• Applied Biological Chemistry
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• v.45 no.1
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• pp.18-24
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• 2002

This study was conducted to find out optimum conditions for kanjang fermented with barley bran. The correlation between taste components and sensory evaluation score was analyzed with stepwise multiple regression analysis. It was revealed that the taste of kanjang was explained with the mix of free amino acids, free sugars and organic acids. The highest multiple correlation coefficient was obtained from absolute value transformed with logarithm. Thus, stepwise multiple regression analysis was conducted with absolute value transformed with logarithm, for which F-value was highest and standard error of estimation was lowest among the multiple regression models transformed with six variables. The stepwise multiple regression analysis showed that the taste components which most contribute to the quality of taste of kanjang fermented with barley bran was salty taste component followed by palatable taste component, and bitter taste component.

• Applied Biological Chemistry
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• v.49 no.1
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• pp.35-42
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• 2006

This study was conducted to find effective components on taste of kanjang made with barley bran. The result of stepwise multiple regression analysis with transformation of variables was that the 70.1% and 80.8% of taste of barley kanjang could be explained at step 6 and step 15, respectively, calculated from absolute value. And, the 83.0% and 84.3% of taste of barley kanjang was explained at step 6 and step 15, respectively, calculated from relative value transformed with logarithm. The contributing proportion of the ${\alpha}-ketoglutaric$ acid was the highest followed by citric acid, lavulinic acid and glutamic acid computed from absolute value, and the ${\alpha}-ketoglutaric$ acid was the highest followed by fructose, glutamic acid and valine calculated from relative value trans-formed with logarithm.

• Korean Journal of Food Science and Technology
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• v.16 no.2
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• pp.242-250
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• 1984

Flavor components extracted from eighty species of Korean ordinary soy sauce were analyzed by gas chromatography. The relationship between the sensory scores of soy sauce flavor and the gas chromatographic data transformed with variables were analysed by method of multiple regression analysis. Simple correlation between values of each peak and sensory scores were totally low. The tenth and 12th peak had the highest correlation, 0.331. Determination coefficients of data obtained by transformation of each variables were not significantly different from each other. Flavor of soy sauce was explained about 56% at step 16 in case of stepwise multiple regression analysis of absolute values. The fact that the minimum standard errors of an estimate was found at the 16th step suggests the importance of selecting of independent variables from the whole gas chromatogram together with the results of F ratio. In the contributing proportion of each peak examined, peak 10 and 12 were contributing mainly to the good flavor of soy sauce.

• 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.

• Tunnel and Underground Space
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• v.16 no.3 s.62
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• pp.251-258
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• 2006

In this paper, the applicability to the Korean rock condition of using the deformation moduli based on Rock Mass Rating (RMR) and Pressuremeter Test (PMT) is evaluated. The correlations among deformation moduli and various rock properties were also analyzed. It appears that the existing correlations using RMR overestimate the deformation moduli and wide variation was found between predicted moduli using these correlations and measured values. As for the correlations among the deformation moduli and various rock properties, Rock Quality Designation (RQD) and unconfined compressive strength (UCS) were found to correlate to deformation moduli reasonably well, but joint spacing and joint conditions appear to correlate poorly to RQD and UCS. Additionally, groundwater can not be correlated with the modulus values. While the depth has very little contribution to deformation modulus, it should be factored in the simple regression analyses with various rock mass properties, especially with the correlations made with UCS, RQD etc. With the deficiencies of these correlations, more in depth analysis techniques such as multivariate correlations may be to reliably estimate deformation modulus of rock mass.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3789-3798
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• 2014

This study examined the factors affecting blood donation intention and behavior in college students based on the theory of planned behavior. The subjects were 258 students from one college in G city, and the data was collected by a survey using self-administered questionnaires structured from June 3 to June 14, 2013. The data was analyzed using the SPSS 19.0 program, the variables affecting the blood donation intention were analyzed by stepwise multiple regression, and the variables affecting the blood donation behavior were analyzed by Logistic regression. The factors affecting the blood donation intention were in order the perceived behavioral control, attitude toward the behavior and subjective norm, and the explanatory power was 65.6%. In addition, the factor affecting the blood donation behavior was only the blood donation intention (OR=1.129, p=.010) except for perceived behavioral control. Therefore, the perceived behavioral control, attitude and subjective norm should be considered when developing blood donation programs for college students.

• Journal of dental hygiene science
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• v.3 no.2
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• pp.71-76
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• 2003

The purpose of this study was to investigate the relationship of job satisfaction and self-esteem of dental hygienists and nurse's aides. Data were obtained from 327 dental hygienists and nurse's aides who were working at dental clinics, hospitals located in Seoul city. The results, derived from using the SPSS 10.0, were as follows: (1) The level of job satisfaction was 3.02 point, the level of self-esteem was 3.41 point. (2) Service organization and types of occupation have influenced meaningfully on job satisfaction. Hospitals(3.14) are higher than dental clinics(3.0), dental hygienists(3.14) are higher than nurse's aides(2.92). (3) Service organization and types of occupation have influenced meaningfully on self-esteem. Hospitals(3.55) are higher than dental clinics(3.39), dental hygienists(3.52) are higher than nurse's aides(3.31). (4) The correlation between job satisfaction and self-esteem of dentistry employee showed statistically significant correlation.

• Korean Journal of Ecology and Environment
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• v.39 no.3 s.117
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• pp.340-351
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• 2006

To reveal physicochemical factors contributing to variation of phytoplankton communities, the study was carried out biweekly at 6 stations from Feb. 2004 to Feb. 2005 in the lower part of the Han River, Korea. As results, water temperature was changed from $0.3^{\circ}C$ to $26.6^{\circ}C$, pH: 6.6${\sim}$9.1, DO: 1.89${\sim}$22.23 mg $L^{-1}$, BOD: 0.38${\sim}$9.20 mg $L^{-1}$, COD: 1.4${\sim}$15.2 mg $L^{-1}$, Conductivity: $62.5{\sim}500.0\;{\mu}s\;cm^{-1}$, SS: 3.00${\sim}$159.3 mg $L^{-1}$, and Chl a $1.7{\sim}71.3\;{\mu}g\;L^{-1}$. Phytoplankton standing crops ranged from min. $3.6{\times}10^2\;cells\;mL^{-1}$ (July 2004, St. 3) to max. $2.3{\times}10^4\;cells\;mL^{-1}$ (Feb. 2005, St. 6), and mean of those varied from $5.9{\times}10^3\;cells\;mL^{-1}$in spring, $2.1{\times}10^3\;cells\;mL^{-1}$ in summer, $4.1{\times}10^3\;cells\;mL^{-1}$ in autumn and $8.5{\times}10^3\;cells\;mL^{-1}$ in winter, respectively. In order to investigate factors influencing the total phytoplankton standing crops a multiple regression analysis was adopted for the correlation between standing crops and environmental factors. The coefficient of determination ($R^2$) value of the regression was 0.465, it showed that environmental factors which predominantly influenced phytoplankton standing crops were water temperature, COD, $NO_2-N$, $PO_4-N$, Discharge and pH. six stations could be divided into 3 groups based on similarity index in terms of environmental factors. In ANOVA analysis for physicochemical and biological factors, water temperature, chlorophyll a, silicate, phytoplankton standing crops were the same group differed little from stations. However, Station 1and 2 were grouped followed in dissolved oxygen, conductivity, COD, nitrite, nitrate, ammonia and phosphate, and Station 3, 4 and 5 were followed in dissolved oxygen, conductivity, pH and phosphate.

• Korean Journal of Ecology and Environment
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• v.36 no.3 s.104
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• pp.269-276
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• 2003

The study was performed to understand the relationships of cyanobacterial bloom and environmental factors in Lake Daechung. The samples were collected weekly from June to October in 2001. The cyanobacterial bloom was divided into the three phases of the early phase, the middle phase and the late phase by phytoplankton standing crops. For the early phase, the correlation coefficients between chl- a and TP, and chl- a and $PO_4$-P were 0.986 and 0.894 respectively. Therefore, phosphorus was a main environmental factor in the development of cyanobacterial bloom. Zeu/Zm ratio and chl-a showed negative correlation of r = -0.995. At the late phase, $PO_4$-P showed the highest relationship (r = 0.958), and TP and temperature showed relatively high relationships (r = 0.857 and r = 0.813). At the late phase, $NH_3$-N showed highly positive relationship (r = 0.921). It was confirmed that $PO_4$-P was the most important contribution factor for the bloom through the regression analysis on the environmental factors. As the result, the decrease of Zeu/Zm ratio and the increase of P concentration influenced cyanobacterial bloom developed rapidly in the early phase. Also the cyanobacterial bloom was decreased in proportion to decreasing of $NH_3$-N concentration in the late phase. It was expected that observation of $NH_3$-N may be a very useful factor on monitoring of the decreasing situation of the bloom.

• Journal of Korea Water Resources Association
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• v.57 no.3
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• pp.151-164
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• 2024

In water treatment plants supplying potable water, the management of chlorine concentration in water treatment processes involving pre-chlorination or intermediate chlorination requires process control. To address this, research has been conducted on water quality prediction techniques utilizing AI technology. This study developed an AI-based predictive model for automating the process control of chlorine disinfection, targeting the prediction of residual chlorine concentration downstream of sedimentation basins in water treatment processes. The AI-based model, which learns from past water quality observation data to predict future water quality, offers a simpler and more efficient approach compared to complex physicochemical and biological water quality models. The model was tested by predicting the residual chlorine concentration downstream of the sedimentation basins at Plant, using multiple regression models and AI-based models like Random Forest and LSTM, and the results were compared. For optimal prediction of residual chlorine concentration, the input-output structure of the AI model included the residual chlorine concentration upstream of the sedimentation basin, turbidity, pH, water temperature, electrical conductivity, inflow of raw water, alkalinity, NH₃, etc. as independent variables, and the desired residual chlorine concentration of the effluent from the sedimentation basin as the dependent variable. The independent variables were selected from observable data at the water treatment plant, which are influential on the residual chlorine concentration downstream of the sedimentation basin. The analysis showed that, for Plant, the model based on Random Forest had the lowest error compared to multiple regression models, neural network models, model trees, and other Random Forest models. The optimal predicted residual chlorine concentration downstream of the sedimentation basin presented in this study is expected to enable real-time control of chlorine dosing in previous treatment stages, thereby enhancing water treatment efficiency and reducing chemical costs.