• Transactions of the Korean Society of Mechanical Engineers
• /
• v.18 no.2
• /
• pp.339-350
• /
• 1994

This paper presents a method for automatic generation of line balanced assembly sequences based on disassemblability and proposes a method of evaluating an assembly work time using neural networks. Since a line balancing problem in flexible assembly system requires a sophisticated planning method, reasoning about line balanced assembly sequences is an important field of concern for planning assembly lay-out. For the efficient inference of line balanced assembly sequences, many works have been reported on how to evaluate an assembly work time at each work station. However, most of them have some limitations in that they use cumbersome user query or approximated assembly work time data without considering assembly conditions. To overcome such criticism, this paper proposes a new approach to mathematically verify assembly conditions based on disassemblability. Based upon the results, we present a method of evaluating assembly work time using neural networks. The proposed method provides an effective means of solving the line balancing problem and gives a design guidance of planning assembly lay-out in flexible assembly application. An example study is given to illustrate the concepts and procedure of the proposed scheme.

• Safety and Health at Work
• /
• v.7 no.2
• /
• pp.138-142
• /
• 2016

Background: Household waste collectors (HWCs) are exposed to hazardous conditions. This study investigates the patterns of workplace injuries and work-related illnesses of HWCs. Methods: This study uses cases of workplace injuries and work-related illnesses of HWCs that occurred between 2010 and 2011. We analyzed 325 cases of injuries and 36 cases of illnesses according to the workers' age, length of employment, size of workplace, injured part of body, day and month of injury, type of accident, agency of accident, and collection process. Results: There were significant differences in the effect of workers' length of employment, injured part of body, type of accident, agency of accident, and collection process. Results show that most injuries occur in workers in their 50s and older. This study also shows that 51.4% of injuries occur at businesses with 49 employees or fewer. Injuries to waste collectors happen most often when workers are electrocuted after slipping on the ground. The second most prevalent form of injury is falling, which usually happens when workers hang from the rear of the truck during transportation or otherwise slip and fall from the truck. Work-related illnesses amongst waste collectors are mostly musculoskeletal conditions due to damaging postures. Conclusion: These findings will be instructive in devising policies and guidelines for preventing workplace injuries and work-related illnesses of HWCs.

• Safety and Health at Work
• /
• v.9 no.4
• /
• pp.454-461
• /
• 2018

Background: Working conditions and psychosocial work factors have acquired an important role explaining the well-being and performance of professional drivers, including those working in the field of public transport. This study aimed to examine the association between job strain and the operational performance of public transport drivers and to compare the expositions with psychosocial risk at work of three different types of transport workers: taxi drivers, city bus drivers, and interurban bus drivers. Method: A sample of 780 professional drivers was drawn from three transport companies in Bogota (Colombia). The participants answered the Job Content Questionnaire and a set of sociodemographic and driving performance questions, including age, professional driving experience, work schedules, and accidents and penalties suffered in the last 2 years. Results: Analyses showed significant associations between measures of socio-labor variables and key performance indicators such road traffic accidents and penalties. Furthermore, multiple linear regression analysis contributed to explain significantly suffered accidents from key variables of the Job Demand-Control model, essentially from job strain. In addition, throughout post-hoc analyses, significant differences were found in terms of perceived social support, job strain, and job insecurity. Conclusion: Work stress is an issue that compromises the safety of professional drivers. This research provides evidence supporting a significant effect of job strain on the professional driver's performance. Moreover, the statistically significant differences between taxi drivers, city bus drivers, and interurban bus drivers in their expositions to work-related stress suggest the need for tailored occupational safety interventions on each occupational group.

• Korean Journal of Occupational Health Nursing
• /
• v.20 no.1
• /
• pp.83-92
• /
• 2011

Purpose: This is a descriptive study that provides basic material to improve occupational health nurses' work conditions and industrial performance status. Methods: The 955 nurses who participated in the training program to understand the purpose of this study from January 2009 to December 2010 conducted by the Korean Association of Occupational Health Nurses agreed to be subjects for the study. The questionnaire included the general characteristics, work conditions and performance of occupational health management. The data were analyzed using descriptive statistics, t-test, ANOVA, and multiple regression analysis. Results: Occupational health management performance of the subjects averaged 3.11 points and detailed area by health management 3.64 points, environment management 2.91 points and occupational management 2.77 points. Health management performance of those factors affecting the duration of occupational health nurse (${\beta}$=.199), type of industry (${\beta}$=.126), average annual income (${\beta}$=-.277) to 11.4% (F=3.175, p<.001) were found to be a significant determinant. Conclusion: Occupational health nurses are the core workforce of occupational health through the prevention of occupational disease and industrial accidents. Findings of this study can be an important resource to increase appropriate occupational health nurses' work conditions and performance of occupational health management.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.33 no.4
• /
• pp.447-454
• /
• 2023

Objective: This study aims to investigate the impact of changes in working conditions on job-related stress and musculoskeletal disorders using the results of seven surveys conducted at a single workplace from 2004 to 2022 regarding factors hazardous to the musculoskeletal system. Additionally, the study aims to propose alternative methods of investigating factors hazardous to the musculoskeletal system. Methods: A car parts manufacturing plant where the same survey was taken seven times from 2004 to 2022 was selected and the survey data was analyzed. The main contents of the survey were weekly working hours, Borg's scale, work intensity, job-related stress, and the prevalence of musculoskeletal symptoms. The statistical analysis was performed using SAS (version 9.4). Results: The results of this study are as follows. Firstly, changes in working conditions have an impact on job-related stress. Secondly, changes in working conditions have an impact on work intensity indicators. Thirdly, changes in working conditions have an impact on the prevalence of musculoskeletal symptoms. Fourthly, even with an increase in age and length of service, job-related stress and musculoskeletal symptoms were alleviated when working conditions were improved. Conclusions: In order for measures to reduce musculoskeletal disorders to be successful, working conditions must not deteriorate, and it is necessary to demand revisions to regulations, etc. to reflect these points in the investigation of hazardous factors to the musculoskeletal system.

• Korean Journal of Occupational Health Nursing
• /
• v.14 no.2
• /
• pp.108-117
• /
• 2005

Purpose: This paper was attempted to focused on the analysis of job stress and job satisfaction according to the moderating effects of social support. Method: Data collected from 302 staff nurses in 2 general hospitals, with self-reporting questionnaires(Wolfgang's HPSI, modified Hagihara's social support, and MSQ). Descriptive statistics, Cronbach's alpha, Pearson correlation, ANOVA, and moderated regression analysis were used. Result: The subjects exhibited significantly highest level of 'the work and patients' conditions'. The perceived job stress was negatively correlated with supervisor and co-workers' support, and job satisfactions. Also supervisor and coworkers' support were positively correlated with job satisfactions. The main factor that affected the job satisfactions was 'work and patient conditions' and it was explained 35.5% out of the total variance of the job satisfactions with 'the work load and disturbing factor', 'supervisor support' and 'co-workers' support'. Supervisor support moderated the relationships between 'the patient care responsibilities and career development factor' and satisfaction. Conclusion: For developing the stress management program for hospital nurses, 'the work and patients' conditions', and the strategies of strengthening 'supervisor and co-workers' support' should be considered. In addition to, it may be considered to examine the effects of social support on the other criterion variables.

• Journal of Technologic Dentistry
• /
• v.17 no.1
• /
• pp.58-71
• /
• 1995

This study was carried out in order to examine demographic variables and personal and working conditions affecting to self-esteem, self-efficacy and work autonomy and mental health of the dental technicians. For this study, questionnaires composed of 50 items for the measurement of psychiatric symptom, work autonomy, self-esteem and self-efficacy index and 14 items related with demographic variables and personal and working conditions were distributed to 400 dental technicians and the 304 of them were statistically analyzed the results were as the following ; 1. Self-esteem and self- efficacy in dental technicians appeared to be interacted. 2. Score of self-efficacy index was higher in dental technicians of young age, or high or professional education than in otherwise dental technicians. 3. Score of self-efficacy index was higher in dental technicians of young age or professional education than in otherwise dental technicians. 4. All of self-esteem, self-efficacy and work autonomy in dental technicians affected directly their psychiatric symptom. 5. Promotion, and communication with fellows and senior workers of dental technicians affected directly their psychiatric symptom. 6. Each of anxiety, anger, depression and cognitive disturbance appeared to be interacted.

• Journal of the Korean Society of Safety
• /
• v.23 no.2
• /
• pp.51-56
• /
• 2008

In these days, work-related musculoskeletal disorders(WMSDs) is one of the issues in the shipbuilding industry. As the number of injured workers and demands for worker's compensation have rapidly increased, improvement of work conditions and environments to prevent WMSDs has been more demanded. To reduce WMSDs' hazards in the shipbuilding industry, simulation technique which showed it's ability of increasing the manufacturing productivity was applied, because simulation technique has the evaluation ability for a worker's danger level of production process by RULA(Rapid Upper Limb Assesment). In this research, worker's altitude had modeled and worker's action has simulated. After the caution level was evaluated, we pointed out clues which had high workload. To reduce work-load, we applied ergonomic principles for improving working conditions and environments. Improved working conditions and environments were simulated using human modelling and simulation and their workload were evaluated again.

• Korean Journal of Occupational Health Nursing
• /
• v.29 no.4
• /
• pp.273-287
• /
• 2020

Purpose: This descriptive correlation study was conducted to investigate factors affecting the absence of adult workers according to their gender. Methods: Secondary data analysis was carried out using data from the fifth Korean Working Conditions Survey. Data on respondents' demographic characteristics, working conditions, health status, and absence were analyzed; a descriptive analysis, χ²-test, t-test, and logistic regression analysis were carried out. Results: The factors that had the greatest impact on male workers' absence from work were service workers (2.74 times; B=.99), having more than 53 hours of work per week (1.17 times; B=.52), and when subjective health conditions were not satisfied (2.27 times; B=.82), whereas the factors that affected female workers' absence the most were a monthly income of 3 million won or more (2.74 times; B=1.34), a weekly work time of 53 hours (2.02 times; B=.71), and having a fewer number of sleep disorders (B=-.36). Conclusion: This study suggests that not only the national interest should be considered in investigating the factors affecting absence but also the enterprise. Systematic support for the health care of workers is also needed.

• Knowledge Management Research
• /
• v.21 no.2
• /
• pp.77-100
• /
• 2020

This study conducted a qualitative study on 23 seniors over 55 years old to understand the digital behavior of seniors in the online education acceptance environment. Grounded Theory methodology was applied to the initial enrollment behavior, login behavior, and utilization behavior of online education program. Through the process of open coding, axis coding, and selective coding, the framework in the online education environment of the senior generation was finally derived. As a causal conditions for the senior generation to participate in the online education environment, goal orientation, relationship orientation, leisure orientation and external compulsory were derived, and shadow work appeared as the central phenomenon. Also, contextual conditions resulted in social change, physical and cognitive aging, and psychological atrophy. The intervening conditions included digital device acceptance, educational attitudes, environmental factors, and self-efficacy. Based on this, the action/interactions strategy formed a positive and negative attitude toward shadow work. As a result, positive response behavior, compromising behavior, and shadow work avoidance behavior were shown. It is hoped that this study will be reflected in future researches for the use of digital devices of the elderly and the expansion of online education participation and government policy.