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6H-SiC $p^{+}n$ 접합의 항복 전압을 위한 해석적 모형 (Analytical Model of Breakdown Voltages for 6H-SiC $p^{+}n$ Junction)

  • 정용성
    • 대한전자공학회논문지SD
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    • 제38권6호
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    • pp.398-403
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    • 2001
  • 본 논문에서는 6H-SiC의 유효 이온화 계수를 추출하였고, 이 이온화 계수를 이용하여 6H-SiC p+n 접합의 해석적 항복 전압 식을 유도하였다. 해석적 항복 전압 결과는 10/sup 15/ cm/sup -3/ ∼ 10/sup 18/ cm/sup -3/의 농도 범위에서 Dmitriev의 수치적 결과[3] 및 Cree Research의 실험 결과[9]와 비교하여 잘 일치하였다.

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DUALITY IN MULTIOBJECTIVE FRACTIONAL PROGRAMMING PROBLEMS INVOLVING (Hp, r)-INVEX FUNCTIONS

  • Jayswal, Anurag;Ahmad, I.;Prasad, Ashish Kumar
    • Journal of applied mathematics & informatics
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    • 제32권1_2호
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    • pp.99-111
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    • 2014
  • In this paper, we have taken step in the direction to establish weak, strong and strict converse duality theorems for three types of dual models related to multiojective fractional programming problems involving ($H_p$, r)-invex functions.

COMPUTATION OF WEDDERBURN DECOMPOSITION OF GROUPS ALGEBRAS FROM THEIR SUBALGEBRA

  • Mittal, Gaurav;Sharma, Rajendra Kumar
    • 대한수학회보
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    • 제59권3호
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    • pp.781-787
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    • 2022
  • In this paper, we show that under certain conditions the Wedderburn decomposition of a finite semisimple group algebra 𝔽qG can be deduced from a subalgebra 𝔽q(G/H) of factor group G/H of G, where H is a normal subgroup of G of prime order P. Here, we assume that q = pr for some prime p and the center of each Wedderburn component of 𝔽qG is the coefficient field 𝔽q.

섬유소(纖維素) 분해효소(分解酵素)에 관(關)한 연구(硏究) (제4보(第4報)) -Trichoderma viride($O_2-1$)가 생성(生成)하는 조효소(粗酵素)의 성질(性質)에 대(對)하여- (Studies On the Cellulase [IV.] -On the Properties of Crude Cellulase produced by Trichoderma viride($O_2-1$))

  • 성락계
    • Applied Biological Chemistry
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    • 제12권
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    • pp.25-31
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    • 1969
  • 반부후(半腐朽) 아까시아나무(Robinia Pseudacacia Linne)에서 분리(分離)한Trichoclerma viride $(O_2-1)$가 생성(生成)하는 조효소(粗酵素)의 성질(性質)을 실험(實驗)하여 다음과 같은 결과(結果)를 얻었다. 1) 각종(各種)의 섬유소기질(纖維素基質)에 반응(反應)시켜본 결과(結果) 수종류(數種類)의 cellulase가 혼존(混存)함을 알았다. 2) C.M.C 및 ${\beta}-glucoside$ 분해효소(分解酵素)는 기질(基質)의 농도(濃度)가 증가(增加)함에 따라 분해율(分解率)이 낮았으며 여지당화효소(濾紙糖化酵素)는 기질(基質) 및 효소량(酵素量)이 증가(增加)되고 시간(時間)의 경과(經過)에 따라 분해율(分解率)이 상대적(相對的)으로 증가(增加)되었다. 3) 각효소(各酵素)의 최적활성(最適浩性) pH는 5.0이였으며 pH 안정성(安定性)은 대체(大體)로 pH $3{\sim}6$ 이였다. 4) 최상활성온도(最適活性溫度)는 여지붕괴력(濾紙崩壞力)이 $50^{\circ}C$ C.M.C.및 $p-nitro-phenyl-{\beta}-glucoside$ 분해력(分解力)이 $60^{\circ}C$ 여지당화력(濾紙糖化力)이 $65^{\circ}C$에서 최고활성(最高活性)을 나타내었다. 열(熱)에 대(對)한 안정성(安定性)은 여지당화력(濾紙糖化力), C.M.C 당화력(糖化力), 여지붕괴력(濾紙崩壞力), ${\beta}-glucoside$ 당화력(糖化力)의 순위(順位)였다. 5) 금속(金屬) Ion에 대(對)한 영향(影響)은 $Hg^{++},\;Ag^+$ 각효소(各酵素)에 대(對)하여 조해(阻害)하였으며 $K^+$는 각효소(各酵素)를 활성화(活性化)하였다.

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GENERATING FUNCTIONS OF (p, q)-ANALOGUE OF ALEPH-FUNCTION SATISFYING TRUESDELL'S ASCENDING AND DESCENDING Fp,q-EQUATION

  • ALTAF A. BHAT;M. YOUNUS BHAT;H. MAQBOOL;D.K. JAIN
    • Journal of applied mathematics & informatics
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    • 제41권2호
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    • pp.373-386
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    • 2023
  • In this paper we have obtained various forms of (p, q)-analogue of Aleph-Function satisfying Truesdell's ascending and descending Fp,q-equation. These structures have been employed to arrive at certain generating functions for (p, q)-analogue of Aleph-Function. Some specific instances of these outcomes as far as (p, q)-analogue of I-function, H-function and G-functions have likewise been obtained.

내연기관용 슬라이드 베어링재의 케비테이션 침식거동과 부식영향 및 윤할유의 거동에 관한 연구 (A Study on the behaviour of Cavitation erosion and lubricating Oils and the influence of Corrosion on Slide Bearing Metals for Internal combustion Engine)

  • 이진열;임우조
    • 수산해양기술연구
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    • 제28권2호
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    • pp.171-183
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    • 1992
  • In this paper, the behaviour of cavitation erosion, influence of corrosion and corrosion control on slide bearing metals for internal combustion engine were investigated, and this experiment was done by the vibratory cavitation erosion tester. The main results obtained are as follows: 1. With decreasing the space between horn and specimen, the weight loss and its rate increased step by step. But the weight loss and its rate of 0.2mm space decreased conversely more than that of 0.4mm space at early stage. 2. The weight loss and its rate with change of pH were appeared to the order of pH2>pH12>pH7>pH4. And the weight loss and its rate at pH 4 decreased at best. 3. The weight loss and its rate by cavitation erosion for bearing metals were shown to the order of W.M7>W.M1>K.M4. 4. There appeared mainly small pit hole at pH2, and appeared the pit of netting thread type at pH12 by the results of the damaged surfaces at pH2 and pH12 environments that were sensitive to cavitation erosion. 5. With increasing the viscosity of lubricating oil, the weight loss rate by cavitation erosion became dull at the space below 0.5mm. 6. The protective efficiency of cavitation erosion-corrosion is superior inhibitor of chormate(25 ppm) to cathodic protection.

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ON THE MEAN VALUES OF DEDEKIND SUMS AND HARDY SUMS

  • Liu, Huaning
    • 대한수학회지
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    • 제46권1호
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    • pp.187-213
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    • 2009
  • For a positive integer k and an arbitrary integer h, the classical Dedekind sums s(h,k) is defined by $$S(h,\;k)=\sum\limits_{j=1}^k\(\(\frac{j}{k}\)\)\(\(\frac{hj}{k}\)\),$$ where $$((x))=\{{x-[x]-\frac{1}{2},\;if\;x\;is\;not\;an\;integer; \atop \;0,\;\;\;\;\;\;\;\;\;\;if\;x\;is\;an\;integer.}\$$ J. B. Conrey et al proved that $$\sum\limits_{{h=1}\atop {(h,k)=1}}^k\;s^{2m}(h,\;k)=fm(k)\;\(\frac{k}{12}\)^{2m}+O\(\(k^{\frac{9}{5}}+k^{{2m-1}+\frac{1}{m+1}}\)\;\log^3k\).$$ For $m\;{\geq}\;2$, C. Jia reduced the error terms to $O(k^{2m-1})$. While for m = 1, W. Zhang showed $$\sum\limits_{{h=1}\atop {(h,k)=1}}^k\;s^2(h,\;k)=\frac{5}{144}k{\phi}(k)\prod_{p^{\alpha}{\parallel}k}\[\frac{\(1+\frac{1}{p}\)^2-\frac{1}{p^{3\alpha+1}}}{1+\frac{1}{p}+\frac{1}{p^2}}\]\;+\;O\(k\;{\exp}\;\(\frac{4{\log}k}{\log\log{k}}\)\).$$. In this paper we give some formulae on the mean value of the Dedekind sums and and Hardy sums, and generalize the above results.

광중합형 복합레진 수리시 표면처리가 전단결합강도에 미치는 영향 (THE EFFECT OF SURFACE TREATMENTS ON THE SHEAR BOND STRENGTH OF REPAIRED COMPOSITES)

  • 문장원;이광원;박수정
    • Restorative Dentistry and Endodontics
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    • 제24권1호
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    • pp.156-165
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    • 1999
  • The purpose of this study was to evaluate the effect of surface treatments on the shear bond strength between new and old composites. Circular cavities prepared on the center of acrylic resin mold and the prepared cavities were filled with composite resin. They randomly assigned into control group and 8 groups according to the difference in surface treatments of old composites; Control group: no surface treatment, Group 1: surface treated with #120 SiC paper & bonding agent, Group 2: surface treated with #400 SiC paper & bonding agent, Group 3: surface treated with #120 SiC paper, 32% $H_3PO_4$ & bonding agent, Group 4: surface treated with #400 SiC paper, 32% $H_3PO_4$ & bonding agent, Group 5: surface treated with #120 SiC paper, primer & bonding agent, Group 6: surface treated with #400 SiC paper, primer & bonding agent, Group 7: surface treated with #120 SiC paper, 32% $H_3PO_4$, primer & bonding agent, Group 8: surface treated with #400 SiC paper, 32% $H_3PO_4$, primer & bonding agent. New composites were applicated on the old composites of experimental groups. The shear bond strengths for the experimental specimen were measured and the results were analyzed by using one way ANOVA. The observations of surface morphology after SiC paper roughening and debonded surface morphology after shear bond strength test were done by SEM. The results were as follows; 1. Shear bond strengths for specimens roughened with #120 SiC paper matching with the particle size of coarse diamond bur were significantly higher than those for the specimens with #400 SiC paper(P<0.05). By SEM, the surface of the specimens roughened with #120 SiC paper was more irregular than the specimens with #400 SiC paper. 2. Shear bond strengths for specimens treated with 32% $H_3PO_4$ etchant, primer, bonding resin were significantly higher than those for specimens treated with 32% $H_3PO_4$ and bonding resin(P<0.05). 3. Shear bond strengths for the specimens treated with 32% $H_3PO_4$ etchant and bonding resin were significantly higher than those for specimens treated with only bonding resin(P<0.05). There was no remarkable change of surface morphology after 32% $H_3PO_4$ etching. 4. It was possible to observe mixed fracture patterns (the cohesive fracture of old composite and the adhesive fracture between old and new composite) in the specimens roughened with #120 SiC paper, but almost adhesive fracture in the specimens roughened with #400 SiC paper.

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