• Journal of the Korean Society of Safety
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• v.39 no.2
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• pp.65-74
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• 2024

We analyzed the relationship between the normal measurement of the seismic accelerometer (SA) and the error rate of the output voltage linear ratio to propose an evaluation method to determine whether the SA in use is measuring normally. Utilizing a test bed, the regular operation of SA in use was evaluated using acceleration data measured through impact tests since there are no regulations regarding performance testing of SA in use. For the used SA, the error rate of the output voltage linear ratio, which is a major performance criterion, was evaluated. We analyzed common characteristics of the SA that satisfied the impact test and the performance criteria of the output voltage linear ratio error rate. The results indicated that we must consider the decreasing trend and convergence of the error rate as the measurement angle increases, ensuring that the average value of the output voltage linear ratio error rate is within 1%.

• Journal of the Korean Society of Safety
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• v.2 no.1
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• pp.17-29
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• 1987

The extraction mechanism of Zinc from aqueous solution with D2EHPA (Di-2-Ethylhexyl Phosphoric Acid) dissolved in Kerosene was studied by the single drop method. The effect of the concentrations of reactant species on the extraction rate, Zinc and hydrogen ion in the continuous phase and D2EHPA in the dispersed, was studied for the drop rise period by the experiment. Then a theoretical analysis on the basis of Handlos-Baron modle was carried out. It becomes clear that the extraction rate was controlled by the neutral complex forming reaction at the drop surface from both analysises. From effect of the concentrations of species on the reaction rate, the extraction rate at the drop surface is considered to be as follows. $${\gamma}_{pn}=9.42{\times}10^{-7}\;\frac{[Zn^{2+}][(HR)_2]^{3/2}}{[H^+]^{3/2}}$$

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.133-135
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• 2012

The Fire growth rate(kW/s²) is significant impact on initial fire behavior in fire safety design of buildings. As a result of domestic existing combustibles, this study analyzed considering matters in techniques for calculating caloric values, and then made an investigation sheet. By utilizing written combustion sheets, the study could suggest a standard model at common houses and dense ones after getting caloric value information in dense ones. As a result, fire growth rate is experiment 1(0.01), experiment 2(0.0048), FDS(0.0072), MATSUYAMA equation(0.0144).

• Journal of the Korean Society of Safety
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• v.23 no.5
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• pp.49-53
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• 2008

Glow discharge has lots of attractive properties, such as lower discharge sustaining voltage, no generation of ozone, and so on. And more, ionizer was developed recently using an atmospheric pressure glow discharge. On the other hand, ionizer needs a compressed or blown air to transport ion for charged objects. This air is very useful in explosive hazardous area to prevent the explosion of flammable gas and/or vapor by ignition sources, e.g. electrical spark. In this paper, we investigated the ionizing characteristic of atmospheric pressure glow discharge by controlled air flow rate from 5 liters to 60 liters a minute, and compared with decay time between the corona discharge and glow discharge as a function of some direction and distance from discharge ion source. We confirmed that an air flow rate needs 25 liters a minute to sustain the most suitable atmospheric pressure glow discharge and to increase an ionizing efficiency.

• Nuclear Engineering and Technology
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• v.50 no.3
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• pp.379-388
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• 2018

Models for the rate of atomization and deposition of droplets for stratified and annular flow in horizontal pipes are presented. The entrained fraction is the result of a balance between the rate of atomization of the liquid layer that is in contact with air and the rate of deposition of droplets. The rate of deposition is strongly affected by gravity in horizontal pipes. The gravitational settling of droplets is influenced by droplet size: heavier droplets deposit more rapidly. Model calculation and simulation results are compared with experimental data from various diameter pipes. Validation for the suggested models was performed by comparing the Safety and Performance Analysis Code for Nuclear Power Plants calculation results with the droplet experimental data obtained in various diameter horizontal pipes.

• Journal of the Korean Institute of Plant Engineering
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• v.23 no.4
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• pp.29-38
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• 2018

Through process quality information, the time required for process quality analysis has been drastically shortened, the process defect rate has been reduced, and the manufacturing lead time has been shortened and the on-time delivery rate has been improved. Therefore, The purpose of this study is to develop a quality information analysis system model that effectively shortens the time required for process quality analysis in automobile safety belt parts manufacturing process. As a result of experiments on communication operation between manufacturing execution system (MES) quality server, injection machine control computer, injection machine programmable logic controller (PLC) and terminal, in analyzing quality information, the conventional handwriting input method took an average of 20 minutes, but the new multi-network method took about 2 minutes on average. In addition, the process defect rate was reduced by 13% and the manufacturing lead time was shortened from 28 hours to 20 hours. The delivery compliance rate improved from 96 to 99%.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.234-240
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• 2011

Preventing incidents occurred in construction process is important for safe implementation of construction projects. Due to the complexity and magnitude of the project and moreover, poor safe planning and management, construction incidents in Korea have been increasing. Reducing construction incidents effectively, appropriate safety management program in consideration of the incident rate of each facility is to be adapted. This study analyzes incident frequency and severity rate of each facility based on the data of construction sites(about 1,560 thousand cases) recorded by Korea Occupational Safety & Health Agency for 3 years from 2007 to 2009, and the incident related data (about 40 thousand cases) of Korea Workers' Compensation & Welfare Service. The results of this study revealed that construction incident rates of 'cold refrigeration storage facilities' are the highest among building types, followed by traditional building religious building, arcade department store and shopping center. In case of other facilities, the incident rate and the rate of intensity of 'pipelining project' are the highest, followed by 'tunneling project'. These results would be used in providing safety programs beneficial for preventing construction incidents.

• Journal of the Korea Institute of Construction Safety
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• v.5 no.1
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• pp.25-30
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• 2023

The Serious Disaster Punishment Act, which has been in effect since January 27, 2022, requires employers or management managers who neglect safety measures to be punished by imprisonment for more than one year in the event of a serious disaster. As this Act on the Punishment of Severe Disasters came into effect this year, it has received a lot of attention from society. According to experts, most of the opinions are that the bill was created focusing on increasing punishment for companies, contrary to the original purpose of the bill to reduce the safety accident rate. This study confirmed whether these contents were true through case studies, and if this continues, the conflict between companies and workers will intensify and the safety accident rate will not decrease. Therefore, this study does not unconditionally increase corporate punishment, but compares many situations through surveys and suggests a way for companies and workers to cooperate with the Critical Accident Punishment Act to reduce the safety accident rate.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.4
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• pp.23-29
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• 2008

This research proposes two sub-models and one integrated model for the classification of safety in curve section of road, where the fatal-rate is relatively higher in accidents. The first sub-model calculates the accident-rate by safety-index that is based on the road geometries. The second decides the safety of curve section by the speed difference between before and in the curve. Finally, the integrated model of two sub-modules can classify the safety of curve section of road.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.3
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• pp.1152-1167
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• 2018

In this paper, I propose an application layer cooperative congestion control scheme for safety message broadcast in vehicular networks, called CMS, that adaptively controls a vehicle's safety message rate and transmit timing based on the channel congestion state. Motivated by the fact that all vehicles should transmit and receive an application layer safety message in a periodic manner, I directly exploit the message itself as a means of estimating the channel congestion state. In particular, vehicles can determine wider network conditions by appending their local channel estimation result onto safety message transmissions and sharing them with each other. In result CMS realizes cooperative congestion control without any modification of the existing MAC protocol. I present extensive NS-3 simulation results which show that CMS outperforms conventional congestion control schemes in terms of the packet collision rate and throughput, especially in a high-density traffic environment.