• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.2
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• pp.21-30
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• 1995

In order to save time and efforts in generating finite element meshes in irregular houndaries of domains, it is needed to develop an automatic mesh-generator which can hoth promote the accuracy of solutions and reduce the run-time in operating finite ele- ment models. In this study, the advancing front technique of triangular mesh generation and the transforming technique from triangular meshes to quadrilateral meshes were used to de- velop a computer program for the automatic triangular and quadrilateral meshes in the mixed shape. Furthermore, to enhance the quadrilateral mesh quality, the techniques of Laplancian smoothing and interior mesh modification were employed. The mesh genera- tor was applied to evaluate its applicability to irregular and complex geometries such as Nakdong river bay. In has hoen shown that the automatic mesh generator developed is capable of automatically generating meshes for irreguiar and complex geometries with high qualities of meshes and with the simple input data of arbitrarily specified nodal spacing in bound- aries.

• KCID journal
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• v.2 no.2
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• pp.10-19
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• 1995

In spite of their high availability in the field of water resources, finite element models generally require large amount of input data in which the preparation of them consists of complicated procedures and time consuming works. In addition, in case of a

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.971-975
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• 2009

본 연구에서는 격자강우량과 GIS와 연계한 격자기반의 공간수문자료들을 모형의 입력매개변수로 활용하고, 수계망을 통하여 유역 출구까지 운동파(kinematic wave)이론에 의해 유출량을 물리적으로 추적해 나가는 격자기반의 분포형 강우-유출모형인 K-DRUM(Kwater Distributed RUnoff Model)을 개발하였고, 지표유출량에 가장 큰 영향을 주지만 실제 관측 및 적용이 용이하지 않은 유역의 초기토양함수상태에 대한 자동보정기법을 개발하였다. 개발된 자동보정기법을 이용하여 남강댐유역을 대상으로 적용가능성을 평가하였다. 연구에서 사용한 강우사상은 남강댐 유역에 큰 영향을 준 태풍 루사 (2002년 8월 31일 01시$^{\sim}$9월1일 23시), 태풍 매미 (2003년 9월 12일 01시$^{\sim}$9월13일 23시), 2004년의 대류성강우 (2004년 7월14일 01시$^{\sim}$7월 16일 10시) 및 태풍 에위니아 (2006년 7월 8일 18시$^{\sim}$7월11일 12시)의 총 4개의 사상을 대상으로 하였다. 개발한 유역의 초기토양함수상태 자동보정기법에 의한 유출모의의 적용성을 검토하기 위하여 모의에 사용된 매개변수 중 토지피복도에 의해 결정되는 조도계수와 토양도에 의해 결정되는 유효토심, 흡인수두계수, 공극률 및 투수계수는 4개의 강우사상에서 모두 동일한 조건으로 설정하였고, 유역내 토양 내부 수분함유량 산정을 위한 초기 기저유출량은 검토대상 기간 시점부에서 관측된 유출량으로 설정하였다. 초기토양함수상태 자동보정기법 적용을 통한 유출해석의 정확도는 체적오차 백분율(VER)과 첨두 유량 오차 백분율(QER)을 이용하여 평가하였으며, 이를 통해 본 모형이 유출량에 대한 정확성을 확보하고자 하였다. 본 연구에서 개발된 자동보정 기법을 적용한 결과, 초기토양조건을 설정하는데 있어서 기존의 시행착오법으로 인해 소요되는 시간과 유역내 토양 특성과 지형형상을 고려하지 않는 설정으로 인해 발생될 수 있는 문제점을 해결할 수 있었으며, 유출계산 결과도 유량의 크기와 첨두시간 모두 관측값과 비교적 잘 맞는 것을 확인할 수 있었다.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.1
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• pp.36-44
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• 2006

In this study, we constructed a forest fire danger map in the Yeongdong area of Gangwon-do and Northeastern area of Gyeongsangbuk-do using a forest fire rating model and geographical information system (GIS). We investigated the appropriate positions of the automatic weather station (AWS) and a comprehensive network solution (a system including measurement, communication and data processing) for the establishment of an optimum mountain meteorological observation network system (MMONS). Also, we suggested a possible plan for combining the MMONS with unmanned monitoring camera systems and wireless relay towers operated by local governments and the Korea Forest Service for prevention of forest fire.

• Korean journal of applied entomology
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• v.29 no.3
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• pp.209-215
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• 1990

Some preliminary studies were conducted to find out whether the levee-burning could justifiable for the suppression of insect pests, particularly the smaller brown planthopper (Laodelphax striatellus F.). Density surveys on pests and their enemies (mostly spiders) were carried out upto the mid May at an experimental paddy field located in Suwon after of it's levee $(72\times1m)$ was burned on Feb. 20, 1987. Results were discussed in relation to density recovering of both pests and their possible enemies (spiders) and summarized as below. Not a single individual of any pest or enemy was found from the levee upto sometime after the levee-burning. Grasses started to grow more vigorously in burned ares than in unburned upto about 60 days after the burning. And densities of both pest and enemies grew higher in burned areas than in unburned from about 75 days after the burning (in Early may). It is suspected that all individuals of pests and enemies fond from the burned areas could have immigrated from the surrounding areas. If levee-burning was carried out in much wider areas, much longer time would be needed to recover the density of both pests and enemies to the center region of the burning. Wingless spiders would require even longer time than winged pest species to re-establish in the center region of the widely burned field. Pirata subpiraticus, the most abundant spider species in Korean paddy fields, starts to move about and searches for food at above $9^{\circ}C$ which is somewhat lower than the critical temperature for the pest species. Thus P. subpiraticus would require more food than other pest species early in the spring, and therefore, it would have lower probability to survive than pest species particularly in burned areas. Experiments for pest suppression with levee-burning would better be carried on in much wider areas, and its justification seems to be discussed after man other disciplines related to both pests and their natural enemies were throughly studied together with their density surveys. However, according to the present point of vie, the opinion that levee-burning is helpful for controlling pests which over winter on levee areas could not be justifiable.