• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.7
• /
• pp.1015-1022
• /
• 2007

The spermatogonial stem cell (SSCs) is unique in that it is the only cell in the adult male that can contribute genes to a subsequent generation. Permanent modification of the germ cell line may be realized if stem cells could be cultured, transfected with unique genes, and then transplanted into recipient testes. We developed a culture system that supported long-term viability of SSCs. We used a retrovirus vector (pMSCV including ${\beta}$-galactosidase) to stably transfect spermatogonia following long-term culture using the system developed. Expression of the reporter gene ${\beta}$-galactosidase controlled by the retroviral vector was stable in long-term cultured SSCs. We confirmed the retroviral-mediated ${\beta}$-galactsidase gene could be expressed in germ cells in recipient mice following SSCs transplantation.

• Journal of the Korean Mathematical Society
• /
• v.47 no.4
• /
• pp.861-877
• /
• 2010

The works of Erd$\ddot{o}$s et al. about expansions of 1 with respect to a non-integer base q, referred to as q-expansions, are investigated to determine how far they continue to hold when the number 1 is replaced by a positive number x. It is found that most results about q-expansions for real numbers greater than or equal to 1 are in somewhat opposite direction to those for real numbers less than or equal to 1. The situation when a real number has a unique q-expansion, and when it has exactly two q-expansions are studied. The smallest base number q yielding a unique q-expansion is determined and a particular sequence is shown, in certain sense, to be the smallest sequence whose corresponding base number q yields exactly two q-expansions.

• Bulletin of the Korean Mathematical Society
• /
• v.53 no.4
• /
• pp.1185-1196
• /
• 2016

We show a class of homogeneous polynomials of Fermat-Waring type such that for a polynomial P of this class, if $P(f_1,{\ldots},f_{N+1})=P(g_1,{\ldots},g_{N+1})$, where $f_1,{\ldots},f_{N+1}$; $g_1,{\ldots},g_{N+1}$ are two families of linearly independent entire functions, then $f_i=cg_i$, $i=1,2,{\ldots},N+1$, where c is a root of unity. As a consequence, we prove that if X is a hypersurface defined by a homogeneous polynomial in this class, then X is a unique range set for linearly non-degenerate non-Archimedean holomorphic curves.

• International Journal of Contents
• /
• v.3 no.2
• /
• pp.35-39
• /
• 2007

The cognitive radio communication is taking the attentions because the development of the technique came to be possible to analyze wireless signals. In the IEEE 802.22 WRAN Systems[1], how to detect a spectrum and signals is continuously studied. In this paper, we propose the efficient signal detection method using SCF (Spectral Correlation Function). It is easy to detect the signal feature when we are using the SCF. Because most modulated signals have the cyclo-stationarity which is unique for each signal. But the fading channel effected serious influence even though it detects the feature of the signal. We applied LMS(Least Mean Square) filter for the compensation of the signal which is effected the serious influence in the fading channel. And we analyze some signal patterns through the SCF. And we show the unique signal feature of each signal through the SCF method. It is robust for low SNR(Signal to Noise Ratio) environment and we can distinguish it in the fading channel using LMS Filter.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.25 no.3
• /
• pp.199-209
• /
• 1997

The purpose of this study is to find major factors which are influential in visual preferences of pergolas and shelters. 33 pergolas and shelters were selected for the study by slides test method. Major findings of this study are summarized as follows. 1. In the degree of visual preferences, pergolas and shelters which are traditional Korean ones in harmony with surrounding environment, and provide sculptural effects, unique images and shade, obtain relatively high scores. 2. The result of factor analysis showed that [dimensions] of visual preferences factors for pergolas and shelters were composition and use and place. 3. The result of regression analysis indicated that the best predictors of visual preferences for pergolas and shelters were atmosphere, aesthetics of form, harmony with surroundings, unique image etc.

• Journal of the Korean Mathematical Society
• /
• v.48 no.1
• /
• pp.1-12
• /
• 2011

The purpose of this paper is to study pseudo-Riemannian algebras, which are algebras with pseudo-Riemannian non-degenerate symmetric bilinear forms. We nd that pseudo-Riemannian algebras whose left centers are isotropic play a curial role and show that the decomposition of pseudo-Riemannian algebras whose left centers are isotropic into indecomposable non-degenerate ideals is unique up to a special automorphism. Furthermore, if the left center equals the center, the orthogonal decomposition of any pseudo-Riemannian algebra into indecomposable non-degenerate ideals is unique up to an isometry.

• KIEAE Journal
• /
• v.9 no.3
• /
• pp.29-36
• /
• 2009

Interior material covering as the final process of house-building, critically influences not only aesthetic character but also air quality of indoor space. Wall covering today, however, caused a serious social problem because of chemicals contained in the industrial wallpaper and artificial glue. In this context, Korean traditional wall covering of Han-ji can be an alternative model due to it's ecological character. Recently 'Hanok' attracts public attention, since society and people become to appreciate the unique beauty and value of our traditional culture. The values include natural beauty, emotional character, and environment-friendliness. Recognizing this, this paper intended to scrutinize the operating process of Han-ji as an interior finish material. Historical research method was employed, tracing the related articles in old literature and interviewing with the witness of the experienced expert. Thereby, healthier and unique aesthetic indoor environment can be expected to be sustainable along with the rich cultural life of ancestors.

• Korean Journal of Mathematics
• /
• v.16 no.3
• /
• pp.355-362
• /
• 2008

We prove the existence of a unique positive solution for a class of systems of the following nonlinear suspension bridge equation with Dirichlet boundary conditions and periodic conditions $$\{{u_{tt}+u_{xxxx}+\frac{1}{4}u_{ttxx}+av^+={\phi}_{00}+{\epsilon}_1h_1(x,t)\;\;in\;(-\frac{\pi}{2},\frac{\pi}{2}){\times}R,\\{v_{tt}+v_{xxxx}+\frac{1}{4}u_{ttxx}+bu^+={\phi}_{00}+{\epsilon}_2h_2(x,t)\;\;in\;(-\frac{\pi}{2},\frac{\pi}{2}){\times}R,$$ where $u^+={\max}\{u,0\},\;{\epsilon}_1,\;{\epsilon}_2$ are small number and $h_1(x,t)$, $h_2(x,t)$ are bounded, ${\pi}$-periodic in t and even in x and t and ${\parallel} h_1{\parallel}={\parallel} h_2{\parallel}=1$. We first show that the system has a positive solution, and then prove the uniqueness by the contraction mapping principle on a Banach space

• Proceedings of the Polymer Society of Korea Conference
• /
• 2006.10a
• /
• pp.278-278
• /
• 2006

Polymer architectures containing metal-ligands in their side chain represent a diverse approach to generating multi-functional materials. The ability to define a versatile synthetic platform will enable many chemistries and architectures to be studied. This report describes our latest efforts to prepare these unique polymers; random and block copolymers have been successfully prepared. Subsequent functionalization with metal ions leads to a variety of properties including metal induced gelation, solvochromic and metal ion sensors, and unique hierarchical self-assembled structures.

• East Asian mathematical journal
• /
• v.24 no.1
• /
• pp.81-95
• /
• 2008

Let E be a uniformly convex Banach space with a uniformly $G{\hat{a}}teaux$ differentiable norm, C a nonempty closed convex subset of E, and $T\;:\;C\;{\rightarrow}\;E$ a nonexpansive mapping satisfying the weak inwardness condition. Assume that every weakly compact convex subset of E has the fixed point property. For $f\;:\;C\;{\rightarrow}\;C$ a contraction and $t\;{\in}\;(0,\;1)$, let $x_t$ be a unique fixed point of a contraction $T_t\;:\;C\;{\rightarrow}\;E$, defined by $T_tx\;=\;tf(x)\;+\;(1\;-\;t)Tx$, $x\;{\in}\;C$. It is proved that if {$x_t$} is bounded, then $x_t$ converges to a fixed point of T, which is the unique solution of certain variational inequality. Moreover, the strong convergence of other implicit and explicit iterative schemes involving the sunny nonexpansive retraction is also given in a reflexive and strictly convex Banach space with a uniformly $G{\hat{a}}teaux$ differentiable norm.