Analysis of transient multiexponential signals using exponential compensation deconvolution

A three-step procedure for the parameter estimation of transient multiexponential signals is proposed. The first step involves the use of the classical Gardner transform to convert the data signal into a convolution model which is deconvolved using exponential compensation deconvolution technique in the second step. In the third step, eigenvector algorithms are used to process the resulting complex exponentials to obtain better estimates of decay rates and number of components. Simulation and experimental results show that this method outperforms previous approaches if a number of preprocessing parameters are correctly selected.     

基于四元极谐变换矩与显著特征的图像鲁棒哈希算法

为了增强哈希序列对各种几何变换攻击的鲁棒性,设计基于四元极谐变换矩与显著特征的图像鲁棒哈希算法。引入线性插值与自适应Wiener滤波器,实现初始图像的预处理;计算预处理图像的颜色向量角度,并基于Fourier变换,得到其对应的幅度信息,以获取两个不同的频谱;计算两个频谱的残差,确定图像中的局部显著性区域;通过LBP算子,提取显著特征;基于四元极谐变换(Quaternion Polar Harmonic Transform,QPHT),获取预处理图像的QPHT矩;联合显著特征与QPHT矩,形成过渡哈希数组。引入Logistic映射,定义加密函数,实现对过渡哈希数组的加密,输出最终的哈希序列,以增强其抗碰撞性能。测量源图像与可疑图像之间的哈希序列所对应的l₂范数距离,并将其与优化阈值比较,对图像的真实性做出判断。在多种几何变换攻击下完成测试,输出数据显示:较当前准确性较高的哈希方法而言,该算法具有更理想的鲁棒性与识别准确率。     

Accounting for no difference/preference responses or ties in choice experiments

The analysis of choice data in which no difference/preference responses, or ties, occur is considered in this paper. A key issue addressed in the paper is the need for “identicality norms” for difference and preference tests. These norms reflect the researcher’s expectation for the number of ties that would have occurred in the experiment had the products tested been putatively identical. Without these norms, the issue of how to account for ties can never be fully resolved. After this idea is developed, some methods from the statistics literature to account for ties are reviewed and the Thurstonian 2-AC (2-Alternative Choice) model is discussed. Common practices of equal or proportional redistribution of ties are noted to be either conservative or liberal, respectively, when the binomial distribution is used to evaluate results. In particular, the exact probability function for the equal allocation method is given as a particular type of mixing distribution, known as a convolution, of binomial probability functions. Regardless of which statistical method is used to test tied data, however, none of the current methods of analysis can account for segmentation or the effect of heterogeneity in individual assessors. To study the possible effect of heterogeneity, the data could first be tested against an identicality norm. Thus, this research clarifies the assumptions that are made when conducting tests on paired comparison data with ties and provides guidance on the choice of analytic method.     

静压桩爆桩的原因分析与对策

根据多年的施工经验和现场调查，参考了管桩部分的规范标准，对静压桩爆桩的原因进行了分析，提出了在管桩生产和静压桩施工中应注意的问题和预防控制措施，从而确保静压桩工程的顺利进行。     

随机向量的逼近及奇异值分隔定理的应用

Ｃ．Ｒ．Ｒａｏ在［１］中都是在协方差矩阵为非奇异的情况下讨论的，作者把它们都推广到奇异的情形．作者在讨论用一个随机向且通过一个已知的随机向量中也得出一些结果，并肯定了Ｃ．Ｒ．Ｒａｏ的一个猜测．     

矩阵范数的应用——矩阵方程解的误差估计

设有矩阵方阵 AX=B,其中 A、B 是 n×n 的复矩阵,当 A、B 都有摄动矩阵或 A、B中的一个有摄动矩阵时,本文应用矩阵范数对矩阵方程 AX=B 的解的误差都作出估计。     

A new approach on designing l1 optimal regulator with minimum order for SISO linear systems

For a SISO linear discrete-time system with a specified input signal, a novel method to realize optimal l1 regulation control is presented. Utilizing the technique of converting a polynomial equation to its corresponding matrix equation, a linear programming problem to get an optimal l1 norm of the system output error map is developed which includes the first term and the last term of the map sequence in the objective function and the right vector of its constraint matrix equation, respectively. The adjustability for the width of the constraint matrix makes the trade-off between the order of the optimal regulator and the value of the minimum objective norm become possible, especially for achieving the optimal regulator with minimum order. By norm scaling rules for the constraint matrix equation, the optimal solution can be scaled directly or be obtained by solving a linear programming problem with l\ norm objective.     

基于H．264标准的混合编码算法分析

H.264标准是ITUT/VCEG和ISO/MPEG委员会联合制定的视频通信新编码标准,它在继承现有混合编码视频标准分块变换、运动估计/补偿、量化和熵编码等成熟技术的基础上,还采用了多种新技术,保证了编码的有效性。本文介绍了最新H.264标准中的差分编码、块匹配运动预测法、归一化准则、可变尺寸块运动补偿、多假设运动补偿。最后,对运动补偿中不同的块大小编码方法进行了实验分析,实验结果表明:对于通常视频内容,选择8×8及更大的分块模式、1/4像素运动补偿精度和混合编码,能够获得最经济的压缩效果。     

基于DMC的满意优化控制算法

在模糊满意度的意义下，将软约束和有关向量无穷范数的取值转换为满意度．结合DMC预测控制算法，提出满意优化控制算法的一般描述，并从提高实时性的角度，给出适用于普通计算机进行在线优化的实用算法．仿真结果说明了该算法的有效性和实用性．     

城市道路交叉口行车环境的综合评判

城市道路交叉口行车环境是导致车辆延误的关键环节，为了提高评价城市道路交叉口行车环境的科学性、客观性和全面性，在分析城市道路交叉口行车环境的指标体系的基础上，利用模糊评价理论，建立了交叉口行车环境模糊综合评判模型，使各交叉口行车环境的评价具有定量性和可比性．为城市道路交叉口以后的改建、扩建以及交通管理的改进提供理论依据．并通过实例分析，使该综合评判模型具有实用性和可行性．