Improved Quantum Evolutionary Computation Based on Particle SwarmOptimization and Two-Crossovers

A quantum evolutionary computation （QEC） algorithm with particle swarm optimization （PSO） and two-crossovers is proposed to overcome identified limitations. PSO is adopted to update the Q-bit automatically, and two-crossovers are applied to improve the convergence quality in the basic QEC model. This hybrid strategy can effectively employ both the ability to jump out of the local minima and the capacity of searching the global optimum. The performance of the proposed approach is compared with basic QEC on the standard unconstrained scalable benchmark problem that numerous hard combinatorial optimization problems can be formulated. The experimental results show that the proposed method outperforms the basic QEC quite significantly.     

Entanglement Evolution of a Two-Qubit System beyond Rotating-Wave Approximation

Two noninteracting qubits, initially entangled in Bell states, are coupled to a one-mode cavity and evolve under its influence. The entanglement evolution of the two qubits is investigated beyond the rotating-wave approximation. It is shown that the counter-rotating wave terms have a great influence on the disentanglement behavior.     

Fractal analysis of en face tomographic images obtained with full field optical coherence tomography

The quantitative modeling of the imaging signal of pathological areas and healthy areas is necessary to improve the specificity of diagnosis with tomographic en face images obtained with full field optical coherence tomography (FFOCT). In this work, we propose to use the depth‐resolved change in the fractal parameter as a quantitative specific biomarker of the stages of disease. The idea is based on the fact that tissue is a random medium and only statistical parameters that characterize tissue structure are appropriate. We successfully relate the imaging signal in FFOCT to the tissue structure in terms of the scattering function and the coherent transfer function of the system. The formula is then used to analyze the ratio of the Fourier transforms of the cancerous tissue to the normal tissue. We found that when the tissue changes from the normal to cancerous the ratio of the spectrum of the index inhomogeneities takes the form of an inverse power law and the changes in the fractal parameter can be determined by estimating slopes of the spectra of the ratio plotted on a log‐log scale. The fresh normal and cancer liver tissues were imaged to demonstrate the potential diagnostic value of the method at early stages when there are no significant changes in tissue microstructures.     

基于小波子带能量加权的人脸识别方法

针对人脸识别中小波变换后信息利用不充分和权系数选择困难的缺点,提出一种基于小波子带能量加权的人脸识别算法.首先应用二维离散小波变换（2D-DWT）对图像进行二层小波分解,然后将得到的第2层4个子带进行加权组合,并给出一种基于小波子带能量权系数求解法,无需进行人工实验选取.在此基础上,采用PCA＋LDA方法进行特征提取,并在ORL人脸库中进行实验,与传统的算法相比有较快的识别速度和较高的识别率.     

A Toy Model for Magnetic Field Configurations in Black Hole Accretion Discs

We discuss the feature of the magnetic field configuration arising from double counter oriented electric currentrings in the accretion disc around a Kerr black hole （BH）. We discuss the relevant physical quantities corresponding to this configuration： （1） the power and torque transferred by the large-scale magnetic field, （2） the angular momentum and energy fluxes transferred from the BIt to the inner disc, （3） the radiation flux from the disc. In addition, we discuss the possibility that the closed magnetic field anchored at the disc probably evolves to the open magnetic field, which is helpful to produce the jet from the disc.     

基于拟牛顿和遗传算法的三维人脸建模

用网格重采样算法和点变形技术把不同人脸纹理全景图进行标准化,实现三维人脸的像素级对齐;根据在不同姿态下用拟牛顿法优化目标函数优化速度的不同和提取的人脸特征点精确计算出输入图像中人脸的姿态;确定三维人脸模型在此姿态下的可见点,最后利用改进的实数遗传算法进行匹配计算,建立完整的三维人脸模型。实验表明,此算法能实现三维人脸像素级的精确对齐,快速的精确计算输入图像中人脸的姿态,减少优化参数,简化目标函数,提高模型匹配效率和重构精度,缩短匹配时间。     

Effects of partial crack–face contact for the bending of thin shell structures

The physical occurrence that crack surfaces are in contact at the compressive edges when a flat or a shell is subjected to a bending load has been recognized. This article presents a theoretical analysis of crack–face contact effect on the stress intensity factor of various shell structures such as spherical shell, cylindrical shell containing an axial crack, cylindrical shell containing a circumferential crack and shell with two non-zero curvatures, under a bending load. The formulation of the problem is based on the shear deformation theory, incorporating crack–face contact by introducing distributed force at the compressive edge. Material orthotropy is concerned in this analysis. Three-dimensional finite element analysis (FEA) is conduced to compare with the theoretical solution. It is found that due to curvature effect crack–face contact behavior in shells differs from that in flat plates, in that partial contact of crack surfaces may occur in shells, depending on the shell curvature and the nature of the bending load. Crack–face contact has significant influence on the stress intensity factor and it increases the membrane component but decreases the bending component.     

Subdivisions of Toric Complexes

We introduce toric complexes as polyhedral complexes consisting of rational cones together with a set of integral generators for each cone, and we define their associated face rings. Abstract simplicial complexes and rational fans can be considered as toric complexes, and the face ring for toric complexes extends Stanley and Reisner’s face ring for abstract simplicial complexes [20] and Stanley’s face ring for rational fans [21]. Given a toric complex with defining ideal I for the face ring we give a geometrical interpretation of the initial ideals of I with respect to weight orders in terms of subdivisions of the toric complex generalizing a theorem of Sturmfels in [23]. We apply our results to study edgewise subdivisions of abstract simplicial complexes.     

On positive decomposable maps

A partial characterization of a class of decomposable positive maps is given. Furthermore, a clarification of the structure of the set of positive maps is provided.     

基于LBP算子和类覆盖捕获图的人脸检测算法

针对传统人脸检测中的过分类问题,提出一种结合LBP算子与类覆盖捕获图的人脸检测算法.该算法首先用ε-LBP算子提取人脸图像纹理特征,并把对应不同ε值提取的LBP特征数据加权融合起来,形成人脸图像特征向量,然后采用类覆盖捕获图构造分类器,最终对人脸图像实现有效检测.与传统方法相比,基于随机图理论的类覆盖捕获图能够克服过分类缺陷,比其他近邻图分类器更具优势,性能也比较稳定.实验结果表明,该算法可以有效检测人脸图像,尤其对存在模糊和光照异常的人脸图像具有较高的精确度和鲁棒性.