Almost Sure Convergence and Complete Convergence for the Weighted Sums of Martingale Differences

Let {(D n, FFFn),n/->1} be a sequence of martingale differences and {a ni, 1≤i≤n,n≥1} be an array of real constants. Almost sure convergence for the row sums ?i = 1n ani D1\sum\limits_{i = 1}^n {a_{ni} D_1 } are discussed. We also discuss complete convergence for the moving average processes underB-valued martingale differences assumption.

Some Properties of the Sum and Geometric Differences of Minkowski

The sets of Minkowski algebraic sum and geometric difference are considered. The purpose of the research in this paper is to apply the properties of Minkowski sum and geometric difference to fractional differential games. This paper investigates the geometric properties of the Minkowski algebraic sum and the geometric difference of sets. Various examples are considered that calculate the geometric differences of sets. The results of the research are presented and proved as a theorem. At the end of the article, the results were applied to fractional differential games.

Effects of Second-Order Sum-and Difference-Frequency Wave Forces on the Motion Response of a Tension-Leg Platform Considering the Set-down Motion

This paper presents a study on the motion response of a tension-leg platform(TLP) under first-and second-order wave forces, including the mean-drift force, difference and sum-frequency forces. The second-order wave force is calculated using the full-field quadratic transfer function(QTF). The coupled effect of the horizontal motions, such as surge, sway and yaw motions, and the set-down motion are taken into consideration by the nonlinear restoring matrix. The time-domain analysis with 50-yr random sea state is performed. A comparison of the results of different case studies is made to assess the influence of second-order wave force on the motions of the platform. The analysis shows that the second-order wave force has a major impact on motions of the TLP. The second-order difference-frequency wave force has an obvious influence on the low-frequency motions of surge and sway, and also will induce a large set-down motion which is an important part of heave motion. Besides, the second-order sum-frequency force will induce a set of high-frequency motions of roll and pitch. However, little influence of second-order wave force is found on the yaw motion.

On the Limiting Behavior of Weighted Partial Sums for B Valued Martingale Difference Sequences

Let {Xn, n≥1} be a martingale difference sequence and {a nk , 1?k?n,n?1} an array of constant real numbers. The limiting behavior of weighted partial sums ∑ k=1 n a nk X k is investigated and some new results are obtained.

Effects on Sum and Difference Patterns by Adaptive Null

This paper presents a simple method of forming sum and difference patterns with adaptivenulls. The effects on the sidelobe level and the pointing null of difference pattern by adaptive null areanalyzed. The result that the increment value of the envelope of the sidelobe level under the effect ofa null is less than l.6dB is proved. The formula about shift value of the pointing null which is thefunction of the jammer direction and array parameters is given in the paper.

Sensibility to Changes of Vibrational Modes of Excited Electron： Sum Frequency Signals Versus Difference Frequency Signals

In this paper, we investigate a two electronic level system with vibrational modes coupled to a Brownian oscillator bath. The difference frequency generation （DFG） signals and sum frequency generation （SFG） signals are calculated. It is shown that, for the same model, the SFG signals are more sensitive than the DFG signals to the changes of the vibrational modes of the electronic two-level system. Because the SFG conversion efficiency can be improved by using the time-delay method, the findings in this paper predict that the SFG spectrum may probe the changes of the microstructure more effectively.

Fractional sum and fractional difference on non-uniform lattices and analogue of Euler and Cauchy Beta formulas

As is well known,the definitions of fractional sum and fractional difference of f(z)on non-uniform lattices x(z)=c1z^(2)+c2z+c3 or x(z)=c1q^(z)+c2q^(-z)+c3 are more difficult and complicated.In this article,for the first time we propose the definitions of the fractional sum and fractional difference on non-uniform lattices by two different ways.The analogue of Euler’s Beta formula,Cauchy’Beta formula on non-uniform lattices are established,and some fundamental theorems of fractional calculas,the solution of the generalized Abel equation on non-uniform lattices are obtained etc.

Research of Tile Type Transceiver Module Integrating with Two-Dimensional Sum Difference Network

Transceiver module and two-dimensional sum difference network are important components of phased array antenna. In this paper, multilayer printed board is used to integrate millimeter wave multi-channel transceiver circuit and sum difference network. The interconnection between them is realized through RF coaxial vertical transition. At the same time, the heat dissipation design and inter channel shielding design of the module are carried out. The RF and low frequency required by the module are completed through the wiring between and within the dielectric plate layers. Finally, 128 arrays are fabricated and verified by multi-channel passive test. The results show that the type transceiver module integrating with two-dimensional sum difference network has good performance, and 128 channels have excellent amplitude and phase characteristics. The integration technology has the characteristics of lightweight, miniaturization, high integration and low manufacturing cost. It can be widely used in miniaturized phased array antennas.

Some Convergence Properties for Weighted Sums of Martingale Difference Random Vectors

Let{X_(ni),F_(ni);1≤i≤n,n≥1}be an array of R^(d)martingale difference random vectors and{A_(ni),1≤i≤n,n≥1}be an array of m×d matrices of real numbers.In this paper,the Marcinkiewicz-Zygmund type weak law of large numbers for maximal weighted sums of martingale difference random vectors is obtained with not necessarily finite p-th(1<p<2)moments.Moreover,the complete convergence and strong law of large numbers are established under some mild conditions.An application to multivariate simple linear regression model is also provided.

应用平均幅度差函数之和分析心电信号对除颤最佳时机的预测价值

目的应用平均幅度差函数之和(the sum of average magnitude difference function,SAMDF)处理室颤的心电信号,通过与常用预测除颤时间方法振幅谱面积(amplitude spectrum area,AMSA)进行对比找到预测除颤时间更优的方法。方法应用56头重(40±5)kg雄性家猪,诱导室颤后进行10 min未处理的室颤、6 min的心肺复苏和除颤。在室颤和心肺复苏过程当中会记录每1 min SAMDF和AMSA的数据并记录下来。进而计算受试者工作特征(receiver operating characteristic,ROC)曲线,应用单向方差分析(one-way analyses of variance,one-way ANOVA)以及正负样本散点图的比较,以此说明两者均能优化最佳除颤时间。比较除颤成功组(Group R)和除颤失败组(Group N)的SAMDF和AMSA的数值以说明两者预测除颤成功的能力。结果散点图显示SAMDF和AMSA均能够区分阳性和负样本(P<0.001)。ROC曲线显示SAMDF(AUC=0.801,P<0.001)和AMSA(AUC=0.777,P<0.001)一样有着相同的能力预测最佳除颤时间。两组SAMDF和AMSA数值比较,Group R的SAMDF和AMSA数值明显高于Group N(P<0.001)。结论SAMDF在优化预测除颤时机方面具有很高的潜力,并且可以作为AMSA等现有有效预测除颤时机特征的补充。

一种和差波束可重构的微带贴片天线

本文设计了一种工作在TM03模式的单层方形和差波束可重构的开槽微带贴片天线。该天线由同轴探针馈电,没有复杂的和差网络和馈电结构。顶层辐射贴片上三个平行排布的矩形槽用于和波束方向图的旁瓣降低和增益增强。槽两侧的八个金属过孔用于产生差波束。底层金属地上设计了简单的二极管开关控制电路用于实现和波束与差波束的切换。测试结果表明,该和差波束天线的中心工作频率为3.53 GHz,-10 dB阻抗带宽为1.4%,和波束的增益为11.35 dBi,旁瓣电平为-22.9 dB,半功率波束宽度为45°,差波束的增益为9.62 dBi,零深深度为-17.95 dB。本文提出的和差波束可重构微带贴片天线结构紧凑,低剖面、高增益,且具有良好的辐射特性,易于在PCB板上与其他平面电路集成。

基于转子铜耗的异步机运行状态分类

提出一个关于异步机运行状态的新的分类方法:转子铜耗法。按此法,异步机运行状态可分为两个:差能态、和能态。差能态包含电动、发电两个态;和能态对应电制态。转子铜耗分类法对学习和巩固异步机制动知识点尤其有帮助。

经柔性高压直流输电并网的海上风电送出线路拟功率和、差波形比较式纵联保护

经柔性高压直流输电并网的海上风电送出线路在故障情况下呈现出的两端电流存在较大相角差等故障特性导致传统纵联保护面临不能正确动作的风险。根据电路中的拟功率定理,分别利用线路两端故障前后电压、电流瞬时值列写拟功率表达式,并对两表达式进行求和与作差运算,得到拟功率和与拟功率差。分析表明,发生区内故障时,两者波形相似性高,波形接近完全重合;发生区外故障时,两者含有成分不同,相似性较差,据此形成拟功率和、差波形比较式纵联保护的保护判据。利用EMTP-RV软件搭建经柔性高压直流输电并网的海上风电场模型,对不同故障类型、过渡电阻、噪声、数据窗长、控制方式、同步误差进行仿真验证,理论分析与仿真结果表明所提保护方法具有较强的适应性。

子阵级单脉冲四通道主瓣干扰对消角度分辨率分析

针对子阵级单脉冲雷达,研究了和差四通道主瓣干扰对消技术。为此,构建了二维子阵级单脉冲四通道干扰对消信号模型,并提出了以有用信号信噪比损失值为指标的定量方法来表征主瓣干扰对消角度分辨率。基于此,进一步推导了干扰对消角度分辨率的解析表达式,并明确了对消角度盲区的理论边界。仿真与暗室实验的结果验证了该解析式的正确性。研究可为四通道主瓣干扰对消技术的理论边界分析和工程实现提供参考。

Triad-displaced ULAs configuration for non-circular sources with larger continuous virtual aperture and enhanced degrees of freedom

Non-uniform linear array(NULA)configurations are well renowned due to their structural ability for providing increased degrees of freedom(DOF)and wider array aperture than uniform linear arrays(ULAs).These characteristics play a significant role in improving the direction-of-arrival(DOA)estimation accuracy.However,most of the existing NULA geometries are primarily applicable to circular sources(CSs),while they limitedly improve the DOF and continuous virtual aperture for noncircular sources(NCSs).Toward this purpose,we present a triaddisplaced ULAs(Tdis-ULAs)configuration for NCS.The TdisULAs structure generally consists of three ULAs,which are appropriately placed.The proposed antenna array approach fully exploits the non-circular characteristics of the sources.Given the same number of elements,the Tdis-ULAs design achieves more DOF and larger hole-free co-array aperture than its sparse array competitors.Advantageously,the number of uniform DOF,optimal distribution of elements among the ULAs,and precise element positions are uniquely determined by the closed-form expressions.Moreover,the proposed array also produces a filled resulting co-array.Numerical simulations are conducted to show the performance advantages of the proposed Tdis-ULAs configuration over its counterpart designs.

自然数等幂和sum (k^m) from k=1 to n计算的新方法

自然数等幂和问题一直受到国内学者的普遍关注,应用多项式空间的差分来计算自然数等幂和sum (k^m) from k=1 to n,是解决该问题的一个新思路.

互质阵MIMO雷达DOA估计性能综合分析

以非相干信号源为研究对象,综合分析了单基地互质阵多输入多输出(MIMO)雷达的波达方向(DOA)估计性能。首先,在总结归纳互质阵结构特点的基础上推导了基于和联合阵列及和差联合阵列的单基地MIMO雷达测向信号模型,然后结合多重信号分类(MUSIC)算法,分别详细介绍了基于和联合阵列及和差联合阵列的单基地MIMO雷达DOA估计方法,最后,进行与等阵元数的均匀线阵MIMO雷达的对比仿真实验,验证了互质阵MIMO雷达DOA估计性能的优越性。

An array of two periodic leaky-wave antennas with sum and difference beam scanning for application in target detection and tracking

An array of two substrate-integrated waveguide(SIW) periodic leaky-wave antennas(LWAs) with sum and difference beam scanning is proposed for application in target detection and tracking. The array is composed of two periodic LWAs with different periods, in which each LWA generates a narrow beam through the n=-1 space harmonic. Due to the two different periods for the two LWAs, two beams with two different directions can be realized, which can be combined into a sum beam when the array is fed in phase or into a difference beam when the array is fed 180?out of phase. The array integrated with 180?hybrid is designed, fabricated, and measured.Measurement results show that the sum beam can reach a gain up to 15.9 dBi and scan from-33.4?to 20.8?. In the scanning range, the direction of the null in the difference beam is consistent with the direction of the sum beam,with the lowest null depth of-40.8 dB. With the excellent performance, the antenna provides an alternative solution with low complexity and low cost for target detection and tracking.

基于统计分析的仿射运动估计快速算法

为降低新一代通用视频编码标准(Versatile Video Coding,VVC)的计算复杂度,提出了一种基于统计分析的仿射运动估计(Affine Motion Estimation,AME)快速算法。从加速AME过程的角度出发,首先摒弃AME的3种运动矢量(Motion Vector,MV)精度中的整像素和1/16像素精度,保留1/4像素精度;其次利用迭代次数与量化参数(Quantization Parameter,QP)、slice类型以及编码单元(Coding Unit,CU)大小的关系,得到一个迭代次数的自适应计算式来减少AME迭代次数;然后将细粒度搜索(Fine Granularity Search,FGS)算法中CU 4个角落的4个整像素用2个对角分像素进行替代;最后运用绝对变换差和(Sum of Absolute Transform Difference,SATD)代价来替代率失真(Rate Distortion Optimization,RDO)代价。实验结果表明,与H.266/VVC参考软件VTM-10.0相比,提出的算法在低延迟(Low Delay B,LDB)和随机访问(Random Access,RA)配置下分别节省了8.34%和8.83%的时间,与此同时性能损失仅为0.10%和0.12%。

一种异形结构的低剖面单脉冲阵列天线

本文提出了一种基于异形结构的Ku波段低剖面单脉冲波导阵列天线。该阵列天线由开口波导辐射槽层、一分四耦合腔层以及不等分馈电网络层组成。采用空气波导结构和全并馈网络以实现宽带和高增益性能。阵列天线共有四组子阵列,对应四个输入口,从而实现了方位面和俯仰面的和差波束生成。此外,该设计还具有异形口径的阵列拓扑结构和9 mm的低剖面优势,可以满足实际工程的需求。由HFSS仿真结果表明,所设计的天线阵列回波损耗低于-10 dB的带宽范围为15.3 GHz-22 GHz,此带宽内天线的最大增益为26.8 dBi,口径效率最高可达到85%,具有较好的天线性能。