This paper proposes a practical tool of incorporating random fuzzy uncertainty into project selection-when there are some projects available for investment, which ones should the investor choose. In the paper, investm...
详细信息
This paper proposes a practical tool of incorporating random fuzzy uncertainty into project selection-when there are some projects available for investment, which ones should the investor choose. In the paper, investment outlays and annual net cash flows of available projects are regarded as random fuzzy variables. Net present value method is employed, and two types of zero-one integer chance-constrained model with random fuzzy parameters are provided. Since it is hard to analytically solve the proposed random fuzzy programming problems, a hybrid intelligent algorithm integrating genetic algorithm and random fuzzy simulation is designed. Numerical examples are also presented to illustrate the modelling idea and to show the effectiveness of the proposed algorithm. (c) 2006 Elsevier B.V. All rights reserved.
Planning for water quality management systems is complicated by a variety of uncertainties and nonlinearities, where difficulties in formulating and solving the resulting inexact nonlinear optimization problems exist....
详细信息
Planning for water quality management systems is complicated by a variety of uncertainties and nonlinearities, where difficulties in formulating and solving the resulting inexact nonlinear optimization problems exist. With the purpose of tackling such difficulties, this paper presents the development of an interval-fuzzy nonlinear programming (IFNP) model for water quality management under uncertainty. Methods of interval and fuzzy programming were integrated within a general framework to address uncertainties in the left- and right-hand sides of the nonlinear constraints. Uncertainties in water quality, pollutant loading, and the system objective were reflected through the developed IFNP model. The method of piecewise linearization was developed for dealing with the nonlinearity of the objective function. A case study for water quality management planning in the Changsha section of the Xiangjiang River was then conducted for demonstrating applicability of the developed IFNP model. The results demonstrated that the accuracy of solutions through linearized method normally rises positively with the increase of linearization levels. It was also indicated that the proposed linearization method was effective in dealing with IFNP problems;uncertainties can be communicated into optimization process and generate reliable solutions for decision variables and objectives;the decision alternatives can be obtained by adjusting different combinations of the decision variables within their solution intervals. It also suggested that the linearized method should be used under detailed error analysis in tackling IFNP problems. (c) 2006 Elsevier B.V. All rights reserved.
The aim of this paper is to solve the portfolio selection problem when security returns contain both randomness and fuzziness. Utilizing a different perspective, this paper gives a new definition of risk for random fu...
详细信息
The aim of this paper is to solve the portfolio selection problem when security returns contain both randomness and fuzziness. Utilizing a different perspective, this paper gives a new definition of risk for random fuzzy portfolio selection. A new optimal portfolio selection model is proposed based on this new definition of risk. A new hybrid intelligent algorithm is designed for solving the new optimization problem. In the proposed new algorithm, neural networks are employed to calculate the expected value and the chance value. These greatly reduce the computational work and speed up the process of solution as compared with the random fuzzy simulation used in our previous algorithm. A numerical example is also presented to illustrate the new modelling idea and the proposed new algorithm. (C) 2007 Elsevier Inc. All rights reserved.
This paper discusses portfolio selection problem in fuzzy environment. In the paper, security returns are regarded as fuzzy variables. Based on credibility measure and the expected value operator and variance operator...
详细信息
This paper discusses portfolio selection problem in fuzzy environment. In the paper, security returns are regarded as fuzzy variables. Based on credibility measure and the expected value operator and variance operator based on credibility, two new types of fuzzy mean-variance models are proposed. A hybrid intelligent algorithm is provided to give a general solution of the optimization problems. Numerical examples are also presented to illustrate the optimization idea and the effectiveness of the proposed algorithm.
This paper presents a two-step interactive satisfactory optimization method for fuzzy multiple objective optimization with preemptive priorities. In contrast to previous works, this proposed approach guarantees the or...
详细信息
This paper presents a two-step interactive satisfactory optimization method for fuzzy multiple objective optimization with preemptive priorities. In contrast to previous works, this proposed approach guarantees the order of satisfactory degrees consistent with priorities. The decision-maker not only acquires satisfactory solution of all the objectives, but also realizes the preemptive priority requirement among them. The originally complex optimization problem is simplified and divided into two subproblems that are solved in sequence. Numerical examples and actual application show the proposed method's effectiveness, flexibility and efficiency in comparison with results from the literature.
In this paper, we discuss a problem of capital budgeting in a fuzzy environment. Two types of models are proposed using credibility to measure confidence level. Since the proposed optimization problems are difficult t...
详细信息
In this paper, we discuss a problem of capital budgeting in a fuzzy environment. Two types of models are proposed using credibility to measure confidence level. Since the proposed optimization problems are difficult to solve by traditional methods, a fuzzy simulation-based genetic algorithm is applied. Two numerical experiments demonstrate the effectiveness of the proposed algorithm. (C) 2005 Elsevier Inc. All rights reserved.
This paper investigates two-player nonzero-sum games with fuzzy payoffs. According to different decision criteria, three new definitions of Nash equilibria as well as their existence theorems are proposed. An example ...
详细信息
ISBN:
(纸本)9781424412099
This paper investigates two-player nonzero-sum games with fuzzy payoffs. According to different decision criteria, three new definitions of Nash equilibria as well as their existence theorems are proposed. An example is also provided for illustrating these new Nash equilibria.
Many practical engineering optimization problems involve discrete or integer design variables, and often the design decisions are to be made in a fuzzy environment in which the statements might be vague or imprecise. ...
详细信息
Many practical engineering optimization problems involve discrete or integer design variables, and often the design decisions are to be made in a fuzzy environment in which the statements might be vague or imprecise. A mixed-discrete fuzzy nonlinear programming approach that combines the fuzzy lambda-formulation with a hybrid genetic algorithm is proposed in this paper. This method can find a globally compromise solution for a mixed-discrete fuzzy optimization problem, even when the objective function is nonconvex and nondifferentiable. In the construction of the objective membership function, an error from the early research work is corrected and the right conclusion has been made. The illustrative examples demonstrate that more reliable and satisfactory results can be obtained through the present method. (C) 2003 Elsevier B.V. All rights reserved.
Material reuse/recycle has gained much attention in recent years for both economic and environmental reasons. Process integration techniques for water network synthesis have evolved rapidly in the past decade. With in...
详细信息
Material reuse/recycle has gained much attention in recent years for both economic and environmental reasons. Process integration techniques for water network synthesis have evolved rapidly in the past decade. With in-plant water reuse/recycle, fresh water and wastewater flowrates are reduced simultaneously. In this work, linear programming and mixed integer linear programming models that include piping cost and process constraints are developed to retrofit an existing water network in a paper mill that was not originally designed with process integration techniques. Five scenarios are presented, each representing different aspects of decision-making in real process integration projects. The fifth scenario makes use of fuzzy optimisation to achieve a compromise solution that considers the inherent conflict between maximising water recovery and minimising capital cost for retrofit.
Most efficiency measures in DEA estimate the distance between DMUs to an efficient frontier as their relative *** there comes forth another method which uses the distance to the inef- ficient frontier to estimate the ...
详细信息
Most efficiency measures in DEA estimate the distance between DMUs to an efficient frontier as their relative *** there comes forth another method which uses the distance to the inef- ficient frontier to estimate the *** paper wants to rank all the DMUs by the Hurwicz criterion, which attempts to find a middle ground between the distances to the efficient frontier and to the inefficient *** varying the parameter in the Hurwicz cri- terion,the ranking method can present various forms. This method can rank all the DMUs including effi- cient ones and inefficient *** many cases,the inputs and outputs can not be given exactly,which can be considered to be *** order to rank the DMUs with fuzzy data,we give the ranking method in DEA under fuzzy environment based on credibility ***,we provide some numerical exam- ples to illustrate the ranking methods that this paper introduced.
暂无评论