再曝氣에 關한 實驗的 硏究

延基錫 大田工業大學 1988 한밭대학교 논문집 Vol.5 No.2

中小河川 水系의 流砂量에 對한 考察

延基錫 大田工業大學 1991 한밭대학교 논문집 Vol.8 No.1

It is well-known that sediment causes the variation of configuration of stream bed the decrement of the reservoir storage capacity and the amount of power out -put, the failure of hydraulic structures, and the shortage of the amount of water available for use. It is an important factor to determine the rate of sediment transportation in the stream, when development projects are to be planned also to be deviced for controlling sediment. It effects on the development of water resources at small stream in the future.

오염물질 전달에 대한 수치모형 접근의 타당성 연구

연기석 大田産業大學校 2000 한밭대학교 논문집 Vol.17 No.1

A numerical model which simulates the convective transport of conservative ions through groundwater aquifers is presented and discussed. The model uses the fully implicit, central finite difference technique to predict transient, two-dimensional areal groundwater level or piezometric head fluctuations, to corresponding flows, and the convective transport of conservative ions. The model uses the fully explicit finite difference technique to calculate the contaminant concentrations. The model neglects the dispersion portion of the convective-dispersion equation. Either square or rectangular grids which remain constant throughout the study period may be used. Simple longitudinal and radial flow problems are solved. In addition. criteria to assure convergence and stability of the model are developed theoretically and empirically. The sensitivity of the model to variations in grid size, time increment and seepage velocity are presented. The study was limited to confined aquifers. However, the model has been developed to handle unconfined aquifers also. The study way also limited to homogeneous and isotropic porous media.

橋脚의 크기에서 接近角度와 開度比에 따른 局部洗掘深의 實驗的 硏究

延基錫,金雄鎔 大田産業大學校 1996 한밭대학교 논문집 Vol.13 No.1

It is necessary to consider the effect of pier skewness and openning ratio when depth of local scour at bridge piers are predicted. It have been known that the depth f local scour at bridge piers and various pier sizes and closed related with the projected width. In this paper, the pier types constructedin the rivers and large stresms in Korea are are investigated based on the shapes. The local scour at Piers with semicircular shape and same openning ratio piers are analyzed based on the experimental studies. The experiments are continued varying the flow depth, the channel bed slope and the angle of attack.

우리나라의 재해 특성에 관한 연구

연기석 한밭대학교 산업과학기술연구소 1994 논문집 Vol.2 No.-

This study focused on the systematic analysis of hzard types in Korea and their periodical and regional characteristics. The result of the damage analysis in recent 10 years('82-'91) have shown that : - it is necessary and urgent for inundated urban areas to develop a damage estimation model. - most casualties in Korea occur form mid-July to early September and arised mainly due to heavy rain and typhoon strikes, - small structures and private sector are vulnerable at most in Korea and their damages will be increased continuously in the futures, - 33 countries of the total 136 countries in Korea are most vulnerable and are heavily affected once on every two years.

교각주변의 정적 세굴심 도달시간에 관한 실험적 연구

연기석,김웅용 大田産業大學校 1999 한밭대학교 논문집 Vol.16 No.1

The temporal development of local scour depth at cylindrical bridge piers is considered. The experimental data are presented and used to quantify the influence of flow duration on the depth of local scour. The equilibrium scour depth( d_se) are subjected to similar influences of flow and times, as might he expected because they are inherently interdependent. This study is limited to local scouring at cylindrical bridge piers in uniform sand beds. The following conclusions are drawn from this study: 1. The equilibrium depth of scour at a bridge pier under clear-water conditions is approached asymptotically as shwon in Fig. 3. and Fig. 4. 2. The proposed relationship is d_se=EXP(0.961n(t_e)-1.9305) and determinant coefficient is 0.898 in this study.

수중보 건설 전후 하천 상ㆍ하류의 수위변화

연기석,김웅용 大田産業大學校 1998 한밭대학교 논문집 Vol.15 No.1

This paper has been examined the water surface variations of construction of a submerged dam on its surrounding areas in hydraulic and hydrologic study, around those stations installed in the basin of the Chung Ju multipurpose dam, and simulated using HEC-RAS models, to examine the effect on the surrounding areas before and after construction of submerged dam. It has been reviewed by calculating, in the HEC-RAS, the effect of change of water level on before and after construction and on the upstream and downstream of a submerged dam and has also been examined the rising effect of water level, by applying the effect on back water in the HEC-RAS. Therefore, it has been simulated five models, and has been reviewed the effect on the upstream and downstream basin of a submerged dam constructed the results are as follows: 1. The results of calculation of variation in water level before and after construction of a submerged dam applying the HEC-RAS, by the standard step method, showed differences in water level 3.79m before construction and 3.98m after construction, which is considered that the effect due to the change of water level will be little worth consideration. 2. In review of the effect on back water, by applying the HEC-RAS, it showed that had no significant effect on a rise in water level, but in case of low starting water level(130.4m), it had more effect on that, reflecting that the effect of submerged dam was relatively high.

GPS를 利用한 地籍測量 基準點成果 分析

延基錫,崔榮洛 한밭대학교 2003 한밭대학교 논문집 Vol.20 No.-

Using the control point structured for land surveying project in 1910s, this study is focused on comparatively analyzing the survey results, which have been gained with appointing 3 cadastral triangulation points and 3 subsidiary cadastral triangulation points laid under the ground of southwest Daejeon Metropolitan City, and the results surveyed using GPS to examine rapidity and economical efficiency. In this way, it can improve precision of the survey results. Results of this study are as follows. 1. Comparatively analyzing the results of existing cadastral survey method by the total station and ones of real-time mobile positioning method, errors have occurred at X axis amounting to average Δx=±0.009m and Y axis to Δy=±0.027m. More precise than the marginal connection error of survey results and examination results amounting to 0.25m, it has turned out to be proper for applying to readjustment of the city streets and control point survey for large unit treatment to contribute to improvement of precision. 2. Comparatively analyzing the results of existing cadastral survey method by the total station and ones of real-time mobile positioning method, errors have occurred at X axis amounting to average Δx=±0.134m and Y axis to Δy=±0.113m. More precise than the marginal connection error of survey results and examination results amounting to 0.25m, it has turned out to be proper for installing subsidiary cadastral triangulation points.

錦江水系의 頻度 洪水量의 추정에 대하여

延基錫 大田工業專門大學 1983 論文集 Vol.32 No.-

To assume an a flood volume tocvard the unexploited districts along nature rivers is very momentous from the stand poit of the puropose for Inundation control. Dae to clatum line of all kinds of facilities, it is necessary to research Inundation volume and a model assuming it there fore in this resarch, to analyse rainfall materials with frequency, and to measure it every spell of inundation correlating these researchs with a common factor of earch and climate, it is also nacessary to exploit a model of frequent inundation volume along the already-exploited of nature rivers.

報靑川 水系의 洪水被害와 流出特性에 關한 硏究

延基錫 大田工業專門大學 1981 論文集 Vol.29 No.-