Relative Membership Degree Research Articles

Fuzzy Variable Assessment of Urban Flood Control System Safety in Jinan

Urban flood control system is a collection of various preventive measures taken to resist and mitigate flood. Assessment of urban flood control system safety is one of the important measures to coordinate the urban social planning and the urban flood control facilities.The assessment can also promote the sustainable development of city.In allusion to urban flood control system safety is a fuzzy concept with vague denotation, a fuzzy variable assessment model of urban flood control system safety is constructed in this paper based on theories of variable fuzzy sets and relative different functions.The method can determine relative membership degrees and functions of various indexes associated with the urban flood control system safety scientifically and reasonably; through changing the model,the stability of grade eigenvalues is tested; the mean of grade eigenvalues is calculated to improve the reliability of assessment results. The synthetical assessment of flood control system safety can be implemented with the method adopted in this paper.By 4 safety grades, 9 key indexes were screened in the urban flood control system of Jinan to implement the safety assessment in this paper. The case study of Jinan shows that the proposed method is of practical use.

The Optimization Model of Insulation Material of External Wall Based on Multi-Attribute Generalized Connection Degree

The optimization of insulation material of external wall is a multi-attribute uncertainty decision-making problem. Herein based on theory of multi-attribute decision making, a novel decision-making model using generalized connection number of set pair was discussed to solve the problem. Namely, the certainty and uncertainty relationship between the evaluation plan and the optimal plan or the worst plan for the optimization of insulation material was described by means of identical-contrary analysis of set pair theory. And a generalized connection degree was introduced to evaluate comprehensively the relative membership degree of the evaluation plan to the optimal plan. The results from a practical example show that the proposed model used to select the plan of insulation material is feasible and reliable, and easy to operate.

The Study on Multi-Attribute Decision-Making with Risk Based on Linguistic Variable

An approach based on relative optimal membership degree is proposed to deal with multiple attribute decision-making (MADM) problems under risk with weight information unknown and attribute value as linguistic variable. Firstly, the operational laws of linguistic variable are introduced, and risk linguistic decision matrix is transformed into certain linguistic decision matrix by expectation value. Then, the ideal solution and negative ideal solution with linguistic variable are defined, and the attribute weight model is developed by relative optimal membership degree between alternatives and ideal solutions. In addition, the alternatives are ranked by relative optimal membership degree. Finally, illustrative example is provided to demonstrate the steps and effectiveness of the proposed approach.

Peak Load Shifting Distribution by Fuzzy Method Based on Weight Compromise Coefficient

The distribution of power supply limiting in multi-zone is discussed by means of combining analytical hierarchy process and fuzzy sets theory. From the greatest factors in power limiting distribution, guide line system and hierarchy structure are established. Also, the relative membership degree functions are determined. A novel multi-objective group decision model is suggested by introducing a compromise coefficient between subjective weight and objective weight, which can give attention to both. The model is applied to peak load shifting distribution and the result manifests this model is reasonable and applicable.

Spatial distribution of ecological security status assessment of West-Liaohe River based on geographic information system

Eco-security assessment is a hot research area in resource and environmental science, which involves data with much spatial, non-linear, and random features. Geographic information system (GIS), as a useful tool to analyze and manage spatial information, has a superior advantage in this field. A case study in the western part of the Liaohe River featuring a method of eco-security spatial differences (ESSD) based on GIS is developed in this paper. The method includes four steps: 1) developing the pressure-state-response (P-S-R) framework with site data; 2) digitizing West-Liaohe River and setting its GRID database of ecosecurity assessment indicators; 3) figuring out the relative membership degree (RMD) of eco-security indicators by using the analytical hierarchy process with the weight of indicator; 4) classifying the security zone and mapping the assessment result of eco-security status in grid by GIS method of assigning and clustering. The visual spatial differences of eco-security based on GIS enables decision makers to know the status of eco-security better in making policies for achieving sustainability.

A fuzzy optimum model to assess bridge design options

In the process of bridge design, it is necessary to select the best from a number of feasible alternatives by comparison and selection or elimination. The set of criteria used to evaluate and select the satisfactory alternative consists of many qualitative and quantitative factors. Therefore, the selection is a problem of multi-criteria and semi-structural decision making. A new framework and methodology for evaluation of bridge alternatives, which differs from the traditional methods used in semi-structural decision making, is presented in this paper. First the set of criteria for the evaluation of alternatives is established. Next, the method of construction of the relative membership degree matrix, in which both qualitative and quantitative factors are consistent with the uniform calculating standard, is studied. A new weight-assessing method is then developed for calculation of the weightings, based on the relative membership degree matrix and finally a fuzzy optimum model is adopted to select the various alternative bridge designs that satisfy the criteria. A case study is then presented, to show the efficiency and robustness of the new framework and methodology.

Multiple criteria data envelopment analysis for full ranking units associated to environment impact assessment

The importance of the environmental impact assessment (EIA) of large development projects is increasingly underlined. Usually, EIA involves a lot of qualitative and quantitative criteria. Data envelopment analysis (DEA), an effective method that is used to rank and select the best alternative from a set of alternatives, is not tailored to address qualitative criteria, thus rendering the application to multiple criteria problems not amenable. This paper presents a new methodology of multiple criteria data envelopment analysis (MCDEA), which can address both qualitative and quantitative criteria. MCDEA is divided into two stages for fully ranking units and each unit has multiple inputs and outputs. In the first stage, a qualitative method is applied to compare the qualitative performance of alternatives. Then, MCDEA is used to rank the alternatives by considering the relative membership degree of qualitative factors as one of the quantitative data. A case study on the selection of dam location illustrates the effectiveness of the proposed methodology.

Fuzzy Pattern Recognition Approach to Construction Contractor Selection

Contractor selection is a complex process crucial to ensuring the success of construction projects. Existing methods by which owners select a suitable contractor have been inadequate because it is difficult for decision-makers to evaluate contractor bids against inexact qualitative criteria. The purpose of this paper is to propose a Multiple-layer Fuzzy Pattern Recognition (MFPR) approach to solve contractor selection problem. Integrating judgments, experience and preferences of decision-makers, this paper uses the paired comparison method to decide relative membership degrees of qualitative criteria as well as weights of the criteria set, a case study for a channel construction project was used to demonstrate the feasibility of this approach. The findings clearly indicate that the techniques may successfully harmonize different opinions and reach a group consensus.

An approach to fuzzy multiattribute decision making under uncertainty

It seems that there is little investigation on fuzzy multiattribute decision making (FMADM) problems under uncertainty, which are of important to scientific researches and real life applications. FMADM problems under uncertainty are investigated in this paper. Novel mathematical programming models are constructed for FMADM problems under uncertainty, and corresponding solving methods are proposed. The approach proposed in this paper may reflect both subjective judgment and objective information. Moreover, pairwise chain comparison methods for determination of relative membership degrees and weights are also proposed. Feasibility and effectiveness of the models and approach proposed in this paper are illustrated with a numerical example.

FUZZY ITERATION METHODOLOGY FOR RESERVOIR FLOOD CONTROL OPERATION1

ABSTRACT: Reservoir flood control is operated in real time so finding the optimal solution is unnecessary since it may not be practical. The key to reservoir flood control operation is quickly generating some feasible and effective alternatives and then selecting one among them. A fuzzy iteration methodology, which gives the objective weight and the relative membership degree of alternatives at the same time, is presented. Since the weight and relative membership degree are directly acquired from the recommended alternatives provided by decision makers, the results are more reasonable and realistic. Besides, the difficulty in giving weights is also avoided. With the aid of a robust and flexible decision support system, the effectiveness of decision making can be improved.