A Novel Two Phase Nonisolated Full Bridge With Shared Primary Switches

In this paper, a new full bridge topology called the two-phase nonisolated full bridge (NFB) is introduced. The proposed two-phase NFB can handle the same power as two parallel NFB converters, but with less MOSFETs, better efficiency, and lower cost. To demonstrate the advantages of the new topology, two prototypes are built on a 12-layer 2-oz PCB board, one with four inductors, the other with three inductors. Two prototypes achieve 82.3% and 82% efficiency at 1-MHz full load (1 V/80 A), respectively. This is compared to 81.8% efficiency of the two paralleled NFB converters. At light load (1 V/10 A), a 4% efficiency improvement is achieved. Experimental results demonstrate that compared with two paralleled NFB converters, the two-phase NFB converter is able to achieve better efficiency with a simplified power train circuit and reduced cost.      

CICQ交换结构中共享缓存的研究与应用

针对带缓存的的交叉开关(Combined Input and Crosspoint Buffered Queuing,CICQ)交换结构在多端口多优先级而引起的存储规模和面积开销增大的问题,提出了一种基于共享缓存思想的CICQ交换结构。它使用虚拟输入排队(VOQ)的方式,支持多优先级流控,并通过动态分配虚拟输出队列的方式设计队列管理结构,从而降低复杂度,减少对缓存区容量的需求。通过对各模块进行VHDL代码设计和使用Modelsim进行仿真,结果表明该结构能够实现交换结构数据的缓存。     

矢量空间秘密共享-多重签名方案

本文把矢量空间秘密共享方案与多重签名方案结合起来,提出了一种新的签名方案,即矢量空间秘密共享-多重签名方案,并对该方案的安全性进行了分析.在该方案中,任何参与者的授权子集能容易地产生群签名,而参与者的非授权子集不可能产生有效的群签名,验证者可通过验证方法验证个体签名和群签名的合法性.该方案能保证一个参与者的授权子集的群签名不能被其他参与者子集所伪造,而且可以跟踪被怀疑的伪造者并将其曝光.该方案能抵御各种可能的攻击.     

A Shared Buffer Memory ATM Access Switch

１ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅＡｓｙｎｃｈｒｏｎｏｕｓＴｒａｎｓｆｅｒＭｏｄｅ（ＡＴＭ）ｉｓｃｏｎｓｉｄｅｒｅｄａｐｒｏｍｉｓｉｎｇｔｅｃｈｎｉｑｕｅｔｏｔｒａｎｓｆｅｒａｎｄｓｗｉｔｃｈｖａｒｉｏｕｓｋｉｎｄｓｏｆｍｅｄｉａ，ｓｕｃｈａｓｔｅｌｅ...     

片上网络通信性能分析建模与缓存分配优化算法

该文建立了一种面向应用设计的片上网络的性能分析模型,并在此基础上提出了片上缓存优化策略和分配算法。在硬件实现平台上的仿真表明,该文建立的片上网络分析模型能很好地分析片上网络通信时延和路由节点各方向的阻塞概率,以此进行片上网络的缓存资源优化,能在同等缓存资源的情况下降低数据通过网络的平均时延,使片上网络的性能得到改善。     

A New Analytical Model of Shared Backup Path Provisioning in GMPLS Networks

As GMPLS and its supporting set of protocols develop into aviable control plane for optical networks, an important function that they will need to support will be the protection and restoration function that has been a major feature of legacy optical networks. A network with a robust set of protection and restoration mechanisms will be able to support data traffic while allowing faster recovery from failures than can be obtained using layer 3 rerouting. Several models have been proposed for protection with GMPLS using shared backup paths. This previous work has not investigated the effect on recovery time critical to the service or the number of backup paths that are required to meet a desired level of performance. Using both restoration time and recovery blocking probability, we have developed a new analytic model for GMPLS-based recovery in M : N protection groups. Furthermore, we show that smaller backup paths can be reserved by capturing the effect of multiple failures in the case of M : N shared protection with revertive mode in an optical network with a GMPLS control plane.     

一种基于Cross—bar空分交换的共享总线型ATM交换单元

本文提出了一种基于Ｃｒｏｓ－ｂａｒ空分交换的共享总线型ＡＴＭ交换单元，—阻塞信元共享总线（ＢＣＳＢ，ｂｌｏｃｋｅｄ－ｃｅｌｓｓｈａｒｅｄ－ｂｕｓ）交换单元，并研究了其中关键电路的实现。ＢＣＳＢ新颖的构思将空分交换和时分交换体制有机的结合在一起。它既有效地降低了普通共享总线交换单元对内部电路加速的要求，又首次在Ｃｒｏｓｓ－ｂａｒ交换单元中不对内部电路进行加速，实现了输出排队策略。理论分析和计算机模拟结果证明，ＢＣＳＢ交换单元具有很好的平均信元时延、吞吐量和信元丢失率性能。     

输入缓冲交换机的缓冲管理方案研究

交换机中设置缓存的目的是暂时保存由于资源冲突而无法立即被交换到输出链路的数据包／信元，缓存的组织和管理方式对交换机的性能具有直接的影响。文章通过模拟实验比较了常用于共享存储器交换机和输出缓冲交换机的缓存管理方案对具有有限容量输入缓冲交换机性能的影响。实验结果显示：交换机性能指标，如吞吐率、延迟、丢包率等对缓冲存在相互矛盾的要求，需要进行折衷、平衡。     

一种新的实现区分服务的可扩展缓存管理算法

目前Internet网络中采用的缓存管理策略大多为丢尾(Drop tail)算法,并不能适应区分服务模型的要求;而RED及其改进算法CHOKe也不能提供公平性和相对优先级的保证。该文简要地分析了目前常见的缓存管理算法RED以及CHOKe所存在的不足,提出了一种基于区分服务模型的新型缓存管理算法D-CHOKe。该算法提供了公平性和相对优先级的保证,并且保持下现有IP网的可扩展性。仿真试验表明,该算法能够较好地满足区分服务的要求,为不同优先级的流分配不同的带宽。     

一种新型的集成电路金属连线温度分析解析模型

研究了金属连线上的焦耳热对连线温度的影响,进而提出了一种新型的集成电路多层金属连线上的温度模拟器(LTem).该模拟器采用一种相对简单的热学解析模型,详细考虑了通孔效应以及边缘效应对温度分布的影响.模拟结果表明,考虑了通孔效应以及边缘效应之后,金属连线上的温度分布情况有了较大程度上的降低,LTem可以得到更贴近实际情况的金属连线温度分布情况     

一种新型的集成电路金属连线温度分析解析模型

研究了金属连线上的焦耳热对连线温度的影响,进而提出了一种新型的集成电路多层金属连线上的温度模拟器(LTem).该模拟器采用一种相对简单的热学解析模型,详细考虑了通孔效应以及边缘效应对温度分布的影响.模拟结果表明,考虑了通孔效应以及边缘效应之后,金属连线上的温度分布情况有了较大程度上的降低,LTem可以得到更贴近实际情况的金属连线温度分布情况.     

A Quantized Delay Buffer Model for Single-Wavelength Fiber Delay Line Buffer

The fiber delay line (FDL) buffer is widely used in optical packet switching networks for contention solution. In this paper, a quantized delay buffer model is proposed to analyze the performance of the single-wavelength FDL buffer. Considering the delay quantization in the FDLs, the delay time and the waiting time of the packet are discussed. Without specific assumptions of the packet arrival process and length distribution, the model presents a generic approach to study the delay time distribution and modify the integral equation for the waiting time distribution. Analytic and exact results of the two aforementioned distributions can be obtained without any approximation. The accuracy of the model is validated through simulation.     

CMOS源极跟随缓冲电路

提出用 CMOS源极跟随缓冲电路以较少的电路段数快速驱动大电容负载 .HSPICE模拟结果表明 ,在负载电容为基本栅电容的 10 0倍及 6 0 0 0倍时 ,CMOS源极跟随缓冲电路具有高于多段倒相器缓冲电路的负载驱动能力 ,且占有面积小 .从而较好地解决了高速驱动芯片内各种数据传输及外部负载的问题 .该电路结构简单 ,易于实现 ,且制作工艺与标准 CMOS工艺完全兼容 .     

CMOS源极跟随缓冲电路

提出用CMOS源极跟随缓冲电路以较少的电路段数快速驱动大电容负载．HSPICE模拟结果表明,在负载电容为基本栅电容的100倍及6000倍时,CMOS源极跟随缓冲电路具有高于多段倒相器缓冲电路的负载驱动能力,且占有面积小．从而较好地解决了高速驱动芯片内各种数据传输及外部负载的问题．该电路结构简单,易于实现,且制作工艺与标准CMOS工艺完全兼容．     

射频MEMS膜开关的力学解析模型

MEMS开关以其固有的低功耗、低插损和低交叉调制损耗等特性 ,在微波领域表现出巨大的应用潜力。但是目前大部分的研究工作都集中在设计新型开关结构和开关制作工艺上 ,对开关力学模型的研究较少。本文根据材料力学 ,通过合理的假设和简化 ,推导出MEMS开关的静电力解析模型 ,并详细探讨开关阈值电压和开关几何尺寸及材料特性之间的关系。这对MEMS开关的设计有一定的指导意义     

A General Queuing Model for Buffer Storage Problems

A mathematical model for a general buffered telecommunication system with the output channel available only periodically is constructed and analyzed in this paper. Under the assumptions that certain system parameters are continuous variables, it is shown that the probability density functions for the peaks and valleys of the buffer content are exactly the same as the density functions for the response time and the waiting time, respectively, for aGI/G/1queuing system, with the density functions for the arrival processGIand the service processGobtained from the statistical functions for the parameters of the original buffered system.     

共享存储器ATM交换机性能分析

本文提出一种分析共享缓冲器ＡＴＭ交换机性能的新方法，该方法为复杂的排队问题的求解提供了新的途径。该方法是采用Ｍａｒｋｏｖ链一步转移概率矩阵求得信元队长稳态概率分布的精确算法，计算机模拟结果验证了该方法的有效性和正确性。     

基于共享Buffer的LIGBT和PLDMOS器件研究

介绍了基于共享Buffer技术的SOI(绝缘体上硅)LIGBT和PLDMOS,相对于传统工艺可以节约2层光刻板和2步工艺流程。主要通过研究在器件漏区的缓冲层特性,对器件特性影响明显。通过实验和仿真结果对比,共享Buffer技术的器件通过工艺和版图优化后能达到原有器件的表现性能。     

A Novel Analytical Model of Resonance Effects of Log-Periodic Planar Antennas

In this paper a new analytical model about the calculation of resonance frequencies and bandwidth of log-periodic planar antennas is proposed. The two previous known models and our novel model are compared to numerical simulations and experimental measurements. In the theoretical part analytical calculations are opposed to the results of reflection parameter simulations. Our model shows a very good coincidence according to the number and position of resonance frequencies. We show that this is not the case for the previous models. For the experimental validation of the novel model several devices with different geometries were fabricated and characterized in the 1–8 GHz frequency range. All considered antenna structures exhibit an excellent coincidence between calculations, simulations and measurements.      

一种共享存储交换结构中的双门限队列控制策略

传统的共享存储交换结构的门限控制算法通常以当前各个队列长度为依据,缺乏对网络节点设备全局流量场景的考虑,且对组播的支持不足.本文提出使用有效业务量作为控制各个端口队列门限的主要依据,让各个端口承担相同的流量压力,从而使系统保持均衡状态.在经典的有效带宽理论的基础上,结合输入流量速率和分配的缓冲区大小一起来定义输出端口的有效业务量,给出了"缓存换带宽"的计算公式,对流量压力进行准确度量.双门限的使用使得共享存储空间既能够保持在平均意义下的平衡,又能实现突发时段的调剂.进一步,对组播信元的转发也可以纳入这个算法框架.模拟结果显示,在不同的流量模式下,这个算法比传统动态门限算法在取典型值α=1和组播浓度为30%时,对芯片的使用效率和端口的公平性分别提高15%和25%以上.