• Title/Summary/Keyword: principal component analysis

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Long-term Variation and Characteristics of Water Quality in the Garolim Coastal Areas of Yellow Sea, Korea (가로림연안 수질환경의 특성과 장기변동)

  • Park, Soung-Yun;Kim, Hyung-Chul;Kim, Pyoung-Joong;Park, Gyung-Soo;Ko, Joen-Young;Jeon, Sang-Baek;Lee, Seung-Min;Park, Jong-Soo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.15 no.4
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    • pp.315-328
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    • 2009
  • Long-term trends and distribution patterns of water quality were investigated in the Garolim coastal areas of Yellow Sea, Korea from 1998 to 2007. Water samples were collected at 3 stations and physicochemical parameters were analyzed including water temperature, salinity, suspended solids(SS), chemical oxygen demand(COD), dissolved oxygen(DO) and nutrients. Spatial distribution patterns were not clear among stations but the seasonal variations were distinct except pH and ammonia. The trend analysis by principal component analysis(PCA) during twenty years revealed the significant variations in water quality in the study area. Annual water qualities were clearly classified into 4 clusters by PCA; year cluster 1997, 1998 and 2000-2002, 1999 and 2003-2006/2008. By this multi-variate analysis the annual trends were summarized as follows; In recent years, salinity increased, whereas dissolved inorganic nitrogen, nitrate nitrogen and COD decreased and water quality generally continued to be in good condition in Gsrolim coastal areas without inflow of freshwater from land. Garolim coastal areas are required to be conserved continuously as important coastal areas for fisheries.

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Long-term Variation and Characteristics of Water Quality in the Gunsan Coastal Areas of Yellow Sea, Korea (군산연안 수질환경의 특성과 장기변동)

  • Park, Soung-Yun;Choi, Ok-In;Kwon, Jung-No;Jeon, Kyeong-Am;Jo, Jo-Yeong;Kim, Hyung-Chul;Kim, Pyoung-Joong;Park, Jong-Soo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.15 no.4
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    • pp.297-313
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    • 2009
  • Long-term trends and distribution patterns of water quality were investigated in the Gunsan coastal areas of Yellow Sea, Korea from 1972 to 2006. Water samples were collected at 6 stations and physicochemical parameters were analyzed including water temperature, salinity, suspended solids(SS), chemical oxygen demand(COD), dissolved oxygen(DO) and nutrients. Spatial distribution patterns of temperature, DO and SS were not clear among stations but the seasonal variations were distinct except COD and SS. The trend analysis by principal component analysis(PCA) during 24 years revealed the significant variations in water quality in the study area. Spatial water qualities were clearly classified into 3 clusters by PCA; station cluster 1, 2~4, and 5~6. Annual water qualities were clearly classified into 4 surface water clusters and 5 bottom water clusters by PCA. By this multi-variate analysis. The annual trends were summarized as follows; Salinity, pH and DO tended to increase since late 1970's, COD to increase since 1987, and SS to decrease and nutrients to increase in Gunsan coastal waters due to the input of fresh water from land same as in Kyoungin coastal area, Asan coastal area and Choensoo bay.

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The Relationship of Psychosocial Factors to Blood Pressure (사회심리학적인 요인과 혈압의 관계)

  • Lee, Choong-Won;Lee, Sung-Kwan
    • Journal of Preventive Medicine and Public Health
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    • v.21 no.1 s.23
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    • pp.99-112
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    • 1988
  • Questionnaires and blood pressure measurements were administered to 279 medical school undergraduates in 1987 to investigate the relationship between psychosocial factors and blood pressure as well as reliability and validity of the Framingham Type A Behavior Scale(FTA). The reliability coefficients of SCL-90-R and nh measured by Spearman-Brown haves split test were $0.57{\sim}0.91$. The factors of FTA extracted by principal component analysis were hard-driving competitiveness factor and impatience factor(2-factor solution) . The total score of nh was positively correlated with relative weight and place raised but the correlations were insignificant, and had significantly positive but weak correlations with depression, anxiety, hostility, paranoid, and psychoticism subscales of SCL-90-R. In the univariate analysis of blood pressures, relative weight and family history were significant in systolic pressure in males and economic status was significant in blood pressures in both sexes. For diastolic pressure, relative weight and frequency of alcohol intake were significant in males and relative weight was in females. After controlling relative weight, the frequency of alcohol intake for diastolic pressure and economic status for systolic pressure were significant in males. The important variables selected by stepwise regression analysis were relative weight and economic status for systolic pressure of males and relative weight and the frequency of alcohol intake for diastolic pressure. At the level of alpha 0.1, depression subscale was added to the model, changing coefficient of determination 0.206 to 0.217. In females, economic status and relative weight were selected for systolic pressure and for diastolic pressure body mass index alone, but the model of blood pressure for females was considered to be unstable due to small sample size(56). FTA was unrelated to the blood pressures in both sexes.

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Using Big Data and Small Data to Understand Linear Parks - Focused on the 606 Trail, USA and Gyeongchun Line Forest, Korea - (빅데이터와 스몰데이터로 본 선형공원 - 시카고 606 트레일과 서울 경춘선 숲길을 중심으로 -)

  • Sim, Ji-Soo;Oh, Chang Song
    • Journal of the Korean Institute of Landscape Architecture
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    • v.48 no.5
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    • pp.28-41
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    • 2020
  • This study selects two linear parks representing each culture and reveals the differences between them using a visitor survey as small data and social media analytics as big data based on the three components of the model of landscape perception. The 606 in Chicago, U.S., and the Gyeongchun Line in Seoul, Korea, are representative parks built on railroads. A total of 505 surveys were collected from these parks. The responses were analyzed using descriptive statistics, principal component analysis, and linear regression. Also, more than 20,000 tweets which mentioned two linear parks respectively were collected. By using those tweets, the authors conducted the clustering analysis and draw the bigram network diagram for identifying and comparing the placeness of each park. The result suggests that more diverse design concept links to less diversity in behavior; that half of the park users use the park as a shortcut; and that same physical exercise provides different benefits depending on the park. Social media analysis showed the 606 is more closely related to the neighborhoods rather than the Gyeongchun Line Forest. The Gyeongchun Line Forest was a more event-related place than the 606.

Changes in Riparian Vegetation After Restoration in a Urban Stream, Yangjae Stream (도시 하천 양재천에서 복원후 하안식생의 변화)

  • Cho, Hyung-Jin;Woo, Hyoseop;Lee, Jinwon;Cho, Kang-Hyun
    • Journal of Wetlands Research
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    • v.10 no.3
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    • pp.111-124
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    • 2008
  • The changes in flora and distribution and structure of vegetation were monitored for seven years at a restored reach of an urban stream, the Yangjae Stream, southeast of Seoul, Korea. In the restored reach, diverse kinds of the close-to-nature stream restoration techniques were adapted and implemented in the winter of 1998-1999. The species numbers and diversity indices of riparian plants at the restored reach were higher than those at the unrestored reach seven years after the restoration implementation. But plant diversity was decreased from the early restoration stage of 1999 - 2001 to seven years after the implementation. The dominant species changed from a ruderal annual, Humulus japonicus, to a perennial, Phragmites australis. The floral structure was distinctly different between in the early stage and seven years later on the results of principal component analysis (PCA) because of decreasing in numbers of exotic or ruderal species and planted or introduced plants in newly disturbed habitats. The distribution areas of communities of Humulus japonicus and Erigeron annuus were decreased and those of communities Phragmites australis and Miscanthus sacchariflorus were increased after the restoration implementation. The results of detrended correspondence analysis (DCA) of plant communities revealed that the community structure were changed from the disturbed vegetations to the stable and natural vegetation after the restoration implementation. Total seven species of willows were found at the restored reach, of which two species were planted and the others were naturally introduced. The monitoring results showed that the stream ecosystem of the study reach were successfully recovered in flora and vegetation and could be used as a model site for the stream restoration in urban streams.

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Factor Analysis of the Seriously-ill Patient인s Family Needs (중환자 가족의 요구 요인 분석 연구)

  • 권성복;이미라
    • Journal of Korean Academy of Nursing
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    • v.17 no.2
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    • pp.122-136
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    • 1987
  • A group of studies revealed that family members of the seriously ill patient had some needs during the period of patient's hospitalization. Needs of the seriously-ill patient family could be classified into three aspect, i. e. needs on the prognosis of patient, needs on the well-being of family members themselves and needs on hospital environment. Several instrument were developed to measure the needs of the seriously ill patient, but their content tended to overemphasize the aspect of the prognosis of patient. The purpose of this study was to develop a new instrument to measure the needs in the aspect of the seriously ill patient's family themselves in details to increase the cummulative Percentage of the scale. Subjects were 134 family members of the seriously-ill patients, who were bung cared in ICU of seven university hospitals and data were collected from march 16, 1987 to April 11, 1987. The instrument used in this study was made by the author on the basis of results of literature review. Content valitity of the instrument was tested by a professor majoring in nursing and reliability by calculation of Cronbach's α with data of the respondents. Data was analyzed as follows, using SAS, computer system. Factor structures of the seriously ill patients' family needs were elicited by factor analysis. The programme was the Principal Component Factor Analysis Method of factoring employing Varimax Orthogonal Rotation. The influences of the demographic variables on the degree of the seriously-ill patients' family need were analyzed by t-test and P-test. Results were as follows. 1. Needs of the seriously-ill patients' family elicited and their cummulative percentage were: Needs to be supported emotionally, 29.2% Needs to be informed on facilities available, 9.6% Needs to be informed on the patient's prognosis, 7.7%. Needs to be supported spiritually, 5.1%. Needs to be informed on hospital environment, 4.2%. Needs to be helped to spare time, 3.9%. Needs to be informed on their role, 3.5%. Needs to be present near patient, 3.3%. 2. Educational background was found to influence on some factors. College-graduate group had higher Bevel of needs to be . informed on facilities available to be informed on the patient's prognosis, needs to be supported spiritually, needs to be helped to spare time, needs to be informed on their role than high school graduate group. 3. Among the parents, sons and daughters and the relative groups, the parents of the seriously ill patient had highest level of needs to be present near patient. Suggestions for further studies were as follows. 1. As the instruments used in the previous studies had high cummulative percentages in the aspect of the prognosis of patient and that in this study in the aspect of the prognosis of patient and that in this study in the aspect of the seriously ill patient's family themselves, development of a new instrument which combined the items of both of them is needed. 2. A study to clarify the influence of type and number of admission on need to be supported emotionally is needed.

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Impact Assessment of Climate Change on Drought Risk (기후변화가 가뭄 위험성에 미치는 영향 평가)

  • Kim, Byung-Sik;Kwon, Hyun-Han;Kim, Hung-Soo
    • Journal of Wetlands Research
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    • v.13 no.1
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    • pp.1-11
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    • 2011
  • A chronic drought stress has been imposed during non-rainy season(from winter to spring) since 1990s. We faced the most significant water crisis in 2001, and the drought was characterized by sultry weather and severe drought on a national scale. It has been widely acknowledged that the drought related damage is 2-3 times serious than floods. In the list of the world's largest natural disaster compiled by NOAA, 4 of the top 5 disasters are droughts. And according to the analysis from the NDMC report, the drought has the highest annual average damage among all the disasters. There was a very serious impact on the economic such as rising consumer price during the 2001 spring drought in Korea. There has been flood prevention measures implemented at national-level but for mitigation of droughts, there are only plans aimed at emergency (short-term) restoration rather than the comprehensive preventive measures. In addition, there is a lack of a clear set of indicators to express drought situation objectively, and therefore it is important and urgent to begin a systematic study. In this study, a nonstationary downscaling model using RCM based climate change scenario was first applied to simulate precipitation, and the simulated precipitation data was used to derive Standardized Precipitation Index (SPI). The SPI under climate change was used to evaluate the spatio-temporal variability of drought through principal component analysis at three different time scales which are 2015, 2045 and 2075. It was found that spatio-temporal variability is likely to modulate with climate change.

Statistical Analysis of Projection-Based Face Recognition Algorithms (투사에 기초한 얼굴 인식 알고리즘들의 통계적 분석)

  • 문현준;백순화;전병민
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.5A
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    • pp.717-725
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    • 2000
  • Within the last several years, there has been a large number of algorithms developed for face recognition. The majority of these algorithms have been view- and projection-based algorithms. Our definition of projection is not restricted to projecting the image onto an orthogonal basis the definition is expansive and includes a general class of linear transformation of the image pixel values. The class includes correlation, principal component analysis, clustering, gray scale projection, and matching pursuit filters. In this paper, we perform a detailed analysis of this class of algorithms by evaluating them on the FERET database of facial images. In our experiments, a projection-based algorithms consists of three steps. The first step is done off-line and determines the new basis for the images. The bases is either set by the algorithm designer or is learned from a training set. The last two steps are on-line and perform the recognition. The second step projects an image onto the new basis and the third step recognizes a face in an with a nearest neighbor classifier. The classification is performed in the projection space. Most evaluation methods report algorithm performance on a single gallery. This does not fully capture algorithm performance. In our study, we construct set of independent galleries. This allows us to see how individual algorithm performance varies over different galleries. In addition, we report on the relative performance of the algorithms over the different galleries.

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Use of Freshness Indicator for Determination of Freshness and Quality Change of Chicken during Storage (신선도표시계를 이용한 계육의 저장 중 신선도 측정 및 품질변화)

  • Shin, Hee-Young;Ku, Kyoung-Ju;Park, Sang-Kyu;Song, Kyung-Bin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.6
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    • pp.761-767
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    • 2006
  • To determine freshness and quality change of chicken products during storage, we manufactured freshness indicator and monitored the surface pH, volatile basic nitrogen (VBN), thiobarbituric acid reacted substance (TBARS), total bacterial counts, electronic nose analysis, and sensory evaluation. All chicken products (drum, wing, thigh) had a change in color of freshness indicator after storage of 3 days at $4^{\circ}C$, indicating poor quality at the time. VBN, TBARS values, and total bacterial counts reached the decay point at the time of color change of freshness indicator attached to the surface of chicken samples. The sensory evaluation also indicated sample was not acceptable by off-odor at day 4 of storage. According to electronic nose analysis to examine off-odor, there were significant differences in terms of principal component analysis values among chicken samples of day 0, day 3, and day 5 of storage. These results suggest that freshness indicator should be useful in determining expiration date of chicken products during marketing by indicating the microbial safety as well as physicochemical and sensory change.

Chemical Composition and Lead Isotope Ratio of Glass Beads Excavated from Eunpyeong Newtown Site (은평 뉴타운 유적 출토 유리구슬의 성분조성과 납동위원소비)

  • Kang, Hyung-Tae;Cho, Nam-Chul;Han, Min-Su;Kim, Woo-Hyun;Hong, Ji-Youn
    • Journal of Conservation Science
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    • v.25 no.3
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    • pp.335-345
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    • 2009
  • This paper presents investigations on 60 glass beads excavated from floorless tombs of Eunpyeong Newtown site to figure out composition and lead isotope ratio by SEM-EDS and TIMS, which show the difference between their compositions and Pb provenance of lead glass. The results of the composition analysis are that excavated glass are mainly divided into Potash glass($K_2O$-CaO-$SiO_2$) and Potash-lead glass($K_2O$-PbO-$SiO_2$) and the samples excavated from III-3 floorless tombs No.1005 are presumed not glass but Quartz. The transparent 9 lead glasses excavated from II-3 floorless tomb No.101 and III-3 floorless tomb No.908 seem to be manufactured by the same raw material at same site because the concentration of their compositions are well accorded with each other and deviations of them are very limited. As a result of principal component analysis(PCA), glass beads excavated are largely assort to two groups, Potash glass and Potash lead glass as well. That is, glass beads excavated from Eunpyeoung Newtown sites are quite different two types of main composition. In addition, the results of Pb provenance analysis used in lead glass confirm that most lead glass are significantly correlated with galena of northern China.

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