975 research outputs found
CASP Solutions for Planning in Hybrid Domains
CASP is an extension of ASP that allows for numerical constraints to be added
in the rules. PDDL+ is an extension of the PDDL standard language of automated
planning for modeling mixed discrete-continuous dynamics.
In this paper, we present CASP solutions for dealing with PDDL+ problems,
i.e., encoding from PDDL+ to CASP, and extensions to the algorithm of the EZCSP
CASP solver in order to solve CASP programs arising from PDDL+ domains. An
experimental analysis, performed on well-known linear and non-linear variants
of PDDL+ domains, involving various configurations of the EZCSP solver, other
CASP solvers, and PDDL+ planners, shows the viability of our solution.Comment: Under consideration in Theory and Practice of Logic Programming
(TPLP
Modeling and Analyzing Timed Security Protocols Using Extended Timed CSP
The article of record as published may be found at http://dx.doi.org/10.1109/SSIRI.2010.29Security protocols are hard to design, even under
the assumption of perfect cryptography. This is especially
true when a protocol involves different timing aspects such as
timestamps, timeout, delays and a set of timing constraints.
In this paper, we propose a methodology for modeling and
analyzing security protocols that are aware of timing aspects. We
develop a formalism for modeling security protocols by extending
Timed CSP with the capability of stating complicated timing
behaviors for processes and events. A reasoning mechanism for
the proposed formalism is developed based on Constraint Logic
Programming (CLP). Using the reasoning engine built in CLP,
the authentication properties of timed security protocols are able
to be verified and attacks can be discovered. We demonstrate the
capability of our method by modeling and verifying real-world
security protocols. New approaches of using timing information
to unfold and prevent potential attacks are also presented
Progress in AI Planning Research and Applications
Planning has made significant progress since its inception in the 1970s, in terms both of the efficiency and sophistication of its algorithms and representations and its potential for application to real problems. In this paper we sketch the foundations of planning as a sub-field of Artificial Intelligence and the history of its development over the past three decades. Then some of the recent achievements within the field are discussed and provided some experimental data demonstrating the progress that has been made in the application of general planners to realistic and complex problems. The paper concludes by identifying some of the open issues that remain as important challenges for future research in planning
Towards Symbolic Model-Based Mutation Testing: Combining Reachability and Refinement Checking
Model-based mutation testing uses altered test models to derive test cases
that are able to reveal whether a modelled fault has been implemented. This
requires conformance checking between the original and the mutated model. This
paper presents an approach for symbolic conformance checking of action systems,
which are well-suited to specify reactive systems. We also consider
nondeterminism in our models. Hence, we do not check for equivalence, but for
refinement. We encode the transition relation as well as the conformance
relation as a constraint satisfaction problem and use a constraint solver in
our reachability and refinement checking algorithms. Explicit conformance
checking techniques often face state space explosion. First experimental
evaluations show that our approach has potential to outperform explicit
conformance checkers.Comment: In Proceedings MBT 2012, arXiv:1202.582
Temporal Reasoning Through Automatic Translation of tock-CSP into Timed Automata
In this work, we present an approach for automatic translation of tock-CSP into Timed Automata (TA) for Uppaal to facilitate using Uppaal in reasoning about temporal specifications of tock-CSP models. The process algebra tock-CSP provides textual notations for modelling discrete-time behaviours, with the support of tools for automatic verification. Automatic verification of TA with a graphical notation is supported by Uppaal. The two approaches provide facilities for automatic verification. For instance, liveness requirements are difficult to specify with the constructs of tock-CSP, but they are easy to specify and verify in Uppaal. We have developed a translation technique and a tool based for translating tock-CSP into a network of small TAs for capturing the compositional structure of tock-CSP. For validating the rules, we begin with an experimental approach based on finite approximations to trace sets. Then, we explore using structural induction to establish the correctness
A general implementation framework for tabled CLP
This paper describes a framework to combine tabling evalua- tion and constraint logic programming (TCLP). While this combination has been studied previously from a theoretical point of view and some implementations exist, they either suffer from a lack of efficiency, flex- ibility, or generality, or have inherent limitations with respect to the programs they can execute to completion (either with success or fail- ure). Our framework addresses these issues directly, including the ability to check for answer / call entailment, which allows it to terminate in more cases than other approaches. The proposed framework is experimentally compared with existing solutions in order to provide evidence of the mentioned advantages
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