• 한국철도학회논문집
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• 제5권3호
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• pp.133-141
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• 2002

Recently developed JES(Joint Element Structure) Method was researched as a more safe and economic method than other under pass construction method and was applied to many construction sites. The joint element connection of JES Method is the most important factor for the to behavior of structure. The connection of JES method is filled with the mortar, and the steel and mortar of connections produce the same behavior as one material. The results of experience and numerical analysis are following: The maximum internal stress of connection is decided by the end of connection. also, The connection of joint element structure method have sufficient internal stress against fatigue.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.973-981
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• 2008

This document presents the JES(Joint Element Structure) method that has been adopted for the firs time in our country for the construction of the structure crossing under the railroad without open excavation. Front Jacking Method, Tubular Roof Construction Method, New Tubular Roof Method and Joint Element Structure Method are commonly used for the construction of structures crossing under the railroad. JES Method, frequently used in Japan recently, is a new method to construct the structures crossing under the railroad in a safe manner and in a relatively short period of time by utilizing the steel elements with the joints through which the load in the vertical angle to the axial direction is transferred to the next element. The elements are tied to each other through the joints to form the permanent walls of a Rahmen structure under the road without open excavation and without limitation to the length in a convenient way. Through the case study in the project of a Subway Box Culvert Improvement for the Gyeonguiseon Railroad in front of Yonsei University using the JES Method, the cost and period of construction in various types of soil is investigated compared to the Front Jacking Method. Furthermore, by analyzing the results of instrumentation measurements carried out throughout the construction, comparison between the actual displacement in the ground and the predicted displacement in the design is made to provide the considerations to be counted for the design. In conclusion, comparison in the field of economic feasibility, constructability and safety between the JES Method and Front Jacking Method, which is most frequently adopted in our country at present, is made to present the JES Method as a new alternative for the non-open excavation construction method for the structures crossing under the railway.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1498-1508
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• 2009

최근 도시로의 인구 집중과 차량 증가로 인하여 보도 및 차도의 확장이 불가피한 반면에 이는 한정된 용지로 인해 많은 제약을 받고 있는 실정이다 이에 대해 JES 공법은 기존 도로나 철도 등의 교통시설 하부를 횡단하면서 이들의 운행에 대해 제약을 최소화 할 수 있는 공법이다. 본문에서는 국내에서 최초로 JES 공법이 적용된 구간에서의 상부, 측벽, 하부 Element에서의 견인력과 침하량을 각각 비교하였다. 추진력을 비교한 결과, 좌측벽 Element 의 경우 실제 측정된 추진력이 구조계산에 의해 얻은 추진력의 2배 정도 큰 값을 보였다. 이는 사전 지반조사와는 달리 지반에 다량의 전석이 함유되어 있어서 시공 중 과도한 추진력이 발생한 것으로 판단된다. 또한 침하량을 검토한 결과, 상부 Element에서 가장 큰 값을 보였으며, 이 역사 지반에 다량의 전석이 포함되어 있어 굴착 시 공동 형성에 인한 결과라고 판단된다. 또한 본문에서는 향후 본 공법을 이용한 여려 가지 활용 방안에 대해서도 연구해 보았다.

• 한국환경과학회지
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• 제13권9호
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• pp.759-765
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• 2004

HEC-RAS model is used for estimation of rating-curve of Musung in Wi stream. Discharge is computed from stage estimated by HEC-RAS model, is compared with the discharge of water surface slope method. The relative deviation of observed and computed discharge is 5.37%, and shows as a good results. A rating-curve by HEC-RAS model shows better results than by water surface slope method.

• Ocean and Polar Research
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• 제31권2호
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• pp.177-187
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• 2009

This study examined the multi-scale variabilities of sea surface temperature (SST) and salinity in the Japan/East Sea (JES) based on statistical analyses of observational data, with a focus on the northwestern part of the sea. The regionality of JES SST variability was estimated for different frequency ranges on semimonthly (11-17 days), monthly to seasonal (30-90 days), quasi-semiannual (157-220 days), and quasi-biennial (1.5-3 years) time scales using cluster analyses of daily gridded SST data for 1996 to 2007 from the Japan Meteorological Agency (JMA). Several significant peaks and regional cores were found in each frequency range of the SST anomaly (SSTA) oscillations. Quasi-semiannual SSTA oscillations with high amplitude were found in the south-southwestern part of the Japan Basin ($41-43^{\circ}N$) and were amplified in the area adjacent to Peter the Great Bay. Oscillations with periods of 79 and 55 days also prevailed over the southwest Japan Basin between the Yamato Rise and the continental slope. A similar method was applied to classify SST and the annual cycle of surface salinity using Generalized Digital Environmental Model (GDEM) gridded data. The Tatarskii Strait and adjacent area showed the most specific annual cycles and variability in salinity on interannual to interdecadal time scales. The most significant inverse relationship between surface salinity in the Tatarskii Strait and southern JES areas was found on the interdecadal time scale. Linkages of sea water salinity in the Tatarskii Strait with Amur River discharge and wind velocity over Amurskii Liman were also revealed.

• 한국환경과학회지
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• 제11권7호
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• pp.679-686
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• 2002

Turbulence greatly influence on atmospheric flow field. In the atmosphere, turbulence is represented as turbulent diffusion coefficients. To estimate turbulent diffusion coefficients in previous studies, it has been used constants or 2-level method which divides surface layer and Ekman layer. In this study, it was introduced Smagorinsky method which estimates turbulent diffusion coefficient not to divide the layer but to continue in vertical direction. We simulated 3-D flow model and TKE equation applied turbulent diffusion coefficients using two methods, respectively. Then we showed the values of TKE and the condition of each term to TKE. The results of Smagorinsky method were reasonable. But the results of 2-level method were not reasonable. Therefor, it had better use Smagorinsky method to estimate turbulent diffusion coefficients. We are expected that if it is developed better TKE equation and model with study of computational method in several turbulent diffusion coefficients for reasonably turbulent diffusion, we will able to predict precise wind field and movements of air pollutants.

• 한국환경과학회지
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• 제11권8호
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• pp.765-771
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• 2002

The current study investigated the relationship between image processed data and human visibility data for natural forest scenes from the perspective of color. In particular, the results indicated relatively low Pearson product-moment correlations between the color ratings obtained from the two methods used in the study. The first method measured the color content of slides using a image processing program, while the second used a panel of human judges to rate the color content of each slide.

• 한국환경과학회지
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• 제11권10호
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• pp.1125-1131
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• 2002

This study was performed to plan pollutant loading allocation by sub-watershed at Kumho river basin located in the north Kyeongsang province. HEC-geoHMS which is extension program of ArcView was used to extract sub-watershed. To simulate water quality, Qua12eu model was calibrated and validated. BOD was simulated under several scenarios to evaluate reduction effects of pollutant loading. Uniform treatment and transfer matrix method was considered. Effects of headwater flow rate and efficiency waste water treatment plant were also considered.

• 한국환경과학회지
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• 제17권12호
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• pp.1325-1330
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• 2008

This study was carried out with the detection for multiresidue of the carbamate pesticide such as carbaryl and cabofuran by enzyme-inhibition method. The check time for determination of acetylcholinesterase(AChE) activity was selected at 60 sec. The AChE activity in chicken brain determined by the Ellman's method was $162{\mu}$mol/min/g protein. $I_{50}$ for AChE by carbamate pesticide with wet kit was 0.169mg/L of carbaryl and 0.089mg/L of cabofuran, respectively. The incubation time for enzyme kit with substrate kit was 30min for determination of AChE activity. Enzyme kit with substrate kit was stable at $4^{\circ}C\;and\;25^{\circ}C$ for 5 days. Limit detection concentration of carbaryl with dry kit for AChE was 0.05mg/L. The dry kit such as wet kit applied Enzyme-Inhibition(EI) method with AChE was confirmed the multi residue method to detect the carbamate pesticides.

• 한국환경과학회지
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• 제15권5호
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• pp.493-501
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• 2006

The increase in environmental loads and energy consumptions has resulted in the need of developed new forms of energy for a sustainable use for the society. Recently, the viability of using unused energy has attracted a great deal of attention. From the view point of using unused energy, the most critical problem can be referred to as the distance between the heat source/sink and heat demand area. The water resource in the city water system was used to solve this distance problem with unused energy. The calculation method of the potential use unit was used to survey the potential of the water resource in the city water system. The amount of theoretical unused energy and energy savings in the model city were estimated using this method. It is estimated that the amounts of energy savings and $CO_2$ reduction correspond to 131.3 GWh and 29280[t-C], respectively, per annual basis.