• Title/Summary/Keyword: SFH

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Design of a Ranging Signal in the Frequency Hopping Satellite Communication System (주파수 도약 위성통신 시스템에서 레인징 신호 설계 방안)

  • Hwang, Seok-gu;Sim, Eun-seok;Jo, Byung-gak;Yoon, Won-Sang
    • Journal of the Korea Institute of Military Science and Technology
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    • v.19 no.6
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    • pp.762-768
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    • 2016
  • In this paper, a method for generating ranging signal to reduce the effects of interference and overcome intentional jamming is proposed in slow frequency hopping(SFH) communication system. A terminal uses ranging signal for initial Up-link synchronization in the frequency hopping communication systems using multi-terminal. However, ranging signal generated by unsynchronized terminal acts as an interference signal to another terminal. Therefore, we propose the design of the ranging signal with PN sequence in order to minimize the affection to the other terminal and simulated its performance. From the simulated result, we confirm synchronization performance.

Effects of a School-based Intervention Program on Attitude and Knowledge of Household Members Towards a Smoke-free Home: a Cluster Controlled Trial

  • Intarut, Nirun;Chongsuvivatwong, Virasakdi;McNeil, Edward
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.1235-1242
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    • 2016
  • Background: A school-based smoke free home (SFH) program is useful in empowering the mother and child to reduce secondhand smoke exposure but the effects of pretesting on knowledge and attitude has been largely ignored. We aimed to test whether such a program can be effective in Southern Thailand with an additional assessment of the net effect of the pretest. Materials and Methods: A Solomon four-group design was used. Twelve rural primary schools were assigned to one of the four conditions (each with 3 schools): intervention with and without a pretest, control with and without the same pretest. The intervention was performed in the classroom and home over a period of 1 month. Outcomes were assessed at baseline and 3 months after the intervention on whether the home was smoke free and related knowledge and attitude. Results: The intervention could lead to a smoke-free home without statistical significance. Attitude, knowledge and self-confidence on creating a smoke-free home, and self-confidence in avoidance of secondhand smoke exposure and persuading smokers to not smoke in their home were significantly improved. No pretest effect was observed. Conclusions: Gain in attitude, knowledge and self-confidence among family members from the brief school-based education should be enhanced by other measures.

A Comparative Genome-Wide Analysis of GATA Transcription Factors in Fungi

  • Park, Jong-Sun;Kim, Hyo-Jeong;Kim, Soon-Ok;Kong, Sung-Hyung;Park, Jae-Jin;Kim, Se-Ryun;Han, Hyea-Young;Park, Bong-Soo;Jung, Kyong-Yong;Lee, Yong-Hwan
    • Genomics & Informatics
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    • v.4 no.4
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    • pp.147-160
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    • 2006
  • GATA transcription factors are widespread eukaryotic regulators whose DNA-binding domain is a class IV zinc finger motif in the form $CX_{2}CX_{17-20}CX_{2}C$followed by a basic region. In fungi, they act as transcriptional activators or repressors in several different processes, ranging from nitrogen source utilization to mating-type switching. Using an in-house bioinformatics portal system, we surveyed 50 fungal and 9 out-group genomes and identified 396 putative fungal GATA transcription factors. The proportion of GATA transcription factors within a genome varied among taxonomic lineages. Subsequent analyses of phylogenetic relationships among the fungal GATA transcription factors, as well as a study of their domain architecture and gene structure, demonstrated high degrees of conservation in type IVa and type IVb zinc finger motifs and the existence of distinctive clusters at least at the level of subphylum. The SFH1 subgroup with a 20-residue loop was newly identified, in addition to six well-defined subgroups in the subphylum Pezizomycotina. Furthermore, a novel GATA motif with a 2f-residue loop ($CX_{2}CX_{21}CX_{2}C$, designated 'zinc finger type IVc') was discovered within the phylum Basidiomycota. Our results suggest that fungal GATA factors might have undergone multiple distinct modes of evolution resulting in diversified cellular modulation in fungi.

Performance Investigation of Visible Light Communication Using Super Bright White LED and Fresnel Lens (조명용 고출력 백색 LED와 프레넬 렌즈를 이용한 가시광 통신 성능연구)

  • Kim, Min-Soo;Sohn, Kyung-Rak
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.1
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    • pp.63-67
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    • 2015
  • White light-emitting diode (WLED) is growing interest in using both illumination and communications. This paper reports visible light communication (VLC) composed of a super bright white light-emitting diode, low cost commercial photo-diode and a Fresnel lens. LED driver is consisted of the power MOSFET and MOSFET driver that switches the LED on and off. The modulation bandwidth of the LED used was determined to be 8 MHz. However, it was possible to communicate up to 1 Mbps under illumination of 500 lx because of the weak signal power and a low spectral sensitivity of the SHF213 as a PIN photodiode. In order to enhance the system bandwidth, the LED light was focused on the PIN photodiode by use of the Fresnel lens. As a result of that, visible light link was operated up to modulation bandwidth of the LED. The signal to noise ratio can be improved by 40 dB using an optical concentration at the receiver.

Early-type Dwarf Galaxies in the Virgo Cluster: An Ultraviolet Perspective

  • Kim, Suk;Rey, Soo-Chang;Sung, Eon-Chang;Lisker, Thorsten;Jerjen, Helmut;Lee, Youngdae;Chung, Jiwon;Pak, Mina
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.81-81
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    • 2012
  • Since the ultraviolet (UV) flux of an integrated population is a good tracer of recent star formation activities, UV observations provide an important constraint on star formation history (SFH) in galaxies. We present UV color-magnitude relations (CMRs) of early-type dwarf galaxies in the Virgo cluster, based on Galaxy Evolution Explorer (GALEX) UV data and the Extended Virgo Cluster Catalog (EVCC, Kim, S. in prep.). The EVCC covers an area 5.4 times larger (750 deg2) than the footprint of the classical Virgo cluster catalog by Binggeli and collaborators. We secure 1304 galaxies as members of the Virgo cluster and 526 galaxies of them are new objects not contained in the VCC. Morphological classification of galaxies in the EVCC is based on the optical image ("Primary Classification") and spectral feature ("Secondary Classification") of the SDSS data. We find that dwarf lenticular galaxies (dS0s) show a surprisingly distinct and tight locus separated from that of ordinary dwarf elliptical galaxies (dEs), which is not clearly seen in previous CMRs. The dS0s in UV CMRs follow a steeper sequence than dEs and show bluer UV-optical color at a given magnitude. Most early type dwarf galaxies with blue UV colors (FUV-r < 6 and NUV-r < 4) are identified as those showing spectroscopic hints of recent or ongoing star formation activities. We explore the observed CMRs with population models of a luminosity-dependent delayed exponential star formation history. The observed CMR of dS0s is well matched with models with relatively long delayed star formation. Our results suggest that dS0s are most likely transitional objects at the stage of subsequent transformation of late-type progenitors to ordinary red dEs in the cluster environment. In any case, UV photometry provides a powerful tool to disentangle the diverse subpopulations of early-type dwarf galaxies and uncover their evolutionary histories.

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