• 유통과학연구
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• 제14권12호
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• pp.79-87
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• 2016

Purpose - Since 1990, the sudden stop in capital flows has caused the economic crisis. The purpose of this research is to suggest the policy measures to mitigate the risk of the sudden stop in capital flows. To this end, we examine the theoretical framework and analyze the case study for countries which are faced with the sudden stop. Also we examine the structural problems of the foreign exchange market in Korea and derive the policy implications to prevent the sudden stop. Research design, data, and methodology - The criteria of whether the sudden stop in capital flows occurs are based upon Calvo et al. (2008). In case the proxy variable for the balance of capital account decreases from the average by over twice standard deviation, we determine that the sudden stop occurs for that country. The sample period is from January 1990 to December 2008, as in Calvo (2014). The sample countries are 17 developed countries and 19 emerging market countries, which are different from those of the previous papers as Agosin and Huaita (2012), and Calvo (2014). When the exchange market pressure index(EMPI) is deviated from the average by over three times standard deviation, we determine that the foreign exchange market is unstable for that country. Results - We find that the characteristics of the sudden stop in capital flows are the bunching or contagion among countries, the rapid drop in real effective exchange rate, and the huge decrease in foreign exchange reserves. Many countries tried to increase foreign exchange reserves and regulate capital flows. Also the foreign exchange market in Korea are found to be the volatile exchange rate, the vulnerable external debt and careless management of the foreign exchange derivatives transaction risk. Conclusions - To lessen the risk in the sudden stop of capital flows, this research suggests the some useful policy measures. To enhance the foreign exchange and distribution market stability, we should improve the price mechanism of exchange rate, hold the appropriate level of foreign exchange reserves, prevent excessive inflows of foreign exchange and promote sound transactions of foreign exchange derivatives.

• 대한음성학회지:말소리
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• 제45호
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• pp.1-14
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• 2003

This paper criticizes S. Kim (1992), claiming that the perception of place cues in the reduced stop consonant clusters ('reducing' means 'cutting off' the acoustic silence in stop clusters) largely depends on the acoustic characteristics such as formant transition and noise frequency distribution of stop burst, rather than the closure duration time as advocated by S. Kim (1992). The claim is based on the perception test conducted upon 111 stimuli over 10 subjects. The finding is that, when the closure duration is cut off up to the point where only one stop is perceived, place of the second stop, not the first one, in the cluster is in most cases perceived regardless of the places of the first and second stops. It is likely that the place cues of the stop in the prevocalic position mask those in the postvocalic position.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1798-1803
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• 2003

In this work the dynamic heat transfer occurring in a cable penetration fire stop system built in the firewall of nuclear power plants is three-dimensionally investigated to develop a test-simulator that can be used to verify effectiveness of the sealants. The dynamic heat transfer can be described by a partial differential equation (PDE) and its initial and boundary conditions. For the shake of simplicity PDE is divided into two parts; one corresponding to the heat transfer in the axial direction and the other corresponding to the heat transfer on the vertical layers. Two numerical methods, SOR (Sequential Over-Relaxation) and FEM (Finite Element Method), are implemented to solve these equations respectively. The axial line is discretized, and SOR is applied. Similarly, all the layers are separated into finite elements, where the time and spatial functions are assumed to be of orthogonal collocation state at each element. The heat fluxes on the layers are calculated by FEM. It is shown that the penetration cable influences the temperature distribution of the fire stop system very significantly. The simulation results are shown in the three-dimensional graphics for the understanding of the transient temperature distribution in the fire stop system.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.288-291
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• 2001

In steel plant, load torque of mill driver motor is changed periodically because working state and idle state are repeated and load current of working state is necessarily higher than rated motor current. The over current limiter is one of the basic thermal protection method from over heating. In this paper, we analyzed the structure of over current limiter for motor and motor driver systems, developed over current limiter with same operation and structured warning system of action of over current limiter. As using this warning system, we can avoid abrupt plant stop by over current limiter in mill driver and lessen producing loss by plant stop. The developed warning system of action of over current limiter is exactly inspected by computer simulation md analysis of acquired data.

• 한국도로학회논문집
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• 제9권1호
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• pp.29-38
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• 2007

경찰은 2005년 정지선 준수율 향상을 위하여 '정지선 지키기 생활화 운동'과 함께 정지선위반 단속을 수행하였다. 단속기간 동안 정지선 준수율이 향상되었으나, 단속기간 이후 정지선 준수율은 단속 이전 수준으로 회귀되어 캠페인 및 단속을 통한 정지선 준수율 향상 노력의 장기적인 실효성 문제가 지적되었다. 교통안전시설물(신호기) 설치위치 조정 등의 교통환경 개선을 통해 장기적이며 근본적인 정지선 준수율 향상 필요성이 공론화 되고 있으나 해당분야의 기초 연구가 부재하다. 본 연구는 신호기 설치위치에 따른 차량의 정지선 준수율 변화 여부를 분석 및 제시한다. 현장자료를 토대로 수행한 통계분석 결과 신호기 위치에 따라 정지선 준수율이 변화하며, 정지선으로부터 신호기까지의 거리가 $10{\sim}20m$일 경우 정지선 준수율이 높아지는 것으로 분석되었다. '교통신호기설치관리매뉴얼'에서 허용하는 신호기 설치위치 범위에 포함되는 정지선 하류 $10{\sim}20m$의 위치를 신호기 적정 설치위치로 제안한다.

• 말소리와 음성과학
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• 제5권4호
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• pp.137-143
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• 2013

Recent investigation of acoustic correlates of Korean stop manner contrasts has reported a diachronic transition in Korean stops: young Seoul speakers are relatively more dependent on the F0 characteristics of the stops than on the VOT characteristics in aspirated and lenis stop distinction. This finding has been examined against tonal dialects of Korean and the results suggested that the speakers of tonal dialects are not sharing the transition. These results also suggested that F0 function for segmental stop classification interferes with the function for lexical tone classification in their tonal speech. The current study investigated these findings in terms of perception. Perceptual behavior of Seoul and Busan speakers of Korean was examined in a comparative manner through the measurement of perceptual cue weight of F0 and VOT in particular. The results from regression and correlation analyses revealed that Busan speakers are closer to older Seoul speakers than to younger Seoul speakers in that the cue weight for VOT and F0 were comparable in the aspirated-lenis stop distinction. This result was in contrast to the perceptual behavior of younger Seoul speakers who showed clear dominance of F0 over VOT for the same distinction. These findings provided perceptual evidence of the dual function of F0 for segmental and lexical distinctions in tonal dialects of Korean.

• Imaging Science in Dentistry
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• 제51권4호
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• pp.439-446
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• 2021

Purpose: The aim of this study was to identify correlations between the STOP-Bang score and upper airway dimensions using cone-beam computed tomography (CBCT) scans. Materials and Methods: This study included 101 subjects (46 men, 55 women) from dental patients who received CBCT scans from 2014 to 2020. The patients were divided into those with a low obstructive sleep apnoea (OSA) risk (STOP-Bang score<3) and those with an intermediate to high OSA risk (STOP-Bang score≥3), and their upper airway dimensions were then analysed on CBCT scans. Comparisons between the low-risk and intermediate/high-risk groups were conducted using the t-test and the Mann-Whitney test. Correlations between the total STOP-Bang score and upper airway dimension parameters were established using Spearman correlation coefficients. P values≤0.05 were considered to indicate statistical significance. Results: Intermediate/high-risk subjects were predominantly male and over 50 years of age, with a higher body mass index. They had significantly longer upper airways, smaller average airway volumes, and smaller widths and antero-posterior dimensions of the narrowest upper airway segment. The total upper airway length was positively correlated with the STOP-Bang score (r_s=0.278). The average volume (r_s= -0.203) and width of the narrowest upper airway segment(r_s= -0.305) were both negatively correlated with STOP-Bang scores. Conclusion: Subjects with higher STOP-Bang scores had upper airways that were longer, narrower, and smaller in terms of average volume. CBCT scans taken for dental patients as part of investigative procedures could be correlated with STOP-Bang scores to screen for patients at risk of OSA.

• 음성과학
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• 제8권1호
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• pp.93-111
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• 2001

This study investigates the contribution of vocalic information following the release of an initial stop to the identification of the three-way stop contrast (aspirated, lax, and tense) in Korean. Recent studies showed that there is a strong interaction between consonant types and tone. The findings raise questions concerning Korean listeners' use of tonal (or vocalic F0) variation in differentiation initial tense, lax, and aspirated stops. The above issues are addressed in the present study using a cross-splicing methodology. The overall results show that low vocalic F0 provided the most salient information for lax stops; tense and aspirated stop identification depended on a combination of VOT, F0, and H1-H2 characteristics. The perceptual dominance of F0 over VOT for lax stops is consistent with the size of the F0 difference in utterance-initial position, as well as their prominent role in Korean intonational phonology.

• 한국화재소방학회논문지
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• 제18권1호
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• pp.24-30
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• 2004

본 논문은 원자력발전소 방화벽에 설치된 케이블관통부 충전시스템(CPFS: Cable Penetration Fire Stop)안에서 일어나는 동적 열 전달 현상을 해석하기 위해 수행된 실험을 다루고 있다. Dow Corning사의 내화성 충전물에 대해서 내화실험이 수행되었으며, 본 실험을 통해 준비된 CPFS 시험체가 성능위주 시험방법인 ASTM E-814의 F-rating과 T-rating을 동시에 만족시킬 수 있는지를 알아보았다. 그리고 여기서 얻어진 실험결과는 CPFS시스템 내화성능 평가용 소프트웨어를 개발하기 위해 사용되었다. CPFS 시스템 내에서의 열전도 현상은 주어진 초기조건과 경계조건 하에서 Parabolic PDE(Partial differential equation)로 수식화 되었으며, 이렇게 수식화된 PDE는 다시 연속과완화법(SOR: Sequential over-relaxation)과 Galerkin 유한요소법(FEM: Finite element method)로 구성된 혼합알고리즘에 따라 풀 수 있었다. PDE을 풀기 위해 널리 사용되고 있는 상용소프트웨어 Femlab을 이용하여 방화시스템 내에서의 온도분포를 계산하여 3차원 그래픽으로 나타내었다. 특히 CPFS시스템 내에서의 시간의 경과에 따른 온도분포의 변화에 대한 실험과 수치해석을 병행함으로써 결과에 대한 신뢰성을 높일 수 있었다.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제6권3호
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• pp.135-140
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• 2017

SMT장비는 전자 부품을 흡착하여 PCB상에 정확히 실장 하는 장비이다. 이를 위해서는 중간 위치에 설치된 카메라 앞에서 정지하여 비전검사를 한 후 실장 위치로 이동한다. 본 논문에서는 카메라 앞에서 멈추어 비전 검사를 한 후 실장하는 방법(stop-motion)과 카메라 앞에서 움직이면서 비전 검사를 한 후 실장하는 방법(fly-motion)을 비교하였다. 그 결과 fly-motion의 시간 효율이 stop-motion보다 9% 증가한 것을 보여주었다.