Many different forms of explanation have been proposed for justifying decisions made by automated... more Many different forms of explanation have been proposed for justifying decisions made by automated systems. However, there is no consensus on what constitutes a good explanation, or what information these explanations should include. In this paper, we present the results of a study into how people justify their decisions. Analysis of our results allowed us to extract the forms of explanation adopted by users to justify choices, and the situations in which these forms are used.
Users are facing an increasing challenge of managing information and being available anytime anyw... more Users are facing an increasing challenge of managing information and being available anytime anywhere, as the web exponentially grows. As a consequence, assisting them in their routine tasks has become a relevant issue to be addressed. In this paper, we introduce an adaptation mechanism that is responsible for dynamically adapting a BDI agent-based running system in order to support software customisation for users.
It is rare for data's history to include computational processes alone. Even when software genera... more It is rare for data's history to include computational processes alone. Even when software generates data, users ultimately decide to execute software procedures, choose their configuration and inputs, reconfigure, halt and restart processes, and so on. Understanding the provenance of data thus involves understanding the reasoning of users behind these decisions, but demanding that users explicitly document decisions could be intrusive if implemented naively, and impractical in some cases.
Abstract The automation of user tasks by agents may involve decision making that must take into a... more Abstract The automation of user tasks by agents may involve decision making that must take into account user preferences. This paper introduces a decision making technique that reasons about preferences and priorities expressed in a high-level language in order to choose an option from the set of those available. Our technique includes principles from psychology, concerning the way in which humans make decisions.
Due to their immense complexity, large-scale multiagent systems are often unamenable to exhaustiv... more Due to their immense complexity, large-scale multiagent systems are often unamenable to exhaustive formal verification. Statistical approaches that focus on the verification of individual traces can provide an interesting alternative. However, due to its focus on finite execution paths, trace-based verification is inherently limited to certain types of correctness properties. We show how, by combining sampling with the idea of trace fragmentation, statistical model checking can be used to answer interesting quantitative correctness properties about multiagent systems on different observational levels. We illustrate the idea with a simple case study from the area of swarm robotics.
The logistics of the aerospace aftermarket raises a number of very interesting challenges from th... more The logistics of the aerospace aftermarket raises a number of very interesting challenges from the perspective of electronic contracting. This is a highly dynamic domain, where contracts are established between airlines and engine manufacturers, as well as between engine manufacturers all the way down the supply lines, providing a particularly illustrative showcase for the technologies developed in the CONTRACT project. In this paper, we describe such a domain, as well as our modelling of it as a multiagent simulator where the ...
Distributed systems comprised of autonomous self-interested entities require some sort of control... more Distributed systems comprised of autonomous self-interested entities require some sort of control mechanism to ensure the predictability of the interactions that drive them. This is certainly true in the aerospace domain, where manufacturers, suppliers and operators must coordinate their activities to maximise safety and profit, for example. To address this need, the notion of norms has been proposed which, when incorporated into formal electronic documents, allow for the specification and deployment of contract-driven ...
In the domain of aerospace aftermarkets, which often has long supply chains that feed into the ma... more In the domain of aerospace aftermarkets, which often has long supply chains that feed into the maintenance of aircraft, contracts are used to establish agreements between aircraft operators and maintenance suppliers. However, violations at the bottom of the supply chain (part suppliers) can easily cascade to the top (aircraft operators), making it difficult to determine the source of the violation, and seek to address it. In this context, we have developed a global monitoring architecture that ensures the detection of norm violations ...
Proceedings of the 3rd International Workshop on Engineering Multiagent Systems (EMAS), Istanbul, Turkey, 2015
Due to their immense complexity, large-scale multiagent systems are often unamenable to exhaustiv... more Due to their immense complexity, large-scale multiagent systems are often unamenable to exhaustive formal verification. Statistical approaches that focus on the verification of individual traces can provide an interesting alternative. However, due to its focus on finite execution paths, trace-based verification is inherently limited to certain types of correctness properties. We show how, by combining sampling with the idea of trace fragmentation, statistical model checking can be used to answer interesting quantitative correctness properties about multiagent systems on different observational levels. We illustrate the idea with a simple case study from the area of swarm robotics.
Proceedings of the 16th International Workshop on Multiagent-based Simulation (MABS), Istanbul, Turkey, 2015
Agent-based simulation has shown great success for the study of complex adaptive systems and coul... more Agent-based simulation has shown great success for the study of complex adaptive systems and could in many areas show advantages over traditional analytical methods. Due to their internal complexity, however, agent-based simulations are notoriously difficult to verify and validate.
This paper presents MC2MABS, a Monte Carlo Model Checker for Multiagent-Based Simulations. It incorporates the idea of statistical runtime verification, a combination of statistical model checking and runtime verification, and is tailored to the approximate verification of large-scale agent-based simulations. We provide a description of the underlying theory together with design decisions, an architectural overview, and implementation details. The performance of MC2MABS in terms of both runtime consumption and memory allocation is evaluated against a set of example properties.
Proceedings of the 2015 International Conference on Autonomous Agents and Multiagent Systems, May 4, 2015
Due to their internal complexity, agent-based simulations are rarely amenable to conventional for... more Due to their internal complexity, agent-based simulations are rarely amenable to conventional formal verification. With its focus on individual traces, runtime verification represents an interesting alternative for correctness assessment. Here, execution traces produced by the running system are observed by a monitor and checked for correctness on-the-fly. If the truth or falsity of a given property cannot be determined at time t, then the monitor creates an obligation that the current trace needs to satisfy at time t+1 in order for the whole property to become true.
With different observational levels, traces produced by agent-based simulations have an inherently hierarchical nature which complicates the structure and manipulation of obligations significantly. However, it turns out that this problem is general enough to be dealt with in an abstract, language-independent way.
In this paper, we provide a general framework for the monitoring of hierarchical traces. It introduces different types of obligations and appropriate manipulation procedures along with minimal requirements that a property specification language needs to satisfy in order to be monitorable. We provide a full formalisation of the framework and an example implementation of a subset in Haskell.
This paper focusses on the usefulness of approximate probabilistic model checking for the interna... more This paper focusses on the usefulness of approximate probabilistic model checking for the internal and external validation of large-scale agent-based simulations. We describe the translation of typical validation criteria into a variant of linear time logic. We further present a prototypical version of a highly customisable approximate model checker
which we used in a range of experiments to verify properties of large scale models whose complexity prevents them from being amenable to conventional explicit or symbolic model checking.
M. Parsons, T. Anderson (Editors): Engineering Systems for Safety: Proceedings of the 23rd Safety-critical Systems Symposium (SSS), 2015
Swarm-based systems, i.e. systems comprising multiple simple, autonomous and interacting componen... more Swarm-based systems, i.e. systems comprising multiple simple, autonomous and interacting components, have become increasingly important. With their decentralised architecture, their ability to self-organise and to exhibit complex emergent behaviour, good scalability and support for inherent fault tolerance due to a high level of redundancy, they offer characteristics which are particularly interesting for the construction of safety-critical systems. At the same time, swarms are notoriously difficult to engineer, to understand and to control. Emergent phenomena are, by definition, irreducible to the properties of the constituents which severely constrains predictability. Especially in safety -critical areas, however, a clear understanding of the future dynamics of the system is indispensable. In this paper we show how agent-based simulation in combination with statistical verification can help to understand and quantify the likelihood of emergent swarm behaviours on different observational levels. We illustrate the idea with a simple case study from the area of swarm robotics.
Studia Informatica Universalis, 10 (3): pp 87-118, 2012
Even though agent-based simulations have been applied successfully to various real-world projects... more Even though agent-based simulations have been applied successfully to various real-world projects, there is still much reluctance to accept them to the same degree as more traditional, equation-based techniques. The main reason for this general scepticism lies in their inherent complexity which makes them difficult to understand, to verify and to validate. We analyse the particular characteristics of agent-based simulations and give recommendations for a model checking-based verification process. Furthermore, we sketch a preliminary verification approach which is based on an iterative, compositional and non-exhaustive model construction process and transient reachability analysis.
Clinical trials are widely adopted for the purpose of evaluating medical research. In particular,... more Clinical trials are widely adopted for the purpose of evaluating medical research. In particular, they are used to study various aspects of medical science, as well as being a vital stage in the deployment of new drug treatments. However, a review of the UK Medical Research Council found that only 31% of trials actually recruited to their planned target, with 30–40% of costs arising during the recruitment phase alone. This is mainly due to the challenges that are involved in designing the clinical trial, and recruiting the required number of patients for this trial within a certain time-frame. Both tasks create significant overhead as they are slow and costly. In response, we propose a multi-agent architecture that helps ease the process of recruiting patients for clinical trials. This paper presents a results from a deployment of the architecture, showing that it succeeds in recruiting a sufficient number of patients for multiple clinical trials. The results also show that recruitment is better for some trials than for others, due to the differing trial requirements and recruitment processes.
Abstract In e-Science experiments, it is vital to record the experimental process for later use s... more Abstract In e-Science experiments, it is vital to record the experimental process for later use such as in interpreting results, verifying that the correct process took place or tracing where data came from. The process that led to some data is called the provenance of that data, and a provenance architecture is the software architecture for a system that will provide the necessary functionality to record, store and use process documentation to determine the provenance of data items.
Abstract Scientific workflows are becoming a valuable tool for scientists to capture and automate... more Abstract Scientific workflows are becoming a valuable tool for scientists to capture and automate e-Science procedures. Their success brings the opportunity to publish, share, reuse and re-purpose this explicitly captured knowledge. Within the equation image Grid project, we have identified key resources that can be shared including complete workflows, fragments of workflows and constituent services.
Many different forms of explanation have been proposed for justifying decisions made by automated... more Many different forms of explanation have been proposed for justifying decisions made by automated systems. However, there is no consensus on what constitutes a good explanation, or what information these explanations should include. In this paper, we present the results of a study into how people justify their decisions. Analysis of our results allowed us to extract the forms of explanation adopted by users to justify choices, and the situations in which these forms are used.
Users are facing an increasing challenge of managing information and being available anytime anyw... more Users are facing an increasing challenge of managing information and being available anytime anywhere, as the web exponentially grows. As a consequence, assisting them in their routine tasks has become a relevant issue to be addressed. In this paper, we introduce an adaptation mechanism that is responsible for dynamically adapting a BDI agent-based running system in order to support software customisation for users.
It is rare for data's history to include computational processes alone. Even when software genera... more It is rare for data's history to include computational processes alone. Even when software generates data, users ultimately decide to execute software procedures, choose their configuration and inputs, reconfigure, halt and restart processes, and so on. Understanding the provenance of data thus involves understanding the reasoning of users behind these decisions, but demanding that users explicitly document decisions could be intrusive if implemented naively, and impractical in some cases.
Abstract The automation of user tasks by agents may involve decision making that must take into a... more Abstract The automation of user tasks by agents may involve decision making that must take into account user preferences. This paper introduces a decision making technique that reasons about preferences and priorities expressed in a high-level language in order to choose an option from the set of those available. Our technique includes principles from psychology, concerning the way in which humans make decisions.
Due to their immense complexity, large-scale multiagent systems are often unamenable to exhaustiv... more Due to their immense complexity, large-scale multiagent systems are often unamenable to exhaustive formal verification. Statistical approaches that focus on the verification of individual traces can provide an interesting alternative. However, due to its focus on finite execution paths, trace-based verification is inherently limited to certain types of correctness properties. We show how, by combining sampling with the idea of trace fragmentation, statistical model checking can be used to answer interesting quantitative correctness properties about multiagent systems on different observational levels. We illustrate the idea with a simple case study from the area of swarm robotics.
The logistics of the aerospace aftermarket raises a number of very interesting challenges from th... more The logistics of the aerospace aftermarket raises a number of very interesting challenges from the perspective of electronic contracting. This is a highly dynamic domain, where contracts are established between airlines and engine manufacturers, as well as between engine manufacturers all the way down the supply lines, providing a particularly illustrative showcase for the technologies developed in the CONTRACT project. In this paper, we describe such a domain, as well as our modelling of it as a multiagent simulator where the ...
Distributed systems comprised of autonomous self-interested entities require some sort of control... more Distributed systems comprised of autonomous self-interested entities require some sort of control mechanism to ensure the predictability of the interactions that drive them. This is certainly true in the aerospace domain, where manufacturers, suppliers and operators must coordinate their activities to maximise safety and profit, for example. To address this need, the notion of norms has been proposed which, when incorporated into formal electronic documents, allow for the specification and deployment of contract-driven ...
In the domain of aerospace aftermarkets, which often has long supply chains that feed into the ma... more In the domain of aerospace aftermarkets, which often has long supply chains that feed into the maintenance of aircraft, contracts are used to establish agreements between aircraft operators and maintenance suppliers. However, violations at the bottom of the supply chain (part suppliers) can easily cascade to the top (aircraft operators), making it difficult to determine the source of the violation, and seek to address it. In this context, we have developed a global monitoring architecture that ensures the detection of norm violations ...
Proceedings of the 3rd International Workshop on Engineering Multiagent Systems (EMAS), Istanbul, Turkey, 2015
Due to their immense complexity, large-scale multiagent systems are often unamenable to exhaustiv... more Due to their immense complexity, large-scale multiagent systems are often unamenable to exhaustive formal verification. Statistical approaches that focus on the verification of individual traces can provide an interesting alternative. However, due to its focus on finite execution paths, trace-based verification is inherently limited to certain types of correctness properties. We show how, by combining sampling with the idea of trace fragmentation, statistical model checking can be used to answer interesting quantitative correctness properties about multiagent systems on different observational levels. We illustrate the idea with a simple case study from the area of swarm robotics.
Proceedings of the 16th International Workshop on Multiagent-based Simulation (MABS), Istanbul, Turkey, 2015
Agent-based simulation has shown great success for the study of complex adaptive systems and coul... more Agent-based simulation has shown great success for the study of complex adaptive systems and could in many areas show advantages over traditional analytical methods. Due to their internal complexity, however, agent-based simulations are notoriously difficult to verify and validate.
This paper presents MC2MABS, a Monte Carlo Model Checker for Multiagent-Based Simulations. It incorporates the idea of statistical runtime verification, a combination of statistical model checking and runtime verification, and is tailored to the approximate verification of large-scale agent-based simulations. We provide a description of the underlying theory together with design decisions, an architectural overview, and implementation details. The performance of MC2MABS in terms of both runtime consumption and memory allocation is evaluated against a set of example properties.
Proceedings of the 2015 International Conference on Autonomous Agents and Multiagent Systems, May 4, 2015
Due to their internal complexity, agent-based simulations are rarely amenable to conventional for... more Due to their internal complexity, agent-based simulations are rarely amenable to conventional formal verification. With its focus on individual traces, runtime verification represents an interesting alternative for correctness assessment. Here, execution traces produced by the running system are observed by a monitor and checked for correctness on-the-fly. If the truth or falsity of a given property cannot be determined at time t, then the monitor creates an obligation that the current trace needs to satisfy at time t+1 in order for the whole property to become true.
With different observational levels, traces produced by agent-based simulations have an inherently hierarchical nature which complicates the structure and manipulation of obligations significantly. However, it turns out that this problem is general enough to be dealt with in an abstract, language-independent way.
In this paper, we provide a general framework for the monitoring of hierarchical traces. It introduces different types of obligations and appropriate manipulation procedures along with minimal requirements that a property specification language needs to satisfy in order to be monitorable. We provide a full formalisation of the framework and an example implementation of a subset in Haskell.
This paper focusses on the usefulness of approximate probabilistic model checking for the interna... more This paper focusses on the usefulness of approximate probabilistic model checking for the internal and external validation of large-scale agent-based simulations. We describe the translation of typical validation criteria into a variant of linear time logic. We further present a prototypical version of a highly customisable approximate model checker
which we used in a range of experiments to verify properties of large scale models whose complexity prevents them from being amenable to conventional explicit or symbolic model checking.
M. Parsons, T. Anderson (Editors): Engineering Systems for Safety: Proceedings of the 23rd Safety-critical Systems Symposium (SSS), 2015
Swarm-based systems, i.e. systems comprising multiple simple, autonomous and interacting componen... more Swarm-based systems, i.e. systems comprising multiple simple, autonomous and interacting components, have become increasingly important. With their decentralised architecture, their ability to self-organise and to exhibit complex emergent behaviour, good scalability and support for inherent fault tolerance due to a high level of redundancy, they offer characteristics which are particularly interesting for the construction of safety-critical systems. At the same time, swarms are notoriously difficult to engineer, to understand and to control. Emergent phenomena are, by definition, irreducible to the properties of the constituents which severely constrains predictability. Especially in safety -critical areas, however, a clear understanding of the future dynamics of the system is indispensable. In this paper we show how agent-based simulation in combination with statistical verification can help to understand and quantify the likelihood of emergent swarm behaviours on different observational levels. We illustrate the idea with a simple case study from the area of swarm robotics.
Studia Informatica Universalis, 10 (3): pp 87-118, 2012
Even though agent-based simulations have been applied successfully to various real-world projects... more Even though agent-based simulations have been applied successfully to various real-world projects, there is still much reluctance to accept them to the same degree as more traditional, equation-based techniques. The main reason for this general scepticism lies in their inherent complexity which makes them difficult to understand, to verify and to validate. We analyse the particular characteristics of agent-based simulations and give recommendations for a model checking-based verification process. Furthermore, we sketch a preliminary verification approach which is based on an iterative, compositional and non-exhaustive model construction process and transient reachability analysis.
Clinical trials are widely adopted for the purpose of evaluating medical research. In particular,... more Clinical trials are widely adopted for the purpose of evaluating medical research. In particular, they are used to study various aspects of medical science, as well as being a vital stage in the deployment of new drug treatments. However, a review of the UK Medical Research Council found that only 31% of trials actually recruited to their planned target, with 30–40% of costs arising during the recruitment phase alone. This is mainly due to the challenges that are involved in designing the clinical trial, and recruiting the required number of patients for this trial within a certain time-frame. Both tasks create significant overhead as they are slow and costly. In response, we propose a multi-agent architecture that helps ease the process of recruiting patients for clinical trials. This paper presents a results from a deployment of the architecture, showing that it succeeds in recruiting a sufficient number of patients for multiple clinical trials. The results also show that recruitment is better for some trials than for others, due to the differing trial requirements and recruitment processes.
Abstract In e-Science experiments, it is vital to record the experimental process for later use s... more Abstract In e-Science experiments, it is vital to record the experimental process for later use such as in interpreting results, verifying that the correct process took place or tracing where data came from. The process that led to some data is called the provenance of that data, and a provenance architecture is the software architecture for a system that will provide the necessary functionality to record, store and use process documentation to determine the provenance of data items.
Abstract Scientific workflows are becoming a valuable tool for scientists to capture and automate... more Abstract Scientific workflows are becoming a valuable tool for scientists to capture and automate e-Science procedures. Their success brings the opportunity to publish, share, reuse and re-purpose this explicitly captured knowledge. Within the equation image Grid project, we have identified key resources that can be shared including complete workflows, fragments of workflows and constituent services.
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This paper presents MC2MABS, a Monte Carlo Model Checker for Multiagent-Based Simulations. It incorporates the idea of statistical runtime verification, a combination of statistical model checking and runtime verification, and is tailored to the approximate verification of large-scale agent-based simulations. We provide a description of the underlying theory together with design decisions, an architectural overview, and implementation details. The performance of MC2MABS in terms of both runtime consumption and memory allocation is evaluated against a set of example properties.
With different observational levels, traces produced by agent-based simulations have an inherently hierarchical nature which complicates the structure and manipulation of obligations significantly. However, it turns out that this problem is general enough to be dealt with in an abstract, language-independent way.
In this paper, we provide a general framework for the monitoring of hierarchical traces. It introduces different types of obligations and appropriate manipulation procedures along with minimal requirements that a property specification language needs to satisfy in order to be monitorable. We provide a full formalisation of the framework and an example implementation of a subset in Haskell.
which we used in a range of experiments to verify properties of large scale models whose complexity prevents them from being amenable to conventional explicit or symbolic model checking.
This paper presents MC2MABS, a Monte Carlo Model Checker for Multiagent-Based Simulations. It incorporates the idea of statistical runtime verification, a combination of statistical model checking and runtime verification, and is tailored to the approximate verification of large-scale agent-based simulations. We provide a description of the underlying theory together with design decisions, an architectural overview, and implementation details. The performance of MC2MABS in terms of both runtime consumption and memory allocation is evaluated against a set of example properties.
With different observational levels, traces produced by agent-based simulations have an inherently hierarchical nature which complicates the structure and manipulation of obligations significantly. However, it turns out that this problem is general enough to be dealt with in an abstract, language-independent way.
In this paper, we provide a general framework for the monitoring of hierarchical traces. It introduces different types of obligations and appropriate manipulation procedures along with minimal requirements that a property specification language needs to satisfy in order to be monitorable. We provide a full formalisation of the framework and an example implementation of a subset in Haskell.
which we used in a range of experiments to verify properties of large scale models whose complexity prevents them from being amenable to conventional explicit or symbolic model checking.