• The korean journal of orthodontics
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• v.35 no.3 s.110
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• pp.163-173
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• 2005

The purpose of this study was to compare the asymmetric degree between maxillofacial hard and soft tissues in individuals with facial asymmetry. Computerized tomographies (CT) of 34 adults (17 male, 17 female) who had facial asymmetry were taken. The CT images were transmitted to personal computers and then reconstructed into three-dimensional (3D) images through the use of computer software. In order to evaluate the degree of facial asymmetry, 6 measurements were constructed as the hard tissue measurements while 6 counterpart measurements were taken as the soft tissue measurements. The means and standard deviations were obtained for each measurement using 3D measure, then t-test was used to investigate the differences between each hard tissue measurement and the corresponding soft tissue measurement All measurements used in the present study showed statistically significant differences between the hard and soft tissues. The degree of soft tissue asymmetry was smaller than that of corresponding hard tissue asymmetry in case of chin deviation, frontal ramal inclination difference, and frontal corpus inclination difference. On the other hand, the degree of soft tissue asymmetry was greater than that of underlying hard tissue asymmetry in the measurement of lip canting and lip cheilion height difference The present study suggests that asymmetric differences of hard and soft tissue is observed nu facial asymmetric subjects and thus soft tissue analysis is needed in addition to hard tissue analysis when making an evaluation of facial asymmetry.

• Convergence Security Journal
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• v.16 no.6_1
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• pp.25-32
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• 2016

We can not respond asymmetric warfare effectively. The asymmetric operation is performed in asymmetric methods and means with different characteristics and functions to their enemy. And the character of the asymmetric operation have 'heterogeneity' and 'superiority' in principle. The type of asymmetric strategy is complex and diverse. Since we can classify the type of the asymmetric strategy in many different way and we must study in many ways and aspects. When we study asymmetric war previous cases from modern to ancient era, we can find that the key factors of the victory have superiority of the asymmetric strategy and discriminatory measures. The asymmetry is created when one party has to adapt to the strategic environment. If we want to secure a strategic advantage, we must take a number of case studies and countermeasures for asymmetric warfare.

• The korean journal of orthodontics
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• v.27 no.3 s.62
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• pp.445-456
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• 1997

This study was designed to examine the dental asymmetry in person with facial asymmetry and to examine the relationship between the degree of mandibular deviation and asymmetry of maxillary dental arch. The sample!, were divided to asymmetry group and normal group. The asymmetry group consisted of 21 subjects(6 males and 15 females) and their mean age was 23.5 years. The normal group consisted of 20 subjects(10 males and 10 females) and their mean age was 18.6 years. Anteroposterior, transverse position of all maxillary teeth except 3rd molars, vortical position of maxillary 1st molars, and angulation of central incisors were measured. The anterioposterior and transverse positions of teeth were measured on the maxillary dental casts, the vertical position of maxillary 1st molars and angulation of maxillary incisors were measured on posteroanterior cephalometric radiographs. The data were analyzed to examine whether significant asymmetries existed in each of the asymmetry and normal groups. The results of this study were as follows : 1. In the asymmetry group, the correlation between the degree of mandibular deviation and that of 3-dimensional dental asymmetry was not so high. 2. In the asymmetry group, the teeth in deviated side were more laterally positioned than that of undeviated side. There were differences in the anteroposterior position of maxillary 1st and 2nd molars and the angulation of maxillary central incisors. 3. In the asymmetry group, the transverse asymmetry was larger in the posterior teeth rather than in the anterior teeth and larger than the anteroposterior asymmetry.

• Environmental and Resource Economics Review
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• v.21 no.1
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• pp.69-92
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• 2012

This paper analyzed price asymmetry of domestic petroleum products by distribution stage. Analyzing the asymmetry by distribution stage, we can investigate the gap between analysis results and consumers' perception. For the first stage, we analyzed asymmetries between retail prices including tax and the spot prices of crude oil. The results show that retail price increases more quickly in response to the crude oil prices rise than to the crude oil prices fall as consumers' perception. For the second stage, we analyzed asymmetry of international petroleum product prices in Korean Won with the change in the crude oil spot prices. The results show that international petroleum product prices increase higher in response to the crude oil prices increase than to the crude oil prices decrease. For the final stage, we examined the asymmetry of wholesale price and retail price with the change in the international petroleum product prices in Korean Won. The results show that wholesale prices increase more quickly in response to the crude oil prices rise than to the international petroleum product prices fall. The retail prices, however, decrease more quickly in response to the crude oil prices fall than to the international petroleum product prices rise.

• The Korean Journal of Financial Management
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• v.19 no.2
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• pp.1-25
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• 2002

본 논문은 한국의 대표적인 두 시장, 코스닥시장과 증권거래소간의 투자전략을 비대칭적 정보가정에서 모형화하고, 정보상의 비대칭요소를 추정하여 최적포트폴리오를 구하는데 목적이 있다. 정보상에 비대칭적 시장들에서는 그 시장에 독특한 위험프리미엄이 존재하게 되는데, 이는 시장간의 효율적 포트폴리오를 구성하는데 있어서 비체계적 위험과 체계적 위험간의 구분이 불분명해지는 상황을 의미하며, 따라서 최적포트폴리오도 보다 복잡한 구조를 갖게 된다. 본 연구는 분석적 차원에서 정보상에 비대칭적인 것으로 가정되는 두 자본시장, 즉 코스닥시장과 증권거래소에서의 최적포트폴리오 전략을 살펴보고, 두 시장간의 비대칭성이 주는 의미와 그것이 최적 투자정책에 미치는 영향의 정도를 분석하고, 비대칭적인 두 시장에서의 균형조건을 살펴본다. 먼저, 최적포트폴리오 전략을 살펴보고, 자산가격 움직임에 있어서 차익거래의 영향을 분석하며 이에 대한 정보상으로 비대칭적인 두 시장간의 포트폴리오 전략과의 관계도 분석하였다. 이어서 비대칭적 상황을 발생시키는 다양한 요소들을 살펴보며 이와 같은 정보비대칭요소가 기대수익수준에 미치는 영향을 분석하기 위해 확률과정의 최적화 방법을 이용하여 추정하였다. 따라서 관련정보를 보유하지 못한 일반투자자들의 경우, 이 추정치를 이용하여 새로운 포트폴리오를 구성하게 될 것이다. 이 또한 불편추정치로서 최적포트폴리오로서의 역할을 하고 있는 것으로 해석된다. 그러나 비대칭요소 추정치의 정확도를 높이기 위해서는 정보를 확보하여야 하며 이에 따라 정보비용도 증가하게 되며 이 또한 최적포트폴리오의 수익성에 영향을 미치게 된다. 따라서 정보비용수준을 포트폴리오의 수익성을 고려하여 결정하여야 하며 이 점에 있어서 본 연구는 어떤 조건하에서 정보비용을 감안한 코스닥시장에의 투자결정이 이루어질 수 있는지를 분석하고 그 기준을 확률적 방법을 이용하여 제시하였다.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.137-138
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• 2016

본 논문에서는 넓은 영전압 스위칭 범위와 작은 DC 오프셋 전류를 가지는 비대칭 하프-브릿지 컨버터를 제안한다. 기존의 비대칭 하프-브릿지 컨버터는 설계 시 홀드업 시간 만족을 위하여 정상 상태에서 극심한 비대칭 동작을 하게 된다. 이는 변압기의 큰 DC 오프셋 전류, 비대칭 전류 스트레스 등의 문제를 야기하며 이로 인하여 전반적인 변환 효율이 감소하게 된다. 이러한 문제점들을 해결하기 위하여, 제안하는 컨버터는 정상 상태에서 비대칭 동작을 최소화하고 낮은 입력전압에서 추가 스위치를 동작시킴으로써 커뮤테이션 구간을 줄여 전압이득을 높인다. 또한 추가 인덕턴스를 사용하여 영전압 스위칭 에너지를 키우고 추가 스위치의 내부 바디 다이오드를 이용하여 2차측 정류단의 전압 스트레스를 줄인다. 이를 통하여 높은 효율을 가지면서 작은 DC 오프셋 전류를 가지는 비대칭 하프-브릿지 컨버터를 제안하였으며, 500W의 프로토타입 컨버터를 제작하고 실험을 통해 이를 검증하였다.

• Journal of the Earthquake Engineering Society of Korea
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• v.5 no.1
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• pp.13-19
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• 2001

본 연구에서는 진동제어를 목적으로 강성이 비대칭적으로 분포된 구조물에 점탄성 감쇠기를 설치할 경우 비틀림 응답을 줄이기 위한 감쇠기의 효과적인 배치방법에 관하여 연구하였다. 비대칭 구조물의 응답에 미치는 점탄성 감쇠기의 효과를 알아보기 위하여 비대칭 비비례감쇠시스템의 특성방정식을 유도하고, 고유치해석을 통해 감쇠기가 설치된 비틀림 건물의 거동특성을 파악하였다. 이를 바탕으로 강성 편심 및 진동수비에 따른 최적 감쇠 편심을 찾아 이를 3차원 그래프로 나타내었다. 이를 이용하여 비대칭건물에 감쇠기를 설치했을 때 같은 양의 감쇠기를 대칭으로 설치하였을 때 보다 그 효과가 더욱 향상되는 것으로 나타났다. 또한 비대칭 건물의 비틀림제어면에서 점탄성 감쇠기가 점점 감쇠기보다 우수한 것으로 나타났다.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.201-202
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• 2014

본 논문에서는 비대칭 하프브리지 컨버터의 비대칭 시비율을 개선한 컨버터를 제안한다. 일반적인 비대칭 하프 브리지 컨버터의 경우 홀드업 타임 조건 때문에 넓은 입력 전압 범위를 가지게 되고, 정상 동작시 스위치의 비대칭 동작이 심화 된다. 이러한 스위치의 비대칭 동작으로 변압기의 자화 전류 옵셋이 증가하고 변압기 부피 및 2차측 정류기들의 전압 불균형이 심화되어 컨버터 효율이 감소하게 된다. 하지만 제안된 컨버터에서는 보조 스위치와 보조 커패시터를 이용, 변압기의 권선비를 조정하여 정상 동작 시 정류기들의 비대칭을 저감하였고, 변압기의 자화 전류 옵셋을 감소시켜 높은 효율을 달성하였다. 제안된 컨버터의 타당성을 검증 하기 위해 300W 프로토 타입을 제작하여 실험을 진행 하였다.

• Environmental and Resource Economics Review
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• v.17 no.4
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• pp.813-843
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• 2008

This paper investigates the presence of long-run and short-run price asymmetries in weekly gasoline prices from January 1997 to July 2008. In accordance with distribution channels, wholesale and retail stages are analyzed separately. An approach based on TAR and M-TAR cointegration tests, which entail matching asymmetric ECMs, is employed. For wholesale prices, asymmetries in the links with crude oil prices and exchange rates are found for both ECMs in the long-run and short-run. Exchange rates appear to play more significant role than crude oil prices in explaining the short-run price asymmetry. The rise in crude oil prices or exchange rates has statistically significant major impact on the increase of wholesale prices on the second week, not immediately as expected in the concept of 'rockets and feathers'. And asymmetrically, the fall does not have any statistically significant effect on the same period. The finding seems to be somewhat unusual. However, for retail prices, asymmetry m connection with wholesale prices is only revealed in the long-run. A symmetric price adjustment can be assumed in the short-run. Contrary to the long-run asymmetry found in the wholesale stage, in the retail stage, the speed of adjustment for negative deviations toward long-run equilibrium is faster than for positive ones, which is a phenomenon not favorable to consumers.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.8C
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• pp.497-504
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• 2011

This paper presents an adaptive retinex algorithm, In order to solve typical problems of retinex algorithm such as expensive computational cost, halo artifact, and color distortion, a function of skewness that represents a statistical distribution of pixels is defined to compensate contrast and color distortion. The experimental results show that the proposed algorithm leads to subjectively better performance than typical retinex algorithm, and that the proposed algorithm has the capability to reduce approximately 40% computational cost than typical retinex algorithm.