• International journal of advanced smart convergence
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• v.12 no.1
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• pp.220-229
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• 2023

The development of logistics technology due to the 4th Industrial Revolution and logistics 4.0 has changed the logistics environment from offline to online, and the growth of the online market has accelerated due to the recent increase in non-face-to-face delivery due to COVID-19. Such growth in the online market has expanded the logistics market for delivery, and contributes to creating an advanced logistics ecosystem as last mile services and logistics technologies begin to grow together. As traffic and environmental problems arise as a result, interest in transportation means of cargo increases, and changes to cargo electric vehicles and delivery cycles are being considered. However, since mass transportation of transportation focused on terminal delivery such as cargo electric vehicles and delivery cycles is limited in handling large quantities in urban areas, methods for efficiently transporting cargo while considering the environment are being devised. In order to solve such environmental problems and increase the efficiency of logistics delivery in urban areas, technologies using underground spaces based on existing urban railroads are being developed. In this study, a study was conducted on the establishment of evaluation criteria for selecting a test bed, which is a space for applying the system.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.06a
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• pp.65-81
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• 2003

During the last few decades in Korea, the development of hillside or mountain areas has rapidly increased for infrastructure construction such as railroads, highways and housing. Many landslides have occurred during these constructions. Also, the amount and scale of damage caused by landslides have increased every year. In the case of Far East Asia including Korea, the damage of landslides is consequently reported during the wet season. In this paper, the effect of stabilizing piles on slope stability is checked and the behavior of slope soil and piles are observed throughout the year by field measurements in the large-scale cut slopes. In particular a large-scale cut slope situated on the construction site for the express highway in Donghae, Korea. First of all, The behavior of the slope soil was measured by inclinometers during slope modification. Landslides occurred in this area due to the soil cutting for slope modification. The horizontal deformations of slope soil gradually increased and rapidly decreased at depth of sliding surface indicating that the depth of sliding surface below the ground surface can be predicted. On the basis of being able to predict the depth of the sliding surface, stabilizing piles were designed and constructed in this slope. To ensure the stability of the reinforced slope using stabilizing piles, an instrumentation system was installed. The maximum deflection of piles is measured at the pile head and it is noted that the piles deform like deflection on a cantilever beam. The maximum bending stress of piles is measured at the soil layer. The pile above the soil layer is subjected to lateral earth pressure due to driving force of the slope, while pile below soil layer is subjected to subgrade reaction against pile deflection. As a result of research, the effect and applicability of stabilizing piles in large-scale cut slopes could be confirmed sufficiently.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.356-362
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• 2011

Usually urban railways are built under ground thus the necessary condition of urban railroad, a linear-shaped track, causes a difficulty in enhancement of speed limits of urban rail. Also the underground construction of city railroad produces speed limit values reduced according to a speed code array, in case of speed decision according to the conventional block section division, thus onventionally it could not but apply speed limit values lower than actual safety speeds. In this study, The above two facts induced the author to study on a method to enhance speed limit values for CBTC within existing urban railroad sectors. Since it is possible to exchange data continuously and to control speeds in case of railroads based on CBTC, the author applied result values of speed limits, which were gained based on a railroad condition, a linear track, to the CBTC system without correction of the result values and then the author compared and analyzed, through simulation, the running times and the efficiencies of running energies between railway stations, between the existing fixed-block system and the CBTC system. As a result simulation, the improvement of speed and the deceleration distance of reduction confirmed that it was effective to reduce the time to travel between stations. A fixed block the set of constraints on the speed limit, he way the operation is optimized based CBTC speed limit by suggesting ways to reset the scheduled speed measures to improve were extracted.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.181-187
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• 2011

Since 2003, state transportation study core technology development is being promoted as part of the bimodal trams operating in accordance with the development of refractive vehicle as research infrastructure for building high-tech road transport system has been the research and development. Bimodal trams of refraction as the vehicle for him to introduce domestic first ever operation management system also developed in Korea according to case-based technology system, but most of the country, and, in this study, mainly those based on technology integration building management system and the bimodal trams of refraction of a vehicle operated was to highlight the features and benefits. Bimodal tram station itself is the way the exclusive properties and to operate the route with large transport capacity has the characteristics of the railway, but the only routes such as railroad lines is not of closed roads under certain circumstances, the flexibility to use has to be integrated operations management system of bimodal trams characteristics of the railroads and public transportation by combining the characteristics of a flexible, convenient and secure services to users with the aim of providing research and will denote the system developed. In this study, bimodal integration system required for the operation of the tram station around the wired and wireless network management center, applying the organic integration into one system so that you have to be centrally managed. In addition, the existing traffic management system operates as a unidirectional rather than monitoring all system-wide management via the interactive network through real-time requests and responses were configured to allow management and control. These findings of the existing traffic operation management system that you can jump step can be based on future unmanned vehicles and related systems through control of the operation management system will be offered as a basis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.2
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• pp.335-341
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• 1994

Laboratory model test results for bearing capacity of a square shallow foundation supported by a sand layer reinforced with layers of geogrid have been presented. Use of geogrids provides an economical and time efficient method for improving load-settlement, and strength characteristics of weak soils. Especially the geogrid reinforced soil will be necessary in the case of foundations supporting machines, embankments for railroads, and foundations of structures in earthquake-prone areas. Based on the present model test results, the bearing capacity ratio (BCR) with respect to the ultimate bearing capacity (UBC), at levels of limited settlement of the shallow foundation. has been determined. Also, it appears that significant improvement in the UBC of medium sands can be achieved by reinforcing elements which shows promise for future work.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.4
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• pp.933-939
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• 1994

This paper has primarily been directed to evaluate the beneficial effects of geogrid reinforcement in a medium sand on the ultimate bearing capacity (UBC) of a surface foundation. Also, this study was conducted to investigate the permanent settlement of a shallow square foundation in improving the cyclic load-settlement characteristics of reinforced sand deposits by conducting a series of laboratory model tests. Use of geogrids provides an economical and time efficient method for improving load-settlement and strength characteristics of weak soils. Especially the geogrid reinforced soil will be necessary in the case of foundation supporting machines, embankments for railroads, and foundations of structures in earthquake-prone areas. Finally, the test results indicate that the use of geogrid reinforcement in sand subgrades improves their performance under dynamic loads which shows promise for future work.

• Journal of the Korea Concrete Institute
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• v.16 no.4 s.82
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• pp.541-548
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• 2004

This study peformed an evaluation of the physical and mechanical properties and sound absorption characteristics of porous concrete according to the target void ratio and content of the recycled aggregate in order to reduce the noise generated in roads, railroads, residential areas and downtown areas and effectively utilize the recycled waste concrete aggregate generated as a byproduct of construction. The test results demonstrated that the difference between the target void ratio and the actual measured void ratio was less than 1.7% and that the tendency of the compression strength was to reduce rapidly when the target void ratio and the content of the recycled aggregate exceeded 25% and 50%, respectively. In addition, the sound absorption characteristics of the porous concrete using recycled waste concrete aggregate showed that the NRC was the highest at the target void ratio of 25% and the content of the recycled aggregate had very little influence on the NRC. Therefore, when considering the compression strength and the sound absorption characteristics of porous concrete, the proper target void ratio and the content of the recycled waste concrete aggregate are thought to be 25% and 50%, respectively

• Journal of Korean Society of societal Security
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• v.1 no.2
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• pp.61-66
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• 2008

More than 70% of Korea consists of mountainous area and during the construction of roads and railroads many cut-slopes are inevitably formed. A number of environmental factors, such as the rainy season and frost heave during winter/thaw during spring, can result in rock falls and landslides. The failure of slopes is increasing every year and can cause damage to vehicles, personal injury and even fatality. In order to help protect people and property, there is a need for real-time monitoring systems to detect the early stages of slope failures. In this respect, the GMG has been using Translation Rotation Settlement (TRS) sensor units installed on slopes to monitor movement in real-time. However, the data lines of this system are vulnerable and the whole system can be damaged by a single lightning strike. In order to overcome this, GMG have proposed the use of Ubiquitous Sensor Networks (USN). The adoption of a USN system in lieu of data cables can help to minimize the risk of lightning damage and improve the reliability of slope monitoring systems.

• Journal of Korean Tunnelling and Underground Space Association
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• v.4 no.3
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• pp.247-260
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• 2002

This paper presents the design case of the 3-arch tunnel under Daejeon railroad station building. The original construction method was the underpinning method supported by pipe-roof, but it was changed to the mined tunnelling method because of the complex construction condition and the safety problem. This 3-arch tunnel has a width of 28 meters and a height of 10 meters. Overburden is only 23m and the ground around the tunnel is a weathered rock. The allowable settlements for the station building and some railroads are very strict. Accordingly, various measurements for the tunnel stability and the settlement minimization was applied and they were reviewed by 2-D and 3-D numerical analysis.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.4
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• pp.17-28
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• 1991

The purpose of this study is to investigate and present a method for measuring public accessibility to urban open spaces. A basic assumption is that, for urban open space policies, accessibility is more important than per capita area. In this study, for the purpose of simplicity, a residential area is assumed to have access to open space if it is within a certain distance from an urban open space. Official city planning map is overlayed with a 200m grid and each cell of dwelling area is checked whether it is within a certain distance from a cell categorized as urban open space. A computer program for widely commercialized personal computer is developed for data processing so that local governments without access to more sophisticated systems can carry out similar studies for their own jurisdictions. Five cities, big, small, old and new, are selected to test the proposed method. Dwelling areas of Ansan new Town have highest accessibility to open spaces(93.4% of dwelling cells have open space cell within 500m). Seoul (91.2%), Suwon(78.2%), Pusan(73.8%), and Inchon(61.4%) have less accessibility. If we assume the Ansan City residents are evenly distributed over the dwelling area, 93.4% of the population has open spaces within walking distance of 500m. However, if we consider physical barriers such as arterial roads, railroads, and streams that reduce the accessibility, less than 93.4% of Ansan city residents enjoy good access to open spaces. Though a further detailed analysis is needed to picture the microscopic accessibility, this method can serve as a useful tool for urban open space policy and open space alternatives evaluations.