• International Journal of Safety
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• v.4 no.2
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• pp.18-23
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• 2005

There are many electrical connections in the electric apparatus and most fires due to a fault contact result from a failure or misuse of electric apparatus and installation. The fault contact happens between electrical connections by the loose and the mechanical vibration. In this paper, we have investigated thermal and electrical properties of screwed electric contacts due to the mechanical vibration. The exciter was connected to a signal generator and power amplifier that provided the vibration frequency and amplitude. The vibration, temperature and voltage data were sent to a data acquisition system (DAQ). In the case that fault contact took place, the arc happened between the screwed electric contact and electric wire, heat due to the arc was transmitted to the adjacent insulators, for which the oxide could be generated more. In addition, a spark was generated and the insulator began to melt. Thus, the possibility of electrical fire became the highest in this case. Finally, when the fault contact takes place due to vibration, the hazard of an electric accident is very high.

• Korean Security Journal
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• no.55
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• pp.31-55
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• 2018

The purpose of this study is to analyze the precedence analysis of traffic safety facilities installation for traffic accidents. The main results were as follows. First, the precedence of the number of traffic safety signs installation for the number of traffic accident is follows. The number of traffic safety signs[total number] (time precedent 1), the number of traffic safety signs[attention] (time precedent 7), the number of traffic safety signs[regulation] (time precedent 7), the number of traffic safety signs[indication] (time precedent 4) precede the number of traffic accidents as negative(-) relationship. Second, the number of traffic signal equipments[pedestrian lamp] (time precedent 2) precedes the number of traffic accidents as negative(-) relationship. Third, the precedence of the increase/decrease rate of traffic safety facilities installation for the increase/decrease rate of traffic accident is follows. The increase/decrease rate of traffic safety signs[total number] (time precedent 1), the increase/decrease rate of traffic safety signs[attention] (time precedent 1), the increase/decrease rate of traffic safety signs[indication] (time precedent 1), the increase/decrease rate of traffic safety signs[auxiliary] (time precedent 1) precede the increase/decrease rate of traffic accidents as negative(-) relationship. Fourth, the increase/decrease rate of traffic signal equipments[pedestrian lamp] (time precedent 0) accompanies the increase/decrease rate of traffic accidents as positive (+) relationship.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.12
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• pp.1128-1133
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• 2006

The most important thing to secure safety and reliability of railway vehicles is to verify performance characteristics of equipments, and related companies or research institutes had many efforts to verify performances and functions of equipments synthetically and efficiently. KHST(Korean High Speed Train) has been developed by KRRI (Korea Railroad Research Institute). An electric railway system is composed of high-tech subsystems, among which main electric equipment such as transformers and converter are critical components determining the performance of rolling stock. We developed a measurement system for on-line test and evaluation of performances of KHST. The measurement system is composed of software part and hardware part. Perfect interface between multi-users is possible. A new method to measure temperature was applied to the ]measurement system. By using the system, fault diagnosis and performance evaluation of electric equipment in Korean High Speed Train was conducted during test running.

• Journal of the Korean Society of Safety
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• v.35 no.1
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• pp.1-11
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• 2020

Article 325 (Prevention of Fire Explosion due to Electrostatic) of the Rule for Occupational Safety and Health Standard specifies that in order to prevent the risk of disasters caused by static electricity, fire, explosion and static electricity in the production process, However, in order to do this, it is absolutely necessary to use a pre-detection technology and a detector for antistatic discharge prediction, which is a precautionary measure by static electricity in a fire / explosion hazard place, but in Korea, And there is no technical standard for the application of the technology of the explosion proof structure of the related equipment. Research methods include domestic and overseas electrostatic discharge detection technology and literature investigation of related equipment explosion proofing technology, domestic and foreign electrostatic discharge detection device production and use situation investigation, advanced foreign technology data analysis and benchmarking. In particular, we sought to verify the results of empirical experiments using electrostatic discharge detection technology through sample purchase and analysis of related major products, development of optimization technology through prototype production, evaluation, and supplementation, and expert knowledge through expert consultation. The results of this study were developed and fabricated two prototypes of electrostatic discharge detector based on the technology / standard related to electrostatic discharge detection technology in Korea and abroad through development of electrostatic discharge detection technology and development and production of detector. In addition, based on the development of electrostatic discharge detection technology, we developed an intrinsic safety explosion proof ib class explosion proof technology applicable to the process of using and handling flammable gas and flammable liquid vapor and combustible dust. In the case of the over voltage and minimum voltage are supplied to the explosion-proof structure ESD detector, check the state of the circuit and the transient and transient currents generated by the coil and capacitor elements during the input and standby of the signal pulse voltage. Explosion-proof equipment-Part 11: Intrinsically safe explosion proof structure The comparative evaluation with the reference curve in Annex A of "i" confirms that the characteristics of the intrinsically safe explosion protection structure are met.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.566-570
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• 2001

Generally, grounding systems are responsible for the safe operation of a power system. Their performance guarantees equipment protection and personnel safety under condition of the limited ground potential rise and touch voltages as well as step voltages under ground fault conditions. Therefore, it is necessary to measure the ground resistance frequently for checking the performance of grounding system, In this paper the ground resistance measuring system using digital signal processor and high-performance L-C resonant band pass filter is presented. The signal current magnitude for measuring ground resistance in this system is $10^{-1}[A]\;to\;5\times10^{-2}[A]$ and the current frequency is 30[Hz].

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1511-1516
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• 2011

The maintenance of the turnout is composed of signal field and track field on business, the electrical and mechanical field on system. adjustment and maintenance carry forward through coordination with these fields. In the case of turnout equipment used in a first phase of Seoul-Busan high-speed train, it is treated by classifying as mechanical adjustments and electrical adjustments. Mechanical adjustment is conducted with focus on fine adjustment to meet maintenance standards limits(1mm or less) about interval of basic rail and tongue rail about each part of track transition equipment. This refers to mechanical adjustments performed mainly with physical changes and movement characteristics between basic rail and tongue rail by considering the overall environment surrounding track side of section installed track transition equipment. However, these series of maintenance are conducted in state that high-speed train is not in the process from 1 am to 4 am at night, but common workers for maintenance are not familiar with the operation and checking about various situation, and the workers are even insufficient. Maintenance training using mixed reality is conducted in the place of business, we tried to overcome several problems of safety and time reduction through this training.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.163-165
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• 2018

Most construction disasters are analyzed to be human factors such as not complying with the safety regulations of construction sites, not using clothing and protective equipment, safety insensitivity, and the health of workers. In order to prevent such a construction disaster, the project site management needs to check the health of workers, but it is difficult to check the condition of workers every hour. Therefore, this paper proposed the design of digital safety-helmet that can automatically identify health conditions by checking workers $SpO_2$ and pulse rates, away from simple protective features.

• Journal of the Korea Safety Management & Science
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• v.14 no.4
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• pp.219-227
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• 2012

The trend is going to obtain the accurate and fast information to the development of information technology and electronic technology as an important part of corporate management. Press equipment to produce products that target is small and medium businesses. Became so economical real-time production information system(R-PIS) model has been implemented. R-PIS configure the embedded hardware and PC application software. This system is easy maintenance and upgrade that general-purpose PC and a modular hardware devices. Consists of modules such as wireless communication, LCD, Key-pad, memory control, and sensor signal. R-PIS is efficient materials and product management to maximize the productivity of the enterprise.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.1
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• pp.95-101
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• 2016

Vehicular communications is system which can be applied for transmission of various safety messages or Intelligent Transportation Systems(ITS) applications by combining vehicle/road technology with Information and Communication Technology(ICT). In recent years, a variety of ITS services are available such as driving information, road conditions, V2X messages as well as navigation and traffic jams notification. In general, vehicular communications can be used for vehicle-to-vehicle and vehicle-to-infrastructure communication by adopting IEEE802.11p/1609 standard which is commonly known as wireless access in vehicular environments. In this paper, WAVE communication standard based on the IEEE802.11p is explained and signal characteristics in WAVE communication is introduced. Also, The H/W and S/W characteristics in Road Side Station and On Board Equipment for the Vehicle to Everything communication are analyzed. Received Signal Strength which is power of receiving signal of communication equipment is measured in test road to estimate the real WAVE communication's performance. It is shown that the implemented WAVE communication technology is satisfactory to provide ITS services.

• Journal of Drive and Control
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• v.14 no.2
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• pp.30-36
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• 2017

This paper presents a sliding mode observer-based fault detection algorithm for steering inputs of an all-terrain crane. All-terrain cranes with multi-axles have several steering modes for various working purposes. Since steering angles at the other axles except the first wheel are controlled by using the information of steering angle at the first wheel, a reliable signal of the first axle's steering angle should be secured for the driving safety of cranes. For the fault detection of steering input signal, a simplified crane model-based sliding mode observer has been used. Using a sliding mode observer with an equivalent output injection signal that represents an actual fault signal, a fault signal in steering input was reconstructed. The road steering mode of the crane's steering system was used to conduct performance evaluations of a proposed algorithm, and an arbitrary fault signal was applied to the steering angle at the first wheel. Since the road steering mode has different steering strategies according to different speed intervals, performance evaluations were conducted based on the curved path scenario with various speed conditions. The design of algorithms and performance evaluations were conducted on Matlab/Simulink environment, and evaluation results reveal that the proposed algorithm is capable of detecting and reconstructing a fault signal reasonably well.