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Experimental design considerations have been virtually ignored by economists who have conducted computer simulation experiments with models of economic systems. The objective of this paper is to spell out in detail the relationship between existing experimental design techniques and techniques of data analysis and the design of simulation experiments with economic systems. We begin by defining the problem of experimental design as applied to computer simulation experiments. With the aid of an example model, we explore several techniques of data analysis and a number of specific experimental design problems. Although this paper is oriented towards the design of computer simulation experiments in economics, the techniques which are discussed are of a general nature and should be applicable to the design of simulation experiments in other disciplines. [ABSTRACT FROM AUTHOR]

The article presents a paper, which shows how to determine the optimal number and routings of containers used to move mail among several cities. This paper extends the above system to more than two cities, with different schedules on different days and with transfer of containers permitted throughout the system. A mathematical formulation is developed that can be readily solved by known linear programming techniques. Critical assumptions are (a) periodic demand patterns and linear transportation costs between each city-pair, and (b) constant fixed cost per container in the system. The optimization problem is transformed into a network flow linear program for which efficient solution methods are known. The researchers have investigated a system where containerized mail would be sent between two cities. The problem solved in reference was that of determining the best number of containers to be sent each day between the two cities, based on (a) the distribution of mail volumes going between the cities each day and (b) the costs for sending containers, full or empty, and for sending mail by other means in case of container shortage. Thus the original convex programming problem has been converted to an especially tractable type of linear program, namely the optimization of a network flow.

This paper gives a description of how to find the 'best' sequence of allocation of resources to projects. The method handles simultaneously a great number of projects. The expression 'best' sequence means here the priority-rating that optimizes some chosen measure for the efficiency of the system. This optimization is done within the limits of the total resources available for allocation to projects. The problem is solved for whatever dependency there may be between resource quantity and system efficiency for the single projects. It works for the 'difficult' case of discontinuous efficiency functions as well. It is shown that in order to handle a great number of projects, one can divide the projects into groups, apply the method within each group of projects, then consider each group as a super project, and finally solve the whole problem by using the same method on groups. The problem is solved by a combination of the dynamic programming method, Lagrange's multiplier method, and numerical calculations on an electronic computer. The main part of the method is shown in a flow-diagram form. In the last sections of this paper practical examples are given, where the method is applied on investment problems. [ABSTRACT FROM AUTHOR]

In this paper we apply the following general scheme to determine toll patterns for multiclass-user transportation networks: we modify the travel cost as perceived by the individual traveler by charging him a 'toll.' Then we try to determine the toll pattern in such a way that the system-optimizing flow pattern becomes at the same time user- optimizing. We discuss two toll policies: (a) Tolls are collected on a link basis. (b) Tolls are collected on a path basis. The study shows that there is a degree of freedom in the path-toll collection policy. Alternative criteria are proposed for the exploitation of the degree of freedom such as: (i) that the tolls collected be nonnegative; (ii) that the personal cost of travelers, before and after the imposition of tolls, remains the same; (iii) that certain classes are treated discriminately in order to attain some social good. [ABSTRACT FROM AUTHOR]

This paper reviews the goal approach and the system resource approach to the study of organizational effectiveness. First, the goal approach is defended with respect to criticisms made by the users of the system resource approach. Next it is criticized for its failure to develop general measures of effectiveness. The system resource approach is then criticized because optimization is not measured, few general measures are used, and the basic rule of mutual exclusiveness is seriously violated. Finally, a general measure of effectiveness is suggested, based on Georgopoulos and Mann's (1902) study of community general hospitals. [ABSTRACT FROM AUTHOR]

In many situations, approximation of a set of data by a polygonal curve is more advantageous than approximation by a polynomial. If the join points of the polygonal curve are known, the problem is quite simple. If, however, they are to be chosen in some expeditious fashion, considerable numerical difficulties can arise if the curve-fitting problem is approached directly. In this paper it is shown that dynamic programming offers a simple direct approach to the determination of an optimal fit. [ABSTRACT FROM AUTHOR]

In [1] a design, referred to as a Factor Sequencing Design (FSD), and analysis are presented for 2[sup p] factorial experiments where the factors are applied sequentially and where order of application may be of importance. The number of units required for an FSD is pi, which may be prohibitively large for p is greater than or equal to 4. This paper presents a method for fractionating the FSI) and gives specific designs with their associated analyses for p equal 3, 4, 5, and 6. [ABSTRACT FROM AUTHOR]

This paper deals with methods of "cluster analysis". In particular we attack the problem of exploring the structure of multivariate data in search of "clusters". The approach taken is to use a computer procedure to obtain the "best" partition of n objects into g groups. A number of mathematical criteria for "best" are discussed and related to statistical theory. A procedure for optimizing the criteria is outlined. Some of the criteria are compared with respect to their behavior on actual data. Results of data analysis are presented and discussed. [ABSTRACT FROM AUTHOR]

The designing of some multi-factor "analytical" studies of survey data is considered in this paper. It is assumed that, for each factor, there are two categories of interest and these are to be compared. The main objective is to allocate the sample so that the desired precision for the specified contrasts is obtained at minimum cost. It is assumed that one may sample independently in each of the sub-populations under investigation. A model is employed to facilitate designing and analyzing such a survey. We discuss the relevance of this model for "analytical studies," and a few examples are presented. Several survey objectives are explored, and an optimal allocation is obtained for each. Two, three and four-factor studies are considered explicitly. [ABSTRACT FROM AUTHOR]

It is claimed that the reasons for using matrices of derivatives, in appropriate situations, are as compelling as those for using matrices. This paper provides basic material for such use. Different types of matrix derivatives are defined and illustrated. Simple and easy techniques are then derived and are shown to be applicable to a considerable collection of matrix functions. Applications are made to such problems as establishing matrix integrals from scalar ones, determining maximum likelihood estimates for complex likelihood functions, optimizing matrix functions when there are matrices of side conditions, and evaluating the Jacobians of certain classes of transformations. The emphasis is on simplicity of derivation and on breadth of application. [ABSTRACT FROM AUTHOR]

Tins paper illustrates, through a special case, an effect of non-independent numerators on F-test's in an analysis of variance. Symmetrical balanced incomplete block designs are considered with "blocks" a random effect and no interaction. The joint density of the adjusted sums of squares is determined under the null hypothesis of no treatment effect. Given the result of testing for the block effect, the conditional probability of a Type I error when testing the null hypothesis concerning the treatment effect is evaluated for a number of designs. [ABSTRACT FROM AUTHOR]

Various versions of the Weber problem deal with the location of facilities in a system with fixed destinations or customers. The object is to minimize the sum of transportation costs, which is represented as the sum of the weighted distances in the system. This paper finds the optimum location for facilities where the object is to minimize the maximum weighted distance in the system. Rectangular distances, which are more appropriate for urban transportation than straight line distances, are used in the model. Optimization is achieved through parametric linear programming. [ABSTRACT FROM AUTHOR]

The article focuses on models of fleet routing and scheduling problems for transportation systems, which are formulated as integer linear programs with 0-1 variables. The topics discussed in this paper are concerned with important operational problems confronting the management of the competitive air transportation system. Some of these problems are significant for other transportation systems, including those with public-service rather than profit objectives. The problems are those connected with fleet utilization, fleet size, routing, and scheduling. Work that is related to some of these problems has been carried out by operations researchers and has been limited because, when optimal solutions were sought, computation times were excessive. The principal method of attack has been dynamic programming, which usually involves a very large state space for any real-life transportation system. The basic models are of the discrete-time rather than of the continuous-time variety. This property permits the formulation of the optimization problems as integer linear programs. The aim is to formulate a realistic model and to obtain its optimal solution

This paper presents a method for developing efficient timetables for the operation of fixed schedule common-carrier passenger transportation systems. The ability to compute such timetables is needed in the consideration of planning alternatives for future transportation systems and/or the efficient operation of existing systems. Here, time- table optimization is accomplished by maximizing an objective function consisting of three basic components: operating costs, revenues, and traveler benefits. Traveler benefits are computed using a consumer preference model that specifies a traveler's willingness to pay for alternative trips, based on the scheduling of those trips. The optimization is based on successive iterations of a dynamic programming algorithm that develops timetables for each vehicle in the system. Solutions are termed optimal to within a 'first-order passenger exchange! Examples are presented to illustrate the utilization of the methodology for computing information relevant to the development of system operating policies and to the consideration of planning alternatives. [ABSTRACT FROM AUTHOR]