• Microbiology and Biotechnology Letters
• /
• v.17 no.1
• /
• pp.81-83
• /
• 1989

The flagella antigenic variation of nine Bacillus thuringiensis serovar kurstaki temperature-sensitive mutants grown at the permissive temperature (3$0^{\circ}C$) was detected by a serological agglutination between H-antigen and antiserum. The flagella antigens were injected to rabbits to prepared their antisera, and then their homologous and heterologous titers of the antisera were measured. The homologous titers were ranged from 1:6,400 to 1:12,800, but the heterologous titers were very low. The H-antigen of the wild type strain was not agglutinated to 4 heterologous antisera, ts-U23 not to 7, ts-U3l not 5, ts-U32 not to 4, ts-U33 not to 7, ts-U7l not to 4, ts-U73 not to 6, ts-U74 not to 6, ts-U91 not to 4 and ts-U603 not to 4 antisera.

• Bulletin of the Korean Mathematical Society
• /
• v.53 no.5
• /
• pp.1585-1596
• /
• 2016

In this paper we investigate the existence of nontrivial solutions for the following fractional boundary value problem (FBVP) $$\{_tD_T^{\alpha}(_0D_t^{\alpha}u(t))={\nabla}W(t,u(t)),\;t{\in}[0,T],\\u(0)=u(T)=0,$$ where ${\alpha}{\in}(1/2,1)$, $u{\in}{\mathbb{R}}^n$, $W{\in}C^1([0,T]{\times}{\mathbb{R}}^n,{\mathbb{R}})$ and ${\nabla}W(t,u)$ is the gradient of W(t, u) at u. The novelty of this paper is that, when the nonlinearity W(t, u) involves a combination of superquadratic and subquadratic terms, under some suitable assumptions we show that (FBVP) possesses at least two nontrivial solutions. Recent results in the literature are generalized and significantly improved.

• Bulletin of the Korean Mathematical Society
• /
• v.56 no.5
• /
• pp.1297-1314
• /
• 2019

In this work, we investigate the following fractional boundary value problems $$\{_tD^{\alpha}_T({\mid}_0D^{\alpha}_t(u(t)){\mid}^{p-2}_0D^{\alpha}_tu(t))\\={\nabla}W(t,u(t))+{\lambda}g(t){\mid}u(t){\mid}^{q-2}u(t),\;t{\in}(0,T),\\u(0)=u(T)=0,$$ where ${\nabla}W(t,u)$ is the gradient of W(t, u) at u and $W{\in}C([0,T]{\times}{\mathbb{R}}^n,{\mathbb{R}})$ is homogeneous of degree r, ${\lambda}$ is a positive parameter, $g{\in}C([0,T])$, 1 < r < p < q and ${\frac{1}{p}}<{\alpha}<1$. Using the Fibering map and Nehari manifold, for some positive constant ${\lambda}_0$ such that $0<{\lambda}<{\lambda}_0$, we prove the existence of at least two non-trivial solutions

• Language and Information
• /
• v.9 no.2
• /
• pp.1-22
• /
• 2005

In this paper I propose the semantics of two modality markers in Korean, keyss and (u)1 kes. I compare the two modality markers with respect to some properties. First, keyss is used to express logical necessity while (u)1 kes can be used to express a simple prediction as well. Second, keyss expresses some logical conclusion from the speaker's own information state without claiming it is true. On the other hand, (u)1 kes expresses the claim that the speaker's prediction will be true. Third, the prediction of keyss is non-monotonic: it can be reversed without being inconsistent. However, that of (u)1 kes cannot. Fourth, (u)1 kes can be used freely in epistemic conditionals, but keyss cannot. Finally, when keyss is used, the prediction cannot be repeated. The prediction from the use of (u)1 kes can be repeated. To account for these differences, I propose that keyss is used when the speaker makes a purely logical presumption based on his/her own information state, and that (u)1 kes is used to make a prediction which is asserted to be true. This proposal accounts for all the differences of the two modality markers.

• Journal of the Korean Wood Science and Technology
• /
• v.36 no.2
• /
• pp.63-72
• /
• 2008

As a part of abating formaldehyde emission of urea-formaldehyde (UF) resin adhesive, this study was conducted to investigate chemical structures of UF resin adhesives with different formaldehyde/urea (F/U) mole ratios, using carbon-13 nuclear magnetic resonance ($^{13}C$-NMR) spectroscopy. UF resin adhesives were synthesized at four different F/U mole ratios such as 1.6, 1.4, 1.2, and 1.0 for the analysis. The analysis $^{13}C$-NMR spectroscopy showed that UF resin adhesives with higher F/U mole ratios (i.e., 1.6 and 1.4) had two distinctive peaks, indicating the presence of dimethylene ether linkages and methylene glycols, a dissolved form of free formaldehyde. But, these peaks were not detected at the UF resins with lower F/U mole ratios (i.e., 1.2 and 1.0). These chemical structures present at the UF resins with higher F/U mole ratios indicated that UF resin adhesive with higher F/U mole ratio had a greater contribution to the formaldehyde emission than that of lower F/U mole ratio. Uronic species were detected for all UF resins regardless of F/U mole ratios.

• Journal of the Korean Mathematical Society
• /
• v.32 no.3
• /
• pp.541-551
• /
• 1995

The nonlinear Klein Gordon equation $$ (1) \frac{\partial t^2}{\partial^2 u} - \Delta u + V_u(u) = f $$ where $\Delta$ is the Laplacian operator in $R^d (d = 1, 2, 3), V_u(u)$ is the derivative of the "potential function" V, and f is a source term independent of the solution u, in various areas of mathematical physics.l physics.

• Journal of the Chungcheong Mathematical Society
• /
• v.29 no.1
• /
• pp.13-22
• /
• 2016

We introduce the concepts of double (r, s)(u, v)-preopen sets, double (r, s)(u, v)-preclosed sets and double pairwise (r, s)(u, v)-precontinuous mappings in double bitopological spaces and investigate some of their characteristic properties.

• Journal of the Korean Mathematical Society
• /
• v.37 no.4
• /
• pp.565-577
• /
• 2000

We consider regularity questions arising in the degenerate elliptic vector valued variational inequalities -div(｜▽u｜p-2∇u)$\geq$b(x, u, ∇u) with p$\in$(1, $\infty$). It is a generalization of the scalar valued inequalities, i.e., the obstacle problem. We obtain the C1,$\alpha$loc regularity for the solution u under a controllable growth condition of b(x, u, ∇u).

• Journal of the Korean Mathematical Society
• /
• v.46 no.1
• /
• pp.31-39
• /
• 2009

A bifurcation problem for nonlinear partial differential equations of the form $$div({\varphi}(|{\nabla}u|){\nabla}u+{\mu}_0{\varphi}(|u|)u=q({\lambda},\;x,\;u,\;{\nabla}u)$$ subject to Dirichlet boundary conditions is discussed. Using a global bifurcation theorem of Rabinowitz type, we show that under certain conditions on $\varphi$ and q, the above equation has an unbounded connected set of solutions (u, $\lambda$).

• Bulletin of the Korean Mathematical Society
• /
• v.32 no.2
• /
• pp.303-308
• /
• 1995

We consider a torus T, that is, a compact surface with genus 1 and $\Omega = D^2 \times S^1$ topologically with $\partial\Omega = T$, where $D^2$ is the open unit disk and $S^1$ is the unit circle. Let $\omega = (x,y)$ denote the generic point on T. For a smooth immersion $u : T \to R^3$, we define the Dirichlet functional by $$ E(u) = \frac{2}{1} \int_{T} $\mid$\nabla u$\mid$^2 d\omega $$ and the volume functional by $$ V(u) = \frac{3}{1} \int_{T} u \cdot u_x \Lambda u_y d\omege $$.