A BLOCK VARIANT OF THE GMRES METHOD FOR UNSYMMETRIC LINEAR SYSTEMS

Iterative methods that take advantage of efficient block operations and block communications are popular research topics in parallel computation. These methods are especially important on Massively Parallel Processors (MPP). This paper presents a block variant of the GMRES method for solving general unsymmetric linear systems. It is shown that the new algorithm with block size s, denoted by BVGMRES(s,m), is theoretically equivalent to the GMRES(s. m) method. The numerical results show that this algorithm can be more efficient than the standard GMRES method on a cache based single CPU computer with optimized BLAS kernels. Furthermore, the gain in efficiency is more significant on MPPs due to both efficient block operations and efficient block data communications. Our numerical results also show that in comparison to the standard GMRES method, the more PEs that are used on an MPP, the more efficient the BVGMRES(s,m) algorithm is.

Analysis and Design of a Kind of Improved Parallel Resonant Converters

Traditional transformer in high-voltage power supplies has many disadvantages such as high turn’s ratio, large volume and great design difficulties. Parallel resonant converters (PRCs) are widely used in high-voltage power supplies. A kind of high-voltage circuit topology can be formed by combining PRCs and voltage-doubler rectifier, which is called parallel resonant dual voltage converters (PRDVCs). In PRDVCs both voltage-doubler rectifier and transformer can boost voltage, which reduced turn’s ratio and volume of the transformer, making it easier to produce. Thus it not only realizes the high-voltage output, but also realizes the miniaturization of high-voltage power supply. Three modes of the converters were researched and simulated. Converting conditions of three modes were given. At last, PRDVCs was used to design a 5000V/50mA high-voltage power supply. The waveforms and results of the experiment were given, which validated the feasibility of the converters and its conversion efficiency might be improved to 93%.

Modulation of Antiviral Immunity and Therapeutic Efficacy by 25-Hydroxycholesterol in Chronically SIV-Infected, ART-Treated Rhesus Macaques

Cholesterol-25-hydroxylase(CH25 H)and its enzymatic product 25-hydroxy cholesterol(25 HC)exert broadly antiviral activity including inhibiting HIV-1 infection.However,their antiviral immunity and therapeutic efficacy in a nonhuman primate model are unknown.Here,we report that the regimen of 25 HC combined with antiretroviral therapy(ART),provides profound immunological modulation towards inhibiting viral replication in chronically SIVmac239-infected rhesus macaques(RMs).Compared to the ART alone,this regimen more effectively controlled SIV replication,enhanced SIVspecific cellular immune responses,restored the ratio of CD4/CD8 cells,reversed the hyperactivation state of CD4^(+)T cells,and inhibited the secretion of proinflammatory cytokines by CD4^(^(+))and CD8^(+)T lymphocytes in chronically SIVinfected RMs.Furthermore,the in vivo safety and the preliminary pharmacokinetics of the 25 HC compound were assessed in this RM model.Taken together,these assessments help explain the profound relationship between cholesterol metabolism,immune modulation,and antiviral activities by 25 HC.These results provide insight for developing novel therapeutic drug candidates against HIV-1 infection and other related diseases.