Studies on Multiple Approaches to Workload Assessment

1. NASA-TLX对一线工作人员的工作量评估：NASA-TLX对一线工作人员进行了修订。在一家空调公司进行了四项调查。结果表明，WWL与AWWL呈极显著相关。重测相关性也很显著。子量表得分可以检测到线条特征的差异。然而，这些量表可能对姿势负荷不敏感。还需要进一步修订。心理生理指标评估心理负荷：记录16例男性受试者的心电（HRV）、TWA、指尖容积图、排汗、呼吸和瞳孔面积。设计了木块拼图制作几何图案（PZ）、二维补偿跟踪任务（FL）和数字逻辑任务（MN）作为心理任务。PZ的任务持续时间为8分钟。FL和MN任务设置了三个难度等级，每个任务的完成时间为4分钟。设计并研制了新的瞳孔测量系统。然而，受试者的眼睑干扰了瞳孔的测量。它必须得到改进。主观工作量采用NASA-TLX量表测量，获得A型评分和状态焦虑评分。结果表明，心率参数受不规则呼吸模式的影响很大，但受试者被指示控制呼吸。另一方面，出汗量与任务难度略有相关。此外，任务特异性反应的观察表明，即使主观工作量水平相同，不同类型的任务之间的生理反应也存在差异。

1. Workload Assessment in Line Workers by NASA-TLX : The NASA-TLX was revised for line workers. Four surveys were performed in an air-conditioner company. The results show significant correlation between WWL and AWWL.The test-retest correlation was also significant. Subscale scores could detect the differences in characteristics of the lines. However, these scales may not have sensitivities to a postural load. Further revisions have to be done.2. Mental Workload Assessment by Psychophysiological Indices : ECG (HRV,TWA), fingertip plethysmogram, perspiration, respiration and pupil area were recorded from sixteen male subjects. Wood piece puzzle to make a geometric pattrn (PZ), two-dimensional compensatory tracking task (FL) and numeric logical task (MN) were designed as mental tasks. The task duration for PZ was eight minutes. Three levels of difficulty were set in FL and MN task and four minutes were allowed to perform each task. New pupil measuring system was designed and developed. However, subject's eyelid disturbed the pupil measurement. It must be improved. Subjective workload was measured by NASA-TLX and Type A scores and state anxiety scores were obtained. The results show that HRV parameters were much affected by irregular respiration patterns nevertheless the subjects were instructed to control their breathing. On the other hand, amount of sweat correlated with task difficulty slightly. Furthermore, task specific responses were observed which suggest that the physiological responses differ between different kind of tasks even if the subjective workload is the same level.