• Title/Summary/Keyword: common large-aperture

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Development of Electron Gun 'S-CXO'

  • Kwon, Yong-Geol;Kim, Deog-Ho;Lee, Yang-Je;Yun, Kwang-Jin;Yoon, Young-Jun
    • Journal of Information Display
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    • v.2 no.1
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    • pp.43-46
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    • 2001
  • To meet the demand of the display market for large, flat, high-resolution screen, the Super Common eXtended field Oval lens (S-CXO) has been developed with resolution improvement of 10% or more compared to a conventional electron gun. A new main lens structure is adopted, to enhance the effectiveness of aperture and the performance. The new main lens can be assembled using an existing assembly system

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Structure and Function of the Reproductive System of Aplysia kurodai

  • Lee, Chi-Hoon;Kaang, Bong-Kiun;Lee, Young-Don
    • Development and Reproduction
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    • v.19 no.4
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    • pp.197-207
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    • 2015
  • This study investigated structure and function of the reproductive system in Aplysia kurodai by means of anatomical, histological, and histochemical observation. Reproductive system of this species is consisted of ovotestis, small hermaphroditic duct, ampulla, accessory genital mass and large hermaphroditic duct. The ovotestis is composed of a large number of follicles, and both oocytes and spermatocytes matured in the same follicle. The small hermaphroditic duct is a single tube and contains a swelling, the ampulla, which functions as a storage organ for endogenous sperm and an oviduct. The accessory genital mass is connected to both the small and large hermaphroditic duct, and consisted of three glands: albumen, membrane (winding) and mucus gland. The albumen gland is consisted of granular cells producing basophilic and neutral mucopolysaccharides. The membrane and mucus gland are consisted of granular cells producing acidophilc and sulfated mucopolysaccharides. The large hermaphroditic duct is a single tubular gonoduct linking the accessory genital mass to the common genital aperture but is consisted of two parallel compartments. Internally, these two compartments are incompletely divided by internal septum or fold, which are called as the red hemiduct and white hemiduct, respectively. The red hemiduct functions as an oviduct and the white hemiduct functions as a copulatory duct. The reproductive system of A. kurodai is externally comprised a single tube, i.e., monaulic type. However, internal structure of duct is incompletely divided into oviduct and copulatory duct, i.e., the oodiaulic type.

Evaluation on Spectral Analysis in ALOS-2 PALSAR-2 Stripmap-ScanSAR Interferometry (ALOS-2 Stripmap-ScanSAR 위상간섭기법에서의 스펙트럼 분석 평가)

  • Park, Seo-Woo;Jung, Seong-Woo;Hong, Sang-Hoon
    • Korean Journal of Remote Sensing
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    • v.36 no.2_2
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    • pp.351-363
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    • 2020
  • It is well known that alluvial sediment located in coastal region has been easily affected by geohazard like ground subsidence, marine or meteorological disasters which threaten invaluable lives and properties. The subsidence is a sinking of the ground due to underground material movement that mostly related to soil compaction by water extraction. Thus, continuous monitoring is essential to protect possible damage from the ground subsidence in the coastal region. Radar interferometric application has been widely used to estimate surface displacement from phase information of synthetic aperture radar (SAR). Thanks to advanced SAR technique like the Small BAseline Subset (SBAS), a time-series of surface displacement could be successfully calculated with a large amount of SAR observations (>20). Because the ALOS-2 PALSAR-2 L-band observations maintain higher coherence compared with other shorter wavelength like X- or C-band, it has been regarded as one of the best resources for Earth science. However, the number of ALOS-2 PALSAR-2 observations might be not enough for the SBAS application due to its global monitoring observation scenario. Unfortunately, the number of the ALOS-2 PALSAR-2 Stripmap images in area of our interest, Busan which located in the Southeastern Korea, is only 11 which is insufficient to apply the SBAS time-series analysis. Although it is common that the radar interferometry utilizes multiple SAR images collected from same acquisition mode, it has been reported that the ALOS-2 PALSAR-2 Stripmap-ScanSAR interferometric application could be possible under specific acquisition mode. In case that we can apply the Stripmap-ScanSAR interferometry with the other 18 ScanSAR observations over Busan, an enhanced time-series surface displacement with better temporal resolution could be estimated. In this study, we evaluated feasibility of the ALOS-2 PALSAR-2 Stripmap-ScanSAR interferometric application using Gamma software considering differences of chirp bandwidth and pulse repetition frequency (PRF) between two acquisition modes. In addition, we analyzed the interferograms with respect to spectral shift of radar carrier frequency and common band filtering. Even though it shows similar level of coherence regardless of spectral shift in the radar carrier frequency, we found periodic spectral noises in azimuth direction and significant degradation of coherence in azimuth direction after common band filtering. Therefore, the characteristics of spectral bandwidth in the range and azimuth direction should be considered cautiously for the ALOS-2 PALSAR-2 Stripmap-ScanSAR interferometry.