http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
실내실험을 통한 Carbon Nanotube의 콘크리트슬래브 열전달 효과
김희수(Heesu Kim),반호기(Hoki Ban) 한국지반환경공학회 2017 한국지반환경공학회논문집 Vol.18 No.12
국내 한랭지역(강원권)의 경우 낮은 연평균 기온으로 인해 도로표면이 자주 결빙된다. 특히 터널의 입출구의 도로면은 지형적 영향으로 그늘이 생기기 때문에 타 도로면에 비해 결빙이 많이 발생하게 된다. 이러한 결빙을 방지하기 위해 염수분사장치, 전열선 설치, 지열이용 등이 주로 사용되고 있다. 하지만 이런 방법들은 환경오염, 많은 공사비, 유지보수비 및 정기적인 점검 등의 문제점들이 있다. 본 연구에서는 기존도로의 결빙을 방지하기 위해 발열체인 CNT를 이용하여 콘크리트 슬래브의 발열효과를 살펴보고 최적의 CNT설치 간격을 결정하였다. In the cold region, road surface is frequently frozen, resulting in property/facility damage as well as people’s death. In order to prevent the road surface from being frozen, conventional deicing methods such as salt, geothermal, and electric wires have been widely used. However, theses methods have some problems such as anti-environment, high-construction and -maintenance cost and so on. To improve the drawbacks of aforementioned methods, carbon nanotube (CNT) was used as an heating material in the laboratory test. Through the test, heat transferring effect of CNT on the concrete slab was investigated and maximum interval of CNT installation was determined.
전단부 혹이 혹등고래 지느러미 모델의 유체역학적 성능에 미치는 영향
김희수(Heesu Kim),김주하(Jooha Kim),최해천(Haecheon Choi) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11
In this study, we experimentally investigate the effect of leading edge tubercles on the hydrodynamic performance of a humpback whale flipper model. The lift and drag forces are measured at Reynolds numbers of 80,000 – 280,000, and PIV is conducted in several streamwise and cross-flow planes at a few different angles of attack. Without tubercles, flow separation occurs near the tip region first, and then propagates rapidly towards the root of the flipper model as the attack angle increases. With tubercles, however, the cross flow above the flipper model shows two types of vortical motions at the post-stall region. One is the single streamwise vortex with negative vorticity which is observed near tip region, and the other is the counter-rotating streamwise vortices which is observed at mid-span region. These structures energize boundary layer by carrying high momentum flow, resulting in separation delay.
혹등고래 가슴지느러미 전단부 혹이 수력학적 성능에 미치는 영향
김희수(Heesu Kim),김주하(Jooha Kim),최해천(Haecheon Choi) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12
In the present study, we experimentally investigate the effect of tubercles on the hydrodynamic performance of a humpback whale flipper. The shape of the flipper used is the same as that of Miklosovic et al. (2004, 2007), and the Reynolds number considered is 100,000. The lift and drag forces on the flipper are measured by varying the angle of attack, and PIV measurements are conducted at a few different angles of attack. As observed in previous studies, with tubercles, the stall angle is delayed and the maximum lift coefficient is increased. Without tubercles, the cross flow above the flipper does not show large-scale vortical motions except tip vortex. With tubercles, however, strong streamwise vortices having negative vorticity are observed along the tubercles, but the vortices with positive vorticity are either relatively weak or unobserved. This result is very different from those found in a two-dimensional wing with tubercles with which strong counter-rotating streamwise vortex pair are observed.
일반적인 GPU 트리 탐색과의 비교실험을 통한 GPU 기반 병렬 Shifted Sort 알고리즘 분석
김희수(Heesu Kim),박태정(Taejung Park) 한국디지털콘텐츠학회 2017 한국디지털콘텐츠학회논문지 Vol.18 No.6
It is common to achieve lower performance in traversing tree data structures in GPU than one expects. In this paper, we analyze the reason of lower-than-expected performance in GPU tree traversal and present that the warp divergences is caused by the branch instructions (“if... else”) which appear commonly in tree traversal CUDA codes. Also, we compare the parallel shifted sort algorithm which can reduce the number of warp divergences with a kd-tree CUDA implementation to show that the shifted sort algorithm can work faster than the kd-tree CUDA implementation thanks to less warp divergences. As the analysis result, the shifted sort algorithm worked about 16-fold faster than the kd-tree CUDA implementation for 2<SUP>23</SUP> query points and 2<SUP>23</SUP> data points in R³ space. The performance gaps tend to increase in proportion to the number of query points and data points.
논문 키워드 네트워크 분석을 통한 군사과학기술 분야의 특징
김희수(Heesu Kim),김재현(Jaehyun Kim),최원석(Wonseok Choi),황인서(Inseo Hwang),김윤영(Yunyang Kim),임현재(Hyunjae Im),조영기(Youngki Cho) 육군사관학교 화랑대연구소 2021 한국군사학논집 Vol.77 No.1
Analysis of characteristic of the academic field is a important field of study handled by many fields, it allows to understand overall view of specific field by analyzing characteristic. The purpose of the study is to identify characteristic of Korean Military Science. First, we extracted 7528 keywords of 1842 published papers from 1998 to 2020 in the Journal of the Korean Military Science and Technology. Second, we build Keyword Network. Finally, using degree, nBetweetness and frequency of measurement Indicator of network, we analyzed the Keyword Network and examined its characteristics.