• Proceedings of the Korea Society for Simulation Conference
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• 1999.10a
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• pp.289-293
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• 1999

디지털 기술을 기반으로 한 조속기 제어시스템의 제어 알고리즘에 대한 적합성과 하드웨어의 신뢰성 시험을 위한 다이나믹 테스트 베드를 구축하기 위해 증기 터빈 및 발전기의 특성을 그대로 모사하는 시뮬레이터 및 하드웨어를 개발하였으며, 개발된 시뮬레이터를 사용자(시험자)가 그 기능들을 적절하고 편리하게 사용할 수 있도록 인간공학의 원칙을 반영하여 설계하였다. 이를 위해 시뮬레이터가 가져야 하는 기능들을 시험 절차의 분석을 통해 도출하고 그 기능들을 사용 목적에 따라 적절하게 그룹핑하였으며, 가장 빈번하게 사용하는 Mimic Display의 경우 사용자가 항상 확인 가능하도록 주 화면에 구성한 인간-기계 연계 설계에 대해 소개하고자 한다.

• Journal of Satellite, Information and Communications
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• v.5 no.2
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• pp.1-7
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• 2010

For many years the development and verification of on-board flight software have been essentially performed on STB (Software Test Bed) environments which consist of real hardware in KARI. During development of on-board flight software on STB, we experienced many difficulties such as the late delivery of target hardware and limitation to access STB simultaneously by multiple developers. And it takes too much time and cost to build up multiple STBs. In order to successfully resolve this kind of problems, the software-based spacecraft simulator has been developed. The simulator emulates the on-board computer, I/O modules and power controller units and it supports the debugging and test facilities to software engineers for developing flight software. Also the flight software can be loaded without any modification and can be executed as pseudo real-time. This paper presents the architecture and design of software-based spacecraft simulator, and flight software development and verification under this environment.

• Journal of Satellite, Information and Communications
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• v.7 no.2
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• pp.80-86
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• 2012

The software-based satellite simulator has been developed from the start of the project to resolve the restriction and limitation of using hardware-based software development platform. It enables the development of flight software to be performed continuously since initial phase. The satellite simulator emulates the on-board computer, I/O modules, electronics and payloads, and it can be easily adapted and changed on hardware configuration change. It supports the debugging and test facilities for software engineers to develop flight software. Also the flight software can be loaded without any modification and can be executed as faster than real-time. This paper presents the architecture and design of software-based GEO satellite simulator which has hot-standby redundancy mechanism, and flight software development and test under this environment.

• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.46.1-46.1
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• 2009

현재 개발 중인 탑재컴퓨터의 메인 프로세서는 MCMERC32SC를 사용하고 있으며, 탑재소프트웨어를 개발하기 위하여 Gaisler Reserach사에서 개발된 소프트웨어 기반의 TSIM-ERC32 에뮬레이터를 이용하여 실시간 위성 시뮬레이터를 개발되어 탑재소프트웨어 개발 및 검증에 사용하였다. 차세대 저궤도 위성 탑재 컴퓨터의 메인 프로세서는 현재 LEON2/3이 사용되고 있으며, LEON2/3 프로세서를 모사해주는 소프트웨어 기반의 에뮬레이터의 경우 LEON2/3의 높은 성능 때문에 실시간 성능을 만족시키지 못하는 문제를 가지고 있다. 현재 ESA에서는 이 문제를 해결하기 위하여 하드웨어 기반의 프로세서 에뮬레이터를 개발/사용하고 있으며, 또 다른 방식으로 기존 프로세서 에뮬레이터가 interpretation방식을 사용한 반면 dynamic translation방식의 에뮬레이터를 개발하여 5~10배 이상의 성능 향상을 통해 실시간 성능을 만족시키고 있다. 이 논문에서는 현재 사용 중인 ERC32 프로세서를 dynamic translation emulation 기법을 사용하여 프로세서 에뮬레이터 개발 방법과 현재 상황에 대해서 설명하며, 추후 LEON2/3를 위한 에뮬레이터 개발의 가능성에 대해서 설명한다.

• Aerospace Engineering and Technology
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• v.12 no.2
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• pp.173-179
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• 2013

This paper describes a testbed that was designed and implemented for the development of KSLV-II onboard equipment simulator. It used the CPCI-based industrial hardware system for scalability and the QNX real-time operating system for reliability and real-time simulation. In addition, a real-time application under QNX for function simulations of the KSLV-I PDU was developed and it was verified through interface experiments with KSLV-I upper-stage test equipment. The implemented simulator testbed will be used to verify the development feasibility in the design and development phase of a real KSLV-II onboard equipment simulator.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.5
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• pp.71-77
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• 2021

Recently, there is a demand for efficient program development of an IoT application support frameworks considering heterogeneous hardware characteristics. In addition, the scope of hardware support is expanding with the development of neuromorphic architecture that mimics the human brain to learn on their own and enables autonomous computing. However, most existing IoT IDE(Integrated Development Environment), it is difficult to support AI(Artificial Intelligence) or to support services combined with various hardware such as neuromorphic architectures. In this paper, we design an AI component abstract model that supports the second-generation ANN(Artificial Neural Network) and the third-generation SNN(Spiking Neural Network), and implemented an autonomous IoT IDE based on the proposed model. IoT developers can automatically create AI components through the proposed technique without knowledge of AI and SNN. The proposed technique is flexible in code conversion according to runtime, so development productivity is high. Through experimentation of the proposed method, it was confirmed that the conversion delay time due to the VCL(Virtual Component Layer) may occur, but the difference is not significant.

• Journal of the Korea Society for Simulation
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• v.25 no.1
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• pp.35-43
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• 2016

Increasing the proportion of an embedded system in automotive industry, test methods for evaluation and fault detection of the embedded system have been researched. HILS is a test method that is used in the development and test of complex real-time embedded systems. In this study, we defined the HILS method of the ECU, one of the embedded systems used in automobiles. Our method is to create a test model that can provide a virtual vehicle environment to the ECU on the basis of the actual vehicle data. The test model has reference information that can transmit the sensor signal and CAN Message into the ECU from HILS tester. In this study, the HILS can detect faults of the target ECU.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.6
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• pp.666-673
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• 2013

This paper proposes the performance evaluation test of attitude heading reference system (AHRS) suitable for small high speed autonomous underwater vehicle(AUV). Although IMU can provides the detail attitude information, it is sometime not suitable for small AUV with short operation time in view of price and the electrical power consumption. One of alternative for tactical grade IMU is the AHRS based micro-machined electro mechanical system(MEMS) which can overcome many problems that have inhibited the adoption of inertial system for small AUV such as cost and power consumption. A cost effective and small size AHRS which incorporates measurements from 3-axis MEMS gyroscopes, accelerometers, and 3-axis magnetometers has been developed to provide a complete attitude solution for AUV and the attitude calculation algorithm is derived based the coordinate transform equation and Kalman filter. The developed AHRS was validated through various performance tests as like the magnetometer calibration, operating experiments using land mobile vehicle and flight motion simulator (FMS). The test of magnetometer calibration shows the developed MEMS AHRS is robust to the external magent field change and the test with land vehicle proves the leveling error of developed MEMS AHRS is below $0.5^{\circ}/hr$. The results of FMS test shows the fact that AHRS provides the measurement with $0.5^{\circ}/hr$ error during 5 minutes operation time. These results of performance evaluation tests showed that the developed AHRS provides attitude information which error of roll and pitch are below $1^{\circ}$ and the error of yaw is below $5^{\circ}$ and satisfies the required specification. It is expected that developed AHRS can provide the precise attitude measurement under sea trial with real AUV.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.11
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• pp.1036-1042
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• 2007

It is rather difficult to improve flight control computer(FLCC) hardware(H/W) development schedule due to lack of commercial off-the-self(COTS) tools or target specific tools. Thus, it is suggested to develop an enhanced process utilizing modeling, simulation and virtual reality tools. This paper presents H/W design process enhancement tool(PET) for FLCC design requirements such as FLCC input/output(I/O) signal flow, I/O fault detection, failure management algorithm, circuit logic, PCB assembly configuration and installation utilizing simulation and visualization in virtual space. New tool will provide simulation capability of various FLCC design configuration including shop replaceable unit(SRU) level assembly/dis-assembly utilizing open flight format 3-D modeling data.

• Journal of Hydrogen and New Energy
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• v.23 no.4
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• pp.323-329
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• 2012

A thermal management system of a proton exchange membrane fuel cell is taken charge of controlling the temperature of fuel cell stack by rejection of electrochemically reacted heat. Two major components of thermal management system are heat exchanger and pump which determines required amount of heat. Since the performance and durability of PEMFC system is sensitive to the operating temperature and temperature distribution inside the stack, it is necessary to control the thermal management system properly under guidance of operating strategy. The control study of the thermal management system is able to be boosted up with hardware in the loop simulation which directly connects the plant simulation with real hardware components. In this study, the plant simulation of fuel cell stack has been developed and the simulation model is connected with virtual data acquisition system. And HIL simulator has been developed to control the coolant supply system for the study of PEMFC thermal management system. The virtual data acquisition system and the HIL simulator are developed under LabVIEWTM Platform and the Simulation interface toolkit integrates the fuel cell plant simulator with the virtual DAQ display and HIL simulator.