• 한국정밀공학회지
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• 제22권12호
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• pp.34-41
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• 2005

There is a strong demand fur the contactless transportation device fur a hard disk and silicon wafer without contaminating and damaging them. To fulfill this requirements, A transportation device fur them has been proposed. But the device needs many of costly displacement sensors positioned along the transportation interval and possesses a very complicated controller and driving scheme. To overcome those kinds of drawback, in this paper, we present a very simple and cost-effective transportation device which only consists of a linear guide, very simple electrostatic suspension system and driving circuit of stepping motor. The principle of stable suspension by relay feedback control, derivation of lateral restoring force, the design of transportation system are described, fellowed by the experimental system. Experimental results show that a 3.5-inch hard disk has been transported with a speed of approximately 20mm/s while being suspended stably at a gap of 0.25mm.

• 대한의용생체공학회:의공학회지
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• 제19권3호
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• pp.285-290
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• 1998

최근 동물 또는 생체에 이식한 인공판막에 표면부식에 의한 파손 예가 보고되어 연구가 진행되고 있으나 가속내구시험에 대해서는 상세한 검토가 이루어지지 않았다. T. Yhuta 교수가 개발한 가속내구시험기를 이용하여 실험한 결과, 판막 주위의 컴플라이언스구조에 의한 부식이 진행되는 것을 관찰하였다. 본 연구에서는 컴플라이언스 구조의 위치와 크기가 다른 판막 고정용 홀더를 제작하여 컴플라이언스구조가 인공판막의 부식에 미치는 영향을 검토해따. 또한, 판막의 폐쇄속도가 표면부식에 영향을 미친다고 생각하여 고속도 비디오 카메라를 사용하여 폐쇄속도를 검토하였다. 그 결과, 컴플라이언스를 증가하면 판막의 속도도 증가하며 디스크표면 부식이 진행되는 것이 관찰됐다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(2)
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• pp.262-265
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• 2000

This paper describes design of a (32, 28) Reed Solomon decoder for optical compact disk provides double error detecting and correcting capability. The most complex circuit in the RS decoder is part for solving the error location numbers from error location polynomial, and the circuit has great influence on overall decoder complexity. We use RAM based architecture with Euclid algorithm, Chien search algorithm and Forney algorithm. We have developed VHDL model and Performed logic synthesis using the SYNOPSYS CAD tool. Then, the RS decoder has been implemented with FPGA. The total umber of gate is about 11,000 gates and it operates at 20MHz.

• 한국항해학회지
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• 제10권1호
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• pp.81-100
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• 1986

Self-contained portable remote-indicating magnetic compass was designed and tested. Its sensing part consists of main scale disk of rotary encoder with photo-etched 180, oopaque slits and three pairs of light sources and detectors seperated by a transparent index scale, so that any angular deflection of main scale disk against the bowl may be detected optically. The outputs from the sensing part are transformed into digital ship's course indication by electronics unit which consists of operational amplifier, phase discriminator, up-down counter and counting starter circuit. The results from testign the above compass with turntable at variable rate of turn are as following : 1) The main scale disk deflection against the bowl can be detected without any disturbing influence to the freedom of its north-seeking function. 2) The digital indication resolution is found to be $\circ \pm$1 degree. 3) Misrepresenting indication can be avoided by ensuring dimension uniformity and arrangement accuracy of slits on main and index scale disks and by centering pivot in the encoder disk. 4) Indication resolution should be improved by modifying the signal processing and by doubling the number of slits on compass card. 5) Further study should be made on developing non-conductive compass liquid, analogue repeater driving system and more compact processing element.

• 조명전기설비학회논문지
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• 제28권9호
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• pp.28-34
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• 2014

A claw pole stepping motor is widely used in various fields such as a compact optical disk drive, computer peripherals, digital cameras, office automation(OA), handheld mobile devices, because it has the suitable structure for compact motor. However 3D analysis is essential for design of Claw pole stepping motor because of axial flux path. Thus, in general, it takes a lot of time in the design of Claw pole motor. In this paper, magnetic equivalent circuit considering axial flux was proposed to reduce design time of Claw pole motor and we has designed by using the magnetic equivalent circuit. In addition, in oder to verify the study, design model was verified by 3D FEM simulation and experiment.

• 한국통신학회논문지
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• 제24권7A호
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• pp.1090-1098
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• 1999

본 논문에서는 자기 디스크 출력 채널에 사용되는 EPR-4 비터비 디코더 회로를 설계하였다. 비터비 디코더는 ACS 회로, 경로 메모리, 최소값 감지회로, 출력 선택 회로로 구성되었다. 설계한 EPR-4 비터비 디코더는 (1,7) RLL 코드를 사용하여 하드웨어 구현에 필요한 상태수를 8개에서 6개로 감소시켰으며, ACS 연산시 누적 동작과정에서 발생할 수 있는 오버플로우 문제를 처리하기 위해 2의 부소 연산에 바탕을 둔 modulo 비교를 사용하였다. 그리고 경로 메모리 회로에서 6개 출력이 수렴하지 않는 경우 최소 state metric 값을 경로에서 최종 결과값을 결정하도록 파이프라인 구조의 최소값 감지회로를 사용하였다. EPR-4 비터비 디코더 회로는 0.35 $\mu\textrm{m}$ CMOS 공정에 맞추어 설계되었으며, 트랜지스터 개수는 약 15,300 이며, 3.3V의 전압조건에서 최대 데이터 수신율은 250Mbps이다.

• 반도체디스플레이기술학회지
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• 제16권3호
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• pp.25-30
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• 2017

Arago's disk system consists of a speed controller of the DC motor (inner loop controller) and a position controller of the magnetic bar angle (main controller), which are implemented by the design of the PI and PID controller, respectively. First, we analyzed the nonlinear characteristics of the Arago disk system and found the operating point range of three locations as a result. In this paper, a gain scheduler method was applied to guarantee a constant control performance in the range of $0{\sim}130^{\circ}C$, and a structure to change the controller according to the control reference value based on the previously obtained operating points was experimentally implemented. The Distributed Control Systems (DCS) configuration using the Controller Area Network (CAN) was used to verify the proposed method by improving the operational efficiency of the entire experimental system. So, simplicity of the circuit and easy diagnosis were achieved through a single CAN bus communication.

• KSBB Journal
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• 제13권5호
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• pp.477-482
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• 1998

A biosensor with PZT piezoelectric ceramic crystal was developed for the detection of formaldehyde gas. Poled PZT piezoelectric ceramic disk was made from ZrO2, TiO2 and Nb2O5, together with the addition of PbO and polyvinyl alcohol, through various processes of mixing, calcination drying, crushing, forming, sintering, polishing, ion coating and poling. Oscillator circuit of sensor was made of operational amplifier(AD811AN). Formaldehyde dehydrogenase was immobilized onto a piezoelectic ceramic crystal, together with the cofactors, reduced glutathione and nicotinamide adenine dinucleotide. The effect of flow rate on the sensitivity was determined by varing the flow rate of carrier gas from 24.7mL/min to 111.7mL/min through detector cell. The results indicated that as the flow rate was increased, the recovery rate was increased. And a significant increase in the sensitivity was observed in enhanced flow rate of carrier gas. Frequency difference(ΔF) of immobilized PZT piezoelectic disk increased proportionally to the concentration gas and reproduced to repeated exposures of formaldehyde gas(28ppm, Δ68Hz).

• Tribology and Lubricants
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• 제3권1호
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• pp.47-51
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• 1987

The purpose of this paper is to study the lubrication characteristics which is occured in contact surface of two meterials. In this study, experimental apparatus which was modelling of the Cold rolling was used. Electric resistance, the temperature variation and the friction coefficient, between Disk and Roller were measured by respectively electric circuit system, temperature probe, and strain gauge. The experiment carried on the disk velocity range of 10m/min to 1000m/min in loading weight 2kg to 18kg.

• 대한인간공학회지
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• 제4권2호
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• pp.3-10
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• 1985

This article developes a cost-effective on-line measurement system of R - R intervals in ECG. The system is composed of a R peak detector, a timer and an Apple II computer (a 6502 microprocessor and memories). The system measures the R - R intervals in msec and stores them in a disk, for off-line analysis. A circuit diagram of the R peak detector and programs for controlling the microprocessor are presented.