• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.9
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• pp.401-408
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• 2014

This paper proposes an optimum operation method for open type ground heat exchangers. A series of TRTs and artificial heating/cooling operations were carried out while monitoring temperature in the hole of SCW. The ground temperature naturally increases with depth, but a switch between the cooling/heating mode results in a change in the distribution of ground temperature. The effect of the mode change was evaluated by performing LMTD and COMSOL multiphysics analysis for a reduced model with the depth of 150 m. As a result, in the cooling mode, the upstream operation is more efficient than the downstream operation and reduces EWT by $2.26^{\circ}C$. On the other hand, in the heating mode, the downstream operation is advantageous over the upstream operation and increases EWT by $3.19^{\circ}C$. The merit of the optimum operation will be enhanced for the typical dimension of SCW with a depth of 400~500 m. In the future, an open type ground heat exchanger system adopting the optimum operation with variation in the ground temperature will be used in practice.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.470-478
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• 2016

This study focused on the emergency evacuation guidelines considering the behaviors of people with disabilities in Korea. For these purposes, this study reviewed the movement behaviors of people with disability and the treatment characteristics of emergency and hazards in United States. The results are as follows. First, it is necessary to suggest establishment requirements and building design guidelines considering the behaviors of inhabitants and the occupant load in social welfare facility for people with disabilities. Second, it is important to establish disaster preparedness and evacuation planning in emergency and hazards reflecting the movement behaviors of people with disabilities in national organizations and institutions on disability. Third, periodical emergency and fire drills are necessary for people with disabilities and should be managed considering the impaired prototypes, evacuation aids and service animals.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.781-781
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• 2012

본 연구에서는 수문-수질 모의가 가능한 SWAT (Soil and Water Assessment Tool) 모형을 이용하여 경안천 상류의 별미천 유역($1.21km^2$)을 대상으로 최적관리기법(Best Management Practice, BMP) 적용에 따른 비점오염원 저감효과를 분석하고자 한다. 이를 위해, 별미천 유역내 논($0.049km^2$)과 밭($0.018km^2$) 지역에 대한 BMP 시나리오를 작성하였다. 먼저, 논에서는 계단식(Terrace) 재배 방법을 적용하였으며, 밭에서는 등고선(Contour farming) 재배 방법과 볏짚지표피복 시나리오를 적용하였다. 여기서, 볏짚지표피복 시나리오는 현재 $1276.6m^2$, 경사도 약 3.2%의 콩 재배가 이루어지고 있는 시험포장에서 수행된 결과를 이용하여 SWAT 모형의 지표유출관련 매개 변수를 조정하였다. SWAT 모형의 적용성 평가를 위해, 1:5,000 수치지도로부터 2m DEM(Digital Elevation Model) 및 QuickBird(2006.05.01) 위성영상으로부터 스크린 디지타이징기법(On-Screen Digitizing Method)을 이용하여 총 21개 토지이용항목의 1:5,000급 정밀토지이용도를 작성하고, 농촌진흥청에서 제공하는 1:25,000 정밀토양도를 구축하였다. 또한, 유역출구점에서 자동수위 및 강우량 계측기, 수질측정을 위한 오토샘플러를 설치하여 시간당 수위(유량), 강우 자료와 강우발생에 따른 수질자료(Sediment, Total Nitrogen, Total Phosphorus)를 이용하여 모형의 검보정(2011.06.08 ~ 2011.10.31)을 실시하였다. 모형의 검보정 후, 논에서의 Terrace 및 밭에서의 Contour farming, 밭 시험포장에서의 저감효과가 분석된 지표피복시나리오의 적용을 위한 SWAT 모형의 관련 매개변수를 정의하고, 각 BMP 시나리오별 비점오염원 저감효과를 분석하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.315-315
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• 2011

본류와 지류가 합류되는 합류부에서는 배수영향으로 수위가 증가하더라도 수면경사가 완만해져 감속흐름이 발생하고 배수영향을 받지 않는 동수위보다 유량이 감소하는 수리특성이 나타난다. 또한 지류의 유역면적이 본 류의 유역면적과 비슷한 경우 홍수사상에 따라 역류현상이 발생하여 본류 유역에서의 유출이 발생하지 않더라도 본류의 수위가 증가하는 현상이 발생하기도 한다. 따라서 수위-유량관계에 있어서도 복잡한 현상이 발생하여 단일 수위-유량관계곡선을 개발하는데 어려움이 있다. 본 연구에서는 한강과 평창강이 합류되는 각 하천 하류에 위치한 국토해양부 팔괴 수위관측소와 영월 수위관측소에서의 강우-유출 사상에 따라 변이하는 유출 특성을 검토하였다. 우선 강우 사상을 검토하기 위하여 평창강 유역의 대표 강우관측소인 유천 및 방림 강우관측소와 한강 상류유역의 대표 강우관측소인 대기 및 정선 강우관측소의 2010년 3월과 7월의 강우 사상을 비교하였다. 또한 유출 사상을 검토하기 위하여 평창강 유역 하류의 팔괴 수위관측소와 한강 상류유역 하류의 영월 수위관측소의 2010년 3월 15일부터 17일과 7월 17일부터 20일까지 두 사상에 대한 관측자료, 2010년 3월 16일과 7월 17일에 유량측정을 실시하여 확보한 측정자료를 비교 검토하였다. 또한, 홍수사상에 따른 한강과 평창강 합류부에서의 배수영향 및 역류현상을 검토하기 위하여 2008년 7월 및 2010년 9월의 유량측정을 통하여 확보한 측정자료를 바탕으로 수리특성을 검토하였다. 그림 1에는 한강 및 평창강 유역의 대표 강우관측소의 위치와 각 유역 출구점인 수위관측소의 위치를 도시하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.186-186
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• 2018

본 연구에서는 매개변수 자동 보정기법인 PEST(Model-Independent Parameter Estimation and Uncertainty Analysis)를 CAT 모형에 연계하여 유출특성 분석을 실시하였다. CAT-PEST 연계모형은 CAT 모형의 모의유출량을 이용하며 PEST의 반복계산을 통하여 최적 매개변수를 추정한다. 침투방법은 CAT에서 제공하는 Rainfall Excess 방법, Green and Ampt 방법 및 Horton 방법을 이용하였으며 각 침투방법에 따른 유출 특성을 비교 및 분석하였다. 연구대상유역은 보령 댐 유역으로 유역면적은 $163.7km^2$이며 전체면적의 약 80%가 산지로 구성되어 있고, 유로연장은 22.3km, 유역평균경사는 40.19%이다. 또한 보령댐 유역의 월평년값 평균기온은 -0.8에서 $25.5^{\circ}C$로 계절변동이 매우 큰 것을 알 수 있다. 최근 몇 년간 심각한 가뭄 피해를 입은 보령댐 유역은 2016년에 도수관로를 완공하여 이를 통해 금강으로부터 물을 끌어다 쓰고 있는 실정이며, CAT 모형에서는 금강도수유입량을 외부유입 처리하여 유출량을 산정하였다. 모의기간은 1999년부터 2017년까지이며 전체기간에 대한 보정 후 연도별 보정을 실시하였다. 통계적 평가수단은 $R^2$, RMSE 및 NSE를 사용하여 유역 최종출구점에서의 유출량과 비교하였으며 전체기간에 대한 보정결과 NSE와 $R^2$가 0.75 이상으로 나타나 대체적으로 모의 유출수문곡선이 관측 수문곡선과 유사한 양상을 보였다.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.1
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• pp.115-126
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• 2019

Recently, in order to solve the traffic congestion in urban areas and to improve the peripheral environment, research on the design and construction technology development of great depth underground double-deck tunnel is under way by using the underground space in the urban area. The network type double-deck tunnel is in the form of an intersection with a small cross section and a steep slope as per construction at the base of a flatland, so that the fire smoke spreads rapidly in case of fire, which is expected to cause damage of human life. Therefore, this study is analyzed the delay effect of fire smoke diffusion according to the installation and non - installation of delay system for fire smoke diffusion at the intersection. Fire fumes were delayed up to 270 seconds when the delay system for fire smoke diffusion was installed at the intersection and it is analyzed that the greater the operating area of the delay system for fire smoke diffusion, the more preventable the damage of human life of the intersection.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.2
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• pp.501-511
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• 2018

As a result of the recent revision of the 'Guideline for Installation and Management of Fire Prevention Facility in Road Tunnels', the thermal buoyancy has to be taken into account when calculating the capacity of jet fans for smoke control in tunnel fires. However, there is no detailed methodologies for considering thermal buoyancy, so further study is needed. In this study, the thermal buoyancy in the tunnel is calculated by 3-D numerical simulation to consider the thermal buoyancy in case of fire in tunnels, and the relationship between heat buoyancy and vehicle drag, And the method of calculating the capacity of the jet fan for smoke control in tunnels. According to the analysis results, heat buoyancy acts as a resistance force in the case of a down-slope tunnel, and the pressure rise of jet fan for smoke control is not simply determined by the value of heat buoyancy at the entrance of the tunnel and the value of the vehicle drag at the exit. And it is analyzed that it is necessary to carry out a comprehensive review according to the location of the fire vehicle in tunnels.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.9
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• pp.952-957
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• 2005

A sensitivity analysis study was performed to examine the effects of cell size on a distributed non-point source pollution model. The model, AnnAGNPS, whiff is a modified version of USDA's AGNPS, was applied to Eung stream watershed, a tributary of Cheongmi stream located in the South Branch of Han River System. The model components and results, such as channel length, slope, land use, and delivery ratio, were analyzed according to the various cell sizes from 10 to 200 ha. As cell sire increases, channel length decreases due to short-circuiting of meandering creek. The decreased channel length has more significant effects on the model results than any other geomorphological change. When the effects of land use and soil distribution are excluded, sediment delivery loads increase due to shorter time to reach the outlet of the watershed in larger tell size. When those effects are included, however, sediment delivery loads decrease in larger fell size because the variety of land use types can not be inputted. The predominant land use in the applied watershed is forest with very low soil erosion such that the predicted sediment delivery might be much lower than real system. The cell size of 30 ha was determined to produce the most appropriate resolution. Surface runoff and non-point source loads of TN, TP and BOD were predicted and the results agree well with the field measurements. From this study, it was shown that the model results would be very dependent on variations of topography, land use, and soil distribution, as a function of cell size, and the optimum cell size is very important for successful application of distributed non-point source pollution model.

• Korean Journal of Ecology and Environment
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• v.46 no.2
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• pp.185-191
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• 2013

This study were classified the type of fishway installed on the tributary of Nakdong River, and analyze the state was to establish a management plan. As a result showed low installation ratio of fishway which includes 9,164 weirs at the 786 streams of the tributary of Nakdong River and 1,263 fishways. The type of fishway is shown as 62% for standard type and 38% for non-standard type. Assessment results of fishway condition, the ones in good condition, moderate and poor condition fishways are examined as 28%, 66%, 6%, respectively. In the past, there happened to install the fishways without discussing with fishery research institution but it is judged to install the verified fishways through powerful legal remedy and enable each community to control the fishways voluntarily through the support of government after installing the fishways.

• Journal of Soil and Groundwater Environment
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• v.11 no.5
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• pp.9-19
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• 2006

The accurate estimation of groundwater recharge is important for the proper management of groundwater systems. The widely used techniques of groundwater recharge estimation include water table fluctuation method, baseflow separation method, and annual water balance method. However, these methods can not represent the temporal-spatial variability of recharge resulting from climatic condition, land use, soil storage and hydrogeological heterogeneity because the methods are all based on the lumped concept and local scale problems. Therefore, the objective of this paper is to present an effective method for estimating groundwater recharge with spatial-temporal variability using the SWAT model which can represent the heterogeneity of the watershed. The SWAT model can simulate daily surface runoff, evapotranspiration, soil storage, recharge, and groundwater flow within the watershed. The model was applied to the Musimcheon watershed located in the upstream of Mihocheon watershed. Hydrological components were determined during the period from 2001 to 2004, and the validity of the results was tested by comparing the estimated runoff with the observed runoff at the outlet of the catchment. The results of temporal and spatial variations of groundwater recharge were presented here. This study suggests that variations in recharge can be significantly affected by subbasin slope as well as land use.