Practical Judgment of Workload Based on Physical Activity, Work Conditions, and Worker's Age in Construction Site.

It is important for construction companies to sustain a productive workforce without sacrificing its health and safety. This study aims to develop a practical judgement method to estimate the workload risk of individual construction workers. Based on studies, we developed a workload model comprising a hygrothermal environment, behavioral information, and the physical characteristics of workers). The construction workers' heart rate and physical activity were measured using the data collected from a wearable device equipped with a biosensor and an acceleration sensor. This study is the first report to use worker physical activity, age, and the wet bulb globe temperature (WBGT) to determine a worker's physical workload. The accuracy of this health risk judgment result was 89.2%, indicating that it is possible to easily judge the health risk of workers even in an environment where it is difficult to measure the subject in advance. The proposed model and its findings can aid in monitoring the health impacts of working conditions during construction activities, and thereby contribute toward determining workers' health damage. However, the sampled construction workers are 12 workers, further studies in other working conditions are required to accumulate more evidence and assure the accuracy of the models.

Psychological Effects of Heart Rate and Physical Vibration on the Operation of Construction Machines: Experimental Study.

BACKGROUND: A construction method has emerged in which a camera is installed around a construction machine, and the operator remotely controls the machine while synchronizing the vibration of the machine with the images seen from the operator's seat using virtual reality (VR) technology. Indices related to changes in heart rate (HR) and physical vibration, such as heart rate variability (HRV) and multiscale entropy (MSE), can then be measured among the operators. As these indices are quantitative measures of autonomic regulation in the cardiovascular system, they can provide a useful means of assessing operational stress. OBJECTIVE: In this study, we aimed to evaluate changes in HR and body vibration of machine operators and investigate appropriate methods of machine operation while considering the psychological load. METHODS: We enrolled 9 remote operators (18-50 years old) in the experiment, which involved 42 measurements. A construction machine was driven on a test course simulating a construction site, and three patterns of operation-riding operation, remote operation using monitor images, and VR operation combining monitor images and machine vibration-were compared. The heartbeat, body vibration, and driving time of the participants were measured using sensing wear made of a woven film-like conductive material and a three-axis acceleration measurement device (WHS-2). We used HRV analysis in the time and frequency domains, MSE analysis as a measure of the complexity of heart rate changes, and the ISO (International Standards Organization) 2631 vibration index. Multiple regression analysis was conducted to model the relationship among the low frequency (LF)/high frequency (HF) HRV, MSE, vibration index, and driving time of construction equipment. Efficiency in driving time was investigated with a focus on stress reduction. RESULTS: Multiple comparisons conducted via the Bonferroni test and Kruskal-Wallis test showed statistically significant differences (P=.05) in HRV-LF/HF, the vibration index, weighted acceleration, motion sickness dose value (MSDVz), and the driving time among the three operation patterns. The riding operation was found to reduce the driving time of the machine, but the operation stress was the highest in this case; operation based on the monitor image was found to have the lowest operation stress but the longest operation time. Multiple regression analysis showed that the explanatory variables (LH/HF), RR interval, and vibration index (MSDVz by vertical oscillation at 0.5-5 Hz) had a negative effect on the driving time (adjusted coefficient of determination R2=0.449). CONCLUSIONS: A new method was developed to calculate the appropriate operating time by considering operational stress and suppressing the physical vibration within an acceptable range. By focusing on the relationship between psychological load and physical vibration, which has not been explored in previous studies, the relationship of these variables with the driving time of construction machines was clarified.

The Effects of Psychological Factors on Perceptions of Productivity in Construction Sites in Japan by Worker Age.

The construction industry is a work environment that poses many dangers to workers, with many hidden factors that affect work awareness. It is important for construction companies to ensure a balance between productivity and safety in the work environment. The purpose of this study was to identify relationships between the feeling of safety in the work environment, proactive work behavior, job satisfaction, work skills, team performance, and health risk indicators, such as heart rate, among construction workers of different ages. Based on previous research, we examined the hypothetical perception model. We then administered a questionnaire survey to construction workers (N = 357) employed at a Japanese construction company. Using structural equation modeling (SEM), we investigated the impact of health risk indicators on worker perceptions among young and older workers. The results showed that workers' heart rate and body mass index (BMI) had a negative effect on the feeling of safety and proactive work behavior among older workers, but showed no significant relationship among young workers. However, regardless of workers' age, it was clear that the feeling of safety affects job satisfaction, and that work skills and proactive work behaviors affect perceptions regarding team performance.

Age-Dependent Influence of Intrinsic and Extrinsic Motivations on Construction Worker Performance.

The increasing sophistication and complexity of construction technology have also increased workers' physical risk and psychological stress. This study examined the relationships between health risks, work motivation, and productivity as perceived by construction workers. A hypothetical model of worker perceptions, and the psychological factors influencing these perceptions, was developed. A total of 324 construction workers at a Japanese construction company participated in the study and were divided into two groups: younger (45 years of age and below) and older adults (46 years of age and above). Data were collected using a questionnaire. The differences between the age groups were analyzed with regard to their perceptions of health risks, motivation, work skills, and productivity. Both younger and older workers were affected by intrinsic motivations and extrinsic motivations, but the effect of these motivations on work performance differed depending on age. Higher health risks are anticipated to affect the work motivation and productivity perceptions of older workers. The proposed model and findings of this study contribute to understanding worker motivations and have important implications for labor management of construction projects. By addressing construction workers' intrinsic (e.g., interest) and extrinsic (e.g., reward) motivations, it is possible to sustainably improve project productivity.