• Journal of the Korean Society of Safety
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• v.35 no.4
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• pp.9-14
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• 2020

It is necessary to apply a non-contact high-speed scanning system that can measure in real time in order to prevent the dropping and deformation of the main parts of railway vehicles during high-speed running. Recently, research on a scanning system that detects the deformation state of main parts from a video image taken using a high-performance camera has been actively pursued. In this study, we researched an analysis algorithm of a high-speed scanning system that uses a high-performance camera to monitor the deformation and drop-out state of the main components of the running units equipment in real time.

• Journal of the Korea Safety Management & Science
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• v.10 no.3
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• pp.73-79
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• 2008

Display's life time is defined as the time of 50% luminance drop. It was used luminance and temperature as accelerated factor to accelerated lifetime at test. When it's working jule-heat is generated and device's temperature is growing as any temperature because OLED is self-luminance display device. So we decided temperature condition is 25, $70^{\circ}C$, and luminance condition is $60{\sim}300cd/m^2$ in test. It's assumed accelerated lifetime model by result of the test.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.2
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• pp.145-148
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• 2008

Cationic surfactant can be used as cosmetics and chemical dispersants. The variation of critical micelle concentration (CMC) with temperature over the range $40^{\circ}C$ to $60^{\circ}C$ for N-octadecyl pyridinium bromide was measured by drop methods. Thermodynamic quantities such as free energy, enthalpy, entropy and heat capacity for micellization of N-octadecyl pyridinium bromide in water were calculated by fourth-degree polynominal equation In the result, free energy change was decreased generally by the increment of temperature.

• Journal of the Korea Safety Management & Science
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• v.8 no.2
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• pp.81-90
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• 2006

As aging society makes rapid progress, various social problems arise. The drop of productive labor and the increase of welfare cost can be taken as examples. From this point of view, a use of aged labor is a matter of great Important to national productivity improvement. But, the participation rate of the aged in economical activity amounts to 49.8 percent and their unemployment rate does 2.1 percent. The purpose of this paper is to analyze the deterioration of skill and the lowering of adaption to new working environments due to aging. Since the aging effect is closely related to worker's productivity, it should be properly measured and analyzed. The coordination tester is used to find out activity limitations. Experimental results show that the expert skill of the workers can be improved through the effective of their experience. Therefore we can say that some operation is not influenced by aging.

• Proceedings of the Safety Management and Science Conference
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• 2004.05a
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• pp.117-127
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• 2004

In U.S.A., minimum wage of New Jersey in April 1, 1992 rose from $4.25 to $5.05. At this assession, there was survey by 410 numbers related back and pro minimum wage in New Jersey and eastern Pennsylvania.. At stores of New Jersey and eastern Pennsylvania, comparison of the increase of employment at constant minimum wag is with estimative effect of increase of minimum wage. Through comparison of stores of low wage and high wage above $5, employment volatility in New Jersey was studied. In U.S.A., increase of minimum wage was not caused to reduce to employment. Contrary to this, result of Korea was not consisted after timing of IMF bailout of 1997. It is because drop of revenue was caused to decrease employees of part-time and full-time job at the viewpoint of cost minimization.

• Journal of the Korea Safety Management & Science
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• v.8 no.5
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• pp.181-191
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• 2006

The main objective of this study is to analyze characteristics on the somatotype of modern adult women In order to standardize of products. The sample for this work chosen from data which were collected and measured by Size Korea during two years($2003{\sim}2004$). In order to analyze feature of the somatotype of modern adult women, analysis was peformed in 1,371 subjects(645 twenties women, 725 thirties women) about 21 body parts such as height(4 parts), width(3 parts), thickness(3 parts), circumference(7 parts), length(3 parts) and body weight. According to the result of analysis, it was found that the twenties group was near in slender somatotype, whereas the thirties group was near in fat somatotype compared to standard somatotype.

• Journal of the Korean Society of Safety
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• v.14 no.1
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• pp.25-32
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• 1999

The objective of this paper is to evaluate the fracture resistance characteristics of SA508 CL.1a carbon steel, TP347 stainless steel and their associated welds manufactured for primary coolant system of Ulchin 3,4 nuclear power plants. The effect of various parameters such as pipe size, welding method, chemical composition, crack plane orientation, metallography and fractography on the material properties were discussed. Test results showed that the effect of pipe size on fracture toughness is negligible while the effect of welding method on fracture toughness is significant. In addition, the drop of fracture toughness in the field fabrication weld of TP347 stainless steel is probably due to the large amount of $\sigma$-phase precipitated on the $\delta$-ferrite boundary and the large size dimples.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.12
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• pp.573-578
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• 2003

In this study, new type of induction charging system for electrostatic spraying was manufactured and proposed to improve the electrical safety and charging efficiency. And parameters of proposed system to generate the maximum deposition current with electrical safety were selected and investigated. The selected parameters were frequency of square pulse and thickness of insulation material, outer diameter of device and thickness and positions of electrode. Charging quantity of water drop was measured by deposition current detected from sensing plate indirectly. The maximum deposition current for each parameter were 3.5[uA] at the frequency of 15[kHz] and thickness of 0.25[mm] insulating layer. And maximum deposition currents were 2.8[uA] and 3.0[uA] at 25[mm] outer diameter of charging device and 0.25[mm] thickness of electrode each. Effects of electrode position from spraying nozzle on deposition current was a little.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.141-142
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• 2022

Recently, fires in logistics warehouses in Korea are continuously increasing. In addition, the need for fire safety in logistics warehouses is emerging. So, it is believed that it is necessary to establish standards for vent facilities under effective smoke control for the evacuation safety of residents in logistics warehouses. Therefore, this paper compares the standards related to combustion facilities in Korea, the United States, and Japan, and applies the design method to logistics warehouses of domestic materials to predict smoke drop time and use it as a basic data for improving domestic smoke facilities standards.

• Applied Biological Chemistry
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• v.38 no.2
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• pp.151-156
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• 1995

Single-drop splash/detachment studies and multiple-drop splash/detachment experiments were carried out to measure detachment by single and multiple drops. A raindrop tower 7.0 m in height was used to study soil splash by single drop raindrop impact over time on repacked soil samples in containers 76.2 mm in diameter. The waterdrop diameter and kinetic energy were 4.1 mm and $1.22{\times}10^{-3}$ J $drop^{-1}$, respectively. The samples consisted of five agricultural topsoils sieved to <2 mm, varying from sandy loam to clay loam in texture. The average weight of splashed soil particles after 75 drops did not show any significant difference between the five soils. The average weight of particles splashed by the first 15 drops showed that the sandy Pelham soil splashed to a greater degree than the others, and was therefore more detachable (p=0.05) than the other soils. The average weight of particles splashed by the last 15 drops also showed that the Pelham soil was the most detachable, with Cecil, Appling, Dyke, and Worsham soils being progressively less detachable. The effect of multiple drops on detachment was studied under a nozzle-type rainfall simulator at 74.9 mm $h^{-1}$ intensity for 85 min using the same soils as the single drop experiments. The total soil splash value for 85 min on Appling, Cecil, Dyke, Pelham, and Worsham soils were 6121, 6206, 4183, 5160, and 3247 g $m^{-2}$, respectively. There were no obvious relationships between soil loss measured from the different experiments.