• 한국지하수토양환경학회지:지하수토양환경
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• 제27권6호
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• pp.22-36
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• 2022

Water resources in Jeju Island are dependent virtually entirely on groundwater. For groundwater resources, drought damage can cause environmental and economic losses because it progresses slowly and occurs for a long time in a large area. Therefore, this study quantitatively evaluated groundwater level fluctuations using principal component and cluster analyses for 42 monitoring wells in Jeju Island, and further identified the types of groundwater fluctuations caused by drought. As a result of principal component analysis for the monthly average groundwater level during 2005-2019 and the daily average groundwater level during the dry season, it was found that the first three principal components account for most of the variance 74.5-93.5% of the total data. In the cluster analysis using these three principal components, most of wells belong to Cluster 1, and seasonal characteristics have a significant impact on groundwater fluctuations. However, wells belonging to Cluster 2 with high factor loadings of components 2 and 3 affected by groundwater pumping, tide levels, and nearby surface water are mainly distributed on the west coast. Based on these results, it is expected that groundwater in the western area will be more vulnerable to saltwater intrusion and groundwater depletion caused by drought.

• 대한가정학회지
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• 제20권4호
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• pp.83-89
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• 1982

The purpose of this study was to analyze the 45 measuring items for the clothing construction in order to observe the factorial structure of items and to extract the common factor and the special unique factor from data. The sample for the study was drawn randomly out of senior high schoolgirls in Seoul urban area. The size of sample was 301 girls between age 16 and 18. The method of analysis was applied by the principal component analysis with orthogonal rotation after extraction of 9 major factors. All of the above data was analyzed by the computer installed at Seoul National University. From these analyses, the major findings can be summerized as follows: 1. The results of factor analysis generally indicated that the first factor was clustered with 15 items, length measures and height measures. The eigenvalue of the first factor was 16.5 and the cumulative percentage of variables 36.6%. 2. The second factor was clustered with width measures, girth measures and weight of 19 items. The eigenvalue of the second factor was 6.5 and the cumulative percentage of variables 51.0%.

• 환경위생공학
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• 제9권2호
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• pp.8-23
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• 1994

During the period from Mar., 1991 to Feb., 1992 66 tSP samples were collected by Hi volume air sampler at 1 sampling site in Seoul and the amount of concentration of 21 components(SO$_{4}$$^{2-}$, NO$_{3}$$^{-}$, NH$_{4}$$^{+}$, Cl$^{-}$, Al, Ba, Ca, Cd, Cr, Cu, Fe, It Mg, Mn, Na, Ni, Pt Si, Ti, Zn, Zr ) were measured. And monthly and seasonal variation were surveyed and the principal component analysis( PCA ) were carried out with respect to these amount of pollutants, minimum of visibility and radiation on a horizontal surface. The total amount of soluble ion in water was high in order o(SO$_{4}$$^{2-}$> NO$_{3}$$^{-}$> N%'>Cl$^{-}$ and metal ion was high in order of Na> Ca>Si> Fe> Al> K> Mg> Zn> Pb> Cu>Ti> Mn > Ba> Cr> Zr> Ni> Cd. There was Seasonal variation in concentration for SO$_{4}$$^{2-}$, NH$_{4}$$^{+}$, Cl$^{-}$, Na, Al, Ca, Bt Mg, Fe and Si. It was assumed that the components of the highest concentration on April were depend on yellow sand and the frequency of wind velocity and direction. As the results of PCA, the amount of pollution components was able to characterized with two principal components(Z$_{1}$, Z$_{2}$ ). The first principal components Z$_{1}$ was considered to be a factor indicating the pollutants originated from natural generation and The second principal components Z$_{2}$ was considered to be a factor indicating the pollutants originated from human work. The monthly concentration of pollutants in ISP, minimum of visibility and radiation on a horizontal surface was possible to evaluate by the use of these two principal components Z$_{1}$ and Z$_{2}$ .

• 동아시아식생활학회지
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• 제16권1호
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• pp.23-28
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• 2006

The purpose of this paper was to clarify the actual conditions of the 'Dietary externalization' mainly by using the economic and nutrition-related data, accompanied by the economic development in Korea and Japan. 'Modernization of food style' and other modernization have taken place, among which 'Dietary externalization' in particular has recently drawn interest. At the time this paper clarified with econometric analysis whether there are differences between the two countries in term of the modernization of food style and dietary externalization trend. The trends of Dietary externalization of both Korea and Japan were studied using Principal Component Analysis method. The food subgroup were investigated based on the annual report on the household income and expenditure survey of Korea and the annual report on the family income and expenditure survey of Japan. The statistical data from both country were analyzed by SAS program. The results are as follows; 1. In Korea, the ratio of carbohydrates in the total calorie intake is quite high and animal protein is rather low compared to those in Japan. 2. Traditional food such as grains and vegetables are consumed much more in Korea than in Japan. 3. The Principal Component 1, 2 were extracted in both countries during the whole analysis period, which suggested the 'Dietary externalization' 4. Principal Component 1 has a positive factor loaded in all food items including meals outside the home and process food. In other words, it is apparent that the 'Dietary externalization' tread in Korea has a simple pattern suggesting that all externalization related items are on the rise. 5. Principal component 1, 2 which indicated the dietary externalization, were detected in Japan.

• 한국환경보건학회지
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• 제18권2호
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• pp.67-74
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• 1992

The lab-scale biological A$_{2}$O system was applied from treating piggery wastewater highly polluted organic material which nitrogen and phosphorous are much contained relatively in conversion with other wastewater. The objective of this study was to investigate the effect of variance parameters on the treatability of this system according to operation conditions. An obtained experimental data were analysed by using principal component analysis (PCA) method. The results are summarized as follows: 1. From Varimax rotated factor loading in raw wastewater, variance of factor 1 was 36.8% and cumulative percentage of variance from factor 1 to factor 4 was 81.5% and of these was related to BOD, TKN and BOD loading. 2. In anaerobic process, variance of factor 1 was 33.5% and cumulative percentage of variance from factor I to factor 4 was 81.8% and of these was related to PO$_{4}$-P, BOD, DO and Temperature. 3. In anoxic process, variance of factor 1 was 30.1% and cumulative percentage of variance from factor i to factor 4 was 84.3% and of these was related to pH, DO, TKN and temperature. 4. In aerobic process, variance of factor 1 was 43.8% and cumulative percentage of variance from factor 1 to factor 4 was 81.5% and of these was highly related to DO, PO$_{4}$-P and BOD. 5. It was better to be operated below 0.30 kg/kg$\cdot$day F/M ratio to keep over 90% of BOD and SS, 80% of TKN, and 60% of PO$_{4}$-P in treatment efficiencies. 6. Treatment efficiencies was over 93% of BOD and SS, 81% of TKN and 60% of PO$_{4}$-P at over 20$^{\circ}$C, respectively.

• 상하수도학회지
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• 제29권6호
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• pp.625-632
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• 2015

The study of water environment system using a multivariate analysis in Changnyeong-Haman weir section has been conducted. The purpose of this study is to establish better understanding related water qualities in the Changnyeong-Haman weir section which can provide useful information. The data were consisted of water quality data and algae data including WT(water temperature), pH, DO, EC, COD, SS, T-N, $NH_3-N$, T-P, $PO_4-P$, Chl-a, TOC, d-silica, t-silica, Cyanobacteria, Diatoms, and Green algae. Statistical analyses used in this study were correlation analysis, principal components, and factor analysis. According to correlation analysis on COD and TOC, it revealed that the each value of correlation coefficient was 0.843. On the other result, a negative correlation was observed between diatoms and d-silica. Furthermore, the results of principal component analysis to the overall water quality were classified into four main factors with contribution rate 81.071%.

• 상하수도학회지
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• 제31권1호
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• pp.93-101
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• 2017

In this study, we investigated the correlation between the number of cyanobacterial species and the water quality factors after installation of Nakdong river weirs. Factor analyses of water quality factors were also performed. The results of correlations showed that there was no significant water quality with the cyanobacterial concentration but the correlation coefficient of nutrients increased from the upstream to the downstream. There was a significant correlation between W T and pH as important water quality factors for the growth of cyanobacteria. In the downstream region of Nakdong river, algae were more frequently detected than in the upstream region, and the blooms of algae species seem to be influenced by the higher pH and the influx of the phosphorus from the upstream tributaries. Nutrient concentration was higher in the downstream region than in the upstream region due to the effects of tributaries Geumho river and Nam river in Nakdong river. As a result of the factor analyses, nitrogen species were the principal factors in the upper region, and phorsphorus species were the principal factors in the downstream region.

• The Journal of Asian Finance, Economics and Business
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• 제2권3호
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• pp.5-15
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• 2015

This research paper has been attempted to inventory the atmospheric factors, contributing to better sales. Exploratory study was undertaken to identify various signs of store atmospherics variables that influence the buying behaviour of buyers. Thirty-four variables identified from this study were used to create a structured questionnaire. This questionnaire was then administered among shoppers in NCR Delhi using non-probability convenience sampling. To determine the atmospheric factors, Principal Component Analysis (PCA) along with Varimax Rotation was attempted. Using principal component factor analysis on the data collected, nine factors were identified to have impact on the store atmospheric. These were Querulous, Music, Sensitive, Budget Seeker, Sensuous, Light, Idler, Space seeker and Comfort Seeker. Contrary to the various earlier studies where music, space seeker and comfort seeker were considered to be most significant factors, light and querulous have emerged out to be the major factor that influences the store atmospheric. This study shows that customers are sensitive, space seekers and sensuous. Constituents of these factors reveal distinct patterns. This research may be used as guidelines for development and management of shopping malls in emerging countries. Retail marketers in India can take this cue in designing their strategies to attract consumers.

• 한국수자원학회논문집
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• 제48권9호
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• pp.757-768
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• 2015

최근 기후변화는 짧은 시간의 지역적인 집중호우와 예상치 못한 폭우에 영향을 미치고 이는 생명과 재산의 손실에 영향을 준다. 본 연구에서는 침수위험도를 결정하기 위한 방법으로 산술평균방법, 가중평균방법, 주성분 분석방법을 이용하여 침수위험도에 따른 순위를 결정하였다. 재해연보 및 도시계획 현황에서 선택한 인자들에 대한 표준화를 통해 단위를 통일시켰으며 표준화를 통한 산술평균방법, 상관관계분석을 통한 가중평균방법, 상관도가 높은 인자들을 묶어 분석한 주성분 분석방법을 통해 침수위험도를 결정하고 그 순위를 나타내었다. 본 연구에서 사용된 산술평균방법의 경우 간단하기는 하지만 각각의 인자들이 동일한 가중치를 가지는 문제점이 있고 가중평균 방법의 경우 각각의 인자들이 다른 가중치를 갖기는 하지만 많은 변수들 때문에 변수들 간의 상관관계가 복잡해지는 문제점이 있다. 이러한 문제점을 극복하기 위해 주성분 분석방법을 사용하였으며 각 지역의 수방능력 및 재해위험을 고려한 침수위험도를 결정하였다.

• 예술인문사회 융합 멀티미디어 논문지
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• 제7권2호
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• pp.437-444
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• 2017

기계구조물 부재의 단면에 구멍이나 또는 단면이 급격히 변화할 경우, 불연속 부분 주위에서 응력집중이 일어나며 파손이 발생하는 주요 원인이 된다. 그 이유는 부재에 작용하는 평균 응력보다 응력집중 부분에서 훨씬 큰 응력이 작용하기 때문이다. 본 논문에서는 시편의 부분 관통 구멍 주위에서 응력해석을 수행하여 구멍을 통과하는 선상의 주응력 차 값을 구하였다. 광탄성에서 최대주응력과 최소주응력의 차이는 등색프린지 차수와 재료의 프린지 상수를 곱한 값을 빛이 통과한 거리 즉, 시편의 두께로 나눈 값과 같다. 즉, 주응력의 차이는 광탄성 프린지 차수와 비례관계가 있으므로 유한요소해석에 의한 주응력 차이의 분포를 광탄성 실험결과에 비교할 수 있다. 유한요소 범용 소프트웨어인 ANSYS Workbench를 이용하였으며 유한요소법으로 해석된 값을 광탄성 실험으로부터 측정된 값과 비교한 결과 유사한 결과를 얻었다. 이로서 유한요소해석 결과는 실험결과와의 비교를 통해 타당성이 입증될 수 있었다. 또한 구멍깊이 변화에 따라 나타나는 응력분포를 사용하여 응력집중계수를 구하였다. 구멍깊이가 증가할수록 응력집중계수는 증가함을 나타냈다.