On Two Parallel Matched Gratings Demodulation Method of Fiber Grating Strain Sensor

The method of demodulation with two parallel matched fiber Bragg gratings( FBGs) system is introduced to enlarge the range of strain that can be detected by the FBG sensor system.

High-Speed Parallel Matched Filter Designing and FPGA Implementation

Matched filter is one of the key technologies to achieve high-speed data transmission. In this paper,a parallel finite-impulse response (FIR) filter structure based on polyphase filter-ing is used to achieve high-speed matched filter in quadrature phase-shift keying (QPSK) demodulation up to 800 Mb·s-1. First,a window function is employed of to obtain impulse response of matched filter. Second,the high-speed parallel FIR structure is presented based on polyphase filtering. Then,the filter with EP2S180F1020 on the Quartus II 7.2 platform is achieved. The final results show that the design is correct and can implement high-speed matched filtering,wherein the equivalent frequency of which is up to 2 037 MHz. In addition,this scheme is easy to real-ize,which brings great value to the application of this filter in high-speed matched filters design in demodulation systems.

Inertia Match of a 3-RRR Reconfigurable Planar Parallel Manipulator

Inertia match of the parallel manipulator means the ratio of the inertial load of the parallel manipulator converted to each actuator shaft and the moment of inertia of the actuator is kept within a reasonable range. Currently there are many studies on parallel manipulators, but few mention inertia parameters and inertia match of parallel manipulators. This paper focuses on the inertia characteristics of the 3-RRR reconfigurable planar parallel manipulator. On the basis of the inverse dynamic formulations deduced with the principle of virtual work, the inertia matrix of the 3-RRR planar parallel manipulator in the actuator space is obtained in algebraic form. Then, by unifying the dimension and averaging diagonal elements of the inertia matrix, the equivalent inertia of the parallel manipulator, which is the inertial load of the parallel manipulator converted to each actuator shaft, is determined. By transforming the inertia problem of the 3-RRR parallel manipulator into that of the serial multi-bar manipulator, the practicality of the equivalent inertia deduced by inverse dynamics is demonstrated. According to the physical meaning of the inertia equation, the manipulator is divided in to three parts. Further analysis is carried out on the contribution of each part to the equivalent inertia and their distributions in the required workspace, revealing that the passive links cannot ignored in calculating the equivalent inertia of the parallel manipulator. Finally, the inertia match for the 3-RRR reconfigurable parallel manipulator under three configurations is accomplished, and reducers are selected. The equivalent inertia calculation and the inertial match results illustrate that the inertia math is a necessary step to the design of the parallel manipulator, and inertia parameters dramatically affect dynamic performances of parallel manipulators. Besides, the equivalent inertia and inertial match principles, proposed in the paper, can be widely applied in the dynamic analysis and servomotors selecting for the parallel manipulator.

Matched-field inversion of sound speed profile in shallow water using a parallel genetic algorithm

A sound speed profile plays an important role in shallow water sound propagation.Concurrent with in-situ measurements,many inversion methods,such as matched-field inversion,have been put forward to invert the sound speed profile from acoustic signals.However,the time cost of matched-field inversion may be very high in replica field calculations.We studied the feasibility and robustness of an acoustic tomography scheme with matched-field processing in shallow water,and described the sound speed profile by empirical orthogonal functions.We analyzed the acoustic signals from a vertical line array in ASIAEX2001 in the East China Sea to invert sound speed profiles with estimated empirical orthogonal functions and a parallel genetic algorithm to speed up the inversion.The results show that the inverted sound speed profiles are in good agreement with conductivity-temperature-depth measurements.Moreover,a posteriori probability analysis is carried out to verify the inversion results.

Theoretical study of magnetic lens with parallel beam matched

The magnetic lens(Zumbro lens) is a critical part in proton radiography. Traditionally the matched beam for Zumbro lens in proton radiography is a virtual point source beam, which is not suitable for some cases, such as cylindrical samples. In these cases, a parallel beam is more appropriate. In this paper, a method, which uses quadrupole beamline, is proposed for designing a magnetic lens with parallel beam matched. Theoretical analysis is given. The results show that the matched beam for this lens is indeed parallel beam, while the major merits of Zumbro lens are inherited. Following this method, a theoretical design based on the 11-Me V cyclotron is presented.

A new parallel algorithm for image matching based on entropy

Presents a new parallel image matching algorithm based on the concept of entropy feature vector and suitable to SIMD computer, which, in comparison with other algorithms, has the following advantages:(1)The spatial information of an image is appropriately introduced into the definition of image entropy. (2) A large number of multiplication operations are eliminated, thus the algorithm is sped up. (3) The shortcoming of having to do global calculation in the first instance is overcome, and concludes the algorithm has very good locality and is suitable for parallel processing.

Parallel Quick Search Algorithm for the Exact String Matching Problem Using OpenMP

String matching is seen as one of the essential problems in computer science. A variety of computer applications provide the string matching service for their end users. The remarkable boost in the number of data that is created and kept by modern computational devices influences researchers to obtain even more powerful methods for coping with this problem. In this research, the Quick Search string matching algorithm are adopted to be implemented under the multi-core environment using OpenMP directive which can be employed to reduce the overall execution time of the program. English text, Proteins and DNA data types are utilized to examine the effect of parallelization and implementation of Quick Search string matching algorithm on multi-core based environment. Experimental outcomes reveal that the overall performance of the mentioned string matching algorithm has been improved, and the improvement in the execution time which has been obtained is considerable enough to recommend the multi-core environment as the suitable platform for parallelizing the Quick Search string matching algorithm.

基于Spark Streaming的海量GPS数据实时地图匹配算法

浮动车GPS数据作为交通信息处理的基础,随着被监控车辆数量的高速增长,产生了海量GPS数据,对地图匹配提出了挑战。为了解决传统匹配方法难以满足匹配效率和精度的不足,提出一种针对海量GPS数据的实时并行地图匹配算法,能够同时保证较高匹配精度和运算效率。为构建一种面向实时数据流的高效、准确实时地图匹配算法,首先通过引入速度、方向综合权重因子对依赖历史轨迹的离线地图匹配算法进行重构,进而引入Spark Streaming分布式计算框架,实现地图匹配算法的实时、并行运算,大幅提升实时地图匹配效率。实验结果表明,该算法在复杂路段的匹配准确率较常规拓扑匹配算法提高10%以上,整体匹配准确率达到95%以上;在匹配效率方面,较同等数量的单机服务器效率可提高4倍左右。实验结果表明,该算法在由11台机器组成的计算集群上实现8000万个GPS数据点的实时地图匹配,证明了该算法可以完成城市地区的实时车辆匹配。

大规模协同虚拟环境下并行层次兴趣匹配算法

大规模协同虚拟环境运行过程中易产生大量冗余通信数据,影响虚拟现实技术性能的发挥。为了提升虚拟环境运行效率,提出并行层次兴趣匹配算法。创建协同虚拟环境概念模型,分解处理订阅区域信息,引入树结构理论搭建兴趣管理树,将订阅区域映射到兴趣管理树节点上,形成层次化结构,结合LSQR并行算法,实现更新区域与订阅区域的快速匹配。实验结果表明,提出算法获得的兴趣匹配消耗时间最小值为0.36 s,兴趣匹配成功指数最大值为0.94,充分证实了提出算法兴趣匹配性能较好。

基于EtherCAT总线的八轴七联动高级海况环境仿真平台

针对水流模拟海况时存在的运动不受控以及常规海况模拟平台模拟海况等级低,运动自由度不足等问题,提出利用八自由度运动平台模拟高级海况环境进行海浪涌动测试的方法。设计了由直线运动平台、旋转机构和6自由度(6-DOF)并联机构组成的串并联混合八自由度高级海况环境仿真平台,其运动加速度大,自由度多,运动方式多样。基于Ether CAT实时总线技术设计了八轴七联动的运动控制算法,并采用惯量匹配技术抑制抖动和噪声,实现了宽惯量范围的精确、稳定、同步(小于1μs)控制。设计了基于外部信号接收器的实时精密补偿技术和双齿轮消隙技术,提高了速率精度和平稳性,定位精度达到10μm。设计了复合叠加摇摆、文件仿真、复合叠加摇摆与文件仿真叠加运动和实时仿真运动方式,可模拟到五级高海况或将实航数据回灌后模拟水下、水面或机载的运动,用于导航系统的姿态模拟测试。

多视密集匹配并行传播GPU-PatchMatch算法

针对多视密集匹配的效率较低的问题,提出了GPU-PatchMatch多视密集匹配算法。该算法使用GPU提高PatchMatch的计算效率;同时充分利用稀疏场景信息,对深度信息进行规则初始化;为提高传播效率,使用了金字塔红黑板并行传播深度信息。最后在DTU、Strecha和Vaihigen数据集上进行了试验,并与常用的多视密集匹配算法进行对比。试验结果表明,本文算法在重建效率上有较大提高,与CPU算法(PMVS、MVE、OpenMVS)相比有7倍以上提升,与GPU算法相比也有2.5倍以上提升,表明本文算法的有效性。

基于SimCSE框架融合预训练模型层级特征的文本匹配

SimCSE框架仅使用分类令牌[CLS]token作为文本向量,同时忽略基座模型内层级信息,导致对基座模型输出语义特征提取不充分.本文基于SimCSE框架提出一种融合预训练模型层级特征方法SimCSE-HFF(SimCSE with hierarchical feature fusion,SimCSE-HFF).SimCSE-HFF基于双路并行网络,使用短路径和长路径强化特征学习,短路径使用卷积神经网络学习文本局部特征并进行降维,长路径使用双向门控循环神经网络学习深度语义信息,同时在长路径中利用自编码器融合基座模型内部其他层特征,解决模型对输出特征提取不充分的问题.在STS-B的中文与英文数据集上,SimCSE-HFF方法效果在语义相似度Spearman和Pearson相关性指标上优于传统方法,在不同预训练模型上均得到提升;在下游任务检索问答上也优于SimCSE框架,具有更优秀的通用性.

7~13 GHz宽带高效率驱动放大器设计

基于0.25μm GaAs PHEMT工艺设计了一款7~13 GHz微波单片高效率驱动放大器。芯片采用两级级联拓扑结构,在输入级引入共源并联负反馈结构拓宽工作带宽,同时为兼顾输出功率和效率,在输出级引入等效RC模型拟合输出管芯的最优阻抗。基于等效RC模型,通过采用电抗匹配方式降低输出宽带匹配网络的损耗来实现较高的输出功率和附加效率。实测与仿真曲线吻合度较好,实测结果显示:在7~13 GHz工作带宽范围内,输入驻波比小于1.5,输出驻波比小于1.8,线性增益大于13 d B,3 d B压缩点输出功率大于24 d Bm,功率附加效率大于35%,芯片面积为1.8 mm×0.8 mm。

基于FPGA的访问控制列表并行查找设计与实现

在高安全要求的网络环境中,多种类型的网络设备均需要部署基于规则的访问控制功能。访问控制列表通过五元组进行规则匹配,实现对网络报文的筛选、过滤、处理、控制等操作。如何利用有限的资源实现更高查表性能、更多规则数量的访问控制列表,是相关设备的关键技术之一。通过分析网络通信设备中访问控制列表的一般工作流程,文章提出了一种改进的基于现场可编程逻辑门阵列(Field Programmable Gate Array,FPGA)实现的访问控制列表并行查找设计方法,并详细阐述了具体模块的实现方案。实验结果表明,该方案可以充分利用FPGA的存储与逻辑资源,实现较大规模的支持范围匹配的规则表项,并可以支持10 Gpbs速率等级网络通信的查表需求。

电动汽车800V高压架构设计及车桩匹配

面对新能源汽车发展中的充电焦虑问题,宽禁带半导体的技术应用,加快了高压快充桩布局和800V电动汽车的开发,有效提高了电动汽车的补能效率。文章围绕电动汽车800V高压架构设计及车桩匹配问题进行论述,从直流快充桩电压现状及标准规划表明直流桩高压化发展趋势,比较不同补能方式,给出电动汽车800V高压平台方案的选型依据,然后对800V架构设计方案进行详细分析,对电机绕组集成升压电路和电池串并联控制策略热点问题重点介绍,为开发800V高压架构提供一定的方案指导。

基于并行小波算法的多模态数据近似匹配模型构建

针对近似匹配过程易受数据冗余性、异构成分等的影响,提出了基于并行小波算法的多模态数据近似匹配模型。该模型首先采用并行小波算法剔除多模态数据中的噪声,避免噪声对匹配过程产生影响;其次采用张量分解的聚类算法将不同相似度的数据划分到不同类簇中,以消除不同类簇的数据差异度;最后将预处理后的数据输入到基于空间方向近似性的数据匹配模型中,通过计算参考数据与待匹配数据之间的空间方向近似度、编辑距离完成多模态数据的近似匹配。实验结果表明,所提方法的匹配查准率高、查全率高、匹配时间短。

基于内插补偿法的时域频域双并行捕获算法

针对传统PMF-FFT(partial matched filter-fast fourier transform)捕获算法在高动态大多普勒频移捕获时扇贝损失严重,多普勒频移估计精度低等问题,提出一种基于内插补偿法与改进PMF-FFT融合双并行捕获算法,通过对中频信号二次采样,利用匹配滤波器进行分段从而加快捕获速度。对PMF和FFT同时进行加窗并选择最优调谐系数,同时利用二次函数内插法,对结果插值补偿,提高频偏估计精度,基本消除栅栏效应。仿真结果表明,该算法兼顾捕获速度和硬件资源消耗的同时,提高了捕获精度,基本消除栅栏效应,适用于大多普勒频偏的扩频信号捕获。

A Study of Rules-Based OPS5 Parallel Firing

Based on the introduction of the PS, this paper analyzes the correlation of parallel firing rules. Then it presents an algorithm to support OPS5 parallel firing during the act phase and a new parallel reasoning model for OPS5. At last, it gives an evaluation on the model in the aspects of time complexity, running efficiency, etc.