• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.787-791
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• 2004

We investigated field-effect ion-transport devices based on carbon nanotubes by using classical molecular dynamics simulations under applied external force fields, and we present model schematics that car be applied to the nanoscale data storage devices and unipolar ionic field-effect transistors. As the applied external force field is increased, potassium ions rapidly flow through the nanochannel. Under low external force fields, ther nal fluctuations of the nanochannels affect tunneling of the potassium ions whereas the effects of thermal fluctuations are negligible under high external force fields. Since the electric current conductivity increases when potassium ions are inserted into fullerenes or carbon nanotubes, the field effect due to the gate, which can modify the position of the potassium ions, changes the tunneling current between the drain and the source.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.28A no.9
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• pp.761-773
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• 1991

In this paper, an algorithm for automatic schematic generation which creates schematic diagram from netlist are proposed. The important objectives on schematic generation are readability and clarity of resulting schematics. Each stage of generation should aim at enhancing these objectives. For this reason, schematic generation problem is divided into 5 subproblems` preprocessing, logical placement, pin assignment and improvement of placement, global routing, and detailed routing. The algorithm is implemented in C language, and it generates schematics from the results of logic synthesis in order to make it east for designers to understand the design and reflect their knowledge into design.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.12
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• pp.83-91
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• 2005

Air-Launching is an effective method that can launch the 'Nanosat' with low launching cost. In this study, system and subsystem design of the air launching rocket for nanosats which perform a simple mission, have been performed. For this purpose, the WBS of the MIRINAEⅡ, and the subsystem schematics have been defined first. Based on these results, detailed configuration and DMU have been developed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.293-298
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• 2005

Air-Launching is an effective method that can launch the 'Nanosat' with low launching cost. In this study, system and subsystem design of the air launching rocket for nanosats which perform a simple mission, have been performed. Foe this purpose, the WBS of the Air-launching Rocket System, and the subsystem schematics have been defined first. Based on these results, detailed configuration and DMU have been developed.

• International journal of advanced smart convergence
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• v.8 no.4
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• pp.200-206
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• 2019

In this study, we compared the VacCAD and VacSim^(Multi), commercial vacuum simulators, to verify the advantages of VacCAD's efficiency. It was emphasized on immediacy and simplicity of simulation modelling, and characteristics of the pump combinations, pumping down curves, and vacuum materials. First, usability of simulation mechanism was estimated through the modeling schematics and obtained simulation results of each employed simulator were compared to evaluate the applicability in practice. Simulation reliability of each simulator was also probed by comparing the pumping characteristics of commercially available high vacuum systems. In addition, the degree of tolerances on VacCAD was also investigated through pumping down analysis considering outgassing effect due to chamber material variations. The higher effectiveness and expediency of VacCAD than VacSim^(Multi) has been presented, and it was expected that the utilization of VacCAD in vacuum applications to be increased.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.11
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• pp.1247-1263
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• 1992

VHDL, which is the IEEE standard HDL, has gradually become popular in the area of hardware design, the VHDL Environment developed in this study consists of VHDL Support Environment and VHDL Using Environment. The VHDL Support Environment is composed of Analyzer, CDFG Generator for synthesis, Synthesizer, and VHDL Generator converting CDFG to VHDL. The VHDL Using Environment provides users with more convenient access to the VHDL Support Environment. The VHDL Using Environment allows accessing the tools in the VHDL Support Environment through Graphical User Interface. VHDL program can be automaticaly generated from schematics in the VHDL Using Environment.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.155-158
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• 2007

As a secondary stage of the liquid rocket engine development test, turbopump-gas generator powerpack tests are being performed. The schematics of the test hardware and the test facility for the TP+GG coupled test are presented. The results of a preliminary test results for the verification of the propellant supply system of the test facility are also presented. Based on the preliminary tests results, the verification of the propellants supply systems of the facility system was performed.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.17 no.1
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• pp.24-28
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• 2009

The reliability assessment is performed for Pressure Control Regulator of Aircraft Fuel System using reliability procedure which consists of the reliability analysis and the Failure Modes and Effects Analysis(FMEA). The target reliability as MTBF(Mean Time Between Failure) is set to 5000hr. During the reliability analysis process, the system is categorized by Work Breakdown Structure(WBS) up to level 3, and a reliability structure is defined by schematics of the system. Since the components and parts that have been collected through EPRD/NPRD. The predicted reliability to meet mission requirements and operating conditions is estimated as 4375.9hr. To accomplish the target reliability, the components and parts with high RPN have been identified and changed by analyzing the potential failure modes and effects. By changing the configuration design of components and parts with high-risk, the design is satisfied target reliability.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1779-1781
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• 1998

We are going to design the Square Pulse Generator use of PCPS (Photo-Conductive Power Switch) for Blumlein lain. The circeuit is made of LC device and it is simulated by Schematics Evaluation Version 8.0 of MicroSim. After charged by DC voltage 15[kV]. When the switch is ON, Square pulse is generated after pause time 1.7857[${\mu}s$]. The square pulse is maximum peak voltage 13.987[kV], pulsed width 3.4017[${\mu}s$], rising time 0.7474[${\mu}s$], falling time 1.1718[${\mu}s$].

• Aerospace Engineering and Technology
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• v.1 no.1
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• pp.55-64
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• 2002

A conceptual design of propulsion system for a geosynchronous communication satellite with 12 years design life is presented in this paper. Propellant mass budget for the design life is calculated using total velocity increment (ΔV) flowed-down from mission requirement analysis. Sizes of the fuel and oxidizer tank are derived based on the calculated propellant mass budget, and mass of the pressurant as well as the size and pressure of pressurant tank are calculated too. Thruster positioning, number of rocket engines, and position of tank are determined through Trade-Off Study with Structure & Mechanical Subsystem. Propulsion system configuration and its schematics are presented finally.