This paper proposes a competitive pricing model based on perceived price, using multinominal logit model (MNL) as a consumer response function and applying non-cooperative game for the behavior of firms. To explain perceived price, many concepts such as reference price and reservation price have been suggested in consumer research. MNL was applied in order to describe consumer choice under these concepts. However, in the literature of competitive strategy, MNL was employed with the assumption that utility function is linear with respect to price. Under this linearity assumption, it is difficult to deal with perceived price except when it is explained by the above two concepts.In this paper, we relax this assumption to capture perceived price. This makes our model adaptable to wide variations of perceived price. We assume that the utility function consists of components of perceived price and perceived attribute. In the case of non-linear utility function, profit of competing firms or equivalent payoff function in game theoretic terminology is no longer assured to be quasi-concave. Moreover, we do not set the upper limit for product price. Therefore, the Nash equilibrium may not be unique in pure strategy. If Nash equilibrium does not exist, some researches have resorted to mixed strategy, which implies randomized price. If multiple equilibria exist, there is a possibility that equilibrium price changes from one to the other. In both cases, the market is unstable. First, we assume a multiplicity of Nash equilibria under a pure strategy. We conduct comparative statics of local equilibria that locally satisfy the conditions of Nash equilibrium. This analysis reveals the monotonicity of price, market share, and profit in local equilibria with respect to a perceived product attribute. Second, we focus on a two-firm game. We analyze the behavior of local best-reply function, which denotes the local optimum in a pure strategy when the strategy of the other firm is given. As a result of this analysis, we specify the conditions for the uniqueness of the Nash equilibrium. Third, we conducted a small numerical experiment of our model in the market of recreational vehicles. When the utility function is a quadratic function with respect to price, our model shows an outcome similar to the linear utility models. When the utility function is a cubic function with respect to price, our model shows an outcome quite different from the linear utility models, We conclude that curvature of the utility function with respect to price plays an important role in determining the uniqueness of Nash equilibrium and the marketing strategy of firms.

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The relation between workload, work performance and work posture in a light repetitive task was investigated. The experiment was performed with eight male subjects. Subjects were asked to do multiplication of one-digit numbers and to enter the last digit of their answers on a key board. The task was of 60 min duration, either with a combination of sitting and standing postures which were changed at 15 and 45 min or 30 min, or with no change of posture at all. The effects of the operational conditions were assessed by measuring critical flicker fusion frequency, ocular accommodation, subsidiary behavior, subjective feelings of fatigue, and work performance. In the experiment with no change in posture, workload was higher and work performance lower than with combinations of postures. Change of posture was recommended to be introduced at an early stage : introduction of a change of posture after 15 min was more effective in enhancing work performance than later introduction.

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The Fuzzy-Set Concurrent Rating Method (FCR method) was introduced to measure subjects' attitudes more naturally than the traditional rating method. This paper presents the fundamental idea and mathematical process of the formulae to obtain integrated values from the results of the responding values on FCR scales. Recently, many kinds of algorithms for "approximate reasonings" have been developed. Oda (1995) introduced two integration algorithms by applying two different approximate reasoning techniques. The integration algorithms were named after the inference techniques applied respectively. They are : (1) the min-max-gravity method and (2) the algebraic product-sum-gravity method. They are applied to calculate the integrated values of the datasets obtained using FCR scales. In this paper, new algorithms are proposed for the integration of FCR-scale datasets. They are the "simple scoring method." "reverse-item averaging method, " "inverted scoring method" and the combined algorithms of these 3 methods. The inverted scoring method was developed using the Hyper Logic Space (HLS) model. The HLS model (Oda (1998)) is the direct product space of truth (T) and false (F) dimensions. To each algorithm, explanations or interpretations of the definitions are listed in table form. After proposal of the algorithms, characteristic analyses using systematic numerical datasets are discussed. The position of the data (β, α) in the HLS model can be helpful to understand some interpretations of each algorithm. The results of the analyses reveal the fundamental deferences existing among them and the merits and demerits of each algorithm.

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In this study, scheduling when the 2nd stage is setup is performed in parallel with pre-stage machining in a 2-stage flow shop is considered. The results revealed the following : 1) When 2nd-stage setup is performed in parallel with prestage machining in a 2-stage flow shop, the optimal scheduling searched that is proposed in this study, through a variation of Johnson's theory, provider better results than the schedule searched by Johnson's theory. 2) A procedure for the scheduling of a variation of Johnson's theory was developed. 3) Application of the availability with the variation in Johnson's theory was confirmed through numerical examples.

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We propose a cell formation method based on the minimization of total material handling cost between and within cells. In general, the transfer cost of a unit between cells is different from the cost within a cell. Therefore, in order to determine cell formation based on the total material handling cost, it is necessary to consider both cell layout and machine grouping. It is assumed that a shop has enough area to allocate cells and inter-cell and intra-cell layouts are not restricted by the layout space. We've already proposed a cell layout method based on cluster analysis, which can often be used as a tool to solve the cell formation problem. We now propose an idea that cell layout and cell formation problems are solved together by the clustering procedures.

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Suppose that a job-shop production system consists of a sales center with order-selection and a production center with switch-over. These main models are of periodic and semi-dynamic types. This paper discusses the problem of setting the leadtime of the two models and gives a scientific basis for economic leadtime. For this purpose, we apply the 2-stage design method to the two models. By the 2-stage design method, the economic traffic that maximizes the net reward (=reward-cost) is decided at the first stage. At the second stage, the economic leadtime is set under the economic traffic. First, the respective mean leadtimes are given by the corresponding stochastic models. The mean leadtimes are then obtained from the total mean holding time divided by the number of mean processing units. Next, the respective behaviors of net rewards and leadtimes are numerically considered under the four traffic variables, two selection criteria and two control levels. The existence of economic leadtime is ascertained here. Finally, a comparison of periodic and semidynamic types is given, and a sensitivity analysis of leadtime is shown. Generally, the semi-dynamic type is superior to the periodic type in terms of the economic leadtime.

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This paper deals with the case of manufacturing products with different processing times, and analyses the relation between the target service rate in terms of shipping the products in a specified ratio within an acceptable response time and the planned inventory levels of finished and semifinished products to satisfy the target service rate. Based on the result of the analysis, a mathematical model to determine the optimal inventory configuration is formulated, which minimizes the total planned inventory of finished and semifinished products. The numerical experiments indicate that the optimal inventory configuration weighing much on semifinished products is obtained by the above method. Furthermore, this paper discusses a sensitivity analysis by examining the influence of change in average processing rates used for the above analysis upon the service rate. Lastly, to back up the analysis, production/inventory simulations including machine breakdown are carried out in order to make sure the target service rate can be achieved in the optimal inventory configuration taking into consideration a change in the average processing rates.

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The most important strategy and concern for companies is how to maintain current client and customer "loyalty" in a matured market. The importance of measuring customer satisfaction (CS) is widely noticed, and its improvement is considered one of most promising means to maintain and increase loyalty. However, that validity is based on the implicit assumption of loyalty=CS, and recently some controversies have come up denying such relationship between loyalty and CS. This paper investigates factors influencing loyalty considering four other factors in addition to CS. A questionnaire survey for 7 products and services was designed and the quantitative structure among loyalty and the five other factors is clarified employing LISREL-type analysis. Some implications such as loyalty≠CS and differences by products and services are given.

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