Abstracts 173

field of artificial intelligence provides two major approaches to the problem of knowledge engineering - expert systems and neural networks. Harnessing the power of flw.se two techniques in a hybrid, cooperating system holds great promise.

and backward inference patterns, which correspond to modus ponens and modus tollens respectively, in two- value logic, are formulated. Various dependency assumptions for binary connectives are also considered.

157 Evidence Theory and Uncertainty Reasoning in Multi-Value Logic E.S. Lee, Qing Zhu, pp 397-402

An.approx'.unate reasoning proeadure is l~3posed, b.ased on mulUvatuea logic ano t~empster-~naxer evlaence reasoning. In formulating this reasoning procedure, a Lukasiewicz implication operator is used. Both forward

158 Categories Fuz and Fuzzy Semantics E.S. Lee, Xue-hal Yuan, pp 403-408

Although setH is not a Topos, subcategory Fuz of SetH can make a WTopos because Fuz has two special objects - Middle Object and WSC. By the use of WTopos Fuz, the fuzzy logic operations and a fuzzy power set of the fuzzy set (A, a) can be obtained naturally, and a new Semantics - Fuzzy Semantics - is introduced logicatly.

Abstracts in this section are from papers presented at:

IFAC WORKSHOP ON A COST EFFECTIVE USE OF COMPUTER AIDED TECHNOLOGIES AND INTEGRATION METHODS IN SMALL AND MEDIUM SIZED COMPANIES

Vienna, Austria, 7-8 September 1992

FuU papers appear in the Postpfint volume to which the page numbers relate, published by IFAC and available from Pergamon Press.

(ISBN: 0 08 042061 3)

*revised version published in Control Engineering Practice Vol.l No.6

159 CIM for Small and Medium Sized Companies P. Kopacek, M. Zauner, pp 1-6

A low-cost modular CIM concept has been developed especially for small and mediom-sized companies, and tested in a pilot project in a company producing welding transformers. This concept is based on a network of PCs (operating system MS-DOS) and a database computer (operating system UNIX). The realization is accomplished by using the C-programming language, Informix database and Informix-SQL as database query language, to create the custom applicatic~s with database management. With these tools, the structure of a relational database and the ANSI-standard Structured Query Language are provided. This concept is described and an application example is discussed, with special emphasis on problems of information techniques.

160 The GRAI Integrated Method: A Technlco- Economical Methodology to Design Manufacturing Systems* B. Vallespir, C. Merle, G. Doumeingts, pp 7-12

Menaging manufacturing taking in account objectives coming from commercial constraints such as flexibility, quality, etc., makes today's industrial systems tremendously complex. Thus, designing such industrial systems leads to the use of structured methods to get a system finally working as expected at the beginning of the

roject. Many methods are currently proposed. However, ey propose no tool to evaluate, during the project, the

technico-economic opportunities of the future system. The purpose of this paper is to present an integrated methodology to design CIM systems including a technico-

economic tool supporting design choices in order to improve manufacturing system performance.

161 The Impact of a Computer Integrated Business Environment on the Operations of a Medium Sized Engineering Company* C.R. Chatwin, A.S. Tsiotslas, B.F. Scott, pp 13-18

This paper reports on a successful stepwise CINI implementation adopted by a Scottish engineering company producing mechanical actuation systems. Over a three-year period the company embarked on a low cost, phased implementation of software and hardware systems that exploit a database to integrate its design, manufacturing and business operations. The company's investments were based on an assessment of its current and planned product range, existing and planned manufacturing facilities, the scale of its operations and business objectives. The impact of this technological change on the business operations of the company and its influence on the evolution of its product range are discussed.

162 A Low Cost Control Structure for Flexible Production Lines with Multitask Workcelis Th. Borangui, A. Hossu, pp 19-23

The paper describes a flow-type production line for can filling, which can be utilized in both the petrochemical and the food industries. A parallel producuon structure with multitask workstations is proposed. The paper proposes a hierarchical control configuration. At the local level, programmable logic controllers are used. Manufacturing is