• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.175-180
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• 2006

This study is carried out the investigation of nonlinear characteristics of the ocean based on the field wave observation data acquired the western sea area in Jeju island during one year. It is aimed to offer the fundamental data for Freak wave forecasting in real sea. For this, the nonlinearity parameters of ocean waves, which are Skewness, Atiltness, Kurtosis and Spectrum band width parameter, are introduced, and the parameters are compared and discussed with some characteristic wave components, ie, significant wave height, maximum wave height, and so on.

• 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.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.11 no.4
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• pp.189-196
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• 1999

In order to verify a numerical model for the calculation of wave motion around an offshore barrier in shallow water, laboratory physical experiments are necessary. In this study, sample experiments are carried out on the wave and wave induced current fields due to a sloping bottom topography and on that due to an isolated structure from the coastline. The water body is divided into 4 levels, in which the current tracking floaters are deployed to measure the wave induced currents. Data measurement was continued using the limited wave gauges and current tracking floaters including a video camera from the top. The wave heights for the preselected surface and time-averaged velocity distributions at each level were measured in detail. The distribution of wave and current fields was analyzed precisely combining the whole measured laboratory data. Moreover, comprehensive analyses were carried out on non-linearity of wave transformation in terms of skewness and atiltness.

• Journal of Navigation and Port Research
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• v.31 no.6
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• pp.471-478
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• 2007

This study is carried out the investigation of nonlinear characteristics of the field wave observation data acquired in the western sea area in Jeju island during one year. It is aimed to offer the fundamental data for Freak wave forecasting in real sea. For this, the nonlinear parameters of ocean waves, which are Skewness, Atiltness, Kurtosis and Spectrum band width parameter et al., are introduced, and the parameters are compared and discussed with some characteristics wave components, ie, significant wave height, maximum wave height, and so on. As a results, we know that the parameters describe nonlinear characteristics of observed wave spectrum broadly, are feebly related with occurrence of abnormal maximum wave height, namely freak event, however the Kurtosis, $K_t$ which is a degree of peakness of mode of surface elevation distribution, has better relationship than others.

• The Korean Journal of Financial Studies
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• v.11 no.1
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• pp.199-216
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• 2005

본 연구에서는 한국을 포함한 4개국의 주식시장을 대상으로 주식시장에 도달하는 정보의 유형 즉, 정보가 나쁜 뉴스(bad news)이냐 또는 좋은 뉴스(good news)이냐에 따라 주가변동성에 미치는 영향을 실증적으로 분석하였다. 주가변동성은 투자위험을 나타내는 것으로 위험프리미엄(risk premium)과 관련이 있으며, 주가변동성이 높을수록 위험프리미엄이 커져서 기대수익률이 높아지게 된다. 따라서 주가변동성에 관한 연구는 자산가격결정 등 투자자산 관리에 있어서 매우 중요한 시사점을 제공할 수 있을 것이다. 실증분석결과에 의하면 전체기간(1991년~2004년)에서 4개국 모두 예상하지 못한 음(-)의 수익률이 예상하지 못한 양(+)의 수익률보다 주가의 변동성을 더욱 증가시킨 것으로 나타났다. 그리고 그 반응 정도의 크기는 한국이 가장 낮게 나타나고 있다. 즉 주식수익률의 정보의 비대칭성은 4개국 모두 볼 수 있으며, 이중 한국에서 정보의 비대칭성이 가장 약하다는 결과로 해석할 수 있다. 본 연구의 이러한 분석결과는 4개국 모두 주식시장에서 정보유형에 따른 주가변동성의 비대칭적 반응이 존재한다는 것을 실증적으로 보여주는 것이다. 또한 두 개의 하위기간(IMF 전후기간)에서도 주가변동성의 비대칭적 반응이 존재하는 것으로 나타났으며, 특이한 점은 주가변동성의 비대칭적 반응을 나타내는 계수값이 한국, 일본, 홍콩 등 아시아 국가들은 IMF 이후기간에서 감소하는(특히 한국의 경우 대폭 감소함) 반면, 미국의 경우에는 대폭 증가하였다. 이는 아시아권의 경우 금융위기를 겪으면서 투자자들이 나쁜 뉴스에 대해 다소 둔감하게 된 결과인 것으로 해석할 수 있다.

• Korean Journal of Acupuncture
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• v.34 no.3
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• pp.179-184
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• 2017

Objectives : Despite the applicability of Korean Medicine(KM) treatments for facial asymmetry, no relevant study has been reported. In this case report, we report the effect and safety of KM treatments on facial asymmetry by mandibular lateral displacement. Methods : Three patients suffering from facial asymmetry received twelve KM treatment sessions composed of Motion Style Treatment(MST), Yinyang Balance Appliance(YBA) of Functional Cerebrospinal Therapy(FCST), and Instrument Assisted Soft Tissue Mobilization(IASTM). The photos of each patient were taken before and after the treatment. And four primary reference lines were assessed before and after the treatment. Results : All subjects were improved after KM treatments on photos. However, no statistical significance was observed. Conclusions : This case report is the first to introduce the effect of KM treatments on facial asymmetry. Further well-designed, randomized, placebo-controlled trials are needed to verify these results.

• The Journal of the Korea Contents Association
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• v.16 no.8
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• pp.387-394
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• 2016

The volatility in the stock market responds differently to information types. That is, the asymmetric volatility exists in the stock market which responds more to unexpected negative returns due to bad news than unexpected positive returns due to good news. This paper examines the asymmetric response of the volatility of KOSPI, large-cap, middle-cap, and small-cap indices returns which is announced in Korea exchange (KRX) by using the MA-GJR model and the MA-EGARCH model. According to empirical analyses, it shows that the asymmetric response of volatility exists in all indices regardless of volatility estimation models and the degree of the asymmetric volatility response of the small-cap index returns is greater than that of the large-cap index returns. Moreover, this results also observed robustly during the period of both before and after the global financial crisis.

• Land and Housing Review
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• v.12 no.3
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• pp.27-37
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• 2021

This paper empirically examined the relationship between the housing market and the stock market to investigate the price and the asymmetric volatility spillover effects. The monthly housing price index and the monthly KOSPI were used for analysis. This research employed the EGARCH model. The analysis period was from January 1986 until June 2021 with periodization centered on the Asian Financial Crisis: before and after the crisis - the end of December 1997. The EGARCH model allows analysis of 'good news' and 'bad news' in understanding volatility. The price spillover effect was observed one way from the stock market to the housing market. On the contrary, the spillover effect was not found from the housing market to the stock market. The empirical evidence suggests that there are price and asymmetric volatility effects in the entire period of analysis in both housing and the stock markets. In the housing market, the negative effects of information were found pre-financial crisis while the positive effects, in other periods. However, in the stock market, the negative effects of information were found in the pre- and post-financial crisis periods. This means that the housing market is more affected by 'good news' than 'bad news' when information spreads to the markets while the stock market is more affected by 'bad news' than 'good news'. It is of significance to discover the variable returns by different information.

• Journal of Ocean Engineering and Technology
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• v.26 no.2
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• pp.8-13
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• 2012

This paper investigates the statistical properties of waves in the sea area of Uljin, which is located in the East Sea area of Korea. The wave data were measured using AWAC (Acoustic Wave and Current Meter), which was installed at a 16-m water depth from November 2010 to March 2011. The wave data acquisition rate, Hmax, monthly mean Hs, Tz, Tp, and wave direction are summarized. The distributions of Hs and Tz were analyzed using the Hs-Tz scatter diagrams. The measurement wave data were analyzed to investigate freak wave characteristics. By comparing the wave spectrum using the measurement wave data with the wave spectrum obtained by varying the JONSWAP wave spectrum, it was possible to approximate the wave spectrum shape at the Uljin Sea area.

• The korean journal of orthodontics
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• v.30 no.5 s.82
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• pp.535-542
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• 2000

The purpose of this study was to find the characteristics of the frontal natural head position(NHP) of patients with facial asymmetry, and to contribute to the diagnosis of facial asymmetry in the clinical examination of orthodontic patients. Twenty adult patients who had apparent facial asymmetry and no severe sagittal skeletal discrepancy were selected as the asymmetry group, and 21 young adults who had symmetric faces were selected as the symmetry group. Frontal cephalograms were obtained in the state of NHP using a pivot-mounted fluid level device. The degree of the menton deviation was defined as the angle between the line drawn through crista galli and anterior nasal spine and the line drawn through crista galli and menton. The following angles were measured and each of them was compared with the degree of the menton deviation one is the angle between the true vertical line and the supra-orbital line which is a tangent line to the extreme cranial point on the supra-orbital margin, and the other is the angle between the true vertical line and the cervical line drawn through the midpoint of atlas and the 4th cervical vertebra. Through the statistical analysis, following results were obtained. 1. The angle between the supra-orbital line and the true vertical line was much mote deviated from the right angle in the asymmetry group than in the symmetry group. 2. The angle between the cervical line and the true vertical line in the asymmetry group showed greater tendency than in the symmetry group, but the difference was not statistically significant. 3. In the asymmetry group, the degree of the menton deviation was positively correlated with the angle between the supraorbital line and the true vertical line. The above results suggest that racial asymmetry patients show the tendency to have the tilted NHP to compensate the deviation of menton position.