• The Journal of Korea Robotics Society
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• v.8 no.4
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• pp.229-237
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• 2013

In this paper, we report a self-balancing robot wheelchair which has the capability of keeping upright posture regardless of the terrain inclination in terms of the three dimensional balancing motion. It has the mobility of five degrees of freedom, where pitching, yawing, and forward motions are generated by the two-wheeled inverted pendulum mechanism and the rolling and vertical motions are implemented by the movement of the tilting mechanism. Several design considerations are suggested for the sliding type vehicle body, wheel actuator module, tilting actuator module, power and control system, and the riding module.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.295-300
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• 1999

In Wireless ATM Networks, the mobility management of that is used currently have been studying variously. In this paper, we show the properties of location registration, update, and handoff control mechanism of these first. And then, for frequent handoff occurring condition under minimized cellular environment by degrees, we did comparison and analysis focucing on handoff delay, call-blocking rate and call-dropping rate with communication break-time and velocity variation.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.4
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• pp.501-505
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• 2015

In this paper, we demonstrated a 4W power amplifier monolithic microwave integrated circuit (MMIC) for Ku-band satellite communication applications. The used device technology relies on $0.25{\mu}m$ GaAs pseudomorphic high electron mobility transistor (PHEMT) process. The 4W power amplifier MMIC has linear gain of over 30 dB and saturated output power of over 36.1 dBm in the frequency range of 13.75 GHz ~ 14.5 GHz. Power added efficiency (PAE) is over 30 %.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.6
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• pp.1161-1167
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• 2003

The nodes of Ad hoc network are made up of location registration for sending informations and a great number of packet transmissions to maintain routing route among the nodes. Under this environment, a huge number of traffics would be generated as mobility variable occurs more than in physical network. Hence, in this paper, focused on to study the relationship of nodes to analyze the extent of the traffic in order to control the traffics of the multi-hop in Ad hoc.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.126.2-126
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• 2001

This paper, the integration of driving simulator and unmanned vehicle by means of new concept for better performance through a tele-operated system is suggested. But autonomous system is one of the most difficult research topics from the point of view of several constrains on mobility, speed of vehicle and lack of environmental information. In these days, however, many innovations on the vehicle provide the appropriate automatic control in vehicle subsystem for reducing human error. This tendency is toward to the unmanned vehicle or the tele-operated vehicle ultimately. This paper describes the motion system ...

• Journal of KSNVE
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• v.10 no.4
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• pp.655-661
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• 2000

Diesel power plant can be used as a power supplier for the isolated place where consumption of electric power is variable. The reason is that mobility and durability of diesel engine is superior to those of other thermal engines. However, there are some disadvantages for using these diesel engines such as bigger vibratory excitation force comparing to the others, which result from high combustion pressure of cylinders and inertia force of piston reciprocating masses. In this paper, control and optimization of torsional vibration of 12K90MC-S engine for diesel power plant using uneven crank angles is identified by theoretical analysis and vibration measurement.

• Annual Conference of KIPS
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• 2005.05a
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• pp.1533-1536
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• 2005

본 논문에서는 유비쿼터스 컴퓨팅 환경에서 단말들의 이동성에 따른 적응적인 혼잡제어 기법을 제안한다. 제안하는 혼잡 제어 기법은 무선환경의 특성에 따른 비트 에러와 혼잡에 따른 패킷 손실을 구별하기 위해서 역 혼잡 회피 단계를 도입하였다. 그리고 혼잡이 발생 했을 때, 대역폭 낭비를 최소화 할 수 있는 슬로우 스톱 단계를 추가하였다. 본 논문에서 제안하는 혼잡 제어 정책은 DCCP(Datagram Congestion Control Protocol)을 기반으로 설계하였고, 리눅스 커널 버전 2.4.19에서 구현하였다. 제안된 혼잡 제어 정책은 기존의 혼잡 제어 정책보다 적응성 있게 혼잡 상태를 제어하며, 실험 결과 무선에서뿐만 아니라 유선에서도 우수한 대역폭 이용률을 보였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.53-53
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• 2010

Graphene comes into the spotlight as an emergent device material on account of its high carrier mobility reflecting its massless Dirac fermion behavior. Chemical technique to control reversibly the carrier concentration of semiconducting graphene for the achievement of a large-area graphene device has been strongly required. Here we show that the adsorptions of a metal and a molecule can manipulate the carrier concentration of single-layer graphene, epitaxially grown on SiC, which was directly observed using angle-resolve photoemission spectroscopy. These results will shed light on the researches for the very large scale integration of a graphene device. Furthermore, the carrier concentration changes can be applied to a highly sensitive gas sensor or a detector for an specific binding between an antigen and an antibody.

• The Journal of Korea Robotics Society
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• v.3 no.2
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• pp.137-145
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• 2008

We present the initial results of on-going research for building a novel Mobile Haptic Interface (MHI) that can provide an unlimited haptic workspace in large immersive virtual environments. When a user explores a large virtual environment, the MHI can sense the position and orientation of the user, place itself to an appropriate configuration, and deliver force feedback, thereby enabling a virtually limitless workspace. Our MHI (PoMHI v0.5) features with omnidirectional mobility, a collision-free motion planning algorithm, and force feedback for general environment models. We also provide experimental results that show the fidelity of our mobile haptic interface.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04a
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• pp.190-192
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• 2000

Interworking of legacy TC application and CORBA-BASED one is important to satisfy emerging market demands of the rapid introduction of new multimedia services and building of scalable, flexible, and interoperable service control architecture. For this, we develop generic TC/CORBA gateway on interworking between. TC and CORBA system Generic TC/CORBA gateway can be used for interworking in many fields of telecommunication service control such as INAP, MAP, other TC-based application parts, and mobility management of IMT-2000. Finally, we propose the object pool mechanism for efficient management of TC-user objects and it is helpful for enhancement of scalability and reduction of the response time of remote service operations.