• Annual Conference of KIPS
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• 2000.04a
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• pp.396-399
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• 2000

이동 네트워크 상에서의 인터넷 서비스가 활성화됨에 따라 이동 호스트에 대한 인증 및 비밀성이 요구되었고, 이동 호스트의 이동성에 따른 익명성 및 불추적성이 중요한 고려사항이 되었다. 본 논문에서는 이동 호스트가 도메인간을 이동하면서 노출될 수 있는 이동 호스트의 identity의 보호를 위한 익명성 보장 및 불추적성을 지원하는 안전한 인증 프로토콜을 제시한다.

• Proceedings of the KIEE Conference
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• summer
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• pp.307-309
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• 2004

A DC railway system has low feeder voltage, The remote fault current can be smaller than the current of load starting. So it is important to discriminate between the small fault current and the train starting current. The train starting current increases step by step but the fault current increases all at once. So the type of $\bigtriangleup I\;relay(50F)$ was developed using the different characteristics between the load starting current and the fault current. As for the train starting current, the time constant of train current at each step is much smaller than that of the fault current. To detect faults in U railway systems, an algorithm that is independent of train starting current. This algorithm use the time constant calculated by the method of least squares is presented in this paper.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.9
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• pp.17-22
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• 2019

A ship's propulsion system is a device to move the ship by means of the power transmitted from the ship's engine to the propeller. In this study, three propeller models, a, b, and c, are designed and their flows are analyzed. Same flows with the same material are applied to all three models. Flow analysis results differ according to the shape of flow model though these models are the same material. In all respects, model C is considered to be more rigid and efficient than models A and B. A propeller model optimized for the driving force and stability can be developed through this study result.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.9
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• pp.23-28
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• 2019

In this study, flow analysis results according to different air cleaner and resonator configurations were used to investigate flow and velocity. Among models A, B, and C, model B had the higher speed and pressure. Model B is therefore considered suitable as an air cleaner. This study aims to design optimal shapes of air cleaners and resonators without noise sources.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.10
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• pp.1-7
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• 2019

Most of people are riding on their own bicycle due to the health and environmental pollution problems. The weight must be light in order to run farther and easier by bicycle. The durability will be reduced due to the light weight of tubes and handles at bicycle. To solve this problem, the three bicycle handle models 1, 2 and 3 were compared with each other for structural analysis. The structural analysis was carried out in this study. Among three models, model 2 and model 3 had the highest and lowest strengths at the structural analysis results, respectively. At this study result, model 1 is thought to be the balanced excellent model with no defect among three models.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.8
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• pp.18-23
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• 2019

In this study, structural and fatigue analyses of the motor gears that control the height of car seat were carried out at angles of $10^{\circ}$, $20^{\circ}$, and $30^{\circ}$. The study aims at examining which angle of the gear is superior in terms of effect on strength. In the structural and fatigue analyses, the force of 3136 N was applied to the gears, and the stress and deformation were obtained. As the analysis results, model B ($30^{\circ}$) is suggested to have the best strength and fatigue durability among the three models.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.281-285
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• 2008

Corrosion of metallic structures arises when an electric current flows from the metal into the electrolyte such as soil and water. The potential difference across the metal-electrolyte interface, the driving force for the corrosion current, can emerge due to a variety of temperature, pH, humidity and resistivity etc.. With respect to a given structure, a stray current is to be defined as a current flowing on a structure that is not part of the intended electrical circuit. Stray currents are caused by other cathodic protection installations, grounding systems and welding posts, referred to as steady state stray currents. But most often traction systems like railroads and tramlines are responsible for large dynamic stray currents. This type of stray current is generally results from the leakage of return currents from large DC traction systems that are grounded or have a bad earth-insulated return path. This paper investigates the reports, which is made for protecting the electrical corrosion by the DC traction stray current before the construction period.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.286-293
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• 2008

DC transit system has been adopted in the metropolitan area, Korea since 1974. EMU in this system always reiterates that acceleration and retardation. When EMU decelerates using electric breaking, regenerative power occurs. Regenerative power can be consumed in vicinity EMC on the same line or in resistor. If DC transit system has inverter for reusing regenerative power, Energy efficiency in DC transit system will be increased. This paper present the developed inverter for regenerative power and its field test. Test result of developed inverter is presented.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.185-189
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• 2008

D.C. traction systems can cause stray currents which could adversely affect both the railway concerned and outside installations, when the return circuit is not sufficiently insulated versus earth. As experience for several decades has not shown evident corrosion effects from a.c. traction systems and actual investigations are not completed, stary currents flowing from a d.c. traction system is issued. D.C. traction systems can cause stray currents can be corrosion and subsequent damage of metallic structures, where stray currents leave the metallic structures. There is also the risk of overheating, arcing and fire and subsequent danger to persons and equipment. Any provision employed to control the effects of stray currents be checked, verified and validated. Direct measurement of stray current is difficult and a provision employed to control the effects of stray currents is proposed.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.423-426
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• 2019

본 연구의 목적은 서로 다른 지역의 공항서비스품질이 고객만족도에 어떤 영향을 미치는지를 규명하고자 하는 것이다. 서로 다른 지역에 있는 공항의 서비스만족도를 고찰하는 것이다. 더 좋은 공항서비스 제고방안을 제시하려고 하는 것이다. 본 연구는 설문조사를 통해 SPSS와AMOS를 사용해 신뢰도분석, 타당성분석 그리고 구조방정식모형을 통해 통계분석을 실시하였다. 분석결과, 한국 인천공항 측에서 모든 가설 다 유익한 결과가 나타났고, 중국 수도공학 측에서 공항서비스 품질이 고객감지품질에 정의 영향과 감지품질이 고객충성도에 정의 영향을 유의하지 않은 결과를 얻었다.