• 한국공작기계학회논문집
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• 제15권6호
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• pp.64-70
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• 2006

The optical element was usually used in optical devices and optical transfer devices, but it has been recently used in communication, computer and medical equipment. With the development of very high speed optical-communication, the development of the kernel parts of optical communication has also increased. Presently, the alignment of the optical element is time consuming, and an effective alignment algorithm has not yet to be developed. In this paper, the alignment automation of the optical element is studied. The ultra precision stage is applied to an optical element alignment to improve the accuracy of the alignment. The automation program of the optical element alignment is developed by LabVIEW programming to save the alignment time. The alignment algorithms of the optical element consist of field search and peak search algorithms.

• 소성∙가공
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• 제8권6호
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• pp.541-553
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• 1999

Cold forging is a special type of forging process in which metal is forced to flow plastically under compressive force into a variety of shapes in room temperature. Gear blank, which is produced by cold forging, is concerned with the production method of transmission gear. Based on the results of simulation of the current four-stage process, the gear blank forging process for improving the conventional process sequence is designed. The rigid plastic finite element analysis for improving the conventional process. The new process consists of three stage operations with one annealing treatment after first operation. Based on the results of simulation of the proposed process, a required equipment could be selected. The new designed process appears to be more economical in producing the gear blank.

• 유공압시스템학회논문집
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• 제7권4호
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• pp.23-31
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• 2010

As the analysis and design technologies for electro-magnetic actuation has advanced over the years, proportional solenoid valve is gaining acceptance in wide range of industrial and commercial applications because of its superior characteristics over the conventional AOV or MOV, such as improved performance, reduced maintenance costs. This research deals with the position controller design of two-stage flow control solenoid valve. Investigation of steady-state characteristics and dynamic model identification for pilot disc is performed. Least square method to minimize the error magnitude of frequency response between the closed-loop and target system is applied to the design of PI-controller gains. From the experiments of step and frequency response, it is concluded that the controller meets the performance specification of target system, which verifies the usefulness of controller design method for proportional solenoid valve.

• 한국안전학회지
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• 제24권6호
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• pp.124-131
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• 2009

In any form of construction work, it is essential that accidents be prevented at every stage, from foundation preparation to build completion. For this, it is necessary to use models that can assess risk and provide instructions for safe work processes so that the risk of accidents is reduced. Currently, however, very few models can perform these tasks. In this paper, we present a model that assesses risk quantitatively by analyzing the risk factors involved in each stage of construction, such as foundation work, temporary work, structural work, equipment work, and finishing work. The model performs assessment based on examples of accidents and by investigating actual conditions during construction. In addition, we present in this paper a safety management system developed to assess risk during construction and to effectively train laborers.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2004년도 춘계학술대회 발표 논문집
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• pp.223-228
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• 2004

Miniaturization is the central theme in modern fabrication technology. Many of the components used in modern products are becoming smaller and smaller. The direct write FIB technology has several advantages over contemporary micromachining technology, including better feature resolution with low lateral scattering and capability of maskless fabrication. Therefore, the application of FIB technology in micro fabrication has become increasingly popular. In recent model of FIB, however the feeding system has been a very coarse resolution of about a few $\mu\;\textrm{m}$. It is not unsuitable to the sputtering and the deposition to make the high-precision structure in micro or macro scale. Our research is the development of nano stage of 200mm strokes and 10nm resolutions. Also, this stage should be effectively operating in ultra high vacuum of about $1\times10^{-7}$ torr. This paper presents the concept of nano stages and the discussion of the material treatment for ultra high vacuum.

• 한국군사과학기술학회지
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• 제8권3호
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• pp.56-63
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• 2005

The radome boresight error degrades the microwave seeker ability and the missile guidance performance. It increases the miss distance, also. This paper propose a method of radome boresight error measurement and compensation. The compensation method consist of radome analysis and radome compensation. In the radome analysis stage, we can know that the electromagnetic characteristics distorted by radome. In the compensation stage, the look-up table is built and used for compensation. The test uses a FMS(Flight motion simulator) and adjusts the FMS setup error for more accuracy. The result shows that not using an elaborate radome measurement equipment, the radome boresight error is well compensated easily.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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• pp.274-276
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• 2000

Recently, the demands of the ultra-precision stage system, such as wafer stepper stages for photolithography, are increasing in the field of manufacturing and test equipment. Since the mechanical elements which convert rotational motion into translational introduce backlash and elasticity in the system, better performance of the drive could be achieved by the linear BLDC motor with appropriate servo control. The analytical design and the FEM analysis about linear BLDC motor is described in this paper. The performance of the servo-drive system will be evaluated through the comparison of results between the designed data and the measured data in the future.

• 드라이브 ㆍ 컨트롤
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• 제15권4호
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• pp.61-66
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• 2018

Almost every hydraulic system is equipped with a pressure relief valve, to maintain working pressure of the system at a pre-determined level. Thus, dynamic characteristics of such a relief valve, in conjunction with other hydraulic components, are important in designing the hydraulic control system. The single stage pressure relief valve is dynamically undesirable, due to relatively low viscous damping, that causes high frequency oscillations. This problem is overcome by introducing orifices in the inner pilot line, and drain line. In this study, for the single stage spool type pressure relief valve, the system equations were derived through an adequate linearisation and several simplifications were made, to use the transfer function formulation technique. All coefficients were evaluated and used, to make some results by using Matlab software. Results of analysis are compared with experimental results. In this study, parameters affecting stability of valve design are determined and suggested relative to the design.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2012년 추계학술대회
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• pp.293-301
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• 2012

공연장의 무대기계설비 시스템 및 조명장비 시스템 설치 완료 후 각 시스템의 최종 검사에 적용되는 검사 기준과 검사 방법을 명시함으로써 효율적으로 최종 설비 상태를 점검하고, 발주처의 최종 검사에 효과적으로 대비할 수 있게 하고 안전사고를 미리 예방할 수 있게 하기 위하여 연구하였다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2002년도 학술대회논문집
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• pp.105-109
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• 2002

A TVS and Varistor are preservative equipment against electro static discharge(ESD). We use a TVS for I/O protection of a circuit which has faster response time than a Varistor. And a Varistor has large power capability, therefore, which be used in input stage for internal pressure prevention. This paper will compare a TVS with a Varistor with respect to response characteristic to ESD in DC 24[V] low voltage circuit.