• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.41-46
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• 2018

Recently, the importance of the northeast economies including Russia has been growing, and according to the Eurasian initiative policy, the enhancement of transportation, logistics and connectivity between the northeast Asian countries is emerging as one of the challenges for future growth. However, due to the different vehicle systems used in each country, the railway connections between countries are not operating smoothly. Especially, the couplers of the railway cars which pass through the countries of northeast Asia including Russia have different regulations, which render their shape and characteristics incompatible. In this study, we propose a method of interconnecting the AAR type coupler used in Korea and China and the CA-3 type coupler compatible with the Russian GOST standard, and verify that its structural safety conforms with each set of regulations. We analyze the possibilities offered by this method of interconnection by performing tests while developing materials satisfying the mechanical properties required for the freight coupler.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.296-302
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• 2004

After the Rio declaration on environment and development in 1992, developed countries are undertaking 'environmentally sustainable transportation (EST)' projects. To meet the needs for EST, current transportation policies in Korea are rapidly reforming and one of its concerns is modernizing and upgrading railway freight system. Planning new railroad construction projects is increasing and subsequent environmental impact assessment (EIA) demands improvements, especially in both the EIA and decision making systems. In this paper, we discuss the present status of EIA for railroad construction projects, especially, by analyzing the EIA documents accumulated for last six years. The EIA for railroad construction projects .accounts for only $4.9\%$ of total project EIAs during 1998-2003. However, the portion is gradually increasing. Major environmental concerns for EIA in railroad construction projects were geomorphological and ecological changes, protection of rare organisms, air pollution, water quality, wast management, noise, etc. We also compared the characteristics of environmental impacts of railroad construction with those of vehicle road construction. The result shows that railroad construction usually requires 3${\~}$4 times longer tunnels and bridges for a given length than vehicle road construction. In addition, the amounts of geomorphological and ecological changes (road-cutting, embankment, devegetation, etc.) in railroad construction were generally less than $40\%$ of those in vehicle road construction. In order to develop environmentally friendly railway systems, monitoring studies for environmental impacts of railroads such as habitat fragmentation and road kills, dispersal of alien plants, tunnelling effects on groundwater and vegetation, and noise impacts are highly required.

• Journal of the Korean Geographical Society
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• v.39 no.4
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• pp.585-601
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• 2004

The purpose of this paper is to examine the change of Korean land transportation system and pattern during 1905-1911 concentrated on road construction so-caued ‘Sinjak-ro’. As conclusions, modem road or ‘Sinjak-ro’ started from modem port to inner hinterland where economic resource or regional center located. A trunk railroad running through Korea Peninsula from Busan to Sinuiju(border between China) is opened its complete operation in 1906 by Japanese investment, when no ‘Sinjak-ro’ road construction begun. Thus from the beginning, railroad station also became important starting point of ‘Sinjak-ro’ as seaports. Before the Japanese annexation of Korea, the ‘Sinjak-ro’ road was constructed mainly between seaport or station, where Japanese commercial settlement located, and hinterlands to help their economic invasion. This study could not deal with other modem transportation systems such as railroads and waterways. It is necessary to examine whole changes of modern transportation systems in this age so that we would comprehend modernization feature of Korea from the viewpoint of transportation history.

• Journal of the Korean Geosynthetics Society
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• v.17 no.2
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• pp.1-7
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• 2018

The number of construction of roads and railroads in soft ground such as coastal areas and wetlands is getting increased. For this reason cases that soft ground improvement is applied are increasing. In general, many ground improvement methods consider only the working conditions at the time or only economy. But if the working condition and economy are taken into consideration together, the number of applicable construction method gets limited. In such a case, a ground improvement method using both the surface layer portion and the deep layer portion is applied. But the basic research on this is still insufficient in practice. Therefore, in this study the reinforcement effect of geogrid was investigated by carrying out the model test realizing the case in which soft surface ground improvement and depth improvement are simultaneously applied. And it was intened to understand the effect of the thickness of surface layer, the diameter and length of the improvement body on the reinforcement effect of geogrid. The result showed that the effect of the surface layer thickness is greater than the effect of the deep layer diameter. Moreover, when the surface layer is reinforced with a geogrid, the strength of the surface layer part is enhanced and this effect of a geogrid reinforcement caused the reduction of surface settlement.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.1
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• pp.1-8
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• 2018

While the number of passengers using urban railroads is increasing day by day, the number of complaints from passengers is also increasing. In order to resolve problems caused by poor communication between urban railroad officials and passengers in this paper. An IOS application using the Internet of Things (IoT) technology is proposed for providing safety and comfort temperature service(s) and for taking prompt action(s) of passengers complaints. In this proposal system, the temperature & humidity sensors were placed in a suitable location within the train. At the same time, transferring measurements to the remote server, allowing passengers to request their desired temperature through the IOS Application. Like this based on the collected data, I suggest a system that urban railroad officials can control temperature & humidity of the train. The proposed system was implemented by the Gwangju Metro Line 1 to validate its effectiveness.

• Journal of Environmental Impact Assessment
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• v.13 no.6
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• pp.295-305
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• 2004

After the Rio declaration on environment and development in 1992, developed countries are undertaking "environmentally sustainable transportation (EST)" projects. To meet the needs for EST, current transportation policies in Korea are rapidly reforming and one of its concerns is modernizing and upgrading railway freight system. Planning new railroad construction projects is increasing and subsequent environmental impact assessment (EIA) demands improvements, especially in both the EIA and decision making systems. In this paper, we discuss the present status of EIA for railroad construction projects, especially, by analyzing the EIA documents for the last six years. The EIA for railroad construction projects accounts for only 4.9% of total 918 project EIAs during 1998-2003, and the portion is gradually increasing. Major environmental concerns for EIA in railroad construction projects were geomorphological and ecological changes, protection of rare organisms, air pollution, water pollution, waste management, and noise, etc. We compared characteristics of environmental impacts of railroad construction with those of vehicle road construction, based on environmental and construction-planning indicators appeared in Environmental Impact Statements. Railroad construction usually requires longer tunnels and bridges for a given length than those for vehicle road construction. In addition, the amounts of geomorphological and ecological changes (road-cutting, embankment, devegetation, etc.) in railroad construction were generally less than 50% of those in vehicle road construction. To develop environmentally friendly railway systems, monitoring studies for environmental impacts of railroads such as habitat fragmentation and road kills, dispersal of alien plants, tunnelling effects on groundwater and vegetation, and noise impacts are highly recommended.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.24 no.5
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• pp.399-408
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• 2006

Railroads have been developed as public transportation and made a great contribution to national economic growth. But after the mid-20th century, its qualities have been getting low because of focusing on the investment and development of cars and airplanes. Its role which is getting the excellent merits on the mass transportation, rapid transit, safety, state period, energy efficiency, and prevention of environmental pollution has been reconsidered. Elements of horizontal alignment are needed in the case where the existing railroad lines should be improved or moved. If its design drawing was lost or damaged, it is impossible to recover. It is not easy to repair for it as disasters. We must understand an existing railroad line to bring a function included a basic geography situation. In this study, we acquire, analyze, and process the digital images of the railroad and then reappear shape of three dimension. And we expect to be utilized to construct the facility information by extracting the alignment elements of existing railroad lines reversely.

• Journal of the Society of Disaster Information
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• v.10 no.1
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• pp.40-48
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• 2014

A number of attempts has been made to reinforce ballasted track substructure to meet the requirement of high-speed operation and effective rehabilitation of existing railroads. For the purpose of this, the use of geogrid has been applied, and the benefit of its use has been recognized via previous studies. In this study, an experimental pullout test was carried out to investigate the influence of normal stress on pullout strength of geogrid using different types of soil and geogrid. The results revealed that the pullout resistance generally tends to increase proportional to normal stress while the pullout coefficient interaction decreases, which is a function of material interface properties, such as the friction angle of soil, and interlocking condition between soil and geogrid. In addition, a methodology based on work-energy concept was proposed to evaluate effectiveness of geogrid and limitedly verified using test results.

• Journal of the Korean Geotechnical Society
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• v.18 no.3
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• pp.73-85
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• 2002

This paper is focused on studying the undrained cyclic triaxial behavior of saturated Nak-dong River sand, using anisotropically consolidated specimens. A test of isotropically consolidated specimens was performed to compare the results of the anisotropically consolidated specimens. The cyclic shear stre3ngth of the sand under various combinations of initial static shear stress and relative density was considered. Failure was defined as a 5% double amplitude cyclic strain and a 5% residual axial strain for both reversal stress and no reversal stress conditions. Using this definition, the cyclic strength of the anisotropically consolidated specimens was affected by the initial static shear stress. For anisotropically consolidated Nak-dong River dense sand, the cyclic strength is greater than that of Toyolura silica sand but is smaller than that of Dogs Bay carbonate sand. By comparing the experimental and predictecl results, it was possible to predict the residual pore pressure of Nak-dong River sand using Hyodo's model with initial static shear stress subjected cyclic loading.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.1
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• pp.130-137
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• 2018

In long freight trains, there is a brake time delay in the neighboring freight cars that causes damage and fractures of couplers, especially the knuckle of them. If there is a problem for couplers in the cars, this could cause a derailment and lead to damage of human life and property damage. In this study, maximum forces on the couplers are studied when a long freight car brakes, with brake delay time and coupler gap. We have made a dynamic model of 50 freight cars and couplers, applying contact between couplers and a characteristic curve for expressing force and displacement of buffers with SIMPACK, a multi-body dynamics program. We use EN 14531-2 from the British Standards Institution, a standard of freight car brakes for the verification of the dynamic model. We also use a simplified method to analyze the dynamic model of 50 freight cars. With changing coupler gap and brake delay time, we do comparative analysis with AAR M-201 from the Association of American Railroads, a standard of AAR couplers. From this result, we find that the standard on fatigue limit is satisfied, such that the brake delay time is within 0.06 second if the coupler gap of the AAR coupler is within 20 millimeters.