• 대한산업공학회지
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• 제36권3호
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• pp.186-192
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• 2010

The present study classified the auto-parts makers into four groups according to their investment ownership. Four groups consist the one fully owned by Koreans, the one fully owned by foreigners, the one owned less than 100% but more than 50% by foreigners, lastly the one owned by less than or equal to 50% by foreigners. Among these, the auto-parts makers, 100% foreign ownership, have the highest Malmquist productivity index while 100% Korean-owned part-makers has the lowest productivity. In case of the 100% foreign ownership companies, the cause of Malmquist change, however, is attributed to the technical efficiency change. In particular, the pure technical change is the main source of the Malmquist change. This may indicate that the 100% foreign-owned companies have successfully transferred their production process technologies to the Korean plants. They are enjoying so called the "imitation-effect." 100% Korean-owned companies were not able to create the "imitationeffect" and therefore failed to close the gap with the foreign-owned companies in terms of the production efficiency. 100% Korean-owned auto-parts makers, however, outperformed the foreign-owned companies in the technological change. The outstanding technological change may indicate that Korean-owned part makers were able to narrow the gap with the foreign-owned companies in the area of engineering technological capabilities. The same results were also observed for 50% foreign-owned companies. Knowing that the core competence of the auto-parts makers lies on the engineering technological capabilities, the research found that the most desirable form of the foreign investment was 50% of foreign ownership.

• 디지털융복합연구
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• 제20권5호
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• pp.375-381
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• 2022

본 연구는 중국 30개 성시를 연구 대상으로 하여 정태적, 동태적 두 가지 각도에서 연구의 시발점으로 하였으며, DEA-BCC 모델과 Malmquist 지수를 사용하여 2011~2020년 중국 30개 성시의 환경 효율성을 산정하였다. 연구에 따르면 중국 30개 성시의 정태 환경 효율성은 평균 0.643으로 전국 범위에서 뚜렷한 차이를 보인다. Beijing, Shanghai는 환경 효율성이 유효하고 나머지 28개 성시는 모두 차원이 다른 비효율 상태를 가지고 있다. 구역발전에서도 차별성이 있어 전반적으로 동고서저형 공간 구도를 보인다. 전국 30개 성시의 환경 효율성인 Malmquist 지수는 상승하는 성장세를 보이며 기술진보가 주요한 추진력이 된다. 향후 정책에서는 동부지역의 방사선 견인능력을 높이고 각 구역 간 시너지를 강화하여 구역 우위를 충분히 발휘해야 할 것이다. 그리고 산업구조 최적화, 과학기술 수준 제고, 전국 환경 효율성의 상승을 견인하여 녹색 발전을 실현한다.

• Structural Engineering and Mechanics
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• 제48권5호
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• pp.587-613
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• 2013

A 3-node 3D co-rotational beam element using vectorial rotational variables is employed to consider the geometric nonlinearity in 3D space. To account for shape versatility and reinforced concrete cross-sections, fibre model has been derived and conducted. Numerical integration over the cross-section is performed, considering both normal and shear stresses. In addition, the derivations associated with material nonlinearity are given in terms of elasto-plastic incremental stress-strain relationship for both steel and concrete. Steel reinforcement is treated as elasto-plastic material with Von Mises yield criterion. Compressive concrete behaviour is described by Modified Kent and Park model, while tensile stiffening effect is taken into account as well. Through several numerical examples, it is shown that the proposed 3D co-rotational beam element with fibre model can be used to simulate steel and reinforced concrete framed structures with satisfactory accuracy and efficiency.

• ETRI Journal
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• 제39권3호
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• pp.364-372
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• 2017

For the reliability of controllers in a software defined network (SDN), a dynamic and self-learning schedule method (DSL) is proposed. This method is original and easy to deploy, and optimizes the combination of multiple controllers. First, we summarize multiple controllers' combinations and schedule problems in an SDN and analyze its reliability. Then, we introduce the architecture of the schedule method and evaluate multi-controller reliability, the DSL method, and its optimized solution. By continually and statistically learning the information about controller reliability, this method treats it as a metric to schedule controllers. Finally, we compare and test the method using a given testing scenario based on an SDN network simulator. The experiment results show that the DSL method can significantly improve the total reliability of an SDN compared with a random schedule, and the proposed optimization algorithm has higher efficiency than an exhaustive search.

• Journal of Communications and Networks
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• 제12권2호
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• pp.158-167
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• 2010

The energy efficiency of wireless infrastructure and terminals has been drawing renewed attention of late, due to their significant environmental cost. Emerging green communication paradigms such as cognitive radios, are also imposing the additional requirement of flexibility. This dual requirement of energy efficiency and flexibility poses new design challenges for implementing radio functional blocks. This paper focuses on the area vs. power trade-offs for the type of channel filters that are required in the digital frontend of a flexible, energy-efficient radio. In traditional CMOS circuits, increased area was traded for reduced dynamic power consumption. With leakage power emerging as the dominant mode of power consumption in nanoscale CMOS, these trade-offs must be revisited due to the strong correlation between area and leakage power. The current work discusses how the increased timing slacks obtained by increasing the parallelism can be exploited for overall power reduction even in nanoscale circuits. In this context the paper introduces the notion of 'area efficiency' and a metric for evaluating it. The proposed metric has also been used to compare the area efficiencies of different classes of time-shared filters.

• The Journal of Asian Finance, Economics and Business
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• 제7권11호
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• pp.1033-1039
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• 2020

Vietnam is conducting an export-led growth model and labour-intensive industries contributing majorly to the total export value. In the context of Industry 4.0, the labour-based industries are significantly affected; hence, enhancing productivity is the key measure to maintain these industries. The garment industry contributes significantly to the total export value of Vietnam. Based on meta-frontier framework, the approach of data envelopment analysis is used to measure technical efficiency of Vietnamese garment firms and the global Malmquist TFP index is utilised to identify productivity change and its components including efficiency, technology and technical gaps between different groups of firms. The data of Vietnamese garment firms from 2013 to 2018 collected from the Vietnam General Statistic Office is used in this study. The results show that: (i) The total factor productivity of Vietnamese garment firms growth, technical progress is the main contributor; (ii) The private garment sector is the leading group; (iii) There is a large technological gap among Vietnamese garment sectors. The private and FDI garment firms have experienced a growth in all components of total factor productivity change. Meanwhile, technological progress change is the main reason to constrain the productivity growth of state-owned garment firms.

• The Journal of Asian Finance, Economics and Business
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• 제6권1호
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• pp.241-248
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• 2019

The purpose of this study is to investigate empirical evidences of productivity of life insurance institutions in Malaysia. Therefore, this study attempts to explore the productivity of the life insurance institutions in Malaysia. The overall findings show that the total factor productivity (TFP) has progressed by 2.5% per year during the study period from 2012 to 2016 in the Malaysian insurance industry. However, TFP change has declined from 2012 to 2015 and observed a negative growth in 2015-16 (3.3%). The highest productivity progress was documented during 2012-13 at a rate of 11.7% while the minimum productivity progress was during 2014-15 (only 0.2%). The results also indicate that the decomposition of TFP found that overall progress could mainly be attributed to technological change (TC). However, technical efficiency change (TEC) and pure technical efficiency change (PTE) have negative impact on TFP. The findings also show that most of the insurance companies have a steady growth. Therefore, this study will contribute new insights for the policy makers and insurance institutions to take appropriate steps in developing relevant policies for increasing productivity of insurance institutions in Malaysia.

• E2M - 전기 전자와 첨단 소재
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• 제11권11호
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• pp.37-45
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• 1998

In this paper, present status of super high-efficiency tandem solar cells has been reviewed and key issues for realizing super high-efficiency have also been discussed. In addition, the terretrial R&D activities of tandem cells, in the New Sunshine Program of MITI(Ministry of International Trade and Industry) and NEDO(New Energy and Industrial Technology Development Organization) in Japan are reviewed briefly. The mechanical stacked 3-junction cells of monolithically grown InGaP/GaAs 2-junction cells and InGaAs cells have reached the highest efficiency achieved in Japan of 33.3% at 1-sun AM1.5. This paper also reports high-efficiency InGaP/GaAs 2-junction solar cells with a world-record efficiency of 26.9% at AM0, 28$^{\circ}C$ and radiation damage recovery phenomena of the tandem cell performance due to minority-carrier injection under light illumination or forward bias, which causes defect annealing in InGaP top cells. Future prospects for realizing super-high efficiency and low-cost tandem solar cells are also described.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권1호
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• pp.364-380
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• 2016

The most popular approach in object classification is based on the bag of visual-words model, which has several fundamental problems that restricting the performance of this method, such as low time efficiency, the synonym and polysemy of visual words, and the lack of spatial information between visual words. In view of this, an object classification based on weakly supervised E2LSH and saliency map weighting is proposed. Firstly, E2LSH (Exact Euclidean Locality Sensitive Hashing) is employed to generate a group of weakly randomized visual dictionary by clustering SIFT features of the training dataset, and the selecting process of hash functions is effectively supervised inspired by the random forest ideas to reduce the randomcity of E2LSH. Secondly, graph-based visual saliency (GBVS) algorithm is applied to detect the saliency map of different images and weight the visual words according to the saliency prior. Finally, saliency map weighted visual language model is carried out to accomplish object classification. Experimental results datasets of Pascal 2007 and Caltech-256 indicate that the distinguishability of objects is effectively improved and our method is superior to the state-of-the-art object classification methods.

• Journal of Ginseng Research
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• 제33권3호
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• pp.240-243
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• 2009

원료삼 생산에 있어 총수익(R)을 결정하는 4요인 승법 모형을 설정하고 (R=AYQP) 세 농가의 수납실적 수치를 사용하여 총수익 결정식임을 확인하였다. 4요소는 자본요소인 재배면적(A), 기술요소인 단위수량(Y)과 가중평균 품질등급(Q) 그리고 시장요소인 평균등급 가격(P)의 3요소로 해석하였다. 기술요소인 YQ는 자본(A)과 수익(R)의 직선모형에서 기울기가 되어 단위자본의 수익창출계수임을 밝혔다. 수익결정식은 인삼산업의 발전이 재배수량과 품질 향상기술 YQ를 증대시켜 면적(A)을 감소시킴으로서 수익(R)을 높여 시장가격(P)을 낮추는데 있음을 보여주었다.