• Journal of Technology Innovation
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• v.11 no.2
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• pp.151-173
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• 2003

This paper analyses the efficiency and productivity of R&D system across time (1991${\sim}$2000) and 16 OECD countries using multi-output and multi-input non-parametric frontier methods such as DEA (data envelopement analysis) and Malmquist productivity indexes. Malmquist productivity indexes are decomposed into two components measures, namely technical change and efficiency change. To calculate R&D efficiency and productivity, we used R&D stock and the number or researchers as R&D input proxies and the number of adjusted SCI papers and U.S. patent applications as R&D output proxies. Empirical result shows that Switzerland, Canada, U.S., Australia's R&D efficiencies are the highest and Korea's R&D productivity growth is the highest in the sample for the period. Technical efficiency growth was a more important source of productivity growth than technological innovation.

• The Journal of Fisheries Business Administration
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• v.34 no.1
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• pp.45-67
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• 2003

Main target of fishing policy was enlargement of fishing catches in Korea after 1960s. This has caused sustainable decrease of the amount on the fisheries resource. In the result, fishing managements in Korea have suffered from aggravation of management. In this research, it is estimated the technical efficiency on Korean Off-shore Stow Nets Fishery that was made publication by Farrel in 1957. According to the analysis, Its were excessive to the gap of technical efficiency among Korean Off-shore Stow Nets Fishing boats. The gaps were excessive not only among each fishing managements but also by tonnage class and by region. Then we can recognize we need the change of Fishing Policy. That is, we should change for main target of fishing policy from enlargement of fishing catches to the policy of Price. And we should consider the supply of standard tonnage boats and specialization of fisheries by regions.

• Proceedings of the Optical Society of Korea Conference
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• 2002.11a
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• pp.192-193
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• 2002

In this paper we investigate the phase modulation efficiency in the electrooptic phase modulator using PPpinNN GaAs/AlGaAs W-type waveguide. The phase change is affected by the refractive index change taking place inside the depletion region. The behavior of the modulator can be understood in terms of two electric field-related and two carrier-related effects linear electrooptic, quadratic electrooptic, plasma, and bandgap shift. As a result, the phase modulation efficiency was measured about 34.6($^{\circ}$/V$.$mm) for the TE polarized light. The quadratic electrooptic coefficient R 5.82${\times}$10$\^$-15/($\textrm{cm}^2$/V$^2$) is Obtained ant the Phase efficiency Caused by the quadratic electrooptic effect is about 10 times larger than that from the conventional linear electrooptic effect.

• The Korean Journal of Financial Management
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• v.23 no.2
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• pp.57-83
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• 2006

The purpose of this paper is to analyze the efficiency and productivity change and inefficiency cause of the korean non-life insurance companies of the before($1993{\sim}1996$) and after($1998{\sim}2004$) of IMF. we use DEA (Data Envelopment Analysis) model to measure company efficiency and MPI(Malmquist productivity indices) to measure company productivity change and Tobit regression to analyze inefficiency cause. we utilize ten non-life insurance companies in korea and the time-series data for eleven from 1993 to 2004 except 1997. The empirical results show the following findings. First, total cost efficiency shows that the after of IMF decrease of 3.7% over the before of IMF and MPI change indicates that the after of IMF increase 7.7% over the before IMF. Second, the results of Tobit regression to analysis the cause of inefficiency show that total cost efficiency is positively related invested assets, acquisition expenses ratio, collection expenses ratio and is negatively related solicitors ratio, personnel expenses ratio, land & buildings expenses ratio, loss ratio, net operating expenses ratio. Especially inefficiency of small-to-mid sized companies is main cause of total cost efficiency of non-life insurance companies in korea. Small-to-mid sized companies endeavored various aspects of business strategies.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.3
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• pp.1-6
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• 2014

We measured color rendering index(CRI) of a LED lamp for lighting for aging-time. We chose bulb type white LED lamp six samples and halogen lamp one sample and applied 220V, 60Hz to all the samples for 1,000hours at ordinary temperature. The CRI was measured every 20hours and the CRI change of the LED lamp was compared with the halogen lamp's CRI change. As time goes, efficiency of the halogen lamp decreased and the CRI maintained uniformly. The other hand, efficiency of the LED lamp decreased but the CRI increased. The CRI of the LED lamp has been stabilized since 600hours. The CRI change of the LED lamp was analyzed with a spectrum, color coordinate and color temperature.

• International Journal of Computer Science & Network Security
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• v.22 no.6
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• pp.1-6
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• 2022

Scene change detection is an important topic because of the wide and growing range of its applications. Streaming services from many providers are increasing their capacity which causes the industry growth. The method for the scene change detection is described here and compared with the State-of-the-Art methods over the Open Video Scene Detection (OVSD) - an open dataset of Creative Commons licensed videos freely available for download and use to evaluate video scene detection algorithms. The proposed method is based on scene analysis using threshold values and smooth scene changes. A comparison of the presented method was conducted in this research. The obtained results demonstrated the high efficiency of the scene cut localization method proposed by authors, because its efficiency measured in terms of precision, recall, accuracy, and F-metrics score exceeds the best previously known results.

• International Journal of Reliability and Applications
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• v.1 no.2
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• pp.115-121
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• 2000

The trend change in aging properties, such as failure rate and mean residual life, of a life distribution is important to engineers and reliability analysts. In this paper we develop a test statistic for testing whether or not the failure rate changes its trend using censored data. The asymptotic normality of the test statistics is established. We discuss the efficiency values of loss due to censoring.

• International Area Studies Review
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• v.14 no.2
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• pp.43-60
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• 2010

This paper measures R&D efficiency and productivity changes of 24 nations including Korea, Japan and China by the non-parametric Malmquist productivity index. The principle findings of this study are as follows. First, R&D efficiency scores of Korea and Japan are 0.837 and 0.834 respectively. Meanwhile China shows 0.420, the worst performance among the selected countries. Second, Korea marked annual productivity increase of 25%, highest among the selected countries', for 2000-2005. R&D productivity in Japan and China, however, decreased 1.9% and 0.9% respectively. Third, annual rates of technology change and technical efficiency change in Japan are 0.6% and -2.5%. Therefore decrease of productivity in Japan is mainly due to technical inefficiency. In case of China, improvement of technical efficiency is the main contributor to productivity growth but technical progress has edged downward in the sample period. In Korea, with annual rate of technology change and technical efficiency change being 5.2% and 18.2% respectively, both efficiency improvement and technical progress has pulled the R&D productivity growth.

• Particle and aerosol research
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• v.12 no.3
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• pp.51-56
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• 2016

Due to recent development in nanotechnology and increasing usage and production of nanomaterials, numerous studies related to environment, sanitation and safety handling of nanoparticle are being conducted. Since nanoparticles can be easily absorbed into human bodies through breathing process, based on their toxic substances and their large specific surface, these particles can cause serious health damage. Therefore, to reduce nanoparticle emissions, nanofiltration technology is becoming a serious issue. Filtration is a separation process during which a fluid passes through a barrier by removing the particles from the stream. Barrier filters can be made of various materials and shapes. One of the most common type of barrier filter is the fibrous filter. Fibrous filters are divided in two types: nonwoven and woven fabrics. Polypropylene is a thermoplastic material, used as a base material for melt blown nonwoven fabric. In this study, we examined filtration property of KCl nanoparticles with a mean particle diameter of 75 nm using multilayer meltblown filter samples. These experiments verify that the penetration of nanoparticle in the filter correlate with pressure drop; the meltblown layer MB1 has the greatest effect on dust collection efficiency of the filter. Among all tested samples, dust collection efficiency of 2-layer filter was best. However, when considering the overall pressure drop and dust collection efficiency, the 4-layer filter has the highest quality factor for particles smaller than 70 nm.

• Journal of Climate Change Research
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• v.9 no.1
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• pp.75-80
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• 2018

The problem of water shortages and water related disasters caused by climate change has increased the seriousness of water problems and the importance of water treatment technology capable of securing clean water is expanding. In this study, we analyzed not only the water pollutant generated by the filtration system technology of various water treatment technologies but also the indirect greenhouse gas emissions generation, and analyzed the influence on the environment. The subjects of study are Fabric Filter, Reverse Osmosis System and Pressurized Microfiltration Device which are widely used for water treatment and we analyzed the impact on the environment using the Life Cycle Assessment (LCA) method using the electricity amount necessary for use, the water purification efficiency, the throughput per ton and the cost. The amount of greenhouse gas generated when the Pressurized Microfiltration Device operates for 1 year is $2.15E+04kg\;CO_2-eq$., Fabric Filter is $3.29E+04kg\;CO_2-eq$., and Reverse Osmosis System is $1.68E+05kg\;CO_2-eq$. As a result of analyzing the amount of greenhouse gas generated at the time of purifying 1 ton of the Pressurized Microfiltration Device and the conventional filtration system, the Pressurized Microfiltration Device was $20.5g\;CO_2-eq$., Fabric Filter was $34.7g\;CO_2-eq$., and Reverse Osmosis System was $191.7g\;CO_2-eq$. The amount of greenhouse gas generated was calculated to be 41.0% less than that of the Fabric Filter by the Pressurized Microfiltration Device and 89.3% less than the Reverse Osmosis System. From the viewpoint of climate change, it is necessary to select a filtration system that takes climate change into account, not from the viewpoint of water quality removal efficiency and economic efficiency according to future water treatment applications, and it is necessary to select a water treatment filtration system more researches and improvements will be made for.