This paper deals with cost analysis model in periodic maintenance policy. The repair policy with minimal repair is considered as follow : as the occurrence of failure between minimal repair and periodic interval time, unit is replaced by a new unit before the periodic maintenance time comes. Then total expected cost per unit time is calculated according to time delta t in a view of customer's. The total expected costs are included repair and usage cost : operating, fixed, minimal repair, periodic maintenance and new unit expected cost. Numerical example is shown in which failure time of item has Normal distribution.

The purpose of this article is about the accelerated product-reliability-test method of the changing colors of mobile products, which are majorly from the frequent touching of sweating fingers. Such problems of changing colors of mobile products have found mostly In metallic paint containing aluminum paste pigments. Also we found that the color of Al Paste is changed by human sweat. Therefore, the accelerated experimental method has been tested as follow: applying the various concentration of lactic acid, which is the changing color components from human sweat, and deeping the testing sample under temperature of $60^{\circ}C$ in dilutelactic acid with water. From the series of tests, the most optimum concentration of lacticacid has been obtained in 10wt% and the sample is observed to be almost same effect as natural changing of colors by human touching after the test. It has been also confirmed from the cross-sectional analysis. In detail, the testing sample has changed its color in 48hr by changing color effect of Alpaste with 10 wt% of lactic acid, and the digit of $\Delta$ E has measured 10.9 after the test.

Social capital contains relational, structural and cognitive dimensions. This study regards social capital as diminishing factor in innovation resistance. Trust, structuring individual tie and vision sharing which are representatives of three dimensions of social capital diminish innovation resistance. So innovation becomes more successful.

This paper proposes a method of modelling the informative dropouts with QoL(quality of life) in survival analysis. QoL is the index to measure the health related quality of life of a patient who got some treatments for a disease. Dropouts are prevalent occurrences on longitudinal study They are commonly dependent to the QoL of patients, that is, severe disease or death and called informative dropouts. Modelling the mechanism of dropouts could achieve the more accurate inference for survival analysis. A likelihood method is proposed to estimate the survival parameter and test the patterns of dropouts.

In this research, first, the effect of Six Sigma activities and business performance will be checked based on case studies involving companies adopting Six Sigma and, secondly, the Six Sigma training effectiveness, Customer Satisfaction and Financial Performance, etc, will be evaluated to find out how related to Six Sigma Implementation. Finally, Six Sigma's Implementation Categories will be analyzed. The method used in this research was to select the research model and research hypothesis based on theoretical studies and the interesting aspects of the recent Six Sigma, along with case studies and research based on actual proof. Case studies and research based on actual proof showed that among 11 companies analyzed, a total of 11 companies obtained good results, and KIs were found to be factors of their success.