bluuebunny/crossref_metadata_2025 huggingface dataset:
The Pit Charging Problem in Steel Production
Authors: Buzacott J. A. , Callahan J. R.
Published: November 2008

In most integrated works, ingots are used as an intermediate form during the production of steel. These ingots, produced by pouring molten steel into molds, are too large to be used as input for the finishing mills which produce steel products. Hence, more manageable forms (blooms, billets and slabs) are rolled from the ingots by primary mills.

The necessity of having uniformly hot steel, provided by a battery of soaking pits, limits the production capacity of any primary mill. At times there is no hot steel and the mill comes into “nothing hot” delays. It is desirable to reduce these delays to a minimum through proper management of the system. One way of doing so is to properly control the charging into the soaking pits of ingots from the queue which builds up there.

The paper investigates the properties of this problem which can be considered in two parts. Firstly, when there are ingots of various temperatures in the queue, which should be charged when space becomes available in the pits? Secondly, if space becomes available when there are no hot ingots in the queue, should the empty pit be kept idle waiting for more to arrive or should it be charged with cold ingots which though readily available require considerably longer to prepare for rolling? There is the possibility of inserted idle time.

A model is made of the ingot queue-soaking pit-rolling mill system. The properties of the optimal control policy for the ingot queue are investigated using Markov programming. Results are presented which illustrate its complex state dependent nature.
Ambulance Location: A Probabilistic Enumeration Approach
Authors: Swoveland C. , Uyeno D. , Vertinsky I. , Vickson R.
Published: November 2008

In this paper a probabilistic branch and bound procedure is developed for the ambulance location problem. Information on system characteristics under various ambulance assignments and dispatch rules was provided by a digital simulation. The output of the simulation was also used to construct the objective function for the optimal location problem. The procedure was used to determine ambulance locations in Vancouver, Canada. Solutions obtained from the branch and bound procedure were verified by simulation runs.
Sure Staf: A Computerized Staff Scheduling System for Telephone Business Offices
Authors: Church J. G.
Published: November 2008

Scheduling of staff between answering incoming calls and processing paper-work has been a continual problem in telephone company Business Offices. A staff scheduling system has been developed and implemented in Bell Canada on a trial basis. Incoming call load data are recorded automatically and are entered daily into a time share computer terminal. The next day's forecast, by half hour, is made by a cyclic exponential smoothing routine and the number of servers required to take calls is calculated using a queueing model of the Business Office. A schedule of call answering periods for the available staff to match the requirements is made using a heuristic algorithm. Managers are able to choose their objective on the accessibility of the office to incoming customer calls and the staff can organize their work day without unplanned interruptions.
An Algorithm for Large Set Partitioning Problems
Authors: Marsten Roy E.
Published: November 2008

An algorithm is presented for the special integer linear program known as the set partitioning problem. This problem has a binary coefficient matrix, binary variables, and unit resources. Furthermore, all of its constraints are equations. In spite of its very special form, the set partitioning problem has many practical interpretations. The algorithm is of the branch and bound type. A special class of finite mappings is enumerated rather than the customary set of binary solution vectors. Linear programming is used to obtain bounds on the minimal costs of the subproblems that arise. Computational results are reported for several large problems.
Self-Scaling Variable Metric (SSVM) Algorithms
Authors: Oren Shmuel S.
Published: November 2008

This part of the paper introduces some possible implementations of Self-Scaling Variable Metric algorithms based on the theory presented in Part I. These implementations are analyzed theoretically and discussed qualitatively. A special class of SSVM algorithms is introduced, which has the additional property of being invariant under scaling of the objective function or of the variables. Experimental results are provided for a particular case of this class. This case has been tested in comparison to the DFP algorithm on a variety of functions with up to 50 variables. The results indicate that the new method has substantial advantage for functions with a large number of variables.
Assembly Line Balancing with Multiple Stations
Authors: Buxey G. M.
Published: November 2008

A case is stated for extending the techniques of assembly line balancing to provide for the parallel operation of identical stations, where this leads to a reduction in idle time. The practical implications of operating with this type of system are discussed, both for the stations themselves and the line as a whole, with reference to various classifications of assembly line, and ways in which balancing can be made to fit into an overall strategy for production line design are touched upon. Two distinct types of computer program have been developed to enable multiple stations to become a recognised feature incorporated into “heuristic” line balancing, rather than an appendage to be applied ad hoc by industrial engineers when current techniques have proven inadequate. One approach is based on a more sophisticated version of the ‘positional weight’ method while the other relies on the contrasting philosophy of the “random generation” method, and a comparison is made of their relative success in solving two assembly line problems, and their potential from an industrial viewpoint.
An Econometric Analysis of Advertising, Retail Availability, and Sales of a New Brand
Authors: Parsons Leonard J.
Published: November 2008

This article is an exploratory study on the question: Does consumer advertising increase retail availability of a new product? Nerlove's procedure is used to estimate a dynamic model. Cross-section and time series data for one product class are pooled. The managerial implications of the model are discussed.
A Mathematical Model for Price Promotions
Authors: Kinberg Yoram , Rao Ambar G. , Shakun Melvin F.
Published: November 2008

A market where two groups of brands, premium (higher priced) and private label (lower priced) are sold is considered. It is assumed price is the only indicator of quality. Using hypotheses about consumer behavior in such markets, a model for changes in market share that would result from temporary price reductions by one of the premium brands is constructed. The model is used to develop promotional strategies for one of the premium brands, given various assumptions about competitive behavior. Methods for use of the model are suggested.
A Model of Wage Bargaining Involving Negotiations and Sanctions
Authors: Trifon Raphael , Landau Moshe
Published: November 2008

This paper presents a model of wage bargaining between an employer and a labour union (or alternatively of collective bargaining). The bargaining is conducted by comparing a claim and an offer at fixed time intervals. These are generated by the respective parties from reaction functions that allow for past submissions and anticipation of future positions. The reaction functions themselves change from one step to the next, and have to be worked out in a sequence. Consequently, the outcome of the process cannot be guessed at the outset. It is assumed throughout that labour slows down production as a sanction, with a total strike as an extreme possibility. Labour may or may not suffer wage losses proportional to the severity of its sanction. Finally, a bluffing strategy is introduced for both parties. The model can serve as a basis for numerical simulation of wage conflicts, and sensitivity tests of behavioural parameters.
The OPRAD Research and Development Management Game
Authors: Truemper Klaus , Dean Burton V.
Published: November 2008

The OPRAD game was developed as an educational and research tool in R&D management. The game is an extension of a previously developed OPSIM management game (Darden and Lucas, [Darden, W. R., W. H. Lucas. 1969. The Decision Making Game: An Integrated Operations Research Management Simulation. Appleton-Century-Crofts, New York.]) to include R&D personnel and project decisions. A methodology of game evaluation includes both player performance and results of a written questionnaire. Utilizing data on player performance in a model of the learning process yields results which correspond to conclusions obtained from the questionnaire, providing justification for the approach taken. These results indicate that the game is useful in the training of both R&D managers and management scientists.
Simplifying the Choice between Uncertain Prospects Where Preference is Nonlinear
Authors: Hammond John S.
Published: November 2008

This work makes analytical progress in reducing or avoiding two practical difficulties in using preference or utility theory in the analysis of decisions involving uncertainty: (1) assessing the preference curve, and (2) doing calculations with the resultant curve, which may not have an analytically-convenient functional form. The paper identifies circumstances under which simplifications can be found which overcome these difficulties, while at the same time properly reflecting attitude towards risk in the analysis.

It is assumed that a decision-maker must choose between risks w̃1 and w̃2. He wishes to make decisions consistent with a preference curve u(·) which exists, but has not necessarily been assessed, so he can choose i to maximize expected preference, Eu(w̃i). Most results require that the cumulative probability distribution of w̃1 and w̃2 cross at most once.

The results are widely but not universally applicable. Situations are identified where an easy-to-assess, easy-to-analyze preference curve will serve as a proxy for the decision-maker's own preference curve. These situations permit use of any preferences curve from a class having a specified relationship with the decision-maker's curve. For example, in some instances a negative exponential (constant risk aversion) preference function can be used in place of the decision-maker's curve, and in others an expected value analysis will suffice.
A Generalized Discrete Dynamic Programming Model
Authors: Grinold Richard C.
Published: November 2008

This paper considers a stationary discrete dynamic programming model that is a generalization of the finite state and finite action Markov programming problem. We specify conditions under which an optimal stationary linear decision rule exists and show how this optimal policy can be calculated using linear programming, policy iteration, or value iteration. In addition we allow the parameters of the problem to be random variables and indicate when the expected values or these random variables are certainty equivalents.
Optimal Policies for a Multi-Echelon Inventory Problem with Periodic Ordering
Authors: Tan Felipe K.
Published: November 2008

A central warehouse supplies two facilities with a product. The facilities are subject in each time period to stochastic demands. The warehouse can allocate stock to the facilities in each period, but can reorder from an exogenous source only after every T periods. Assuming convex holding and shortage costs, linear ordering and allocation costs, backlogging and no transshipment between facilities, the optimal ordering and allocation policies are characterized. It is also shown that after the last ordering instant, the optimal allocation policy reduces to a much simpler form when the cost-functions are separable in their variables, and that results on the zero time lag allocation problem apply to the fixed time lag case when the holding and shortage costs are functions only of the facility inventories and the total system inventory.
Priority Pricing
Authors: Marchand Maurice G.
Published: November 2008

The purposes of this paper are (i) to study the price structure that should be set to charge the services of a facility subject to queueing phenomena, (ii) to state a rule to determine the optimal capacity of such a facility, and (iii) to investigate if customers could be left free to choose their own priorities.
Note—A Note on “Substitution Effects in Geometric Programming”
Authors: Dinkel John J. , Kochenberger Gary A.
Published: November 2008

The purpose of this paper is to present a computationally attractive view of sensitivity analysis in geometric programming. The approach is motivated by the need to obtain numerical solutions to large-scale geometric programs and provides a summary of some sensitivity analysis results in a readily usable computational form.
The Researcher and the Manager: A Comparative View of the Need for Mutual Understanding
Authors: Duncan W. Jack
Published: November 2008

This paper concerns itself with the problem of managerial implementation of scientific research. It employs a survey technique designed to test the manager's and researcher's reactions to propositions developed by Churchman and Schainblatt [Churchman, C. W., A. H. Schainblatt. 1965. The researcher and the manager: A dialectic of implementation. Management Sci. (February) B-16–B-87.], Bennis [Bennis, W. G. 1965. Commentary. Management Sci. (October) B-13–B-16.], and Dyckman [Dyckman, Thomas R. 1967. Management implementation of scientific research: An attitudinal study. Management Sci. (June) B-612–B-619.]. The sample surveyed reflects opinions derived from groups unlike those studied to date.

As with previous studies, the results suggest the respondents viewed the implementation issue as a multi-dimensional problem and refused to accept a single position as being the most effective means of obtaining meaningful researcher-manager cooperation. The primary conclusion accentuates both groups' rejection of the separate functions position and advocacy of mutual understanding and provides a general reinforcement of prior investigations. It is suggested that managers and researchers might do well not only to understand their own self-motivation but also to understand the unique problems of implementation faced by both groups. This appreciation would no doubt assist in developing the trust and valid communication necessary for the effective transfer of theory to practice.
A Pattern Recognition Model for Forecasting
Authors: Fogler H. Russell
Published: November 2008

Corporate planning has been increasingly assisted by advances in the three major areas of economic forecasting: (1) econometric models, (2) time-series analysis, and (3) business cycle indicators. The purpose of this article is to examine the effect of pre-classifying economic observations into more homogeneous groups (“patterns”). It will be shown that the formation of these groups adds further power to our more standard techniques of statistical inference.

Early work in pattern recognition began with the development of computer programs for playing chess and checkers. After a brief description of pattern-recognition methodology, a procedure will be presented for pre-classifying economic events into subgroups. Empirical testing and results will be presented, as well as the refinements of this tool for better economic forecasting and planning.
Optimal Location of Inspection Stations in a Multistage Production Process
Authors: Eppen Gary D. , Hurst E. Gerald
Published: November 2008

A method for determining where to locate the inspection stations in a multistage production process with imperfect inspection is presented. Dynamic programming is used to establish that the optimal expected total cost function at every stage is piecewise linear and concave. While the optimal policy at every stage usually consists of one “inspect” region and one “do not inspect” region, this policy structure is found not to hold in general. A computation scheme based directly on the dynamic programming formulation is proposed, a time-sharing computer program is discussed, and the results of an example problem are presented.
Optimal Control of a Graded Manpower System
Authors: Grinold Richard C. , Stanford Robert E.
Published: November 2008

We consider a fractional flow model of a graded manpower system and develop algorithms for calculating optimal control policies in four situations: (i) finite time horizons with no constraints on staff distributions, (ii) finite time horizon with constraints on final staff distribution, (iii) infinite horizon with constraints on staff distribution and (iv) problems with a nonstationary transient stage and an infinite stationary stage. In each case results developed in solving the simpler problems are useful in analyzing more complicated situations. In addition to providing computational procedures we apply the algorithms to a three rank model and discuss the possible uses and limitations of our procedure.
Inventory Depletion Management When the Field Life is Random
Authors: Nahmias Steven
Published: November 2008

This paper considers the problem of describing optimal issuing policies when the field life, X(s), is a nonnegative random variable. A new optimality criterion involving stochastic ordering is introduced and sufficient conditions given for the optimality of FIFO and LIFO. Two specific models of perishable inventory are then considered; Model I allows for the perishing of items in the stockpile and Model II does not. It is demonstrated that both LIFO and FIFO are optimal for Model I when the items age at the same rate in the stockpile as in the field. Under the assumption that X(s) is uniformly distributed the optimality of FIFO is established for Model II.
Dynamics of Exponential Smoothing with Trend and Seasonal Terms
Authors: McClain John O.
Published: November 2008

The characteristics of seasonally adjusted, exponentially smoothed forecasts are studied through the frequency response and impulse response functions. The appropriateness of using exponential smoothing for updating the seasonal base series is called into question, due to its tendency to store random noise for long periods.

Exponential smoothing with trend is also examined. It is concluded that Brown's formulation has the property of being critically damped, so that its response to changes in the time series under study is the most rapid possible without overshoot.
Note—A Replacement Problem using a Wald Identity for Discounted Variables
Authors: Serfozo Richard F.
Published: November 2008

A fundamental model is presented for determining optimal replacement times for stochastically deteriorating equipment. It is an elementary Markov decision model in which an optimal policy is to replace an item when and only when its operating cost reaches a certain level Wald type identities for discounted random variables are introduced to derive a tractable method for computing these replacement levels. The analysis herein simplifies and corrects earlier work in this area.
On Rutenberg's Decomposition Method
Authors: Hsia Wei Shen
Published: November 2008

David P. Rutenberg [Rutenberg, David P. 1970. Generalized networks, generalized upper bounding and decomposition of the convex simplex methods. Management Sci. 16 (5) 388–401.] provided a method to solve separable nonlinear objective functions with large-scale linear constraints by using W. I. Zangwill's Convex Simplex Method [Zangwill, W. L. 1967. The convex simplex method. Management Sci. 14 (3) 221–238.] However, there seem to be several errors in §4.3 [Rutenberg, David P. 1970. Generalized networks, generalized upper bounding and decomposition of the convex simplex methods. Management Sci. 16 (5) 397]. Two counterexamples to his conclusions are given in this paper. A revised definition of subproblem, therefore, an optimal criterion of the large-scaled program, is also given.
A Primal Algorithm to Solve Network Flow Problems with Convex Costs
Authors: Weintraub Andres
Published: November 2008

The problem of determining continuous flows of minimum cost in a network with convex cost functions is considered.

The approach used is that of finding, for any given feasible flow, circuit flows of negative incremental costs. In the main theoretical result of this paper, it is proved that if at each stage, given a feasible nonoptimal flow X, the circuit flow with most negative incremental cost is added to X, linear convergence to the optimal solution will be obtained. In addition, this most negative incremental cost determines an upper bound on the difference in cost between the given feasible solution and the optimal.

Based on these concepts, an algorithm, which preserves linear convergence, is presented to determine minimum cost flows in networks with convex costs in the arcs.

Results of computer runs made for this algorithm are given. The special case of networks with linear costs is also considered.
An Aircraft Collision Model
Authors: Machol Robert E.
Published: November 2008

In the 1960's a controversy arose regarding the safety of navigation standards of jet aircraft over the North Atlantic Ocean, which led to a confrontation between airline owners and pilots. A systems analysis led to a redesigned and improved system which resolved the controversy by giving each side at least as much as it originally requested, in terms of minimizing cost on the one hand and maximizing safety on the other. This paper describes the problem, the controversy, the model, the data collection and reduction, the solution, and the implementation.
The Importance of “Weltanschauung” in Operations Research: The Case of the School Busing Problem
Authors: Stimson David H. , Thompson Ronald P.
Published: November 2008

Busing of children to achieve racial balance in schools is an important and controversial social issue. In studying the school busing problem, various groups (e.g., operations researchers, educators, sociologists, psychologists) proceed quite differently because of their different “Weltanschauungen”—their different perceptions of reality, their different world views. Operations researchers have viewed the school busing problem as a desegregation problem (i.e., simply physically mixing the races) while others have seen it as an integration problem (i.e., helping to bring about a viable, multi-racial society). The usefulness of the desegregation view of operations researchers is evaluated in light of findings from the educational literature about various aspects of the school busing problem. Explicit attention by operations researchers to the concept of “Weltanschauung” should result in studies more useful to school officials and administrators. Statements made about the role of “Weltanschauung” in operations research studies of the school busing problem may be applied to operations research studies in other areas of social concern such as health, welfare, and law enforcement.
Optimization of Pentathlon Training Plans
Authors: Ladany Shaul P.
Published: November 2008

An approach has been outlined to determine the optimal weekly training plan of a pentathlon athlete, (a woman) in order to maximize her score at week-end competitions. The various training activities which have an influence on the results in each of the five pentathlon events, as well as the relationship between the amount of training in these activities and the results, have been established by regression analysis. The total score from the five events, depending on the result in each event, and subject both to the total time which the athlete is willing to devote to training and to various physiological requirements for balancing the development of the athlete's body, has been maximized using linear programming. Suggestions have also been put forth for the application of the method to cases in which nonlinear relationships between results and training activities exist.
Recent Advances in R&D Benefit Measurement and Project Selection Methods
Authors: Baker Norman , Freeland James
Published: November 2008

The purpose of this paper is to provide a current assessment of the literature addressed to quantitative models of the R and D project selection and resource allocation decision. In order to facilitate the critique and assessment the literature is somewhat arbitrarily divided into benefit measurement and resource allocation methods. The strengths and limitations of existing knowledge are identified with an emphasis on empirical investigations. Several research areas are identified and briefly described.
Antithetic Variates, Common Random Numbers and Optimal Computer Time Allocation in Simulation
Authors: Kleijnen Jack P. C.
Published: November 2008

Two simple variance reduction techniques are discussed, viz. antithetic variates and common random numbers. Their joint application creates undesirable negative correlations between the responses of two simulated systems. Therefore three alternatives are considered: antithetics only, common random numbers only, antithetic and common random numbers combined. No alternative is always best as is shown by analytical results for extremely simple systems and simulation results for simple queuing systems. Therefore a procedure is derived that starts with some pilot runs for both systems and estimates which alternative minimizes the variance; at the same time this procedure allocates the limited amount of computer time to the two systems in an optimal way. Results of the application of the procedure to several queuing systems are presented. Because of certain disadvantages of the procedure we may decide to select alternative 1 (antithetics only) a priori. Then the procedure can still be used for the optimal computer time allocation.
Optimal and Heuristic Decisions in Single-and Multi-Item Inventory Systems
Authors: Naddor Eliezer
Published: November 2008

A comparison of optimal solutions of single-item inventory systems for the three classical policies tZ, sq, and sZ shows that the optimal order levels in the tZ and sZ policies are usually the same, and so are the optimal reorder points in the sq and sZ policies.

The total cost for each of the three policies can be expressed as that of a fundamental model using an appropriate equivalent distribution. The fundamental model can be analyzed with ease. It also provides closed-form results for the normal distribution.

Heuristic rules are presented allowing the analysis of inventory systems on the basis of their average demand, standard deviation of demand, probability of no demand, lead-time, carrying cost, replenishing cost, and an availability index. Compared with the optimal decisions and costs for identical inventory systems, in which the probability distribution of demand is known, the heuristic rules give excellent results.

The optimal and heuristic decisions are extended to multi-item systems in which there is a cost for placing and receiving an order for a family of items every reviewing period. An algorithm is presented for finding the optimal reviewing period and the corresponding decisions and costs. The heuristic decisions compare very favorably with the optimal ones.
Optimal and System Myopic Policies for Multi-Echelon Production/Inventory Assembly Systems
Authors: Schwarz Leroy B. , Schrage Linus
Published: November 2008

In this paper optimal and near optimal policies are proposed for multi-echelon production/inventory assembly systems under continuous review with constant demand over an infinite planning horizon. Costs at each stage consist of a fixed charge per order or production setup plus a linear holding cost on “echelon” inventory. The objective is minimization of average cost per unit time.

The major results of this paper are: a mathematically simple, often optimal, “system myopic” solution, a lower bound on the closeness to optimality of this solution, and a branch and bound algorithm which usually finds the optimal solution quickly.
Optimality of Myopic Inventory Policies for Certain Dependent Demand Processes
Authors: Johnson G. D. , Thompson H. E.
Published: November 2008

This paper shows that the optimal policy for single-product periodic ordering systems with proportional holding and stockout costs and zero lead time is myopic for both stationary and nonstationary demand processes as described by Box and Jenkins. The proof of optimality is based on a theorem by Veinott showing that the myopic policy is optimal in each period if the beginning inventory for that period is less than the critical number which is the optimal policy for that period considered in isolation.
On the Evaluation of a Class of Inventory Policies for Perishable Products Such as Blood
Authors: Brodheim Eric , Derman Cyrus , Prastacos Gregory
Published: November 2008

A class of inventory and distribution policies for scheduled deliveries of perishable products subject to variable demand is modeled as a Markov chain with a manageable number of states. From its stationary distribution, such measures as probability of shortage, the average age of the inventory, and the average number discarded per time period are obtained. Easily computable bounds on these measures that indicate how they behave as functions of demand, and inventory policy parameters are developed.
Economic Optimization of Offshore Petroleum Development
Authors: Frair Les , Devine Mike
Published: November 2008

Due to shortages in crude oil supplies there is considerable motivation to develop the vast petroleum resources located on our outer continental shelf. Offshore oil operations require great outlays of capital, and this paper presents a model and solution procedure for optimizing the economics of developing a given offshore field. The model considers the following variables: (1) How many offshore drilling platforms are needed? (2) How many wells should be drilled from each platform? (3) What is the location of each platform? (4) From which platform should each well be drilled? (5) What are the time schedules for placing the platforms and drilling the wells? (6) What is the production schedule for each reservoir?

The objective of this model is the maximization of discounted after-tax cash flows subject to production limiting constraints. Because of the nonlinear nature and size of this model for realistic problems, it is decomposed into sub-models for which effective solution procedures are developed. Computational results are presented for two example problems.
The Costs of Industrial Product Innovations
Authors: Mansfield Edwin , Rapoport John
Published: November 2008

To help shed new light on the factors associated with the large differences among innovations in the percent of innovation costs devoted to R and D, detailed data were obtained concerning a sample of chemical innovations. A simple econometric model was used to test a number of tentative hypotheses advanced to help explain these differences. The model can explain about half of the observed variation.
On Optimal Pollution Control Policies
Authors: Bawa Vijay S.
Published: November 2008

In recent years, on the basis of static allocative efficiency properties economists have advocated the use of taxation as an economically efficient means of control to implement environmental protection policy. Environmental problems, however, do not always develop smoothly and gradually but are often characterized by infrequent serious crises that require rapid, but temporary, changes in the controlling mechanism. Tax policy is inappropriate for such crises, but direct controls can be implemented rapidly to handle such emergencies. Using simple stochastic models to represent the physical environment, we show that the pollution control policy which minimizes total social costs (stationary social costs plus short-term emergency costs) is a mixed policy in which taxes are used to control the long-run equilibrium level of pollution and direct controls are used in short-term emergencies to maintain the pollution at satisfactory level. We also show that although tax policy alone is not optimal, in some special circumstances, direct controls alone may be the optimal way to control pollution.
A Simplified Algorithm for Obtaining Approximate Solutions to Zero-One Programming Problems
Authors: Toyoda Yoshiaki
Published: November 2008

This paper is intended to present a simple and quick method for obtaining approximate solutions to large scale zero-one programming problems. The method does not use enumeration. Instead, it assigns measures of preferability to zero-one variables that change the values of the variables from zero to one. The method yields very good approximate solutions to zero-one programming problems in dramatically short computation time. Even for problems involving more than a thousand zero-one variables the computation time is of little concern. The method is applicable not only to those problems associated with obtaining the optimal package of variables with the value one but also to a great variety of binary choice (“Yes-No”) problems.
Stochastic Dominance Tests for Decreasing Absolute Risk Aversion. I. Discrete Random Variables
Authors: Vickson R. G.
Published: November 2008

Stochastic dominance (SD) theory is concerned with orderings of random variables by classes of utility functions characterized solely in terms of general properties. This paper discusses a type of stochastic dominance, called DSD, which is denned by the utility functions having decreasing absolute risk-aversion. Necessary and sufficient conditions for DSD are presented for discrete random variables which, after the possible addition of points of zero probability, are concentrated on finitely many equally-spaced points. The problem is cast as a nonlinear program, which is solved through an efficient dynamic programming routine. Examples are presented to illustrate the increased effectiveness of DSD relative to previous types of stochastic dominance.
Estimating the Mean and Variance of Subjective Distributions in PERT and Decision Analysis
Authors: Perry C. , Greig I. D.
Published: November 2008

The original PERT formulae [5] employ the mode and endpoints to estimate the mean and standard deviation of subjective probability distributions. Though widely-used, they have met with criticism for their inaccuracy, and for their being limited to the beta distribution when there is no a priori reason why the distribution should be beta ([4], [6]). This note presents alternative, accurate and relatively distribution-free formulae for estimating the means and standard deviations of subjective probability distributions.
Factors Affecting Adoption of a Quantitative Method for R&D Project Selection
Authors: Maher P. Michael , Rubenstein Albert H.
Published: November 2008

In the field of research and development (R&D), “state-of-the-art” project selection models are not being widely adopted. This paper reports on the results of an attempt to develop, test, and evaluate systematically an R&D project selection technique in an operating R&D organization. The technique employed was a modified risk analysis model. The results suggest that an individual's assessment of the value of the data generated by an R&D project selection technique is an extremely important factor in determining his willingness to adopt the technique. The relative importance of two determinants of adoption: perceived changes in organizational processes resulting from the use of a project selection model and the importance of the strategies used to introduce a model into an organization, appear to run counter to the thinking of many management theorists who tend to emphasize the importance of the organizational process and the importance of the strategy for change.
Optimal Foreclosure Policies
Authors: Pye Gordon , Tezel Ahmet
Published: November 2008

The value of a collateralized loan subject to default is obtained using a dynamic programming approach. The optimal foreclosure policy for a special case is derived based on the number of payments which are late. These results are then applied to an example taken from a casebook on financial institutions.
Coefficient of Network Complexity
Authors: Kaimann Richard A.
Published: November 2008

The degree of complexity of a critical path network may be classified by calculating a Coefficient of Network Complexity. It is defined as the quotient of activities squared divided by events or preceding work items squared divided by work items. Three distinct contributions are offered. First, the CNC may serve as an indicator of the attention spent in planning the project. Second, the CNC may be used to derive a predictor of network computer processing time. Third, the CNC value suggests the appropriate processing scheme.
Two-Stage Replacement Strategies and Their Application to Manpower Planning
Authors: Robinson David
Published: November 2008

Two-stage replacement strategies are described and related to manpower systems. This consists of setting up a training grade to supplement an organisation of fixed size. Results are obtained to show what site the training grade should be in order that, on average, people spend some predetermined length of time in the training grade before promotion. Two promotion rules are used, viz. promotion by seniority and promotion at random. Numerical results are given for particular completed length of service distributions.
Calculation of Investment Portfolios with Risk Free Borrowing and Lending
Authors: Ziemba W. T. , Parkan C. , Brooks-Hill R.
Published: November 2008

We consider the problem of portfolio selection for a risk averse investor wishing to allocate his resources among several investment opportunities in order to maximize the expected utility of final wealth. The calculation of the optimal investment proportions generally requires the solution of a stochastic program whose dimension is the number of risky investments. The computations are simplified dramatically when there is a risk free asset and the investment returns are jointly normally distributed. In this case Tobin has shown that the investment proportions in the risky assets are independent of the utility function and Lintner has shown that these proportions may be obtained from the solution of a fractional program. It is shown under mild hypotheses that the fractional program has a pseudo-concave objective and that the program always has a unique solution. The solution may be sought in several ways, perhaps moat efficiently via Lemke's algorithm applied to a linear complementarity problem. The optimal investment proportions in all assets may be found by solving a stochastic program having one random variable and one decision variable via a search technique. Data on the major pooled Canadian equity pension funds were used to provide an empirical test of the suggested solution approach. Five common classes of utility functions were utilised with varying parameter values. For each class there are smooth curves that related the investment in the risk free asset to the parameters of the utility function. The investor is more risk averse when faced with quarterly data.
Optimal Allocations in the Construction of k-Out-of-n Reliability Systems
Authors: Derman C. , Lieberman G. J. , Ross S. M.
Published: November 2008

We want to build n components so as to form an n component system which will function if at least k of the components function. If x dollars are invested in building a component, then this component will function with probability P(x). Given a total income of A dollars, the problem of interest is to determine how much money we should invest in each component so as to maximize the probability of attaining a functioning system. This problem is considered both in the sequential and in the nonsequential cases. Conditions under which it is optimal to allocate A/n units at each stage, when A is your initial fortune, are presented. The special case P(x) = min(x, 1) is also considered in detail.
Planning Horizons for the Dynamic Lot Size Model with Backlogging
Authors: Blackburn Joseph D. , Kunreuther Howard
Published: November 2008

Planning horizons are developed for the dynamic economic lot site model with backlogging when the marginal production cost is either constant or variable. The inventory holding and backlogging cost functions are assumed to be concave. An efficient forward algorithm generalizes the Eppen-Gould-Pashigian procedure and enables us to place bounds on the optimal production plan should a horizon not be found.
A Linear Program for Economic Lot Sizes using Labor Priorities
Authors: May J. Gaylord
Published: November 2008

This paper presents the development of a mathematical model to generate economic lot sizes, on a weekly basis, for an assembly-type shop. The model appears as a linear program which optimizes assigned labor priorities. Included is a description of the results achieved from a successful implementation of the model into the assembly operations.

The paper also identifies this shop's problem within the general context of multi-product, multi-period scheduling. In particular, a certain class of scheduling problems is formulated using described techniques.
Marketing Strategy and the Optimal Production Schedule
Authors: Leitch Robert Alan
Published: November 2008

Incorporation of marketing strategy in production planning can reduce overall costs and significantly increase profits.

In this paper a solution procedure similar to the traditional Holt, Modigliani, Muth, and Simon production smoothing model is used to find a combined marketing and production plan in which advertising promotion is utilised to avoid peak-load production costs by shifting seasonal demand for a product. The solution procedure is applicable to a wide variety of market characterizations, and the technique may also be readily adapted to analyse impacts of various aspects of market behavior on the optimal production schedule.
Dispatching from Depot Repair in a Recoverable Item Inventory System: On the Optimality of a Heuristic Rule
Authors: Miller Bruce L.
Published: November 2008

This paper examines real-time decision rules for a U.S. Air Force inventory system where items are repaired rather than “used up.” The problem is to decide which user in the system has the greatest need for the newly available inventory items coming out of repair.

The system is modeled as a Markov decision process and a heuristic rule is presented. This rule, the Transportation Time Look Ahead policy, is justified theoretically by showing that the rule is optimal for a modified model. Thus we have a theoretical justification of a decision rule in a large scale dynamic programming application.
A Linear Programming Analysis of Paper Recycling
Authors: Glassey C. Roger , Gupta Virendra K.
Published: November 2008

A simple linear model is constructed for production, use and recycling of various paper and related products. This model is used to estimate the maximum feasible recycling rate given the current state of pulp and paper technology. Parametric linear programming is used to investigate the effect of the efficiency of collecting, sorting and transporting waste paper on the fraction recycled.
Aspects of One-Stage Voting Rules
Authors: Fishburn Peter C.
Published: November 2008

Under the assumption that voters have linear preference orders, this study investigates the propensity of simple weighted scoring rules to yield a winning alternative which is the same as the alternative (if any) which would win using a norm rule such as the simple-majority rule or the Borda rule. The scoring rules examined are of the types implemented by ballot instructions such as “vote for two of the following seven alternatives” and “indicate your first (1), second (2), and third (3) choices from the following list of ten candidates.” The results, which apply only to situations where one of a number of alternatives is to be chosen on the basis of a single ballot, may be useful in designing balloting and scoring procedures for these types of situations.
Determination of Optimum Packaging Frequency of Items Jointly Replenished
Authors: Goyal S. K.
Published: November 2008

This paper presents a systematic procedure for obtaining the optimum packaging frequencies for a number of items which are manufactured jointly but packaged individually immediately alter manufacture. The method described in the paper is equally applicable to those problems where the optimum purchasing policy is to be obtained for a number of items procured from a single supplier. An example involving twenty jointly replenished items is solved to illustrate the procedure given in the paper.
Forecasting Market Shares of Alternative Home-Heating Units by Markov Process using Transition Probabilities Estimated from Aggregate Time Series Data
Authors: Ezzati Ali
Published: November 2008

The purpose of this study is to forecast the market shares of alternative home-heating units: oil-burners, gas-burners and electric-heating units for the United States. The forecasting method used is The Markov Process with estimated transition probability matrices. The transition probabilities represent whether households will continue to use the same heating unit which they have used in the recent past or switch to another type unit. Maximum likelihood and Bayesian estimation techniques have been used to estimate these transition probabilities from aggregate historical market shares of alternative home-heating units.
Note—On the Maximization of the Geometric Mean with Lognormal Return Distribution
Authors: Elton Edwin J. , Gruber Martin J.
Published: November 2008

In this paper we discuss the relevancy of the geometric mean as a portfolio selection criteria. A procedure for finding that portfolio with the highest geometric mean when returns on portfolios are lognormally distributed is presented. The development of this algorithm involves a proof that the portfolio with maximum geometric mean lies on the efficient frontier in arithmetic mean variance space. This finding has major implications for the relevancy of much of portfolio and general equilibrium theory. These implications are explored.
The Steady-State Queueing Time Distribution for the M/G/1 Finite Capacity Queue
Authors: Lavenberg Stephen S.
Published: November 2008

We derive an expression for the Laplace-Stieltjes transform of the steady-state distribution of the queueing time for the M/G/1 finite capacity queue. The derivation proceeds in terms of a related 2-stage closed cyclic queueing network. The resulting expression is a rational function of the steady-state probabilities of the imbedded Markov chain at departure epochs and of the Laplace-Stieltjes transform of the service time distribution. The expression can be differentiated readily in order to obtain moments of the steady-state queueing time and some numerical results for the mean and coefficient of variation are presented.
Minimizing the Time-in-System Variance for a Finite Jobset
Authors: Schrage Linus
Published: November 2008

There are a finite number of jobs to be scheduled on a single machine. All jobs are available from the start and the objective is to sequence the jobs so that the time-in-system (or equivalently, the completion time) variance is minimized. A number of necessary conditions for an optimal sequencing (which for small jobsets turn out to be sufficient) are presented.
Production Smoothing with Fluctuating Price
Authors: Pekelman Dov
Published: November 2008

The model presented in this paper deals with a firm facing a known price which varies over time during some finite period [0, T]. The firm wishes to determine the production rate at each instant of that interval which will maximize profit, when adjustment of output incurs additional cost.

In the paper we characterize the optimal solution and construct a forward algorithm which is shown to converge to the unique optimal solution. We also specify the conditions for planning and forecast horizons, both of which can be identified by the described algorithm. We use control theory to achieve these results.