A fuzzy synthetic evaluation of transportation satisfaction among translocal migrants across Ghana’s urban spaces

A general methodology for fuzzy synthetic evaluation is developed and illustrated with a case study of trophic status assessment for Fei-Tsui Reservoir in Taiwan. The historical data base was collected from the management agency of Fei-Tsui Reservoir from 1987 to 1996. In fuzzy synthetic evaluation, the classification is determined by a matrix operation of the weighted vector with the fuzzy evaluation matrix. After all individual membership functions of evaluated factors have been determined, the fuzzy evaluation matrix can be established. The weighted vector is determined by the analytic hierarchy process method (AHP). The results of this investigation show that the long-term change of water quality and the overturn phenomena cannot be observed with the Carlson index from 1987 to 1992 but is expressed by fuzzy synthetic evaluation. Fuzzy synthetic evaluation is better suited than the Carlson index to rating the trophic status of self-sustaining lakes. Interpretation of the results can provide valuable information to decision makers and aid reservoir management.

In order to ensure the uninterrupted supply of items, the suppliers' performance needs to be evaluated periodically. The evaluation process typically consists of identifying the attributes and criteria relevant to the decision, and measuring the performance of a supplier by considering the relevant criteria. But the evaluation process is complex. Linguistic assessment of suppliers may be carried out based on several criteria. Much of the data are difficult to obtain and ambiguous or vague to interpret. Nonetheless, a rational process of evaluation must exist to select the most appropriate suppliers. This paper develops a supplier evaluation approach based on the analytic network process (ANP) and fuzzy synthetic evaluation under a fuzzy environment. The importance weights of various criteria are considered as linguistic variables. These linguistic ratings can be expressed in triangular fuzzy numbers by using the fuzzy extent analysis. Fuzzy synthetic evaluation is used to select a supplier alternative and the Fuzzy ANP (FANP) method is applied to calculate the importance of the criteria weights. Then an integrated FANP and fuzzy synthetic evaluation methodology is proposed for evaluating and selecting the most suitable suppliers. A hypothetical example is presented and the results indicated that the combination of ANP and fuzzy synthetic evaluation provided useful tool to select the optimal supplier.

Condition monitoring system (CMS) is now widely used in engineering fields. It plays an important role if it’s reliable. But many factors affect reliability of CMS. The traditional reliability theory and approach or fuzzy reliability theory and approach can only assess how one of these factors affects CMS’s reliability. More comprehensive reliability evaluation theory and approach need be developed to assess the reliability of CMS, as well as to analyze impact factors of reliability of CMS. Fuzzy synthetic evaluation theory is becoming a new method of assessing or decision making step-by-step and used broadly in many fields. Based on fuzzy synthetic evaluation and reliability theory, this paper studies the fuzzy synthetic evaluation approach of reliability of CMS and proposes a new method to evaluate reliability of CMS. It first reviews recent development in the study of reliability of CMS, then a fuzzy synthetic evaluation model of reliability for CMS is built, and a practical paradigm is given to show the application of proposed fuzzy synthetic evaluation for reliability of CMS and some conclusions are presented.KeywordsFuzzy reliabilityfuzzy synthetic evaluationmodeling of fuzzy reliabilityimpact factors of fuzzy reliabilitycondition monitoring system

Effective risk management is essential to the success of real estate projects. However, in fact most of statistics emerging in the process of risk management are either ambiguous or unquantifiable, which makes it very hard to fathom. Fuzzy mathematics, to the contrary, is superior and feasible in the way to enable assessment by means of expressive variables. This article constructs a risk index system for real estate enterprise's construction project by means of Delphi method, and then quantifies and analyzes the risk factors by the method of entropy weight fuzzy synthetic evaluation. The case study demonstrates that the fuzzy synthetic evaluation model is practical for estate enterprise's agent construction project prior to the investment and during the contract negotiation.

A new method is proposed for selecting the most appropriate rapid prototyping process according to user's specific requirements by using the expert system and fuzzy synthetic evaluation. The selection process is divided into two stages. First, it is necessary to generate feasible alternatives, which are executed under the expert system environment. Second, given those feasible alternatives, the fuzzy synthetic evaluation approach is employed to produce a ranking order of the alternatives and to finalize the most suirapid prototyping system. One distinctive characteristic of this method is that quantitative as well as qualitative measures are employed, providing more accurate results. The decision system developed based on the proposed method is composed of four modules: a database to store the specifications of various rapid prototyping processes; a knowledge-based expert system for determining the feasible alternatives; a fuzzy synthetic evaluation model to select the most suitable rapid prototyping process; and a user interface and an expert interface to interact with the system. The fuzzy synthetic evaluation approach used in the system is illustrated in detail by a numerical example. Furthermore, a Java-enabled solution, together with web techniques, is employed for developing such a networked decision support system. Finally, two examples of rapid prototyping process selection are designed to demonstrate the application of the system. The system has been implemented and can run at a rapid prototyping and manufacturing networked service platform that the authors have developed.

Entropy method for determination of weight of evaluating indicators in fuzzy synthetic evaluation for water quality assessment

Considering the difficulties of calculation and the defects that the relationship among evaluation objects are ignored when using Fuzzy synthetic Evaluation Method to determine weights to the multi-factors, this paper put forward a new idea of determining weights to the Multi-objective evaluation factors using information entropy. The differences of determining weights using Entropy method and the method of over standard with weight was compared in the weight calculation of evaluating indicators by using the fuzzy mathematics through using the atmosphere monitoring data of 10 monitoring points in the city of Changchun. The results showed that when the evaluation involves a number of evaluation objects using this method was very convenient for fuzzy synthetic evaluation. Only one calculation was enough and it need not to calculate every monitoring point. This method predigested the fuzzy synthetic evaluation process greatly and the evaluation results were objective and reasonable.

A general methodology for fuzzy synthetic evaluation is developed and illustrated with a case study of trophic status assessment for Fei-Tsui Reservoir in Taiwan. The historical data base was collected from the management agency of Fei-Tsui Reservoir from 1987 to 1995. The results of this investigation show that the long-term change of water quality and the overturn phenomena cannot be observed with the Carlson index from 1987 to 1992 but is expressed by fuzzy synthetic evaluation. Fuzzy synthetic evaluation is better suited than the Carlson index to rating the trophic status of self-sustaining lakes.

Considering the difficulties of calculation and the defects that the relationship among evaluation objects are ignored when using Fuzzy synthetic Evaluation Method to determine weights to the multi-factors, this paper put forward a new idea of determining weights to the Multi-objective evaluation factors useing information entropy. The differences of determining weights using Entropy method and the method of over standard with weight was compared in the weight calculation of evaluating indicators by using the fuzzy mathematics through using the atmosphere monitoring datas of 10 monitoring points in the city of Changchun. The results showed that when the evaluation involves a number of evaluation objects using this method was very convenient for fuzzy synthetic evaluation. Only one calculation was enough and it need not to calculate every monitoring point. This method predigested the fuzzy synthetic evaluation process greatly and the evaluation results were objective and reasonable.

This paper develops a supplier evaluation approach based on the analytic network process (ANP) and fuzzy synthetic evaluation under a fuzzy environment. The importance weights of various criteria are considered as linguistic variables. These linguistic ratings can be expressed in triangular fuzzy numbers by using the fuzzy extent analysis. Fuzzy synthetic evaluation is used to select a supplier alternative and the Fuzzy ANP (FANP) method is applied to calculate the important of the criteria weights. Then an integrated FANP and fuzzy synthetic evaluation methodology is proposed for evaluating and selecting the most suitable suppliers. A hypothetical example is presented and the results indicated that the combination of ANP and fuzzy synthetic evaluation provided useful tool to select the optimal supplier.

This study examines the relationship between transport infrastructure and agriculture in Sub-Saharan Africa using new data obtained from geographic information systems (GIS). First, the authors analyze the impact of road connectivity on crop production and choice of technology. Second, they explore the impact of investments that reduce road travel times. Finally, they show how this type of analysis can be used to compare cost-benefit ratios for alternative road investments in terms of agricultural output per dollar invested. The authors find that agricultural production is highly correlated with proximity (as measured by travel time) to urban markets. Likewise, adoption of high-productive/high-input technology is negatively correlated with travel time to urban centers. There is therefore substantial scope for increasing agricultural production in Sub-Saharan Africa, particularly in more remote areas. Total crop production relative to potential production is 45 percent for areas within four hours’ travel time from a city of 100,000 people. In contrast, it is just 5 percent for areas more than eight hours away. Low population densities and long travel times to urban centers sharply constrain production. Reducing transport costs and travel times to these areas would expand the feasible market size for these regions. Compared to West Africa, East Africa has lower population density, smaller local markets, lower road connectivity, and lower average crop production per unit area. Unlike in East Africa, reducing travel time does not significantly increase the adoption of high-input/high-yield technology in West Africa. This may be because West Africa already has a relatively well-connected road network.

Distributed generation (DG) is becoming the indispensable supplement to the centralized generation. Micro-turbine is paid more and more attention in scientific research and commercial application due to its unique advantages and gradually becomes the core of distributed generation. It is essential to make a synthetic and scientific evaluation on the performance of micro-turbine in order to promote the progress of the distributed generation technology using micro-turbine. This article gives the synthetic performance evaluation of micro-turbine. Some performance characters (rated capacity, generating efficiency, rotation speed, pressure ratio, fuel consumption, multi-fuel, intake temperature, exhaust temperature, NOx emission level, noises and life time) were chosen as evaluating indicators and some common micro-turbines were taken as evaluating objects in this paper. Considering the difficulty of fuzzy synthetic evaluation method in calculation of the multiple factors and the ignorance of the relationship among evaluating objects, a new weight evaluation process using entropy method was introduced. The entropy method is an objective way for weight determination. The improved method for weight determination of the evaluating indicators was applied in performance assessment of the micro-turbines. The evaluation result of the example showed that this method was favorable for fuzzy synthetic evaluation when there was more than one evaluating objects and the entropy method for determination of weight was a very effective method for evaluating indicators. The method predigested the fuzzy synthetic evaluation process greatly and the evaluation results are more reasonable.

The fuzzy synthetic evaluation method and the example that the fuzzy synthetic evaluation is applied in ecology environment impact assessment along the Xi'ning-Golmud section among the Qinghai-Tibet railway are introduced in detail so as to reveal the important significance and value of the fuzzy synthetic evaluation.

How to evaluate the validity of the system dynamics models, which is a subject of interest to us. Generally speaking, it is necessary to test the model extensively from different angles, so that people can understand and believe in that model all through, this is so called the validity of the model. Of course, this shouldn’t be all right to evaluate the validity of the whole model only depend on a single test. Hence, the problem is how to evaluate completely the validity of the model through multiple tests. In practice, this is a problem about the synthetical evaluation. The synthetical evaluation can use the approach to find the sum, namely keep the score for the result of each test and then count up them. It can also use the weighted average method. But they aren’t suitable to evaluate the validity of the models. Because the validity is a fuzzy conception. Only using a simple fraction to evaluate the validity of the system dynamics model is not precise. Therefore, it probably is a better method to evaluate the validity of the model synthetically using the fuzzy sets theory. This paper discusses the multilevel evaluation system and fuzzy synthetical evaluation method for the validity of the system dynamics model, and gives a computation example at last. The example proves that fuzzy synthetical evaluation can give satisfactory results.

To deal with subjective artificial and uncertain factor problem of six sigma projects selection, fuzzy synthetic evaluation method on project selection referring to the characteristics of six sigma projects selection was presented. Firstly, in order to provide a better reference for decision-makers, a evaluation index set of six sigma project selection has been set down; Secondly, Taking the five grades of index set as a standard, the experts scoring method is used to confirm the membership of appraisement index for every grade, which can help us to establish a membership matrix; Thirdly, the relatively important degree of level 1 index and level 2 index in the evaluation index set is obtained, and the weight set of evaluation index of all level is founded; Fourthly, the fuzzy synthetic evaluation matrix of first level and second level of spare projects are established by using the membership matrix and the weigh set of index; Lastly, The projects are arranged by the first level fuzzy evaluation matrix, in order to determine the project which should be firstly implemented by enterprise. The fuzzy evaluation method reduces subjective and artificial as well as the indeterminate factors' impact in selection of project, greatly improves the accuracy for enterprise selecting project, which makes the enterprise obtain the greatest success and benefit through the implement of the most appropriate project.