• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.5
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• pp.19-33
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• 2019

There have been enormous efforts to develop an innovative public transport bus service for enhancing its operational efficiency based on Automated Vehicle(AV). However, since the vehicle operating environment in the public transport system varies with the purpose and method of mobility service, it is necessary to preferentially evaluate the current roadworthiness for an effective way to introduce the AV. Therefore, this study classified and redefined AV-based mobility service based on literature reviews. This research conducted the roadworthiness test for checking the feasibilities of the AV-based mobility services. Furthermore, we suggested some deployment strategies of the AV-based mobility service considering the Level-Of-Service (LOS) of road infrastructure based on the results of roadworthiness tests. The proposed direction would have a great potential to introduce the AV-based public transport system in the near future.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.1
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• pp.9-16
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• 2019

In the present study, to investigate flows around space launch vehicles at mid-high altitudes efficiently, a three-dimensional unstructured mesh Navier-Stokes solver employing a Maxwell slip boundary condition was developed. Validation of the present flow solver was made for a blunted cone-tip configuration by comparing the results with those of the DSMC simulation and experiment. It was found that the present flow solver works well by capturing the velocity slip and the temperature jump on the solid surface more efficiently than the DSMC simulation. Flow simulations of space launch vehicles were conducted by using the flow solver. Mach number of 6 at the mid-high altitude around 86km was considered, and the flow phenomena at the mid-high altitude was discussed.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.6
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• pp.107-117
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• 2020

With the recent development of autonomous vehicles, various sensors installed in vehicles have become common, and big data generated from those sensors is increasingly being used in the transportation field. In this study, we proposed a grid index method to efficiently process real-time vehicle sensing big data and public data such as road weather. The applicability and effect of the proposed grid space division method and grid ID generation method were analyzed. We created virtual data based on DTG data and mapped to the road link based on coordinates. As a result of analyzing the data processing speed in grid index method, the data processing performance improved by more than 2,400 times compared to the existing link unit processing method. In addition, in order to analyze the efficiency of the proposed technology, the virtually generated data was mapped and visualized.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.3
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• pp.207-213
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• 2023

The control center of an urban railway operator provides railway users with various information on railway use through a 1:N same-time broadcasting system. However, the facilities of the broadcasting system are aging, exposing many limitations in meeting the needs of urban railway users who have become familiar with mobile services. To overcome these challenges, this study analyzed the mobile-based same-time broadcasting services using location information of urban railway users and the requirements of various stakeholders (urban railway users, an operator, and external service providers, etc.) to suggest optimal service models and physical structures. Through this study, it aims to secure safer operations of urban railway as well as to improve better disaster responses through rapid and efficient spread of the situation in case of disaster.

• Journal of Advanced Navigation Technology
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• v.28 no.4
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• pp.566-573
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• 2024

Applying autonomous driving technology to construction sites is very difficult due to safety issues. However, the application of various positioning and sensing devices, such as cameras and radars, to construction equipment is very active. Based on these technological trends, the government is making various efforts, including the Serious Accident Punishment Act and support for industrial safety management expenses, to reduce the incidence of accidents caused by construction equipment and industrial vehicles. And, related industries have been developing various safety equipment over the past few years and applying them to the field. In this paper, we investigate the current status of safety equipment-related technologies currently applied to construction equipment and industrial vehicles, and propose a direction for the development of safety technology in construction equipment based on artificial intelligence. Improving the safety and work efficiency of construction equipment based on the technology proposed in this paper should be reviewed through simulation in the future.

• Journal of the Korea Convergence Society
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• v.11 no.1
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• pp.237-246
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• 2020

The background of the research is the following: As a result of ultra-light flying device industry development, the utilization of drones and their efficiency have been increasing. However, problems regarding flight permission·approval procedure have not been improved, resulting in increased number of civil complaints. Thus, the purpose of this research is to minimize such civil petition according to the required standards of the two government organizations through enhancing the procedure for managing and employing the system. The research methods entail pinpointing the problems by analysing ultra-light flying device related literature review and by holding focus-interviews with field experts, thereby verifying and providing improved solutions. Under (MLIT) Ministry of Land, Infrastructure and Transport supervision and in accordance with aviation security law, the research provides various updated functions such as improved civil petition processing system's employment and management system, flight approval, integration of names, process, format regarding aviation photographing approval, tool buttons such as the 'Main' button in the system's homepage. This research has the following expected effects : Firstly in the law and regulations section, the clear distinction in the missions and roles of each organization enhances cooperations in tackling civil petition. Secondly the integration of civil petition process reduces time and improves efficiency. And lastly, the improvement of supplementary tools for the public is expected to minimize civil petitions. Future research needs to be conducted under the supervision of the Ministry of National Defense(MND). Factors such as systematic infrastructure for flight photography approval, related unit's reorganization following the defense reform 2.0, and guaranteed conditions for field security action units need to be ameliorated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.778-784
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• 2017

In this paper, we propose wired and wireless distributed control systems designed to improve the freight logistics efficiency and verify wired distributed control systems. The verification condition required that 50 cargo vehicles be connected and operated to travel 21 km from Busan Sinhang station to Jinlye Station at an average speed of about 100km/h. The verification results show that the traction output and braking output of the control and controlled cars are dispersed by the wired distributed control system. The application is expected to more than double the efficiency of the logistics compared to the existing freight transportation system. However, in the case of the wired distributed control system, cable installation and maintenance are difficult, and it is impossible to change the combination of freight vehicles. Through the verification of the wired distributed control system, the applicability of distributed control systems to freight vehicles in Korea was confirmed and the system was further developed to produce a wireless distributed control system. In order to apply the wireless distributed control system, a propagation environment analysis for the ISM band was performed in the testbed and, as a result, it was confirmed that Wifi technology using the ISM band could be utilized. In order to use the WDP (Wireless Distributed Power) devices newly installed in the target vehicles, the transmission / reception control signals associated with the propulsion / braking / total control devices are defined. In the case of wireless distributed control systems, the convenience of their application and operation is guaranteed, but reliability and emergency safety measures should because of the dependence of the control of the vehicle on radio signals.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.792-795
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• 2008

AGT system is a kind of light railway train. AGT system use of concrete track and rubber tire, so it can be reduce the noise and vibration, compare to the normal train system. And, the dynamic responses of normal bridge are influenced by the dynamic characteristics of bridge, the speed of vehicle and the surface roughness of railway. But the AGT system bridge is influenced not only the above facts but also the guiderail unevenness, because, AGT vehicle steered by guiderail. So, in this study, optimized service condition is suggested for the design and operation of AGT system, by the means of experimental study. The experiments are executed for PSC bridge with length of 30m, at the AGT test line in Kyongsan. The test results are compared and investigated according to the prominence. In the test result, the guiderail prominence influenced on the dynamic response of bridge. It shows a increase as compared with no guiderail prominence in the dynamic response value acceleration, displacement, stain.

• Applied Chemistry for Engineering
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• v.30 no.3
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• pp.384-388
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• 2019

In winter season, the snow and ice accretion on the bottom of the high speed railway rolling stock and boogie part has fallen at a high speed from the ballast section (gravel section for the transmission of the rolling stock load received by sleepers and fixing sleepers), causing the gravel to be scattered, thereby damaging the railway rolling stock structures and facilities. In order to solve these problems, the gravel scattering prevention net, manual de-icing, and movable hot air machine were used, but their efficiency was low. For the more efficient de-icing than ever before, an optimum material for de-icing fluid for high speed railway rolling stock was developed by evaluating the ice melting capacity, kinematic viscosity, evaporation of the material used as a chemical de-icing fluid. Four kinds of organic acid salts (sodium formate, sodium acetate, potassium formate and potassium acetate) and two different alcohols (propylene glycol, glycerol) were used as evaluation materials. Potassium formate, potassium acetate, and propylene glycol had similar ice melting capacities in the indoor test, but the propylene glycol showed the best ice melting capacity in spraying the system simulation test. This is because the kinematic viscosity of propylene glycol was 2.989029 St, which is higher than those of other materials therefore, it could stay longer on the ice and de-icing. In addition, potassium formate and potassium acetate were difficult to be used since the crystals precipitated and adversely affected the appearance of the rolling stock. The propylene glycol is the most optimum as an de-icing fluid for the high speed railway rolling stock.

• Journal of the Society of Disaster Information
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• v.17 no.4
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• pp.794-801
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• 2021

Purpose: The effectiveness of the transport vehicle management system of the Chemical Substances Control Act will be studies and used as basic data for future system improvement plans. Method: After the enforcement of the Chemical Substances Control Act, the effectiveness for the transport vehicle management system was studies by comparing the transport plan, guidance and inspection status, safety training completion management, ect., and the reduction rate of chemical accidents. Results: The average number of chemical accidents in transport vehicles nationwide is 20 each year. And It is decreasing with the stabilization of the Chemical Substances Control Act('15.1.1). The first reason for the decrease in chemical accidents is the increase in submission of transport plans. Second, as the guidance and inspection rate increased every year, the shipper company's management of transport companies was naturally strengthened. Finally, it is judged that chemical accident caused by transport vehicles decrease through safety education. Conclusion: The current tranport vehicle management system of the Chemical Substances Control Act is effective. However, further research is needed to improve the practical and efficient transport vehicle management system.