Showing papers in "Operations Research Letters in 2004"

TL;DR: An (1-e^-^1)-approximation algorithm for maximizing a nondecreasing submodular set function subject to a knapsack constraint is obtained and requires O(n^5) function value computations.

TL;DR: This work explicitly characterize the robust counterpart of a linear programming problem with uncertainty set described by an arbitrary norm as well as providing guarantees for constraint violation under probabilistic models that allow arbitrary dependencies in the distribution of the uncertain coefficients.

TL;DR: An O(mn) algorithm is presented to determine whether a graph G with m edges and n vertices has an odd cycle transversal of order at most k, for any fixed k, and an algorithm is obtained that determines a graph has a half integral packing of odd cycles of weight k.

TL;DR: Morphologic structures that confirm the presence of bacterial biofilms were identified on the sinus mucosa of patients infected with Pseudomonas aeruginosa, a known biofilm former, which may explain the recalcitrant nature of some forms of chronic sinusitis.

TL;DR: It is shown that the two formulations without additional binary variables have the same LP bounds as those of the corresponding formulations with binary variables and therefore are preferable for efficient computation.

TL;DR: Improved algorithms for graph colouring and computing the chromatic number of a graph are constructed by giving tight upper bounds on the number of maximal independent sets of size k in graphs with n vertices.

TL;DR: This work considers the natural relaxation of 2KP given by the one-dimensional KP with item weights equal to the rectangle areas, and presents and compares computationally four exact algorithms based on the above relaxation, showing their effectiveness.

TL;DR: A branch and bound algorithm for robust shortest path problems on interval digraphs, where intervals represent uncertainty about real costs and a robust path is not too far from the shortest path for each possible configuration of the arc costs.

TL;DR: CPP for connected speech is a more valid objective measure of hoarseness than jitter, shimmer or CPP for sustained vowels and that perception ofHoarseness may be most accurate in connected speech, rather than isolated vowels.

TL;DR: In this paper, a constant factor approximation algorithm for covering the nodes of a graph using trees (rooted or unrooted) under the objective function of minimizing the weight of the maximum weight tree, subject to an upper bound on the number of trees used.

TL;DR: An easier proof of the known result that the car sequencing problem is NP-hard is given, and it is pointed out that it isNP-hard in the strong sense.

TL;DR: Patients with comorbid disease are at risk for having increased vertigo, anxiety, and disequilibrium compared to other patients.

TL;DR: Although it is still unclear whether basal cochlear trauma influences apical co chlear function or not, adapted surgical procedures and no forceful insertion maneuvers should be used when performing coChlear implantations with hearing preservation.

TL;DR: It is shown that straightforward extensions of Smith's ratio rule yield smaller competitive ratios than the previously best-known deterministic on-line algorithms.

TL;DR: For the single-machine total weighted tardiness scheduling problem, an enhanced dynasearch neighborhood obtained by the generalized pairwise interchange (GPI) operators is developed and a fast search procedure using also elimination criteria is developed.

TL;DR: This work considers the reduction of multi-quadratic 0-1 programming problems to linear mixed 0-2 programming problems, where the number of additional continuous variables is O(kn) (n is the numberof initial 0- 1 variables and k is thenumber of quadratic constraints).

TL;DR: A thorough history and physical examination, tuberculin test, staining for acid-fast bacilli, radiologic examination, fine-needle aspiration and PCR will be instrumental in arriving at an early diagnosis early institution of treatment before a final diagnosis can be made by biopsy and culture.

TL;DR: Why the distinctions between exponential-type and power-type tails are surprisingly difficult for popular methods in the literature is explained, and why particularly large samples are needed for clear discrimination.

TL;DR: The patients encountered patients who had their static direction-changing positional nystagmus canceled at about 20–30° yaw head rotation from the supine position, which was thought to occur due to a ‘heavy cupula’ or ‘light cupula' which may be determined by the specific gravity of its endolymph.

TL;DR: New lower bounds for the capacitated lot sizing problem are presented, applying decomposition to the network reformulation and a comparison to other lower bounds is presented.

TL;DR: It is shown that the problem is NP-complete, settling the conjecture of Kouvelis and Yu, and that it remains so for complete graphs or when the intervals are all [0,1].

TL;DR: For an inventory control problem in which the purchasing cost changes, it is shown that an order up to policy is optimal and conditions under which the optimal up to levels are monotonically ordered are determined.

TL;DR: CDDP toxicity generates reactive radical species in the SV, which causes mitochondrial membrane permeabilization leading to apoptosis of marginal cells, indicating a caspase-dependent, mitochondrion-mediated apoptotic pathway in marginal cells.

TL;DR: This paper shows that the unbounded single machine parallel batch scheduling problem with family jobs and release dates to minimize makespan is strongly NP-hard, and gives an O(n(n/m+1)m) time dynamic programming algorithm and a polynomial-time approximation scheme for the problem.

TL;DR: This work constructed families of TSP instances with n cities for which the nearest neighbor rule yields a tour-length that is a factor @W(logn) above the length of the optimal tour.

TL;DR: The Euler algorithm for Laplace transform inversion can be extended to functions defined on the entire real line, if they have specific decay features, especially when inverting Laplace transforms of the option price in the logarithm of the strike.

TL;DR: A lifted version of the ''jump'' inequalities introduced by Dahl is presented and it is shown that this class of inequalities subsumes inequalities contained in the complete linear description for the case H=3 as well as a large class of facet defining inequalities for the cases H=4.

TL;DR: It is shown that the resulting allocation of flows in an electricity network to particular generators and loads is equal to the Shapley value of an equivalent co-operative game.

TL;DR: The identification of tiny microscopic foci of spread of tumor in regional nodes by more sophisticated techniques by more exhaustive pathologic sampling techniques will reliably yield a greater incidence of positive cervical lymph nodes (‘micrometastases’) than do conventional pathologic techniques.

TL;DR: This paper implemented a program using exact rational arithmetic to compute proofs for the feasibility and optimality of an LP solution and reports the exact optimal objective values for all NETLIB problems.