Liu Si-feng

The GM models that x(n) be taken as initial value

In this paper, the starting conditions of GM model group are studied. By choosing the nth component of X(1) as the starting conditions of the grey differential model, improvements are made on the models. As the new information is fully used, the accuracy of prediction is improved greatly. Therefore, it has high theoretical and practical value.

Study of integrate models of rough sets and grey systems

This paper firstly compares rough sets theory with grey system theory, then the concept of grey sets is proposed and the grey degree of grey sets and the basic relationships and operations of grey sets are defined. Next, we set up the models of grey rough sets and wide grey rough sets as well as study their properties. Moreover, the definition of rough grey sets is given and their basic characters are investigated. Furthermore, the relations between rough grey sets and grey rough sets are researched. Finally, we come to the conclusion that it is possibly more effective to deal with some uncertain problems if the theories and methods of rough sets and grey systems are combined.This paper firstly compares rough sets theory with grey system theory, then the concept of grey sets is proposed and the grey degree of grey sets and the basic relationships and operations of grey sets are defined. Next, we set up the models of grey rough sets and wide grey rough sets as well as study their properties. Moreover, the definition of rough grey sets is given and their basic characters are investigated. Furthermore, the relations between rough grey sets and grey rough sets are researched. Finally, we come to the conclusion that it is possibly more effective to deal with some uncertain problems if the theories and methods of rough sets and grey systems are combined.

Grey system and grey data management in medicine

Based on the grey characteristics of medical data, some basic concepts of grey medicine are introduced, including grey medical cognition mode, grey-relational-coefficient, grey relational grade, grey relational sequence, grey polarity, together with the latest advances in grey relational analysis.

A new computation model of Grey incidence degree met four axioms and its application in OFR

The basic principle of Grey incidence analysis is to judge compactness of sequences according to the extent of geometry similitude between data curves. By Grey incidence analysis, we can find the osculation extent between system behaviors data. Since Prof Deng established this analysis method in 1980s, some computation methods are developed, but according to the four Grey incidence axioms developed by Prof Deng, there is all more or less unseemliness in these computation models. Based on the theories of Grey incidence theory, in this paper we summarize firstly several representative Grey incidence computation models of present. Then, we point out their shortcomings respectively and review them simply. Furthermore, seeing into the meaning of Grey incidence axioms, we establish a new computation model of Grey incidence degree - Integrated Model, which considers the absolute differences and relative differences of data sequences and gets over the shortcomings of present models. Lastly, we prove this computation model to be scientific and to satisfy the four Grey Incidence Axioms, and then with this model we analyze the outsource of firms resource.

Multi-stratum medical grey relational theory and its application research

This article is to explore the theory and the application of multi-stratum medical grey relation. The axiom system of multi-stratum medical grey relational analysis is introduced; Some concepts of multi-stratum medical grey relation are defined including the primary reference factor, the assistant factor, the stratum comparison factor, the leading comparison factor, the dominant assistant factor, the recessive assistant factor and the cooperative factor; multi-stratum grey relational space and GRG matrix are also defined. Based on the data from the hypertensive, the multi-stratum (e.g. endocrine-stratum, blood pressure-stratum, and heart-stratum) medical grey relational analysis revealed the same conclusions as most clinical researches, and satisfactory specialty explanations were also offered.

Study on expansion and properties of grey accumulating generation operator

By utilizing Gamma function expanded for integer factorial, this paper deduces the analytical expression of integer order accumulating generation operator based on the one order accumulating generation operator, then expands the integer order accumulating generation operator into the fractional order accumulating generation operator, and gives the analytical expression of fractional order accumulating generation operator. Actually, one order accumulating generation operator and integer order accumulating generation operator are both special cases of the fractional order accumulating generation operator. Theoretical proof and numerical simulation proves that the fractional order accumulating generation operator satisfies commutative law and exponential law. Study on the fractional order accumulating generation operator would help develop grey prediction model with the fractional order operators and would widen the application fields of the grey prediction model.

Research on extended cluster of grey incidence and its application

This paper studies extended clusters of grey incidence for indexes in panel data. First, it discusses the expression of a panel data by matrix sequence, and describes its geometric characteristic through a cluster of curved surfaces. Thereafter, in three dimensional space, the paper analyzes the geometric similarity of indexes in panel data. According to the principle of grey incidence analysis, it proposes an absolute degree of grey incidence for matrixes, which maintains the consistent form with the classic one. Furthermore, the formula of zero starting point operator and parameters are redefined. On this basis, the paper constructs the extended incidence matrix of indexes and discusses the cluster analysis process of panel data. Finally, an example is presented to illustrate the proposed mehtod. The results prove the method is effective.

Research on the new algorithms of simple grey numbers, complex grey numbers and multiple grey numbers

Although grey systems theory has been successfully utilized in many fields and demonstrated promising results, literatures show its performance still could be improved. Remarks on grey number and algorithms of grey numbers need to be farther discussed. Grey number is the basic element of grey systems theory. The algorithms of grey numbers are the foundation of grey mathematics. This paper modifies the definition of grey number and discusses several remarks on grey number. We propose a method for abstracting information of grey number covered set. And we propose the algorithms of simple grey numbers, complex grey numbers and multiple grey numbers. All these works are meaningful to bring grey mathematics to perfection and propose more grey applying models.

A grey rough set model based on (α,β) grey similarity relation

Combining the methods of rough set theory and grey system theory and by introducing the grey number concept, the conventional incomplete information system method is extended and a kind of (alpha, beta)-grey similarity relation GSIM(alpha, beta) of grey information system is proposed, then the model of grey rough set based on the (alpha, beta)-grey similarity relation is established and investigation is made in the related foundational theories. Methods are proposed to describe the positive, boundary and negative regions and the reduction of grey decision-making table in the grey rough set by the recognition degree mode of grey theory, and a solution to the problem of incoherence is brought forward in the grey decision-making table from the angle of recognition degree mode. Example shows that this kind of model is more intuitive and rational. It breaks through the limitation of the study on conventional rough set theory which is restricted to the classic relations.

Grey incidence decision-making method of grey hesitant fuzzy sets based on kernel and grey degree

Firstly, this paper expands hesitant fuzzy into grey hesitant fuzzy sets; Secondly, the “kernel and grey degree” method of grey systems is used instead of the data supplement method that traditionally presupposes the risk preferences of decision-makers. It enhances reliability on the premise of maintaining the information domain; Then we extended the “kernel and grey degree” algorithm to the decision making process of grey relational grade. Finally, an example is given to demonstrate the feasibility and applicability of this method, we study and analyze it, and we compare it with related methods in the literature. This research has a positive effect of extending the application scope of grey systems, enriching and improving the theory system of the grey correlation model.