bluuebunny/crossref_metadata_2025_split huggingface dataset:
A dynamic, nonstationary inventory problem for a price/quantity setting firm
Authors: Thowsen Gunnar T. 
Published: May 2007

AbstractA dynamic and nonstationary model is formulated for a firm which attempts to minimize total expected costs over a finite planning horizon. The control variables are price and production. The price p and the demand ζ are linked through the relationship ζ = g(p) + η, where g(p) is the riskless demand curve and η is a random variable. The general model allows for proportional ordering costs, convex holding and stockout costs, downward sloping riskless demand curve, backlogging, partial backlogging, lost sales, partial spoilage of inventory, and two modes of collecting revenue. Sufficient conditions are developed for this problem to have an optimal policy which resembles the single critical number policy known from stochastic inventory theory. It is also shown what set of parameters will satisfy these sufficiency conditions.
A special case of the 3 × n flow shop problem
Authors: Burns Fennell , Rooker John 
Published: May 2007

AbstractJohnson [2] in 1954 solved the two machine flow shop problem by giving an argument for a sufficient condition of optimality and by stating an efficient algorithm which produces a solution via satisfaction of the sufficient condition. Moreover, Johnson solved two special cases of the corresponding three machine flow shop problem. Since that time, six other special cases have been solved, two contributed by Arthanari and Mukhopadhyay [1], two by Smith, Panwalkar, and Dudek [3], and two of a different nature by Szwarc [5]. This paper contributes an extension to one of the classes described by Szwarc.
Allocation of resources to offensive strategic weapon systems
Authors: Shere Kenneth D. , Wingate John W. 
Published: May 2007

AbstractIn this paper a very versatile game model is developed for use in the long range planning of our strategic force posture. This highly aggregate model yields optimal force mixes for the triad (land‐ and sea‐based missile systems and bombers) under a variety of constraints. The model described here is a survivability model; however, it is shown how the model can still be used as a measure of overall system effectiveness. Constraints imposed on the problem include both SALT and budget limitations.
Selection of the optimal setup policy
Authors: Ladany Shaul P. , Bedi Dina N. 
Published: May 2007

AbstractA model is developed taking into consideration all the costs (namely cost of sampling, cost of not detecting a change in the process, cost of a false indication of change, and the cost of readjusting detected changes) incurred when a production process, using an unscheduled setup policy, utilizes fraction‐defective control charts to control current production. The model is based on the concept of the expected time between detection of changes calling for setups. It is shown that the combination of unscheduled setups and control charts can be utilized in an optimal way if those combinations of sample size, sampling interval, and extent of control limits from process average are used that provide the minimum expected total cost per unit of time.The costs of a production process that uses unscheduled setups in conjunction with the appropriate optimal control charts are compared to the costs of a production process that uses scheduled setups at optimum intervals in conjunction with its appropriate control charts.This comparison indicates the criteria for selecting production processes with scheduled setups using optimal setup intervals over unscheduled setups. Suggestions are made to evaluate the optimal process setup strategy and the accompanying optimal decision parameters, for any specific cost data, by use of computer enumeration. A numerical example for assumed cost and process data is provided.
The bilinear programming problem
Authors: Vaish Harish , Shetty C. M. 
Published: May 2007

AbstractThe paper deals with bilinear programming problems and develops a finite algorithm using the “piecewise strategy” for large‐scale systems. It consists of systematically generating a sequence of expanding polytopes with the global optimum within each polytope being known. The procedure then stops when the final polytope contains the feasible region.
MARKOVIAN DETERIORATION WITH UNCERTAIN INFORMATION — A MORE GENERAL MODEL
Authors: Rosenfield Donald 
Published: May 2007

AbstractA model of a deteriorating system with imperfect information is considered. The structures appropriate for such a model include failing machinery and depleted inventory systems. In an effort to add a new dimension to such models, it is assumed that the operator must pay an inspection cost to determine the precise state of the system. At the start of every time period, the operator is faced with three choices: repair, no action, or inspection. Under fairly general assumptions, the optimal policy for repair is found to be straightforward and intuitive. This result has two important areas of application.
Flowshop sequencing problem with ordered processing time matrices: A general case
Authors: Smith M. L. , Panwalkar S. S. , Dudek R. A. 
Published: May 2007

AbstractThe ordered matrix flow shop problem with no passing of jobs is considered. In an earlier paper, the authors have considered a special case of the problem and have proposed a simple and efficient algorithm that finds a sequence with minimum makespan for a special problem. This paper considers a more general case. This technique is shown to be considerably more efficient than are existing methods for the conventional flow shop problems.
Mean square invariant forecasters for the weibull distribution
Authors: Tiago Oliveira J. De , Littauer Sebastian B. 
Published: May 2007

AbstractMany techniques of forecasting are based upon extrapolation from time series. While such techniques have useful applications, they entail strong assumptions which are not explicitly enunciated. Furthermore, the time series approach not based on an indigenous forecast principle. The first attack from the present point of view was initiated by S. S. Wilks.Of particular interest over a wide range of operational situations in reliability, for example, is the behavior of the extremes of the Weibull and Gumbel distributions. Here we formulate forecasters for the minima of various forms of these distributions. The forecasters are determined for minimization in mean square of the distance. From n original observations the forecaster provides the minimum of the next m observations when the original distribution is maintained.For each of the forecasters developed, tables of efficiency have been calculated and included in the appendix. An explicit example has been included for one of the forecasters. Its performance has been demonstrated by the use of Monte Carlo technique. The results indicate that the forecaster can be used in practice with satisfactory results.
A comparison of several attribute sampling plans
Authors: Gelfand Alan E. 
Published: May 2007

AbstractThe purpose of this research is to examine several types of procedures for attribute sampling inspection‐the widely used Military Standard 105D plans [8], the lesser known Double Zero plans as developed by Ellis [4] and the Narrow Limit gaging plans of Ott and Mundel [9]. Each of the procedures is described with an effort made to illuminate their more subtle features. Then the plans are compared, whence it is revealed that (i) Narrow Limit gaging plans have a serious weakness in comparison to the others and (ii) Double Zero plans tend to be essentially conservative, but that sufficiently tight Military Standard 105D plans can be selected to achieve comparable performance in all ways.
(R.Q) inventory problem with unknown mean demand and learning
Authors: Kaplan Alan J. 
Published: May 2007

AbstractWe address a single product, continuous review model with stationary Poisson demand. Such a model has been effectively studied when mean demand is known. However, we are concerned with managing new items for which only a Bayesian prior distribution on the mean is available. As demand occurs, the prior is updated and our control parameters are revised. These include the reorder point (R) and reorder quantity (Q).Deemer, taking a clue from some earlier RAND work, suggested using a model appropriate for known mean, but using a Compound Poisson distribution for demand rather than Poisson to reflect uncertainty about the mean. Brown and Rogers also used this approach but within a periodic review context.In this paper we show how to compute optimum reorder points for a special problem closely related to the problem of real interest. In terms of the real problem, subject to a qualification to be discussed, the reorder points found are upper bounds for the optimum. At the same time, the reorder points found can never exceed those found by the Compound Poisson (Deemer) approach. And they can be smaller than those found when there is no uncertainty about the mean.As a check, the Compound Poisson and proposed approach are compared by simulation.
Joint pricing and ordering policy for exponentially decaying inventory with known demand
Authors: Cohen Morris A. 
Published: May 2007

AbstractThis paper is concerned with the problem of simultaneously setting price and production levels for an exponentially decaying product. Such products suffer a loss in utility which is proportional to the total quantity of stock on hand. A continuous review, deterministic demand model is considered. The optimal ordering decision quantity is derived and its sensitivity to changes in perishability and product price is considered. The joint ordering pricing decision is also computed and consideration of parametric changes of these decisions indicates a non‐monotonic response for optimal price to changes in product decay. Issues of market entry and extensions to a model with shortages are also analyzed.
Probabilistic ideas in heuristic algorithms for solving some scheduling problems
Authors: Gertsbach I. 
Published: May 2007

AbstractHeuristic algorithms for positioning a maximal number of independent units and constructing a schedule with minimal fleet size are proposed. These algorithms consist of two stages: defining the “leading” job and finding an optimal position for it. Decisions on both stages use some special criteria which have a probabilistic interpretation. Some experimental data are given.
Compound distributions with efficient computation in inventory model applications
Authors: Bott Donald L. 
Published: May 2007

AbstractIn an inventory model, the distribution of total units demanded can be considered as a compound distribution arising from the distributions of demand occurrence and individual demand size. Three such compound distributions are considered, where the number of demands is Poisson distributed. The demand size distribution will depend on the observed or desired variance‐to‐mean ratio. An approximation using the gamma distribution is given in terms of the cumulants of the compound distribution for both fixed and stochastic lead times.
A nonconvex max‐min problem
Authors: Falk James E. , Hoffman Karla 
Published: May 2007

AbstractAn algorithm designed to solve a large class of nonconvex max‐min problems is described. Its usefulness and applicability is demonstrated by solving an extension of a recently introduced model which optimally allocates strategic weapon systems. The extended model is shown to be equivalent to a nonconvex mathematical program with an infinite number of constraints, and hence is not solvable by conventional procedures. An example is worked out in detail to illustrate the algorithm.
A model for the determination of optimal interfiring times
Authors: Friedman Yoram 
Published: May 2007

AbstractVarious models of stochastic duels with round dependent hit probabilities have appeared in the literature [1]. However, none of them analyzed the effect interfiring times will have on the hit probability.In this paper we formulate a model for a marksman versus a passive target where the probability of a hit at a given round is a function of the interfiring times.We show how to solve for the optimal interfiring times and prove that under certain assumptions the optimal rate of fire is a non‐decreasing function of the round fired.
A continuous review inventory model with compound poisson demand process and stochastic lead time
Authors: Dirickx Yvo M. I. , Koevoets Danielle 
Published: May 2007

AbstractUsing Markov renewal theory, we derive analytic expressions for the expected average cost associated with (s, S) policies for a continuous review inventory model with a compound Poisson demand process and stochastic lead time, under the (restrictive) assumption that only one order can be outstanding.
Computation of constrained optimum quantities and reorder points for time‐weighted backorder penalties
Authors: Matthews John P. 
Published: May 2007

AbstractThe purpose of this paper and the accompanying tables is to facilitate the calculation of constrained optimum order quantities and reorder points for an inventory control system where the criterion of optimality is the minimization of expected inventory holding, ordering, and time‐weighted backorder costs. The tables provided in the paper allow the identification of the optimal solution when order quantities and/or reorder points are restricted to a set of values which do not include the unconstrained optimal solution.
Numerical investigations on quadratic assignment problems
Authors: Burkard Rainer E. , Stratmann Karl‐Heinz 
Published: May 2007

AbstractThis paper contains a comparative study of the numerical behavior of different algorithms for solving quadratic assignment problems. After the formulation of the problem, branch and bound algorithms are briefly discussed. Then, starting procedures are described and compared by means of numerical results. Modifications of branch and bound procedures for obtaining good suboptimal solutions are treated in the next section. Subsequently, numerical results with the Gaschütz‐Ahrens algorithm are reported. In the last section, exchange algorithms are discussed, and it is pointed out how they can be combined efficiently with the Gaschütz‐Ahrens procedure and the perturbation method. All suboptimal solutions found in the literature could be improved by these combined methods. In the appendix, test examples and the best known solutions are listed.
Novel corrective equations for complete estimation of human tissue lipids after their partial destruction by perchloric acid pre‐treatment: high‐resolution 1H‐NMR‐based study
Authors: Srivastava Niraj Kumar , Pradhan Sunil , Mittal Balraj , Kumar Raj , Pandey Chandra Mani , Gowda G. A. Nagana 
Published: May 2007

AbstractOwing to the small quantity of tissue available in human biopsy specimens, aqueous and lipid components often have to be determined in the same tissue sample. Perchloric acid (PCA) used for the extraction of aqueous metabolites has a deleterious effect on lipid components; the severity of the damage is not known. In this study, human muscle tissue was first treated with PCA to extract aqueous metabolites, and the residue was then used for lipid extraction by conventional methods, i.e. the methods of Folch and Bligh & Dyer and a standardised one using methanol/chloroform (1:3, v/v) used in our laboratory. A 1H‐NMR spectrum was obtained for each lipid extract. Lipid was quantified by measuring the integral area of N+‐(CH3)3 signals of phospholipids (PLs). Triacylglycerol (TG) and cholesterol (CHOL) were quantified using the ‐CH2‐ signals of glycerol and the C18 methyl signal, respectively. This study shows that prior use of PCA caused marked attenuation of TG, PL, and CHOL. This was confirmed by recovery experiments and observation of the direct effect of PCA on the standard lipid components. On the basis of the quantity of lipid lost in each case, three novel equations (with respect to TG, PL, and CHOL) were derived. Application of these equations to lipid quantities estimated in different pathological tissues after PCA pre‐treatment produced values equivalent to those estimated without PCA use. This study conclusively shows that PCA pre‐treatment damages all three lipid moieties, TG, PL, and CHOL. When PCA is used in a fixed ratio to the tissue, the lipid damage is also proportional and correctable by statistically derived equations. These equations will be useful in human biopsy specimens where aqueous and lipid components have to be studied using the same tissue sample because of the small quantity available. Copyright © 2007 John Wiley & Sons, Ltd.
The angiogenic factor thymidine phosphorylase up‐regulates the cell adhesion molecule P‐selectin in human vascular endothelial cells and is associated with P‐selectin expression in breast cancers
Authors: Gunningham SP , Currie MJ , Morrin HR , Tan EY , Turley H , Dachs GU , Watson AI , Frampton C , Robinson BA , Fox SB 
Published: May 2007

AbstractThymidine phosphorylase (TP) is an angiogenic enzyme, catalysing the reversible phosphorylation of thymidine to thymine and 2‐deoxyribose. TP is up‐regulated in neoplasia, being associated with advanced tumour stage, microvessel density and prognosis in several tumour types. Although TP is a non‐mitogenic migratory factor for endothelium, the mechanism by which TP mediates these effects is still unclear. We compared the gene expression profile of endothelial cells grown in vitro in the presence or absence of TP by cDNA microarray analysis. To determine the time‐course of TP angiogenic induction, endothelial cells were stimulated with TP (10 ng/ml) for 5 and 18 h. Gene expression levels of Tie2, angiopoietin (Ang)1 and Ang2, measured by RNase protection assay (RPA), showed maximal alteration at 18 h. cDNA from human umbilical vein endothelial cells (HUVEC) grown for 18 h in the presence or absence of TP (10 ng/ml) was hybridized to a human cDNA cytokine array representing 375 angiogenic genes. Significantly altered expression occurred in 89 human angiogenic genes (72 genes were up‐regulated and 17 down‐regulated). Changes in five genes relevant to vascular remodelling biology (Tie2, nNos, P‐selectin, ephrin‐B1 and TP) were validated in triplicate experiments by real‐time RT–PCR. But only P‐selectin gene expression remained significant. Correlation between P‐selectin and TP was assessed by immunohistochemistry on 161 human breast cancers, using human tissue microarray. Tumour cell TP correlated with tumour cell P‐selectin but not with endothelial cell P‐selectin. These data show that TP stimulates changes in mRNA expression maximally after 18 h culture in vitro. It confirms a role for TP in vascular remodelling involving several classes of genes, including the cell adhesion molecule, P‐selectin. Although confirmation of the role of TP‐mediated cell adhesion molecule (CAM) induction is required; however, this pathway may provide an attractive therapeutic target, since it is likely to affect several important tumour processes, including angiogenesis and metastasis. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Bisphenol containing novel polyimides/glass fiber composites
Authors: Bhuvana S. , Saroja Devi M. 
Published: May 2007

AbstractA new diamine was synthesized using bisphenol‐A and p‐amino benzoic acid. Polyimides I and II were prepared with the diamine and pyromellitic dianhydride/3,3′,4,4′ benzophenone tetracarboxylic acid dianhydride. Bismaleimide (BMI) was synthesized using the same diamine and maleic anhydride. The prepared diamine and polyimides were characterized using FTIR. Thermo gravimetric analysis was used to study the thermal properties of synthesized polyimides and BMI. Woven glass fabric/unidirectional glass fiber‐polyimide/BMI composites were made and their properties (fiber volume fraction, density, tensile, flexural, impact, and hardness) were studied and compared with a few representative carbon fiber polyimide, carbon fiber–epoxy, and glass fiber–epoxy composites. The prepared composites were subjected to thermal aging and moisture absorption and their effects on tensile and flexural properties were studied. POLYM. COMPOS., 28: 372–380, 2007. © 2007 Society of Plastics Engineers
Elastic response of nanocomposite poly(vinylacetate)‐hydroxyapatite with varying particle shape
Authors: Kalfus J. , Jancar J. 
Published: May 2007

AbstractThe mechanisms by which hydroxyapatite nanofiller promotes reinforcement in poly(vinylacetate) matrix is investigated. Hydroxyapatite nanofillers with spherical and platelet particle shape were synthesized. Particle size was in the range from 5 to 60 nm. Filler concentration in composites was limited to maximum of 5 vol% to minimize filler networking. Effect of the nanofiller particle shape on the elastic response of nanocomposite was examined using dynamic‐mechanical thermal spectroscopy. Attempt to interpret the observed phenomena was based on the molecular approach. POLYM. COMPOS., 28: 365–371, 2007. © 2007 Society of Plastics Engineers
Energetic and structural characterization of 2‐R‐3‐methylquinoxaline‐1,4‐dioxides (R = benzoyl or tert‐butoxycarbonyl): experimental and computational studies
Authors: Gomes José R. B. , Sousa Emanuel A. , Gonçalves Jorge M. , Gales Luís , Damas Ana M. , Gomes Paula , Pandey Siddharth , Acree William E. , da Silva Maria D. M. C. Ribeiro 
Published: May 2007

AbstractThe gaseous standard molar enthalpies of formation of two 2‐R‐3‐methylquinoxaline‐1,4‐dioxides (R = benzoyl or tert‐butoxycarbonyl), at T = 298.15 K, were derived using the values for the enthalpies of formation of the compounds in the condensed phase, measured by static bomb combustion calorimetry, and for the enthalpies of sublimation, measured by Knudsen effusion, using a quartz crystal oscillator. The three dimensional structure of 2‐tert‐butoxycarbonyl‐3‐methylquinoxaline‐1,4‐dioxide has been obtained by X‐ray crystallography showing that the two NO bond lengths in this compound are identical. The experimentally determined geometry in the crystal is similar to that obtained in the gas‐phase after computations performed at the B3LYP/6‐311 + G(2d,2p) level of theory. The experimental and computational results reported allow to extend the discussion about the influence of the molecular structure on the dissociation enthalpy of the NO bonds for quinoxaline 1,4‐dioxide derivatives. As found previously, similar NO bond lengths in quinoxaline‐1,4‐dioxide compounds are not linked with NO bonds having the same strength. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of substitution of oxygen by sulfur in the nonleaving group of a carbonate: kinetics of the phenolysis and benzenethiolysis of S‐methyl aryl thiocarbonates
Authors: Castro Enrique A. , Aliaga Margarita , Santos José G. 
Published: May 2007

AbstractThe phenolysis and benzenethiolysis of S‐methyl 4‐nitrophenyl thiocarbonate (1) and S‐methyl 2,4‐dinitrophenyl thiocarbonate (2) in water are studied kinetically. The Brønsted plots (log k
N versus nucleophile basicity) are linear for all reactions. The Brønsted slopes for 1 and 2 are, 0.51 and 0.66 (phenolysis) and 0.55 and 0.70 (benzenethiolysis), respectively. These values suggest a concerted mechanism for these reactions, as found in the corresponding carbonates. Namely, substitution of OMe by SMe in the nonleaving group does not change the mechanism. Copyright © 2007 John Wiley & Sons, Ltd.
Minimum electrophilicity principle in photocycloaddition formation of oxetanes
Authors: Noorizadeh S. 
Published: May 2007

AbstractThe regio‐ and stereoselectivity of some Paternó–Büchi reactions are studied within a density functional framework with B3LYP exchange‐correlation energy functional and 6‐31G** basis set. It is shown that although in most cases the Minimum Polarizability and the Maximum Hardness Principles (MPP and MHP) successfully predict the major oxetane products of these reactions, but in all of the considered reactions, with no exception, the main products have the lesser electrophilicity values than the minor isomers, and therefore the Minimum Electrophilicity Principle (MEP) correctly predicts the most stable stereoisomer of the reaction. Copyright © 2007 John Wiley & Sons, Ltd.