• 한국수자원학회논문집
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• 제55권5호
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• pp.357-370
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• 2022

본 연구는 공공하수처리시설의 다양한 운영방식(직영, 공공 위탁, 민간 대행)에 따른 성과의 차이를 분석하고 연구 결과를 토대로 국민에게 가장 효율적이고 높은 수준의 하수처리 서비스를 제공할 수 있는 운영방식과 개선방안을 도출하고자 하는 목적을 가진 연구이다. 이를 위해 경제적 성과지표(하수처리 비용, 하수도 요금)와 사회적 성과지표(수질, 민원 수)를 선정하여 횡단 분석(cross-section data)과 종단 분석(longitudinal analysis)의 방법으로 세 집단 이상의 평균 차이 검증을 일원분산분석(ANOVA)을 통해 실시하였다. 분석 결과 횡단 분석에서의 경제적 성과 차원에서는 운영방식에 따라 차이가 나타나지 않았으나, 사회적 성과 차원에서는 운영방식별로 차이가 나타나는 것을 알 수 있었다. 수질 지표의 경우 공공 위탁에서, 민원 발생 건수에서는 민간 대행에서 직영 대비 우수한 성과를 보이고 있었다. 종단 분석에서는 대부분 성과지표에서 운영방식별로 유의미한 차이가 나타나지 않았다. 따라서 공공서비스의 효율성 제고와 서비스 수준 제고를 위해서는 공공 위탁이나 민간 대행 도입 논리 외에 서비스별 특성에 맞는 다양한 접근이 요구된다고 하겠다. 아울러 향후 지자체가 하수도 위탁을 추진한다면 서비스의 성격과 지자체별 특수성, 서비스 이용자의 니즈 등을 잘 파악하여 추진하는 것이 필요하다.

• 한국환경과학회지
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• 제23권9호
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• pp.1537-1549
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• 2014

The objectives of this study were to analyze reservoir trophic state, based on Trophic State Index (TSI), spatial variation patterns of three zones (riverine, transition, and lacustrine zone), and empirical models through 20-years long-term data analysis. Trophic variables of TP and CHL-a were highest during the summer monsoon, and decreased along the main axis from the riverine to lacustrine zone. In the mean time, TN did not show the trend. Ratios of N:P and Secchi disc transparency (SD) increased from the riverine to lacustrine zone. The analysis of trophic state index (TSI) showed that mean TSI (TP) and TSI (CHL-a) were 62 and 57, respectively, and these values were highest in the transition zone during the summer. This zone should be managed well due to highest lake water pollution. The analysis of Trophic State Index Deviation (TSID) showed that algal growth was primarily limited by light penetration, and this was most pronounced in the monsoon season. The analysis of empirical models showed that the value of $R^2$, based on CHL-SD model, was 0.30 (p < 0.0001) in the transition zone and the $R^2$, based on TP-SD model, was 0.41 (p < 0.0001) in the transition zone.

• 기술사
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• 제30권4호
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• pp.99-116
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• 1997

In order to obtain safe drinking water, free from surface contamination, a study to determine the potential for developing a bank-filtrate system in the Iryong and Yongsan, Nakdong River Basin, Korea was conducted. The main type of aquifer In the study area is alluvial, consisting mostly of sand and gravel. The hydraulic conductivity(k) of the Iryong and Yongsan test areas were 8.63${\times}$10$^-2$cm/s and 9.90${\times}$10$^-2$cm/s, respectively, indicating that these areas are satisfactory for bank filtrate production. Pilot plants(IRPL and YSPL) were set up In Iryong and Yongsan to monitor the change in the quality of bank-filtered water and to determine the effect pumping had on the surrounding hydrogeologic system. The pilot plants operated continuously for about two months and the data obtained were used to validate the groundwater flow model. Computer simulations were conducted to predict the effects of producing bank filtrate using MODFLOW. MODPATH was also linked with the flow model to analyze particle tracking. According to the results of the model simulations and the hydrogeologlc study, long-term pumping, the minimization of drawdown and the availability of uncontaminated sell and groundwater conditions for the catchment area were all Important factors for successful bank-titrate system development.

• 한국항해항만학회지
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• 제34권9호
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• pp.711-718
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• 2010

Redevelopment of the domestic small fishing ports is being started in earnest by applying the environmentally friendly technology in order to attract tourists. For the purpose of improving water quality in the harbor, selection of breakwater type might have the priority to secure calmness and stability. Therefore, this study is to determine the hydraulic characteristics of reflective ratio, installation efficiency and stability of the special type of blocks through the hydraulic model experiment. The results were introduced to analyze for the effect of infield construction work through numerical analysis. Gujora, a small fishing port in southern Korea, is affected by the waves of SSE, S, SSW direction and strong tidal currents. The results of applying cylindrical slit block show that stability of the blocks and harbor calmness were secured. Considering that the pass rate of a long period wave is still excellent, the primary objective of wave control and the secondary objective of improving water exchange are satisfied simultaneously.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2005년도 학술발표논문집
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• pp.673-678
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• 2005

The objective of this paper is to develop the microorganism concentration simulation model for the health related effect analysis while farmers and water managers reuse the wastewater for agricultural irrigation. This model consists of the CE-QUAL-R1 model and the CREAMS-PADDY model. The CE-QUAL-R1 model is the 1-D numerical model to analyze the water quality of the reservoir and the CREAMS-PADDY model is modified from CREAMS model for considering the hydrologic cycles in paddy field. This model was applied to examine the application by the observed data from 2003 in Byoungjum study area. From this research, the average root mean square error (RMSE) for the simulated concentration during the calibration period was 0.51 MPN/100ml and correlation coefficient $(R^2)$ was 0.71. And the RMSE for the simulated concentration during the verification period was 0.46 MPN/100ml and $R^2$ was 0.73. This simulation results show that the coliform inflow concentrations by the wastewater irrigation wield great influence upon the temporal coliform concentrations in paddy field.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2006년도 춘계학술논문 발표대회 제6권1호
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• pp.23-26
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• 2006

The study about the concrete to use recently a light weight aggregate, processed actively. And concrete pumping with a high pressure pump has been popularized, the mechanical development, such as high pressure pumps or pipes, is progressing rapidly. Concrete placing by pumping has the advantage of the reduction of the construction period with workability, easiness of work and the increase of placing, but the quality variation of concrete is caused by pumping is seldom considered, including the increase of the pipe length by high-rising and large-sizing, there by the loss of the unit quantity of water, with pumpability or workability deteriorated. In this research, we will compare and analyze before pumping and after pumping samples of ready-mixed light weight concrete. The result of study as follow. The case of a light weight concrete which the low slump is more decrement compared with high slump light weight concrete in after pumping samples. After pumping the water by pressure of a pump was absorbed to the aggregate inside, and it showed an increase of compression strength about $5{\sim}20%$.

• Journal of Pharmaceutical Investigation
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• 제30권3호
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• pp.219-222
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• 2000

The purpose of this research was to investigate the general properties and main ingridients of Hwangtoh, which is the Korean loess. It is well known as a raw material of pottery shown to be widely scattered on the earth, especially in Korea. It belongs to primary clay that was found to be rich on mountain surface or field. In this study, XRF Spectral method was employed to analyze the chief ingredients of Hwangtoh, being found to consist of $43{\sim}50%\;SiO_2,\;2{\sim}34%\;Al_2O_3,\;2{\sim}3%\;Mg,\;2{\sim}3%\;Na\;and\;1{\sim}2%\;K$. The ferric oxide contents of Hwangtoh from San Chung, Ha Dong, Ko Ryung, Ouk Chong, Bang Gae and Song Kwang were 6.46, 7.96, 11.26, 9.36, 9.06 and 9.28 %, respectively. The general characteristics of Hwangtoh from different places were studied by determining the content of water and the capacity to maintain temperature. Based on the above results, Hwangtoh could be said to have better quality than primary clay of Kaolin dose, and also would be able to find an application in construction formulations.

• 한국실내디자인학회논문집
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• 제18권1호
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• pp.108-116
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• 2009

As an aging society accelerates its pace for the present, providing a pleasant environment to nursing homes is such an environmental requirement with which elderly people could improve their quality of life and even acquire the effects of healing. As an optimal element of ensuring amenity, nature is a general hospital that heals human beings physically and mentally. In this vein, the investigator drew out the frame of analysis, namely emotional/healing/relating amenity, by means of theoretical examination of such natural elements as water, light, soil/stone, and plant. And on the basis of the drawn amenity, the investigator examined the application of natural elements to study subjects in order to analyze the ensured amenity. Study findings show that the existing nursing homes have ensured healing amenity sufficiently, but they are unsatisfactory in ensuring emotional and relating amenity. Based on interview survey, the investigator suggests that the introduction of natural elements into nursing homes such public space as mediation space, interaction space, and rest places to ensure emotional/healing/relating amenity must be ideally equipped with the formation of outdoor forest in which water, light, soil/stone, and plant get joined together, rather than Introducing a single element respectively. In addition, the plan of construction of nursing homes must take residing elderly people's emotional/healing/relating amenity into account on the basis of physical amenity.

• 한국지하수토양환경학회지:지하수토양환경
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• 제12권2호
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• pp.9-19
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• 2007

본 연구는 하상인공구조물에 의해 유도되는 지하수-하천수 시스템의 상호작용을 지하수 순환을 중심으로 연구하였다. 연구지역은 충청남도 금산군 남이면 건천리의 남이휴양림으로 연구의 목적을 달성하기 위해 수리물리적 방법(수위관측)과 수리화학적 특성(pH, EC, 주 이온분석)을 분석하였으며, 이들 자료간의 연관성을 파악하기 위해서 상호상관분석을 실시하였다. 수리물리적 방법에 의한 연구결과 하상 보 수평부의 BH-14의 수위변동은 다른 지하수관정과 비교 할 때 이중퇴행양상이 빈번하게 나타났으며, 그 폭도 크게 나타났다. 또한, 수리화학적 방법에 의해 얻은 결과를 자연추적자의 개념으로 사용해 보면 지하수인 BH-14가 하천에 유사한 성향을 나타내었다. 상관성분석결과에서 수리물리적 측면인 수위에 대한 상관성분석에서 BH-14와 하상 보에서 가장 높게 나타났으며, 반면 수리화학적 측면에 대한 상관성분석에서는 하상 보와 다리의 상관성이 가장 높게 나타났다. 이는 수위와 같은 물리적 상호작용은 용질거동 없이 압력의 전파에 의해 일어나는데 반하여 수리화학적 상호작용은 용질의 거동에 의해 반응이 일어나기 때문에 더 많은 시간이 걸리기 때문인 것으로 판단된다. 결과적으로 하상의 불투수성의 보에 의해 하천과 주변대수층의 경계조건이 바뀌고, 이때 지하수 시스템으로 유입되는 하천수에 의해 BH-14의 수위가 즉각적으로 상승하며, 수질에서 하천수적 성향을 나타내는 것으로 판단된다. 이러한 현상은 보의 수위가 높아질수록 더욱 증가하는 경향을 나타낸다.

• 환경영향평가
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• 제3권2호
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• pp.47-56
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• 1994

AGNPS model is an event-based model to analyze nonpoint-source and to examine potential water quality problems from agricultural watershed. This model uses a square grid-cell system to represent the spatial variability of watershed conditions, and simulates runoff, sediment, and nutrient transport for each cell. AGNPS model was applied on Yeonwha watershed, and the test results were compared with the measured data for runoff volume, peak runoff rate, suspended solids, and phosphorus concentration. The watershed of 278.8 ha was divided into 278 cells, each of which was 1 ha in size. The coefficients of determination for runoff volume and peak flow were (0.893 and 0.801 respectively from regression of the estimated values on the measured values. The concentration of suspendid solid was increased but decreased that of phosphate with runoff volume.