• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.6
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• pp.398-403
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• 2001

In this paper, effective ionization coefficient for 6H-SiC is determined. Analytical formulas for the parallel plane breakdown voltage of the 6H-SiC p＋n junction are derived by employing the ionization coefficients. The analytical breakdown voltages show good agreement with the numerical results of Dmitriev＇s［3］and the experimental results of Cree Research［9］over the doping range from 10$^{15}$ cm$^{-3}$ to 10$^{18}$ cm$^{-3}$.

• Journal of applied mathematics & informatics
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• v.32 no.1_2
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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.

• Bulletin of the Korean Mathematical Society
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• v.48 no.4
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• pp.847-851
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• 2011

In this paper we provide examples of pairs of conformally non-equivalent, but topologically equivalent, p-groups $H_1$, $H_2$ < Aut(S), where S is a closed Riemann surface of genus g ${\geq}$ 2, so that $S/H_j$ has genus zero and all its cone points are of order equal to p.

• Journal of the Korean Mathematical Society
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• v.44 no.4
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• pp.915-929
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• 2007

The main result of this paper is to construct the derivative twisted p-adic (h, q)-L-functions at s = 0. We obtain twisted version of Theorem 4 in [17]. We also obtain twisted (h, q)-extension of Proposition 1 in [3].

• Bulletin of the Korean Mathematical Society
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• v.59 no.3
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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 𝔽_qG can be deduced from a subalgebra 𝔽_q(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 = p^r for some prime p and the center of each Wedderburn component of 𝔽_qG is the coefficient field 𝔽_q.

• Applied Biological Chemistry
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• v.12
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• pp.25-31
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• 1969

The characteristics of crude enzyme produced from Trichoderma viride($O_2-1$) which isolated from half spoiled Locust acacia wood (Robinia Pseudacacia Linne) were examined in this paper. The results obtained were summarized as follows: 1) As a results of enzymatic action on several cellulose substrate it was found that there were some sorts of cellulase in crude enzyme. 2) The activity of C.M.C. ase and ${\beta}-glucosidase$ were decreased in accordance with increasing concentration of substrate, and filter paper saccharifying enzyme relatively increased in accordance with increasing concentration of substrate and enzyme in couse of time. 3) The optimal pH of each enzyme was 5.0 and the range of stability on pH generally from 3 to 6. 4) In disintegrating activity on filter paper, in decomposing activity on C.M.C. and $p-nitrophenyl-{\beta}-D-glucoside$, and in saccharifying activity on filter paper, the optimal temperatures were $50^{\circ}C.,\;60^{\circ}C,\;and\;65^{\circ}C$. 5) The order of stability on temperature was as follow; saccharifying activity on filter paper decomposing activity on C.M.C. disintegrating activity on filter paper>decomposing activity on $p-nitrophenyl-{\beta}-D-glucoside$. 6) The activity of the enzymes was inhibited with mercuric and silver ion, and activated with potassium.

• Journal of applied mathematics & informatics
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• v.41 no.2
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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 F_p,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.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.28 no.2
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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.

• Journal of the Korean Mathematical Society
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• v.46 no.1
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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.

• Restorative Dentistry and Endodontics
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• v.24 no.1
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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.