• Journal of Korean Society of Environmental Engineers
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• v.34 no.1
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• pp.23-31
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• 2012

Measures against non-point sources pollution in Saemangeum watershed should be established to control water quality of Saemangeum lake, because non-point sources pollution discharge portions of BOD (Biological Oxygen Demand) and TP (Total Phosphorous) in the watershed were 68.4 and 61.4%, respectively. In this study, target regions for the non-point sources pollution control were selected to apply BMP (Best Management Practices) for the agricultural area of Saemanguem watershed in terms of TP that caused eutrophication at the lake. Target regions were selected by the NPSI (Non-point source index) that was calculated by the total 12 indexes at the steps of non-point source production, emission and outflow. Weights of the indexes were determined by the watershed management experts oriented AHP (Analytic Hierarchy Process) analysis. The target region was selected at the unit of Korean basic administrative district 'Dong/Li'. At the results of NPSI calculations through the GIS (Geographical Information System) tools, two sets of 5 regions were selected in the Man-kyung River and Dong-gin River. The main reason for the selected target regions was livestock activity in the district. The results of this study can be useful for implementing the reduction projects of agricultural non-point sources pollution to control water quality in Saemangeum lake.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.36-42
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• 2019

Europe and North America are paying attention to residential ESS(Energy Storage System) that can manage energy efficiently. The ESS is a system that stores and manages the electric power by charging and discharging the battery. The ESS is generally used in conjunction with photovoltaic systems. The ESS supplies the load of the power generation time and stores the remaining PV power to supply the load at the non-power generation time. However, due to the high price of residential ESS, low electric rates and increasing block rates, there is no market of residential ESS in Korea. This paper reviews the price condition and the capacity for applying PV and residential ESS to household of apartments using HOMER in Korea.

• Journal of Bio-Environment Control
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• v.25 no.3
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• pp.218-223
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• 2016

The calculation method of ground heat exchange in greenhouses has different ideas in each design standard, so there is a big difference in each method according to the size of greenhouses, it is necessary to establish a more accurate method that can be applied to the domestic. In order to provide basic data for the formulation of the calculation method of greenhouse heating load, we measured the soil temperature distribution and the soil heat flux in three plastic greenhouses of different size and location during the heating period. And then the calculation methods of ground heat exchange in greenhouses were reviewed. The soil temperature distributions measured in the heating greenhouse were compared with the indoor air temperature, the results showed that soil temperatures were higher than room temperature in the central part of greenhouse, and soil temperatures were lower than room temperature in the side edge of greenhouse. Therefore, it is determined that the ground heat gain in the central part of greenhouse and the perimeter heat loss in the side edge of greenhouse are occurred, there is a difference depending on the size of greenhouse. Introducing the concept of heat loss through the perimeter of building and modified to reflect the size of greenhouse, the calculation method of ground heat exchange in greenhouses is considered appropriate. It was confirmed that the floor heat loss measured by using soil heat flux sensors increased linearly in proportion to the temperature difference between indoor and outdoor. We derived the reference temperature difference which change the direction of ground heat flow and the perimeter heat loss factor from the measured heat flux results. In the heating design of domestic greenhouses, reference temperature differences are proposed to apply $12.5{\sim}15^{\circ}C$ in small greenhouses and around $10^{\circ}C$ in large greenhouses. Perimeter heat loss factors are proposed to apply $2.5{\sim}5.0W{\cdot}m^{-1}{\cdot}K^{-1}$ in small greenhouses and $7.5{\sim}10W{\cdot}m^{-1}{\cdot}K^{-1}$ in large greenhouses as design standard data.

• The Korean Journal of Nuclear Medicine
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• v.32 no.6
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• pp.497-508
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• 1998

Purpose: Using rest T1-201/dipyridamole stress gated Tc-99m-MIBI/ 24 hour delay T1-201 SPECT, we investigated the predictive values of the markers of the stress-rest reversibility (Rev), T1-201 rest perfusion (Rest), T1-201 24 hour redistribution (Del) and Tc-99m-MIBI gated systolic thickening (Thk) for wall motion improvement after coronary artery bypass surgery. Materials and Methods: In 39 patients (M;F= 34:5, age $58{\pm}8$), preoperative and postoperative (3 months) SPECT were compared. 24 hour delayed SPECT was done in 16 patients having perfusion defects at rest. Perfusion or wall motion was scored from 0 to 3 (0: normal to 3: defect or dyskinesia). Wall motion was abnormal in 142 segments among 585 segments of 99 artery territories which were surgically revascularized. Results: After bypass surgery, ejection fraction increased from $37.8{\pm}9.0%$ to $45.5{\pm}12.3%$ in 22 patients who had decreased ejection fraction preoperatively. Wall motion improved in 103 (72.5%) segments among 142 dysfunctional segments. Positive predictive values (PPV) of Rev, Rest, Del, and Thk were 83%, 76%, 43%, and 69% respectively. Negative predictive values (NPV) of Rev, Rest, Del, and Thk were 48%, 44%, 58%, and 21%, respectively. Rest/gated stress/delay SPECT had PPV of 74% and NPV of 46%. Though univariate logistic regression analysis revealed Rev (p=0.0008) and Rest (p=0.024) as significant predictors, stepwise multivariate test found Rev as the only good predictor (p=0.0008). Conclusion: Among independent predictors obtained by rest T1-201/ stress gated Tc-99m-MIBI/ delayed T1-201 myocardial SPECT for wall motion improvement after bypass surgery, stress-rest reversibility was the single most useful predictor.

• Journal of Korea Water Resources Association
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• v.41 no.2
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• pp.149-162
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• 2008

The Soil and Water Assessment Tool (SWAT) developed by the USDA-Agricultural Research Service for the prediction of land management impact on water, sediment, and agricultural chemical yields in a large-scale basin was applied to Daecheong Reservoir basin to estimate the amount of soil losses from different land uses. The research outcomes provide important indications for reservoir managers and policy makers to search alternative watershed management practices for the mitigation of reservoir turbidity flow problems. After calibrations of key model parameters, SWAT showed fairly good performance by adequately simulating observed annual runoff components and replicating the monthly flow regimes in the basin. The specific soil losses from agricultural farm field, forest, urban area, and paddy field were 33.1, $2.3{\sim}5.4$ depending on the tree types, 1.0, and 0.1 tons/ha/yr, respectively in 2004. It was noticed that about 55.3% of the total annual soil loss is caused by agricultural activities although agricultural land occupies only 10% in the basin. Although the soil erosion assessment approach adopted in this study has some extent of uncertainties due to the lack of detailed information on crop types and management activities, the results at least imply that soil erosion control practices for the vulnerable agricultural farm lands can be one of the most effective alternatives to reduce the impact of turbidity flow in the river basin system.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1307-1311
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• 2007

유역의 자연 유출량이 줄어드는 갈수기 동안 낙동강 본류의 수질은 상류지역의 댐 방류량에 큰 영향을 받는다. 따라서 수질이 취약한 중 하류부지역의 수량과 수질을 종합적으로 고려한 낙동강 수계의 물 관리를 위해서는 댐 방류량과 하류 수질의 정량적인 관계에 근거한 다목적댐군의 연계운영이 필요하다. 본 연구의 목적은 정상상태 하천수질모델을 이용하여 낙동강수계 다목적댐군의 방류량과 하류 하천의 수질 관계를 정량적으로 분석하고, 갈수기 동안 낙동강 수질개선을 위해 필요한 적정 댐 용수공급 시나리오를 제시하는데 있다. 낙동강수계 댐 군의 하류 하천 수질을 고려한 저수지운영 계획 수립을 지원하기 위하여 1차원 정상상태 수질예측모델인 QUAL2E를 구축하고 실측 유량과 수질자료를 이용하여 모델을 보정하고 검증하였다. 검증된 모델은 낙동강수계 상류에 위치한 안동댐, 임하댐, 그리고 중 하류 지류에 위치한 합천댐과 남강댐의 용수공급 시나리오별 하천 수질개선 효과를 분석하는데 적용하였다. 연구결과 낙동강 수질이 악화되는 갈수기 동안 중 하류부에 위치한 상수원의 수질을 개선하기 위해서는 합천댐과 남강댐에서보다는 상류에 위치한 안동댐과 임하댐에서 용수를 추가 공급하는 것이 더욱 효과적인 것으로 평가되었다. 댐 방류량 증감에 따라 수질영향을 가장 크게 받는 하천구간은 수질오염도가 가장 크게 나타나는 금호강합류점${\sim}$고령교구간인 것으로 분석되었다. 본 연구결과는 낙동강과 같이 수량이 부족한 하천은 오염부하량 삭감 대책과 함께 갈수기 유량조절이 매우 중요한 요소임을 보여주며, 주기적인 수질악화를 겪는 낙동강 중 하류 지역의 수질개선을 위한 상류 다목적댐군의 연계운영 계획 수립에 활용될 수 있을 것으로 사료된다.치모의 결과와 현장에서 관측한 유속장을 비교함으로써 본 연구에서 제시한 실제 탁수배제능력을 검증하였다.를 구축하였다는데 의의가 있다.로와 접하는 건물의 경우 모서리부 광고 효과가 지배적이며 대부분 곡선돌출형이 사용되고 있었다. 그러므로 모서리 저층부를 필로티로 계획하여 보행흐름을 원활하게 하고 대신 입면을 투명하게 하여 간접광고(내부전시) 효과를 유도하는 것이 좋다. 특히 원형모서리는 건물 특화 성격이 강하므로 불가피할 경우 소형 액센트 광고 위치를 미리 벽면으로 할애하는 것이 경관 및 입면계획에 유리한 것으로 분석되었다. 불확실도 해석모형 등의 새로운 기능을 추가하여 제시하였다. 모든 입출력자료는 프로젝트 단위별로 운영되어 data의 관리가 손쉽도록 하였으며 결과를 DB에 저장하여 다른 모형에서도 적용할 수 있도록 하였다. 그리고 HyGIS-HMS 및 HyGIS-RAS 모형에서 강우-유출-하도 수리해석-범람해석 등이 일괄되게 하나의 시스템 내에서 구현될 수 있도록 하였다. 따라서 HyGIS와 통합된 수리, 수문모형은 국내 하천 및 유역에 적합한 시스템으로서 향후 HydroInformatics 구현을 염두에 둔 특화된 국내 수자원 분야 소프트웨어의 개발에 기본 토대를 제공할 것으로 판단된다.았다. 또한 저자들의 임상병리학적 연구결과가 다른 문헌에서 보고된 소아 신증후군의 연구결과와 큰 차이를 보이지 않음을 알 수 있었다. 자극에 차이가 있지 않나 추측되며 이에 관한 추후 연구가 요망된다. 총대장통과시간의 단축은 결장 분절 모두에서 줄어들어 나타났으나 좌측결장 통과시간의 감소 및 이로 인한 이 부위의 통과시간 비율의 저하가 가장 주요하였다. 이러한 결과는 차가운 생수 섭취가 주로 결장 근위부를 자극하는 효과를 발휘하는 것이

• Journal of Broadcast Engineering
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• v.16 no.2
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• pp.258-273
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• 2011

This paper designs and implements a multi-view 3D video player system which is operated faster than existing video player systems. The structure for obtaining the near optimum speed in a multi-processor environment by parallelizing the component modules is proposed to process large volumes of multi-view image data at high speed. In order to use the concurrency of bottleneck, we designed image decoding, synthesis and rendering modules in a pipeline structure. For load balancing, the decoder module is divided into the unit of viewpoint, and the image synthesis module is geometrically divided based on synthesized images. As a result of this experiment, multi-view images were correctly synthesized and the 3D sense could be felt when watching the images on the multi-view autostereoscopic display. The proposed application processing structure could be used to process large volumes of multi-view image data at high speed, using the multi-processors to their maximum capacity.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.9
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• pp.67-74
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• 2008

This paper proposes, designs and implements an architecture of a server involved with the network camera based video surveillance systems to solve common problems including lack of inter-network operability at the video information sharing, drawback of bandwidth and processing-overhead caused by increase of the number of users, and difficulty of continuous monitoring over changes of network configurations. The proposed saver was designed to manage and service numerous network cameras and users as well as solving the existing problems by providing video distribution facility. Through the empirical study after applying the implemented server to a real video surveillance system we proved that the server can provide reasonable service quality while it processes several hundreds of simultaneous user connections under persisting more than one hundred connections to network cameras. We expect the developed video distribution server to enhance service quality of the large scale video surveillance systems for citizen-wide services such as traffic reporting informatics or natural calamities supporting.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.364-364
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• 2023

최근 환경부에서 발표한 「제3차(2021~2025) 강우유출 비점오염관리 종합대책(2020)」에 의하면, 우리나라는 지난 50년간 급격한 도시화, 산업화 과정을 거치면서 불투수면적이 전 국토의 약 22.4%에 달한다고 보고되고 있다. 특히 전체 소권역의 6%에 해당하는 51개 소권역의 경우 불투수 면적률 25%를 넘어서고 있는 것으로 조사되었다. 이러한 불투수면의 증가는 기후변화에 의한 영향으로 토양 침투량과 기저유출량을 감소, 갈수기 하천건천화 심화, 우기 표면유출수 증가를 가중시키며 이로인한 비점오염물질 유입 증가, 수질 악화의 원인으로 작용 될 수 있다. 이에 정부에서는 저영향개발(Low Impact Development, LID) 사업 및 친환경그린인프라(Green Infrastructure, GI) 기술요소를 적용하여 도시지역 기후위기 대응 수단의 일원으로 우수유출 저감, 물순환 구조 개선, 비점오염원을 관리하고자 '그린빗물인프라(Green Stormwater Infrastructure, GSI) 조성 사업'을 추진하여 공공청사를 중심으로 학교, 도서관, 체육시설, 공원 등 적용 범위를 확대하고 있다. 이에 본 연구에서는 기후변화에 가장 취약한 해안도시지역인 경상남도에 위치하고 있으며, 불투수면적이 높고 노후화된 소규모 청사 2곳을 시범 구역으로 선정하였다. 각 시범 구역별 GSI 시설 적용이 가능한 주차장, 화단, 옥상 등의 개선방안을 제시하였으며, 적용 규모를 달리하여 물순환·물 환경 개선 효과를 검증하였다. 검증에는 국내에서 개발된 K-LIDM 모형을 활용한 우수유출저감 및 직접유출체적 산정결과를 통해 물순환 효과를, 국립환경과학원에서 제시되고 있는 '토지계 지목별 발생부하원단위', 수질환경개선 보고서에서 제시된 침투형, 식생형 비점오염저감시설의 저감효율을 활용하여 물순환 저감효과를 분석하여 비교하였다.

• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.156-160
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• 1997

The combination of biological wastewater treatment process and membrane separation has many advantages such as better effluent quality and system stability over the conventional biological wastewater treatment process. In this study, direct membrane separation using nonwoven fabric was applied to biological wastewater treatment. A nonwoven fabric module was submerged in the aerated bioreactor. And accumulated biomass in the bioreactor was separated by suction. The system was operated with various condition to investigate pollutant removal efficiencies and flux. After formation of biomass layer on nonwoven fabric surface, a day, the stable effluent water quality was obtained. The flux decreased at a high suction pressure faster than a low pressure. The stable flux was obtained at the pressure of $21{\sim}25cmHg$. In spite of variation of hydraulic retention time, organic loading rate, the removal efficiencies of BOD, $COD_{Cr}$. $COD_{Mn}$ were very high as follows : $95.2%(0.14{\sim}0.97\;BODKg/m^3/day)$, $86.0%(0.17{\sim}1.39\;COD_{Cr}Kg/m^3/day)$, $90.0%(0.097{\sim}0.61\;COD_{Mn}Kg/m^3/day)$.