• Fire Science and Engineering
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• v.25 no.6
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• pp.21-26
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• 2011

The purpose of this paper is to present the damage patterns of cellular phone (SCH_W830) batteries according to energy sources and have them utilized as data for the settlement of disputes between manufactures and consumers. The reliability was secured by maintaining the ambient temperature and humidity at $22{\pm}2^{\circ}C$ and 40~60 %, respectively. The voltage of the battery used for the tests was measured to be 4.18V between positive pole (+) and negative pole (-)(1), and 4.19 V between positive pole (+) and negative pole (-)(2). This study applied the Korean Industrial Standard (KS) to the flammability test of cellular phones due to a general flame applied to them and found that no damage occurred to the built-in battery even though the flame was applied to the cases of cellular phones for 30 seconds. From the results of immersing the cellular phones in the saline solution (NaCl, 0.9 %) for 180 seconds, it was found that there was a trace of carbonization and melting due to the heat caused by leaking current. It can be seen that when the cellular phones were heated for 70 seconds using a microwave oven (MWO), the areas containing the metal holder, recharging connector, antenna, etc., were melted and discolored and that other areas showed no particular problems. That is, while the external carbonization of cellular phones, built-in metals and dielectric materials, and damage and deformation of the battery terminal block, etc., occurred differently depending on the types of energy sources, the voltage showed comparatively constant characteristics. Therefore, it is thought to be possible to attribute the cause of damage to the battery by performing analysis taking into consideration comprehensively the characteristics of the flame spread pattern as well as the melting and deformation of metals.

• The Korean Journal of Emergency Medical Services
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• v.14 no.1
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• pp.47-63
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• 2010

Objective : The objective of this study was to survey the job-related empowerment and job satisfaction of 119 emergency medical technicians provide emergency patients with first aid, to examine the correlation between their empowerment and job satisfaction, and to provide basic materials for developing programs to enhance 119 emergency medical technicians' empowerment and job satisfaction. Methods : The survey was conducted with 249 119 emergency medical technicians working at fire stations in an area of Gyeonggi-do during the period from June 26 to August 21, 2009. Using SPSS 14.0 program, we obtained frequencies percentages, means, and standard deviations, and performed independent two sample t-test, one way ANOVA, and Pearson correlation analysis, and Cronbach's ${\alpha}$. Results : 1) The mean score of the subjects' empowerment was 3.32, and that of their job satisfaction was 2.94. 2) As to difference according to general characteristics, no statistically significant difference was observed in empowerment but job satisfaction was statistically significantly different according to gender(t = 2.296, p = .023). 3) As to difference according to job related characteristics, empowerment was significantly different according to license type(F = 3.767, p = .011), and job satisfaction was statistically significantly different according to position(t = 3.222, p = .042), fire fighting experience(t = 2.689, p = .035), and first aid experience(t = 3.991, p = .007). 4) Empowerment was in a positive correlation with job satisfaction(r = .502, p = .000) in general, and by the sub areas of job satisfaction, the correlation with empowerment was high in order of job itself(r = .695, p = .000), interaction area(r = .493, p = .000), organizational demand area(r = .328, p = .000), working condition area(r = .153, p = .015), and wage area(r = .137, p = .031). By the sub areas of empowerment, the correlation with job satisfaction was high in order of significance(r = .424, p = .000), influence(r = .397, p = .000), competence(r = .372, p = .000), and self determination(r = .259, p = .000). Conclusion : The 119 emergency medical technicians' empowerment was in a high correlation with their job satisfaction, and had a strong effect on it. This suggests that 119 emergency medical technicians' job performance can be enhanced by improving their empowerment. These results are expected to be useful in making human resource management plans to enhance 119 emergency medical technicians' job satisfaction by empowering them.

• The Korean Journal of Emergency Medical Services
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• v.14 no.1
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• pp.65-80
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• 2010

Objective : The objective of this study was to survey the job satisfaction and turnover intention of 119 emergency medical technicians who are fire fighters and, at the same time, provide emergency patients with first aid, to examine the correlation between their job satisfaction and turnover intention, and to provide basic materials for the human resource management of 119 emergency medical technicians. Method : The survey was conducted with 152 119 emergency medical technicians working at fire stations in an area of Gyeonggi-do during the period from July 15 to September 14, 2009. Job satisfaction was measured with a tool developed by Kim Sun-sim and Kwon Hye-ran (2002) based on the Index of Work Satisfaction, and turnover intention with the tool developed by Becker (2002) and translated and used by Cho Yeong-sook (2002). The questionnaire was composed of 11 questions on general characteristics, 35 on job satisfaction, and 4 on turnover intention, so a total of 50 questions. The reliability of the questionnaire was Cronbach's ${\alpha}=0.922$ for job satisfaction and Cronbach's ${\alpha}=0.854$ for turnover intention. Using SPSS 14.0, we obtained frequencies, percentages, means, and standard deviations, and performed independent two-sample t-test, one-way ANOVA, and Pearson correlation analysis, and Cronbach's ${\alpha}$. Results : 1) The mean score of the 119 emergency medical technicians' job satisfaction was 2.71, and that of their turnover intention was 2.64. By area of job satisfaction, the mean score was 3.44 for the area of job itself, 2.92 for the interaction area, 2.67 for the organizational demand area, 2.64 for the autonomy area, 2.14 for the wage area, and 1.91 for the working condition area, showing that emergency medical technicians were generally satisfied with their job itself but not with their working condition. 2) As to difference according to the 119 emergency medical technicians' general characteristics, statistically significant difference was observed in job satisfaction according to license type (F = 4.729, p < .010), and in turnover intention according to position (F = 3.768, p < .025). 3) The 119 emergency medical technicians' job satisfaction and turnover intention was in a negative correlation with each other (r = -.44, p < .000) in general, and by the sub-areas of job satisfaction, the correlation with turnover intention was high in order of the autonomy area (r = -.42, p = .000), interaction area (r = -.42, p = .000), job itself (r = -.35, p < .000), organizational demand area (r = -.30, p = .000), wage area (r = -.23, p = .000), and working condition area (r = -.21, p = .008). Conclusion : The 119 emergency medical technicians' job satisfaction showed a negative correlation with their turnover intention. This suggests that turnover intention can be reduced by improving job satisfaction. Furthermore, 119 emergency medical technicians' job satisfaction was high with the job itself, showing their high pride in their job, but was low with working condition and wage. Thus, it is necessary to enhance their job satisfaction by improving the 24-hour work system through supplementing manpower, compensating for overtime works, adjusting work hours per week, etc. These results are expected to be useful in making human resource management plans to lower turnover intention by enhancing 119 emergency medical technicians' job satisfaction.

• Journal of the Korea Concrete Institute
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• v.24 no.2
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• pp.173-183
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• 2012

Recently, experimental studies to prevent explosive spalling based on spalling mechanism and addition of Polypropylene fiber in high strength concrete (HSC) are performed actively. However, with respect to ultra high strength concrete (UHSC), its compact internal structure is more difficult release vapor pressure at rapid rising temperature compared to HSC. Therefore, in this study, an experiment was conducted to evaluate spalling properties of UHSC using ${\Box}$ $100mm{\times}100{\times}H200mm$ rectangular specimen according to ISO-834 standard fire curve. With respect melting point of fiber, three fiber types of Polyethylene, Polypropylene, and Nylon fibers with melting temperature of $110^{\circ}C$, $165^{\circ}C$, and $225^{\circ}C$, respectively, were considered. Mixed fiber of 0.15% and 0.25% of concrete volume was used to consider spalling properties based on water vapor pressure release. Then, TGDTA test on fiber and FEM analysis were performed. The results showed that it is difficult to prevent initial spalling without loss of fiber mass even if fiber melting temperature is low. Also, in preventing thermal spalling, fiber that melts to rapidly create porosity within 10 minutes of fire is more effective than that of low melting temperature property of fiber.

• The Korean Journal of Emergency Medical Services
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• v.12 no.3
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• pp.99-113
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• 2008

In order to protect Rescue 119 workers exposed on the spot from potential infection, this study identified their awareness and practices of infection control so that it could help preventing them from infection and also provide basic materials necessary for pre-hospital infection control. This study applied questionnaire survey to total 215 Rescue 119 workers at fire stations in Jeonbuk province, Jeonnam province and Gwangju city from July 14 to Sept. 14, 2006 for the benefit of data collection. The questionnaire about possible associations between awareness and practices of infection control consisted of total 46 times across 6 categories such as washing hands during emergency activities ; fluid therapy and injection ; respirator maintenance; individual hygienics ; disinfectant supplies and equipments maintenance ; and control of infectious wastes. And collected data were processed using SPSS statistic program to analyze frequency and percentage, mean and standard deviation, Pearson's correlation coefficient, t-test and one-way ANOVA. As a result, this study came to the following conclusions : In terms of awareness about infection control, our respondents showed highest awareness about infectious waste control, and also showed highest level of practices in washing hands during emergency activities. Throughout all domains, awareness means were higher than practice means. In particular, infectious waste control was the domain of significant differences between awareness and practices. In terms of associations between awareness and individual characteristics, it was found that female rescue worker group and hospital/general hospital career group (before joining the Rescue 119) showed significantly higher awareness on statistic level. In regard to associations between individual characteristics and practices, it was found that female rescue worker group showed higher level of practices than male group on statistic level. This study also analyzed correlations between rescue workers' awareness and practice of infection control. As a result, it was found that the higher awareness was in correlations with the higher practices across all 6 domains including washing hands. In addition, the higher awareness of a questionnaire item was in significantly positive correlations with the higher practice of other items. However, our respondents showed high awareness about anti-infection, but low practices in reality. This indicates necessity of devising possible solutions to improve the practices as much as awareness. Especially, it was noted that major reasons for insufficient practices of infection control guideline come from unhabituated practices and lack of supports for infection-preventing supplies and protective device (mask, etc). Hence, it is necessary to provide more infection-preventing supplies for local rescue workers sufficiently, in parallel with steady habituation of infection control. Furthermore, it is required to manage and study infection control policies even at pre-hospital step in efforts for effective infection control, education and activities.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.642-649
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• 2021

Energy saving standard for buildings are strengthened, the application of exterior insulation finishing system and thickness of insulation materials are increasing. Most buildings with exterior insulation finishing system is applied organic insulating material. Organic insulating material have workability, economic feasibility, reduction in construction cost, and excellent thermal insulation performance. However, Organic insulating material is very vulnerable to heat, so when a fire occurs, rapid fire spread and toxic gas are generated, causing many casualties. Inorganic insulating material can be non-combustible performance, but it is heavy and has low thermal insulation performance. Mineral wool has higher thermal insulation performance than other types of inorganic insulating material, but mineral wool is disadvantageous to workability and vulnerable to moisture. Glass bubble are highly resistant to water and chemically stable substances. In addition, the density of the glass bubble is very low and the particles are spherical, fluidity is improved by the ball bearing effect. Glass bubbles can be used with cement-based ino rganic insulating material to impro ve the weight and thermal insulatio n perfo rmance o f cement-based inorganic insulation. This study produced a inorganic insulating materials were manufactured using cement-based materials and glass bubble. In order to evaluate the insulation performance and flame retardant performance of cement-based super light-weight inorganic insulating materials using with glass bubble, insulation performance or flame retardant and non-combustible performance were evaluated after manufacturing insulating materials using micro cement and two types of glass bubbles. From the test result, Increasing the mixing ratio of glass bubbles improved the insulation performance of cement-based super light-weight inorganic insulating materials, and when the mixing ratio of glass bubbles was 10%, it sho wed sufficient flame retardant and no n-co mbustible perfo rmance.

• Clean Technology
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• v.25 no.2
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• pp.140-146
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• 2019

Flammable substances, such as organic solvents, are commonly used in laboratories and industrial processes. The flash point of flammable liquid mixtures is a very important parameter for characterizing the ignition and explosion hazards, and the flash points of mixtures of $C_2{\sim}C_3$ alcohols and 2,2,4-trimethylpentane were measured in the present study. The 2,2,4-trimethylpentane is an important component of gasoline and is frequently used in the petroleum industry as a solvent. Lower flash point data were measured for the binary systems {ethanol + 2,2,4-trimethylpentane}, {1-propanol + 2,2,4-trimethylpentane}, and {2-propanol + 2,2,4-trimethylpentane}. The flash point measurements were carried out according to the standard test method (ASTM D3278) using a Stanhope-Seta closed cup flash point tester. The measured flash points were compared with the predicted values calculated using Raoult's law and also following $G^E$ models: Wilson, Non-Random Two Liquid (NRTL) and UNIversal QUAsiChemical (UNIQUAC). These models were able to predict the experimental flash points for different compositions of {$C_2{\sim}C_3$ alcohols + 2,2,4-trimethylpentane} mixtures with minimal deviations. The average absolute deviation between the predicted and measured lower flash point was less than 1.28 K. A minimum flash point behaviour was observed in all of the systems as in the many observed cases for the hydrocarbon and alcohol mixtures.

• The Journal of the Korea Contents Association
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• v.19 no.1
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• pp.404-412
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• 2019

The purpose of this study is to develop the usability evaluation contents based on the needs of different stakeholder's related to the usability of the product, and to derive the design direction and apply it as the evaluation standard by applying the product design based on the results. I created a stakeholder map for a fire detector product and identified stakeholders related to usability. Based on 3 factors(Physical, cognitive, emotional) of the usability evaluation, I conducted survey on the building users and the building managers who have different requirements. There are 12 directions (ease of installation, durability, maintainability, additional functionality, effectiveness, attractiveness, visibility, consistency of information, environmental harmony, consistency, Image suitability, reliability). Through weighted analysis of three usability evaluation factors, I found factors were ranked in the same order of importance, but they were different in importance figure. Based on the results of the survey, overall product usability aspects were improved but effectiveness and environmental coordination aspects needed to be improved.

• Journal of Korean Public Health Nursing
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• v.29 no.1
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• pp.40-52
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• 2015

Purpose: This study examined the characteristics of preparation to perform activities of suicide prevention according to professional type. Methods: A structural survey was conducted from Dec. 10, 2012 to Jan. 4, 2013 for 355 participants working at suicide prevention institutions in S city. The data were analyzed in terms of frequency, percentage, mean, standard deviation, t-test, ANOVA, Pearson's correlation coefficient, and multiple regression using SPSS/WIN 18.0. Results: Self-evaluation knowledge of characteristics was a significant distance depending on education and economic status. Participants were classified according to four groups based on professional type; public health nurse, social worker, fire officer, and administrative staff. Significant differences in experiences in suicide, the several items of self-evaluation knowledge, and the preparation to perform activities of suicide prevention were observed according to professional type (p<.05). Correlation among the experience, self-evaluation knowledge and preparation to perform activities of suicide prevention showed a positive correlation in public health nurse, social worker, and administrative staff (p<.05). In all professional types, the variable that predicted preparation to perform activities of suicide prevention was self-evaluation knowledge (p<.001). Conclusion: Tailor-made suicide prevention programs that affect changes in preparation to perform activities of suicide prevention should be developed by professional types.

• Korean Chemical Engineering Research
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• v.54 no.3
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• pp.367-373
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• 2016

Many of plastic powders handled in industry are combustible and have the hazard of dust fire and explosion accidents. However poor information about the safe handling has been presented in the production works. The aim of this research is investigated experimentally on explosive characteristics of various plastic powders used in industry and to provide additional data with safety informations. The explosibility parameters investigated using standard dust explosibility test equipment of Siwek 20-L explosion chamber. As the results, the dust explosion index ($K_{st}$) of ABS ($209.8{\mu}m$), PE ($81.8{\mu}m$), PBT ($21.3{\mu}m$), MBS ($26.7{\mu}m$) and PMMA ($14.3{\mu}m$) are 62.4, 59.4, 70.3, 303 and 203.6[$bar{\cdot}m/s$], respectively. And flame propagation velocity during plastic dust explosions for prediction of explosive damage was estimated using a flame propagation model based on the time to peak pressure and flame arrival time in dust explosion pressure assuming the constant burning velocity.