• 한국산업정보학회논문지
• /
• 제5권3호
• /
• pp.111-116
• /
• 2000

현재 많은 모니터 생산업체의 모니터 최종 품질검사에서는 자동화가 미흡한 실정이며, 검사방식이나 검사기준 등이 사람의 시각을 바탕으로 하고 있기 때문에 생산효율 및 생산품질 향상을 위해 검사기준의 일률성이나 검사의 정확성을 위한 검사 시스템이 요구되고 있다. 최근 컴퓨터 시스템의 급속한 발전과 이에 적용할 수 있고 비교적 저렴한 비젼 시스템 구성요소들의 성능이 향상됨에 따라 저가인 검사 시스템의 구성이 용이해지고 또한, 이러한 시스템 상에서 구현할 수 있는 새로운 알고리즘들이 많이 개발되고 있다. 본 연구에서는 저가이면서, 고속이고, 현장에 쉽게 적응할 수 있고 현실적으로 자본력이 튼튼하지 않는 업체에서도 쉽게 도입하여 사용할 수 있는 모니터 검사장비 시스템을 개발한다. 본 검사 시스템은 컴퓨터 비젼 기술을 바탕으로 하고 있으며, GUI 환경을 이용한 편리한 사용자 인터페이스와 모니터의 각종 품질특성 즉 모니터 화면의 중심일치(centering), 요크회전(yoke rotation), 핀쿠션(pincushion), 모니터 화면의 사이징, 밝기(brightness), 그리고 그레이스케일 트래킹에 대한 검사기능 등을 내장하고 있다. 본 연구에서 개발된 모니터 검사 시스템은 모니터 최종 검사공정에서 사용될 수 있으며, 이로 인해 생산효율의 증대 및 설비투자와 장비 개발비용 절감에 대한 파급효과가 기대된다.

• 소성∙가공
• /
• 제31권2호
• /
• pp.51-56
• /
• 2022

In this study, finite element analyses were performed by applying a stress ring and split die design to relieve the tensile stress acting on the die due to high surface pressure during warm-closed forging. The applied material was a yield-ratio-control-steel (YRCS). It was used without quenching or tempering after forging. In the case of stress rings design, the number of stress rings and the tolerance for shrink fit were different. Vertical and horizontal splits were applied for insert die split design. Case 5 die with three stress rings, 0.2 % shrink fit tolerance, and vertical split was selected as an effective die design for tensile stress reduction. Based on die stress reduction analyses, Case 5 die for warm-closed forging was produced and smooth forgeability was secured, making it possible to manufacture forging product of yoke with the required geometry. In addition, controlled cooling using warm forging heat was applied to secure mechanical properties of yokes. When oil cooling was used for direct controlled cooling after warm-closed forging, a relatively uniform Rockwell hardness distribution and high mechanical properties could be obtained.

• Asian-Australasian Journal of Animal Sciences
• /
• 제5권4호
• /
• pp.709-715
• /
• 1992

In this study attempts were made to identify the areas of single animal ploughing (SAP) in Bangladesh, causes of its localization and the socio-economic constraints hindering the expansion of the system. To determine the areas of single animal ploughing, 123 upazilas of 15 districts were surveyed. Of them, 16 upazilas were found heavily engaged with this system. A detailed investigation of 469 SAP and 439 double animal ploughing (DAP) farmers revealed that there was significant difference between the two systems in respect of cost of production and yield per unit of land. The benefit/cost (B/C) ratio was higher in SAP system. However, no significant difference was observed in respect of time required for ploughing, intensity of cropping, cost of implements, and cost of repairing implements (except yoke). The study recommends for expansion of SAP system in areas where buffaloes are concentrated. Fro this purpose, logistic and institutional supports need to be made available.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2001년도 추계학술대회 논문집
• /
• pp.150-153
• /
• 2001

The present work concerns optimal design for the injection molding process of a deflection yoke (coil separator). The optimal design for the injection molding process is developed using design of experiments and finite element analysis. Two design of experiments approaches are applied such as: the design of experiment for mold design and the design the experiments for determination of process parameters. Finite element analyses have been carried out as a design of experiments for mold design: runner system and cooling channel. In order to determine optimal process experiments have been performed for various process conditions with the design of experiments scheduling.

• 한국소음진동공학회논문집
• /
• 제11권8호
• /
• pp.338-348
• /
• 2001

A hybrid self-hearing motor, which Is a functional combination of general permanent magnet (PM) motor and hybrid active magnetic bearing(AMB), was proposed a few years ago. In this paper the hybrid self-bearing motor is modified to a disk type, in which one of two magnetic hearings was substituted for a thin yoke to make the system more compact. An outer rotors in this self-hearing motor is actively controlled only in two radial directions while the ocher motions are passively salable owing to the disk-type structure. Main advantages of the proposed self-hearing motor are simple control mechanism, low power consumption and smart structure. Mathematical model for the magnetic force Is built wish consideration of the radial displacement of the rotor. The model helps us not only to design a levitation controller but also to expect the system performance. Some experimental results show good capability and feasibility of the Proposed self-bearing motor.

• Journal of Magnetics
• /
• 제15권2호
• /
• pp.70-73
• /
• 2010

A magnetic phase is partly produced in a steam generator tube due to stress and heat, because steam generator tubes are exposed to high temperature, high pressure and radioactivity conditions. This adversely affects the safety of steam generator tubes. However, it is difficult to detect it using conventional eddy current methods. Therefore, a new type of probe is needed to separate the signals from the defects and magnetic phases. In this study, a new U-type yoke, which contained two types of coils, a magnetizing coil and detecting coil, was designed. In addition, the signal induced by the magnetic phase and defect in an Inconel 600 plate were simulated.

• 한국정밀공학회지
• /
• 제22권4호
• /
• pp.99-106
• /
• 2005

In this study, the electromagnetic characteristics of a flat-type two-dimensional proportional solenoid were analyzed by the magnetic reluctance method. The equivalent magnetic circuit equation for the solenoid was derived by modeling the reluctance of air gaps and magnetic structural components such as pole core, armature and yoke. It was solved iteratively because of the nonlinear magnetization properties of the iron parts. The solutions showed good agreement with experimental data. Based on the equivalent magnetic circuit equation, the influence of design parameters on the force-to-armature displacement curves was mathematically derived and experimentally verified. In this way, dominant design parameters could be analytically determined.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1996년도 하계학술대회 논문집 A
• /
• pp.250-252
• /
• 1996

In this paper, the principle of operation. the part characteristic, characteristic of component movement, analysis are carried out for camcoder iris assembly which is one of the important element component in Video large projection TV instrument, and some Know-how for development of element component is also included. The magnetic field circuit for the small and simple structure with low power consumption is introduced and new materials of yoke for small motor system is suggested. Especially, the relation with remained magnetic field and operation duration time is analyzed by experimental results. Some problems of nonlinear torque characteristics include to obtain the simple and low cost structure in domestic production of element component is analyzed. Furthermore, development procedure is suggested for iris assembly and some methods to reduce the burr with some check points for small precise accessories are explained.

• 한국복합재료학회:학술대회논문집
• /
• 한국복합재료학회 2002년도 춘계학술발표대회 논문집
• /
• pp.22-26
• /
• 2002

The goal of this study is to replace the current forward 2-piece propeller shaft of 8 ton large truck made of steel with 1-piece composite propeller shaft. A low cost Glass/Epoxy composite propeller shafts were successfully developed, which satisfy requirements such as the capacity of static torque transfer, fatigue strength and bending natural frequency. Devising secure joining method of a composite tube and metal yoke was the most critical issue in successful development of a high torque composite propeller shaft. In this study, joining method using thermal interference fit was adopted for composite to metal joint. Optimum conditions of heating temperature and interference level of thermal interference fit were determined from thermal stress analysis using 3D finite element method. Static torsion test, fatigue test, RPM and balance test were performed to verify the design.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 추계학술대회
• /
• pp.876-881
• /
• 2004

In this study, A special quality analysis and experiment for low power consumption type pneumatic on-off micro valve was performed. And flow characteristics of the micro valve by stroke change was numerically investigated. As a result, it is shown that magnetic force(2.4N) is exerted enough to move poppet with 0.3mm stroke with 0.01 seconds of response time, and that there is no magnetic force emitted by yoke. Under the condition of poppet stroke smaller than about 0.8mm, dynamic pressure acts to poppet wall up to supply pressure level. But, that is decreasing to 40% when poppet stroke is 0.8mm.