关键词： 电压暂降   检测   p-q-r理论   数学形态滤波器  

摘要： 针对适用于动态电压恢复器的电压暂降检测进行了分析研究,提出一种基于p-q-r变换和数学形态滤波的快速检测方法。利用单相电压构造三相系统,通过坐标变换将电压的基波分量转换成直流分量,通过数学形态滤波器对非直流量进行滤波,得到相应的暂降幅值和相位跳变。由于改进的方法中用参考电压代替了PLL环节,从而减少锁相过程中的延时以及误差;同时利用数学形态滤波器代替传统的低通滤波器,基于该方法的滤波主要是布尔运算和少量的加减运算,与一般低通滤波器相比,计算简单且延时短。仿真结果证明了该方法的快速性和有效性。

关键词： 边缘检测   小波变换   数学形态学   尺度相关   融合  

摘要： 针对传统图像边缘检测方法中出现噪边、边缘定位不精确等缺点,提出一种融合小波变换和数学形态学的图像边缘检测算法。先将图像进行小波分解,高频部分利用小波模极大值噪声抑制和尺度相关子带关联算法进行边缘检测,可以很好地减弱噪声;低频部分利用修正的形态算子进行形态学边缘检测,能够检测出弱边且定位准确;最后对两种方法得到的边缘图像进行融合。实验结果表明,该算法能有效抑制噪声,提高边缘精度并且定位准确.

关键词： 算法思想   数学思想   试题   例析   高中课程   数学素质   数学课程   思想渗透  

摘要： 新课程将算法引入了高中数学课程,并明确提出要将算法思想渗透到高中课程的其它相关内容,并使之成为学生数学素质的一部分.事实上算法思想已成为现代人不可或缺的一种素质.在中国算法思想源远流长,许多精典的数学故事都给算法思想提供了丰富的实例.本文列举几例加以说明.

关键词： 牛顿切线法   雅可比迭代法   高斯-赛德尔迭代法  

摘要： 本文讲述了运用C语言来编写求一元二次、一元三次和多元线性方程的解的思路方法。首先对每个功能方法的原理进行阐述,最后我们对计算出来的结果进行了检验。在方程中,我们用到公式法、牛顿切线法、雅可比迭代法和高斯-赛德尔迭代法。

关键词： Line balancing   Multi-manned workstations   Ant colony optimization   Cycle time  

摘要： In real-world assembly lines, that the size of the product is large (e.g., automotive industry), usually there are multi-manned workstations where a group of workers simultaneously perform different operations on the same individual product. This paper presents a mixed integer programming model to solve the balancing problem of the multi-manned assembly lines optimally. This model minimizes the total number of workers on the line as the first objective and the number of opened multi-manned workstations as the second one. Since this problem is well known as NP (nondeterministic polynomial-time)-hard, a heuristic approach based on the ant colony optimization approach is developed to solve the medium- and large-size scales of this problem. In the proposed algorithm, each ant tries to allocate given tasks to multi-manned workstations in order to build a balancing solution for the assembly line balancing problems by considering the precedence relations, multi-manned assembly line configuration, task times, and cycle time constraints. Through computational experiments, the performance of the proposed ACO is compared with some existing heuristic on various problem instances. The experimental results validate the effectiveness and efficiency of the proposed algorithm.

关键词： Convolutional encoder   Grobner basis   Syndrome matrix   Algebraic decoder   Maximum likelihood decoder  

摘要： A representation of an multidimensional (m-D) convolutional encoder is analogous to the representation of a transfer function for a MIMO m-D FIR system. The encoder matrix is usually not square and thus finding its inverse (decoder matrix) typically employs the Moore-Penrose generalized inverse. However, the result may not be FIR (polynomial matrix) even if the generator matrix is a polynomial matrix. In this paper a constructive algorithm for computing the FIR pseudo inverse, based on the usage of Grobner basis is presented along with detailed examples. The result obtained can be parameterized to cover the class of all possible FIR inverses. In addition, by using the computation method of syzygy with the Grobner basis module, the syndrome matrix for a given m-D convolutional encoder is shown. Furthermore, the theory of Grobner basis is applied to solve the algebraic syndrome decoder problems using the maximum likelihood (nearest neighborhood) criteria and the procedure for 2-D convolutional code error correction is proposed. Despite the complication of the decoding process, the proposed method is the only error correcting decoder for multidimensional convolutional code available to date.

关键词： Algebraic phase unwrapping   Zero distribution   Directions-of-arrival distribution   Array signal processing  

摘要： We present nontrivial utilization methods of a pair of symbolic algebraic algorithms (Yamada et al. in IEEE Trans Signal Process 46: 1639-1664, 1998;Yamada and Bose in IEEE Trans Circuits Syst 1 Fundam Theory Appl 49: 298-304, 2002) which were developed originally for multidimensional phase unwrapping and zero-distribution problems. Given the minor subspace of the covariance matrix of the data measured at a uniform linear array of sensors, the proposed methods provide estimates of the Directions-of-Arrival (DOA) distribution of multiple narrowband signals, i.e., the number of DOA in an arbitrarily specified range, without using any numerical search for each direction of arrival. The proposed methods can serve as powerful mathematical tools to extract global information in the high-resolution DOA estimation problems.

关键词： MR damper   semi-active control   smart damping system   unified Lyapunov algorithm  

摘要： This paper presents a new algorithm which is applicable in designing a smart damping system for vibration mitigation. The algorithm, which is extended into a unified system from Lyapunov stability theory, enables us to decrease the errors by its increased stability. The validity of this design method was proved in the experiment on a control model of three-storied building structure. Smart damper was used for MR (Magneto-Rheological fluid) damper in the experiment, and its control effectiveness was evaluated. In order to make a more accurate control model mathematically, we updated the model on the basis of the analysis of dynamic characteristics of structure and of the mathematical analysis of a lumped mass model, and then employed a state space model redefined by structural property matrix. Using this improved control model, control effect on structures that were under the influence of each different earthquake magnitude was analyzed with various performance indexes, and thus the algorithm presented here is proved to be valid.

关键词： 复习课   研讨课   教学实录   普通高中课程   实验教科书   江苏教育出版社   几何意义   导学   堂课   课例  

摘要： 本文是一堂高三数学复习研讨课的教学实录,这堂课是一次对"导学式教学"模式的尝试和推广.课例所复习的内容是江苏教育出版社普通高中课程标准实验教科书《数学选修2-2》第三章数系的扩充与复数的引入,教学环境是多媒体教室,上课前,班上学生被分成若干小组.整个教学过程教师设计了以下几个环节:预习测评、导学互动。

关键词： 图像融合   数学形态学   形态梯度检测算子   小波变换   频率系数  

摘要： 在分析了图像经小波分解后边缘信息容易丢失等问题的基础上,给出了小波形态学图像融合改进方法。为了提高图像质量,提出改进主要在低频系数选择算法上,采用形态学灰度形态梯度边缘检测算子对低频子图像进行边缘检测,能够更好的保存原图边缘细节信息;对高频系数选择采用基于绝对值最大的原则。对三组图像进行实验,实验表明采用改进方法使得局部对比度信息得到更好的保留,提高了分辨率,具有一定的实用性。