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  • Title/Summary/Keyword: 구동압력

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Electro-Optical Characteristics of an ICP Light Source Depending on Driving Temperature and Length of Discharge Tube (구동 온도와 방전관 길이에 따른 ICP 광원의 전기.광학적 특성)

  • Yim, Youn-Chan;Park, Dae-Hee
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.4
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    • pp.107-113
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    • 2008
  • We investigated the electro-optical characteristics of an ICP(Inductively Coupled Plasma) light source depending on driving temperature, and length of discharge tube. An electro-optical stability of a sample at operating was measured to see a steady state of a sample. In this results, we can see that a stability of power loss and luminous flux of a sample at operating of upper 70[min] was 1.45[%1 and 0.36[%]. We measured the optical characteristics of a sample in a thermal chamber operated at a specific temperature divided into 5 steps. While luminance increased with temperature increasing, the decrement of luminance a eared at u or 46.7[C]. According to Parchen's and Boyle-Charles' law, we can speculate that a pressure was increased and a higher voltage was needed but a ballaster having a rating power can't support a higher voltage corresponding to a pressure change, 0.02[Torr] at 46.7[C]. Moreover, we measured an a lied power and current of samples depending to a various length of a discharge tube.

A Study on the Control Characteristics of Thrust Vector Control Actuation System for Movable Nozzle of Solid Motor (고체모터 가동노즐 추력벡터제어용 구동장치시스템의 제어특성 연구)

  • Min, Byeong-Joo;Lee, Hee-Joong;Park, Moon-Su;Choi, Hyung-Don
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.1
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    • pp.85-92
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    • 2005
  • The motion of flexseal bearing for movable nozzle has inherent nonlinear characteristics due to floating rotational center and compression by combustion pressure of solid motor. To perform precise attitude control in spite of these characteristics, the TVC actuation system requires counter potentiometer as an extra position feedback sensor of movable nozzle to form a compensated control loop. The prototype TVC actuation system, test equipments and compensated controller are newly designed, manufactured and tested in consideration of counter potentiometer. On the basis of integration test, the inherent characteristics of movable nozzle and control characteristics of its TVC actuation system are analyzed and summarized in this paper.

Current Research Trends on Surface Modification of Pressure-driven Membranes for Fouling Mitigation (압력 구동 기반 분리막의 막 오염 저감을 위한 표면 개질 방법 최신 연구 동향)

  • Jun, Byung-Moon;Lee, Hyung Kae;Kim, Woo Jeong;Park, Jihun;Kim, Jong Hyeok;Kwon, Young-Nam
    • Membrane Journal
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    • v.28 no.1
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    • pp.1-20
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    • 2018
  • Fresh water is an important resource for humans, and pressure-driven membrane technology has been widely known as an energy-efficient method to obtain water resource. However, membrane fouling phenomenon, which is one of the major issue during operation, deteriorates membrane permeability. These fouling is usually affected by interaction between surface of membrane and various foulants, therefore, modification of membrane's surface is one of the methods to improve fouling-resistance. This review focuses on the method to modify surface of pressure-driven membranes such as microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO). Specifically, there are two different surface modification methods: (1) adsorption and coating as the physical modification methods, (2) cross-linker, free radical polymerization (FRP), atom transfer radical polymerization (ATRP), plasma/UV-induced polymerization as the chemical modification methods. This review introduces the physico - chemical surface modification methods reported in recent papers and suggests research directions for membrane separation which can increase membrane fouling resistance.

Development of Ankle Power Assistive Robot using Pneumatic Muscle (공압근육을 사용한 발목근력보조로봇의 개발)

  • Kim, Chang-Soon;Kim, Jung-Yup
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.8
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    • pp.771-782
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    • 2017
  • This paper describes the development of a wearable robot to assist ankle power for the elderly. Previously developed wearable robots have generally used motors and gears to assist muscle power during walking. However, the combination of motor and reduction gear is heavy and has limitations on the simultaneous control of stiffness and torque due to the friction of the gear reducer unlike human muscles. Therefore, in this study, Mckibben pneumatic muscle, which is lighter, safer, and more powerful than an electric motor with gear, was used to assist ankle joint. Antagonistic actuation using a pair of pneumatic muscles assisted the power of the soleus muscles and tibialis anterior muscles used for the pitching motion of the ankle joint, and the model parameters of the antagonistic actuator were experimentally derived using a muscle test platform. To recognize the wearer's walking intention, foot load and ankle torque were calculated by measuring the pressure and the center of pressure of the foot using force and linear displacement sensors, and the stiffness and the torque of the pneumatic muscle joint were then controlled by the calculated ankle torque and foot load. Finally, the performance of the developed ankle power assistive robot was experimentally verified by measuring EMG signals during walking experiments on a treadmill.

Pressure Control of a Piezoactuator-Driven Pneumatic Valve System (압전 작동기로 구동 되는 공압 밸브의 압력제어)

  • Jo, Myeong-Su;Yu, Jung-Gyu;Choe, Seung-Bok
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.2
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    • pp.399-405
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    • 2002
  • This paper proposes a new type of piezoactuator-driven valve system. The piezoceramic actuator bonded to both sides of a flexible beam surface makes a movement required to control the pressure at the flapper-nozzle of a pneumatic valve system. After establishing a dynamic model, an appropriate size of the valve system is designed and manufactured. Subsequently, a robust H control algorithm is formulated in order to achieve accurate tracking control of the desired pressure. The controller is experimentally realized and control performance for the sinusoidal pressure trajectory is presented in time domain. The control bandwidth of the valve system, which directly represents the fastness, is also evaluated in the frequency domain.

증기주입기 계통 해석 코드 개발

  • 이경진
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05b
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    • pp.126-131
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    • 1996
  • 증기주입기간 고온, 고압의 증기 열에너지를 운동에너지로 전환하여, 저압의 피주입수를 고압의 계통으로 펌핑하는 장치를 말한다. 원자로에서 과도상태나 사고 발생시, 저온 저압의 냉각수를 고온 고압의 계통으로 주입시켜야 되는 상황이 종종 발생한다. 기존 원자로의 경우 먼저 여러 가지 능동적인 수단을 사용하여 계통의 압력을 떨어뜨린 후, 능동기기를 사용하여 냉각수를 주입시킨다. 냉각수를 주입시키기 위해서는 먼저 계통의 압력을 떨어뜨려야 한다. 기존 방식의 단점으로는 감압이 어렵고, 능동기기에 대한 전원 유지가 필수적이며, 능동기기(펌프)의 고장 가능성을 들 수가 있다. 증기주입기는 감압 및 구동력이 필요하지 않고, 움직이는 부분이 없이 노즐과 밸브로만 구성되어 있이, 냉각수 주입계통의 신뢰도를 크게 향상시킬 수 있다. 따라서 광범위한 운전 조건하에서 안정되게 작동할 수 있는 증기주입계통을 개발하기 위한 분석 기법연구 및 분석 코드를 개발하였다.

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Electrical and Optical Characteristics of Flat Fluorescent Lamp for LCD Back-lighting (LCD 후면 광원용 FEL의 전기적 및 광학적 특성)

  • 김명녕;권순석
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.4
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    • pp.725-729
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    • 2003
  • In this paper, a mercury-free flat discharge lamp with opposite electrode structure, a couple of phosphor layer and discharge vessel has been studied for LCD back-lighting. When the drive voltage conditions were set properly, a uniform discharge generates over entires emitting surface. The firing voltage was increased with increasing the discharge gas pressure. It was considered that this tendency was resulted from the decrease of mean free paths due to the increase of discharge gas pressure. The maximum luminance of 2700[cd/m2] was obtained in the green emitting FFL.

Pressure Control Drive of SRM for Hydraulic Pump with Pressure Predict Method and Direct Torque Control Method (압력예측기법과 직접순시토크제어기법을 통한 유압펌프용 SRM의 압력제어구동)

  • Seok, Seung-Hun;Liang, Jianing;Lee, Dong-Hee;Ahn, Jin-Woo
    • Proceedings of the KIPE Conference
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    • 2007.11a
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    • pp.163-165
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    • 2007
  • Direct Instantaneous Pressure Control(DIPC) method of SRM using pressure predict method is presented in this paper. A hydraulic pump system has an inherent defect that its dynamic behavior causes by interaction between the sensor and hydraulic load. It will make sometimes the whole system become oscillatory and unstable. Proposed system integrates direct instantaneous torque control (DITC) and Smith predictor to improve dynamic performance and stabilization. The proposed hydraulic oil pump system is verified by computer simulation and experimental results.

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Phase Matching of Pressure Wave in a Drop-On-Demand Inkjet Print Head (요구 적출형 잉크젯 프린트 헤드에서의 압력파 위상 정합)

  • Kim, Myong-Ki;Hwang, Jun-Young;Lee, Sang-Ho;Kang, Kyung-Tae;Kang, Heui-Seok
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.9
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    • pp.116-125
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    • 2008
  • Inkjet printing technology with a drop-on-demand (DOD) inkget head technology has been recognized as one of versatile and low cost manufacturing tools in the electronics industry. Concerned with control of driving signal, however, general strategy to optimize jetting stability has not been understood well, because of the inherent complex multi-physics nature in inkjet phenomena. Motivated by this, present study investigates the effect of driving waveforms of piezoelectric head on jetting characteristics of DOD inkjet system focused on jetting stability with phase matching of pressure waves in the print head. The results show that velocities and volumes of the ink jetted droplets were linear relations with the driving signal's maximum voltage, while periodic behaviors are observed with the driving signal's pulse widths.

Phase Matching of Pressure Wave in a Drop-On-Demand Inkjet Print Head (요구 적출형 잉크젯 프린트 헤드에서의 압력파 위상 정합)

  • Kim, Myong-Ki;Hwang, Jun-Young;Lee, Sang-Ho;Kang, Kyung-Tae;Park, Mun-Su
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1444-1449
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    • 2007
  • Inkjet printing technology with a drop-on-demand (DOD) inkjet head technology has been recognized as one of versatile and low cost manufacturing tools in the electronics industry. Concerned with control of driving signal, however, general strategy to optimize jetting stability has not been understood well, because of the inherent complex multi-physics nature in inkjet phenomena. Motivated by this, present study investigates the effect of driving waveforms of piezoelectric head on jetting characteristics of DOD inkjet system focused on jetting stability with phase matching of pressure waves in the print head. The results show that velocities and volumes of the ink jetted droplets were linear relations with the driving signal's maximum voltage, while periodic behaviors are observed with the driving signal's pulse widths.

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