• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.11
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• pp.1758-1764
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• 2012

A large number of wire rope has been used in various inderstiries as Cranes and Elevators from expanding the scale of the industrial market. But now, the management of wire rope is used as manually operated by rope replacement from over time or after the accident.It is caused to major accidents as well as economic losses and personal injury. Therefore its time to need periodic fault diagnosis of wire rope or supply of real-time monitoring system. Currently, there are several methods has been reported for fault diagnosis method of the wire rope, to find out the feature point from extracting method is becoming more common compared to time wave and model-based system. This method has implemented a deterministic modeling like the observer and neural network through considering the state of the system as a deterministic signal. However, the out-put of real system has probability characteristics, and if it is used as a current method on this system, the performance will be decreased at the real time. And if the random noise is occurred from unstable measure/experiment environment in wire rope system, diagnostic criterion becomes unclear and accuracy of diagnosis becomes blurred. Thus, more sophisticated techniques are required rather than deterministic fault diagnosis algorithm. In this paper, we developed the fault diagnosis of the wire rope using probability density estimation techniques algorithm. At first, The steady-state wire rope fault signal detection is defined as the probability model through probability distribution estimate. Wire rope defects signal is detected by a hall sensor in real-time, it is estimated by proposed probability estimation algorithm. we judge whether wire rope has defection or not using the error value from comparing two probability distribution.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.7
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• pp.622-628
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• 2016

The prosperity of IT technologies and the removal of restrictions regarding Unmanned Aerial Vehicles (UAVs), also known as drones, have driven growth in their popularity. However, without a proper solution to the problem of accident avoidance for UAVs, this popularity increases the potential for collisions between UAVs and between UAV and terrain features. These collisions can occur because UAVs to date have flown using radio control or image recognition based autonomous navigation. Therefore, we propose efficient UAV routing schemes to tackle the collision problem using vehicular communication systems. Performance evaluation by computer simulation shows that the proposed methods effectively reduce the collision probability and improve the routing efficiency of the UAV. Furthermore, the proposed algorithms are compatible and can be directly applied with small overhead to the commercial vehicular communication system implementation.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.12
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• pp.903-913
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• 1988

Induced voltage causing disturbances on the communication lines of electric train is dealt with when the AT power supply system is employed. Induction interference is of three types, namely, normal state induced voltage, unusual induced voltage in case of power faults, and noise-induced voltage. Calculation of induced voltages occurring in the AT system is more complicated and extensive than in the BT system. In this paper we obtain an algorithm to calculate the induced voltages on the communication lines in the AT system and an algorithm for the induced current in case of the accident that the line falls to the ground. These algorithms are developed to a package of computer programs and their validity was checked on a simulated system. We supply the measures to protect the communication lines suitable for the AT system and we can also evaluate the protection capabilities. Because of the ability to evaluate the protection measures, this package is expected to be very useful when electric train system is constructed on communication lines near the railroad.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.10
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• pp.107-113
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• 2006

The number of confine-disease for elevator increases every year and then sudden stop, error of level indication stand; those can bring to uneasiness of elevator passenger and malfunction accidents related life accident are increasing. So we researched power quality counterplan equipment(SPD, Filter, Reactor) at site elevator controller room and malfunctions of elevator movement. We could confirm installation of power quality counterplan equipment recently and unchanging the number of malfunction. This data will be used the analysis for mutual relation between Power Quality(Sag, Interruption, ESD, ect.) and malfunction of elevator movement by testing the elevator equipment with EN12016(2004) and IEC standard level.

• Safety and Health at Work
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• v.4 no.3
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• pp.160-165
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• 2013

Background: Occupational accidents are unplanned events that cause damage. The socio-economic impacts and human costs of accidents are tremendous around the world. Many fatalities happen every year in workplaces such as electricity distribution companies. Some electrical injuries are electrocution, electric shock, and burns. This study was conducted in an electricity distribution company (with rotational 12-hour shift work) in Iran during an 8-year period to survey descriptive factors of injuries. Methods: Variables collected included accident time, age of injured worker, employment type, work experience, injury cause, educational background, and other information about accidents. Results: Results indicated that most of the accidents occurred in summer, and 51.3% were during shift work. Worker negligence (malpractice) was the cause of 75% of deaths. Type of employment had a significant relationship with type of injuries (p < 0.05). Most injuries were electrical burns. Conclusion: High rate of accidents in summer may be due to the warm weather or insufficient professional skills in seasonal workers. Shift workers are at risk of sleep complaints leading to a high rate of work injuries. Acquiring knowledge about safety was related to job experiences. Temporary workers have no chance to work all year like permanent workers, therefore impressive experiences may be less in them. Because the lack of protective equipment and negligence are main causes of accidents, periodical inspections in workshops are necessary.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.5
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• pp.106-113
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• 2010

If leakage current is neglected, it can become a cause for disasters such as electric shock and fire, therefore a continuous monitoring is necessary. However in most cases, because management of substations is performed by unmanned systems, or walk-around inspections, continuous monitor is difficult. So when an accident occurs and the cause is not immediately resolved causing the emergency generator's OCGR getting activated by the leakage current that in turn cut off the ACB, the emergency generator may stop working. To prevent such a problem, a real-time integrated monitoring system for monitoring the leakage current returning to the grounding wire of neutral point of the low voltage side of transformer is proposed. Therefore in this paper, the effects of flow of leakage current, which is caused by insulation degradation phenomena or insulation destroy phenomena, were identified by simulation. And through cases studies; the excellence of integrated monitoring system was verified.

• Plant Journal
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• v.12 no.4
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• pp.37-43
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• 2016

Power system which provides electricity to the accident mitigation load for nuclear power plant should be verified to maintain the proper voltage level under the various loading and source conditions. For this purpose, it was needed to collect the voltage data of safety related buses during operation of the Reactor Coolant Pump(RCP) motor and Component Cooling Water Pump(CCWP) motor, respectively, under the certain loading condition of the plant. The data (such as, voltage, current, power factor) collected from actual measurement were used to modify the existing ETAP model and then the reanalysis was conducted to simulate the testing conditions. Through these actual measurement and analysis, it ensures that the existing electrical system analysis including assumptions and methods was conducted properly. Finally, the voltage of safety related buses was not dropped below the acceptable level, and the discrepancy between two results was within the limit.

• Journal of the Korean Institute of Gas
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• v.20 no.6
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• pp.89-94
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• 2016

The number of camping population and sites are rapidly increasing with to the expansion of camping culture and the advancement of leisure culture. It is necessary to develop an effective strategy of safety management, as a lot of accidents occur due to the increase of population and sites for camping. Particular attention needs to be paid for accident prevention in the increasing accidents of explosion awing to the overheating of bytane gas, and carbon monoxide poisoning due to the use of non-ventilated areas. In this study, the direction of safety management strategy is analyzed by a survey and analysis of risk factors in campsite about gas facilities and gas appliances in camp site. Accordingly, some directions are suggested. Conclusively, it is expected that the results of this study could help to improve efficiency management for camping.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5838-5842
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• 2011

The study mainly aims to explore how deterioration of motor control center, namely MCC, and vibration put impact on temperature of bus bar as well as temperature change of bolt-nut joint. The motor control center consists of three internal parts (i.e. R, S, T) which are for motor operation of high capacity. Two dimensional mechanism for measuring temperature was designed and manufactured with infrared temperature sensor. Installing it in inner motor control center enabled researcher to monitor temperature of bus bar as well as amount of change of current regularly. Temperature change of bus bar according to load was primarily examined based on a bolted joint in the experiment. It was clearly verified that temperature change of bus bar was proportional to current consumption. Therefore, installing non-contact two dimensional mechanism for measuring temperature in motor control center would be expected to prevent temperature rise owing to overload current and power outage as well as fire accident which can be triggered by poor electrical contact.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.1
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• pp.35-41
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• 2006

Although reachers have studied for a long time, they don't make criteria for anesthesia depth. anesthetists can't make a prediction about patient's reaction. Therefor, patients have potential risk such as poisonous side effect late-awake, early-awake and strain reaction. EEG are received from twenty-five patients who agreed to investigate themselves during operation with Enflurane-anesthesis in progress of anesthesia. EEG are divided pre-anesthesia, before incision of skin, operation 1, operation 2, awaking, post-anesthesia by anesthesia progress step. EEG is applied pre-processing, base line correct, linear detrend to get more reliable data. EEG data are handled by electronic processing and the EEG data are calculated by bicoherence. During pre-anesthesia and post anesthesia, appearance rate of bicoherence value is observed strong appearance rate in high frequency range($15\~30Hz$). During the anesthesia of patient, a strong appearance rate is revealed the low frequency area(0~10Hz). After bicoherence is calculated by percentage of a appearance rate, that is, Bicpara$\#$1, Bicpara$\#$2, Bicpara$\#$3 and Bicpara$\#$4 parameter are extracted. In result of bicoherence analysis, Bicpara$\#$2 and Bicpara#4 are considered that the best parameter showed progress of anesthesia effectively. And each separated bicoherence are calculated by average bicoherence's numerical value, divide by 2 area, appear by each BicHz$\#$1, BicHz$\#$2, and observed BicHz$\#$1/BicHz$\#$2's change. In result of bicoherence analysis, BicHz$\#$1, BicHz$\#$2 and BicHz$\#$1/BicHz$\#$2 are considered that the best parameter showed progress of anesthesia effectively. In conclusion, I confirmed the anesthesia progress phase, concluded to usefulness of parameter on bispectrum and bicoherence analysis and evaluated the depth of anesthesia. In the future, it is going to use for doctor's diagnosis and apply to protect an medical accident owing to anesthesia.