• Bulletin of the Korean Mathematical Society
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• v.60 no.6
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• pp.1523-1537
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• 2023

Let R be a commutative ring with identity and S a multiplicative subset of R. First, we introduce and study the u-S-projective dimension and u-S-injective dimension of an R-module, and then explore the u-S-global dimension u-S-gl.dim(R) of a commutative ring R, i.e., the supremum of u-S-projective dimensions of all R-modules. Finally, we investigate u-S-global dimensions of factor rings and polynomial rings.

• Communications for Statistical Applications and Methods
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• v.12 no.3
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• pp.545-556
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• 2005

Hjort(1990) obtained the nonparametric Bayes estimator $\^{F}_{c,a}$ of $F_0$ with respect to beta processes in the random censorship model. Let $X_1,{\cdots},X_n$ be i.i.d. $F_0$ and let $C_1,{\cdot},\;C_n$ be i.i.d. G. Assume that $F_0$ and G are continuous. This paper shows that {$\^{F}_{c,a}$(u){\|}0 < u < T} converges weakly to a Gaussian process whenever T < $\infty$ and $\~{F}_0({\tau})\;<\;1$.

• Transactions of Materials Processing
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• v.10 no.6
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• pp.449-456
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• 2001

The concept of stress wave was introduced through the quantized kinetic energy which is related to the potentional energy change of atom, molecular bond energy. Differentiated molecular bond energy $\varphi$() by the lst order displacement u becomes force F(F = d$\varphi$($u_i$)/du), if resversely stated, causing physically atomic displacement $u_i$. Such physical phenomena lead stress(force/area of applied force) can be expressed by wave equation of linearly quantized physical property. Through the stress wave concept, formation of dislocation, which could not explained easily from a theory of continuum mechanics, can be explained. Moreover, this linearly quantized stress wave equation with a stress concept for grains in a crystalline solid was applied to three typical metallic microstructures and a simple shape. The result appears to be a product from well treated equations of a quantized stress wave. From this result, it can be expected to answer the reason why the defect free and very fine diameters of long crystalline shapes exhibit ideal tensile strength of materials.

• Journal of applied mathematics & informatics
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• v.28 no.3_4
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• pp.711-721
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• 2010

Values of the parameter $\lambda$ are determined for which there exist positive solutions of the system of boundary value problems, $u^{(n)}+{\lambda}p(t)f(\upsilon)=0$, $\upsilon^{(n)}+{\lambda}q(t)g(u)=0$, for $t\;{\in}\;[a,b]$, and satisfying, $u^{(i)}(a)=0$, $u^{(\alpha)}(b)=0$, $\upsilon^{(i)}(a)=0$, $\upsilon^{(\alpha)}(b)=0$, for $0\;{\leq}\;i\;{\leq}\;n-2$ and $1\;{\leq}\;\alpha\;\leq\;n-1$ (but fixed). A well-known Guo-Krasnosel'skii fixed point theorem is applied.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.5
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• pp.423-429
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• 2012

This study evaluated the effects of adding sea mustard Undaria pinnatifida glycoprotein to the diet of juvenile olive flounder Paralichthys olivaceus on its growth, and levels of insulin-like growth factor I (IGF-I), IGF binding proteins (IGFBPs), and interleukins. Three experimental diets (U0, U0.5, and U1.0) were formulated that contained different amounts of an extract of U. pinnatifida (0, 0.5, and 1.0%, respectively). Experimental groups were established in triplicate (30 fish/group) and fed for 12 weeks. The experimental group fed 1.0% added U. pinnatifida glycoprotein had the greatest rate of weight gain, which differed significantly from the other experimental groups. SDS-PAGE of the plasma IGF-I and muscle protein showed that the experimental groups taking U. pinnatifida glycoprotein had significantly more IGF-I and a ca. 200 kDa protein, as compared to the control group. In addition, the amount of IGFBP-3 at ca. 43 kDa increased in the group given the U. pinnatifida extract, as compared to the control group. The interluekin-2, -4, -6, and -12 levels paralleled the level of growth factor in the groups given the U. pinnatifida extract. In conclusion, supplementing the diet of olive flounder with U. pinnatifida glycroprotein improved its growth and immunity.

• Proceedings of the KSPS conference
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• 2000.07a
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• pp.86-87
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• 2000

In this paper, we discuss why two different surface forms appear in loanwords for English and German /${\int}$/ In Korean, a vowel is inserted into loanwords if a consonant cannot be properly syllabified. Therefore, /${\int}$/ in some positions of loanwords trigger vowel insertion. Interestingly, /${\int}$/s in the onset cluster of English and German words were borrowed in Korean as Iful with the inserted vowel [u] whereas If Is in the coda position of English and German words were borrowed as Ifil with the inserted vowel [i]. For example, 'shrimp' is adopted as [${\int}urimphi$] whereas 'rush' is adopted as [$ra{\int}i$]. In this paper, we attempt to find out the phonetic reason for the distribution of the surface forms of /${\int}$/. We assume that since the formant frequency of [i] is higher than that of [u], the peak frequency of /${\int}$/ with the surface form of [${\int}$i] in loanwords may be higher than that of /${\int}$/ with the surface form of [${\int}u$]. We also assume that duration may be another factor for the distribution of [${\int}i$] and [${\int}u$]. Since /${\int}$/ and /u/ use lip rounding whereas /i/ doesn't, the duration for [${\int}i$] might be longer than that of [${\int}u$]. German supports our assumption. /${\int}$/ in the onset cluster is longer than /${\int}$/ in the coda position. It also has higher peak frequency than that of /${\int}$/ in the coda position. In loanwords, ${\int}$ in the onset cluster is borrowed as [${\int}u$] as in Spiegel whereas /${\int}$/ in the coda position is borrowed as [${\int}i$] as in Bosch. English, however, does not support our assumption. Peak frequency of [${\int}$] depends on the preceding vowel, not on its position in the syllable structure. If the preceding vowel is front, then the peak freuency of the following of the following /${\int}$/ is high but if the preceding vowel is back, than the peak frequency of the following /${\int}$/ is low. The peak frequency of /${\int}$/ in the onset cluster seems to be in between. As we assumed, however, the duration of /${\int}$/ in the coda position is longer than of /${\int}$/ in the onset cluster. With the mixed results, we question whether Koreans really hear two different xounds for /${\int}$/ in English words. For the future experiment, we would like to perform the perception tet for /${\int}$/ in English words.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.6
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• pp.577-583
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• 2001

The digestive enzyme activities such as $\alpha-amylase$, trypsin and pepsin from the laboratory-reared river puffer Takifugu obscurus were measured from the time course of 1 day until the 65 day after hatching. In the case of $\alpha-amylase$, it was showed minimum activity of 0.0493 U/mg at the total length (TL) 10 mm, and showed maximum activity of 0.1480 U/mg at 19 mmTL. Trypsin and pepsin were showed their maximum activities of 0.0264, 0.0258 U/mg and 0.0178, 0.0201 U/mg when the total length of 16 and 24 mm, and represented remarkable correlations between the changes of enzyme activity and growth rate. The ontogenetic variations of digestive enzymes were represented clearly different patterns; i.e, the pepsin showed higher activity when the periods of larva ($4\~5\;mmTL$) and juvenile II ($19\~24\;mmTL$), however, the trypsin represented maximum activity at the stages of juvenile I ($11\~16\;mmTL$) and young fish (27 mmTL), respectively.

• Korean Journal of Mathematics
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• v.17 no.4
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• pp.473-480
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• 2009

We prove the existence and multiplicity of nontrivial solutions for a fourth order problem ${\Delta}^2u+c{\Delta}u={\alpha}u-{\beta}(u+1)^-$ in ${\Omega}$, ${\Delta}u=0$ and $u=0$ on ${\partial}{\Omega}$, where ${\lambda}_1{\leq}c{\leq}{\lambda}_2$ (where $({\lambda}_i)_{i{\geq}1}$ is the sequence of the eigenvalues of $-{\Delta}$ in$H_0^1({\Omega})$) and ${\Omega}$ is a bounded open set in $R^N$ with smooth boundary ${\partial}{\Omega}$. The results are proved by applying minimax arguments and linking theory.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.149-149
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• 2002

• Proceedings of the Mineralogical Society of Korea Conference
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• 2001.06a
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• pp.40-40
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• 2001

The sorption behavior of Cs(I), Sr(II), and U(VI) on representative single minerals(oxide and clay) and rocks were comparatively studied by using batch type sorption experiment. The effects of pH, ionic strength and the sorption mechanism were also discussed. It was found that mineral structure played as a main factor governing the sorption characteristics of Cs(I), Sr(II). The sorption of Cs(I) and Sr(II) on minerals showed ionic strength-dependency, which is a indirect sign of weak binding between metal cation and mineral surfaces. However, the sorption behavior of U(VI) was quite different compared with that of Cs(I), and Sr(II). Fe-oxide minerals showed strong tendency for U(VI) sorption, dominating the sorption in the composite/mixture systems. The surface characteristics which arise from mineral structure, and the affinity of metal ions to the sorption sites of minerals are the key to understand the role of minerals in the radionuclide sorption.