• Journal of the Korean Society of Safety
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• v.28 no.5
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• pp.1-4
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• 2013

The main objective was to design and develop a prototype robot system for assessing slip resistance. The developed robot system will be able to be used for stochastic nature of friction in the whole workplace. The second objective was to evaluate its operating condition in the laboratory, using a dreg sled type slipmeter(BOT-3000) as reference device. It was found that COF(Coefficient of Friction) measured with robot system was similar to that of BOT-3000 when sliding velocity was reached at 0.2m/s. The robot system might be the more promising one than any traditional measurement devices. A further evolution of prototype devices, as well as the development of test methods for that's various applications, is to be started in forthcoming studies.

• Journal of the Korean Society of Safety
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• v.31 no.4
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• pp.22-26
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• 2016

"Always-on" small ventilators are likely to experience thermal decomposition of insulating material due to thermal, electrical, mechanical and environmental influences, and lose insulating properties by the process of oxidation and physiochemical reaction. This increases the risk of electrical fire because of layer short, short circuit, overload and Plastics are usually used to make ventilator and ventilator enclosures since they make less noise and are cheaper. Although more preferred than iron, plastic, a combustible material, has a higher risk of fire. In this study, several experiments were carried out to find out how RCD(Residual Current Protective Device) and Thermal fuses, which are electric motor protection devices, work and what needs to be done to reduce the risk of fire.

• Nuclear Engineering and Technology
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• v.41 no.8
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• pp.995-1004
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• 2009

The Advanced Power Reactor 1400 (APR1400) is an evolutionary advanced light water reactor (ALWR) based on the Optimized Power Reactor 1000 (OPR1000), which is in operation in Korea. The APR1400 incorporates a variety of engineering improvements and operational experience to enhance safety, economics, and reliability. The advanced design features and improvements of the APR1400 design include a pilot operated safety relief valve (POSRV), a four-train safety injection system with direct vessel injection (DVI), a fluidic device (FD) in the safety injection tank, an in-containment refueling water storage tank (IRWST), an external reactor vessel cooling system, and an integrated head assembly (IHA). Development of the APR1400 started in 1992 and continued for ten years. The APR1400 design received design certification from the Korean nuclear regulatory body in May of2002. Currently, two construction projects for the APR1400 are in progress in Korea.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.123-126
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• 2000

An elevator system which is a essential equipment for a vertical movement of object, as a property of building, have been drove by various expenditure and purpose. Since developing electrical control technology, control systems are highly developed. An elevator equipment is expended to wide, but a data accuracy acquisition technique and safety predict technique for securing system safety is still basic level. So, objective verification for elevator confidence condition is required absolutely accuracy measurement technique. Therefore, this study is accomplished in order to conquer a method of depending on sense of a manager with a simple numeric measurement data, and construct a logical, analytical foresight system for more efficient elevator management system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.378-383
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• 2004

Bogie is the connection device between carbody and wheel. It is the core part that exert a important effect on the passenger safety and running safety. Bogie largely consist of bogie frame, suspension, brake, wheel set. Static and Dynamic load have acted on it complexly. So when the bogie is designed, finite element method, static load test, fatigue test running test should be considered. Some bogie frame of high speed railway freight car have the problem. It's end beam was cracked. The crack of the end beam have a bad effect on brake system. ROTEM co. made an improved end beam and applied one set to freight car. this report showed the vibration characteristic which was compared conventional bogie to improved bogie for running safety.

• International Journal of Safety
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• v.10 no.1
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• pp.22-31
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• 2011

Seismic response control method of the bridge structures with semi-active control device, i.e., magneto-rheological (MR) damper, is studied in this paper. Design of various kinds of clipped optimal controller and fuzzy controller are suggested as a semi-active control algorithm. For determining the control force of MR damper, clipped optimal control method adopts bi-state approach, but the fuzzy control method continuously quantifies input currents through fuzzy inference mechanism to finely modulate the damper force. To investigate the performances of the suggested control techniques, numerical simulations of a multi-span continuous bridge system subjected to various earthquakes are performed, and their performances are compared with each other. From the comparison of results, it is shown that the fuzzy control system can provide well-balanced control force between girder and pier in the view point of structural safety and stability and be quite effective in reducing both girder and pier displacements over the existing control method.

• Journal of the Korea Society of Computer and Information
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• v.23 no.12
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• pp.145-151
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• 2018

While commercialization of IoT technologies in the safety management sector is being promoted in terms of industrial safety of large indoor businesses, implementing a system for risk management of small outdoor work sites with frequent site movements is not actively implemented. In this paper, we propose an efficient dynamic workload balancing strategy which combined low-power, wide-bandwidth (LPWA) communication and low-power Bluetooth (BLE) communication technologies to support customized risk management alarm systems for each individual (driver/operator/manager). This study was designed to enable long-term low-power collection and transmission of traffic information in outdoor environment, as well as to implement an integrated real-time safety management system that notifies a whole field worker who does not carry a separate smart device in advance. Performance assessments of the system, including risk alerts to drivers and workers via Bluetooth communication, the speed at which critical text messages are received, and the operation of warning/lighting lamps are all well suited to field application.

• The Journal of the Korea Contents Association
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• v.19 no.9
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• pp.348-356
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• 2019

This study is was to suggest improvement of assistive device for the elderly according to investigate the satisfaction and the needs of assistive device for elderly. The subjects were 184 beneficiary older adults in long-term health insurance who used home care service in I city and D city. Data were analyzed using SPSS 20.0. With the exception of cognitive assistance grade, subjects were showed from 'normal' to ' satisfied' on a types of assistive device and services related to assistive device. I, II grade subjects needed assistive device for self-care. III, IV and V grade subjects needed assistive device for safety and health maintenance. In the service related assistive device, All subjects needed service on 'periodic follow-up service', 'expert on assistive device' and 'comprehensive evaluation'. This results is significant in that it suggest to needed assistive device in accordance with grade unlike previous studies. Results of this study will expected to utilize as a basic evidence for improvement of assistive device, service related to assistive device for elderly.

• Journal of Energy Engineering
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• v.15 no.1 s.45
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• pp.23-27
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• 2006

This paper presents the evaluation of LPG (Liquefied petroleum gas) regulators for home use. For the evaluation, several properties of the regulators were experimentally analyzed, such as the operation of safety device, the adjusting and lock-up pressure, the adjusting spring and the diaphragm, with respect to the used time of the regulators. Experimental results showed that the initial operation performance of regulators were degraded with increase of the service time and also showed that the degradation of the performance and material property could become serious after six-year-use of the regulator.

• Journal of Korean society of Dental Hygiene
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• v.16 no.2
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• pp.205-214
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• 2016

Objectives: The purpose of the study is to investigate the current status and radiographic safety management in Korea. Methods: A self-reported questionnaire was completed by 200 dental hygienists in Jeonbuk province from September 1, 2014 and October 31, 2014. The questionnaire consisted of general characteristics of the subjects, radiation knowledge, radiation safety management, and radiation exposure anxiety. Data were analyzed using SPSS 18.0 program. Results: Duration of clinical experience(r=0.142) and number of daily radiation shot(r=0.145) showed a positive correlation to radiation safety management, and a nrgative correlation to use of intraoral films and digital devices(r=-0.587). A logistic regression analysis was performed in order to evaluate the influence on radiography knowledge. The results showed that the factors had significant influences on the age group over 41 years old(OR 7.25; 95% CI 1.30-40.43) and those who took a position above team leader(OR 0.23; 95% CI 0.59-0.90). Conclusions: It is very important to have the safety management toward dental intraoral imaging and radiograpgic shot in the dental hygienists. Continuous efforts should be emphasized on radiographic safety management and behavior.