• Journal of Technology Innovation
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• v.17 no.1
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• pp.69-95
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• 2009

This paper examines the motives for location decisions of startups and dynamics of cluster growth. Because the location decision is intrinsically strategic choice by entrepreneurs, it is an interplay of three critical forces; cost-benefit of the choice, R&D ability of new entrants, and R&D capability of incumbents in clusters. The effect of knowledge spillovers influences the cluster growth like a double-edge sword; both a positive effect of technology learning and a negative effect of knowledge de-learning. Using data on 710 bio-tech venture firms in Korea, this paper tests the hypotheses about the factors influencing the growth of the cluster. The empirical analyses suggested that early entrepreneurial activity in the clustered regions were important, however other factors such as the organizational legacy, internal dynamics inside a cluster, and the existence of cooperation norm in the cluster, affected long term viability of the cluster.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.6
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• pp.47-64
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• 2014

Considering the network externality and spill-over effects, this paper constructs the theoretical model for analyzing the financial policies focusing on the credit guarantee system for Creative Economy, which has been set as the new policy paradigm for the Korean Economy. The analytical results show that it is as much as important to improve the efficiency of the financial markets and construct the infrastructure for reducing the information asymmetry problem which would be more serious in the creative finance. Although it is important to fill the gap due to the market failure it is also crucial to construct the appropriate financial schemes for the various stages of the innovative firms growth. Without these, the impacts of current public funding policies may crowd out the amount of private market funds for the innovative firms or reduce the possibility of commercialization of new technologies in these firms. Based on the evaluation of current related public policies from the perspectives of creative finance, we imply that the current financial policies appear to be quantity oriented not the quality based. Although the policy goals would be appropriately set for vitalizing the Creative Economy in Korea, they appear to be still unsuccessful to address the information asymmetry issue which is the major concern in vitalizing the creative economy. Thus we emphasize the market friendly policies, risk-sharing between the various market participants, revitalizing the relationship banking and efficient management of credit guarantee system in Korea based on the analytical model as well as the evaluation of related policies regarding the creative economy.

• Journal of Korea Game Society
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• v.10 no.5
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• pp.87-94
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• 2010

This research investigated the relationship between MMORPG players' leadership-related game experience and offline leadership using online survey samples(N=664). According to the correlation results, MMORPG players' leadership-related game experience, age, game usage time and offline leadership exhibited a significantly positive relationship. When players had more leadership-related game experience, they reported higher offline leadership scores. In terms of "spillover effect", more valuable implications of using MMORPGs are discussed in conclusion.

• Korean Journal of Organic Agriculture
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• v.27 no.4
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• pp.391-408
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• 2019

The purpose of this study is to analyze the spillover effect of R & D investment focusing on agriculture sector. Therefore, the Korean industry is divided into 18 industries and the data period including 1970 ~ 2014 is analyzed. In addition, the method is based on the analysis of the production function, the growth contribution of the production factor, and the spillover effect of other industries that affect the agricultural output. The results of this study are summarized as follows. First, R & D investment has a positive effect on the production of Korean agriculture. Second, the impact of high tech industry R & D investment on Korean agriculture is positive. Third, the R & D investment in the public sector is relatively higher than the R & D investment in the private sector. In the R & D stage, the R & D investment of the first level technology has a great influence on the production of agriculture. As a result of this study, governments should consider the above mentioned research results to determine resource priorities based on limited resources in relation to R & D investments that contribute to production and economic growth.

• The Korean Journal of Nuclear Medicine
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• v.31 no.1
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• pp.73-82
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• 1997

Regional myocardial blood flow (rMBF) can be noninvasively quantified using N-13 ammonia and dynamic positron emission tomography (PET). The quantitative accuracy of the rMBF values, however, is affected by the distortion of myocardial PET images caused by finite PET image resolution and cardiac motion. Although different methods have been developed to correct the distortion typically classified as partial volume effect and spillover, the methods are too complex to employ in a routine clinical environment. We have developed a refined method incorporating a geometric model of the volume representation of a region-of-interest (ROI) into the two-compartment N-13 ammonia model. In the refined model, partial volume effect and spillover are conveniently corrected by an additional parameter in the mathematical model. To examine the accuracy of this approach, studies were performed in 9 coronary artery disease patients. Dynamic transaxial images (16 frames) were acquired with a GE $Advance^{TM}$ PET scanner simultaneous with intravenous injection of 20 mCi N-13 ammonia. rMBF was examined at rest and during pharmacologically (dipyridamole) induced coronary hyperemia. Three sectorial myocardium (septum, anterior wall and lateral wall) and blood pool time-activity curves were generated using dynamic images from manually drawn ROIs. The accuracy of rMBF values estimated by the refined method was examined by comparing to the values estimated using the conventional two-compartment model without partial volume effect correction rMBF values obtained by the refined method linearly correlated with rMBF values obtained by the conventional method (108 myocardial segments, correlation coefficient (r)=0.88). Additionally, underestimated rMBF values by the conventional method due to partial volume effect were corrected by theoretically predicted amount in the refined method (slope(m)=1.57). Spillover fraction estimated by the two methods agreed well (r=1.00, m=0.98). In conclusion, accurate rMBF values can be efficiently quantified by the refined method incorporating myocardium geometric information into the two-compartment model using N-13 ammonia and PET.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.5
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• pp.377-385
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• 2008

In this study, we demonstrated that, although hydrogen molecules can be adsorbed onto the adsorbent such as MOF and MC itself, the loading of noble metal such as Pt is necessary to enhance the $H_2$ storage capacity since $H_2$ molecules can be dissociatively adsorbed on Pt metal and migrated to high-surface-area adsorbent via the primary spillover. In addition, the hybrid material have been prepared coupling MOF-5 with Pt/MC through carbon bridges formed by sucrose polymerization/carbonization. That this material showed the highest $H_2$ uptake at room temperature and about 100 bar is believed to be associated with the secondary spillover effect. Thus, such a strategy is very promising in developing $H_2$ storage technology using porous adsorbents. However, further experiments should be carried out to explore the choice of bridge carbon, the hybridization method, the dispersion technique of noble metals, etc.

• Applied Chemistry for Engineering
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• v.34 no.6
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• pp.674-678
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• 2023

The effect of Pt was investigated to the catalytic methane decomposition of CH₄ to H₂ over Pt(1)-Fe(30)/MCM-41 and Fe(30)/MCM-41 using a fixed bed flow reactor under atmosphere. The Fe₂O₃ and Pt crystal phase behavior of fresh Pt(1)-Fe(30)/MCM-41 were obtained via XRD analysis. SEM, EDS analysis, and mapping were performed to show the uniformed distribution of nano particles such as Fe, Pt, Si, O on the catalyst surface. XPS results showed O^2-, O^- species and metal ions such as Pt⁰, Pt²⁺, Pt⁴⁺, Ft⁰, Fe²⁺, Fe³⁺ etc. When 1 wt% of Pt was added to Fe(30)/MCM-41, automic percentage of Fe2p increased from 13.39% to 16.14%, and Pt4f was 1.51%. The yield of hydrogen over Pt(1)-Fe(30)/MCM-41 was 3.2 times higher than Fe(30)/MCM-41. The spillover effect of H₂ from Pt to Fe increased the reduction of Fe particles and moderate interaction of Fe, Pt and MCM-41 increased the uniform dispersion of fine nanoparticles on the catalyst surface, and improved hydrogen yield.