• 대한원격탐사학회지
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• 제28권3호
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• pp.297-305
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• 2012

This study was performed to estimate forest canopy density (FCD) using airborne hyperspectral data acquired in the Independence Hall of Korea in central Korea. The airborne hyperspectral data were obtained with 36 narrow spectrum ranges of visible (Red, Green, and Blue) and near infrared spectrum (NIR) scope. The FCD mapping model developed by the International Tropical Timber Organization (ITTO) uses vegetation index (VI), bare soil index (BI), shadow index (SI), and temperature index (TI) for estimating FCD. Vegetation density (VD) was calculated through the integration of VI and BI, and scaled shadow index (SSI) was extracted from SI after the detection of black soil by TI. Finally, the FCD was estimated with VD and SSI. For the estimation of FCD in this study, VI and SI were extracted from hyperspectral data. But BI and TI were not available from hyperspectral data. Hyperspectral data makes the numerous combination of each band for calculating VI and SI. Therefore, the principal component analysis (PCA) was performed to find which band combinations are explanatory. This study showed that forest canopy density can be efficiently estimated with the help of airborne hyperspectral data. Our result showed that most forest area had 60 ~ 80% canopy density. On the other hand, there was little area of 10 ~ 20% canopy density forest.

• 사회복지연구
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• 제43권2호
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• pp.319-344
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• 2012

본 연구는 2010년 국민건강영양조사 원자료를 이용하여 의료이용 형평성지수인 집중지수와 Hiwv지수를 성별, 연령, 지역의 하위집단에 따라 집단 간 차이(Between)에 의한 부분과 집단 내부의 불평등(Within)에 의한 부분, 그리고 잔여 부분(R)으로 분해하였다. 본 연구의 분석결과는 다음과 같다. 첫째, 외래이용 횟수에서 남녀의 집단 간 차이가 Hiwv지수에 미치는 영향은 0으로 나타났다. 반면 외래비용에서는 Hiwv지수 .1035 중 여성들의 집단 내부불평등이 .0441을 설명하고 있어 빈곤여성들의 의료서비스 저이용이 의료이용 형평성에서 중요한 문제가 됨을 알 수 있었다. 둘째, 외래이용 횟수 형평성에 연령집단의 차이는 크게 영향을 미쳤는데, 미세한 양이지만 Hiwv지수 -.0107에서 대부분인 -.0085을 설명하고 있다. 셋째, 외래비용의 Hiwv지수에는 집단 내부의 불평등 특히, 노년층의 내부 불평등이 .0253을 설명하여 설명력이 크게 나타났다. 넷째, 외래비용의 Hiwv지수에 지역의 내부 격차(Within)가 가장 크게 영향을 미쳐서 Hiwv지수 .1035 중 .0569를 설명하였으며, 이 중 대부분인 .0535를 도시지역의 불평등이 설명하였다. 분석결과를 종합하면 분석된 집단범주 중 외래이용 횟수의 형평성에 가장 크게 영향을 미치는 집단은 연령집단이었으며, 외래비용에서는 집단 간 격차보다 집단 내부의 불평등이 더 크게 영향을 미치는 것으로 나타났다. 빈곤여성일수록, 빈곤노인일수록, 도시빈민일수록 기대비용에 못 미치는 외래진료비를 지출하고 있음을 나타냈는데, 이들에 대한 의료비지원 정책이 요구된다고 하겠다.

• Journal of the Korean Data Analysis Society
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• 제20권6호
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• pp.2759-2769
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• 2018

The behavioral finance view on the existence of asset pricing anomalies is based on two factors: investors' sentiment and limits to arbitrage. This paper tries to examine the effect of investors' sentiment on the stock price in the Korean stock market. In order to measure investors' sentiment, we constructed the sentiment index using principal component of five sentiment variables. By using sentiment index as an additional independent variable to three risk factors, impacts of the sentiment index on individual stocks and 25 portfolios sorted by BM-size are examined. Main results found are as follows: 1) not only all three risk factors show positive impacts on the return of individual stock, but also the sentiment index has a positive impact. SI alone explains 15% of individual return variation. 2) among four independent variables, the most important factor turned out to be the market risk factor and investors' sentiment has better explanatory power on stock price than the size effect. 3) after controlling the market risk factor, the coefficient of the sentiment index for the smallest size and highest book/market value portfolios is significantly positive. 4) all the coefficients of the sentiment index for 25 portfolios sorted by BM-size have significant positive value after controlling size or (and) value.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(4)
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• pp.238-241
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• 2000

A fingerprint core-point detection algorithm is presented in this paper. Core-point is useful for fingerprint classification and also for the fingerprint verification since it giver a reference to a fingerprint. Traditional methods of finding the core-point is introduced. These methods are the method using poincare index and the method using sine component of ridge directions. The proposed method is modified algorithm of the latter using the poincare index. The experimental results show that the proposed algorithm achieves almost the same accuracy with faster speed.

• 유통과학연구
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• 제14권3호
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• pp.63-71
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• 2016

Purpose - A variety of indicators are used for the diagnosis of economic situation. However, most indicators explain the past economic situation because of the time difference between the measurement and announcement. This study aims to argue for the resurrection of an idea: electricity demand can be used as an indicator of economic activity. In addition, this study made an endeavor to develop a new Real Business Index(RBI) which could quickly represent the real economic condition based on the sales statistics of industrial and public electricity. Research design, data, and methodology - In this study monthly sales of industrial and public electricity from 2000 to 2015 was investigated to analyze the relationship between the economic condition and the amount of electricity consumption and to develop a new Real Business Index. To formulate the Index, this study followed next three steps. First, we decided the explanatory variables, period, and collected data. Second, after calculating the monthly changes for each variable, standardization and estimating the weighted value were conducted. Third, the computation of RBI finalized the development of empirical model. The principal component analysis was used to evaluate the weighted contribution ratio among 3 sectors and 17 data. Hodrick-Prescott filter analysis was used to verify the robustness of out model. Results - The empirical results are as follows. First, compatibility of the predictability between the new RBI and the existing monthly cycle of coincident composite index was extremely high. Second, two indexes had a high correlation of 0.7156. In addition, Hodrick-Prescott filter analysis demonstrated that two indexed also had accompany relationship. Third, when the changes of two indexes were compared, they were found that the times when the highest and the lowest point happened were similar, which suggested that it is possible to use the new RBI index as a complementing indicator in a sense that the RBI can explain the economic condition almost in real time. Conclusion - A new economic index which can explain the economic condition needs to be developed well and rapidly in a sense that it is useful to determine accurately the current economic condition to establish economic policy and corporate strategy. The salse of electricity has a close relationship with economic conditions because electricity is utilized as a main resource of industrial production. Furthermore, the result of the sales of electricity can be gathered almost in real time. This study applied the econometrics model to the statistics of the sales of industrial and public electricity. In conclusion, the new RBI index was highly related with the existing monthly economic indexes. In addition, the comparison between the RBI index and other indexes demonstrated that the direction of the economic change and the times when the highest and lowest points had happened were almost the same. Therefore, this RBI index can become the supplementary indicator of the official indicators published by Korean Bank or the statistics Korea.

• 한국운동역학회지
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• 제25권2호
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• pp.157-165
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• 2015

Object : The goals of this research were to make Performance Enhanced Model(PE) taken the largest performance index (PI) through artificial variation of principle components calculated by principle component analysis for trial data, and to verify the effect through comparing kinematic factors between trial data (Raw) and PE. Method : Ten subjects (5 men, 5 women) were recruited and 80% of their maximal record was considered. The PI is a regression equation. In order to develop PE, we extracted Principle components from trial position data (by Principle Components Analysis (PCA)). Before PCA, we made 17 position data to 3 row matrix according to components. We calculated 3 eigen value (principle components) through PCA. And except Y (medial-lateral direction) component (because motion of Y component is small), principle components of X (anterior-posterior direction) and Z (vertical direction) components were changed as following. Changed principle components = principle components + principle components ${\times}$ k. After changing the each principle component, we reconstructed position data using the changed principle components and calculated performance index (PI). A Paired t-test was used to compare Raw data and Performance Enhanced Model data. The level of statistical significance was set at $p{\leq}0.05$. Result : The PI was significantly increased about 12.9kg at PE ($101.92{\pm}6.25$) when compared to the Raw data ($91.29{\pm}7.10$). It means that performance can be increased by optimizing 3D positions. The difference of kinematic factors as follows : the movement distance of the bar from start to lock out was significantly larger (about 1cm) for PE, the width of anterior-posterior bar position in full phase was significantly wider (about 1.3cm) for PE and the horizontal displacement toward the weightlifter after beginning of descent from maximal height was significantly greater (about 0.4cm) for PE. Additionally, the minimum knee angle in the 2-pull phase was significantly smaller (approximately 2.7cm) for the PE compared to that of the Raw. PE was decided at proximal position from the Raw (origin point (0,0)) of PC variation). Conclusion : PI was decided at proximal position from the Raw (origin point (0,0)) of PC variation). This means that Performance Enhanced Model was decided by similar motion to the Raw without a great change. Therefore, weightlifters could be accept Performance Enhanced Model easily, comfortably and without large stress. The Performance Enhance Model can provide training direction for athletes to improve their weightlifting records.

• 대한기계학회논문집A
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• 제37권3호
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• pp.325-331
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• 2013

본 논문에서는 상용 프로그램 ABAQUS를 이용하여 브레이크 시스템의 불안정 모드를 알아보기 위한 복소고유치해석을 수행하였다. 또한 전체 시스템의 불안정 복소 고유모드에서 가장 진동에너지가 큰 부품을 알아보기 위한 기여도해석과 전체 복소 고유모드와 해당 부품의 부품모드간의 기여도해석을 통해 모드 연성의 가능성이 높은 모드를 알아보았다. 본 연구에서는 디스크 로터의 2차 굽힘모드와 토크멤버의 3차 축방향 횡모드의 연성에 의해 1.4kHz의 불안정 모드가 발생하는 것을 알 수 있었다. 이러한 모드 연성을 차단하기 위해 불안정성을 유발하는 토크멤버에서 해당모드의 주파수 변화에 대한 감도 해석을 실시하였다. 감도 해석 결과를 토대로 질량 가중에 의한 구조물 동특성 변경을 수행한 결과 저주파 영역에서 불안정 모드가 발생하지 않아 본 연구에서 제시된 저감방법의 유효성을 확인할 수 있었다.

• 한국생활과학회지
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• 제8권2호
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• pp.313-325
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• 1999

This study aimed to classify the data of children's bodies into several clusters by principal component scores that were extracted through the factor analysis in the former study, and to describe the distribution and body characteristics of the clusters. The sample was 308 elementary school children aged from 6 to 8 and the anthropometric measurements were performed indirectly from the photographs of the subjects, which was the same as the first analysis. The data were analysed statistically using SPSSWIN Ver. 8.0. Through the statistical analysis, 3 clusters were obtained from the data. The first cluster distributed more in the children aged 7 and 8 than in the children aged 6. The somatotype of this group was the tallest among the three groups, and they were the most developed group compared to the two other groups in lateral component as well as in linear component. The second cluster group wasn't well developed in lateral components, and had lowest level in Rohrer Index, so this group had thin figures compared to the other groups. The third cluster revealed dominant distribution in the group aged 6, and the group had the least developed linear components but higher level in Rohrer Index. Each cluster group revealed peculiar somatotype that was dominant in one group but rarely in other cluster groups. Lateral views of these characteristics were showed using the average of the measurements of clusters.

• 한국보건간호학회지
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• 제18권2호
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• pp.299-311
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• 2004

Purpose: Somatotype drawing developed by Sorensen et al.(1983) has been evaluated as a simple instrument of obesity level without real somatic measuring as height and weight. This study was designed to validate somatotype drawings for obesity assessment by bioelectrical impedance body component analysis. Method: At first questionnaire of somatotype drawing was done. Subjects were measured body component by bioelectrical impedance analysis as weight, BMI(body mass index), WHR(waist-hip ratio), body water, protein mass, mineral mass, body fat mass, skeletal muscle mass, soft lean mass, fat free mass and percent body fat. We evaluated correlations between these data and somatotype drawings and tried to grouping of somatotype drawings with the means of major body component value. Result: The data were collected from 205 college women whose height and weight were $161.2\pm4.8,\;55\pm8.3$. Spearman's correlation coefficients of somatotype drawing were 0.74 with BMI, 0.68 with weight 0.69 with body fat mass, 0.65 with WHR. 0.64 with percent body fat after adiusted age. The grade of somatotype drawings were grouped as 1-2, 3-4, 5-6. 7-9 by BMI, body fat mass, weight, 1, 2-4, 5-6, 7-9 by WHR and 1-2, 3-4, 5-9 by percent body fat(ANOVA and Duncan's method). Conclusion: So quick instrument using somatotype drawings were useful tools for evaluation of obesity level and is applicable to screen degree of body fat in self-administered questionnaire survey.

• Journal of Astronomy and Space Sciences
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• 제30권3호
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• pp.169-174
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• 2013

BOH magnetometer was installed at Mt. Bohyun in 2007 and has provided continuous dataset for 3-axis geomagnetic field over the South Korea. We have calculated real-time K-index based on BOH magnetic field data using well-known FMI method. Local K-index is calculated eight times a day, per every three hours. To calculate K-index, it is critical to get the Quiet Day Curve (QDC). For QDC calculation, we take the previous one month's average of H-component. In this paper, we compared four geomagnetic stations' magnetic field data over South Korea and Japan and K-indices of each stations; Bohyun, Gangneung, Jeju, and Kakioka for two years data, 2011-2012. To investigate the difference depending on the latitude, longitude and local time in more detail, we compare K-index on International Quiet Days (IQDs) and International Disturbed Days (IDDs). As a result, we report the correlation between local K-indices are higher than those between Kp and local K-indices, and the correlation is much better after sunset than after sunrise. As the geomagnetic activity becomes stronger, the correlation between the local K-indices and global Kp-index become higher.