• 약학회지
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• 제43권5호
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• pp.577-583
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• 1999

Concentrations of heavy metals, including As, Cd, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Se, Si, Sn, V and Zn in the internal organs (liver, kidney, heart, lung, spleen, cerebrum and bone) of Korean obtained from 91 forensic medical autopsy cadavers, with an age range of 12-87 years, were determined by inductively coupled plasma atomic emission spectrometry. From the results, positive correlation with age was observed in the following cases : Cd in liver, kidney and cerebrum; Fe in cerebrum and bone; Pb in bone; v in lung. Copper in heart, Hg in bone and Mn in kidney correlated negatively with age. A significantly positive correlation between Se and Hg was only observed in heart. Significant correlation coefficients between Se and As were observed in liver, kidney, heart spleen and bone. The correlation between Cd and Zn was significant in liver and kidney, indicating that the distribution of Cd is similar to that of Zn in the liver and kidney.

• 산업공학
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• 제14권1호
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• pp.79-83
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• 2001

In this paper, we propose a simple method to reduce categorical variables into smaller, but significant numbers, and also demonstrate how the proposed method can be applied to the problem of reduction that empirical research often faces in the course of data processing. For the purpose, we introduce a concept of pseudo-correlation coefficient to make it possible to use factor analysis (FA) as a tool for reducing variables. The main idea of the concept is to deal with the measures of association of categorical variables in the sense of the concept of Pearson's correlation coefficient in order to meet the input requirement of FA. Upon examination of existing measures that could play as pseudo-correlation coefficients, Cramer's V coefficient is selected for the best result among them. To show the detailed procedure of the proposed method, a specific demonstration with the data from 329 R&D projects conducted in 18 private laboratories in electric and electronics industry is presented.

• 한국구조물진단유지관리공학회 논문집
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• 제3권3호
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• pp.157-165
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• 1999

The nondestructive testing methods are commonly used to determine the in-situ compressive strength of concrete. The correlation curves to evaluate the effect of aging on the development of concrete strength was proposed. Thirty two ${\Phi}10{\times}20cm$ cylinder specimens were cast from 5 batches having different strength levels. The correlation curves for rebound hammer method, ultrasonic pulse velocity method and combined method were derived from the laboratory tests and multiple regression analysis. To account for the change of condition such as surface hardness, internal moisture contents, the aging coefficients are applied to the correlation curves. From the comparison the nondestructive strength with the core strength taken from the existing reinforced concrete structures, the validity of the proposed correlation curves are verified.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.791-795
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• 2005

A simulation model is proposed to evaluate the effect of correlations between activity durations on the overall project duration. The proposed model incorporates NORTA, a recent developed statistical method, into the simulation process to allow arbitrarily specified marginal distributions for activity durations and any desired correlation structure. The generality is of practical value when systematic data is not available and planners have to rely on arbitrary experts' estimation, which may involve a mixed situation when some activity durations are continuously distributed whereas others are discrete outcomes. The proposed model is validated by showing that the correlation coefficients of the simulation results are close to the originally specified ones. The simulation results are compared to two conventional approaches: PERT and simulation without correlation. The comparisons illustrate that the proposed model can provide important management information, which would otherwise be distorted due to the neglect of the correlations between activity durations.

• 한국산학기술학회논문지
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• 제15권1호
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• pp.323-330
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• 2014

본 연구의 목적은 전문대학생의 전공만족도, 취업스트레스, 우울의 관계를 알아보고, 전공만족도, 취업스트레스가 우울에 미치는 영향을 확인하기 위함이다. 자료수집은 B, C시의 전문대학 3개교에서 졸업을 앞둔 2학년 학생 196명을 대상으로 연구의 목적을 설문에 동의한 자를 대상으로 구조화된 설문지로 조사하였다. 수집된 자료는 SPSS WIN 18.0을 이용하여 빈도와 백분율, 평균과 표준편차, t-test, one-way ANOVA, Pearson's correlation coefficients, multiple regression으로 분석하였다. 연구의 대상자의 전공만족도와 우울 간에 유의한 음의 상관관계가 나타났고, 취업스트레스와 우울 간에 유의한 양의 상관관계가 나타났다. 대상자의 우울에 영향을 미치는 요인은 전공만족도와 취업스트레스로 나타났으며, 총 설명력은 26.0%였다. 본 연구를 통하여, 전문대학생의 우울에 영향을 미치는 전공만족과 취업에 관련된 다양한 요인들을 파악하였다. 이에 우울을 예방할 수 있는 중재 프로그램 개발이 필요할 것으로 사료된다.

• 한국작물학회지
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• 제11권
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• pp.99-103
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• 1972

들깨 수량에 영향하는 형질을 정확히 알기 위하여 형질상호간의 상관관계와 경로계수를 분석한 바 그 결과를 요약하면 다음과 같다. 1. 경장은 경식경, 화방수, 경중과 유효분지수는 화방수와 높은 정의 상관을 그리고 유효분지수는 1,000입중과 화방수는 1,000입중과 각각 높은 부의 상관을 보였다. 2. 수량에 직접적으로 영향하는 형질은 경중, 화방수 1,000입중 유효분지수, 경직경등이다. 3. 간접적 효과는 경장대 경중, 유효분지수 대 화방수, 화방수 대 경중간에 높은 값을 보였다. 4. 들깨의 수량은 경장이 길고 유효분지수 및 화방수가 많으며 1,000입중과 경중이 무거운것일수록 수량이 많다는 사실을 알수 있다.

• 한국환경보건학회지
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• 제32권1호
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• pp.8-18
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• 2006

The aim of this study is to evaluate the emission characteristics of mercury, lead, arsenic, and selenium from medium size municipal solid waste incinerators(MSWIs) in Korea. The concentrations of mercury, lead, arsenic, and selenium emitted from medium size MSWI stack were $2.67\;{\mu}g/Sm^3,\;0.38\;mg/Sm^3,\;1.33\;{\mu}g/Sm^3,\;0.28\;{\mu}g/Sm^3$, respectively. The concentration levels of mercury, lead, arsenic in flue gas from medium size MSW incinerator stacks selected were nearly detected under the Korea criteria level. Removal efficiencies of mercury, lead, arsenic, and selenium in waste heat boiler(WHE) and cooling tower(CT) were $90.36\%,\;69.76\%,\;43.04\%,\;40.64\%$, respectively. In general, the removal efficiencies of mercury and lead in WHE were higher than those of arsenic and selenium in WHE. Emission gas temperature reduction from waste heat boiler(WHB) and cooling tower(CT) can control mercury and lead of medium size MSWIs. To evaluate the relationship between mercury, lead, arsenic, selenium of fly ash and those of flue gas, it was carried out to correlation analysis of each metal concentration in the fly ash and in the flue gas from medium size MSWIs. From the correlation analysis, the coefficients of mercury, lead, arsenic, and selenium were 0.61, -0.38, 0.87, 0.28, respectively. The results of correlation analysis revealed that it should be highly positive to the correlation coefficients of mercury and arsenic in the fly ash and those of the flue gas emitted from medium size MSWIs. As it were, the concentrations of mercury and arsenic of flue gas from medium size MSWIs are high unless mercury and arsenic in fly ash are properly controlled in dust collection step in medium size MSWIs. It was also concluded that mercury, lead, arsenic, and selenium from MSWIs stacks could be controlled by waste heat boiler(WHE) and dust collecting step in medium size MSWIs.

• 한국환경보건학회지
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• 제46권5호
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• pp.532-538
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• 2020

Objectives: The study evaluated correlations among monthly PM_2.5, PM₁₀, Cd, Pb concentrations and the number of Asian dust days. Methods: Based on data from 'The annual report on air quality in Korea from 1999 to 2017', concentrations of PM₁₀, PM_2.5, Cd, Pb, and the number of Asian dust days were recalculated to mean, standard deviation, minimum, and maximum. Correlation coefficients were calculated among PM_2.5, PM₁₀, Cd, Pb, and Asian dust days. Results: Asian dust days were correlated only with PM₁₀ among the four factors of PM₁₀, PM_2.5, Cd, and Pb. The four factors of PM₁₀, PM_2.5, Cd, and Pb were very significantly correlated with each other (p<0.01). Their correlation coefficients for PM₁₀ were 0.800 for PM_2.5, 0.823 for Cd, and 0.892 for Pb. PM_2.5 was also correlated strongly with Cd (0.845) and Pb (0.830). Cd had a correlation with Pb of 0.971. The maximums of PM_2.5, PM₁₀, and Pb were shown to exceed the atmospheric environmental standard of Korea, which necessitates national continuous exposure control. Based on exposure data, Asian dust days were thought to be an exposure factor for Cd and Pb. Conclusion: Asian dust might be a factor in Cd and Pb exposure. National exposure controls are required for exposure to PM_2.5, PM₁₀, Cd, and Pb.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2006년도 학술발표회 논문집
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• pp.643-646
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• 2006

An operational calibration is applied to improve radar rainfall intensity using rainfall obtained from rain gauge. The method is applied under the assumption of the temporal continuity of rainfall, the rainfall intensity from rain gauge is linearly related to that from radar. The method is applied to the cases of typhoon and rain band using the reflectivity of CAPPI at 1.5km obtained from Jindo radar. The CAPPI is obtained by bilinear interpolation. For the two cases, the rainfall intensities obtained by operational calibration are very consistent with the ones by the rain gauges. The present study shows that the correlation between the rainfall intensity by operational calibration and rain gauges is better than the one between the rainfall intensity by M-P relationship and rain gauges. The correlation coefficients between the total rainfall intensity obtained by operational calibration and rain gauges in typhoon and rain band cases are 0.99 and 0.97, respectively. Areal rainfalls are estimated using the field of calibration factor interpolated by Barnes objective analysis. The method applied here shows an improvement in the areal rainfall estimation. For the cases of typhoon and rain band, the correlation between the areal rainfall by operational calibration and rain gauges is better than the one between the area rainfall by M-P relationship and rain gauges. The correlation coefficients between the areal rainfall obtained by operational calibration and rain gauges in typhoon and rain band cases are 0.97 and 0.84, respectively. The present study suggests that the operational calibration is very useful for the real-time estimation of rainfall intensity and areal rainfall.

• 한국도서관정보학회지
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• 제21권
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• pp.159-193
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• 1994

This study is to analyze correlations between 14 factors related to university libraries and the number of professional staff, nonprofessional staff, and total library staff. The results of this study are summarized as follows: 1. In the case of 1992, there are high positive correlations between the number of library staff and 10 of 14 variables : the number of undergraduate enrollments, graduate enrollments, departments, faculty members, school employees and volumes in library, size of library building, total university expenditure and library materials expenditure (coefficient: 0.70-0.99). However, there are little significant correlations between the number of library staff and 2 variables : library open hours and university expenditure per student. Among the above factors, the correlations of the total university expenditure and the library expenditure show a significant difference more than ones of the other factors. 2. In the case of the analysis by 3 years interval in 1984-1992, there are high positive correlations between the number of total library employees and 7 of the above 9 variables, excepted to library open hours and 4 factors related to expenditure (coefficient : 0.73-0.93 in 1984;0.77-0.88 in 1988;0.70-0-92 in 1992). But there are little significant differences among the correlation coefficients by each year. 3. In the results of the correlation analysis between the professional staff and the nonprofessional staff, the number of graduate enrollments, departments, volumes in library and school employees, library expenditure and total university expenditure show higher positive correlation to the professional staff than the nonprofessional staff. However, the number of undergraduate enrollments, faculty members, volumes added in library and volumes loaned, size of library building and library materials expenditure show little significant differences in the correlation coefficients between the professional staff and the nonprofessionalstaff.