• Korean Journal of Mathematics
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• v.17 no.2
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• pp.197-210
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• 2009

We prove the existence of multiple solutions (${\xi},{\eta}$) for perturbations of the elliptic system with Dirichlet boundary condition $$(0.1)\;\begin{array}{lcr}A{\xi}+g_1({\xi}+ 2{\eta})=s{\phi}_1+h\;in\;{\Omega},\\A{\xi}+g_2({\xi}+ 2{\eta})=s{\phi}_1+h\;in\;{\Omega},\end{array}$$ where $lim_{u{\rightarrow}{\infty}}\frac{gj(u)}{u}={\beta}_j$, $lim_{u{\rightarrow}-{\infty}}\frac{gj(u)}{u}={\alpha}_j$ are finite and the nonlinearity $g_1+2g_2$ crosses eigenvalues of A.

• Bulletin of the Korean Mathematical Society
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• v.52 no.3
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• pp.907-914
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• 2015

In this paper, we consider a viscoelastic plate equation with p-Laplacian $u^{{\prime}{\prime}}+{\Delta}^2u-div({\mid}{\nabla}u{\mid}^{p-2}{\nabla}u)+{\sigma}(t){\int}_{0}^{t}g(t-s){\Delta}u(s)ds-{\Delta}u^{\prime}=0$. By introducing suitable energy and Lyapunov functionals, we establish a general decay estimate for the energy, which depends on the behavior of both ${\sigma}$ and g.

• 한국IT서비스학회:학술대회논문집
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• 2009.05a
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• pp.3-7
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• 2009

최근 우리 사회는 유비쿼터스 컴퓨팅 기술의 발전과 지자체별 u-City 건설 붐에 힘입어 도시민의 삶의 질 개선과, 도시관리 기능의 효율화를 위한 차세대 서비스 사업이 활발히 전개되고 있다. 반면 유비쿼터스 사회에서의 기술 수명주기의 단축과 시장의 급변은 사업 전개에 있어 커다란 부담으로 작용하고 있어 사업 계획 단계에서부터 사업의 타당성에 대한 충분한 고려가 필요하다. 본 논문은 과거의 전통적인 Business로부터 u-Business로의 진화과정을 살펴보고 기술의 발전과 가치의 변화에 따른 u-Business의 성공요인과 u-City 사업의 특징 분석을 바탕으로 u-City 사업 계획 단계에서 적용 가능한 u-City Business Model의 사업타당성 평가지표를 도출하고자 한다.

• Asia pacific journal of information systems
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• v.12 no.4
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• pp.37-53
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• 2002

The three main purposes of this paper are to (1) identify critical success factors(CSF's) for electronic commerce(EC), (2) investigate the explanatory power of these CSF's on firm performance, and (3) compare differences in evaluating CSF's and explaining impact of CSF's on performance between Korean and U.S.A. EC managers. Through a literature review and interviews with managers in EC firms, a list of 16 CSF's consisting of 111 items was compiled. In the second stage, questionnaires were administered to managers of EC companies in Seoul, Korea and Texas, U.S.A. Survey results show that CSF's have very significant explanatory power for firm performance in both Korean and U.S.A. While security, privacy, technical expertise, information about goods/services, and variety of goods/services are the most explanatory CSF's in Korea, evaluation of EC operations, technical expertise, and ease of use show most explanatory power in U.S.A. This analysis confirms the fact that customers use EC if they feel comfortable about navigating EC for information about a variety of goods/services without technical difficulty and in a secure and private way.

• Journal of Korean Elementary Science Education
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• v.33 no.2
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• pp.231-241
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• 2014

This study is subject to compare the STEAM and the STEM education of Korea, the U.K., and the U.S. to find their differences and similarities, as well as the implications in implementing the STEAM education in Korea. In order to accomplish this, the educational objectives, contents and topics, teaching and learning methods, subjects and timing for education, and convergence curriculum were compared; also, after choosing the representative program of each country, a cross-comparative analysis was done for the teaching and learning method distribution ratio, content element distribution ratio, program distribution ratio, STEAM domain ratio, curriculum structure and domain ratio, frequency of inquiry process, basic inquiry, integrated inquiry frequency, hourly basic inquiry, and integrated inquiry process. As a result, it was possible to obtain 77 programs, a total of 656 class hours of Korea, 65 programs and 846 class hours of the U.S., and 75 programs and 774 class hours of the U.K. The results are as follows: Korea's STEAM and the U.K. and the U.S.' STEM all include science, technology, engineering, arts, and mathematics, but in terms of frequency, Korea's STEAM has higher figure in arts. However, the U.K. and the U.S. have higher frequency of debate and discussion, and there were many cases of a student, after receiving feedback from other students, modifying the work.

• Korean Journal of Agricultural Science
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• v.45 no.2
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• pp.308-316
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• 2018

The Korean government introduced the $6^{th}$ industrialization in the agricultural sector to increase farmers' income and value-added agricultural products. The U.S. government has also supported farmers' efforts to increase their income and value-added products in a similar way even though the $6^{th}$ industrialization is not the usual concept in the U.S. Especially, direct-to-consumer and intermediated marketing is one of the main methods to increase farmers' income and value-added agricultural products in the U.S. The purpose of this paper was to analyze direct-to-consumer and intermediated marketing in the U.S., through a survey and frequency analysis. The results of this study are as follows: First, U.S. farmers have shifted their concern and efforts from direct-to-consumer marketing to intermediated marketing because intermediated marketing may offer higher value-added agricultural products. However, consumers' perception and interest are higher for direct-to-consumer marketing than for intermediated marketing of agricultural products and related services. Consumers also will increase the portion of consumption of agricultural products and related services through direct-to-consumer marketing. This difference between farmers and consumers may cause difficulties in increasing farmers' income and value-added agricultural products in the U.S. Korean farmers may have same problem in the future, even though they have not encountered it yet. Especially, the Korean government needs to develop the capabilities of farmers so that they can solve this problem.

• Strategy21
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• s.36
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• pp.94-120
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• 2015

The Asia-Pacific Region has emerged as a arena of geopolitical competition between the U.S. and China. The Obama administration of the U.S. had laid out the concept of rebalancing strategy toward the region, concentrating its 60 percent of Naval Forces to the region till 2020 and consolidating its network of allies and partners. Whereas Chinese leader Xi Jinping also put forward the concept of new type of major power relations concerning its relations with the U.S. and a concept of 'the Asian Community of Common Destiny' aiming at a more intensified mutual relation among countries in the region. In doing so, Asia-Pacific region gradually became the arena where mutual competition and cooperation between the U.S. and China has crossfired. As a close ally to the U.S. and a partner to Japan, South Korea should develop trilateral naval cooperation by holding joint naval drill with the aim of humanitarian support and disaster relief. At the same time, Seoul also should make efforts to proceed mutual confidence building with Beijing by deepening military-to-military cooperation. These policy options will be helpful to enhance Seoul's security posture in the region.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1997.12a
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• pp.206-212
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• 1997

• The Korean Journal of Financial Management
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• v.11 no.2
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• pp.195-221
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• 1994

This study investigates the wealth effect of foreign acquisition of U.S. based firms. Contrary to previous studies, this analysis demonstrates that after appropriate control of domestic-acquired targets, the wealth gains to the shareholders of targets in foreign takeovers are similar to those in domestic takeovers. This paper investigates the validity of the competitive acquisition market in cross-border takeovers and concludes that : 1) in cases of inward foreign direct investment into the U.S., foreign firms do not realize significant net benefits from acquisitions; and 2) the foreign acquirer is as well informed as its U.S, counterparts about the target's market. The results of this study are consistent with the view that each country has different motivations for investing in the U.S. market. Consider, for example, Japan. The evidence suggests that Japanese companies pay a considerable price for U.S. targets which have performed poorly before the takeover. While there is no specific rationale to explain why Japanese firms buy the most volatile and worst performing firms, international barriers may provide a possible reason for these anomalies. Overall, the evidence of this paper supports the view that foreign takeovers occur in a competitive acquisition market.

• Molecules and Cells
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• v.40 no.10
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• pp.761-772
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• 2017

Glioblastoma is the most frequent and most aggressive brain tumor in adults. Solute carrier family 8 member 2 (SLC8A2) is only expressed in normal brain, but not present in other human normal tissues or in gliomas. Therefore, we hypothesized that SLC8A2 might be a glioma tumor suppressor gene and detected the role of SLC8A2 in glioblastoma and explored the underlying molecular mechanism. The glioblastoma U87MG cells stably transfected with the lentivirus plasmid containg SLC8A2 (U87MG-SLC8A2) and negative control (U87MG-NC) were constructed. In the present study, we found that the tumorigenicity of U87MG in nude mice was totally inhibited by SLC8A2. Overexpression of SLC8A2 had no effect on cell proliferation or cell cycle, but impaired the invasion and migration of U87MG cells, most likely through inactivating the extracellular signal-related kinases (ERK)1/2 signaling pathway, inhibiting the nuclear translocation and DNA binding activity of nuclear factor kappa B ($NF-{\kappa}B$), reducing the level of matrix metalloproteinases (MMPs) and urokinase-type plasminogen activator (uPA)-its receptor (uPAR) system (ERK1/2-$NF-{\kappa}B$-MMPs/uPA-uPAR), and altering the protein levels of epithelial to mesenchymal transitions (EMT)-associated proteins E-cardherin, vimentin and Snail. In addition, SLC8A2 inhibited the angiogenesis of U87MG cells, probably through combined inhibition of endothelium-dependent and endothelium-nondependent angiogenesis (vascular mimicry pattern). Totally, SLC8A2 serves as a tumor suppressor gene and inhibits invasion, angiogenesis and growth of glioblastoma.