• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.12
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• pp.1086-1092
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• 2012

It has been studied for DGPS/INS(Differential Global Positioning System/Inertial Navigation System) to offer the more precise and reliable navigation data with the aviation industry development. The flight performance evaluation of navigation system is very significant because the reliability of navigation data directly affect the safety of aircraft. Especially, the high-level navigation system, as DGPS/INS, need more precise flight performance evaluation method. The performance analysis is performed by comparing between the DGPS/INS navigation data and reference trajectory which is more precise than DGPS/INS. The GPS receiver, which is capable of post-processed CDGPS(Carrier-phase DGPS) method, can be used as reference system. Generally, the DGPS/INS is estimated the CG(Center of Gravity) point of aircraft while the reference system is output the position of GPS antenna which is mounted on the outside of aircraft. For this reason, estimated error between DGPS/INS and reference system will include the error due to lever arm. In order to more precise performance evaluation, it is needed to compensate the lever arm. This paper presents procedure and result of flight test which includes lever arm compensation in order to verify reliability and performance of DGPS/INS more precisely.

• Journal of the Korean Geotechnical Society
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• v.19 no.3
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• pp.23-31
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• 2003

Over the past half century, borehole seismic surveys have been diversified into the three techniques such as crosshole, downhole, and suspension logging according to their devices and testing configurations. These field techniques have been improved, in terms of equipment and testing procedures, and are very valuable in the evaluation of ground characteristics for geotechnical and earthquake engineering problems. Yet, despite the importance and significance of the techniques as engineering tools, the techniques are not much used as standard penetration test (SPT) by practicing engineers. The possible explanations are cost and operational difficulties of the surveys as well as sophistication and complexity of the devices. An in-hole seismic method has been developed to meet the requirement of economical testing cost and practicality in engineering practice to measure dynamic soil properties. The prototype in-hole probe developed herein is small and light enough to be fit in three-inch boreholes and to be handled with bare hands. The performance of the source has been evaluated through extensive crosshole tests at various sites. The in-hole seismic method was adopted at three test sites and verified by comparing with crosshole results.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.11a
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• pp.59-60
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• 2018

The oscillating-water-column wave energy converter represents the complex physical characteristics associated with the water column, turbines, generator, and power converter. This study focuses on the derivation of the physical relationship between the water column and turbine based on the 1/ 4 scale model test. The aerodynamic characteristics of the OWC ducted turbine were simulated using an orifice. The turbine effect, a key element in the OWC-chamber performance evaluation, can be represented by the flow rate and pressure drop through the orifice. The turbine effect of OWC-WEC was confirmed to have a non-linear relationship from the measured flow rate and pressure drop in the model test.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.1
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• pp.140-148
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• 2012

Recently there are many attempts to introduce PC construction method in buildings. But the study on PC structural wall has been made progress so slowly because it is very difficult to develop new items. In this study, we have developed new vertical joint on PC wall in order to upgrade constructivity and structural performance of the existing connections, then we have evaluated the seismic resistance performance. As a result of the cyclic loading tests for two specimens, proposed vertical joint on PC wall has shown that it behave the excellent structural performance in comparison to PC wall having no joint. Therefore, we think that proposed vertical joint is the system to apply buliding structure.

• Journal of the Korean Geotechnical Society
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• v.21 no.1
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• pp.105-114
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• 2005

An in-hole seismic method, which has been developed for measuring dynamic properties of subsurface materials, was improved in terms of cost effectiveness and practicality. The upgraded features include the motorized triggering system rather than the manual prototype version in the previous studies and a connecting rod between source and receiver in the module. The probe, thus, can be used for the field measurements of soil properties as well as those of rocks. The performance of the probe has been evaluated through extensive cross-hole tests and in-hole tests at various sites.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.941-947
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• 2008

In the braking of a railroad car, mechanical brake systems using wheel tread and brake disk are applied as well as electrical brake systems by regenerator and rheostat. During disk braking, kinetic energy of the vehicle is converted into thermal energy through friction between disk and brake pad. And it causes high temperature concentration and generates thermal crack on the brake disk surface. In this study, comparative test process for heat-resistance of candidate materials was designed for development of brake disk materials having high heat-resistance. We also verified the efficiency of the process by experiments using conventional brake disk materials.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.993-996
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• 2008

It has been reported that destruction test by core collection is the most reliable of the structural concrete strength in present building construction field. But it causes low efficiency by damage and cutting in structure due to the core collection. It also has some problems in repairing. Additionally in case of strength test with management specimen, different environment compared to the structure environment cause problems about estimation precise structure strength. Therefore, it is required to develop structure direct strength test that has test values and credibility above the ones obtained by core specimen collection strength test and seasonal specimen test to suggest a reasonable and practical management method of structural concrete.

• Composites Research
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• v.24 no.2
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• pp.46-50
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• 2011

This paper describes the state of the art for the development of metallic armor materials which are mainly used as armor plates of the combat vehicles. Several important micro-structural features affecting ballistic properties of the metallic armor are discussed. Optimization of the strength and toughness balance of the metallic armor is necessary for the improvement of the ballistic performance resulting from maximizing the resistance to the penetration of the bullet and also to brittle failure of the plates. Understanding and control of the adiabatic shearing phenomenon developed remarkably during high strain rate deformation is needed to prevent brittle failure of the metallic armor materials.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.127-128
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• 2013

본 논문은 POSCO ICT가 개발한 2MVA/500kWh급 BESS(Battery Energy Storage System)의 가파도 마이크로그리드 적용사례와 실증결과에 대해 기술하였다. 이를 위해 가파도 마이크로그리드 구성과 BESS 역할을 설명하였고, 적용된 기술을 소개하였다. 또한 시험항목과 의의를 서술하고, 시험결과를 통해 계통망의 전력품질 및 BESS 제어성능을 검증하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.786-789
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• 2007

교차-개발환경을 기반으로 한 임베디드소프트웨어 개발은 일반적인 데스크톱 컴퓨터에서의 개발방법론 및 도구와의 차이점이 발생한다. 이러한 문제점들로 인해 난이도가 높은 임베디드 소프트웨어 애플리케이션을 쉽게 개발 해주는 기술에 대한 수요가 확산됨에 따라 다양한 기종과 규격의 임베디드소프트웨어 개발환경에 최적화된 시험검증시스템이 절실히 필요하다. 본 논문은 내장형 시스템 개발자가 쉽고 편리하게 원하는 GUI 형태의 결과 분석도구를 생성할 수 있도록 하기 위한 프로파일 로그 분석 방법을 제안한다. 제안하는 로그 분석 방법에 의한 API를 통해 개발자나 사용자는 자신의 취향에 맞는 GUI 형태의 결과 분석 도구를 쉽고 빠르게 생성하여 내장형 소프트웨어 개발의 효율성을 높일 수 있으며, 고가의 해외 개발도구의 수입대체 효과를 가져와 관련 산업 발전에 크게 기여할 것으로 기대 된다. 또한 국내 시장의 활성화를 통하여 개발업체간 상호교류를 통하여 보다 나은 국내 산업 시장을 형성하여 기존 임베디드 산업의 경쟁력을 강화하고 고난도의 응용 S/W의 개발과 시험 검증을 용이하게 할 수 있어 넓은 신 시장 창출 효과를 불러올 수 있다.