32位并行浮点乘法器设计

本文讨论了32位浮点乘法器的设计,算法采取了二阶Booth算法;部分积产生阵列采用了由反极性CSA加法器组成的IA与wallace树折衷方法;最后并给出了设计结果与验证。     

一种新的Booth乘法器设计方法

文章在分析了数字电路实现乘法运算的基本原理及部分积优化原理的基础上,提出了一种具有动态加速浮点乘法运算功能的变基Booth算法,该算法可以在不增加加法器负担的条件下收到较好的加速效果。在一个普通的2输入加法器的支持下,平均加速效果至少好于8基Booth,而面积和速度都优于前者。同目前集中于乘法器中阵列结构的优化方法相比,该文为乘法器优化设计提出了一种新的研究方向。     

32位并行浮点乘法器设计

讨论了32位浮点乘法器的设计,算法采取了二阶Booth算法;部分积产生阵列采用了由反极性CSA加法器组成的IA与wallace树折衷方法;最后给出了设计结果与验证.     

Radix-16 Booth流水线乘法器的设计

设计了一种新颖的32×32位高速流水线乘法器结构.该结构所采用的新型Radix-16 Booth算法吸取了冗余Booth编码与改进Booth编码的优点,能简单、快速地产生复杂倍数.设计完成的乘法器只产生9个部分积,有效降低了部分积压缩阵列的规模与延时.通过对5级流水线关键路径中压缩阵列和64位超前进位(CLA)加法器的优化设计,减少了乘法器的延时和面积.经现场可编程逻辑器件仿真验证表明,与采用Radix-8 Booth算法的乘法器相比,该乘法器速度提高了11%,硬件资源减少了3%.     

MIPS的流水线技术和基于流水线的乘法器设计

在Booth算法的基础上，结合微处理器中流水线的结构，提出了1种改进的Booth乘法器，以适合全定制版的设计，有效地减小版图的面积、简化了电路的设计，并降低了芯片的功耗。     

基于冗余算法和跳跃式结构的54位乘法器的研究

为了提高乘法器的综合性能,提出了一种新的冗余Booth三阶算法和跳跃式Wallace树结构,前者可以减少部分积的数目,提高部分积的产生速度,后者可以加快部分积的压缩,减少电路内部的伪翻转,从而降低功耗.基于冗余Booth三阶算法和跳跃式Wallace树结构,采用0.25μmCMOS工艺,实现了54×54位全定制乘法器,其乘法延时为4.3 ns,芯片面积为1.38 mm2,50MHz频率下的动态功耗仅为47.2 mW.模拟验证表明,与采用传统Wallace树结构和改进Booth二阶算法的乘法器相比,该乘法器的乘法延时减少了23%,功耗降低了17%,面积减少了20%.     

Booth编码在补码乘法中的应用

在数字信号处理中,乘法器是运算单元的核心部件之一,通过Booth编码减少部分积的数量,能提高乘法运算的速度。该文分析了优化乘法器的两种思路,推导了2基Booth编码及4基Booth编码,指出在实现乘法器中优先考虑4基Booth编码的原因,阐述了在应用Booth编码时注意的问题,在实际应用中验证了该方案的有效性和稳定性。     

乘法器模块在FPGA中的实现

作为数字信号处理领域的基本运算单元,乘法器在其中起到了至关重要的作用。本文设计了三种基于FPGA的数字乘法器模块,包括传统乘法器,LUT乘法器和Booth算法的乘法器,利用Modelsim仿真软件分别对三种算法进行了仿真,并用QuartusⅡ软件对所编写的Verilog程序进行编译综合,这里用到的FPGA芯片是Altera公司生产的cycloneⅡ器件,最后对结果进行了说明。     

RSA加密中基于二次Booth编码的Montgomery乘法器

研究可用于Montgomery算法的基于二次编码的不同阶的Booth大数乘法器的性能和面积。 通过SMIC 0.13μm工艺实现的阶64, 128和256的128 bit和256 bit的Booth大数乘法器, 分别在160 MHz和125 MHz的频率下实现模乘运算。 实验结果表明, 阶64, 128和256的Booth乘法器在速度上性能一致, 但随着阶的增加, 由于预计算和产生部分积的复杂度上升, 乘法器的面积将增加。     

双字节Booth乘法器的优化设计

在分析改进Booth算法双字节(16bit)乘法器的基础上,提出一种并行的乘法器结构,并且在最后的快速进位链中运用了新的设计,提高了乘法器的速度,相对于传统的结构减少了一位全加器的数量,达到减小电路规模和芯片面积,降低乘法器功耗的目的。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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