Detailed Cost Model Research Articles

Design of Irrigation Canals: Integrated Approach

A design methodology is developed to obtain the least‐cost design of irrigation canals. The proposed methodology incorporates elements of the water section and the above‐water section, and is applicable to both lined and unlined canals. Every reach of the canal is described by four basic design variables; bed slope, bed width, upstream bed level, and upstream berm level. A systematic procedure is used to generate design alternatives covering the solution domain. Only those alternatives satisfying a group of preset functional, hydraulic, operational, maintenance, and construction constraints are considered feasible, and are screened to find the least cost. The total cost included the cost of earthwork, lining and trimming (if any), control structures, land acquisition, operation, and maintenance. A detailed cost model is used to estimate the earthwork cost taking into account excavation, deposition, haulage, and soil import or export. The usefulness of the proposed methodology is demonstrated through its a...

Cost optimum heat exchanger networks—2. targets and design for detailed capital cost models

Part 1 of this paper presented a procedure for the design of near-optimum cost heat exchanger networks. The procedure is based on setting targets for capital and energy costs and optimizing these targets prior to design. The procedure in Part 1, however, uses a simple model of capital cost. The present paper extends the model of capital cost to allow for: • —exploiting differences in heat transfer coefficients for reduced network area; • —a non-linear exchanger cost law; • —non-countercurrent heat exchangers; • —non-uniform materials of construction, pressure ratings and exchanger types in the network. /lt Using these extensions both targeting and design for minimum capital cost are considered.

Optimization problems and solution methods in the design of data distribution

The design of data distribution requires solving interrelated optimization problems, concerning data fragmentation and allocation, operations optimization and allocation, and the evaluation of system's performance for given data and operation allocations. Each problem can be solved with several different solution methods; thus, designing data distribution is a very difficult task. In this paper, we characterize each problem and the interactions between them, presenting a general framework for the design of data distribution. We present an entity-relationship schema of the design data dictionary, which stores all information useful during the design, and we use the data dictionary to specify the input and output data for each design problem. We then discuss how the design problems interact. Finally, we present an integrated toolset for the vertical partitioning of relations, which uses different solution methods, called DIVIDE and CONQUER. DIVIDE has a simple analytic model for performance evaluation, while CONQUER uses a detailed cost model. The complexity of methods and experimental results are presented.