• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.180-188
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• 2006

수리 전도도는 hydraulic gradient에 대한 flux의 비율 또는, flux-hydraulic gradient 직선의 기울기를 나타내며, 포화된 토양에서의 물의 이동이 포화수리 전도도이고 불포화된 토양에서의 이동이 불포화수리전도도이다. 일반적인 밭 상태에서의 토양수분 조건은 불포화수리 전도도로 표시하는 것이 적절하나 그 상태를 표현하기가 쉽지 않다. 토양의 불포화 상태를 나타내는데 가장 많이 쓰이고 있는 VGM(van Genuchten Mualem) 모형은 토양수분 포텐셜과 수분함량의 함수로 구성된 모형이며 몇 가지 매개변수가 필요하다. VGM 모형의 매개변수를 얻기 위해 본 연구에서는 VGM 모형의 매개변수를 계산해주는 프로그램인 Rosetta를 사용하였다. Rosetta 모형은 신경그물 얼개(neural network)를 이용하여 토양의 물리적 자료들인 토성이나 모래, 미사, 점토 함량 또는 용적밀도나 33kPa, 1500kPa에서의 토양수분 함량 자료를 가지고 VGM의 매개변수인 Ko(effective saturated hydraulic conductivity), ${\theta}r$(residual soil water content), ${\theta}s$(saturated soil water content), L, n, m(=1-1/n)을 예측하는 모형으로 미국 농무성(USDA-ARS)에서 개발한 프로그램이다. Rosetta를 이용하여 10kPa에서의 불포화수리 전도도를 예측하였다. 또한 Gardner(1958)와 Wooding (1968)의 모형을 기반으로 하여 만들어진 tension infiltrometer의 포화수리 전도도 값을 Gardner 식에 적용하여 1, 3, 5, 7kPa에서의 불포화수리 전도도 값을 17개 토양통을 대상으로 하여 구했다. 토양수분 potential이 3kPa에서는 물의 이동이 거의 없는 토양들이 있었는데 반해 남계통을 비롯한 학곡통, 회곡통, 백산통, 상주통, 석천통, 예산통 등 7개의 토양은 3kPa에서도 약간의 물의 이동이 있었다. 이는 모암이 화강 편마암인 관계로 토양 내에 물의 이동에 영향을 미치는 자갈의 함량이 높았기 때문일 것으로 생각되고 추후의 연구에서는 이 부분에 대한 내용도 검토되어야 할 것이다. 또한, 1kPa에서 물의 이동은 삼각통에서 35.21 cm/day로 이동 속도가 가장 컸으며 그 뒤로 예산통, 화봉통, 학곡통, 백산통 등이 토양에서 빠른 속도로 이동하였다. 가천통이나 석천통 및 우곡통은 1kPa에서의 이동 속도가 아주 느린 토양으로 판단되었다. 또한, 포화되지 않은 상태인 1kPa에서 물의 이동 속도를 VGM 모형에 의해 예측된 값과 측정된 값으로 비교하였을 때 불포화 수리 전도도가 예측되지 않은 토양(석천통, 지곡통, 풍천통)이 존재하여 불포화 수리 전도도 특성평가에 대한 VGM 모형의 적용성에 문제를 보였다. 이는 결과적으로 논이라는 영농형태가 존재하는 우리나라에서 토양의 수리적 특성해석을 위한 VGM 모형의 적용성에 한계가 있을 것으로 판단되었다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.4
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• pp.567-571
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• 2005

In this study, the effects of varying the amount of water, soaking time at $25^{\circ}C$ and drying time after soaking at $45^{\circ}C$ on the induction of resveratrol were evaluated to optimize the soaking treatment by response surface methodology (RSM). After response surface regression (RSREG), the second-order polynomial equation was fitted to the experimental data. The analysis of variance showed that the model appeared to be adequate $(R^2=0.9547)$ with no significant lack of fit (p>0.1). From statistical analysis, amount of water and soaking time were found to be significant factors. On the other hand, drying time was not significant. Ridge analysis showed that the optimized parameters were $67.15\%$ for amount of water, 19.58 hr for soaking time, 65.56 hr for drying time. It was confirmed that resveratrol content was increased from $0.1\;{\mu}g/g$ to $4.55\;{\mu}g/g$ under the optimized conditions. In addition, the experimental values at the optimized condition agreed with values predicted by ridge analysis. The analytical method validation parameters such as accuracy, precision, and specificity were calculated to ensure the method's validity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.4
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• pp.595-600
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• 1997

To extend the shelf-life of Kochujang, the effects of anti-browning agents and their optimum concentrations were evaluated using organic acids as synergists. Among the physicochemical analyses, amino nitrogen content exhibited the highest correlation with sensory score. Ascorbic acid and citric acid were selected among the anti-browning agents(ascorbic acid, potassium sorbate, calcium chloride) and organic acids(citric acid, lactic acid, oxalic acid) tested on the basis of the highest amino nitrogen content during storage at 55$^{\circ}C$. The appropriate concentration of ascorbic acid was 0.03% based on amino nitrogen content during storage at 55$^{\circ}C$. Combination of 0.06% citric acid with 0.03% ascorbic acid showed the highest amino nitrogen content during storage at 55$^{\circ}C$. From the results, the 0.03% ascorbic acid and 0.06% citric acid were selected as additives for extending the shelf-life. Control(no additive) and additives(0.03% ascorbic acid and 0.06% citric acid) were tested for physicochemical and sensory analyses during storage at 45$^{\circ}C$ and 55$^{\circ}C$. Amino nitrogen content was also highly correlated with sensory score, The marginal amounts of amino nitrogen for control and additives were 174.9mg% and 173.2mg%, respectively. Degradation rate of amino nitrogen was a first order reaction. Compared to control, the predicted shelf-life for adding additives increased 69% and 56% at 45$^{\circ}C$ and 55$^{\circ}C$, respectively.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.6 no.2
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• pp.81-92
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• 2001

According to analyses of high-resolution seismic profiles (air gun, sparker, and SBP) and a deep-drill core(YSDP 105) in the mid-eastern Yellow Sea, stratigraphic and geoacoustic models have been established and seismo-acoustic modeling has been fulfilled using ray tracing of finite element method. Stratigraphic model reflects seismo-, litho-, and chrono-stratigraphic sequences formed under a significant influence of Quaternary glacio-eustatic sea-level fluctuations. Each sequence consists of terrestrial to very-shallow-marine coarse-grained lowstand systems tract and tidal fine-grained transgressive to highstand systems tract. Based on mean grain-size data (121 samples) of the drill core, bulk density and P-wave velocity of depositional units have been inferred and extrapolated down to a depth of the recovery using the Hamilton's regression equations. As goo-acoustic parameters, the 121 pairs of bulk density and P-wave velocity have been averaged on each unit of the stratigraphic model. As a result of computer ray-tracing simulation of the subsurface strata, we have found that there are complex ray paths and many acoustic-shadow zones owing to the presence of irregular layer boundaries and low-velocity layers.

• The Korean Journal of Malacology
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• v.29 no.4
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• pp.325-334
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• 2013

The purpose of this paper is to compare and analyze family variations for growth-related traits of Pacific abalone, Haliotis discus hannai. Genetic parameters and breeding values were estimated using all measurement data like shell length, shell width, and total weight as 18-month-old growth traits of 5,334 individuals of selected third generation's Pacific abalone produced in 2011. Family variations of 865 individuals of the upper 10 families with the largest number were inspected. Overall mean in phenotypic traits of 18-month-old Pacific abalone which was investigated in this study showed 54.5 mm of shell length, 36.8 mm of shell width and 21.3 g of total weight respectively. And, variation coefficient of total weight was 51.0%, so variability of data was shown to be higher than 21.1% of shell length and 20.7% of shell width. The family effects showed significant difference by each family (p < 0.05), and heritability of shell length, shell width, and total weight was medium with 0.370, 0.382, and 0.367 respectively. So it is considered that family selection is more advantageous than individual selection. On the basis of breeding values of estimated shell length and total weight, to investigate distribution and ranking by each individual about the upper 10 families with the largest number of individuals, the values were used by being changed into standardized breeding values. Based on shell length, it was investigated that the individual number of the upper 5.4% is 152 and the number of the lower 5.4% is 8. In case of total weight, it was inspected that the individual number of the upper 5.4% is 164 and the number of the lower 5.4% is 1. Like these, phenotypic and genetic diverse variations between families could be checked. By estimating genetic parameters and breeding values of a population for production of the next generation, if they are used properly in selection and mating, it is considered that more breeding effects can be expected.

• Journal of Wetlands Research
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• v.18 no.3
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• pp.301-312
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• 2016

This study has performed comparative analysis on characteristics of contaminated 35 tributaries on seasonal variation/point discharge load/pollutant distribution of water quality factors(8) in order to understand the effect of the watershed in Nakdong River Basin. As a results, the water quality of $BOD_5$(Biochemical Oxygen Demand), Chl-a(Chlorophyll a) and Fecal E. Coli shows II grade at tributaries of more than 50% without COD(Chemical Oxygen Demand), TP(Total Phosphate), TOC(Total Oxygen Carbon) and TN(Total Nitrogen) factors. The specific discharge(Q) were occupied about 54.4% (19 sites) as $0.05m^3/sec/km^2$ value. Among these results, the contaminant level of Dalseocheon, Hyeonjicheon, Seokkyocheon 1, Uriyeongcheon and Dasancheon was also high, which has to consider a discharged pollutant load(kg/day). The 35 major tributaries of Nakdong River were included in 7 mid-watershed, such as Nakdong Waegwan, Geumho River, Nakdong Goryung, Nakdong Changnyung, Nam River, Nakdong Milyang, Nakdong River Hagueon. Especially, the discharged pollutant load of Nam River and Geumho River also was high according to the amount of discharge such as Kachang dam, Gongsan dam and Nam river dam. Seasonal difference of the water quality factors such as $BOD_5$, TN, SS and Q was observed largely, on the other hand the TP and Chl-a was not. This is guessed due to the precipitation effect of site, biological and physicochemical degradation properties of pollutant and etc. The co-relationship between the seasonal difference and water quality factors was observed using a Pearson correlation coefficients. Besides, the Multiple Regression analysis using a Stepwise Regression method was conducted to understand the effect between seasonal difference and water quality factors/regression equations. As a result, the Multiple Regression analysis was adapted in the spring, summer and autumn without the winter, which was observed high at spring, summer and autumn in the order COD/TP, Chl-a/TOC, TOC/COD/$BOD_5$ water quality factors, respectively.

• Korean Journal of Plant Resources
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• v.19 no.1
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• pp.180-188
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• 2006

This study was carried out to offer the raw data on the method of cultivation and ecological characteristic by systematical analysing habitat environment of Tulipa edulis that was expected as medicinal and ornamental resource. The habitat environment was that the altitude was 245 m, the aspect of south, the size of approximately $49\;m^2$, and there was analyzed that Tulipa edulis grew wild in the dryly sunny spot. The vascular plants were summarized as 62 taxa; 28 families, 59 genera, 50 species, 11 varieties and 1 forms, and the resource plants were classified that there were 23 taxa of ornamental plants(37.1%), 43 taxa of edible plants(69.4%), 34 taxa of medicinal plants(54.8%) and 29 taxa of others(46.8%). In the results of soil factors analysis, there showed that acidity was pH 4.9, organic matter content of 4.9%, available $P_{2}O_{5}$ of 3.6 mg/kg, exchangeable $K^+$ of $0.5\;cmol^{+}/kg$, exchangeable $Ca^{2+}$ of $3.0\;cmol^{+}/kg$, exchangeable $Mg^{2+}$ of $0.8\;cmol^{+}/kg$, cation exchange capacity(C.E.C) of $12.3\;cmol^{+}/kg$ and electrical conductivity(EC) of 0.3 dS/m. In the results of correlation analysis between soil factors, exchangeable $Ca^{2+}$ and C.E.C were highly correlative. The growth characteristics of Tulipa edulis were surveyed that height was 7.6 cm, leaf width of 0.6 cm, leaf length of 12.7 cm, flower width of 2.8 cm, peduncle of 5.4 cm and chlorophyll of $34.7\;{\mu}g\;mg^{-1}$. In the results of correlation analysis between growth characteristics, height and peduncle were highly correlative. In the results of correlation analysis between soil factors and growth characteristics, exchangeable $K^{+}$ and leaf length were high relativity but they were confirmed negative relation. In the results of growth model analysis, R-square of leaf width and exchangeable $K^{+}$ was some 86.4% and that of chlorophyll and exchangeable $K^{+}$ was some 83.7%.

• Journal of Korean Society of Transportation
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• v.20 no.7
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• pp.155-166
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• 2002

Since 1990s. there has been an increasing number of traffic accidents at intersection. which requires more urgent measures to insure safety on intersection. This study set out to analyze the road conditions, traffic conditions and traffic operation conditions on signalized intersection. to identify the elements that would impose obstructions in safety, and to develop a traffic accident prediction model to evaluate the safety of an intersection using the cop relation between the elements and an accident. In addition, the focus was made on suggesting appropriate traffic safety policies by dealing with the danger elements in advance and on enhancing the safety on the intersection in developing a traffic accident prediction model fir a signalized intersection. The data for the study was collected at an intersection located in Wonju city from January to December 2001. It consisted of the number of accidents, the road conditions, the traffic conditions, and the traffic operation conditions at the intersection. The collected data was first statistically analyzed and then the results identified the elements that had close correlations with accidents. They included the area pattern, the use of land, the bus stopping activities, the parking and stopping activities on the road, the total volume, the turning volume, the number of lanes, the width of the road, the intersection area, the cycle, the sight distance, and the turning radius. These elements were used in the second correlation analysis. The significant level was 95% or higher in all of them. There were few correlations between independent variables. The variables that affected the accident rate were the number of lanes, the turning radius, the sight distance and the cycle, which were used to develop a traffic accident prediction model formula considering their distribution. The model formula was compared with a general linear regression model in accuracy. In addition, the statistics of domestic accidents were investigated to analyze the distribution of the accidents and to classify intersections according to the risk level. Finally, the results were applied to the Spearman-rank correlation coefficient to see if the model was appropriate. As a result, the coefficient of determination was highly significant with the value of 0.985 and the ranks among the intersections according to the risk level were appropriate too. The actual number of accidents and the predicted ones were compared in terms of the risk level and they were about the same in the risk level for 80% of the intersections.

• The korean journal of orthodontics
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• v.27 no.1
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• pp.65-78
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• 1997

This study was carried out in order to determine soft tissue response to incisor movement and mandibular repositioning and to determine feasibility of predicting vertical and horizontal changes in soft tissue with hard tissue movement. For this study, cephalometric records of 41 orthodontically treated adult females who had Angle's Class II division 1 malocclusion were selected and stepwise multiple regression analysis was employed. Following conclusions were obtained by analysing the changes of soft tissue and hard tissue before and after treatment. 1. Hard tissue measurements that showed significant changes before and after treatment were horizontal and angular changes of maxillary incisor, horizontal,vertical and angular changes of mandibular incisor, overjet, overbite, interincisal angle, mandibular repositioning, A,B, skeletal convexity and soft tissue measurements that showed significant changes were horizontal, thickness and angular changes of upper lip, horizontal and angular changes of lower lip, interlabial angle, nasolabial angle labiomental angle, Sri, Ss, Si and soft tissue convexity(P<0.05). 2. All Soft tissue measurements changed significantly before and after treatment had between one and four hard tissue independent variables at statistically significant level, indicating that all soft tissue changes were direct relationship with hard tissue changes 3. Ova jet, horizontal change of maxillary incisor, horizontal change of maxillary root apex and horizontal change of pogonion entered into prediction equations most frequentely indicating that they were more significant variables in prediction of vertical and horizontal changes in the soft tissue with treatment, but vertical changes of mandibular incisor not entered any prediction equations, indicating that it was not considered a good predictor for soft tissue changes with maxillary incisor retraction. 4. Horizontal and vertical changes in subnasale were found to have most independent variables, significant at the 0.05 level in prediction-equations(${\Delta}$Sn(H):Ur, Is(H), Pg(H), UIA,${\Delta}$Sn(V): Is(H), Pg(H), overjet, A), indicating that subnasale changes are influenced by complex hard tissue interaction. 5. Multiple correlation coefficient($R^2$) of the soft tissue prediction equations ranges from 0.2-0.6.

• Tuberculosis and Respiratory Diseases
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• v.40 no.5
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• pp.532-539
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• 1993

Background: Physician's estimates of patient survival often influence clinical decisions, especially those near the end of life. In addition. clinical decisions frequently reflect trade-offs between morbidity and length of survival. As a result, accurate estimates of survival can be extremely useful in clinical decision. When the episode of acute respiratory failure in chronic obstructive lung disease, evaluation of the severity of the condition and short term prognosis is difficulit based on the available clinical or paraclinical data at the time of admission. Method: In this study, we performed a retrospective study in Chung Ang University Hospital, 74 patients (51 males, 23 females), who were hospitalized with chronic obstructive lung disease with acute respiratory failure from 1980 to 1992. We evaluated these patients to determine lung prognostic factors at time of admission in the Intensive Care Unit (ICU) that predict short term survival, and to determine the possible application of the Simplified Acute Phsiology Score (SAPS) to this population, All patients were treated with similar regimen during the hospitalization. Results: The results were as follows: 1) Hospital mortality was 34%(25/74 patients) and surival rate was 66%(49/74 patients) in COPD with acute respiratory failure. The prognosis of the older age was much poorer than those of the young age. 2) There was no difference in mortality according to the results of basal pulmonary test and arterial blood gas analysis. 3) The SAPS at admission was higher in those patients who expired(10.8) than the survived(6.5), and there was positive correlation between SAPS and mortality (r=0.91, p<0.05). 4) Prognostic factors in acute respiratory failure complicating COPD which were identifiable at time of admission to the ICU were as follows: cachexia, encephalopathy, serum creatinine and phosphate. Conclusion: In conclusion, the SAPS might have a good prognostic value for determination of short term survival among chronic obstructive lung disease with acute respiratory failure.