The state of the field of expert systems and knowledge engineering in transmission planning is reviewed. A detailed analysis of the goals, definition, requirements and methodology of transmission planning is presented. Potential benefits of knowledge-based applications in transmission planning are reviewed. This is followed by a thorough review of the area broken down into subareas or important related topics. The conclusions offer a number of suggestions for possible future research and development. Finally, a detailed bibliography divided into subareas is presented.>

A methodology based on the theory of Boolean equations has been developed which permits a unified approach to the analysis and synthesis of combinational logic circuits. The type of circuits covered by the approach includes both the classical loopless combinational networks as well as those that contain closed feedback loops and thus have internally a sequential character. To that end, a general multiple-output circuit represented by a Mealy-type machine is studied using characteristic equations (functions) that describe its internal structure. It is shown how behavioral properties of the circuit are reflected through the sosutions of these equations. Moreover, it is demonstrated that a multiple-output incompletely specified switching function is reaeized if a ≤ relation is satisfied between the corresponding charchteristic functions. This leads to a new unified outlook on functional decomposition as used in modular synthesis procedures. Although the building modules are allowed to be sequential circuits, it is shown under which conditions the feedback loops are redundant with respect to the realization of a given output characteristic function, and thus the existence conditions of nondegenerate combinational circuits with loops are stated.

A method has been investigated for the synthesis of memoryless logical networks using a restricted repertoire of functional modules. The method is based on the reduced general solution to a generalized system of Boolean equations (BE) as applied to the decomposition of Boolean functions. The aim of the synthesis is to obtain the most constrained circuit having at most two levels of gating. The constraints take the form of single input variables or constant logic levels applied to the inputs of the first level gate. This is achieved by assembling a set of constraint equations which are then a part of the generalized system of BE. The method is then tested on some synthesis examples of single and multiple output functions in terms of the NAND and (WOS) modules.

The automated synthesis of TANT combinational networks (Three-level AND-NOT networks with True inputs) is studied using the advantages of Svoboda Boolean Analyzer (SBA) (see Svoboda, 1968). The synthesis procedure consists of (i) calculating the ordinary prime implicants of the given function f using operation Mode I of SBA, (ii) calculation of all generalised prime implicants of f by solving a system of Boolean equations (operation Mode II), (iii) solution of a covering problem using a special Petrick function and operation Mode I of the SBA. The synthesis procedure yields a TANT network containing a minimum number of AND-NOT elements. FORTRAN IV programs have been developed which implement the proposed synthesis method; however, the SBA hardware unit, when available, will prove an efficiency factor in processing time of approximately 104.