• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.792-796
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• 2006

In recent years, the semiconductor industry and the optical industry is developed rapidly. The recent demand has expanded for optical components such as a optical lens, a optical semiconductor and a measuring instrument. Object transport systems are driven typically by the magnetic field and the conveyer belt. Recent industry requires more faster and efficient transport system. However, conventional transport systems are not adequate for transportation of optical elements and semiconductors. Because conveyor belts can damage precision optical elements by the contact force and magnetic systems can destroy the inner structure of semiconductor by the magnetic field. In this paper, the levitation transport system using ultrasonic wave is developed for transporting precision elements without damages. This transport system is using 2-mode ultrasonic wave excitation and flexural beam modes shapes are evaluated. It compared simulation results with experimental results

• Progress in Superconductivity
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• 제5권2호
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• pp.89-93
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• 2004

We have studied alternating transport current losses in the vertically stacked high temperature superconducting tapes(HTS) using numerical techniques. In the case of stacked conductors, HTS tapes are exposed to self-field generated by transport current itself and also experienced external magnetic field around adjacent tapes. It is well known that magnetic interactions between neighbored tapes have significant effect on their properties of superconducting tapes such as current distribution, AC loss, and critical current. In this paper, we investigated the transport current losses in stacked conductors consisting of a few of the HTS tapes using numerical analysis. Current distributions are calculated in HTS tape cross-section taking account of magnetic field dependencies, which are represented superconducting nonlinear properties. Dissipated losses in tape and stacked conductors were integrated with current distribution and electric field intensity in the whole conductor region. Finally estimated results were discussed and verified through the analytical theory.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.331-332
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• 2006

Transport systems which are the important part of the factory automation have much influence on improving productivity. Object transport systems are driven typically by the magnetic field and conveyer belt. In recent years, as the transmission and processing of information is required more quickly, demands of optical elements and semiconductors increase. However, conventional transport systems are not adequate for transportation of those. The reason is that conveyor belts can damage precision optical elements by the contact force and magnetic systems can destroy the inner structure of semiconductor by the magnetic field. In this paper, the levitation transport system using ultrasonic wave is developed for transporting precision elements without damages. Vibration modes of each flexural beam are verified by using Laser Scanning Vibrometer.

• 한국자기공명학회논문지
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• 제24권1호
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• pp.16-22
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• 2020

Based on quantum transport theory, we investigated theoretically the magnetic field dependence of the quantum optical transition of quasi 2-dimensional Landau splitting system, in CdS and ZnO Through the analysis of the current work, we found the increasing properties of the cyclotron resonance line-profiles (CRLPs) which show the absorption power and the cyclotron resonance line-widths (CRLWs) with the magnetic field in CdS and ZnO We also found that that CRLWs, γ_total(B) of CdS < γ_total(B) of ZnO in the magnetic field region B < 15 Tesla.

• 한국공작기계학회논문집
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• 제17권2호
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• pp.30-37
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• 2008

An object transport system is driven by a conveyor belt system or a magnetic levitation system. It is an indispensable device in many fields and especially it is very important in the factory automation. However, the conventional transport system can damage precision optical components by the contact force and destroy the inner structure of semiconductor by the magnetic field. The new transport system for transporting without damage is required. The ultrasonic transport system is a device that transports objects on the elastic body using ultrasonic wave. In this paper, an object transport system using the ultrasonic wave is developed for transporting precision elements without damage. Traveling waves are generated by the ultrasonic wave generator fixed in both ends of the beam. The traveling wave of the ultrasonic transport system is theoretically analyzed. Transport direction of the object is examined according to phase difference and frequency. The theoretical results are verified by experiments.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.226-226
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• 2010

Microstructure, magnetic and transport properties of as-deposited electron-doped $La_{1-x}Ce_xMnO_3$ and hole-doped $La_{1-x}Ce_xMnO_3$ films prepared by pulse laser deposition, with x = 0.1 and 0.3, have been investigated. The microstructural analysis reveals that the $La_{1-x}Ce_xMnO_3$ films have a column-like microstructure and a strip-domain phase with a periodic spacing of about 3c, which were not found for the $La_{1-x}Ce_xMnO_3$ ones. At the same time, the experimental results manifest that there is no fundamental difference in the magnetic and the transport properties between electron- and hole-doped manganite films, except the appearance of ferromagnetic response in the low-doped $La_{0.9}Ce_{0.1}MnO_3$ film at temperatures above the Curie point. The observed magnetic behavior, typical for the Griffiths-like phase, for this film is explained by the percolation mechanism of the ferromagnetic transition and by the presence of strip-domain phase which stimulates the magnetic phase separation.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 추계학술대회
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• pp.25-29
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• 2003

In the semiconductor and the optical industry a new transport system which can replace the conventional sliding system is required. These systems are driven by magnetic field and conveyer belt. The magnetic field damages semiconductor and contact force scratches the optical lens. The ultrasonic wave driven system can solve these problem. In this paper, the object transport system using the excitation of ultrasonic wave is proposed. The experiments for finding the optimal excitation frequency, finding phase-difference between two ultrasonic wave generators are performed. The relationship of transporting speed according to the change of flexural beam shape is verified and the system performance for practical use is evaluated.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1608-1613
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• 2003

In the semiconductor and the optical industry, a new transport system which can replace the conventional sliding system is required. These systems are driven by the magnetic field and the conveyer belt. The magnetic field damages semiconductor and contact force scratches the optical lens. The ultrasonic wave driven system can solve these problems. In this paper, the object transport system using the excitation of ultrasonic wave is proposed. The experiments for finding the optimal excitation frequency, finding phasedifference between two ultrasonic wave generators are performed. The relationship of transporting speed according to the change of flexural beam shape is verified. In addition, the system performance for practical use is evaluated.

• 한국공작기계학회논문집
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• 제15권6호
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• pp.8-14
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• 2006

The object transport system is used in many industry field such as the conveyor belt, which transports huge goods in container harbor, the magnetic levitation system, and the indexing system which transports precision components such as semiconductor and optical components. In conventional transport system, the magnetic field may damage semiconductor and the contact force may scratch on the optical lens. So ultrasonic wave transport system has been proposed to replace the previous transport system. In this paper, the good transport condition of optical lens is obtained according to the flexural beam shapes. The working frequency and transport speed are measured and the vibration characteristics of the flexural beams are investigated by Laser Scanning Vibrometer.

• Transactions on Electrical and Electronic Materials
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• 제9권6호
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• pp.265-272
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• 2008

In this paper, AC losses of long wire Bi-2223 tapes with different twist pitch of superconducting core were fabricated, measured and analyzed. These samples produced by a powder-in-tube method are multi-filamentary tape with Ag matrix. Also, it's produced by non-twist. The critical current measurement was carried out under the environment in Liquid nitrogen and in zero field by 4-prob method. And the Magnetic measurement was carried out under the environment of applied time-varying transport current by transport method. From experiment, the susceptibility measurements were conducted while cooling in a magnetic field. Flux loss measurements were conducted as a function of ramping rate, frequency and field direction. The AC flux loss increases as the twist-pitch of the tapes decreased, in agreement with the Norris Equation. Neutron-diffraction measurements have been carried out investigate the crystal structure, magnetic structures, and magnetic phase transitions in Bi-2223([Bi, Pb]:Sr:Ca:Cu:O).