ISSN:0263-0257    

DOI:10.1080/02630258508970396

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The development and implementation of a Fortran computer program called OGSDP to design a least-cost gravity sanitary sewer system are presented. OGSDP is a model that finds the least-cost design for a non-looping, gravity sanitary sewerage system for a given set of design parameters, costs and lay-out. The final design is the least-cost combination of pipe sizes, upstream and downstream invert elevations (of each pipe) and the corresponding manhole sizes. OGSDP respects most Ten States Standards' (1978) design guidelines. OGSDP determines an initial sewer system design using a heuristic procedure, and then improves the design using discrete dynamic programming with successive approximations to obtain the final least-cost design. It is a practical and efficient tool in the design of sanitary sewer systems.

ISSN:0263-0257    

DOI:10.1080/02630258508970397

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

This paper shows that the iterative optimization-equilibrium algorithm used to solve the continuous network design problem does not solve the original Abdulaal-LeBlanc normative network design model, but rather is an exact and efficient solution procedure for a descriptive model in which the planner and the network users compete in a Cournot-Nash setting. The existence of a solution to this descriptive model is proved, numerical results which illustrate convergence and efficiency of the algorithm are given, and suggestions for future research are made.

ISSN:0263-0257    

DOI:10.1080/02630258508970398

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

A method for simulating systems that have components controlled in an ON/OFF manner is presented. The method is particularly suited to systems with an identifiable component structure such as those found in network problems. The primary feature of the method is that control strategies are modelled separately from the dynamics of the physical system so that various strategies may be added, modified or deleted without affecting either the model of the physical system or the computer code. Control strategies are expressed as combinations of comparators, logic operators (gates) and self-defined control functions such as hysteresis. The complete mathematical model for representing a control strategy, the procedure for automatically formulating the resulting system of control equations, directly from the control strategy, and the interconnection of the physical system model and the control model, are presented. Pipe-network examples are given.

ISSN:0263-0257    

DOI:10.1080/02630258508970399

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

A methodology for ranking pavement sections according to maintenance urgency has been developed using fuzzy multi-attribute decision-making concepts. First. the pavement sections in a highway network are grouped according to their maintenance needs, using fuzzy pavement serviceability indices. Then, the attributes relevant to each category of maintenance are identified, and an expert knowledge base containing priority values for selected combinations of attribute values is formed in collaboration with decisionmakers. Finally, it is shown how the fuzzy attribute values for each pavement section can interact with the expert knowledge base to produce a unique set of rankings for these sections. This ranking scheme is capable of handling possible fuzziness in the priorities assigned by the decision makers.

ISSN:0263-0257    

DOI:10.1080/02630258508970400

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

This note suggests a technique for including pressure dependent demand and leakage terms in simulation models for water distribution systems. Empirical functions are used to relate consumer outflows and leakage losses to the network pressures and the inclusion of these functions in the mathematical formulation of the network analysis problem is described. An application to an existing distribution system is presented where it is shown that the extended network model proposed leads to more realistic simulation results when the network pressures are too low to provide specified consumer demands, or high enough to cause significant leakage losses. It is also found that the computational requirements of network analysis and simulation are not significantly affected by the inclusion of the additional terms.

ISSN:0263-0257    

DOI:10.1080/02630258508970401

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

ISSN:0263-0257    

DOI:10.1080/02630258508970403

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

ISSN:0263-0257    

DOI:10.1080/02630258508970404

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor