• Journal of the Korean Society of Safety
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• v.36 no.4
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• pp.12-19
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• 2021

This paper presents a safety assessment method for FTA-based induction heating systems; the failures and causes of electrical fire are first analyzed for each part and module qualitatively, and methods to manage high probabilities of failure and electrical fire are considered, thereby improving the reliability of the induction heating system. The cumulative importance value (ACC) of the minimal cut set is drawn by setting failure as the top event, and STACK and SMPS are observed to account for about 70% of the induction heating system failures. Thus, intensively managing the basic events contained in the minimal cut set of failures for STACK and SMPS is expected to provide effective and stable operation of the induction heating system. When electrical fire is set as the top event, the STACK percentage is 90%. Accordingly, the current IGBT is changed to a FET to increase the applied voltage and prevent induction heating system failure, and a heat sink plane is installed to prevent FET heating caused by switching, thereby preventing an electrical fire. By classifying the parts and modules of the induction heating system in detail and by applying FTA based on actual failure rates and relevant data, more practical and reasonable results may be expected. Hence, continuous research must be conducted to ensure safety when using induction heating systems.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.4
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• pp.367-374
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• 2005

Recently, forest damage has occurred often and made big issues. Among them, the damage by forest fire is not only damage of itself but also being connected with secondary damage like a flood. This is the fact that a forest fire is caused rather artificially by people than nature. In this study, we try to investigate damage of a forest fire through spectral reflectance of a plant community surveyed using a near infrared CCD camera and a SPM (Spectral Radiometer) as advanced work to use satellite image data. That is, damage of a forest fire by the naked eye observation was divided into the No damage, the light damage, the serious damage and we estimated activity of forest and grasped revival possibility of forest. Through correlation analysis between the spectral reflectance by SPM and the near infrared CCD camera, we could get high correlation in the No damage and light damage. Therefore, when we surveyed damage of a forest fire, we could grasp damage, that is hardly observed by the naked eye by, using jointly the spectral radiometer and the near infrared CCD camera.

• Fire Science and Engineering
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• v.34 no.4
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• pp.29-35
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• 2020

This study was conducted to examine the performance in the space for a single alarm type detector installed in a single house. Three types of houses were used, including two types of one-story and two-story houses. A computer simulation program was used to predict the sound pressure level in response to the occurrence of an alarm sound in a residential space. The characteristics of the sound source applied to the simulation were directly measured and used as input data. As a result of simulation, it was found that the sound pressure level in the kitchen and living room generally met the standard when the alarm sound of the detector occurred. However, the sound pressure level in the bedroom was predicted to be at least 20 dB (A) lower than the American Fire Protection Association standard of 75 dB (A). Therefore, a plan should be prepared to maintain a sufficient sound level in the bedroom space inside the house, and efforts will be needed to ensure safe evacuation in case of fire by establishing relevant standards.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.5
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• pp.827-839
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• 2009

Sizing system of Korean structural firefighting protective clothing that is national approved should be met for specification of structural firefighting protective clothing that is identified by Ministry of Public Administration and Security(MOPAS). However if you look over the specification of sizing system, the standard is based on only 'height' and the others are indicated as the size of completed product. KS K ISO 13688 and EN 340 which is met on ISO 13688 which indicates sizing system about protective clothing has the standards of height, chest and waist circumference. Also NFPA 1971 that has standards of sizing system is based on chest circumference, cervical to wrist length, waist circumference and inseam. That is different from Korean standards. Therefore, fire fighting protective clothing standards which is based on only height should be compensated and not be relied on foreign standards like ISO. It is indispensable for developing our own sizing system of structural fire fighting protective clothing. In this studying, Korean new sizing system of structural fire fighting protective clothing was developed for providing basic information of ergonomic structural fire fighting protective clothing. The analyzed target age was between 20 and 59 years old fire fighter who extinguish the fire. And it was analyzed by 3D measurement among data of the $5^{th}$ Size Korea. On conclusion, in case of structural fire fighting protective clothing coat, physical dimension was to be chest circumference, cervical to wrist length. Three dimensions as 5cm space of circumference and four dimensions as 2.5cm space of cervical to wrist length were derived, which means that totally 12 dimensions were defined. Dimension standards of pants was based on the analysis of waist circumference and crotch height. Six dimensions as 5cm space of waist circumference and three dimensions as 5cm space of crotch height were derived, which means that totally 14 dimensions were defined.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.2
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• pp.23-31
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• 2018

In recent years, as the development of construction technology and population increase, buildings are becoming more complex and high-rise. These large scale buildings are difficult to secure fire and evacuation safety when fire occurs. So it is necessary to prepare specific measures. According to this situation, in 2011, Republic of Korea officially launched Performance-based Design in "Fire-fighting system Installation business Act". But even 6 years passed since the enforcement, there are still faces manifold problems in the course of implementation. In order to examine the necessary improvements, in this study, I conducted interviews and questionnaires with experts, investigated the improvement items under current laws. And draw up a measures for that items. The subjects of the survey were fire-fighting officer, professional engineer fire fighting, fire protection planner and professor in Daegu. As a result of twice surveys, a total of 19 items are derived. And then compared and analyzed the criteria of overseas countries, and suggested improvement directions for final items. In addition, conducted a third questionnaire survey on the proposed improvement direction to verify the appropriateness of the alternative. The results of this study will be used as basic data to deal with the general problems of performance-based design in future, and further study on each item will be needed.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.4
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• pp.213-217
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• 2003

Forest fire spread and intensity were modeled as a function of wind and fuel. Spread rate and intensity of forest fire were related to weight and thickness of forest fuel beds and to wind speed. Forest fire spread rate and fire intensity were differentiated according to wind speed. Rapid wind speed causes a faster forest fire spread rate and greater fire intensity than does slow wind speed. Relative burning time of the fire from beginning to end in the model was 161 sec at a wind speed of 0.5 m/sec and 146 sec at 1m/sec on the model. Average forest lire spread rate was 0.014 m/sec at a wind speed of 0.5 m/sec and 0.020 m/sec at 1m/sec. Average fire intensity was 0.183 ㎾/m at a wind speed of 0.5 m/sec, 0.259 ㎾/m at 1m/sec. Fire intensity was greater when forest fire spread rate was rapid.

• Fire Science and Engineering
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• v.29 no.1
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• pp.38-44
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• 2015

This study suggested the problems and their improvement measures for the operation of fire detectors and sprinkler heads installed at apartment houses. According to a census on population and housing in 2010, apartment houses account for 71.6% of the total housing facilities. And by fire statistics data of the National Emergency Management Agency, approximately 25.0% of fire accidents and 46.4% of casualties occur at apartment houses every year. Therefore, this study conducted for identifying the causes and characteristics of fire to establish the fire safety improvement measures for apartment houses. And this study was carried out virtual fire simulation at domestic apartment houses. The scenario of the simulation contains a comparative analysis on the operation time of standard sprinkler heads and residential sprinkler heads, heat detectors and smoke detectors. As a result of simulation, it was found that standard sprinkler heads and heat detectors installed at the existing apartment houses should be replaced with residential sprinkler heads and smoke detectors for rapid fire suppression. In addition, sprinkler systems should be considered to be installed for excluded floor at apartment houses. Especially, it is necessary to construct remote inspect systems like advanced countries for efficiency of apartment houses safety management.

• Structural Engineering and Mechanics
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• v.67 no.6
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• pp.629-641
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• 2018

The paper describes the development of a two-dimensional (2D) co-rotational nonlinear beam finite element that includes advanced path-following capabilities for detecting bifurcation instability in elasto-plasticity of steel elements subjected to fire without introducing imperfections. The advantage is twofold: i) no need to assume the magnitude of the imperfections and consequent reduction of the model complexity; ii) the presence of possible critical points is checked at each converged time step based on the actual load and stiffness distribution in the structure that is affected by the temperature field in the elements. In this way, the buckling modes at elevated temperature, that may be different from the ones at ambient temperature, can be properly taken into account. Moreover, an improved displacement predictor for estimating the displacement field allowed significant reduction of the computational cost. A co-rotational framework was exploited for describing the beam kinematic. In order to highlight the potential practical implications of the developed finite element, a parametric analysis was performed to investigate how the beam element compares both with the EN1993-1-2 buckling curve and with experimental tests on axially compressed steel members. Validation against experimental data and numerical outcomes obtained with commercial software is thoroughly described.

• Korean Journal of Occupational Health Nursing
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• v.20 no.2
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• pp.153-162
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• 2011

Purpose: The purpose of this study is to investigate the impact of job stress, self-efficacy and empowerment of 119 Emergency medical technicians in Jeollanam-do. Methods: This study used the data collected from 346 respondents working for first aid in a fire station. To answer research questions, this study employed frequency analysis, reliability test, F (t)-test, ANOVA, Scheffe' post-hoc test, and multiple-regression analysis. Results: In terms of demographic characteristics, marital status and age had significant impact on job stress, but sex and education did not. In terms of job characteristics, first placement, rank, and tenure made significant difference on job stress, whereas certificate, department, and area did not. These results address that general characteristics, self-efficacy and job stress are critical variables on empowerment. Conclusion: From the research findings, it is concluded that fire fighters' job stress can be reduced if professional development programs are given to them, which is likely to provide better public services such as first aids and welfare, as well as to increase job satisfaction.

• Journal of the Korean Society of Safety
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• v.38 no.6
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• pp.50-59
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• 2023

As the diversity of disasters continues to increase, the concept of "complex disasters" has gained prominence in various policies and studies related to disaster management. However, there has been a certain limitation in the availability of the systematic statistics or data in advancing policies and research initiatives related to complex disasters. This study aims to analyze the macro-level characteristics of the complex disasters that have occurred domestically utilizing a 30-year span of a news data. Initially, we categorize the complex disasters into the three types: "Natural disaster-Natural disaster", "Natural disaster-Social disaster", and "Social disaster-Social disaster". As a result, the "natural diaster-social disaster" type is the most prevalent. It is noted that "natual disaster-natural disaster" type has increased significantly in recent 10 years (2011-2020). In terms of specific disaster types, "Storm and Flood", "Collapse", "Traffic Accident", "National Infrastructure Paralysis", and "Fire⋅Explosion" occur the most in conjunction with other disasters in a complex manner. It has been observed that the types of disasters co-ocuuring with others have become more diverse over time. Parcicularly, in recent 10 years (2011-2020), in addition to the aforementioned five types, "Heat Wave", "Heavy Snowfall⋅Cold Wave", "Earthquake", "Chemical Accident", "Infectious Disease", "Forest Fire", "Air Pollution", "Drought", and "Landslide" have been notable for their frequent co-occurrence with other disasters. These findings through the statistical analysis of the complex disasters using long-term news data are expected to serve as crucial data for future policy development and research on complex disaster management.