Probabilistic teleportation via multi-parameter measurements and partially entangled states

In this paper, a novel scheme for probabilistic teleportation is presented with multi-parameter measurements via a non-maximally entangled state. This is in contrast to the fact that the measurement kinds for quantum teleportation are usually particular in most previous schemes. The detail implementation producers for our proposal are given by using of appropriate local unitary operations. Moreover, the total success probability and classical information of this proposal are calculated. It is demonstrated that the success probability and classical cost would be changed with the multi-measurement parameters and the entanglement factor of quantum channel. Our scheme could enlarge the research range of probabilistic teleportation.     

An optical gate for simultaneous fusion of four photonic W or Bell states

In order to create large-scale polarization entangled W states, there have been several proposals and some experimental demonstrations. An outstanding proposal is a simple setup which probabilistically fuses two W states of arbitrary sizes $n\ge 3$ and $m\ge 3$ , creating a W state of size $n+m-2$ (Ozdemir et al., in: New J Phys 13:103003, 2011). Using this setup as building blocks, we propose a new setup which can fuse four W states simultaneously. The proposed setup can fuse W states of size 2, i.e. Bell states, as well. We study the resource cost of our fusion process for two main scenarios, i.e. starting from sizes 2 and 3. We present some cost efficient cases, as compared to the previous work.     

Generation of steady three- and four-dimensional entangled states via quantum-jump-based feedback

A scheme is presented for generating steady three- (four-) dimensional entangled states for two atoms trapped in a strongly dissipative single-mode (double-mode) cavity via quantum-jump-based feedback. The cavity decay is no longer undesirable, but plays an integral part in the schemes. Numerical results show that the target states could be obtained from any initial states via quantum-jump-based feedback. Moreover, our scheme is insensitive to moderate fluctuations of experimental parameters and detection inefficiencies without atomic decay since the system can always reach the target state. Nevertheless, the atomic decay still plays a negative role in the current scheme. The scheme can be generalized to realize $N$ -dimensional entanglement for two atoms.     

Biseparability of noisy pseudopure,W and GHZ states using conditional quantum relative Tsallis entropy

We employ the conditional version of sandwiched Tsallis relative entropy to determine \(1:N-1\) separability range in the noisy one-parameter families of pseudopure and Werner-like N-qubit W, GHZ states. The range of the noisy parameter, for which the conditional sandwiched Tsallis relative entropy is positive, reveals perfect agreement with the necessary and sufficient criteria for separability in the \(1:N-1\) partition of these one parameter noisy states.     

Genuine three-partite entanglement in coherent states via permutation and parity symmetries

By using the works, Spiridonov (Phys Rev A 52:1909, 1995), and Wang et al. (J Phys A Math Gen 33:7451, 2000), we propose an approach to obtain genuine three-partite entangled coherent states in which the permutation symmetry and the parity one play crucial roles. We exploit the permutation and parity symmetry to construct entanglement in the standard coherent states of a system composed of three-mode bosonic field and three identical atoms. It is shown that by making use of entanglement witnesses (EW) based on GHZ-states the reduced density matrices of the three-mode bosonic field and three-atomic subsystems, after encoding as three-qubit systems, in some range of their respective parameters, are genuinely entangled.     

基于相干检测的偏振光时域反射光纤振动传感系统

提出将相干检测技术和偏振光时域反射技术POTDR(Polarization Optical Time Domain Reflectometry)相结合,利用相干检测技术的高探测灵敏度和偏振光时域反射技术中偏振态对外界环境敏感的特点,实现光纤分布式传感,测量微弱振动信号并实现定位功能.首先分别介绍了相干检测技术及其与POTDR相结合的相关原理,分析可行性,然后提出实验测试方案并搭建了测试系统.实验结果表明,基于相干检测技术的POTDR传感系统能成功地实现振动信号的探测和振动点的定位功能,这对于光纤分布式传感系统的进一步发展具有重要意义.     

Preparing large-scale maximally entangled <Emphasis Type="Italic">W</Emphasis> states in optical system

We propose an optical scheme to prepare large-scale maximally entangled W states by fusing arbitrary-size polarization entangled W states via polarization-dependent beam splitter. Because most of the currently existing fusion schemes are suffering from the qubit loss problem, that is the number of the output entangled qubits is smaller than the sum of numbers of the input entangled qubits, which will inevitably decrease the fusion efficiency and increase the number of fusion steps as well as the requirement of quantum memories, in our scheme, we design a effect fusion mechanism to generate \(W_{m+n}\) state from a n-qubit W state and a m-qubit W state without any qubit loss. As the nature of this fusion mechanism clearly increases the final size of the obtained W state, it is more efficient and feasible. In addition, our scheme can also generate \(W_{m+n+t-1}\) state by fusing a \(W_m\), a \(W_n\) and a \(W_t\) states. This is a great progress compared with the current scheme which has to lose at least two particles in the fusion of three W states. Moreover, it also can be generalized to the case of fusing k different W states, and all the fusion schemes proposed here can start from Bell state as well.     

Schemes generating entangled states and entanglement swapping between photons and three-level atoms inside optical cavities for quantum communication

We propose quantum information processing schemes based on cavity quantum electrodynamics (QED) for quantum communication. First, to generate entangled states (Bell and Greenberger–Horne–Zeilinger [GHZ] states) between flying photons and three-level atoms inside optical cavities, we utilize a controlled phase flip (CPF) gate that can be implemented via cavity QED). Subsequently, we present an entanglement swapping scheme that can be realized using single-qubit measurements and CPF gates via optical cavities. These schemes can be directly applied to construct an entanglement channel for a communication system between two users. Consequently, it is possible for the trust center, having quantum nodes, to accomplish the linked channel (entanglement channel) between the two separate long-distance users via the distribution of Bell states and entanglement swapping. Furthermore, in our schemes, the main physical component is the CPF gate between the photons and the three-level atoms in cavity QED, which is feasible in practice. Thus, our schemes can be experimentally realized with current technology.     

Enhancing and protecting quantum correlations of a two-qubit entangled system via non-Hermitian operation

We investigate the dynamics of geometric measure of quantum discord and negativity as a measure of quantum entanglement for the system under the local non-Hermitian operation. Numerical calculations demonstrate that quantum discord and entanglement as two kinds of typical measures of quantum correlations can exceed respective initial value, and their evolution behaviors appear to violate conventional properties which formulates quantum discord and quantum entanglement are invariants under local operations. Our results show that non-Hermitian operation achieves distinctive effects on enhancement and protection of quantum correlations, which is mostly aroused by the non-Hermiticity and the non-unitarity of the non-Hermitian operation.     

基于NSCT的SAR与可见光图像融合方法

为了更好地将可见光图像与噪声干扰严重的合成孔径雷达图像融合, 提出了一种最大尺度硬阈值去噪的方法, 在此基础上设计了一种融合规则, 根据噪声和信号在NSCT(nonsubsampled Contourlet transform)域的分解系数特性, 将NSCT分解的最大尺首先进行硬阈值去噪, 其他高频尺度与最大尺度对应的像素点取值方式保持一致, 在低频系数采用“简单绝对值取大”的融合规则, 最后进行NSCT逆变换得到融合图像。实验结果表明, 该方法能有效抑制斑点噪声, 并能充分保留源图像重要特征。     

一种基于光学测角技术验证陀螺定向的方法

介绍了由半导体激光器、线阵CCD传感器及图像采集系统等组成的小角度测量系统的工作原理,搭建了实验平台。同时,对利用数据采集系统采集陀螺仪输出的角速率进行积分,得到陀螺仪转动的角度值。通过把小角度测量系统测量的数据与积分得到的数据进行比较,验证了陀螺仪在小角度定向应用中的精确性。实验证明,该陀螺仪的测量精度达到0.01°以内。     

基于直线和区域显著性融合机制的机场检测

针对遥感图像数据量大和现有机场检测方法存在的不足,提出了一种去除重复模式,融合直线显著性和区域显著性的机场检测方法。首先利用改进的基于超复数傅里叶变换的显著性模型,去除遥感图像中的重复模式,减少后续数据处理量;然后根据跑道平行长直线特性和机场与周围环境的差异性,计算基于直线和基于区域的显著图,并进行融合;最后结合跑道宽度确定候选区,通过深度卷积神经网络和支持向量机进行特征提取和识别。实验证明所提算法对机场定位更加准确,具有识别率高、虚警率低、速度快的特点。     

Block-regression based fusion of optical and SAR imagery for feature enhancement

This paper focuses on the establishment of a pixel-level fusion framework for optical and synthetic aperture radar (SAR) images to combine these two types of remotely sensed imagery for feature enhancement. We have proposed a new fusion technique, namely block-based synthetic variable ratio (Block-SVR), which is a technique based on multiple linear regression of block regions to fuse optical and SAR imagery. In order to investigate the effectiveness of the method, the fusion results of a higher resolution airborne SAR image and a lower resolution multispectral image are presented. According to the fusion results, the fused images have enhanced certain features, namely the spatial and textural content and features that are invisible in multispectral images, while preserving colour characteristics. The spectral, spatial and textural effects of the presented algorithm were also evaluated mainly by visual and quantitative methods, and compared to those of intensity-hue-saturation (IHS), principal component analysis (PCA) and wavelet-based methods. During the implementation of the block-regression based technique there are at least two advantages. One is that the block-regression based technique drastically decreases the amount of computation, whereas regression of the whole scene image is almost impossible. The other, most important, advantage is that adjustment of regressed block size can result in different emphasis between preservation of spectral characteristics and enhancement of spatial and textural content. The larger the regression block, the more the spatial and textural details are enhanced. In contrast, the smaller the regression block, the more the spectral features are preserved. The assessments indicate that the block-regression based method is more flexible than others, because it can achieve a satisfactory trade-off between preservation of spectral characteristics and enhancement of spatial and textural content by selection of optimal block size with respect to visual interpretation and mapping. This paper also proposes a scheme for the fusion of SPOT5 panchromatic, XS images with airborne SAR images using the block-regression based technique.     

基于反馈注意力机制和上下文融合的非模式实例分割

非模式实例分割是最近提出的对实例分割的扩展,其任务是对每个对象实例的可见区域和被遮挡区域都进行预测,感知完整的物理结构和语义概念。在预测对象被遮挡部分的形状和语义时,往往由于特征表示的识别能力不够和对上下文信息缺乏而导致对遮挡区域预测欠拟合甚至错误。针对这个问题,提出一个上下文注意模块和反馈注意力机制的特征金字塔结构,引入反馈连接进行再学习。该方法能够有效捕获全局语义信息和精细的空间细节,通过在COCO-amodal数据集训练和验证,非模式实例分割掩码平均精确率从8.4%提高到14.3%,平均召回率从16.6%提高到20.8%。实验结果表明,该方法能够显著提高对物体被遮挡部分预测的准确率,有效解决欠拟合问题。     

基于特征融合和注意力机制的图像超分辨率模型

现有的基于深度学习的单张图像超分辨率(single image super-resolution, SISR)模型通常是通过加深网络层数来提升模型的拟合能力,没有充分提取和复用特征,导致重建图像的质量较低。针对该问题,提出了基于特征融合和注意力机制的图像超分辨率模型。该模型在特征提取模块使用残差中嵌入残差(residual in residual, RIR)的结构,该网络的特征提取模块由包含多个残差块的残差组构成,并且在每个残差组内进行局部特征融合,在每个组之间进行全局特征融合。此外,在每一个残差块中引入坐标注意力模块,在每一个残差组中引入空间注意力模块。经验证,该模型能充分提取特征并且复用特征。实验最终结果表明,该模型在客观评价指标和主观视觉效果上都优于现有的模型。     

基于多尺度和注意力机制的红外与可见光图像融合

现有的红外与可见光图像融合算法通常从单一尺度提取图像特征,导致融合图像无法全面保留原始特征信息.针对上述问题,提出一种基于多尺度和注意力机制的自编码网络结构实现红外与可见光图像融合.首先,采用密集连接和多尺度注意力模块构建编码器网络,并引入自注意力机制增强像素间的依赖关系,充分提取红外图像的显著目标和可见光图像的细节纹理;然后,特征融合阶段采用基于通道与空间的联合注意融合网络,进一步融合图像典型特征;接着,设计基于像素、结构相似性和色彩的混合损失函数指导网络训练,进一步约束融合图像与源图像的相似性;最后,通过对比实验的主观和客观评价结果,验证所提出算法相比于其他代表性融合算法具有更优异的图像融合能力.     

线特征融合光流的单目SLAM算法

针对移动机器人的定位与建图问题,提出了基于图优化的单目线特征融合光流的同时定位和地图构建(SLAM)的算法。首先,针对主流视觉SLAM算法因采用点作为特征而导致构建的点云地图稀疏、难以准确表达环境结构信息等缺点,采用直线作为特征来构建地图,并采用图优化方法来提高定位精度和地图构建的准确性。然后,针对定位系统的处理速度很难达到实时性要求,将光流法引入以达到实时定位的效果。实验表明,基于线特征的地图构建有较高的建图精度,并且融合算法克服了光流法定位精度差和特征法处理速度慢的缺点,可提供较准确的实时定位输出,并对光照变化和场景纹理较少的情况有一定的鲁棒性。     

双向特征融合与注意力机制结合的目标检测

目标检测使用特征金字塔检测不同尺度的物体时,忽略了高层信息和低层信息之间的关系,导致检测效果差;此外,针对某些尺度的目标,检测中容易出现漏检。本文提出双向特征融合与注意力机制结合的方法进行目标检测。首先,对SSD(single shot multibox detector)模型深层特征层与浅层特征层进行特征融合,然后将得到的特征与深层特征层进行融合。其次,在双向融合中加入了通道注意力机制,增强了语义信息。最后,提出了一种改进的正负样本判定策略,降低目标的漏检率。将本文提出的算法与当前主流算法在VOC数据集上进行了比较,结果表明,本文提出的算法在对目标进行检测时,目标平均准确率有较大提高。     

基于多尺度特征融合和残差注意力机制的目标检测

作为一个多任务的学习过程,目标检测相较于分类网络需要更好的特征.基于多尺度特征对不同尺度的目标进行预测的检测器性能已经大大超过了基于单一尺度特征的检测器.同时,特征金字塔结构被用于构建所有尺度的高级语义特征图,从而进一步提高了检测器的性能.但是,这样的特征图没有充分考虑到上下文信息对语义的补充作用.在SSD基准网络的基...     

融合视觉词与自注意力机制的视频目标分割

目的 视频目标分割(video object segmentation, VOS)是在给定初始帧的目标掩码条件下,实现对整个视频序列中感兴趣对象的分割,但是视频中往往会出现目标形状不规则、背景中存在干扰信息和运动速度过快等情况,影响视频目标分割质量。对此,本文提出一种融合视觉词和自注意力机制的视频目标分割算法。方法 对于参考帧,首先将其图像输入编码器中,提取分辨率为原图像1/8的像素特征。然后将该特征输入由若干卷积核构成的嵌入空间中,并将其结果上采样至原始尺寸。最后结合参考帧的目标掩码信息,通过聚类算法对嵌入空间中的像素进行聚类分簇,形成用于表示目标对象的视觉词。对于目标帧,首先将其图像通过编码器并输入嵌入空间中,通过单词匹配操作用参考帧生成的视觉词来表示嵌入空间中的像素,并获得多个相似图。然后,对相似图应用自注意力机制捕获全局依赖关系,最后取通道方向上的最大值作为预测结果。为了解决目标对象的外观变化和视觉词失配的问题,提出在线更新机制和全局校正机制以进一步提高准确率。结果 实验结果表明,本文方法在视频目标分割数据集DAVIS(densely annotated video segme...