bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of completely reduced matrices in solving transportation problems with fixed charges
Authors: Dwyer Paul S. 
Published: May 2007

AbstractThis paper shows how completely reduced matrices can be used in obtaining exact or approximate solutions to transportation problems with fixed charges. It does not treat methods for obtaining reduced matrices, which are available elsewhere, but it does discuss the problem of obtaining a completely reduced matrix, and then a general parametric solution to the primal problem, from any particular solution. Methods for obtaining particular solutions with determinacies of maximum order (solutions for the constant fixed charges problem) are then presented. The paper terminates with a discussion of methods which are useful in obtaining approximations to solutions of fixed charges problems with charges not constant.
Optimal policy for a dynamic multi‐echelon inventory model
Authors: Bessler Stuart A. , Veinott Arthur F. 
Published: May 2007

AbstractA general multiperiod multi‐echelon supply system consisting of n facilities each stocking a single product is studied. At the beginning of a period each facility may order stock from an exogenous source with no delivery lag and proportional ordering costs. During the period the (random) demands at the facilities are satisfied according to a given supply policy that determines to what extent stock may be redistributed from facilities with excess stock to those experiencing shortages. There are storage, shortage, and transportation costs. An ordering policy that minimizes expected costs is sought. If the initial stock is sufficiently small and certain other conditions are fulfilled, it is optimal to order up to a certain base stock level at each facility.The special supply policy in which each facility except facility 1 passes its shortages on to a given lower numbered facility called its direct supplier is examined in some detail. Bounds on the base stock levels are obtained. It is also shown that if the demand distribution at facility j is stochastically smaller (“spread” less) than that at another facility k having the same direct supplier and if certain other conditions are fulfilled, then the optimal base stock level (“virtual” stock out probability) at j is less than (greater than) or equal to that at facility k.
An attack‐defense game with matrix strategies
Authors: Cohen N. D. 
Published: May 2007

AbstractThis paper presents the results and the method of analysis for an attack‐defense game involving allocation of resources. Each player is assumed to have several different types of resources to be divided in optimal fashion among a fixed set of targets. The payoff function of the game is convex.The “No Soft‐Spot” principle of M. Dresher, and the concept of the generalized inverse of a matrix are used to determine optimal strategies for each player and the value of the game.
Alliance games of n‐persons
Authors: Eisenman Richard L. 
Published: May 2007

AbstractA generalization of n‐person games, called “Alliance Games.” is defined. The relations with von Neumann and Morgenstern's games and with Thrall's games in partition function form are shown. The conceptual value of alliance games is discussed, and the mathematical value is illustrated by answering questions which Thrall raised concerning points between partitions.
On queueing systems with variable service capacities
Authors: Yadin M. , Naor P. 
Published: May 2007

AbstractIn some queueing systems the total service capacity utilized at any given time is a variable under the control of a decision maker. Management doctrines are examined which prescribe the actual service capacity as a function of the queue length and the recent history of the system. Steady state probabilities, expected queue lengths and frequencies of change in capacity are evaluated for a wide class of possible control schemes. Optimization procedures are outlined.
Programming the procurement of airlift and sealift forces: A linear programming model for analysis of the least‐cost mix of strategic deployment systems
Authors: Fitzpatrick George R. , Bracken Jerome , O'brien Mary J. , Wentling Lee G. , Whiton Justin C. 
Published: May 2007

AbstractA linear programming model for analyzing the strategic deployment mix of airlift and sealift forces and prepositioning to accomplish the composite requirements of a set of possible contingencies is described in this paper. It solves for the least‐cost mix of deployment means capable of meeting any one of a spectrum of contingencies, or meeting simultaneous contingencies. The model was developed by RAC as part of the U.S. Army's study program and has been used in analyses of deployment systems conducted in support of the U.S. Army, the Joint Chiefs of Staff and the Office of the Secretary of Defense. Results of analyses have influenced the preparation of long‐range plans as well as the formulation of the FY67 Department of Defense budget. The paper gives the background and assumptions of the model, describes the model by means of a simple hypothetical example followed by a selected subset of a complete version, and discusses how the model is used.
On some stocxastic tactical antisubmarine games
Authors: Charnes A. , Schroeder R. G. 
Published: May 2007

AbstractMathematical models of tactical problems in Hntisubmarine Warfare (ASW) are developed. Specifically, a game of pursuit between a hunter‐killer force. player 1, and a possible submarine, player 2 is considered. The game consists of a sequence of moves and terminates when player 2 is tcaught or evades player 1. When the players move they observe the actual tactical configuration of the forces (state) and each player choosa‐s a tactical plan from a finite collection. This joint choice of tactical plans determines an immediate payoff and a transition probability distribution over the states. Hence an expected payoff function is defined, Formally this game is a Terminating Stochastic Game (TSG). Shapley demonstrated the existence of a value and optimal strategies (solution), An iterative technique to approximate the solution to within desired accuracy is proposed. Each iteration of the technique is obtained by solving a set of linear programs. To introduce more realism into the game several variations of the TSG are also considered. One variation is a finite TSG and linear programming techniques are employed to find the solution.
Linear programming and the reliability of multicomponent systems
Authors: Kolesar Peter J. 
Published: May 2007

AbstractSeveral problems in the assignment of parallel redundant components to systems composed of elements subject to failure are considered. In each case the problem is to make an assignment which maximizes the system reliability subject to system constraints. Three distinct problems; are treated. The first is the classical problem of maximizing system reliability under total cost or weight constraints when components are subject to a single type of failure. The second problem deals with components which are subject to two types of failure and minimizes the probability of one mode of system failure subject to a constraint on the probability of the other mode of system failure. The third problem deals with components which may either fail to operate or may operate prematurely. System reliability is maximized subject to a constraint ori system safety.In each case the problem is formulated as an integer linear program. This has an advantage over alternative dynamic programming formulations in that standard algorithms may be employed to obtain numerical results.
Bayes sequential strategies for crossing a field containing absorption points
Authors: Zacks S. 
Published: May 2007

AbstractA sequential decision problem is considered in which N particles have to cross a given field. Two alternative crossing paths are available. An unknown number of absorption points J1 and J2 are planted at each of the crossing paths. The bivariate prior distribution of (J1,J2) is given. If a particle passes close to an absorption point it may survive with probability s, 0 < s < 1. If a particle is absorbed, both the particle and the absorption point are ruined. There is no replacement of ruined absorption points. All absorption points act independently. The particles crciss the field in a consecutive order, and a crossing path can be chosen for each particle. The objective is to maximize the expected number of survivors. The Bayes sequential procedure is characterized. The csmditions under which the Bayes strategy is determined by the maximal posterior survival probabilities are specified.
A deterministic inventory model for reparable items
Authors: Schrady David A. 
Published: May 2007

AbstractA reparable inventory system has two distinct inventories within it—the inventory of items ready‐for‐issue and the inventory of carcasses available for repair. A reparable item is usually rebuilt upon failure, but the scrap rate in the repair process is generally positive. Consequently, new items must be procured from time to time to replace those item: which were scrapped. The ready‐for‐issue inventory has two input sources—procurement and repair, This paper develops a deterministic inbentory model for the reparable inventory system, and determines the optimal procurement and repair quantities.
A comparison of usage data among types of aircraft
Authors: Haber Sheldon E. 
Published: May 2007

AbstractIt has long been an accepted proposition that base level usage df technical repair items for aircraft is related to program elements. The program element most often cited in this connection is flying hours. Evidence of this relationship on a line item basis, however, has been sparse. This study suggests that although the supposed relation is intuitively plausible, for most line items it cannot be effectively utilized in projecting base level requirements. The basis of this conclusion is an analysis of demand characteristics for technical repair items for a variety of naval aircraft.
The probability of survival of a subterranean target under mtensive attack
Authors: Harris Bernard , Karreman Herman F. , Rosser J. Barkley 
Published: May 2007

AbstractThis paper deals with the analysis of a model for studying the probability of survival of a subterranean target under an intensive attack. Most of the analysis is based on the assumption that the explosions are circularly distributed about the target and that the number of explosions is known. In the last two sections it is shown what effect a relaxation of these assumptions has on the probability of survival of the target.
Minimax surveillance schedules for replaceable units
Authors: Roeloffs Robert 
Published: May 2007

AbstractAn analysis is made of the problem of finding optimal schedules for checking an operating unit subject to random failure detectable only by inspection of the unit. It is assumed that only partial information, in the form of .a single percentile of the otherwise unknown life distribution of the unit, is available. In a previous paper [5] some results were given for the case with a finite time horizon. Tn this work it is assumed that tne unit is replaceable at will with a new, statistically identical unit, and the horizon is infinite.
Allocation of resources to randomly occurring opportunities
Authors: Donis John N. , Pollock Stedhen M. 
Published: May 2007

AbstractAn allocation problem is considered in lvhich different kinds of resources must be allocated to various activities, within a given time period. The opportunities for allo'cation appear randomly during this period. Certain assumptions about the values of possible allocations and the distribution of occurrences of opportunities lead to a dynamic programming formulation of the problem. This leads to a system of ordinary differential equations which are (in theory) solvable recursively, and can be solved numerically to any desired degree of precision.An example is given for the allocation of aircraft‐carried weapons to targets of opportunity.
Pursuit around a hole
Authors: Isbell J. R. 
Published: May 2007

AbstractThe solution of isaacs1 problem of optimal pursuit in a plane with a circular disk removed, given constant speeds, zero turning radius, and perfect visibility for both players is presented herein. The hole has three effects: the trivial effect that shortest paths are not straight, the trapping effect to turn the evader from running into the hole, and the screening effect causing an evader retreating behind the hole not to retreat across a line through its center.
The fixed charge problem
Authors: Steinberg David I. 
Published: May 2007

AbstractThe fixed charge problem is a nonlinear programming problem of practical interest in business and industry. Yet, until now no computationally feasible exact method of solution for large problems had been developed.In this paper an exact algorithm is presented which is computationally feasible for large problems. The algorithm is based upon a branch and bound approach, with the additional feature that the amount of computer storage required remains constant throughout (for a problem of any given size).Also presented are three suboptimal heuristic algorithms which are of interest because, although they do not guarantee that the true optimal solution will be found, they usually yield very good solutions and are extremely rapid techniques.Computational results are described for several of the heuristic methods and for the branch and bound algorithm.
On computing the expected discounted return in a markov chain
Authors: Hitchcock David F. , Macqueen James B. 
Published: May 2007

AbstractThe discounted return associated with a finite state Markov chain X1, X2… is given by g(X1)+ αg(X2) + α2g(X3) + …, where g(x) represents the immediate return from state x. Knowing the transition matrix of the chain, it is desired to compute the expected discounted return (present worth) given the initial state. This type of problem arises in inventory theory, dynamic programming, and elsewhere.Usually the solution is approximated by solving the system of linear equations characterizing the expected return. These equations can be solved by a variety of well‐known methods. This paper describes yet another method, which is a slight modification of the classical iterative scheme. The method gives sequences of upper and lower bounds which converge mono‐tonely to the solution. Hence, the method is relatively free of error control problems.Computational experiments were conducted which suggest that for problems with a large number of states, the method is quite efficient. The amount of computation required to obtain the solution increases much slower with an increase in the number of states, N, than with the conventional methods. In fact, computational time is more nearly proportional to N2, than to N3.
A note on constraint preconditioners for nonsymmetric saddle point problems
Authors: Lin Yiqin , Wei Yimin 
Published: May 2007

AbstractA class of constraint preconditioners for solving two‐by‐two block linear equations with the (1,2)‐block being the transpose of the (2,1)‐block and the (2,2)‐block being zero was investigated in a recent paper of Cao (Numer. Math. 2006; 103:47–61). In this short note, we extend his idea by allowing the (1,2)‐block to be not equal to the transpose of the (2,1)‐block. Results concerning the spectrum, the form of the eigenvectors and the convergence behaviour of a Krylov subspace method, such as GMRES are presented. Copyright © 2007 John Wiley & Sons, Ltd.
Preparation and application of polystyrene‐grafted ZnO nanoparticles
Authors: Hong R. Y. , Chen L. L. , Li J. H. , Li H. Z. , Zheng Y. , Ding J. 
Published: May 2007

AbstractThe precursor of ZnO was prepared by precipitation and ZnO nanoparticles were obtained by calcination afterwards. Poly(styrene) (PSt) was grafted onto the ZnO nanoparticles in a non‐aqueous suspension to reduce the aggregation among nanoparticles and to improve the compatibility between nanoparticles and the organic matter. The obtained samples were characterized by X‐ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT‐IR), zeta potential measurement, lipophilic degree (LD) test, photocatalytic experiments, sedimentation test, and contact angle measurement. The LD of composite particles after a high‐temperature treatment was stable. The photoluminescence of PSt‐grafted ZnO nanoparticles was observed by naked eyes and was recorded using a digital camera. The ZnO nanoparticles were used to reinforce poly(vinylidene fluoride) (PVDF) films and the mechanical and electric properties of the films were also measured. Copyright © 2007 John Wiley & Sons, Ltd.
Preparation, characterization and performances of biodegradable thermoplastic starch
Authors: Wang Hong‐Yuan , Huang Ming‐Fu 
Published: May 2007

AbstractA biodegradable thermoplastic starch (TPS) was successfully prepared from plasticizer ethanolamine and native cornstarch. The hydrogen bonding interaction between starch and ethanolamine was investigated using Fourier transform infrared (FT‐IR). When the ethanolamine mass content was 30%, after the ethanolamine‐plasticized thermoplastic starch (ETPS) was stored at RH 50% for 14 days, the mechanical testing showed that the maximum tensile stress of the ETPS reached 5.98 MPa, the tensile strain reached 106.52%, Young's modulus increased from 38.14 MPa of glycerol‐plasticized thermoplastic starch (GTPS) to 75.32 MPa of ETPS, and the breaking energy increased from 1.921 N·m to 2.305 N·m, which indicated that the mechanical properties of ETPS evidently excelled those of the GTPS. The effects of water contents on the mechanical properties of ETPS and GTPS were studied. A differential scanning calorimetry (DSC) analysis revealed that the low‐temperature transition and the glass transition temperature (Tg) of the ETPS were −58 and 22°C respectively, which were lower than that of the GTPS. The ETPS effectively restrained the re‐crystallization of traditional GTPS, which was proved by the X‐ray diffraction (XRD). The scanning electron microscopy (SEM) images presented that ethanolamine made starch uniform. Copyright © 2007 John Wiley & Sons, Ltd.
Parabolas of medication use and discontinuation after myocardial infarction—are we closing the treatment gap?
Authors: Hudson Marie , Richard Hugues , Pilote Louise 
Published: May 2007

AbstractPurposeLittle is known on the use of evidence‐based medications in patients with acute myocardial infarction (AMI) across all ages. We undertook this study to describe the patterns of prescription and discontinuation of anti‐platelet agents, beta‐blockers, angiotensin converting enzyme (ACE) inhibitors and/or angiotensin receptor blockers (ARBs) and statins in all patients post‐AMI.MethodsUsing population‐based administrative databases, patients with an AMI between 1999 and 2004 (21 494 men and 13 241 women) were identified. Rates of prescriptions after discharge and time to discontinuation of the study drugs were computed for various age groups.ResultsThe proportion of patients prescribed a study drug increased throughout the study period. In 2003–2004, 90% of patients were prescribed an anti‐platelet agent, 77% a beta‐blocker, 72% a statin and 70% an ACE inhibitor and/or an ARB within 30 days of discharge from their AMI. However, the rates of discontinuation increased significantly during follow‐up and, in men, reached 27% by 2 years and 42% by 5 years for beta‐blockers. The rates of discontinuation of all four study drugs had a parabolic shape with the youngest and oldest patients having the highest rates.ConclusionsThe use of evidence‐based drugs for patients after AMI is increasing. However, efforts aimed at closing the treatment gap may be mitigated by high rates of discontinuation, especially in patients at the extremes of the age spectrum. Copyright © 2007 John Wiley & Sons, Ltd.
Laser isolation of shunted regions in industrial solar cells
Authors: Abbott M. D. , Trupke T. , Hartmann H. P. , Gupta R. , Breitenstein O. 
Published: May 2007

AbstractThis paper provides proof of concept for a technique that uses laser‐ablated grooves to locally isolate shunted regions in industrial silicon solar cells. The shunted regions are located using photoluminescence imaging and then isolated from the active cell area with a Nd:YAG laser. By applying this shunt isolation technique, we demonstrate that a strongly shunted 9·6% efficient industrial screen‐printed solar cell could be recovered to 13·3%. With further development this technique could be applied in an industrial environment to mitigate yield losses and improve average cell efficiencies. Copyright © 2007 John Wiley & Sons, Ltd.
Epoxies toughened with triblock copolymers
Authors: Hydro Ryan M. , Pearson Raymond A. 
Published: May 2007

AbstractThree different commercial triblock copolymers from Arkema were evaluated as potential toughening agents for two different lightly crosslinked epoxies. It was found that the plane strain fracture toughness, KIC, was on the order of 3.0 MPa√m for 10 parts per hundred resin (phr) of NanoStrength™ E20 resin (a styrene–butadiene–methylacrylate, SBM, type triblock copolymer) in epoxies cured with either aminoethylpiperazine or piperidine. In contrast, 10 phr NanoStrength E40 resin (also an SBM type triblock copolymer) was ineffective in toughening such epoxies. The difference in toughening effectiveness was attributed to the smaller amount of polybutadiene present in the E40 resin. The third toughening agent from Arkema was NanoStrength M22 resin, which is a symmetric triblock copolymer consisting of side blocks of PMMA surrounding a center block of poly(butyl acrylate) and is designated as MAM. At 10 phr MAM both lightly crosslinked epoxies exhibited improvements in toughness. Morphologies were characterized using TEM and toughening mechanisms revealed using SEM and TOM. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1470–1481, 2007
Pseudomonas‐induced defence molecules in rice plants against leaffolder (Cnaphalocrocis medinalis) pest
Authors: Saravanakumar Duraisamy , Muthumeena Kannappan , Lavanya Nallathambi , Suresh Seetharaman , Rajendran Lingan , Raguchander Thiruvengadam , Samiyappan Ramasamy 
Published: May 2007

AbstractFluorescent pseudomonad strains Pf1, TDK1 and PY15 individually and in combination were evaluated against leaffolder, Cnaphalocrocis medinalis Guen., in rice under in vitro, glasshouse and field conditions. Among the various treatments used, a combination of Pf1, TDK1 and PY15 strains effectively reduced the incidence of leaffolder pest in rice plants to an extent comparable with chlorpyrifos‐methyl. In addition, morphogenesis of the insect pest in all stages, larval, pupal and adult, was greatly affected by a combination of Pseudomonas Pf1, TDK1 and PY15 strains. Further, the induction of defence‐related molecules was demonstrated. An increased accumulation of defence molecules such as chitinase and proteinase inhibitors was observed with a combined Pf1, TDK1 and PY15 treatment compared with all other treatments. Western blot analysis of chitinase revealed the extra induction of 18, 28 and 35 kDa isoforms in rice plants treated with a mixture of Pf1, TDK1 and PY15 strains against leaffolder pest. The study revealed that a combination of fluorescent pseudomonad strains affects the development of leaffolder pest by inducing defence molecules in rice plants which in turn enhance resistance to leaffolder attack. Copyright © 2007 Society of Chemical Industry