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ELECTRICAL GROUND SUPPORT EQUIPMENT (EGSE) DESIGN FOR SMALL SATELLITE

  • Park, Jong-Oh;Choi, Jong-Yoen;Lim, Seong-Bin;Kwon, Jae-Wook;Youn, Young-Su;Chun, Yong-Sik;Lee, Sang-Seol
    • Journal of Astronomy and Space Sciences
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    • 제19권3호
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    • pp.215-224
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    • 2002
  • This paper describes EGSE design for the small satellite such like KOMPSAT-2 satellite. Recent design trend of small satellite and EGSE is to take short development time and less cost. For this purpose, the design for KOMPSAT-2 satellite and EGSE are not much modified from KOMPSAT-1 heritage. It means that it is able to be accommodated the verified hardware and software modules used in KOMPSAT-1 satellite program if possible. The objective of EGSE is to provide hardware and software for efficient electrical testing of integrated KOMPSAT-2 satellite in three general categories. (1) Simulators for ground testing (e.g. solar-simulation power, earth scenes, horizons and sun sensor). (2) Ground station type satellite data acquisition and processing test sets. (3) Overall control of satellite using hardline datum. In KOMPSAT (KOrea Multi-Purpose SATellite) program, KOMPSAT-2 EGSE was developed to support satellite integration and test activities. The KOMPSAT-2 EGSE was designed in parallel with satellite design. Consequently, the KOMPSAT-2 EGSE was based on the KOMPSAT-1 heritage since the spacecraft design followed the heritage. The KOMPSAT-2 baseline was elaborated by taking advantage of experience from KOMPSAT-1 program. The EGSE of KOMPSAT-2 design concept is generic modular design with preference in part selection with commercial off-the-shelf which were proven from KOMPSAT-1 programs, flexible/user friendly operational environment (graphical interface preferred), minimized new design and self test capability.

줄기세포를 이식한 척수손상 흰쥐에서 반복자기자극의 효과 (The Effect of Repetitive Magnetic Stimulation in an SCI Rat Model with Stem Cell Transplantation)

  • 배영경;박해운;조윤우;김수정;이준하;권정구;안상호
    • The Journal of Korean Physical Therapy
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    • 제22권1호
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    • pp.67-73
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    • 2010
  • Purpose: We tested whether repetitive transcranial magnetic stimulation (rTMS) improved recovery following spinal cord injury (SCI) in rats with transplantation of adipose tissue-derived stromal cells (ATSCs). Methods: Twenty Sprague-Dawley rats (200-250 g, female) were used. Moderate spinal cord injury was induced at the T9 level by a New York University (NYU) impactor. The rat ATSCs (approximately $5{\times}10^5$ cells) were injected into the perilesional area at 9 days after SCI. Starting four days after transplantation, rTMS (25 Hz, 0.1 Tesla, pulse width=$370{\mu}s$, on/off time=3 sec/3 sec) was applied daily for 7 weeks. Functional recovery was assessed using the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale as well as pain responses for thermal and cold stimuli. Results: Both groups showed similar, gradual improvement of locomotor function. rTMS stimulation decreased thermal and cold hyperalgesia after 7 weeks, but sham stimulation did not. Conclusion: rTMS after transplantation of ATSCs in an SCI model may reduce thermal hyperalgesia and cold allodynia, and may be an adjuvant therapeutic tool for pain control after stem cell therapy in SCI.

Box-Behnken 및 반응표면 분석법을 이용한 음식물류 폐수 부상 스컴의 혐기성 소화를 위한 열-알칼리 전처리 최적화 (Optimization of Thermal-alkaline Pre-treatment for Anaerobic Digestion of Flotation Scum in Food Waste Leachate Using Box-Behnken Design and Response Surface Methodology)

  • 이동영;최재민;김정광;한선기;이채영
    • 상하수도학회지
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    • 제29권2호
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    • pp.183-192
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    • 2015
  • Response surface methodology (RSM) based on a Box-Behnken Design (BBD) was applied to optimize the thermal-alkaline pre-treatment operating conditions for anaerobic digestion of flotation scum in food waste leachate. Three independent variables such as thermal temperature, NaOH concentration and reaction time were evaluated. The maximum methane production of 369.2 mL $CH_4/g$ VS was estimated under the optimum conditions at $62.0^{\circ}C$, 10.1% NaOH and 35.4 min reaction time. A confirmation test of the predicted optimum conditions verified the validity of the BBD with RSM. The analysis of variance indicated that methane production was more sensitive to both NaOH concentration and thermal temperature than reaction time. Thermal-alkaline pretreatment enhanced the improvement of 40% in methane production compared to the control experiment due to the effective hydrolysis and/or solubilization of organic matters. The fractions with molecular weight cut-off of scum in food waste leachate were conducted before and after pre-treatment to estimate the behaviors of organic matters. The experiment results found that thermal-alkaline pre-treatment could reduce the organic matters more than 10kD with increase the organic matters less than 1kD.

Introcordal Injection of Autologous Fibroelastic Cartilage - Introcordal Injection of Autologous Fibroelastic Cartilage in the Paralyzed Canine Vocal Fold

  • Lee, Byung-Joo;Wang, Soo-Geun;Lee, Jin-Choon
    • 대한음성언어의학회:학술대회논문집
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    • 대한음성언어의학회 2003년도 제19회 학술대회
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    • pp.180-180
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    • 2003
  • Objectives : Vocal fold augmentation by injectable material under direct visual control is an easy and simple operation. However, when autologous fat or bovine collagen is used, resorption creates a problem. And autologous fascia is debating about absorption now days. This study is to evaluate the histology of minced and injected autologous auricular cartilage and fat graft in the augmentation of unilateral vocal fold paralysis using a canine model. Methods : Nine dogs were operated. At first, a piece of auricular cartilage was harvested from ear and minced into tiny chips with a scalpel. And also, a piece of fat tissue was harvested from inguinal area and minced into tiny chips with a scalpel. Cutting off a section of the recurrent nerve paralyzed the right vocal fold. The minced cartilage and fat-paste (0.2ml) was injected using a pressure syringe into the paralyzed thyroarytenoid muscle under direct laryngoscopy. Two animals were sacrificed at 3 days, three at 3 weeks, two at 3 months, one at 6 months, one at 12 months. Each dog underwent laryngectomy and serial coronal sections of paraffin blocks from the posterior part of the vocal fold were made. Results : There was no significant complication perioperatively and during follow-up. There was acute inflammatory findings in the graft at 3 days and 3 weeks. The injected cartilage remained in the larynx until 12 months. Conclusion : The autologous auricular cartilage graft is well tolerated and may be very effective material for volumetric augmentation on paralyzed vocal cord.

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온도장 가시화를 위한 연성회로기판을 이용한 온도센서 어레이 제작 및 성능평가 (Fabrication and Performance Evaluation of Temperature Sensor Matrix Using a Flexible Printed Circuit Board for the Visualization of Temperature Field)

  • 안철희;김형훈;차제명;권봉현;하만영;박상후;정지환;김귀순;조종래;손창민;이정호;고정상
    • 한국가시화정보학회지
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    • 제7권2호
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    • pp.17-21
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    • 2010
  • This paper presents the fabrication and performance measurement of a temperature sensor array on a flexible substrate attachable to a curved surface using MEMS technology. Specifically, the fabrication uses the well-developed printed circuit board fabrication technology for complex electrode definition. The temperature sensor array are lifted off with a $10{\times}10$ matrix in a $50\;mm{\times}50\;mm$ to visualize temperature distribution. Copper is used as temperature sensing material to measure the change in resistances with temperature increase. In a thermal oven with temperature control, the temperature sensor array is Characterized. The constant slope of resistance change is obtained and temperature distribution is measured from the relationship between resistance and temperature.

기상요소별 사고 시나리오에 따른 정량적 위험성평가 피해영향범위 분석 (Analysis of Impact Zone of Quantitative Risk Assessment based on Accident Scenarios by Meteorological Factors)

  • 김현섭;전병한
    • 대한환경공학회지
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    • 제39권12호
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    • pp.685-688
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    • 2017
  • 장외영향평가의 정량적 위험성평가에 사용되는 ALOHA와 PHAST 프로그램으로 화학물질관리법상 사고대비물질로 지정하고 있는 염소의 누출 사고 시나리오를 가정하여 모델링 하였다. 연평균 기온, 풍속, 습도, 대기안정도를 변화시키면서 ERPG-2 농도에 해당하는 끝점거리를 산출하였으며, 산출된 끝점거리 값을 비교하여 각각의 기상요소와 끝점거리 간의 상관관계와 ALOHA와 PHAST의 장단점 분석하였다. 연구결과 ALOHA는 연평균 기온과 습도와의 상관관계는 없거나 작고, 풍속과 대기안정도와의 상관관계가 큰 것으로 조사되었다. PHAST의 경우 연평균 기온, 풍속, 습도, 대기안정도 모든 기상요소와의 상관관계가 있었으며, 그 중 대기안정도의 영향을 가장 크게 받는 것으로 조사되었다.

스마트무인기 후보엔진 기술검토 (Technical Review of the Proposed Engines for SUAV)

  • 전용민;양수석
    • 한국추진공학회지
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    • 제10권1호
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    • pp.64-71
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    • 2006
  • 수직이착륙 및 고속 전진비행 능력을 갖는 스마트무인기를 개발하기 위해 채택된 틸트로터방식은 통상의 헬리콥터방식과 터보프롭방식을 모두 포함하고 있다. 엔진측면에서 보면 엔진운용방식, 엔진제어 방식, 동력계통의 동력학적 특성, 흡/배기구 개념, 엔진장착요구도 등과 같은 요인들이 헬리콥터와 터보프롭, 두 가지 방식의 요구조건을 모두 만족시킬 수 있어야 한다. 또한 틸트로터의 특성상 헬리콥터와 터보프롭, 두 모드에서의 최적 로터회전수가 상이하여 이를 만족시킬 수 있는 방안이 요구되었다. 본 연구에서는 기존의 상용터보샤프트 엔진으로부터 틸트로터방식을 위한 특이한 엔진요구사양을 충족 시킬 수 있는 방안을 모색하였으며 이를 위해 가장 적합한 엔진을 선정하게 되었다.

강조류에서 중량물 운반 부선의 예인력에 관한 연구 (A Study on the Towing Force of Heavy Loaded Barge against Strong Current)

  • 김철승;임긍수
    • 해양환경안전학회지
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    • 제17권2호
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    • pp.179-185
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    • 2011
  • 예인선 A호와 B호가 재킷을 실은 부선을 예인하기 위하여 진도 벽파항에서 출항하여 진도대교 부근 조력발전소 예정지로 운항 중 예인능력을 갑자기 상실하고 진도대교로 표류하여 바지선에 실려 있던 대형 철구조물인 일명 '재킷'이 제1진도대교 교각 및 중앙부 상판과 충돌한 사고가 발생하였다. 이 사고로 바지선에 살려 있던 조력 발전소 건설용 철구조물이 진도대교 중앙부 하단지점 바다로 추락했으며 제1진도대교 교각 1개가 일부 파손되고 상판의 바람막이도 세 군데가 구겨지는 등의 피해가 발생했다. 본 연구에서는 상기의 해양사고와 관련하여 부선의 운항경로가 갑자기 바뀌며 예인력을 상실하였던 해역의 시간대별 조류속도를 추정하고, 재킷을 실은 부선을 예인하기 위한 적정한 예인력을 산정함과 동시에 당시 기상 상황 하에서의 부선의 예인 안전성을 검토하고자 한다.

정밀질량분석기를 활용한 우레탄폼의 장기열전도도 예측을 위한 분석기법 (Long-Term Thermal Conductivity Prediction of Polyurethane Foam Applying Precision Mass Spectrometer for Cell Gas Analysis)

  • 김진석;전종한;이진복;이효진
    • 설비공학논문집
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    • 제22권10호
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    • pp.679-686
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    • 2010
  • A proprietary device is adopted to break out the membrane of cell in the rigid polyurethane foam. As it is known, the membrane of cell is hardly tearing-off thoroughly in a mechanical way due to both its elastic characteristic and micro sized pores. In this study, a novel experimental approach is introduced to burst out all gases inside the cells of the rigid polyurethane foam by abrasively grinding micro-cells completely into fine powder. The biggest advantage of this approach is to be capable of releasing all gases out from the cell even in the micro pores. As clearly reflected from the repeatability, the accuracy of the result is highly improved and high confidence in the data sets as well. For the measurements of not only gas composition but partial pressure for each gas simultaneously as well, a precision gas mass spectrometer is used in-line directly to the abrasive grinding device. To control the starting point of the polyurethane foam, all samples were prepared on site in the laboratory. Manufactured time is one of the most critical factors in characterization of cell gas composition because it is known that one of gas composition, especially, carbon dioxide, is diffused out dramatically in a short period of time as soon as it is foamed.

에너지저장장치를 이용한 제주지역 풍력발전 한계용량 증대효과 분석 (Increasing Effect Analysis of the Wind Power Limit Using Energy Storage System in Jeju-Korea)

  • 김영환;김세호
    • 한국태양에너지학회 논문집
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    • 제34권1호
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    • pp.81-90
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    • 2014
  • The Jeju-Korea power system is a small-sized network with a system demand ranging from a autumn minimum of 350MW to a summer peak of 716MW. Because Jeju island is well exposed to north-east winds with high speed, applications to connect to Jeju power system are flooded. Considering physical/environmental constraints, Jeju Self-governing Province has also target for the wind power capacity of 1,350MW by 2020. It amounts to two or three times of Jeju average-demand power and wind power limit capacity announced by Korea Power Exchange (KPX) company. Wind farm connection agreements will be signed to maximize utilization of wind resource. In spite of submarine cable HVDC connected to Korea mainland, Jeju power system is independently operated by frequency and reserve control. This study reevaluates wind power limit based on the KPX criteria from 2016 to 2020. First of all wind power generation limit are affected by off-peak demand in Jeju power system. Also the possibility capacity rate of charging wind power output is evaluated by using energy storage system (ESS). As a result, in case of using 110MWh ESS, wind power limit increases 33~55MW(30~50% of ESS), wind power constraint energy decreases from 68,539MWh to 50,301MWh and wind farm capacity factor increases from 25.9 to 26.1% in 2020.