1-3hit |
Weiqin YING Xing XU Yuxiang FENG Yu WU
A conical area evolutionary algorithm (CAEA) is presented to further improve computational efficiencies of evolutionary algorithms for bi-objective optimization. CAEA partitions the objective space into a number of conical subregions and then solves a scalar subproblem in each subregion that uses a conical area indicator as its scalar objective. The local Pareto optimality of the solution with the minimal conical area in each subregion is proved. Experimental results on bi-objective problems have shown that CAEA offers a significantly higher computational efficiency than the multi-objective evolutionary algorithm based on decomposition (MOEA/D) while CAEA competes well with MOEA/D in terms of solution quality.
Field Programmable Gate Array (FPGA) implementation of Elliptic Curve Cryptography (ECC) over GF(p) is commonly not fast enough to meet the request of high-performance applications. There are three critical factors to determine the performance of ECC processor over GF(p): multiplication structure, modular multiplication algorithm, and scalar point multiplication scheduling. This work proposes a novel multiplication structure which is a two-stage pipeline on the basis of Karatsuba-Ofman algorithm. With the proposed multiplication structure, we design a 256-bit modular multiplier based on Improved Barret Modular Multiplication algorithm. Upon the modular multiplier, we finish the scalar point multiplication scheduling and implement a high-performance ECC processor on FPGA. Compared with the previous modular multipliers, our modular multiplier reduces the 256-bit modular multiplication time by 28% at least. Synthesis result on Altera Stratix II shows that our ECC processor can complete a 256-bit ECC scalar point multiplication in 0.51ms, which is at least 1.3 times faster than the currently reported FPGA ECC processors over GF(p).
Huanyu WANG Lina HUANG Yutong LIU Zhenyuan XU Lu ZHANG Tuming ZHANG Yuxiang FENG Qing HUA
This paper proposes the new series highly integrated intelligent power module (IPM), which is developed to provide a ultra-compact, high performance and reliable motor drive system. Details of the key design technologies of the IPM is given and practical application issues such as electrical characteristics, system operation performance and power dissipation are discussed. Layout placement and routing have been optimized in order to reduce and balance the parasitic impedances. By implementing an innovative direct bonding copper (DBC) ceramic substrate, which can effectively dissipate heat, the IPM delivers a fully integrated power stages including two three-phase inverters, power factor correction (PFC) and rectifier in an ultra-compact 75.5mm × 30mm package, offering up to a 17.3 percent smaller space than traditional motor drive scheme.