基于改进粒子群优化算法的火电厂机组负荷分配

以坑口电厂厂级监控信息系统的机组负荷在线优化分配功能模块为应用背景,针对模块所运用的基本粒子群优化算法在优化过程中容易陷入局部收敛、收敛速度慢的缺点,提出一种基于惯性权重非线性减小策略的改进粒子群优化算法,使惯性权重呈对数减小;测试函数仿真结果表明,改进粒子群优化算法在收敛速度和寻优精度方面,优化性能均优于基本粒子群优化算法;通过MATLAB与Visual C++混合编程,开发了机组负荷在线优化分配功能模块,提高了算法的计算效率和工程应用价值。     

Robust video hashing based on representative-dispersive frames

This study proposes a robust video hashing for video copy detection.The proposed method,which is based on representative-dispersive frames(R-D frames),can reveal the global and local information of a video.In this method,a video is represented as a graph with frames as vertices.A similarity measure is proposed to calculate the weights between edges.To select R-D frames,the adjacency matrix of the generated graph is constructed,and the adjacency number of each vertex is calculated,and then some vertices that represent the R-D frames of the video are selected.To reveal the temporal and spatial information of the video,all R-D frames are scanned to constitute an image called video tomography image,the fourth-order cumulant of which is calculated to generate a hash sequence that can inherently describe the corresponding video.Experimental results show that the proposed video hashing is resistant to geometric attacks on frames and channel impairments on transmission.     

Bidirectional controlled quantum teleportation and secure direct communication using five-qubit entangled state

A scheme is presented to implement bidirectional controlled quantum teleportation (QT) by using a five-qubit entangled state as a quantum channel, where Alice may transmit an arbitrary single qubit state called qubit A to Bob and at the same time, Bob may also transmit an arbitrary single qubit state called qubit B to Alice via the control of the supervisor Charlie. Based on our channel, we explicitly show how the bidirectional controlled QT protocol works. By using this bidirectional controlled teleportation, espcially, a bidirectional controlled quantum secure direct communication (QSDC) protocol, i.e., the so-called controlled quantum dialogue, is further investigated. Under the situation of insuring the security of the quantum channel, Alice (Bob) encodes a secret message directly on a sequence of qubit states and transmits them to Bob (Alice) supervised by Charlie. Especially, the qubits carrying the secret message do not need to be transmitted in quantum channel. At last, we show this QSDC scheme may be determinate and secure.     

遗传-神经网络算法在水下隧道涌水量预测中的应用

水下隧道涌水问题受到多种因素的综合影响,具有非线性和高度复杂性。本文应用遗传算法和BP神经网络,结合工程实例,选用隧道围岩裂隙发育情况、上覆含水体富水性、上覆水压、隧道埋深、隧道围岩上覆相对隔水层强度和上覆基岩破碎带与隧道顶板的距离作为影响水下隧道涌水的主要因素,以调查的数据作为训练样本,使用遗传算法优化BP神经网络的初始权值和阈值,建立了水下隧道涌水量的遗传-神经网络预测模型,并进行了计算分析。结果表明:该模型收敛性能好,预测精度高,简单可行。该方法为水下隧道涌水量的预测提供了一条新思路。     

高职计算机应用基础课程实训教学改革的探索与实践

根据高等职业教育的培养目的和教学特点以及非计算机专业《计算机应用基础》课程实践教学标准的要求,文章从加强《计算机应用基础》课程的实训教学出发,根据学生的不同专业和实际情况,探讨了加强实训教学的方法和科学合理检查和评价学生的方法,总结了《计算机应用基础》课程在高职教育教学改革中一些行之有效的经验,全面提高学生的计算机实际应用能力。     

基于B/S结构的高校教学管理信息系统的实现

教学管理信息系统的建立可以确保学校教学数据的一致性,实现数据信息资源的分级共享,替代原始的纸张流转。通过计算机和网络系统得以规范教务管理流程、学生管理流程。本文结合目前高等院校教学特点,介绍如何利用对象关系映射技术（ORM）构建B/S三层模式的教学管理信息系统。     

Numerical simulation of a nonlinearly coupled Schrödinger system: A linearly uncoupled finite difference scheme

This article describes a finite difference scheme which is linearly uncoupled in computation for a nonlinearly coupled Schrödinger system. This numerical scheme is proved to preserve the original conservative properties. Using the discrete energy analysis method, we also prove that the scheme is unconditionally stable and second-order convergent in discrete _L2$L_2$-norm based on some preliminary estimations. The results show that the new scheme is efficiency.     

声学参量换能器阵及其测试系统设计

根据声学参量阵原理,设计了一个3×3的九元矩形换能器阵及其测试系统,并在空气进行验证性实验;系统包括正弦信号产生电路、信号控制电路、功率放大电路以及回波信号接收电路等,辅以LabVIEW平台,实现正弦信号和脉冲控制信号的产生,发射信号时间长度控制以及功率放大,并最终驱动换能器阵;实验表明,当有85kHz和90kHz的正弦信号产生时,系统各部分均能正常工作,能够听到天花板处有声响,且回波信号中含有5kHz的频率成分,即证明换能器阵及其系统的设计均是可行的.     

Iterative SNR estimation using a priori information

A class iterative signal-to-noise ratio (SNR) estimation algorithm is proposed in this paper. The data samples are governed by a given distribution with a priori. The expectation maximization (EM) algorithm is applied to iteratively maximize the likelihood function so as to realize the SNR estimation. Cramer–Rao bounds (CRB) with different a priori are compared for binary phase shift keying and orthogonal phase shift keying systems, which show the potential of the SNR estimator in turbo-like systems. In high-order modulations, simulation results show that the reduced-complexity iterative method with equal a priori has better performance in middle or high SNR region than the foregone ones. Moreover, the new method with feedback information is the best when its iteration number is 4 and extrinsic information larger than 0.4. These methods are applied in the bit-interleaved coded modulation with iterative decode (BICM-ID) system to validate the effect of the proposed methods.     

遗传编程在符号回归中的应用

遗传编程是一种新型的搜索优化技术,文章介绍了遗传编程的基本原理,以及遗传编程的算法设计及其实现的几个关键问题,并研究了基于遗传编程方法的符号回归。与传统回归方法相比,该方法得到的拟合函数更精确,具有更广泛的适用性。文中通过对一个函数进行符号回归验证,说明此方法合理可行。