• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05c
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• pp.148-151
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• 2002

In order to prevent the failures of underground distribution power cables we need to measure insulation condition in the field. Until now we used DC high voltage as a power source for the cable diagnosis but it was not proper method to the XLPE insulation cables because DC high voltage can affect sound insulation and can't diagnose exactly insulation degradation. For these reasons we imported isothermal relaxation current measurement system called by KDA-1 from germany but it's reliability did not proved in our URD cables. DC voltage decay measurement system was developed by domestic company but they don't have field experience. In this paper we tried to prove reliability of these two systems in the field. Through the field diagnosis and Ac breakdown test the two systems showed similar results.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.47-48
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• 2003

This new family of portable real time SEQUENTIAL MOBILITY PARTICLE COUNTER and SIZER (SMPS+C) is designed for mobility and easy field use. An integrated battery assures hours of operation, a data logger system storage of all optioned results and a user friendly powerful software easy operation. This technology not only simplifies the SMPS operation, but it permits new on site application monitoring up to a remote wireless telephone operation. (omitted)

• KSTLE International Journal
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• v.7 no.1
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• pp.1-4
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• 2006

The electro rheological behavior of the hollow polyaniline pimelate suspension in silicone oil was investigated. Hollow polyaniline pimelate suspension showed a typical ER response (Bingham flow behavior) upon application of an electric field. The shear stress for the suspension exhibited the dependence with a factor equals to 0.84 power on the electric field. The experimental results for the hollow polyaniline pimelate suspension correlated with the conduction models of Tang et al., and this suspension behaved as an ER fluid.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1396-1398
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• 1997

This paper presents experimental results on the recycling aluminum wires used in the actual field. Several testings were carried out with the recycled aluminum wires to prove that they are reusable. Mechanical, electrical and oxidation properties of recycled and new ACSR $160\;mm^2$ were campared after 7.5 year service aging at the salt comtaminated areas of Korean peninsular.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.11a
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• pp.433-439
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• 2002

In this paper, we implemented technology assessment on the public R＆D activities in IT field in order to select the promising technologies, so called "star technology," making for national industry development. Technology assessment frame in this study included qualitative factors. IT technologies are classified five sector - network, wireless/broadcasting, SW/application/computer/terminal equipment, semiconductor/component. Expert opinion interviews on each field are carried out. Assessment factors consist of technology usefulness and technology competitiveness. In the final analysis, 23 technology items selected as a promising technologies and the results can be used public R＆D planning and If industry policy.

• Journal of the Korean GEO-environmental Society
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• v.16 no.3
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• pp.23-34
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• 2015

In this study, a newly modified soil nailing technology using bamboo is developed. And field tests were performed to confirm applicability of bamboo soil nailing system. For the practical use of bamboo soil nailing system, laboratory tests, field instrumentations and pullout tests were also performed to investigate the applicability. The results of field measurement through field tests were compared with the results of numerical analyses for verifying the field construction. As a result, the results of comparing with the field measurement and numerical analyses shows the similar behavior characteristics. Based on this study, applicability for bamboo soil nailing systems were confirmed for the case of comparatively low scale nailed-soil excavation wall. And it is expected that the bamboo soil nailing system can be used as satisfactory reinforcement technique taking the place of existing steel reinforcement soil nailing system. Hereafter, it needed the research for the applicability for the various types of excavation condition, also the active practical application of bamboo soil nailing system is needed.

• Progress in Superconductivity and Cryogenics
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• v.4 no.1
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• pp.55-60
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• 2002

$100 A/mm^2$ class Bi-2223 tapes have recently become commercially available. Some important characteristics of the tapes, e .g. critical current, ac loss, characteristics at joint, fault current characteristics, are required for an application such as a power cable or a power transformer. In this paper they have been investigated experimentally. The results indicate that the self-field loss of the high current density tapes is not negligible, compared to resistive loss in a copper wire for the same currents. In a cable, the self-field loss for relatively large currents is much larger than the magnetization loss due to an external field. But in a transformer, the magnetization loss is dominant, compared to the self-field loss. Finally the fault current characteristics show that the high current density tapes are never safe from burn-out even for fault currents with a few cycles.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.139-142
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• 1999

Recently, the application of the linear machine for industrial field is remarkable increased, especially for the gantry machine and machine tool system. In these application, high precise position control performance is essentially required in steady/transient state. This paper presents the generalized PID position control algorithm which have rare sensitivity to mass and disturbance. Through the experimental results, it is shown that the proposed algorithm have good performance for the linear machine drives in the steady state and transient state in spite of the load mass varing.

• The Journal of Engineering Geology
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• v.26 no.4
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• pp.497-503
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• 2016

The cement grouting by vibration method (CGVM), a new construction technology developed in Korea, aims to efficiently reinforce a target ground area by injecting vibrated grout into it. The present study applies the CGVM to test sites and verifies its effect. Standard penetration tests (SPTs), field permeability tests, and geophysical surveys were conducted in two study areas, and the results were compared between before and after CGVM application. The SPT conducted before and after the CGVM application showed that the N value was increased by 33.57% point to 60.90% point. The field permeability test showed that the permeability coefficient decreased. These results indicate that CGVM may increase imperviousness and improve reservoir system stability. In addition, a resistivity survey found no low-resistivity zone, unlike before the CGVM application, thereby indicating the excellent grouting effect of the CGVM.

• Journal of Information Technology Applications and Management
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• v.9 no.4
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• pp.65-78
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• 2002

We propose a new application method of the datamining technique that might help building an efficient trade strategy in the stock market, where the analysis of the huge database is essential. The proposed method utilizes the association rules among the price changes of individual stock from the market basket analysis (a datamining technique typically used in the Marketing field) in building the strategy We also apply the proposed method to the daily stock prices in Korean stock market, from Jan. 2000 to Dec. 2001. The application results show that the proposed method gives an significantly higher yield rate than the actual stock chage rate.