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The Computer Revolution in Philosophy
"Computing can change our ways of thinking about many things, mathematics, biology, engineering, administrative procedures, and many more. But my main concern is that it can change our thinking about ourselves: giving us new models, metaphors, and other thinking tools to aid our efforts to fathom the mysteries of the human mind and heart. The new discipline of Artificial Intelligence is the branch of computing most directly concerned with this revolution. By giving us new, deeper, insights into some of our inner processes, it changes our thinking about ourselves. It therefore changes some of our inner processes, and so changes what we are, like all social, technological and intellectual revolutions." This book, published in 1978 by Harvester Press and Humanities Press, has been out of print for many years, and is now online, produced from a scanned in copy of the original, digitised by OCR software and made available in September 2001. Since then a number of notes and corrections have been added. Atlantic Highlands, NJ: Humanities Press.
The heuristic search: An alternative to the alpha-beta minimax procedure
By placing various restrictions on the heuristic estimator it is possible to constrain the heuristic search process to fit specific needs. This paper introduces a new restriction upon the heuristic, called the โbandwidthโ condition, that enables the ordered search to better cope with time and space difficulties. In particular, the effect of error within the heuristic is considered in detail. Beyond this, the bandwidth condition quite naturally allows for the extension of the heuristic search to MIN/MAX trees. The resulting game playing algorithm affords many desirable practical features not found in minimax based techniques, as well as maintaining the theoretical framework of ordered searches.
The efficiency of the alpha-beta search on trees with branch-dependent terminal node scores
An analysis of the efficiency of the alpha-beta algorithm is carried out based on a probabilistic model in which terminal node scores depend on random branch values. Explicit expressions are derived for the expected number of terminal nodes scored for the cases of uniform trees of fanout N and of depths 2 and 3. For trees of depth 2, the expected number is of order O(NHN); for trees of depth 3, the expected number is of order O(N2). An upper bound on the expected number of terminal nodes scored for trees of depth 4 is shown to be no greater than O(N2HN2) and no less than O(N2).
An improved bi-directional heuristic search algorithm
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.
On the complexity of admissible search algorithms
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 Aโ, 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 โconsistency assumptionโ 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 Aโ.
Meta-level knowledge: Overview and applications
"We define the concept of meta-level Knowledge, and illustrate it by briefly reviewing four examples that have been described in detail elsewhere. The examples include applications of the idea to tasks such as transfer of expertise from a domain expert to a program, and the maintenance and use of large Knowledge bases. We explore common themes that arise from these examples, and examine broader implications of the idea, in particular its impact on the design and construction of large programs."IJCAI 5, 920-927
An analysis of alpha-beta pruning
The alpha-beta technique for searching game trees is analyzed, in an attempt to provide some insight into its behavior. The first portion of this paper is an expository presentation of the method together with a proof of its correctness and a historical discussion. The alpha-beta procedure is shown to be optimal in a certain sense, and bounds are obtained for its running time with various kinds of random data.