• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.465-467
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• 1999

The data transmission system in MAGLEV is required a high quality and high speed for a train safety and reliability driving. In the transmission channel between a vehicle and a ground-site, Gaussian noise is negligible, but impulse noise from the chopper controlled propulsoin unit and the Power supplying device is very severe. The transmission channel must be protected from these noise. In this paper, we propose a DSSS (direct-sequence spread spectrum) modulation as a new data transmission technique in the railway and analyze this data transmission characteristics.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1433-1435
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• 2000

Currently KERI is participating a project whose goal is to develop the Korean High-Speed Train(KHST) with maximum speed of 350kph. KERI's responsibility is the electrical system engineering that includes engineering design of an on-board computer system for diagnosis and control of train set and electrical/mechanical devices. A system engineering approach of the design is performed in order to guarantee the passenger safety and economically viable train for on-board control system construction, operation and maintenance. This paper presents the draft engineering des on-board computer system that ensures the s and reliability of KHST. The draft is focuse network interfaced distributed processing system.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.04a
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• pp.139-142
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• 2004

As fiber reinforced composite materials are widely used in aircraft, space structures and robot arms, the study on the non-destructive testing methods of the composite materials has become an important research area for improving their reliability and safety. In this paper, the AE signal analyzer with the resonance circuit to extract the specified frequency of the acoustic emission signal were designed and fabricated. The noise levels of the fabricated AE signal analyzer by the disturbance such as impact or mechanical vibration had a very small value comparable to those of the conventional AE signal analyzer. Also, the crack detection capabilities of the fabricated AE signal analyzer under the static and dynamic tensile test were evaluated and compared with the conventional AE signal analyzer.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.360-367
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• 2000

This paper is intended to provide a method to design control software for the TCMS, train control and monitoring system. The TCMS with this control software will be applied KOREA Standard EMU. The control software is designed by SCADE Case tool to concern safety and reliability. The function for the EMU is implemented in software easily programmed, using a functional block, graphic programming language. The control software has modular design and each module is tested with SCADE simulator. This time we focus a Driving control module, including brake control module, and present a design method and a simulation method for that module.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.516-521
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• 2005

The challenge for companies is to bring to the market a stream of new and improved, added-value, products and services that enable the business to achieve higher margins and thus profits to re-invest in the business. Especially in these days, railway industry has met the competitive challenges of new transportation technologies or the demands of new passenger transportation needs with a spirit of innovation and change that has reshaped the business several times over the course of the century. Like other railway organization, KR-network business is committed to optimising long term performance for its clients in terms of safety, reliability and profitability.

• IEMEK Journal of Embedded Systems and Applications
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• v.9 no.4
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• pp.211-217
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• 2014

Cyber-Physical Systems(CPS) that mostly provides safety-critical and mission-critical services requires high reliability, so that system testing is an essential and important process. Hardware-In-the-Loop Simulation(HILS) is one of the extensively used techniques for testing hardware systems. However, most conventional HILS has problems that it is difficult to support a distributed operating environment and to reuse a HILS platform. In this paper, we introduce EcoHILS(ETRI CPS Open Human-Interactive hardware-in-the-Loop Simulator) in order to test CPS effectively. Moreover, feasibility tests and performance tests of EcoHILS are performed to confirm its effectiveness.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.109-112
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• 2006

In this study, an approach that installs seismic isolation bearings was proposed for the seismic retrofit of the existing bridges. The method that replaces all existing bearings with seismic isolators was proposed already. However, in this study, we recommend to utilize the existing bearings for the benefit of safety and cost. According to our proposal, the seismic isolators do not support vertical loads but they just function as the period shifter and the horizontal damper. To verify this approach experimentally, the real scale bearings and isolators for the real highway bridges were designed and fabricated. And the responses of this isolated bridges to the assumed earthquakes were determined by the pseudo dynamic test scheme. The test results were also compared to the responses computed by the well known structural analysis software to check the reliability of the test. From the test results, we found that the retrofitted bridges using the proposed method showed stable performances under earthquakes.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.555-556
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• 2007

This paper proposes a new concept's IDSFHA(Intelligent Digital Switchgear For Home Automation) which can obtain the safety, the reliability and the easy to correspond to the request of the general electric customer or electric power company under the ubiquitous-based home automation environments The IDSFHA is designed by analyzing their requirement functions, a 32-bit micro processor is adopted as main controller to support efficiently the designed functions. The single phase power IC(ADE7753) is utilized to collect the electric power information, and makes it possible to communicate as internet among the IDSFHA and their using the ethernet convertor. In the proposed IDSFHA, the several functions are implemented such as the earth leakage level display and waveform transmitting, the electric power using fee display, voltage management, load management and load control function. Finally, the prototype of the IDSFHA is made experimently based on the designed results.

• Journal of Korean Institute of Industrial Engineers
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• v.42 no.2
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• pp.151-164
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• 2016

In this paper, we deal with a risk analysis for an IPS (Integrated power system) and propose a simulation model combining the fault tree and event tree in order to estimate the system availability and risk level, together. Firstly, the basic information such as operational scenarios, physical structure, safety systems is explained in order to make the fault tree and event tree of the IPS. Next, we propose a discrete-event simulation model using a next-event time advance technique to advance the simulation time. Also the state transition and activity diagrams are explained to represent the relationship between the objects. By numerical examples, the redundancy allocation is considered in order to decrease the risk level of the IPS.

• Transactions of Materials Processing
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• v.19 no.2
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• pp.88-94
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• 2010

The next generation of diesel engine can operate at high injection pressure up to 1,800bar. The common rail pipe must have higher internal strength because it is directly influenced by the high-pressure fuel. Folding defects in the Common rail pipe can not ensure the structural safety. Therefore, Preform design and fatigue-life analysis are very important for preventing the head of the common rail pipe from folding in the heading process and for predicting fatigue life according to the amount of folding. In this study, a closed form equation to predict fatigue life was suggested by Goodman theory and pressure vessels theory in ASME Code in order to develop an optimization technique of the heading process and verified its reliability through fatigue-structural coupled field analysis. The results calculated by the theory were in good agreement with those obtained by the finite element analysis.