beyond the recently proposed case for finite-state continuous-time Markov chains, to an important class of infinite-state Markov chains. We present syntax and semantics for CSL and develop efficient model checking algorithms for the steady-state operator and the time-bounded next and until operator. For the former, we rely on the so-called matrix-geometric solution of the steady-state probabilities of the infinite-state Markov chain. For the time-bounded until operator we develop a new algorithm for the transient analysis of infinite-state Markov chains, thereby exploiting the quasi birth-death structure. A case study shows the feasibility of our approach.

Two-hop ad-hoc networks, in which some nodes forward traffic for multiple sources, with which the... more Two-hop ad-hoc networks, in which some nodes forward traffic for multiple sources, with which they also compete for channel access suffer from large queues building up in bottleneck nodes. This problem can often be alleviated by using IEEE 802.11e to give preferential treatment to bottleneck nodes. Previous results have shown that differentiation parameters can be used to allocate capacity in a more efficient way in the two-hop scenario. However, the overall throughput of the bottleneck may differ considerably, depending on the differentiation method used. By applying a very fast and accurate analysis method, based on steady-state analysis of an QBD-type infinite Markov chain, we find the maximum throughput that is possible per differentiation parameter. All possible parameter settings are explored with respect to the maximum throughput conditioned on a maximum buffer occupancy. This design space exploration cannot be done with network simulators like NS2 or Opnet, as each simulation run simply takes to long. The results, which have been validated by detailed simulations, show that by differentiating TXOP it is possible to achieve a throughput that is about 50% larger than when differentiating AIFS and CWmin.

Among others, drinking water belongs to the socalled critical infrastructures. To ensure that the... more Among others, drinking water belongs to the socalled critical infrastructures. To ensure that the water production meets current and future societal needs, a systematic and rigorous analysis is needed. In this paper, we report our first experience with dependability analysis of the last phase of a water treatment facility, namely the water distribution. We use the architectural language Arcade to

In this paper algorithms for model checking CSL (continuous stochastic logic) against infinite-st... more In this paper algorithms for model checking CSL (continuous stochastic logic) against infinite-state continuous-time Markov chains of so-called quasi birth-death type are developed. In doing so we extend the applicability of CSL model checking beyond the recently proposed case for finite-state continuous-time Markov chains, to an important class of infinite-state Markov chains. We present syntax and semantics for CSL and

Optics Express, 2010

A hybrid Petri net formalism that is specifically tailored towards so-called fluid critical infra... more A hybrid Petri net formalism that is specifically tailored towards so-called fluid critical infrastructures is introduced, allowing for timed, generally distributed and fluid transitions. Such models are analyzed with Parametric Reachability Analysis, by separating the deterministic and the stochastic evolution of the system. Several performance metrics, such as the distribution of fluid over time, can be derived by deconditioning according

Mathematical Methods of Operations Research, 2012

Recently, many systems consisting of a large number of interacting objects were analysed using th... more Recently, many systems consisting of a large number of interacting objects were analysed using the mean-field method, which has only been used for performance evaluation. In this short paper, we apply it to model checking. We define logic, which allows to describe the overall properties of the large system.

Physics of Fluids, 2011

Peer-to-peer botnets, as exemplified by the Storm Worm and Stuxnet, are a relatively new threat t... more Peer-to-peer botnets, as exemplified by the Storm Worm and Stuxnet, are a relatively new threat to security on the internet: infected computers automatically search for other computers to be infected, thus spreading the infection rapidly. In a recent paper, such botnets have been modeled using Stochastic Activity Networks, allowing the use of discrete-event simulation to judge strategies for combating their

Lecture Notes in Computer Science, 2008

Recently, a quality-of-service (QoS) extension of the IEEE 802.11 standard (known as IEEE 802.11e... more Recently, a quality-of-service (QoS) extension of the IEEE 802.11 standard (known as IEEE 802.11e) for wireless LANs has been proposed. We present a versatile and accurate performance model to study how these new QoS enhancements can be used to improve the performance of wireless nodes competing for bandwidth in a multi-hop ad hoc network. The paper presents the QoS enhancements, and shows how they can be modeled using a simple, yet effective, parameterized quasi-birth-death model. The model is developed hierarchically, in that results at packet level (e.g., as developed by Bianchi and others) are used in our flow-level model, in which a single bottleneck station interacts with a time-varying number of traffic sources. Thus, we are able to study the impact of the QoS enhancements on the flow-level performance. This has not been done before. The results of our analyses are compared with extensive simulations (using Opnet), and show excellent agreement for throughput, mean number of active sources and mean buffer occupancy at the bottleneck station. An important asset of our model is that it allows for very quick evaluations: where simulations require up to an hour per scenario, our model is solved in seconds.

Lecture Notes in Computer Science, 2007

Jackson queueing networks (JQNs) are a very general class of queueing networks that find their ap... more Jackson queueing networks (JQNs) are a very general class of queueing networks that find their application in a variety of settings. The state space of the continuous-time Markov chain (CTMC) that underlies such a JQN, is highly structured, however, of infinite size in as many dimensions as there are queues. We present CSL model checking algo- rithms for labeled JQNs.

Lecture Notes in Computer Science, 2008

We present a model checking procedure for the CSL until operator on the CTMCs that underly Jackso... more We present a model checking procedure for the CSL until operator on the CTMCs that underly Jackson queueing networks. The key issue lies in the fact that the underlying CTMC is infinite in as many dimensions as there are queues in the JQN. We need to compute the transient state probabilities for all goal states and for all possible starting states. However, for these transient probabilities no computational procedures are readily available. The contribution of this paper is the proposal of a new uniformization-based approach to compute the transient state probabilities. Furthermore, we show how the highly structured state space of JQNs allows us to compute the possible infinite satisfaction set for until formulas. A case study on an e-business site shows the feasibility of our approach. ⋆ The work presented in this paper has been performed in the context of the MC=MC project (612.000.311), financed by the Netherlands Organization for Scientific Research (NWO). The authors thank Lucia Cloth for fruitful discussions on the topic.

Lecture Notes in Computer Science, 2005

In this paper algorithms for model checking CSL (continuous stochastic logic) against infinite-st... more In this paper algorithms for model checking CSL (continuous stochastic logic) against infinite-state continuous-time Markov chains of so-called quasi birth-death type are developed. In doing so we extend the applicability of CSL model checking beyond the recently proposed case for finite-state continuous-time Markov chains, to an important class of infinite-state Markov chains. We present syntax and semantics for CSL and develop efficient model checking algorithms for the steady-state operator and the time-bounded next and until operator. For the former, we rely on the so-called matrix-geometric solution of the steady-state probabilities of the infinite-state Markov chain. For the time-bounded until operator we develop a new algorithm for the transient analysis of infinite-state Markov chains, thereby exploiting the quasi birth-death structure. A case study shows the feasibility of our approach.

Proceeding from the 2006 workshop on Tools for solving sturctured Markov chains - SMCtools '06, 2006

A large variety of computer and communication systems can be modeled adequately as infinite-state... more A large variety of computer and communication systems can be modeled adequately as infinite-state continuoustime Markov chains (CTMCs). A highly-structured class of such infinite-state CTMCs is the class of Quasi-Birth-Death processes (QBDs), on which we focus in this paper. We present an efficient variant of uniformization for the comprehensive transient analysis of infinite-state QBDs, namely computing the transient probability of being in each state of the QBD for any possible initial state. Both, the set of starting states and the set of end states are infinite. The key idea of our algorithm is to split the infinite set of starting states into a finite part and an infinite part. The transient probabilities of the infinite part are then indicated using the new notion of representatives.

Lecture Notes in Computer Science, 2014

Resilience Assessment and Evaluation of Computing Systems, 2012

Lecture Notes in Computer Science, 2011

Peer-to-peer botnets, as exemplified by the Storm Worm and Stuxnet, are a relatively new threat t... more Peer-to-peer botnets, as exemplified by the Storm Worm and Stuxnet, are a relatively new threat to security on the internet: infected computers automatically search for other computers to be infected, thus spreading the infection rapidly. In a recent paper, such botnets have been modeled using Stochastic Activity Networks, allowing the use of discrete-event simulation to judge strategies for combating their

2013 43rd Annual IEEE/IFIP International Conference on Dependable Systems and Networks (DSN), 2013

This paper investigates the survivability of a water cleaning facility using Fluid Stochastic Pet... more This paper investigates the survivability of a water cleaning facility using Fluid Stochastic Petri Nets (FSPN). Water cleaning facilities are responsible for providing drinking water to a specific district. The provided service is very important and makes such facilities belong to a nation's critical infrastructures. Therefore, such a facility should be able to recover in a timely manner after the occurrence of disasters. The use of FSPNs in survivability research is new and promising due to its general applicability. In this paper we model and analyze the survivability of the last phases of the water cleaning process in a Dutch water company. Analysis results identify the weaknesses of the process and redundancy is suggested to improve the survivability.

The endorsement of information technologies for critical infrastructures control introduces new t... more The endorsement of information technologies for critical infrastructures control introduces new threats in their security and surveillance. Along with certain level of protection against attacks, it is desirable for critical processes to survive even if they succeed. A stochastic Petri Nets-based model of a SCADA control loop is presented in this paper, modelling both, the system functioning and attacks. Together

Nutsvoorzieningen, zoals water-, gas- en stroomfaciliteiten zijn dikwijls gebaseerd op Supervisor... more Nutsvoorzieningen, zoals water-, gas- en stroomfaciliteiten zijn dikwijls gebaseerd op Supervisory Control And Data Acquisition (Scada). Steeds vaker wordt dit soort systemen met de publieke netwerken verbonden en gebaseerd op Windows. Dat maakt ze gevoelig voor dezelfde dreigingen als op het publieke internet. Boudewijn Haverkort, Anne Remke en Pieter Hartel gaan in op deze gevaren en de maatregelen die we