A Comparison Study of Inspector's Performance between Regular and Complex Tasks
This research was to study a comparison of inspector’s performance between regular and complex visual inspection task. Visual task was simulated on DVD read control circuit. Inspection task was performed by using computer. Subjects were 10 undergraduate randomly selected and test for 20/20. Then, subjects were divided into two groups, five for regular inspection (control group) and five for complex inspection (treatment group) tasks. Result was showed that performance on regular and complex inspectors was significantly difference at the level of 0.05. Inspector performance on regular inspection was showed high percentage on defects detected by using equal time to complex inspection. This would be indicated that inspector performance was affected by visual inspection task. Keywords—Visual inspection task, Regular and complex task.
The Effect of Visual Search Patterns of Non-Geometric Shape Inspection Tasks
— Product inspection is an important step and a major quality control component for many industrial tasks. Visual inspection is based on the use of the human eye to search surface defects. The objective of this research was to compare three types of visual search patterns, investigate and identify differences between different pattern of visual search in terms of performance measures to identify an effective means of significantly the inspector for non-geometric shape inspection tasks. The random search pattern, vertical search pattern and horizontal search pattern were used to instruct participants on visual inspection. Participants were provided information about number of defect per inspection tasks, provided with verbal description and graphical of the defect types, visual search method of each groups and rotation method for inspected. Then, the trials of visual inspection. The performance of visual inspections measured by the mean search time and the percentage of defects detected for each visual search patterns. Analysis of one-way ANOVA both indicated a significant treatment effect, (F (2, 15) = 56.425, p < 0.05), (F (2, 15) = 15.943, p < 0.05). Fisher’s Protected LSD Comparison procedure was conducted to determine what differences, least significant difference multiple comparison analysis indicated that the performance of the horizontal search was significantly better than that of the random search and vertical search. One reason for this might be that the horizontal search pattern was a systematic search method that covered the total inspection area. Based on the results of this study, the horizontal search pattern was the appropriate pattern of visual search of complicated shapes or non-geometric shapes, it is recommended that horizontal search pattern be used in the visual search of inspectors for non-geometric shape inspection tasks.
Evaluation of Impact of Yarn Count and Stitch Length on Pilling, Abrasion, Shrinkage and Tightness Factor of 1 ? 1 Rib Cotton Knitted Fabrics
This study investigates the impact of yarn count and stitch length of 100% cotton knitted fabrics. 1 × 1 ribs structured fabrics were used in this research work. The stitch length 2.50 mm, 2.52 mm, 2.60 mm, 2.70 mm, 2.80 mm and 2.96 mm were used of the yarn count of 26Ne, 28Ne and 36Ne. The areal densities of the grey fabrics were in various amounts. The impacts of yarn count and stitch length were measured concerning pilling resistance, abrasion resistance, and shrinkage and tightness factor. The result showed that the fabric pilling grade decreased while number of cycle increased. Abrasion resistance decreased but length wise shrinkage increased despite the fact that the stitch length increased. The results also exposed that the tightness factor of the fabric increased with the increase of the stitch length in both dyeing and washing state and finished state compared to grey state for the yarn count 26Ne and homogeneous result not found for yarn count 28Ne and 36 Ne. Evaluation of Impact of Yarn Count and Stitch Length on Pilling, Abrasion, Shrinkage and Tightness Factor of 1 × 1 Rib Cotton Knitted Fabrics