• International conference on construction engineering and project management
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• 2022.06a
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• pp.721-727
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• 2022

Construction safety remains an ongoing concern, and project managers have been increasingly forced to cope with myriad uncertainties related to human operations on construction sites and the lack of a skilled workforce in hazardous circumstances. Various construction fatality monitoring systems have been widely proposed as alternatives to overcome these difficulties and to improve safety management performance. In this study, we propose an intelligent, automatic control system that can proactively protect workers using both the analysis of big data of past safety accidents, as well as the real-time detection of worker non-compliance in using personal protective equipment (PPE) on a construction site. These data are obtained using computer vision technology and data analytics, which are integrated and reinforced by lessons learned from the analysis of big data of safety accidents that occurred in the last 10 years. The system offers data-informed recommendations for high-risk workers, and proactively eliminates the possibility of safety accidents. As an illustrative case, we selected a pilot project and applied the proposed system to workers in uncontrolled environments. Decreases in workers PPE non-compliance rates, improvements in variable compliance rates, reductions in severe fatalities through guidelines that are customized according to the worker, and accelerations in safety performance achievements are expected.

• Journal of the Korea Safety Management & Science
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• v.17 no.1
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• pp.179-192
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• 2015

In an automated industry PLC plays a central role to control the automation system. Therefore, fault free operation of PLC controlled automation system is essential in order to maximize a firm's productivity. A prior test of control system is a practical way to check fault operations, but it is a time consuming job and can not check all possible fault operation. A formal verification of PLC program could be a best way to check all possible fault situation. Tracing the history of the study on formal verification, we found three problems, the first is that a formal representation of PLC control system is incomplete, the second is a state explosion problem and the third is that the verification result is difficult to use for the correction of control program. In this paper, we propose a transformation method to reproduce the control system correctly in formal model and efficient procedure to verify and correct the control program using verification result. To demonstrate the proposed method, we provided a suitable case study of an automation system.

• Journal of the Korean Society of Safety
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• v.32 no.2
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• pp.92-97
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• 2017

This study deals with new application method of the connecting tuned mass damper (CTMD) system for efficient vibration control of adjacent twin structures which have the same dynamic properties such as natural frequency and damping characteristics to each other. In the existing research, the vibration control of the twin structures has a limit to the application of the conventional damper-connection method of the twin structures. Due to the same frequency characteristics leading to the equally vibrating behaviors, it is impossible to apply the conventional connection method of the adjacent structures. In order to overcome these limitations induced by the symmetry of the dynamic characteristics, we propose a new CTMD-based control system that adopts the conventional connection configuration but unbalances the symmetric system by arranging the control device asymmetrically and then can finally achieve the efficient control performance. In order to demonstrate the applicability of the proposed system, numerical simulations of the optimally designed proposed system have been performed in comparison with the optimal design results of the existing independent single tuned mass damper (STMD) control system and the another optimal control system previously proposed by the same author, hereafter called CTMD-OsTMD. The comparative results of the control performances among STMD, CTMD-OsTMD and the proposed CTMD systems verified that the newly proposed control system can be a control-efficient and cost-effective system for vibration suppression of the two adjacent twin structures.

• Journal of Aerospace System Engineering
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• v.11 no.2
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• pp.23-29
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• 2017

Since the flight-control system is critical for the safety of an aircraft, a fail-safe system is needed in a flight demonstrator used to test a new flight-control system. A backup control system is also needed to ensure safety in using a mechanical flight-control system. This paper presents a development of an MFCS (Mechanical Flight Control System) model for simulating control authority switching of a helicopter technical demonstrator, as well as the results of evaluating the developed MFCS model.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.8
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• pp.856-864
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• 2008

This paper describes a vehicle low speed driving assistant (VLDA) system that is composed of laser scanner. This vehicle is designed for following lead vehicle (LV) without driver's operation. The system is made up several component systems that are based on unmanned ground vehicle (UGV). Each component system is applied to use advanced safety vehicle developed to complete UGV system. VLDA system was divided into vehicle control system and obstacle detecting system. The obstacle detecting system calculate distance and angle of LV and transmit these data to vehicle control system using front, left and right laser scanners. Vehicle control system makes vehicle control values such as steering angle, acceleration and brake position and control vehicle's movement with steering, acceleration and brake actuators. In this research, we designed VLDA system like as low speed cruise control system and test it on real road environments.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1255-1263
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• 2008

A Safety Case is an railway organization's formal arrangement, through the provision of policies, resources and processes, to ensure the safety of its work activity within safety management system. An effective system helps the organization to identify and manage risks effectively. It allows an organization to demonstrate its capability in achieving its safety objectives and in meeting regulatory requirements. The purpose of this research is to give how to the risk assessments are described within Railway Safety Cases can be prepared and maintained to meet the criteria specified by the upcoming railway regulations. Through this research, we propose the elements of safety management system that include arrangements for the ongoing identification of hazards, assessment of risks and the implementation of necessary control measures.

• Journal of the Korea Institute of Building Construction
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• v.15 no.3
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• pp.339-349
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• 2015

A large-scale research project to develop a robot-based automated building construction system for steel structures was successfully conducted in South Korea. This paper discusses the results of the real-scale test and the key lessons gained from the testing process. The system was assessed in terms of system productivity, construction cost, quality control, and safety improvements. While the productivity of the automated system showed an improvement of about 9.5%, the construction cost was about six times higher than that of the conventional method. The field test also indicated that the automated system requires more on-site quality control measures. However, because the system can eliminate the causes of various safety accidents, safety levels might be expected to be improved significantly. It is expected that this paper will provide knowledge and insight for developing new systems, and the results of the real-scale test might be useful for other researchers and similar research projects in the future.

• International Journal of Railway
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• v.3 no.2
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• pp.68-72
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• 2010

Railway vehicles equipped with semi-active suspension system can improve the ride quality of car bodies. Semi-active suspension system is usually applied onto high speed train, and therefore higher running safety requirement is desirable. The influence of semi-active suspension system on safety of vehicles running on straight line and curve line is studied, and the influences of sky hook damping coefficient and system time-delay on operational safety of cars fitted with semiactive suspension system is analyzed. The results show that in vehicles equipped with semi-active suspension system, while the vibration of car body is decreased, the running safety of cars is not affected to any significant degree. As a result, the ride quality is much improved with negligible deterioration of the running safety of cars.

• International Journal of Railway
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• v.2 no.4
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• pp.147-151
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• 2009

Railway vehicles equipped with semi-active suspension system can improve the ride quality of car bodies. Semi-active suspension system is usually applied onto high speed train, and therefore higher running safety requirement is proposed. The influence of semi-active suspension system on safety of vehicles running on straight line and curve line is studied, and the influences of sky hook damping coefficient and system time-delay on operation safety of cars fitted with semiactive suspension system is analyzed. The results show that the vehicles equipped with semi-active suspension system, not only the vibration of car body is decreased, it can also give little influence on running safety of cars, as a result, it will not endanger the running safety of cars.

• Journal of the Korean Society for Railway
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• v.6 no.1
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• pp.1-9
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• 2003

This article proposes an integrated systems engineering and safety analysis model for safety-critical systems development. A methodology in system design for safety is considered during the early phase of the development life cycle of systems engineering process. The evolution of the design automation technology has enabled engineers to perform the model-based systems engineering. A Computer-Aided Systems Engineering(CASE) tool, CORE, is utilized to integrate the systems engineering model with a system safety analysis model. The results of the functional analysis phase can drive the analysis of the system safety. An example of Communications-Based Train Control(CBTC) system for an Automated Guided Transit(AGT) system demonstrated an application of the integrated model.