자기공명영상용 라디오주파수 코일의 제작에 있어서 동조 및 매칭에 영향을 미치는 전기 용량 값들의 실험적 측정

양경승,신용진,김영섭,한재진,이성길,김승국,김영근,지연상 조선대학교 기초과학연구소 2003 自然科學硏究 Vol.26 No.-

Radio frequency coil which is capable of transmit and receive the signal has been used for image production in magnetic resonance imaging(MRI). Tuning and matching characteristic of radio frequency coil is major factor determining the image quality. In experiment the used coil was called a staircase type coil which is simplified the birdcage coil and referred to a simple LC resonant circuit. Because the inductance values of the coils are fixed coil performance was examined by changing of the capacitance values. In this study capacitance values were experimentally determined to increase of-tuning and matching effect in junction of the coil between coil endring and BNC cable to obtain the high quality of image.

당뇨병성 말초신경병의 평가에 대한 전류감지검사의 임상적 유용성

김승현,심충섭,김주한,김명호 대한신경과학회 1998 대한신경과학회지 Vol.16 No.5

최소차 하천의 임계면적에 따른 유역 지형매개변수의 변화특성

안승섭,박노삼,김종호,임기석,송시훈 한국환경과학회 2005 한국환경과학회지 Vol.14 No.1

The size of minimum order stream has a very sensitive effect on runoff analysis model using the divergence characteristic of stream. Therefore, in this study, the threshold area of minimum order stream has been examined the change characteristic of topographical parameters. The subject basin of the research was the upper basin of the Kumho water gage station which is located in the middle of the Kumho river. The 1:25,000 numerical geography which was constructed 10×lOm mesh was used. The range of investigation of topographical parameters are number of stream order, length, area, slope, basin relief, sinuosity ratio, drainage density and total stream length etc. It was found from the result of analysis that the threshold value of minimum order stream has a very big effect on topographical parameters of basin. It was found that the threshold area of minimum ord er stream revealed under 0.10km². Furthermore, the parameters showed a serious change except for over 0.10km².

글로우 방전을 이용한 이산화탄소의 전환특성

신용섭,송승훈,곽동주 慶星大學校 1998 論文集 Vol.19 No.2

In this study, the characteristics of CO₂conversion and glow discharge were investigated using glow discharge plasma reactor with a parallel copper electrode system. A pure CO₂ gas was used for the carrier gas under gas pressure of 10∼80 torr in a glow discharge. For glow discharge, discharge current was increased with the increase of discharge voltage. In the case of constant discharge voltage, the discharge current tend to increase with the decreasing of gas pressure. Using pure CO₂only, the CO₂conversion was increased with the increase of discharge power and the decreased of gas pressure. The maximum CO₂ conversion was 28% at 10 torr, 598 W, 902.4V. Energy yield was decreased with the increase of discharge power and discharge voltage. Also, the concentrations of CO₂and O₂in the produced gas were slightly increased with the increase of CO₂ conversion.

컴퓨터를 이용한 冷·暖房 負荷의 簡易 計算法에 관한 硏究

정광섭,유승호 서울産業大學校 1996 논문집 Vol.44 No.1

The variables affecting heating and cooling load calculations are numerous, often difficult to define precisely, and always intricately interrelated. Many heat load components vary in magnitude over a wide range during a 24-h period. Since these cyclic changes in load components are often not in phase with each other, they must be analyzed to establish the resultant maximum heating and cooling load for a building or zone. Building designers have traditionlly employed a wide range of methods to ensure that the performance characteristics of a building will be acceptable. Typically, simple(and sometimes not so simple) calculations and rule of thumb are appiled throughout the design process in an attempt to minimize heat loss, maximize the utilization of solar energy, prevent inefficient plant operation, ensure high comfort satisfaction, control problematic air movement and so on. First of all, this paper has outlined the issues surrounding the creation of simulation-based design tools for the assessment of energy systems behaviour and hear load calculation methods. And then, the objectives of the paper is to suggest the simplified heat load calculation method of building by using computer programs.

신경망모델을 이용한 일유출량 해석

安勝燮,金成原 慶一大學校 1997 論文集 Vol.14 No.2

The objectives of this study is to introduce and apply neural network theory to real hydrologic systems for predicting of daily runoff discharge in the river basin. Back propagation algorithm of neural network model is applied for the estimation of daily stochastic runoff discharge using past daily rainfall and observation results. As a result of analysis, it is presented that method 3 model which has much input layer processing elements than any other model is adjacent model as to observation runoff discharge. Therefore, as a foundation of this study, it is considered that continuous studies are need to the development of adaption network algorithm for the flood prediction including real time analysis and a field concerning with optimal decision system for dam operating.

HEC-RAS/GIS를 이용한 홍수 범람지역 분석

안승섭,이증석,김종호 한국환경과학회 2004 한국환경과학회지 Vol.13 No.1

The purpose of the study was to construct a forecast system of flood inundation area at natural stream channels. The study built the system to interpret the flood inundation area in four stages ; constructing topography data around the stream channel, interpreting flood discharge, interpreting flood elevation in the stream channel, and interpreting the flood inundation and mapping. According to the result of the analysis, as for the characteristic of flood inundation around the area within the purview of this study, although there were areas where flood inundation over a bank caused a flooded area, the failure of the internal drainage in the ground lower than flood elevation caused more serious problems. Rather than the existing method where only the estimated flood elevation data is used based on the hydrographical stream channel trace model(such as the HEC-RAS model) to establish the flood inundation area, if the procedure introduced in this study was applied to interpret the floodplain, actual flood inundation area could be visibly confirmed.

소규모 농업용 저수지의 저류량-용수공급능력 결정에 관한 연구

안승섭,정순돌,이증석,윤경덕,장인수 한국환경과학회 2002 한국환경과학회지 Vol.11 No.12

This study aims at the effective estimation of water supply capacity of small scale reservoir and the proposal of the data which is necessary to establish the water resources management plan of down stream area of the reservoir in the future by comparison and examination about reservoir operation technique for the security of agricultural water in small scale reservoir. The result of flow calculation by Tank model is used for the input data as the inflow data which is needed for the analysis of water supply capacity. Stochastic method, simulation method, and optimization method are used to examine the water supply capacity, and water security amount is compared with each method. From the analyses of water supply capacities by each method, slightly different results are shown in spite of the effort to compare them equally using input data such as inflow data under equal conditions, and the comparison of water supply capacities by each method are follows; linear planning method, and transition probability matrix method in the order of amount from the largest. It is thought that the simulation method in which comparatively reasonable application of the inflow data is possible and is simulated in successive time series dam operation of the three methods used in this study thus, simulation model is proper to estimate the water supply capacity of agricultural small scale reservoir. And it is judged that the heightening of efficiency of water resources utilization according to the development of downstream area of dam may be possible using the upward readjusted water supply amount of 55.18×10^6ton at 95% and 90% supply reliability respectively which are above the planning water supply amount of 50.0×10^6ton when the simulation method is introduced as the standard.

수공구조물이 하천환경에 미치는 영향에 관한 연구(I) : 수리학적특성 Hydraulic Characteristics

안승섭,최윤영,이수식 한국환경과학회 2002 한국환경과학회지 Vol.11 No.3

In this study, water protection reservoir is selected as the target which is located at the estuary of Teahwa river to analyze and examine the effects of hydraulic structure on river environment. This study aims at the definition of factors which cause the change of ecological environment of river due to the effects of the sediment protection reservoir, and the proposal of the direction of environmental friendly river space development through the analysis and examination of stream variation conditions and riverbed variation characteristics among many effects of hydraulic structure on river environment before and after removal of the sediment protection reservoir when design flow is yielded. Firstly, in case of removal the existing sediment protection reservoir, the hydraulic variation characteristics like depth drop due to removal of the sediment protection reservoir are thought of little because it is examined that depths drop with about 0.01m and 0.01~0.56m when low flow is yielded and design flood yielded, respectively. Nextly, as the examination result of the variation characteristics of flow velocity in case of removal the existing sediment protection reservoir, it is thought that the concern about riverbed erosion is not serious according to the analyzed result as the mean velocity of the channel section where the velocity varies in case of removal the sediment protection reservoir is about 0.07~1.36m/s when low flow is yielded, and is about 1.02~2.41m/s when design flood is yielded despite riverbed erosion is concerned as it is examined that flow velocity is getting increase as about 0.01m/s when low flow is yielded and about 0.01~0.44m/s when design flood is yielded. Lastly, from the prediction result of riverbed variation for each flow amount condition before and after removal the sediment protection reservoir, it is known that the variation range of riverbed is nearly constant when flow amount of the channel exceeds a specific limit as it is analyzed that the more flow amount, the more erosion and sediment in the channel section of down stream part of the sediment protection reservoir and the sediment protection reservoir-Samho-gyo, and the variation ranges according to flow amount between flood condition and design flood condition have little difference in the channel section of the upstream of Samho-gyo.

수공구조물이 하천환경에 미치는 영향에 관한 연구(II) : 수질 및 생태학적특성 Water Quality and Ecological Characteristics

안승섭,최윤영,이수식 한국환경과학회 2002 한국환경과학회지 Vol.11 No.4

In this study, water protection reservoir is selected as the target which is located at the estuary of Taehwa river to analyze and examine the effects of hydraulic structure on river environment. This study examined the water quality variation characteristics among many effects of hydraulic structure on river environment before and after removal of the sediment protection reservoir when low flow is yielded. This study aims at the definition of factors which cause the change of ecological environmental friendly river space development through the comparison of stream variation conditions(depth, velocity, and etc.) and riverbed variation characteristics with ecological depth condition of Taehwa-river's channel for each representative species of fish and examination those. Firstly, form the examination result of water quality when low flow is yielded before and after removal of the sediment protection reservoir for problems about water quality of river due to flow amount decrease in river, it is found that DO decreases about 0.78~0.86ppm at the lower stream of Myeongchon-gyo, and BOD decreases about 0.06~0.24ppm from right upper stream to the direction of estuary when the sediment protection reservoir is removed. It is known from the above that there is some improvement of water quality from the lower stream of Taehwa-gyo to the estuary in case of removal the sediment protection reservoir. Nextly, it is thought that the effects on ecosystem due to water depth and draw down in channel is not serious on the basis of the examination of water quality analysis result according to removal of sediment protection reservoir and hydraulic depths for reservation of ecosystem, these are 10~40㎝ for breeding season, 10~50㎝ for fry period, and 10~100㎝ for adult period of the representative species of fish in Korea.