• Title/Summary/Keyword: RFI

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RF ENVIRONMENT TEST ON A PROPOSED SITE FOR THE SENSOR STATION OF THE NEXT GENERATION SATELLITE NAVIGATION SYSTEM, GALILEO: I. THE RESULT OF THE TEST ON THE VICINITY OF KVN TAMLA SITE IN THE YEAR OF 2006 BY KASI (차세대 위성항법체계 갈릴레오 센서스테이션 유치 후보지 전파 수신환경 조사: I. KVN 탐라전파천문대 인근 부지에 대한 2006년 한국천문연구원 조사 결과)

  • Jo, Jung-Hyun;Je, Do-Hyeung;Cho, Sung-Ki;Choi, Byung-Kyu;Baek, Jeong-Ho;Lee, Dae-Kyu;Chung, Hyun-Soo;Lim, Hvung-Chul;Cho, Jung-Ho;Lee, Woo-Kyoung;Jung, Sung-Wook;Park, Jong-Uk;Choe, Nam-Mi
    • Journal of Astronomy and Space Sciences
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    • v.25 no.1
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    • pp.43-52
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    • 2008
  • As the next generation of global satellite navigation system, the Galileo project is about to witness an initial orbit validation stage as the successful test of navigation message transmission from Giove-A in 2007. The Space Geodesy division ana the Radio Astronomy division of the Korea Astronomy & Space Science Institute had collaborated on the field survey for the Galileo Sensor Station (GSS) RF environment of the proposed site near Jeju Tamla University from August 3rd to August 5th, 2006. The power spectrums were measured in full-band $(800{\sim}2000MHz)$ and in-band (E5, E6 and L1 band) in frequency domain for 24 hours respectively. Finally, we performed a time domain analysis to characterize strong in-band interference source based on the result of the previous step.

Effects of Green Tea-Soybean Paste on Weights and Serum Lipid Profiles in Rats Fed High Fat Diet (녹차 된장이 고지방식이를 급여한 흰쥐의 체중 및 혈청 지질성분에 미치는 영향)

  • Park, Jin-Hee;Ha, Ae-Wha;Cho, Jung-Soon
    • Korean Journal of Food Science and Technology
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    • v.37 no.5
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    • pp.806-811
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    • 2005
  • Effects of green tea-soybean paste on weight-changes and serum lipid profiles in rats fed high fat diet were investigated. Sprague-Barley male rats divided into five groups were fed five different diets for 10 weeks: B group, basal diet H group, high fat-diet containing 0.5% cholesterol+15% lard H-S group, high fat diet containing soybean paste H-0.6GS group, high fat diet containing 0.6% green tea-soybean paste H-4GS group, high fat diet containing 4% green tea-soybean paste. H group showed highest weight gain (p<0.05). Addition of green-tea soybean paste to high-fat diet significantly decreased weight gain, H-4GS group showing highest weight loss (p<0.05). No significant differences in food efficiency ratio and total food intake were found among groups. Liver weight of H group was highest. Addition of green tea-soybean paste to high fat diet significantly reduced liver weight (p<0.05, Table 2). Concentrations of glucose, uric acid, bilirubin, and total protein were similar among all group. Mean GPT values of H-4GS group were significantly different from these of H- and H-S groups (p<0.05). H-S, H-0.6GS, and H-4GS groups had significantly lower triglyceride and total cholesterol, and higher HDL than H-group (p<0,05). H-4GS group had significantly lower serum triglyceride than H-0.6GS group (p<0.05).

Study on Compensation Method of Anisotropic H-field Antenna (Loran H-field 안테나의 지향성 보상 기법 연구)

  • Park, Sul-Gee;Son, Pyo-Woong
    • Journal of Navigation and Port Research
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    • v.43 no.3
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    • pp.172-178
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    • 2019
  • Although the needs for providing resilient PNT information are increasing, threats due to the intentional RFI or space weather change are challenging to resolve. eLoran, which is a terrestrial navigation system that use a high-power signal is considered as a best back-up navigation system. Depending on the user's environment in the eLoran system, the user may use one of E-field or H-field antennas. H-field antenna, which has no restriction on setting stable ground and is relatively resistant to noise of general electronic equipment, is composed of two loops, and shows anisotropic gain pattern due to the different measurement at the two loops. Therefore, the H-field antenna's phase estimation value of signal varies depending on its direction even at the static environment. The error due to the direction of the signal should be eliminated if the user want to estimate the own position more precisely. In this paper, a method to compensate the error according to the geometric distribution between the H-field antenna and the transmitting station is proposed. A model was developed to compensate the directional error of H-field antenna based on the signal generated from the eLoran signal simulator. The model is then used to the survey measurement performed in the land area and verify its performance.