• Journal of Korean Society for Quality Management
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• v.23 no.4
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• pp.13-27
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• 1995

This paper considers the design of life test sampling plans based on Type II censored accelerated life tests. The lifetime distribution of products is assumed to be exponential. An estimator of acceleration factor between use condition stress and an accelerated level of stress higher than use condition stress is assumed to be known. The critical value for lot acceptance and the number of failure before censoring which satisfy the producer's and consumer's risk requirements are determined. The properties of the proposed life test sampling plans are investigated.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.10
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• pp.1139-1143
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• 2009

Pneumatic cylinder is widely used as key component of various industry fields just like automation production line. Recently, people begin to pay attention to reduce development period and cost of pneumatic cylinder so research requirements of accelerated life test of pneumatic cylinder have been increased more than ever. In this research, we shall evaluate availability of acceleration model by statistical analysis of acceleration model's predicted value and life data which acquired in a real operation condition after finish accelerated life test of pneumatic cylinder. Also to predict the life of pneumatic cylinder in the operation condition we shall develop new acceleration model equations.

• The Korean Journal of Applied Statistics
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• v.13 no.2
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• pp.563-573
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• 2000

In this paper, we propose three estimators of Kullback-Leibler Information functions using the data from accelerated life tesb. This acceleration model is assumed to be a tampered random variable model. Some asymptotic properties of proposed estimators are proved. Simulations are performed for comparing the small sample properties of the proposed estimators under use condition of accelerated life test.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.10a
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• pp.25-28
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• 2000

In this paper, the technology for accelerating degradation & life estimation on the traction motor was introduced with the stator form-winding sample coils of the 200 Class insulation system The accelerative degradation was performed in 10 cycles, which were composed of thermal stress, fast rising surge voltage, vibration, water immersion and overvoltage applying. After aging of 10 cycles, condition diagnosis test such as insulation resistance & polarization index, capacitance & dielectric loss and partial discharge properties were investigated in the temperature range of $20{\sim}160^{\circ}C$. Relationship between degradation conditions and diagnosis results were analyzed to find an dominative degradation factor at the end-life point

• Korean Journal of Human Ecology
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• v.15 no.2
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• pp.239-249
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• 2006

The purpose of this research is to examine the relationship among religiosity, self-esteem, and life satisfaction of the elderly. The subjects of this study are 228 elders living in Busan and Gyeongnam areas, who have religions such as Christianity or Catholicism. The main results of this study are as follows: 1) Elders' health condition, starting age of religion, and social religious activity are revealed to be significant variables which influence their self-esteem. 2) Self-esteem, individual religious activity, and health condition are revealed to be significant variables which influence their life satisfaction.

• Korean Journal of Human Ecology
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• v.14 no.6
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• pp.1047-1058
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• 2005

The objective of this research is an investigation and analysis of life style and preference trend for dwelling for 450 university students. The major findings are as follows: (1) The life style is classified into 3 categories according to the priority of fashion and privacy, brand and social relationship, and family and domesticity. Women give priority to fashion and privacy as well as family and domesticity than men do. (2) Dwelling awareness is grouped into 3; one for pursuing the value of asset, another with the inclination to residential transition and the other for preferring for a detached house. Women have a stronger inclination to the economical value of house and prefers to live in the big city than men do. (3) As a factor affecting the dwelling preference, men give priority to the exterior condition such as environment, but women do the interior condition like the size of house. Men and Women showed various preferences for housing style such as detached house, villa, apartment and commercial complex dwelling, which is accord with the present housing style.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.4
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• pp.134-140
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• 2016

Main Spindle System has effect on performance of machine tools and working quality as well as is required of high reliability. Especially, it takes great importance in producing automobiles which includes a large number of working processes. However, main spindle unit in Machine tools are often cases where damage occurs do not meet the design life due to driving in harsh environments. This is when excessive maintenance and repair of machine tools or for damage stability has resulted in huge economic losses. Therefore, this studying propose a method of accelerated life test for diagnosing and prognosis the state of life assessment main spindle system. Time status monitoring of diagnostic data - through the analysis of the frequency band signals were carried out inside the main spindle bearing condition monitoring and fault diagnosis.

• Proceedings of the KWS Conference
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• 2007.11a
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• pp.181-183
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• 2007

Experimental analysis was carried out to understand the fatigue phenomena of different thickness stainless steel overlap joining structure by Nd:YAG laser welding. The fatigue life was obtained through fatigue tests with the various levels of applied load. The fatigue life is related with the parameters such as gap condition and penetration depth through experiment. As the results, tensile and fatigue strength were proportional in heat input level and bead width was identified the major factor for joining strength. Also the fatigue life were decreased depend on gap condition, it was more affected at the low load level.

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.04a
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• pp.72-73
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• 2000

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.05a
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• pp.419-420
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• 2006