• 대한기계학회논문집
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• 제9권5호
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• pp.613-620
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• 1985

본 연구의 목적은 수평 Blasius유동의 열적 불안정성 문제에서 유동방향 좌표 에도 의존하는 교란양을 최초로 도입함으로써 보다 합리적인 안정성 해석을 수행하고 그 결과를 기존의 실험적 및 이론적인 자료들과 비교하며 이를 토대로 한 보다 실제적 인 열전달 상관관계를 얻고자 하는데 있다.

• 한국간호교육학회지
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• 제8권1호
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• pp.145-154
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• 2002

Purpose : The purpose of this study was to investigate the experiences of masturbation among high school students. Method : The subjects were 925 high school students in Busan. Masturbation experience, hygienic management and physical, psychological condition after masturbation were measured. The data was collected from December 1998 to February 1999. The collected data was analyzed with frequency, percentage, mean, $x^2$ -test, t-test. Result : 1) There were significant differences in masturbation experiences according to frequency($x^2$=547.94, p=.000), educational participation($x^2$=12.11 p=.001) and hygienic management(t=3.661, p=.001) between boys and girls. 2) Contact of lewd mass media stimulated students to do masturbation and they used various methods such as stimulating genital area by using hand or tools, fantasizing about sex 3) Subjects reported that they experienced fatigue, sleeping disturbance, decreasing concentration and learning desire after masturbation. Conclusion : This study suggests that replicate studies are needed. The results are also useful in developing various sex education program.

• 한국식품영양학회지
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• 제21권2호
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• pp.256-262
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• 2008

This study was carried out to compare the hair mineral status of obese, over-weighted and non-obese individuals, to gather basic data for customizing menu development and to create an education manual for the obese persons. Food preferences or various disease states could be suggested by different mineral patterns in TMA(tissue mineral analysis). The results indicated that Zn status was considerably lower in the obese individuals than in the non-obese(p<0.001) whereas hair Na(p<0.0001), K(p<0.01) and Fe(p<0.05) were at significantly higher levels in the obese individuals. The ratio of Ca/K(p<0.001) was significantly lower in the obese than in the non-obese. But the levels of hair toxic minerals such as Sb, As, Hb, Al et al. were not differ according to BMI groups. The obtained data demonstrate the changes of hair mineral content in both overweight and obese individuals thus suggesting metabolic mineral disturbance in those groups.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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• pp.24.2-24.2
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• 2009

We present the results of new CCD photometry for the contact binary BX Peg, made during three successive months beginning on September 2008. As do historical light curves, our observations display an O'Connell effect and the November data by themselves indicate clear evidence for very short-time brightness disturbance. For these variations, model spots are applied separately to the two data set of Group I (Sep.--Oct.) and Group II (Nov.). The former is described by a single cool spot on the secondary photosphere and the latter by a two-spot model with a cool spot on the cool star and a hot one on either star. These are generalized manifestations of the magnetic activity of the binary system. Twenty light-curve timings calculated from Wilson-Devinney code were used for a period study, together with all other minimum epochs. The complex period changes of BX Peg can be sorted into a secular period decrease caused dominantly by angular momentum loss due to magnetic stellar wind braking, a light-travel-time (LTT) effect due to the gravitational effect of a low-mass third companion, and a previously unknown short-term oscillation. This last period modulation could be produced either by a second LTT orbit with a period of about 16 yr due to the existence of a fourth body or by the effect of magnetic activity with a cycle length of about 12 yr.

• 지역사회간호학회지
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• 제16권4호
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• pp.488-497
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• 2005

Purpose: This study examined the relation of BMI to lipid metabolism and health promoting behavior in middle-aged women. Methods: The subjects were 113 women between 40 to 60 years of age. The data was collected from April 2003 to July 2004. BMI was measured using body composition analyzer and lipid metabolism were measured using automatic biochemical analyzer. Health promoting behavior was collected using a structured questionnaire. The SPSSWIN(10.0 version) program was used to analyze the data and get the descriptive statistics and Pearson's correlation coefficients. Results: BMI was negatively correlated with HDL-c and positively correlated with triglyceride, but there was no significance between BMI and total cholesterol. There was no significance of correlation between BMI and total health-promoting behavior. Conclusion: This study showed that BMI is meaningful in the identification of the high risk women to prevent HDL-c & triglyceride metabolism disturbance, but additional research is needed to study the correlation between BMI and health promoting behaviors in middle-aged women.

• Spatial Information Research
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• 제10권4호
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• pp.501-513
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• 2002

Eurasian otter (Lutra lutra) is one of endangered wildlife species whose population size is declining in Korea. To manage and conserve habitat for Eurasian otter, it is crucial to understand which habitat components affect otter habitat qualities. The objectives of this study were to develop a habitat suitability model of Eurasian otter in Soraksan National Park, to validate the model in Odaesan National Park. The research methods of this study were as follows. First, trace data and characters of Eurasian otter habitat were collected with Geographic Information System (GIS) data and Global Positioning System (GPS) receivers between 2000 and 2002. Second, the habitat use factors were identified as habitat characteristics of Eurasian otter and classified with habitat use and availability analyses. Third, significant factors of habitat model were extracted by Chi-square test. The last, Eurasian Otter Habitat Suitability Model (EOHSM) was employed by logistic regression method. Otter habitat use was positively associated with the reeds and shrubs areas adjacent to streams, the size of boulders, and low human disturbance in Soraksan National Park by EOHSM. This model had a classification accuracy of 74.4% at cutoff value of 0.5. Model validation showed a classification accuracy of 86.6 % at cut off value of 0.5 for otter habitat in Odaesan National Park.

• 한국유체기계학회 논문집
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• 제16권4호
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• pp.5-9
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• 2013

An experimental investigation has been carried out in order to evaluate characteristics of wetted-type multi-path ultrasonic flowmeters. The multi-path ultrasonic flowmeters were installed at various entrance and exit locations for several cases of pipe fitting(straight, $90^{\circ}$ double elbow) and valve(gate valve, butterfly valve). We measured the flow-rate at each location. The measurement data of test flowmeter were compared with the measured data of reference flowmeter. The uncertainties of reference flowmeter and test flowmeter are 0.3 %, 0.4 %, respectively. The results demonstrate the effects of flowmeter location as well as the measurement errors in flow rate. The distance between the flow disturbance factor and a flowmeter was an important element of the test.

• 대한전기학회논문지:전력기술부문A
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• 제48권5호
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• pp.494-501
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• 1999

In this research, ANN modeling method of SMES unit is developed for stability analysis, and the optimal site is selected to maximize stabilization effect of SMES unit. The ANN is trained by learning data which is obtained through the application of complex test function into the traditional mathematical mode. In order to verify the validity of proposed modeling method, fault data of sample power system is applied to both the traditional and the ANN models. When the response of traditional and proposed models are compared, the average error for the active and reactive power are 2.51[%], and 0.24[%], respectively. From the comparison, the relevance of proposed method is validated. For the transient stability analysis, an application method of the proposed model is presented, and the transient stability performance index, which describes system stabilization effect of SMES at disturbance, is also suggested, and optimal site selection method of SMES is presented. In the viewpoint of the voltage stability, system stabilization criterion of local bus is presented from P­V curve, and then optimal site which can maximize the voltage stabilization of the whole power system, is decided from the proposed voltage stability performance index.

• 한국위성정보통신학회논문지
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• 제6권2호
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• pp.107-111
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• 2011

세계2차대전을 통해 태양폭발은 레이더시스템에 큰 영향을 주는 것으로 밝혀졌다. 1942년 2월 28일의 전파교란 현상은 태양활동의 극대기에 증가한 우주 광선(cosmic ray)에 의한 것이었다. 이러한 사실들이 밝혀지면서 태양폭발 및 태양 입자 활동에 관한 연구가 활발히 이루어졌다. 태양폭발이 우주선에 미치는 영향, 극 운행 비행기에 미치는 영향, 레이더 시스템에 미치는 영향, 무선통신시스템에 미치는 영향 등에 대한 연구가 다양하게 이루어 지고 있다. 본 논문에서는 지난 40여년 간의 태양전파 관측자료를 분석하여 태양폭발에 의해 무선통신에 미치는 영향과 태양활동주기간의 상관관계를 분석하였다.

• 전력전자학회논문지
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• 제8권6호
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• pp.527-533
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• 2003

최근 민감한 전자부하의 사용증대에 기인하여 전직의 안정도와 신뢰도에 대한 관심이 증대되고 있다. 이에 전력풀질문제가 근래에 있어 일반적인 중요한 과제로 대두되었다. 이러한 전력품질문제를 진단하기 위하여 실효치나 FFT 등의 기법을 이용한 많은 알고리즘이 연구되어 왔으나 모든 전력품질문제를 진단하기에는 아직도 미진한 상황이다. 본 논문은 이산 웨이블릿을 응용한 전력품질문제의 진단 방법을 제안하고 웨이블릿의 이론에 대한 기본적인 설명과 함께 제안된 이론의 타당성을 입증하기 위하여 실제 전력품질문제 진단시스템을 설계하고 실험결과를 제시하였다.