초고속 무선 멀티미디어(인터넷) 서비스를 위한 밀리미터파 대역 Pico Cell 광무선 통신 기술

김호영,전동석,이상석,남은수,김제하,김해천,조경익,김보우,이우용,Kim, H.Y.,Jeon, D.S.,Lee, S.S.,Nam, E.S.,Kim, J.H.,Kim, H.C.,Cho, K.I.,Kim, B.W.,Lee, W.Y. 한국전자통신연구원 2005 전자통신동향분석 Vol.20 No.6

최근 국내외에서 연구되고 있는 가입자에 초고속 멀티미디어 서비스가 가능하도록pico cell 가입자 통신망을 구성하여 100Mbps-수 Gbps의 대용량 초고속 데이터를 통신할 수 있는 밀리미터파 pico cell 광무선 통신 기술의 개념, 필요성, 기술 동향과ETRI를 중심으로 연구 개발되고 있는 핵심 부품들의 개발 현황과 기술의 활용성에 대하여 조사하였다.

20d_b 정착길이를 가지는 SD700 갈고리철근과 확대머리철근의 정착성능 실험

김호영,심혜정,Kim, Ho Young,Sim, Hye Jung 인천대학교 도시과학연구원 2018 도시과학 Vol.7 No.2

With the increase of the skyscraper center, the development of large-diameter and high-strength reinforcing bars is being carried out to solve the dense reinforcement. In case of the steel reinforced concrete with a small cross section such as beam-column joints, the development length becomes short when straight bars are used. Therefore, it is possible to solve the problem that the development length becomes short by using the bearing strength of the hooked bar and headed bar. In this study, the exterior beam-column joint test of SD700 hooked bar and headed bar with anchorage length of 20db was conducted to extend the development length limitation of hooked bar and headed bar. As a result of the evaluation of the anchorage strength using the design equation by KCI, the average of the [measured value]/[predicted value] ratio was 1.31 for the hooked reinforcing bars. In the case of headed bars, the average of the [measured value]/[predicted value] ratio was 1.12. In addition, in order to compare the anchorage performance of the hooked bar and the headed bar, the measured values were divided by the square root of the compressive strength of the concrete to compare the anchorage strength. Under the same conditions, the anchorage strength of headed bars was 8.5% higher than the hooked bars.

금속폭발억제재가 충진된 LPG 탱크의 비정상 열전달 및 압력변화 해석

김호영,장효환,전철균,Kim H. Y.,Chang H. W.,Chun C. K. 대한설비공학회 1987 설비저널 Vol.16 No.4

As one of the explosion suppression methods of LPG tank exposed to hot environment by an accident or fire, some material which has large heat capacity and thermal conductivity can be installed inside the LPG tank in order to suppress the temperature increasement of tank wall. In the present study, theoretical model for the horizontally locating cylindrical LPG tank with and without the aluminum explosion suppression material has been developed to predict the characteristics of system. As a parametric study, effects of two major parameters, thickness of material filling and initial vapor volume fraction, on the time variation of wall temperature, temperature and pressure in tank are numerically examined. The results of present study show that the thickness of material filling does not give big differences in the suppression characteristics when the thickness of filling is larger than three inches. In case of material filling, there are marked suppression effects to the increase-ment of wall temperature, average vapor temperature and pressure in tank compared with the case of no filling.

스토커형 소각로의 연소특성 및 연소 모델에 관한 연구

김호영,황호영,전철균,Kim, Ho-Yeong,Hwang, Ho-Yeong,Jeon, Cheol-Gyun 대한기계학회 1998 大韓機械學會論文集B Vol.22 No.5

A combustion model for the incineration of municipal solid waste(MSW) in the stoker type incinerator was developed by considering the variation of physical composition of MSW. Theoretical analysis and numerical simulation for the combustion characteristics in incinerator were conducted by using the present model and the effects of compositional variation on the incineration characteristics of MSW was examined theoretically. It is found that large excess air enhances drying, but depresses volatilization. For the large value of moisture content, pyrolysis is fast but drying is slow. As the value of plastic content increases, devolatilization becomes slower. Larger amount of primary air supply to the rear side of stoker leads to increase the possibility of delaying the combustion.

이동패킷 무선망을 위한 ISMA 프로토콜

김호영,Kim, Ho-Yeong 한국전자통신연구원 1989 전자통신 Vol.11 No.2

패킷무선망의 성능분석을 위해 기제안된 경합형 프로토콜중 ISMA 방식을 선정하여 그에대한 throughput 및 delay 특성을 패킷발생률, SNR; 패킷 오율, 단말기의 이동속도, 변복조 방식 등 여러가지 시스팀 변수를 고려하여 모델링하고 평가하였으며, 특히 링크의 상태가 열악한 레일리 페이딩 환경에서의 해석을 행함으로서 이동 패킷 무선망에의 적용 가능성을 검토하였다. 또 해석결과를 바탕으로 컴퓨터 시뮬레이션에 의해 여타 방식과의 비교 평가를 행함으로서 ISMA 방식이 레일리 페이딩 환경에서 특히 우수함을 입증하고, 이동무선 환경에서 이용할 수 있음을 보였다. 시뮬레이션 결과에 의하면 ISMA 방식은 round trip delay가 비교적 길경우 CSMA나 slotted-ALOHA에 비교하여 매우 유효한 프로토콜이다.

백내장 수술 후 후낭혼탁 발생 억제에 대한 트라닐라스트의 유용성

김호영,이헌일,전연숙,김재찬,Ho Young Kim,Hyeon Il Lee,Yeoun Sook Chun,Jae Chan Kim 대한안과학회 2008 대한안과학회지 Vol.49 No.12

Purpose: To evaluate the inhibitory effect of tranilast on the formation of posterior capsular opacity (PCO) after a cataract operation ex vivo and in a rabbit model. Methods: A human lens epithelial cell line (B3) was treated with 0.005-0.1 mM tranilast. Cytotoxicity assessment and effective dosage determination of tranilast were performed using MTT assays. B3 cell lines were cultured in Eagle's minimal essential medium (EMEM) containing 20% FBS with different concentrationsof tranilast, and morphological differences were observed. To investigate the effect of tranilast on cytokine production in B3 cell lines, cells were treated with 0.01 mM tranilast and expression profiles of cytokines were analyzed by RT-PCR. After performing phacoemulsification and intraocular lens implantation in 10 white rabbits, 0.5% tranilast eye drops were given 4 times per day, and the severity of PCO was evaluated bi-weekly using POCOman for 8 weeks after the operation. Results: Cell death was observed in the 0.05 mM tranilast-treated B3 cell lines, and inhibition of epithelial- mesenchymal transition (EMT) was also observed in the 0.01 mM tranilast-treated B3 cell lines. TGF-β1/2, IL-18, and CDK7 mRNA expression decreased in the 0.01 mM tranilast-treated B3 cell lines. Significant suppression of PCO formation was observed in rabbits treated with 0.5% tranilast eye drops 5 weeks post operative (p<0.05). Conclusions: The results from this study show that tranilast suppresses EMT through inhibition of TGF-β, IL-18,and CDK7 expression. The results suggest that tranilast can be used toprevent PCO formation after cataract surgery.

디지틀 이동통신과 ISDN

김호영,Kim, Ho-Yeong 한국전자통신연구원 1988 전자통신동향분석 Vol.3 No.2

본 고에서는 디지틀 이동통신 기술개발에 의한 FPLMTS의 구축시 검토하여 할 사항에 대하여 논하였다. ISDN의 개요와 이동통신계의 ISDN화에 따른 문제점, 디지틀 이동통신 개발현황 및 CCIR을 비롯한 국제표준기구에서의 표준화 동향에 관하여 소개하였으며, 디지틀 이동통신 시스팀 개발시 극복해야 할 과제를 제시하였다.

경쟁력 강화를 위한 아웃소싱 방안

김호영,Kim, Ho-Yeong 한국주류산업협회 1999 주류산업 Vol.19 No.2

지하냉장 저장기술

김호영,박연준,박준택,Kim, H.Y.,Park, Y.J.,Park, J.T. 대한설비공학회 1995 설비저널 Vol.24 No.3

열 기포에 의한 고체 박막의 변형 해석

김호영,이윤표,Kim, Ho-Young,Lee, Yoon-Pyo 대한기계학회 2003 大韓機械學會論文集B Vol.27 No.2

Thermal bubbles find their diverse application areas in the MEMS (MicroElectroMechanial Systems) technology, including bubble jet printers, microactuators, micropumps, etc.. Especially, microactuators and micropumps, which use a microbubble growing by a controlled heat input, frequently involve mechanical and thermal interaction of the bubble with a solid structure, such as a cantilever beam and a membrane. Although the concept is experimentally verified that an internal pressure of the bubble can build up high enough to deflect a thin solid plate or a beam, the physics of the entire process have not yet been thoroughly explored. This work reports the experimental study of the growth of a thermal bubble while deflecting a thin cantilever beam. A physical model is presented to predict the elastic response of the cantilever beam based on the experimental measurements. The scaling law constructed through this work can provide a design guide for micro- and nano-systems that employ a thermal bubble for their actuation/pumping mechanism.