ISSN:0263-0257    

DOI:10.1080/02630258808970495

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The concepts of target probability, safety margin and other safety measures are considered. For codes of practice, frequently used in structural engineering to act as guidelines for safety, unmodified economic figures can lead to unrealistically high target probability values. Codes of practice are seen as a constraint on the design process to achieve desired safety targets and a utility function is proposed for this purpose.

ISSN:0263-0257    

DOI:10.1080/02630258808970496

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A new approach to modelling probabilistic and stochastic engineering systems using graph theory is outlined. This approach emphasizes the introduction of probabilistic and stochastic concepts at the very beginning of the model building process. This is in marked contrast to past tendencies to add probabilistic concepts to the end of an otherwise deterministic model building process. The development of topological models founded on oriented probabilistic measurements is given. which leads to the identification of some useful statistical properties of the’ random interconnection equations’. The development of probabilistic component models is given, where a component can be characterized independently of other components. Methods for automatically building the second moment representation of the Mixed Nodal Tableau are discussed. The application of the above theory to the probabilistic analysis of a pipe network problem is briefly described.

ISSN:0263-0257    

DOI:10.1080/02630258808970497

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

There are presently no established guidelines available for a bridge inspector to follow when assessing the significance of multiple deterioration factors on the bridge condition rating. As such, the evaluation of an existing bridge is based on a highly subjective and non-uniform procedure, and usually suffers from imprecision and personal bias. Hence, any attempt to find the optimal solution for bridge management based on such rating procedure can be misleading. However, with the development of a fuzzy mathematical approach, human subjectivity and imprecision can be included systematically in the decision making process.

ISSN:0263-0257    

DOI:10.1080/02630258808970498

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A comparative analysis between two methods for steady-state simulation of high-pressure gas networks has been made. Computation time has been taken as a criterion for comparison assuming that sensible accurate results are given. Investigations have shown that one of these methods is very much better in all cases considered.

ISSN:0263-0257    

DOI:10.1080/02630258808970499

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Trihalomethane (THM) and other by-products are formed by the reaction of free chlorine and organic precursors. The collective effects of different raw water quality and chlorine treatment measures are used as candidate variables in the formulation and parameter estimation of models to predict THM concentration in treated water. Some of these predictor variables involving raw water quality (state variables) are highly correlated. In addition, retrospective studies often involve treatment measures (control variables) which, either because of practical exigencies or poor design, are correlated. As a result of correlations among variables, regression models that are fit with ordinary least squares are of questionable merit because model parameter estimates are generally poor. Yet, the potential value of such studies and modelling efforts should not be ignored. An approach consisting of the use of condition indexes and variance-decomposition proportions, ridge regression, and path analysis is used for model development. These techniques are used to identify the extent and possible causes of ill-conditioning, and to offer a means of rationally eliminating predictor variables that are considered to cause ill-conditioning or to have an insignificant effect on prediction. Four case studies are used to demonstrate the approach and to show that our final models contain only predictor variables that are both statistically and physically significant. Critical evaluation of the models reinforces theoretical concepts for explaining THM formation in finished water.

ISSN:0263-0257    

DOI:10.1080/02630258808970500

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

This paper introduces a new technique in construction networking. A modified fault tree analysis was employed to determine the critical paths, sequence of activities, and the basic events that have the potential to induce the delays of any activity in the network. This method can be used for both deterministic and non-deterministic approaches. It also incorporates the provision of minimal cut sets that guarantee the occurrence of a delay. The cut sets can be evaluated qualitatively, quantitatively, or both, in order to determine their rank of importance.

ISSN:0263-0257    

DOI:10.1080/02630258808970501

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

ISSN:0263-0257    

DOI:10.1080/02630258808970502

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

ISSN:0263-0257    

DOI:10.1080/02630258808970503

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

ISSN:0263-0257    

DOI:10.1080/02630258808970504

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor