• 제목/요약/키워드: passive imaging

검색결과 80건 처리시간 0.027초

Discussion of Critical Design Review (CDR) for MIRIS, the Main Payload of STSAT-3

  • Han, Won-Yong;Lee, Dae-Hee;Nam, Uk-Won;Park, Young-Sik;Jeong, Woong-Seob;Ree, Chang-Hee;Moon, Bong-Kon;Park, Sung-Joon;Cha, Sang-Mok;Park, Jang-Hyun;Lee, Duk-Hang;Ka, Nung-Hyun;Lee, Mi-Hyun;Seon, Kwang-Il;Yuk, In-Soo;Yang, Sun-Choel;Park, Jog-Oh;Rhee, Seung-Wuh;Lee, Hyung-Mok;Matsumoto, Toshio
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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    • pp.44.3-44.3
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    • 2009
  • The MIRIS (Multi-purpose IR Imaging System), as the main payload of Science and Technology Satellite-3 (STSAT-3), is being developed by KASI in collaboration with several institutes for wide-field space observation in near IR wavelength. The Engineering Qualification Model (EQM) of MIRIS has been designed and fabricated in the laboratory. The system performance tests have been made including opto-mechanics, vibration test, thermal-vacuum environmental test and passive cooling test down to 200K. Most of the performance test results were satisfied with system requirements. The results of MIRIS performance tests have been presented at Critical Design Review (CDR) on September 2009. Several revisions were also recommended for Flight Model (FM) design, and detailed plan to develop FM of MIRIS is discussed in this paper.

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First Light of the MIRIS, a Compact Wide-field Space IR Telescope

  • Han, Wonyong;Lee, Dae-Hee;Jeong, Woong-Seob;Park, Youngsik;Moon, Bongkon;Park, Sung-Joon;Pyo, Jeonghyun;Kim, Il-Joong;Park, Won-Kee;Lee, Duk-Hang;Seon, Kwang-Il;Nam, Uk-Won;Cha, Sang-Mok;Park, Kwijong;Park, Jang-Hyun;Yuk, In-Soo;Ree, Chang Hee;Jin, Ho;Yang, Sun Choel;Park, Hong-Young;Shin, Ku-Whan;Suh, Jeong-Ki;Rhee, Seung-Wu;Park, Jong-Oh;Lee, Hyung Mok;Matsumoto, Toshio
    • 천문학회보
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    • 제39권1호
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    • pp.49.2-49.2
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    • 2014
  • The MIRIS (Multi-purpose InfraRed Imaging System) is a compact IR space Telescope, which has been developed by KASI since 2008 as the main payload of Korean STSAT-3. It was launched successfully by a Dnepr Rocket at Yasny Launch site, Russia in November 2013. After the launch, the STSAT-3 successfully settled down at Sun synchronous orbit with altitude of ~ 600km. Communications were regularly made between the ground station and the MIRIS with other secondary payload. We made a series of tests of the MIRIS during the verification period and found that all functions including the passive cooling are working as expected. The MIRIS has a wide-field of view $3.67{\times}3.67$ degrees and wavelength coverage from 0.9 to 2.0 micro-meter with the angular resolution of 51.6 arcsec. The main science missions of the MIRIS are (1) mapping of the Galactic plane with Paschen-alpha line (1.88 micro-meter) for the study of warm interstellar medium and (2) the measurement of large angular fluctuations of cosmic near infrared background radiation with I (1.05 micro meter) and H (1.6 micro meter) bands to identify their origin. We present the results of MIRIS initial operation in this paper.

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Development of the Infrared Space Telescope, MIRIS

  • 한원용;이대희;박영식;정웅섭;이창희;남욱원;문봉곤;박성준;차상목;표정현;박장현;가능현;선광일;이덕행;이성우;박종오;이형목
    • 천문학회보
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    • 제36권1호
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    • pp.64.1-64.1
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    • 2011
  • MIRIS (Multipurpose Infra-Red Imaging System), is a small infrared space telescope which is being developed by KASI, as the main payload of Science and Technology Satellite 3 (STSAT-3). Two wideband filters (I and H) of the MIRIS enables us to study the cosmic infrared background by detecting the absolute background brightness. The narrow band filter for Paschen ${\alpha}$ emission line observation will be employed to survey the Galactic plane for the study of warm ionized medium and interstellar turbulence. The opto-mechanical design of the MIRIS is optimized to operate around 200K for the telescope, and the cryogenic temperature around 90K for the sensor in the orbit, by using passive and active cooling technique, respectively. The engineering and qualification model of the MIRIS has been fabricated and successfully passed various environmental tests, including thermal, vacuum, vibration and shock tests. The flight model was also assembled and is in the process of system optimization to be launched in 2012 by a Russian rocket. The mission operation scenario and the data reduction software is now being developed. After the successful mission of FIMS (the main payload of STSAT-1), MIRIS is the second Korean space telescope, and will be an important step towards the future of Korean space astronomy.

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Peliminary Performance Test for MIRIS, the Main Payload of STSAT-3

  • Han, Won-Yong;Lee, Dae-Hee;Park, Young-Sik;Nam, Uk-Won;Jeong, Woong-Seob;Ree, Chang-Hee;Moon, Bong-Kon;Park, Sung-Joon;Cha, Sang-Mok;Lee, Duk-Hang;Park, Jang-Hyun;Ka, Nung-Hyun;Seon, Kwang-Il;Yang, Sun-Choel;Park, Jong-Oh;Rhee, Seung-Wu;Lee, Hyung-Mok;Matsumoto, Toshio
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2010년도 한국우주과학회보 제19권1호
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    • pp.37.4-37.4
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    • 2010
  • KASI is developing the MIRIS (Multi-purpose IR Imaging System), as the main payload of Science and Technology Satellite-3 (STSAT-3). The Engineering Qualification Model (EQM) of the MIRIS has been recently fabricated, and Flight Model (FM) is now in final development stage. The system performance tests have been made mainly with EQM, and partly with FM in the laboratory, including opto-mechanics test, vibration test, thermal-vacuum test and passive cooling test down to 200K, using a thermal controlled vacuum chamber. Most of the system performance test results of the MIRIS are satisfied with the required specifications and its results were reflected in development of the FM with several revisions of the system design. In this paper, we present detailed system performance test procedures of the MIRIS and its results.

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Torticollis Management Using the Customized Soft Neck Collar in CATCH 22 Syndrome Combined with Klippel-Feil Anomaly: A Case Report

  • Moon, Myung-Hoon;Kim, Soo-Yeon
    • Journal of Interdisciplinary Genomics
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    • 제1권2호
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    • pp.19-22
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    • 2019
  • CATCH 22 syndrome is rare genetic disease that has various manifestations. Cervical vertebral anomaly, such as Klippel-Feil anomaly, is frequently observed in the patients with CATCH22 syndrome. We present the case of an 11-year-old female patient with CATCH22 syndrome and Klippel-Feil anomaly who had been treated torticollis using the customized soft neck collar. During the patient's first visit to our clinic, she presented with low ear set, skull deformity, intellectual disability, and tilting of the head to the left by approximately 25 degrees. Imaging studies revealed multisegmental fusion and C3 hemivertebrae of the cervical spine and left thoracic scoliosis at T4 with 50 degrees of Cobb's angle. We instructed passive stretching and applied the customized soft neck collar we invented. The ipsilateral aspect of the neck collar is designed to provide vertical support between the clavicle and mandibular angle and is adjustable in height. The Velcro was attached to the neck collar at the point of contact with the ipsilesional mandibular angle, which provides negative sensory feedback, inducing her to tilt neck to the contralesional side. We applied the neck collar for 2 hours a day. After 1 year of treatment, her neck inclination angle improved from 25 to 10 degrees. Providing negative sensory feedback using the customized soft neck collar can be one of the treatment options of postural management in patients with torticollis in cases of CATCH 22 syndrome combined with Klippel-Feil anomaly.

Sentinel-1 C-band SAR 영상을 이용한 용담댐 유역의 시공간 토양수분 산정 (Estimation of spatiotemporal soil moisture distribution for Yongdam-dam watershed using Sentinel-1 C-band Synthetic Aperture Radar images)

  • 정지훈;이용관;장원진;김성준
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2020년도 학술발표회
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    • pp.162-162
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    • 2020
  • 토양수분은 TDR(Time Domain Reflectometry)이나 Tensiometer 등의 장비를 이용하여 측정을 시행하고 있으나, 이를 위해서는 많은 인력과 경제적 자원이 소비될 뿐만 아니라 시공간적으로 측정할 수 있는 범위에 한계가 있다. 지상 관측의 대안으로 MIRAS(Microwave Imaging Radiometer with Aperture Synthesis)나 SMAP(Soil Moisture Active Passive), AMSR2(Advanced Microwave Scanning Radiometer 2) 등의 수동 마이크로파 위성 센서를 이용한 공간 토양수분 관측이 수행되었으나, 낮은 공간 해상도(9~36km)는 지역 규모의 토양수분 분포를 나타내기 충분하지 않고, 높은 불확실성을 내포하고 있다. 본 연구에서는 금강 상류의 용담댐 유역(930.0㎢)을 대상으로 Sentinel-1 C-band SAR(Synthetic Aperture Radar) 영상을 이용한 토지 피복 및 토양 속성을 고려한 10m 해상도의 토양수분 산출을 수행하였다. 용담댐 유역은 산림 79.7%, 논 9.0%, 밭 5.4%, 주거지 2.9%의 토지 피복 비율을 가지며 토양은 사양토(66.6%)와 양토(20.9%)가 우세하다. Sentinel-1 C-band SAR 영상은 SeNtinel Application Platform(SNAP)을 이용하여 전처리 후, 후방산란계수로 변환하였다. 토양수분 알고리즘은 TU-Wien change detection algorithm과 Regression model을 활용하였고, 검증을 위한 실측 토양수분 자료는 한국수자원공사(K-water)에서 제공하는 5년(2014~2018)간의 토양수분 관측자료를 이용하였다. 산출된 토양수분은 결정계수(Coefficient of determination, R2) 및 평균제곱근오차(Root Mean Square Error, RMSE)를 이용하여 실측 토양수분과 비교하였다. Sentinel-1 C-band SAR 영상을 이용한 고해상도의 토양수분 산출은 토지 피복 및 토양 속성을 고려한 지역 규모의 공간 토양수분 분포 및 시간적 변화를 표현 가능할 것으로 판단된다.

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STSAT-3 Main Payload, MIRIS Flight Model Developments

  • 한원용;이대희;박영식;정웅섭;이창희;문봉근;박성준;차상목;남욱원;박장현;이덕행;가능현;선광일;양순철;박종오;이승우;이형목
    • 천문학회보
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    • 제35권1호
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    • pp.40.1-40.1
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    • 2010
  • The Main payload of the STSAT-3 (Korea Science & Technology Satellite-3), MIRIS (Multipurpose Infra-Red Imaging System) has been developed for last 3 years by KASI, and its Flight Model (FM) is now being developed as the final stage. All optical lenses and the opto-mechanical components of the FM have been completely fabricated with slight modifications that have been made to some components based on the Engineering Qualification Model (EQM) performances. The components of the telescope have been assembled and the test results show its optical performances are acceptable for required specifications in visual wavelength (@633 nm) at room temperature. The ensuing focal plane integration and focus test will be made soon using the vacuum chamber. The MIRIS mechanical structure of the EQM has been modified to develop FM according to the performance and environment test results. The filter-wheel module in the cryostat was newly designed with Finite Element Analysis (FEM) in order to compensate for the vibration stress in the launching conditions. Surface finishing of all components were also modified to implement the thermal model for the passive cooling technique. The FM electronics design has been completed for final fabrication process. Some minor modifications of the electronics boards were made based on EQM test performances. The ground calibration tests of MIRIS FM will be made with the science grade Teledyne PICNIC IR-array.

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MR Technology to 4T

  • Vaughan, Thomas
    • 대한자기공명의과학회:학술대회논문집
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    • 대한자기공명의과학회 2003년도 제8차 학술대회 초록집
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    • pp.103-105
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    • 2003
  • After fifteen years of development, Magnetic Resonance (MR) technology for human imaging and spectroscopy is reaching a refined state with FDA approved 3T clinical products from Siemens, GE, and Philips. Broker has cleared CE approval with a 4T system. Varian supports a 4T system platform as well. Shielded magnets are standard at 3T from GE, Oxford, Magnex, and IGC. A shielded 4T whole body magnet is available from Oxford. Stronger switched gradients and dynamic shim coils, desired at any field, areespecially useful at higher static magnetic fields B0. In addition to the higher currents required for higher resolution slice or volume selection afforded by higher SNR, whole body gradient coils will be driven at increasing slew rates to meet the needs of new cardiac applications and other requirements. For example 3T and 4T systems are now being equipped with 2kV, 500A gradient coils and amplifiers capable of generating 4G/cm in 200msec, over a 67+/-cm bore diameter. High field EPI applications require oscillation rates at 1 kHz and higher. To achieve a benchmark 0.2 ppm shim over a 30cm sphere in a high field magnet, at least four stages of shimming need to be considered. 1) A good high field magnet will be built to a homogeneity spec. falling in the range of 100 to 150 ppm over this 30cm spherical "sweet spot" 2) Most modern high field magnets will also have superconducting shim coils capable of finding 1.5 ppm by their adjustment during system installation. 3) Passive ferro-magnetic shimming combined with 4) active, high order room temperature shim coils (as many as five orders are now being recommended) will accomplish 0.2 ppm over the 30cm sphere, and 0.1 ppm over a human brain in even the highest field magnets for human studies. Safety concerns for strong, fast gradients at any B0 field include acoustic noise and peripheral nerve stimulation. One or more of the mechanical decoupling methods may lead to quieter gradients. Patient positioning relative to asymmetric or short gradient coils may limit peripheral nerve stimulation at higher slew rates. Gradient designs combining a short coil for local speed and strength with a longer coil for coverage are being developed for 3T systems. Local gradients give another approach to maximizing performance over a limited region while keeping within the physiologically imposed dB0/dt performance limits.

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MIRIS 우주관측카메라의 기계부 개발 (DEVELOPMENT OF THE MECHANICAL STRUCTURE OF THE MIRIS SOC)

  • 문봉곤;정웅섭;차상목;이창희;박성준;이대희;육인수;박영식;박장현;남욱원;;;양순철;이선희;이승우;한원용
    • 천문학논총
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    • 제24권1호
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    • pp.53-64
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    • 2009
  • MIRIS is the main payload of the STSAT-3 (Science and Technology Satellite 3) and the first infrared space telescope for astronomical observation in Korea. MIRIS space observation camera (SOC) covers the observation wavelength from $0.9{\mu}m$ to $2.0{\mu}m$ with a wide field of view $3.67^{\circ}\times3.67^{\circ}$. The PICNIC HgCdTe detector in a cold box is cooled down below 100K by a micro Stirling cooler of which cooling capacity is 220mW at 77K. MIRIS SOC adopts passive cooling technique to chill the telescope below 200 K by pointing to the deep space (3K). The cooling mechanism employs a radiator, a Winston cone baffle, a thermal shield, MLI (Multi Layer Insulation) of 30 layers, and GFRP (Glass Fiber Reinforced Plastic) pipe support in the system. Optomechanical analysis was made in order to estimate and compensate possible stresses from the thermal contraction of mounting parts at cryogenic temperatures. Finite Element Analysis (FEA) of mechanical structure was also conducted to ensure safety and stability in launching environments and in orbit. MIRIS SOC will mainly perform Galactic plane survey with narrow band filters (Pa $\alpha$ and Pa $\alpha$ continuum) and CIB (Cosmic Infrared Background) observation with wide band filters (I and H) driven by a cryogenic stepping motor.

회전근 개 파열의 수술적 치료시 초음파 연속 검사의 유용성 (Usefulness of Serial Ultrasonography of the Rotator Cuff Repair)

  • 박재현;최원기;최창혁
    • 대한정형외과 초음파학회지
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    • 제1권2호
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    • pp.78-85
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    • 2008
  • 목적: 회전근 개 파열 환자에서 수술 전의 자기 공명 영상 검사와 초음파 검사에 따른 관절경 소견을 비교하고, 수술 후 2주, 6주 및 3개월의 회전근 개의 건재 상태를 초음파로 확인하는데 있다. 대상 및 방법: 2008년 2월부터 5월까지 본원 정형외과에 내원하여 회전근 개 파열로 관절경적 치료를 시행한 환자 29명을 대상으로 초음파 검사와 자기 공명 영상 검사를 시행한 후 관절경적 시술을 이용하여 비교하였으며, 수술 후 2주, 6주 및 3 개월에 회전근 개의 건재 상태를 초음파를 이용하여 관찰하였다. 결과: 회전근 개 파열을 확인할 수 있는 초음파 검사와 자기 공명 영상 검사의 예민도는 각각 100%였다. 전층 회전근 개 파열에서 초음파 검사와 자기 공명 영상 검사의 예민도는 각각 95%, 82%였으며, 부분층 회전근 개 파열에서 초음파 검사는 50%, 자기 공명 영상 검사는 33%의 예민도를 나타내었다. 전체 환자에 대한 초음파 검사의 정확도는 86%, 자기 공명 영상 검사의 정확도는 69%이었다. 전층 회전근 개 파열로 복원술을 시행한 22예 중 수술 후 2주에 시행한 추시 관찰 초음파 검사상 11예(50%, 소 및 중 파열 2예, 대 및 광범위 파열 9예)에서 회전근 개의 봉합 부위에서 수술 소견과 일치하는 틈새로 진단되는 저에코를 확인할 수 있었으며, 수동적 신장 운동을 시행한 후 수술 6주의 추시 관찰 초음파 검사상 5예(23%, 소 및 중 파열 1예, 대 및 광범위 파열 4예)에서 재파열 소견을, 능동적 운동을 시행한 후 수술 3개월의 추시 관찰 초음파 검사상 7예(32%, 소 및 중파열 2예, 대 및 광범위 파열 5예)에서 재파열 소견을 보였다. 결론: 회전근 개 파열에 대한 관절경적 치료 후 초음파 연속 검사는 술 후 틈새와 술 후 재파열을 구분하는데 도움을 줄 수 있었으며, 수술 후 6주에 23%, 3개월에 32%의 재파열 소견을 보인 바 재활 치료시 추가 치료의 방침을 세우는데 도움을 줄 수 있을 것으로 생각되었다.

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