• Journal of Life Science
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• v.29 no.8
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• pp.895-903
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• 2019

The aim of the present study was to improve the cell viability of human dental papilla derived single-induced pluripotent stem cells (iPSCs) using a Rho-associated protein kinase (ROCK) inhibitor, Y-27632. The iPSCs were produced using an episomal plasmid-based reprogramming method. After cell separation using trypsin, the iPSCs were treated with 0, 0.5, 1, 2.5, 5, 7.5, or $10{\mu}M$ Y-27632 for 5 d. Cell viability increased significantly following the $5{\mu}M$ Y-27632 treatment (p<0.05). When the iPSCs were exposed to medium containing $10{\mu}M$ Y-27632 for 0, 1, 2, 3, 4, and 5 d, the cell viability rate increased significantly in accordance with the cell viability rate (p<0.05). To evaluate the effect of the Y-27632 treatment on stemness characteristics, the expression of stem cell-specific transcripts and telomerase activity were investigated in the iPSCs treated with $10{\mu}M$ Y-27632 for 5 d. The expression levels of stem cell-specific transcripts, such as OCT-4, NONOG, and SOX-2, and telomerase activity were not significantly different in the iPSCs treated with $10{\mu}M$ Y-27632 as compared with those of untreated control iPSCs (p>0.05). Taken together, the results demonstrated that cell viability can be improved by treatment with the ROCK inhibitor Y-27632, without losing iPSC stemness characteristics.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.289-292
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• 2008

본 연구에서는 u-City인력수급 전망을 토대로 국토해양부의 u-City 관련 인력양성에 대한 실천계획이 효율적으로 실행될 수 있는 방안을 제시하였다. u-City를 추진하는 지자체, 개발사업자마다 공통적으로 제기하는 문제점은 u-City 관련 고급 및 기능 인력의 절대적인 부족이다. 그러나 u-City 전문인력은 u-City건설의 특성상 도시계획 개발, 정보통신망, IT 등 다양한 분야에 대한 전문지식을 갖추어야하나 이러한 고급인력이 배출되고 있지 않다. 따라서 본 연구에서는 인력양성방안의 목표를 'u-City의 성공적인 추진에 부합하는 전문인력양성'으로 설정하였으며, 수요자 중심의 교육, 지역 균형적인 전문인력양성, u-City 관련 분야의 융 복합교육, u-City 관련 교육인프라 구축을 추진전략으로 수립하였다. u-City 인력양성의 추진목표 및 전략을 실행하기 위한 중점추진과제로는 'u-City건설 전문인력교육 관련 수요전망', '지역별 거점대학 선정을 통한 전문인력의 양성', 'u-City 인력양성센터 건립추진', '교육포탈을 통한 온라인 교육', '교육인프라 구축' 등 5개를 선정하였다. u-City 인력양성을 위한 추진전략의 성공적 실행을 위해서는 중점 추진과제들간의 유기적인 연계가 필수적이다.

• Journal of the Korean Wood Science and Technology
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• v.27 no.2
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• pp.38-45
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• 1999

This study was to figure out proper Formaldehyde/Urea molar ratio of UF resin with satisfactory bonding strength of plywood and properties of particleboard. The six kinds of UF resins were manufactured with F/U molar ratio 1.0, 1.2, 1.4, 1.6, 1.8, and 2.0. The boards were made of three kinds of raw materials : Veneer, Sliver-Particle and Strand-Particle. Manufacturing condition of plywood : amount of mixing resin was 150g/$m^2$. The fourty secs/mm simple-pressing schedule in the pressure 10kgf/$m^2$ was applied for 480mm${\times}$700mm board at the temperature of $110^{\circ}C$ in a hot press. Manufacturing condition of particleboard : Target density was 0.65g/$cm^2$. The stepwise 9 minutes- multi-pressing schedule in the maximum pressure 40kgf/$cm^2$, the minimum pressure 15kgf/$cm^2$ was applied for $480mm{\times}634mm{\times}12mm$ board at the temperature of $150^{\circ}C$ in a hot press. The results are as follows : I. In bonding strength, plywood which was made by F/U molar ratio 1.2 showed the highest value. Other molar ratio resin also gave the satisfied value of KS standard, 7.5kgf/$cm^2$. 2. In internal bond strength of particleboard, Sliver-Particleboard(SLPB) and Strand-Particleboard(STPB) varied respectively from 5.9kgf/$cm^2$ to 4.8kgf/$cm^2$, from 6.7kgf/$cm^2$ to 5.4kgf/$cm^2$. SLPB with F/U=1.2 and STPB with F/U=1.6 had higher IB value. Also, both SLPB and STPB showed lower IB value in F/U molar ratio 2.0 and 1.0. 3. SLPB and STPB with six kinds of UF resin respectively satisfied bending strength of KS standard 150 Type(130kgf/$cm^2$) and 200 Type(180kgf/$cm^2$). Bending strength data for both of SLPB and STPB showed little or no loss from F/U=1.8 to F/U=1.2. Also, STPB was approximately two times higher than that of SLPB. Therefore, the raw material's shape had more effect on bending strength than the FlU molar ratio. 4. F/U=1.6 and 1.4 showed the lower thickness swelling in SLPB and STPB. All of STPBs satisfied thickness swelling of KS standard, under 12%.

• Journal of applied mathematics & informatics
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• v.33 no.5_6
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• pp.593-605
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• 2015

In this study, we define r-circulant, circulant, Hankel and Toeplitz matrices involving the integer sequence with recurrence relation U_n = pU_n-1 + U_n-2, with U₀ = a, U₁ = b. Moreover, we obtain special norms of above mentioned matrices. The results presented in this paper are generalizations of some of the results of [1, 10, 11].

• 한국IT서비스학회:학술대회논문집
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• 2009.11a
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• pp.202-206
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• 2009

u-City사업은 완성까지 5년 이상이 소요되는 대형 장기사업으로, 정보시스템 개발 및 정보통신공사가 동시에 이루어지는 복합공종 사업이다. 이러한 대규모 사업을 차질없이 수행하기 위해 u-City사업에는 감리도 동시에 수행된다. 그러나 u-City감리는 아직 단일화된 감리기준이 없어 정보시스템 감리기준 및 정보통신공사감리 업무수행지침이 각각 적용되고 있으며, 이로 인해 감리 현장에서는 통일된 일정계획 수립이 어렵고, 업무 분장이 불명확하여 감리대상 일부가 누락되는 경우도 발생한다. 본 논문에서는 정보시스템 감리기준 및 정보통신공사감리 업무수행지침으로 이원화된 감리기준으로 인해 발생되는 문제점들을 살펴보고 이의 개선방향을 제시하였다.

• Economic and Environmental Geology
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• v.36 no.3
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• pp.225-232
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• 2003

Three piston cores. obtained from the northwestern Ulleung Basin of the East Sea, are analyzed to study the tephrostratigraphy of the late Quaternary core sediments and to reveal the comparative characteristics of the tephra layers. The cores consist mainly of the muddy sediments that are partly interbedded with lapilli tephra and ash layers. The muds are further divided into hemipelagic and turbiditic mud facies. The hemipelagic facies is dominated by bioturbated mud and crudely laminated mud, whereas the turbiditic facies includes mainly thinly laminated mud and homogeneous mud, and often alternates with non-turbiditic muds. According to microscopic observation and EDX analysis, three tephra layers of the Ulleung-Oki (U-Oki; ca. 9.3 ka), Aira-Tanzawa (AT: ca. 22~24.7 ka) and Ulleung-Yamato (U-Ym; ca. 25~33 ka) are identified in the study cores. Among these, the U-Oki and U-Ym layers, originating from the Ulleung Island, consist mainly of massive-type glass shards with alkali feldspar. Both of the tephra layers contain a lower content of SiO$_2$ (57~66.5 wt.%) and a higher content of Na$_2$O+K$_2$O (11~16 wt.%) than the AT layer (SiO$_2$=75~78.5 wt.%, Na$_2$O+K$_2$O=6.5~9 wt.%) that consists of typical plane-type and/or bubble-wall glass grains. Compared with that of the U-Ym layer, a sedimentary facies of the U-Oki layer is very thick and contains three stratigraphic units, probably due to relatively large and different supplies of pyroclastic sediments. Thus, the eruption of Ulleung Volcano (ca. 7,300 B.C.) is thought to have had a more powerful effect on depositional environment than the U-Ym eruption.

• Korean Journal of Veterinary Research
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• v.31 no.1
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• pp.11-18
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• 1991

The purpose of this study was designed to investigate the methods for the functional elevations of sperm-host (utero-vaginal, U-V) glands in domestic hens. The laying hens were assigned to five groups of low-, medium-, high- fecundity, gonadotrophin-, and caffeinetreated hen groups, these group hens were sacrified at interval after last artificial inseminations (AI). Number of U-V gland observed in tissue preparation of each hen U-V region were investigated, and also the appearance rates of spermatozoa-contained U-V glands were calculated. 1. In low-fecundity hen groups, the appearance rates of spermatozoa-contained U-V glands were found to be 13.5, 15.6, 11.8, 13.6, 2.3, 0, and 0% respectively at the hens of 1, 3, 7, 10, 13, 16, and 19 days after AI. 2. In medium-fecunditiy hen groups, the appearance rates of spermatozoa-contained U-V glands were found to be 21.7, 22.7, 13.4, 10.4, 10.0, 7.7 and 0% respectively at the hens of 1, 3, 7, 10, 13, 16, and 19 days after AI. 3. In high-fecundity hen groups, the appearance rates of spermatozoa-contained U-V glands were found to be 30.8, 31.8, 28.9, 13.0, 10.3, 10.8, and 0.9 respectively at the hen of 1, 3, 7, 10, 13, 16, and 19 days after AI. 4. In gonadotrophin-treated hen groups, the appearance rates of spermatozoa-contained U-V glands were found to be 31.8, 33.7, 32.3, 17.3, 12.0, 5.0, and 1.0% respectively at hens of 1, 3, 7, 10, 13, 16, and 19 days after AI. 5. In caffeine-treated hen groups, the appearance rates of spermatozoa-contained U-V glands were found to be 33.2, 29.2, 22.4, 17.8, 12.7, 0, and 1.1% respectively at hens of 1, 3, 7, 10, 13, 16, and 19 days after AI. 6. The appearance rates of completely filled U-V glands and partially filled U-V glands of spermatozoa-contained U-V glands were found to be 3.8:1. So we suggested as follows: The appearance rates of spermatozoa-contained glands tend to be high from 1 day after AI to 7 days and tend to declined rapidly from 10 days. Also higher fecundity hen groups tend to be higher in the appearance rates and longer in spermatozoa-contained duration in U-V glands than in lower fecundity hen groups. Gonadotrophin hormone tend to increase the appearance rates of spermatozoa-contained U-V glands than those in control group, whereas caffeine tend to increase those rates at 1 day and to declined more rapidly from 3 day than in control group.

• Journal of the Korean Mathematical Society
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• v.37 no.5
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• pp.665-685
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• 2000

The aim of this paper is to obtain nonlinear operators in suitable spaces whise fixed point coincide with the solutions of the nonlinear boundary value problems ($\Phi$($\upsilon$'))'=f(t, u, u'), l(u, u') = 0, where l(u, u')=0 denotes the Dirichlet, Neumann or periodic boundary conditions on [0, T], $\Phi$: N N is a suitable monotone monotone homemorphism and f:[0, T] N N is a Caratheodory function. The special case where $\Phi$(u) is the vector p-Laplacian $\mid$u$\mid$p-2u with p>1, is considered, and the applications deal with asymptotically positive homeogeneous nonlinearities and the Dirichlet problem for generalized Lienard systems.

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

• East Asian mathematical journal
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• v.32 no.5
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• pp.659-675
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• 2016

In this paper, we study the generalized Kirchhoff type equation in the presence of past and finite history $$\large u_{tt}-M(x,t,{\tau},\;{\parallel}{\nabla}u(t){\parallel}^2){\Delta}u+{\normalsize\displaystyle\smashmargin{2}{\int\nolimits_0}^t}\;h(t-{\tau})div[a(x){\nabla}u({\tau})]d{\tau}\\\hspace{25}-{\normalsize\displaystyle\smashmargin{2}{\int\nolimits_{-{\infty}}}^t}\;k(t-{\tau}){\Delta}u(x,t)d{\tau}+{\mid}u{\mid}^{\gamma}u+{\mu}_1u_t(x,t)+{\mu}_2u_t(x,t-s(t))=0.$$ Under the smallness condition with respect to Kirchhoff coefficient and the relaxation function and other assumptions, we prove the expoential decay rate of the Kirchhoff type energy.