• 한국농공학회지
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• 제19권2호
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• pp.4377-4384
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• 1977

The curvilinear hydrograph can be replaced by an equivalent triangular hydrograph which is more easily constructed and, for routing through reservoirs or stream channels, gives results about as accurate as those obtained using the curvilinear hydrograph. A synthetic hydrograph is prepared using the data from a number of watersheds to develop a dimensionless unit hydrograph applicable to ungauged watersheds. The dimensionless unit hydrograph for the NakDong River Basin was prepared from the unit hydrographs of a variety of nine subwatersheds. The equation for the peak rate of flow (unit volume of runoff in 1.0mm) was derived as {{{{ { q}_{p } = { 0.21AR} over { {T }_{p } } }}}} The results summarized in this study are as follows: 1) It found that the watershed lag time (Lg, hrs) could be expressed by Lg=0.253(L.Lca)0.4171 The product L.Lca is a measure of the size and shape of the watershed. Correlation coefficient for Lg was 0.97 which defined with high significance. 2) The base length of the unitgraph, in hours, was adopted as Tb=17.51+2.073Lg with high significant correlation coefficient, 0.92. 3) Time in hour from start of rise to peak rate (TP) generally occured at the position of 0.289 Tb with some indication of higher values for larger watershed. 4) Triangular hydrograph is a dimensionless unitgraph prepared from the 40 unitgraphs. The equation is shown as {{{{ { q}_{p } = { K.A.R} over { { T}_{p } } }}}}. The constant K=0.21 is defined to NakDong River basin. 5) In the light of the results analyzed in this study, average errors in the peak discharge of the Trjangular unitgraph was estimated as 5.34 percent to the peak of observed average unitgraph. Each ordinate of the Triangular unitgraph was approached closely to the observed one.

• 자원ㆍ환경경제연구
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• 제23권2호
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• pp.225-248
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• 2014

본 연구는 Parry and Small(2005)이 제시한 외부효과를 고려한 최적 휘발유세 추정이론 모형을 토대로 휘발유에 대한 우리나라의 최적 세율을 추정하였다. 시뮬레이션 결과, 우리나라의 최적 휘발유세는 리터당 382원으로 산출되었다. 세목별로 살펴보면, 연료소비에 따른 외부비용을 고려한 우리나라의 피구세는 미국과 영국의 피구세 대비 높으며, 그 차이는 주로 교통혼잡 비용과 교통사고 비용에 기인한다. 람지세는 아주 미미한 편인데, 이는 유류의 소비탄력성에 비해 노동 공급이 상대적으로 비탄력적인 데 기인한다. 단, 연구 모형의 한계상 교통에너지 환경세와 지방주행세의 합 추정에만 초점을 두었으며, 복잡한 우리나라의 유류세 구조를 모두 반영하지 못하였다는 점을 명시한다.

• 분석과학
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• 제23권6호
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• pp.551-559
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• 2010

본 연구는 칼럼 전 유도체화와 HPLC-형광검출을 이용해 염소 소독 음용수 중 7가지 nitrosamine 화합물을 분석하는 방법을 추출 과정(액-액 추출 vs. 고상 추출)과 형광 유도체화 과정(denitrosation 및 dansylation)으로 나누어 평가하여 확립하였다. 최적화된 유도체화 방법으로 두 가지의 추출법을 비교하였을 때, Ambersorb 572를 이용한 고상 추출에 대한 회수율과 재현성(상대표준편차, RSD)이 각각 54.4-88.7%와 1.9-19.4%로 액-액 추출의 51.4-87.7%와 4.2-33.3%에 비해 더 좋게 나타났다. 확립된 방법은 기존의 HPLC를 이용한 분석 방법에 비해 회수율과 재현성 모두 개선되었으며, 방법검출한계(method detection limits, MDLs)는 0.5-4.4 ng/L이었다. 이 방법으로 춘천의 염소로 소독하는 두 곳의 정수장과 10 곳의 수도꼭지에서 채취한 물 시료 중 nitrosamine 화합물을 분석한 결과, N-nitrosodimethylamine (NDMA)이 주요 화합물이었으며, 농도 범위는 26.1-112 ng/L이었다.

• 한방재활의학과학회지
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• 제23권2호
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• pp.73-83
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• 2013

Objectives : This study was performed to investigate the effects of Foeniculum Vulgare(FV) extract on the anti-inflammatory of lipopolysaccharide(LPS) exposed rats. Methods : We divided LPS exposed Sprague-Dawley rats into 4 groups. They were control group, feed with 100 mg/kg, 200 mg/kg, 300 mg/kg FV groups. They were administered for 6 weeks. We measured the concentration of plasma interleukin-1${\beta}$(IL-1${\beta}$), plasma interleukin-6(IL-6), plasma tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), plasma interleukin-10(IL-10), the concentration of liver IL-1${\beta}$, IL-6, TNF-${\alpha}$ and IL-10. Results : 1. Plasma IL-1${\beta}$, plasma IL-6 and plasma TNF-${\alpha}$ concentration increased rapidly at 2hours after LPS injection and maintained high levels at 5hours after LPS injection. The concentration of these cytokines in the FV extract groups showed lower values than control group(P<0.05). 2. The concentration of Plasma IL-10 in FV extract groups showed higher values than control group at all times(P<0.05). 3. The concentration of liver IL-1${\beta}$ and IL-6 in FV extract groups showed lower values than control group(P<0.05). The concentration of liver TNF-${\alpha}$ in FV extract groups showed a tendency to decrease and that of liver IL-10 in FV extract groups showed a tendency to increase; however, these values showed no significantly different. Conclusions : In inflammatory response by LPS derivation, the FV gives positive effect.

• 한국물환경학회지
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• 제31권2호
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• pp.151-158
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• 2015

The aim of this research is to derive an optimum operating condition for the thermal solubilization equipment that is employed to increase concentration of soluble organic materials and to assess whether it would be possible to use the waste sludge generated by thermal solubilization reaction as an external carbon source in biological denitrification process. For the purpose, we have constituted a laboratory-size thermal solubilization equipment and have assessed thermal hydrolysis efficiency based on various reaction temperature and reaction time. We have also derived SDNR using the waste sludge generated by thermal solubilization reaction through a batch experiment. As a result of research, the highest thermal hydrolysis efficiency of about 42.8% was achieved at $190^{\circ}C$ of reaction temperature and at 90 minutes of reaction time. And when SDNR was derived using the waste sludge, the value obtained was $0.080{\sim}0.094\;g\;NO_3{^-}-N/g\;MLVSS{\cdot}day$, showing SDNR that is higher than that obtained by the results of existing researches that used common wastewater as an external carbon source. Accordingly, in view of the fact that food wastes vary quite a bit in characteristics based on the area they are generated from and seasonal change, it seems that a flexible operation of thermal solubilization equipment is required through on-going monitoring of food wastes that are imported to food wastes recycling facilities.

• Molecules and Cells
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• 제25권3호
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• pp.358-367
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• 2008

The embryonic germ cell (EGCs) of mice is a kind of pluripotent stem cell that can be generated from pre- and post-migratory primordial germ cells (PGCs). Most previous studies on DNA methylation of EGCs were restricted to 12.5 days post coitum (dpc). This study was designed to establish and characterize murine EGC lines from migrated PGCs as late as 13.5 dpc and to estimate the degrees of methylation of their imprinted genes as well as of the non-imprinted locus, Oct4, using an accurate and quantitative method of measurement. We established five independent EGC lines from post migratory PGCs of 11.5-13.5 dpc from C57BL/6 ${\times}$ DBA/2 F1 hybrid mouse fetuses. All the EGCs exhibited the typical features of pluripotent cells including hypomethylation of the Oct4 regulatory region. We examined the methylation status of three imprinted genes; Igf2, Igf2r and H19 in the five EGC lines using bisulfite genomic sequencing analysis. Igf2r was almost unmethylated in all the EGC lines irrespective of the their sex and stage of isolation; Igf2 and H19 were more methylated than Igf2r, especially in male EGCs. Moreover, EGCs derived at 13.5 dpc exhibited higher levels of DNA methylation than those from earlier stages. These results suggest that in vitro derived EGCs acquire different epigenotypes from their parental in vivo migratory PGCs, and that sex-specific de novo methylation occurs in the Igf2 and H19 genes of EGCs.

• 자원환경지질
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• 제29권6호
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• pp.689-698
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• 1996

The coal-bearing metapelites from the Hoenam area are interbedded within the Ogcheon Supergroup, which are composed mainly of graphite, quartz, muscovite and associated with trace amount of biotite, chlorite, pyrite, rutile and barite. Although the formation was mined for coal, and the contents of V, U and Mo are a higher grade in coal formations than the host metapelites. The ratios of Al/Na and K/Na in coal formation are very heterogeneous and wide range from 10.28 to 90.91 and from 3.73 to 36.60, respectively. The V content increase with increasing Al and Ba contents, but the U and Mo are not related with other elements. Those are suggested that controlled of mineral compositions in coaly metapelites due to substitution, migration and reequilibrium of elements by regional metamorphism. These coal formation were deposited in basin of marine environments and the REE of these rocks are not influenced with metamorphism and hydrothermal alterations on the basis of Al content versus La, La against Ce, the ratios of La/Ce (0.23 to 0.73) and Th/U (0.03 to 16.6). These rocks also show much variation in $La_N/Yb_N$ (0.53 to 14.19), Th/Yb (0.51 to 6.00) and La/Th (0.15 to 18.92), and their origin is explained by derivation from a mixture of sedimentary and metasedimentary rocks. The wide range in trace and REE element characteristics as Co/Th (0.07 to 3.00), La/Sc (0.04 to 23.48), Sc/Th (0.06 to 7.57), V/Ni (2 to 3319), Cr/V (0.03 to 1.06) and Ni/Co (1.00 to 79.85) of these coaly metapelites argues for inefficient mixing of the various source lithologies during sedimentation.

• 농촌계획
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• 제26권2호
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• pp.39-49
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• 2020

This study was attempted to grasp the push-pull factors of urban to rural migrants in relation to services and infrastructure of rural welfare and culture. Online and offline survey were conducted for urban residents who were willing to return to the rural area and those who were already returning to the rural area. In the fields of health care, social welfare, and education, it was found that the satisfaction level of urban-to-rural migrants was relatively higher than those of latent urban-to-rural migrants. In the field of culture, leisure and sports, the level of satisfaction and concern were similar, so it was found that the expectations for the field were relatively high before returning rural area. As for the agreement degree to expand support, the demand for emergency medical facilities and dementia care program was the highest, and the demand for health care was found to be relatively high. The results of the survey on the top priority items indicate that latent urban-to-rural migrants require support of facility and space item and expansion of program item, and urban-to-rural migrants have high demand for expansion of program item in all field except healthcare field. The results of this study are expected to provide useful information for establishing the direction of the rural area development project in connection with the revitalization of policy of people return to rural area.

• 한국수자원학회논문집
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• 제35권3호
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• pp.285-294
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• 2002

침투는 수문 순환에서 물의 분배를 결정하는 중요한 과정 중의 하나이며, 이에 대해 다양한 이론들과 방법들이 제시되었으나 이들은 주로 침투능보다 큰 강우에 대해서만 적용이 가능하였다. Diskin과 Nazimov (1975, 1996)의 연구에서는 두 개의 요소로 구성된 개념적 침투 모형을 제시하여 단순히 시간의 함수로서 침투를 나타내는 것보다 합리적으로 침투 과정에 접근하였다. 본 연구에서는 이러한 침투 과정에서 초기 함수량을 추가적으로 고려하여 기존의 개념적 침투 모형을 개선하였다. 다양한 초기 함수량 조건에 대해 침투능 곡선의 변화를 분석한 결과 본 모형에 의해 보다 합리적으로 침투 과정에 접근할 수 있음을 판단할 수 있었다. 또한 다양한 토양형에 대해 호우 사상-수막 시간의 관계를 고찰한 결과 침투 과정에 대한 본 모형의 적용성이 상당히 높게 나타남을 알 수 있었다.

• 한국융합학회논문지
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• 제10권3호
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• pp.23-30
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• 2019

본 연구는 당뇨병 치료제 후보약물 정보를 이용하여 항당뇨에 영향을 미치는 물질구조를 발견하는데 목적이 있다. 정량적구조 활성관계를 이용한 기계 학습 모델을 만들고 부분최소자승 알고리즘을 통해 실험데이터 별로 결정계수를 파악한 후 변수중요도척도를 활용하여 주요 분자표현자를 도출하였다. 연구 결과, 후보약물 구조정보를 반영한 molecular access system fingerprint 데이터로 분석한 결과가 in vitro 데이터를 이용한 분석 결과보다 설명력이 높았으며, 항당뇨에 영향을 미치는 주요 분자표현자 역시 다양하게 도출할 수 있었다. 제안된 항당뇨 예측 및 주요인자 분석 방법을 활용한다면 유사한 과정을 반복 실험하는 기존 신약개발 방식과는 달리, 많은 비용과 시간이 소요되는 후보물질 스크리닝 (screening) 기간을 최소화하고, 신약개발 탐색기간도 단축하는 계기가 될 수 있을 것으로 기대한다.