최근 5년간 약진으로 입원한 환자의 고찰 - 임상양상 및 검사소견(1986∼1990) -

고우석,조광현,윤재일 大韓臨床藥理學會 1993 臨床藥理學會誌 Vol.1 No.1

상향류식 嫌氣性 生物 反應器에서 有機性 廢水의 유기물 부하량에 따른 biogas 성상에 관한 연구

김재우 건국대학교 1992 대학원 학술논문집 Vol.35 No.-

The effect of hydraulic ratention time (HRT) on the upflow anaerobic sludge blanket has been studied in order to use the gas produced as an energe source when the HRT was descreased from 10.0day to 0.5day step by step with constant influent COD of 7000 mg/1, organic removal efficiency was gradually decreased down to the HRT of 0.7day, and at HRT less than 0.7day, digester operation was failed. In the experiment, the Cod removal rate was the direct function of origanic loading rate and maximum organic removal efficiency was 89.4%.

非均質 帶水層에서의 地下水 流動에 대한 2차원 數植模型에 관한 硏究

宋在優,金智鎬,鄭祐昌 弘益大學校 科學技術硏究所 1996 科學技術硏究論文集 Vol.7 No.1

The role and importance of groundwater are increased with the deficiency of surface water and contamination of river on the development and management of water resources. But in recent, imprudent development gave the negative impact on the aspect of the quantity and quality of groundwater. For example, the excessive pumping leads to exhaution of groundwater, and waste materials bring about contamination of groundwater. On the contaminant problem, the groundwater flow is the important media of pollutant transport and its phase is different hydraulic conductivity. Therefore, 2-D numerical model using FEM is developed. To verify this numerical model, it is compared with Theis's analytical solution for unsteady groundwater flow and existed model(used FDM). In this study, numerical model(used FEM) gives good agreement between analytical solution and existed model(used FDM). In this numerical simulation, homogeneous aquifer is supposed to use coarse sand, heterogeneous aquifer is supposed to consist of coarse sand and coarse gravel, and coarse sand and silt. The result of numerical simulation generally shows good agreements with real groundwater flow through homogeneous and heterogeneous aquifer.

流路彎曲部 橋脚주위의 洗掘 및 保護工

宋在偶,李鎔桓,崔仁鎬 弘益大學校 科學技術硏究所 1997 科學技術硏究論文集 Vol.8 No.-

Laboratory flume experiments to investigate the characteristics of the flows and local scour around circular shapes of bridge pier in a curved channel are performed. This study examines the effect of a circular collar devices for controlling the depth of scour. The scour depth due to a collar is about 40% of the scour depth without collar in a straight course of the flume while it is about 44% of the scour depth without collar at the location of 150˚in a curved channel. when the collar is placed yd/h=-0.2 for which the diameter of a collar is twice of the pier diameter, reduction o scour depth is very effective in a straight channel but when the collar is placed at yd/h=-0.1, the reduction of scour depth is very effective in a curved channel.

텅스텐 소결에 미치는 Cu 첨가효과

이재성,박상우 한양대학교 공학기술연구소 1993 공학기술논문집 Vol.2 No.1

The influence of Cu addition on sintering behaviour of W powder compacts was investigated. The addition of Cu (0-5wt%) to fine W powder(1.02㎛) was done in the form of CuC12H2O for improving mixing homogeneity. After reduction W-Cu powders were compacted and sintered at 1000∼1400℃ in hydrogen atmosphere for 1 h. The densification process of W-Cu compacts strongly depended on Cu content. Below 1%Cu the compacts had the same temperature dependence as pure W compact. Volume shrinkage was abruptly decreased by addition of 0.1%Cu and then increased with increasing Cu content at all temperatures. Such negative effect is thought to result from the lowering of W grain boundary self diffusion process by Cu segregants. Remarkable growth of W particles occured in the W-5%Cu sintered at 1400℃, which might be considerably affected by Ostwald ripening process beside particle coalescence.

동적세굴에 의한 교각주위 세굴특성

宋在偶,李尙度 弘益大學校 科學技術硏究所 2000 科學技術硏究論文集 Vol.11 No.-

Laboratory flume experiments to investigate the characteristics of scour around bridge pier by live-bed scour condition are performed. This study examines the comparison of maximum scour depth on clear-water condition and live-bed condition at the circular shape of bridge pier. The experiments were conducted in a 0.9m-wide, 0.45m-deep flume with 8m-length in a straight channel. An approximately 15cm layer of sand with a median diameter of 0.2mm formed the bed. Both the water and the sediment transported were recirculated throughout the flume and return curcuit by a centrifugal pump. For the sake of live-bed condition, sediment supply apparatus utilized. The results show that clear-water condition is larger maximum scour depth than live-bed condition. The aspect of scour depth also appeared that clear-water condition is longer time of scour depth because bed material grain is big and velocity is slow.

月 및 年 流量의 模型化 技法에 關한 硏究

宋在偶,李鎔桓 弘益大學校 科學技術硏究所 1993 科學技術硏究論文集 Vol.3 No.-

The purpose of stochastic models for synthetic generation of river flows based on the short-term observed data is to provide abundant data to the water resources systems of which the system performance and operation policy are to be determined beforhand. The stream flow data which were collected at Naju gauging station in Yeongsan river for 30years were used in this study. Stream flow data on Naju gauging station were normal distribution that was the results from the goodness of fit test of distribution. From the hydrological persistence test, the annual discharge was random time series. From the previous data analysis, the simulation model for the generation of monthly stream flow was Thomas-Fiering model, and that of annual stream flow was Monte-Carlo model. Two models that mentioned above were developed as suitable models of Naju gauging station by the comparison and examination of the hydrological characteristics (statistical characteristics and serial correlation) of the generated data and historical data.

河川空間의 效率的인 活用에 關한 硏究

宋在偶 弘益大學校 科學技術硏究所 1994 科學技術硏究論文集 Vol.4 No.-

The function of riverine-space is classified, in general, in to function as riverine-space use, geographical division and others. Riverine-space development is an integrated development of riparian part of river and high water river site. They can be converted public park, play ground, parking lots, etc. The results of this study are summarized briefly as follows 1. The river regime coefficient is very different between Korean rivers and continental ones. It is hydraulic and spatial characteristics of Korean rivers so Korea has broad open space as the riverine-space. 2. The most important function of riverine-space is free flood flow and previous to plan, this have to be brought to mind without fail. 3. For the effective use of riverine-space, regional properity is considered surely and synthetic plan of all over the river side including branch river is needed at any cost. 4. Natural space must be preserved as possible. The study and examination for the image of future river means a lot to plan up of rivers.

東津江 水系의 計量形態學的 特性

宋在偶,李元熙 弘益大學校 1987 弘大論叢 Vol.19 No.2

This paper analyzed the correlation among the stream morphological characteristics and correlation between the hydraulic geometrical characteristics and frequency of discharge for Dongjin river. The purpose of this study was to provide the informations for stream development projects. The stream morphological characteristics were analyzed by the Horton's three laws. This river basin was well developed very closely to the pattern described by Horton's laws. The concept of proportional stream ordering system was employed to describe continuously the longitudinal variation of the stream morphological characteristics. The flow duration curves obtained with the daily stream flow data of 1090% frequency occurences at the gauging stations in this river basin, were expressed an exponential functions. But relationship with frequency of discharge, morphological characteristics and hydraulic geometrical characteristics were not analyzed because of lack of data. Also the result of regression analysis of meander belt and meander length showed power curve for Dongjin river

東海岸 河口 閉塞 要因 考察 : A Study on the Causes of River Mouth Closing Along the East Coast

宋在偶 연세대학교 대학원 1975 원우론집 Vol.3 No.1

The east coast seems to have remarkably different features from the west arid south coast in the geographical, geomorphological, and oceanographical senses. In this paper the auther wishes to introduce some results of investigation the causes of river mouth closing along the east coast. There are various closing form in river mouth by many causes, but the east coast has the same closing form(the ratio of closing; roughly 0.18), as well known, by the sand spit, and has not hyd-rological but littoral drift background. The river of the east coast is proved mature age from hypsometric analysis. The wave and longshore current must be principal factor to be considered, in the analysis of the closing phenomenon owing to littoral drittoral drift. The research of the blown sand is considered valuable for the next study of this subject.