• 제목/요약/키워드: B13

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Fin-Line 구조의 Ku대역 추적레이더 수신단용 평형 믹서 설계 (Fin-Line Balanced Mixer Design for Ku-band Tracking Radar Receiver)

  • 나재현;노돈석;김동길
    • 한국전자통신학회논문지
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    • 제13권4호
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    • pp.685-694
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    • 2018
  • 본 논문에서는 Ku대역 추적레이더의 핵심부품인 고주파 헤드 내 주파수 믹서(혼합기)의 설계 및 제작 결과에 대해서 다룬다. 단일종단(Single-Ended) 및 단일평형(Single-Balanced) 믹서의 단점을 보완하기 위해서, Fine-Line 구조의 평형(Balanced) 믹서를 설계하여 낮은 변환손실 특성을 가지도록 하였으며, Ku대역 RF신호를 입력받아 L밴드 IF신호를 생성하도록 하였다. 제작된 믹서에 대해서 Ku밴드 5개 샘플주파수를 대상으로 실험한 결과, 최대 잡음지수(Noise Figure Max) 6.823dB, 이득(Gain) 4.159dB ~ 4.676dB, 통과대역(Band Pass) 61MHz의 값을 확인하였다.

일부 치위생과 학생들의 임상실습교육 시 임상실습지도자의 교수효율성 및 임상실습만족도에 관한 연구 (Study on the teaching efficiency and satisfaction levels of clinical practice instructors during clinical practice training for some dental hygienists and students)

  • 오혜승
    • 한국치위생학회지
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    • 제13권5호
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    • pp.777-786
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    • 2013
  • Objectives : The purpose of the is to investigate the teaching effectiveness of clinical practice instructors and the satisfaction level of dental hygiene majoring students in clinical practice training. Methods : Subjects were second and third grade 480 dental hygiene majoring students in Seoul and Gangwondo. Except 48 incomplete answers, 438 data were analyzed. Questionnaire consisted of general characteristics, teaching of clinical practice instructors, educational content, organization al skills, leadership, learning environment, evaluation skills and clinical practice satisfaction level. Results : 1. A strong positive correlation (r = 0.832) was found between teaching effectiveness and clinical practice satisfaction. A positive correlation more than 0.50 was found between the clinical practice satisfaction, encouragement and support for teaching effectiveness, educational contents, and leadership. 2. There were significant correlations between the encouragement and support (B = 0.209), educational content (B = 0.199), leadership ability (B = 0.257) and ability to create an environment (B = 0.084), evaluation ability (B = 0.083). Conclusions : Teaching effectiveness of the clinical practice instructors had influences on the clinical practice satisfaction. It is necessary to connect clinical practice instructions with satisfaction towards clinical practice to the students.

$B_2O_3$첨가에 따른 $0.97MgTiO_3-0.03SrTiO_3$ 세라믹스의 마이크로파 유전특성 (Microwave dielectric properties of the $0.97MgTiO_3-0.03SrTiO_3$ ceramics with $B_2O_3$)

  • 남규빈;김지헌;이문기;배선기;이영희
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 추계학술대회 논문집 전기물성,응용부문
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    • pp.94-96
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    • 2002
  • The $0.97MgTiO_3-0.03SrTiO_3$ ceramics with $B_2O_3$(10wt%) were prepared by the conventional mixed oxide method. The structural properties were investigated with sintering temperature by XRD and SEM. According to the X-ray diffraction patterns of the $0.97MgTiO_3-0.03SrTiO_3$ ceramics with $B_2O_3$(10wt%), the ilmenite $MgTiO_3$ and perovskite $SrTiO_3$ structures were coexisted and secondary phase $MgTi_2O_5$ were appeared. Increasing the sintering temperature. the grain size was increased. In the case of $0.97MgTiO_3-0.03SrTiO_3$ ceramics with $B_2O_3$(10wt%), dielectric constant, quality factor and temperature coefficient of resonant frequency were $13.52{\sim}18.13,\;32750{\sim}51736GHz$, $-15.78{\sim}25.64ppm/^{\circ}C$, respectively.

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Fucoxanthin derivatives from Sargassum siliquastrum inhibit matrix metalloproteinases by suppressing NF-κB and MAPKs in human fibrosarcoma cells

  • Nguyen, Van-Tinh;Qian, Zhong-Ji;Lee, Bonggi;Heo, Soo-Jin;Kim, Kil-Nam;Jeon, You-Jin;Park, Won Sun;Choi, Il-Whan;Jang, Chul Ho;Ko, Seok-Chun;Park, Sun-Joo;Kim, Yong-Tae;Kim, GeunHyung;Lee, Dae-Sung;Yim, Mi-Jin;Je, Jae-Young;Jung, Won-Kyo
    • ALGAE
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    • 제29권4호
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    • pp.355-366
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    • 2014
  • Fucoxanthin is known to be an effective cell proliferation inhibitor with anti-tumor and anti-angiogenic activities. However, there is a lack of data regarding the biological effects of cis isomers of fucoxanthin. To assess the potential therapeutic properties of 9'-cis-(6'R) fucoxanthin (FcA), and 13-cis and 13'-cis-(6'R) fucoxanthin complex (FcB) isolated from Sarggassum siliquastrum, we investigated their inhibitory effects on matrix metalloproteinases (MMPs) in phorbol 12-myristate 13-acetate (PMA)-induced human fibrosarcoma (HT1080) cells. FcA and FcB reduced MMP-2 and MMP-9 protein and mRNA levels, as well as the migration of these cells, in a dose-dependent manner. Additionally, FcA and FcB increased levels of MMPs inhibition factors such as tissue inhibitor of metalloproteinase-1. FcA and FcB significantly inhibited the transcriptional activity of nuclear factor ${\kappa}B$ (NF-${\kappa}B$) and by inhibiting c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinases. Our results demonstrate that suppression of the NF-${\kappa}B$, JNK, and p38 signaling pathways may inhibit PMA-induced MMP-2 and MMP-9 activity. Therefore, FcA and FcB may be useful in noninvasive therapeutic strategies against fibrosarcoma metastasis.

친화성 고분자 유도체의 합성 및 단백질의 분리정제에 관한 연구 - p-Aminoanilinylsuccinyl-AH-Sepharose 4B의 합성 및 흰느타리버섯 중 단백질의 정제 - (Synthesis of Resin Derivatives and Purification of Protein - Synthesis of p-Aminoanilinylsuccinyl-AH-Sepharose 4B and Purification of Protein in Pleurotus cornucopiae -)

  • 민태진;김용립;박상신;이수용
    • 한국균학회지
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    • 제17권3호
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    • pp.105-113
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    • 1989
  • 흰느타리버섯 Pleurotus cornucopiae 중의 단백질을 선택적으로 분리 정제하기 위하여, 출발물질인 AH 4B와 숙신산 무수물을 반응시켜 SAH 4B를 얻은 다음 이에 P-PD을 반응시켜 P-ASAH 4B를 합성하여 친화성 크로마토그래피하였다. 1) SAH 4B겔 중의 succinyl기의 capacity는 겔 1ml당 $9.0{\mu}mol$이었으며, p-ASAH 4B 겔 중의 p-aminoanilinyl기의 capacity는 겔 1ml당 $6.1{\mu}mol$ 이었다. 2) 합성한 P-ASAH 4B겔에 친화성 있는 단백질의 총 겉보기 분자량은 167KD이었으며, 이는 37KD와 130KD단백질의 복합체 이었다. 출발물질인 AH 4B겔에 친화성 있는 단백질의 총 겉보기 분자량은 97.2KD이었으며, 이는 3.2KD, 31KD및 61KD단백질의 복합체 이었다. 3) 합성한 P-ASAH 4B겔에 친화성이 있는 단백질 중의 아미노산 함량은 비극성 아미노산이 44.57%, 극성 아미노산이 24.75%, 양성 아미노산이 21.25% 및 음성 아미노산이 9.43%였고, AH 4B겔에 친화성이 있는 단백질 중의 아미노산 함량은 비극성 아미노산이 44.05%, 극성 아미노산이 29.13%, 양성 아미노산이 13.91% 및 음성 아미노산이 12.91%로 차이가 있었다. 4) 합성한 P-ASAH 4B겔 중의 p-amino-anilinyl기가 AH 4B겔 중의 아미노기보다 양전하를 가진 아미노산을 더 많이 함유하는 단백질을 선택적으로 분리하였다.

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한국형 육가공 제품류의 물리적 및 관능적 품질 특성 (Physical and Sensory Characteristics of Korean Style Meat Products)

  • 김일석;진상근;하경희;류현지;박기훈
    • Journal of Animal Science and Technology
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    • 제47권1호
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    • pp.49-56
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    • 2005
  • The Korean styled meat products such as grilled and/or roasted ham(Jikhwagui: J), Bulgogi ham(B), Kimbab ham(K) and sliced roasted ham(DDukgalbi: D) were obtained from different Korean meat processing companies and investigated for their salinity, saccharinity, pH, moisture and fat content, meat color and sensory evaluation. The results obtained were as follows; Percentage of saccharinity in J, B, K and D ranged 7.5 %(13) - 12.7% (J2), 5.3 0/«B2) -7.5 o/«BI), 5.2 0/«K4) - 6.6 o/«KI, K2, KS), and 6.60/«04) - 14.4o/«Dl), respectively. Percentage of salinity in J, B, K and D ranged 2.260/«13)- 2.38 0/«J4), 1.850/«B2) - 2.45 0/«B3), 1.94o/«KI) - 2.40% (K3), and 1.830/«02) - 2.19 o/«Dl), respectively. The pH value of J, B and K were ranged 6.30 - 6.44, 6.266.37 and 6.20 - 6.42, respectively, which are slightly higher than that of D(5.86 - 6.25). Content of average moisture were higher in B(61.0 %), K(59.94%) and J(59.63%) compared to the D(55.93%). In crude fat, B and D were ranged 14-21 %, which are very lower than those of K(59.94%) and J(59.63%). In meat color, $L^*$ value were above 50.0, except D2 and D3. $a^*$ value of B were slightly higher than those of other meat products. Compared to sensory evaluation, the overall acceptability of J is excellent in the range of saccharinity 12.7%, salinity 2.3 %, moisture 61 %, crude fat II - 12%, $L^*$ value 52 - 54, and $a^*$ value 12.3- 12.7. In the case of B, the overall acceptability is excellent in the range of saccharinity 6.6 - 7.5 %, salinity 1.90- 2.45 %, moisture 60 %, crude fat 15 %, $L^*$ value 56, and $a^*$ value 15. In the case of K, the overall acceptability is excellent in the range of saccharinity 6.5 %, salinity 2.4 %, moisture 61 %, crude fat 16%, $L^*$ value 53, and $a^*$ valuce 15. In the case of D, the overall acceptability is excellent in the range of saccharinity 14.0%, salinity 2.1 %, moisture 55%, crude fat 55%, $L^*$ value 50, and $a^*$ value 13.

WEAKLY B-REGULAR NEAR-RINGS

  • Chelvam Thirugnanam Tamizh;Cho Yong-Uk
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제13권2호
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    • pp.157-165
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    • 2006
  • The notion of regularity in near-ring was generalized by the concept of b-regular and some characterizations of the same was obtained through the substructures viz bi-ideals in near-rings. In this paper, we generalize further and introduce tile notion of weakly b-regular near-rings and obtain a characterization of tile same.

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Rubratoxi B가 흰쥐의 신장에 나타낸 病變에 대한 病理組織學的 연구 (Histopathologic Studies on Kidneys of Mice Administered Rubratoxin B.)

  • Ha, Man-Kwang
    • 한국환경보건학회지
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    • 제13권1호
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    • pp.41-46
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    • 1987
  • The purpose of this experiment was to investigate the leisons of mice produced by intraperitoneal injection of rubratoxin B. But the mice injected 3$\mu$g and 5$\mu$g of rubratoxin B showed retardation of growth, and slight swelling of kidneys. The hemorrhage in the renal cortex tubular dilation containing the desquamated epithelial cells, and adhesion of Bowman's spaces by proliferation of endothelial cells were histopathoglogically characterized in the kidneys of mice.

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KB 암세포에 효과있는 Streptomyces plicotosporus가 생산하는 항암증강물질 Rubiginone $B_2$ 에 관한 연구 (Rubiginone $B_2$, Isotetracenone Antibiotics which Reverses Multidrug-Resistance in KB Tumor Cells)

  • 하상철;홍순덕
    • 한국미생물·생명공학회지
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    • 제22권5호
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    • pp.491-494
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    • 1994
  • Antibiotic HS-2 was purified from the culture broth of Streptomyces plicatosporus which was isolated from soil, by solvent extraction, silica gel column chromatography and gel filtration. Through the analysis of UV, $^{1}$H-NMR, $^{13}$C-NMR spectrum, HS-2 was identified as rubiginone B$_{2}$. It was confirmed that HS-2 enhanced the cytotoxicity of colchicine against multidrug-resistant tumor cells.

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APPROXIMATION OF QUADRIC SURFACES USING SPLINES

  • Ahn, Young-Joon
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제13권3호
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    • pp.217-224
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    • 2009
  • In this paper we present an approximation method of quadric surface using quartic spline. Our method is based on the approximation of quadratic rational B$\acute{e}$zier patch using quartic B$\acute{e}$zier patch. We show that our approximation method yields $G^1$ (tangent plane) continuous quartic spline surface. We illustrate our results by the approximation of helicoid-like surface.

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