• Title/Summary/Keyword: 저압 측정

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A Study on the Combustion Characteristics of Composite Solid Propellants at Low Pressure using Vacuum Strand Burner (Vacuum Strand Burner를 이용한 혼합형 고체 추진제의 저압 연소특성 연구)

  • 박영규;유지창;김인철;이태호
    • Journal of the Korean Society of Propulsion Engineers
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    • v.3 no.1
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    • pp.95-103
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    • 1999
  • Low pressure combustion characteristics of the composite solid propellants were studied in terms of the propellant burning rate, ignition processes, and the structure of the extinguished surfaces. Optical Vacuum Strand Burner(OVSB) system was designed and configured for this purpose. Burning rates of the propellants were measured at subatmospheric pressure by developed test method in OVSB. The ignition and combustion phenomena of the studied propellants in the combustion chamber of OVSB were recorded and analyzed with the camera and VCR(30 frames/s). Burning surfaces of the propellants were extinguished by rapid depressurization method and analyzed with Scanning Electron Microscope(SEM).

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Study on Channel Characteristics and Feasibility of Narrowband Power Line Communication over Underground Low Voltage Power Lines (지중 저압 전력선의 협대역 전력선통신 채널특성 및 적용성에 대한 연구)

  • Yoo, Hyunwoo;Yoon, Kyung Shub;Kang, Sukyung;Choi, Inji;Park, Byungseok;Kim, Il Han;Kim, Wonsoo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.10
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    • pp.874-884
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    • 2013
  • This paper presents in details channel and noise characteristics over narrow bands below 500kHz based on the field tests over underground low voltage(LV) power lines in residential areas in Korean grid. We show that the channel characteristics of narrowband signals over underground LV power line are decent. We first describe methodology of channel characteristic measurements including channel frequency response, noise, and line impedance, and obtain channel characteristics over the underground LV lines in the residential areas. Also based on the measurement results, we adopt the IEEE P1901.2 standard on the FCC High band, and bring up narrow band power line communication network.

Development of High Efficiency Electronic Ballast for Low Pressure Sodium Lamp (저압 나트륨 램프용 고효율 전자식 안정기 개발)

  • 최현배;이진우
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 1999.11a
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    • pp.247-249
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    • 1999
  • 본 논문에서는 91[W] 저압 나트륨 램프용 고효율 전자식 안정기를 제작하여 전기적 특성을 측정하였다. 개발된 고효율 전자식 안정기는 입력 전압 220[V], 입력 전류 435[mA], 입력 전력 94[W], 역률은 98[%], 전류 고조파 함유율 19[%]로 측정되었다.

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A Study on the Temperature Properties of Plug-In MCCB Applied Installment for Low Voltage (저압용 설비에 적용된 Plug-In MCCB의 온도 특성에 관한 연구)

  • Lee, Byung-Seol;Choi, Chung-Seog
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2013.11a
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    • pp.63-64
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    • 2013
  • 개발된 Plug-In MCCB를 저압용 부스바에 설치하여 온도 특성을 분석한 결과 모든 상(phase)에서 기준 범위보다 적은 값을 나타냈고, 가장 높게 측정된 곳의 온도 역시 $13.7^{\circ}C$ 이었다. 또한 단시간 전류 시험 및 기계적 동작 시험 후의 온도 상승 시험에서도 $18.5^{\circ}C$로 측정되어 모든 부분의 특성이 양호한 것을 알 수 있다.

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Development of a High Efficiency Electronic Ballast for Low Pressure Sodium Lamps (131W 저압 나트륨 램프용 고효율 전자식 안정기 개발)

  • 이진우;최현배;박재권;박기도
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2003.11a
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    • pp.215-217
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    • 2003
  • 본 논문에서는 91[W] 저압 나트륨 램프용 고효율 전자식 안정기를 제작하여 전기적 특성을 측정하였다. 개발된 고효율 전자식 안정기는 입력 전압 220[V], 입력 전류 641[mA], 입력 전력 137[W], 역률은 99[%], 전류 고조파 함유율 13[%]로 측정되었다.

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전기설비의 검사 점검 및 시험 [18]

  • Gwon, Sun-Gu;Kim, Gi-Uk;Lee, Gyu-Bok
    • Electric Engineers Magazine
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    • v.257 no.1
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    • pp.33-40
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    • 2004
  • 나. 계기용 변성기 - (1) PT의 경우 - 그림1·59단자간 저항측정으로 단선이나 단란이 아닌 것이 확실하면 <그림1·59>와 같이 고압측 끼리 접속하고, 한쪽의 저압측에서 전압조정기를 통하여 전압을 가하고, 이 전압과 다른쪽의 저압측 전압을 비교한다. 대략 정격전압까지 더하여 양편의 전압계의 차가 1~2%이면 문제없다. (중략)

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A Electronic Ballast for 200 W Class Low Pressure UV Lamp (200W급 저압 자외선램프용 전자식 안정기)

  • 최현배;이진우
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2002.11a
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    • pp.257-258
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    • 2002
  • 본 논문에서는 200 [W]급 저압 자외선램프용 전자식 안정기를 제작하여 전기적 특성을 측정하였다. 입력전압 220 [V], 구동주파수는 용으로, 안정된 전기적 특성을 갖는 것으로 입증되었다.

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Plantar Pressure Distribution Characteristics of Hallux Valgus (엄지 발가락외반증환자의 발바닥 압력분포 특성)

  • 김영호;박시복;양길태;임송학;이강목;문무성
    • Journal of Biomedical Engineering Research
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    • v.18 no.4
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    • pp.439-446
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    • 1997
  • We undertook this study to determine the plantar pressure distribution characteristics of hallux valgus, major increasing foot disease. Twenty three valgus Patients were evaluated with clinical examinations, radiologic studies and dynamic plantar pressure distribution measurements. The present study also suggested a masking method for detailed analyses on plantar pressure distribution measurements. With higher grade of hallux valgus, pressure, contact area, and impulse on metartasus are significantly increased Pressure concentration is very important in foot diseases and an approximate plantar pressure distribution should be considered on any shoe design.

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Effect of Joint Mobilization and Insole on Pain, Pelvic Angle, and Foot Pressure in Patient with Sacroiliac Joint Pain : A Randomized Controlled Pilot Trial (관절가동술과 깔창적용이 엉치엉덩관절통증환자의 통증과 골반경사각, 족저압에 미치는 효과: 무작위배정예비임상시험)

  • Lim, Chae-Gil
    • Journal of Korea Entertainment Industry Association
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    • v.14 no.3
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    • pp.383-392
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    • 2020
  • This study was to compare the effects of joint mobilization, treadmill with insole, and joint mobilization and treadmill with insole on pain, pelvic angle, and foot pressure in patients with sacroiliac joint pain. 24 patients randomly assigned to joint mobilization group(n=8), treadmill with insole group(n=8), or joint mobilization and treadmill with insole group(n=8). Each groups were conducted 30 minutes a day, two days a week for four weeks. Pain was evaluated using visual analogue scale and pelvic angle was measured using palpation meter and foot pressure(fore/rear ratio) was measured using Gateview AFA-50 before intervention and after 4 weeks. All groups were significant differences pain in intragroup(p<.01). In pelvic angle, the joint mobilization group was statistically significant in the anterior tilt only, the joint mobilization and treadmill with insole group showed statistically significant improvement in both anterior and posterior tilt(p<.01), and the treadmill with insole group did not show any statistically significant change(p>.05). Also the joint mobilization and treadmill with insole group were significant differences in foot pressure(p<.01). All the interventions reduce sacroiliac joint pain and joint mobilization and treadmill with insole training are most effective changes in pelvic angle and foot pressure. This study can be used as a basic data for prevention of injury, posture correction and gait training in patients with sacroiliac joint pain, as well as chronic low back pain and plantar pressure problem.