• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.710-714
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• 2006

지역빈도해석기법은 수문학적으로 성질이 유사한 지점을 하나의 군으로 구성한 자료를 이용해서 빈도해석을 하는 기법으로, 지점빈도해석이 가질 수 있는 단점들을 보완하기 위한 방안의 하나로 기대되고 있다. 본 논문은, 지역빈도해석기법을 적용하기 위한 단계중의 하나인 군집해석에 사용되는 변수들을 보다 효율적으로 선택하기 위한 연구로서, 다변량 분석방법인 주성분분석과 요인분석, 그리고, 변수선택을 위한 Procrustes Analysis를 통해서 보다 효율적으로 변수를 선택하는 방법을 제안하기 위한 연구이다.

• Journal of Korea Technology Innovation Society
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• v.15 no.3
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• pp.481-499
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• 2012

This paper shows a empirical results by adopting Kauffman' NK model. First, we find interdependence parameter K is nine in the technological ecosystem Landscape. According to principal component analysis, our technological ecosystem landscape is based on K=N-1 technology structure. Second, to Kauffman NK model, our technological ecosystem landscape is completely uncorrelated each other and contains a large number of local optima. As additional technology rises, the number of local optima rises rapidly. Our results mean that the more complexity in the technological ecosystem landscape, the less effective technology innovation will be in our country's technology system.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.325-328
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• 2001

본 연구는 가전제품의 정보음을 평가할 수 있는 어휘 척도의 개발을 목적으로 행해졌다. 21명의 주부를 대상으로 8개의 주파수혼 정보음을 제시하여 각 정보음에 대해 30개의 형용사 쌍 체크리스트를 이용하여 5점 척도로 평가하게 하였다. 요인분석은 SPSS S/W를 이용하였고 요인추출 방법은 주성분법(principal component method)으로 하였으며 요인추출 갯수는 scree test와 최종요인구조의 심리적 해석에 기초하여 4개로 결정하였으며 해석의 용이성을 위하여 직교회전방법을 적용하였다. 가전제품의 경고음그룹 4개와 종료음그룹 4개로 구성된 주파수혼합 정보음의 적합성평가에 사용된 30개 형용사 쌍의 요인분석 결과, 4가지 요인구조로 가장 잘 설명할 수 있었으며, 첫 번째 요인은 긴박성 요인, 두 번째 요인은 명료성 요인, 세 번째 요인은 역능 요인, 네 번째 요인은 평가 요인으로 나타났다.

• The Korean Journal of Financial Management
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• v.15 no.1
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• pp.329-350
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• 1998

이 논문에서는 자산의 수익률과 공통요인이 시간가변적 변동성을 갖는 경우의 APT를 검증하고자 시도하였다. 이를 위하여 1980년 1월부터 1995년 12월까지의 17개업종별 포트폴리오 수익률로부터 주성분분석에 의하여 4개의 공통요인을 추출하였다. (이중 첫 번째 요인은 동일가중 시장수익률과 거의 1에 가까운 상관성을 갖고 있으므로, 추출된 첫 번째 요인 대신에 시장수익률을 사용하였다.) 17개 업종별 포트폴리오에 대한 ARCH모형을 추정한 결과, 12개 포트폴리오의 수익률이 조건부 이분산성을 보이고 있다. 또 네 개의 공통요인 중 시장수익률을 포함한 3개의 요인은 뚜렷한 조건부 이분산성을 보이고 있다. 따라서 요인위험--즉, 공통요인에 대한 개별자산의 민감도$({\beta}_{ij})$--은, 개별자산과 공통요인의 상관계수가 일정하다고 가정하여, ARCH모형에 의해 측정된 자산 및 공통요인의 시간가변 표준편차로부터 계산되었다. 이와 같이 계산된 요인위험에 대하여 어느 정도의 위험프리미엄이 주어지고 있는가는 일반화 적률법(GMM)에 의하여 추정하였다. 그 결과, APT의 추정에 사용된 4개의 공통요인 중 시장수익률을 포함한 3개의 요인에 대하여 유의한 위험프리미엄이 추정되었다.

• Journal of Labour Economics
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• v.28 no.1
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• pp.61-82
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• 2005

We investigate wage differentials in Korea in the manufacturing industry, as well as factors affecting structural change in wage determination for the pre- and post-financial crisis regimes. We use the 1995 and 1999 data from the Survey Report on the Wage Structure (SRWS) from the Ministry of Labor. Principal components regression analysis is used to tackle multicollinearity. We employ factor analysis to reduce a set of variables to a smaller number, which contain observed and latent variables. Our empirical investigation provide evidences for changes in wages structure between 1995 and 1999. In 1995, the job quality factor is the most critical in the determination of wages, while in 1999, the industry attributes factor impacts greatly on the wages.

• 한국체육학회지인문사회과학편
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• v.57 no.4
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• pp.387-394
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• 2018

The purpose of this study is to provide information regarding the strategies by identifying the main variables that determines the winning team based on the records of all games of the 2017 IIHF World Championship Top league. 64 matches were analyzed for the study. 6 variables were analyzed which included ratio of saves, shots on goal, penalties in minutes, time for power play, power play goals, and face off wins. Logistic regression analysis (LRA), multiple regression analysis (MRA), and principal component analysis (PCA) were implemented to examine the relationship between win and loss. In case of LRA, shots on goal (p<.001), face-off wins (p<.001) had significantly positive relation to winning of game whereas, penalties in minutes (p<.01) and time on power play (p<.01) had significantly negative. Using MRA, win percentage was calculated which had significant positive correlation to ratio of saves (p<.01) and face-off wins (p<.001) whereas, a significant negative with penalties in minutes (p<.001). For PCA, the winning team consisted of penalty, attack, and defense factors whereas, losing teams consisted only the attack and defense factors.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.05a
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• pp.342-347
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• 2002

한국인 20대 여성 얼굴을 대표하는 30개 얼굴의 감성 형용사 평정을 통해 아름다운 얼굴의 감성 특징을 파악하였다. 얼굴 감성을 나타내는 14개 형용사 평정에 대해 주성분 분석을 실시한 결과 얼굴 감성은 샤프 요인과 소프트 요인으로 나뉘며, 사람들이 소프트한 느낌보다 샤프한 느낌을 지닌 얼굴을 더 아름답다고 느끼는 것으로 나타났다. 아름다운 얼굴의 감성 특징 검증을 위해 얼굴 합성법을 이용하여 합성한 이미지에 대해 얼굴 미모와 감성 형용사 평정을 실시하였다. '상위 평균' 이미지는 '전체 평균' 이미지보다, 전체 평균과 상위 평균의 얼굴 특징 차이를 50% 과장한 '상위+50' 이미지는 '상위 평균' 이미지보다 유의미하게 더 아름다운 것으로 평정되었다. 합성 얼굴의 감성 평정 결과 '전체 평균' 이미지는 소프트 감성에서 높은 평정을 받았으며, '상위 평균' 이미지는 샤프 감성, '상위150'이미지는 두 감성 요인을 모두 지니는 것으로 나타났다. 이러한 결과는 샤프 혹은 소프트 중 하나의 감성 요인이 두드러진 얼굴보다 두 가지 감성 요인 모두에서 높은 평정을 받은 얼굴을 더욱 아름답다고 지각하는 것을 암시한다.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.236-241
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• 2011

Soil microbial diversity was responsible for a strong effect on the chemical properties of orchard soils. This study evaluated a relationship between soil chemical properties and soil microbial diversities at 25 sites in orchard soils in Gyeongnam Province. The average nutrients in the orchard soils were 2.6 times for available phosphorous, 2.3 times for exchangeable potassium and 1.3 times for exchangeable calcium higher compared to recommend concentrations in the orchard soils. Contents of available phosphorous and organic matter in the inclined piedmont soils were higher than those in the other topographical soils (p<0.05). Populations of fungi and fluorescence Pseudomonas sp. in the silt loam soils were significantly higher than those in the sandy loam soils (p<0.05). In principal component analysis of chemical properties and microbial populations in the upland soils, our findings suggested that population of bacteria should be considered as potential factor responsible for the clear orchard soils differentiation. The soil organic matter was significantly negative correlation with population of bacteria whereas was positive correlation with population of fungi in orchard soils.

• The Korean Journal of Applied Statistics
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• v.21 no.4
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• pp.571-580
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• 2008

The logistic regression analysis is widely used in the area of customer relationship management and credit risk management. It is well known that the maximum likelihood estimation is not appropriate when multicollinearity exists among the regressors. Thus we propose the logistic principal components regression to deal with the multicollinearity problem. In particular, new method is suggested to select proper principal components. The selection method is based on the condition index instead of the eigenvalue. When a condition index is larger than the upper limit of cutoff value, principal component corresponding to the index is removed from the estimation. And hypothesis test is sequentially employed to eliminate the principal component when a condition index is between the upper limit and the lower limit. The limits are obtained by a linear model which is constructed on the basis of the conjoint analysis. The proposed method is evaluated by means of the variance of the estimates and the correct classification rate. The results indicate that the proposed method is superior to the existing method in terms of efficiency and goodness of fit.

• Journal of the Korean Society for Marine Environment & Energy
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• v.3 no.4
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• pp.3-22
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• 2000

To know characteristics of water quality in coastal sea around the Keum river estuary in summer, we studied the water quality of surface, middle and bottom level during Jun e～september, 1998. The mean concentrations of COD, DIN, DIP & chlorophyll-a were 1.36mg/L, 28.60㎍-at/L, 0.48㎍-at/L and 4.14㎍/L, respectively, which were over eutrophication criteria in sea water. After the Keum river dyke was constructed, seasonal freshwater discharge was largely changed. About 80% of total annual freshwater discharge was concentrated in summer as rainy season from July to September. The correlation coefficient of DIN versus salinity was shown to be high, and thus the concentration of DIN was closely related to freshwater discharge. Maximum Chlorophyll-a concentration was occurred in September, due to increased DIP concentration, high water temperature and low salinity after heavy rainfall in August. The results of Principal Component Analysis showed that the first factor represented a series of eutrophication factors, the second factor w3s a valiance of seasonal fluctuation, and the third was a variance of progress of mass change.