Grey Incidence Method Research Articles

Wind farm active power dispatching algorithm based on grey incidence

This study proposes a wind farm active power dispatching (WFAPD) algorithm based on the grey incidence method, which does not rely on an accurate mathematical model of wind turbines. Based on the wind turbine start-stop data at different wind speeds, the weighting coefficients, which are the participation degrees of a variable speed system and a variable pitch system in power regulation, are obtained using the grey incidence method. The incidence coefficient curve is fitted by the B-spline function at a full range of wind speeds, and the power regulation capacity of all wind turbines is obtained. Finally, the WFAPD algorithm, which is based on the regulating capacity of each wind turbine, is compared with the wind speed weighting power dispatching (WSWPD) algorithm in MATLAB. The simulation results show that the active power fluctuation of the wind farm is smaller, the rotating speed of wind turbines is smoother, and the fatigue load of high- speed turbines is effectively reduced.

A dynamic grey target evaluation method with multiple reference points for new R&D institution performance

As a new business form of innovation and development, new R&D institutions are characterized by their focus on regional and industrial major technical needs, diversified investment subjects, diversified construction models, and marketization of operation mechanism. Their performance evaluation faces new problems and challenges. This paper proposes a new dynamic grey target evaluation model of R&D institutions’ performance in regard to four evaluation indexes, three reference points, and four stages. Aiming at resolving the multi-attribute dynamic decision problem with the attribute value being an interval grey number and the decision-maker’s weight information unknown, we propose the use of the close degree of grey incidence method to determine the index weight. Our approach revolves around three reference points: peers, development, and expectations. Value matrices of the three reference points are expressed according to the Cumulative Prospect Theory, which also determines the distance from the center of the grey target. Based on the Orness measure, we establish a multi-stage weight optimization model to calculate the stage weight and the comprehensive cumulative prospect value of each agency. Finally, we verify the validity and practicability of our method with the use of parameter sensitivity analysis, a comparison with other methods, and a case study.

Application of grey clusters in the development of a Synthetic Model of the goals of Polish family enterprises' successors

PurposeThe knowledge of goals of the successor, who is preparing to take over the business, is extremely important for the succession process and further operation of a family enterprise. The aim of this study is to structure the goals of Polish family enterprises’ successors and to develop a Synthetic Model of the goals of Polish family enterprises' successors with the application of grey clustering evaluation models.Design/methodology/approachResearch into the specifics of the diagnosis and assessment of the goals set for the successors of the first succession in family businesses in Poland was carried out in the third quarter of 2016 at two stages using two research methods: in-depth group interview and individual interview. The main aim of the first stage was the extraction of subjectively identified goals by family enterprises' successors (based on their succession experience). The statements were open and obtained during two in-depth group interviews (2 FGI) with successors being in the process of succession at its various stages (total, n = 14). The respondents presented their experiences connected with the succession process along with emotions that are associated with it. In one of the interview stages, the respondents were asked to enumerate their individual goals they set for themselves in the context of upcoming changes. Next, the group agreed on the most frequently mentioned goals by creating their verbal interpretation. The obtained list of 20 goals was recorded and discussed, and thanks to the application of the elimination rule in the collective decision-making process, that list was reduced to 10 goals, which was approved by all participating successors.FindingsThe results show the developed Synthetic Model of the goals of family enterprises’ successors. The study singled out four groups of successors: (1) successors who do not work in the family enterprise yet, (2) successors holding lower-level positions, (3) successors holding managerial positions, (4) successors who manage the entire company. As a result of the calculations, the developed Synthetic Model of the goals of family enterprises' successors was positively verified for successors working in higher-level positions and successors managing the entire family enterprise.Research limitations/implicationsIn order to use the results of clustering, e.g. for conducting studies on large samples with the use of statistical tools, a reduced number of goals should be taken into account. A thorough study of three goals may bring results similar to the study of the original ten successors of Polish family enterprises in the process of succession. The aim of future research is to develop a mathematical model using optimization functions that enable selection of elements representing individual clusters in such a way that it leads to the extraction of the elements with the highest value in relation to the accepted criterion for assessing their value.Originality/valueIn the future, conducting family business research in accordance with the developed methodology requires a look at the proposed list of successor goals obtained during the Focus Group Interview (FGI) as it could be shortened using the Cluster of Grey Incidence method. Shortening the list of goals has its analytic and practical justifications. The study of the full list of goals in subsequent (and numerous further studies) could lead to errors related to, for example, different interpretation of goals among the investigated successors. Furthermore, the full list of goals would increase costs and extend research time.

A Dynamic Decision Making Method Based on GM(1,1) Model with Pythagorean Fuzzy Numbers for Selecting Waste Disposal Enterprises

With the rapid development of society and the economy, most cities have to face a serious problem of “Garbage Siege”. The garbage classification is imperative because the traditional disposal method for household solid waste is not suitable for this situation. The Chinese government proposed a public private partnership (PPP) style to increase the efficiency of garbage disposal in 2013. An effective method to evaluate the waste disposal enterprises is essential to choose suitable ones. A reasonable evaluation method should consider enterprises’ performance not only now but also in the future. This paper aims to propose a dynamic decision making method to evaluate the enterprises’ performance based on a GM(1,1) model and regret theory with Pythagorean fuzzy numbers (PFNs). First, we proposed a GM(1,1) model for predicting score function of PFNs. Then, we put forward a method to obtain the prediction of grey degree using OWA operator. Based on the prediction of score function and grey degree, we established a novel GM(1,1) model of PFNs. Furthermore, we utilized the grey incidence method to obtain the criteria weights with Pythagorean fuzzy information. We used the regret theory to aggregate information and rank the alternatives. Finally, we applied our proposed method to solve the selecting waste disposal enterprises problem in Shanghai. By the case study we can obtain that our method is effective to solve this problem.

灰色关联分析法在双目视觉测量系统误差分析中的应用

According to the excessive error factors and difficult analysis of the binocular vision measurement systems,an error analysis method based on grey incidence technology was proposed.The grey attributes of the vision system were analyzed,and grey system theory and its correlation technologies were introduced into the error analysis of the vision measurement system.9 factors or parameters such as lens distortion,centroid positional error,internal and external parameters in binocular vision system were all selected as independent variables,then sampled data were obtained for error analysis through experiments based on single factor variation.According to grey data processing method and grey incidence analysis technology,the influences of all error factors on final measurement accuracy were definited by irregular samples.Experimental results demonstrate the exactitude and validity that the grey theory is used for quantitatively analysis of errors for the vision system.Under grey theory significance,the incidence degrees of measurement errors with four kinds of factors,the radial distortion and tangential distortion of a lens,the included angle between two cameras and centroid positional error in feature points are larger than 0.859,which is higher than those of other factors.

An Urban Rail Transit Hazard Evaluation Methodology Based on Grey System Theory

Identification and evaluation of urban rail transit operating hazard can prevent accidents, and minimize damages caused by the accidents. In the process of urban rail transit operations, various factors may interact with each other that they function with. After analyzing the security factors of urban rail transit, the urban rail transit hazards are identified. According to the characteristics of urban rail transit systems, three hazard factors such as the potential risk, the existence conditions and trigger factors are chosen as the evaluation indicators. The approach of Grey Correlation Analysis is introduced and used for analyzing and determining the extent of the influences among the factors in a system and the degree of correlation among these factors. The grey incidence method is used for evaluating the hazards of urban rail transit dynamic operating systems and conducting quantitative analysis of risks in the operation process. By studying the actual operating situation of Tianjin metro, the risk points and the hazards of correlation degree are identified in this paper; and the relative high risk hazards are obtained. The calculated results of hazards show consistency between the model and the real situation and feasibility of the method. This research provides a new way to identify and evaluate the hazard of urban rail transit.

Approach to the representativeness of evapori-meters in arid area by grey incidence method

Approach to the representativeness of evapori-meters in arid area by grey incidence method