• Clinical and Experimental Reproductive Medicine
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• v.13 no.2
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• pp.145-151
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• 1986

The purpose of this study is to investigate the cytogenetic characteristics of Down's syndrome in Korea. For this study, selected were 92 patients who were diagnosed as Down's syndrome by the chromosomal analyses, among 115 patients who were supected of Down's syndrome and referred to the Cytogenetic Laboratory, Institute of Reproductive Medicine and Population, Seoul National University, for 2 years from January 1984 to December 1985. Among 92 patients with Down's syndrome 83 (90.2%) had G-trisomy, 4 (4.3%) had translocation, and 2 (2.2%) had mosaicism of normal and G-trisomic cell lines. Two patients of the remaining 3 had both G-trisomic and translocation, 47, XX, t (1:21) (p32:q22), +21, 47, XX, t (9:11) (q34:q14), +21. The remaining 1 patient had 47, XY, +mar.

• Water for future
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• v.27 no.2
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• pp.121-128
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• 1994

Reduced trend of surface velocity, length of the separated drop area and width of potential core have been verified through experimental study of flow characteristics at the step down. To inverstigate sediment behaviors, experimental study which involved accumulated sediment transport reducing water velocity in the separated drop area was performed. From the experimental results, surface velocity, length of the separated drop area and width of potential core were formulated, and calculated output was corroborated by experimental outcome. Furthermore an examination of the parameter which is defined by $q_{sf}$/$q_{uo}$ was performed by detecting sediment in the separated drop area. Therefore these experiments can express the phenomena of flow characteristics and sediment behaviors at the step down.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.6
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• pp.671-676
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• 2006

A convolution with HRTF DB and the original sound is generally used to make the method of sound image localization for virtual speaker realization. But it can decline localization by the confusion between up and down or front and back directions due to the non-individual HRTF depending on each listener. In this paper, we study a virtual speaker using a new HRTF, which is grouping the HRTF around the virtual speaker to improve localization between up and down or front and back directions. To effective HRTF grouping, we decide the location and number of HRTF using informal listening test. A performance test result of virtual speaker using the grouped HRTF shows that the proposed method improves the front-back and up-down sound localization characteristics much better than the conventional methods.

• The Journal of the Korea Contents Association
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• v.19 no.9
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• pp.122-134
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• 2019

This study aims to conceptualize characteristics of the Korean traditional dance, and to categorize and analyze the recognition of experience of passing down education of Seungmu(Buddhist Dance), Salpurichum(Exorcism Dance) and Taepyeongmu(Dance of Peace). Dividing into groups of two: an experienced person twenty years or more in the Korean dance and a person who completed the traditional dance three years or more, three groups were selected. We connected the characteristics of the traditional dance experienced in passing down education with the recognition experience in the training courses. Categorizing thematically the process and the recognition of experience in the passing down education program, we attempted mutual group discussion and inductive area analysis on the basis of in-depth interview, tutorial discussion and analysis contents. As a result of this study, first, the characteristics of the Korean traditional dance that graduates of the program by repertory empathize were the experience of the sinmyung(the excess of mirth) and improvisation, the supreme self-controlling beauty and the best beauty of expression. Second, the recognition of experience in the passing down education program runs as follows: Interacting in the centre of the process, new education system for transmission, and formation of social discourse for appreciation. Conclusionally, the experience and the new vision for transmission of passing down education of the traditional dance are required to be based on the appreciation of the rationality of mutual communication and recognition of experience.

• Journal of Biomedical Engineering Research
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• v.4 no.1
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• pp.29-36
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• 1983

In this paper, center frequency down slift of ultrasonic echo signals which for the measurements of frequency dependent attenuation in the biological tissue are estimated. Center frequency down shift of echo-signals are estimated after signal spectrum analysis of whole echo-signals. In case of signal spectrums are simple, estimation of down shift frequency is very simple and in case of complicate spectrum, estimation of down shift frequency is depend on spectral shape. In case of unable to estimate, frequency dependence of medium is nonlinear(n) 1), in which upper shift of spectrums are presented. In case of unable to estimate, spectrum analysis are performed at local position. At consquence, we know that spectral dispersions are caused complicately by biological tissue layer.

• Transactions on Electrical and Electronic Materials
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• v.13 no.6
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• pp.292-296
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• 2012

An optimum heat sink for a 30 W chip on board (COB) LED down-light is designed, fabricated, and characterized. By using the SolidWorks Flow simulator and thermal analysis software, the thermal characteristics of the optimum heat sink is analyzed. Four different types of heat sink are simulated and an optimum structure of the heat sink is found. The simulated temperature of the heat sink when operating the LED down-light is $55.9^{\circ}C$, which is only a difference of $2^{\circ}C$ from the measured temperature. In order to reduce the temperature further, a copper spreader is introduced to the heat sink. The temperature of the heat sink with the copper spreader is $3^{\circ}C$ lower than without the copper spreader.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.9
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• pp.94-99
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• 2011

This paper verified the characteristics of electrical continuity and mechanical strength of steelwork required to use it as a down-conductor in lightning protection system. It was proven that the steelwork in reinforced concrete apartment has an excellent electrical continuity with low resistance(less than 0.2[${\Omega}$].). But it was confirmed that a poor connection between two reinforcement bars can easily cause serious damages of the concrete even with the impulsive current of 50[kA], 10/350[${\mu}s$]. These results of experiments mean that the additional measures are necessary in using the steelwork as the down-conductor of the lightning protection system.

• Transactions of the Society of Information Storage Systems
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• v.7 no.2
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• pp.65-69
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• 2011

Head Disk Interface (HDI) in a Hard Disk Drive (HDD) has decreased to achieve high areal density. Thus, the contact between a slider and a disk becomes more important. The contact between the slider and the disk can cause severe wear and damage of both the slider and the disk. Especially, Touch Down (TD) that the contact occurs continuously and repeatedly is extremely dangerous. Therefore, it is necessary to analyze the unstable bouncing vibration of the slider in head-disk interface. In this paper, we investigate the characteristic and causes of the Touch Down.

• Journal of Drive and Control
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• v.14 no.3
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• pp.32-39
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• 2017

In this study, a mathematical model of the pneumatic part in a gas blow-down system is proposed. The mathematical model consists of four major parts: pressure vessel, reservoir, pressure regulator and pipe-line. To ensure accuracy in long-time simulations, heat transfer between gas and pressure vessel is considered. The model is validated by comparing simulation results with experimental data. Experiments are conducted on the ground, where free convection can be assumed. Simulation results indicate the proposed model can accurately describe behavior of a gas blow-down system. Therefore, it may be used for design and analysis of similar systems with a slight modification.

• Nuclear Engineering and Technology
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• v.50 no.6
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• pp.854-859
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• 2018

Calculating minimal cut sets is a typical quantification method used to evaluate the top event probability for a fault tree. If minimal cut sets cannot be calculated or if the accuracy of the quantification result is in doubt, the Monte Carlo method can provide an alternative for fault tree quantification. The Monte Carlo method for fault tree quantification tends to take a long time because it repeats the calculation for a large number of samples. Herein, proposal is made to improve the quantification algorithm of a fault tree with circular logic. We developed a top-down iteration algorithm that combines the characteristics of the top-down approach and the iteration approach, thereby reducing the computation time of the Monte Carlo method.