Evaluation for Success Probability of Chaff Centroid Jamming

As the chaff centroid jamming can introduce the guiding error of the anti-warship missile's seeker and decrease its hitting probability,a new quantitative analysis method and a mathematic model are proposed in this paper to evaluate the success jamming probability.By using this method,the optimal decision scheme of chaff centroid jamming in different threat situations can be found,and also the success probability of this scheme can be calculated quantitatively.Thus,the operation rules of the centroid jamming and the tactical approach for increasing the success probability can be determined.

Modeling and Analysis of OFDMA-NOMA-RA Protocol Considering Imperfect SIC in Multi-User Uplink WLANs

To address the problems of network congestion and spectrum resources shortage in multi-user large-scale scenarios,this paper proposes a twice random access OFDMA-NOMA-RA protocol combining the advantages of orthogonal frequency division multiple access(OFDMA)and non-orthogonal multiple access(NOMA).The idea of this protocol is that OFMDA is used to divide the entire frequency field into multiple orthogonal resource units(RUs),and NOMA is used on each RU to enable more users to access the channel and improve spectrum efficiency.Based on the protocol designed in this paper,in the case of imperfect successive interference cancellation(SIC),the probability of successful competition subchannels and the outage probability are derived for two scenarios:Users occupy the subchannel individually and users share the subchannel.Moreover,when two users share the channel,the decoding order of the users and the corresponding probabilities are considered.Then,the system throughput is obtained.To achieve better outage performance in the system,the optimal power allocation algorithm is proposed in this paper,which enables the optimal power allocation strategy to be obtained.Numerical results show that the larger the imperfect SIC coefficient,the worse the outage performance of weak users.Compared with pure OFDMA and NOMA,OFDMA-NOMA-RA always maintains an advantage when the imperfect SIC coefficient is less than a specific value.

Increasing Success Probability of a Probabilistic Quantum Teleportation

The probabilistic quantum teleportation scheme [Phys.Lett.A 305 (2002) 12] is improved via twoseemingly different methods (i.e., the usual ancilla method and the so-called Kraus method), respectively.The essenceof the improvements is to fetch a part from the residues so that the success probability is accordingly increased.The twoimproved versions and a similar protocol proposed by Li et al.[Phys.Rev.A 61 (2000) 034301] are compared mutuallyand discussed.It is found that they are equally efficient and can reach the success probability threshold determined bythe inherent entanglement of the quantum channel.

POS辅助航带间航摄影像的自动转点

提出一种利用POS提供的影像定向参数辅助区域航空摄影测量中航带间影像自动转点方法。首先,对航带内影像采用金字塔影像匹配策略寻求同名像点,以获得航向间影像连接点的精确像片坐标;然后利用POS提供的影像定向参数预测航带间的影像连接点。再通过对相邻航线间待匹配窗口影像的几何变形改正,在由POS数据辅助建立的核线几何条件约束下,直接在原始影像上找寻同名像点;最后经最小二乘匹配使影像匹配结果达到子像素级精度。试验表明,将POS数据引入航带间的影像自动转点中,不但可以简化影像匹配过程、提高自动化水平,而且较常规影像匹配方法可以提高航带间自动转点的成功率34.0%,并节省76.7%的CPU耗时。

基于回溯原子支撑集的广义正交匹配追踪算法研究

为解决广义正交匹配追踪算法(gOMP)在迭代过程中无法删除匹配错误原子问题,提出了一种新的算法:基于回溯原子支撑集的广义正交匹配追踪算法(BgOMP)。该算法在每次迭代选择原子前,首先检验支撑集中是否存在由先前迭代错误选择的原子,并据此更新原子支撑集。这一改进策略允许算法在每次迭代中回溯并纠正先前的错误。通过仿真实验,使用一维信号的成功重构概率和二维信号的峰值信噪比作为评价指标来验证BgOMP算法的性能,实验结果表明:与原始的gOMP算法相比,BgOMP算法显著提高了信号的重构性能。

基于干扰辅助下的多监听器COMP联合监听技术

在无线通信领域,COMP联合通信因其能够显著增强信号质量被广泛运用。考虑利用COMP技术提升物理层信息监听性能,文中采取多个合法监听器对多个正交的可疑通信对进行联合监听,并进一步利用无人机对这些可疑通信对实施干扰,旨在联合优化无人机的位置以及干扰功率分配,以最大化多个可疑通信对的最小监听成功概率。文中使用蒙特卡罗法验证了COMP信噪比的累积分布函数(CDF)近似值和精确值,鉴于提出的优化问题高度非凸,采用连续凸近似和块坐标下降算法对无人机的位置和干扰功率分配进行交替优化,以获取局部最优解。仿真结果表明,相较于其他方案,所提出的方案能够显著提升系统最小监听成功概率。

基于贝叶斯网络多馈入直流系统相继换相失败概率推断

大规模多馈入高压直流各回路之间紧密复杂的耦合可能恶化高压直流换相条件,增加了多馈入高压直流系统发生相继换相失败的风险。该文基于贝叶斯网络理论,以换流母线电压降、直流电流变化率和谐波畸变率这三大影响因素作为相继换相失败的证据指标,分别建立3个证据指标的证据概率函数和相继换相失败免疫因子,根据这些证据建立多馈入直流系统相继换相失败的贝叶斯网络,推断多馈入直流输电系统相继换相失败的概率。依据该文所提出的多馈入直流系统相继换相失败的概率推断方法和相关性的风险分析,可预警多馈入直流系统相继换相失败风险,也可提出多馈入直流相继换相失败的抑制措施。

基于视觉传达优化的低清晰度船舶图像复原研究

针对图像复原易出现复原图像颜色视觉特征失真问题,提出基于视觉传达优化的低清晰度船舶图像复原方法。该方法通过帧扫描方法,提取低清晰度船舶图像视觉传达信息的像素二维特征;使用基于最大后验概率的高分辨率船舶图像重组方法,将所提取低清晰度船舶图像视觉传达信息的像素二维特征,进行高分辨率特征重组,并引入基于视觉颜色模型的视觉传达效果优化复原方法,优化高分辨率特征重组后复原图像的颜色视觉传达效果。实验数据验证:该方法对低清晰度海域通行船舶监控图像复原处理后,图像视觉传达效果得到明显提升,且复原后船舶图像峰值信噪比、结构相似性指数接近1,图像特征失真小;复原后图像颜色特征显著性指数最大值达1.0,颜色特征细节显著性得以改善。

Efficient scheme for remote preparation of arbitrary n-qubit equatorial states

Recently,a scheme for deterministic remote preparation of arbitrary multi-qubit equatorial states was proposed by Wei et al.[Quantum Inf.Process.1770(2018)].It is worth mentioning that the construction of mutual orthogonal measurement basis plays a key role in quantum remote state preparation.In this paper,a simple and feasible remote preparation of arbitrary n-qubit equatorial states scheme is proposed.In our scheme,the success probability will reach unit.Moreover,there are no coefficient constraint and auxiliary qubits in this scheme.It means that the success probabilities are independent of the coefficients of the entangled channel.The advantage of our scheme is that the mutual orthogonal measurement basis is devised.To accomplish the quantum remote state preparation(RSP)schemes,some new sets of mutually orthogonal measurement basis are introduced.

Effects of initial states on the quantum correlations in the generalized Grover search algorithm

We investigate the correlations between two qubits in the Grover search algorithm with arbitrary initial states by numerical simulation.Using a set of suitable bases,we construct the reduced density matrix and give the numerical expression of correlations relating to the iterations.For different initial states,we obtain the concurrence and quantum discord compared with the success probability in the algorithm.The results show that the initial states affect the correlations and the limit point of the correlations in the searching process.However,the initial states do not influence the whole cyclical trend.

On the System Performance of Mobile Edge Computing in an Uplink NOMA WSN With a Multiantenna Access Point Over Nakagami-m Fading

In this paper,we study the system performance of mobile edge computing(MEC)wireless sensor networks(WSNs)using a multiantenna access point(AP)and two sensor clusters based on uplink nonorthogonal multiple access(NOMA).Due to limited computation and energy resources,the cluster heads(CHs)offload their tasks to a multiantenna AP over Nakagami-m fading.We proposed a combination protocol for NOMA-MEC-WSNs in which the AP selects either selection combining(SC)or maximal ratio combining(MRC)and each cluster selects a CH to participate in the communication process by employing the sensor node(SN)selection.We derive the closed-form exact expressions of the successful computation probability(SCP)to evaluate the system performance with the latency and energy consumption constraints of the considered WSN.Numerical results are provided to gain insight into the system performance in terms of the SCP based on system parameters such as the number of AP antennas,number of SNs in each cluster,task length,working frequency,offloading ratio,and transmit power allocation.Furthermore,to determine the optimal resource parameters,i.e.,the offloading ratio,power allocation of the two CHs,and MEC AP resources,we proposed two algorithms to achieve the best system performance.Our approach reveals that the optimal parameters with different schemes significantly improve SCP compared to other similar studies.We use Monte Carlo simulations to confirm the validity of our analysis.

A New Method of Global Path Planning for AGV

Path planning is important in the research of a mobile robot （MR）. Methods for it have been used in different applications. An automated guided vehicle（ AGV） , which is a kind of MR, is used in a flexible manufacturing system （FMS）. Path planning for it is essential to improve the efficiency of FMS. A new method was proposed with known obstacle space FMS in this paper. FMS is described by the Augmented Pos Matrix of a Machine （ APMM ） and Relative Pos Matrix of Machines （ RPMM）, which is smaller. The optimum path can be obtained according to the probability of the path and the maximal probability path. The suggested algorithm of path planning was good performance through simulation result： simplicity, saving time and reliability.

Generalization of Some Problems with <i>s</i>-Separation

In this article we apply and discuss El-Desouky technique to derive a generalization of the problem of selecting k balls from an n-line with no two adjacent balls being s-separation. We solve the problem in which the separation of the adjacent elements is not having odd and even separation. Also we enumerate the number of ways of selecting k objects from n-line objects with no two adjacent being of separations m, m + 1, …, pm, where p is positive integer. Moreover we discuss some applications on these problems.

存在窃听者的协作中继NOMA系统安全性能分析

在不完全信道状态信息和非理想连续干扰消除条件下对存在窃听者的非正交多址系统安全性能问题进行研究,提出一个存在窃听者的解码转发中继辅助非正交多址接入系统(Decode and Forward Cooperative Relay in Non-Orthogonal Multiple Access System with Eavesdropper,DFCR-E-NOMA)。在该系统中,分析了在不完全的信道状态信息和非理想连续干扰消除同时存在的条件下系统的安全性能,利用中断概率和截获概率表征系统的安全性能,通过蒙特卡罗模拟仿真分析了功率分配系数、信道估计误差对所提系统性能的影响。验证结果表明,在信道条件一定的情况下,可通过设置较高的数据传输速率,在基站或中继处选择合适的功率分配系数能够有效降低窃听者的截获概率。

基于人工噪声和NOMA安全传输策略分析研究

物理层安全技术利用无线信道特征来实现信息的安全通信,有效克服了传统安全技术依赖于窃听者有限计算能力的缺陷。此外,由于非正交多址接入技术(NOMA)满足多用户同时接入,大大提高了频谱效率而备受关注。针对下行多输入单输出(MISO)系统的安全和速率(SSR)最大化问题,提出了一种基于人工噪声(AN)的NOMA波束成形方案;构建了满足用户最小安全中断概率的约束条件下的SSR最大化问题,并确定最优传输参数闭合表达式。最后,通过数值结果验证了所提方案优于传统的基于AN的正交多址方案和没有AN的NOMA方案。

航空搜救范围与成功概率研究

从遇险对象分布情况和理想发现概率分析入手,对影响航空搜索的修正因素、扫视宽度以及可搜索范围进行了解读,全面梳理了实际发现概率、成功概率、包含概率和累积成功概率,为航空搜救行动中搜救范围的确定以及搜索成功概率的分析提供了有效手段和支撑。

轿车底盘整体合装成功概率计算与误差分布模型

底盘盒装是整车装配关键环节,合装部件的形位公差决定合装成功率和成本。文章首先描述了合装误差概率的物理模型,然后运用尺寸链理论将其抽象为一个适当简化的合装数学模型,对合装成功率进行了公式推导和概率计算。最终在相关工装设备的公差、精度要求条件下得出理论上99.986%的成功概率,相比于实际值较大,经分析考虑到模型经适度简化且有假设条件此差异符合预期。该模型已广泛运用于多条标准化多平台汽车混合装配线。

基于攻击图的网络安全概率计算方法

针对基于攻击图的概率计算中循环路径导致的攻击图难以理解和概率重复计算问题以及渗透之间的相关性导致的概率错误计算问题,通过将攻击图与通用安全脆弱点评估系统结合,删除攻击图中的不可达路径,简化了攻击图,提出了适用于大规模网络的最大可达概率的概念和计算方法,解决了概率重复计算问题,有效避免了相关性导致的概率错误计算问题,并通过真实实验和模拟实验验证了所提方法的合理性和有效性.与相关的研究成果相比,最大可达概率计算方法可以适应于更复杂的攻击图,具有很好的扩展性.

一种高移动场景下基于CoMP的切换方案及性能分析

随着高速铁路的不断发展和列车速度的不断提高,高铁场景下车地通信的可靠性和高效性引起广泛关注。列车速度的提升导致更加频繁的越区切换,使系统的可靠性得不到保障,因此列车速度的提升对高铁通信网络的安全性和可靠性产生严重影响。本文提出1种将LTE-A(Long Term Evolution-Advanced)网络应用到高速铁路场景并基于协同多点传输/接收CoMP(Coordinated Multi-Point transmission/reception)技术的切换优化方案模型,方案参考协作集加入模型。对系统切换成功率等进行性能分析,并与传统切换方案进行性能对比。分析表明:本文基于CoMP的切换方案可有效提升高移动性下网络的切换成功概率,明显改善系统的可靠性和效率。

一种改进的网络安全态势量化评估方法

在基于隐马尔可夫模型的网络安全态势评估中,观测序列的获取和状态转移矩阵的确立是影响评估准确性的关键.目前观测序列多以随机方式获取,不能有效表征网络的安全性;而状态转移矩阵往往依据经验给出,具有很强的主观性.该文提出改进方法:首先,基于警报的统计特性提出警报质量的概念,依据警报质量获取的观测序列,可改进数据源的有效性;其次,基于安全事件和防护措施的博弈过程,提出确定状态转移矩阵的方法,并结合攻击成功的概率对其进行修正,提高状态转移矩阵的有效性.对比实验证明,基于改进算法生成的风险值对网络安全态势的量化更加合理.