• Industrial Engineering and Management Systems
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• v.8 no.3
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• pp.139-147
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• 2009

Control charts are used to distinguish between chance and assignable causes in the variability of quality characteristics. When a control chart signals that an assignable cause is present, process engineers must initiate a search for the assignable cause of the process disturbance. Identifying the time of a process change could lead to simplifying the search for the assignable cause and less process down time, as well as help to reduce the probability of incorrectly identifying the assignable cause. The change point estimation by likelihood theory and the built-in change point estimation in a control chart have been discussed until now. In this article, we discuss two kinds of process change point estimation when the CUSUM ($\bar{x}$, s) control chart for monitoring process mean and variance simultaneously is operated. Throughout some numerical experiments about the performance of the change point estimation, the change point estimation techniques in the CUSUM ($\bar{x}$, s) control chart are considered.

• Journal of Korean Elementary Science Education
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• v.17 no.1
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• pp.23-32
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• 1998

A good example of the persistence of naive theories about change in seasons is well knowned: A filmmaker carried a camera into the crowd of gowned graduates at the 1987 commencement of Harvard University and asked a simple question, that is, "Why is it hotter in summer than in winter?" to twenty five students chosen at random. All of the answers except two were that the Earth is closer to the Sun in summer, so it is hotter in summer, but the Earth is farther from the Sun in winter, so it is cooler in winter. Until now, naive theories about the cause in seasons have been extensively studied. However, few studies to overcome these naive theories were reported. Author takes two steps: first, a new model on the cause in seasons is developed. Second, preservice students concepts' change on the cause in seasons through the new model is observed. The author concludes that the new model have a good effect on the preservice students concepts' change on the cause in seasons.

• Fire Science and Engineering
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• v.29 no.5
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• pp.57-66
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• 2015

This thesis is based on a research to investigate the electrical fire risk due to the single and composite cause in a terminal block. This paper analyzed the thermal characteristics depending on the screw torque change and contact resistance change to measure the fire risk due to the poor contact from single cause first. To measure the fire risk due to the composite cause, the acceleration tracking depending on the contact resistance change was experimented to check the correlation of poor contact and tracking to fire. The experiment result showed that the thermal characteristics were clearer as the screw torque in poor contact status and magnitude of contact resistance increased and that the thermal characteristics of terminal block depending on the contact resistance change was more reliable than the thermal characteristics depending on the screw torque change. Moreover, the terminal block poor contact and tracking were correlated in the case of the composite cause, and when two composite causes were interacted, the electrical fire risk was higher than the single cause.

• Journal of Korean Elementary Science Education
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• v.30 no.2
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• pp.204-212
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• 2011

This research is about the six graders' preconceptions in elementary school about a cause of the seasonal change before learning. The result of this research is that the patterns of six graders's preconceptions in elementary school are earth's rotation, earth's revolution, the distance between the earth and the sun and the location factor between the sun and our country, which are mixed up with two more things. Especially many patterns of students explain the seasonal change of our country using the change of location of our country by earth's rotation, the location factor between the earth and the sun and the distance between the earth and the sun by earth's revolution.

• Proceedings of the Korean Society for Quality Management Conference
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• 2004.04a
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• pp.436-441
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• 2004

Knowing the time of the process change could lead to quicker identification of the responsible special cause and less process down time, and it could help to reduce the probability of incorrectly identifying the special cause. In this paper, we propose a generalized maximum likelihood estimate. (MLE) of the process change point when a control chart with variable sample size (VSS) scheme signals a change in the process mean, and evaluate the performance of this estimator when it mi used with a VSS EWMA chart.

• Journal of the Korean Society of Costume
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• v.51 no.3
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• pp.141-153
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• 2001

The Purpose of this research is to compare the feminine modesties expressed in the clothes of women's college students in 1980s and 1990s, and to find out the social cause of the change of modesty by reference data. Korean women's college students in 1980s considered feminine modesty very important in the selection of clothes but students in 1990's had quite different attitudes. The major cause of this change may be due to the fact that the traditional conservative values in clothes were diminished in 1990's. The main cause of different values in 1980s and 1990s is the rapid social change of korean society in this Period. The concrete factors of changes were the change of authoritarian aesthetic values and the Positive orientation to diversity individuality sensibility and sexuality.

• Maritime Security
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• v.1 no.1
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• pp.31-59
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• 2020

The purpose of this study is to clarify why Russia has changed its position on the Caspian Sea Convention to allow cross-Caspian routes. The theory that explains Russia's change of position on Eurasian integration suggests isolation from the West and rising political and economic importance in the Asia-Pacific as cause, but fails to explain the cause of the change in position that could allow Western influence. Thus, this article suggests that a change in Russia's perception on expanding Eurasia's influence as the cause of the change on its position on the Caspian Sea.

• Proceedings of the Korean Statistical Society Conference
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• 2005.05a
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• pp.191-196
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• 2005

Knowing the time of the process change could lead to quicker identification of the responsible special cause and less process down time, and it could help to reduce the probability of incorrectly identifying the special cause. In this paper, we propose a MLE of the process change point when control charts with the fixed sampling rate (FSR) scheme or the variable sampling rate (VSR) scheme monitor a process to detect changes in the process mean and/or variance of a normal quality variable.

• Journal of Korean Medical classics
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• v.20 no.4
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• pp.251-265
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• 2007

This study is a research on the etiology in Wu Youke's wenyi theory. In regard to the etiology of epidemic disease that had been spread on a very large scale at that time, Wu Youke denied the traditional theory which urged the irregular change of climate as the cause of epidemic disease, and proposed the concept of 'zaqi' which was considered by him to be something that could be the real cause of epidemic disease. And He treated the wenyi disease as something that has the same meaning with wenbing, so his concept on wenbing was basically the thing that treats 'zaqi' as the fundamental cause of wenbing and treats the concept of 'wen(溫)' as an environmental cause that could help activate the virulence of 'zaqi'. Such concept like this was the thing somewhat different from the traditional etiological theory that considers the change of climate as the principal cause of waigan(外感)-disease, and it must for the most part have been originated from the experience of Wu Youke himself. But this study, in contrast, based on the thing he denied the traditional theory on the irregular change of climate, has been done in the point of view that fundamental concept of his wenyi theory such as 'zaqi' was not only originated from his clinical experience but also from the influence of paradigm shift in the natural philosophy of that time. There had been so much change in cosmology and natural philosophy from the fundamental basis at that time, and the the most principal concept of it was that there always exists irregular faces in the change of nature. Such concept like this got into its stride from about 17th century, and it was expressed in the form of the severe criticism against the traditional natural philosophy. In regard to this, this study has outlined the academic thought of the leading scholars who made a significant progress in such a paradigm shift, and it includes the scholars like Wang Tingxiang, Wang Fuzhi, Hu Wei, Huang Zongxi, who played their role in the time of the latter period of Ming dynasty and the former period of Qing dynasty.

• Communications for Statistical Applications and Methods
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• v.10 no.3
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• pp.825-833
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• 2003

Knowing the time of the process change could lead to quicker identification of the responsible special cause and less process down time, and it could help to reduce the probability of incorrectly identifying the special cause. In this paper, we propose a maximum likelihood estimator of the process change point when a Shewhart $\bar{X}$ chart with variable sample size (VSS) scheme signals a change in the process mean. Also we build a confidence interval for the process change point by using the likelihood function.