• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.5
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• pp.703-712
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• 2014

To improve the efficiency and safety of railway systems, the train control system has been considerably evolved from the ground-equipment-based control system (e.g. track circuit, interlocking system, etc.) into the on-board-equipment-based control system. In addition, this train control system enables the rolling stock to intelligently control the trackside facilities by introducing the information and communication technologies (ICT). Accordingly, since the ICT-based train control system makes the railway system be simplified (i.e. the heavy ground-equipment can be removed), the efficient and cost-effective railway system can be realized. In this paper, we perform the feasibility test of the ICT-based train control system via a simulation. To this end, we have developed the prototypes of the on-board controller and wayside object control units which control the point and crossing gate and performed the integrated operation simulation in a testbed. In this paper, before the field test of the on-board-controller-based train control system, we perform the Consecutive operation test for prototypes of the on-board controller, wayside object control units and local control computer.

• Journal of the Korean Society of Safety
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• v.23 no.6
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• pp.76-83
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• 2008

In the course of increasing in human and material damage caused by fire, it is an important research field to develop clean extinguishing agent which does no harm to global environment as well as has a good extinguishing efficiency. This research is a basic step to develop a new clean extinguishing agent. In order to get a satisfactory result, we tested fire extinguishing ability using nitrogen and Novec mixtures gas which are inert gas and new clean extinguishing agent. We used Cup Burner Test made by international standard ISO-14520 regulations of gaseous extinguishing agent ability test, and the fuels used in the test are n-heptane, methanol, ethanol, iso-propanol and 1-butanol. The experimental results of flame extinguishing concentration are n-heptane 6.54%, methanol 8.47%, ethanol 6.98%, isopropanol 6.10% and butanol 6.54% by pure Novec agent. So the finding is that a new clean agent, Novec has an efficient extinguishing ability in a state of gas. Also, in a test as to mixtures gas of nitrogen and Novec, it has a good result for minimum oxygen concentration is under 16%.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.8
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• pp.120-128
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• 2004

The impulse between launch vehicle and atmosphere can generate a lot of noise and vibration during the process of launching a satellite. Structurally, the electronic equipment of a satellite consists of an aluminum case containing PCB. Each PCB has resistors and IC. Noise and vibration of the wide frequency band are transferred to the inside of fairing, subsequently creating vibration of the electronic equipment of the satellite. In this situation, random vibration can cause malfunctioning of the electronic equipment of the device. Furthermore, when the frequency of random vibration meets with natural frequency of PCB, fatigue fracture may occur in the part of solder joint. The launching environment, thus, needs to be carefully considered when designing the electronic equipment of a satellite. In general, the safety of the electronic equipment is supposed to be related to the natural frequency, shapes of mode and dynamic deflection of PCB in the electronic equipment. Structural vibration analysis of PCB and its electronic components can be performed using either FEM or vibration test. In this study, the natural frequency and dynamic deflection of PCB are measured by FEM, and the safety of the electronic components of PCB is evaluated according to the results. This study presents a unique method for finite element modeling and analysis of PCB and its electronic components. The results of FEA are verified by vibration test. The method proposed herein may be applicable to various designs ranging from the electronic equipments of a satellite to home electronics.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.143-144
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• 2014

The demand of diesel engine on the construction equipment has been rapidly increased because of thermal efficiency and power. But some of the construction equipment is imported from other country, since the their demands are not so large as compared with the other construction equipment. The imported construction equipments will be tested for emission with standard measurement mode. This study was conducted to measure emission characteristics of the construction equipment with changed standard measurement experimentally.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.1
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• pp.70-78
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• 2021

Naval surface ships and submarines could be exposed to non-contact underwater explosion(UNDEX) environment. Equipment installed on the ships and submarines could be damaged by shock load generated by UNDEX environment. Therefore, shock survivability of equipment generally evaluated by shock tests. Ground based shock test machine such as Light weight shock test machine(LVSM) is developed to simulate shock load caused by UNDEX environment. In this study, linear dynamic model of LVSM is proposed and evaluated to improve shock test design procedure. Parameters of the model are decided by optimizing time domain response compared to zero payload experiment. Proposed model is verified by comparing simulation results and test results of maximum payload experiment. Finally, shock test design using the model is described for various test equipment weight.

• Journal of Environmental Impact Assessment
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• v.4 no.2
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• pp.123-130
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• 1995

The equipment composed of many complicated electronic stuffs undergoes diverse stresses caused by mechanical vibrations during its service. Thus, to ensure its proper operation in the field a simulated vibration test has to be carried out in the laboratory with the Vibration Qualification Level, the test specification, which can include the real environment. In this paper we intent to deal with method and procedure for determining the Vibration Qualification Level so as to estimate the vibration-endurance for the equipment precisely.

• Journal of the Korean Society for Nondestructive Testing
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• v.7 no.2
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• pp.52-57
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• 1988

This article presents a newly developed equipment system for computer-aided, magneto-inductive testing of metals for material properties. The advantages of ultramodern computer technology over conventional test mothods are illustrated, in particular the greatly simplified equipment adjustment and the extended possibilities of test data evaluation. The characterisitics of the new system of equipment are demonstrated by way of practical testing examples.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.308-309
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• 2018

This paper proposes new D/A(Digital to Analog) Design method for improving accuracy in high-performance test equipment. The proposed new D/A design can improve accuracy of the equipment even with low-resolution D/A converters. The validity of proposed D/A design is verified by analysis and experiment.

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.187-187
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• 2017

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.4 s.121
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• pp.317-323
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• 2007

Non-contact underwater explosions against surface ships could cause extensive equipment damage and render the ship inoperative. As an analytical method, DDAM(dynamic design and analysis method) is used for ship shock design. In this paper, in order to verify the finite element model of large shipboard equipment, modal test of equipment was performed. Major objective of this paper is to describe shock analysis methodology for large shipboard equipment attacked to the top and bottom foundations.