• Journal of the Korean Society for Railway
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• v.6 no.1
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• pp.21-28
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• 2003

Environment-dependent fatigue life of Cu-Cd alloy wires used as messenger wires was investigated. Tensile test results showed the decrease of tensile strength and elongation of messenger wires by 3.7% and 16.8%, respectively, in used specimens when compared to new ones. Messenger wires used at industrial region for 26 yeras showed 35∼50% decrease in fatigue life, which is partly due to the in stress concentrations by formation of corrosion products at the surface. Single wires showed better fatigue properties than stranded wires, especially at low cycle regions with higher stresses. Stranded wires showed shorter fatigue lives than single wires because of friction between wires by surface contact. Service life of messenger wires was dependent upon the environments which they were exposed to. SO$_2$ and humidity deteriorated the fatigue properties by environmental degradation.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.55-58
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• 2005

In this paper, the measuring of the current distribution ratio between catenary and messenger wire on the condition of directly applying voltage to catenary at the Chungbuk line catenary in a process of de-icing system performance test is described. measuring" method and measured data are explained. Result values are also reviewed.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.846-851
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• 2007

The contact and messenger wire is important parts in the electric power system of the railroad. There are so many measurement method like voltage, current, scratch of surface, and glow longer of length. In this paper suggest real time monitering system of messenger wire so called RTU (Remote Terminal Unit) and this system includes CDMA module to transfer real time or saved data of memory to the end user directly who is in the long distance. The hyper terminal program of windows shows the downloaded data from RTU through CDMA communication and this data can be transferred to excel sheet easily.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.9
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• pp.1590-1596
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• 2016

In this paper, catenary wires were analyzed aging through the experiment about a new product and a test sample in accordance with temperature changes from long-term use. In case of the contact wire, the maximum load was reduced within 7% and the tensile strength showed a reduced within 6.7% compared with a new reference standard $110mm^2$. 19 Strands of messenger wire have a little more than a standard value, but result data on tensile test were less than the reference value about stranded wire. Also parts among 49 strands of dropper was found to be smaller than the reference value and it appeared greatly increasing intensity as toward the center of the strand.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.924-931
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• 2011

This paper deal with maximum span calculation technique for 350km/h high speed catenary system. Considers a geometric interaction, possible maximum span length is between two pole. Wind condition and the train current collector is moving even to being pantograph does not escape while operating. Uses like this justice and possible maximum span length is follow next condition. (i) Operating range of pantograph fan head, (ii) The wind velocity which assumes from system, (iii) Width in pantograph from operation height moving, (iv) Type of processing Catenary system, specially tensile strength of overhead contact wire and messenger wire etc. When accurately calculates the maximum permission span, the dropper between of overhead contact wire and messenger wire and must consider the correlation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.5
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• pp.1181-1186
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• 2013

Mobile network has become an essential tool for mutual communications, so a survey research published that most of the smartphone users use Mobile Instant Messenger every day. In this paper, we developed a wire-wireless integrated web messenger that can be used in various platform of mobile devices and desktop computer for communicating between users of some companies. We defined a multi-organization as several independent companies. Our web messenger was developed for communicating of users of a multi-organization. So one of functions of our web messenger is to restrict access to some particular departments in each company for the security of their company. Developed web messenger worked reliably from variety of web browsers on most of platforms such as android, iOs and desktop computers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.3
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• pp.658-663
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• 2008

In this study, we estimated the influence of electrical pole by FEM(Finite Element Method) and developed protective system by designing and interpreting protective system for electrical pole and overhead optical communication line when abnormal strength worked on messenger wire. Protective system did not shed messenger wire under wind pressure and discontent load but did assign a part to preventing rupture of electrical pole and disconnection of optical communication line through automatically shed messenger wire over fixed strength. Structure of protective system analysis by FEM and prove property by measuring tensile strength for practical product.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.375-378
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• 2007

In these days, Korea Railway apply simple catenary system to general lines and high speed lines of Korea Electric Railway. Circulation Current in catenary system frequently bring undesirable consequences. Namely, the Connector wire has many problems according to a flow of excessive circulation (or traction current) and a sudden rise of temperature on catenary when electric car or locomotive is running in high speed. The occurrence of events by the load increasement do considerable damages to peoples, organizations and systems. On a case by case accidents, the reeltype protective cover as part of various methods has some problems. In this project, we proposed the improved changes on the catenary system of a improvement and change of a messenger wire protector, improvement of connector wire's institution angle and of a replacement the connector wire with a dropper. Its tridimensional space limitation dictated the scale of the $32{\times}{\Phi}55$ to be as small as possible. It is easier to install than work by the existing cover on the messenger wire.

• Proceedings of the KIEE Conference
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• 2004.05b
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• pp.156-158
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• 2004

In the ATs(Auto-Transformers)-fed AC electric railroad system, the trolley wire with high power is supported with a messenger by the dropper. As the dropper maintains the height of the trolley wire and plays a role in distributing the supply power, it should be stabilized in that an electric and mechanical character accord ins the change of the open air circumstance and constructed easily. Consequently, this paper propose C5111 Sn(3.5$\sim$4.5%) and hexagonal round bolt for the way of the efficient stabilization as a result of the test that the correlation of the Sn content and the change of temperature affect a character of product.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.886-892
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• 2007

This paper presents examples of trolley wire resistance influential on the movement of tensioning devices. Therefore, this study is on the examples of trolley wire resistance which keep tensioning devices from working properly to the expansion and contraction in accordance with temperature change of overhead trolley wire system such as messenger wire and contact wire. Trolley wire resistance interrupts the working of tensioning device and drops the capacity of trolley wire. Reduced trolley wire capacity lowers the performance of current collection and has a bad effect on electrical train operation. So it is desirable to reduce the factors increasing trolley wire resistance to the minimum from the designing and construction stage of overhead trolley wire system. This study will introduce this problem and suggest the solution.