• Title/Summary/Keyword: ${\gamma}-ray$

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Camera for Quasars in Early Universe

  • Park, Won-Kee;Pak, Soojong;Im, Myungshin;Choi, Changsu;Jeon, Yiseul;Chang, Seunghyuk;Jeong, Hyeonju;Lim, Juhee;Kim, Eunbin;Choi, Nahyun;Lee, Hye-In;Kim, Sanghyuk;Jeong, Byeongjoon;Ji, Taegeun
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.68.2-68.2
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    • 2013
  • Camera for QUasars in EArly uNiverse (CQUEAN) is an optical CCD camera system made by Center for Exploration of the Origin of the Universe (CEOU). CQUEAN is developed for follow-up observation of red sources such as high-redshift quasar candidates ($z{\geq}5$), gamma-ray bursts (GRB), brown dwarfs and young stellar objects. The CQUEAN is composed of a science camera with deep-depletion CCD chip which is sensitive at around $1{\mu}m$, a set of custom-made wide-band filters for detection of quasar candidates at z~5, and a guide camera. A focal reducer was developed to secure $4.8^{\prime}{\times}4.8^{\prime}$ field of view, and an in-house user software for efficient data acquisition. CQUEAN was attached to 2.1m Otto Struve Telescope in McDonald Observatory, USA, in August 2010. About 1000 quasar candidates including 3 confirmed with follow-up spectroscopy, have been observed so far, and many high-z galaxy cluster candidates, GRBs and supernovae were also observed. And monitoring of HBC 722, a young stellar object, is under way since 2011. Further enhancement of CQUEAN including the introduction of narrow-band filters is planned.

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The environments of GRB 100205A field

  • Kim, Yongjung;Im, Myungshin
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.42.1-42.1
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    • 2013
  • GRB 100205A is a Gamma Ray Burst (GRB) which is suspected to be at $11{\leq}Z{\leq}13.5$ due to its very red H-K color ($(H-K)_{vega}=2.1{\pm}0.5$). We observed a field centered at GRB 100205A with the Wide Field Camera (WFCAM) at the United Kingdom Infrared Telescope (UKIRT) in Hawaii, so as to find a 11 < z < 13 quasar that could be located around the GRB. The images were obtained in J, H, and K filters covering a square area of 0.75 $deg^2$ to the depths of 22.5, 21.4, and 20.2 in Vega magnitude at $5{\sigma}$, respectively. Also using a z-band image observed by MegaCam in Canada France Hawaii Telescope (CFHT), we found 12 candidates that have colors consistent with a quasar at 11 < z < 13 with two criteria; (1) non-detection in z-, J-bands and $(H-K)_{vega}$ > 1.6 (2) only detection in K-band with $(Hlimit-K)_{vega}$ > 1.6. However, we also find 627 red ($(H-K)_{vega}$ > 1.4) objects that are likely to be old or dusty galaxies at $z{\leq}3$, so the 12 candidates could be these red objects. These red objects are found to be strongly clustered in the Ultra Deep Survey (UDS) fields of UKIRT Infrared Deep Sky Survey (UKIDSS) than those in the GRB 100205A field. We suggest a lack of a strongly clustered region surrounding an extremely high-redshift GRB with some limitations.

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Performance Measurement of SMT(Slewing Mirror Telescope) Optical System

  • Ahn, Ki-Beom;Jeong, Soo-Min;Kim, Ji-Eun;Kim, Sug-Whan;Lee, Jik;Lim, Heui-Jin;Lindere, V.;Nam, Ji-Woo;Nam, Koo-Hyun;Park, Il-H.;Smoot, G.F.
    • Bulletin of the Korean Space Science Society
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    • 2011.04a
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    • pp.23.1-23.1
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    • 2011
  • The SMT is a subsystem of the UFFO (Ultra-Fast Flash Observatory) pathfinder onboard the Lomonosov spacecraft planed to be launched in November 2011. The UFFO is designed for extremely fast observation of optical afterglow of Gamma Ray Burst (GRB). This study is primarily concerned with performance measurement of the SMT optical system under the integration and test phase. SMT is a 100mm Ritchey-Chretien type telescope with a motorized slewing mirror and a $256{\times}256$ pixels Intensified Charge-Coupled Device (ICCD) of 22.2${\mu}m$ in pixel size. SMT is designed to operate over the wavelength coverage between 200 nm and 650 nm. It has 17 arcmin FOV (Field of View), providing 4arcsec in detector pixel resolution. In this study, we describe the integration and test process of the SMT optical system and interim performance measurement results with motorized slewing mirror and ICCD.

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Total En Bloc Thoracic and Lumbar Spondylectomy for Non-Small Cell Lung Cancer with Favorable Prognostic Indicators : Is It Merely Indicated for Solitary Spinal Metastasis?

  • Park, Jong-Hwa;Hyun, Seung-Jae;Kim, Ki-Jeong;Jahng, Tae-Ahn
    • Journal of Korean Neurosurgical Society
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    • v.56 no.5
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    • pp.431-435
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    • 2014
  • A fifty-year-old female non-smoker with no other specific medical history visited our institute. She complained of axial back pain with no other neurological deficit. Chest X-ray, chest computed tomography (CT) scan, CT-guided needle aspiration biopsy, whole-body positron emission tomography, spine CT and spine magnetic resonance image findings suggested NSCLC with epidermal growth factor receptor (EGFR) mutation, multiple brain metastases, and two isolated metastases to the T3 and L3 vertebral bodies. She underwent chemotherapy with gefitinib ($Iressa^{TM}$) for NSCLC and gamma knife surgery for multiple brain metastases. We performed a two-staged, total en bloc spondylectomy of the T3 and L3 vertebral bodies based on several good prognostic characteristics, such as the lack of metastases to the appendicular bone, good preoperative performance status, and being an excellent responder (Asian, never-smoker and adenocarcinoma histology) to EGFR inhibitors. Improved axial back pain after the surgery enabled her to walk with the aid of a thoracolumbosacral orthosis brace on the third postoperative day. Her Karnofsky performance status score (KPS) was 90 at the time of discharge and has been maintained to date 3 years after surgery. In selected NSCLC patients with good prognostic characteristics, we suggest that locally curative treatment such as total en bloc spondylectomy or radiosurgery should be emphasized to achieve longer term survival for the selected cases.

Realization of single supply to reduce power on portable radiation detection device (소모전력 감소를 위한 단일 전원 휴대용 방사선 검출장치 구현)

  • Oh, Jae-Kyun;Nam, Hye-Jin;Kim, Young-Kil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.4
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    • pp.1024-1030
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    • 2015
  • Safety and security system have been internationally enhanced in a field of shipping logistics. Accordingly, techniques for safety and security have been studied steadily. The need of portable radiation detection device is increasing by the search of the container is enhanced. In this paper, we propose a study to improve the life of the system and the realization of portable radiation detection device based on Cortex-A9. Configuration of a portable radiation detection device is configured largely to an analog board and the digital platform and the sensor module. The power used in each stage of the analog board is varied. Uses a switching regulator to use various power supply thereby to generate an error result and cause the switching noise. It is proposed to reduce the power consumption reducing technique for the study.

3D Reconstruction Using Segmentation of Myocardial SPECT Images (SPECT 심근영상의 영상분할을 이용한 3차원 재구성)

  • Jung, Jae-En;Lee, Sang-Bock
    • Journal of the Korean Society of Radiology
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    • v.3 no.2
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    • pp.5-10
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    • 2009
  • Myocardial imaging in SPECT (Single Photon Emission Computed tomography) scan of the gamma-ray emitting radiopharmaceuticals to patients after intravenous radiopharmaceuticals evenly spread in the heart region of interest by recording changes in the disease caused by a computer using the PSA test is to diagnose. Containing information on the functional myocardial perfusion imaging is a useful way to examine non-invasive heart disease, but the argument by noise and low resolution of the physical landscape that is difficult to give. For this paper, the level of myocardial imaging by using the three algorithms to split the video into 3-D implementation of the partitioned area to help you read the proposed plan. To solve the difficulty of reading level, interest in using the sheet set, partitioned area of the left ventricle was ranked the partitioned area was modeled as a 3-D images.

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Establishment of some Conditions for the Development of Legume Inoculant (근류균 접종제 개발을 위한 우수 증량제의 선발 및 생산 최적조건)

  • Kim, Chang-Jin;Rhee, Yoon;Yoo, Ick-Dong
    • Korean Journal of Soil Science and Fertilizer
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    • v.23 no.2
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    • pp.146-151
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    • 1990
  • The viability of rhizobia according to various kinds of carrier materials, inoculum size, storage temperature and sterilization methods was investigated for the development of legume inoculat. The results were followings. 1. Peat and perlite were favorable as a carrier material. 2. Rhizobia counts were reached to $5{\times}10^8cells/g$ carrier 1-2 weeks after inoculation with inoculum size below $10^4cells/g$ carrier. 3. $10^9cells/g$ carrier was maintained 12 weeks after storage at room temperature. 4. Steam heat sterilization was the best method for carrier sterilization among methods used in this study. Dry heat and ${\gamma}$-ray sterilization were also applicable.

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Development and Performance Estimation of Wide-ranged Fine Current Module for NPP Instrumentation (원전 계측용 광범위 미세전류모듈의 개발 및 성능평가)

  • Kim, Jong-ho;Chang, Hong-ki;Che, Gyu-shik
    • Journal of Advanced Navigation Technology
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    • v.20 no.5
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    • pp.482-489
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    • 2016
  • Detection of gamma ray can be available using optical fiber scintillator under radiation environment. It monitors the transfer energies of these ions by photodiodes and then convertes into currents. The module which converts those currents into voltages and processes signals is named fine current module TIA, and it is essentially important to convert currents into voltages with high linearity. We have studied and developed the TIA, improving converting linearity and minimizing noises and off-set voltages. Also, we have made efforts to develop precise and accurate current module in compliance with concerned requirements. First of all, we established developing theory, developed related circuits, and then made the current module. And, we confirmed its stability and linearity to be more excellent than any other equipment proposed by other references. We tested the developed fine current modules in the real radiation environment under authorized supervising, confirmed them to meet related requirements.

3D Reconstruction Using Segmentation of Myocardial SPECT (SPECT 심근영상의 영상분할을 이용한 3차원 재구성)

  • Jung, Jae-Eun;Lee, Jun-Haeng;Choi, Seok-Yoon;Lee, Sang-Bock
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.6
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    • pp.2240-2245
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    • 2010
  • Myocardial imaging in SPECT (Single Photon Emission Computed tomography) scan of the gamma-ray emitting radiopharmaceuticals to patients after intravenous radiopharmaceuticals evenly spread in the heart region of interest by recording changes in the disease caused by a computer using the PSA test is to diagnose. Containing information on the functional myocardial perfusion imaging is a useful way to examine non-invasive heart disease, but the argument by noise and low resolution of the physical landscape that is difficult to give. For this paper, the level of myocardial imaging by using the three algorithms to split the video into 3-D implementation of the partitioned area to help you read the proposed plan. To solve the difficulty of reading level, interest in using the sheet set, partitioned area of the left ventricle was ranked the partitioned area was modeled as a 3-D images.

Transformation Behavior of Retained Austenite on Microstructure and Mechanical Properties in Fe-0.7wt%C-2.3wt%Si Steel (Fe-0.7%C-2.3%Si강의 미세조직과 기계적 성질에 미치는 잔류 오스테나이트 변태 거동)

  • Son, Je-Young;Kwon, Do-Young;Kim, Ji-Hun;Kim, Won-Bae;Kim, Hak-Jin;Ye, Byung-Joon
    • Journal of Korea Foundry Society
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    • v.32 no.3
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    • pp.138-143
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    • 2012
  • This steel has been synthesized integrating concepts from Austempering Ductile Cast Iron (ADI) technology. While ADI has excellent mechanical and physical properties, the Young's modules of ADI is approximately 20% lower than steel. In addition, the presence of graphite nodules in ADI can be sites of crack initiation, where fracture takes place at graphite matrix interface. Because of this limitations of ADI, there has been a growing interest in austempered steels as structural materials in resent years. In this investigation, a new steel with microstructure composed of ferrite and austenite and with simultaneous high tensile strength (1,150 MPa) and high ductility (33%) was developed. The goal of this investigation is to obtain a better understanding of deformation and transformation behaviour in high carbon retained austenite(${\gamma}_{HC}$) and over-saturated ferrite(${\alpha}$) during the plastic deformation. A detailed study of the microstructure of this steel was carried out by means of X-ray diffraction (XRD) and electron back scattering diffraction (EBSD) technic. In this way it was shown that BCC phase (BCC) took up the larger part of the nominal strain whereas the a part of retained austenite responded to the mechanincal load by partial martensite transformation, and misorientation change in the retained austenite after plastic strain could be attributed to the large elongation.