Commercial gas stoves feed primary air to the burner and burn the fuel-air mixture in a partially premixed combustion. This mechanism produces carbon monoxide during combustion. In this study, design parameters of a commercial gas stove were optimized by considering the carbon monoxide emission. Gas consumption rate, carbon monoxide emission, and water boiling temperature as a heating performance were determined. Carbon monoxide emission was measured using a Korean Industrial Standards standard collector. Water boiling temperature was measured by first soaking the pot in water for approximately 10 min and then heating the pot filled with water. A thermocouple was installed inside the pot. Carbon monoxide increased as the nozzle diameter was increased and the burner-pot height was decreased. This result was due to the insufficient mixing between the fuel and air. Heating performance was enhanced when the nozzle diameter was increased and the burner-pot height was decreased. However, the heating performance deteriorated when the nozzle diameter was 1.8 mm and the burner-pot height was reduced to 50 mm. This phenomenon was due to the formation of a flame on the side of the pot. A merit factor was defined to find the optimal design parameters to satisfy gas consumption rate, carbon monoxide emission, and heating performance. Optimal design values were established to be a nozzle diameter of 1.5 mm and a burner-pot height of 60 mm.

Hydrogen-based electricity and transportation systems are widely recognized as sustainable power sources. However, the low ignition energy of hydrogen, only 1/10th that of conventional fossil fuels, poses a safety concern involving the risk of ignition due to electrostatic discharge from facility workers. Therefore, anti-static systems are imperative for hydrogen-based electricity facilities. To address this, we propose a reliable conductive rubber mat (CRM) to ensure the safety of these facilities. Unlike conventional anti-static floors that utilize conductive paint (CP), the CRM features a uniform distribution of conductive components in chemically and mechanically stable rubber. As a result, the CRM is unyielding to polar solvents (such as ethanol and hydrosulfuric acid) and non-polar solvents (like mineral oil) without increasing its resistance. Moreover, the CRM can withstand mechanical stress. Consequently, the human-body voltage of workers on the CRM would be sufficiently low enough to protect them from hydrogen explosions, thereby enhancing overall safety.

This study aims to introduce a method for risk assessment analysis aimed at preventing electrical fires within the manufacturing industry. Initially, we provided a functional block diagram illustrating the electrical equipment employed in various processes within a food manufacturing company in Chungcheongbuk-do. Subsequently, we categorized the components of each machine outlined in the functional block diagram and determined the priority of failure for each classified component. Upon implementing the model in the frying process of the food manufacturing company, specific components, including MC, motor, mixer heater, electric wiring, and terminal block, exhibit a risk priority number (RPN) of 40 or higher. This identified an electrical issue within the manufacturing process and environment. Consequently, we propose a methodology to identify latent failure modes that could escalate into fires or systemic issues if not promptly addressed. It is essential to note that while the FMEA presented in this study may not immediately impact food manufacturing, its applicability extends to various workplaces.

This study analyzed cases of hydrogen (H₂) and natural gas (CH₄) leakage from a hydrogen-blended natural gas pipeline to determine a range of leakage characteristics, including leakage type, pipe material, pipe diameter, pressure, and damage size. Based on the results of this analysis, five hydrogen-blended natural gas leakage scenarios were selected. The national vision for a carbon-neutral society by 2050 is a very important strategic objective and promotes environmentally sustainable economic development in the age of the climate crisis. Accordingly, zero-carbon and low-carbon policies are being promoted in various fields, including energy production, consumption, and industrial processes. Hydrogen-blended natural gas is eco-friendly and is considered an important step towards carbon neutrality, with various countries including the United States and several European countries conducting empirical research to further investigate its potential. In Korea, a national research project commenced in April 2023 to verify and demonstrate the life cycle safety of blending hydrogen into the natural gas network. The results of this study will provide important data for the analysis of the damage impacts caused by the leakage of hydrogen-blended natural gas, such as the diffusion of gas clouds, fires, and gas explosions.

This study analyzes the impact of regular preventive maintenance (PM) on reducing the failure rate and occurrence of falling accidents of industrial overhead doors. A reliable safety device model with an additional safety device, which is installed to replace a defective one, is proposed. The research methodology involves collecting breakdown and falling accident records, comparing and analyzing data before and after regular PM implementation, and experimenting with two types of retrofittable safety devices. Key findings are as follows. 1. Regular PM implementation significantly reduces the failure rate of old overhead doors. 2. A parallel structured model with two alternative safety devices can minimize falling accident risks. The study's contributions include the following. 1. The positive impact of PM on extending overhead door lifespan is quantified. 2. A general safety device model that can be retrofitted and used as replacement with a fail-safe function is proposed.

Efforts to reduce on-site safety incidents have expanded, leading to active research in this domain. However, a systematic analysis to improve the utility of technology is lacking. In this study, we conducted a survey on the various institutional and technical improvement measures to promote the application of smart construction safety technology over three years after the implementation of the "Smart Safety Equipment Support Project." The results showed that financial constraint was the primary obstacle in the adoption of this innovation. Fostering a flexible environment in the utilization of management fees and financial support of projects was determined to aid in the extensive application of the technology. Ensuring cost efficiency and user-friendliness were principally necessary for technical enhancements in the smart construction safety technology. Technologies, such as VR/AR safety education, real-time location tracking, wearable devices, and innovation on streamlining safety-related work efficiency, had been anticipated to contribute to on-site safety. Operating a smart safety control center was expected to be beneficial in the systematic securing of data and reduction of safety blind spots. Effective methods had been suggested to overcome the barriers that hindered the development and application of smart construction safety technology. This study facilitates in the technological improvements in this field.

In response to the COVID-19 pandemic, the logistics industry in Korea has rapidly been expanding, with offline demand concentrating on online platforms owing to the development of digital infrastructure. This has increased the workload of courier drivers considerably, along with labor intensity. A delivery driver died recently from overwork due to the continuous increase in delivery volume, which raises social concerns. Delivery drivers work long hours, (over 12 hours) and are greatly affected by weather conditions, such as snow, rain, heat waves, and cold waves. In addition, they lack a fixed workplace; perform atypical work handling workpieces of various sizes, weights, and shapes; and spend a large amount of time driving as part of their work. This work involves a high level of tension and requires attention and concentration. Despite the frequency of industrial accidents in the courier industry, studies on safety and health to quantitatively analyze and systematize the work of courier workers are very scarce. Therefore, to define the work process necessary for investigating the harmful factors in delivery service and the work analysis, this study conducted interviews and on-site surveys to analyze the unit work of the delivery service by targeting delivery workers. In other words, a framework of unit work for work analysis was presented to enable research and analysis by considering the aforementioned characteristics of the courier industry. The process was broadly divided into work, transport, storage, delay, and inspection. Work was divided into loading, sorting, unloading, and door subcategories, and transportation was divided into vehicle, cart, and walking subcategories as well as 10 small processes. Moreover, 22 unit works were again drawn by conducting field surveys and interviews. The risk of unit work derived from this study was ergonomically evaluated, and the ergonomic analysis revealed that uploading and transportation were the most dangerous. The results of this study could be used as basic data for preventing industrial accidents among courier workers, whose work has increased with the logistics volume and the development of the logistics industry.

Ensuring swift on-site access to fire engines is crucial in preserving the golden time and minimizing damage. However, various mobility constraints in alleyways hinder the timely entry of fire engines to the fire scene, significantly impairing their initial response capabilities. Therefore, this study analyzed the significant mobility constraints of fire engines, focusing on Seoul, which has many old town areas. By leveraging survey responses from firefighting experts and actual observations, this study quantitatively assessed the frequency and severity of mobility constraint factors affecting the disaster responses of fire engines. Survey results revealed a consistent set of top five factors regarding the frequency and disturbance level, including illegally parked cars, narrow paths, motorcycles, poles, and awnings/banners. A comparison with actual road-view images showed notable consistency between the survey and observational results regarding the appearance frequency of mobility constraint factors in vulnerable areas in Seoul. Furthermore, the study emphasized the importance of tailored management strategies for each mobility constraint factor, considering its characteristics, such as dynamic or static. The findings of this study can serve as foundational data for creating more detailed fire safety maps and advancing technologies that monitor the mobility of fire engines through efficient vision-based inference using CCTVs in the future.

With heavy rainfall due to extreme weather causing increasing damage, the importance of urban flood forecasting continues to grow. To forecast urban flooding accurately and promptly, a sewer network and surface grid with appropriate detail are necessary. However, for urban areas with complex storm sewer networks and terrain structures, high-resolution grids and detailed networks can significantly prolong the analysis. Therefore, determining an appropriate level of network simplification and a suitable surface grid resolution is essential to secure the golden time for urban flood forecasting. In this study, InfoWorks ICM, a software program capable of 1D-2D coupled simulation, was used to examine urban flood forecasting performance for storm sewer networks with various levels of simplification and different surface grid resolutions. The inundation depth, inundation area, and simulation time were analyzed for each simplification level. Based on the analysis, the simulation time was reduced by up to 65% upon simplifying the storm sewer networks and by up to 96% depending on the surface grid resolution; further, the inundation area was overestimated as the grid resolution increased. This study provides insights into optimizing the simplification level and surface grid resolution for storm sewer networks to ensure efficient and accurate urban flood forecasting.

Analyzing the aftermath of events at domestic nuclear power plants brings in the question: "Why do workers not comply with the prescribed procedures?" The current investigation of nuclear power plant events identifies their reasons considering the factors affecting the workers' behaviors. However, there are some complications to it: in addition to confirming the action such as an error or a violation, there is a limit to identifying the intention of the actor. To overcome this limitation, the study analyzed and examined the reasons for non-compliance identified in nuclear power plant events by Reason's rule-related behavior classification. For behavior analysis, I selected unit behaviors for events that are related to human and organizational factors and occurred at domestic nuclear power plants since 2017, and then I applied the rule-related behavior classification introduced by Reason (2008). This allowed me to identify the intentions by classifying unit behaviors according to quality and compliance with the rules. I also identified the factors that influenced unit behaviors. The analysis showed that most often, non-compliance only pursued personal goals and was based on inadequate risk appraisal. On the other hand, the analysis identified cases where it was caused by such factors as poorly written procedures or human system interfaces. Therefore, the probability of non-compliance can be reduced if these factors are properly addressed. Unlike event investigation techniques that struggle to identify the reasons for employee behavior, this study provides a new interpretation of non-compliance in nuclear power plant events by examining workers' intentions based on the concept of rule-related behavior classification.

The demand for mass calculation of offsite consequence analysis to conduct exhaustive single-unit or multi-unit Level 3 PSA is increasing. In order to perform efficient offsite consequence analyses, the Korea Atomic Energy Research Institute is conducting model optimization studies to minimize the analysis time while maintaining the accuracy of the results. A previous study developed a model optimization method using efficient plume segmentation and verified its effectiveness. In this study, we investigated the possibility of optimizing the model through particle size distribution setting by checking the reduction in analysis time and deviation of the results. Our findings indicate that particle size distribution setting affects the results, but its effect on analysis time is insignificant. Therefore, it is advantageous to set the particle size distribution as fine as possible. Furthermore, we evaluated the effect of multithreading and confirmed its efficiency. Future optimization studies should be conducted on various input factors of offsite consequence analysis, such as spatial grid settings.

Unlike in general manufacturing process, safety management in laboratory-based research area is complicated because the latter generally involves trying untested methods or handling unusual substances in small amounts. Laboratory accidents in South Korea have recently shown an increasing trend. Unfortunately, statistics on such accidents are not officially published by any domestic public agencies. In this study, multivariate analysis was performed on the relationships between variables to develop effective strategies for preventing laboratory accidents. A Cross-Tabulation Analysis of accident-related factors in 179 accident cases revealed that the laboratory type, accident type, and unsafe-act type are all statistically significant, whereas the unsafe condition and management factors differ with the statistical criteria. Furthermore, the results of a Multiple-Correspondence Analysis showed that accidents can be divided largely into three groups having different accident causes and injury types; this confirms the necessity of different strategies to prevent accidents of each type. The findings also reveal differences between the distribution of accident types mentioned in the accident case collection books and actual reported cases. This suggests that an official statistical system administered by a public institution would be necessary for effective prevention of laboratory accidents.

This study aimed to identify the multiple mediation effects of job satisfaction and job commitment on the relationships between job stress and workers' safety behavior in terms of compliance and participation, in which the multiple mediation effects are a hybrid of parallel and serial mediating relationships. The multiple mediation model was analyzed using the bootstrapping method through the PROCESS macro tool in SPSS. The results showed that job stress negatively affects job satisfaction, job commitment, and workers' safety behavior, and the relationship between job stress and safety behavior is mediated by both job satisfaction and job commitment. The serial mediation effects of job satisfaction and job commitment were also found to be statistically significant in the regression relationship between job stress and safety behavior. Further analysis of the compliance and participation subdimensions of safety behavior showed similar results. Specifically, the serial mediation effects of job satisfaction and job commitment on participation and compliance behavior were further supported; however, the mediation effect of job satisfaction was not significant, whereas that of job commitment did remain significant. Further research is needed to determine if the mediation effect of job satisfaction found in this study can be extended and generalized to workers in various fields and industries.