• Title/Summary/Keyword: POL

Search Result 281, Processing Time 0.022 seconds

SPECKLE IMAGING TECHNIQUE FOR LUNAR SURFACES

  • Kim, Jinkyu;Sim, Chae Kyung;Jeong, Minsup;Moon, Hong-Kyu;Choi, Young-Jun;Kim, Sungsoo S.;Jin, Ho
    • Journal of The Korean Astronomical Society
    • /
    • v.55 no.4
    • /
    • pp.87-97
    • /
    • 2022
  • Polarimetric measurements of the lunar surface from lunar orbit soon will be available via Wide-Field Polarimetric Camera (PolCam) onboard the Korea Pathfinder Lunar Orbiter (KPLO), which is planned to be launched in mid 2022. To provide calibration data for the PolCam, we are conducting speckle polarimetric measurements of the nearside of the Moon from the Earth's ground. It appears that speckle imaging of the Moon for scientific purposes has not been attempted before, and there is need for a procedure to create a "lucky image" from a number of observed speckle images. As a first step of obtaining calibration data for the PolCam from the ground, we search for the best sharpness measure for lunar surfaces. We then calculate the minimum number of speckle images and the number of images to be shift-and-added for higher resolution (sharpness) and signal-to-noise ratio.

Prevalence of PERVs from Domestic Pigs in Korea (pol gene sequences) (국내 돼지에 존재하는 내인성 레트로 바이러스의 분포)

  • Kim, Y.B.;Yoo, J.Y.;Lee, J.Y.;Kim, G.W.;Park, H.Y.
    • Journal of Animal Science and Technology
    • /
    • v.46 no.3
    • /
    • pp.307-314
    • /
    • 2004
  • Xenotransplantation of porcine organs has the potential to overcome the severe. shortage of human tissues and organs available for human transplantation. The swine represents an ideal source of such organs because of their plentiful supply and their numerous anatomical and physiological similarities to the human. However, this procedure also carries with a number of safety issues relating to the zoonotic infections. Porcine endogenous retrovinJses(PERVs), \Wich are germ line transmitted and persist without symptoms in the pigs, are most concerning zoonotic viroses. In order to analyze the prevalence of PERV in domestic pigs, four kinds of pigs'(Landrace, Berkshire, Yorkshire, and Duroc) genomic DNA were isolated from their hair follicles. PCR analysis was carried out for detection of PERVs using subgroup A/B/C and E pol sequence primers. All pigs (20 heads) tested had high copy number of PERVs within genomes. Subgroup A/B/C and E pol gene sequences from 20 isolates were determined by direct sequencing. Sequence analysis showed pol sequences are highly conserved among intra- and inter-subspecies(99.l and 98.8%, respectively). As a first report of PERV prevalence in Korea pigs, our data would be the basic concepts of PERV transmission study in xenotransplantation.

The obstacle collision avoidance methods in the chaotic mobile robots

  • Youngchul Bae;Kim, Juwan;Kim, Yigon
    • Proceedings of the Korean Institute of Intelligent Systems Conference
    • /
    • 2003.09a
    • /
    • pp.591-594
    • /
    • 2003
  • In this paper, we propose a method to avoidance obstacle in which we assume that obstacle has an unstable limit cycle in the chaos trajectory surface. In order to avoid the obstacle, we assume that all obstacles in the chaos trajectory surface in which has an unstable limit cycle with Van der Pol equation. In this paper show also that computer simulation results are satisfy to avoid obstacle in the chaos trajectory with Chua's circuit equation of one or multi obstacle has an limit cycle with Van der Pol (VDP) efuation and compare to rate of cover in one robot which have random walk and Chua's equation.

  • PDF

Estimation Model for RF Signal Strength over Sea and Land Surfaces (바다와 지표면의 산란을 고려한 RF 수신신호세기 계산 모델)

  • Hyun, Jong-Chul;Kim, Sang-Keun;Oh, Yi-Sok
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
    • /
    • 2005.11a
    • /
    • pp.143-148
    • /
    • 2005
  • The objective of this study is to estimate RF signal strength over sea and land surfaces. For this work we calculated scattering by land with DEM(Digital Elevation Model) and sea surface with RMS surface height. and we selected two area inland and sea shore as RX point. And for each area, we get VV-pol and HH-pol characteristic of scattering at 2.2GHz.

  • PDF

Histone H4-Specific Deacetylation at Active Coding Regions by Hda1C

  • Lee, Min Kyung;Kim, TaeSoo
    • Molecules and Cells
    • /
    • v.43 no.10
    • /
    • pp.841-847
    • /
    • 2020
  • Histone acetylation and deacetylation play central roles in the regulation of chromatin structure and transcription by RNA polymerase II (RNA Pol II). Although Hda1 histone deacetylase complex (Hda1C) is known to selectively deacetylate histone H3 and H2B to repress transcription, previous studies have suggested its potential roles in histone H4 deacetylation. Recently, we have shown that Hda1C has two distinct functions in histone deacetylation and transcription. Histone H4-specific deacetylation at highly transcribed genes negatively regulates RNA Pol II elongation and H3 deacetylation at inactive genes fine-tunes the kinetics of gene induction upon environmental changes. Here, we review the recent understandings of transcriptional regulation via histone deacetylation by Hda1C. In addition, we discuss the potential mechanisms for histone substrate switching by Hda1C, depending on transcriptional frequency and activity.

Ozone resistance of radiosensitive strains of escherichia coli K-12 (Escherichia coli K-12 방사선 감수성 균주의 오존 내성)

  • Harvey, Michel
    • Korean Journal of Microbiology
    • /
    • v.26 no.2
    • /
    • pp.113-121
    • /
    • 1988
  • Ozone, an atmospheric pollutant, can damage similar UV and X-rays DNA and its components. It is possible then that the KNA damage produced by this gas are similar, to some extent, to those of radiations and that they could be repaired by the same DNA repair mechanisms. It has been observed in Escherichia coli that radiosensitive strains such as lex A, rec A and pol A, all deficient to some extent for DNA repair, are more sensitive to ozone than a wild type strain. We have thendetermined the ozone resistance and host-cell reactivation of ozone-damaged T3 phages for the E. coli double mutants pol A, lex A, uvr B, lex A, uvr A, rec A and rec A lox A. According to the results, the DNA polymerase 1 plays a key role in ozone resistance and Type 11 mechanism and/or shory patch excision repair are the most important for it. The interactions between the different DNA repair mechanisms are secondary. There is a strong correlation between ozone resistance and the capacity to reactivate T3 phages damaged by ozone.

  • PDF