Tracking a maneuvering target in clutter with out-of-sequence measurements for airborne radar

There are many proposed optimal or suboptimal al- gorithms to update out-of-sequence measurement（s） （OoSM（s）） for linear-Gaussian systems, but few algorithms are dedicated to track a maneuvering target in clutter by using OoSMs. In order to address the nonlinear OoSMs obtained by the airborne radar located on a moving platform from a maneuvering target in clut- ter, an interacting multiple model probabilistic data association （IMMPDA） algorithm with the OoSM is developed. To be practical, the algorithm is based on the Earth-centered Earth-fixed （ECEF） coordinate system where it considers the effect of the platform＇s attitude and the curvature of the Earth. The proposed method is validated through the Monte Carlo test compared with the perfor- mance of the standard IMMPDA algorithm ignoring the OoSM, and the conclusions show that using the OoSM can improve the track- ing performance, and the shorter the lag step is, the greater degree the performance is improved, but when the lag step is large, the performance is not improved any more by using the OoSM, which can provide some references for engineering application.

Vibration parameter measurement using the temporal digital hologram sequence and windowed Fourier transform

Real time digital recording and numerical reconstruction of a temporal digital hologram sequence have become feasible in recent years.They provide a new measurement method which enjoys the valuable advantages of being full-field,noncontact and high precision.In this paper,a combined method of temporal digital hologram sequence and windowed Fourier transform is proposed to measure the kinematic parameters of random vibration.A series of holograms are recorded by CCD camera and the original phase can be reconstructed by Fresnel reconstruction algorithm.The three-dimensional windowed Fourier transform is used to filter noise in phase and extract the instantaneous kinematic parameters of the specimen,such as the displacement,velocity and acceleration.An experiment is conducted on a chloroprene rubber latex membrane.Results demonstrate that the proposed method determines the vibration parameters precisely and enjoys many merits.

Sequence Hiberarchy Evolution Measurement Method and its Application

A novel method based on discrete wavelet transform （DWT） and cross-covariance for revealing the evolution of species at different spatial resolutions is presented. The trypsin proteins of different species are chosen as an example to describe the evolution relationship according to the evolution vectors by using this method. The results indicated that this method is a promising approach to reveal species evolution at different spatial resolutions.

Influence of characteristics' measurement sequence on total ionizing dose effect in PDSOI nMOSFET

The influence of characteristics’ measurement sequence on total ionizing dose effect in partially-depleted SOI nMOSFET is comprehensively studied. We find that measuring the front-gate curves has no influence on total ionizing dose effect.However, the back-gate curves’ measurement has a great influence on total ionizing dose effect due to high electric field in the buried oxide during measuring. In this paper, we analyze their mechanisms and we find that there are three kinds of electrons tunneling mechanisms at the bottom corner of the shallow trench isolation and in the buried oxide during the backgate curves’ measurement, which are: Fowler–Nordheim tunneling, trap-assisted tunneling, and charge-assisted tunneling.The tunneling electrons neutralize the radiation-induced positive trapped charges, which weakens the total ionizing dose effect. As the total ionizing dose level increases, the charge-assisted tunneling is enhanced by the radiation-induced positive trapped charges. Hence, the influence of the back-gate curves’ measurement is enhanced as the total ionizing dose level increases. Different irradiation biases are compared with each other. An appropriate measurement sequence and voltage bias are proposed to eliminate the influence of measurement.

New Method of Measuring the Positive-sequence Capacitance of T-connection Transmission Lines

A novel method of measuring the positive-sequence capacitance of T-connection transmission lines is proposed. The mathematical model of the new method is explained in detail. In order to obtain enough independent equations, three independent operation modes of T-connection transmission lines during the line measurement are introduced. The digital simulation results and field measurement results are shown. The simulation and measurement results have validated that the new method can meet the needs of measuring the positive-sequence capacitance of T-connection transmission lines. This method has been implemented in the newly developed measurement instrument.

Sequence stratigraphic analysis of superimposed coal measure gas-bearing system in Daning-Jixian block,eastern margin of Ordos Basin,China

The identification of superimposed gas-bearing systems in coal measures is the basis for expediting the optimization of coal measure gas co-production.Through the analysis of drill cores and log data of Upper Carboniferous Benxi Formation to the member 8 of Middle Permian Lower Shihezi Formation in Daning-Jixian block,eastern margin of Ordos Basin,four distinct superimposed coal measure gas-bearing systems were identified,and their formation mechanism was discussed from the sequence stratigraphic perspective.Type Ⅰ system mainly contains multiple coal seams,shales and sandstone layers.Type Ⅱ system is dominated by multiple coal seams and shales.Type Ⅲ is characterized by multiple sandstone layers,and type Ⅳ system is dominated by limestones and mudstones.In general,the gas-bearing systems deposited in barrier-lagoon are type Ⅱ,those deposited in carbonate tidal flats are type IV,and those deposited in the delta front are types Ⅰ and Ⅲ.The marine mudstone,acting as a key layer near the maximum flooding surface,exhibits very low permeability,which is the main factor contributing to the formation of superimposed gas-bearing systems.The sedimentary environment plays a significant role in controlling the distribution of gas-bearing systems.Notably,the vertical gas-bearing systems in the south-western region,where delta front and lagoon facies overlap,are more complex than those in the north-eastern delta front facies.

CHARACTERIZATIONS OF COMPACT OPERATORS ON SOME EULER SPACES OF DIFFERENCE SEQUENCES OF ORDER m

In the past, several authors studied spaces of m-th order difference sequences, among them, H.Polat and F.Basar （[17]） defined the Euler spaces of m-th order difference sequences e r 0 （△ （ m ） ）, e r c （△ （ m ） ） and e r ∞ （△ （ m ） ） and characterized some classes of matrix transformations on them. In our paper, we add a new supplementary aspect to their research by characterizing classes of compact operators on those spaces. For that purpose, the spaces are treated as the matrix domains of a triangle in the classical sequence spaces c 0 , c and ∞ . The main tool for our characterizations is the Hausdorff measure of noncompactness.

ON THE m^(th) ORDER DIFFERENCE SEQUENCE SPACE OF GENERALIZED WEIGHTED MEAN AND COMPACT OPERATORS

In this article, using generalized weighted mean and difference matrix of order m, we introduce the paranormed sequence space l（u, v, p; △（m））, which consist of the sequences whose generalized weighted △（m）-difference means are in the linear space l（p） defined by I.J.Maddox. Also, we determine the basis of this space and compute its α-, β- and γ-duals. Further, we give the characterization of the classes of matrix mappings from l（u, v, p, △（m）） to l∞, c, and co. Finally, we apply the Hausdorff measure of noncompacness to characterize some classes of compact operators given by matrices on the space lp（U, v, △（m）） （1 ≤ p 〈 ∞）.

Upper Large Deviations for Mixing Random Sequence

In this article, we prove upper large deviations for the empirical measure generated by stationary mixing random sequence under some suitable assumptions and upper large deviations for the mixing random sequence.

2-D localization system utilizing M-sequence encoded laser beam scanning

In this paper, as the active position measurement system, a novel method for a two-dimensional localization system using M-sequence signal is proposed. The feature of this system is to realize a position measurement only by scanning the encoded laser beams from fixing points to a measurement field, and by observing it. First, both the system configuration and encoding method were practically considered, and an order and an initial value of M-sequence signal were selected for encoding. This method is based on discrete angle measurement therefore the resolution has its own limitation. To overcome this limitation, analogue phase shift detecting method was introduced. System design was performed and applied to position measurement experiments. The experimental results show that the measurement error of the analogue method is 1/3 of that of the discrete method.

丢番图逼近与三角数列的极限

利用丢番图逼近理论中的无理测度方法得到了三角数列的一些极限公式,并给出了其在幂级数中的一些应用.

基于低压侧负序量特征的小电流系统单相接地故障检测方法

随着台区智能终端量测技术的逐步成熟,实现低压侧全息感知的同时,具备对上级中压配网的多点监测能力。提出基于低压侧负序量特征的小电流系统单相接地故障检测方法。分析了中压侧发生单相接地故障后低压侧负序量的变化规律;利用负序电流大小区分故障线路和非故障线路;提出通过负序电压与正序电压的比值系数,多点协同计算对比判断故障点区段位置,且考虑了低压侧不平衡负荷,以及故障点位于线路一端的特殊情况。通过MATLAB软件和动模实验对中低压联合配电系统的仿真计算,验证了所提方法具有良好的鲁棒性和准确性。通过智能配变终端监测上级中压配网负序量信息,实现小电流接地系统故障检测,具有实际应用和推广价值。

APPLICATION OF CHAOS IN MEASUREMENT

Using the high sensitivity to initial values of chaotic systems, this paper describes an application of chaos in the field of measurement. A general method for signal coding based on symbolic sequences and the relationship between the variable (to be measured) and its symbolic sequence are presented. Some performances of the chaos based measurement system are also discussed. Theoretical analysis and experimental results show that chaotic systems are potentially attractive in the field of measurement.

“88542”水平沟整地措施下土壤微生物群落空间分异特征

为探明宁夏黄土丘陵区“88542”水平沟整地措施下土壤微生物群落结构的空间分异特征,选取整地措施下形成的水平沟(FL)和上、下相邻水平沟间的隔坡地(GL)表层土壤为对象,通过高通量测序技术,研究整地措施下土壤微生物组成及多样性的变化及其影响环境因素。结果表明,在2种样地共检测到细菌30门、82纲和真菌13门、29纲的微生物。土壤中的主要细菌门为变形菌门、放线菌门和酸杆菌门,主要真菌门为子囊菌门、担子菌门和被孢霉门。2种样地下主要微生物类群的相对丰度存在明显差异,水平沟土壤中变形菌门和担子菌门的相对丰度分别高于隔坡地43.8%和79.6%,隔坡地土壤中放线菌门和子囊菌门的相对丰度分别高于水平沟28.1%和42.1%。α多样性显示,在2种样地间土壤细菌多样性指数无显著差异,但隔坡地上的土壤真菌Shannon、Simpson指数显著高于水平沟。此外,冗余分析显示,脲酶、微生物量碳、有机质以及全N是驱动土壤细菌和真菌群落变化的主要因子。研究结果可为黄土丘陵区整地措施后的生物地球化学过程和微生物变化机制提供理论依据和数据支撑。

考虑相量量测单元数据不同步的双端输电线路正序以及零序参数辨识方法

针对相量量测单元(phasormeasurementunit,PMU)数据不同步导致参数辨识结果误差大的问题,提出了考虑PMU数据不同步的输电线路正序以及零序参数辨识方法。首先,分析线路集中参数模型和分布参数模型在一定电压等级下的长度适用范围。基于线路的集中参数模型,利用正常运行情况下PMU装置获取的线路两端功率以及电压信息,构建以正序参数和不同步角度为未知量的非线性方程,并运用Levenberg-Marquardt(L-M)算法求解正序参数以及不同步角度。其次,在辨识出正序参数以及不同步角度的基础上,分析单相接地故障情况下的正序、负序以及零序等效电路图,通过正序和负序网络求解出故障距离。在故障距离已知的情况下,基于零序网络构建以零序参数为未知量的方程,并利用L-M算法求解方程。最后,利用MATLAB软件搭建单回双端输电线路系统,并对所提正序以及零序参数辨识方法进行仿真,验证了所提参数辨识方法的有效性和精确性。

基于柔性调控零序电压的不平衡配电网故障检测方法

在柔性消弧过程中实现故障选线、过渡电阻测量与故障性质判定对现有配电网单相接地故障检测具有重要意义。针对配电网三相对地参数不对称的柔性接地系统,首先分析不平衡零序电压对消弧效果的影响,提出柔性消弧全补偿电流的计算方法。然后分析正常运行状态下和单相接地故障状态下注入电流和母线零序电压之间的约束关系。结果表明:无论系统处于何种状态,均可通过改变注入电流来柔性调控母线零序电压,进而调控各线路零序电流。并根据柔性调控零序电压前后各线路零序电流的变化规律,提出一种可实现故障选线、过渡电阻测量和故障性质判定的故障检测方法。Matlab/Simulink仿真验证了该方法的有效性和准确性。

基于负序量排序及5G通信的主动配电网有界面保护原理

针对大量分布式电源(distributed generation, DG)接入配电网对传统保护带来的新挑战,提出了一种基于负序量排序与5G通信相结合的配电网有界面保护原理。为实现保护范围的有界及灵活配置,并应对极端工况下的主判据失效问题,设计了一种免整定的实测-补偿电压幅值比较判据。在信息交互方面,结合配电网通信特点,提出了带时标的5G通信方式,进一步降低了所提保护对同步通信的要求。仿真结果表明,对于带不可测分支的线路,所提判据均可成功应用,并且不依赖于数据同步通信。相较于传统三段式电流保护,保护新方案能够大大提升配电网的故障切除速度,保证故障极限响应时间均在90 ms以内。在数十欧姆的相间弧光过渡电阻和接地电阻的情形下,该方案仍能具有良好的故障辨识能力。相比于幅值差动保护,所提保护具有对不可测分支更强的适应性和动作稳定性。

基于分组地图匹配的异常轨迹检测

为提高轨迹数据的质量,提出一种轨迹点的多尺度综合映射算法。采用分组匹配的思想,依据每组特性剪枝无效的轨迹点,加快映射轨迹点的连接速度,快速得到路网轨迹。在此基础上,为有效进行异常轨迹的检测,提出一种基于分组地图匹配的异常轨迹检测算法,研究字符串相似性搜索,构建相似轨迹序列寻找代表轨迹,基于交叉点行驶状况对轨迹点进行约减,减少轨迹间的计算量,计算轨迹的异常阈值,判定异常轨迹。在真实的出租车数据集上进行实验,验证了提出方法的执行效率和准确性。

基于伪随机序列的松散煤体声学测温方法及应用

长期以来,采空区、煤堆、煤仓等空间的煤自燃火灾时有发生,受限于工作区域的复杂环境和火源探测技术瓶颈等因素,较难实现煤自燃灾害高温点的快速量化识别。而声学测温技术具有测量精度高、测温范围宽、测量空间大等特点,可实现采空区等隐蔽火源位置精准探测且极具发展前景。目前该技术在松散煤体温度测量领域尚处于基础研究和实验室研究阶段,仍需开展大量研究。基于伪随机序列的优越性能,将其引入作为声源信号,并根据声学测温原理和伪随机序列声源信号产生原理,搭建了松散煤体声波测温试验系统。系统主体部分包括声学测试系统、程序升温系统、隔音系统和煤样箱体,结合试验测试和仿真模拟方法,验证了系统的准确性。利用理论分析、Matlab仿真和试验测试相结合的方法,开展伪随机序列声源信号的失真特性研究,确定了该信号的最佳处理方法,成功将其应用于松散煤体测温中。结果表明:伪随机序列可以作为采空区、煤堆、煤仓等空间的松散煤体声学测温的声源信号,但需运用二次相关PHAT–β算法对伪随机序列声源信号发生频率区间(1000~3000 Hz)进行处理,使频带变窄,能量集中;运用伪随机序列声源信号测量声波在松散煤体中飞渡时间,发现不同距离下声波飞渡时间测量结果误差小于5%,并通过了对比验证;伪随机序列作为松散煤体的测温声源信号时,所反演温度与不同粒径的煤样温度之间的平均绝对误差为2.051℃,平均误差率5.293%,能够较为精准、可靠地反演煤温。

基坑开挖顺序对围护结构及既有高铁站的影响分析

依托绍兴高铁北站TOD综合体深基坑工程,分析了基坑分区、分块施工等开挖顺序对地连墙水平位移和临近高铁站房竖向位移的影响和变形规律。研究结果表明:不同开挖顺序对基坑及周边建筑物的变形影响显著,而仅考虑优化基坑的开挖顺序是不全面的,必须考虑地下主体结构施工引起的基坑地连墙刚度和边界条件的变化等因素。对于超大型基坑,综合考虑施工工期和经济性等因素,跳坑开挖可以显著地减少对周边的影响,开挖后应及时进行地下梁、板等的浇筑,与地下结构不浇筑相比,地连墙最大水平位移可减小45.96%、相邻高铁站房最大竖向位移减小34.65%。文中得出的结论可为类似工程设计和施工提供依据和参考。