The conventional dynamic programming-based track-before-detect (DP-TBD) methods are usually intractable in multi-target scenarios. The adjacent targets may interfere with each other, and the computational complexity is increased with the number of targets. In this paper, a DP-TBD method using parallel computing (PC-DP-TBD) is proposed to solve the above problems. The search region of the proposed PC-DP-TBD is divided into several parts according to the possible target movement direction. The energy integration is carried out independently and parallel in each part. This contributes to reducing the computational complexity in each part, since the divided search region is smaller than the whole one. In addition, the target energy can only be integrated adequately in the part in which the search direction matches the target movement. This is beneficial to improve the ability to detect the targets with various movement directions in different parts with different search directions. The solution to the problem of the adjacent targets interfering with each other is discussed. The procedure of the parallel computing in the proposed PC-DP-TBD is presented in detail. Simulations are conducted to verify the superiority of the proposed PC-DP-TBD in terms of detection probability and computational complexity.

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Self‐healing polyurethane elastomers allow increasing the life cycle, adapting to the circular economy, thus reducing the generation of waste. In this work, ureido‐4[1H]‐pyrimidinone (UPy) compounds was used to construct on supramolecular polymer. The self‐healing polyurethane elastomers were successfully prepared by supramolecular polymer based on UPy via a simple blending way. The self‐healing performance of the polyurethane elastomers with UPy were investigated by the scratch test and the cut‐off test, respectively. The scratch of the self‐healing polyurethane elastomer (PU‐15UPy) was totally healed in 1 h at 35°C. The tensile strength and the elongation at break of PU‐15UPy were 0.81 MPa and 563.8%. After the cut‐off test, the healing efficiencies of tensile strength were 63.8% (0.51 MPa) and 85.2% (0.69 MPa) after healing for 10 h at 35 and 80°C, respectively. The healing efficiency of tensile strength reached the value of 90.1% (0.73 MPa) after healing for 24 h at 80°C. The chemical resistance of the self‐healing polyurethane elastomers was tested by immersion in water, NaCl solution (3%), HCl solution (5%), NaOH solution (5%), and diesel, respectively. The mass loss of self‐healing polyurethane elastomers were all less than 2% after immersed in these solutions for 1 month, indicating the excellent chemical resistance performance of PU‐15UPy.

During the monocular measurement of multiple mechanical parts with non-negligible thickness at the same time, the physical dimensions of the pixels on the upper and lower surface edges of the mechanical parts in the image taken by the camera are different, resulting in the deviation of the actual measurement results of the mechanical parts In this paper, a measurement method based on unit pixel size compensation is proposed. This method compensates the measurement data by the distance between the upper and lower surfaces of the mechanical parts and the camera, thus reducing or even eliminating the measurement error caused by the thickness of mechanical parts. The simulation results show that, under the same measuring platform, for the mechanical parts of different sizes and thicknesses, this method can achieve a significant improvement in measurement accuracy.