• Proceedings of the KAIS Fall Conference
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• 2011.12b
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• pp.635-638
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• 2011

항공기 착륙 시 발생되는 높은 충격하중에서 승무원 및 기체를 보호하기 위해 높은 충격흡수율이 요구된다. 따라서 착륙 시 발생하는 충격을 효과적으로 흡수할 수 있는 착륙장치는 항공기 핵심 구성요소이다. 다양한 종류의 완충장치가 존재하나, 소형항공기 주착륙장치에는 판스프링 방식을 이용하여 충격에너지를 흡수할 수 있다. 착륙장치의 완충 성능은 반드시 낙하시험을 통해 입증하여야 하며, 이는 미 연방 항공 규정에서 요구하고 있는 사항이다. 이 논문에서는 소형항공기 낙하시험을 위한 설비, 시험 절차 및 낙하시험 수행 결과를 제시한다.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.11
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• pp.1093-1100
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• 2016

This study is to demonstrate the superiority and stability of the solar - wind power hybrid power generation system for street lamps using super capacitor EDLC(:Electric Double Layer Capacitor). It is aiming to apply the lighting device using LED light source as the load of solar-wind power hybrid power generation system for independent power source and to develop the street light system device with high output power generation system. Unlike conventional controllers, EDLC, which is used as an auxiliary device for storing the developed power in the battery, can guarantee the high output and long life of the battery.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.4
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• pp.227-234
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• 2005

In this paper, a smart wireless MEMS-based accelerometer(MA) system has been designed and experimented for smart monitoring system of civil structures. Various performance and experimental tests have been carried out to evaluate whether this system is suitable for monitoring system of civil structures. First, we examined its sensitivity, resolution, and noise, specifically to evaluate the performance of the smart wireless MA system. The results of experiments enabled us to estimate performance of the MA in SWMAS in comparison to the value of data sheet from MA. Second, characteristics of model structure were analyzed by the ambient vibration test based on the NExT combined with ERA. Finally, this analysis was compared to the one that was made by FE results, and the comparison proved that a smart wireless MA system was fitted in smart monitoring system effectively.

• Journal of the Korean Society for Railway
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• v.12 no.5
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• pp.663-669
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• 2009

In the electrical railway, the increase of tensions in an overhead contact lines is essential to speed-up of train, because current collection quality largely depends on the ratio of a wave propagation speed to a train speed. For Kyungbu high-speed line, a pulley-type tensioning device is required to have a tension variation of maximum 3%. Therefore we developed a pulley-type tensioning device in order to meet tension variation requirement of the high-speed tensioning device. To verify the performance of the developed device, a performance test, overload test and failure test were carried out according to the factory test procedure of the Kyung-Bu High-speed line. Furthermore, we also performed reliability performance through not only a fatigue test in a factory, but also on-line verification test in Chungbuk line for over 1 year. These tests verified that the tensioning device had applicability to a main line.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.194-197
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• 2017

Aircraft engine and auxiliary power units are certified in processes of design, production according to airworthiness requirements. The aircraft engines shall demonstrate compliance with the design and production through the Type Certificate and the auxiliary power unit shall demonstrate compliance with the design and production through the Technical Standards Order Approval. MOLIT(Ministry of Land, Infrastructure and Transport) established the law and the airworthiness requirements for aircraft engines such as KAS Part 33 but didn't issue the Technical Standards Order for auxiliary power unit. In this paper, we proposed and explained the plan for improvement of our aircraft engines industry through building and expanding the certification infra-structure for aircraft engines and auxiliary power unit.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.364-367
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• 2011

The development of the DCS thrust unit during the attitude control thruster of the launch vehicle and guided missile is introduced. The DCS thrust unit using solid propellants based on a two-axis control is designed and through the thermo-structural and flow analysis is designed in detail. The performance of the thrust unit based on the detail design is demonstrated through a combustion test.

• Proceedings of the KIEE Conference
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• 2008.10c
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• pp.111-113
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• 2008

본 논문에서는 복합형 하이브리드 굴삭기의 전력 변환 장치의 구조 및 제어 방법을 제안한다. 제안된 전력 변환 장치는 엔진 다이나모 장치를 이용하여 그 타당성을 입증하였으며, 제한된 실험 환경 내에서도 기존의 유압식 굴삭기와 비교하였을 때, 약 8% 정도의 연비 향상의 효쏙를 얻을 수 있었다. 현재 실제 굴삭기에 장착하여 성능과 연비 측정을 위한 실험이 진행 중이다.

• 전기의세계
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• v.53 no.6
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• pp.32-36
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• 2004

한국형 고속전철은 국책과제인 G7(선도기술개발사업) 고속전철기술개발사업의 일환으로 개발되었다. 이로 인해 우리의 독자적인 기술이 해외 선진국과 경쟁할 수 있는 능력을 보여 줌은 물론, 21세기 국가철도망 요소 중 가장 중요한 한국형 고속전철차량을 국내 기술로 구축할 수 있게 되어, 향후 수입 대체, 관련 산업기술 파급 및 수출 증대 등 효과가 클 것으로 기대된다. 특히 고속전철의 핵심이라고 할 수 있는 주요 전장품을 자체 개발하였으며 300km/h 주행 성공 및 지속적인 안정화 시험을 통해 그 성능을 입증해 보이고 있다. 본 글에서는 한국형 고속전철의 주요 전장품인 주 전력 변환장치, 보조전원장치, 견인전동기의 주요 성능 및 특징에 대해 설명하고자 한다.(중략)

• Journal of the Korea Society of Computer and Information
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• v.10 no.4 s.36
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• pp.221-228
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• 2005

Data storage was thought to be inside of or next to server cases but advances in networking technology make the storage system to be located far away from the main computer. In Internet era with explosive data increases, balanced development of storage and transmission systems is required. SAN(Storage Area Network) and NAS(Network Attached Storage) reflect these requirements. It is important to know the capacity and limit of the complex storage network system to got the optimal performance from it. The capacity data is used for performance tuning and making purchasing decision of storage. This paper suggests an analytic model of storage network system as queuing network and proves the model though simulation model.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.207-212
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• 2017

Korean civil airworthiness requirements of powerplant system are regulated on KAS Part 23 and Part 33. These are equivalent to FAR Part 23, Part 33 of FAA and CS-23, CS-E of EASA. FAA and EASA rewrites entire airworthiness requirements for the small airplane. It changed current 'prescriptive regulation' into 'performance-based regulation' which makes the object of safety performance. Powerplant requirements are also changed extensively by these concept revolution. In accordance with reorganization, we studied new powerplant system requirements of FAR Part 23 and proposed ideal direction to rewrite of Korean Airworthiness Standard rewrite.