Recent research shows that SAT (propositional satisfiability) techniques can be employed to build efficient systems to compute answer sets for logic programs. ASSAT and CMODELS are two well-known such systems. they fi...
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In this paper we present a hybrid approach to handwritten symbol recognition based on two different methods and principles. A fuzzy rules based recogniser and a Self-Organizing Map recogniser are combined to form our ...
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the dynamic nature of incident command systems and their requirement for high flexibility raise a challenge to the research and implementation of workflows. the significance of applying formal approaches to the modeli...
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ISBN:
(纸本)354034652X
the dynamic nature of incident command systems and their requirement for high flexibility raise a challenge to the research and implementation of workflows. the significance of applying formal approaches to the modeling and analysis of workflows has been well recognized and several such approaches have been proposed. However, these approaches require users to master considerable knowledge of the particular formalisms, which impacts their application on a larger scale. To address these challenges, we developed an intuitive, yet formal approach to workflow modeling, enactment and validation. In this paper, we further develop a set of theorems to support dynamic modeling, modification and on-the-fly verification of the workflows. A prototype has been implemented to demonstrate the feasibility of the theoretical approach.
the problem of verifying multi-threaded execution against the memory consistency model of a processor is known to be an NP hard problem. However polynomial time algorithms exist that detect almost all failures in such...
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ISBN:
(纸本)354037406X
the problem of verifying multi-threaded execution against the memory consistency model of a processor is known to be an NP hard problem. However polynomial time algorithms exist that detect almost all failures in such execution. these are often used in practice for microprocessor verification. We present a low complexity and fully parallelized algorithm to check program execution against the processor consistency model. In addition our algorithm is general enough to support a number of consistency models without any degradation in performance. An implementation of this algorithm is currently used in practice to verify processors in the post silicon stage for multiple architectures.
Most genetic programming paradigms are population-based and require huge amount of memory. In this paper, we review the Instruction Matrix based Genetic programming which maintains all program components in a instruct...
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Integrity checking is aimed at determining whether an operation execution violates a given integrity constraint. To perform this computation efficiently, several incremental methods have been developed. the main goal ...
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ISBN:
(数字)9783540346531
ISBN:
(纸本)354034652X
Integrity checking is aimed at determining whether an operation execution violates a given integrity constraint. To perform this computation efficiently, several incremental methods have been developed. the main goal of these methods is to consider as few of the entities in an information base as possible, which is generally achieved by reasoning from the structural events that define the effect of the operations. In this paper, we propose a new method for dealing withthe incremental evaluation of the OCL integrity constraints specified in UML conceptual schemas. Since our method works at a conceptual level, its results are useful in efficiently evaluating constraints regardless of the technology platform in which the conceptual schema is to be implemented.
Predicate abstraction is a technique for automatically extracting finite-state abstractions for systems with potentially infinite state space. the fundamental operation in predicate abstraction is to compute the best ...
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ISBN:
(纸本)354037406X
Predicate abstraction is a technique for automatically extracting finite-state abstractions for systems with potentially infinite state space. the fundamental operation in predicate abstraction is to compute the best approximation of a Boolean formula phi over a set of predicates P. In this work, we demonstrate the use for this operation of a decision procedure based on the DPLL(T) framework for SAT Modulo theories (SMT). the new algorithm is based on a careful generation of the set of all satisfying assignments over a set of predicates. It consistently outperforms previous methods by a factor of at least 20, on a diverse set of hardware and software verification benchmarks. We report detailed analysis of the results and the impact of a number of variations of the techniques. We also propose and evaluate a scheme for incremental refinement of approximations for predicate abstraction in the above framework.
We address the verification problem of programs manipulating one-selector linked data structures. We propose a new automated approach for checking safety and termination for these programs. Our approach is based on us...
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ISBN:
(纸本)354037406X
We address the verification problem of programs manipulating one-selector linked data structures. We propose a new automated approach for checking safety and termination for these programs. Our approach is based on using counter automata as accurate abstract models: control states correspond to abstract heap graphs where list segments without sharing are collapsed, and counters are used to keep track of the number of elements in these segments. this allows to apply automatic analysis techniques and tools for counter automata in order to verify list programs. We show the effectiveness of our approach, in particular by verifying automatically termination of some sorting programs.
Atomicity is an important generic specification that assures that a programmer can pretend blocks occur sequentially in any execution. We define a notion of atomicity based on causality. We model the control flow of a...
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ISBN:
(纸本)354037406X
Atomicity is an important generic specification that assures that a programmer can pretend blocks occur sequentially in any execution. We define a notion of atomicity based on causality. We model the control flow of a program withthreads using a Petri net that naturally abstracts data, and faithfully captures the independence and interaction between threads. the causality between events in the partially ordered executions of the Petri net is used to define the notion of causal atomicity. We show that causal atomicity is a robust notion that many correct programs adopt, and show how we can effectively check causal atomicity using Petri net tools based on unfoldings, which exploit the concurrency in the net to yield automatic partial-order reduction in the state-space.
Software applications that exploit implicit programming by demonstration should be able to detect repetitive patterns in user's actions in an autonomous and efficient way. We present a software agent for the detec...
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