• Journal of the Korean Society for Railway
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• v.19 no.6
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• pp.792-801
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• 2016

Standard Penetration Test (SPT) and Cone Penetration Test (CPT) are widely used in geotechnical investigation methods for railway roadbed. However, SPT can not be used on the Railway track, since the equipment may contact to the electric lines. However, a portable equipment can be used for geotechnical investigation without electrical hazard. Dynamic Cone Penetrometer (DCP) is one of representative portable equipments. A normal portable DCP has usually not enough driving energy and the rigidity of cone-rod, so it is impossible to investigate the required investigate penetration depth. In this study, The adaptability of Pagani cone test which is one of portable dynamic cone penetrometer is studied and compared with SPT-N data. As a result of this study, the proposed correlation factors between Pagani cone test and SPT-N values after corrections is 1.48 for sandy soil and 1.33 for clayey soil.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1663-1665
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• 1998

The power distribution system is 22.9 kV-y neutral point multi-ground one in our country. So, if conducting materials contacted, to the power line electrical equipment faults or stoppage of electrical power supply happened in the line. contacts are caused by magpie or its nest materials, especially, electrical power incidents by magpie from February to May, season layed egg, is high as 30% as. It is important to electrical power supplier to protect electrical power equipment caused by magpie. From now, KEPCO have tried to protect electrical power equipment faults caused by magpie using several methods, but have not acquired good results and continued to withdraw the nest. Recently, nature environment protection expand to around country and KEPCO also changed the nest withdrawal method to new pre-protection method coexisted with magpie, "Environmental Affinitive Pre-protection Counterplan". Therefore, we planned environmental affinitive pre-protection equipment, set test line. Also, after analyzed its effects during 1 year, we satisfied with results, and then expanded to other test lines and regions.

• International journal of advanced smart convergence
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• v.12 no.4
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• pp.26-34
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• 2023

A high-speed data transmission system is designed for the ground inspection equipment of satellite measurement and control. Based on USB2.0, the system consists of interface chip CY7C68013A, programmable logic processing unit EP4CE30F23C8, analog/digital and digital/analog conversion units. The working principle of data transmission is analyzed, and the system software logic and hardware composition scheme are detailed. The system was utilized to output/capture and store specific data packets. The results show that the high-speed data transmission speed can reach 38MB/s, and the system is effective for satellite test requirements.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.694-696
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• 2002

Transformers together with all equipment and accessories shall be designed and constructed to withstand the mechanical and thermal stresses produced by external short circuit which include three phase, single line-to-ground, double line-to-ground and line-to-line faults etc. Generally the Short Circuit Test of transformers is tested according to the ANSI/IEEE, IEC/JEC, KS etc, in domestic. In this study, it will be showed and compared the difference of symmetrical current for short circuit test of a Pad -mounted transformer according to with ANSI /IEEE and IEC.

• Journal of Positioning, Navigation, and Timing
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• v.9 no.2
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• pp.125-129
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• 2020

In this paper, Zero velocity UPdaTe (ZUPT) is implemented on the navigation system of Remotely Piloted Aircraft for GNSS denied environment. RPA's navigation system suffers from lack or loss of satellite signal while maintenance or ground test inside a hangar. Although some of the hangars install GPS repeaters for indoor tests, the anti-jamming equipment with array antenna blocks the repeater signal regarding them as hostile jamming signal. With ZUPT, an aircraft navigation system can be tested free from the divergence of navigation solution without line-of-sight satellites. The designed ZUPT aided centralized Kalman Filter is implemented on the Embedded GPS&INS and simulated with Captive Flight Test data. The simulation result shows stable navigation solution without GNSS updates.

• Journal of the Korean Society of Systems Engineering
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• v.5 no.2
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• pp.27-34
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• 2009

This paper analyze technical review entry criteria and review process based on system property, and review checklist to conform technical review is also showed. The execution of review is determined according to the preparation of review item and identification for risk element. Risk level should be mitigated before technical review by appropriate plan. This paper described the entering condition of technical review for developmental phase, and tailoring consideration for technical review condition. Described technical review entry criteria, review process, and tailoring consideration is applied to development of test equipment for ground ant-air missile system. Applied system specific technical review process, tailored entry condition for test equipment for ground ant-air missile system and review check list is showed and the effectiveness of described system specific technical review process is presented.

• Aerospace Engineering and Technology
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• v.8 no.2
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• pp.98-104
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• 2009

A solid kick motor is used for propulsion system of KSLV-I 2nd stage. During combustion of the kick motor, vibration and shock could be generated. And it could be transferred to the vehicle equipment bay through the kick motor body. If vibration and shock transferred to the vehicle equipment bay are considerable, electrical equipments could be disordered. Therefore we need to verify influence of vibration and shock caused by combustion of the kick motor. In this research, we measured vibration of the kick motor on the ground firing test. Based on this measurement data, we analyzed random vibration and shock response spectrum.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.09a
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• pp.411-418
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• 2003

This paper presents the results of experimental studies on the equipment isolation effect in the nuclear containment. for this Purpose, shaking table tests were performed. The natural rubber bearing (NRB) and high damping rubber bearing (HDRB) were selected for the isolation. Peak ground acceleration, damping characteristics of isolation system and frequency contents of selected earthquake motions were considered. finally, it is presented that the NRB and HDRB systems are effective for the small equipment isolation and the damping of isolation systems can be affected to the seismic isolation effect.

• Journal of the Korean GEO-environmental Society
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• v.2 no.1
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• pp.91-101
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• 2001

This paper investigates the effectiveness of quick lime piles for soft ground improvement. The field tests based on the results of the laboratory test were performed, and the results of field tests were compared with those of numerical analyses(FEM). The results of the field test showed that the domestic quick lime was very effective in reducing the water contents of the surrounding ground quickly due to its characteristics such as digestion, absorption, and exothermic reactions. Accordingly, consolidation occurred without any additional load increment and the shear strength of surrounding ground was increased more than twice. Therefore the quick lime pile method could be considered as an excellent improvement technique reducing the improvement period for soft ground. For the practical applications of the quick lime pile method, issues such as hydration heat, particulation and equipment enhancement should be solved through continuous research and development.

• Journal of the Korean Geotechnical Society
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• v.30 no.10
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• pp.19-31
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• 2014

In order to investigate ground state change visually in physical model during centrifuge testing, electrical resistivity survey was adopted. Commercial resistivity survey equipment verified at various in-situ sites was utilized. The resistivity survey equipment installed in centrifuge facility was remotely controlled through intranet and electrical resistivity images obtained while centrifuge testing was being checked by real-time inversion. To verify the stable operation of the developed resistivity survey system, preliminary tests were conducted. Model ground was uniformly constructed using unsaturated soil and saline water was dropped on the ground surface to simulate contaminant flow situation. During the 10 g centrifuge tests, electrical resistivity was continuously detected and the testing results were compared with those of identically carried out 1 g centrifuge tests. In addition, the electrical resistivity was directly measured immediately after the centrifuge test by open cutting the model. Finally, reliability of electrical resistivity survey in the centrifuge test was verified by comparing those testing results.