• Title/Summary/Keyword: IR signal

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A Method of ISAR Geometric Calibration for Point Target Using Impulse-Radio UWB (임펄스 초광대역 레이다를 이용한 점표적의 ISAR 기하 보정 방법)

  • Yu, Jiwoong;Nikitin, Konstantin;Paek, Inchan;Jang, Jong Hun;Ka, Min-Ho
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.26 no.4
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    • pp.397-403
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    • 2015
  • In this paper, a method of ISAR geometric calibration is represented by using impulse-radio UWB radar. The ir-UWB is good for using a signal processing in time domain, so, it does not occur a multi-path or coupling problem. If a signal that between antennas and target is assumed a plane wave, a center of rotation in ISAR geometry model can be estimated by using point target. Before image is reconstructed with sinogram, the center of rotation can be calculated by using least square fitting. This method can be obtained a more contrast image, and a maximum value of entropy of image. The method, that estimates a center of rotation in received data, will be used a initial setup of instruments or a periodic compensation to reconstruct image. It would be useful in medical, security and surveillance imaging equipments that have a fixed geometry.

Optimization of Image Tracking Algorithm Used in 4D Radiation Therapy (4차원 방사선 치료시 영상 추적기술의 최적화)

  • Park, Jong-In;Shin, Eun-Hyuk;Han, Young-Yih;Park, Hee-Chul;Lee, Jai-Ki;Choi, Doo-Ho
    • Progress in Medical Physics
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    • v.23 no.1
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    • pp.8-14
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    • 2012
  • In order to develop a Patient respiratory management system includinga biofeedback function for4-dimentional radiation therapy, this study investigated anoptimal tracking algorithmfor moving target using IR (Infra-red) camera as well as commercial camera. A tracking system was developed by LabVIEW 2010. Motion phantom images were acquired using a camera (IR or commercial). After image process were conducted to convert acquired image to binary image by applying a threshold values, several edge enhance methods such as Sobel, Prewitt, Differentiation, Sigma, Gradient, Roberts, were applied. The targetpattern was defined in the images, and acquired image from a moving targetwas tracked by matching pre-defined tracking pattern. During the matching of imagee, thecoordinateof tracking point was recorded. In order to assess the performance of tracking algorithm, the value of score which represents theaccuracy of pattern matching was defined. To compare the algorithm objectively, we repeat experiments 3 times for 5 minuts for each algorithm. Average valueand standard deviations (SD) of score were automatically calculatedsaved as ASCII format. Score of threshold only was 706, and standard deviation was 84. The value of average and SD for other algorithms which combined edge detection method and thresholdwere 794, 64 in Sobel, 770, 101 in Differentiation, 754, 85 in Gradient, 763, 75 in Prewitt, 777, 93 in Roberts, and 822, 62 in Sigma, respectively. According to score analysis, the most efficient tracking algorithm is the Sigma method. Therefore, 4-dimentional radiation threapy is expected tobemore efficient if threshold and Sigma edge detection method are used together in target tracking.

Development of the Blind Spot Detecting System for Vehicle (차량용 사각지대 감지시스템의 개발)

  • Yoon, Moon-Young;Kim, Se-Hun;Son, Min-Hyuk;Yun, Duk-Sun;Boo, Kwang-Seok;Kim, Heung-Seob
    • Transactions of the Korean Society of Automotive Engineers
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    • v.17 no.2
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    • pp.34-41
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    • 2009
  • The latest vehicle yields a superior safety and reduction of driving burden by monitoring the driving state of vehicle and its environment with various sensors. To detect other vehicles and objects of the rear left and right-side blind spot area of driver, provide the information about a existence of objects inside the blind spot, and give a signal to avoid collision, this study proposes the intelligent outside rear-view mirror system. This task has substantially complicated several factors. For example, the size, geometry and features of the various vehicles which might enter the monitored zone is varied widely and therefore present various reflective characteristics. This study proposes the optimal specification and configuration of optical system and IR array sensor of blind spot detection system, and shows the results of the performance evaluation of developed system.

Protein Tyrosine Phosphatase 1B Activity of Quercetin from Houttuynia Cordata (어성초로부터 분리된 Quercetin의 Protein Tyrosine Phosphatase 1B 활성)

  • Choi, Hwa-Jung;Bae, Eun-Young;No, Yong-Ju;Baek, Seung-Hwa
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.22 no.6
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    • pp.1532-1536
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    • 2008
  • Quercetin which isolated form the roots of Houttuynia cordata. was determined on the basis of IR, ID and 2D NMR specta by direct comparison with authentic compounds. Protein tyrosine phophatase 1B (PTP1B) is thought to be a negative regulator in insulin signal-transduction pathway. Insulin-resistance by the activation of PTP1B is a hallmark of both type 2 diabetes and obesity. Thus, the compound inhibiting PTP1B can improve insulin resistance and can be effective in treating type 2 diabetes and obesity. Quercetin which measured the inhibitory activity against PTP1B was 92.1% inhibition in the 30 ${\mu}g$/mL, 83.4% inhibition in the 6 ${\mu}g$/mL and 76.5% inhibition in the 3 ${\mu}g$/mL. These results suggest that quercetin retains a potential PTP1B activity.

Spaceborne Cryogenic Cooler Development Status (우주용 극저온 냉각기 기술개발동향)

  • Kim, Hong-Bae;Lee, Seung-Yup;Lee, Won-Beom;Kim, Gyu-Sun
    • Current Industrial and Technological Trends in Aerospace
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    • v.7 no.2
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    • pp.48-58
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    • 2009
  • Since 1960s, cryogenic cooling technologies has been adopted in the development of spacecraft with components that must be cooled to cryogenic temperatures of 2 to 150 K. In recent years this technology has been a substantial growth in the emerging number of programs that include such spacecraft to service scientific, military, and weather observation missions. The cooling of optics and detectors to reduce signal noise in infrared (IR) telescopes is the principal applications of cryogenic cooling technologies. The choice of cooling technologies depends on the desired temperature level, the amount of heat to be removed, and the required operating life. This paper will present the status of modern cryogenic cooling technologies especially for space application.

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Spectroscopic characterization of N,N'-bis(salicylidene)pentane-1,3-diamine nickel(II) complex

  • Kim, Gilhoon;Won, Hoshik
    • Journal of the Korean Magnetic Resonance Society
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    • v.18 no.2
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    • pp.74-81
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    • 2014
  • The $N_2O_2$ tetradentate Schiff base ligand, N,N'-bis(salicylidene)pentane-1,3-diamine (Salpn), coupled with 1:2 concentration ratio of 1,3-diaminopentane and salicylaldehyde was used to produce a series of macrocyclic Nikel(II) complexes. In the metal complexation, it was observed that Salpn macrocyclic ligand can adopt more than a metal ion giving an unique multinuclear metal complexes including Ni(II)Salpn and $Ni(II)_3(Salpn)_2$. Characteristic IR ${\upsilon}(M-O)$ peaks for Ni(II)Salpn and $Ni(II)_3(Salpn)_2$ were observed to be $1028cm^{-1}$ and $1024cm^{-1}$, respectively. Characteristic UV-Vis absorption ${\lambda}_{max}$ peaks for $Ni(II)_3(Salpn)_2$ were observed to be 241nm and 401 nm. Structural characterization of $Ni(II)_3(Salpn)_2$ by NMR exhibits that the salicylidene ring moiety has two different resonance signals originated from the magnetically asymmetric diligand and trinuclear bis complex. Complete NMR signal assignments and characterizations elucidating structural features of $Ni(II)_3(Salpn)_2$ were described in detail.

Detection Property of Red Blood Cell-Magnetic Beads Using Micro Coil-Channel and GMR-SV Device

  • Park, Ji-Soo;Kim, Nu-Ri;Jung, Hyun-Jun;Khajidmaa, Purevdorj;Bolormaa, Munkhbat;Lee, Sang-Suk
    • Proceedings of the Korean Magnestics Society Conference
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    • 2015.05a
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    • pp.161-163
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    • 2015
  • The micro device, coil, and channel for the biosensor integrated with the GMR-SV device based on the antiferromagnetic IrMn layer was fabricated by the light lithography process. When RBCs coupled with several magnetic beads with a diameter of $1{\mu}m$ passed on the micro channel, the movement of RBC + ${\mu}Beads$ is controlled by the electrical AC input signal. The RBC + ${\mu}Beads$ having a micro-magnetic field captured above the GMR-SV device is changed as the output signals for detection status. From these results, the GMR-SV device having the width magnitude of a few micron size can be applied as the biosensor for the analysis of a new magnetic property as the membrane's deformation of RBC coupled to magnetic beads.

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An Instrument for Continuous Measurement of Double Layer Capacitance (이중층 전기용량 연속 측정 장치)

  • Czae Myung-Zoon;Woo Seung-Soo;Choi Q. Won
    • Journal of the Korean Chemical Society
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    • v.36 no.5
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    • pp.674-678
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    • 1992
  • An instrument is described that can obtain directly the whole capacitance vs. potential curve and accurately even in dilute solutions using positive feedback for IR correction. Applying a small (7∼10 mV) triangular signal, controlled rectification of the resulting square wave using sample-and-hold circuit allows one to plot the corrected double layer capacitance over a wide potential range. Several illustrations involving the improved performance characteristics of its applicability are given and its limitations discussed.

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HIGH-RESOLUTION NEAR-INFRARED SPECTRA OF NEARBY QUASARS

  • Le, Huynh Anh Nguyen;Pak, Soojong;Im, Myungshin;Ho, LuisC.
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.91-91
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    • 2012
  • We present high-resolution near-infrared host galaxy spectra of low-z quasars, PG0844+349 (z=0.064), PG1226+023 (z=0.158), and PG1426+015 (z=0.086). The observation was done by using the near-IR high resolution echelle spectrometer, IRCS, at the SUBARU 8.2 m telescope. The full width at half maximum of the point spread function was about 0.3 arcsec by using an Adaptive Optics system, which can effectively resolve the quasar spectra from the host galaxy spectra. The signal-to-noise ratios are increased by the total exposure time up to several hours per targets and the development of data reduction method. We compare our results to the stellar spectra library and sample spectra from Dasyra et al. (2007) and Watson et al. (2008). The identified spectral lines will be used to study the physical mechanism of quasars, and the velocity dispersions of the stars in the bulge of the host galaxy.

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Synthesis and Characterization of Thallium (Ⅲ) Complexes with Tetracyanoquinodimethane, TI$(TCNQ)_3$ and $TICI_2(TCNQ)_{2.5}$

  • 김미경;김영인;문성배;최성낙
    • Bulletin of the Korean Chemical Society
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    • v.17 no.5
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    • pp.424-428
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    • 1996
  • TlCl2(TCNQ)2.5 and Tl(TCNQ)3 were obtained from the reaction of LiTCNQ (TCNQ=tetracyanoquinodimethane) and TlX3 (X=Cl and NO3). These compounds were characterized by spectroscopic(IR, UV, EPR), electrochemical methods, and electrical conductivity measurements. Thermal analysis (TG, DSC) was also conducted. The room temperature electrical conductivities of these compounds are in the range of semiconductors. Spectroscopic studies indicate that Tl(TCNQ)3 has fully ionized TCNQ- ions in a form of simple salt, whereas TlCl2(TCNQ)2.5 is consisted of TCNQ- and TCNQ0 as a complex salt. EPR values of TCNQ- radical anion are 1.999 in both compounds and the signal attributable to metal ion is not observed, suggesting that any unpaired electrons are localized on TCNQ radicals, and metal atoms have diamagnetic state. Ligand decomposition and reduction process are simultaneously progressed in both compounds above at 200 ℃. The endothermic activation energy of TlCl2(TCNQ)2.5 is shown somewhat larger than that of Tl(TCNQ)3, it may be due to Tl-Cl bond strength. The mid-peak potentials of these compounds are very similar to those of TCNQ and the values of Epa and Epc are almost equal to 1. The wave of thallium ion is not detected in cyclic voltammogram, hence the redox processes of the complexes might be mainly localized to the TCNQ ligand rather than thallium ion.