• Title/Summary/Keyword: AM-to-AM

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Power Efficient Multi-level Digital Transmission Technique in Non-Linear Mobile Satellite Channel (비선형 이동위성 통신채널에서 전력 효율적 고차 디지털 전송 방식)

  • 이상진;강우석;서종수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.8A
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    • pp.1133-1140
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    • 1999
  • In order to provide high-speed wide-band multimedia services via Low earth(LEO) mobile satellire, power and bandwidth efficient digital transmission technique should to employed. This paper analyzes the performance of Trellis-soded 16QAM and 8PSK-2AM which can transmit twice as much inforemation as QPSK in nonlinearly amplified LEO mobile satellite channel. In the analysis the nonlinear mobile satellite channel is modelled by Rician fading channel amplified by Fujitsu's GaAs FET HPA. Our simulation result shows that 8PSK-2AM is less sensitive to the satellite channel nonlinear distortion and its BER performance is better than that of 16QAM. The BER performance of 8PSK-2AM is further improved by optimizing its signal constellation. Accocordingly it is found that Trellis-coded 8PSK-2AM could provide multimedia services such as Satellite Internet, DBS, DAB and ISDB more efficiently in the power and bandwidth limited mobile satellite channel.

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Type-Based Group Delay Equalizer Considering the Nonlinear Phase Distortion of HPA (HPA의 비선형 위상 왜곡을 고려한 타입기반 군 지연 등화기)

  • Kim, Yongguk;Jo, Byung Gak;Baek, Gwang Hoon;Ryu, Heung-Gyoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37A no.10
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    • pp.895-902
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    • 2012
  • In this paper, we propose a novel equalizer to compensate for the group delay including AM/PM nonlinear distortion characteristics by the nonlinear power amplifier (PA). The group delay characteristic is a nonlinear non-constant time delay that appears differently depending on each frequency component. The phase distortion by AM/PM characteristics arising from the power amplifier is a major factor to increase group delay. By the group delay distortion, the signal in the constellation expands and is rotated. Considering the problem mentioned above, the nonlinear time delay that appears differently depending on each frequency component is classified as a static group delay and AM/PM characteristic of PA, the different phase transitions depending on the size of input signal as a dynamic group delay. Static group delay estimates and compensate for phase distortions in the frequency domain with type-based method and dynamic group delay compensates for phase rotation in the time domain. We confirmed that the group delay compensation techniques were enough to compensate the group delay characteristics including AM/PM characteristics of the power amplifier.

Mutual Separation of Am and Eu by Solvent Extraction with di-(2-ethylhexyl)phosphoric acid Containing Zirconium(III) (Zr을 함유한 di-(2-ethylhexyl)phosphoric acid에 의한 Am과 Eu의 상호분리(III))

  • Yang, Han-Beom;Lee, Eil-Hee;Lim, Jae-Gwan;Kim, Jong-Gu;Kim, Jung-Suk;Yoo, Jae-Hyung
    • Applied Chemistry for Engineering
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    • v.8 no.6
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    • pp.1006-1013
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    • 1997
  • This study was carried out to elucidate the chemical characteristics of mutual separation for Am and Eu, which were selected as a stand-in from minor actinide and rare earth elements, by solvent extraction with di-(2-ethylhexyl)phosphoric acid containing zirconium at batch system. As results, 92.3% of Am and 99.1% of Eu were coextracted with 1M DEHPA/n-dodecane containing zirconium (Zr $concentration=8.7g/{\ell}$) at 0.5M $HNO_3$ in the extraction step. The extraction yields of Am and Eu were proportionally increased with the concentration of Zr in Zr salt of 1M DEHPA/n-dodecane having the synergistic effect. In the lst stripping step for the selective separation of Am, 38.1% of Am and 3% of Eu were stripped with the mixed solution of 0.05M DTPA and 1M lactic acid adjusted pH of 3.0. At that time, the separation factor calculated from the distribution coefficients of Am and Eu was 14.2. In the 2nd Stipping step to remove the Eu remained the organic phase after the lst stripping step, 94.4% 0f Eu was stripped into aqueous phase with 6M $HNO_3$.

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Functional Characteristics from the Barley Leaves and its antioxidant mixture - Study on the Nitrite Scavenging Effect - (맥엽 및 항산화 조성물의 생리 기능적 특성에 관한 연구 - 아질산염 소거능을 중심으로 -)

  • Hong, I-Jin;Park, Hyeung-Geun;Jew, Sang-Sup;Kim, Kyung-Tack;Lee, Sung-Hee
    • Applied Biological Chemistry
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    • v.46 no.4
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    • pp.333-337
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    • 2003
  • This study was conducted to estimate the biofunctional characteristics, namely nitrite scavenging effect of barley leaves (BL) and their mixture (AM) with other antioxidants. Aqueous or methanol extracts were obtained from BL and AM. Aqueous and methanol extracts from barley leaves had relatively higher nitrite scavenging effects and its activities and contents increased in a concentration-dependent manner. The activities and contents of methanol extracts obtained from BL and AM were higher than those of aqueous extracts. Especially, AM containing BL and other antioxidant mixture had the highest activities and contents increased in a concentration-dependent manner. BL or AM were added to macrophage cells of RAW 264.7. Survival rates of the cells treated with BL and AM were measured to be different. $IC_{50}$ value decreased in a concentration-dependent manner by the addition of aqueous or methanol extracts from BL and AM. Especially, methanol extracts of AM had the highest nitrite scavenging effects. Thus, BL and AM may have protective effect against carcinogen and immune ability against reactive molecules through NO (nitric oxide) signal pathway. From the above results, barley leaves appear to contain natural anticancer and immune-related agents and may have potentiality to be used as functional food ingredients.

Genome sequence of Ochrobactrum anthropi AM3 isolated from compost (퇴비에서 분리한 Ochrobactrum anthropi AM3의 유전체 염기서열)

  • Patil, Kishor Sureshbhai;Lee, Seung Je;Park, Soo-Je;Chae, Jong-Chan
    • Korean Journal of Microbiology
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    • v.52 no.4
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    • pp.503-504
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    • 2016
  • Ochrobactrum anthropi AM3 was isolated for the ability to utilize lignin as a sole carbon and energy source from compost in South Korea. Here we report the 5.11 Mb draft genome of strain AM3 with a G+C content of 56.2%, which is helpful for understanding the genetic diversity among Ochrobactrum spp. and the mechanism of lignin degradation.

Pharmacognostical Studies on the Folk Medicine 'Am Cho' (민간약 "암초"의 생약학적 연구)

  • Park, Seong-Su;Kim, Jeong-Myo;Park, Jong-Hee
    • Korean Journal of Pharmacognosy
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    • v.32 no.2 s.125
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    • pp.128-134
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    • 2001
  • The Korean folk medicine 'Am Cho' has been used as the folk remedy for diuretic, stomach and liver cancer. The botanical origin of the crude drug has not been studied pharmacognostically. To clarify the botanical origin of 'Am Cho', the comparative morphological and anatomical characteristics have been studied of Lepisorus species growing wild in Korea, i.e. L. annuifrons, L. onoei, L. thunbergianus, L. ussuriensis and 'Am Cho' form Korea. As a result, it was clarified that 'Am Cho' from Korea was derived from Lepisorus onoei.

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A literature study on the diagnostic value of the cervical lymph node in the application of large intestine tonification of Sa-Am acupuncture (대장정격(大腸正格)의 활용에 있어 경두부(頸項部) 결핵(結核)의 진단의의(診斷意義)에 관한 문헌고찰(文獻考察))

  • Kim, Kwang-Sung;Yim, Yun-Kyoung
    • Korean Journal of Acupuncture
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    • v.23 no.3
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    • pp.29-35
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    • 2006
  • Objectives & Methods : This study aimed to investigate the diagnostic value of the cervical lymph node in the application of large intestine tonification of Sa-Am acupuncture. Results & Conclusions : Cervical lymph node appeared in 76% of the cases for which large intestine tonifying Sa-am acupuncture was used in ${\ulcorner}$Sa-Am-Do-In-Chim-Gu-Yo-Kyul(舍岩道人鍼灸要訣)${\urcorner}$. We suggest that cervical lymph node can be used as an important diagnostic point for the application of large intestine tonification of Sa-Am acupuncture.

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The Depressive effect of Sa-Am Acupuncture(膀胱正格) treatment in Stroke Patients (뇌졸중 환자에서 사암침의 혈압강하에 대한 고찰)

  • Park, Young-soo;Kim, Eun-mi;Kim, Young-il;Hong, Kwon-eui;Lee, Hyun
    • Journal of Acupuncture Research
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    • v.21 no.4
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    • pp.217-223
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    • 2004
  • Objective: The aim of this research was to investigate the depressive effect of Sa-am Acupuncture(膀胱正格) in stroke patients. Methods: We measured the blood pressure of the patients who were admitted in the Oriental Medical hospital of Dae-Jeon University from June. 2003. to September. 2003. If systolic blood pressure was over 160mmHg or diastolic blood pressure was over 100 mmHg, 40 patients were treated by Sa-am Acupuncture(膀胱正格) and the other 20 patients were taken a rest in bed. Then 30 minutes and 60 minutes later, systolic, diastolic blood pressure were measured. Results: After 30 minute treatment, Sa-am Acupuncture(膀胱正格) significantly depressed the systolic and diastolic blood pressure, but bedrest can't do it. After 60 minute treatment, both Sa-am Acupuncture(膀胱正格) and bedrest significantly depressed the systolic and diastolic bood pressure. Conclusion: These results suggest that Sa-am Acupuncture(膀胱正格) is effective in depressing the systolic and diastolic blood pressure.

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Pre-distorter Method Using LUT with 2ι Partition Interpolation in the OFDM System (OFDM 시스템에서 2ι 분할 보간을 LUT에 결합한 전치왜곡기에 관한 연구)

  • 권오주;이호근;하영호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.7A
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    • pp.668-675
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    • 2002
  • This paper proposes pre-distorter combined LUT with 2ιpartition interpolation method to reduce nonlinear distortion which was caused by high PAPR and to update LUT quickly. Pre-distorted gain and phase can be found by using LUT which consisted of AM/AM and AM/PM value, and OFDM signal amplitude. The proposed 2ιpartition interpolation can accurately find predistorted gain and phase using bit shift and add component instead of increasing size of LUT which requires increasing the amount of computation. The performance of the proposed method was measured by the difference between HPA input and output characteristics by the LUT size, constellation, SER performance by the HPA, and LUT update error by the HPA characteristic changes. As a result, it is shown that when the size of the LUT is 32 and 64 for 16-QAM and 64-QAM, nonlinear distortion nearly didn't occurred.

Effect of acidified milk feeding on the intake, average daily gain and fecal microbiological diversity of Holstein dairy calves

  • Chen, Yong;Gao, Yan;Yin, Shuxin;Zhang, Shuai;Wang, Lu;Qu, Yongli
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.8
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    • pp.1265-1272
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    • 2020
  • Objective: To evaluate the effect of feeding acidified milk on the growth and fecal microbial diversity of dairy calves. Methods: Twenty healthy 3-day-old female Holstein calves with similar body weights were selected and randomly divided into two groups. One group was fed pasteurized milk (PM, Control), while the other was fed acidified milk (AM) ad libitum until weaned (day 60). The experiment lasted until day 180. Results: There was no difference in the nutritional components between PM and AM. The numbers of Escherichia coli and total bacteria in AM were lower than in PM. At 31 to 40 and 41 to 50 days of age, the milk intake of calves fed AM was higher than that of calves fed PM (p<0.05), and the solid feed intake of calves fed AM was higher than that of calves fed PM at 61 to 90 days (p<0.05). The average daily gain of calves fed AM was also higher than that of calves fed PM at 31 to 60, 61 to 180, and 7 to 180 days (p<0.05). The calves fed AM tended to have a lower diarrhea rate than those fed PM (p = 0.059). Bacteroides had the highest abundance in the feces of calves fed AM on day 50, while Ruminococcaceae_UCG_005 had the highest abundance in the feces of calves fed AM on day 90 and calves fed PM on days 50 and 90. At the taxonomic level, the linear discriminant analysis scores of 27 microorganisms in the feces of calves fed AM and PM on days 50 and 90 were higher than 4.0. Conclusion: Feeding AM increased calf average daily gain and affected fecal bacterial diversity.