• Journal of Korean Elementary Science Education
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• v.17 no.1
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• pp.33-46
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• 1998

This study researched the concepts that elementary school students have after having learned volcano and earthquake. The reacher collected and adjusted the journals related to this study, and sampled the concepts included in Chap. One "Moving Earth", the first term of the elementary school sixth year. The students' descriptive responses were analyzed after subjective questions on the basis of above were developed and put into. After the contents described in the answer sheets were categorized by key words and the types of concept were made out by qualitative analysis, it was showed what was differences between the sexual, regional and achievement levels. The results of this study were as follows; first, though the types of concept about volcano and earthquake were found variably, it was showed that wrong preconception was not corrected, especially the exact understanding about terms not attained to, which led to the trouble in conceptual readjustment of students. Second, though the response rate about the types of scientific concept was found high that volcano was made out of explosion and eruption of magma and lava, there were also children who described not the interior factor of globe but the surface factor. Third, according to the results divided into the interior factor of globe and the surface factor and analyzed about earthquake, there were a great number of children who responded as the surface factor though most of the students responded to the interior factor of globe. Fourth, through some types of concept, it was found that the formation of concept was much influenced by experience of children's life, curriculum, and the method of study. Fifth, In the most test question, the scientific concept was found that boys were higher than girls in the distinction of sex, the children of cities than those of town and island, and the upper group than the lower group in the achievement levels.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.545-550
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• 2023

A pretensioner is a safety device that protects occupants by pulling the seat belt in the event of a vehicle collision. However, since the pretensioner is driven by a explosive method, it is necessary to replace not only the gas generator but also all connecting parts including the manifold after an accident. Therefore, in this paper, we propose an elastic force-based pretensioner that can be used safely and semi-permanently. After analyzing the operating mechanism of the existing pretensioner from a thermodynamic/dynamic point of view, the spring stiffness that can be deployed within an appropriate operating time was determined by converting the gas explosion energy into elastic energy. In addition, the coil spring shape that satisfies the elastic stiffness was designed in consideration of the vehicle interior installation standard. Finally, the operating performance of the pretensioner driven by elastic force was verified through fabrication.

• Journal of the Korean Wood Science and Technology
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• v.43 no.2
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• pp.224-237
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• 2015

We hypothesized that the extract from steam exploded Q. variabilis might be cytoprotective for tenofibroblasts cells during oxidative stress. In the present study, the extracts obtained from steam exploded (severity log Ro 4.68) Q. variabilis contained high quantities of phenolics and flavonoids contents. Also, the extracts appear to have, on these tenofibroblasts, a protective effect against oxidative stress. Tenofibroblasts cells incubated with the extracts and stressed with $H_2O_2$ showed an increase in cell viability by MTT assay. The extracts is found to inhibit $H_2O_2$-induced apoptosis in tenofibroblasts cells, as shown by Annexin V/PI double staining analysis. Western blot data showed that in the extracts/$H_2O_2$-treated cells, the extracts inhibited the $H_2O_2$-dependent phosphorylation of ERK and p38. From these results, it is suggested that the extracts showed the protective effect on $H_2O_2$-mediated oxidative stress. The main chemical compounds of the extract was identified as 1,8-cineole by GC-MS analysis. The anti-apoptosis activity is accordingly believed to be attributable to the 1,8-cineole.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.6
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• pp.1742-1748
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• 2006

In order to establish the manifestational symptoms in men and women and highly frequent symptoms(HFS) of deficiency of Qi and blood(氣虛, 血虛), stagnation of Qi(氣滯), deficiency of Yin(陰虛), deficiency of Yang(陽虛), and, 546 questionaires were analyzed through Cronbach alpha value and Pearson's correlative efficient. Symptomatic differences of male and female specimens were as follows. HFS of Qi deficiency were similar in terms of inactivity like mental and physical fatigue, enervation in men and women. In blood deficiency, dizziness and light sleep were common in men and women, but mucosal symptoms of conjunctiva, lip, nail bed were more frequent in women than men. Emotional explosion was common in Qi stagnation, then women had more motivation-related symptoms than men. Inner heat was frequently arisen in Yin deficiency in both, and the heat was expressed more common in exterior and upper part in women but in interior abdominal part in men. In Yang deficiency, main symptoms of men were feeling coldness in peripheral, but Qi deficiency symptoms were more common in women former than coldness.

• Journal of the Korea Institute of Building Construction
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• v.19 no.2
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• pp.167-174
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• 2019

Protective facilities are the last means of ensuring the survivability of personnel and assets, and there is a greater amount of matters to consider than those of general buildings. However, the Defense Military Facilities Criteria and the Ministry of the Interior and Safety, Ordinance No. 20, are only considering the expected enemy threats. In this study, we use objective and statistical methods to refine the consideration of the required capacity of protection based on the opinions of the experts. Specifically, the study adopts the Delphi technique associating the experts related to 30 defense military facilities criteria. The first-round questions were open-ended, and it compiled the points to consider related to the bulletproof and explosion - proof design. The second questionnaire was applied as closed questionnaire with 7 points scale methods. As a result of the factor analysis on the opinions of the experts, it was confirmed that the protection requirement level was due to METT + TC.

• Fire Science and Engineering
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• v.34 no.2
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• pp.14-21
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• 2020

This paper presents the study of a fire risk to the backside of two miniatures of ISO 9705 2/5 using a lightweight partition for indoor space division and reproduction of the ISO 9705 test. An SGP partition, stud partition, glass wool panel, urethane foam panel, sandwich panel, and glass partition were selected as the test specimens, which are frequently used in construction. According to the ISO 9705 test standard, stabilization was achieved using a measuring device that recorded data before the ignition of a burner and continued recording for 120 s thereafter. After ignition was achieved, the power was increased to 300 kW for 600 s and then reduced to 100 kW for 600 s. The specimens were subsequently observed for 180 s, and the fire risk to the backside and the fire pattern of the wall unit were analyzed. Owing to the amount of heat generated by the ignition source, the maximum temperature of the backside was observed to be 67.7 ℃ for the SGP partition, 55.1 ℃ for the stud partition, 52.4 ℃ for the glass wool panel, 727.4 ℃ for the sandwich panel, 561 ℃ for the urethane foam panel, and 630.5 ℃ for the glass partition. In the cases of the sandwich and urethane foam panels, the explosion of flammable gas occurred by virtue of fusion of the interior materials. The reinforced glass was fractured owing to the temperature difference between the heat- and nonheat-responsive parts. Ultimately, the fire risk to the nearby section room was deemed to be high.

• Journal of the Korean Institute of Gas
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• v.18 no.3
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• pp.38-43
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• 2014

This paper is to analyze and study the failure examples of fire by inflammables and electric contact faulty in interior of vehicle. The first example, the driver used to air freshener that remove the air conditioner bad smell. He get out of a car. And then, he put it on the crash pad. Before long, a fire breaks out because of explosion solar radiation. The second example, the driver used in room of a car. It certified the fire by disconnection phenomenon happened the electric overload. The third example, the driver install the heat rays to warm his body, In the initial stages, it didn't seek the dangerous of fire during using a car to 5,000km. This heat rays become to down durability so that produced the electric overload in an instant. The fourth example, after the man smoked the cigarette on riding with rear seat, he put it on seat in vehicle no extinguishing the burning cigarette. It knew the fact that burnt to ashes a car by on well combustible paper. Thus, the driver must consider a countermeasure for minimize the fire production when he use the inflammable and install adding electric system.

• Fire Science and Engineering
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• v.27 no.5
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• pp.19-25
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• 2013

The fire took place in the synthetic heat transfer fluid boiler. This study uses simulation to investigate the first, second and third passes and the temperature in the fire burner. The boiler's internal fluid is more or less unsteady due to the out of order inverter. As the operation continues, the flame's flow and speed are unsteady. The synthetic heat transfer fluid leak spouted about 120 kg/min in the form of vapor in the early period of the fire. The flame extended to the second and third passes. The highest temperature of the second and third pass is $1059^{\circ}C$ and $1007^{\circ}C$, respectively. The simulation shows that the temperature is $767^{\circ}C$ in the low part of the third pass. The synthetic heat transfer fluid spouted through the cracked part of the fire box in the first pass and accumulated on the turn table. The temperature rises to $183^{\circ}C$ in the low part of the burner. Therefore, it is expected that the temperature of the interior of the fire box is above $1200^{\circ}C$. The temperature of the burner rises to a maximum level several times in a short period. On account of that, several explosions occur in the fire burner.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.1
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• pp.83-93
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• 2021

Objectives: 'Confined space' was only defined in the Safety and Health Regulations as a place where oxygen deficiency and hydrogen sulfide must be dealt with at the time of the initial enactment (1982). The danger of fire and explosion were added in 2003. We will compare and review the regulations related to confined space work under the current safety and health rules alongside regulations in other countries and prepare a plan to improve the system through enhanced clarity and execution. Methods: In a comparison of systems for the prevention of suffocation in confined spaces in major countries (Germany, United States, Japan) different concepts of the definition of confined spaces in different countries apparently due to differences in each country's legal implementation system, accident analysis methods, the status of safety and health implementation in workplaces, the precautions against actual confined space work, and the definition of confined spaces were found to be not much different between Korea and the other foreign countries. Results: In the case of Germany and the United States, a confined space is defined as a contextual concept rather than a place, so more careful attention is needed from operators or enclosed space managers as it is often necessary to judge the actual workplace. In the case of Korea and Japan, the interior of the place is mainly defined as a place, especially in the case of Japan, which concentrates on oxygen deficiency and hydrogen sulfide poisoning. Conclusions: For measures to improve regulations on the prevention of suffocation accidents in Korea, I would like to propose three major measures to improve the system in the rules on domestic industrial safety and health standards. It is necessary to prepare and provide a guide to ensure that the 18 types of confined spaces currently defined as confined spaces are clearly understood by field management supervisors or workers.