• Journal of Electrical Engineering and Technology
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• 제2권2호
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• pp.152-156
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• 2007

This paper proposes a method for real-time control of both capacitors and ULTC in a distribution system to reduce the total power loss and to improve the voltage profile over the course of a day. The multi-stage consists of the off-line stage to determine dispatch schedule based on a load forecast and the on-line stage generates the time and control sequences at each sampling time. It is then determined whether one of the control actions in the control sequence is performed at the present sampling time. The proposed method is presented for a typical radial distribution system with a single ULTC and capacitors.

• Journal of Genetic Medicine
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• 제1권1호
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• pp.17-22
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• 1997

The angiotensin converting enzyme (ACE) is a key component of the renin-angiotensin system thought to be important in the pathogenesis of hypertension and cardiovascular diseases. Deletion polymorphism in the ACE gene may be a risk factor for myocardial infarction. The insertion/deletion (I/D) polymorphism of the ACE detected by PCR analysis appears to be associated with hypertension in Koreans and its nucleotide was subcloned into T-vector and its nucleotide sequences were determined. We also examined an association between hypertension and genetic variance of ACE. We identified the angiotensin I-converting enzyme genotype in 127 hypertensive and 189 normotensive Korean subjects. The distribution of ACE genotype II, ID, DD were 39.2%, 40.2%, 20.6% respectively and the frequency for ACE alleles I and D were 0.593 and 0.407, respectively in all subjects. The frequency of D allele in Korean males is higher than that of Korean females (male; 0.438 : female; 0.267), and the frequency of I allele in Korean females is higher than that of Korean males (female; 0.733 : male; 0.562). Genotype distributions of angiotensin I-converting enzyme genes in Korean normal adult population were different from that of Caucasians (P<0.001). There were no significant differences in genotype frequency between the hypertensive control group (n=127) and the normotensive group (n=189). We observed significant differences of ACE genotype distribution between the male group and the female group in total (P=0.001) and in hypertensive Korean subjects (P=0.013).

• Computers and Concrete
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• 제19권1호
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• pp.111-120
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• 2017

This study aimed to design the accelerated life testing (ALT) of concrete, which stimulating the special natural environment maximumly. Its evaluation indexes, such as dynamic elastic modulus, mass and ultrasonic velocity were measured, and the variation of relative mass and relative dynamic elastic modulus of concrete were studied. Meanwhile, the microanalysis method was used. Moreover, an exploratory application of the stochastic approach, the Weibull distribution and the lognormal distribution, were made to assess the durability of concrete structures. The results show that the ALT for simulating natural environment is more close to the service process of concrete structure under actual conditions; The relative dynamic elastic modulus can be used as the dominant durability evaluation parameters, because it is more sensitive to the environmental factors compared with the relative quality evaluation parameters; In the course of the concrete deterioration, the destruction of the salt freezing cycle is the dominant factor, supplemented by other factors; Both of those two stochastic approaches can be used to evaluate the reliability of concrete specimens under the condition of ALT; By comparison, The lognormal distribution method is better to describe the reliability process.

• 유통과학연구
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• 제17권9호
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• pp.83-92
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• 2019

Purpose - This research is to verify job fitness, empowerment, and recognition of career development support having the influence on formation of occupational identity in Korean food franchise distribution company. Research design, data, and methodology - Total 600 copies have been distributed and 394 copies have been collected, the covariance structure analysis has been implemented to verify the presented research hypothesis. Results - Demand fit and competency fit being the lower level of job fitness appeared not to have significant influence on occupational identity, and also these do not have the significant influence on the empowerment. Even though formal career development support being lower level of career development recognition appeared to have significant influence on empowerment, nonformal career development support appeared not to have significant influence on empowerment. Formal career development support and nonformal career development support appeared to have significant influence on occupational identity. Finally, empowerment appeared to have significant influence on occupational identity. Conclusions - It is implied that the psychological and subjective success felt in employee's career course may be improved by the job related job fitness, the initiative being individual characteristic and formal and formless career development support being organizational characteristic.

• 지능정보연구
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• 제16권3호
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• pp.121-145
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• 2010

매 학기마다 반복되는 대학의 강의시간표 작성 방법은 대학 상황에 따라 다르며, 교육환경의 변화에 따라 그 복잡도와 문제의 크기가 증가되는 NP-hard 문제로 알려져 있다. 그 동안, 효과적인 강의자원 배분을 위한 강의시간표 자동생성의 필요성으로 대학 강의시간표 작성에 관한 여러 방법의 연구가 진행되어 왔다. 일반적으로 교양과목 강의시간표는 대학행정부서에서, 전공과목은 학과에서 작성하는데 각 학과 단위의 전공강의시간표작성지원시스템은 학생들의 편의를 도모하고 수업의 효과와 전공강의자원의 효과적인 배분를 위해 중요한 역할을 한다. 이를 위하여 본 연구는 한신대학교의 새로운 강의시간표 작성체계에 따라, 사례 기반의 템플릿을 생성하고, 이로부터 규칙 기반의 상호대화형으로 효과적인 강의자원 배분이 가능한 전공강의시간표를 작성하는 두 단계 지원시스템을 제안하였으며, 사례 데이터를 이용한 프로토타입으로 그 효과를 검정하였다. 과거 사례와의 유사도는 학과 평균 41.72%로 템플릿의 유용성을 볼 수 있으며, 민감도 분석 결과에서 동일 시간 개설과목 허용 임계치를 90% 이상 설정한다면 강의시간표가 더 고른 분포를 갖게 됨을 검정하였다.

• 한국컴퓨터정보학회논문지
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• 제16권12호
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• pp.297-304
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• 2011

본 논문은 멀티미디어 교육자료와 전통적 수업방식의 효과성을 실질적으로 검증하고자 전문계 고등학교의 수업 방법을 비교분석하였다. 실업계의 전문교과 중 유통관리실무과목을 학습내용으로 선정하고, 멀티미디어 교육자료를 MS파워포인트로 디지털화하였다. 이를 위하여 30명의 학생들을 각각 실험집단과 통제집단의 표본집단으로 하고 동질성과 학업성취도를 고려하여 구성하였다. 동일한 교사가 두 집단을 같은 자료로 가르쳤다. 차이점은 두 집단간의 전달방법인데 두 유형의 교수방법으로 학습효과성과 만족도를 분석하기 위하여 사후검증을 실시하였다. 방법은 사전검사 점수를 공변인으로 통제한 후, 학생들의 학업성취도 사후검사 점수를 종속변인으로 공변량분석을 수행하였으며, 결과는 집단 간에 통계적으로 유의미한 차이가 있었다.(F=5.06, p<.05). 그것은 멀티미디어 교육자료를 활용한 수업의 학업성취도가 교과서 위주의 전통적 설명식 수업보다 더 높은 것으로 나타났다. 수업방식에 대한 만족도는 실험 통제집단 검증에서 통계적으로 유의미한 차이가 나타났다(t=5.65, p<.001). 따라서 멀티미디어 교육자료를 활용한 실험집단의 수업방식이 전통적 수업방식을 적용한 통제집단 보다 수업성취도와 만족도 측면에서 더 높은 것으로 나타났다.

• 유통과학연구
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• 제16권2호
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• pp.53-65
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• 2018

Purpose - The purpose of this study is to investigate the effect of gamma - irradiation on the effluent from food distribution in the large agricultural and marine products market. This study will contribute to the distribution process as well as the agricultural and fishery distribution facilities. Research design, data, and methodology - In order to reduce the odor, the smell was examined in the anaerobic digestion process by irradiating gamma rays to the wastewater of mixed food discharged from a large restaurant. An odor determination panel list was constructed to determine if the odor was present in the air dilution drainage and the odor concentration was analyzed by instrumental analysis. Results - It was confirmed that the sulfur content increased gradually from 3 months. Ammonia decreased from 33.57ppm at the initial measurement to 4.12 ppm at the end of the experiment. Methane production was highest at 100kGy when exposed to gamma rays of 0-200kGy at pH 12. In other words, it is considered that gamma irradiation doses are most effective at 100kGy and are suitable for large capacity wastewater treatment facilities in terms of economic feasibility. Conclusions - In pre-treatment of compound food wastewater, gamma irradiation is most cost effective when examined at 100kGy. The economic efficiency of the pre-treatment method by gamma irradiation is much higher than the wastewater treatment in the large-scale agricultural and marine products distribution market.

• Journal of Welding and Joining
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• 제23권1호
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• pp.41-47
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• 2005

Arc pressure is one of important factors in understanding physical arc phenomena. Especially it affects on the penetration, size and shape of TIG welding. Some researches were reported on the effect of arc pressure in low and middle current region. But there are not any research in high current region. The purpose of this study is to investigate the arc pressure distribution with mixing ratio of shield gas such as Ar and He gases. A Cu block with water cooling was specifically designed and used as an anode electrode in order to measure the arc pressure in high current region. Then, the arc pressure distribution was measured with change in welding current and mixing ratio of shield gases. The arc force was obtained by numerically integrating the measured results. As the results, it was shown that the arc pressure was concentrated at the central part of the arc in middle and high current regions when a pure Ar gas was used. In case of Ar + He mixing gas, the arc pressure was much lower than that of pure Ar gas. In addition, it was widely distributed to radial direction.

• Journal of Welding and Joining
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• 제27권2호
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• pp.44-50
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• 2009

The characteristics of arc pressure, current density and heat flux distribution are important factors in understanding physical arc phenomena, which will have a marked effect on the penetration, size and shape of a weld in TIG welding. The purpose of this study is to find out the effect of the heat flux on the melting efficiency and penetration shape in TIG welding using the results of the previous investigators. The conclusions obtained permit to draw a proper method which derived the heat flux distributions by arc pressure distribution measurements, but previous researchers calculated heat flux and current distribution with the heat intensity measurements by the calorimetry. Heat flux of Ar gas arc was concentrated at the central part and distributed low from the arc axis to the radial direction, that of He mixing arc was lower than that of Ar gas, and it was wide distributed to radial direction. That showed a similar characteristic with the Nestor's by calorimetry calculated values. Throughout heat flux drawn in this study was discussed melting efficiency and penetration shape on Ar gas and He mixing gas arc.

• Communications for Statistical Applications and Methods
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• 제8권3호
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• pp.633-641
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• 2001

The least squares method is usually applied when estimating the parameters in the regression models. However the least square estimator is not very efficient when the distribution of the error is skewed. In this paper, we propose the asymmetric least square estimator for a particular nonlinear time series regression model, and give the simple and practical sufficient conditions for the strong consistency of the estimators.