• 제목/요약/키워드: M&C

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C. G. M을 이용한 회전형 완전도체의 전류분포해석 (The Current Distribution of Revolution-Body Using Conjugate Gradient Method)

  • 이광천;김정기
    • 한국통신학회:학술대회논문집
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    • 한국통신학회 1987년도 춘계학술발표회 논문집
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    • pp.184-187
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    • 1987
  • The method of Conjugate Gradient(C.G.M) is applied to the solution of current distribution from body of revolution (B.O.R).Using the C.G.M it is possible to analyze electrically large arbtrarily oriented B.O.R. The fundamental differences between C.G.M and moment method are outlined. This method converges for any initial guess and this techniqe gurantees a monotonic convergence. Numerical results are presented for electromagnetic case which show good agreement with moment solution.

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The Role of (111)MgO Underlayer in Growth of c-axis Oriented Barium Ferrite Films

  • Erickson, D.W.;Hong, Y.K.;Gee, S.H.;Tanaka, T.;Park, M.H.;Nam, I.T.
    • Journal of Magnetics
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    • 제9권4호
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    • pp.116-120
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    • 2004
  • Hexagonal barium-ferrite ($BaFe_{12}O_{19}$, magnetoplumbite structure; BaM) film with perpendicularly c-axis orientation was successfully deposited on (100) silicon substrates with an MgO (111) underlayer by rf diode sputtering and in-situ heating at $920^{\circ}C$. The magnetic and structural properties of 0.27 ${\mu}m$ thick BaM films on MgO (111) underlayers were compared to films of the same thickness deposited onto single-crystal MgO (111) and c-plane ($000{\ell}$) sapphire ($Al_2O_3$) substrates by vibrating sample magnetometry (VSM), x-ray diffractometer (XRD), and atomic force microscopy (AFM). The thickness dependence of MgO (111) underlayers on silicon wafer was found to have a large effect on both magnetic and structural properties of the BaM film. The thickness of 15 nm MgO (111) underlayers produced BaM films with almost identical magnetic and structural properties as the single-crystal substrates; this can be explained by the lower surface roughness for thinner underlayer thicknesses. The magnetization saturation ($M_s$) and the ratio $H_{cII}/H_{c{\bot}}$ for the BaM film with a 15 nm MgO (111) underlayer is 217 emu/cc and 0.24, respectively. This is similar to the results for the BaM films deposited on the single-crystal MgO (111) and sapphire substrates of 197 emu/cc and 0.10, 200 emu/cc and 0.12, respectively. Therefore, the proposed MgO (111) underlayer can be used in many applications to promote c-axis orientation without the cost of expensive substrates.

감과실의 성숙과 추숙중의 Polygalacturonase활성 변화 및 특성 (Characteristics and Activity Changes of Polygalacturonase during Maturation and Postharvest of Persimmon Fruits)

  • 신승렬;김진구;김순동;김광수
    • 한국식품영양과학회지
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    • 제19권6호
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    • pp.596-604
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    • 1990
  • Polygalacturonase의 활성은 미숙감과실에서 나타나지 않았으나 완숙감과 연시에서 각각 55.01. 206.70unit/100g-fr. wt.로 연시에서 급격히 증가하였다. 연시에서 추출한 polygalacturonase의 isoenzyme은 2종이었고, 분자량은 다같이 55,000 dal-ton이었다. Polygalacturonase isoenzyme의 특성을 조사한 결과, polygalacturonase I의 Vmax는 0.195$\mu$ mole reducing-sugar/$m\ell$/30min., Km값은 3.50mg/$m\ell$이었고, 최적온도 4$0^{\circ}C$, 최적 pH 3.5이었으며, 열처리시 6$0^{\circ}C$까지 안정하였다. Polygalacturonase II 의 Vmax는 0.11$\mu$mole reducing-sugar /$m\ell$/30min., Km값은 2.50mg/$m\ell$이었고, 최적 온도와 pH는 35$^{\circ}C$와 4.0이었으며. 4$0^{\circ}C$까지 안정하였다. Polygalacturonase I 과 II는 K+, Cu++, Zn++, SDS, EDTA에 의해서 활성이 저해되었고 Ca++ 의해 다소 촉진되었다.

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Apostichopus japonicas (Echinodermata; Holothuroidea)에서 온도 스트레스에 의한 Hsp90 및 Ferritin 유전자의 발현 (The Expression of Hsp90 and Ferritin Genes under Thermal Stress in the Sea Cucumber (Apostichopus japonicas))

  • 김철원;진영국;김태익;정달상;강한승
    • 환경생물
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    • 제33권4호
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    • pp.433-440
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    • 2015
  • The Apostichopus japonicus is an important species in some Asia countries including Korea, China and Japan. The purpose of the present study was to investigate the differential gene expression of heat shock protein90 (Hsp90) and ferritin as a biomarker for the thermal stress during water temperature rising in the sea cucumber, A. japonicus. The A. japonicus (1.4 g) was cultured in incubator of separate temperature ($15^{\circ}C$, $20^{\circ}C$, $25^{\circ}C$ and $30^{\circ}C$) for each 0, 3, 6, 12, 24, 48 hours. The mRNA expression levels of Hsp90 and ferritin were examined using RT-PCR assay. Results showed that, the expression of Hsp90 mRNA was not significantly changed at $15^{\circ}C$. The expression of Hsp90 mRNA was significantly increased at high temperature such as $20^{\circ}C$ and $25^{\circ}C$. Furthermore, Hsp90 mRNA was early increased at $25^{\circ}C$ than $20^{\circ}C$. The ferritin mRNA was similar expression pattern with Hsp90. But, Hsp90 mRNA was more sensitive than ferritin mRNA at high thermal stress. These results indicate that Hsp90 and ferritin mRNAs were involved in the temperature changes response and may be play an important role in mediating the thermal stress in A. japonicas.

확산-유추 지형학적 순간단위도 모형의 최적매개변수 추정 (Optimal Parameters Estimation of Diffusion-Analogy Geomorphologic Instantaneous Unit Hydrograph Model)

  • 김주철;최용준
    • 한국습지학회지
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    • 제13권3호
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    • pp.385-394
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    • 2011
  • 본 연구에서는 유역의 배수구조를 지표면과 하천으로 구분하여 확산-유추 지형학적 순간단위도의 최적 매개변수를 산정하였다. 모형의 매개변수는 지표면과 하천 각각의 유속($u_c$, $u_h$) 및 확산계수($D_c$, $D_h$)로 구성하였다. 대상유역은 보청천 유역의 탄부 소유역을 선정하였으며, 대상유역의 하천망은 Strahler 차수법칙에 의해 4차 하천으로 분류되었다. 최적화 기법은 SCE-UA을 적용하였으며, 추정된 최적 매개변수는 다음과 같다; $u_c$ : 0.589 m/s, $u_h$ : 0.021 m/s, $D_c$ : $34.469m^2/s$, $D_h$ : $0.1333m^2/s$. 추정된 매개변수의 검증결과 평균 첨두유량 오차는 약 11 %, 첨두시간 오차는 0.3 hr로 양호하게 나타났다. 또한 매개변수들의 변동성을 살펴본 결과 하천확산계수($D_c$)는 수문응답함수에 큰 영향을 미치지 못함을 알 수 있었으며, 향후에는 이러한 결과들을 고려함으로서 모형을 좀 더 간편화할 수 있을 것으로 기대된다.

Cellulomonas 속 종간 원형질 융합체의 특성 (Physiological Characteristics of Fusants by Interspecific Protoplast Fusion of the Genus Cellulomonas)

  • 배무;임정화
    • 미생물학회지
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    • 제28권1호
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    • pp.47-54
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    • 1990
  • 섬유소를 분해할 수 있는 Cellutomonas flavigena NCIB 12901 과 Cellulomonas bibula NCIB 8142의 종간 원형질체 융합을 하고 그로부터 얻은 융합체의 특성을 조사하였다. C. bibuta의 원형질체는 lysozyme(600Ieιllulomoηas libula NCIB 8142의 종간 원형 섣처l 융 한응 하고:1로부터 얻은융합셰익 특성을 조사하였다 . C bibula의 원형선셰는 lysozyme $600{\mu}{\textrm{g}}$/ml)를 6시간 처리하여 얻었으며, 삼투안정제로는 O.5M sorbitol의 최저이었고 원형질체 재생률은 6.7%였다. 원형질체 융합은 25mM $CaCl_{2}$를 포함하는 40% PEG (M.W.6000)를 $30^{\circ}C$에서 30분간 처리함으로 수행하였고 C. bibuιl와 C. flavigeηa의 융합 빈도는 $5\times 10^{-4}$으로 원형질체 형성 및 합체를 얻었고, 모균주와 융합체의 영양요구성, 항생물질 내성, 효소활성, 세포벽 성분, 운동성 등을 비교하여 융합체는 모균주의 재조합체임을 밝히었다.

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Validity of self-reported height and weight in elderly Poles

  • Niedzwiedzka, Ewa;Dlugosz, Anna;Wadolowska, Lidia
    • Nutrition Research and Practice
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    • 제9권3호
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    • pp.319-327
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    • 2015
  • BACKGROUND/OBJECTIVES: In nutritional epidemiology, collecting self-reported respondent height and weight is a simpler procedure of data collection than taking measurements. The aim of this study was to compare self-reported and measured height and weight and to evaluate the possibility of using self-reported estimates in the assessment of nutritional status of elderly Poles aged 65 + years. SUBJECTS/METHODS: The research was carried out in elderly Poles aged 65 + years. Respondents were chosen using a quota sampling. The total sample numbered 394 participants and the sub-sample involved 102 participants. Self-reported weight (non-corrected self-reported weight; non-cSrW) and height estimates (non-corrected self-reported height; non-cSrH) were collected. The measurements of weight (measured weight; mW) and height (measured height; mH) were taken. Using multiple regression equations, the corrected self-reported weight (cSrW) and height (cSrH) estimates were calculated. RESULTS: Non-cSrH was higher than mH in men on average by 2.4 cm and in women on average by 2.3 cm. In comparison to mW, non-cSrW was higher in men on average by 0.7 kg, while in women no significant difference was found (mean difference of 0.4 kg). In comparison to mBMI, non-cSrBMI was lower on average by $0.6kg/m^2$ in men and $0.7kg/m^2$ in women. No differences were observed in overweight and obesity incidence when determined by mBMI (68% and 19%, respectively), non-cSrBMI (62% and 14%, respectively), cSrBMI (70% and 22%, respectively) and pcSrBMI (67% and 18%, respectively). CONCLUSIONS: Since the results showed that the estimated self-reported heights, weights and BMI were accurate, the assessment of overweight and obesity incidence was accurate as well. The use of self-reported height and weight in the nutritional status assessment of elderly Poles on a population level is therefore recommended. On an individual level, the use of regression equations is recommended to correct self-reported height, particularly in women.