• Journal of the Economic Geographical Society of Korea
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• v.12 no.4
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• pp.627-644
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• 2009

In the knowledge-based economy highlighting the importance of human capital, there has been a growing interest in human capital externalities as a fundamental engine of growth and development of a region. The purpose of this study is to analyze human capital externalities using 3-level hierarchical linear model(3-HLM), decomposing determinants of wages into three levels involving workers(level-1) nested within firms(level-2) nested within regions(level-3). This study separately estimates the effect of the average education level on the wages by three different schooling groups on the assumption that the intensity of knowledge spillovers varies with each group's schooling level. The main results are as follows; First, the coefficient of the average education level of a region shows 0.044, indicating that one-year increase in the average level of schooling could increase average individual earnings by 4.4%. Secondly, the external effects of human capital on three different schooling groups are considerably different, raising less than high school graduates' wages by 3.0%, college graduates' wages by 4.7%, and graduate schools' wages by 11.8%, respectively. Thirdly, well educated workers are much more sensitive to the variation of the regional education level than less educated ones when we apply the shares of each schooling group as alternative measures for the average level of education. Such findings of this study draw an implication that local governments could speed up regional economic growth in the knowledge-based economy by not only raising total human capital stock in a region but building the close networks that promote productivity-enhancing human capital external effects.

• Journal of Digital Convergence
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• v.16 no.2
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• pp.93-102
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• 2018

This study suggests external knowledge search as a way of creating knowledge and efforts for reaching out to the innovation and examines the relationship between innovation speed and the breadth and depth of external knowledge search. As a part of efforts to overcome the limitations of the routines of external knowledge search in the domestic market, the efforts of a firm to enter the foreign market have been examined with a moderate effect. Although previous research focused on exploration of external knowledge that is mostly effected in single country or similar industry, this study expands it by introducing the concept of market expansion and empirically inspect the interaction effect. 818 valid samples used in this study are based on the innovation survey published by STEPI and empirical results are as follows. First, the breadth and depth of external knowledge search have a positive impact on innovation speed. Second, export performance as the effect of expanding the market has a moderating effect on the speed of innovation. Third, younger companies prefer various networks while older companies prefer depth networks in order to increase the speed.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.3
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• pp.178-186
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• 2005

In this study, the PSC girder bridge retrofitted with external tendons is tested to verify the strengthening effects. We measure the variations of the displacement and strain at mid-span of each beam as external tendons are removed in sequence. The structural behavior of the bridge are examined using controlled truck load tests for the systems before and after all external tendons were removed. From the test results, the characteristics of structural behavior of the bridge do not change significantly, but the natural frequency is decreased after the external tendons are removed. The strengthening effects of bridges can be exactly estimated by analytical methods some extent. As a result of this study, when a PSC girder bridge is deteriorated, the bridge can be retrofitted effectively by External Prestressing Strengthening Method, and the strengthening effects can be predicted through accurate structural analysis.

• Journal of Korea Technology Innovation Society
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• v.21 no.3
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• pp.1077-1100
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• 2018

The present study analyzed the effect of firms' external research and development (R&D) on corporate productivity, while investigating the moderating effect of firm size on the external R&D-productivity nexus. In the empirical analysis, we estimated South Korean manufacturing firms' total factor productivity (TFP) using the firm level data drawn from the Survey of Business Activities (Korea National Statistical Office) for the years 2006-2015. Thereafter, focusing on the role of external R&D and its interaction with the firm size in determining firms' TFP, the productivity function was estimated as well. To this end, we used ordinary least squares (OLS) and quantile regression to highlight the heterogeneous impacts of external R&D by companies' productivity level. Empirical results confirmed that firms' external R&D significantly enhanced corporate productivity in all manufacturing industries, from high-tech to low-tech. The moderating effect of firm size in determining the productivity effect of external R&D was not as prominent as in the case for internal R&D, which exhibited some degree of the size premium in the productivity-enhancing effect. These results suggest that regardless of the firm size, external R&D can be an important channel for corporate productivity improvement, and can be a particularly effective strategy for SMEs with relatively limited internal R&D capacities.

• KDI Journal of Economic Policy
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• v.30 no.2
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• pp.27-59
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• 2008

This paper empirically investigates the finance-growth linkage in Korea by utilizing firm-level data of manufacturing industries before and after the 1997 financial crisis. We find that, first, an increase in external finance is associated with a faster subsequent capital accumulation of firms. However, this capital accumulation channel became relatively attenuated after the crisis. Second, the total factor productivity growth effect of external finance has been considerably weak both before and after the crisis. Third, the information production and industry restructuring effects of external finance have also remained weak after the crisis. The limited role of external finance in post-crisis Korea partially reflects sluggish corporate investment and weakening dependence of good credit firms on external finance. The evidence suggests that, in order to effectively sustain economic growth, further reform efforts may be required to strengthen resource allocation and corporate restructuring roles of financial markets and institutions.

• Environmental and Resource Economics Review
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• v.9 no.1
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• pp.1-23
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• 1999

배출권거래제도의 비용절감효과를 분석함에 있어 요소간 대체가능성 등 외부환경 변화에 대한 기업의 적응도를 반영하지 않은 공학적 추정치는 그 신뢰성에 한계가 있다. 또한 경제학적 분석방식을 시도한 연구의 대부분이 외부거래만을 대상으로 해온 반면에 거래실적의 다수를 차지하고 있는 내부거래에 대한 연구는 미미한 실정이다. 본 연구에서는 Gollop and Roberts (1985)의 경제학적 추정모형을 이용하여 미국 석탄발전소를 대상으로 $SO_2$ 배출권에 대한 내부거래의 비용절감정도를 측정한 후 효과의 크기 변에서 외부거래와의 차이를 규명하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.519-521
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• 2023

온라인 뉴스 플랫폼의 발전은 에코 챔버(echo chamber) 효과와 정치적 양극화를 심화시키며, 이를 완화하기 위한 선행 연구로 뉴스 기사의 정치적 성향을 판단하는 연구가 필요하다. 기존 연구는 외부 지식 그래프를 활용하여 뉴스 기사의 텍스트 정보를 더욱 풍부하게 표현한다. 그러나, 외부 지식을 임베딩하는 지식 그래프 임베딩(knowledge graph embedding, KGE) 방법은 다양하며, 각 KGE 방법이 정치적 성향 예측 정확도에 미치는 효과에 대해서 충분히 연구되지 않았다. 본 논문에서는 정치적 성향 예측에 외부 지식의 활용을 최대화하기 위한 다양한 KGE 방법들의 효과를 분석한다. 실험 결과, 외부 지식 그래프 내의 개체들 간 복잡한 관계를 간단하고 정확하게 표현 가능한 ModE 방법을 활용하는 것이 정치적 성향 예측에 가장 효과적이라는 것을 확인하였다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.3
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• pp.40-47
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• 2013

Most experiments carried out in the previous studies dealt with the highly reinforced concrete beams (RC beams) in case of rehabilitating with external tendon. However, the reinforcing effect of external tendons cannot be clearly analyzed in this kind of RC beams because the rehabilitating tendon quantity for it is too small. By this reason, this study chose the low RC beams rehabilitated with external tendons. Therefore, in this study, 7 test beams were manufactured and flexural behavior tests were performed to assess the reinforcing effect and to find more proper rehabilitating method by external tendon. The reinforcing effect increased according to the quantity of tendons, and was especially added by repairing cracks with epoxy resin. It was shown that the design equations of AASHTO 1994 and ACI-318 did not show a good agreement with test results. The result of this study will be able to be used effectively in finding the more proper rehabilitating method of the damaged RC beams.

• International Commerce and Information Review
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• v.15 no.3
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• pp.3-24
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• 2013

This study has examined the relationship between entrepreneurial orientation(EO), dynamic capability(DC) and export performance of international new ventures(INVs). Also, the moderating effect of external environment factors(the hostility at domestic markets and the industrial dynamics) were analysed. Empirical analysis was performed on 101 INVs. It was conducted using the PLS(Partial Least Square). The result of empirical analysis showed that there is a positive relationship between EO, DC and export performance. The result of moderating effect showed that two external environment factors have positive moderating effect on the relationship between EO and DC. However, there was not moderating effect of external environment factors on the relationship between DC and export performance.

• Korea Trade Review
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• v.41 no.2
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• pp.29-60
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• 2016

Research and Development(R&D) investment is an issue of central importance in any economy. In this paper we analyze the relationship between R&D spillovers and trade-related variables, using a two-stage model where duopolists simultaneously decide on R&D in the first stage and engage in Cournot competition in the second stage. We characterized and compared the free-trade and trade-restriction R&D equilibrium in a two-stage game of R&D investment followed by Cournot market competition. We also assessed the impact of varying the R&D spillover on the equilibrium outcomes and tariff. We showed for both free trade and protection cases that there exists a unique symmetric solution(subgame perfect Nash equilibrium). As the solution, while analytical, cannot be stated in closed form, we resorted to numerical experiments to investigate the equilibrium results. Our estimates indicate for both free trade and protection cases that the level of R&D investment and the rate of R&D expenditure decrease as the degree of R&D spillovers increases, and that there is an inverse relation between the degree of R&D spillovers and level of protection. The latter implies that the larger the degree of R&D spillovers, the lesser the level of protection.