• 정보저장시스템학회:학술대회논문집
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• 정보저장시스템학회 2005년도 추계학술대회 논문집
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• pp.229-234
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• 2005

A novel method to measure the interaction movement, focusing direction and tracking direction in an optical pick-up, is proposed and the decoupling control for it is discussed. First, the basic principle of the coupline analysis method using back electromotive farce is introduced. Second, the interaction analysis between focusing direction and tracking direction fur commercial slim type actuator is performed using the proposed method. Finally, the coupling analysis and decoupling control for the slim type optical pick-up are discussed. From the brief simulation, we shows that the effectiveness and validity of the proposed method.

• 대한수의학회지
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• 제38권1호
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• pp.209-216
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• 1998

The purpose of present study is to improve the efficiency of fusion and the developmental rates of nuclear transplanted embryos to produce genetically identical twins from Korean native cattle. The diameter of aspirated follicles had no significant effect on the recovery rates of oocytes collected by ovum pick-up technique. The fusion rates of nuclear transplanted embryos were significantly higher in 50 and $100{\mu}s$ DC duration groups(73.3 and 72.0% ; respectively) than that in $30{\mu}s$ group(55.6% ; p<0.05). The cleavage rates of nuclear transplanted embryos appeared to be significantly higher in donor nuclei derived from in vivo (65.0%) than in those from in vitro (50.5% ; p<0.01), but the developmental rates to morulae and blastocysts were not significantly different between them(13.7 vs 10.9%, respectively).

• 한국자기학회지
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• 제14권4호
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• pp.115-119
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• 2004

2쌍의 pick-up코일을 이용하여 퍼멀로이 박막의 면내 2차원 자화벡터를 측정하고 이방성자기저항을 조사하였다. 면내의 x, y축 방향의 모멘트를 동시에 측정함으로써 자화벡터를 정확하게 결정하였다. 퍼멀로이 박막의 이방성자기저항은 일축이방성이 증가할수록 전류와 자화벡터의 사잇각의 함수로 표현되는 관계식에 근접한 거동을 나타냈다. 자기저항비 변화는 전류방향에 평행한 y모멘트 성분의 변화와 잘 부합하였으며 y모멘트의 크기에 비례함을 알 수 있었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.362-365
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• 2004

'Coil' occupies a much important position in delivering driving force of optical pick-up actuators. Up to now the main stream has been a winding coil type actuator, but actuators using FP-Coil(Fine Pattern Coil) have been considered for the more compacted and simple manufacturing process and have variously spreaded the application fields by product. We have tried to design actuators using PCB-Coil(Printed Circuit Board Coil) which has benefits in terms of price and manufacturing process. Especially this research has two main things those are to reduce the vibration of sub-resonance and to assure the do sensitivity in the performance of asymmetric optical pick-up actuator with PCB-Coil.

• Nuclear Engineering and Technology
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• 제30권5호
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• pp.396-402
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• 1998

Experiments on the steamside corrosion and hydrogen pick-up of Zircaloy-4 under high pressure up to 10.3MPa are carried out to estimate the pressure effects on the kinetics. Temperature and reaction time are determined to be 37$0^{\circ}C$ and 72hours for the pre-transition test and $700^{\circ}C$ and 210minutes for the post-transition test, respectively. Results show that under 10.3MPa pressure the oxidation reaction is 50% and 100% enhanced in the pre-and the post-transition regime, respectively. Total amount of hydrogen uptake in the reaction is proportionally increased as corrosion weight gain is elevated. However, pick-up fraction is not affected by the high pressure. The fraction is almost twice greater than that in the waterside corrosion. Edges in the specimens play a certain role in the enhancement, especially in the post-transition regime. To identify physical property changes of oxide film such as micro-cracks or micro-pores, careful and thorough examination must be needed with some special techniques.

• 소음진동
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• 제6권4호
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• pp.521-528
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• 1996

Recently, higher speed optical disk drives including computer CD-ROM drives tend to be increasingly demanded to read or write the enormous volume of digital data. To this end, both structure and controller designs of the optical pick-ups should be improved concurrently. In this paper, the pick-up during auto-focusing motion is mathematically modelled retaining all its peculiar features. The model turns out a linear time invariant system suitable for a control design namedH${\infty}$ which ensures robust stability in the presence of system uncertainties. Numerical simulations are performed to demonstrate the robustness with appropriate performance specifications being satisfied. In addition, as the implementation issue of it, procedures of temporal discretization as well as model reduction of the controller are also addressed.

• 농업생명과학연구
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• 제51권1호
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• pp.187-192
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• 2017

농업현장에서는 각종 작물을 재배할 때, 작물 성장을 빠르고 효과적으로 하기 위하여 일정한 크기로 성장한 묘를 밭으로 옮겨 심게 되는데, 이러한 묘 정식작업을 수행할 때 채소 정식기가 사용된다. 본 채소 정식기는 인력에 의존하고 있는 채소 정식작업의 기계화를 촉진하기 위하여 2조식의 전자동 육묘트레이 공급 및 취출된 묘를 식부호퍼에 이송할 수 있도록 개발하였다. 또한 두 가지 취출방식에 따른 묘 결주율을 비교하여 판단하였다. 핑거타입 묘 취출 시험결과 256주 묘에서 묘를 뽑아내지 못하는 경우가 17주, 상토가 부서지는 경우가 15주 등 결주율이 13.7%로 나타났으며, 포크타입 묘 취출 시험결과 200주 묘에서 묘는 100% 뽑아내지만 이송 중 낙하되는 경우가 6개 등 결주율이 4%로 나타났다. 따라서 전자동 2조식 정식의 묘 취출장치로서 포크타입이 적당한 것으로 판단되었다.

• 한국주조공학회지
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• 제3권3호
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• pp.159-166
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• 1983

In order to develope domestic carburizers, the experiment was carried out by applying crystallization heat treatment to domestic anthracites and also to foreign products to compare with domestic anthracites.The present work was mainly concerned with the effect of their degree of crystallization of carbon-bearing materials on carbon pick-up in molten iron.Those effects were evaluated by the measurement of density, chemical composition, specific electric resistivity, and X-ray intensity of carbon-bearing materials. Experimental results thus obtained were summurized as follows. 1. The degree of crystallization of domestic anthracites and foreign products was increased with increasing heat treatment temperature. 2. The more degree of crystallization, the shorter the dissolving time of domestic anthracites in molten iron was obtained, while that of foreign products was remained constant. 3. As the degree of crystallization of domestic anthracites and foreign products was increased, the carbon content as well as carbon recovery in molten iron was increased.

• Applied Microscopy
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• 제45권4호
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• pp.208-213
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• 2015

Nanomanipulators installed in focused ion beam (FIB), which is used in the lift-out of lamella when preparing transmission electron microscopy specimens, have recently been employed for electrical resistance measurements, tensile and compression tests, and in situ reactions. During the pick-up process of a single nanowire (NW), there are crucial problems such as Pt, C and Ga contaminations, damage by ion beam, and adhesion force by electrostatic attraction and residual solvent. On the other hand, many empirical techniques should be considered for successful pick-up process, because NWs have the diverse size, shape, and angle on the growth substrate. The most important one in the in-situ precedence, therefore, is to select the optimum pick-up process of a single NW. Here we provide the advanced methodologies when manipulating NWs for in-situ mechanical and electrical measurements in FIB.

• 소음진동
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• 제10권2호
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• pp.221-228
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• 2000

In this paper, analytical study is performed to reduce residual vibration in seeking mode of optical pick-up. The conditions for acceleration adn deceleration time in trapezoidal velocity profile to reduce residual vibration are derived for undamped vibration system. To verify the validity of conditiosn two example studies are carried out. Numerical and experimental implementations for flexible arm system attached to moving part show that residual vibration is effectively reduced by calculated velocity profile. In addition, simulation study for optical pick-up reveals that by changing natural frequency to resonance frequency the conditions derived assuming undamped system can be applied to obtain velocity profile for minimum residual energy in damped vibration system.