• Structural Engineering and Mechanics
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• 제22권6호
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• pp.685-700
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• 2006

The effective length factor is a familiar concept for practicing engineers and has long been an approach for column stability evaluations. Neglecting the effects of axial force in the restraining members, in the case of sway prevented frames, is one of the simplifying assumptions which the Alignment Charts, the conventional nomographs for K-Factor determination, are based on. A survey on the problem reveals that the K-Factor of the columns may be significantly affected when the differences in axial forces are taken into account. In this paper a new iterative approach, with high convergence rate, based on the general principles of structural mechanics is developed and the patterns for detection of the critical member are presented and discussed in details. Such facilities are not available in the previously presented methods. A constructive methodology is outlined and the usefulness of the proposed algorithm is illustrated by numerical examples.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.527-528
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• 2006

A dissipation factor standard of decade type having the range of 1 to 0.0001 at the frequency of 1 kHz and 10 kHz was fabricated using "T" networks combined R and C components. The values of the fabricated dissipation factor standard were adjusted within 1% of the nominal values at 0.0001 dial range and 0.05% at the others. This dissipation factor standard is used as a working standard for calibration of a impedance measurement meter at KRISS and as a primary standard of dissipation factor field at NML-SIRIM in Malaysia.

• 전자공학회논문지
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• 제53권7호
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• pp.121-127
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• 2016

본 논문에서는 고조파로 전압과 전류가 왜곡된 상황에서 정확하게 기본파의 역률을 측정할 수 있는 방법을 제안한다. 제안한 역률 계측 방법에서는 전압과 전류를 DQ회전좌표계로 변환한 후 유효전력과 무효전력을 계산하여 역률값을 구하게 된다. 기존의 역률 계측방법과 제안한 방법을 수식적으로 비교하여 제시하고, 제안한 방법은 전압과 전류 모두 고조파 왜곡된 상황에서도 기본파의 역률을 정확하게 계측할 수 있는 것을 MATLAB을 이용한 모의실험에서 확인한다. 제안한 역률 계측방법을 자동역률제어장치에 적용할 경우 고조파 왜곡 환경에서 역률 보상 성능을 최대화 할 수 있다. 그 결과 수용가에서는 역률 개선을 통한 전기료 감소, 선로손실 감소, 부하 용량 증대 효과가 기대된다. 특히 발전 사업가 측에서는 역률 보상 성능의 향상으로 송전 여유 용량 확보와 발전량 절감이 가능하다.

• 전자공학회논문지
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• 제54권8호
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• pp.115-122
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• 2017

본 논문에서는 슬라이닥을 이용하는 새로운 역률보상시스템을 제안한다. 제안하는 역률보상시스템은 슬라이닥의 출력전압을 커패시터에 인가하여 역률을 보상하는 구조이다. 기존의 커패시터 뱅크 방법을 이용하는 역률보상시스템은 선택 가능한 커패시터 용량이 한정되어 있어 부하 상황에 따라 역률 보상 오차가 발생하지만, 제안 시스템은 커패시터 인가 전압을 슬라이닥을 이용하여 세밀하게 변화시킬 수 있어 변화하는 부하를 추종하여 오차 없이 역률을 100%까지 보상할 수 있다. 기존 시스템과 제안 시스템을 비교하여 제시하고, 제안 시스템의 역률 보상 성능이 우수함을 모의실험과 실험을 통해 확인한다. 제안 시스템을 수용가에 설치할 경우 역률 개선을 통한 전기료 감소, 선로손실 감소, 부하 용량 증대 효과가 기대된다. 특히 발전 사업가측에서는 역률 보상 성능의 향상으로 송전 여유 용량 확보와 발전량 절감이 가능하다.

• 한국운동역학회지
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• 제25권1호
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• pp.11-19
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• 2015

Objective : The purpose of this study was to analyze the correlation between physical factors (X-factor, X-factor stretch) and club factors (club speed, ball speed, club path, smash factor, vertical launch angle, spin rate, flight time, total length) during impact and it affect on the total distance of the ball during a golf driver swing. Background : There were not enough studies that analyzed the correlation between physical factors(X-factor, X-factor stretch) and club factors(club speed, ball speed, club path, smash factor, launch angle, spin rate, flight time, total length) during a purpose swing to increase total distance. Method : For this study, 9 right handed professional male golfers (KPGA) were chosen. The test subject group used their own drivers and each took a total of 10 swings. These swings consisted of 5 purpose swings to increase total distance and 5 normal swings. Results : The purpose swing to increase total distance showed larger physical factors(X-factor, X-factor stretch) compared to a normal swing however the results were not statistically significant. Total distance increased during a purpose swing as a result of ball and club speed. Conclusion : The results showed that club factors, ball speed and club speed contributed the most in affecting the total distance of the ball during a purpose swing.

• Nuclear Engineering and Technology
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• 제28권2호
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• pp.185-196
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• 1996

이 연구의 목적은 원자력발전소 페라이트 배관에 존재하는 원주방향 표면균열을 평가하는데 사용되는 ASME Code Z-Factor를 수정하는데 있다. ASME Code Z-Factor는 소성하중을 탄소성하중으로 보정하는 하중 보정 계수로서, 현재 사용되는 ASME Code Z-Factor는 최대하중을 과소평가하는 문제점이 있다. 이 연구에서는 먼저 기존의 SC. TNP방법이 수정되었으며, 그 이유는 기존의 SC. TNP 방법으로 예측된 최대허용하중이 실험에서 측정된 방법보다 약간 큰 결과를 주는 문제가 있기 때문이다. 이 수정된 SC. TNP 방법을 사용하여 페라이트 배관에 대한 새로운 Z-Factor를 개발하였다. 수정된 SC. TNP 방법의 타당성 과 새로 개발된 Z-Factor의 타당성을 원주방향 표면균열을 갖는 배관에 대한 실험 결과를 통해 조사하였다. 평 가결과는 수정된 SC. TNP 방법은 페라이트 및 오스테나이트 배관의 원주 방향 표면균열의 거동을 잘 예측할 수 있음을 보여 주며, 또한 수정된 SC. TNP 방법으로 구한 새로운 Z-Factor는 페라이트 배관에 존재하는 원주방향 표면균열의 거동을 잘 예측할 수 있음을 보여준다.

• 한국학교ㆍ지역보건교육학회지
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• 제15권3호
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• pp.67-80
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• 2014

Objectives: This study is aimed to analyze the influential factors on the fear that college students and elderly people feel during the dental treatment and provide basic data needed to develop a plan which can lead them to have a positive perspective on dentistry. Methods: A questionnaire was distributed to 241 outpatients (39 college students, 202 elderly people) visiting dental clinic of 'K' University Hospital in Seoul from January to April, 2013. It was filled in a self-administered manner and collected right away. Results: factor analysis, three factors were configured when the factors with 1.0 or higher of eigenvalue were extracted using 19 questions through which dental fear and anxiety were measured against college students and elderly people. The questionnaires were classified into three categories: Factor I (stimulus response), Factor II (avoidance of the treatment) and Factor III (physiological response which occurs when a patient feels fear). As a result, it was confirmed that the questionnaire tool is highly feasible. In college students, the responses they felt during the dental treatment in the said three factors were as follows: 52.00% in Factor II, 14.14% in Factor II and 6.99% in Factor III (73.129% in total). In elderly people, on the contrary, they were 52.41% in Factor I, 10.57% in Factor II and 7.98% in Factor III (70.958% in total), lower than the college student group. Conclusions: This study is significant in that it confirmed complex relations between dental fear and related variables against college students and elderly people.

• 패션비즈니스
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• 제20권3호
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• pp.54-67
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• 2016

The purpose of this study was to investigate the The effect of fashion consumer's need for uniqueness in their clothing purchase behavior and switching intention. A total of 332 cases were included as the subjects of this study and a survey method was used. The data were analyzed by factor analysis, reliability analysis, t-test and multiple regression analysis using the SPSS 22.0 statistical program. The results were as follows. 1. The 3 dimensions (creative choice, unpopular choice, and avoidance of similarity) were extracted from the consumer's need for uniqueness and consumer divided high uniqueness group, middle uniqueness group, low uniqueness group. 2. The 3 factor (esthetic, functional, practical) were extracted from the clothing selection criteria. The three group had a significant difference in clothing selection and switching intention. Aesthetic factor and practical factor were the highest in high uniqueness group. 3. The need for uniqueness has influence on the aesthetic factor and practical factor. The creative choice factor had positive effect on the aesthetic and practical factor, yet unpopular choice factor had negative effect on the practical factor. The need for uniqueness and aesthetic factor has positive influence on brand switching intentions. 4. There was difference in unpopular choices factor by gender. A monthly average expenditure on fashion products had a significant difference in three kind of need for uniqueness. Results of this study provide a basis understand need for uniqueness and their effect on consumer behavior.

• Journal of the Korean Data and Information Science Society
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• 제19권2호
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• pp.451-461
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• 2008

In this study, factor and cluster analysis have been conducted to group the differences in Korean view on national economic policy in the sample of the 2006 Korean General Social Survey (KGSS). According to the 2006 KGSS, the 6 items with a 5-point Likert scale include the questions about whether or the extent to which each respondent supports the specific types of governmental economic policy. In our study, at first, the factor analysis has converted the original 6 items into the 3 composite variables that account for 81% in the total variability. As the second step of factor analysis, factor scores have been computed. Then, the K-means cluster analysis based on the factor scores has been conducted to group the survey respondents into the 3 clusters. In particular, the cross-tabulation analysis has shown that the distribution of the 3 clusters varies with the respondents' socio-demographic characteristics.

• 한국환경성돌연변이발암원학회지
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• 제21권2호
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• pp.106-112
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• 2001

In view of the effect of factor Ⅶ as a risk factor for essential hypertension, we investigated the length (I/D) polymorphism at position 323 promoter region and exon 8-Msp I RFLP of the human factor Ⅶ gene in the Korean patients with essential hypertension and normal controls. There were no significant differences in the allele, genotype and haplotype frequencies of these polymorphisms between normotensive and essential hypertensive subjects. The significant linkage disequilibrium was however, detected between two polymorphic sites. The Msp I RFLP and I/D polymorphism were also significantly associated with plasma triglyceride (TG) levels. Therefore, our results suggest that the significant association between two genetic variations in the human factor Ⅶ gene and plasma TG level may reflect the potential role of human factor Ⅶ gene as one of the genetic components for cardiovascular risk.