Emerald | Grey Systems: Theory and Application | Table of Contents

A summary on the research of GRA models

Fri, 25 Jan 2013 00:00:00 +0000

Abstract

Purpose – The purpose of this paper is to review systematically the research of grey relation analysis (GRA) models. Design/methodology/approach – Three different approaches, the springboard to build a GRA model, the angle of view in modelling, and the dimension of objects, are analysed, respectively. Findings – The GRA models developed from the models based on relation coefficients of each point in the sequences in early days to the generalized GRA models based on integral or overall perspective. It evolved from the GRA models which measure similarity based on nearness, into the models which consider similarity and nearness, respectively. The objects of the research advanced from the analysis of relationship among curves to that among curved surfaces, and further to the analysis of relationship in three-dimensional space and even the relationship among super surfaces in n-dimensional space. Originality/value – The further research on GRA models is proposed. One is about the property of GRA model. An in-depth knowledge about the properties of GRA model will help people to understand its function, applicable area and requirements for modelling. The other one is about the extension of research object system. The object to be analysed should be extended from the common sequence of real numbers to grey numbers, vectors, matrices, and even multi-dimensional matrices, etc.

Selection method of monitoring parameter optimization in prognostics and health management based on grey clustering decision

literatinetwork@emeraldinsight.com (Jianghong Yu, Daping Wang, Chengwu Hu) — Fri, 25 Jan 2013 00:00:00 +0000

Abstract

Purpose – The purpose of the paper is to propose a novel approach, based on grey clustering decision, to fill in an omission of quantitative monitoring parameter selection methods. Design/methodology/approach – The basic monitoring parameter selection criteria and the corresponding calculation methods are presented. Then, the grey clustering decision model for monitoring parameter optimization selection is constructed, and an integrated weight determination method based on analytic hierarchy process (AHP) and information entropy is provided. Findings – Basic principle for monitoring parameter selection is proposed and quantitative description is carried out for selection principle in engineering application. Grey clustering decision-making model for monitoring parameter optimization selection is established. Comprehensive weight ascertainment method based on AHP and information entropy is provided to make the index weight more scientific. Practical implications – At system design stage, it is of significance to carry out selection and optimization of monitoring parameters. After the optimization of monitoring parameters is confirmed, measurability analysis and design in parallel are carried out for convenience of timely information feedback and system design revision. Therefore, the system integration efficiency is improved and the cost of research and manufacturing is reduced. Originality/value – Monitoring parameter optimization selection process based on grey clustering decision-making model is described and the analysis result shows that the proposed method has certain degree of effectiveness, rationality and universality.

Random simulation method for accuracy test of grey prediction model

literatinetwork@emeraldinsight.com (Zhang ke) — Fri, 25 Jan 2013 00:00:00 +0000

Abstract

Purpose – The purpose of this paper is to establish a random simulation method to compare the forecasting performance between grey prediction models, and between grey model and other kinds of prediction models. Then, the different performance of three grey models and linear regression prediction model is studied, based on the proposed method. Design/methodology/approach – A random simulation method was proposed to test the modelling accuracy of grey prediction model. This method was enlightened by Monte Carlo simulation method. It regarded a class of sequences as population, and selected a large sample from population though random sampling. Then, sample sequences were modeled by grey prediction model. Through modeling error calculation, the average error of grey model for the sample was obtained. Finally, the grey model accuracy for this kind of problem was acquired by statistical inference testing model. Through the statistical significant test method, the modeling accuracy of grey models for the same problem can be compared. Also, accuracy difference between grey prediction model and regression analysis, support vector machine, neural network, and other forecasting methods can be also compared. Findings – Though random simulation experiments, the following conclusion was obtained. First, grey model can be applied to the long sequence whose growth rate was less than 20 per cent, and the short sequence whose growth rate was less than 50 per cent. Second, GM(1,1) cannot be applied to a long sequence with high growth. Third, growth rate was a more important factor than growth length on modeling accuracy of GM(1,1). Fourth, when the sequence length was short, accuracy of GM(1,1) model was higher than linear regression. While the length of the sequence was more than 15, and the growth rate in [0-10 per cent], two kinds of modeling error was not significantly different. Practical implications – The method proposed in the paper can be used to compare the performance of different prediction models, and to select appropriate model for a prediction problem. Originality/value – The paper succeeded in establishing an accuracy test method for grey models and other prediction models. It will standardize the grey modelling and contribute to application of grey models.

Grey theory based MCDM procedure for sniper selection problem

literatinetwork@emeraldinsight.com (Erkan Kose, Mehmet Kabak, Hakan Aplak) — Fri, 25 Jan 2013 00:00:00 +0000

Abstract

Purpose – Personnel selection is an important process in management due to the high cost of unfavorable employee procurement. The multi criteria nature and the presence of both qualitative and quantitative factors make it considerably more complex. The purpose of this paper is to propose a grey theory-based hybrid approach to solve personnel selection problems in uncertain environments. Design/methodology/approach – The work procedure is as follows: first, grey analytic network process (GANP) is applied to calculate selection criteria weights and then candidates are ranked by using grey possibility degrees. Finally, an example of a selection problem of sniper for a military unit was used to illustrate the proposed approach. Findings – The analyses of the results show that grey theory-based methods have enormous chance of success for personnel selection problems in uncertain situations. Originality/value – Although there are some applications for personnel selection problems that used grey system theory in the literature, the combination of GANP and grey possibility degrees is used for personnel selection problem in this study.

Research on complex product cost estimation based on the N-GM (0, N) model

literatinetwork@emeraldinsight.com (Chen Hongzhuan, Fan Kaifeng, Fang Zhigeng) — Fri, 25 Jan 2013 00:00:00 +0000

Abstract

Purpose – The purpose of this paper is to propose a prediction model to predict the cost of complex products with lack of data. The cost estimating is one of the key elements of arguments around technological economy and investment decision-making process of complex product. Design/methodology/approach – A complex product has many characteristics, such as complex structure, large investment, high risk and it usually falls into small-batch-production category. Its cost estimation samples are small and cost data are very limited. Based on the characteristics of complex product and cost estimating, this paper introduces performance parameters sequence of associated known data, establishes an N-GM (0, N) model of characteristic sequence with straddle missing data. Findings – On the basis of the known key performance parameter sequence, N-GM (0, N) model is used to predict the grey interval of overall cost vacancy data. Overall cost vacancy data is whitened by sorting reference sequence and realizing complex product overall cost estimation. Practical implications – The method introduced in the paper can be used to solve practical problems, especially cost prediction of complex products with poor data. The model is also applied on the overall cost and the key component cost estimation of similar but different complex products. Moreover, it provides potential theoretical support for the development of complex product industry in the future. Originality/value – In this paper, the complex product, which now plays a strategic industrial role in China, is systematically studied by utilizing a new methodology based on grey systems, especially the cost evaluation of the complex product. The use of grey correlation analysis in screening control key item index of complex product cost, the overall cost sequence of the complex product as related sequence and sorting reference sequence, the paper predicts and whitens vacant key item index, obtaining the key item cost index of complex product.

Supply chain optimization modeling in uncertain environment with prediction mechanism

literatinetwork@emeraldinsight.com (Chong Li, Kejia Chen) — Fri, 25 Jan 2013 00:00:00 +0000

Abstract

Purpose – The purpose of this paper is to explore new methods to improve supply chain management in uncertain environment, more specifically, to tackle the uncertain demand problem and the inventory optimization problem faced by most supply chain systems. Design/methodology/approach – The paper develops a multi-objective inventory optimization model, which combines the classic grey prediction GM(1,1) model with the metaheuristic method. The former is applied to achieve the forecasting mechanism in supply chain operations, and the latter is applied to optimize the model solution. Findings – Results show that the grey-based forecasting mechanism performs better than other prediction methods, such as the double exponential smoothing method used in this paper. The solution of the multi-objective inventory optimization model is also improved with the integration of grey prediction method. These indicate the importance of a forecasting mechanism in supply chain management. Originality/value – The paper succeeds in constructing a novel inventory optimization model and in providing a novel supply chain management framework. It shows for the first time that grey prediction method combined with metaheuristic method may be a valid approach to supply chain management under uncertain environment.

Business School ranking with grey relational analysis: the case of Turkey

Fri, 25 Jan 2013 00:00:00 +0000

Abstract

Purpose – The purpose of this paper is to explore the teaching performance of Turkish Business Schools (BSs). It also aims to determine the degree of importance of factors affecting the teaching performance of Turkish BSs. The final objective is to test the functionality and applicability of the model. Design/methodology/approach – This study presents a ranking approach based on grey relational analysis (GRA). While evaluating the BSs, data were collected for 19 Turkish BSs in terms of five main criteria such as OSS score; Number of faculty members; Number of students per faculty member; the mean of KPSS score; and the standard deviation of KPSS score. In the analysis, three weighted methods were integrated into the GRA in order to weight the criteria. Findings – According to this result, the main factor influencing the teaching performance of Turkish BSs is the OSS score. This study can also confirm that the results obtained from the ranking orders using the proposed methods are reliable and these results can help decision makers to identify the best alternative. Research limitations/implications – In order to provide benchmarking data more effectively, in future, it would be helpful to collect data from both foundation and state universities with a research focus. Moreover, as an interesting suggestion for future research, fuzzy environment may be further integrated into the framework of GRA. Originality/value – In contrast to prior research, this study makes comparisons based on the scores of national exams instead of different bibliometric indicators. Furthermore, there are no studies which have used GRA and these weighted methods as combined in education sector.

Conflict analysis based on the graph model for conflict resolution and grey matrix

Fri, 25 Jan 2013 00:00:00 +0000

Abstract

Purpose – The purpose of this paper is to propose a complete theory of grey conflict analysis model based on grey game and the graph model for conflict resolution and also, to illustrate a case of “prisoner's dilemma” in the traditional grey game as an example. Design/methodology/approach – Based on the theories of grey game and graph model for conflict resolution, this paper concentrates on the model of grey conflict analysis in a case of two players under the condition of symmetrical loss information. By analyzing decision makers, strategies, states, graph model and grey potential, and the number of decision makers' steps, the pure strategy Nash equilibrium is extended to grey potential-general metarationality, grey potential-symmetrical metarationality, and grey potential-sequential stability. Meanwhile, the logical relationships between solutions are discussed. A specific case study is carried out to illustrate how the proposed grey conflict analysis model is used in practice. Findings – The results in this paper indicate that more stable solutions are found when one considers the grey potential-general metarationality, the grey potential-symmetrical metarationality, and the grey potential-sequential stability, and then solve the paradox of “prisoner's dilemma”. Practical implications – This new grey conflict analysis model could be used to provide useful information for policy makers during existing conflicts or negotiations among parties or enterprises. Originality/value – The paper succeeds in constructing a new grey conflict analysis model, in which the solution concepts are studied; and the two-player grey game will be extended to n-players in the near future.

Editorial comment to models in grey system theory

literatinetwork@emeraldinsight.com (Nai-ming Xie) — Fri, 25 Jan 2013 00:00:00 +0000

The 4th IEEE International Conference on Grey Systems and Intelligent Services

Fri, 25 Jan 2013 00:00:00 +0000