In the manufacturing industry, it is common to conduct visual inspections in order to ensure the quality of products' external appearance. The inspection work, which involves thoroughly checking products, is very tiring and straining on the eyes. One of the reasons for this eye strain is that under the current inspection methods, inspectors are required to use their "central visual acuity" to focus on each inspection item. Previous studies have presented alternative inspection methods which allow inspectors to use their "peripheral visual acuity," which allows more sensitive detection of contrast, and thus may lead to less defects missed and less fatigue. However, the proposed methods fail to consider the size or visibility of each defective item, and the procedures for establishing inspection methods are not specified. This study thus aims to achieve the following three objectives. 1) Experimentally examine the broadening of effective visual field in proportion to the contrast ratios of products and defective items. We define effective visual field as the visual field identified with peripheral visual acuity. 2) Explain the inspection method, which uses the effective visual field concept, and describe the procedures for establishing the inspection method. 3) Present a case in which the established inspection method was applied to an actual business and verify the effectiveness of the method.

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Measuring the optimal safety stock quantity for demand is one of the most significant issues in inventory management. However, it has not been mathematically guaranteed that it is possible to determine the optimal safety stock quantity for correlated demands by applying the approaches which were proposed under the assumption of independently and identically distributed demands in previous studies. To achieve this, a powerful scheme for deriving the optimal safety stock level for trend commodities, which are influenced greatly by the observed demands, must be developed theoretically. To this end, this study presents a novel analysis for finding the optimal safety stock quantity using the large deviation principle. Furthermore the rate function, which plays an important role in cross-disciplinary fields including statistical science, information science, machine learning, the convex optimization problem and statistical mechanics, is explained to resolve issues regarding the optimality of our proposed method. Fortunately, the effectiveness of our framework is confirmed using several distributions of demand. Without loss of generality, using our procedure, we are able to accurately estimate safety stock quantities that are more precise than any approaches published to date.

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Most previous studies concerning the effects of job enlargement were focused on productivity and psychological responses, but there are very few studies being carried out on physiological aspects. The aim of this study is to examine the effectiveness of job enlargement system by comparing monotonous repetitive work and job enlargement, which is the horizontal expansion of a job, in assembly work using several psycho-physiological parameters. The subjects were instructed to assemble Lego blocks, and we measured EEG, heart rate, Jikaku-sho Shirabe, and NASA-TLX. As a result, in job enlargement, the arousal level of workers during assembly work was highly maintained, and psychological stress was reduced by increasing motivation of workers. However, in monotonous repetitive work, workers showed slow wave activities in EEG, low morale, and lack of concentration. The results suggest that the effectiveness of job enlargement system was demonstrated by EEG and psychological parameters.

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Most of the algorithms for the facility layout problem (FLP) attempt to solve the problem through encoding layout candidates and using combinational optimization techniques to obtain the best encoded candidates. However, since FLP is a continuous optimization problem by nature, layouts exist which cannot be represented by these encoding techniques. Therefore, there is possibility that the opportunity to search for the optimal solution will be missed. Furthermore, some algorithms attempt to solve FLP as a continuous problem; however, since FLP is a non-convex problem, it is known that these algorithms have the problem of being trapped into local optima. To overcome these problems, this paper proposes an algorithm to solve FLP through applying a real coded genetic algorithm (RCGA), which is known to be effective for many types of continuous optimization problems.

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According to data released by the Ministry of Internal Affairs and Communications on Respect for the Aged Day in September, 2007, the number of aged people (over 65 years) in Japan is 27.44 million, a figure estimated to be 21.5% of the total Japanese population. This figure and percentage are the highest ever recorded. At the same time, due to the influence of the shift of residential areas to the suburbs and more automobiles, there are many large shopping malls with spacious parking lots operating mainly in suburban areas. In addition, Internet sales and catalog mail orders are increasing in popularity. On this basis, in local shopping areas, there is less traffic and a trend of slowing business that cannot be stopped. However, as places where daily necessities can be bought, local shopping areas are a lifeline for aged people who cannot drive. In this paper, we discuss the policy to maintain local shopping areas as a lifeline for vulnerable people such as aged, and revitalize local shopping areas. This is based on questionnaires to visitors of two local shopping areas in Tobata-ku and Wakamatsu-ku in Kitakyushu, Fukuoka Prefecture, which is referred to as the gateway to Kyushu.

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