P-88: Numerical Simulation and Quantitative Evaluation for Motional Display Uniformity in a Directional Backlight Glasses-free 3D Display

Remotely operated construction machines are used in cases where the operators are in danger, such as on steep slopes or contaminated sites. However, remote operation differs from what operators perceive during hands-on machine operation. Various studies have focused on improving work efficiency by employing remote control operation to reduce operator workload. In these studies, questionnaires were generally employed to evaluate the operator workload. However, the results obtained from the questionnaires varied depending on the physical conditions and the mood of the person on that day. It was therefore concluded that an accurate evaluation cannot be performed based on this method. Hence, in this study, the eye strain of machine operators was measured using an Auto Refractor/Keratometer. In particular, the ciliary muscle activities were measured before and after operating three display systems used for remote control of construction equipment. A quantitative evaluation was then conducted based on the eye strain data. The 2D display system exhibited low work accuracy and efficiency and resulted in significant eye strain. Although the 3D display system that required glasses exhibited high accuracy and efficiency, it resulted in significant eye strain. The 3D display system that did not require glasses demonstrated high accuracy and lower eye strain. From the results presented above, it was confirmed that the autostereoscopic 3D system is suitable for operators.

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Quantitative evaluation of perceived depth of transparently-visualized medical 3D data presented with a multi-view 3D display

International Journal of Modeling Simulation and Scientific Computing ◽

10.1142/s1793962318400093 ◽

2018 ◽

Vol 09 (03) ◽

pp. 1840009 ◽

Cited By ~ 1

Author(s):

Yuichi Sakano ◽

Yurina Kitaura ◽

Kyoko Hasegawa ◽

Roberto Lopez-Gulliver ◽

Liang Li ◽

...

Keyword(s):

Quantitative Evaluation ◽

Binocular Disparity ◽

Medical Images ◽

Motion Parallax ◽

Psychophysical Experiment ◽

3D Display ◽

3D Structures ◽

3D Data ◽

Transparent Object

Transparent visualization is used in many fields because it can visualize not only the frontal object but also other important objects behind it. Although in many situations, it would be very important for the 3D structures of the visualized transparent images to be perceived as they are simulated, little is known quantitatively as to how such transparent 3D structures are perceived. To address this question, in the present study, we conducted a psychophysical experiment in which the observers reported the perceived depth magnitude of a transparent object in medical images, presented with a multi-view 3D display. For the visualization, we employed a stochastic point-based rendering (SPBR) method, which was developed recently as a technique for efficient transparent-rendering. Perceived depth of the transparent object was smaller than the simulated depth. We found, however, that such depth underestimation can be alleviated to some extent by (1) applying luminance gradient inherent in the SPBR method, (2) employing high opacities, and (3) introducing binocular disparity and motion parallax produced by a multi-view 3D display.

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Dimensionless Charts for Predicting the Range of Goaf Roof Caving

Mathematical Problems in Engineering ◽

10.1155/2021/7382550 ◽

2021 ◽

Vol 2021 ◽

pp. 1-14

Author(s):

Jing Zhang ◽

Rongxing He ◽

Fengyu Ren ◽

Zhihua Ouyang

Keyword(s):

Numerical Simulation ◽

Quantitative Evaluation ◽

Working Conditions ◽

Linear Interpolation ◽

Hazard Evaluation ◽

Potential Hazard ◽

Fracture Spacing ◽

Fuzzy Function ◽

Roof Caving ◽

Zero Growth

In engineering, the method of charts can provide a convenient query for specific engineering problems. To provide the basis for the potential hazard evaluation and rational governance of the goaf, it is necessary to study the quantitative evaluation for the range of goaf roof caving. Undoubtedly, the charts used to visually query the caving range can simplify the workload of the quantitative evaluation. Therefore, the methods of dimensional analysis, numerical simulation, and linear interpolation are introduced to study the dimensionless charts for predicting the caving range. The dimensionless analysis is used to establish the fuzzy function relationship among the influence factors of the goaf roof caving, and the numerical simulation is used to calculate the dimensionless groups in the fuzzy function. Using the linear interpolation, the dimensionless charts in this work can predict the range of goaf roof caving under more working conditions. The results show that the characteristics of the goaf roof caving corresponding to the dimensionless curves are consistent with the actual situation. With the continuous increase of the goaf span l, the dimensionless curves of the caving range experience zero growth, rapid growth, and steady growth. The growth degree varies with the fracture spacing S. Especially in the zero growth phase, the duration of the relatively stable state in the overlying strata of the goaf increases with the increase of fracture spacing S. Moreover, based on the case study of Shirengou Iron Mine, the dimensionless charts obtained in this work can predict the range of goaf roof caving under different working conditions, which indicates the findings of this study have certain guiding significance to the treatment of the goaf.

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Partially Overlapping Printing with Digital Filter to Improve Quality of Volume Hologram Printer – Numerical Simulation –

Applied Sciences ◽

10.3390/app10113963 ◽

2020 ◽

Vol 10 (11) ◽

pp. 3963

Author(s):

Hangbo Hua ◽

Takeshi Yamaguchi ◽

Hiroshi Yoshikawa

Keyword(s):

Numerical Simulation ◽

Image Quality ◽

Spatial Filter ◽

Improve Quality ◽

3D Display ◽

Improve Image Quality ◽

Volume Hologram ◽

Final Volume ◽

Printing Speed

The volume hologram printer is useful for 3D display, because it is selective to the wavelength and be able to reconstruct with the natural illumination. There are many studies of a volume hologram printer been studied to output a volume hologram from a computer-generated hologram. The final volume hologram consists of tiled small holograms and the tiling manner often causes spilt lines which will have impact on image quality. With an intent to get rid of the split lines and improve the quality, fully overlapping printing was proposed recently. Each elemental hologram is overlapped both in vertical and horizontal directions by 50%. Then, the hologram is printed four times in each area and it makes the printing speed four times slower. For this case, partially overlapping printing is proposed in this paper to improve image quality with small effect in printing speed. For partial overlapping, a digital spatial filter is projected and added to every elemental hologram. Using the digital spatial filter, different partially overlapped holograms are calculated and reconstructed to compare to the non-overlapped ones. The simulation result shows that the overlapped one (10% in both vertical and horizontal) has much weaker gaps and black lines.

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