• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2473-2475
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• 1998

In this paper, we implemented RS232C serial communication by the 2 wires(Data,GND), and multiple access, by the applying Collision Sensing Multiple Access(CSMA) Protocol. Multiple access is implemented by assigning a unique ID to each controller. The multiple access control operation starts by sending a command packet from a host to another host and the command packet is composed of ID bytes of source and target host computer, data bytes and the check sum, byte. In host computer, after sending command packet, the collision from loop back data. If collision is detected, it means a command packet was collided with another command packet for another host. The packet communication of the controller enables the multiple acces of the controller through the common serial data link. The application of this serial communication through CSMA protocol and the usage of two wires, have an effect on saving the wires and convenient of layout work.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.506-508
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• 2003

In the case of a fire in the mountains, steel wires coated with zinc and aluminum wires of those power cables exposed to the fire or near around will be deteriorated by the blaze and the high temperature. This paper shows the experimental results that apply to a new wire by an artificial flame-maker and results including the intensity of extension and wrench for a conductor. In addition, there's been an experiment and analysis about the mechanical characteristics of the wire of ACSR $480mm^2$ which was removed from A T/L by a forest fire. Then, the database will be made to predict the state of deteriorated wires by a forest fire using those two data, and data necessary to diagnose the life state of an ACSR wire affected by a forest fire will be given.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.86-92
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• 2000

Recently, the Korea National Railways (KNR) is undertaking a program of electrification of the existing railway routes. In order to implement the ongoing plan, KNR authorized a preliminary engineering study of its electrical systems. This effort included a comprehensive analysis of new grounding networks. The new grounding system runs in parallel with the rails and is connected to all metal structures such as rails, overhead protection wires and substation grounding grids etc., creating an equipotential ground network. This paper presents a study on coupling levels that can disturb signaling and telecommunications in adoption of the new grounding network The simulation for the study is carried out using Matlab software, Several different scenarios are analyzed, including the load condition and a few fault conditions with different fault locations. The induced potentials on the communication cables are computed. The effect of the buried ground wires is also analyzed by comparing the results with and without the presence of the ground wires, The results presented in the paper can be used as a reference for estimating coupling levels in similar rail systems.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.95-97
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• 2005

Loss in the multi-stacked HTS wires are affected by a number of factor, such as, number of wires used in the stack, direction of external magnetic field and insulation thickness between the wire. This paper examines the effects of the insulation thickness on the magnetization loss of the multi-stacked YBCO coated conductor. Measurements of magnetization loss were performed using 4 different typo of multi-stacked wires and under various angle of external magnetic field. Test results show that loss density per unit volume increased for YBCO coated conductors when thickness of insulation increased. Loss density per unit volume decreased for YBCO coaled conductors when stacking number of tapes increased.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.1
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• pp.61-64
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• 2010

Footing Resistance of a 154 kV transmission towers in korea is commonly required to be less than 15 ohm to avoid lightning back-flashover accident. The periodic measurement of Footing Resistance is important to verify that the grounding performance of the towers has been maintained good. Towers are electrically connected in parallel with overhead grounding wire, therefore footing resistance of each tower will be measured after disconnecting the overhead ground wires from the towers. however, In this paper, three direct measurement methods of footing resistance are presented. There are very useful methods without disconnecting overhead ground wires from the tower under measurement. They are compared in KEPCO 154 kV transmission towers. The experimental results describe performances of them.

• Korean Journal of Materials Research
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• v.15 no.1
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• pp.37-41
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• 2005

Stainless steel fibers with a diameter of $17\;{\mu}m$ and 630 nm were produced from stainless steel wires by the drawing/annealing/exfolitation process. The suitable sheath material to draw the core stainless steel wires to fibers was the Cu coating. The low melting metal of Zn was not a suitable sheath coating. Also, an attempt was made to produce $20\;{\mu}m{\Phi}Ti$ fibers from the core titanium wires. The main obstacles in producing Ti fibers were their resistance to deformation owing to the Ti's hop structure, and high reactivity of Ti with the exfolitation solution.

• Fire Science and Engineering
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• v.18 no.2
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• pp.7-11
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• 2004

In this paper, we have simulated the force between the two electrical wires using the finite element method(FEM) according to the value of current and distance when overcurrent flows in the vinyl-insulated vinyl-cabtyre cord(flat-type, 600 V, VCTFK, $2C{\times}1.25mm^2$). And we will present the basic data for the identification of electrical fire by experiment for maximum distance between the two wires according to current and time using large current supply device(Model : EHT_EFAD, Korea) in case of overcurrent.

• Clinics in Shoulder and Elbow
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• v.23 no.4
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• pp.198-202
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• 2020

Simple clavicle fractures can achieve satisfactory results through conservative treatment, and the less frequency of nonunion. Non-union or malunion can occur in displaced clavicle fractures or comminuted shaft fractures. Treatment of displaced comminuted clavicle shaft fractures is performed by holding together the free fragments with interfragmentary screws or wires and fixing them to the clavicle with a plate. Therefore, we performed interfragmentary fixation using open reduction and internal fixation with bioresorbable screws (Mg-Ca alloy, Resomet bioresorbable bone screw; U&I Corp.) and bioresorbable wires (Mg-Ca alloy, Resomet bioresorbable K-wire and pin, U&I Corp.) for displaced comminuted clavicle fractures (Robinson type 2B) and additionally used a metal plate. We expected decreased irritation and infection due to absorption after surgery. We report four cases that were treated in this way.

• Journal of Conservation Science
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• v.31 no.1
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• pp.21-27
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• 2015

The Phoenix-shaped Glass Ewer, which is No. 193 National Treasure, was seriously damaged by a unique form of green glass pieces when excavated among a number of burial accessories of Hwangnamdaechong known to have been formed in the 5th century. While it has long been exhibited at the National Museum of Korea since its treatment for conservation treatment at conservation science laboratory in 1984, the existing adhesive materials seriously deteriorated for the 30 years, and the condition was quite unstable. The epoxy resin used as a restorative materials turned yellowing due to the light and heat so much that it was no longer able to exhibit it in a stable and effective manner. As a result, a re-treatment for conservation was conducted lately. This study focuses on the three pieces of Gold wires used to carefully wrap up the handle of the Phoenix-shaped Glass Ewer broken into three pieces, which has not been studied so far. As for the analysis method for Gold wires, SEM-EDS and Stereo Microscope were used for nondestructive analysis. First of all, the result of the SEM-EDS analysis shows that the composition was Au 91.9 wt.%-Au 92.8 w.t% and Ag 5.9 wt.%-Ag 6.5 wt.%, which indicates that it was an alloy made of Au and Ag. The production technique of Gold wires was also observed by means of optical microscopes. In general, Gold wires were manufactured by a drawing process in which a lump of gold was beaten or pulled out of a hole or by a process of twisting a gold plate. However, Gold wires separated from the handle of the Phoenix-shaped Glass Ewer did not involve any trace of twisting on the surface. Rather, fine vertical stripes were observed with the sections filled up. Hence, it is thought that this Ewer went through a drawing process and then was mended. As a result, no certain relation with the golden mending material used for the Phoenix-shaped Glass Ewer was verified. The findings above indicate that most of the existing researches on Gold wires recognized them, not as separate remains, but merely as a component of other golden remains. Thus, there has been little systematic study on the manufacturing techniques of Gold wires. The future study on Gold wires may verify the correlation between the Gold wires used to fix the handle of the Phoenix-shaped Glass Ewer, which is examined in this study, with that of golden remains in the Silla era.

• The korean journal of orthodontics
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• v.35 no.4 s.111
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• pp.302-311
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• 2005

This study was performed to compare the fatigue limit of stainless steel wires and Fiber-reinforced composites (FRC) under conditions of permitting physiologic tooth movement. and to evaluate the clinical value of FRCs which was used to reinforce the anchorage unit. The stainless steel wire groups were divided into round and rectangular wire groups. The FRC groups were divided into uni-directional and woven groups, with resin coating and without resin coating in the Proximal area After the number of cycles to failure of each of the 6 groups were measured within the $5{\times}10^5\;cycle$ fatigue limit simulating the orthodontic treatment period. the fatigue limit of each group was compared with each other The findings of this study were as follows. In stainless steel wires, the fatigue limit of rectangular wires were higher than that of round wires. But there was no statistically significant difference (p>0.05). In FRCs with resin coating and without resin coating in the interproximal area, the fatigue limit of uni-directional type was higher than that of the woven type (p<0.05). In uni-directional and woven type FRCs, the fatigue limit of FRC with resin coating in the interproximal area was higher thar that of FRC without resin coating (P<0.05) As the FRCs and stainless steel wires did not fracture until the $5{\times}10^5\;cycle$ fatigue limit which clinically is useful. it is sufficient to use FRC and stainless steel wire for reinforcing anchorage. When esthetics is important and the attachment of additional devices are necessary. it seems sufficient to use FRC as anchorage reinforcement.