• Applied Microscopy
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• 제45권2호
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• pp.63-73
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• 2015

Shear banding is an evidence of plastic instability that localizes large shear strains in a relatively thin band when a material is plastically deformed. Shear bands have attracted much attention in amorphous metals, because shear bands are the key feature that controls the plastic deformation process. In this article, we review recent advances in understanding of the shear bands in amorphous metals regarding: dislocations versus shear bands, the formation of shear bands, hot versus cold shear bands, and property manipulation by shear band engineering. Although there are many key issues that remain puzzling, the understanding built-up from these approaches will provide a new insight for tailoring shear bands in amorphous metals, which potentially leads to unique property changes as well as improved mechanical properties. Indeed, this effort might open a new era to the future use of amorphous metals as a new menu of engineering materials.

• 한국정보처리학회논문지
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• 제7권10호
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• pp.3290-3299
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• 2000

멀티미디어 데이터의 저작권 보호를 위해 데이터의 조작에 강인한 특성을 가져야 하는 디지털 워터마크는 잡음 환경에서 최대한 오류를 줄이면서 데이터를 전달하고자 하는 채널 코딩 기법과 유사한 개념을 가진다. 본 논문에서는 정지영상을 대상으로 이러한 채널 코딩 알고리즘을 이용하여 각종 데이터의 조작에 강인한 디지털 워터마킹 기법을 제안한다. 저작권 정보는 길쌈 부호(convolutional code)를 사용하여 부호화되며, 데이터의 연속적인 손실을 방지하기 위하여 블록 인터리빙(block interleaving) 기법이 적용된다. 부호화된 저작권 정보는 데이터의 조작에 강인한 특성을 갖는 대역 확산 기법에 의해 영상 데이터에 은닉된다. 저작권 정보의 복원을 위해 워터마크된 영상과 은닉 과정에서 사용된 가상 랜덤 잡음 시퀀스(pseudo random noise sequence)와의 공분산(covariance)에 의해 워터마크 신호가 검출되며, 이 신호를 디인터리빙(de-interleaving)하고 복호화(decoding)하여 은닉된 저작권 정보를 복구한다. 실험 결과 일반적인 대역 확산 기법보다 채널 코딩과 블록 인터리빙을 활용한 기법이 동일한 PSNR에서 가우시안(Gaussian) 잡음 추가, 필터링 및 JPEG 압축 등의 공격에 대해 보다 정확하게 은닉된 저작권 정보를 검출할 수 있다는 것을 확인하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.155.4-155
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• 2001

This paper deals with the inertia property-based redundancy resolution in posture control of a mobile manipulator. As a measure for the redundancy resolution of a mobile manipulator, an effective inertia at the end effector in the operational space is proposed and investigated. The reduced effective inertia has a significant effect on reducing the impulse force in collision with environment. To find a posture satisfying both the reduced inertia and joint limit constraints, we propose a combined potential function method that can deal with multiple constraints. The proposed reduced inertia property algorithm is integrated into a damping controller to reduce the impulse force at collision and to regulate the contact force in mobile manipulation ...

• Korean Journal of Acupuncture
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• 제21권4호
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• pp.1-19
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• 2004

Objectives : To understanding biological mechanism of acupuncture therapy, we have proposed a hypothesis. First of all, there exists electric property in meridian and meridian point. Second of all, energy flowing in meridian is related with electric property. Third of all, there is electronic interaction between the operator who performs acupuncture therapy and the receiver who is given acupuncture therapy. Forth of all, acupuncture effects may depend on the electric capacity which is transferred between the operator and the receiver via acupuncture needle. Methods : Under the hypothesis, we studied the effects of electric change in $ST_{37}(+)\;and\;ST_{39}(-)$ generated by Tanchim (彈鍼) manipulation which was stimulated at $ST_{36}$ point. And compared with data on the changes of electric change from the hand of the operator during acupuncture stimulation. Electric charge induced via acupuncture needle from the operator may be important factor that causes the changes of electric change in meridian and acupoint in the receiver. Therefore we investigated the changes of electric charge induced by the operator using Maclab 400 by the following methods. The one was in stable electric circle condition and the other was in unstable electric circle condition. Results : In this experiments, the changes of electric change from the stimulation type of Tanchim manipulation performed in our lab condition in acupuncture therapy was induced at least three factor, one was the difference of bio-potentials between the operator and the receiver of acupuncture therapy, another was the depth of acupuncture insertion from the skin of the receiver, the other was an electromyogram of the receiver. Conclusion : The data imply that the first factor should make a capacitance current when the operator touched the acupuncture needle which was inserted in the receiver. Therefore, the results suggest that capacitance currents stimulus in electronic view may be important factor in acupuncture therapy between the operator and the receiver of acupuncture therapy.

• 대한치과의사협회지
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• 제4권1호
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• pp.5-7
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• 1963

The purpose of this investigation was to study the preperty of flow for seven different impression materials presently available in KOREA. In this study ,200 grams of a load was applied at regular intervals. As the result of this study, following points were revealed in terms of flow property of respective materials. 1)Impression plaster and irreversible hydrocolloid impression materials were found to have insufficient working time due to their tendency to set rapidly after mixing. 2)Regarding to impresssion pastes, it was found that it has manifested an ideal flow property until 2 minutes after mixing. Clinically, this material seems to allow sufficient working time for its manipulation.

• 산업경영시스템학회지
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• 제31권4호
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• pp.77-85
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• 2008

생물학적인 셀 인젝션 기술은 유전자 주입, 시험관 배양, 인공수정 및 신약개발 분야에서 광범위하게 사용되어 오고 있는 기술이다. 생물공학에서 다루는 셀 인젝션 기술은 크게 착생세포 인젝션과 서스펜디드 셀 인젝션으로 구분할 수 있다. 최근 상용화 장비로 출시되고 있는 것들은 착생세포에 대한 자동 인젝션 시스템이 대부분을 차지하고 있다. 반면, 서스펜디드 셀 인젝션 시스템의 경우는 비교적 최근들어 자동화 장비 및 방법론의 개발에 대한 논의가 이루어지고 있는 실정으로 실제 수많은 연구자들의 노력에 힘입어 서스펜디드 셀을 대상으로 한 통합 자동화 셀 인젝션 시스템의 개발이 가속화되고 있기는 하지만 이에 대한 만족할 만한 성과는 아직 이루어 지지 않고 있는 실정이다. 본 논문은 서스펜디드 셀을 대상으로 한 인젝션 시스템 개발에 관한 것으로 특히 셀 홀딩 시스템과 최적의 인젝션 피펫 궤적을 결정하기 위한 시스템 개발에 관한 것이다. 본 논문에서 다루어지는 서스펜디드 셀은 통합 자동화를 위하여 특별히 고안된 셀홀딩 시스템에 의하여 배열의 형태로 고정되며, 셀 인젝션 시스템은 엠브리오와 인젝션 피켓을 이미지 프로세싱 기술에 의하여 인식하고 피펫의 인젝션 궤적을 결정하는 것을 포함하고 있다.

• 한국지리정보학회지
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• 제23권4호
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• pp.16-41
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• 2020

실제 공간의 분포 또는 양적 속성을 대변하는 지리정보 입력은 지구시스템 모의 내에서 주요 관심사가 되고 있다. 많은 연구에서 다양한 격자 해상도에서의 지표면 특성에 대한 부정확한 추정이 모델링 결과를 크게 바꾸는 것으로 나타났다. 따라서, 이 논문은 도시지역 건물들의 분포와 면적·체적 속성을 반영하기 위해서, 항공라이다로 수집된 3DPC(three-dimensional point cloud) 샘플링 체계에 Monte Carlo Integration(MCI) 기법 기반 공간확률(spatial probability)을 적용을 제안하였다. 건물 식별과 관련해 공간확률(SP) 임계치, 격자 크기, 3차원점군 밀도 세 인자의 결정규칙 적용 결과가 비교되었다. 연구 결과, 건물의 격자가 커짐에 따라 식별되는 건물의 면적 속성이 증가하였다. 공간 모델링 및 분석의 신뢰성을 높이기 위해서는 샘플링 체계에서의 결정규칙을 사용하여 건물의 면적 속성을 조정하는 것이 권장된다. 제안된 방법은 모델링 분야가 요구하는 크고 작은 격자의 변화에서도 일정하게 건물 면적 속성이 유지되도록 지원할 것이다.

• Korean Journal of Acupuncture
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• 제22권4호
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• pp.9-27
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• 2005

Objective : hypothesis. First of all, there exists electric property in meridian and meridian point. Second of all, energy flowing in meridian is related with electric property. Third of all, there is electronic interaction between the operator who performs acupuncture therapy and the receiver who is given acupuncture therapy. Forth of all, acupuncture effects may depend on the electric capacity which is transferred between the operator and the receiver via acupuncture needle. Methods : Under the hypothesis, I studied the effects of electric charge in ST37(+) and ST39(-) generated by Apchim (押鍼) manipulation which was stimulated at ST36 point. And compared with data on the changes of electric charge from the hand of the operator during acupuncture stimulation. Electric charge induced via acupuncture needle from the operator may be important factor that causes the changes of electric charge in meridian and acupoint in the receiver. Therefore we investigated the changes of electric charge induced by the operator using Maclab 400 by the following methods. The one was in stable electric circle condition and the other was in unstable electric circle condition. In this experiments, the changes of electric charge from the stimulation type of Apchim manipulation performed in our lab condition in acupuncture therapy was induced at least three factor, one was the difference of bio-potentials between the operator and the receiver of acupuncture therapy, another was the depth of acupuncture insertion from the skin of the receiver the other was an electromyogram of the receiver. Results :The data imply that the first factor should make a capacitance current when the operator touched the acupuncture needle which was inserted in the receiver. Therefore, the results suggest that capacitance currents stimulus in electronic view may be important factor in acupuncture therapy between the operator and the receiver of acupuncture therapy.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.233-233
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• 2015

We report on a simple method for inducing physical and chemical property-gradient on nanoimprinted patterns by intensity-regulated plasma treatment under caved sample stage. As for the size gradient, a line pattern having a linewidth of 294.9 nm was etched to have gradually varying width from 277.4 nm to 147.9 nm. Modified pattern was proven to be adaptable to replica stamp for reversal patterning. To investigate the wettability gradient, imprinted nanopatterns were coated with fluoroalkylsilane to increase the hydrophobicity, and the surface was modified to have gradually varying wettability from hydrophobic to hydrophilic (contact angle was ${\sim}160^{\circ}$ to ${\sim}5^{\circ}$ on a single chip). This method is expected to be applicable to the selective adsorption of biological entities and hydrodynamic manipulation of liquid droplets for the pumpless microfluidics.

• 한국전자파학회논문지
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• 제15권9호
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• pp.848-855
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• 2004

본 논문에서는 긴 코드 DS/CDMA DMB 하향링크 시스템에서의 신호공간에 기초한 새로운 채널추정기법을 제안한다. 신호공간과 잡음공간과의 직교성을 이용하는 종래의 부분공간 방식과는 달리 신호공간만을 이용하여 채널응답을 추정할 수 있다. 신호공간만을 이용하므로 제안된 기법은 종래의 부분공간 방식에서의 연산복잡도 문제를 해결할 수 있고 따라서 실제 구현 가능한 적절한 사이즈의 공분산 행렬로 부분공간 분석을 통한 채널추정기법에 사용될 수 있다. 논문을 통하여 제안된 기법과 관련된 수식을 도출하고 시뮬레이션 및 수치결과를 통해 제안된 기법의 유효성을 보인다.