ISSN:0160-5682    

DOI:10.1057/jors.1980.181

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

AbstractThis paper summarizes how the Project Independence Evaluation System (PIES) was used to estimate impacts of the National Energy Plan presented to the U.S. Congress and the public April 20, 1977. For completeness a summary of the structures and underlying methodologies is also included. The key components considered are: oil and gas price controls, coal conversion, and conservation.

ISSN:0160-5682    

DOI:10.1057/jors.1980.182

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

AbstractIn planning investment to meet growth in demand on the telephone system, it is highly desirable to be able to predict how well proposed configurations of exchange equipment will meet specified future demand. The methods developed for this purpose form the body of telephone traffic theory.This paper describes approximate queueing theoretic methods used in the analysis of queueing delay in the TXK3 crossbar exchange, and compares the results obtained from these models with results from simulation study. The methods have already been used in the analysis of exchanges but, in the author's view, are not yet fully validated.

ISSN:0160-5682    

DOI:10.1057/jors.1980.183

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

AbstractThis paper considers, by means of a case study, some practical applications of regional input-output analysis. The paper outlines the underlying methodology of regional input-output and discusses the use of the model in the derivation of regional multipliers, in impact analysis and in regional forecasting. These techniques are applied to the Shetland economy. Estimates of industry output multipliers are given and discussed. The impact of oil on the Shetland economy in 1976 and its forecast impact in 1985 are analysed using the input-output model.

ISSN:0160-5682    

DOI:10.1057/jors.1980.184

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

AbstractSolutions of linear programming formulations of some problems may be unsatisfactory, because they inherently tend to be extreme, sparse, and ruthless. A method of non-linear optimisation is described which is cautious in the sense that a progressive restraint is imposed on departures from some reference solution. Constraints can be incorporated provided they are regarded as somewhat flexible. Multiple objectives may also be pursued. Large problems (more than 1000 variables) may be handled without difficulty by employing conjugate gradient methods of optimisation. Computing requirements are no greater than for an equivalent LP problem, and execution times to obtain satisfactory approximate solutions may be less.The method has been successfully applied to a large fishery management problem, which is described. It yields stable, realistic solutions, and enables a range of solutions corresponding to different assumptions about the importance of various processes to be generated with confidence.

ISSN:0160-5682    

DOI:10.1057/jors.1980.185

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

AbstractThis paper discusses the implications for analysis and parameter estimation of optimization using S-shaped (convex-concave) response functions.

ISSN:0160-5682    

DOI:10.1057/jors.1980.186

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

AbstractIn this paper, concepts of dynamic programming are used within a discrete time Markovian model for the development of a graded population. Optimal recruitment and transition patterns are determined by minimizing expected discrepancies between actual states and preferred goals.

ISSN:0160-5682    

DOI:10.1057/jors.1980.187

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

AbstractThe existence of reliable and flexible FORTRAN programs for integer linear programming has recently enabled the development of very efficient algorithms for the travelling salesman problem. The main characteristic of these algorithms is the relaxation of most of the constraints of the problem during its solution. The same approach can be used for the solution of them-salesmen problem in whichmsalesmen starting from the same city must visit only oncencities at minimum cost. The number of salesmen can be fixed in advance or allowed to vary, upper and lower bounds set on the number of salesmen and even fixed costs associated with the salesmen. The results obtained so far are very encouraging. Problems of up to 100 cities have been solved optimally for them-travelling salesmen case and other more complex problems are currently under study.

ISSN:0160-5682    

DOI:10.1057/jors.1980.188

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

AbstractA preference order dynamic programming model proposed in the literature for solving stochastic knapsack problems is shown to be somewhat limited from both the methodological and computational points of view. A counterexample is presented contradicting the optimality of a procedure designed for normal variates.

ISSN:0160-5682    

DOI:10.1057/jors.1980.189

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

AbstractIn simulation an input variable like interarrival time is sampled, and hence its average deviates from its known expectation. This information can be used to improve the estimated simulation response: regression sampling or control variate technique. The usual crude estimator is shown to be biased. If local linearity holds, then the regression estimator becomes unbiased. Moreover its variance becomes smaller under mild conditions. The assumption of local linearity is an alternative to the normality assumption of other authors. This paper further emphasizes the difference between resultsex ante(unconditional) andex post(given the experimental input values). A telephone-exchange simulation provides a case study.

ISSN:0160-5682    

DOI:10.1057/jors.1980.190

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor