• 제목/요약/키워드: NUC

검색결과 120건 처리시간 0.029초

비냉각형 TEC-less 열상 시스템에 적합한 선형보간 기반 동적 보정 계수 추정 기법 (Dynamic Calibration Coefficients Estimation with Linear Interpolation for Uncooled TEC-less IRFPA)

  • 한상혁;곽동민
    • 항공우주기술
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    • 제11권1호
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    • pp.98-102
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    • 2012
  • 비냉각형 열상 시스템에 대한 관심이 국방 및 항공우주 분야에서 증가하고 있다. 특히, 국방분야 무기체계에서는 무인화 및 주야간 적군 탐지를 위한 요소기술로 활용되고 있다. 비냉각형 열상 시스템의 연구 분야 중 저비용, 저전력, 소형화를 위한 비냉각형 TEC(Thermal Electric Cooler)-less 열상 시스템에 대한 연구가 활발히 진행되고 있다. 그러나 TEC-less로 운영하기 위해서는 최적화된 불균일보정 계수의 추출 및 적용이 요구된다. 본 논문에서는 TEC-less로 최적화 된 보정 계수 획득 방법으로 선형 보간법을 이용한 보정 계수 추정 방법인 DCCE-LI(Dynamic Calibration Coefficient Estimation with Linear Interpolation)을 제안하고, 실험을 통해 제안 기법이 기존의 정적 보정 계수를 적용한 것에 비해 IR 영상 품질이 우수하고, 실시간 보정 계수 추정이 가능함을 보인다.

New Non-uniformity Correction Approach for Infrared Focal Plane Arrays Imaging

  • Qu, Hui-Ming;Gong, Jing-Tan;Huang, Yuan;Chen, Qian
    • Journal of the Optical Society of Korea
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    • 제17권2호
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    • pp.213-218
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    • 2013
  • Although infrared focal plane array (IRFPA) detectors have been commonly used, non-uniformity correction (NUC) remains an important problem in the infrared imaging realm. Non-uniformity severely degrades image quality and affects radiometric accuracy in infrared imaging applications. Residual non-uniformity (RNU) significantly affects the detection range of infrared surveillance and reconnaissance systems. More effort should be exerted to improve IRFPA uniformity. A novel NUC method that considers the surrounding temperature variation compensation is proposed based on the binary nonlinear non-uniformity theory model. The implementing procedure is described in detail. This approach simultaneously corrects response nonlinearity and compensates for the influence of surrounding temperature shift. Both qualitative evaluation and quantitative test comparison are performed among several correction technologies. The experimental result shows that the residual non-uniformity, which is corrected by the proposed method, is steady at approximately 0.02 percentage points within the target temperature range of 283 K to 373 K. Real-time imaging shows that the proposed method improves image quality better than traditional techniques.

Detection of Methicillin Resistance in Staphylococcus aureus Isolates Using Two-Step Triplex PCR and Conventional Methods

  • Cho, Joon-Il;Jung, Hye-Jin;Kim, Young-Joon;Park, Sung-Hee;Ha, Sang-Do;Kim, Keun-Sung
    • Journal of Microbiology and Biotechnology
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    • 제17권4호
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    • pp.673-676
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    • 2007
  • A two-step triplex PCR assay targeting the mecA, femA, and nuc genes was developed for the detection of methicillin resistance genes harbored by some Staphylococcus aureus isolates and for the simultaneous identification of such isolates at the species level. The triplex PCR revealed the presence of the femA and nuc genes in all the S. aureus isolates examined (n=105). Forty-four clinical isolates were mecA positive and no foodborne isolates were mecA positive. The PCR results had a 98 or 99% correlation with the results of PBP2a latex agglutination tests or oxacillin susceptibility tests, respectively.

Favorable effect of corticosteroids in treating acute-on-chronic liver failure underlying chronic hepatitis B

  • Kim, Hyeji;Kwon, Jung Hyun;Kim, Yong Hee;Nam, Soon Woo;Lee, Jong Yul;Jang, Jeong Won
    • 대한간학회지
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    • 제24권4호
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    • pp.430-435
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    • 2018
  • Acute-on-chronic liver failure (ACLF) occurs in the presence of a chronic liver disease or cirrhosis, and often results from exacerbation of chronic hepatitis B (CHB). The efficacy of corticosteroid treatment in ACLF patients with underlying CHB remains unclear. We report the case of a 50-year-old woman who experienced ACLF due to CHB exacerbation and was treated with a combination of corticosteroids and nucleot(s)ide analogue (NUC). The patient showed rapid decompensation due to CHB exacerbation. Three months of antiviral therapy produced no improvement in liver function. Combination therapy with corticosteroids and NUC was started, which did result in improvement of liver function. This case shows that the combined therapy of corticosteroids and NUC can be effective in treating ACLF due to CHB exacerbation.

Non Uniformity Error of MSC (Multi Spectral Camera) System

  • Jang YoungJun;Yong SangSoon;Kang KeumSil;Kim JungAh;Kang SungDuk;Youn HeongSik
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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    • pp.432-435
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    • 2004
  • MSC (Multi Spectral Camera) system is a remote sensing payload to obtain high resolution ground image. In this application, uniformity characteristic is important as well as GSD (Ground Resolved Distance) and SNR (Signal to Noise Ratio). MSC image chain is consisted of OM (Optical Module), CCD, Video processor, NUC and DCSU (Data Compression and Storage Unit). Each block makes and corrects MSC's nonuniformity response. This paper shows the cause of nonuniformity error and the correction scheme of MSC system from the electronic point of view.

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Design of a Reorganization and Non-Uniformity Correction Module for CCD Pixels in MSC(Multispectral Camera)

  • Kong, Jon-Pil;Yong, Sang-Soon;Heo, Haeng-Pal;Kim, Young-Sun;Paik, Hong-Yul
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.177.1-177
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    • 2001
  • This paper describes the design of a NUC(Non-uniformity Correction) module in MSC(Multispectral Camera) which will be a payload on KOMPSAT. This module is required inside a system with data compression module like MSC to minimize the loss of imagery due to non-uniform characteristics between CCD pixels when the imagery is received and processed on a ground station. It comprises Hotlink input/output for imagery data, RS-422 interface with main controller in MSC, a number of SRAMS for storing imagery data and parameters, FPGA controllers which control the entire NUC module under the control of main controller, etc. It inputs 8-channel imagery pixel data which consist of 2-channel MS(Multispectral) band and ...

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The magnitude of ${\rho}x({\rho}_{nuc})$ versus the extent of bond formation in $S_N2$ Reactions

  • Lee, Ik-Choon;Koh, Han-Joong;Lee, Byung-Choon;Park, Byong-Seo
    • Bulletin of the Korean Chemical Society
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    • 제15권7호
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    • pp.576-581
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    • 1994
  • The secondary deuterium kinetic isotope effects (SDKIE) involving deuterated aniline nucleophiles are reported for the reactions of benzyl bromides and chlorides and benzoyl chlorides in acetonitrile. The benzyl systems behave normally as to the trend of changes in SDKIE with the magnitude of ${\rho}X({\rho}_{nuc})$, whereas benzoyl system shows ananomaly; ${\mid}{\rho}_X{\mid}$ decreases with increase in the extent of bond making estimated by the SDKIE. This has been ascribed to the negative charge accumulation at the reaction center carbon in the transition state. The magnitude of ${\rho}_{XY}$ is found to decrease by ca. 0.03 with ten degree rise in the reaction temperature.

A Kinetic Study on Aminolysis of t-Butyl 4-Pyridyl Carbonate and Related Compounds: Effect of Leaving and Nonleaving Groups on Reaction Mechanism

  • Kang, Ji-Sun;Lee, Jae-In;Um, Ik-Hwan
    • Bulletin of the Korean Chemical Society
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    • 제33권9호
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    • pp.2971-2975
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    • 2012
  • Second-order rate constants $k_N$ have been measured spectrophotometrically for nucleophilic substitution reactions of t-butyl 4-pyridyl carbonate 8 with a series of alicyclic secondary amines in $H_2O$ at $25.0{\pm}0.1^{\circ}C$. The Br${\emptyset}$nsted-type plot for the reactions of 8 is linear with ${\beta}_{nuc}$ = 0.84. The ${\beta}_{nuc}$ value obtained for the reactions of 8 is much larger than that reported for the corresponding reactions of t-butyl 2-pyridyl carbonate 6 (i.e., ${\beta}_{nuc}$ = 0.44), which was proposed to proceed through a forced concerted mechanism. Thus, the aminolysis of 8 has been concluded to proceed through a stepwise mechanism with a zwitterionic tetrahedral intermediate $T^{\pm}$, in which expulsion of the leaving-group from $T^{\pm}$ occurs at the rate-determining step (RDS). In contrast, aminolysis of benzyl 4-pyridyl carbonate 7 has been reported to proceed through two intermediates, $T^{\pm}$ and its deprotonated form $T^-$ on the basis of the fact that the plots of pseudo-first-order rate constant $k_{obsd}$ vs. amine concentration curve upward. The current study has demonstrated convincingly that the nature of the leaving and nonleaving groups governs the reaction mechanism. The contrasting reaction mechanisms have been rationalized in terms of an intramolecular H-bonding interaction, steric acceleration, and steric inhibition.

영상센서의 비균일 응답특성 보정을 위한 흑체 설계 및 성능검증과 보정오차 분석 (Black Body Design and Verification for Non-Uniformity Correction of Imaging Sensor and Uncertainty Analysis)

  • 신소민
    • 한국항공우주학회지
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    • 제41권3호
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    • pp.240-245
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    • 2013
  • 영상센서 중 적외선 센서는 시간경과 및 작동/비작동 반복에 따라 적외선 광원에 대한 응답특성이 조금씩 변화하며, 그 결과 영상품질이 저하된다. 그래서 인공위성에 탑재되는 적외선 센서의 경우 정상적인 임무수행을 위해 교정용 흑체로 주기적인 비균일 응답특성 보정을 실시할 수 있도록 해야 한다. 본 논문에서는 비균일 응답특성 보정을 위해, 적외선 센서의 파장대역 $3.3{\sim}5.2{\mu}m$에서 흑체 방사율이 0.995이상 평균온도차 $1^{\circ}C$ 이하가 되도록 V-그루브(groove) 타입의 흑체를 설계하였다. 성능검증을 위해 흑체의 방사율과 표면온도를 측정하여 검증하였으며, 그 결과로부터 비균일 응답특성 보정오차를 산출하였다.