• ETRI Journal
• /
• 제31권1호
• /
• pp.83-85
• /
• 2009

Compared with unicast, multicast over wireless ad-hoc networks do not support reliability due to their inability to exchange request-to-send/clear-to-send (RTS/CTS) and ACK packets with multiple recipients. Although several media access control (MAC) layer protocols have been proposed to provide reliable multicast, these introduce additional overhead, which degrades system performance. A novel MAC protocol for reliable wireless multicast is proposed in this paper. By adapting orthogonal frequency division multiple access characteristics in CTS and ACK packets, the protocol achieves reliability over wireless multicast with minimized overhead.

• 한국마린엔지니어링학회:학술대회논문집
• /
• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
• /
• pp.49-50
• /
• 2005

This paper presents a scheme for state observer-based stabilization control of inverted pendulum systems. The feedback gain matrices of both the state feedback controller and the state observer are obtained by a real-coded genetic algorithm(RCGA) such that the given performances indices are minimized.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1996년도 춘계학술대회 논문집
• /
• pp.466-471
• /
• 1996

This work is concerned with the development of digital contouring controller formulti-axial servosystems. Digital optimal contouring controller is proposed to coordinate each of the controllers of multiple feed drives and specifically improve the controuring performance. The optimal control formulation includes the contour error explicity in the performance index to be minimized. The contouring control is exercised for straight line and circular contours. Substantial improvement in contouring perfomance is obtained for a range of contouring conditions. Both steady state and transient error measures have been considered. The simulation study presented has estiblished the potential of the proposed controller to improve contourning perfomance.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
• /
• pp.1078-1083
• /
• 1992

Extracting the process planning information from the CAD data is the key issue in integrated CAD/CAM system. In this paper, we develop algorithms for extracting the shape and setup configuration for NC machining of prismatic parts. In determining the workpart shape, the minimum-enclosing condept is applied so that the material waste is minimized. To minimize the number of setups, feature based algorithm is developed considrint the part shape, tool shape, and tool approach direction. The validity and effectiveness of the developed algorithms were tested by computer simulations.

• 한국광학회지
• /
• 제5권2호
• /
• pp.225-230
• /
• 1994

홀로그래피 HUD의 제작에 필요한 주요 파라미터를 살펴보고 이들 값을 결정하기 위한 관계식을 유도하여 설계 값을 설정하였다. 기록 방법으로는 간섭무늬에 의한 잡음을 최소화할 수 있는 공기층 반사 기록방법을 제시하였다. 특히, DCG필름을 처리한 후에 생기는 중심파장의 이동을 보정하기 위한 새로운 방법을 소개하였다.

• 한국산학기술학회논문지
• /
• 제5권2호
• /
• pp.118-122
• /
• 2004

2005년부터 도시 지역에서는 음식물 쓰레기 재활용 시설을 완료하여야 한다. 기존에 시설된 음식물 재활용 설비는 염분을 적절히 제거하지 못하여 퇴비로 사용할 경우 농작물에 해가 되는 경우가 많았다 호기성 발효에서 물세척 방식에 의하여 음식물 쓰레기에 포함된 염분을 0.02% 이하로 처리할 수 있었고, 혐기성 밀폐순환식에서도 물분무에 의하여 법정 기분치 이하를 얻을 수 있었다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
• /
• pp.334-337
• /
• 2005

We have found that the hysteretic behavior of a polymer stabilized ferroelectric liquid crystal system coincides with Blinov et. al's model qualitatively. The hysteresis inversion frequency could be promoted up to 7000 Hz by connecting external capacitor and resistor in serial. In addition, the influence of temperature and the amplitude of the applied field on hysteresis-free switching of the cell could be minimized.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
• /
• pp.859-862
• /
• 1988

This paper discusses one overall reactive power installation pattern that will satisfy system performance constraints for base case. The cost of installation is minimized, Existing controllers are fully utilized prior to any addition of new installation. Installation pattern for the required new shunt compensation is comprised of discrete, standard size components.

• 산업기술연구
• /
• 제9권
• /
• pp.101-107
• /
• 1989

The magnetic forming system must be able to store very important electric energy, several tens kilojoules, and flow this energy through the forming coil within some hundreds microseconds. So several hundreds kiloamperes of current can flow through the branch conductor. For the good performance of this type of machine, internal impedance must be minimized. By the computation of distribution of current inside the conductors using integral equation method, we can obtain the inductance and resistance of some dispositions of branch conductors and by comparison obtain some principles for the design of branch conductors in the high power magnetic pulse generator.

• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
• /
• pp.1191-1194
• /
• 1993

We consider a fuzzy controller corresponding to PI controller. This controller is applied to a controlled object which is a first order lag system with dead time. An antecedent part is divided into 3, 5, and 7 parts ( membership function of triangle shape ), and a consequent part into 3, 5, and 7 parts ( membership function of singleton ). In each combination of an antecedent part and a consequent one. We compare control efficiency under the performance criteria such that the overshoot is kept 20% and the ITAE index is minimized.