• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2002.04a
• /
• pp.25-26
• /
• 2002

가스터빈 엔진의 성능모사는 개발단계에서의 개발위험도 감소나 개발비용 절감의 목적뿐만 아니라 운용단계에서 최적의 정비를 위한 엔진의 상태 진단을 위해서도 그 필요성이 매우 크다. 가스터빈 엔진의 성능모사를 위해서는 "각 구성품의 성능은 구성품 성능선도를 따라야 한다"는 제약조건을 만족해야 하며 이를 위해서는 구성품의 특성을 나타내는 성능선도가 매우 중요하다. 구성품 성능선도는 다양한 조건에서의 성능시험을 통해 얻는 것이 당연하나 이는 엔진 개발사에서나 가능하며 대부분 공개를 기피한다. 따라서 일반 구매자나 가스터빈 엔진의 성능을 연구하는 사람들은 일부 공개된 성능도를 축척하여 이용하고 있다.여 이용하고 있다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.15 no.2
• /
• pp.149-156
• /
• 1997

This study extracts the several informations by computerizing the maps of the new city, i.e. Yang-San, MuI-Gum. This cities are being constructed by Land Coporation, and a map of province based on 1:50,000 scales were digitalized depending on topography by digitizer. Several information was taken, by computerizing a existing design maps, with digitalized maps used. Also, there is map number based on each scale, and measure a settlement of the foundation for constructing a facility in a study region, then intend to use information. This paper aims at using old data such as ancient writing books by computerization permanently.

• Journal of Korean Society for Geospatial Information Science
• /
• v.2 no.1 s.3
• /
• pp.93-98
• /
• 1994

This image of Kangseogu in Pusan, is a digital merge of aerial photos by scale of 1/1,200 map. The merge was carried out 2nd affine and bilinear interpolation. It can improve digital classification to help choose training sites and interprete classification results, and improve visual interpretation, as in this case, by adding detailed information to the multispectral TM data.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 1998.04a
• /
• pp.11-11
• /
• 1998

다목적으로 활용할 수 있는 터보축 엔진의 개발을 위한 정상상태 및 동적모사 프로그램을 개발하였다. 개발비, 개발시간, 개발위험도의 절감을 위해 가스발생기 부분은 성능이 잘 알려진 기존의 터보제트 엔진을 활용하였으며 약 3000hr 이상의 수명을 확보하기 위해 터빈재질을 교체하고, Larson-Miller 곡선을 이용하여 최대회전속도와 최대 터빈 입구온도를 각각 35000 RPM과 1140 K의 결정하였다 추가되는 동력터빈의 구성품 성능선도는 압축기 터빈 성능선도를 축척하여 사용하였다. 정상상태 성능해석에는 유량 및 일평형 방정식을 이용하였으며, 동력터빈이 각각 73%, 80%, 90%, 100% RPM일 때 가스발생기를 75%(24500 RPM)에서 100%(35000 RPM)까지 5% 간격으로 나누어 계산을 수행하였다.

• Journal of the Korean Society for Library and Information Science
• /
• v.39 no.3
• /
• pp.207-224
• /
• 2005

This study investigated the intellectual structure of records management and archives field in Korea and America using author cocitation analysis. Major journals in the field from 2000 to 2004 are used to select frequent cited authors. Cocited authors are analyzed in details by means of multi-variate statistical techniques such as multidimensional scaling. To the analysis of this intellectual structure, main research topics in Korea were laws and policies related to records management and archives whereas information technology based electronic records management in America.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2011.05a
• /
• pp.370-374
• /
• 2011

기후변화에 따른 수해를 대비하기 위해서는 미래의 확률강수량을 알아야 한다. Global Circulation Model(GCM)은 미래의 기후변화를 예측하기 위하여 많은 분야에서 널리 쓰이고 있다. GCM의 시간축척은 일반적으로 월단위로 시간단위 자료를 사용하는 수공학 분야에 직접적으로 적용하기에는 많은 문제가 있다. 또한 GCM 예측값은 실강우값과 큰 편의(bias)를 가지고 있어 직접적인 적용이 힘들다. 이런 문제를 해결하고자 다양한 다운스케일(downscale)기법이 연구되고 있다. 다운스케일기법을 적용하여 시간자료를 예측하면 전반적인 통계값을 잘 재현해내나, 극치값의 경우 잘 재현해내지 못하는 문제가 있다. 이런 문제점을 극복하고자 본 연구에서는 연최대 월강수량과 연최대 시간강수량의 이변량빈도해석을 통하여 기후변화를 고려한 강우-지속기간-빈도 관계의 변화를 평가해보고자 한다. 본 연구는 연최대 월강수량과 연최대 시간강수량과의 관계가 변하지 않는다는 가정하에 관측강수량을 이용하여 연최대 월강수량과 연최대 시간강수량의 이변량분포모형을 구축하였다. 이변량 분포모형을 구축하기 위하여 copula 모형을 적용하였다. 구축된 모형에 GCM으로 예측된 연최대 월강수량을 적용하여 미래의 확률강수량을 평가하였다. 본 연구에서는 서울지점을 대상지점으로 선정하였으며, A2 기후변화시나리오를 적용한 GCM 예측값을 이용하였다. 적용결과 A2 기후변화 시나리오 상에서 미래의 확률강수량이 크게 증가하는 것이 확인되었다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.20 no.2
• /
• pp.137-143
• /
• 2002

In this study we generated digital orthophoto from LIDAR data. To generate digital orthophoto, we make TIN from raw laser scanning data(XYZ point data) and compiled DSM from this TIN. In this procedure much noise appeared along the break lines in DSM and this can give bad effect to the quality of digital orthophoto. Therefore, we applied various techniques which can refine the break line. In the result, we concluded that the fusion of LIDAR DEM of lowland and extracted buildings was adequate to generating DSM. So we generated the digital orthophoto from DSM generated from this technique. In the result of quality test, the positional accuracy of this digital orthophoto was better than the positional accuracy of 1:5,000 map.

• Journal of Korean Society for Geospatial Information Science
• /
• v.2 no.2 s.4
• /
• pp.131-142
• /
• 1994

Generally, there are two methods which generates the base map of Geo-Spatial Information System(GSIS). one is the digitizing of existing map, and the other is the analytical plotting method editing data acquired by sensors using computers. But the analytical plotting method and method of the digitizing of existing map is technically complex and has the disadvantages in the costs and time. The subject region of study(the Kwangyang province), was photographed by aircraft, and photographing scale was 1/6,000. Then this area was divided into two specific regions, the residential area, and the agricultural area. In this study, we developed the algorithm that generated base map of database in GSIS from the aerial photo. This algorithm is as followed. First, the digital aerial photos were generated using these aerial photos. Second, these digital aerial photos were enhanced by implementing the histogram equalization. Third, the objects of the enhanced images were extracted by implementing thresholding and edged detection techiques of image segmentation. Finally, these images could be used to updated the base map of database in GSIS. The result obtained from this study showed that method used by this study were more efficient than existing method in costs and time.

• 한국공간정보시스템학회:학술대회논문집
• /
• 2000.06a
• /
• pp.67-76
• /
• 2000

Recently, SAR Interferometry method is actively being studied as a new technic in topographic mapping using satellite imageries. it extract height values using two SAR imageries covering same areas. Unlike when using SPOT imageries, it isn't affected by atmospheric conditions and time. But it is difficult to process radar imageries and the height accuracy is very low where relief displacements are high. In this study, we produced DEM(Digital Elevation Model) using ERS-1, ERS-2 tandem data and analysed the height accuracy over 14 ground control points. The mean error in height was 14.06m. But when using airborne SAR data, it Is expected that we can produce more accurate DEM which will be able to ue used in updating 1/10,000 or 1/25,000 map.

• Journal of Korean Society for Geospatial Information Science
• /
• v.12 no.2 s.29
• /
• pp.43-52
• /
• 2004

This study presents the application of aerial photographs and the Korea Multi-Purpose Satellite, KOMPSAT-1 Electro-Optical Camera(EOC) imagery in detecting change in an urban area that has been rapidly growing. For the study, we used multi-temporal images which were acquired by two different sensors. Image registration and resampling were rallied out before performing change detection in a common reference system with the same spatial resolution. for all of the images. Results from image differencing and image ratioing techniques show that panchromatic aerial photographs and KOMPSAT-1 EOC images collected by different sensors have potential to detect changes of urban features such as building, road and other man-made structure. And the optimal threshold values were suggested in applying image differencing and image ratioing techniques for change detection.