• 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.

• 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.

• 드라이브 ㆍ 컨트롤
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• 제19권1호
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• pp.16-25
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• 2022

The purpose of this study was to calculate and analyze the engine load factor of major agricultural operations using a 78 kW class agricultural tractor for estimating the emission of air pollutants and greenhouse. Engine load data were collected using controller area network (CAN) communication. Main agricultural operations were selected as plow tillage (PT), rotary tillage (RT), baler operation (BO), loader operation (LO), driving on soil (DS), and driving on concrete (DC). The engine power was calculated using the measured engine load data. A weight factor was applied to load factor for considering usage ratio according to agricultural operations. Weight factors for different agricultural operations were calculated to be 27.4%, 32.9%, 17.5%, 7.7%, 4.5%, and 10.0% for PT, RT, BO, LO, DS, and DC, respectively. As a result of the field test, load factors were 0.74, 0.93, 0.41, 0.23, 0.27, and 0.21 for PT, RT, BO, LO, DS, and DC, respectively. The engine load factor was the highest for RT. Finally, as a result of applying the weight factor for usage ratio of agricultural operations, the integrated engine load factor was estimated to be 0.63, which was about 1.31 times higher than the conventional applied load factor of 0.48. In future studies, we plan to analyze the engine load factor by considering various horsepower and working conditions of the tractor.

• 한국항해항만학회지
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• 제38권1호
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• pp.65-71
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• 2014

국내 경부고속도로와 남해고속도로는 부산항을 각각 남북방향과 동서방향으로 연계하며 20%이상의 중대형화물트럭 혼재율과 특정시간대 통행량이 집중되는 핵심 간선도로로 시간교통량계수(K-factor)에 대해 연구의 필요성을 깨닫게 되었다. 그리하여 본 연구에서는 경부고속도로와 남해고속도로의 기본구간에서 단기간동안 수집된 차량검지시스템(vehicle detection system, VDS)자료를 이용하여 고속도로의 K-factor와 K-factor추정치(estimate)사이의 상관분석을 통해서 고속도로의 K-factor추정모형 구축을 목적으로 연구하였다. 결과적으로 7일 VDS자료의 K-factor추정치(estimate)와 함께 파워(POW)모형이 K-factor를 추정에 높은 설명력과 신뢰성이 있음을 확인할 수 있었다.

• 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.

• 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.

• 한국태양에너지학회 논문집
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• 제27권4호
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• pp.157-165
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• 2007

Typical meteorological data is fundamental to computer simulation introduced for environment-friendly architecture designs. Therefore, in order to improve accuracy of computer simulation, typical meteorological data should be established. By examining how to choose typical meteorological data, this study selected the optimized weight factor for TRY where weighting factor was not clearly set. As a result, the same weighting factor was applied to each climatic element and TRY data where the weight factor was applied could have the distribution very similar to measurement data. The weighting factor is considered to reflect geographical characteristics of Seoul and applied climatic elements.

• Journal of the Korean Data and Information Science Society
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• 제21권2호
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• pp.297-308
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• 2010

This article deals with the problem of testing mean when the coefficient of variation in normal distribution is known. We propose Bayesian hypothesis testing procedures for the normal mean under the noninformative prior. The noninformative prior is usually improper which yields a calibration problem that makes the Bayes factor to be defined up to a multiplicative constant. So we propose the objective Bayesian hypothesis testing procedures based on the fractional Bayes factor and the intrinsic Bayes factor under the reference prior. Specially, we develop intrinsic priors which give asymptotically same Bayes factor with the intrinsic Bayes factor under the reference prior. Simulation study and a real data example are provided.

• 한국항해항만학회지
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• 제30권7호
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• pp.579-583
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• 2006

The purpose of this paper is to study a relationship between alliance success factors and performances of strategic alliance. In order to achieve the purpose of this research, factor analysis, reliability and validity and regression method are used. In conclusion, alliance success factors can be divided as mutual complementarity and information sharing factor, sharing and mutual agreement of vision and goal factor, performance management factor and culture and organization factor. According to regression results, all of four factors affects significantly dependent variables. Among them, mutual complementarity and information sharing mostly affects each dependent variable.

• Journal of the Korean Data and Information Science Society
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• 제18권3호
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• pp.833-845
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• 2007

When X and Y have independent exponential distributions, we develop a Bayesian testing procedure for the ratio of two quantiles under reference prior. The noninformative prior such as reference prior is usually improper which yields a calibration problem that makes the Bayes factor to be defined up to a multiplicative constant. So we develop a Bayesian testing procedure based on fractional Bayes factor and intrinsic Bayes factor. We show that the posterior density under the reference prior is proper and propose the Bayesian testing procedure for the ratio of two quantiles using fractional Bayes factor and intrinsic Bayes factor. Simulation study and a real data example are provided.