Robust rotation angle estimator

The conventional method of estimating the rotation angle of a pattern using the principal axes is not suitable for circular symmetric patterns since their eigenvalues are similar in both directions. In the paper, a robust method of estimating a rotation angle using the phase information of Zernike moments is presented. The experimental results show that the proposed method estimates the rotation angle of the circular symmetric patterns more accurately than the principal axes method, even in the presence of noise     

Quantum information splitting of an arbitrary three-qubit state by using two four-qubit cluster states

A new application of the four-qubit cluster state is investigated for quantum information splitting (QIS) of an arbitrary three-qubit state. Muralidharan and Panigrahi (Phys Rev A 78:062333, 2008) argued that a four-qubit cluster state is impossible for QIS of an arbitrary two-qubit state. In this paper, we demonstrate that two four-qubit cluster states can be used to realize the deterministic QIS of an arbitrary three-qubit state by performing only the Bell-state measurements. Our scheme considered here is secure against certain eavesdropping attacks.     

Quantum state sharing of an arbitrary three-qubit state by using three sets of W-class states

A new application of the W-class state for quantum state sharing (QSTS) of an arbitrary three-qubit state with a certain probability is presented explicitly. We show that three sets of W-class states can be used to realize the QSTS of an arbitrary three-qubit state involving Bell-state measurement, single-qubit measurement and one high dimensional unitary operation. The performance demonstrates that our scheme can considerably reduce the difficulty of physical implementation.     

Quantum state sharing of an arbitrary four-qubit GHZ-type state by using a four-qubit cluster state

We demonstrate that a four-qubit cluster state can be used to realize the deterministic quantum state sharing (QSTS) of an arbitrary four-qubit GHZ-type state among three parties by introducing three ancillary qubits and performing three controlled-NOT operations. In our scheme, any one of the two agents has the ability to reconstruct the original state if he/she collaborates with the other one, whilst individual agent obtains no information.     

Euler angles: conversion of arbitrary rotation sequences to specific rotation sequence

Euler angles have been used to describe the orientation of objects in two‐dimensional and three‐dimensional spaces since its formulation by Leonhard Euler. Many applications intended to represent the rotation of a body have been developed on the basis of Euler angles. Two‐dimensional rotations are combined in sequence to represent three‐dimensional rotations. Because there are three axes in a three‐dimensional Euclidean space (X, Y and Z), 12 rotation sequences in three dimensions are possible: XYZ, XZY, YXZ, YZX, ZXY, ZYX, XYX, ZYZ, ZXZ, YXY, XZX and YZY. Each rotation sequence yields different results, and different applications implement a different rotation sequence. Thus, conversion between different rotation sequences becomes essential to make applications developed in different rotation sequences compatible with each other. In this paper, a new method is introduced to convert arbitrary rotation sequences to a specific rotation sequence of choice. A sample program is also developed in a MATLAB‐Simulink environment to demonstrate the use of the new method in converting an arbitrary Euler rotation sequence to the specific Euler rotation sequence of XYZ. A six‐degrees‐of‐freedom animation block is used in the program to aid users to graphically see the rotation of a body in three‐dimensional space. Copyright © 2013 John Wiley & Sons, Ltd.     

Quantum image matching

Quantum image processing (QIP) means the quantum-based methods to speed up image processing algorithms. Many quantum image processing schemes claim that their efficiency is theoretically higher than their corresponding classical schemes. However, most of them do not consider the problem of measurement. As we all know, measurement will lead to collapse. That is to say, executing the algorithm once, users can only measure the final state one time. Therefore, if users want to regain the results (the processed images), they must execute the algorithms many times and then measure the final state many times to get all the pixels’ values. If the measurement process is taken into account, whether or not the algorithms are really efficient needs to be reconsidered. In this paper, we try to solve the problem of measurement and give a quantum image matching algorithm. Unlike most of the QIP algorithms, our scheme interests only one pixel (the target pixel) instead of the whole image. It modifies the probability of pixels based on Grover’s algorithm to make the target pixel to be measured with higher probability, and the measurement step is executed only once. An example is given to explain the algorithm more vividly. Complexity analysis indicates that the quantum scheme’s complexity is \(O(2^{n})\) in contradistinction to the classical scheme’s complexity \(O(2^{2n+2m})\), where m and n are integers related to the size of images.     

用于任意旋转角度景象匹配的圆投影算法

在分析、研究传统圆投影算法的基础上,提出一种扩展的圆投影算法用以解决传统圆投影算法引入的任意旋转角度景象匹配问题。该算法通过对匹配模板添加辅助点加以约束,可以实现旋转中心的准确定位,并且能快速准确地计算出旋转角度。实验表明,扩展的圆投影算法均能获得精确的匹配结果。     

Quantum information splitting of an arbitrary three-qubit state by using a genuinely entangled five-qubit state and a Bell-state

A new application of the genuinely entangled five-qubit state introduced by Brown et al. (J Phys A 38(5), 1119–1131, 2005) is investigated for quantum information splitting (QIS) of an arbitrary three-qubit state. We demonstrate that such a genuine five-qubit entangled state and a Bell-state can be used to realize the deterministic QIS of an arbitrary three-qubit state by performing the Bell-state measurements and single qubit measurement. The presented protocol is showed to be secure against certain eavesdropping attacks.     

任意锥角盘锥天线的研究

运用CST电磁场仿真技术,对四种不同角度盘锥天线的电磁特性进行了数值研究.得到了四种不同角度的盘锥天线的阻抗特性和远区场辐射特性.计算结果和实验结果有较好的吻合,得出盘锥天线的各种参数随锥角变化的关系.为设计盘锥天线者提供可靠的依据.     

旋转角可变的人体检测算法

常用的人体检测算法多应用于无旋转角的情况,而在旋转角可变的情况下检测性能有限,为此提出了一种适用于有旋转角的人体检测算法。首先,通过径向梯度转换(RGT)获得具有旋转不变性的梯度;其次,使用类似于梯度方向直方图(HOG)特征中相互重叠块的组合方式,获取多个带有旋转角信息的特征描述子,按旋转角大小将它们一维线性连接成具有旋转不变性的特征描述子组;最后,利用基于支持向量机(SVM)的二级级联分类器实现了带旋转角的人体检测。基于INRIA行人数据库的144个不同旋转角的人体测试集检测率都不低于86%,144个不同旋转角的非人体样本误检率均低于10%。实验证明了该算法可用于在任意旋转角图像上进行人体检测。     

变频泵控锚杆钻臂摆角动态滑模自适应控制

巷道支护锚杆/锚索安装过程中, 液压锚杆钻机钻臂通常人工控制, 定位精度低, 导致钻杆安装偏离设计位置, 引起设备故障和巷道坍塌. 因此, 设计一种基于动态切换函数的滑模自适应摆角控制器. 针对变频泵控液压锚杆钻臂旋转系统存在的诸多内外部干扰, 设计自适应律和动态滑模控制器, 有效降低抖振和抑制干扰. 联合仿真实验表明, 动态滑模自适应摆角控制能够有效克服诸多不确定性对系统的影响, 无超调的准确跟踪设定值, 满足煤炭安全规程中锚杆/锚索安装偏转角控制和巷道稳定支护的需求.     

一种改进的图像水平倾斜角度测量算法的应用

在汽车面板检测过程中,由于检测设备制造工艺影响,摄像头拍摄到的汽车面板图像在水平面上存在微小角度偏移,需测量其角度大小以保证后续汽车面板检测的正确性.通过图像字符连通域中心坐标算法获取相应的坐标数据,根据最小二乘直线拟合法对图像数据进行处理,计算倾斜角度为-0.6°.图像字符连通域的中心坐标直线拟合角度计算法,根据这种改进的算法能够在短时间内精确地计算出图像水平倾斜角度.     

图像中任意三角形检测方法

提出了一种基于加窗Hough变化的任意三角形检测方法。选择适当大小窗口在图像中滑动,以窗口中心为坐标原点对窗口内图像作Hough变换,在图像的Hough域中检测直线段,从检测出的直线段中找出满足三角形条件的线段组合,然后定位这些线段构成的三角形。实验表明该算法能够有效检测出任意三角形,改变线段的长度条件或角度条件还可以检测直角三角形、等腰三角形、等边三角形等特殊三角形。该算法还可以实现在图像中检索三角形目标的功能。     

改进的频域内亚像素级旋转角估计方法

亚像素级配准是超分辨率重构的前提,其中旋转角估计的准确程度对重构效果有直接影响。针对传统的频域内旋转角估计在小角度估计不精确的缺点,提出了用部分幅值进行配准的改进算法。实验结果表明,改进算法对小角度旋转角估计比传统算法效果好。     

利用纠缠态实现任意N粒子量子态的秘密共享

针对量子秘密共享的量子态局限于最大纠缠态的问题,提出一种实现任意N位量子态的秘密共享方案。该方案使用纠缠态作为量子信道,首先发送方对粒子进行Bell基测量,然后接收方Bob或Charlie使用单粒子测量,最后参与者根据Alice和单粒子测量得到的结果,选用合适的联合幺正变换对量子态进行相应的变换,这样可以实现任意N粒子量子态的秘密共享。该方案能够抵御外部窃听者和内部不诚实参与者的攻击,安全性分析表明此方案是安全的。     

Optimum anamorphic image generation using image rotation and relative entropy

Multimedia Tools and Applications - Anamorphosis is related to the art that gives illusion (distortion) over the image or object when the viewer looks the original image or from the random...     

陀螺壳体旋转角度的测控系统

介绍了一种应用多极旋转变压器和单片机实现的陀螺壳体旋转角度测控系统。给出了多极旋转变压器的测角原理,设计了相应的硬件电路和软件的算法与软件实现,并进行了相关的测角实验。实验结果表明：此系统测量误差小,性能稳定,能够满足整体性能要求,达到了预定的测量效果。     

一种平移旋转图像的角点匹配方法

在图像角点匹配过程中,目标图像往往存在平移旋转现象,直接影响匹配效果,为此提出了一种平移旋转图像的角点匹配方法。该方法首先利用角点检测生成自相关矩阵的梯度信息与仿射变换相结合,构造确定性退火算法中的自由能函数,然后对该自由能函数进行优化,获取待匹配角点间的仿射变换参数,最后利用该变换参数实现角点匹配。实验结果表明,该方法能够在目标图像发生平移旋转的情况下,有效实现角点匹配。     

Quantum computation for large-scale image classification

Due to the lack of an effective quantum feature extraction method, there is currently no effective way to perform quantum image classification or recognition. In this paper, for the first time, a global quantum feature extraction method based on Schmidt decomposition is proposed. A revised quantum learning algorithm is also proposed that will classify images by computing the Hamming distance of these features. From the experimental results derived from the benchmark database Caltech 101, and an analysis of the algorithm, an effective approach to large-scale image classification is derived and proposed against the background of big data.