• Journal of the Korea Institute of Building Construction
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• v.18 no.5
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• pp.429-437
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• 2018

The aim of the research is to analyze a feasibility of rapid evaluation method for cement fineness by the relation analysis between density measurement using hydrometer and fineness of ordinary Portland cement. Additionally, based on the commercially available cement product, relation between a series of fundamental properties of cement mortar and fineness of cement powder was analyzed. As an experimental result, the actually measured fineness value of cement powder showed a good correlation with the fineness value obtained by hydrometer while there was poor correlation with the fineness value on specification. Especially, the density measurement in three minutes showed the closest relation with cement powder fineness, thus rapid quality evaluation of cement powder can be possible by using the regression equation obtained from the three minutes density measurement. Additionally, there was a high relation between cement powder fineness with a fundamental properties of the cement mortar such as fluidity, air content, setting time, and strength development.

• Journal of Wetlands Research
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• v.6 no.4
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• pp.35-43
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• 2004

The non-parametric Mann-Kendall(MK) statistical test has been widely used to assess the significance of trend in hydrologic time series. The test requires sample data should be serially independent. If sample data is serially correlated, the presence of serial correlation in a time series will affect the test ability for trend analysis. So, we would like to use the modified MK test which uses the effective sample size(ESS) to eliminate the effect of serial correlation in a series. This study investigates the ability of ESS to eliminate the influence of serial correlation of MK test by Monte Carlo simulation and by real series. As the results, MK test shows the increase of trend rate as the serial correlation is increased but the modified MK test shows ESS can eliminate the serial correlation for trend analysis. Therefore we confirmed the modified MK test is a very useful tool for trend analysis.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.8
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• pp.845-852
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• 2018

Mayer-Schönberger and Cukier(2013) explain why big data is important for our life, while showing many cases in which analysis of big data has great significance for our life and raising intriguing issues on the analysis of big data. The two authors claim that correlation is in many ways practically far more efficient and versatile in the analysis of big data than causality. Moreover, they claim that causality could be abandoned since analysis and prediction founded on correlation must prevail. I critically examine the two authors' accounts of causality and correlation. First, I criticize that corelation is sufficient for our analysis of data and our prediction founded on the analysis. I point out their misunderstanding of the distinction between correlation and causality. I show that spurious correlation misleads our decision while analyzing Simpson paradox. Second, I criticize not only that causality is more inefficient in the analysis of big data than correlation, but also that there is no mathematical theory for causality. I introduce the mathematical theories of causality founded on structural equation theory, and show that causality has great significance for the analysis of big data.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5345-5349
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• 2012

Recently obesity from the child until being early in the adult, there is to an increase tendency. The obesity influences to various metabolicdisease and there is a possibility of an effect in relationship disease of the heart, brain vascular system etc. This research analyzed the interrelation -ship of apolipoprotein AI consistency and body mass index. It used spss 19.0 with t-test and a regression analysis. Analytical result the interrelationship of apolipoprotein AI and body mass index was -0.484 (p=0.01). The high density cholesterol was 0.89 (p=0.01). The trigriceride was -0.88 (p=0.01). Free fatty acid were not interrelationship. Conclusively, interrelationship of apolipoprotein AI and body mass index was not high. Encourage to examine trigriceride or cholesterol and prevent Arteriosclerosis.

• Journal of Korea Soil Environment Society
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• v.3 no.1
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• pp.45-54
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• 1998

The riverbed structures and heavy metal concentrations of the sediments in the Naktong River, Western Naktong River, and Suyoung Stream were investigated, and then the correlationships between heavy metals were examined. Naktong River was the deepest among the three streams. The deepest and the shallowest sites were site 11(11.58m) and 9(3.35m) in Naktong River, site 7(6.25m) and 4(2.06m) in Western Naktong River, add site 8(2.89m) and 1(0.61m) in Suyoung Stream, respectively. The mean concentration of Cd(45.79ppm) was higher in the sediment of Western Naktong River than in other two streams and those of Pb(76.25ppm), Cr(48.13ppm), and Cu(77.50ppm) were higher in the sediment of Suyovng Stream than in other two streams. The analytical results for correlationships between heavy metals showed that Cu was highly correlated with Cr and Pb was very highly correlated with Cr and Cu in Naktong River. Cu was relatively highly correlated with Cd and Cr and Cr was highly correlated with Pb in Western Naktong River Cd was relatively higlky correlated with Pb and Cu and Cr and Cd, Pb, Cu and Pb, Cr were highly correlated in Suyoung Stream.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.06a
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• pp.32-39
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• 2010

수도권의 도시화 과정은 서울로의 교통 접근성의 변화에 따라 급속하게 확산되었고, 현재도 진행 중이다. 도시화 과정 속에 인구 교외화, 주택 수의 증가, 도심용지 토지이용 증대, 토지가격의 증가 등의 다양한 공간적 변화가 이루어지고 있다. 이러한 급속한 도시화의 과정 속에 국토의 난개발이 이루어졌고 자연생태 파괴, 주택부족 및 교통 문제, 토지 투기 등의 사회적 문제를 야기했다. 본 연구에서는 도시화 현황을 살펴보고 교통접근성의 변화에 따른 주변 토지이용 변화의 상관성을 분석하였다 상관성 분석 결과를 토대로 멀티 에이전트 시스템(MAS)을 이용하여 교통접근성과 토지이용 에이전트 간 상호작용의 관점에서 시뮬레이션 하였다. 그래서 교통접근성의 변화로 인한 주변 토지 이용 변화를 공간적으로 예측하려고 한다. 도시화 현황을 살펴보기 위해서 지적도 자료를 이용하여 미시적인 경관 분석을 실시한 후 교통접근성의 변화에 따른 주변 토지이용 변화의 상관성을 분석하기 위해 교통자료와 토지이용 자료를 GIS분석 및 통계 분석하였다. 그리고 상관성 분석 결과를 멀티 에이전트 시스템 전용 플랫폼에 적용하여 시뮬레이션 분석을 하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1460-1464
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• 2006

강수량의 특성 및 계절적인 양상은 지협적인 원인이기 보다는 해수면 온도(sea surface temperature)와 같은 기상 현상에 주로 영향을 받는다. 이러한 관점에서 강수량과 같은 수문변량의 장기적인 거동을 기상인자로부터 유추하고자 하는 연구는 무엇보다 중요하며 이러한 추론을 바탕으로 강수량의 장기예측 및 모의를 위한 기본적인 도구로 활용을 가능케 한다. 따라서 본 연구의 주요 목적은 해수면 온도를 기본으로 강수량과 기온의 변동성 및 상관성을 분석하고자 하며, 무엇보다 한반도 근해의 해수면 온도와의 직 간접적인 개연성을 살펴봄으로서 보다 효과적인 강수량 예측을 위한 하나의 변수로서의 가능성을 평가하고자 한다. 이를 위해 다양한 분석 방법 즉, 연주기를 제거하지 않은 자료의 선형적인 지체 상관 분석, 연주기를 제거하기 위해 표준화 된 자료의 지체 상관 분석 및 비모수적 상관분석을 수행하였다. 연주기를 제거하지 않은 자료의 경우 매우 강한 상관관계를 나타내었지만 이는 주로 계절 특성으로 인한 것으로 사료된다. 그러나 연주기를 제거한 Anomaly는 상대적으로 매우 작은 상관성을 보이고 있으나 유의성 검토를 통해 통계적으로 유의한 관계가 존재함을 확인 할 수 있었다. 따라서 강수량의 예측을 하나의 변수로서 이용이 가능할 것으로 사료되나 근해뿐만 아니라 한반도 기상의 연관성을 갖는 타 지역기상인자와의 보다 통합적인 검토가 필요하다 하겠다.

• Journal of Nutrition and Health
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• v.42 no.5
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• pp.464-473
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• 2009

The serum levels of antioxidant materials (${\alpha}$-carotene, ${\beta}$-carotene, ${\beta}$-cryptoxanthin, lutein, lycopene, ${\alpha}$-tocopherol, ${\gamma}$-tocopherol, retinol) of the healthy Korean middle-aged adults (n = 373) were measured and their relationships with the serum lipids and anthropometric indices were analyzed. The serum levels of ${\beta}$-cryptoxanthin, ${\beta}$-carotene, lutein were higher than those of lycopene and ${\alpha}$-carotene. The levels of all measured carotenoids except lutein were significantly higher in females than in males, but retinol level was vice versa. There was a tendency of increase in serum levels of antioxidant vitamins with increasing age. The serum carotenoid levels had a positive correlation with serum cholesterol and a negative correlation with serum triglyceride. The serum levels of tocopherols or retinol showed a significantly positive relationship with blood cholesterol or triglyceride. In overall, anthropometric indices showed negative relations with serum carotenoids levels, but vice versa with serum tocopherol or retinol levels. Particularly, ${\beta}$-carotene and lutein levels showed a significantly negative relation with blood pressure in male subjects. The serum levels of ${\alpha}$-carotene, ${\beta}$-carotene and ${\beta}$-cryptoxanthin had significantly negative relations with body fat-related indices in female subjects. The results demonstrated that blood antioxidants levels differed by sex and age, and had significant relations with blood lipid levels and anthropometric indices. Therefore, the rationale and significance of the relationships need to be elucidated in the future study related to dietary intakes and life style.

• Korean Journal of Remote Sensing
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• v.30 no.2
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• pp.315-329
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• 2014

In order to analyze the Land Surface Temperature (LST) in metropolitan area including Seoul, Landsat and MODIS land surface temperature, Automatic Weather Station (AWS) temperature, digital elevation model and landuse are used. Analysis method among the Landsat and MODIS LST and AWS temperature is basic statistics using by correlation coefficient, root-mean-square error and linear regression etc. Statistics of Landsat and MODIS LST are a correlation coefficient of 0.32 and Root Mean Squared Error (RMSE) of 4.61 K, respectively. And statistics of Landsat and MODIS LST and AWS temperature have the correlations of 0.83 and 0.96 and the RMSE of 3.28 K and 2.25 K, respectively. Landsat and MODIS LST have relatively high correlation with AWS temperature, and the slope of the linear regression function have 0.45 (Landsat) and 1.02 (MODIS), respectively. Especially, Landsat 5 has lower correlation about 0.5 or less in entire station, but Landsat 8 have a higher correlation of 0.5 or more despite of lower match point than other satellites. Landsat 7 have highly correlation of more than 0.8 in the center of Seoul. Correlation between satellite LSTs and AWS temperature with landuse (urban and rural) have 0.8 or higher. Landsat LST have correlation of 0.84 and RMSE of more than 3.1 K, while MODIS LST have correlation of more than 0.96 and RMSE of 2.6 K. Consequently, the difference between the LSTs by two satellites have due to the difference in the optical observation and detection the radiation generated by the difference in the area resolution.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.162-167
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• 2015

매년 여름철 피서지 1순위로 손꼽히는 해수욕장은 해양레포츠의 발달과 관광사업의 촉진으로 수많은 관광객들이 방문하고 있다. 하지만 우리나라 대부분의 해수욕장에서는 건전한 해수욕을 위한 수질안전지표 설정이 매우 미흡한 편이며 오염수준 또한 심각하다. 이에 강원도 강릉시 경포해수욕장을 대상지역으로 2012년 7월 17일부터 9월 4일까지 매주 화요일 오전에 채취한 시료로부터 병원성 수질지표인 장구균과 대장균, 총대장균군의 오염도를 분석하였다. 시료는 경포해수욕장 오리바위 배후부터 연안방향을 따라 200m 간격으로 3지점과 이안방향을 따라 백사장(dry beach), 포말대(swash zone), 유영층(swimming zone)의 3지점에서 총 9개를 채취하였다. 기온, 강우, 장소 등의 해안 환경 변화에 따른 병원균 증식 유리조건 및 인자들간의 상관성을 분석한 결과 백사장에서는 총대장균군, 포말대에서는 장구균, 유영층에서는 대장균의 농도가 가장 높았다. 또한 주간 누적 강우량과 평균 기온에 따라 시료채취 지점마다의 상관성에서는 백사장은 강우량과 정비례, 기온과는 반비례, 포말대와 유영층은 강우량과 반비례, 기온과는 정비례의 관계를 보였다. 백사장과 해수층인 포말대, 백사장과 유영층 각각은 반비례 관계를 보였지만 미비한 수준이었으며 포말대와 유영층간의 상관성은 약 90%의 매우 높은 수치를 띄었다. 본 연구는 건전한 수계 레크레이션 문화의 수질 안전지표 설정을 위해 해수욕장의 대표 관광명소 중 하나인 경포해수욕장을 대상으로 병원성 수질 지표들의 증식 유리 조건 및 확산특성 예측에 목적이 있다. 나아가 본 과정은 해변을 찾는 관광객들의 수질 안전 정보 제공 및 체계적인 가이드라인 제시로도 가치 있을 것으로 기대된다.