• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.26 no.10
• /
• pp.1348-1354
• /
• 2002

We investigate the flame behavior and spatial distribution of OH, PAHs and soot in a confined buoyant diffusion flame with decrease of the coflowing air flow rate. Direct photographs and Schlieren images represent that flame is Ally occupied by blue flame and becomes unstable, which is partially detached to the fuel nozzle tip in a near extinction flame under extremely reduced oxidizer condition. Laser induced fluorescence profiles clearly shows that OH is still generated in near-extinction flame, although intensity becomes weak with decreasing air flow rate. But soot scattering image cannot be seen any more in an oxidizer deficient ambience and simultaneously the PAHs are widely distributed downstream. These results are due to that a decrease of oxygen concentration in the combustion chamber leads to a temperature drop of flame, as a consequence, to a delay in soot growth and to a expanding of the PAHs, as soot precursors.

• Journal of KIISE:Computing Practices and Letters
• /
• v.16 no.5
• /
• pp.616-620
• /
• 2010

Generally, most people use the photo management method which clusters lots of photos into each folders according to photo shooting time and date. However, since the number of photos to manage is getting more increasing, it takes much time and burdensome work. This paper describes PHOTOLAND, a system that visualizes hundreds of photos on a 2D grid space to help users manage their photos. It closely places similar photos in the grid based on temporal and spatial information. Most photograph management systems use a scrollable view based on a sequential grid layout that arranges the thumbnails of photos in some default order on the screen. Our system decreases drag and drop mouse interaction when they classify their photos into small groups comparing to the sequential grid layout. We conducted experiments to evaluate temporal coherence and space efficiency.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.9 no.3
• /
• pp.92-100
• /
• 2005

An optimal fuel manifold is suggested to improve the cooling performance of an injector face plate. The cooling performance at the center area of the injector face plate is to be augmented while the spatial injection uniformity is maintained. The comparison of the cooling performance of f candidates gives the conclusion that the dividing plate from 2-3 injector .ow to 9-10 injector. row is an optimal. The maximum face plate temperature decreases by 27$\%$ while the injection uniformity is close to that of the original design. The pressure drop in the fuel manifold of the optimal design is also same as the original design.

• Journal of Korean Society for Geospatial Information Science
• /
• v.15 no.1 s.39
• /
• pp.17-22
• /
• 2007

In this study, we recognized and joined parts of buildings separated during LIDAR point segmentation utilizing scan line characteristics, with an additional function to recognize neighboring relation among point segments. And we applied the relation to suggest a method to recognize earth point segment. From the test, we could confirm that it does not drop down the efficiency of point segmentation to be added with the function of recognizing neighboring relation and it is possibile to combine point segments to form a complete shaped building and to recognize earth point segment.

• Korean Institute of Interior Design Journal
• /
• v.16 no.3 s.62
• /
• pp.119-129
• /
• 2007

This study illustrates a prototype proposal and its evaluation for the development of floor plans in the condominium housing remodeling. For this I evaluated the survey of the residents of the 'K' town in Joonge-dong, Nowon-gu, Seoul, against the proposal which was developed based on the resident's pre-survey. The result includes that the residents' preference for community actions such as the removal of fences which are reviewed as negative, whereas the introduction of a fitness center and community facilities in the library are reviewed as positive. The residents preferred the open space by the piloti structure, although which is the wall column structure, where they anticipated a rest area, sports facilities, and bicycle drop-off spots. The sidewall proposal in the main building and the full use of the roof floor were underestimated in terms of design concept. The research also illustrated the residents' desired space planning options, those tending to use of space 'B type', personalization 'C type' and spatial size 'A type'. Residents responded positively to the introduction of the 'Alpha' space in which two households share one space that could be used for multiple purposes such as a rest area, an environment-friendly garden, and hobby room, etc, and also there is another possibility it plays an important role to the sociality in community.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.4 no.1
• /
• pp.36-45
• /
• 2000

Most researches for impinging jet spray have been focused on under-standing the breakup mechanism of a liquid sheet formed by the collision of jets and modeling the spray breakup using experimental data. For this reason, there have been few studies on the characteristics of the spatial spray distribution which affects significantly the combustion efficiency. Hence, we measured the radial distribution of fuel massflux using a like-doublet type injector. Instead of PDPA(Phase Doppler Particle Analyzer) which has been used only for the point measurement of the drop size of spray, PLIF(Planar Laser Induced Fluorescence) technique was developed lot the 2-D measurement of the massflux distribution of spray Indirect photography technique was also used to verify PLIF data.

• The Bulletin of The Korean Astronomical Society
• /
• v.43 no.2
• /
• pp.59.4-60
• /
• 2018

Ultra-diffuse galaxies (UDGs) are an unusual galaxy population. They are ghostlike galaxies with fainter surface brightness than normal dwarf galaxies, but they are as large as MW-like galaxies. The key question on UDGs is whether they are 'failed' giant galaxies or 'extended' dwarf galaxies. To answer this question, we study UDGs in massive galaxy clusters. We find an amount of UDGs in deep HST images of three Hubble Frontier Fields clusters, Abell 2744 (z=0.308), Abell S1063 (z=0.347), and Abell 370 (z=0.374). These clusters are the farthest and most massive galaxy clusters in which UDGs have been discovered until now. The color-magnitude relations show that most UDGs have old stellar population with red colors, while a few of them show bluer colors implying the existence of young stars. The stellar masses of UDGs show that they have less massive stellar components than the bright red sequence galaxies. The radial number density profiles of UDGs exhibit a drop in the central region of clusters, suggesting some of them were disrupted by strong gravitational potential. Their spatial distributions are not homogeneous, which implies UDGs are not virialized enough in the clusters. With virial masses of UDGs estimated from the fundamental manifold, most UDGs have M_200 = 10^10 - 10^11 M_Sun indicating that they are dwarf galaxies. However, a few of UDGs more massive than 10^11 M_Sun indicate that they are close to failed giant galaxies.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2009.04a
• /
• pp.340-343
• /
• 2009

u-GIS 환경에서 GeoSensor로부터 수집되는 시공간 데이터는 데이터 스트림의 특징을 포함한다. 데이터 스트림은 다양한 입력 속도로 끊임없이 입력되고, 데이터의 크기 또한 가변적이다. 이런 이유로 한정적인 메모리와 처리능력의 시스템은 과부하 현상이 발생한다. 이를 해결하기 위해 초과되는 데이터를 버려 메모리 초과를 방지하는 기법들이 연구되고 있다. 공간질의는 공간과 위치 값을 기반으로 이루어지는 연산으로 공간질의 정확도는 공간과 위치 정보를 통해 보장된다. 그러나 기존 기법인 랜덤부하제한 기법과 의미적부하제한 기법은 공간질의가 요구하는 공간과 위치 값에 대해 고려하지 않고 삭제하기 때문에 공간질의에 대한 정확도가 감소하는 문제를 갖는다. 본 논문에서는 공간의 이용도를 이용하여 차등적 비율을 적용한 부하제한 기법은 연구하였다. 이 기법은 등록된 공간질의의 영역 겹침 정도에 따라 중요 레벨을 증가시키고, 이를 토대로 시공간 데이터의 중요도를 파악하여 중요도마다 주어진 비율에 의하여 차등적으로 삭제한다. 결과적으로 기존 기법보다 다소 높은 Drop rate를 통해 질의 처리 속도를 빠르게 회복시켰으며, 중요 데이터를 최대한 유지하여 Error rate를 감소시켰다.

• Atmosphere
• /
• v.34 no.3
• /
• pp.273-281
• /
• 2024

Analyzing the information about climate change on Korean Peninsula is essential for the national defense. In this study, we used HadGEM3-RA model output (a member of CORDEX-EA) and analyzed the 3 operational weather factors (VMC, runway temperature, WBGT), which affect the aircraft field. The number of future limited days was quantitatively calculated based on the model outputs applying SSP1-2.6 and SSP5-8.5 and the operational limits of the previous three factors, and the spatial distribution, time series, and correlation of each result were analyzed. In conclusion, it was analyzed that the number of limited days by VMC would decrease, resulting from the rise in temperature and the drop in relative humidity. This means the operational environment in VMC will improve. On the other hand, the number of limited days by the runway temperature and WBGT would increase, resulting from the rise in temperature. This means the operational environment in runway temperature and WBGT will worsen.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.5
• /
• pp.1791-1798
• /
• 2010

This research predicted the change and characteristics of space structure by new residential area development through objective and quantitative analysis of urban spatial configuration using space syntax and associated the prediction with the city status statistics data and quantitative analysis, and the results are summarized as follows: (1) If large scale new residential area of Dongnae township proceeds to be developed according to present plan, accessibility to the new residential area will drop, and also as the outside space ripple effects by new residential area development also are anticipated small, the new residential area apprehensibly will not succeed to play the role of integrating the entire city structurally, but will cause structural problem, severing the city structure. (2) If the city planned road between existing urban center planned based on 2004 Chuncheon city plan overall drawing and main road which is the entrance road of the planned new residential area is developed together, the accessibility to the entire space of Chuncheon city and the new residential area will be easy, allowing the new residential area properly integrated into the entire space of Chuncheon city, consequently giving a prediction that classification of land use between the central part of Chuncheon city and surrounding residential area would become conspicuous.