• Information and Communications Magazine
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• v.33 no.8
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• pp.82-88
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• 2016

본고에서는 은밀 수중음향통신과 관련한 연구동향과 수중 채널 환경의 특징들에 대해 소개한다. 육상 무선통신 환경과 마찬가지로 수중 채널에서도 전달 손실, 다중경로 전달, 도플러 효과 및 잡음이 장애 요인으로 작용하나 물 속의 상황을 정확히 예측하기 어렵고 시간에 따른 변동성이 매우 심하기 때문에 통신 시스템 설계를 어렵게 한다. 이러한 장애 요인들을 극복하면서 은밀 수중음향통신으로써 대표적인 대역확산 기법과 함께 수중 생체 모방형 신호를 사용하는 방법을 소개하고, 실제 국내 해역에서 획득한 데이터를 이용한 결과들을 제시한다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2008.04a
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• pp.135-138
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• 2008

최근 인간을 모방하는 휴머노이드 로봇(Humanoid robot)에 대한 관심이 증가함에 따라, 기계공학, 생체공학, 제어이론 등 여러 분야에서 관련 연구가 활발히 진행되고 있다. 이에 본 논문에서는 액츄에이터(Actuator)가 없이 경사진 지면을 걸을 수 있는 두 발을 가진 패시브 로봇(Passive robot)을 대상으로 강화학습과 메니폴드(Manifold control) 기법을 사용하여 안정적으로 걸을 수 있도록 제어기(Controller)를 설계하는 방안을 고려한다.

• Proceedings of the KOSOMBE Conference
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• v.1991 no.05
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• pp.98-100
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• 1991

A sensitive surface acoustic wave (SAW) sensor for the detection of odorants has been constructed by depositing different phospholipids and fatty acids on the surface of the SAW device wi th the Langmuir-Blodgett technique. The characteristics of SAW device operating at 310 MHz deposited with phosphatidylcholine were analyzed. Amyl acetate, acetoin, menthone and other organic gases showed different affinities. The identification of odorants depending on the species of lipid used for coating is discussed in terms of the similarity of the normalized resonant frequency shift pattern. Using a number of different lipid-coated SAW devices, odorants could be identified by a neural-network pattern recognition with back-propagation algorithm.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.360-363
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• 2005

Biomimetic actuators composed of cellophane with an electrically conducting polyaniline(PANI) film have been fabricated and tested in air ambience conditions doped with two different counter ions such as perchlorate (${ClO_4}^-$) and tetrafluoroborate (${BF_4}^-$). Fabrication of the trilayer CP//CELLOPHANE//CP substantially enhanced the tip displacement (13.2mm) compared to the small displacement (8.3mm) of the bilaye. CP//CELLOPHANE. The ion migration among layers is the main factor behind the expansion of cellophane, while the expansion/contraction of PANI are dependent on the redox reaction of the polymer. The displacement of the composite is dominated by the humidity content. This implies that the actuation principle is possibly due to the assistance of water existing.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.444-450
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• 2006

IPMC actuators have been developed with multi-walled carbon nanotubes(MWNT) and $Nafion^{\circledR}$ ionic polymers. MWNT with different diameters of $3{\sim}5,\;4{\sim}6$ and $10{\sim}15$ nm and length of $10{\sim}20{\mu}m$ were used to enhance the mechanical and electrical performances of IPMC actuators. Ultrasonic treatment and high speed mixing were used to disperse MWNT homogeneously in $Nafion^{\circledR}$ solution. The electroless plating technique is used to make electrodes on the both side of the composite membrane. SEM and TEM images were taken to characterize the surface and micro-structures of the composite actuators. In this study, improved IPMC actuators were developed and compared with respect to bending actuation performance and electrical power consumptions.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.6
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• pp.456-465
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• 2003

It is well-known that bio-systems does not calculate inverse dynamics for trajectory planning, but they move by proper modulation of system impedances. Inspired by bio-systems, a biomimetic trajectory planning method is proposed in this work. This scheme is based on employment of redundant actuation which prevails in bio-systems. We discuss that for the generation of the biomimetic trajectory, intelligent structure of bio-systems plays an important role. Redundant actuation and kinematic redundancy fall into such a category of intelligent structure. The proposed biomimetic trajectory planning modulates the complete dynamic behavior such as natural frequencies and damping ratios by using the intelligent structure. Experimental work is illustrated to show the effectiveness of the proposed biomimetic trajectory planning for a five-bar mechanism with redundant actuators.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.11
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• pp.1242-1250
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• 2011

Several biomimetic artificial muscles including the electro-active synthetic polymers (SSEBS, PSMI/PVDF, SPEEK/PVDF, SPSE, XSPSE, PVA/SPTES and SPEI), bio-polymers (Bacterial Cellulose and Cellulose Acetate) and nano-composite (SSEBS-CNF, SSEBS-$C_{60}$, Nafion-$C_{60}$ and PHF-SPEI) actuators are introduced in this paper. Also, some applications of the developed biomimetic actuators are explained including biomimetic robots and biomedical active devices. Present results show that the developed electro-active polymer actuators with high-performance bending actuation can be promising smart materials applicable to diverse applications.

• Information and Communications Magazine
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• v.33 no.5
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• pp.12-19
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• 2016

미래의 IoT, 클라우드 빅데이터, 모바일 환경에서 퍼베이시브 정보통신(Pervasive information network)은 우리 사회에 스며들어 다양한 기기를 통해 접근한다. 이를 실현하기 위해, 새로운 네트워크 아키텍처와 서비스 플랫폼이 요구된다. 현재의 네트워크 환경에서 이러한 형태의 퍼베이시브 정보통신을 지원하는 것은 매우 어렵다. 실제 환경과 가상 공간 사이의 간극을 극복하기 위한 연구는 도전적인 주제이다. 관련 연구 결과 중 가장 발전된 형태의 성과를 보이는 것으로 일본 AKARI 프로젝트와 유럽 FP6 BIONETS 프로젝트가 있다. AKARI 프로젝트는 차세대 네트워크의 구현을 목표로 하고 있으며, 이를 위해 완전히 새로운 형태의 미래인터넷 아키텍처를 설계했다. BIONETS 프로젝트는 미래인터넷 환경에서의 새로운 서비스 프레임워크를 확립했다. 이러한 프로젝트의 연구 및 결과물 융합을 통해 미래 사회에 기여할 수 있는 보다 발전된 형태의 네트워크를 준비한다.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.11
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• pp.971-975
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• 2004

This paper deals with the idea of Electroactive paper (EAPap) actuator and its application possibility. EAPap is a paper that produces large displacement under electrical excitation. EAPap is made with a cellulose paper by constructing thin electrodes on both sides of the paper. When electrical voltage is applied on the electrodes, the EAPap produces bending displacement. EAPap has merits in terms of lightweight, dryness, large displacement output, low actuation voltage and low power consumption. Since the power requirement is so small that it is suitable for microwave-driven smart actuators. This paper describes the working principle and performance of EAPap as an artificial muscle and its possibility far many applications.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.11
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• pp.1082-1088
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• 2010

In this paper, we propose a new gel-type biomimetic variable-focus lens system. The miniaturization of conventional lens system is limited due to the use of a set of glass lenses for adjusting the focal length. Biologically inspired by the focus adjustment mechanism of the human eye, a gel-type single lens system with variable-focus is presented. The proposed system consists of a gel-type lens, mechanical parts such as body, rotation ring, and winding-type SMA actuator. In addition, the proposed system is designed to operate with a simple and miniaturized mechanical structure using a new attachment and driving mechanism. The focusing performance of the proposed system is verified through a series of experiments and measurements of the shape of the lens using tomography.