• 대한설비공학회:학술대회논문집
• /
• 대한설비공학회 2005년도 동계학술발표대회 논문집
• /
• pp.329-334
• /
• 2005

As more high power wide band gap devices are being utilized. the thermal management issues associated with these devices need to be resolved. High power small devices dissipate excessive heat that must be cooled, but traditional cooling methods are insufficient to provide such a cooling means. This paper will evaluate a micro-capillary pumped loop thermal management system that is incorporated into the shim of the device, taking advantage of phase-change to increase the thermal conductivity of the system. The results of the modeling of the thermal management system will be discussed.

• 한국전기전자재료학회논문지
• /
• 제22권9호
• /
• pp.751-755
• /
• 2009

We proposed circular AlGaN/GaN schottky barrier diode, which has no mesa structure near the current path. Proposed device showed low leakage current of 10 nA/mm at -100 V while that of the rectangular device was 34 nA/mm at the same condition. Proposed circular AIGaN/GaN SBD showed high forward current of 88.61 mA at 3,5 V while that of the conventional device was 14.1 mA at the same condition.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
• /
• pp.437-438
• /
• 2008

The Conventional patterned vertical alignment (PVA) device shows a very high contrast ratio at normal direction and does not require rubbing process. However it has a disclination area in which the liquid crystal can be collision in the boundary domain region. In this paper, we studied PVA(Z-shape) device in which the liquid crystal can be tilted down in multiple directions stably because the surface pretilt angle is controlled by photopolymerization of the UV - curable reactive mesogen (RM) under a proper condition. Consequently, the device shows improved electro optical properties as compared to conventional PVA mode.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2005년도 전력전자학술대회 논문집
• /
• pp.595-597
• /
• 2005

This paper shows the development of remote control system for manipulators which consists of PHANToM Device as a master, Samsung FARA robot as a slave and TCP/IP based LAN fortheir Communication. This work includes the motion mapping between the master and the slave, Generation of virtual viscosity force preventing operator's unwilled action and 3D remote control simulators for the stable operation of the remote control system, etc. The remote control implementation has been performed and the results shows that the developed system can allow the operator to effectively control the manipulator.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
• /
• pp.364-366
• /
• 2009

We successfully fabricated flexible electronic paper display (EPD) by using toner particles on plastic (PC) substrate. It has high resolution (WVGA : 800 ${\times}$ 480) and 7 inch diagonal viewable image size. The response time was about 0.25 msec at 90 V, a contrast ratio of about 2, a driving voltage of 60 V which we successfully demonstrated to display several images at.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
• /
• pp.497-500
• /
• 1999

This paper reports on the fabrication and characteristics of recessed gate GaN MESFETs fabricated using a photoelectrochemical wet etching method. The unique etching process utilizes photo-resistive mask and KOH based etchant. GaN MESFETs with successfully recessed gate structure was characterized in terms of dc and RF performance. The fabricated GaN MESFET exhibits a current saturation at $V_{DS}$ = 4 V and a pinch-off at $V_{GS}$ =-3V The peak drain current of the device is about 230mA/mm at 300 K and the value is remained almost same for 500K operation. The $f_{T}$ and $f_{max}$ from the device are 6.357Hz and 10.25 GHz, respectively.y.y.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 초전도 자성체 연구회
• /
• pp.50-54
• /
• 2003

The output characteristics of thin film NiO/NiFe bilayered magnetoresistive device have been measured as a function of the direction of external magnetic field. Each layer was fabricated by rf magnetron sputtering method, and especially, the under layer, NiO, was fabricated under the in-situmagnetic field of about 1000Oe. The magnetoresistive devices were designed with the angle of 45degree between the direction of current of the device pattern and the induces magnetic field in the NiO film layer. The output of the devices had a good linearity when the devices were placed on the external magnetic field perpendicular to induced field direction and also 45 degree with the currenr path direction.

• 한국전기전자재료학회논문지
• /
• 제28권4호
• /
• pp.222-228
• /
• 2015

Power MOSFETs (metal oxide semiconductor field effect transistor) operate as energy control semiconductor switches. In order to reduce energy loss of the device, it is essential to increase its conductance. However, a trade-off relationship between the breakdown voltage and conductance of the device have been the critical difficulty to improve. In this paper, theoretical analysis of electrical benefits on single floating island power MOSFET is proposed. By the method, the optimization point has set defining the doping limit under single floating island structure. The numerical multiple 2.22 was obtained which indicates the doping limit of the original device, improving its ON state voltage drop by 45%.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 A
• /
• pp.363-365
• /
• 2003

Recently, the concern of power qualiaty problem is increasing. Especially, Voltage quality problem have been increased important problem. Electronic device was affected by voltage sag. So, sensitive load that included many electronic Device was affected by voltage sag. also, it may have economic loss. In this paper, we argue the coordination scheme considering the loss of sensitive load. The coordination device of distribution system for instaneous fault is recloser and sectionalizer, But, the fault clearing time of recloser is more than 2 seconds. So, voltage sag generates long time that affected sensitive load. HS(high speed switchgear) has fast fault clearing time(0.015s) that not affected sensitive load. Therefore, the coordination applied HS is used. The proposed schemes are proved and evaluated by a case study using PSCAD/EMTDC simulation.

• 대한전자공학회논문지
• /
• 제10권5호
• /
• pp.1-6
• /
• 1973

본논문은 자동급수기의 설계 및 제작연구를 한 것으로 digital scanning circuits를 이용하여 10개의 probe를 차례로 scanning하여 지표의 습도를 검출하여 reference level과 비교하여 필요한곳에 자동적으로 급수하도록 설계하였다. 이 system의 control을 위하여 main clock oscillator와 controloscillator를 사용하였고 control circuit로는 programmable unijunction transistor를 이용하여 reference level을 조절하게하여 임의의 원하는 습도에 급수하도록 하였다. 제작된 급수재는 모래의 습도가 6%에서 51%로 변화시키면서 실험하여 언제나 input level이 reference level보다 약 0.6V보다 높을때 완전동작하였으며 reference level은 임의로 조절할 수 있었다.