• 경영과학
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• 제12권1호
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• pp.61-77
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• 1995

The Ergonomic Workload Stress Index (EWSI) was developed to predict the existence and level of the ergonomic workload stress in the workplace. To determine the validity of model, the values of the EWSI and two other similar techniques, Job Severity Index (JSI) and Physical Work Stress Index (PWSI) were evaluated in two actual industrial environments. The results from the validation study provide further substantial evidence that two techniques, JSI and PWSI, which have similar objective considerations, are significantly associated with the value of the EWSI among the employees participating in the experimentation.

• 드라이브 ㆍ 컨트롤
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• 제19권4호
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• pp.29-35
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• 2022

In this paper, we developed a workload index for monitoring the durability test using operation information of an excavator. First, the acceleration and cylinder pressure were selected as load factors by analyzing operation data. Through load correlation analysis according to each load factor, Root Mean Square (RMS) and Work Load Range (WLR) were respectively derived as a load feature representing mechanical load. In addition, the workload index was used to quantify load features. For applying the workload index to monitoring, a real-time monitoring system consisting of sensors and embedded controller was installed on the excavator and the system was integrated with a remote monitoring environment using a wireless network. Results of load monitoring and analysis verified that the developed workload index was effective from the viewpoint of the relative comparison of the workload.

• Journal of Biosystems Engineering
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• 제38권2호
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• pp.163-170
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• 2013

Purpose: The purpose of this study is to provide analysis of physiological, biomechanical responses occurring from the operation to lifting or twist lifting task appears frequently in agricultural work. Methods: This study investigated the changes of physiological factors such as heart rate, heart rate variability (HRV) and biomechanical factors such as physical activity and kinetic analysis in the task of twisting at the waist while lifting. Results: Heart rates changed significantly with the workload. The result indicated that the workload of 2 kg was light intensity work, and the workload of 12 kg was hard intensity work. Physical activity increased as the workload increased both on wrist and waist. Besides, stress index of the worker increased with the workload. Dynamic load to herniated discs was analyzed using inertial sensor, and the angular acceleration and torque increased with the workload. The proposed measurement system can measure the recipient's physiological and physical signals in real-time and analyzed 3-dimensionally according to the variety of work load. Conclusions: The system we propose will be a new method to measure agricultural workers' multi-dimensional signals and analyze various farming tasks.

• 대한인간공학회지
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• 제29권4호
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• pp.687-691
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• 2010

Workload assessment is one of the important elements of the human factors evaluation for the nuclear power plants in operation. This paper describes a further study upon the additional elements of the workload which elements should be considered in the subjective workload assessment. We have tried to predict the burden of the work and to improve the work through a comparison of the objective workload and the subjective workload in the previous studies in nuclear power plants. However, there is a restriction to perform a precise assessment because of the limitations of the method itself. The objective workload assessment is performed by relative comparison using the quadrant analysis with objective workload and subjective workload because there were no clear criteria of objective workload assessment. And the subjective workload assessment is performed by NASA-TLX (NASA Task Load Index) which includes six evaluation dimensions of subjective workload. NASA-TLX is difficult to grasp the other aspects that could influence on the subjective workload because the analysis relies on predetermined assessment items. We conduct a factor analysis between the factors that affect the workload and the assessment adopted from ISO 10075 and NASA-TLX. At the same time, this study suggests other evaluation elements which can be added for subjective workload assessment except for evaluation elements of NASA-TLX.

• 대한교통학회지
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• 제35권6호
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• pp.545-556
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• 2017

운전자 작업부하를 평가하기 위해 다양한 평가지표가 개발되어 활용되고 있으나, 기존의 작업부하 평가지표의 경우 개별 운전자의 운전습관과 주행패턴을 충분히 반영하지 못하고 있다. 또한, 운전자마다 체감하는 작업부하량과 작업부하를 극복하는 능력은 개인차가 있다. 따라서, 본 연구를 통해 개별 운전자의 주행패턴을 반영한 새로운 작업부하 평가지표를 도출하였다. 개별 운전자의 주행패턴을 반영하기 위해 운전자 별 Steering Velocity 절대값의 평균을 임계값으로 설정하고 임계값을 초과하는 영역의 Steering Velocity 면적의 합을 계량화한 ESA (Erratic Steering Velocity Area)를 제시하였다. 본 연구에서는 주행 시뮬레이션 실험을 통해 자율주행차가 비자율차와 혼재되어 주행하는 군집주행 환경을 구축하여 비자율차의 운전자가 군집주행 환경에서 어떠한 영향을 받는지를 ESA를 활용하여 평가하였다. 주행 시뮬레이션 실험을 통해 군집유무에 따른 일반 비자율차 운전자의 반응행태자료를 추출하여 NASA-Task Load Index (NASA-TLX) 점수와 운전자 작업부하 평가지표간의 관계를 분석하였다. 그 결과, 차로변경 시나리오에서는 다양한 운전자 작업부하 평가지표 중 ESA가 NASA-TLX 점수와 상관관계가 가장 큰 것으로 나타나 ESA의 유용성을 확인하였다.

• Nuclear Engineering and Technology
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• 제51권2호
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• pp.453-462
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• 2019

Mental workload (MWL) is a major consideration for the user interface design in nuclear power plants (NPPs). However, each MWL evaluation method has its advantages and limitations, thus the evaluation and control methods based on multi-index methods are needed. In this study, fuzzy comprehensive evaluation (FCE) theory was adopted for assessment of interface designs in NPP based on operators' MWL. An evaluation index system and membership functions were established, and the weights were given using the combination of the variation coefficient and the entropy method. The results showed that multi-index methods such as performance measures (speed of task and error rate), subjective rating (NASA-TLX) and physiological measure (eye response) can be successfully integrated in FCE for user interface design assessment. The FCE method has a correlation coefficient compared with most of the original evaluation indices. Thus, this method might be applied for developing the tool to quickly and accurately assess the different display interfaces when considering the aspect of the operators' MWL.

• 중환자간호학회지
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• 제2권1호
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• pp.48-57
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• 2009

Purpose: The purpose of this study is to establish reliability and validity and to identify the conversion index. Method: The WMSCN for ICU was revised from Workload Management System for Nurses(WMSN) of Walter Reed Army Hospital. Reliability of the WMSCN was evaluated interrater reliability between head nurses and staff nurses at 124 patients in April 2008. Validity through the correlation between direct nursing care hours and WMSCN score was conducted at 20 ICUs of 10 hospitals. Finally the conversion index was identified by total nursing hours and it divided by WMSCN score. Results: The scores by nurses were highly correlated with head nurses’(p=.967), and also scores of the WMSCN were highly correlated with the direct nursing care hours(p<.001). The distribution of patient classification ranks into class V(61.3%), class IV(24.2%) and class VI(11.3%). The scores of the WMSCN were no differences between MICU and SICU. Finally, the conversion index was 8.2 minutes. Conclusion: WMSCN is available to classify the nursing workload for critical care patients. The repeated evaluation of validity and reliability are requisite to use WMSCN effectively. And the conversion index should be adjusted to estimate the appropriate staffing in Korea.

• 대한인간공학회지
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• 제21권3호
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• pp.47-58
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• 2002

The similarity of shape of shape of interface between human cognitive map and real product is the important factor to determine the human performance. Nevertheless, the degree of similarity between these has not been defined quantitatively in recent studies. Therefore, in this study, the cognitive map and the mental workload were measured by SMM(Sketch Map Method) and RNASA-TLX(Revision of NASA-Task Load Index). And the numerical expression of the accuracy point was suggested for the quantitative calculation of relative positional similarity between cognitive map and real product. In the experiment, nine subjects were participated and two kinds of vehicles were used. Mental workload was mental workload was measured immediately after the road test. The result of analysis on the relationship between accuracy and mental workload shows that the negative correlation exists on each vehicle, and the lower score of mental workloads id measured on the vehicle that has the higher score of accuracy between two vehicles.

• Safety and Health at Work
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• 제10권3호
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• pp.341-346
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• 2019

Background: Although the concept of workload is important to nursing practice, only a few nursing researchers have focused on the issue of workload within the nursing context. Knowledge of how the dynamics of workload affects the job stress of nurses working in a specific unit or department in a hospital setting, and the influence of coworker support on this relationship, still remains limited. This study, therefore examined the effect of workload on job stress of Ghanaian outpatient department nurses and the moderating effect of coworker support on this relationship. Methods: A cross-sectional survey design was used, and questionnaire was used to collect data from a sample of 216 outpatient department nurses from four major hospitals in Ghana. The data collected measured workload, job stress, and coworker support using National Aeronautics and Space Administration (NASA) Task Load Index, job stress scale, and coworker support scale, respectively. Data were analysed using descriptive statistics, correlation, and hierarchical regression. Results: High levels of workload were associated with high levels of job stress of the nurses. Also, higher levels of workload were related to higher levels of job stress for nurses who received high levels of coworker support, but this was not the case for those who received low levels of coworker support (reserve buffering effect). Conclusion: The finding reiterates the adverse effect of workloads on employees' health, and the reverse buffering effect implies that supporting a colleague at work should be conveyed in a positive manner devoid of negative appraisal.

• 한국안전학회지
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• 제28권5호
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• pp.66-70
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• 2013

This study examined the relative effects of education and eco-IVIS(in-vehicle information system) to reduce fuel consumption and greenhouse gas emissions. Also the study investigated the increasing of driving workload when drivers interact with intervention technique. Thirty participants randomly assigned into two groups(training and eco-IVIS) and conducted driving before and after the each intervention technique. While driving, we observed three driving behaviors: Frequency of excessive RPM, percent of speeding, and mean fuel efficiency. Also the Driver Activity Load Index was used to rate participants' subjective ratings of driving workload. Although the results showed positive impact of both education and eco-IVIS to increasing the eco-driving behaviors, eco-IVIS was more effective than education. However, we found comparable level of driving workload in the education and eco-IVIS.