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In order to solve the optimization design problem of complex shape of underwater glider and improve the optimization efficiency of Kriging surrogate model while improving its lift drag ratio, an adaptive surrogate optimal algorithm is proposed. The proposed improved parallel expectation improvement（PEI） criterion and probability of improvement（PI） criterion are used for global exploration, and the minimizing surrogate prediction（MSP） criterion is used for local exploration. The switching between global exploration and local exploration is realized according to the relationship between new sample points and known sample points. The proposed algorithm, the maximum expected improvement（EI） criterion multiple expectation of improvement（q-EI） and the improved probability improvement（IPI） are combined through a mathematical example. The result shows that the proposed algorithm converges faster and has higher accuracy. Finally, the optimal algorithm is used to optimize the shape of the underwater glider, and the maximum lift drag ratio is increased by 19.37%.

Assembly tasks of conventional end-effectors are generally performed by complex compliance mechanisms, sophisticated control strategies and force sensing. The process is often costly, coupled with difficulty in picking up such small parts as aviation sockets. A low-cost solution end-effector was designed for the above problem, implementing two pick-up strategies: inward-clamped and outward-supported. First, the geometric constraints of the gripping fingers and the advantages of gravity were used to pick up and place different structural types of parts such as small sheet-like or hollow cylindrical parts, and then the experimental assembly system is built and physically assembled for verification. The experimental results show that the end-effector can complete the tasks of picking up and placing parts with different sizes, with the assembly task finished in the system, and the coaxiality error is less than 0.3 mm.

In order to improve the surface quality and reduce the edge burrs, the effects of current, pulse width and pulse spacing on the machining effect of PtIr alloy WIM were studied. The results show that the machining parameters have an important effect on the surface roughness and edge burr of the material. The machining parameters of wire electrical discharge machining(WEDM) were optimized, the current was 5 A, the pulse width was 5 µs, the pulse distance was 5 µs, the machining speed was 150 steps/S, the diameter of molybdenum wire was 0.1 mm, the surface roughness Ra was 0.14 µm, and the cutting precision tolerance reached ±0.006 mm. [ABSTRACT FROM AUTHOR]

For the edges between objects and background in an image are intertwined or their common boundaries are vague as well as the textures of objects and background are similar, a new method based on graph theory and closed-form solution was proposed. First, it uses closed-form solution to initially separate the objects from background roughly, then, to extract the detailed information of inter objects, it applies an improved graph-based algorithm to obtain the final image segmentation results. The test results show that the algorithm of matting avoids aliasing of foreground and background and the improved graph-based algorithm increases segmentation accuracy by 6%~ 12% effectively. Compared to the traditional algorithms such as region merging, ordinary graph, and thresholding, the new algorithm has the better accuracy and effect, therefore it has the significant superiority. [ABSTRACT FROM AUTHOR]