An evolutionary model for market bevavior of consumer

♦ учитывающих ограничения и не выводя щих потомка из сферы допустимых решений.

Возникающая, таким образом, зависимость генетического алгоритма от проблемной области приводит к невозможности его использования для оптимизации БП из другой проблемной области, равно как и к невозможности сравнительного анализа применения таких алгоритмов. Однако, в настоящее время, разрабатываются подходы [5] к построению универсальных генетических алгоритмов для случаев не ортогональных ,

Литература

УДК 658.512

S. Dergatchev*

AN EVOLUTIONARY MODEL FOR MARKET BEVAVIOR OF CONSUMER

Extended Abstract: Demand and fashion are strongly influenced by psychological effects. Until now both sides, the economical and the psychological one, have been investigated mainly separately and seldom in mathematical approaches. This article combines both aspects in a mathematical model comprising the dynamics of demand for normal goods as well as for fancy goods. An explicit example shows how the interaction of the snob effect and the bandwagon effect leads to new dynamics on the demand side in the case of fancy goods. Fashion is a driving force in economy as well as in total society. Therefore this phenomenon is investigated within various social sciences like psychology, sociology, economics, and history. However, all the different sciences look at it from different points of view applying different approaches. In psychology scientists concentrate on the behaviour of an individual. It is considered to be influenced by two main antagonistic forces, the striving for uniqueness on the one hand and for conformity on the other. Numerous studies have already been made about the influence of social pressure. S.E. Asch (Asch 1956) and M. Sherif and C.W. Sherif (Sherif 1956) have shown the strong effect of the latter in experiments. The impact of social pressure on fashion has been shown e.g. in Davis/Miller (1983). Though not so well investigated, the desire for uniqueness is also of high importance. The work ofC.R. Snyder and H.L. Fromkin is to be mentioned here. They have carried out many empirical studies about the phenomenon of this desire including its relation to fashion (Snyder/Fromkin 1980). Although besides the desire for uniqueness or conformity also other psychological effects play a role in the formation of fashion, we shall focus on these two main individual driv*

Работа выполнена при финансовой поддержке РФФИ (проект №0-01-00125)

Материалы Международной конференции

“Интеллектуальные САПР”

ing forces in modelling the demand behaviour for fancy goods. In economics many studies have been made on the macro-level. Already G. Simmel (Simmel 1904) has developed a theory explaining the occurrence of fashion, the trickle-down-theory. It describes fashion as a process of interaction between different social groups, in his case social classes. The upper class always wants to distinguish itself from the others whereas the lower class wants to imitate the upper one. In our modern society classes are probably not that important any more. Nevertheless, there still exist different kinds of people and different groups in society and still imitation and differentiation play an important role as suggested by H. Blumer (Blumer 1968) and G.D. McCracken (McCracken 1985).

Only in the recent years many economists widely discussed the issue of fashion demand. The classical models are not able to include the socio-dynamics or as Adams and McCormick put it, &mainstream economics has no theory of fashion changes& (Adams / McCormick 1992). Except for the work of H. Leibenstein in 1950 (see Leibenstein 1976) the existence of fancy goods was widely neglected. In the last few years many very different models have been developed to deal with fashion demand, e.g. the works Maclntegre/Miller (1992), Bikhchandani et al. (1992), and Adams /McCormick (1992) just to mention some of them. However, it is either only mathematical models without psychological backgrounds or non-mathematical discussions about the reasons of fashion. The only exception known by the authors is the work of P. Weise (Weise 1993). In this work the psychological interactions between consumers are discussed and a corresponding mathematical model is set up. In his approach P. Weise combines the microlevel of individuals and the macro-level of the collective behaviour of consumer groups. This line of modelling is embedded into the framework of Synergetics as formulated by H. Haken (Haken 1990). The present paper presents a model which includes the main aspects of consumer’s market behavior. This model is mathematically analysed and its main characteristics are discussed.

УДК 658.512

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ГЕНЕТИЧЕСКИЕ ЭВРИСТИКИ ДЛЯ ОПРЕДЕЛЕНИЯ ПЛАНАРНОСТИ

ГРАФА

Определение планарности графа, т.е. расположение ребер графа на плоскости без пересечений является важнейшей комбинаторно-логической задачей. Все существующие методы определения планарности разбивают на два класса [1]. В первый класс входят методы, основанные на проверке критериев:

Во второй класс входят эвристические методы в той или иной степени использующие критерии первого класса это: