Showing papers in "Information Processing Letters in 1987"

TL;DR: It is shown that a polynomial learning algorithm, as defined by Valiant (1984), is obtained whenever there exists aPolynomial-time method of producing, for any sequence of observations, a nearly minimum hypothesis that is consistent with these observations.

TL;DR: It is proved that if the complexity class co -NP is contained in IP[k] for some constant k, then the polynomial-time hierarchy collapses to the second level and if the Graph Isomorphism problem is NP-complete, then this hierarchy collapses.

TL;DR: In the special case of a simple polygon, their algorithm produces the convex hull without first identifying two of the hull vertices, as was re- quired in [2], but the price that the authors pay is the use of a deque instead of a queue.

TL;DR: An efficient snapshot algorithm that needs no control messages and does not require channels to be first-in-first-out and several stable properties can be detected with uncoordinated distributed snapshots are shown.

TL;DR: The direct sum of two term rewriting systems is the union of systems having disjoint sets of function symbols, and it is shown that the direct sum is not terminating, even if these systems are both terminating.

TL;DR: It is proved that the problems of finding maximum and connected maximum k-colorable subgraphs in chordal graphs are polynomially solvable when k is fixed and NP-hard when kIs not fixed.

TL;DR: An old and simple algorithm for garbage collection gives very good results when the physical memory is much larger than the number of reachable cells, and the overhead associated with allocating and collecting cells from the heap can be reduced to less than one instruction per cell by increasing the size of physical memory.

TL;DR: A polynomial algorithm for the b-matching problem differing from the algorithm of Cunningham and Marsh (1979) is presented and an integral solution is obtained which is used as input to Pulleyblank's (1973) b- matching algorithm.

TL;DR: It is shown that deciding if a graph has a VLSI layout with a specified maximum edge length is NP-complete.

TL;DR: Two methods for calculating the weakest specification of each operation on a concrete data type from the specification of the corresponding abstract operation, together with a single simulation relation, which specifies the correspondence between the two types.

TL;DR: Some sufficient conditions are given for the termination of the direct sum of two term-rewriting systems: either no right-hand side of a rule is a variable, or no righthand side contains more occurences of a variable than the corresponding left- hand side.

TL;DR: This paper illustrates how recent advances in graph theory and graph algorithms dramatically alter the situation for classifying problems as decidable in polynomial time by nonconstructively proving only the existence ofPolynomial-time decision algorithms.

TL;DR: It is proved that a large class of distributed tasks cannot be solved in the presence of faulty processors, and the notion of the decision graph of a task is introduced, and it is shown that every problem whose decision graph is disconnected cannot be unsolved by reducing the unsolvability of this problem to the unsoliability of the consensus problem.

TL;DR: It is proved that this result actually follows immeadiately from Yao's theorem, using a simple construction of Ajtai and Ben-Or (1984) to eliminate randomization in bounded-depth Boolean circuits.

TL;DR: It is crucial that any confidence theory to assess the reliability of software through testing be plausible, so the foundations of program sampling are examined in detail and preliminary results include an analysis of partition testing, and suggestions for textual sampling.

TL;DR: It is shown that the presented techniques can increase the number of detectable errors as compared with error detection through data flow analysis alone.

TL;DR: A technique is developed which selectively stores the received messages in order to account for the backward dependencies and which coordinates the checkpoints to eliminate the retransmission dependencies, thus achieving domino-free rollback.

TL;DR: Using regular tree grammars weighted over a semiring, Kleene's theorem is established in the context of formal tree power series.

TL;DR: Methods of combinatorial geometry developed on polygons can be extended, with the same algorithmic complexity, to R 2 surfaces bounded by line segments and arcs of a circle, which is illustrated in robotics by collision-free path finding.

TL;DR: A strongly polynomial algorithm based on a network flow technique, which minimizes the mean weighted execution time loss for an arbitrary number of identical as well as uniform processors.

TL;DR: This work considers the problem of determining whether there exists a straight line that goes through every object in S, and gives an O(n log n γ (n) time algorithm for this problem, where γ(n) is a very slowly growing function of n.

TL;DR: A symmetrical implicit double-ended priority queue implementation, which can be built in linear time, where the smallest and the largest element can be found in constant time, and deleted in logarithmic time.

TL;DR: An algorithm is presented and analysed in the worst case that asymptotically halves the number of comparisons made by the common Heapsort, which usually is referred to as the fastest in-place sorting method, using 1.38n log n − O(n) in the average case.

TL;DR: It is proved that there is afamily of permutations which are computable by a family of NC0 circuits while their inverses are P-hard to compute, and these permutations are one-way from the point of view of parallel computation.

TL;DR: This article proves the IW-completeness of the maximum satisfiability problem for Morn formulas even under strong restrictions on the I-Iom formulas and shows that there exists a polynomial-time algorithm for the corresponding Maximum Satisfiability Problem.

TL;DR: This paper gives an O(n 2) algorithm for computing efficient lower and upper bounds of the rotation distance using the weight sequences introduced in [10], and proves that this rotation induces a lattice structure on binary trees.