城市表层土壤重金属污染的分析与评价

根据2011年全国大学生数学建模竞赛A题,讨论了城市表层土壤重金属的污染问题.对于问题(1),采用Muller地积累指数法来描述土壤重金属污染程度;对于问题(2),利用因子分析法确定各元素的相关系数阵,分析出城市表层土壤重金属的污染主要来源;在问题(3)中,结合重金属污染传播特征及运用高次曲面的拟合建立城市表层土壤重金属污染源的数学模型.     

基于FPGA的全局异步局部同步四相单轨握手协议实现

在常规FPGA中设计了基于LUT的异步状态保持单元,实现了全局异步局部同步系统的接口电路、时钟暂停电路,进一步完成四相单轨握手协议。基于Quartus软件的逻辑锁定技术,采用Verilog HDL进行行为描述,构建了无冒险C单元库。在Altera CycloneⅡEP2C35F672C6器件上,完成了GALS系统的时序仿真,证明了四相单轨握手的正确性。     

TD—LTE系统Reed—Muller译码的仿真及FPGA实现

主要基于FPGA实现TD—LTE系统中的Reed—Muller译码,包括Reed—Muller译码的介绍、方案的构成、FPGA实现流程、以及实现结果分析。并在Virtex-6芯片上,进行了仿真、综合、板级验证。实现结果表明,该Reed—Muller译码算法应用到TD—LTE射频一致性测试仪表中具有良好的高效性和可靠性。     

Unit Commitment by improved pre-prepared power demand table and Muller method

This paper proposes a new methodology for solving Unit Commitment (UC) problem. In the proposed approach, Improved Pre-prepared Power Demand (IPPD) table solves the UC problem and then the Muller method solves the Economic Dispatch (ED) sub-problem. The proposed method has been tested on 3-, 10-, 38- and 40-100 units. Comparison of the simulation results of the proposed method with the results of previous published methods shows that the proposed method provides better solution with less computational time.     

光纤型偏振OCT 系统中光偏振特性的研究

建立了偏振光在生物组织中传播的模型,并利用该模型模拟了偏振光在生物组织中传播的过程,重建了多种偏振态输入光的情况下光偏振态在生物组织中的分布及生物组织的偏振特性模型.分析了光偏振度与光被生物组织散射次数的关系,阐明了由于偏振光在组织中传播,其偏振态逐渐改变而造成的偏振OCT 干涉计两臂光束失去相干性及偏振OCT 图像质量下降现象.通过分析斯托克斯(Stokes)矢量和穆勒(Muller)矩阵在光纤型偏振OCT系统中的应用,说明Muller 矩阵不受输入光偏振态的影响,因此它比Stokes 矢量更适用于光纤型偏振OCT 系统研究.     

量子可逆逻辑电路综合的快速算法研究

可逆逻辑有许多应用,尤其在量子计算领域,量子可逆逻辑电路是构建量子计算机的基本单元,量子可逆逻辑电路综合就是根据电路功能,以较小的量子代价自动构造量子可逆逻辑电路.文中结合可逆逻辑电路综合的多种算法,提出了一种新颖高效的算法,自动构造正极性Reed-Muller展开式(RM),在生成量子可逆逻辑电路的解空间树上,采用总体层次遍历,局部深度搜索,借鉴模板优化技术,构造限界函数快速剪去无解或非最优解的分枝,优先探测RM中的因子,以极高的效率生成最优电路.以国际公认的3变量可逆函数测试标准,该算法不仅能够生成全部最优电路,而且运行速度远远超过同类算法.     

Code Combining of Reed–Muller Codes in an Indoor Wireless Environment

Radio communications are often desirable for data and voice communications in an indoor environment. Wireless technology offers an improved mobility since the users are not confined to any particular location by wires. This paper investigates the use of Reed–Muller codes in an indoor wireless environment. Code combining is used to exploit the multiple signal copies resulting from the inherent frequency diversity of spread spectrum. The performance of Reed–Muller codes is compared with that of convolutional codes of similar rates and comparable decoding complexity. The complete weight distribution of various Reed–Muller codes is presented.     

Modular design and implementation of field-programmable-gate-array-based Gaussian noise generator

The modular design of a Gaussian noise generator (GNG) based on field-programmable gate array (FPGA) technology was studied. A new range reduction architecture was included in a series of elementary function evaluation modules and was integrated into the GNG system. The approximation and quantisation errors for the square root module with a first polynomial approximation were high; therefore, we used the central limit theorem (CLT) to improve the noise quality. This resulted in an output rate of one sample per clock cycle. We subsequently applied Newton's method for the square root module, thus eliminating the need for the use of the CLT because applying the CLT resulted in an output rate of two samples per clock cycle (>200 million samples per second). Two statistical tests confirmed that our GNG is of high quality. Furthermore, the range reduction, which is used to solve a limited interval of the function approximation algorithms of the System Generator platform using Xilinx FPGAs, appeared to have a higher numerical accuracy, was operated at >350 MHz, and can be suitably applied for any function evaluation.     

数字电路可测性设计的一种故障定位方法

在逻辑函数ReedMuller模式的电路可测性设计方面，文章采用AND门阵列和XOR门树结构来设计电路，提出了一种设计方案，可实现任意逻辑函数的功能，而且所得电路具有通用测试集和完全可故障定位的特点。给出了进行故障定位的方法，并可把它应用于其他相关电路的可测性设计。