• Journal of Biomedical Engineering Research
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• v.20 no.2
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• pp.231-236
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• 1999

Understanding the exgenous water induced thermomechanical effect on the dental hard tissue by the Q-switched Er:YAG laser (1-$mutextrm{s}$-long pulse width) has an important impact on the further understanding of the free-running Er:YAG laser (250-$mutextrm{s}$-long pulse width) ablation on the dental gard tissue because one macroscopic effect in the free-running laser is an accumulation of microscopic effects we investigated in this study. The Q-switched Er:YAG laser with exogenous water on the tooth enhanced ablation rate compared to the case of no water on the tooth. The frequency of exogenous-water jet on the tooth has affected the ablation rate in such a way that as we dispensed water drops less frequently we could get more enhanced ablation rate. The amplitude of the recoil pressure depends on the tooth surface conditions such that as surfaces wet, and as the volume of the exogenous water drop increased, the amplitude of the recoil pressure increased also. From this study we realized that the 1 $mutextrm{s}$ long pulsed induced thermomechanical effect provides us useful information for the understanding of the free-running Er:YAG laser induced ablation with exogenous water.

• Korean Journal of Culture and Social Issue
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• v.21 no.3
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• pp.511-534
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• 2015

The primary goal of the present study was to examine the moderating effects of coping strategies, cultural identity, and bicultural self-efficacy on the relationship between perceived discrimination and depressive symptoms of Korean Canadian college students. Data were collected from 214 Korean Canadian college students studying in Canada through an online and offline survey. A direct effect of perceived discrimination on depressive symptoms and the moderating effects of coping strategies on the relationship between perceived discrimination and depressive symptoms were examined by using hierarchical regression analysis. And three-way interaction of perceived discrimination, coping strategies, and cultural identity, and perceived discrimination, coping strategies, and bicultural self-efficacy on depressive symptoms were examined. Results from a hierarchical regression indicated that perceived discrimination significantly predicted depressive symptoms and this finding is in line with previous studies. Second, reflective, suppressive, and reactive coping strategies did not moderate the relationship between perceived discrimination and depressive symptoms. Third, the three-way interaction effect of perceived discrimination, suppressive coping strategy, and heritage identity predicted the depressive symptoms. Low heritage identity, high level of perceived discrimination and the frequent use of suppressive coping strategy increased the level of depressive symptoms. Fourth, the three-way interaction effect of perceived discrimination, coping strategies, and bicultural self-efficacy did not predict the depressive symptoms. Limitations and applied implications of the results are discussed.

• Journal of the Korean Data and Information Science Society
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• v.7 no.1
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• pp.161-170
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• 1996

이 글에서는 지난 2년 반동안 4권의 '통계이론방법연구'를 편집하면서 얻은 편집에 관련된 경험과 지식을 종합하여 기록하여 둔다. 여기에서 제시된 편집원칙 등이 본 논문집의 형태에 관한 기준이 되고자 한다. 워드프로세서의 선정에 관한 문제, 글씨체와 크기의 선정문제 등 제반의 형식적인 문제를 다룬다. 또한 실제 예시를 통하여 본 잡지에 논문을 투고하는 저자들의 논문작성에 도움이 되도록 한다.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2000.05a
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• pp.278-300
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• 2000

일본에서는 이미 1997년에 제 6회 기술예측조사를 실시하여 2025 년까지의 미래기술예측을 실시하였고 우리나라에서도 1998 년 6 월부터 약 1 년 반동안 중장기 기술예측을 실시하여 1999 년 11 월에 제 2 회 과학기술예측 결과를 발표하였다. 양국의 전자 정보ㆍ통신분야의 기술예측 결과를 비교ㆍ분석하여 양국의 기술예측결과의 특징을 살펴보고 정책적 활용방법을 모색해 본다.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2427-2429
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• 2002

본 논문에서는, 지붕위로 뛰어오르기 위하여 벽의 반동을 이용하는 고양이의 운동상태를 흉내내어 수직의 방향으로 운동하는 고양이 로봇 시스템을 연구한다. 또한 이러한 로봇 시스템의 3-link 부분시스템의 운동은 slider-link에서 구속되어지고, 또한 singular자세를 쉽게 피할 수 있는 운동계획방법(motion planning method)을 제안한다. 제안되어진 연구결과는 수직동작에 대한 메카니즘에 유용한 방법이고 이론적 개념, 모델링, 그리고 제어를 논의한다. 마지막으로, 모의실험을 통한 결과로서 제안되어진 방법의 유용성을 설명한다.

• Fire Science and Engineering
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• v.26 no.6
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• pp.57-63
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• 2012

The modern trend for high-rise buildings makes the application of fire protection systems difficult and the current systems have a limitation to provide appropriate functions. Indoor hydrant systems are fire suppression systems installed in most buildings that require valves, hoses, and nozzles to be manually operated in the event of a fire. Therefore, high discharge pressure can cause difficulty in the operation of indoor fire hydrant systems and damage to hoses due to a high reaction force. To prevent these problems, the pressure is reduced and decompression valves are commonly installed at angle valves which are the discharge points of indoor hydrants. In the case of high-rise buildings, however, there are cases where stable operation is difficult even with the installation of decompression valves. To verify this, we have measured the decompression performance by the orifice diameter and calculated the reaction force. Results of the study showed that decompression valves need to be produced in different sizes to provide stable decompression where high pressure is required as in high-rise buildings.

• Journal of Korea Water Resources Association
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• v.36 no.6
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• pp.949-960
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• 2003

The resolution issue of wetness index with relaxation of the steady state assumption is explored on the platform of Digital Elevation Model (DEM). The variabilities of the quasi-dynamic wetness index and the dynamic wetness index are discussed on the base of the spatial and statistical aspects depending upon resolutions of DEM and the drainage time. The organization patterns of the wetness index can be observed upon various drainage times and pixel size. The transient behaviour of wetness patterns of the Sulmachun watershed are shown in the relatively short drainage time. The statistical analysis of the quasi-dynamic and dynamic wetness analysis provide the convergence of analysis results to the steady state characteristics later than 10,000 hours drainage time. The probability density functions of the quasi-dynamic and the dynamic wetness index shows the existence of the threshold pixel size of DEM which provide stability and consistency in the computation result of these two wetness index.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.9
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• pp.681-689
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• 2020

This paper presents methods and results of both flight test examining roll angle estimation performance of slowly rolling munition forced to spin in the air, and fabricating a replica of guided munition. Guided munition was deployed from multi rotor type UAV mother ship whose altitude and velocity was conveyed to it as initial state. Flight test scenario is composed of a sequence of munition drop(deployment), munition spin, roll angle estimation and stabilization. Munition was deployed from mother ship at around 200m high with horizontal velocity of 15m/s, and was made spun using internal reaction wheel. Performance analysis on roll angle estimation is provided in comparison with commercial aerospace graded GPS/INS. Moreover, several mechanisms that rotates munition using reaction wheel, and actual product that realizes one of them are introduced.

• Korean Journal of Social Welfare
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• v.58 no.2
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• pp.5-31
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• 2006

Since enforcement of the anti-prostitution law, in spite of systematic setting helping escape prostitution of the women who engage in prostitution that they have had the will lasting prostitution. Therefore, this study aimed to devise intervention plan helping their escape prostitution and return to social by examining individual and structural factor obstructing their escape prostitution The data were collected through the in-depth interview and text. And these were analysed according to coding, constitution of concept, matching, construction of explanation on the phenomenon. The nine women who engaging in prostitution were participated in this study. As a result of the data analysis, 46 concepts and 10 categories were generated. By classification of individual and structural factor, the outcomes of an interpretation were as follows: The cause obstructing Prostitutes' escape prostitution were (1) distrust on the policy of the government, (2) life-script was made by reaction-formation, (3) predestined resignation caused by anxiety, (4) body as capital goods, and (5) the commensal model with pimp. Based on this result, we proposed practical and political alternative plans for prostitutes.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.323-326
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• 2004

에어컨 실외기의 구조 방사 소음을 줄이기 위해 제진재를 적용함에 있어 구조 인텐서티(structural intensity)법을 사용할 수 있다. 에어컨 실외기 각 패널의 법선 방향의 속도는 레이져 스케닝 바이브로미터(laser scanning vibrometer)에 의해 측정되며, 측정된 데이터는 공간 주파수 영역(k-domain)으로 변환하여 구조 인텐서티 계산에 필요한 공간 미분값이 구해진다. 이러한 과정을 통하여 계산된 구조 인텐서티 중 반동 전단 구조인텐서티(reactive shearing structural intensity)값이 가장 높은 부분에 사각형 형상의 제진재를 적용한다. 본 논문은 패널에 비해 그 크기가 작은 제진재의 적용으로 에어컨 실외기의 구조 방사 소음을 줄일 수 있음을 보여준다.