• Title/Summary/Keyword: DME

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Monitoring of the Jamming Environment in the GNSS L5 Band in Korea Region

  • Lee, Hak-beom;Song, Young-Jin;Park, Dong-Hyuk;Lee, Sanguk;Won, Jong-Hoon
    • Journal of Positioning, Navigation, and Timing
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    • v.10 no.4
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    • pp.353-361
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    • 2021
  • This paper presents the jamming effect on the L5 band of Global Navigation Satellite System (GNSS) by analyzing real data collected via measurement campaigns in Korea region. In fact, the L5 band is one of the dedicated bands for various satellite navigation systems such as Global Positioning System (GPS), Galileo, BeiDou (BDS), and Quasi Zenith Satellite System (QZSS). And this band is also allocated along with various systems used for aeronautical radio navigation systems (ARNS). Among ARNS, the Distance Measuring Equipment (DME) and the Tactical Air Navigation System (TACAN) are systems that transmit and receive strong power pulse signals, which may cause unintentional jamming in the reception of GNSS signals. In this paper, signals in the main lobe of GPS L5, Galileo E5a, BDS B2a, and QZSS L5 are collected in Korean region to confirm whether the jamming effect exists in the band. And then, the pulse blanking technique, which is a simple signal processing technique capable of responding to pulsed jamming, is applied to analyze the jamming effect of DME/TACAN on the L5 band.

Protective Effect of Methanolic Extracts from Dendrobium nobile Lindl. on $H_{2}O_{2}$-induced Neurotoxicity in PC12 cells (석곡 MeOH 추출물이 $H_{2}O_{2}$에 의한 신경세포 보호효과에 미치는 영향)

  • Yoon, Mi-Young;Kim, Ju-Young;Hwang, Ji-Hwan;Cha, Mi-Ran;Lee, Mi-Ra;Jo, Kyung-Jin;Park, Hae-Ryong
    • Applied Biological Chemistry
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    • v.50 no.1
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    • pp.63-67
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    • 2007
  • The neuroprotective effect of methanolic extracts from Dendrobium nobile Lindl. (DME) against $H_{2}O_{2}$-induced neurotoxicity in PC12 cells was investigated. The treatment of PC12 cells with various DME concentrations under $H_{2}O_{2}$ resulted in the induction of protective effect in a dose-dependent manner, as determined by the results of an MTT reduction assay, an LDH release assays, and a morphological assay. Interestingly, we also detected reduction of apoptotic bodies and inhibition of caspase-3 activity by DME in $H_{2}O_{2}$-indeced PC12 cells. These data show that the neuroprotective effect of DME against PC12 cells might be related to the suppression of caspase-3 activation. Therefore, these results suggest that DME could be a new potential candidate as chemotherapeutic agents against neuronal diseases.

A Study on the Development of the Scale for Measuring Perception of Equity in Marital Relationship (한국부부간 공평성 인지척도 개발에 관한연구)

  • 박정희
    • Journal of Families and Better Life
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    • v.16 no.2
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    • pp.107-122
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    • 1998
  • It has been suggested that equity theory a social psychological theory concerned with the fairness in casual relationships should be applicable to marital relationships. This study describes the development of the scale for measuring perception of equity which measure the level of equity in marital relationships among Korean couples. PES(Perception of Equity Scale) is composed of two subscales; detailed measure of equity(DME) and global measure of equity(GME). The PES which include items from two areas of concern for intimates-pschological-emotional concern day-to-day concern-are describes. As results of test reliability of areas of DME range from .86 to .88 and reliability of GME is .92. And there are primarily evidences of construct validity of PES. Therefore PES is very reasonable scale to measure of equity/inequity perception in married couples. Finally analyzing of the level of equity in this sample husbands and wives has generally equitable relationships with their partn rs. Another findings suggest that husbands are overbenefited of their patners through marriage whereas wives are not.

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An Investigation of a Stratified Charge Mixture's HCCI Combustion Processes Using a Rapid Compression Machine (급속압축장치를 이용한 HCCI기관에서 층상혼합기에 의한 압력상승률의 저감효과에 대한 연구)

  • Lim, Ock-Taeck
    • Transactions of the Korean Society of Automotive Engineers
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    • v.18 no.5
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    • pp.1-8
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    • 2010
  • The introduction of mixture heterogeneity has been considered to be one of the ways to avoid knocking, as it reduces the pressure rise rate in HCCI Combustion. The purpose of this research was to investigate the effects of heterogeneity, in particular thermal stratification and fuel strength stratification, on HCCI Combustion fueled with DME and n-Butane. Thermal stratification is formed in the Combustion Chamber of a Rapid Compression Machine with three kinds of pre-mixture, each with different properties. The stratified charge mixture was adiabatically compressed, throughout which cylinder gas pressure and two-dimensional chemiluminescence images were measured and analyzed.