• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.8
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• pp.1169-1176
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• 2013

PES have been recently required to implement railway industry for its application flexibility. The PES should be commensurated with railway safety requirements. It achieved its safety through redundant PES. The redundant systems run with voting functions. The successful major voting result becomes the output of the redundant system. The redundant system have to be synchronized to vote each output results. This paper proposed an algorithm for synchronizing and a voter. The proposed algorithm and the voter are verified using simulation.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.201-203
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• 2001

Safety is emphasized in nuclear power plant system for its characteristic. One of the most important systems to guarantee the safety of nuclear power plant is the PPS(Power protection system). The measurement control system includes PPS, which is similar to the human nervous system, is very important factor not only for the safety but also for the operation. Therefore, developing a technology to level up the performance of measurement system and reliability of the plant will bring cost-effective and safe generation of nuclear power. In this study, I researched composition of digitized PPS and algorithm for cyclic inspection.

• Journal of the Korea Safety Management & Science
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• v.2 no.3
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• pp.81-88
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• 2000

In this research, the system is assumed to carry a single item of which the demand types vary. Demand type is defined as a management's classification of the item according to the demand source or to the service purpose. The purpose of this research is to find the optimal inventory control policy when the system carries a single item which consists of multiple demand types. In this research, the optimizing algorithm contains a heuristic, therefore, the optimal is not guaranteed by the algorithm. At least, this research provides the solution to the problems that have not been solved by the existing algorithms.

• Proceedings of the Safety Management and Science Conference
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• 2000.11a
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• pp.127-130
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• 2000

In this research, the system is assumed to carry a single item of which the demand types vary. Demand type is defined as a management's classification of the item according to the demand source or to the service purpose. The purpose of this research is to find the optimal inventory control policy when the system carries a single item which consists of multiple demand types. In this research, the optimizing algorithm contains a heuristic, therefore, the optimal Is not guaranteed by the algorithm. At least, this research provides the solution to the problems that have not been solved by the existing algorithms.

• Journal of the Korea Safety Management & Science
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• v.7 no.5
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• pp.59-67
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• 2005

The main objective of the statistical analysis about industrial accidents is to find out what is the dangerous factor in its own industrial field so that it is possible to prevent or decrease the number of the possible accidents by educating those who work in the fields for safety tools. However, so far, there is no technique of quantitative evaluation on danger. Almost all previous researches as to industrial accidents have only relied on the frequency analysis such as the analysis of the constituent ratio on accidents. As an application of data mining technique, this paper presents analysis on the efficiency of the CHAID algorithm to classify types of industrial accidents data and thereby identifies potential weak points in accident risk grouping.

• Proceedings of the KIEE Conference
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• summer
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• pp.1300-1303
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• 2004

Using AF(Audio Frequency) track circuits to control block signal automatically. ATC(Automatic Train Control) system employed in urban transit 3/4 line, Gwacheon-line, Bundang-line and Ilsan-line pursues the safety of train operation. ATC is employed as important means for the safety. in which the distance between trains is controlled to satisfy the safety requirement. In this paper, we analyze the control algorithm of ATC and investigate the improvement plan of urban transit driving control mode to guarantee the automatic driving function.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1354-1359
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• 2008

In this paper, we propose a vision based passenger monitoring system for passenger's safety in railway station. Since 2005, Korea Railroad Research Institute (KRRI) has developed a vision based monitoring system, funded by Korean government, for passenger's safety in railway station. The proposed system uses various types of sensors, such as, stereo camera, thermal-camera and infrared sensor, in order to detects danger situations in platform area. Especially, detection process of the system exploits the stereo vision algorithm to improve detection accuracy. The paper describes the overall system configuration and proposed detection algorithm, and then verifies the system performance with extensive experimental results in a real station environment.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.238-246
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• 2021

Collision of small vessels such as fishing boats cause great personal injury. Prior to this study, the collision prevention algorithm was developed to assess the collision risk and make the collision alarm. However, a service provided for safety, such as a collision warning, not only prevents risks, but also requires a certain degree of user satisfaction to function effectively. In this study, the collision prevention algorithm for small vessels was improved to be more practical, and the effects of the improvement were confirmed by applying the algorithm. A survey conducted on the users of the collision warning service confirmed the user requirements for improving the accuracy of the collision warning system and reducing the volume and number of alarms. Accordingly, the algorithm was improved for user satisfaction, and the actual vessel experiment was performed applying the improved algorithm in an actual maritime environment. As a result, the frequency of alarm occurrence decreased compared to former algorithm, but the alarm was relatively steadily generated in dangerous situations. It was analyzed that the accuracy and practicality of the collision alarm were improved. If the practicality and reliability of the improved algorithm are verified in the further study, it will be able to effectively contribute to the prevention of collisions of small vessels.

• Journal of the Korea Institute of Building Construction
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• v.13 no.2
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• pp.159-168
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• 2013

Construction projects have become increasingly complex in recent years, resulting in substantial safety hazards and frequent fall accidents. In an attempt to prevent fall accidents, various safety management systems have been developed. These systems have mainly been evaluated qualitatively and subjectively by practitioners or supervisors, and there are few tools that can be used to quantitatively evaluate the performance of safety management systems. We propose an expertise-based safety performance evaluation model (EXSPEM), which integrates a fuzzy approach-based analytic hierarchy process and a regression approach. The proposed model uses S-shaped curves to represent the degree of contribution by subjective expertise and is verified by a genetic algorithm. To illustrate its practical application, EXSPEM was applied to evaluate the safety performance of a newly developed real-time mobile detector monitoring system. It is expected that this model will be a helpful tool for systematically evaluating the application of a robust safety control and management system in a complex construction environment.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.3
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• pp.281-287
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• 2023

Establishing a ship's passage plan is an essential step before it starts to sail. The research related to the automatic generation of ship passage plans is attracting attention because of the development of maritime autonomous surface ships. In coastal water navigation, the land, islands, and navigation rules need to be considered. From the path planning algorithm's perspective, a ship's passage planning is a global path-planning problem. Because conventional global path-planning methods such as Dijkstra and A^* are time-consuming owing to the processes such as environmental modeling, it is difficult to modify a ship's passage plan during a voyage. Therefore, the D^* algorithm was used to address these problems. The starting point was near Busan New Port, and the destination was Ulsan Port. The navigable area was designated based on a combination of the ship trajectory data and grid in the target area. The initial path plan generated using the D^* algorithm was analyzed with 33 waypoints and a total distance of 113.946 km. The final path plan was simplified using the Douglas-Peucker algorithm. It was analyzed with a total distance of 110.156 km and 10 waypoints. This is approximately 3.05% less than the total distance of the initial passage plan of the ship. This study demonstrated the feasibility of automatically generating a path plan in coastal navigation for maritime autonomous surface ships using the D^* algorithm. Using the shortest distance-based path planning algorithm, the ship's fuel consumption and sailing time can be minimized.