• KIEE International Transactions on Power Engineering
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• 제2A권3호
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• pp.114-120
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• 2002

This paper describes the symptoms with the fault causes of pole transformers analyzed by Korea Electric Power Corporation(KEPCO) branch offices' request in 2001, and ultimately aims to devise proper countermeasures against the faults. The fault causes are generally divided into problems in manufacturing, mounting and operating. The pole transformers encounter the fault with unique aging mechanisms. To verify the mechanisms with the faults and to devise proper countermeasures, a flowchart for analyzing the fault causes is proposed, by which the fault causes of the pole transformers can be analyzed more exactly.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1001-1006
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• 2004

Railroad disasters are frequently occurred by man-made causes or natural causes. In general, man-made causes are illegal construction practices, deterioration with the lapse of time and railroad crossing accidents, and natural causes are rainfall. snow, wind, earthquake, etc. Of cause, railroad disasters by man-made causes are prevented from keeping the safety principle, constructing multi-level crossing, securing enough men of ability and financial resources and making a thorough check using equipments with high capacity. And railroad disasters by natural causes are also minimized by construction of disaster prevention facilities, introduction and operation of general disaster prevention system and reasonable train passage control. Therefore, to setup the criterion of train passage control for train safety at railroad bridge under heavy rainfall, risky factors, national and oversea criteria under such circumstances are reviewed and a scheme to setup the criterion is suggested.

• 대한수학교육학회지:수학교육학연구
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• 제21권2호
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• pp.201-220
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• 2011

본 연구에서는 초등학교 5학년과 중학교 2학년 학생들이 측정상황과 우연상황에서 통계적 변이성을 설명하고 제어할 때 나타나는 사고 수준을 살펴본다. 연구결과, 측정상황에서 변이성을 설명할 때는, 원인 설명에 대한 이해가 부족한 수준, 원인 인식이 미흡한 수준, 물리적 원인을 제시하는 수준, 설명되지 않는 원인을 변이성의 근원으로 인식하는 수준, 설명되지 않는 원인을 의사-우연변이성으로 간주하는 수준이 확인되었다. 우연상황에서 변이성을 설명할 때는, 원인 설명에 대한 이해가 부족한 수준, 원인 인식이 미흡한 수준, 물리적 원인을 제시하는 수준, 우연변이성을 인식하는 수준, 분포의 원인을 인식하는 수준이 확인되었다. 변이성을 제어할 때는, 측정상황과 우연상황 모두에서 변이성 제어에 대한 인식이 미흡한 수준, 물리적 제어 방법을 고려하지 않으며 또한 통계적 방법 역시 부적절하게 적용하는 수준, 물리적 제어 방법은 고려하지 않지만 통계적 방법을 적절하게 적용하는 수준, 물리적 제어 방법은 제시하지만 통계적 방법을 부적절하게 적용하는 수준, 물리적 제어 방법을 고려하며 또한 통계적 방법을 적절하게 적용하는 수준이 확인되었다.

• 대한인간공학회지
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• 제34권2호
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• pp.103-113
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• 2015

Objective: This study proposes a systematic process to present the analysis methods and solutions of organizational root causes to human errors on the railroad. Background: In fact, organizational root cause such as organizational culture is an important factor in the safety concerns on human errors in the nuclear power plant, railroad and aircraft. Method: The proposed process is as follows: 1) define analysis boundary 2) select human error taxonomy 3) perform accident analysis 4) draw root causes with FGI 5) review root causes analysis with survey 6) chart analysis of root causes, and 7) propose alternatives and solutions. Results: As a result, root causes of the organizations like railroad and nuclear power plant came from the educational problems, violations, payoff system, safety culture and so forth. Conclusion: The proposed process does predict potential railroad accident through retrospect error analysis by building new human error taxonomies and problem solution. Application: This study would contribute to examination of the relationship between human error-based accidents and organizational root causes.

• 임상간호연구
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• 제17권3호
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• pp.363-374
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• 2011

Purpose: The purpose of this study was to identify the types and causes of non-value-added (NVA) activities in nursing practice, and to determine the frequency of each NVA type and causes of NVA in clinical area. Methods: This study was conducted using Delphi technique. First, in order to identify NVA and their causes, 24 nurses with 7 years or more of clinical experience were recruited from medical/surgical units in six general hospitals in Korea. Then the NVA types and causes were tested using a larger sample of 130 nurses with more than 3 years of clinical experience at two general hospitals in Korea. Results: NVA was categorized into 6 different types, which are repeating, duplicating, waiting, reverse-proxy working, reworking, and searching. The most prevalent NVAs were repeating and duplicating works. Reworking and searching were less frequent types than others. The causes of NVA were classified into personnel-related, supporting departments, records, regulations, information, materials or instruments, and others. Among them, personnel-related and supporting departments were reported with the highest scores. Conclusion: NVA leads to waste cost and time. These results demonstrated the situations and causes of NVA occurred in nursing practice. Further studies on the typology and moderation of NVA activities are warranted to improve the efficiency and quality of nursing care in day-to-day practice.

• 품질경영학회지
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• 제31권2호
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• pp.183-193
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• 2003

A special cause producing temporary deviation in the underlying process can influence on process adjustment in responsive feedback control system. In this paper, the impact of special causes on the EWMA(Exponentially Weighted Moving Average) forecasts and the process adjustment that is based on the EWMA forecasts are derived. For some special causes with patterned type of contamination, the influence of the causes on the output process are explicitly investigated. A data set, contaminated by a special cause of level shift, is analyzed to evaluate the impact numerically.

• Journal of the Korean Data and Information Science Society
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• 제19권1호
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• pp.53-69
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• 2008

Six Sigma is a proven management philosophy that can be employed to improve productivity dramatically in various fields of industries. However some companies where Six Sigma is adopted confront stagnancy due to many kinds of causes of impediment. In this paper, the causes of stagnancy in the diverse stages of Six Sigma implementation are studied. Moreover in this paper results of such causes are also discussed.

• 한국안전학회지
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• 제7권3호
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• pp.89-98
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• 1992

In this study, the methods to identify the causes of electrical fires are suggested. Among several causes of electrocal fires, it is focused upon a short-circuit and an over-current accidents, which take the highest ratio compare with any other causes. To propose the exact method of identification, electric wires(HIV, IV), fuses and plug-receptacls are tested under the conditions of electrical accidents and external fires, respectively. By analyzing the microphotographs, the differences between the results from electrical fires and the others are found out.

• 보건행정학회지
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• 제21권2호
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• pp.329-348
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• 2011

This research analyzed 168,010 cases of death of the aged over 65 from 244,867cases of death excluding 7 unknown age cases from 244,874 all age cases of death by using the death data of the National Statistical Office for 2007 to figure out factors affecting the quality of causes of death statistics of the aged and to suggest the ways of improving the quality of death statistics of the aged in korea. This research tried to derive factors affecting ill-defined cause of death category in acordance with WHO's guidelines and to find causes of lowering the accuracy of causes of death statistics of the aged. This research identified the problems of causes of death statistics of the aged by using both demographic characteristics such as sex, age, marital status, educational attainment, residential region, region size and factors of death items as independent variable to find causes of ill-defined cause of death of the aged. Logistic regression analysis was executed to calculate the hazard ratio about the ill-defined causes of death of the aged and multiple regression analysis was conducted to derive factors affecting the ill-defined cause of death by regional groups through using these independent variables such as the component ratio of over age 65, female death rates, doctors insitutions rate, medical institutions rate, attaching rates of death certificate by neighborhood. As a results of this research, R-code was the highest of ill-defined causes of death, accounting for 82.1%, and senility death(R54) of R-code was the highest, accounting for 91.2%. through subdivided order distribution of the ill-defined causes of death of the aged. As ill-defined causes of death by regional groups, attaching rates of death certificate by neighborhood was the most important factor(p<0.05) and also showed regression model's description with 83.8% ($R^2$=83.8%). Furthermore, Jeon-nam was the highest in the regional groups and these regions such as Je-ju, Jeon-buk, Chung-nam were not only attaching the death certificate by neighborhood but also were high at the rate of ill-defined causes of death. Therefore, this research found that both reconsideration about death certificate by neighborhood and education for doctors who write death certificate were needed the most.

• 한국수학교육학회지시리즈A:수학교육
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• 제42권1호
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• pp.19-39
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• 2003

The purpose of this study is to find out effective ways to take care of the 8th and 10th graders' disposition causing math. disliking. To accomplish this goal, we proceeded as follows : First we categorized the 11 factors recognized as the reasons of math. disliking into 4 math. disliking causes such as psychological f: environmental cause, conceptual cause, relational cause and application related cause. Second, to take care of these tow causes, we developed materials which are closely related with the contents of the 8th and 10th graders' school mathematics. Third with these materials we taught the students who had proved to have the math. disliking trend, for one semester. As a consequence of this experiment we arrived at the following results. As for psychological & environmental causes, 35.7% of the 8th graders and 17% of the 10th graders proved to have been improved significantly. This result shows that the curing of the psychological & environmental causes is more effective in the 8th graders than in the 10th graders. i.e., the curing effects of the students' psychological & environmental cause for disliking math. decline as they get older. As for conceptual causes, 35% of the 5th graders and 30% of the 10th graders proved to have been improved significantly. In case of the 8th graders this ratio was similar to that of the other causes. But as for the 10th graders this ratio was a little low compared with that of the case of relation causes and application related causes. As for relational causes, 35% of the 5th graders and 49% of the 10th graders proved to have been improved significantly. Especially the 10th graders improved greatly. Among the four factors that compose this cause, especially hierarchy and connection factors were effectively cured. On application related causes, 47% of the 5th graders and 57% of the 10th graders proved to have been cured significantly. And among the four types of causes listed above, this was the most successfully cured one. Of the two factors of this cause, the basic application factor appeared to have been improved in all experimental groups. In connection with teaching methods, we found out the followings two facts. First, the more teachers push students to solve their tasks with their own efforts, the higher is the ratio of owe. Second, the more teachers teach students personally, the more effective are the teaching results.