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A novel approach is introduced in this paper to detect abnormal behavior based on global motion orientation. Compare to the normal behavior (walking, shaking hands etc.), abnormal behavior has different orientation. The method we introduced divides each frame into blocks, makes statistical analysis of the global motion direction histogram of all frame blocks and extracts characteristics. At last, behavior is detected with support vector machine (SVM). Experiment shows that the method proposed in the paper has certain robustness and can achieve real-time monitoring.

Polymer Electrolyte Membrane fuel cell converts directly electrochemical energy into electricity. Channels in bipolar Plate, a critical component of fuel cell, is designed with Hilbert pattern, which are obtained through offsetting Hilbert curves to both sides according to working size. Polarization curve expresses the same characteristics between Hilbert channel and traditional serpentine and parallel channel. Output current densities of Hilbert channel are equivalent to that of the serpentine channel but larger than that of parallel channel. Simulation demonstrates that fluid flowing states in Hilbert channel are similar to that in serpentine channel and investigates that pressure drop changes with composite Hilbert channel arrangement. Temperature is an important factor influencing fuel cell performance and optimal temperature is close to 333K in this research.

The paper discusses CAD design on the pores created with simple units such as cylinder, whose structures are determined by unit space array mode and size. Pore ratio, independent to unit models, only relates to orifice diameter and scanning space in fused deposition manufacturing (FDM). Mechanical strength is measured to verify the influences of array modes and inside sizes. The tests demonstrate that 0/90°array mode has larger strength and that the cylinder bears the more pressure along the axis. Stress-strain curve reveals the 4 sections when the parts deform, including linear stage, slightly change stage, increasing stage and damage stage.