We extend a planning algorithm to cover simple forms of arithmetics. The operator preconditions can refer to the values of numeric variables and the operator postconditions can modify the values of numeric variables. The basis planning algorithm is based on techniques from propositional satissability testing and does not restrict to forward or backward chaining. When several operations aaect a ...

Quantitative QFD (Q2FD) is an extension of conventional Quality Function Deployment (QFD). Q2FD incorporates quantitative requirements decomposition models into the QFD framework. It also rearranges conventional QFD matrices to facilitate quantitative capture and both forward and backward chaining of performance values. The rearranged matrices also allows full representation of QFD matrices wit...

In this paper we introduce two improvements to the method of verification of hybrid systems by constraint propagation based abstraction refinement that we introduced earlier. The first improvement improves the recursive propagation of reachability information over the regions constituting the abstraction, and the second improvement reasons backward from the set of unsafe states, instead of reas...

Most expert system designers suffer from knowledge acquisition complications. Expert system shells contain facilities that can simplify knowledge acquisition to make domain experts themselves responsible for knowledge structuring and encoding. The aim of this research is to develop an Arabic Expert System Shell (AESS) for diagnosing diseases based on natural language. The suggested AESS mainly ...

Verifying the implementation of concurrent objects essentially proves the fine-grained implementation of object methods refines the corresponding abstract atomic operations. To simplify the specifications and proofs, we usually need auxiliary history and prophecy variables to record events occur historically and to predict the occurrence of certain events, respectively. Although the meaning of ...

Graphplan has attracted considerable interest because of its extremely high performance, but the algorithm's inability to handle action representations more expressive than STRIPS is a major limitation. In particular, extending Graphplan to handle conditional e ects is a surprisingly subtle enterprise. In this paper, we describe the space of possible alternatives, and then concentrate on one pa...

Temporality and uncertainty are important features of many real world systems. Solving problems in such systems requires the use of formal mechanism such as logic systems, statistical methods or other reasoning and decision-making methods. In this paper, we propose a linguistic truth-valued temporal reasoning formalism to enable the management of both features concurrently using a linguistic tr...

Since its introduction, the Event Calculus (EC) has been recognized for being an excellent framework to reason about time and events, and it has been applied to a variety of domains. However, its use inside logic-based frameworks has been mainly a-posteriori, based on specific queries and backward reasoning. This has somehow limited its applicability in dynamic environments. We fill this gap by...

The paper describes a question answering system for German called InSicht. All documents in the system are analyzed by a syntactico-semantic parser in order to represent each document sentence by a semantic network (in the MultiNet formalism) or a partial semantic network (if only a parse in chunk mode succeeds). A question sent to InSicht is parsed yielding its semantic network representation ...

The techniques of propositional analysis are used to examine the protocols of seven cardiologists in a task involving the diognosis of a case of acute bocterial endocarditis and an explonotion of its underlying pathophysiology. It is shown that the explanations of physicians making an accurate diagnosis can be accounted for in terms of a model consisting of pure forword reasoning through a netw...