• 전기전자학회논문지
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• 제3권1호
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• pp.69-78
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• 1999

본 논문에서는 우수 고조파 Anti-parallel 다이오드 링 혼합기를 이용한 직접변환 수신기를 설계하였다. 설계된 Anti-Parallel 다이오드를 사용한 SHP 혼합기는 LO 신호의 제 2 고조파를 이용한 혼합작용으로 LO신호원을 사용하는 대신에 1/2의 주파수를 갖는 저가의 LO신호원을 이용한다. 따라서, LO신호에 의한 낮은 스퓨리어스 특성과 넓은 주파수 대역에 걸쳐서 우수한 분리도 특성을 나타낸다. 또한, 링 형태의 혼합기는 고유의 LO신호에 대한 고조파 상쇄특성을 가지므로 RF 입력단을 통한 LO신호의 불요복사를 최대한으로 줄일 수 있다. 제작된 Anti-Parallel SHP 혼합기의 LO/IF, RF/IF와 LO/RF 분리도는 각각 24.6dB, 36.2dB 22.5dB로 우수한 특성을 나타내고 있다. 또한 링혼합기의 변환손실은 LO 신호전력이 5.5dBm일때, RF 입력전력 -20dBm에서, IF 출력은 -35.6dBm의 값을 얻었다. 따라서, 링혼합기의 변환손실은 약 15.6dB이고 또한, 1dB 압축점은 0dBm일 때 나타났다.

• 한국전자파학회논문지
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• 제25권9호
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• pp.895-902
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• 2014

본 논문에서는 CMOS $0.18-{\mu}m$ 공정을 이용하여 1.75 GHz 대역에서 동작하는 이단으로 구성된 CMOS 전력증폭기를 설계하였다. 무선통신시스템에 적합한 전력증폭기 설계를 위하여 ADS 모의실험을 통하여 전력이득, 출력 전력, 효율을 각각 28 dB, 27 dBm, 45 %로 설계를 하였다. 실제 제작된 전력증폭기의 성능은 전력 이득, 출력 전력, 효율은 각각 22.9 dB, 24.8 dBm, 41.3 %로 특성을 나타냈으며, 변조된 LTE(Long-Term Evolution) 신호에 대하여 인접 채널 누설비(ACLR)가 -30 dBc 이하를 만족하며, 전력 이득, 출력 전력, 효율이 각각 22.6 dB, 23.1 dBm, 35.1 %의 특성을 나타냈다.

• International Journal of Industrial Entomology and Biomaterials
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• 제13권1호
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• pp.31-35
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• 2006

The ubiquitin conjugating enzyme 2 (E2) is core component of ubiquitin proteasome pathway (UPP) which represents a selective mechanism for intracellular proteolysis in eukaryotic cells. The E2 has been implicated in the intracellular transfer of ubiquitin to target protein. We show here the involvement of E2 in antiviral immune of Bombyx mori to Bombyx mori nuclear polyhedrosis virus (BmNPV). In this study, mRNA fluorescent differential display PCR (FDD-PCR) was performed with BmNPV highly resistant silkworm strain NB and susceptible silkworm strain 306. At 24 h post BmNPV infection, FDD-PCR with the arbitrary primer AP34 showed that one cDNA band was down-regulated in the midgut of resistant strain, but highly expressed in susceptible strain. The deduced amino acid sequence of this cDNA clone share 99% identity with the recently published B. mori ubiquitin conjugating enzyme E2 (Genbank NO: DQ311351). Fluorescent quantitative PCR corroborated down regulation of E2 in resistant strain. We there conclude that BmNPV infection evokes strong response of susceptible strain including activation of UPP. BmNPV may evolve escape mechanisms that manipulate the UPP in order to persist in the infected host. In addition, the identification of down-regulation of E2 in resistant strain, as well as structure data, are essential to understanding how UPP operates in silkworm antiviral immune to BmNPV disease.

• Asian-Australasian Journal of Animal Sciences
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• 제19권7호
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• pp.938-942
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• 2006

Genetic diversity of Magra - a lustrous carpet wool breed of India, was investigated by means of 25 ovine microsatellite markers proposed by the Food and Agriculture Organization and the International Society for Animal Genetics (FAO-ISAG). All used microsatellites amplified well and exhibited polymorphisms. A wide range of genetic variability was observed as allele number from 3 (BM6506, OarCP20) to 10 (CSSM31), observed heterozygosity from 0.200 (BM6506) to 0.947 (OarHH35), expected heterozygosity from 0.368 (CSSM47) to 0.864 (BM1314) and Polymorphism Information Content (PIC) from 0.347 (CSSM47) to 0.849 (BM1314). This supported the utility of these microsatellite loci in the measurement of genetic diversity indices in Indian sheep too. Various average genetic variability measures viz., allele diversity (5.7), observed heterozygosity (0.597), expected heterozygosity (0.694) and mean PIC (0.648) values showed high genetic variability despite accumulated inbreeding as reflected by the high average inbreeding coefficient ($F_{IS}=0.159$) due to the unequal sex ratio of the breeding animals.

• 한국식품영양과학회지
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• 제35권10호
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• pp.1329-1335
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• 2006

AIDS로의 진행과정은 단순히 몇몇 기작에 의한 것이 아니라 여러 경로를 거쳐 발생하며 그 진행속도도 개개인에 따라 다양하게 나타나고 있다. 본 연구에서는 쥐 AIDS 모델을 이용하여 항산화호르몬으로 알려진 DHEAS의 면역조절 효과를 확인하고자 하였다. DHEAS의 투여는 LP-BM5 retrovirus 감염으로 인한 T와 B 임파구의 mitogenesis를 증가시켰으며 Th1/Th2 type cytokines의 발현에도 영향을 미쳤는데 주로 전사수준에서 작용한 것으로 생각된다/ 또한 retrovirus 감염으로 인한 간조직의 지질과산화 유발을 억제하여 조직 내의 항산화제인 vitamin E의 함량을 유지시킴으로 NF-kB의 활성화를 통한 retrovirus의 복제를 억제시켜 Th1/Th2 type cytokines의 불균형적인 발현을 저해하였을 것으로 여겨진다. 따라서 쥐 AIDS모델에 있어서 DHEAS의 면역조절 효과를 확인한 본 연구는 향후 HIV감염 이후 AIDS로의 진행 과정 시 항산화제의 역할과 기작 규명에 대한 가능성을 제시할 수 있을 것으로 생각된다.

• International Journal of Industrial Entomology and Biomaterials
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• 제7권2호
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• pp.197-201
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• 2003

The recombinant plasmids harboring a heterologous gene coding mouse endostatin were transfected and expressed stably in Trichoplusia ni Tn 5B1-4 cells and Bombyx mori BmN cells, respectively. Recombinant endostatin expressed in the stably transformed Tn 5B1-4 and BmN cells was secreted into the medium. BmN cells are relatively lower in maximum cell growth and recombinant endostatin production than Tn 5B 1-4 cells. Recombinant endostatin was also purified to homogeneity using a simple one-step ${Ni^2+}$ affinity fractionation method. Purified recombinant endostatin inhibited endothelial cell proliferation in a dose-dependent manner. The concentration at half-maximum inhibition $({ED_50})$ for recombinant endostatin was approximately 0.35 ${\mu}g$/ml.

• 한국초지조사료학회지
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• 제35권3호
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• pp.225-231
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• 2015

Improving current pasture productivity by precision management requires practical tools to collect site specific pasture biomass data. Recent developments in unmanned aerial vehicle (UAV) technology provide cost effective and real time applications for site specific data collection. For the mapping of herbage biomass (BM) on a hill pasture, we tested a UAV system with digital cameras (visible and near-infrared (NIR) camera). The field measurements were conducted on the grazing hill pasture at Hanwoo Improvement Office, Seosan City, Chungcheongnam-do Province, Korea on May 17 and June 27, 2014. Plant samples were obtained from 28 sites. A UAV system was used to obtain aerial photos from a height of approximately 50 m (approximately 30 cm spatial resolution). Normalized digital number (DN) values of Red and NIR channels were extracted from the aerial photos and a normalized differential vegetation index using DN ($NDVI_{dn}$) was calculated. The results show that the correlation coefficient between BM and $NDVI_{dn}$ was 0.88. For the precision management of hilly grazing pastures, UAV monitoring systems can be a quick and cost effective tool to obtain site-specific herbage BM data.

• Animal Bioscience
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• 제35권9호
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• pp.1418-1425
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• 2022

Objective: An experiment was conducted to determine the standardized ileal digestibility (SID) of amino acids (AA) in fish meal (FM) and blood-derived protein sources including spray-dried porcine plasma (SDPP), porcine red blood cells (PRBC), and blood meal (BM) fed to growing pigs. Methods: Ten barrows (mean initial body weight of 22.1±1.54 kg) surgically fitted with T-cannulas at the distal ileum were allotted to a duplicated 5×4 incomplete Latin square design with 5 experimental diets and 4 periods. Four experimental diets were prepared to contain FM, SDPP, PRBC, or BM as the sole source of nitrogen. A nitrogen-free diet was prepared and included to estimate the basal ileal endogenous losses of AA. For the 7-day experimental period, pigs were fed for 5 days as adaptation, and ileal digesta samples were collected for 9 hours on days 6 and 7. Results: The SID of crude protein in BM (48.0%) was less (p<0.05) than in FM, SDPP, and PRBC (83.4%, 83.9%, and 87.3%, respectively). Pigs fed the diet containing BM had less (p<0.05) SID of AA, except isoleucine and proline, than those fed the diet containing FM, SDPP, or PRBC. Among FM, SDPP, and PRBC, there was no difference in the SID of crude protein and all AA, except isoleucine. The SID of isoleucine in PRBC and BM (62.7% and 48.3%, respectively) was less (p<0.05) than in FM and SDPP (88.0% and 84.9%, respectively). The SID of lysine in FM, SDPP, PRBC, and BM was 85.4%, 84.9%, 89.7%, and 51.9%, respectively. Conclusion: The SID of most AA was not different among FM, SDPP, and PRBC, but BM had lower SID of most AA than FM, SDPP, and PRBC.

• 한국전자파학회논문지
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• 제12권1호
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• pp.99-106
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• 2001

본 논문에서는 선형화 특성이 우수하고, 대역폭이 넓은 feedforward 선형화 기법을 이용하여 IMT-2000용 1-Watt 급 증폭기를 설계 제작하였다. Feedforward는 외부환경(온도, 입력 전력 레벨, 시간 등)의 변화에 민감하므로 마이크로컨트롤러를 이용하여 이를 제어하였다. 35dB 의 이득과 40dBm의 최고전력을 갖는 주증폭기를 설계하였고, 각 루프의 신호를 상쇄하기 위해서 반사형 가변감쇄기와 위상변화기를 사용하였다. 2.11 2.17GHz 대역에서 측정 결과 신호루프에서 주신호를 35dB이상 상쇄하였으며, 오차루프에서 30dB 이상 오차신호를 상쇄하여 60dBc 이상의 선형화 특성을 얻을 수 있었다.

• 한국잠사곤충학회지
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• 제40권1호
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• pp.60-62
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• 1998

To understand expression of some early and late genes of Bombyx mori nuclear polyhedrosis virus (BmNPV) in the B. mori-derived BmN cell line, the transcripts were analyzed by polymerase chain reaction with synthetic primers. After infection, the transcript of early genes, which include p35, IE1 and helicase p143, was immediately detected in the infected cells. In addition, the transcript of late genes, which include p10 and polyhedrin, was also detected in just-infected cells. In conclusion, our results revealed that transcripts of early and late genes of BmNPV are immediately expressed from the cells after infection.