Hsin-Chieh Wu 1, *, Yu-Chen Lo 1 , Cheng-Lung Lee 1 , Mom-Hang Lin 2
1
Department of Industrial Engineering and Management, Chaoyang University of Technology,
No.168, Jifeng E. Rd, Wufeng District, Taichung, 41349, Taiwan, R.O.C.
2
Department of Industrial Engineering, FungChia University
No.100, WengHua Rd, Taichung city, 40049, India
Abstract
The purpose of the study was to explore the influences of the visual distance and monitor on the visual performance and visual fatigue. 30 participants took part in the study whose ages are between nineteen to twenty-five years old. Independent variables of the experiment are display type
(E-book and projector) and visual distance (1.5 and 3 times of the diagonal line of the screen).
Dependent variables were visual performance and visual fatigue. Each participant had to perform four experimental trials in four different days. The experimental trials were performed in random sequence and each trial took about 20 minutes. The content of article was compiled with random capital letters, and participants should look for the letter “z”. The results showed that no significant influences of display type and visual distance were found on visual performance and visual fatigue at the visual angle of 20 min arc. This study suggests that the users should utilize high PPI medium while watching in a short distance. The users face downward while using E-books and the users face upward while using the projector. The difference of head posture could be explored in the future. An important technique of analyzing sales data for customer importance evaluation is RFM analysis. However, there are some shortcomings in traditional crisp RFM models. To overcome these shortcomings, a fuzzy set approach is proposed. Firstly, the formula for calculating the R, F, and M scores as well as that for calculating the RFM total score are fuzzified, and a customer’s importance is now evaluated with a more reasonable fuzzy value instead.
Keywords : E-book, visual performance, visual fatigue, eyestrain, ergonomics
*Corresponding author: E-mail: hcwul@cyut.edu.tw
; Tel: 886-4-2332-3000 ext.4537; Fax: 886-4-2374-2327