14,376 research outputs found
The key node method: a highly-parallel alpha-beta algorithm
Journal ArticleA new parallel formulation of the alpha-beta algorithm for minimax game tree searching is presented. Its chief characteristic is incremental information sharing among subsearch processes in the form of "provisional" node value communication. Such "eager" communication can offer the double benefit of faster search focusing and enhanced parallelism. This effect is particularly advantageous in the prevalent case when static value correlation exists among adjacent nodes. A message-passing formulation of this idea, termed the "Key Node Method", is outlined. Preliminary experimental results for this method are reported, supporting its validity and potential for increased speedup
Speculative parallelism in Intel Cilk Plus
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 37).Certain algorithms can be effectively parallelized at the cost of performing some redundant work. One example is searching an unordered tree graph for a particular node. Each subtree can be searched in parallel by a separate thread. Once a single thread is successful, however, the work of the others is unneeded and should be ended. This type of computation is known as speculative parallelism. Typically, an abort command is provided in the programming language to provide this functionality, but some languages do not. This thesis shows how support for the abort command can be provided as a user-level library. A parallel version of the alpha beta search algorithm demonstrates its effectivenesss.by Ruben Perez.M.Eng
Comparative study of performance of parallel Alpha Beta Pruning for different architectures
Optimization of searching the best possible action depending on various
states like state of environment, system goal etc. has been a major area of
study in computer systems. In any search algorithm, searching best possible
solution from the pool of every possibility known can lead to the construction
of the whole state search space popularly called as minimax algorithm. This may
lead to a impractical time complexities which may not be suitable for real time
searching operations. One of the practical solution for the reduction in
computational time is Alpha Beta pruning. Instead of searching for the whole
state space, we prune the unnecessary branches, which helps reduce the time by
significant amount. This paper focuses on the various possible implementations
of the Alpha Beta pruning algorithms and gives an insight of what algorithm can
be used for parallelism. Various studies have been conducted on how to make
Alpha Beta pruning faster. Parallelizing Alpha Beta pruning for the GPUs
specific architectures like mesh(CUDA) etc. or shared memory model(OpenMP)
helps in the reduction of the computational time. This paper studies the
comparison between sequential and different parallel forms of Alpha Beta
pruning and their respective efficiency for the chess game as an application.Comment: 5 pages, 6 figures, Accepted in 2019 IEEE 9th International Advance
Computing Conference(IEEE Xplore
Cost-Sensitive Classification: Empirical Evaluation of a Hybrid Genetic Decision Tree Induction Algorithm
This paper introduces ICET, a new algorithm for cost-sensitive
classification. ICET uses a genetic algorithm to evolve a population of biases
for a decision tree induction algorithm. The fitness function of the genetic
algorithm is the average cost of classification when using the decision tree,
including both the costs of tests (features, measurements) and the costs of
classification errors. ICET is compared here with three other algorithms for
cost-sensitive classification - EG2, CS-ID3, and IDX - and also with C4.5,
which classifies without regard to cost. The five algorithms are evaluated
empirically on five real-world medical datasets. Three sets of experiments are
performed. The first set examines the baseline performance of the five
algorithms on the five datasets and establishes that ICET performs
significantly better than its competitors. The second set tests the robustness
of ICET under a variety of conditions and shows that ICET maintains its
advantage. The third set looks at ICET's search in bias space and discovers a
way to improve the search.Comment: See http://www.jair.org/ for any accompanying file
Setting Parameters by Example
We introduce a class of "inverse parametric optimization" problems, in which
one is given both a parametric optimization problem and a desired optimal
solution; the task is to determine parameter values that lead to the given
solution. We describe algorithms for solving such problems for minimum spanning
trees, shortest paths, and other "optimal subgraph" problems, and discuss
applications in multicast routing, vehicle path planning, resource allocation,
and board game programming.Comment: 13 pages, 3 figures. To be presented at 40th IEEE Symp. Foundations
of Computer Science (FOCS '99
Solution trees as a basis for game tree search
A game tree algorithm is an algorithm computing the minimax value of the root of a game tree. Many algorithms use the notion of establishing proofs that this value lies above or below some boundary value. We show that this amounts to the construction of a solution tree. We discuss the role of solution trees and critical trees in the following algorithms: Principal Variation Search, alpha-beta, and SSS-2. A general procedure for the
construction of a solution tree, based on alpha-beta and Null-Window-Search, is given.
Furthermore two new examples of solution tree-based algorithms are presented, that surpass
alpha-beta, i.e., never visit more nodes than alpha-beta, and often less
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