The inference rule ✵-resolution was introduced in [18] as a technique for developing an SLD-style query answering procedure for the logic programming subset of annotated logic. This paper explores the properties of ✵-resolution in the general theorem proving setting. In that setting, it is shown to be complete and to admit a linear restriction. Thus ✵-resolution is amenable to depth-first contr...

This year’s TREC 2003 web task incorporated two retrieval tasks into a single set of experiments for Known-Item retrieval. We hypothesized that not all retrieval tasks should use the same retrieval approach when a single search entry point is used. We applied task classifiers on top of traditional web retrieval approaches. Our traditional retrieval is based on fusion of result sets generated by...

We examine the problem of computing multivariate scenarios sets for skewed distributions. Our interest is motivated by the potential use of such sets in the stress testing of insurance companies and banks whose solvency is dependent on changes in a set of financial risk factors. We define multivariate scenario sets based on the notion of half-space depth (HD) and also introduce the notion of ex...

A* with lookahead (AL*) is a variant of A* that performs a cost-bounded DFS lookahead from a node when it is generated. We show that the original version of AL* (AL0) can, in some circumstances, fail to return an optimal solution because of the move pruning it does. We present two new versions, AL1 and ELH , that we prove to always be correct and give conditions in which AL0 is guaranteed to be...

We investigate new approaches for frequent graph-based pattern mining in graph datasets and propose a novel algorithm called gSpan (graph-based Substructure pattern mining), which discovers frequent substructures without candidate generation. gSpan builds a new lexicographic order among graphs, and maps each graph to a unique minimum DFS code as its canonical label. Based on this lexicographic ...

In this paper, we present a new heuristic for orthogonal graph drawings, which creates drawings by performing a depth-first search and placing the nodes in the order they are encountered. This DFS-heuristic works for graphs with arbitrarily high degrees, and particularly well for graphs with maximum degree 3. It yields drawings with at most one bend per edge, and a total number of m−n+1 bends f...

Abs t rac t . The coincidence of the declarative and procedural interpretations of logic programs does not apply to Prolog programs, due to the depth-first left-to-right evaluation strategy of Prolog interpreters. We propose a new semantics for Prolog programs based on a new fourvalued logic. The semantics is based on a new concept of completion analogous to Clark's and it enjoys the nice prope...

This work presents the results obtained from comparing different tree depths in a Genetic Programming Algorithm to create agents that play the Planet Wars game. Three different maximum levels of the tree have been used (3, 7 and Unlimited) and two bots available in the literature, based on human expertise, and optimized by a Genetic Algorithm have been used for training and comparison. Results ...

The goal of model based diagnosis is to iso late causes of anomalous system behavior and recommend cost e ective repair actions In general precomputing optimal repair policies is intractable To date investigators address ing this problem have explored approxima tions that either impose restrictions on the system model such as a single fault assump tion or that compute an immediate best ac tion ...

Let G = (V,E) be an n-vertices m-edges directed graph. Let s ∈ V be any designated source vertex, and let T be an arbitrary reachability tree rooted at s. We address the problem of finding a set of edges E ⊆ E\T of minimum size such that on a failure of any vertex w ∈ V , the set of vertices reachable from s in T ∪ E\{w} is the same as the set of vertices reachable from s in G\{w}. We obtain th...