• The korean journal of orthodontics
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• v.39 no.5
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• pp.289-299
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• 2009

Objective: The purpose of the present study was to evaluate the effectiveness of the use of Head Posture Aligner (HPA) during cone-beam computed tomography (CBCT) scan in generation of frontal cephalograms using 3D CBCT images. Methods: CBCT scans and frontal cephalograms were made in 30 adult individuals. While a couple of CBCT scan was made for one subject, one was made with conventional method, without use of HPA, the other was acquired with the use of HPA. After creation of virtual frontal cephalogram from each 3D CBCT image, it was traced and compared with the tracing of real frontal cephalogram. Results: In the comparison of the measurements, the virtual cephalograms with the use of HPA did not show statistically significant differences with the real cephalograms whereas the virtual cephalograms without the use of HPA presented significant differences with real cephalograms in many measurements. In the correlation analysis with the measurements of the real cephalograms, the virtual cephalograms with the use of HPA showed higher correlations in all measurements than the virtual cephalograms without the use of HPA. Conclusions: Measurements from CBCT-generated cephalograms become similar to those from real cephalograms with the use of HPA during CBCT scan. Thus, the use of HPA is suggested during the CBCT scan in order to construct accurate virtual frontal cephalograms using 3D CBCT images.

• Communications for Statistical Applications and Methods
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• v.4 no.3
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• pp.645-661
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• 1997

연속형 변수들의 상관관계와 범주형 변수들의 연관성 측도들을 비교 연구하였다. 이 연구를 위하여 연속형 변수들이며 +1에서 -1까지 완벽한 상관관계를 갖고 있는 2 변량 정규분포를 이용하여 2$\times$2 분할표와 확장하여 일반적인 I$\times$J 분할표를 대신하는 3$\times$3 분할표를 생성하였다. 2 차원 분할표에서 정의된 연관성 측도들을 구하여 논의하였는데 2$\times$2 분할표에서는 교차적비 $\alpha$ 통계량과 교차적비의 함수로 표현되는 Yule [1912]의 Q와 Y의 통계량 그리고 상관계수 R 통계량과 R 통계량의 함수인 P 통계량을 설명하고 생성된 분할표에서 구한 통계량값을 분석하였으며, 3$\times$3 분할표에서는 Pearson의 독립성 검정통계량 $X^2$의 함수로 표현되는 P. T. V 통계량과 Goodman과 Kruskal [1954]의 $\lambda_{C/R}$통계량과 Light와 Margolin [1971]의 $\tau_{R/C}$ 통계량을 설명하고 그 값들을 Pearson의 상관계수와 비교 분석하였다.

• Korean Journal of Biological Psychiatry
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• v.2 no.2
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• pp.257-265
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• 1995

The object of this study is to apply a chaotic signal analysis method to the EEG research, especially in the aspect of neuropsychiatry, and to get some inspection of the chaotic phenomena according to the brain sites and subjects. We have acquired 21 channel EEG data and one EOG according to the international 10-20 system and calculated the correlation dimension. The subject groups are schizophrenics, bipolar disorder, major depression and normal control. They were all awoke and eye-closed. We have found no distinctive features from our experiments except temporal regions have slightly higher correlation dimension. There is also no specific distinctions between groups. We conjecture that these results are mainly because the subjects were not well controlled. EEG dimension may change in accordance with to the age, sex, medication and the time data were selected to calculate. We have also considered some conditions for a better and more objective research of chaotic analysis to EEG research. Better conditioning and standardizing the calculation of correlation dimension is necessary for the application of the chaotic analysis to neuropsychiatry.

• The Journal of the Korea Contents Association
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• v.8 no.10
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• pp.268-277
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• 2008

The Purpose of this study is to explore the personality dispositions of crime Youth. Subjects in this Study are 148(High School Students) and 150(Juvenile Reformatory). Instrument used in this study is Korean-Version Eysenck Personality Questionnaires standardized by Hyun-Soo Lee(2004) and were administered to two groups respectively. Procedures for processing data were used t-test and sought the statistical differences between two groups.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2004.11a
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• pp.29-35
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• 2004

유방암 환자의 임상정보(clinical features)와 cDNA microarray 기술을 이용하여 얻은 유전자 발현 프로파일은 유방암 예후 인자를 찾는 데에 매우 중요하다. 본 논문에서는 임상정보와 유전자 발현 정보를 접목해서 분석하는 방법으로써 주성분 분석(Principal Component Analysis)을 이용하였다. 이 방법은 다변량 자료의 차원을 줄이는 방법으로써, 대용량 실험 데이터로 인해 발생하는 문제점을 해결하기 위하여 많이 쓰이고 있다. 본 연구에서는 주성분 분석을 이용하여 먼저 한국인 유방암 환자 73명의 cDNA microarray 데이터 차원을 줄이고, 이를 통해 얻어진 주성분(Principal Components)과 임상정보 데이터와의 상관관계를 보았다. One-way ANOVA를 이용한 상관관계 분석 결과의 P-value는 permutation test를 통해 검증하였다. 동일한 방법을 estrogen receptor(ER)(+) 환자 20명과 ER(-) 환자 31명에 적용해본 결과, ER(-) 환자 중에서 재발과 관련된 유전자를 찾을 수 있었다. 주성분 분석을 molecular phenotypic profiles of clinical features에 이용한 결과 발견된 유전자는 유방암의 재발과 관련된 예후 인자로서 의미가 있다.

• The Journal of the Acoustical Society of Korea
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• v.20 no.2
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• pp.86-92
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• 2001

Various array processing techniques to identify the noise source position or bearing have been developed. Typical array processing techniques which are based on time delay between received signals at two sensors, are classified as conventional beamforming, correlation function and NAH (Near-Field Acoustic Holography) techniques which have their own characteristics with respect to application field and signal processing method. In this study, correlation function technique which could be applied for broadband noise source detection, is adopted and the effective detection technique is proposed considering the effects of source bandwidth and measurement noise correlation of noise sources. The validity of the Proposed technique is evaluated using the 3-dimensional nonlinear any which does not give 3-dimensional Position or bearing ambiguity

• Journal of the Korean earth science society
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• v.26 no.5
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• pp.429-435
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• 2005

3D RMR (Rock Mass Rating) analysis has been performed by applying the Geostatistical integration technique for geophysical and borehole data. Of the various geostatistical techniques for the integrated data analysis, in this study, we applied the SKlvm (Simple Kriging with local varying means) method that substitutes the values of the interpreted geophysical result with the mean values of the RMR at the location to be inferred. The substitution is performed by the indicator transform between the result of geophysical interpretation and the observed RMR values at borehole sites. The used geophysical data are the electrical resistivity and MT result, and 10 borehole sites are investigated to obtain the RMR values. This integrated analysis makes the interpretation to be more practical for identifying the realistic RMR distribution that supports the regional geological situation.

• Communications for Statistical Applications and Methods
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• v.17 no.6
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• pp.917-925
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• 2010

The canonical correlation biplot is a 2-dimensional plot for graphically investigating the relationship between two sets of variables and the relationship between observations and variables in the canonical correlation analysis. Recently, Choi and Choi (2008) suggested a method for investigating the relationship between skill and competition score factors of KLPGA players using this biplot. Choi et al. (2010) used this biplot to analyze the player characteristic factors and competitive factors of tennis Grand Slam competition. Moreover, Huh (1999) provided a generalized canonical correlation analysis and biplot for more than three sets of variables. A Procrustes analysis is a useful tool for comparing shapes between configurations. This study will provide a method to investigate the relationship between physique, physical fitness and basic skill factors of tennis players in the Korea Tennis Association using a generalized canonical correlation biplot and Procrustes analysis.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.674-677
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• 2006

토양수분은 토양입자나 공극에 포함되어 있는 물을 의미하는 것으로서 여러 수문현상을 연계하는 주요변수이며, 올바른 물순환 체계를 이해하기 위해서는 토양수분에 대한 활발한 관측과 연구가 수반되어야 한다. 하지만, 우리나라의 토양수분 자료는 지상관측 자료로서 관측기간이 짧고 결측치가 많아 장기 추세나 공간변화도를 분석하기엔 미흡할 뿐만 아니라 2차원 토양수분 자료는 보유하고 있지 않은 실정이다. 따라서, 본 연구에서는 이를 보완하기 위해 우리나라와 위도가 비슷한 지역인 미국 Illinois 지역의 토양수분자료와 정규식생지수의 상관관계를 이용하여 우리나라의 2차원 토양수분을 산출하였으며, 산출된 장기 토양수분 자료를 이용한 시 공간 변화도 분석을 수행하였다.

• The Journal of Engineering Geology
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• v.15 no.3
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• pp.269-280
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• 2005

We assigned points on surface of standard roughness profile by 0.1mm along the length and measured coordinates of points. Then, the lengths of profile were measured with different scales using modified divider method. The fractal dimensions and intercepts of slopes were determined by plotting the length vs scale in log-log scale. The fractal dimensions as well as intercepts of slopes show well correlation with joint roughness coefficients(JRC). However, multiplication of the kactal dimension by intercept show better correlation with IRC and we derived a new equation to estimate JRC from fractal dimension and intercept. The crossover length in which we can determine the correct fractal dimension was between 0.3-3.2mm. We measured joint roughness of 26 natural joints and calculated JRC using the equation suggested by Tse and Cruden(1979) and new equation derived by us. IRC values calculated by both equations are almost the same, indicating new equation is effective in measuring IRC.