• Proceedings of the KSR Conference
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• 2007.11a
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• pp.401-410
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• 2007

Form the application of long rail system the non-ballast steel plate bridges, fatigue strength increase and rail noise reduction can be expected. This is mainly form the reduction of the rail impact at the rail joint locations which already made to behave together from welds. In the high speed rail, application of long rail system is essential because without long rail system, the required serviceability level can not be achieved. But even with this long rail systems, the thermal expansion from the girder can not be absorbed in the normal bearing systems, and these expansion cause between girder and rail. Also unexpected rail buckling and fracture through rail thermal tension may happen. It was found through numerical analysis and field measurement that these problems can be avoided by semi-fixed bearing system. In this study, the benefits of non-ballast plate bridge through long rail system, especially at the point of girder stability, girder stiffness increase and bearing maintenance will be reviewed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.3
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• pp.272-278
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• 2008

This paper investigated the a-si:H gate driver with the stepwise gate signal. In 1-chip type mobile LCD application the stepwise gate signal for low power consumption can be used by adding simple switching circuit. The power consumption of the a-Si:H gate driver can be decreased by employing the stepwise gate signal in the conventional circuit. In conventional one, the effect of stepwise gate signal can decrease slew rate and increase the fluctuation of gate-off state voltage, In order to increase the slew rate and decrease the gate off state fluctuation, we proposed a new a-Si:H TFT gate driver circuit. The simulation data of the new circuit show that the slew rate and the gate-off state fluctuation are improved, so the circuit can work reliably.

• Progress in Superconductivity and Cryogenics
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• v.7 no.2
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• pp.16-20
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• 2005

As power systems grow more complex and power demands increase, the fault current tends to gradually increase. In the near future, the fault current will exceed a circuit breaker rating for some substations, which is an especially important issue in the Seoul metropolitan area because of its highly meshed configuration. Currently, the Korean power system is regulated by changing the 154kV system configuration from a loop connection to a radial system, by splitting the bus where load balance can be achieved, and by upgrading the circuit breaker rating. A development project applying 154kV Superconducting Fault Current Limiter (SFCL) to 154kV transmission systems is proceeding with implementation slated for after 2010. In this paper, SFCL is applied to reduce the fault current in power systems according to two different application schemes and their technical impacts are evaluated. The results indicate that both application schemes can regulate the fault current under the rating of circuit breaker, however, applying SFCL to the bus-tie location is much more appropriate from an economic view point.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.516-528
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• 2009

Form the application of long rail system the non-ballast steel plate bridges, fatigue strength increase and rail noise reduction can be expected. This is mainly form the reduction of the rail impact at the rail joint locations which already made to behave together from welds. In the high speed rail, application of long rail system is essential because without long rail system, the required serviceability level can not be achieved. But even with this long rail systems, the thermal expansion from the girder can not be absorbed in the normal bearing systems, and these expansion cause between girder and rail. Also unexpected rail buckling and fracture through rail thermal tension may happen. It was found through numerical analysis and field measurement that these problems can be avoided by semi-fixed bearing system. In this study, the benefits of non-ballast plate bridge through long rail system, especially at the point of girder stability, girder stiffness increase and bearing maintenance will be reviewed.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.197-200
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• 2004

The increase of the use of recycled aggregate is necessary for the decrease of building waste, but it is not possible to use concrete because of the various range of quality. Therefore, the quality grade and application method of recycled aggregate should be prescribed before the site application so in that this study we investigated the effect of the quality of recycled aggregate on the compressive strength, resistance freezing and thawing. As results of this study, the compressive strength of recycled aggregate concrete used recycled aggregate, as if it had high quality recycled aggregate is similar or higher to that of crushed stone. Also, this high quality recycled aggregate affect the increase of resistance freezing and thawing.

• KIEE International Transactions on Electrophysics and Applications
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• v.3C no.1
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• pp.15-18
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• 2003

The characteristics of accelerated soft error rate (ASER) for fabricated 8M SRAM are evaluated for various well structures. The application of the Buried NWell (BNW) and the variations of each well structure, well dose in process conditions are checked by ASER failure in time (FIT) in terms of reliability. The application of only the BNW shows the lowest ASER FIT value. The BNW added to the Buried PWell (BPW) shows a 200% increase and the BNW plus the Striped BPW (SBPW) shows a 100% increase compared to applying the BNW. The cases of applying SBPW show very high ASER FIT.

• Journal of Sensor Science and Technology
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• v.22 no.5
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• pp.357-363
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• 2013

An ultraviolet pulsed laser ablation of polyimide film coated with platinum has been used to enhance the sensitivity for the application as an electrochemical biosensor. Densely packed cones are formed on polyimide surface after UV irradiation which results in increase of surface area. In order to apply the sensitivity improvement of laser ablated polyimide film electrodes, the glucose oxidase modified biosensor was fabricated by using an encapsulation in the gel matrix through sol-gel transition of tetraethoxysliane on the surface of laser ablated polyimide film. The optimum conditions for glucose determination have been characterized with respect to the applied potential and pH. The linear range and detection limit of glucose detection were from 2.0 mM to 18.0 mM and 0.18 mM, respectively. The sensitivity of glucose biosensors fabricated with laser ablated polyimide film is about three times higher than that of plain polyimide film due to increase in surface area by laser ablation.

• Journal of the Korea Safety Management & Science
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• v.19 no.4
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• pp.53-62
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• 2017

It has come to attention that a risk-assessing organization, that will benchmark a company's safety department, is imperative, following an increase in large-scale SOC-business project, construction of higher-raised buildings, development of underground space; all that have increase accident rates. Having faced problems that arise in firms that demand diversity, complexity and instantaneity, the purpose of the thesis is to arrive at efficient and practical problem-solving means. In order to solve the problems that would surface theoretically during an actual risk assessment, the state of the operation systems of the top five national construction firms having a hazard rate of 0.25 times less than the average rate have been analyzed, while a hierarchal recognition research of the employees who not only function at the operating level but are the practice subjects of a firm, has also been conducted, bringing the main text.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.7
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• pp.2434-2454
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• 2021

This paper developed the software testing factory-cloud testing platform (STF-CTP) to address the software compatible issues in various smart devices. Software developers who only require uploading the application under test (AUT) and test script can test plenty of smart devices in STF-CTP. The challenge for the cloud test platform is how to optimize the resource and increase the performance in the limited resource. This paper proposed a new scheduling mechanism and a new process of the system operation which is based on the OpenStack platform. We decrease about 40% memory usage of OpenStack server, increase 3% to 10% Android device usage of STF-CTP, enhance about 80% test job throughput and reduces about 40% test job average waiting time.

• Korean Journal of Environmental Agriculture
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• v.30 no.1
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• pp.1-8
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• 2011

BACKGROUND: With increasing public awareness to environment-friendly agriculture, many efforts have been run to develop organic farming technologies in Korea as of late 90s. The objective of this study was to investigate the effects of different organic farming practices on soil chemical properties and water quality in paddy fields. METHODS AND RESULTS: Total nitrogen (TN) and total phosphorus (TP) were monitored for a two-year period (2006 to 2007) from the study organic paddy fields located in Wan-ju, Jeonbuk Province in Korea. TN and TP of organic paddy water were gradually increased for 2~3 weeks after organic manure application and then gradually decreased afterward. The overall variation of TP in the paddy fields was much greater than that of TN. The phosphorus content in organic paddy field appeared to increase with the organic farming period. CONCLUSION(s): This indicates that long-term organic farming is likely to cause phosphorus accumulation in soils and increase vulnerability to rainfall runoff. Thus, appropriate phosphorus management needs to be implemented, particularly, to reduce excessive phosphorus supply owing to nitrogen-based determination of organic manure application amount.