• The Journal of the Korea Contents Association
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• v.19 no.12
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• pp.565-572
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• 2019

Optimization of production system of polyester manufacturing companies is an important task for strengthening the competitiveness of the domestic polyester industry. The purpose of this study is to present a way to evaluate the goodness of the polyester manufacturing systems determined by the combinations of production facilities and to derive the optimal configuration of the production system. To this end, the criteria or factors for the evaluating polyester production system were derived and the Analytic Hierarchy Process (AHP) was used. Using the AHP model, we derived weights on the criteria for evaluating polyester production system and drew priorities for the configurations of the production systems under consideration.

• KDI Journal of Economic Policy
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• v.17 no.4
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• pp.3-61
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• 1995

기업활동의 범세계화(汎世界化), WTO 출범 등으로 세계경제(世界經濟)의 통합(統合)과 무국경화(無國境化)가 진행되고 있다. 이에 따라 자본 고급인력 등 국제이동성(國際移動性)이 높은 자원들이 유동화(流動化)할 것이고, 그 결과 토지, 사회간접자본, 미숙련 노동력, '경기규칙', 사회 전반적인 과학기술수준, 문화 등 국제이동성(國際移動性)이 낮은 광의(廣義)의 생산요소(生産要素)들이 한 나라의 경제적 특성을 결정하고 경제 기반을 이룰 것이다. 무국경시대(無國境時代)에는 자원배분뿐 아니라 자원유치(資源幽致)가 한 나라의 경제성과에 큰 영향을 미칠 것이며, 따라서 자원유치가 경제운영의 중요한 과제로 등장할 것으로 예상된다. 자원의 국제적(國際的) 유동화(流動化)는 국제이동성(國際移動性)이 높은 생산요소들이 국제이동성이 낮은 생산요소들을 찾아 경제활동의 근거지를 선택하는 것이므로, 무국경시대(無國境時代)에는 저이동성(低移動性) 생산요소(生産要素)들의 양적(量的) 확충(擴充)및 질적(質的) 수준(水準) 제고(提高)를 통한 자원유치(資源誘致)의 가능성이 커지며, 따라서 일부 첨단기술산업의 육성보다는 전반적인 과학기술(科學技術) 수준(水準) 제고(提高)가, 소수의 고급인력 확보보다는 다수(多數) 미숙련(未熟練) 인력(人力)의 질적(質的) 수준(水準) 제고(提高)가 경제성과를 높이는 데 상대적으로 더 중요해진다. 또한 경제적(經濟的) 무국경화(無國境化)는 국적에 관한 속인주의(屬人主義)의 퇴조와 속지주의(屬地主義)의 보편화, 한 나라 국경 안에 상이한 특성을 가진 지방경제(地方經濟)들의 부상, 국내 산업들 사이의 산업연관관계(産業聯關關係) 약화(弱化) 등의 변화를 수반할 것으로 예상된다. 이같은 변화로 개방주의(開放主義) 및 무차별주의(無差別主義)의 확대(擴大)가 불가피하게 되고 특정 산업에 대한 정부지원 및 보호의 근거가 약화되는 반면, 자원배분의 참고단위로서 개별(個別) 경제주체(經濟主體)들의 중요성이 높아지며 그만큼 시장경쟁을 지배하는 '경기규칙(鏡技規則)'의 올바른 정립이 중요해진다. 그러므로 정부는 자원배분에 대한 개업을 축소하고, 저이동성(低移動性) 생산요소(生産要素)들의 양적 질적 수준 제고, 특히 '경기규칙(競技規則)'의 공정성(公正性) 및 투명성(透明性)을 높여야 한다. 즉 정부가 폐쇄성 높은 경제의 지배인으로부터 개방(開放)된 시장경제(市場經濟)의 후견인으로 바뀌어야 한다. 이것이, 시장질서(市場秩序)가 우리를 먹여 살리는 손이라는 인식이나 국제분업(國際分業)이 살 길이라는 확신이 부족한 우리 사회에 무국경시대(無國境時代)가 던지는 어려운 도전(挑戰)이다.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.05a
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• pp.88-95
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• 2001

VR(Virtual Reality)의 개념이 제조공학 분야로 확대 적용되면서 설계분야에서의 가상조형 (Virtual Prototyping), 제조분야에서의 가상제조시스템(Virtual Manufacturing System)이라는 새로운 형태의 제조 시스템 및 설계기술이 차세대 제조기술로서 발전해 오고있으며 이런 가상제조방법(Virtual Manufacturing)은 컴퓨터를 이용하며 생산과정에서 제품뿐만이 아니라 유한요소해석을 유용하여, 공정까지도 모의실험을 하며 생산성(manufacturability), 최종 형태(final shape), 잔류 응력(residual stress), 제품 수명 주기(life-cycle)등과 같은 요소들의 최적화 정보를 제공하게 된다. 본 연구에서는 이러한 가상제조방법을 구현하기 위한 기초적 단계로서 가상단조기계를 가상현실기법을 이용하여 모델링하고 Java를 이용하여 모델링된 단조기계를 제어하고 제조되는 단조물에 대한 내부 응력 및 형태변환을 유한 요소법을 이용하여 분석하고 분석된 단조물의 자료를 WEB상을 통하여 닥 수 있게 유한 요소 해석결과를 VRML언어로 변환하는 작업을 수행하였다.

• 한국해양학회지
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• v.29 no.4
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• pp.402-413
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• 1994

To understand the significance of urea in the pool size of nitrogenous nutrients and in nitrogen (N) requirements of primary producers in and estuarine system of Mankyung and Dongjin rivers nutrients, and urea decomposition rates between June 1992 and February 1994. Urea concentration during the study period ranged from undetectable to 12.5 ug-at. N 1/SUP -1/, contributing to 0-96% (mean of 11%) of the total nitrogenous nutrients in the study area. Urea comprised a major component of the total nitrogenous nutrients when concentration of total nitrogenous nutrients was low. Urea decomposition rates in the water column ranged from 0.02 to 5.77 nM h/SUP -1/, and netplankton was the major decomposer of urea. Vertical distributions of urea decomposition rates in the water column showed generally small variabilities (i.e. < 3 fold). The decomposition rates of urea in the MD estuary would supply 0.2 ∼88.4% of phytoplankton N requirements. The major contribution of urea to phytoplankton N requirements was found when phytoplankton production was low (<50 mg C m/SUP -2/d/SUP -1/).

• KDI Journal of Economic Policy
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• v.36 no.2
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• pp.137-174
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• 2014

This paper examines whether the TFP growth of the Korean economy slowed down in 2000s based on growth accounting, focusing on how sensitive the results are to the particular aspects of the growth accounting method. There has been no consensus on this issue as the previous studies have provided very diverse results due to the differences in the details of the growth accounting method. Main results of this paper are as follows. First, it is how to calculate the labor income of the self-employed that has the most significant impacts on the estimated TFP growth. Measuring capital stock also matters. Second, the TFP growth of the Korean economy appears to be sustained in 2000s when the extreme assumptions on the labor income of the self-employed are excluded and capital stock is measured by the most frequently-adopted method in the previous studies. For more reliable estimation of the TFP growth, further studies on measuring the labor income of the self-employed are needed.

• International Area Studies Review
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• v.22 no.4
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• pp.19-35
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• 2018

This paper is to estimate the total factor productivity(TFP) in the Korean manufacturing and service industries during the period 1975:1-2016:4 using the stochastic frontier analysis model. In order to analyze the determinants for the total factor productivity the paper estimates the industry-specific determinant elasticities of TFP using the autoregressive distributed model. The industry-specific determinants, which reflect the industrial structure and properties include markup, the ratio of capital to labor(KL), and the ratio of foreign intermediate goods (FIG) to industrial output. The average value for total factor productivity growth was estimated to be 0.0199 in manufacturing and 0.0063 in the service industry. The markup and KL elasticities of TFP were estimated to be 2.481 and 0.651 in manufacturing respectively and -1.403 and 0.042 in the service industry respectively. The empirical results suggest that the industrial markup and the ratio of capital to labor have had decisive effects on the changes in the total factor productivity in the Korean manufacturing and service industries during the period 1975:1-2016:4.

• Environmental and Resource Economics Review
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• v.27 no.1
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• pp.29-66
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• 2018

This study constructs an energy-extended KLEM DB of 35 Korean industries, and estimates the elasticities of substitution under various nesting structures of production technologies. Unlike most existing studies that employed only three inputs, K, L, and E, we applied a dual approach where non-energy intermediate input M is also incorporated as a production input. Our dual approach which extended that of van der Werf (2008)'s 3-input model successfully identified and estimated the multi-nested production functions. We provide the estimates of the elasticities of substitution among 4 different energy sources as well. Our estimation results would be used for energy-environment model building for Korea.

• Environmental and Resource Economics Review
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• v.28 no.3
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• pp.415-435
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• 2019

The purpose of this study is to analyze the returns to scale by estimating the bigeye tuna production function of Korean distant longline fisheries in WCFPC waters. In the analysis, number of crews, vessel tonnage, number of hooks, and bigeye tuna biomass are used as input variables and the catch amount of bigeye tuna is used as an output variable in the Cobb-Douglas production function. Prior to the function estimation, the biomass of bigeye tuna was estimated by the Bayesian state-space model. Results showed that the fixed effect model was selected based on the hausman test, and vessel tonnage, hooks, and biomass would have direct effects on the catch amount. In addition, it was shown that the bigeye tuna distant longline fisheries in WCFPC water would have increasing returns to scale.

• Environmental and Resource Economics Review
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• v.23 no.3
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• pp.453-472
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• 2014

Analyzing the effects of carbon emissions trading, which is scheduled to be introduced in Korea in 2015, requires an accurate assessment of $CO_2$ abatement costs by both industries and firms. Firms faced with regulatory constraints are unlikely to minimize their production costs due to rising production costs caused by allocative inefficiency of inputs. The use of a distance function would results in underestimation of $CO_2$ abatement costs, because it fails to capture the allocative distortion costs. Recognizing the disadvantage of the previous approach, first, this paper tests for allocative efficiency of input for the Korean steel industry over the period 1990-2010, then derives the marginal $CO_2$ abatement costs by applying a cost function approach. The hypothesis of allocative efficiency in inputs is rejected and the steel industry pays an annual average cost of 92,000 won in removing an additional ton of $CO_2$ over the sample period.

• International Area Studies Review
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• v.12 no.2
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• pp.99-123
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• 2008

In this paper, technology gap between Korea's manufacturing industries compared to technology frontier countries was estimated in order to take into account Korea's status as a technology follower country. Then by using this measure the role of technology gap was investigated in explaining total factor productivity growth of the Korean manufacturing at industry level. The main empirical findings are as follows: First, the conventional factors that were emphasized in the previous literature such as R&D intensity, trade openness and human capital play important role in explaining the growth rate of Korea's total factor productivity. Second, the larger the technology gap between Korea and technology leader country (and the faster the technology growth rate in the leader country), the higher the growth rate of total factor productivity in Korea as well. Third when the technology gap is large, the most efficient way of absorbing higher technology from frontier country seems to be the international trade channel rather than R&D or human capital accumulation.