SpMV (Sparse matrix‐vector multiplication) is an important computing core in traditional high‐performance computing and also one of the emerging data‐intensive applications. For diagonal sparse matrices, it is frequently necessary to fill in a large number of zeros to maintain the diagonal structure as for using DIA (Diagonal) storage format. The fact that filling with zeros may consume additional computing and memory resources, will certainly lead to degradation of the parallel computing performance of SpMV, further causing computing and storage redundancy. To solve the deficiencies of the DIA format, a Two‐stage parallel SpMV method is presented in this paper, which can reasonably distribute the data of diagonal matrix and irregular matrix to different CUDA kernels. As different corresponding compression methods are particularly designed for different matrix forms, a partition‐based hybrid format of DIA and CSR (HPDC) is therefore adopted in the two‐stage method to ensure load balancing among computing resources and continuity of data access on the diagonal. Simultaneously, a standard deviation among blocks is used as a criterion to obtain the optimal number of blocks and distribution of data. The experimental data were implemented in the Florida data set. Compared to DIA, cuSPARSE‐CSR, HDC, and BRCSD, the execution time of the Two‐stage method is shortened by 4, 3.4, 1.9, and 1.15, respectively.
In order to solve the problem of low mechanization level of hairy vetch harvesting, a feeding device for an anti-winding hairy vetch harvester was designed. Firstly, the physical properties of hairy vetch stalk were studied. According to the mechanical properties of hairy vetch stalk, the key components of the feeding device were designed and analyzed, the structure and working principle of the feeding device were described. Secondly, the discrete element method was used to simulate and analyze the movement performance of the feeding device. On this basis, the ternary quadratic regression orthogonal rotation combination test was established with the vertical drum, the machine forward speed, and the spiral conveyor speed as the test factors and the stem loss rate as the test index. The simulation results showed that when the vertical drum was 1037.5 r/min, the machine forward speed was 2.76 m/s, the spiral conveyor speed was 348.88 r/min, and the straw loss rate was 2.38%, and the feeding device performs best at this time. Finally, the on-site performance test of the feeding device was carried out. The results showed that: all the test indicators met the requirements of the national standard; the actual cutting width was 1.66 m; the cutting stubble height was 6.41 mm; the over stubble loss rate was 0.45%; the missed cutting loss rate was 0.20%; and the stem loss rate was 3.00%, which verified the rationality of the design of the feeding device. In order to solve the problem of low mechanization level of hairy vetch, which easily becomes entangled in the working process, an anti-winding feeding device for hairy vetch harvesting was designed.
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