• The Journal of Engineering Geology
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• v.29 no.3
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• pp.303-314
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• 2019

Surface permeability and shallow geological structures play significant roles in shaping the groundwater recharge of shallow aquifers. Surface permeability can be characterized by two concepts, intrinsic permeability and hydraulic conductivity, with the latter obtained from previous near-surface geological investigations. Here we propose a hydraulic equation via the cross-correlation analysis of the rainfall-groundwater levels using a regression equation that is based on the cross-correlation between the grain size distribution curve for unconsolidated sediments and the rainfall-groundwater levels measured in the Gyeongju area, Korea, and discuss its application by comparing these results to field-based aquifer test results. The maximum cross-correlation equation between the hydraulic conductivity derived from Zunker's observation equation in a sandy alluvial aquifer and the rainfall-groundwater levels increases as a natural logarithmic function with high correlation coefficients (0.95). A 2.83% difference between the field-based aquifer test and root mean square error is observed when this regression equation is applied to the other observation wells. Therefore, rainfall-groundwater level monitoring data as well as aquifer test are very useful in estimating hydraulic conductivity.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.24 no.5
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• pp.409-416
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• 2006

To use image data obtained from different sensors and different techniques, the preprocessing step that registers them in a common coordinate system is needed. For this purpose, we developed the methodology to register middle- and low-resolution satellite images automatically. Firstly, candidate matching points were extracted using the Harris and Harris-affine algorithm. Secondly, we used the correlation coefficient, normalized correlation coefficient and SIFT algorithm to detect conjugate matching points from candidates. Then, to test the feasibility of approaches, we applied the developed methodology to various kinds of satellite images and compared results. The results clearly demonstrate that the methology using the SIFT is appropriate to register these multi-resolution satellite images automatically, compared with the classical cross-correlation.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.6
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• pp.37-46
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• 2013

Many factors about the stability for the reservoir embankments is determined when the facility is completed. Therefore the initial design of the embankment is important. Many researchers focused the effect of soil parameters although the cross section greatly affects the stability and can be controlled in design step. The objective of this research is to analysis of the effects for the safety factor of slope and seepage according to change cross-section in embankment. As a result, the quantity of seepage decreased as the gradient of downstream slope decreased and was proportional to the height of embankments. There was a linear relationship between the gradient of slope and the safety factor of slope. However the gradient of slope did not affect other side slope. All in a relationship, regressive equations with a high correlation coefficient were calculated and can be applied the simple estimation method of the stability using the cross-section. As results of analyzing the sensitivity, the friction angle and permeability critically effect for the slope stability and the seepage, respectively. The effect of the slope gradient was similar to major soil properties.

• Journal of Environmental Science International
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• v.4 no.5
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• pp.28-28
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• 1995

The aim of the present study is to investigate the interannual variabilities of the East Asia monsoon rainfall associated with the global sea surface temperature anomaly(SSTA). For this study, the summer rainfall(from June to August) over the twenty-eight period of 1961-1988 were analyzed with being divided by nine-subregions over East Asia including Korea, China and Japan. From the analysis of the principal modes explaining the interannual variation, the interannual variabilities of summer rainfalls in South Japan and Korea are larger than those of the other subregions of the East Asia. There is a strong negative correlation between the summer rainfalls of south China and Korea. In this study, the relationship between the summer monsoon of each subregion and SSTs of the tropical NINO regions, of western Pacific warm pool, and of the subtropical ocean were investigated. The longitudinal sections of the lagged cross correlations of the summer rainfal1 anomaly in (a) Korea and (b) south China, and the monthly SSTA in the equatorial(averaged from 65 to 6N) Pacific were analyzed. The negative maximum correlation pattems of Korea''s stammer rainfal1 and SSTs over the eastern Pacific is transfered to positive maximum conrlation over central Pacific region with a biennial periodicity. In South China, the significant positive correlations are found at -12 month lag over the eastern Pacific and maximum negative correlation at 16 month lag over the central Pacific with the quasi-biennial oscillation. But the correlation coefficient reverses completely to that in Korea. In order to investigate the most prevailing interannual variability of rainfall related to the favored SSTA region, the lagged cross correlations between East Asia rainfall and SSTs over the moO regions(NINO 1+2(0-105, 90W-80W), NINO 3(5N-5S, 150W-90W), NINO 4(5N-5S, 160E-l50W) and the western Pacific worm pool (5N-5S, 120E-l60E) were analyzed. Among the lagged cross-correlation cycles in NINO regions, the maximum correlations for the negative lagged months prevail in NINO 1+2 and NINO 3, and the cross correlations for the positive lagged months NINO 4. It is noteworthy that correlation between the western Pacific warm pool SSTA and the monsoon rainfall in Korea and South China have the maximum value at negative 4 month lag. The evolution of the correlation between the East Asia monsoon rainfall and SSTA is linked to the equatorial convective cluster and related to northward propagating situation, and raising the possibility that the East Asia monsoon precipitation may be more fundamentally related to the interaction of intraseasonal oscillations and the sub-regional characteristics including the surface boundary conditions and the behavior of climatological air mass.

• Journal of Environmental Science International
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• v.4 no.5
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• pp.413-426
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• 1995

The aim of the present study is to investigate the interannual variabilities of the East Asia monsoon rainfall associated with the global sea surface temperature anomaly(SSTA). For this study, the summer rainfall(from June to August) over the twenty-eight period of 1961-1988 were analyzed with being divided by nine-subregions over East Asia including Korea, China and Japan. From the analysis of the principal modes explaining the interannual variation, the interannual variabilities of summer rainfalls in South Japan and Korea are larger than those of the other subregions of the East Asia. There is a strong negative correlation between the summer rainfalls of south China and Korea. In this study, the relationship between the summer monsoon of each subregion and SSTs of the tropical NINO regions, of western Pacific warm pool, and of the subtropical ocean were investigated. The longitudinal sections of the lagged cross correlations of the summer rainfal1 anomaly in (a) Korea and (b) south China, and the monthly SSTA in the equatorial(averaged from 65 to 6N) Pacific were analyzed. The negative maximum correlation pattems of Korea's stammer rainfal1 and SSTs over the eastern Pacific is transfered to positive maximum conrlation over central Pacific region with a biennial periodicity. In South China, the significant positive correlations are found at -12 month lag over the eastern Pacific and maximum negative correlation at 16 month lag over the central Pacific with the quasi-biennial oscillation. But the correlation coefficient reverses completely to that in Korea. In order to investigate the most prevailing interannual variability of rainfall related to the favored SSTA region, the lagged cross correlations between East Asia rainfall and SSTs over the moO regions(NINO 1+2(0-105, 90W-80W), NINO 3(5N-5S, 150W-90W), NINO 4(5N-5S, 160E-l50W) and the western Pacific worm pool (5N-5S, 120E-l60E) were analyzed. Among the lagged cross-correlation cycles in NINO regions, the maximum correlations for the negative lagged months prevail in NINO 1+2 and NINO 3, and the cross correlations for the positive lagged months NINO 4. It is noteworthy that correlation between the western Pacific warm pool SSTA and the monsoon rainfall in Korea and South China have the maximum value at negative 4 month lag. The evolution of the correlation between the East Asia monsoon rainfall and SSTA is linked to the equatorial convective cluster and related to northward propagating situation, and raising the possibility that the East Asia monsoon precipitation may be more fundamentally related to the interaction of intraseasonal oscillations and the sub-regional characteristics including the surface boundary conditions and the behavior of climatological air mass.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.3
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• pp.151-156
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• 2002

The heritability of sink-source characters was estimated by regression coefficient between F$_2$ and F$_{5}$ in two crosses of IR 66738-118-1-2/Gayabyeo and the Ilpumbyeo/YR 15965 Acp 33. In order to get the some basic information for breeding of high yielding rice, genetic resources of new plant type with low tiller and heavy panicle were used. Most of the sink and source characters in Ilpumbyeo/YR 15965 Acp 33 cross showed high heritability over than 0.224. But the specific leaf area and sink-source ratio displayed low heritability being 0.009 and 0.013, respectively. Heritability of all sink and source characters in IR 66738-118-1-2/Gayabyeo cross ranged from 0.115 to 0.247. Correlation coefficient between yield and yield components in both combination were in the ranged between 0.001 and 0.247. But correlations among the yield components were not significant. Correlations between the yield and sink-source characters in both combinations were also highly significant. Particularly, correlation between the grain tiling ratio and most of the sink-source characters in IR 66738-118-1-2/Gayabyeo cross were not significant. In Ilpumbyeo/YR 15965 Acp 33 cross, correlations between grain filling ratio and source characters were positively significant. but sink characters (sink capacity and sink-source ratio, etc) were negatively significant.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.12
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• pp.6054-6068
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• 2017

In this paper, we defined the relative cross-sectional area of forearm cortical bone and investigated its correlation with hip bone mineral density values of total femur, femoral neck, femoral trochanter, femoral inter-trochanter and femoral ward's triangle, respectively. Based on the correlations, we established a linear transformation between the relative cross-sectional area of forearm cortical bone and each hip bone BMD. We obtained forearm images using CBCT and hip bone BMDs using dual-energy X-ray absorptiometry (DXA) for 28 subjects. We also investigated the optimal forearm region to provide the strongest correlation coefficient. We used the optimized forearm region to establish each linear transformation to estimate BMD values for total femur, femoral neck, femoral trochanter, femoral inter-trochanter and femoral ward's triangle from the relative cross-sectional area of forearm cortical bone, respectively. We observed the strong correlations with total femur (r=0.889), femoral neck (r=0.924), femoral trochanter (r=0.821), femoral inter-trochanter (r=0.867) and femoral ward's triangle (r=0.895), respectively. The strongest correlation was observed in the forearm mid-shaft regions. Our results suggest that the hip bone BMD values can be simply estimated from forearm CBCT images in a convenient sitting position without X-ray exposure on a hip including genital organs, and may be useful for screening osteoporosis.

• Journal of Korean Medicine Rehabilitation
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• v.28 no.3
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• pp.87-96
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• 2018

Objectives The purpose of this study is to provide more whiplash injury-specific measurement tools for Korean patients by measuring the validity and reliability of Korean version of Whiplash Disability Questionnaire (WDQ). Methods Bilingual clinicians translated the original WDQ into Korean. After consensus conference between researchers, it was back-translated into English. The pre-final version was completed and administered to 71 hospitalized patients diagnosed with whiplash injury. Validity was evaluated by concurrent validity. Reliability was assessed using Cronbach's ${\alpha}$ and intraclass correlation coefficient. Results The Korean WDQ showed good reliability with high internal consistency and intra-class correlation coefficient (Cronbach's ${\alpha}=0.96$, intraclass correlation coefficient [ICC]=0.82). Concurrent validity demonstrated positive correlations between Neck Disability Index, 36-Item Short Form Health Survey and WDQ. Conclusions The Korean version of WDQ is a valid and reliable tool for use as a measurement of whiplash injury in Korean patients, and it will be a very useful evaluation tool for both clinicians and researchers.

• Journal of radiological science and technology
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• v.44 no.4
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• pp.389-397
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• 2021

The purpose of this study was to compare the demographic and job characteristics and job satisfaction of sonographers (SONO) and radiological technologists (RT). The subjects were a total of 148 people (69 SONO, 79 RT), who had been working in clinical and hospitals. The method was conducted using a questionnaire with a total of 54 questions consisting of demographic characteristics, job characteristics, and job satisfaction. Reliability was secured with Cronbach's alpha coefficient of 0.6 or higher for the response of the questionnaire. For statistical analysis, descriptive statistics, cross-analysis, independent sample T-test, and correlation analysis using Pearson's correlation coefficient and Spearman's correlation coefficient were performed for each occupation. As a result, first, the SONO had more female workers than RT. They are more than three times as many in graduate school and above. Second, the SONO had 4.5 times more morning shift than the RT and no form of weekend shift. Third, the average monthly salary of the SONO is higher than that of the RT, but when a certain portion of the salary goes up, the salary no longer goes up. Fourth, satisfaction with expectations, growth desire, positive mentality, growth opportunity, job importance, organizational attachment was higher SONO than the RT, but self-efficacy was higher in RT than SONO. Last, SONO had higher educational background than RT. It is hoped that the results of this study will be able to understand the job characteristics of SONO and RT and identify the factors of job satisfaction and provide them as fundamental materials for job selection.

• Journal of Integrative Natural Science
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• v.10 no.2
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• pp.78-84
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• 2017

CXC chemokine receptor 2 (CXCR2) is a prominent chemokine receptor on neutrophils. CXCR2 antagonist may reduce the neutrophil chemotaxis and alter the inflammatory response because the neutrophilic inflammation in the lung diseases is found to be largely regulated through CXCR2 receptor. Hence, in the present study, Hologram based Quantitative Structure Activity Relationship Study was performed on a series of CXCR2 antagonist named pyrimidine-5-carbonitrile-6-alkyl derivatives. The best HQSAR model was obtained using atoms, bonds, and chirality as fragment distinction parameter using hologram length 151 and 6 components with fragment size of minimum 4 and maximum 7. Significant cross-validated correlation coefficient ($q^2=0.774$) and non cross-validated correlation coefficients ($r^2=0.977$) were obtained. The model was then used to evaluate the six external test compounds and its $r^2_{pred}$ was found to be 0.614. Contribution map show that presence of cyclopropyl ring and its bulkier substituent's makes big contributions for improving the biological activities of the compounds. We hope that our HQSAR model and analysis will be helpful for future design of novel and structurally related CXCR2 antagonists.