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|Title: ||Differential magnification methods and interface factors for improving visual inspection performance|
|Other Titles: ||Yong yu ti gao mu jian biao xian de cha lü fang da fang fa ji xiang guan jie mian yin su yan jiu|
|Authors: ||Lee, Choi Hung (李彩紅)|
|Department: ||Department of Manufacturing Engineering and Engineering Management|
|Degree: ||Doctor of Philosophy|
|Issue Date: ||2009|
|Publisher: ||City University of Hong Kong|
|Subjects: ||Engineering inspection.|
Quality control -- Optical methods.
|Notes: ||CityU Call Number: TS156.2 .L59 2009|
xiv, 204 leaves : ill. 30 cm.
Thesis (Ph.D.)--City University of Hong Kong, 2009.
Includes bibliographical references (leaves 169-181)
|Abstract: ||Magnification is a commonly used means of improving task visibility in
quality inspection tasks. In this study, two novel differential magnification methods,
namely differential linear and differential nonlinear magnifications, were developed.
With differential magnification, a lower scaling is applied in the high resolution
central fixation area while the more peripheral objects are scaled with a higher
magnification power. The idea is well supported by the variable visual acuity nature
of human vision across fovea and periphery and the effectiveness of linear and
nonlinear magnification on target detection performance. The differential
magnifications which match the psychophysical properties of human eyes are
expected to improve the interface design of video magnifiers and ultimately the
visual inspection performance. In order to investigate the effectiveness of
differential magnification methods, versatile computer software was developed to
simulate the visual inspection task and to produce the desired magnification effects.
A series of experiments were then conducted, focusing on the learning effect and the
auditory cueing effect in using the two differential magnifying lenses.
For the examination of learning effects with the novel magnification methods,
a learning programme was designed with performance and process feedback given
to learners in order to facilitate their learning process. Exponential learning curves
were established and greater improvement from repeated practice was noted for the
two novel differential magnification methods than the traditional linear
magnification method. Based on the learning curve models, the traditional linear
magnification method was outperformed by the differential linear and nonlinear
methods after four and ten repeated practice sessions, respectively. Given the
favorable influence of sensory cueing on attention orientation, the effectiveness of
auditory cues for directing subjects’ attention from the peripheral to the neglected
foveal areas on visual inspection performance was also examined in this study. The
results showed positive cueing effects on attention orientation and the auditory cues
proved to be useful for improving inspection performance with the two novel
differential magnification methods. Detailed discussion on the effectiveness of the
auditory cues was made with reference to the Wickens’ multiple resources model
and Wolfe’s Guided Search model.
In addition to the novel design and testing of differential magnification
methods, other probable magnification interface factors including magnification
mode, location cues, magnifier shape, magnification power, and target difficulty
were examined together with subject factors including visual acuity and visual lobe
area. It was found that considerations of screen space design for displaying
magnified window and original product image were important concerns for video
magnifiers. And, the results suggested that the use of location cues was particularly
useful when the visual task demanded a high level of search memory and the
subjects employed an unsystematic search strategy.
To summarize, the effectiveness of the differential magnification methods
was found greatly improved with repeated practices and the aid of auditory cues.
Second, the study furnishes specific knowledge of magnification interface factors for
improving visual inspection performance. The findings of this research have useful
implications for the interface design of video magnifiers, and provide vital
information for establishing more optimal inspection system designs which will be
particularly beneficial to industrial inspection tasks.|
|Online Catalog Link: ||http://lib.cityu.edu.hk/record=b2340791|
|Appears in Collections:||MEEM - Doctor of Philosophy |
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