• 대한전기학회논문지:시스템및제어부문D
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• 제51권12호
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• pp.583-595
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• 2002

Homing operation can be defined as a series of actions which are necessary for a mobile robot to move from the current position with any arbitrary orientation to a desired position with a specified orientation, while avoiding possible obstacles. In this paper, a homing and obstacle avoidance algorithm for nonholonomic mobile robots is proposed. The proposed algorithm consists of a local goal generator, a discrete state controller, and local path tracking controller based on Aicardi's path following algorithm. In the discrete state controller, 4 states are defined according to the environmental conditions and 4 desired high-level command for the states are given as follows: avoid, wander, home and homing zones. The proposed local goal generator is designed to generate the desired local path by using weighted distance transforms which are newly made to satisfy the nonholonomic constraints of mobile robots. Here, subgoals are also found as vertices of the desired local path. To demonstrate result effectiveness and applicability of the proposed algorithm, computer simulations are illustrated and experimental results for a real mobile robot system are also provided.

• 한국항해항만학회지
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• 제37권3호
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• pp.309-313
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• 2013

본 연구는 복합센서를 활용한 무인지게차의 주행 시스템에 대한 것이다. 무인지게차가 화물 이 적재를 위해 랙에 진입할 시 필요한 주행기술로 무인지게차의 위치 및 방향을 정확하게 파악하기 위해 RFID, IMU센서 및 근접센서로 구성된 복합센서 시스템을 이용하였고, 각 센서의 성능실험을 통해 특성을 파악한다. 이를 직접 설계/제작한 실험용 차량에 부착하여 복합센서 시스템을 적용하는 실험을 수행하고 이를 통해 개발된 시스템의 성능을 검증하였다.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2009년도 춘계 종합학술대회 논문집
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• pp.807-809
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• 2009

압전성을 갖는 산화아연 박막을 스퍼터링을 이용하여 실리콘 기판위에 증착하였고 여러 증착 공정변수들이 물성에 미치는 영향과 박막의 구조적 특성 및 전파경계조건을 고찰하였다. 특히, 평탄한 표면을 갖는 압전 박막을 제조하여 전파 특성에 우수한 증착조건을 제시하고 탄성표면파의 전파및 경계조건을 분석한다. 박막의 구조적 특성 분석을 위하여 여러가지 증착조건 중 아르곤과 산소의 가스비율 과 기판온도가 박막의 제조에 미치는 특성을 분석하였다. 스퍼터링 가스인 산소양이 50%이상으로 증가할수록 박막의 표면 거칠기가 나빠지는 특성을 보였다. 비저항과 표면형상은 유입되는 산소에 큰 영향을 받는다는 것을 알 수 있었다.

• 한국세라믹학회지
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• 제40권6호
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• pp.547-552
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• 2003

RF 마그네트론 스퍼터링법을 이용하여 유리기판위에 인가전력 100 W, 1.33Pa, Ar/O2=50 : 50, 20$0^{\circ}C$ 그리고 타겟과 기판사이의 거리 4 cm의 조건으로 ZnO 압전 박막을 성장시켰다. 증착된 박막의 결정성, 표면형상, 화학적 결합비와 전기적 특성을 XRD, SEM, AFM, RBS와 electrometer를 이용하여 측정 분석하였다 제조된 박막은 우수한 c축 우선 배향성을 보였고 또한 화학 양론적인 결합비를 나타내었다. 전극 구조가 single 및 double IDT를 갖는 ZnO/1DT/glass SAW 필터를 제작하여 특성을 분석한 결과, 전파속도는 각각 2,589 m/sec, 2,533 m/sec이었고, 삽입손실은 -11 dB과 -21 dB 값을 나타내어 박막형 SAW 필터로 응용이 기대된다.

• 한국의류학회지
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• 제35권5호
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• pp.601-611
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• 2011

This research evaluates the availability of consumers moving to integrated multi channels by a target analysis on the integrated online channel and verifies the possibility of a synergy effect created by the expansion of an integrated online channel. The objectives are to define the scope of benefits desired in fast fashion and online shopping, compare the desired benefits of fast fashion consumers, online shopping consumers and fast fashion, and online shopping consumers, investigate the acceptance intention of the integrated online channel of consumers, and verity its relationship with the desired benefits. As a result, all consumers indicate the desire to pursue social recognition, pleasure, individuality, economic and convenience orientation, and fashion-innovativeness through shopping activities. In addition, there were differences in the mean of social recognition benefit individuality benefit, economical and convenience orientation benefit, and fashion-innovativeness benefit. Lastly, the acceptance intention of the integrated online channel was significant in all groups and the desired benefits that affect the acceptance intention of the integrated online channel were social recognition for fast fashion consumers along with pleasure and individuality for fast fashion and online shopping consumers.

• 한국재료학회지
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• 제4권5호
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• pp.535-540
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• 1994

Thin film magnet was fabricated by radio frequency magnetron sputtering using $Nd_13/(Fe.Co)_{70}B_{17}$ alloy target and magnetic properties were investigated according to sputtering conditions from the metallurgical point of view. we could obtain the best preferred orientation of $Nd_2Fe_{14}B$ phase at substrate temperatures between $450^{\circ}C$ and $460^{\circ}C$ with the input power 150W, and thin films had the anisotropic magnetic properties. But, as the thickness of thin film increased, the c-axis orientation gradually tended to be disordered and magnetic properties also become isotropic. Just like Nd-Fe-B meltspun ribbon, the microstructure of thin film magnet was consisted of very find cell shaped $Nd_2Fe_{14}B$ phase and the second phase along grain boundary. While, domain structure showed maze patterns whose magnetic easy axis was was perpendicular to film plane of thin film. It was concluded from these results that the perpendicualr anisotropy in magnetization was attributed to the perpendicular alignment of very find $Nd_2Fe_{14}B$ grains in thin film.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 춘계학술대회 논문집
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• pp.10-14
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• 2005

Zinc Oxide(ZnO) thin films on Si (100) substrates were deposited by RF magnetron reactive sputtering. The characteristics of zinc oxide thin films with changing sputtering conditions such as argon/oxygen gas ratios, RF power, and substrate temperature, chamber pressure and target-substrate distance were investigated. To analyze a crystallographic properties of the films, $\theta/2{\theta}$ mode X -ray diffraction, SEM, and AFM analyses. C-axis preferred orientation, resistivity, and surface roughness highly depended on Ar/$O_2$ gas ratios. The resistivity of ZnO thin films rapidly increased with increasing oxygen ratio and the resistivity value of $9{\times}10^7\;{\Omega}cm$ was obtained at a working pressure of 10 mTorr with Ar/$O_2$=50/50. The surface roughness was also improved with increasing oxygen ratio and the ZnO films deposited with Ar/$O_2$=50/50 showed the excellent roughness value of $28.7{\AA}$.

• Journal of Ceramic Processing Research
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• 제13권spc2호
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• pp.407-410
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• 2012

The properties of Al-doped ZnO (AZO) films were investigated as a function of H2/(Ar + H2) gas ratio using an AZO (2 wt% Al2O3) ceramic target in a radio frequency (RF) magnetron sputtering system. The deposition process was done at 200 ℃ and in 2 × 10-2Torr working pressure and with various ratios of H2/(Ar + H2) gas. During the AZO film deposition process, partial H2 gas affected the AZO film characteristics. The electron resistivity (~ 9.21 × 10-4 Ωcm) was lowest and mobility (~17.8 ㎠/Vs) was highest in AZO films when the H2/(Ar + H2) gas ratio was 2.5%. When the H2/(Ar + H2) gas ratio was increased above 2.5%, the electron resistivity increased and mobility decreased with increasing H2/(Ar + H2) gas ratio in AZO films. The carrier concentration increased with increasing H2/(Ar + H2) gas ratio from 0% to 7.5%. This phenomenon was explained by reaction of hydrogen and oxygen and additional formation of oxygen vacancy. The average optical transmission in the visible light wavelength region over 90% and an orientation of the deposition was [002] orientation for AZO films grown with all H2/(Ar + H2) gas ratios.

• 반도체디스플레이기술학회지
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• 제22권4호
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• pp.119-123
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• 2023

This study is normal orientation technology of slit coating equipment to improve the quality of curved displays. Currently, the demand for curved displays is increasing significantly due to advantages such as screen immersion or design in various industries. Accordingly, changes in the display coating process are essential. In the curved display coating process, unlike the existing flat coating process, the nozzle must be rotated along the curvature of the curved surface to spray the coating solution. The coating solution must be applied while maintaining a uniform thickness. If the thickness of the coating liquid applied to the target surface is non-uniform, the quality of the product may be degraded such as image quality deterioration and light spreading. This paper presents technology and experimental results for keeping the nozzle of slit coating equipment perpendicular to the curved surface and is expected to contribute to the quality improvement of curved displays.

• 대한화학회지
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• 제47권5호
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• pp.439-446
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• 2003

Au와 Ag 콜로이드 단일막 표면위에 흡착된 4-biphenylcarboxylic acid(BPCA)의 유도체인 4''-cyano-BPCA(c-BPCA), 4''-mercapto-BPCA(m-BPCA), 그리고 4''-amino-BPCA(a-BPCA)가 어떠한 배향을 하는지 알아보기 위해 표면증강라만(SER)분광법을 이용하여 연구하였다. 체계적인 분석을 위해 benzoic acid, biphenyl, 그리고 BPCA의 분자 배향에 대한 정보를 기본으로 위 분자들에 대한 흡착정보를 유추해내었다. 배향에 대한 정보를 위해 벤젠고리 모드, C-H 신축진동모드, carboxylate 음이온의 신축진동모드, 그리고 각각의 주요 작용기에 해당되는 모드들의 거동변화를 살펴보았으며 이로부터 m-BPCA는 thiol 그룹이 금속에 흡착되고 biphenyl 그룹이 기울어 서 있는 형태를 취하고 있고 나머지 분자들은 금속표면에 편평한 형태로 흡착됨을 알아내었다.