摘要:

Bayesian decision theory is applied to determine an optimum sampling frequency for chlorides in a public water supply well. The well is located approximately one mile downstream of a landfill with an established contaminant plume and has exhibited increasing chloride concentrations. A digital computer program is utilized to solve the optimization problem using Bayes' theorem for continuous probability distributions. The sampling frequency obtained by this method is compared with the frequency used by the authority operating the public water supply well and to the frequencies estimated by other methods that have been recommended for determining sampling frequency. The sampling frequencies obtained using Bayesian decision theory are close to those obtained with other mathematical methods. The results are also similar to the sampling frequency chosen by the operating authority when monitoring the well.

ISSN:0263-0257    

DOI:10.1080/02630258508970405

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Uncertain inference can be modelled in various ways. Probability and fuzzy logics are special cases of a more general result involving intervals of possibilities. It is argued that uncertainty analysis is unlike engineering science because it is difficult to test under controlled conditions. It is therefore important to expose its basic assumptions if engineers are to choose sensibly between alternative techniques. The minimal statements of the assumptions are the mathematical axioms, and it is the interpretation of these axioms which makes the inference model.

ISSN:0263-0257    

DOI:10.1080/02630258508970406

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

This paper describes an algorithm for performing extended algebraic operations such as those encountered in risk and decision analysis under fuzzy conditions. The method makes use of the lambda-cut representations of fuzzy sets and interval analysis. It is an approximate computational technique but is highly efficient compared with the exact method of nonlinear programming, with an accuracy which is much better than the conventional discretization approach. The effectiveness and utility of the procedure are illustrated with examples of fuzzy risk and decision analysis taken from available literature.

ISSN:0263-0257    

DOI:10.1080/02630258508970407

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Similarities and differences exist between various inventory systems. This paper discusses the issues involved in transferring optimization modelling techniques from water reservoir systems to grain reservoir systems. A two-objective linear programme is formulated that ensures minimum return to corn and wheat producers in the USA over a 10-year (1 968-1977) study period. The solutions of this model and the resulting trade-offs between the two objectives are presented. The limitations of the market price models generally used in conventional system analysis-are discussed. A conceptual model based on the topologic concepts of structural stability is presented. The role of descriptive economic models as a value measure for ranking alternative solutions to a multi-objective planning problem is also examined.

ISSN:0263-0257    

DOI:10.1080/02630258508970408

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The least-cost allocation of snow-producing zones among available elimination sites is formulated as a classical transportation problem. The assumptions underlying this formulation, which proves useful in the study of large-scale allocation problems, are discussed. A numerical example is solved and used to illustrate two post-optimal analysis questions. One assesses the influence of a reduction in the unit transportation cost on the optimal solution; the results are used to determine solutions slightly more expensive than the optimal allocation for studying possible trade-offs. The other defines areas where it would be economically advantageous to locate new elimination sites.

ISSN:0263-0257    

DOI:10.1080/02630258508970409

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Since their first serious introduction in the early 1 960s, systems analysis methods have held out a promise of providing information that can help improve decision making. This paper surveys a number of actual applications of optimization and simulation modelling that illustrate the variety of problems studied, the variety of approaches used to study them, and the variety of outcomes or results of such studies. Some studies have been very successful, some have not. Given the varying but generally beneficial results of such studies, it seems clear that research on, together with application of, systems analysis techniques to water resources and environmental problems should continue. The paper concludes with some suggestions for facilitating the development and effective application of this methodology.

ISSN:0263-0257    

DOI:10.1080/02630258508970410

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

ISSN:0263-0257    

DOI:10.1080/02630258508970413

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

ISSN:0263-0257    

DOI:10.1080/02630258508970415

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

ISSN:0263-0257    

DOI:10.1080/02630258508970416

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor