• Journal of Korea Water Resources Association
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• v.56 no.12
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• pp.871-881
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• 2023

This study investigates the geomorphic changes and Bed Relief Index of the river downstream of the Yeongju Dam by Nays2DH, a two-dimensional numerical model, in order to grasp the dynamics of the downstream river while applying various flow patterns such as pulse discharge. It shows that the geomorphic and the bed elevations changes are the largest under the condition of the normalized pulse discharge. The total change in the riverbed is 29.88 m for uniform flow, 27.46 m for normalized hydrograph, 29.63 m for pulse flow and 31.87 m for pulse flow with normalized hydrograph which result in the largest variation in scour and deposition. The Bed Relief Index (BRI) increases with time under conditions of uniform flow, pulse flow and pulse flow with normalized hydrograph. However, BRI increased rapidly until 30 hrs after the peak flow (14 hrs), but decreased from 56 hrs under the condition of normalized hydrograph. Therefore, the condition of normalized hydrograph gives greater dynamics than the condition of a single flood or constant flow, and the dynamics increase downstream than upstream, resulting in an effect on improving the environment of the river downstream of the dam.

• Korean Journal of Ecology and Environment
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• v.43 no.2
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• pp.307-318
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• 2010

This study was to analyze the ecological conditions, based on physical habitat, chemical, and biological conditions before (2006, 2007) and after ecological restoration (2009) in five sites of Changwon Stream (CS) and six sites of Nam Stream (NS), respectively, and then to compare ecological health between the two period. The analysis of ecological health was based on the multimetric models of Index of Biological Integrity (IBI) and Qualitative Habitat Evaluation Index (QHEI) along with water chemistry in the streams. For the study, the models of IBI and QHEI were modified as 8 and 11 metric attributes, respectively. For the evaluations, the survey was conducted in the period of 2006~2007 before the restoration and in 2009 after the restoration by the city. Chemical conditions, based on conductivity, in both streams showed a typical longitudinal declines along the axis of the upstream-to-downstream. There were no significant differences (p>0.05) in water quality between the two periods. Values of IBI in the CS and NS averaged 21.6 and 19.7, respectively, indicating a C grade in the criteria of Ministry of Environment, Korea, and there was no significant differences in the IBI between the two periods. Values of QHEI after the restoration averaged 29.2 and 63.2 in the CS and NS, respectively and the values decreased markedly especially, in the NS (35.3) after the restoration. The habitat disturbance was mainly attributed to destructions (i.e., the narrower width of riparian vegetation and higher substrate exposure by the air) of artificial materials by massive flood in 2009. Overall, our results suggest that the restoration was not effective in the two streams between the two periods, even if the budget was used a lot and that such ecological restoration, not considered the natural disaster, may not effect for the stream restoration.

• Korean Journal of Ecology and Environment
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• v.42 no.2
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• pp.260-269
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• 2009

Hwabuk Dam has been under construction to reduce flood damage in Nakdong River watershed and to supply stable water for middle area of Gyeongbuk Province. Therefore, fish investigation in up and downstream of the dam was conducted from 2004 to 2008 in order to determine any negative effect on fish community due to dam construction and to use as fundamental data for conserving species diversity and maintaining stream health. According to data analysis on water quality, temperature, dissolved oxygen, pH, suspended solids, and total E-coli had seasonal variation, but they did not significantly differ in sites. However, biological and chemical oxygen demand, chlorophyll-a, nitrogen, and phosphorus representing organic matter and nutrient concentration were higher in upper site and decreased to lower site so that they differed by site. Concentration of arsenic among the heavy metals was less than 0.05 mg $L^{-1}$, which is regulated for protection of human health in water quality standard, except for 0.092 mg $L^{-1}$ in June 2005. During the study period, the total number of fish caught from the 6 sites was 10,263 representing 7 families 19 species. Among them, dominant and subdominant species were Korean chub (Zacco koreanus, 62.5%) and Chinese minnow (Rhynchocypris oxycephalus, 10.6%) which inhabit mostly in mid and upper streams, Korea. Among the 19 species, Korean endemic species were 9 species (47.4%) including Korean slender gudgeon (Squalidus gracilis majimae), Korean dark sleeper (Odontobutis platycephala), and Korean shiner (Coreoleuciscus splendidus). There was several individuals of the $1^{st}$-class endangered species, Naktong nose loach (Koreocobitis nahtongensis), caught in 2005${\sim}$2007, and no introduced species of fish was found in entire sampling period. According to result of community analysis, dominance index decreased toward lower site, but diversity and richness indices increased toward lower site. The equation of length-weight relationship on the dominant species was TW=0.000003$(TL)^{3.2603}$. The parameter b in the equation was greater than 3.0 indicating good nutritional condition in the populations. Compared to populations of Korean chub in other streams, the population in Hwabuk Dam watershed had higher mean of condition factor by size indicating better growth rate. With fish fauna and multi-metric health assessment model in each sampling attempt, index of biotic integrity (IBI) was evaluated and it resulted mostly in good (26${\sim}$35) and excellent (36${\sim}$40) condition in all sites, and the mean of IBI was the highest in site 5. The results indicate that it is very important to study not only environmental impact assessment with fish composition but also stream health assessment in order to conserve healthy aquatic ecosystem.

• Journal of Korean Society of Forest Science
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• v.79 no.2
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• pp.187-195
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• 1990

The following conclusions have been obtained with special reference to the walnut marketing system in Cheonwongun districts 1. The marketing channel of walnut in the producing areas was mainly depended on the individual selling by 89.58%. and sale through farmer's coops and forest owner's association by 10.42%, and share of walnut through fatmer's coops was 84.58%. 2. The market structure in assembling stage of walnut can be represented as oligopoly considering the market share of 86.26% derived by CR3 method. 3. Direct selling from producers to consumers would be recommendable to reduce marketing margin considering the 77.20% of sale's dependency on assembler-commisioner. 4. Two major reasons to follow the marketing channel of assembler-commissioner were the convieniency (45.00%) and dealing with small quantity of walnut (20.00%). Let the walnut producers follow the institutional marketing channels such as farmer's coops and forest owner s association, special actions including better conveniency, smaller quantity and the procedures should be improved. 5. Farmer's share of walnut was estimated as 54.93% and total marketing margin was 45.0% of which 36.70% destined to the retail stage. 6. The price index in November was the lowest(83.63) due to the flood and hunger sale and the index in April was the highest(115.74). To cope with the severe price fluctuation and to stabilize seasonal walnut price, sale's in advance, credit supply and provision of storage facilities must be considered in policy-making decision for forest farmers.

• Journal of Nutrition and Health
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• v.35 no.4
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• pp.414-420
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• 2002

The effects of Cordyceps militaris on weight gain, flood intakes, flood efficiency ratios, serum and hepatic lipid concentrations, serum protein levels and serum enzyme activities, were studied in adult male rats. Sprague-Dawley rats, 35 weeks old, were given four different types of diets for a succeeding period of five weeks: either a normal diet(5% com oil), a high fat diet(5% com oil + 15% lard). a CF diet (high fat diet + 3% Suiting body of cordyceps militaris), or a CM diet (high fat diet + 3% mycelium of cordyceps military). The body weight gains, hepatic weights and food efficiency ratios of the rats find (high fat) diets with CF and CM were significantly decreased compared with those find the high fat diet, but were similar to those find the normal diet. The concentrations of serum and hepatic triglycerides, and hepatic total lipids and cholesterol, of rats given CF or CM diets were significantly lower than those given the high fat diet. But the concentrations of total cholesterol, HDL-cholesterol, phopholipid and total protein in the serum of rats find the high fat, CF or CM diets were significantly higher than those find the normal diet. In the serum of the rats find the CF diet, the HDL-cholesterol/total cholesterol ratio was significantly higher but the atherogenic index was significantly lower than those fed the high fat diet. The alkaline phosphatase activity in the serum of the rats find the high fat, CF, and CM diets was more significantly decreased compared to rats on the normal dirt. No differences were noted in the weights of the pancreas, kidney and heart, the serum concentrations of glucose, hemoglobin and albumin, and the activities of GOT, GPT and ${\gamma}$-GTP, among the rats on all the experimental diets. In conclusion, the rats find the Cf or CM diets maintained normal body and hepatic weights. Despite of the high intake of fats in the CF and CM diets, the concentrations of total lipids, cholesterol and triglycerides were decreased in the liver, also, the concentration of triglycerides was decreased in the serum.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1492-1496
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• 2006

수공구조물의 설계에 있어 가중 중요한 변수 중에 하나가 확률 강우량이다. 우리나라의 경우 매개변수적인 지점빈도해석을 통해 확률 강우량을 산정하고 있으나, 최근 들어 지점별 관측자료의 부족으로 인한 지역빈도해석을 수행하여 확률강우량을 산정하고 있는 실정이다. Index Flood 기법이나 L-moment 기법과 같은 기존의 지역빈도해석은 여러 관측 지점에서 관측된 강우자료를 이용하여 매년최대 시간강우량 자료를 추출하여 동질성 분석을 통해 이질성이 없는 것으로 분석된 연최대 강우량을 빈도해석 하여 확률 강우량을 결정한다. 그러나 이와 같은 지역빈도해석은 매개변수적 지점빈도해석과 마찬가지로 적합도 검정에 통과한 다수의 분포형이 선정되는 경우에 어떤 분포형을 사용하느냐 하는 문제점이 발생할 수 있다. 그리고 선정된 여러 강우 관측 지점의 연최대 강우량 자료에 모두 동일한 확률 분포형을 이용하므로 선정된 확률 분포형이 모든 지점의 강우 자료와 적합하지 못할 가능성을 내포하고 있으며, 또한 수문자료가 여러가지 요인으로 인하여 복합분포(mixed distribution)형태를 가질 때, 매개변수적 해석방법으로는 다중 첨두를 갖는 확률밀도함수를 해석하는데는 여러 가지 어려움이 따른다. 따라서 이러한 매개변수적 확률분포형을 이용한 빈도해석의 문제점을 해결할 수 있는 비매개변수적 빈도해석이 하나의 대안으로 제시될 수 있다. 본 연구에서는 강우자료의 선별을 통해 신뢰성 있는 자료를 구축하고, 기존의 매개변수를 갖는 확률 분포형을 이용한 지역빈도해석을 적용하여 확률 강우량을 산정하였다. 그리고 동질성분석을 통해 선정된 강우자료에 대해 비매개변수적 지역빈도해석을 적용하여 확률 강우량을 산정하고 각각의 방법에 대한 빈도해석 결과를 비교하여 확률강우량 해석에 있어 하나의 대안을 제시하고자 한다.X>${\mu}_{max,A}$는 최대암모니아 섭취률을 이용하여 구한 결과 $0.65d^{-1}$로 나타났다.EX>$60%{\sim}87%$가 수심 10m 이내에 분포하였고, 녹조강과 남조강이 우점하는 하절기에는 5m 이내에 주로 분포하였다. 취수탑 지점의 수심이 연중 $25{\sim}35m$를 유지하는 H호의 경우 간헐식 폭기장치를 가동하는 기간은 물론 그 외 기간에도 취수구의 심도를 표층 10m 이하로 유지 할 경우 전체 조류 유입량을 60% 이상 저감할 수 있을 것으로 조사되었다.심볼 및 색채 디자인 등의 작업이 수반되어야 하며, 이들을 고려한 인터넷용 GIS기본도를 신규 제작한다. 상습침수지구와 관련된 각종 GIS데이타와 각 기관이 보유하고 있는 공공정보 가운데 공간정보와 연계되어야 하는 자료를 인터넷 GIS를 이용하여 효율적으로 관리하기 위해서는 단계별 구축전략이 필요하다. 따라서 본 논문에서는 인터넷 GIS를 이용하여 상습침수구역관련 정보를 검색, 처리 및 분석할 수 있는 상습침수 구역 종합정보화 시스템을 구축토록 하였다.N, 항목에서 보 상류가 높게 나타났으나, 철거되지 않은 검전보나 안양대교보에 비해 그 차이가 크지 않은 것으로 나타났다.의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전거래전략을 활용하는 경우 주식투자기간은 24개월이하의 중단기가 적합함을 발견하였다. 이상의 행태적 측면과 투자성과측면의 실증결과를 통하여 한국주식시장에 있어서 시장수익률을 평균적으로 초과할 수 있는 거래전

• Journal of Community Nutrition
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• v.3 no.2
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• pp.96-102
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• 2001

A cross-sectional study was performed to estimate the nutritional status of Korean male lead workers and to assess the relationship between calcium nutritional status and blood lead levels. A flood consumption survey was conducted by the 24-hr recall method with 118 lead workers and 63 non-lead exposed controls. Blood lead levels were analyzed from whole blood and serum calcium concentrations were also assessed. Results of dietary analysis showed Korean lead workers consumed relatively sufficient nutrients (more than 75% of RDA) except, calcium. Mean dietary calcium intake of lead workers was 502.2mg(72% of RDA) while that of the non-lead workers was estimated as 600.8mg(86% of RDA). Intakes of protein, iron, niacin and vitamin C of lead workers were significantly lower than those of non-lead workers. There was a wide range of blood lead levels(5.5 to 73.5$\mu\textrm{g}$/㎗) observed while mean blood lead level of lead workers was 30.9$\mu\textrm{g}$/㎗. However, 98% of lead workers showed normal serum ca1cium concentrations (range ; 8.9 to 10.7mg/㎗, mean ; 9.77mg/㎗) while 66% of lead workers were estimated to intake a dietary calcium lower than 75% of RDA. Mean blood lead levels of non-1ead workers were significantly lower(mean ; 5.1$\mu\textrm{g}$/㎗, p ＜ 0.001) and the serum calcium concentration was significantly higher(mean ; 10.20mg/㎗, p ＜ 0.001) than lead workers. Results of unadjusted correlation showed that serum calcium level and dietary calcium intake were negatively correlated with blood lead concentration. In a multiple regression of blood lead levels with variables known as affecting blood lead 1eve1 such as age, body mass index and occupational lead exposure, serum calcium was insignificant while dietary calcium intake showed statistically significant(p ＜ 0.05) relation. Since calcium is a very important nutrient to reduce hazardous effects of lead, it should be strongly recommended that lead workers need to increase dietary calcium intake.

• Ecology and Resilient Infrastructure
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• v.2 no.4
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• pp.274-283
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• 2015

The reservoir shores seem to be vulnerable to biological invasion. The purpose of this research was to find out the floristic composition of alien plants and their relationship between environmental factors on reservoir shorelines in Korea. We investigated flora of alien plants and environmental factors of geomorphology, hydrology, water quality and soil on the shoreline of a total of 35 reservoirs with different water level managements. There were 56 species of alien plants, which was 15% of the total plant species identified in the study of reservoirs. A total of 57% of these alien species were the species which were introduced shortly after opening the port from 1876 to 1921 in Korea. More than 80% of the alien plants on the reservoir shores originated from America and Europe. The current distribution of Ambrosia trifida and Paspalum distichum were restricted in the central part and the southern region of the Korean Peninsula, respectively. The water level fluctuation, flood frequency at the median water level, water pollution index, coverage of rock exposure and mean degree of shoreline slope were determined as important environmental factors that have an effect on the characteristics of shoreline alien flora. Our results suggest that the reservoir shore was in danger of being invaded by alien plants due to the water level management and other human disturbances. For effective conservation of the reservoir ecosystem, periodic monitoring systems are required for the early detection of alien species on the reservoir shore.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.542-550
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• 2020

A stream serve the functions of different water utilization, flood control, and the environment, and contributes to the development of national life and culture. On the other hand, it is difficult to efficiently evaluate various projects, such as effectiveness verification and comparison between projects, because the evaluation procedures and evaluation techniques of projects are not uniform and different for each institution. Therefore, a standardization technology was developed for a post-assessment of stream projects that can recognize stream problems and comprehensively evaluate stream-related projects. To this end, various projects, such as project evaluation techniques, national R&D projects, and social welfare projects, were compared and analyzed, and the standardization stages of the project were first suggested. In addition, based on the standardization stage, the evaluation indices for each stage were derived to develop an evaluation table that can evaluate stream-related projects comprehensively. Finally, it is possible to prevent the repeated use of failure factors in the planned projects.

• Korean Journal of Remote Sensing
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• v.27 no.5
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• pp.601-611
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• 2011

Land cover changes are occurring for a variety of reasons such as urbanization, infrastructure construction, desertification, drought, flood, and so on. Many researchers have studied the cause and effect of land cover changes, and also the methods for change detection. However, most of the detection methods are based on the dichotomy of "change" and "not change" according a threshold value. In this paper, we present a change detection method with the integration of probability, spatial autocorrelation, and hotspot detection. We used the AMOEBA (A Multidirectional Ecotope-Based Algorithm) and developed the AMOEBA-CH (core hotspot) because the original algorithm tends to produce too many clusters. Our method considers the probability of land cover changes and the spatial interactions between each pixel and its neighboring pixels using a local spatial autocorrelation measure. The core hotspots of land cover changes can be delineated by a contiguity-dominance model of our AMOEBA-CH method. We tested our algorithm in a simulation for land cover changes using NDVI (Normalized Difference Vegetation Index) data in South Korea between 2000 and 2008.