• Title/Summary/Keyword: Air Tool

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Performance Evaluation of Motor-Operated Valve Using Electrical Signatures

  • Park, Joo-Moon;Joo, Hyung-Jun;Jung, Jae-Cheon;Sung, Key-Yong;Seong, Se-Jin
    • Proceedings of the KIPE Conference
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    • 2001.10a
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    • pp.52-55
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    • 2001
  • This paper is to see the availability of electrical signatures as a means for evaluating the performance and monitoring mechanical anomalies of (MOVs). To estimate motor torque, two methods such as d-q frame conversion and air-gap method are suggested and estimated results are compared with measured values. The error between measured and estimated torques is within acceptable error bound with below $1\%$ under varied load. Frequency domain analysis of calculated torque has been done as well. It is shown that monitoring of peak frequency could give useful clues to detect anomalies of MOV. As results, electrical signatures at MOV motor is expected to be an available tool for estimation of motor capacity and monitoring of electrical and mechanical abnormalities.

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Application of Microbeam Technique to Atmospheric Science

  • Ma Chang-Jin
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2005.11a
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    • pp.67-74
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    • 2005
  • Microbeam PIXE, often called micro-PIXE, is a powerful tool tot analyzing a wide range of elements for various samples, as well as, it has important applications of interest to the atmospheric science. In this study, qualitative elemental imagination for various atmospheric environmental species was attempted using micro-PIXE. Here, we present the results of an application of micro-PIXE to the study of atmospheric environment. The detailed spatial resolution of multiple elements lot various samples like individual ambient particles, individual raindrops, individual fog droplets, and individual snow crystals could be successfully achieved by scanning 2.6 MeV H+ micro beam (1-2 ${\mu}m$) accelerated by 3 MV single-end accelerator.

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Development of High Speed & Precision Mould/Die Machining Center (고속.고정밀 금형가공센터 개발)

  • 최원선;김태형;이재윤
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.04a
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    • pp.87-94
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    • 2002
  • In order to manufacture a precision mold/die by machining, users need high speed & precision mold/die machining center. So, for development of this machine, we intend to use linear motor that is instead of ball-screw, servo-motor and coupling, high-speed spindle of pressurized air journal bearing and composite materials. In this paper we research column moving type and table moving type. The former is mainly piling 3 axes on one moving body, the latter is consist of two independent carriages. Both types are available to high speed & precision machine, but we finally draw a conclusion column moving type due to an advantage of high-speed control of linear motor.

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Development of a pneumatic actuator for Micro-Positioning control (미세 변위제어를 위한 공압 액추에이터 개발)

  • 손영선;이동주;이종옥
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.04a
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    • pp.429-434
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    • 2002
  • In order to improve the accuracy in the field of simiconductor and LCD research equipment, the demand of XYZ stage which is possible to control X axis, Y axis and Z axis has been increased steadly in place of the existing XY stage which is only practicable to X & Y axis positioning control. This paper presents a new pneumatic actuator for Micro-positioning control in the XYZ stage. Air pressure in a pneumatic actuator is controlled by the E/P Regulator. The control range of pneumatic actuator is about 100 micro-meters and it's construction concept is easy to apply a practical state

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Characterics of Meter-In / Meter-Out Circuits to pneumatic System (공압회로에서 미터인 회로와 미터아웃 회로의 특성 비교)

  • 박재범;염만오
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.04a
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    • pp.446-450
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    • 2002
  • Pneumatic system has been mainly used as main equipment for actuation and control of compressed air force in manufacturing industry, pneumatic circuit for the most part is used in Meter-Out circuit. Meter-Out circuit method is Flow Control Valve to fit in exhaust part of cylinder port. In the reverse, Meter-In circuit is Flow Control Valve to fit in input part of cylinder port. This study examines the dynamic characteristics comparison of Meter-In and Meter-Out Circuits in the pneumatic circuits. The results of the experimental research are obtained to the followings: i ) System Response is Meter-In Circuit more than Meter-Out one before cushion zone. ii) we conjectured that the collision of piston and head cover is ease to collide Meter-In Circuit more than Meter-Out one at the stroke end part.

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On the Design of the Latch Mechanism for Wafer Containers in a SMIF Environment

  • Lee, Jyh-Jone;Chen, Dar-Zen;Pai, Wei-Ming;Wu, Tzong-Ming
    • Journal of Mechanical Science and Technology
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    • v.20 no.12
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    • pp.2025-2033
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    • 2006
  • This paper presents, the design of a latch mechanism for wafer containers in a standard mechanical interface environment. For an integrated circuits fabrication factory, the standard mechanical interfaced wafer container is an effective tool to prevent wafers from particle contamination during wafer storage, transporting or transferring. The latch mechanism inside the container door is used to latch and further seal the wafer container for safety and air quality. Kinematic characteristics of the mechanism are established by analyzing the required functions of the mechanisms. Based on these characteristics, a methodology for enumerating feasible latch mechanisms is developed. New mechanisms with one degree-of-freedom and up to five links are generated. An optimum design is also identified with respect to the criteria pertinent to the application. The computer-aided simulation is also built to verify the design.

Flow Analysis of Building Pressurization System for Smoke Control (건물의 가압방연시스템 설계를 위한 유동해석에 관한 연구)

  • 김명배;한용식
    • Fire Science and Engineering
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    • v.14 no.2
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    • pp.14-20
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    • 2000
  • Many pressurization systems are designed and built with the goal of providing a smoke-free escape route in the event of a building fire. A secondary objective is to provide a smoke-free staging area for fire fighters. In the present study, a computer program is developed to calculate pressure loss and flow rate at several building elements such as a room, a ]tabby a staircase and an air supply shaft. By the program as the dosing tool for the pressurization system, the capacity of the injection fan is calculated, and the design method is proposed for the optimization of the fan capacity.

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Simulation of Natural Gas Injected Dual-Fuel DI 2-Stroke Diesel Engine (천연가스를 파이럿오일과 이원공급하는 직접분사식 2행정 디이젤기관의 시뮬레이션)

  • Choi, In Su
    • Transactions of the Korean Society of Automotive Engineers
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    • v.3 no.3
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    • pp.9-18
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    • 1995
  • The substitution of conventional fuel oil by alternative fuels is of immense interest due to liquid oil shortage and requirements of emission control standard. Among the alternative fuels, natural gas may be the most rational fuel, because of its widespread resource and clean est burning. Meanwhile, engine simulation is of great importance in engine development. Hence a zero-dimensional combustion model was developed for dual-fuel system. Natural gas was injected directly into the cylinder and small amount of distillate was used to provide the ignition kernel for natural gas burning. The intake air and exhaust gas flow was modeled by filling and emptying method. Although the single zone approach has an inherent limitation, the model showed promise as a predictive tool for engine performance. Its simulation was also made to see how the engine performance was influenced by the fuel injection timings and amount of each fuel.

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Radiographic and CT Diagnosis Of Otitis Media In a Dog (개에서 컴퓨터 단층촬영상을 통한 중이염의 진단)

  • 이기창;서은정;권정국;송경진;윤정희;최민철
    • Journal of Veterinary Clinics
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    • v.21 no.2
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    • pp.184-186
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    • 2004
  • A castrated male, 6 year-old Shih-Tzu, weighing 4.6 kg with a discharge from the external ear canal and a mal-odor was referred to Verterinary Medical Teaching Hospital, Seoul National University. Radiographic findings were narrowing and focal loss of an air density in the left ear canal and bilateral thickening of the osseous bullae. For more detail examination, computed tomography was used. In computed tomographic findings, bilateral thickening of the bulla wall and increased opacity of the bulla space were observed. Thus this dog was diagnosed as bilateral otitis media. Then surgical correction, total ear canal ablation, was performed successfully and the patient showed a good prognosis thereafter. It is considered that computed tomography might serve as an useful imaging tool for otitis media and that it supplies information not obtained with a conventional radiography.

Study on the Basic Properties of Platanus occidentalis L. for Its End-use Development (양버즘나무의 용도개발(用途開發)을 위(爲)한 기초재질시험(基礎材質試驗))

  • Lim, Kie-Pyo;So, Won-Tek
    • Journal of the Korean Wood Science and Technology
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    • v.18 no.2
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    • pp.8-15
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    • 1990
  • This study was carried out to investigate the wood qualities for the end-use development of sycamore (Platanus occidentalis L.) grown in Korea. The results obtained were as follows: 1. The average length of wood fibers was l.56mm and the average width of annual rings was 9.5mm. It had very fast growth rate. 2. The specific gravity in air-dry was 0.66. The shrinkage and water absorption were relatively large. The shear and impact strengthes were very strong, while the compressive, tensile, and bending strengthes were weak in comparison to it's specific gravity. 3. The contents of ash, holocellulose, lignin were relatively high 0.74%, 83.08%, 28.79%, but that of pentosan was low 18.53%. 4. The expected uses of sycamore wood are plywood. fancy veneer, small furniture, musical instrument, door and window frame, tool handels, boxes, etc.

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