Axis of visual field rotation and order of presentation differentially affect postural responses in a virtual environment

Author(s):  
Ravi Buddharaju ◽  
Lois Lanaria ◽  
Emily A. Keshner
Author(s):  
Li Li

Focusing on the topic of improving the table tennis teaching quality with the visual field training, the test is to grab images repeatedly by using a camera in a speed of 119s, and the final result shows that it gets the correct hitting points on racket coordinating with correct racket angles, which verifies the effectiveness of the visual field training. Finally, it's concluded that the visual field training can improve the athletes' abilities of focus and judgment, and enhance their exercise stability.


Author(s):  
Yiwei Wu ◽  
Zhili Zhou ◽  
Zhiqiang Xi ◽  
Jishun Li

Aimed at the drawbacks of traditional method of spot evaluation for tractor cabs, such as low effectiveness and high expense, this paper established a new method of tractor cab design and evaluation, which included formulating ergonomic evaluation process, creating virtual models of tractor cab and operators, building virtual environment of tractor cab man-machine system and conducting ergonomic evaluation. The YTO-1604 wheeled tractor has been taken as the analysis object, the layouts of its seat, accelerator pedal, clutch pedal, brake pedal, gear shift lever, steering wheel and other major parts were optimized. The optimized model was created by UG, then it was imported into JACK, thus the object for analysis was created. To accommodate the Chinese tractor operator population, the 95th, 50th and 5th percentile virtual operator models which respectively stands for the big figure, medium figure and small figure of Chinese adult males for ergonomic evaluation were created in JACK, and the angular comfort range for human body joints were determined. The 50th percentile operator was adjusted to a cozy posture through human control module, with hands holding steering wheel, left foot naturally put on clutch pedal, while right foot flat placed on the floor. The operator was located to the h point of seat in the optimized cab model, thus the man-machine virtual environment was completely built. Then the reach zone of the 5th percentile operator and the visual field of the 95th percentile operator were generated, the 95th percentile operator’s comfort was evaluated and the forces of the 95th percentile operator’s spinal L4/L5 were calculated. The results showed that the gear shift lever, steering wheel and control panel were located in the accessible reach zones, conforming to manipulation requirements. Control panel and windshield (except for part of the side windshield which could be observed by moving head) were contained in the visual field, according with vision design standard. The overall comfort score of the 95th percentile operator’s different body parts was 24.5, which indicated that the operator was in good condition and the design conformed to physiological requirements. The lower back compression force of the 95th percentile operator was 742, representing a nominal risk of lower back injury for operators. Thus, the rationality of cab layout scheme was well verified. This paper provides a method for the ergonomic design and evaluation of tractor cabs.


2006 ◽  
Vol 72 (2) ◽  
pp. 188-197 ◽  
Author(s):  
Semyon Slobounov ◽  
Tao Wu ◽  
Mark Hallett ◽  
Hiroshi Shibasaki ◽  
Elena Slobounov ◽  
...  

Neurosurgery ◽  
2006 ◽  
Vol 59 (1) ◽  
pp. 134-193 ◽  
Author(s):  
Semyon Slobounov ◽  
Rick Tutwiler ◽  
Wayne Sebastianelli ◽  
Elena Slobounov

1986 ◽  
Vol 30 (4) ◽  
pp. 408-412
Author(s):  
Helmut T. Zwahlen

This paper contains data on the peripheral detection distances of a reflectorized license plate (24 CIL) at night. Detection distances were obtained for two car heading angles (-3 degrees to the left and 10 degrees to the right), and seven detection angles (-30, −20, −10, 0, 10, 20, and 30 degrees) using two groups of 7 young and healthy drivers each. The order of presentation for the 7 detection angles was random and balanced. Each driver sat in a stationary car on a 2000 feet long runway and detected an approaching target under low beam conditions against a background containing a number of luminaires and other light sources. There were three parallel approach paths on the runway. A total of nine consecutive approaches were made for each detection angle. The approaches were divided into 3 blocks and within each block each approach path was randomly chosen once. Each subject detected a total of 63 approaching targets. The results of this study indicate that the average peripheral detection distance for a 30 degree peripheral detection angle can be as short as 25 percent of the average foveal detection distance, while a 20 degree peripheral detection angle resulted in an average peripheral detection distance 3 6 percent of the average foveal detection distance and a 10 degree peripheral detection angle resulted in an average peripheral detection distance of 54 percent of the average foveal detection distance. Based upon the peripheral detection distances obtained in this study we conclude that in roadway situations such as in horizontal curves where reflective targets could become visible for the first time in the periphery of a driver's visual field, appropriate increases in the reflecitvity of a target must be made in order to assure timely detection.


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