미끄럼 환경의 변화에 따른 ${Si_3}{N_4}$의 마멸거동

이영재,Lee, Yeong-Jae 대한기계학회 1996 大韓機械學會論文集A Vol.20 No.6

The wear behaviors of ${Si_3}{N_4}$ under the different sliding conditions were investigated. The cylinder-on-disc wear tester was used. Using the servo-metor, the sliding speed did ot alternate due to the frictional forces. Threekinds of loads and speeds were selected to watch the variation of the wear rates and the frictional forces. Also three kinds of sliding condition under a constant speed were used to see the effects of the oxidationand the abrasion. The contact pressure was more effective than the repeated cycle on the wear behavior of ${Si_3}{N_4}$. With the low loads, the effect of the asperity-failure was more dominant than that of oxidation and abrasion. As increasing the load, the effects of oxidation and abrasion were increased, but the asperity-failure effects were decreased. The wear particles destroyed the ozide layers formed on sliding surfaces. The wear rate could be decreased due to delaying the oxidation. The frictional power and the wear weight per time were usefuel to see the transition of wear.

웹캠과 공간정보를 이용한 체감형 기능성게임

이영재,이대호,이상봉,Lee, Young-Jae,Lee, Dae-Ho,Yi, Sang-Hong 한국정보통신학회 2009 한국정보통신학회논문지 Vol.13 No.9

Motion based serious game is a new style of game and exercise using hands, arms, head and whole body. At that time gamer's reachable movement space is an important game space and interaction happening place. We propose efficient game spatial division and analysis algorithm that gives special information for collision avoidance of game objects. We devide into 9 parts of game space and check the enemy position and upper, down, left and right side movement information of gamer and calculate optimal path for collide avoidance of the enemy. To evaluate the method, we implemented a motion base serious game that consists of a web cam, a player, an enemy, and we obtained some valid results of our method for the collision avoidance. The resole demonstrated that the proposed approach is robust. If movement information is in front of enemy, then the enemy waits and finds the place and runs to avoid collision. This algorithm can be used basic development of level control and effective interaction method for motion based serious game. 웹캠을 사용한 체감형 기능성게임은 손과 팔 머리 등 온몸을 인터페이스로 사용하는 게임과 운동을 병행하는 새로운 형태의 게임이다. 이때 게이머의 움직임이 미치는 공간이 게임 정보공간으로 이 공간상에 가상객체와의 상호작용이 발생하는 곳이다. 이 공간을 효과적으로 분할, 분석하여 게이머의 공격으로부터 적 캐릭터가 효과적으로 피할 수 있는 방법을 제안한다. 본 논문에서는 게임 공간을 9등분하여 적 캐릭터의 위치와 상, 하, 좌, 우의 게이머의 움직임 정보를 이용하여 충돌 회피를 구현한다. 이를 검증하기 위하여 웹캠, 게임플레이어, 적 캐릭터로 구성된 체감형 기능성 게임을 제작하고, 제안한 기법을 사용하여 충돌 회피를 실험하여 그 타당성을 확인하였다. 특히 적 캐릭터 앞 공간 영역에 움직임 정보가 있는 경우 제자리 뛰기를 하면서 기다리며 충돌회피 공간을 찾음으로써 보다 재미있고, 효과적인 충돌회피가 가능하였다. 제안한 알고리즘은 웹캠을 이용한 체감형 기능성게임의 효과적인 상호작용과 레벨조정 등 개발 알고리즘으로 활용될 수 있다.

타이타늄 상악 주연결장치에 디자인에 따른 주조성 및 견고성 비교

이영재,방몽숙,양홍서,박상원,박하옥,임현필,Lee, Young-Jae,Vang, Mong-Sook,Yang, Hong-So,Park, Sang-Won,Park, Ha-Ok,Lim, Hyun-Pil 대한치과보철학회 2007 대한치과보철학회지 Vol.45 No.4

Statement of problem: Injuries along with discomfort may result on the oral mucosa when non-rigid material is used as the major connector in construction of RPD, since nonrigid major connectors transmit unstable forces throughout the appliance. Titanium which recently draws attention as a substitute of Co-Cr had a difficulty in fabricating due to high melting temperature but the development of casting technique makes it possible to apply to the clinical case. Purpose: The purpose of this study was to investigate the rigidity and the castability of titanium upper major connector by design and make a comparison with Co-Cr major connectors which are widely used in clinical cases now. Material and methods: Casting was done using CP-Ti(Grage 2) (Kobe still Co., Japan) for the experimental groups, and 4 various designs namely palatal strap, U-shaped bar, A-P strap, and complete palatal plate were casted and 5 of each designs were included in each group. For the experimental group, Universal testing machine (Model 4502; Instron, Canton, Mass) was used to apply vertical torsional force vertically to the horizontal plane of major connector. In the second experiment, Vertical compressive force was applied to the horizontal plane of major connector. As a comparative group, Co-Cr major connector was equally manufactured and underwent the same experimental procedures Strain rate was measured after constant loading for one minute duration, and statistical analysis was done with SPSS ver.10.0 for WIN(SPSS. Inc. USA). From the one-way ANOVA and variance analysis (P=0.05), Scheffe's multiple comparison test implemented. Results: 1. Least amount of strain was observed with complete palatal plate followed by A-P bar, palatal bar, and the U-shaped bar having most amount of strain. 2. In all designs of titanium major connector, less strain rate was observed under compressive loading than under torsional loading showing more resistance to lateral force. 3. For titanium major connector, less strain rate was observed when the force is applied to the first premolar area rather than to the second molar area indicating more strength with shorter length of lever. 4. In Comparison of Co-Cr major connector with titanium major connector, palatal strap and U-shaped bar designs showed higher strength under torsional force that is statically significant, and under compressive force, no significant difference was observed expert for U-shaped bar. 5. In titanium major connector, complete palatal plate showed lowest success rate in casting when compared with the Co-Cr major connector. Conclusion: Above results prove that when using titanium for major connector, only with designs capable of generating rigidity can the major connector have almost equal amount of rigidity as Co-Cr major connector and show lower success rate in casting when compared with the Co-Cr major connector.

바이어스 스퍼터링 법으로 제조된 LiCoO₂박막 I. 전기화학적 특성

이영재,박호영,조병원,조원일,김광범,Lee, Y.J.,Park, H.Y.,Cho, W.I.,Cho, B.W.,Kim, K.B. 한국전기화학회 2003 한국전기화학회지 Vol.6 No.4

박막전지의 제조공정 중 열처리 공정은 많은 문제점들을 가지고 있다. 본 연구에서는 열처리 공정 없이 박막의 구조변화를 유발하는 바이어스 스퍼터링(Bias sputtering) 방법으로 $LiCoO_2$ 양극 활물질 박막을 제조하여 그 특성을 고찰하였다. 제조된 박막은 다양한 분석 방법을 이용하여 결정구조, 표면형상, 방전용량을 관찰하였다, 제조된 $LiCoO_2$양극활물질 박막 중 -50 V의 기판 바이어스 전압$(substrate\;bias\;voltage:\;V_b)$을 인가하여 제조된 $LiCoO_2$ 양극 활물질 박막에서 약 $60{\mu}Ah/cm^2{\mu}m.$의 초기 방전 용량을 가짐을 확인하였다. 본 연구는 열처리 공정 없이도 박막전지의 양극활물질로서 $LiCoO_2$ 박막을 사용할 수 있음을 알 수 있었다. The heat treatment process of thin film microbatteries manufacturing processes has several Problems. This study, without heat treatment, considered the characteristics of $LiCoO_2$ thin films deposited by bais sputtering method inducing the structural change of the thin film. The properties of deposited $LiCoO_2$ thin films such as crystal structure, morphology, and discharge capacity were observed by various analysis methods. Among $LiCoO_2$ thin films deposited by substrate bias $voltage(V_b)$, the one deposited by substrate bias voltage of -50V had the highest initial discharge capacity of about $60{\mu}Ah/cm^2{\mu}m.$ We confirmed that $LiCoO_2$ thin film could be used as cathode material of lithium thin film microbatteries without annealing.

국가 재난관리 상호협력체계

이영재,한상준,Lee, Yeong-Jae,Han, Sang-Jun 한국방재안전학회 2009 한국방재안전학회 논문집 Vol.2 No.4

인적재난에서 재난전조 정보관리

이영재,Lee, Yeong-Jae 한국방재안전학회 2010 한국방재안전학회 논문집 Vol.3 No.2

특집 : 양계산업 불황 타개 방안 - 산란계 산업 안정화 방안

이영재,Lee, Yeong-Jae 대한양계협회 2012 월간 양계 Vol.44 No.8

온라인 데이터베이스 서비스의 원가계산과 가격결정에 관한 연구(Ⅰ)

이영재,Lee, Yeong-Jae 한국데이터베이스진흥원 1995 디지털콘텐츠 Vol.1 No.-

멀티미디어 콘텐츠화면에서의 효과적인 PPL 배치

이영재,Lee, Young-Jae 한국정보통신학회 2007 한국정보통신학회논문지 Vol.11 No.5

최근 멀티미디어 분야에서 새로운 수익모델로 주목받고 있는 PPL(Product Placement)을 활용하여 멀티미디어 콘텐츠 화면의 주목도를 분석하였다. 이를 위해 컴퓨터 화면을 9사분면으로 분할한 후 각각의 위치에 2D, 3D 숫자 정지 영상, 숫자 부분 동영상, 동영상 등을 배치하여 영상의 유형과 위치에 따라 사용자의 주목도에 어떠한 변화가 있는가에 관해 연구하였다. 분석 결과 2D 숫자 정지 영상과 동영상의 경우엔 5사분면에 높은 주목도를 나타냈으며, 3D 숫자 정지영상과 동영상의 경우 역시 일관성 있게 5사분면에 높은 주목도를 나타냈다. 특히 정지영상 내 동영상이 존재하는 부분 동영상의 경우엔 동영상이 존재하는 분면에 압도적인 주목도를 나타냈다. 이는 영상의 노출형태가 사용자의 주목도에 유의미한 영향을 미치는 것으로 정지영상보다는 동영상 형태의 노출이 사용자의 주목효과(attention of effects)를 높일 수 있는 것을 의미한다. 이 같은 연구결과는 멀티미디어 콘텐츠 화면에서의 PPL 제작 시 어떤 위치에 PPL을 배치해야 사용자의 주목도를 극대화할 수 있는가에 대한 문제를 해결하는데 기여할 수 있을 것으로 사료된다. This study explores the attention effects of PPL(product placement) in multimedia contents. PPL has been attracted attention in multimedia as well as marketing communication field as a beneficiary model. For the research, multimedia screen is divided into 9 sections and the serial 9 digit($1{\sim}9$) is assigned to the each part of the screen. The visual exposure forms of each 9 digit are composed by 2-dimension(2D) and 3-dimension(3D). And the visual exposure patterns of each 9 digit are consisted of stopping and moving image. As a result, the 5th quartering has been proved the most attracted attention regardless of all exposure forms including 2D/3D and slopping/moving image. This means center of the multimedia screen is the best place for PPL. Especially in one digit moving screen the attention of the digit has reached the climax. This suggests moving PPL is able to get more attention than stopping. These results provide the most effective PPL position in the screen of the multimedia and PPL's visual exposure forms for maximizing multimedia user's attention. Finally, these findings can be a guideline fer message arrangements of the multimedia screen.

후열 처리에 따른 Ga₂O₃/4H-SiC 이종접합 다이오드 특성 분석

이영재,구상모,Lee, Young-Jae,Koo, Sang-Mo 한국전기전자재료학회 2020 전기전자재료학회논문지 Vol.33 No.2

Ga₂O₃/n-type 4H-SiC heterojunction diodes were fabricated by RF magnetron sputtering. The optical properties of Ga₂O₃ and electrical properties of diodes were investigated. I-V characteristics were compared with simulation data from the Atlas software. The band gap of Ga₂O₃ was changed from 5.01 eV to 4.88 eV through oxygen annealing. The doping concentration of Ga₂O₃ was extracted from C-V characteristics. The annealed oxygen exhibited twice higher doping concentration. The annealed diodes showed improved turn-on voltage (0.99 V) and lower leakage current (3 pA). Furthermore, the oxygen-annealed diodes exhibited a temperature cross-point when temperature increased, and its ideality factor was lower than that of as-grown diodes.