• Nuclear Engineering and Technology
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• v.51 no.7
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• pp.1842-1852
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• 2019

The AP1000 reactor coolant pump is a vertical shielded-mixed flow pump, is the most important coolant power supply and energy exchange equipment in nuclear reactor primary circuit system, whose steadystate and transient performance affect the safety of the whole nuclear island. Moreover, safety demonstration of reactor coolant pump is the most important step to judge whether it can be practiced, among which software simulation is the first step of theoretical verification. This paper mainly introduces the fluid-solid coupling simulation method applied to reactor coolant pump, studying the feasibility of simulation results based on workbench fluid-solid coupling technology. The study found that: for the unsteady calculations of the pure liquid media, the average head of the reactor coolant pump with bidirectional fluid-solid coupling decreases to a certain extent. And the coupling result is closer to the real experimental value. The large stress and deformation of rotor under different flow conditions are mainly distributed on impeller and idler, and the stress concentration mainly occurs at the junction of front cover plate and blade outlet. Among the factors that affect the dynamic stress change of rotor, the pressure load takes a dominant position.

• Journal of the Korean Society of Systems Engineering
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• v.19 no.1
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• pp.64-78
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• 2023

This paper introduces urban air mobility (UAM) and the definition and types of vertiports required for UAM operations. It also examines domestic policy trends related to UAM and identifies UAM routes in Seoul currently planned by the government. To do so, we reviewed prior research on vertiports, analyzed new regulations from the European Aviation Safety Agency, and studied domestic vertiport specifications and deployment plans for UAM operations based on the size of the S-A1 airframe being developed by Hyundai, and applied them to Samsung Station, the core area of the demonstration routes. Next, using the 'Travel Time Savings Ratio', a method for evaluating transportation economics, we compared and analyzed the time taken by passenger vehicles and the time saved by using UAMs to derive a highly economical demonstration route. As a result, the Samsung Station↔Cheongnyangri Station section was found to be the most efficient. These findings are expected to be utilized for adjusting the distribution of UAMs when operating the demonstration route in the future.

• International Journal of Safety
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• v.6 no.2
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• pp.38-42
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• 2007

As railway signaling system is computerized, the significance on safety demonstration and assessment has been increased. Therefore, railway signaling system should reflect the needs for safety assessment technique. Various studies on safety assessment technique for railway signaling have been made in Europe and standardization of the requirements for safety acceptance has been initiated by IEC. In order to develop and establish the safety assessment techniques for railway signaling in Korea, we try to review safety assessment activities for signaling system via reviewing relevant case studies and consulting with experts. And also we propose the safety assessment activity/methodology for Korean railway signaling system.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.1
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• pp.1-15
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• 2022

In order to trust and use autonomous vehicles, safe driving on the road must be guaranteed. For this, the first infrastructure to be equipped with autonomous driving is traffic safety facility. On the other hand, autonomous vehicles(Level 3) and general vehicles are driving on the road, it is necessary to additionally manage existing general traffic safety facilities. In this study, a field management system for traffic safety facilities based on autonomous driving infrastructure was studied, and a pilot field management system was implemented in the demonstration area(Pangyo). The pilot system consists of a GNSS(Global Navigation Satellite System) receiver, a field management equipment, and a field management app. As a result of field demonstration,, it was confirmed that traffic safety facility information was easily transmitted and received even in downtown areas and that could be efficiently operated and managed. It is expected that the results of this study will be used as reference materials for the spread of autonomous driving infrastructure to local governments and infrastructure construction in the future.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.5
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• pp.224-239
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• 2023

C-ITS (Cooperative-Intelligent Transportation System) refers to user safety-oriented technology and systems that provide forward traffic situation information based on a two-way wireless communication technology between vehicles or between vehicles and infrastructure. Since the Daejeon-Sejong pilot project in 2016, the C-ITS infrastructure has been installed at various locations to provide C-ITS safety services through highway and local government demonstration projects. In this study, a methodology was developed to verify the effectiveness of the warning information using individual vehicle data collected through the Gwangju Metropolitan City C-ITS demonstration project. The analysis of the effectiveness was largely divided into driving behavior impact analysis and environmental analysis. Compliance analysis and driving safety evaluation were performed for the driving impact analysis. In addition, to supplement the inadequate collection of Probe Vehicle Data (PVD) collected during the C-ITS demonstration project, Digital Tacho Graph ( DTG ) data was additionally collected and used for effect analysis. The results of the compliance analysis showed that drivers displayed reduced driving behavior in response to warning information based on a sufficient number of valid samples. Also, the results of calculating and analyzing driving safety indicators, such as jerk and acceleration noise, revealed that driving safety was improved due to the provision of warning information.

• Proceedings of the KSR Conference
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• 2003.10a
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• pp.27-43
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• 2003

Reliability Lifecycle from Concept to In-Service Operation and Maintenance. Reliability management must consider - SAFETY - SERVICE REQUIREMENTS. Reliability targets/objectives can be specified at feasibility stage. Reliability analysis to support design process. Reliability assessment to support reliability growth or contractual demonstration. Maintenance optimisation to improve reliability during lifetime of operation. Lessons learnt incorporated into next generation of trains.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1197-1198
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• 2007

According to the computerization of railway signalling systems, the safety demonstration and assessment of railway signalling system is very important. For this reason, railway signalling systems reflect the needs of methodology to assessment the safety. Then many studies of safety assessment methodology for railway signalling systems centering on the Europe, have been made continuously, and the requirements for safety acceptance are currently standardized by IEC. To develop and establish the safety assessment technology for railway signalling system in Korea, we are reviews the safety assessment activities for signalling system through the reviews of related std., case study and consulting by experts.

• The Journal of Korea Robotics Society
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• v.17 no.4
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• pp.477-483
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• 2022

In this paper, we propose waste collection vehicle system with a safety device for worker safety and an autonomous driving function. The steering system is applied as MDPS (Motor Drive Power Steering) system to control the waste collection vehicle of the internal combustion engine. Safety-related errors is prevented through redundancy brake of the integrated system and the control braking system. In order to ensure safety between workers and waste collection vehicles, work guidelines and safety devices for emergency stop in case of danger are applied to vehicles. In addition, this research is conducted on improving the working efficiency through vehicle condition monitoring system and a short-range control system for field test. This research is aimed to secure stability through demonstration and contribute to the industrialization of unmanned waste collection vehicles.

• Journal of the Korean Society for Railway
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• v.11 no.3
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• pp.233-239
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• 2008

It is very important to set a reliability target and verify the requirement when procuring the rolling stock in the aspect of safety, availability and LCC. While there are a few different methods to verify the reliability target, it is required that the most appropriate method should be used considering the characteristics of rolling stock itself and the operation environment. Even though recently the quantitative reliability requirements are widely adopted in domestic market, there is no substantial contents in the various standards and guidelines. In this study we investigate the various reliability demonstration test plans and evaluate them for rolling stock application. And three test plans among them were applied to the real operation data.

• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.85-91
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• 2015

As the interest in hydrogen energy is being increased, it is a widely issue to develop a lot of hydrogen technologies in the field of production, storage, transportation, application and others. In the aftermath, there is a hydrogen town in Ul San, which is expected to expand application fields of hydrogen energy, as a demonstration project. The hydrogen town in Ul San can consist of high and low pressure part by the gas pressure. The high pressure part is managed by 'the high pressure gas safety control act'. And, low pressure part is managed by 'the guideline for the safety management of demonstration project of hydrogen town'. In this paper, to improve efficiency of safety management, the direction of safety management is reviewed by an analysis of low pressure hydrogen facility and safety management items. And then, some improvement directions are suggested. In the end, it is expected that the results of this study could help to activate construction of hydrogen town and improve efficiency of safety management as well.