• IEMEK Journal of Embedded Systems and Applications
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• v.3 no.2
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• pp.82-90
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• 2008

In this paper, we introduce a biped walking robot which can do static walking with 22 degree-of-freedoms. The developed biped walking robot is 480mm tall and 2500g, and is constructed by 22 RC servo motors. Before making an active algorithm, we generate the motions of robot with a motion simulator developed using C language. The two dimensional simulator is based on the inverse kinematics and D-H transform. The simulator implements various motions as we input the ankle's trajectory. Also the simulator is developed by applying the principle of inverted pendulum to acquisite the center of gravity. As we use this simulator, we can get the best appropriate angle of ankle or pelvic when the robot lifts up its one side leg during the walking. We implement the walking motions which is based on the data(angle) getting from both of simulators. The robot can be controlled by text shaped command through RF signal of wireless modem which is connected with laptop computer by serial cable.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.1385-1388
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• 2006

위치기반서비스는 기본적으로 사용자의 위치를 파악해야 한다. 측위방법은 옥외용과 옥내용으로 구분되며, 옥외용에는 GPS 방법, 이동통신망을 이용한 방법, GPS와 이동통신망을 복합적으로 활용한 방법이 있고, 옥내용에는 적외선을 이용한 방법, 초음파를 이용한 ActiveBat과 Cricket, RF 신호를 이용한 RADAR가 있다. 기존의 옥외용 측위방법은 옥내에서는 사용이 제한되고, 기존의 옥내용 측위방법은 특수한 환경을 꾸며주어야 하는 단점이 있다. 본 논문에서는 이러한 단점을 보완한 방법으로 GPS 수신모듈과 무선LAN용 AP의 신호의 세기를 이용하여 사용자의 위치를 판단하는 옥내외 통합 측위시스템을 소개한다. 검증을 위해 제안하는 시스템을 구현해 보았으며, 실험 결과로 성능평가를 한다.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.419-421
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• 2008

Sputter deposition on a Pt counter electrode was studied using RF plasma as the improvement of conversion efficiency for dye-sensitized solar cells (DSC). The effects of the sputtering thickness and incident angle on a Pt counter electrode for DSC was scrutinized. We conducted the experiment to get the optimal sputtering time for the performance of the DSC. Under the sputtering time condition of 120 seconds, we varied the incident angles of substrate from $0^{\circ}$ to $60^{\circ}$. Under standard test condition (AM 1.5, 100mW/$cm^2$), we obtained the maximum efficiency of 4.61% at the incident angle of $40^{\circ}$ with an active cell area of $1cm^2$.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1412-1413
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• 2011

Effects of thermal annealing on electrical characteristics of thin film transistors (TFTs) using hydrogenated zinc oxide (ZnO:H) films as active channel were extensively investigated. The ZnO:H films were deposited at room temperature by RF sputtering. The device parameters of the ZnO:H-based TFTs, such as threshold voltage ($V_{th}$), subthreshold swing (S.S.), and on-off current ratio ($I_{on}/I_{off}$), were characterized in terms of the annealing temperature as well as the gas flow ratio of $H_2$/Ar.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.224-224
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• 1996

홍삼 총 사포닌 투여군은 대조군과 비교시 total free radical 및 malondialdchydc 농도는 유의상 있게 감소되었으며, 단백질의 carbonyl 농도는 다소 감소하는 경향을 나타내었다. 그리고 홍삼 총 사포닌 투여군의 경우 Cu, Zn-SOD, catalasc, GSII reductase 등의 항산화 효소와 nonprotein-SH가 대조군 보다 증가되었다. 홍삼 총 사포닌의 구성성분들인 ginsenoside Rb$_1$, Rb$_2$, Rc, Rd, Re, Rg$_1$, Rh$_1$, Rh$_2$, Rf 중 ginsenoside Rh$_2$는 catalase 활성을 대조군보다 유의성있게 증가시켰으며, ginsenoside Rh$_1$ 및 Rc의 경우 GSII peroxidase 활성이 증가하는 경향을 나타내었다. 그리고 Cu, Zn-SOD의 경우 ginsenoside Rc는 대조군보다 유의성있게 감소시켰으며, GSII reductase의 경우 유의성있는 변화는 관찰되지 않았다.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.11-14
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• 2007

CMOS technology 기반의 고주파 직접회로에서는 충분한 이득과 안정성을 얻기 위하여 inductor, capacitor와 같은 수동 소자를 적절히 사용하여 설계하여야 한다. 이와 같은 수동 소자는 CMOS 집적회로에서 넓은 면적을 차지하는 단점이 있다. 고주파 증폭기의 부하를 능동 소자로 대체하게 되면 작은 크기로 회로의 제작이 가능하게 되나, 능동 소자는 수동 소자에 비하여 선형 특성이 좋지 않기 때문에 실제로 고주파 증폭기 설계에 사용하지 않는다. 본 논문에서는 이와 같은 능동 소자의 비선형성을 억제하면서, 동시에 회로의 크기를 줄일 수 있는 기능성 능동 부하를 적용한 고주파 증폭기를 설계하였다. 기능성 능동 부하는 2개의 MOSFET은 대칭으로 연결된 구조를 가지며, 하나의 MOSFET은 일반적인 load로 동작하며, 다른 MOSFET은 gate에 가변 전압을 인가함으로써, 증폭기의 전달함수를 변화시킬 수 있다. 이와 같은 특성을 이용하여 고주파 증폭기의 선형성을 보상할 수가 있다.

• The Korean Journal of Food And Nutrition
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• v.11 no.6
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• pp.678-682
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• 1998

A strain of Streptomyces sp. SK-862, isolated from soil in Wonju city, was able to prodce a biologically active substance that has a strong inhibitory activity against proteolsis by trypsin. The inhyibitory substance was extracted by n-butanol, and then purified by the adsorption chromatography followed by the reverse-phase high performacne liquid chromatography. The purified substance was stable over the pH range from 2 to 10, but was unstable when treated at 8$0^{\circ}C$ for 60 min. This substance was soluble in water, methanol, ethanol nd butanol, but insoluble in chlorofrom and ethylacetate. The Rf value of the purified substance on the thin layer chromatography were 0.56 in n-butanol : methanol : water(5 : 3 : 1v/v) solvent system compare dto 0.23 in ethanol : ammonium hydoxide : water(8 : 1 : 1v/v) solvent system. This substance has maximum absorption at 259 nm. The chemical reaction of the substance was negative for sugar but positive for ninhydrine and iodine reaction.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.874-877
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• 2001

SOI(Silicon-On-Insulator) technology is proposed as an alternative to bulk silicon for MEMS(Micro Electro Mechanical System) manufacturing. In this paper, we fabricated the SOI wafer with uniform active layer thickness by silicon direct bonding and mechanical polishing processes. Specially-designed electrostatic bonding system is introduced which is available for vacuum packaging and silicon-glass wafer bonding for SOG(Silicon On Glass) wafer. We demonstrated thermopile sensor and RF resonator using the SOI wafer, which has the merits of simple process and uniform membrane fabrication.

• Journal of environmental and Sanitary engineering
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• v.15 no.2
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• pp.102-111
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• 2000

As IR-sensor for detecting pollution material, the iron silicide has a fit band gap, high physicochemical stability at high temperature and good acid resistance. The growing film was formed with the Fe-Si bond and the organic compound because plasma resolved the injected precursors into various active species. In the Raman scattering spectrum, the Fe-Si vibration mode showed at 250 {TEX}$cm^{-1}${/TEX}. The FT-IR peak indicated that the various organic compounds were deposited on the films. The iron silicide was epitaxially grown to β-phase by the high energy of plasma. The lattice structure of films had [220]/[202] and [115]. The thickness of the films increased with the flow rate of silane. But rf-power increased with decreasing the thickness. The optical gap energy and the band gap were shown about 3.8 eV and 1.182∼1.194 eV. The band gap linearly increased and the formula was below: {TEX}$E_g^{dir}${/TEX}= 8.611×{TEX}$10^{-3}N_{D}${/TEX}＋1.1775

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2350-2355
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• 2005

In this paper, we introduce biped walking robot which can static walking with 22 degree-of-freedoms. The developed biped walking robot is 480mm tall and 2500g, and 22 RC servo motors are used to actuate. Before made an active algorithm, we generated the motions of robot with the motion simulator which developed using by C language. The two dimension simulator is Based on the inverse kinematics and D-H transform. The simulator implements various motions as inputted the ankle's trajectory. Also we developed a simulator which is applied the principle of inverted pendulum to acquires the center of gravity. As we use this simulator, we can get the best appropriate angle of ankle and pelvis when the robot lifts up its one side leg during the working. We implement the walking motions which is based on the data(angle) getting from both of simulators. The robot can be controlled by text shaped command through RF signal of wireless modem which connected with laptop computer by serial cable.