Rectangle packing with additional restrictions

We formulate a generalization of the NP-complete rectangle packing problem by parameterizing it in terms of packing density, the ratio of rectangle areas, and the aspect ratio of individual rectangles. Then we show that almost all restrictions of this problem remain NP-complete and identify some cases where the answer to the decision problem can be found in constant time.     

基于FPGA的PUSCH信道估计仿真与实现

基于最小平方(LS)算法,利用FPGA实现了一种适用于TD-LTE系统的上行信道估计算法。主要研究了如何利用FPGA实现LS算法,包括算法的介绍、方案的形成、FPGA实现的处理流程、FPGA实现结果及分析。以Virtex-5芯片为硬件平台,完成了仿真、综合、板级验证等工作。实现结果表明,该信道估计算法应用到TD-LTE系统具有良好的稳定性和可行性。     

Functional linear regression after spline transformation

Functional linear regression has been widely used to model the relationship between a scalar response and functional predictors. If the original data do not satisfy the linear assumption, an intuitive solution is to perform some transformation such that transformed data will be linearly related. The problem of finding such transformations has been rather neglected in the development of functional data analysis tools. In this paper, we consider transformation on the response variable in functional linear regression and propose a nonparametric transformation model in which we use spline functions to construct the transformation function. The functional regression coefficients are then estimated by an innovative procedure called mixed data canonical correlation analysis (MDCCA). MDCCA is analogous to the canonical correlation analysis between two multivariate samples, but is between a multivariate sample and a set of functional data. Here, we apply the MDCCA to the projection of the transformation function on the B-spline space and the functional predictors. We then show that our estimates agree with the regularized functional least squares estimate for the transformation model subject to a scale multiplication. The dimension of the space of spline transformations can be determined by a model selection principle. Typically, a very small number of B-spline knots is needed. Real and simulation data examples are further presented to demonstrate the value of this approach.     

多位LED串行显示电路设计与应用

74HC595A芯片具有串行输入、并行输出功能,利用该集成电路可设计多位LED(发光二极管)串行显示电路。文中介绍了利用该芯片设计的12位LED串行显示电路,详细说明了该电路的工作原理及编程思路,并给出了参考程序。该电路只占用单片机3根口线,较并行显示方式极大地节省了系统资源,已在实际系统中得到应用。     

交换机LS中继全自动维护的实现

环路启动(LS)中继在电力专网中使用非常广泛,人工恢复长时间不拆线的LS中继的维护方式已经不能满足需求,故利用开发工具(Delphi)编写软件实现和交换机通信,自动检测所有LS中继线的状态,自动恢复长时间处于维护忙状态的LS中继。文章介绍了该系统的实现过程及系统中各模块的功能。该系统的实现提高了工作效率,保障了交换网的通信质量。     

基于RBF神经网络的AOA定位算法

基于几何结构的单次反射统计信道模型,提出了基于RBF神经网络的AOA定位算法。应用RBF神经网络对非视距传播（NLOS）误差进行修正,然后利用最小二乘（LS）算法进行定位。仿真结果表明：该算法减小了NLOS传播的影响,提高了系统的定位精度,性能优于LS算法。     

基于Multisim12的电机驱动模块设计与仿真

随着汽车工业的迅速发展,汽车智能化成为大势所趋.电机驱动模块是智能车的重要组成部分.基于探索不同频率PWM控制电机输出的目的,采用Multisim12仿真软件以B车模为研究对象,对电路的工作波形进行了仿真实验测试,给出了仿真实验方案,分析了PWM选取不同频率时电路工作波形.通过实际测试,该电机驱动模块能很好完成智能车电机驱动.     

14位串行A/D转换器MAX194的特性及应用

MAX194是一种14位逐次逼近型串行输出的模数转换器,它具有高速度,高精度,低功耗等特点,并且带采样保持电路,具有10μA的停机模式,能够满足最高采样频率为85kPS的转换。其最快转换时间为9.4μs,具有单极性和双极性两种输入和三态串行数据输出方式,同时价格也比同功能并行输出的模数转换器要低得多。文中介绍了它的功能和用途,同时给出了MAX194在锅炉测量系统中的单片机进行接口的硬件电路和软件程序。     

线搜索(LS)共轭梯度法非单调算法的全局收敛性

非单调线搜索技巧在非线性优化中得到成功的应用与扩展,非单调线搜索下的共轭梯度法则可以提高大规模非线性优化问题的收敛速度。对LS共轭梯度法做了某些变型,在非单调线搜索下,该方法保证每次迭带都会产生下降的方向,在较弱的条件下得到算法全局收敛性。     

OFDM系统中信道估计方法的研究

LS算法是OFDM系统信道估计方法中计算复杂度最低性能最差的方法.根据有限长度h的能量分布,提出了一种改进算法.通过仿真,与LS算法和性能较好的LMMSE比较,验证了改进后的LS算法性能优于最初的LS算法,并可在实际中得到较好的应用.