Most practitioners use a variant of the Alpha-Beta algorithm, a simple depth-first procedure, for searching minimax trees. SSS*, with its best-first search strategy, reportedly offers the potential for more efficient search. However, the complex formulation of the algorithm and its alleged excessive memory requirements preclude its use in practice. For two decades, the search efficiency of “sma...

Artificial Intelligence search algorithms search discrete systems. To apply such algorithms to continuous systems, such systems must first be discretized, i.e. approximated as discrete systems. Action-based discretization requires that both action parameters and action timing be discretized. We focus on the problem of action timing discretization. After describing an -admissible variant of Korf...

In satisficing planning where suboptimal plans are accepted, many planners use greedy best-first search (GBFS). Despite recent advances in automatic heuristic function generation, GBFS often suffers from performance degradation caused by inaccurate state evaluations. Diverse best-first search (DBFS) (Imai and Kishimoto 2011) avoids plateaus of search due to such inaccuracies by occasionally sel...

In this paper, we present a web-based automatic marking system that aims to assist the tutor in assessing the performance of students in interactive exercises related to breadth-first search (BFS) and depth-first search (DFS) algorithms. The system has been tested on a number exercises for BFS and DFS search algorithms and its performance has been compared against that of an expert tutor. The e...

Rare itemsets are important sort of patterns that have a wide range of practical applications, in particular, in analysis of biomedical data. Although mining rare patterns poses specific algorithmic problems, it is yet insufficiently studied. In a previous work, we proposed a levelwise approach for rare itemset mining that traverses the search space bottomup and proceeds in two steps: (1) movin...

We describe Tree Flow, a new technique for visualizing changes to the structure of a hierarchy, and discuss a prototype tool that implements this method. Roughly speaking, Tree Flow works by creating a timeline in which the x-axis corresponds to date information, and the y-axis corresponds to the depth-first ordering of data in a time-varying tree structure. We present several examples of real-...

We propose a method to gradually expand the moves to consider at the nodes of game search trees. The algorithm begins with an iterative deepening search using the minimal set of moves, and if the search does not succeed, iteratively widens the set of possible moves, performing a complete iterative deepening search after each widening. When designing carefully the different sets of possible move...

Suzuki and Niida (Ann. Pure. Appl. Logic, 2015) showed the following results on independent distributions (IDs) on an AND-OR tree, where they took only depth-first algorithms into consideration. (1) Among IDs such that probability of the root having value 0 is fixed as a given r such that 0 < r < 1, if d is a maximizer of cost of the best algorithm then d is an independent and identical distrib...

In this paper, we consider two methods for computing lower cover of elements in closure systems for which we know an implicational basis: intersecting meet-irreducible elements or computing minimal transversals of sets of minimal generators. We provide experimental results on the runtimes for single computations of lower covers and depth-first searches.

We consider the conjecture stating that a matrix with rank o(n) and ones on the main diagonal must contain nonzero entries on a 2 2 submatrix with one entry on the main diagonal. We show that a slightly stronger conjecture implies that an explicit linear transformation cannot be computed by linear size and logarithmic depth circuits. We prove some partial results supporting the conjecture.