• 한국항공우주학회지
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• 제31권5호
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• pp.100-109
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• 2003

$SIMULINK^R$를 이용하여 Pt6A-62 터보프롭엔진의 성능모사모델이 정상상태 및 천이성능 예측을 위해 제안되었다. $SIMULINK^R$모델은 GUI 방식으로 사용자 편의와 컴퓨터프로그램의 수정이 용이하다는 장점을 가지고 있다. $SIMULINK^R$모델은 유동경로에 따른 구성품들 즉, 대기조건, 압축기, 연소기, 압축기 터빈, 동력터빈, 배기노즐, 적분기 서브시스템들로 구성하였다. 이러한 서브시스템외에 보다 정확한 기체상수값을 계산하기위한 Gasprop 서브시스템블록, 2-D look-up 테이블로부터 스케일링에 의해 적합한 작동 점을 탐색하기 위한 탐색 서브시스템블록이 있다. 정상상태 해석 타당성 확인 경우, 제안된 $SIMULINK^R$에 의한 해석결과는 사용프로그램인 GASTURB와 해석결과에 잘 일치하였다. 또한 천이모델의 타당성 확인 경우에 있어서는, 제안된모델에의한 동적성능모사 결과가 기 성능이 입증된 FORTRAN프로그램을 이용한 해석결과와 합리적으로 일치함이 확인되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.377-379
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• 2001

When a wide area blackout occurres, reenergizing transmission lines should be done at first. The KEPCO(Korea Electric Power Corporation) divides whole power system grid into seven subsystem, and each subsystem has one of two blackstart power plants which are usually hydro or combined-combustion type, one priority power plant which should be first supplied with electric energy, and transmission lines between them. Voltage rising, line charging, and operation stability problem should be considered when these lines are reenergized. In this paper, building-up process for primary transmission system that should be energized at first is analyzed.

• ETRI Journal
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• 제19권3호
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• pp.116-140
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• 1997

The base station transceiver subsystem (BTS) of the CDMA Mobile System is interfaced to mobile stations over the air and to the wired network through a packet switched interconnection network. The potential benefits of CDMA technology are achieved when the transmitter and the receiver are properly designed and implemented. The physical layer of the interface at the base station is implemented with the CDMA ASICs and control circuits in channel card of the BTS. We present the design perspectives and structural illustration of the BTS. Base station modem ASICs and their control to implement the CDMA receiver, Baseband and RF signal processing blocks, and BTS controller are described. Elaborate power control is essential to ensure the high capacity which is one of advantages of the CDMA technology. The closed loop reverse link power control and the forward link power control operated in the BTS are described.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.204-207
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• 2006

COMS will receive two different meteorological signals in S-Band from IDACS (Image Data Acquisition and Control System) in ground station before transmitting them in L-Band to user station. MODCS (Meteorological Ocean Data Communication Subsystem) in satellite released the value of required PFD (Power Flux Density) to receive two signals. Thus, DATS (Data Acquisition and Transmission Subsystem) needs to send two signals to satellite with a satisfied EIRP. The value of minimum HPA (High Power Amplifier) output power was estimated by subtracting antenna directional gain and path loss between antenna and HPA from the needed EIRP in this paper. Besides the minimum output power of HPA, the maximum output power was also calculated with considering IMD (Inter-Modulation Distortion) characteristics. IMD is always occurred in the output of HPA when LRIT and HRIT are amplified by using single HPA as COMS application. In this paper, the setting of maximum output power was determined when the IMD of modelled HPA was corresponded to the requirement of MODCS.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.220-223
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• 2006

The COMS(Communication, Ocean and Meteorological Satellite) EPS(Electrical Power Subsystem) is derived from an enhanced Eurostar 3000 EPS which is fully autonomous operation in normal conditions or in the event of a failure and provides a high level of reconfiguration capability and flexibility. This paper introduces the COMS EPS preliminary design result. The COMS EPS consists of a battery, a solar array wing, a PSR(Power Supply Regulator), a PRU(Pyrotechnic Unit), a SADM(Solar Array Drive Mechanism) and relay and fuse brackets. This can offer a bus power capability of 3 kW. The solar array is made of a deployable wing with two panels. One type of solar cells is selected as GaAs/Ge triple junction cells. Li-ion battery is base lined with ten series cell module of five cells in parallel. PSR associated with battery and solar array generates a power bus fully regulated 50 V. Power bus is centralised protection and distribution by relay and fuse brackets. PRU provides power for firing actuators devices. The solar array wing is routed by the SADM under control of the AOCS(Attitude Orbit Control Subsystem). The control and monitoring of the EPS especially of the battery, is performed by the PSR in combination with on-board software.

• 항공우주기술
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• 제1권1호
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• pp.84-96
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• 2002

본 연구는 차세대 국내 통신위성 전력계 서브시스템 비행모델 설계의 기본 지침서로 사용하기 위한 것이다. 이러한 목적을 위해 전력계 시스템은 모든 기대되는 위성 임무기간동안 서브시스템 규격서에 제시된 성능요구사항을 만족시키기 위해 설계되어졌다. 조절된 전력 버스는 전력제어 및 분배장치로부터 다양한 위성부하까지 42.5V로 분배되어지고 태양전지 어레이들은 6개의 패널로 구성하였다. 한 패널은 3개의 회로로 구성되며 각 회로는 7개의 스트링으로 설계되어졌다. 배터리 시스템은 2개의 배터리로 구성되어졌으며 각 배터리는 26개(IPV) NiH2셀로 구성되어졌다. 배터리는 80% DOD(Depth of Discharge)에서 에너지의 2878Watt-hours를 공급할 수 있는 용량으로 설계되어졌다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(II)
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• pp.98-103
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• 2003

Recently, to solve the urban transportation problem, the introduction of Light Rail Transit system has been proceeded positively. therefore, development of the Korean standard LRT system in which safety, efficiency and cost effectiveness are emphasized. The Korea Railroad Research institute study on Rubber Tired AGT system of Light Rail Transit to obtain the essential technology and engineering know-how, which leads lower LRT construction cost. In the development procedure, SE(system Engineering) is needed for combination of subsystem and optimum operation effect. This study is focused on the interface of LRT subsystem(Development of the rubber tired LRT, Power supply system, signalling and train control system, Elevated track structure for the rubber tired LRT), a important part of SE, to develop of the driverless LRT system and establish the test and evaluation.

• 대한임베디드공학회논문지
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• 제1권1호
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• pp.1-7
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• 2006

In this paper, a novel power management structure for an energy harvesting pervasive system is proposed. The system considers the power state of each subsystem to assign proper power sources. The switch matrix structure utilizes each power source to reduce the peak current of the battery. The power management structure can be interfaced to an embedded system power supply without significant design change.

• 대한전기학회논문지:전력기술부문A
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• 제54권7호
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• pp.323-327
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• 2005

This paper presents an operator training simulator for power system restoration against massive black-out. The system is designed especially focused on the generality and convenient setting up for initial condition of simulation. The former is accomplished by using power flow calculation methodology, and PSS/E data is used to define the initial situation. The proposed simulator consists of three major components - the power flow(PF) module, data conversion(COW) module and GU subsystem. PF module calculates power flow, and then checks overvoltage of buses and overflow of lines. COW module composes an Y-Bus array and a data base at each restoration action. The initial Y-Bus array is constructed from PSS/E data. The user friendly GUI subsystem is developed including graphic editor and built-in operation manual. As a result, the maximum processing time for one step operation is 15 seconds, which is adequate for training purpose. Comparison with PSS/E simulation proves the accuracy and reliability of the training system.

• International Journal of Aerospace System Engineering
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• 제9권1호
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• pp.1-15
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• 2022

Pyrotechnic initiators provide a source of pyrotechnic energy used to initiate a variety of space mechanisms. Pyrotechnic systems build in electromagnetic environment that may lead to critical or catastrophic hazards. Special precautions are need to prevent a pulse large enough to trigger the initiator from appearing in the pyrotechnic firing circuits at any but the desired time. The EMC verification shall be shown by analysis or test that the pyrotechnic systems meets the requirements of inadvertent activation. The MIL-STD-1576 and two range safeties, AFSPC and CSG, require the safety margin for electromagnetic potential hazards to pyrotechnic systems to a level at least 20 dB below the maximum no-fire power of the EED. The PC23 is equivalent to NASA standard initiator and the 1EPWH100 squib is ESA standard initiator. This paper verifies the two safety margins for electromagnetic potential hazards. The first is verified by analyzing against a RF power. The second is verified by testing against a DC current. The EMC safety margin requirement against RF power has been demonstrated through the electric field coupling analysis in differential mode with 21 dB both PC23 and 1EPWH100, and in common mode with 58 dB for PC23 and 48 dB for 1EPWH100 against the maximum no-fire power of the EED. Also, the EMC safety margin requirement against DC current has been demonstrated through the electrical isolation test for the pyrotechnic firing circuits with greater than 20 dB below the maximum no-fire current of the EED.