• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.4A
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• pp.256-266
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• 2003

In this paper, scattering characteristics of the rectangular waveguide with elliptical conducting post and equivalent impedance of post are analyzed by mode matching method and generalized scattering method. The scattcring characteristics of rectangular waveguide are varied by the height and eccentricity of elliptical conducting post. When the height of post(2.54mm, 4mm) is small, variation in scattering characteristics appears in total simulated frequency. But as the height of post(7.62mm, 9mm) is increased, it is dominant in higher frequency. The simulated result shows good agreement with the HFSS's result. Proposed structure and analysis method are easily applied to the design and manufacture of waveguide component with elliptical conducting post.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.55.1-55.1
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• 2012

2010년과 2011년의 관측시즌에 총 23일의 BVR 측광 관측을 통하여 처음으로 얻은 2세트의 BVR 광도 곡선을 분석하였다. 새로운 두 세트의 BVR 광도곡선은 제1식과 제2식의 깊이가 거의 비슷하지만, 식바깥 부분에서 관측 시즌에 따라 서로 다른 모양의 잘 발달된 파형 모양을 보인다. 이는 BD And가 흑점이 활동이 매우 심한 짧은 주기의 RS CVn형 식쌍성임을 나타내는 것이다. 우리의 극심시각을 포함한 모든 극심시각을 분석하여 BD And의 공전주기가 규칙적으로 변하는 것을 발견하였다. 이 변화를 보이지 않는 제3천체에 의한 광시간 효과로 가정하여, 궤도이심율이 0.83이며, 9.15년의 주기를 가진 광시간 궤도를 결정하였다. Wilson-Devinney 쌍성 모형을 이용하여 흑점과 제3광도를 고려한 두 세트의 광도곡선 해를 산출하였고, BD And의 절대량을 구하였다. 식바깥의 파형 모양의 변화는 주성의 표면에 매우 큰 두 개의 흑점과 그 위치와 이동으로 잘 설명되며, 전체 광도의 약 15%에 해당되는 제3광도가 검출되었다. 주기연구에서 구한 제3천체의 궤도요소와 제3광도의 결합으로 제3천체의 질량과 궤도경사각을 유추하였다. BD And의 성분별의 평균 나이가 등연령 곡선으로부터 태양과 비슷한 4.6${\times}$109년으로 산출되었다. BD And를 포함하여 현재까지 알려진 짧은 주기의 RS CVn형 쌍성들의 H-R도가 항성진화 경로와 함께 제시되며, 그 천체물리학적 의미를 살펴본다.

• Journal of the East Asian Society of Dietary Life
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• v.10 no.3
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• pp.245-251
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• 2000

This study was conducted to investigate the influence of different nutrient databases in estimating nutrient intake. A nutrient survey with Food Frequency Questionnaire containing 65 food items was conducted with 2,426 subjects over 30 years of age living in Yeonchon-gun, Kyungki province. The nutrient intakes were first estimated by using one (A) nutrient database which was based on the Korean Food Composition Table, 4th edition. With the other (B) nutrient database which was based on the Korean RDA(Recommended Dietary Allowances) 6th edition, it was reestimated and two resu1ts were compared. For most nutrients except carbohydrate, calcium, vitamin C and $eta$-carotene, mean nutrient intake level estimated from database B was significantly higher than that from database A(p<0.05). Mean intake level of most nutrients from two databases were significantly correlated by Pearson's correlation coefficients(p<0.001). Results from the ranking of nutrient intake levels of the subjects by two databases were highly correlated ( P >0.9, p<0.001). Weighted kappa values representing measures of agreement ranged from 0.55 databases ranged from 45% for vitamin C to 96% for carbohydrate. This result implies that different nutrient database may produce substantial differences in estimating the absolute nutrient intake but may not be crucial in ranking or classifying individuals with regard to specific nutrient intake.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.351-354
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• 2006

In underwater environment, the control of AUV is difficult, because of the existence of parameter uncertainties and disturbances as well as highly nonlinear and coupled system dynamics. The requirement for the simple and robust controller which works satisfactorily in those dynamical uncertainties, call for a design using the PD or sliding mode controller. The PD controller is very popular controller in the industrial field and the sliding mode controller has been used successfully for the AUV controller design. In this paper, the two controllers arc designed for ISiMI(Integrated Submergible Intelligent Mission Implementation) AUV and the performances are compared by numerical simulation under the modeling uncertainty and disturbances. The design process of PD and sliding mode controller for ISiMI AUV and simulation results are included to compare the performances of the two controllers.

• Journal of Astronomy and Space Sciences
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• v.17 no.2
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• pp.173-180
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• 2000

All times of minimum light of V651 Cas, which is still less studied so far, were analyzed. From our analysis, it was found that the orbital period of the system may have varied in a periodic manner. After assuming that the period change is produced by the light-time effect due to a third body in the system, attempts to derive the orbital elements of the light-time orbit were made. The resultant values for the period, semi-amplitude, and eccentricity of the light-time orbit were 6.${y}^{25}$, 0.${d}^{0013}$, and 0.77, respectively. The future observations of times of minimum light of V651 Cas are needed to confirm the existence of the third body we suggested in this paper.

• Journal of Astronomy and Space Sciences
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• v.14 no.2
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• pp.381-385
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• 1997

A long-term prediction algorithm of geostationary orbit was developed using the analytical method. The perturbation force models include geopotential upto fifth order and degree and luni-solar gravitation, and solar radiation pressure. All of the perturbation effects were analyzed by secular variations, short-period variations, and long-period variations for equinoctial elements such as the semi-major axis, eccentricity vector, inclination vector, and mean longitude of the satellite. Result of the analytical orbit propagator was compared with that of the cowell orbit propagator for the KOREASAT. The comparison indicated that the analytical solution could predict the semi-major axis with an accuracy of better than $pm35$ meters over a period of 3 month.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.12
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• pp.890-896
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• 2019

Due to the eccentricity of the Earth's orbit around the Sun and the obliquity of the Earth rotation axis against ecliptic frame, the apparent solar time differs from the mean solar time. Since the solar array of a GEO satellite makes a turn in mean solar day, the Sun pointing error of solar array is introduced over the year due to the equation of time. In this paper, efficient methods of compensating the equation of time to keep the solar array pointing the Sun are presented and verified with realistic simulation.

• Journal of the Korean Home Economics Association
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• v.39 no.12
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• pp.51-63
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• 2001

With the development of information technology, more and more internet sites are available to consumers. Increasing on the interests of diet and health in modem society, there are numerous internet sites dealing with food, nutrition and health. Considering the importance and expected roles of internet sites in information dissemination in the future world, it is important to put more efforts to encourage internet sites with more accurate an useful information. Up to present, not much work has been done on quality analysis and evaluation of the internet information. This study aimed to develop a model to evaluate and rank the internet information according to its quality so that consumers can be guided toward correct information source. Three models were adapted from the literature for pilot study to develop a model suitable for evaluation of contents of sites related to food and nutrition information. From the pilot study, a evaluation model was developed with criteria more relevant to Korean internet site by expert panel. Evaluation criteria of the model is authority, accuracy, objectivity, coverage, and user-friendliness. For the objective and systematic evaluation, scores were assigned totaling maximum 100 point to each evaluation criteria factors. The model developed in this study could be used as one for other internet sites in area other than food and nutrition.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.9
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• pp.60-66
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• 2006

Now, on developing COMS(Communication, Ocean and Meteorological Satellite) has solar panel on the south panel only. Therefore, the wheel off-loading has to be performed periodically to reduce a induced momentum energy by a asymmetric solar panel. One of two East/West station keeping maneuver to correct simultaneously longitude and eccentricity, orbit corrections may be performed during one of the two wheel off-loading manoeuvres per day to get enough observation time for meteorological and ocean sensor. In this paper, we applied a linearized orbit maneuver equation to acquire maneuver time and delta-V. Nonlinear simulation for the station keeping is performed and compared with general station keeping strategy for fuel reduction.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.6
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• pp.691-699
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• 2014

The purpose of this study was to examine the effect of temple food intake on health improvement. The survey was conducted from September to October 2013. The subjects in this study were 46 adults who participated in short-term 'Temple Stay' program. Every meal was prepared according to prearranged temple food menu, and it was provided to subjects for 4 weeks. Dietary intake, anthropometric measurements and biochemical parameter were measured and nutritional & health status were analyzed to find the effect of the program. Nutrients content of the temple food was sufficient to dietary reference intake while content of fat, fiber, vitamin A and calcium from the meal was significantly higher than the subjects' usual diet. Mean body weight, BMI and blood pressure (systolic and diastolic) related with obesity and hypertension decreased after the program. The index referring to liver function and cardiovascular disease risk such as serum ALT, ${\gamma}$-GTP, TG and LDL decreased while HDL increased thereby showing positive effect. The above results anticipate that temple foods with an affirmative effect in improving health status have a potential benefit that can be applied to general food service. Further detailed study might provide information in developing healthy diet for a corresponding clinical problem.