• Title/Summary/Keyword: 17B

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Isoflavonoids of Belamcanda chinensis (II)

  • Eu, Gang-Hae;Woo, Won-Sick;Chung, Ha-Sook;Woo, Eun-Hee
    • Korean Journal of Pharmacognosy
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    • v.22 no.1
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    • pp.13-17
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    • 1991
  • Dimethyltectorigenin, irisflorentin, muningin and iristectorigenins A and B were isolated from the rhizomes of Belamcanda chinensis.

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과학리포트 - 보이지 않는 비행기시대

  • Lee, Gwang-Yeong
    • The Science & Technology
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    • v.30 no.6 s.337
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    • pp.16-17
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    • 1997
  • 레이더에 탐지되지 않는 비행기 B2스텔스 폭격기가 미국서 4월부터 전투수행임무에 투입되었다. B2스텔스 폭격기의 가격은 1대당 4천7백억원. 현재 화이트먼 공군기지에는 13대의 스텔스가 배치되어 있는데 이중 6대가 미 국방부의 핵전쟁계획에 참여하고 있다.

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Characteristics of Antitumorial Antibiotics B-1123 from Aspergillus terreus (Aspergillus terreus 균주가 생산하는 항암항생물질 B-1123의 성상)

  • 박부길;박현묵;이진하;함승시;한재우
    • Microbiology and Biotechnology Letters
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    • v.18 no.4
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    • pp.331-337
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    • 1990
  • An antitumor antibiotic named B-1123 substance was isolated from the culture filtrate of a new isolate fungus identified as Aspergillus terreus. The fermentation yield reached about 23 mg per liter of the broth. The B-1123 substance, chlorine containing antibiotic, has the molecular formular of $C_{17}H_{12}0_7C_{12}$. Its structure was determined to be geodin by spectroscopic data. It is active against some Gram-positive bacteria and it prolongs the life span of mice inoculated with Ehrlich carcinoma.

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Electrical and Optical properties of B-doped ZnO films Deposited by RF Magnetron Sputtiering (RF 마그네트론 스퍼터링법으로 증착한 B-doped ZnO 박막의 전기 및 광학적 특징)

  • 임주수;이재신
    • Journal of the Korean Ceramic Society
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    • v.35 no.1
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    • pp.17-22
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    • 1998
  • B-doped ZnO thin films on glass substrates were prepared by sputtering the ceramic targets which had been prepared by sintering disks consisting of ZnO and various amounts of B2O3 While pure ZnO films show-ed a c-axis oriented growth the B-doping retarded the prefered orientation and grain growth of the film. Electron concentrations for undoped and B-doped ZnO films were on the order of 7.8${\times}$1018 cm-3 and 5${\times}${{{{ {10 }^{20 } }} c{{{{ {m }^{-3 } }} respectively. The electron mobility however decreased with the B-doping concentration. Optical meas-urements on the films showed that the average transmittance in the visible range was higher than 85% The measurements also indicated a blueshift of the absorption edge with doping.

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Design and Implementation of UWB BPFs (UWB BPF의 설계 및 구현)

  • Kang, Sang-Gee;Lee, Jae-Myung;Hong, Sung-Yong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.5
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    • pp.815-820
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    • 2008
  • Recently the frequency assignment and the technical specifications of UWB systems for communications are completed. Therefore many UWB systems have been developed. In our country $3.1{\sim}4.8GHz$ and $7.2{\sim}10.2GHz$ are assigned for UWB systems for communications. When we consider RF technologies and the easy implementation of UWB systems, UWB systems used in the low band are more developed than high band systems. In this paper we design and implement a BPF for low band UWB systems by means of considering the easy implementation of UWB systems. The designed and implemented BPFs are low band filter and low band channel filters. The measured results of the low band filter show that the filter has 21.85dB and 17.91dB attenuation at 3.1GHz and 4.8GHz, 1.53GHz of -10dB bandwidth and 2dB of insertion loss. Low band can be divided into 3 channels with 500MHz of the channel bandwidth. The channel filter for channel number 1 has the characteristics of 24.85dB attenuation at 3.1GHz, 0.61GHz of -10dB bandwidth and 1.87dB of insertion loss. The filter for channel 3 in low band has 19.2dB of attenuation at 4.8GHz, 0.49GHz of -10dB bandwidth and 2.49dB of insertion loss.

Magnetization Switching of MTJs with CoFeSiB/Ru/CoFeSiB Free Layers (CoFeSiB/Ru/CoFeSiB 자유층을 갖는 자기터널 접합의 스위칭 자기장)

  • Lee, S.Y.;Lee, S.W.;Rhee, J.R.
    • Journal of the Korean Magnetics Society
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    • v.17 no.3
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    • pp.124-127
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    • 2007
  • Magnetic tunnel junctions (MTJs), which consisted of amorphous CoFeSiB layers, were investigated. The CoFeSiB layers were used to substitute for the traditionally used CoFe and/or NiFe layers with an emphasis given on understanding the effect of the amorphous free layer on the switching characteristics of the MTJs. CoFeSiB has a lower saturation magnetization ($M_s\;:\;560\;emu/cm^3$) and a higher anisotropy constant ($K_u\;:\;2800\;erg/cm^3$) than CoFe and NiFe, respectively. An exchange coupling energy ($J_{ex}$) of $-0.003\;erg/cm^2$ was observed by inserting a 1.0 nm Ru layer in between CoFeSiB layers. In the Si/$SiO_2$/Ta 45/Ru 9.5/IrMn 10/CoFe 7/$AlO_x$/CoFeSiB 7 or CoFeSiB (t)/Ru 1.0/CoFeSiB (7-t)/Ru 60 (in nm) MTJs structure, it was found that the size dependence of the switching field originated in the lower $J_{ex}$ using the experimental and simulation results. The CoFeSiB synthetic antiferromagnet structures were proved to be beneficial for the switching characteristics such as reducing the coercivity ($H_c$) and increasing the sensitivity in micrometer size, even in submicrometer sized elements.

Integer Factorization for Decryption (암호해독을 위한 소인수분해)

  • Lee, Sang-Un;Choi, Myeong-Bok
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.6
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    • pp.221-228
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    • 2013
  • It is impossible directly to find a prime number p,q of a large semiprime n = pq using Trial Division method. So the most of the factorization algorithms use the indirection method which finds a prime number of p = GCD(a-b, n), q=GCD(a+b, n); get with a congruence of squares of $a^2{\equiv}b^2$ (mod n). It is just known the fact which the area that selects p and q about n=pq is between $10{\cdots}00$ < p < $\sqrt{n}$ and $\sqrt{n}$ < q < $99{\cdots}9$ based on $\sqrt{n}$ in the range, [$10{\cdots}01$, $99{\cdots}9$] of $l(p)=l(q)=l(\sqrt{n})=0.5l(n)$. This paper proposes the method that reduces the range of p using information obtained from n. The proposed method uses the method that sets to $p_{min}=n_{LR}$, $q_{min}=n_{RL}$; divide into $n=n_{LR}+n_{RL}$, $l(n_{LR})=l(n_{RL})=l(\sqrt{n})$. The proposed method is more effective from minimum 17.79% to maxmimum 90.17% than the method that reduces using $\sqrt{n}$ information.

A Study on Preference to Korean Spicy Fish Soups by Questionnaire Methods in Busan and Development of a Standardized Recipe (부산지역 생선횟집을 중심으로 생선 매운탕 소비실태 및 최적 조리법 확립)

  • Kim, Jung-Sun;Cho, Young-Je;Lee, Nahm-Gull
    • Journal of Fisheries and Marine Sciences Education
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    • v.18 no.2
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    • pp.150-163
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    • 2006
  • A study on sliced raw fish consumption was conducted on 300 citizens of Busan (89 men and 192 women), attending high school and university, housekeepers and employees. A self-administered questionnaire was used to record the results. The results were as follows: 93 percent of the respondents appeared to like or not be reluctant to eating Maeun-Tang. Most of the panelists had eaten at a seafood restaurant. The taste of Maeun-Tang varied differently by the spicy fish soup recipe. 56 percent of the respondents appeared to want this dish to have a fiery taste. Therefore, 89 percent of the respondents appeared to desire Maun-Tang to have a standardized recipe. The qualities of four kinds of stock made of water (A recipe), anchovy added with sea tangle (B recipe), fish bone (C recipe) and vegetable (D recipe) were investigated by using sensory evaluation and instrumental analysis for amino acids and nucleotides. The C recipe score was 80.9${\pm}$15.9 and D, B recipe was $75.7{\pm}17.1$, $75.4{\pm}17.2$, respectively. The A recipe score was $61.8{\pm}22.8$. The Degree of smooth taste were D recipe >A recipe >B recipe>C recipe. The Degree of spicy taste were C recipe >B recipe >D recipe>A recipe. In sensory evaluation, the C recipe obtained the highest score for overall preference. However, no difference of extractive nitrogen content, nucleotide and amino acid contest were observed in the C recipe after cook of Maeun-Tang.