A Study About The Knowledge Task Efficiency Of The Digital Systems

100 years ago, "Motion-time" study on operation tasks was done by Taylor and Gilbreth, which laid the foundation for scientific management. It improved the process of operation tasks from describing、measuring、evaluating、optimizing、managing and controlling. Management began with it and created that "The most prominent and unique contribution of management that was it improved the efficiency of workers in manufacture more than 50 times". Due to the essential differences between the operation tasks and knowledge tasks, the existing methods on operation tasks couldn’t be applied to knowledge tasks completely. It’s different from the man-machine systems of the operating task, the man-machine system made up of the knowledge task and the digital system which aimed to solve modern tasks and meet the modern needs of modern life. Even if the knowledge tasks had been the main form of tasks nowadays, the study of knowledge tasks had been just started; it was still far behind the requirements of current management.Aiming at the status and scarcity of current studies, in this dissertation, it focused on investigating the efficiency of knowledge tasks under digital systems with the Cognitive ergonomics approach. The main research contents were as follows:Firstly, it proposed an analytical model for efficiency of knowledge tasks based on digital systems.Based on the cognitive science, the knowledge task was the process of solving problem in knowledge network of digital systems, which was a cognitive process. It was regarded as the man-machine interactive process between the operator and digital work system, rather than simple operations with clicking the mouse and knocking the keyboard. Through experiments on cognitive work efficiency, eye movement and electroencephalogram, the dissertation mainly studies the human’s efficiency on information inputs in digital work system, man-machine conversation efficiency and its reliability and the cooperative work efficiency. Based on these research, it built the analytical model of knowledge task efficiency in digital system. The contents were as follows:Secondly, research on information input efficiency and recognition reliability.Digital work system can do information exchange with human through cognition interface. The physical property of cognition interface is the key factor on effecting the information input efficiency.It studied the influence of physical properties on recognition efficiency through cognitive experiments. The experimental result showed the matching relationship of foreground or background on common ten kinds of colors. It was confirmed that the green and black (foreground/background) had the highest identification efficiency while the white and yellow (foreground/background) did the worst. It was also discovered the asymmetry existed in color combination. The recognition efficiency was changed once swapping foreground and background colors.It built efficiency chart of screen position recognition through experiments. It was found the recognition efficiency of screen center was obviously higher than its four corners. The screen center was the optimal recognizing position while the bottom left was the worst. The study showed that the position identification of the screen had asymmetry as well, the upper was higher than the lower while the left side was higher than the right side.It adopted event-related potentials (ERP) analysis method and found that music significantly affected the color of the identification process in the color and environment interaction studies. The study also found that, compared to other colors, the song’My Old Classmate’affected on the identification process of green at minimum. Studies suggested that the higher coupling degree on cognitive template matching resulted in less interference on green.Thirdly, research on man-machine conversation efficiency and reliability in digital system.Digital work system can finish processing on knowledge tasks through man-machine conversation. Whether man-machine dialogue can be performed depends on the mutual recognition of human and machines. On the basis of the theory on recognition process and interaction, it built the man-machine conversation model with the core as task mental module and interface mental module. It was also described the formal description, stated the process of digital system man-machine conversation.Taking "SMS" for example, the study investigated the influence of man-machine conversation on knowledge task efficiency by simulation experiment. The result showed that the good and bad of man-machine conversation did effect the knowledge task efficiency. The more difficult on tasks, the efficiency on man-machine reduced as well, and the individual differences became more obviously.Fourthly, research on work efficiency in digital work system.Cooperation was the effective method to improve the work efficiency. Under the digital work system, cooperation reflected on the knowledge sharing among operator, rather than the simple movement delivery.Knowledge sharing was the key factor of affecting on multi-operation cooperation. The key issues of knowledge sharing were whether operators could share the knowledge or would like to share. Considering the difficulty on observing the knowledge sharing attitude, the study imported the "cellular automata" to simulate the process of the knowledge sharing, and studied the impact on the efficiency of knowledge tasks from different position, different number of knowledge workers. The result showed that the individual attitude would affect the entire group, and the influence of key employee’s sharing attitude was greater than that of the non-key employee. Moreover, the distance of employees was also the key factor on effecting the sharing efficiency.