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• Vision-based monitoring depends on ladder safety rules. • Worker height estimated by bounding box height ratio. • Correlation of keypoints enhances helmet identification. • Improved regression loss boosts unsafe behavior detection. Introduction: Fatal fall from height accidents, especially on construction sites, persist, underscoring the importance of monitoring and managing worker behaviors to enhance safety. Deep learning showed the possibility of substituting the manual work of safety managers. However, applying detection results to determine compliance with safety regulations has limitations. Method: This study estimated the actual working height depending on the height of the object detection bounding box by specifying the consistent hinge part as a target marker based on ladder manufacturing regulations. Furthermore, an attempt was made to improve the separation between workers, coworkers, and persons unconnected to ladder activities by applying an optimized loss function alongside an attention mechanism. Results: The experimental results showed that an average precision increased from 87.60% to 90.44%. The performance of the monitoring unsafe behavior of ladder worker following the Korea Occupational Safety and Health Agency (KOSHA) guide was evaluated by 91.40 F1-Score, which accumulated sorted according to the working height. Conclusions: Experimental results show the feasibility of the real-time automate safety monitoring in ladder work. Practical Applications: By linking the estimated working height and deep learning multi-detection results to established safety regulations, the proposed method shows the potential to automatically monitoring unsafe behaviors in construction site. [ABSTRACT FROM AUTHOR]

Fire safety on building construction sites as an important part of on-site safety management has rarely been studied for construction sites. To fill the knowledge gap, this research was conducted to identify important influencing factors on fire safety on construction sites, as well as their relationships, through a questionnaire administered to 1,492 fire officers in South Korea. The authors divided the questions into three factors (building, fire, and human) to distinguish factors affecting construction site fire safety. For the majority of the factors, there was high agreement on the importance level of factors affecting fire safety during construction between administrative and field firefighters. However, perception disparity did exist. The authors identified the interrelationships between factors through path analysis and structural equation modeling. The paths of factors showed the highest direct relation between building and fire factors, and the human factor played a mediator role between human and fire factors. The study contributes to the overall body of knowledge by providing officers' insights into the factors contributing to fire safety on construction sites, as well as the quantification of the interrelationship among the factors, which will serve as the basis to develop effective safety measures, such as policies and regulations at both the project level and industry level, to address fire safety on construction sites. The SEM model developed in this study can also be used as a base model for future related studies. [ABSTRACT FROM AUTHOR]

Featured Application: Relative importance of multi-participant perception is discussed in this study to improve safety design efforts in South Korea. For several decades, the number of reported accidents and fatal incidents in the construction industry has remained high compared to those in other industries. Therefore, many studies have been conducted in an effort to reduce accidents and fatal incidents in the construction industry. Recently, construction safety management has shifted from the construction phase to the pre-construction phase, ultimately to eliminate fatal incidents. In line with this change, South Korea enacted the Design for Safety (DfS) process in 2016. However, the current DfS process remains not well implemented for several reasons. Therefore, this study aims to present eight alternatives to improve the DfS process and suggests DfS improvement priorities by considering construction project participants and career levels using what is known as a fuzzy-analytical hierarchy process (F-AHP) analysis. The results of this study are as follows. First, respondents overall suggested improvements in the area of 'assignment of responsibility for DfS to the client' (0.196). Second, improvement priorities were also identified according to construction project participants and career levels. The results of the study can be utilized as basic information for DfS improvements during construction projects. [ABSTRACT FROM AUTHOR]

• The proposed method can classify and predict occupational accident types using a random forest (RF) model. • We presented key construction safety factors that affect the occupational accident types in Korea using feature importance. • The accuracy score of the RF model was obtained as 71.3%. • It will give a significant contribution to safety management of both practitioners and researchers in the construction industry. Although industrial accident rates are gradually decreasing in Korea, the construction industry's accident rate is still higher compared with other industries. Human errors, mentally unstable workers, insufficient safety training, and safety policy affect the occurrence of construction accidents. Owing to the characteristics of this industry, occupational accident types, such as fall from height, collision with objects, rollover, and those due to falling objects, can be related to the weather data. Therefore, to reduce and prevent occupational injury, it is necessary to classify and predict occupational accident types in detail. In this study, we built a model to classify and predict occupational accident types using a random forest (RF). We extracted important factors that affect the occupational accident types at construction sites using feature importance, and we analyzed the relationship between these factors and occupational accident types. The accuracy score of the RF model was obtained as 71.3%, and we presented key construction safety factors considering the feature importance. For future research, we will collect data and develop models to predict occupational accident types in real-time. Real-time construction accident prediction research will reduce accident at construction sites. [ABSTRACT FROM AUTHOR]

Abstract: On average, approximately 90 workers are injured or killed every year while lifting and installing steel beams in South Korea. Rotation-controllable tower-crane hook-blocks (RTH) remotely rotate beams horizontally to the target position, thus helping to prevent accidents related to steel beam installation. In this study, the expected safety improvements and economic effects of the RTH were analyzed. the real discount rate, and operation and maintenance costs in accordance with the general cash flow analysis practice as well as the CO2 offset price. The results of the analysis showed that when the effects of the RTH were at their maximum and average levels, the break-even points occurred in the first year and the second year, respectively. Although the RTH might not be profitable in the minimum case, this study demonstrated that using it would generally contribute to economic efficiency, and more importantly to worker safety. [Copyright &y& Elsevier]

A fabricated mobile scaffold has various components, including vertical members, horizontal members, braces, work plates, and castor wheels. In Korea, the structural performance of each member must be validated based on member-level structural safety criteria; this means that rigorous evaluation methods are required to secure the system-level structural safety of the fabricated mobile scaffold. To suggest rational system-level structural safety criteria and effective evaluation methods, the characteristics of the structural behaviors of the assembled structure must be investigated first. Unlike other temporary equipment, it is a product that requires convenience of use and ease of movement. Therefore, to secure the safety and usability of the structure, it is necessary to evaluate the ultimate behavior of a mobile scaffold fabricated with various material and structural types. In an experimental study, the ultimate mode and load-bearing capacity were investigated, and the appropriateness of the required performance of the mobile scaffold was reviewed. Three types of experimental test models with different materials (steel and aluminum) and stories (single-story and three-story erection) were selected and examined for vertical loads. Based on the experimental results, the ultimate behavior characteristics of the fabricated mobile scaffold were analyzed, and the ultimate load was identified. [ABSTRACT FROM AUTHOR]

• The practical roles to reduce construction accidents are necessary. • The organically linked characterization of each stage are considered. • A questionnaire was developed to diagnose the implementation level. • This study investigated the safety level of the construction life cycle. The law and various systems are necessary to efficiently manage safety in the construction process. However, policy almost always focuses on the contractor stage because of the high risk of accidents. The objective of this study is to suggest practical roles to reduce construction accidents by considering the organically linked characterization of each stage (client, designer, supervisor, and contractor) in construction to realize preventive policies. First, the Construction Technology Promotion Act and Occupational Safety and Health Act, overarching laws in South Korea applicable to construction safety, are reviewed. Next, the basic implemented roles of each stage are summarized to satisfy safety and health activities. Subsequently, a questionnaire is developed to diagnose the implementation level under current conditions using multiple-choice questions to easily gather responses and short answers. The survey was conducted with the safety coordinators (clients, designers, supervisors, and contractors) to determine their rates of accidents, contracting rankings, recommendations by the council, and ease of access. Through the surveying results, the current status of South Korea's construction safety system is examined, and rational roles to interconnect the various elements of this system are suggested. This study is significant because it investigates the safety level of the construction life cycle. Our suggestions are expected to play a critical role at each construction stage in reducing the accident rates of construction in South Korea. [ABSTRACT FROM AUTHOR]