Obesity has been related to postural instability during static standing. It remains unknown how obesity influences stability during dynamic movements like gait. The primary aim of this study was to investigate the effects of obesity on dynamic gait stability control in young adults during gait. Forty-four young adults (21 normal-weight and 23 obese) participated in this study. Participants walked five times at their self-selected gait speeds on a linear walkway. Their full-body kinematics were gathered by a motion capture system. Compared with normal-weight group, individuals with obesity walked more slowly with a shorter but wider step. People with obesity also spent an elongated double stance phase than those with normal weight. A reduced gait speed decreases the body center of mass’s velocity relative to the base of support, leading to a reduction in dynamic stability. On the other hand, a shortened step in accompanying with a less backward-leaning trunk has the potential to bring the center of mass closer to the base of support, resulting in an increase in dynamic stability. As the result of these adaptive changes to the gait pattern, dynamic gait stability among people with obesity did not significantly differ from the one among people with normal weight. Obesity seems to not be inducing dynamic stability disadvantage in young adults during level overground walking. These findings could provide insight into the mechanisms of stability control among people affected by obesity during dynamic locomotion.

Objective To study expert and novice eye movement pattern during simulated landing flight for providing references to evaluate flight performance and training of pilots. Methods The subjects were divided in to two group s of expert and novice according to their flight simulation experience. Eye movement data were recorded when they were performing landing task. Comparison of expert and novice flight performance data and eye movement data was made. Results It was found that the differences between expert and novice lay not only in flight performance but also in eye movement pattern. Performance of expert was better than novice. Expert had shorter fixation time, more fixation points, faster scan velocity, greater scan frequency and wider scan area than novice. It was also found that eye movement pattern of expert bring lower mental workload than novice. Conclusion Flight performance is related to eye movement pattern. Effective eye movement pattern is related to good flight performance. The analysis of eye movement indices can evaluate pilots’ flight performance and provide reference for flight training.

In order to evaluate pilot performance objectively, back propagation (BP) neural network model of 621423 form in topology with eye movement data was established. Data source of BP neural networks that came from former experiment and random interpolation was divided into training set and test set and normalized. Based on neural networks toolbox in Matlab, hidden layer nodes of BP networks were determined with empirical formula and experimental comparison ; BP algorithms in the toolbox were optimized; The training set data and test data were input into model for training and simulation; Pilot performance of the three skill levels was predicated and evaluated. The research shows that pilot performance can be accurately evaluated by setting up BP neural networks model with eye movement data and the evaluation method can provide a reference for flight training.

Objective to establish a system to evaluate the mental workload on visual display interface in airplane cockpit after synthesizing three kinds of mental workload assessment techniques, i.e. main task measure method, physiology measure method and subjective evaluate method. Methods The evaluation indices of every kind of assessment techniques was defined, and the amount of each index through experiment and subjective inquiry was gained, weighted average was calculated and a quantification evaluation value of each kind of evaluation methods was got. At last, with weighted calculation of above three evaluation values, the evaluation value of mental workload on visual display interface in airplane cockpit was obtained Results in M kinds of different designs of visual display interface in airplane cockpit, the synthetic evaluation value of one design was the smallest and the mental workload of this design was the smallest. The design of the smallest mental workload was chosen prior as the final scheme of visual display interface in airplane cockpit .Conclusion The evaluation system is combined with present main evaluation methods of mental workload and utilizes their advantages. The evaluating results can be quantified more directly and clearly. With this evaluation system, the mental workload can be evaluated during the design of visual display interface of airplane cockpit and the best scheme can be confirmed.

It is common to use space arm for maintaining and assembling. The major technology problems to solve first are the deformability, the soft and tightening contact with the target. Use ER as the contactor of end effector which is learned from the space station end effector can overcome many problems, as the poor location precision and uncontainable attitude which is bring by the big space arm. The design of multi-DOF Deformable-Contact-Surface-Based shape adaptive end effector is introduced in this text. The simulation result by Matlab software proves the design not only can tight connect the target, but also can suppress vibration and meet the precise demand of location, precise force control and deformability. It can meet the multi-mission in the future.

A novel high-strength foam (PSA foam) was prepared by adding foaming agent in silicon-containing arylacetylene (PSA) via free heat foaming. The dispersion of foaming agent was observed by Scanning Electron Microscopy-Energy Disperse Spectroscopy (SEM-EDS) and the result indicated that the foaming agent was dispersed uniformly in PSA. The microstructure of the PSA foams prepared with different foam temperatures were characterized by SEM and the results showed the PSA foam had uniform pores when the foaming temperature was 165°C. Compressive strength of the PSA foam could reach 10.3 MPa. Furthermore, PSA foam possessed excellent thermal stability, dimensional stability and heat insulation performance: char residue reached 92.3% at 800°C under nitrogen atmosphere; the highest coefficient of thermal expansion was 83*10-6/K; the thermal conductivity was 0.0724 W/(m•K).