介绍了一种MIPS体系结构下,北桥在SDRAM的操作规范下控制dual port RAM的新型系统结构设计方案,结合实际实现过程,较清楚地突出了设计的创新点,并介绍了测试结果,结论是该设计完全适用于MIPS系统下的数据交换系统,达到了国外同类产品的...介绍了一种MIPS体系结构下,北桥在SDRAM的操作规范下控制dual port RAM的新型系统结构设计方案,结合实际实现过程,较清楚地突出了设计的创新点,并介绍了测试结果,结论是该设计完全适用于MIPS系统下的数据交换系统,达到了国外同类产品的速度性能要求。展开更多
The functionally graded thermal barrier coatings （FG-TBCs） with 80%ZrO2-13%CeO2-7%Y2O3 （C-YSZ）/NiCoCrAlY were prepared using a recently developed supersonic plasma spraying（S-PS） with dual powder feed ports syst...The functionally graded thermal barrier coatings （FG-TBCs） with 80%ZrO2-13%CeO2-7%Y2O3 （C-YSZ）/NiCoCrAlY were prepared using a recently developed supersonic plasma spraying（S-PS） with dual powder feed ports system. The thermal shock experiment of FG-TBCs specimens was carried out by means of the automatic thermal cycle device, in which the samples were heated to 1200℃ by oxygen-acetylene flame jet then water-quenched to ambient temperature. The temperature—time curves of specimens and photographs can be watched on-line and recorded by a computer during the test. The results show that the totally 1mm-thick FG-TBCs have excellent thermal shock resistance due to the fact that the coatings have no any peeling-off after 200 thermal cycles. The microstructures and morphologies of FG-TBCs were characterized and analyzed by SEM.展开更多
Dual mechanical port machine（DMPM）, as a novel electromechanical energy conversion device, has attracted widespread attention. DMPM with spoke type permanent magnet arrangements（STPM-DMPM）, which is one of several...Dual mechanical port machine（DMPM）, as a novel electromechanical energy conversion device, has attracted widespread attention. DMPM with spoke type permanent magnet arrangements（STPM-DMPM）, which is one of several types of DMPM, has been of interest recently. The unique coupling characteristics of STPM-DMPM are beneficial to improving system performance, but these same characteristics increase the difficulties of control. Now there has been little research about the control of STPM-DMPM, and this has hindered its practical application. Based on a mathematical model of STPM-DMPM, the coupling characteristics and the merits and demerits of such devices are analyzed as applied to a hybrid system. The control strategies for improving the disadvantages and for utilizing the advantage of coupling are researched. In order to weaken the interaction effect of torque outputs in the inner motor and the outer motor that results from coupling in STPM-DMPM, a decoupling control method based on equivalent current control is proposed, and independent torque control for the inner motor and outer motor is achieved. In order to solve address the problem of adequately utilization of coupling, minimizing the overall copper loss of the inner motor and the outer motor of STPM-DMPM is taken as the optimization objective for optimal control, and the purpose of utilizing the coupling adequately and reasonably is achieved. The verification tests of the proposed decoupling control and optimal control strategies are carried out on a prototype STPM-DMPM, and the experimental results show that the interaction effect of torque outputs in the inner motor and the outer motor can be markedly weakened through use of the control method. The overall copper loss of the inner motor and the outer motor can be markedly reduced through use of the optimal control method, while the power output remains unchanged. A breakthrough in the control problem of STPM-DMPM is accomplished by combining the control methods. Good performance in the control of STPM-DMPM will enhance its practicality, particularly as applied to hybrid systems.展开更多
Multicore systems oftentimes use multiple levels of cache to bridge the gap between processor and memory speed.This paper presents a new design of a dedicated pipeline cache memory for multicore processors called dual...Multicore systems oftentimes use multiple levels of cache to bridge the gap between processor and memory speed.This paper presents a new design of a dedicated pipeline cache memory for multicore processors called dual port content addressable memory(DPCAM).In addition,it proposes a new replacement algorithm based on hardware which is called a near-far access replacement algorithm(NFRA)to reduce the cost overhead of the cache controller and improve the cache access latency.The experimental results indicated that the latency for write and read operations are significantly less in comparison with a set-associative cache memory.Moreover,it was shown that a latency of a read operation is nearly constant regardless of the size of DPCAM.However,an estimation of the power dissipation showed that DPCAM consumes about 7%greater than a set-associative cache memory of the same size.These results encourage for embedding DPCAM within the multicore processors as a small shared cache memory.展开更多
文摘The functionally graded thermal barrier coatings （FG-TBCs） with 80%ZrO2-13%CeO2-7%Y2O3 （C-YSZ）/NiCoCrAlY were prepared using a recently developed supersonic plasma spraying（S-PS） with dual powder feed ports system. The thermal shock experiment of FG-TBCs specimens was carried out by means of the automatic thermal cycle device, in which the samples were heated to 1200℃ by oxygen-acetylene flame jet then water-quenched to ambient temperature. The temperature—time curves of specimens and photographs can be watched on-line and recorded by a computer during the test. The results show that the totally 1mm-thick FG-TBCs have excellent thermal shock resistance due to the fact that the coatings have no any peeling-off after 200 thermal cycles. The microstructures and morphologies of FG-TBCs were characterized and analyzed by SEM.
基金Supported by National Hi-tech Research and Development Program of China (863 Program,Grant No.2011AA11A238)
文摘Dual mechanical port machine（DMPM）, as a novel electromechanical energy conversion device, has attracted widespread attention. DMPM with spoke type permanent magnet arrangements（STPM-DMPM）, which is one of several types of DMPM, has been of interest recently. The unique coupling characteristics of STPM-DMPM are beneficial to improving system performance, but these same characteristics increase the difficulties of control. Now there has been little research about the control of STPM-DMPM, and this has hindered its practical application. Based on a mathematical model of STPM-DMPM, the coupling characteristics and the merits and demerits of such devices are analyzed as applied to a hybrid system. The control strategies for improving the disadvantages and for utilizing the advantage of coupling are researched. In order to weaken the interaction effect of torque outputs in the inner motor and the outer motor that results from coupling in STPM-DMPM, a decoupling control method based on equivalent current control is proposed, and independent torque control for the inner motor and outer motor is achieved. In order to solve address the problem of adequately utilization of coupling, minimizing the overall copper loss of the inner motor and the outer motor of STPM-DMPM is taken as the optimization objective for optimal control, and the purpose of utilizing the coupling adequately and reasonably is achieved. The verification tests of the proposed decoupling control and optimal control strategies are carried out on a prototype STPM-DMPM, and the experimental results show that the interaction effect of torque outputs in the inner motor and the outer motor can be markedly weakened through use of the control method. The overall copper loss of the inner motor and the outer motor can be markedly reduced through use of the optimal control method, while the power output remains unchanged. A breakthrough in the control problem of STPM-DMPM is accomplished by combining the control methods. Good performance in the control of STPM-DMPM will enhance its practicality, particularly as applied to hybrid systems.
文摘Multicore systems oftentimes use multiple levels of cache to bridge the gap between processor and memory speed.This paper presents a new design of a dedicated pipeline cache memory for multicore processors called dual port content addressable memory(DPCAM).In addition,it proposes a new replacement algorithm based on hardware which is called a near-far access replacement algorithm(NFRA)to reduce the cost overhead of the cache controller and improve the cache access latency.The experimental results indicated that the latency for write and read operations are significantly less in comparison with a set-associative cache memory.Moreover,it was shown that a latency of a read operation is nearly constant regardless of the size of DPCAM.However,an estimation of the power dissipation showed that DPCAM consumes about 7%greater than a set-associative cache memory of the same size.These results encourage for embedding DPCAM within the multicore processors as a small shared cache memory.
