A relational production system (rps) is a general purpose, formal information processing model developed to support research in artificial intelligence and related areas where a conjunction of predicate calculus literals is a convenient state description language. Rps maintains a strong analogy with type O string grammars. It consists of a “situation”, which is a conjunction of literals, and an unordered set of “relational productions”, analogous to type O string productions. These productions cause the replacement of a subset of literals in the situation by other literals, just as type O string productions cause the replacement of substrings by other substrings. Predictably, this system resembles the more empirical, existing knowledge representation systems, particularly STRIPS, while maintaining a mathematical precision and simplicity which allows proof of useful results.

There are a number of transportation applications that require the use of a heuristic shortest path algorithm rather than one of the standard, optimal algorithms. This is primarily due to the requirements of some transportation applications where shortest paths need to be quickly identified either because an immediate response is required (e.g., in-vehicle route guidance systems) or because the shortest paths need to be recalculated repeatedly (e.g., vehicle routing and scheduling). For this reason a number of heuristic approaches have been advocated for decreasing the computation time of the shortest path algorithm. This paper presents a survey review of various heuristic shortest path algorithms that have been developed in the past. The goal is to identify the main features of different heuristic strategies, develop a unifying classification framework, and summarize relevant computational experience.

This paper analyzes the complexity of heuristic search algorithms, i.e. algorithms which find the shortest path in a graph by using an estimate to guide the search. In particular, algorithm A∗, due to Hart, Nilsson and Raphael, is shown to require O(2N) steps, in the worst case, for searching a graph with N nodes, if the so called “consistency assumption” does not hold for the estimate. Furthermore, a new search algorithm is presented which runs in O(N2) steps in the worst case and which never requires more steps than A∗.

This paper describes krl, a Knowledge Representation Language designed for use in understander systems. It outlines both the general concepts which underlie our research and the details of KRL-0, an experimental implementation of some of these concepts. These forms provide a variety of ways to express the logical structure of the knowledge, in order to give flexibility in associating procedures (for memory and reasoning) with specific pieces of knowledge, and to control the relative accessibility of different facts and descriptions. The formalism for declarative knowledge is based on structured conceptual objects with associated descriptions. These objects form a network of memory units with several different sorts of linkages, each having well-specified implications for the retrieval process.

Cutting-edge and "big-picture" in perspective, this popular introduction to cognitive development focuses on both the fascinating nature of children's thinking and the excitement and change in work in this area. Using an integrated topical approach, it explores the developmental aspects of social cognition, perception, memory, and language. Theoretically balanced, it considers the full spectrum of approaches--from Piaget's developmental stages, to information-processing (including connectionism), dynamic systems, contextual, theory-change, neo-Piagetian, evolutionary, neuroscience, and constraint approaches.

Diagrams are of substantial benefit to WHISPER, a computer problem-solving system, In testing the stability of a "blocks world" structure and predicting the event sequences which occur as that structure collapses. WHISPER'S components include a high level reasoner which knows some qualitative aspects of Physics, a simulated parallel processing "retina" to "look at" Its diagrams, and a set of re-drawing procedures for modifying these diagrams. Diagrams enable WHISPER to work with objects of arbitrary shape, detect collisions and other motion discontinuities, discover coincidental alignments, and easily update its world model after a state change.

This note describes LIFER, a practical facility for creating natural language interfaces to other computer software. Emphasizing human engineering, LIFER has bundled natural language specification and parsing technology into one convenient package.

The ROBOT project is to develop an English interface to data base management systems (DBMS). Our approach calls for mapping English language questions into a language of data base semantics that is independent of the content of the data base. In this way we work in a "movable miniworld" since the semantic primitives are fixed, but the area of discourse varies with the content of the data base. Thus, by making only dictionary changes we have interfaced a student grade file and employee file and a data dictionary.

Torres D. D and Rocco S. C A comparative study for assessing the reliability of complex networks using rules extracted from different machine learning approaches Proceedings of the 18th Australian Joint conference on Advances in Artificial Intelligence, (954-958)

Programs in the artificial intelligence domain impose unusual requirements on control structures. Production systems are a control structure with promising attributes for building, generally intelligent systems with large knowledge bases. This paper presents examples to illustrate the unusual position taken by production systems on a number of control and pattern-matching issues. Examples are chosen to illustrate certain powerful features and to provide critical tests which might be used to evaluate the effectiveness of new designs.