• Wind and Structures
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• v.7 no.1
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• pp.29-40
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• 2004

This study has focused on aerodynamics for a wind-resistance design about the single and tandem box girder sections to realize a super-long span bridge in the near future. Three-dimensional static analysis of flows around the fundamental single and tandem box girder sections with fairing is carried out by means of the IBTD/FS finite element technique with LES turbulence model. As the results of the analysis, computations have verified aerodynamic characteristics of both sections by the histories of aerodynamic forces, the separation and reattachment flow patterns and the surface pressure distributions. The relationship between the section shapes and the aerodynamic characteristics is also investigated in both sections. And the mechanism about the generation of fluctuating aerodynamic forces is discussed.

• East Asian Economic Review
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• v.19 no.2
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• pp.189-220
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• 2015

Multi-scale representations are effective in characterising the time-frequency characteristics of financial return series. They have the capability to reveal the properties not evident with typical time domain analysis. Given the aforesaid, this study derives crucial insights from multi scale analysis to investigate the co-movements between Indian and emerging Asian equity markets using wavelet correlation and wavelet coherence measures. It is reported that the Indian equity market is strongly integrated with Asian equity markets at lower frequency scales and relatively less blended at higher frequencies. On the other hand the results from cross correlations suggest that the lead-lag relationship becomes substantial as we turn to lower frequency scales and finally, wavelet coherence demonstrates that this correlation eventually grows strong in the interim of the crises period at lower frequency scales. Overall the findings are relevant and have strong policy and practical implications.

• Korean Journal of Computational Design and Engineering
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• v.22 no.2
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• pp.181-189
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• 2017

In this paper, we develop a human error-free wire connection guide system. The only related work is Japanese patent by Hitachi. The patent is guiding the wire connection using PC server. And no implementation details have been reported publicly. We propose a new method based on smart mobile devices. The proposed methods are registered as two Korean patents. We implement a prototype wire connection guide system to verify the patents. Through human experiments, we verify the system can reduce the human error more than 90% and speed up the connection process more than twice faster than working without the system. To be used in the industrial fields, the prototype system needs more product packaging works.

• Journal of Mechanical Science and Technology
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• v.20 no.10
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• pp.1607-1613
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• 2006

GIS (Gas Insulated Switchgear) is used in electric power system to insure non conductivity, breaking capacity and operating reliability. In the present study, dynamic analysis on the closing resistors of the GIS has bees carried out by the commercial dynamic analysis code COSMOS MOTION and 3-D modeling program SOLID WORKS. In order to find the minimum value of chatter vibration of closing resistors, the motion of moving and fixed resistor parts of closing resistors were simulated by varying the spring constant, the damping coefficient and the mass of moving and fixed resistor parts. The simulated results were compared with experimental results. The application of the results could reduce chatter vibration of closing resistors of the GIS. These data are also useful on the development of future model GIS with minimum chatter vibration for the determinations of the spring constant, the damping coefficient and mass of a moving part.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05b
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• pp.34-37
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• 2004

It is well known that Ag-CdO alloy for electrical contactor has been widely used in weak or middle electric current field. But it is necessary to decrease Cd contents without decrease of contactor property because Cd is harmful to human body. The present work has been carried out to investigate effects of Mm (misch metal) addition on the property of Ag-CdO alloy for electrical contactor. As the results of present works, hardness and strength was improved and arc resistance was improved, also, in spite of decrease Cd contents by the Mm addition. It was estimated that Ag-oxide particle was refined by Mm addition.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.695-697
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• 2008

Reduction of $CO_2$ emission is one of major issues in the whole industries, especially transport system. Railroad companies in the advanced countries such as EU, Japan, etc. have made great efforts on the improvement of their systems including energy sources, operational efficiency and PR of achievement resulted. Recently, to emphasize the environment-friendly characteristics of the railroad as public transport, the importance of PR is emerging. The achievements were listed in annual, sustainability and corporate responsibility reports. And the superiority of railroad in $CO_2$ emission can be confirmed in web sites and simple advertizing materials. In this study, we proposed the PR programs of achievement and ongoing works in Korean railroad through the case studies on web-based and off-line programs of railroad companies in EU and Japan.

• Journal of Climate Change Research
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• v.9 no.3
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• pp.245-251
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• 2018

Creating Shared Value (CSV) is a new business paradigm in which enterprises benefit from social works. The goal of this study is to assess greenhouse gas emission reduction through CSV-related activities of Yuhan-Kimberly (YK) Company. YK Company has planted over 50 million trees between 1984 and 2016 as a part of CSV activities. Through planting of trees, annual $CO_2 $ emission reduction ranged from 196.2 thousand to $336.3\;thousand\;tCO_2-eq$ depending on forest type in 2016, representing 44 million to 84 million KRW. Those results indicate that the company can contribute to reduction of greenhouse gas emissions as well as obtain economic profits through CSV-related activities. Furthermore, this study provides motives for other companies interested in similar CSV projects.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.1
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• pp.47-56
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• 2010

The main objectives of this comparative study were 1) to quantify the potential contribution of wood chips to revegetation on the cut slope in a constructed area, 2) to compare the floristic similarity of species composition whether existing of wood chips in the soil media or not. Wood chips were combined with soil media in the ratio of 30%. The thin layer (1 cm, 3 cm) soil media revegetation methods and the thick layer (10 cm) soil media revegetation method were constructed on the cut slopes by machineries respectively. Also, comparative experiments the existence of wood chips in the soil media were conducted to evaluate the effects of wood chips on revegetation works. The total size of quadrat was $300m^2$ ($100m^2{\times}3$). The results of monitoring for 3 years on cut slopes were as follows: 1) All the quadrat existed in the proper range for vegetation. 2) Species richness of quadrat including wood chips was 10% more than those of commercial soil medias. 3) The coverage rates of quadrat including wood chips were similar or superior to those of conventional methods. It can be concluded that the use of wood chips would be effective to promote establishment of diverse landscape and vegetation. However, it behooves to continue monitoring on succession of vegetation for ecological restoration. Finally, adequate wood chips deposit and gathering methods should be studied properly.

• Journal of the Korean Society for Railway
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• v.14 no.3
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• pp.271-275
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• 2011

According to governmental policies for green growth, the increase in the traffic volume of railroad is a representative method to reduce total greenhouse gas (GHG) emitted from transport. Comprehensive assessment for the GHG emission of railroad has been studied to compare the difference of transport modes just in the operating step excluded the construction step. The purpose of this study was to evaluate GHG emissions in railroad construction sector. The targets were some construction works for civil, track, building, and electric system in A line. The GHG emission source of constructing railroad infrastructure was mainly the energy consumption of heavy equipments. As a result, the civil construction sector showed more than 96% of total GHG emissions and its specific GHG emission was 2.191 ton $CO_2e/m$. Also, the specific GHG emissions of civil construction works were of the order: earthworks > tunnels > bridges > station. In future, it will be required to calculate the overall GHG emission of railroad through life cycle approaches including operation, maintenance and disposal step.

• Journal of IKEEE
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• v.14 no.1
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• pp.1-7
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• 2010

This paper presents an implementation of the DisplayPort AUX(Auxiliary) Channel. DisplayPort uses Main link, AUX Channel and Hot Plug Detect line to transfer the video & audio data. For isochronous transport service, source device converts to image and audio data which are to be transported through the Main Link and transports the restructured image and audio data to sink device. The AUX Channel provides link service and device service for discovering, initializing and maintaining the Main link. Hot Plug Detect line is used to confirm the connection between source device and sink device. The AUX Channel is implemented with 3315 LUTs(Look Up Table), 1466 Flip Flops and 168.782MHz max speed synthesized using Xilinx ISE 9.2i at SoC Master3.