• The Bulletin of The Korean Astronomical Society
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• 제37권1호
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• pp.67.2-67.2
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• 2012

경희대학교와 UC Berkeley, Imperial College London은 우주관측을 위한 초소형 인공위성인 TRIO-CINEMA(TRIO-CINEMA) Project를 수행하고 있다. TRIO-CINEMA는 총 3기의 인공위성으로 경희대학교에서 2기의 위성을, UC Berkeley에서 1기의 위성을, Imperial College에서 3개의 자력계를 제작하고 있다. CINEMA는 Cubesat의 3U 규격으로 크기는 $100mm{\times}100mm{\times}340.5mm$이고 무게는 약 3 kg, 소비전력은 약 3 W이며, 지구 주변의 ENA측정을 위한 주 탑재체인 STEIN(SupraThermal Electrons, Ions, and Neutrals)과 자기장 측정을 위한 부 탑재체인 MAGIC(MAGnetometer from Imperial College)이 탑재되어 약 1년간 800 km 태양동주기 궤도에서 임무를 수행할 예정이다. 위성의 발사는 별도의 POD(Picosatellite Orbital Deployer)라는 Adaptor를 사용해 발사체에 탑재되는데, 발사환경에서 위성이 받을 모든 현상에 관하여 NX Nastran을 사용해 계산을 진행하였다. 계산 결과의 검증을 위해 위성의 Structure Model을 가지고 Random Vibration test를 수행해 위성의 고유 진동수를 측정하였다. 또한 위성이 궤도에서 운용 중 다양하게 받게 되는 열원에 따른 위성의 각 부분의 온도변화를 NX TMG program을 사용하여 계산하였다. 계산 결과의 검증을 위해 3월 Thermal Cycle test 및 Thermal Balance test를 수행할 예정이다. UC Berkeley에서 제작한 위성 1기는 제작완료 후 발사를 위해 발사장으로 배송을 완료하였고, 경희대학교에서 제작 중인 CINEMA 위성 2기는 2012년 후반기 러시아에서 Dnepr 로켓을 사용해 발사 예정이다.

• Journal of the Korean Society of Propulsion Engineers
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• 제1권2호
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• pp.67-73
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• 1997

This paper shows the development status of attitude control thruster for KOMPSAT(Korea Multi-Purpose Satellite). Hanwha Corp. has manufactured and delivered 1.0 lbf monopropellant thrusters under the technology transfer of TRW Co. in U.S.A regarding design, analysis and manufacturing of MRE-1 thruster These thrusters will be installed to KOMPSAT which is scheduled to be launched in July 1999. Monopropellant thrusters can provide reliable and cost-effective means of propulsive control for middle class satellite and maneuvering control systems. Some information concerning with system specification, performance analysis/simulations and manufacturing process has been introduced in this paper.

• Proceedings of the KSR Conference
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.488-497
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• 2010

8100 series Electric locomotive was imported from SIEMENS of Germany on 2001. 8100 series model is modified from BR152 model to be complied with national environment. After 8100 series Electric locomotive carried out main line test for long time, 8200 series Electric locomotive produced in 10 locomotives with improvement and supplement on some parts. the one of supplement is to install the HEP equipment. In paper, about total harmonic distortion of HEP equipment power, it compares the result of combination with the result of actual measurement. It checks whether the measurement meets the specification of design or not. And it describes international standard about total harmonic distortion of supply system.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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• pp.426-430
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• 2008

Though the air-conditioners in each train model have almost identical function, there is incompatibility between them because of their different electric capacity and parts, even spares manufactures are different in the manufactured year. It cause over cost in the maintenance and repair of the each air-conditioner. In this paper, all the air-conditioners in each train model have been classified by their capacity and features so that grasp the operation status and the repair process of the air-conditioners, and draft systematically cost-effective solutions. By finding a way to deal with the emergency repair and extending the air-conditioner life though improvement of checking up progress, increase of passenger revenue can be reached considerably.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제18권9호
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• pp.1395-1403
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• 1993

Protocol conformance is crucial to inter-operability and cost effective computer communication. Given a protocol specification, the task of checking whether an inplementation conforms to the specification is called conformance testing. The efficiency and fault coverage of conformance testing are largely dependent on how test cases are chosen. Some states may have more one UIO sequence when the protocol is represented by FSM (Finite State Machine). The length of test sequence can be minimized if the optimal test sequences are chosen. In this paper, we construct the depth-tree to find the maximum overlapping among the test sequence. By using the resulting depth-tree, we generate the minimum-length test sequence. We show the example of the minimum-length test sequence obtained by using the resulting depth-tree.

• 한국IT서비스학회:학술대회논문집
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• 한국IT서비스학회 2009년도 추계학술대회
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• pp.198-201
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• 2009

오늘날 운영체계와 미들웨어는 수많은 API를 제공하고 있다. 최종 사용자들이 사용하는 응용 프로그램들은 이러한 API를 활용하여 개발되어지고 있다. 기존의 문서와 같은 형태의 API에 대한 기술은 기계가 자동적으로 처리하기 힘들며 개발자 입장에서도 API를 이해하기 위해서 책을 직접 읽고 이해해야 한다는 단점이 있다. 이를 극복하기 위하여 docgen과 같은 도구들이 있으나 결국은 개발자 관점에서는 API를 직접 숙지하여야 하며 응용 프로그램 상에서 직접 운영체계에서 제공하는 API 호출 부분을 작성하여 개발하여야 한다는 부분은 동일하다. 또한 서로 다른 다양한 운영체계에서는 형식은 다르지만 유사한 기능을 제공을 하는 API들이 있으나 개발자는 특정 운영체계의 API에 맞추어서 각각의 운용체계에 맞는 응용 프로그램을 개발하여야 하는 문제점이 있다. 본 연구에서는 API에 대한 정보에 대한 규격을 정의하고 각각의 API의 기능 및 특성에 대하여 메타 기술언어를 사용하여 기술하여 저장소에 저장해두고 실행시에 이러한 API정보를 사용하여 응용 프로그램과 동적으로 바인딩시켜서 실행시키는 체계에 대해서 논의한다. 응용 프로그램에서 사용하려고 하는 API와 운영체계에서 제공하는 API를 동적으로 결합시키는 엔진에서는 운영체계별 API의 차이에 의한 부분을 상쇄시키는 역할을 담당한다. 이러한 체계를 활용하면 동적으로 재구성 가능한 응용을 개발하는데 있어서 하부 시스템으로 활용될 수 있다. 향후 표준 API를 기술하는데 있어서도 본 연구에서 제시하는 메타 방식의 API 기술표현을 활용하면 보다 정확한 표준 규약 준수 여부를 확인할 수 있는 방법을 제공할 수 있다.

• Journal of IKEEE
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• 제14권2호
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• pp.41-50
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• 2010

TETRA is the standard of Digital Trunked Radio System suggested by the ETSI(European Telecommunications Standards Institut ). It is adopted as Electric Power IT Wireless Backbone Network in Korea. Police station and Fire Station are using TETRA network. Currently, Power Automation Protocols are DNP3.0 in Distribution Automation System, DLMS in Auto Metering Infrastructure, IEC61850 in Substation Automation. These protocols are transmissions using CDMA or WCDMA modem. If Power Automation protocol uses TETRA networks, it can be interoperable with the systems in police or fire stations. And it has outstanding ability to handle problems in a disaster situation. So, This paper propose a gateway system of Power Automation which can transmit the power automation protocol using TETRA.

• Aerospace Engineering and Technology
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• 제9권1호
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• pp.72-77
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• 2010

A hydraulic test on a filament wound case of Kick-Motor was conducted to evaluate the structural stiffness degradation and to confirm the burst performance. Failure criteria have been defined with bursting above 150% of MEOP(Maximum Expected Operation Pressure) and failure in the cylinder. The analysis result showed that filament fiber in the cylinder should be broken at about 2088psig. From a hydraulic test it has been verified that composite case meets the failure requirements, and that the stiffness does not decrease even after a year since the manufacturing.

• Aerospace Engineering and Technology
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• 제7권1호
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• pp.142-150
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• 2008

In order to ensure the individual and mutual performances among the telemetry system, tracking system, flight termination system, GPS, and inertial navigation & guidance system which are installed in the KSLV-I 2nd stage and ground equipment of the Naro space center, flight test using a light airplane is required. Since the high degree of test efficiency is fulfilled through the minute plan and analysis about selection of the equipment which are applicable to the test, harness, operation strategy, and antenna installation. KSLV-I communication environment and flight profile should be precisely taken into account during the flight test. In this document, overall aspect of the KSLV-I 2nd stage equipment specification, a rack for the installation, harness, the airplane specification, and flight route which are required for the effective flight test are presented.

• Aerospace Engineering and Technology
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• 제7권1호
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• pp.161-169
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• 2008

This paper introduces test configuration and operation method for the GPS receiver system under electromagnetic test of KSLV-I upper-stage as a system qualification level and describes performance analysis of the test results. The GPS receiver system has clearly passed the electromagnetic test specifications of component level which is based on MIL-STD-461E through several design changes. Under electromagnetic test as a system qualification level, the GPS receiver system normally operates in spite of electromagnetic interferences with other systems. Performance of the GPS receiver system is also, not degraded on the condition of electromagnetic field incidence and electrostatic discharge. The KSLV-I GPS receiver system, as a result, is verified on the electromagnetic condition of the KSLV-I upper-stage.