트랙터 전·후진 변속 제어 기술 개발 동향

김용현,김택진,김용주,Kim, Yong Hyeon,Kim, Taek Jin,Kim, Yong Joo 유공압건설기계학회 2020 드라이브·컨트롤 Vol.17 No.1

우리 나라 대학과 사회교육참여

김용현,Kim, Yong-Hyeon 한국대학교육협의회 1983 大學敎育 Vol.3 No.-

미래전쟁에 대비한 군 구조 개선방향

김용현,Kim, Yong-Hyeon 대전대학교 군사연구원 2004 군사학연구 Vol.2 No.-

Development of science technology, computer network and software technology has not only changed various areas of the society, but also brought rapid change in the condition and the way of performing war. Historical lessons learned from the war in Iraq tells that military capabilities corresponding to the new paradigms of war needs to be assured in order to preserve national interest and take victory in future warfare. Thus, the performance in the latest war in Iraq, the estimated performance in future war and the performance of war in the Korean Peninsula has been put together and analyzed to indicate the direction our force should be built and the structure to be improved. Under all circumstances and threats the military must defend our nation and territory. When war breaks out the military must perform it's basic duty to end war by decisive operations. As the saying is "To preserve peace, prepare for war," continuous increase of military strength and improvement of military structure corresponding to the change of national security environment and weapon system is necessary.

천맥탕(天麥湯)의 알레르기 염증반응 및 기전탐색에 관한 연구

김용현,이승연,김원일,Kim, Yong-Hyeon,Lee, Seung-Yeon,Kim, Won-Il 대한한방소아과학회 2010 대한한방소아과학회지 Vol.24 No.1

Objectives The purpose of this study was to examine the pathway of anti-allergic effects of Cheonmaec-tang (CMT). Methods We examined the cell viability, $\beta$-hexosaminidase release, pro-inflammatory cytokines secretion and mRNA expressions, nuclear factor-kappa B (NF-${\kappa}B$) (p65) activation, inbibitor kappa B-alpha ($I{\kappa}B-{\alpha}$) degradation, and MAPKs activation in RBL-2H3 cells pre-treated by CMT of 2.0 mg/ml, 4.0 mg/ml separately. Results We observed that CMT reduced the secretion of $\beta$-hexosaminidase, TNF-$\alpha$, IL-4 and the expression of COX-2 mRNA in RBL-2H3 cells. Furthermore, CMT inhibited the levels of activation of NF-${\kappa}B$ (p65) protein, ERK MAPK, and degradation of $I{\kappa}B-{\alpha}$ in RBL-2H3 cells. Conclusions These results show that CMT has an anti-histamine effect and inhibitory effect of NF-${\kappa}B$ (p65) through regulation of $I{\kappa}B-{\alpha}$ degradation. These suggest that CMT could be used as an anti-allergic medicine.

엔드밀의 코너 가공시 가공 정밀도 향상에 관한 연구

김용현,고성림,Kim, Yong-Hyeon,Go, Seong-Rim 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.3

The Surface, generated by end milling operation, is deteriorated by tool runout, vibration, friction, tool deflection, etc. Especially in cornering cut, surface accuracy is usually determined by varying cutting forces, which causes tool deflections. Cutting conditions like feed rate is usually kept constant during machining a part, which causes dimensional error in severe cutting. Cornering cut is a typical example of deterioration of surface accuracy when constant feed rate is applied. Therefore it becomes important to develop NC post processor module to determine optimal cutting conditions in various cutting situations. In this paper, cutting force is predicted in cornering cut with flat end mill and feed rate is determined by constraining constantly resultant force. Also some control characteristics of CNC machining center are evaluated.

코팅된 시편과 레이저 빔과의 상호 작용 연구

김용현,백원계,신완순,여재익,Kim, Yong-Hyeon,Baek, Won-Kye,Sin, Wan-Soon,Yoh, Jai-Ick 한국군사과학기술학회 2011 한국군사과학기술학회지 Vol.14 No.6

The beam-matter interaction with various coating effects has received continued attention in the high power laser community. Previous works suggest that coatings promote target damage when compared to beaming on uncoated surface. Three types of paint coatings(Acrylic urethane, Silicone alkyd and Stealth blend) and a water coat on metals(Al, Ti and STS) are irradiated with a $CO_2$ laser. Both strain and temperature measurements are provided for assessing the instantaneous response characteristics of each coating on different metals. A selective combination of surface coats with metals has proven effective in either preventing or enhancing damage, both thermal and mechanical, associated with focused beaming on a target.

당분흡수 억제제

김용현,Kim, Yong-Hyeon 사단법인 한국당뇨협회 2006 당뇨 Vol.204 No.-

폴리머용액법 및 알루미나 seed를 도입한 YAG:Ce³⁺ 형광체 분말 합성

김용현,이상진,Kim, Yong-Hyeon,Lee, Sang-Jin 한국분말야금학회 2013 한국분말재료학회지 (KPMI) Vol.20 No.1

$YAG:Ce^{3+}$ phosphor powders were synthesized using a $Al_2O_3$ seed (average particle size: 5 ${\mu}m$) by the polymer solution route. PVA solution was added to the sol precursors consisting of the seed powder and metal nitrate salts for homogeneous mixing in atomic scale. All dried precursor gels were calcined at $500^{\circ}C$ and then heated at $1400^{\circ}C{\sim}1500^{\circ}C$ in $N_2/H_2$ atmosphere. The final powders were characterized by using XRD, SEM, PSA, PL and PKG test. All synthesized powders were crystallized to YAG phase without intermediate phases of YAM or YAP. The phosphor properties and morphologies of the synthesized powders were strongly dependent on the PVA content. Finally, the synthesized $YAG:Ce^{3+}$ phosphor powder heated at $1500^{\circ}C$, which is prepared from 12:1 PVA content and has an average particle size of 15 ${\mu}m$, showed similar phosphor properties to a commercial phosphor powder.

Experimental Outdoor Visible Light Data Communication Systems with Optical Filter

김용현,정연호,Kim, Yong-Hyeon,Chung, Yeon-Ho The Korea Institute of Information and Commucation 2014 한국정보통신학회논문지 Vol.18 No.8

본 논문은 태양광 혹은 인공광이 존재하는 외부 환경에서 광필터를 적용한 실험적 실외 광무선 데이터 통신 시스템을 제안한다. 광잡음의 효과적인 차단을 위해 마이크로루버 필름을 사용한 광필터를 광다이오드에 직접 적용하였으며 잡음광이 광다이오드에 정면으로 입사하지 않는다는 가정하에 입사각 30도를 초과하는 잡음광을 차단하도록 설계하였다. 제안하는 시스템을 낮시간 실외에서 데이터 전송을 통해 검증하였는데 지정한 입사각 혹은 그 이상의 입사 잡음광에 대해 거의 완벽하게 차단할 수 있었으며 전송된 패킷데이터의 90%이상을 성공적으로 수신하였다. 본 제안 시스템은 향후 실외 자유공간 광무선 데이터 전송에 효과적으로 사용될 수 있을 것이다. An experimental outdoor optical wireless data communication system with an optical filter in the presence of sunlight or artificial light is presented. For the efficient blocking of light noise outdoors, we employ an optical filter made of microlouver film on the top of the photo diode. This filter is designed to block any light noise incident from an angle higher than $30^{\circ}$ on the assumption that light noise does not face the photo diode horizontally. Outdoor experiments daytime with the optical filtering have been conducted. The experimental results demonstrate that the optical filter effectively blocks nearly all light noise incident from the specified angle or higher and more than 90% of the transmitted data packets are successfully received. The proposed outdoor visible light data communication can thus facilitate a practical free space outdoor optical wireless data transmission.

Zr₂WP₂O₁₂ 세라믹스의 합성과 소결거동 연구

김용현,김남옥,이상진,Kim, Yong-Hyeon,Kim, Nam-Ok,Lee, Sang-Jin 한국세라믹학회 2012 한국세라믹학회지 Vol.49 No.6

$Zr_2WP_2O_{12}$ powder, which has a negative thermal expansion coefficient, was synthesized by a solid-state reaction with $ZrO_2$, $WO_3$ and $NH_4H_2PO_4$ as the starting materials. The synthesis behavior was dependent on the solvent media used in the wet mixing process. The $Zr_2WP_2O_{12}$ powder prepared with a solvent consisting of D. I. water was fully crystallized at $1200^{\circ}C$, showing a sub-micron particle size. According to the results obtained from a thermal analysis, a $ZrP_2O_7$ was synthesized at a low temperature of $310^{\circ}C$, after which it was reacted with $WO_3$ at $1200^{\circ}C$. A new sintering additive, $Al(OH)_3$, was applied for the densification of the $Zr_2WP_2O_{12}$ powders. The cold isostatically pressed samples were densified with 1 wt% $Al(OH)_3$ additive or more at $1200^{\circ}C$ for 4 h. The main densification mechanism was liquid-phase sintering due to the liquid which resulted from the reaction with amorphous or unstable $Al_2O_3$ and $WO_3$. The densified $Zr_2WP_2O_{12}$ ceramics showed a relative density of 90% and a negative thermal expansion coefficient of $-3.4{\times}10^{-6}/^{\circ}C$. When using ${\alpha}-Al_2O_3$ as the sintering agent, densification was not observed at $1200^{\circ}C$.