A unified linear expression of plastic work rate per unit volume is deduced from the unified linear yield criterion and the associated flow rule. The expression is suitable for various linear yield loci in the error t...A unified linear expression of plastic work rate per unit volume is deduced from the unified linear yield criterion and the associated flow rule. The expression is suitable for various linear yield loci in the error triangle between Tresca’s and twin shear stress yield loci on the π-plane. It exhibits generalization in which the different value of criterion parameter b corresponds to a specific linear formula of plastic work rate per unit volume. Finally, with the unified linear expression of plastic work rate and upper-bound parallel velocity field the strip forging without bulge is successfully analyzed and an analytical result is also obtained. The comparison with traditional solutions shows that when b=1/(1+ 3 ) the result is the same as the upper bound result by Mises’ yield criterion, and it also is identical to that by slab method with m=1, σ0=0.展开更多
Based on the constellation diagram of the different modulations, a novel S and Π-decision rule is designed for the analog demapper of the orthogonal frequency-division multiplexing (OFDM) systems. The dedicated short...Based on the constellation diagram of the different modulations, a novel S and Π-decision rule is designed for the analog demapper of the orthogonal frequency-division multiplexing (OFDM) systems. The dedicated short-range communications (DSRC) system is chosen as an OFDM platform to compare the performance among the proposed S and Π-decision decoder, hard-decision and soft-decision decoders. Simulation results demonstrate that both the complexity and performance of S and Π-decision demapper used for M-ary quad-rature amplitude modulation (QAM) OFDM system can be greatly improved. The number of decisions be-tween the received symbol and constellation points can be simplified to look up table times for M-ary QAM OFDM system.展开更多
基金Project(50474015) supported by the National Natural Science Foundation of ChinaProject(RAL–SD-2008-2) supported by RAL Self-determination Science Foundation
文摘A unified linear expression of plastic work rate per unit volume is deduced from the unified linear yield criterion and the associated flow rule. The expression is suitable for various linear yield loci in the error triangle between Tresca’s and twin shear stress yield loci on the π-plane. It exhibits generalization in which the different value of criterion parameter b corresponds to a specific linear formula of plastic work rate per unit volume. Finally, with the unified linear expression of plastic work rate and upper-bound parallel velocity field the strip forging without bulge is successfully analyzed and an analytical result is also obtained. The comparison with traditional solutions shows that when b=1/(1+ 3 ) the result is the same as the upper bound result by Mises’ yield criterion, and it also is identical to that by slab method with m=1, σ0=0.
文摘Based on the constellation diagram of the different modulations, a novel S and Π-decision rule is designed for the analog demapper of the orthogonal frequency-division multiplexing (OFDM) systems. The dedicated short-range communications (DSRC) system is chosen as an OFDM platform to compare the performance among the proposed S and Π-decision decoder, hard-decision and soft-decision decoders. Simulation results demonstrate that both the complexity and performance of S and Π-decision demapper used for M-ary quad-rature amplitude modulation (QAM) OFDM system can be greatly improved. The number of decisions be-tween the received symbol and constellation points can be simplified to look up table times for M-ary QAM OFDM system.
