Elham Sahebkar Khorasani

An inference engine toolkit for computing with words

Computing with Words is an emerging paradigm in knowledge representation and information processing. It provides a mathematical model to represent the meaning of imprecise words and phrases in natural language and introduces advanced techniques to perform reasoning on inexact knowledge. Since its introduction, there have been many studies on computing with words but mostly from the theoretical point of view and the paradigm still lacks sufficient support from the software side. This paper is an attempt to fill this gap by presenting an enhanced inference engine toolkit for supporting computing with words. The scope of the presented toolkit, as opposed to many available fuzzy logic tools, goes beyond simple fuzzy-if-then rules and performs a chain of inferences on complex fuzzy propositions containing fuzzy arithmetics, fuzzy quantifiers, and fuzzy probabilities. The toolkit may be appealing to researchers, practitioners, and educators in knowledge based applications and soft computing as it implements a powerful declarative language which allows users to express their knowledge in a more natural and convenient way and performs a chain of reasoning on imprecise propositions.

CWJess: Implementation of an expert system shell for Computing with Words

Computing with Words (CW) is an emerging paradigm in knowledge representation and information processing. It provides a mathematical model to represent the meaning of imprecise words and phrases in natural language, and to perform reasoning on perceptual knowledge. This paper describes a preliminary extension to Jess, CWJess, which allows reasoning in the framework of Computing with Words (CW). The resulting inference shell significantly enhances the expressiveness and reasoning power of fuzzy expert systems and provides a Java API which allows users to express various types of fuzzy concepts, including: fuzzy graphs, fuzzy relations, fuzzy arithmetic expression, and fuzzy quantified propositions. CWJess is fully integrated with jess and utilizes jess Rete network to perform a chain of reasoning on fuzzy propositions.

A generic mobile agent framework for ambient intelligence

The purpose of this paper is to introduce an innovative framework for implementation of ambient intelligence (AmI) environments. Compared to the existing state-of-the-art approaches, this framework creates a more decentralized and distributed AmI environment. In addition, the proposed approach is not limited to one specific domain, unlike many others. The openness of the presented architecture allows it to support a variety of devices ranged from small-embedded sensors to complex computing facilities. Finally, given that this approach is formulated based on multi-agent standard concepts, it can be easily implemented as add-on for existing software agent platforms to achieve rapid deployment. Implications for the development of this framework and future directions are discussed.

A Reasoning Methodology for CW-Based Question Answering Systems

Question Answering Systems or (QA systems for short) are regarded as the next generation of the current search engines. Instead of returning a list of relevant documents, QA systems find the direct answer to the query posed in natural language. The key difficulty in designing such systems is to perform reasoning on natural language knowledgebase. The theory of Computing with Words (CW), proposed by Zadeh, offers a mathematical tool to formally represent and reason with perceptive information. CW views a proposition in natural language as imposing a soft/hard constraint on an attribute and represents it in form of a generalized constraint . In this paper we develop a reasoning methodology for the restricted domain CW-based QA systems. This methodology takes, as input, the knowledgebase and the query in form of generalized constraints and organizes the knowledge related to the query in a new tree structure, referred to as a constraint propagation tree . The constraint propagation tree generates a plan to find the most relevant answer to the query and allows improving the answer by establishing an information-seeking dialog with user.

An API for generalized constraint language based expert system

Human possess inherent capabilities to store, processes and reason on imprecise information in the form of perceptions in natural language. Generalized theory of uncertainty (GTU) is a methodology for reasoning, representing, and performing computations on such imprecise information. Generalized constraint, the basic data structure in GTU, is used to represent and propagate information. There is no previous attempt to implement this theoretical methodology. This paper reports the implementation of a Java API toolkit for generalized constraint language (GCL) that can be easily expanded for practical applications of GTU in the form of an expert system. Toolkit allows users to express various types of GTU concepts, such as generalized constraint, fuzzy graphs, fuzzy relations, and fuzzy arithmetic expression. Toolkit is fully integrated with Jess (Java Expert System Shell) and utilizes Jess Rete network for deductions on generalized constraints.

Formalization of Generalized Constraint Language: A Crucial Prelude to Computing With Words

The generalized constraint language (GCL), introduced by Zadeh, serves as a basis for computing with words (CW). It provides an agenda to express the imprecise and fuzzy information embedded in natural language and allows reasoning with perceptions. Despite its fundamental role, the definition of GCL has remained informal since its introduction by Zadeh, and to our knowledge, no attempt has been made to formulate a rigorous theoretical framework for GCL. Such formalization is necessary for further theoretical and practical advancement of CW for two important reasons. First, it provides the underlying infrastructure for the development of useful inference patterns based on sound theories. Second, it determines the scope of GCL and hence facilitates the translation of natural language expressions into GCL. This paper is an attempt to step in this direction by providing a formal syntax together with a compositional semantics for GCL. A soundness theorem is defined, and Zadehs deduction rules are proved to be valid in the defined semantics. Furthermore, a discussion is provided on how the proposed language may be used in practice.

Towards an automated reasoning for computing with words

This paper paves the path for the design and implementation of a practical automated reasoning mechanism for computing with words. The presented methodology aims at filling the gap between the raw theory and the implementation of CW paradigm. As part of this methodology, a portion of a formal grammar for Generalized Constraint Language (GCL) as well as a systematic approach for applying the deduction rules are introduced.

An Open-Bisimilarity Based Automated Verification Tool for -Calculus Family of Process Calculi

The complexity of designing concurrent and highly-evolving interactive systems has grown to a point where system verification has become a hurdle. Fortunately, formal verification methods have arrived at the right time. They detect errors, inconsistencies and incompleteness at early development stages of a system formally modeled using a formal specification language. -calculus Milner, 1999 is one such formal language which provides strong mathematical base that can be used for verifying system specifications. But manually verifying the specifications of concurrent systems is a very tedious and error-prone work, especially if the specifications are large. Consequently, an automated verification tool would be essential for efficient system design and development. In addition, formal verification tools are vital ingredient to fully harness the potential of component-based software composition. The authors developed such an automated verification tool which is highly portable and seamlessly integrates with the visualization, reduction and performance evaluation tools introduced Ahmad & Rahimi, 2008; Rahimi, 2006; Rahimi et al., 2001, 2008 to provide a comprehensive tool for designing and analyzing multi process/agent systems. Open-Bisimulation Sangiorgi, 1996 concept is utilized as the theoretical base for the design and implementation of the tool which incorporates an expert system implemented in Java Expert System Shell JESS Friedman-Hill, 2003.

Towards retranslation of fuzzy values in computing with words

Any conceptual computer or computing with words (CW) system is expected to represent its results with a reasonable output, such as a sentence in natural language. A CW system is required to translate the fuzzy values provided as its result into words. This paper explores different similarity measures as well as linguistic approximation methods for generating natural language sentences for CW systems. Methods in both approaches are evaluated through various measures such as fuzziness, specificity, validity, and sigma-count. Evaluation results suggest certain linguistic methods may result in complex and incomprehensible phrases in natural language. They might even include an invalid linguistic term in their linguistic approximation. On the other hand, methods based on similarity measures may result in simpler and more comprehensible linguistic terms but might not be able to select a perfect match.

An Extension to Pi-Calculus for Performance Evaluation

Pi-Calculus is a formal method for describing and analyzing the behavior of large distributed and concurrent systems. Pi-calculus offers a conceptual framework for describing and analyzing the concurrent systems whose configuration may change during the computation. With all the advantages that pi-calculus offers, it does not provide any methods for performance evaluation of the systems described by it; nevertheless performance is a crucial factor that needs to be considered in designing of a multi-process system. Currently, the available tools for pi-calculus are high level language tools that provide facilities for describing and analyzing systems but there is no practical tool on hand for pi-calculus based performance evaluation. In this paper, the performance evaluation is incorporated with pi-calculus by adding performance primitives and associating performance parameters with each action that takes place internally in a system. By using such parameters, the designers can benchmark multi-process systems and compare the performance of different architectures against one another.