• Title/Summary/Keyword: radio lines

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Analyses of the Effect of Inserting Border Lines between Adjacent Color Regions on Detecting Boundaries (경계선 검출에 대한 인접 칼라 영역간 테두리 선 삽입 효과의 분석)

  • Yoo, Hyeon-Joong;Kim, Woo-Sung;Jang, Young-Beom
    • Journal of IKEEE
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    • v.10 no.1 s.18
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    • pp.87-95
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    • 2006
  • This paper presents the analyses of the effect of inserting border lines between different color regions on edge detection in color codes, and is not intended to present any new algorithm for color-code recognition. With its role to complement the RFID (radio frequency identification) and the wide and fast spread of digital cameras, an interest on color codes is fast increasing. However, the severe distortion of colors in obtained images prohibits color codes from expanding their applications. To reduce the effect of color distortion it is desirable to process the whole pixels in each color region statistically, instead of relying on some pixels sampled from the region. This requires segmentation, and the segmentation usually requires edge detection. To help detect edges not disconnected, we inserted border lines of the width of two pixels between adjacent color regions. Two colors were used for the border lines: one consisting of white pixels, and the other black pixels. The edge detection was performed on images with either of the two kinds of border lines inserted, and the results were compared to results without inserted border lines. We found that inserting black border lines degraded edge detection by causing zipper effect while inserting white border lines improved it compared to the cases without inserted border lines.

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KVN Observation on Radio-selected AGNs hosted by Elliptical Galaxies

  • Park, Song-Youn;Yi, Suk-Young K.;Sohn, Bong-Won
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.2
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    • pp.61.1-61.1
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    • 2011
  • We have performed simultaneous observations at 22GHz and 43GHz on AGNs hosted by elliptical galaxies using KVN radio telescope. We have constructed the sample, based on two major surveys in radio and optical band, i.e. Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) and Sloan Digital Sky Survey (SDSS) DR7, respectively. We restricted the redshift range 0.01 < z < 0.06 and the absolute magnitude Mr < -19.4 in order to satisfy volume limited sample. We also checked clear detection of four distinctive emission lines ([NII], [OIII], $H{\alpha}$, $H{\beta}$) so as to utilize on BPT diagram, distinguishing AGNs from star-forming galaxies. Elliptical galaxies have been selected by visual inspection making use of SDSS optical images. Then, we cross-matched the elliptical galaxies with FIRST detections. About 35% of the galaxies have been detected throughout KVN observations. We derive spectral index, applying the flux of different radio frequencies from FIRST (1.4GHz) and KVN (22GHz) and classify into steep, flat or inverted spectrum. We have found that most of the detected galaxies have flat spectrum while the rest of them have steep spectrum. This implies that a number of detected galaxies might have compact structure associated with the central region of the galaxies. The relation between black hole mass and radio luminosity has shown relatively tighter correlation in high frequency than in low frequency, which confirms that high frequency in radio band is appropriate to study the center of the galaxies.

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Development and Test Result of Fast Digital Conversion System with Variable Sampling Frequencies for Astronomical Radio Siginal Processing (우주 전파 신호 처리용 가변 샘플링 고속 디지털 변환 장치 개발)

  • Kang, Yong-Woo;Song, Min-Gyu;Kim, Hyo-Ryoung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.16 no.6
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    • pp.1175-1182
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    • 2021
  • The receiver of each radio telescope of KVN, has a sampler that converts astronomical radio signal to digital data. The ability of this sampler (the bandwidth, sampling frequency, and sampling bits) is improved by sqrt(n), if the bandwidth is increased by n times, and the number of observable objects increases exponentially in the case of continum spectrum radio sources. As the bandwidth increases, there are the more spectrum lines that can be simultaneously monitored in the radio source. This will greatly expand the research area in astronomical radio observation. For this reason, we are trying to independently develop the technology of the fast digital sampler. Therefore, based on the research experience and technology accumulated so far, An ability of sampling up to 3.5 GHz, that can vary the sampling frequency and can observe in a wider band, was designed and made for proto-type. In this study, we introduce the development details and test results for new sampling system.

Microwave Filter Design using Tapered Transmission Line Theory (테이퍼 전송선 이론을 이용한 마이크로파 여파기 설계)

  • Gwon, Jin-Uk;Choe, Hyeong-Seok;Jang, Ho-Seong
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.37 no.3
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    • pp.28-34
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    • 2000
  • In this paper, we derive a spectral function and a new impedance profile of non-uniform tapered transmission lines by applying the Fourier transform to a linearized Riccati equation. We compensate the error which is from a linearized Riccati equation by adding a Taylor series to the impedance profile. Added terms remove discontinuities In the impedance profile at both ends of the non-uniform section. We show that a calculated spectrum approaches to a target spectrum of filter by an iterative method and numerical examples are given to illustrate the role of the phase function. As the design method which is shown in present paper provides a excellent adaptability for the design of non-uniform tapered transmission lines, the present method can be applied to design filters and impedance matching circuits with various passband characteristics.

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Corona generated Radio Interference of the 750 kV AC Bundle Conductors in Sandy and Dusty Weather Condition in the High Altitude Area

  • Liu, Yun-Peng;Zhu, Lei;Lv, Fang-Cheng;Wan, Bao-Quan;Pei, Chun-Ming
    • Journal of Electrical Engineering and Technology
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    • v.9 no.5
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    • pp.1704-1711
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    • 2014
  • Sandy and dusty weather condition often occurs in the high altitude areas of China, which may greatly influence the corona generated radio interference (RI) characteristics of the bundle conductors of 750 kV AC power transmission lines. Corona generated RI of the conductors of the 750 kV AC power transmission lines used in practice is measured by EMI receiver with a coupling circuit and a coupling capacitor connected between the high voltage side and the earth side in fine and sandy and dusty condition. The measuring frequency is 0.5 MHz, and the quasi-peak detection is used. RI excitation function is calculated based on the corona RI current measured by the EMI receiver. Corona generated RI characteristics were analyzed from sand concentration and sand particle size. The test result shows that the corona generated RI excitation function is influenced by the sandy and dusty condition. Corona discharge of the conductors is more serious in sandy and dusty condition with an ultraviolet (UV) detector. Corona generated RI excitation function increases with the increase of sand concentration and also increases with the increase of particle size.

Radio-sensitivity Analysis and Selection of Useful Mutants of Rape (Brassica napus L.) by Gamma Irradiation (방사선 처리에 의한 유채의 생육 및 감수성 조사)

  • Goh, Eun Jeong;Kim, Wook-Jin;Kim, Jin-Baek;Kim, Dong Sub;Kim, Sang Hoon;Kang, Si-Yong
    • Journal of Radiation Industry
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    • v.4 no.3
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    • pp.277-283
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    • 2010
  • Rape (Brassica napus L.) plants are one of the major oilseed crops. The main components of rapeseed are oil (35 to 47%) and protein (15 to 32%). For the biodiesel production, the development of a new variety of rape plant with high biomass and/or oleic acid contents is required. In order to determine the optimum dose of gamma-ray irradiation, the rape seeds of cvs. Hanra (Hr), Youngsan (Ys), Tammi (Tm), and Tamra (Tr) were irradiated with a 100~4,000 Gy dose range of gamma-rays. Considering the growth factors, the optimum doses were determined to be within the range of 600~1,000 Gy for the selection of useful mutant lines. Six-hundred and eighty-eight (688) $M_2$ mutant lines were obtained from 600~1,000 Gy gamma-ray-irradiated $M_1$ plants through selfing. The growth characteristics, leaf shape, early flowering, and flower color were all investigated. The selected mutant numbers of early flowering, leaf shape, and flower color were 34, 52, and 3 from the four cultivars, respectively. These mutant lines will be used for the development of a new variety of rape plant with high biomass and oleic acid contents.

Environmentally Friendly Design Program for HVAC Overhead Transmission Lines (HVAC 가공 송전선로 환경친화설계프로그램 TLCALC)

  • Yang, Kwang-H.;Ju, Mun-N.;Myung, Sung-H.;Shin, Koo-Y.;Lee, Sung-D.;Lee, Dong-I.
    • Proceedings of the KIEE Conference
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    • 2005.05b
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    • pp.67-70
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    • 2005
  • HVAC transmission lines must be designed to satisfy environmental regulations. Therefore it is necessary to pre-evaluate environmental problems for transmission line designer using prediction program. In this study, environment design software, TLCALC 2001 for transmission lines was developed as a comprehensive window program. It has 6 modules that are audible noise, radio noise, television noise, magnetic field, electric field and conductor surface gradient. TLCALC 2001 solved a few problems in use of the existing foreign tools and took several advantages. Experienced designers can get the results of calculation within about 15 minutes. Because the use of TLCALC 2001 is easy and practical, this program will be usefully applied to the environmental friendly design and construction of HVAC transmission lines. In the future, it is expected that public complaints and social environmental cost will be reduced by the use of TLCALC 2001.

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Development of an Environmental Friendly Design Program for HVAC Overhead Transmission Lines (HVAC 가공 송전선로 환경친화설계프로그램 개발)

  • Yang, Kwang-H.;Ju, Mun-N.;Myung, Sung-H.;Shin, Koo-Y.;Lee, Sung-D.;Lee, Dong-I.
    • Proceedings of the KIEE Conference
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    • 2002.07a
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    • pp.469-471
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    • 2002
  • HVAC transmission lines must be designed to satisfy environmental regulations. Therefore it is necessary to pre-evaluate environmental problems for transmission line designer using prediction program. In this study, environment design software, TLCALC 2001 for transmission lines was developed as a comprehensive window program. It has 6 modules that are audible noise, radio noise, television noise, magnetic field, electric field and conductor surface gradient TLCALC 2001 solved a few problems in use of the existing foreign tools and took several advantages. Experienced designers can get the results of calculation within about 15 minutes. Because the use of TLCALC 2001 is easy and practical, this program will be usefully applied to the environmental friendly design and construction of HVAC transmission lines. In the future, it is expected that public complaints and social environmental cost will be reduced by the use of TLCALC 2001.

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The Design, Manufacture and Applications of a Gap Noise Generator for Testing the Characteristics of EMI from Transmission Lines (송전선로 EMI 특성 실험용 인공잡음발생장치 설계, 제작 및 적용)

  • Ju, Yun-Ro;Yang, Gwang-Ho;Myeong, Seong-Ho;Lee, Dong-Il;Sin, Gu-Yong
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.51 no.1
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    • pp.23-28
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    • 2002
  • In order to survey the radiation characteristics of pure line noise of unwanted noise from overhead high voltage AC transmission lines, a disk type gap noise generator was manufactured. Disk size which decides capacitance between the noise generator and earth was selected through preliminary indoor experiments and analysis by using surface charge method. The capacitance is one of principal parameters related to the injection of a proper noise current into lines. On the basis of the capacitance obtained from calculation, 5mm of space was given to the gap of the noise generator to be installed o test line and an aluminum disk of 60cm radius was made. The field experiments were performed with the noise generator hung on the Kochang 765 kV full scale test line. As the results, the useful data which can be used to analysis the radiation characteristics of noise from transmission lines were obtained. Those are the directivity of antenna toward the line, lateral profiles, frequency spectra, height pattern and so on.

SIMULTANEOUS OBSERVATIONS OF H2O AND SIO MASERS TOWARD KNOWN EXTRAGALACTIC WATER MASER SOURCES

  • CHO, SE-HYUNG;YOON, DONG-HWAN;KIM, JAEHEON;BYUN, DO-YOUNG;WAGNER, JAN
    • Journal of The Korean Astronomical Society
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    • v.48 no.6
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    • pp.357-364
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    • 2015
  • We observe ten known 22GHz H2O maser galaxies during February 19-22, 2011 using the 21 m Tamna telescope of the Korean VLBI Network and a new wide-band digital spectrometer. Simultaneously we searched for 43GHz SiO v = 1, 2, J = 1-0 maser emission. We detect H2O maser emission towards five sources (M 33, NGC 1052, NGC 1068, NGC 4258, M 82), with non-detections towards the remaining sources (UGC 3193, UGC 3789, Antennae H2O-West, M 51, NGC 6323) likely due to sensitivity. Our 22GHz spectra are consistent with earlier findings. Our simultaneous 43GHz SiO maser search produced non-detections, yielding - for the first time - upper limits on the 43GHz SiO maser emission in these sources at a 3 σ sensitivity level of 0.018K-0.033K (0.24 Jy-0.44 Jy) in a 1.75 km s−1 velocity resolution. Our findings suggest that any 43GHz SiO masers in these sources (some having starburst-associated H2O kilomasers) must be faint compared to the 22GHz H2O maser emission.