• 제목/요약/키워드: Low possibility of interception

검색결과 2건 처리시간 0.018초

수입 생약(生藥)의 국산화(國産化)에 관한 연구-황연(黃蓮)의 순화재배(馴化栽培)에 대하여- (Studies on Domestic Production of Imported Botanical Drugs-On Domesticational Cultivation of Coptis japonica-)

  • 한대석;허인옥
    • 생약학회지
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    • 제18권3호
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    • pp.196-201
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    • 1987
  • A study was carried out to investigate the possibility of acclimation of Coptis japonica Makino in Korea. Coptis japonica could be grown within 4 years as a medicinal crude drug if it is cultivated in the area of mountain facing north(300m above sea level) with 70% light interception and appropriate soil texture. It is to be noted that the propagation of the plant is more important than the yield of berberine because the berberine contents do not change in different conditions. The results were as follows; 1. The germination rates of the seeds by covering with the pine tree leaves were the highest and averaged 63%. 2. The germination rates of dry seeds were not affected in spite of low temperature and $GA_3$ treatment. 3. The germination rates of the seeds stored in moistured sand were averaged 85%, but in dry state, they were not germinated. 4. The number of leaves and fresh weight of Coptis japonica from the area of mountain facing north were increased significantly. 5. The growth and fresh weight of Coptis japonica were reduced in clay. 6. The best growth was obtained under 70% light interception. It is possible to intercrop between evergreen trees. 7. The foliage dressing did not affect the growth. 8. The number of leaves and fresh weight were increased from the 3rd year, and the average weight of rhizomes was 5.7g in 4th year. 9. The berberine contents of the rhizomes of Coptis japonica under various treatment conditions ranged from 9 to 10%. Coptidis Rhizoma from this study and from Korean market showed much higher berberine contents than those from Japanese market.

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다중 밴드 기반 대역 확산 수중통신 기법 성능분석 (Performance Analysis of Spread Spectrum Underwater Communication Method Based on Multiband)

  • 신지은;정현우;정지원
    • 한국정보전자통신기술학회논문지
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    • 제13권5호
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    • pp.344-352
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    • 2020
  • 수중음향통신의 적용을 위해 고려되어야 할 두 가지 지표인 성능과 은밀성 관점에서 다중 밴드 통신 기법 및 직접 확산 변조 방식을 적용한 효율적인 통신 모델을 설정하고 성능 분석을 하였다. 최적의 모델에 대한 성능 분석을 위해 송수신기의 채널 부호화 알고리즘을 부호화 비트 수 336 bit를 가지는 부호화율 1/3인 turbo pi 부호화기를 적용하여 등화기와 채널 복호화기를 반복하여 성능을 향상시키는 터보 등화 구조를 제시하였다. 본 논문에서는 다중 밴드 기반 대역 확산 구조의 Rake 처리 과정에서 임계값을 설정하여, 대역 확산 신호의 chip 수를 8개, 16개, 32개로, 다중 밴드 수는 1개에서 4개로 변경하면서 성능을 분석하였다. 시뮬레이션 결과 밴드 수 및 chip 수가 증가함에 따른 성능 이득을 확인할 수 있었으며, 동일한 밴드 수에서 chip 수를 증가시켰을 때 2~3dB 정도 성능이 향상되었다.