율촌 LNG 발전소의 공냉식 복수기 사용에 따른 열확산 수치모의

김유근,이화운,문윤섭,황미경 부산대학교 환경문제연구소 2000 環境硏究報 Vol.18 No.-

In this study, thermal diffusion caused by using air cooled condenser at LNG power plant in Yulchon was simulated through in numerical method (Matsuno scheme). The input data of model was used to seasonal wind components (u, v) of automatic weather system (AWS) and seasonal temperature ranges between inflow and outflow of opening air. The aim of this study was twofold : (1) to investigate sensibility analysis of thermal diffusion coefficient : (2) to simulate diffusion of heat source through the calculated effect height for season and stability variations. These sensibility analyses were performed in detail using two case studies one is to apply horizontal and vertical thermal diffusion coefficient as 50 m-ls-1 and 10 m-ls-1, the other is 30 m-ls-1 and 10 m-ls-1 respectively. It is well known that the sensibility for thermal diffusion coefficient is low owning to very similar results. Consequently, thermal diffusion for the first case is simulated by using effect height for season and stability variation. The temperature is under 1℃ at surface whereas that is high at near the center of effect height.

Potential Precipitating Day의 추정에 관한 연구

김유근 제주대학교 1986 논문집 Vol.23 No.-

With a view to estimate the potential precipitating day (PPD). the author was calculated the regression relation between precipitable water and thickness from surface to 500mb level among the physical elements of the atmosphere of the previous day at Osan area, and established the boundary of PPD after the case studies has examined. And the data analyzed in this study were based on the precipitation days which measured at Suweon during the year between 1980 and 1981. Seasonal boundary equations of PPD have been calculated as follows; Spring : log Wp= -5.439+1.164H. Summer: log wp= -5.611+1.227H. Autumn : log Wp= -7.188+1.469H. Winter: log Wp= -3.984+0.845H. From the comparision between precipitable water(W) at 1800 Z of the specific day and equation of PPD. if Wp≤W, the next day is estimated PPD, and if Wp>W. the next day is estimated non-PPD.

마산연안지역의 국지풍 순환 및 대기오염물질 확산에 관한 연구

김유근,이화운,문윤섭,김해동,원경미,정우식,오인보 부산대학교 환경문제연구소 1997 環境硏究報 Vol.15 No.1

To investigate a horizontal windrose and the mixing height in Masan coastal area, a local atmospheric flow and the concentration of air pollutants were analyzed by abserved data from AWS, airsonde and air sampler. The land-sea breeze model and the ISCST2 model of U. S. EPA(Environmental Protection Agency) were used to predict the concentration of air pollutants such as SO2 and TSP. As a result, during spring the principal wind direction in the Masan region is mainly represented by windrose of the WNW and NW, which can be induced by land breeze and the SE and SSW of sea breeze even if weak wind speed. The mixing height during the measurement was marked with the range from 400 m(0900 LST) to 1450 m(1500 LST), and the height of an inverse layer was presented as the range from 30 m(2100 LST) to 150 m(0300 LST). It is very important to cosider the local wind field for the accurate diffusion and movement of air pollutants in coastal urban area. The atmospheric flow was simulated by the two-dimensional local wind model upon considering the orographic characteristics such as land-sea contrast, mountain valley and urban building. The result of air quality simulated by ISCST2 support that the dispersion pattern of the pollutants in that area was followed as local circulation system in coastal urban area.

부산연안역에서의 대기오염기상 예보시스템 개발에 관한 연구 : 고농도 오존일의 예측을 중심으로 Centering around Forecast of Ozone Episode Day

김유근,이화운,전병일,홍정혜,문윤섭 한국환경과학회 1996 한국환경과학회지 Vol.5 No.4

Pusan is the largest coastal city with a population of about four million in Korea. Because of increased and confused traffic, photochemical air pollution become a major urban environmental problem recently. The photo-chemical air pollution weather forecasting method preciser than existing air pollution forecast method has been developed to forecast ozone episode days with meteorological conditions using the data measured at 7 air quality continuous monitoring stations from June to September using 2 years (1994, 1995). The method developed in present study showed higher percentage correct and skill score than existing air pollution forecasting in KMA (Korea Meteorological Administration).

부산지역 시정악화의 원인 분석

김유근,문윤섭,배주현,곽진 한국환경과학회 1999 한국환경과학회지 Vol.8 No.6

After analyzing the correlation between air pollution and visibility, TSP and NO_2 is responsible for poor visibility in Pusan. After analyzing the correlation between meteorological factors and visibility, general pattern of humidity has clear negative correlation. The variation of wind speed has a positive correlation. In order to investigate the cause of poor visibility in Pusan area, the Andersen sampler and PM-2.5 are used to collect and analyze aerosol. This study was carried out to monitor the visibility using Forward scattering meter and to find out the characteristics and the cause of good visibility case and poor visibility case by measuring and analyzing a variety of parameters, such as particle size distributions, chemical compositions, and meteorological conditions in Pusan. According to the analysis of intensive sampling, NO_3^-, NH_4^+ ion concentration increased together with the mass concentration around 0.5∼2.5㎛ approximately during the case of poor visibility. NH_4NO_3, NH_4Cl, and NaCl were thought to be the major components of fine particles.

펄스 옥시미터 시스템 구현에 관한 연구

유동주,허 웅,김근이,이호재,임현수 明知大學校 産業技術硏究所 1992 産業技術硏究所論文集 Vol.11 No.-

In this paper, we implemented a pulse oximeter system which is measured oxygen saturation coefficient of a human blood in vivc We use the Beer-Lambert Law to measure the percentage of hemoglobin is oxygen saturation. The oximeter sensor are consisted of two LED(RED and INFRARED LED) and a single photodiode. The photodiode measures lights which transmitted through the tissue from two light source alternately, We calculated a ratio of light transmittance between two LEDs and then, it applied for the oxygen saturation coefficient calculation to formula. As a result, the oxygen saturation coefficient that measured from normal conditions men was 96.43[%]

우리나라 行政區劃線의 不合理要因과 그 改善方向에 관한 硏究

金裕赫,琴東信,梁在乾,李鳳三 단국대학교 법정대학 지역개발학과 1980 地域開發論叢 Vol.2 No.-

1. This thesis aims at analyzing the characteristics of the demarcation line of the administration areas in Korea by reviewing the history and background of how it was drawn and at the same time at exploring ways of correcting factors contributing to problems and ineffectiveness of administration. In order to collect data of opinions on this matter from officials actually assigned to the counties and their sub-level administration areas where administration is bifurcated in two separated blocks of areas, irrespective of the administrative efficiency and convenience of the populace in the areas, we selected eight kuns of this nature and sent questionaires to 488 chiefs and leading officials of kuns, myuns and villages. A total of 237 persons, 48.6% out of 488 responded. This data proved to be very expedient and instrumental in carrying out this study. 2. One of the characteristics of the demarcation line of administration areas is that it is drawn on the basis of natural conditions such as the extention of mountains, meandering lines of rivers, the formation of the community, traditional reasons, and so forth rather than on the theoretical as well practical backgrounds imbued with administrative philosophy, which seeks for rational and balanced development of a whole community with two factors in mind: the principle of spatial division as an administrative skill and the principle of spatial harmony for balanced division of administration zones. However, it is true that a large number of local inhabitants have felt inconveniences due to the boundary lines being zigzag or meandering. When we surveyed on the frequency of going to market as an indicator of economic activities of the people living along the boundary lines, it is found that almost 77.6% of the people questioned answered that they were going to markets located in the neighboring kun rather than those in their own administration zones. The factors that lead to choosing markets are usually two: one is spatial distance and the other is the peoples norm of life. Although the nature of the responses may vary according to where people live within the divided block of the administration area, a total of 86.6% of the questioned expressed their hope that the boundary lines would be straightened. This reflects their wishes of improving the efficiency of local administration and convenience of living for effectiveness of the administration cantrol. For example, state boundary lines of the U.S and Australia belong to the theoretical type is whereas sung boundary lines of China and kun(county) demarcation lines of Korea belong to the natural condition (or setting) type. Especially, some of administration demarcation lines of Korea have been zigzay so that one kun is divided into two or more separate blocks of areas as the result of city administration areas within the kun becoming enlarged. There are eight cases of this nature in Korea. 3. Our survey which was conducted to discover in part the extent of awareness of such bifurcation or division by the inhabitants living in the divided zones, showed that only 83.4% of those who responded said that they had knows the fact and the remaining 15.5% were quite unaware of the fact until they came to realize it upon reading our questionaire. This extent of unawareness means that local ranking administration leaders did not pay much attention to the effect of the local administration with respect to the boundary lines. 4. Speaking from the above finding, we are to propose that irrational factors related to the present administration demareation lines be corrected and improved for the following reasons: 1) To enhence the efficiency of administration, 2) To reestablish the system of utilization of resources 3) And finally to enlarge the integrated potentials of various social dynamics. We hope that efforts will be made to straighten administration demarcation lines as far as possible, taking into consideration the opinions and wishes of the people living in the affected areas and zones so that directions of development and improvement on this matter may be effectively explored. At the same time we propose the establishment of long range policies with a view of eliminating disparity in the development between the regions, by implementing necessary measures for development of local cities.

부산지역의 도시기후 특성

김유근,박종길,오인보,임윤규 부산대학교 환경문제연구소 1999 環境硏究報 Vol.17 No.1

Long-term changes of urban climate in Pusan was analyzed for 79 years(1920-1988) and estimated the risirrate to be 0.16℃/(10years) for the annual mean temperature, -0.07℃/(10years) for daily temperature range and 19.7mm/(10 years) for annual lotal precipitation. In horizontal distnbution for two years(1997-1998), urban heat island errect was found to be signficant at coastal and urbarized areas(△Tu-r max-2.1℃)with large anthropogenic heat emissions. In case of Precipitation, large amounts was doserved at the coastal area(Kwangbok-dong: 1813mm)and the lee of the city(Seomyun:1525mm, Tongnae: 1522mm).

최근 Flat Scanner와 기술 동향에 관한 분석

김두식,정기영,유건룡 혜전대학 1998 論文集 Vol.16 No.-

These days, the scanner systems is one of the electronic products which the speed of development is very fast. It has the inseparable relation to computers, its application has extended to INTERNET. In this paper, we research the its internal structure and the field of the related application regarding the color flat scanner system. Specially we have analyzed its architecture in detail; Opto-Mechanical system, Electronic system, Function block diagram, CAL, VIN Test etc., choose the VISTA-T630 model as a sample. Day by day the computer´s function has been elevated, also the processing technology for the graphics become to diversify. Therefore, many kinds of peripherals have appeared, but our realistic given conditions are inclined to the investment for the field of data communications, disregard that on concerning the image capturing equipments. All of technology can not develop suddenly, so we hope to pave the developing way for the field of scanners by this paer.

接地境界層內의 諸 擴散係數와 大氣安定度에 關하여

金有根,黃水鎭 부산대학교 환경문제 연구소 1985 環境硏究報 Vol.3 No.-

In order to study on effects of stability on diffusion coefficients which concerned with diffusion of pollutant in the surface boundary layer, we carried out the field observation on bare soil surface at the University of Tsukuba in August,1983. The results can be summarized as follows: 1.On the estimation of sensible heat coefficient, it should be taken stability into account. If it were not for taken, the sensibie heat diffusion coefficients are two or three times smaller than the real one. 2.As it shows high frequency of low value of stability parameter ζthrough the observation, the calculation formula of universal function φ(ζ) should be reconsidered. 3.Consequently, the estimated sensible heat flux is somewhat greater than the observed one at the unstable state. On the other hand,it show good coincidence each other at the stable and neutral state.