基于单片机的自适应等精度频率测量

在电子测量中,频率是重要的测量量之一。本文以单片机为核心实现高精度、宽范围的自适应频率测量。由于无需增加外部逻辑器件控制闸门,同时测量结果直接由上位PC实时显示,因此系统具有体积小、可靠性高、功耗低以及便于应用等特点。测试结果表明,在0.1Hz—1MHz范围内,最大相对误差为0.82%(50Hz处),最大绝对误差为48Hz(800kHz处)。     

Visual‐quality estimation using objective metrics

Abstract— In the past few years, a big effort in the scientific community has been devoted to the development of better image‐ and video‐quality metrics that correlate well with the human perception of quality. In this paper, an overview of the main ideas used in the design of objective quality metrics is given. More specifically, we briefly describe the different types of objective metrics and present a representative set of the different approaches taken by these algorithms. Finally, the challenges and recent developments in the area of image and video quality are discussed.     

Objective evaluation of qualified viewing spaces for near‐to‐eye and autostereoscopic two‐view displays

Abstract— Virtual‐image (near‐to‐eye) and two‐view autostereoscopic (3‐D) displays share similar optical properties in the comfortable user position for viewing. In this paper, the definitions and criteria of qualified viewing space (QVS) and qualified stereoscopic viewing space (QSVS) are discussed. Due to the complex nature of these viewing spaces, the related presumptions and the required optical characteristics and their measurements are specified. The effects of different display and observer parameters, such as interpupillary distance, to the resulting viewing spaces are discussed. Finally, real measurement data of two autostereoscopic display devices are presented.     

Intelligently tuned wavelet parameters for GPS/INS error estimation

This paper presents a new algorithm for de-noising global positioning system (GPS) and inertial navigation system (INS) data and estimates the INS error using wavelet multi-resolution analysis algorithm (WMRA)-based genetic algorithm (GA) with a well-designed structure appropriate for practical and real time implementations because of its very short training time and elevated accuracy. Different techniques have been implemented to de-noise and estimate the INS and GPS errors. Wavelet de-noising is one of th...     

Efficient bit-parallel multipliers over finite fields GF(2)

Hardware implementation of multiplication in finite field GF(2^m) based on sparse polynomials is found to be advantageous in terms of space-complexity as well as the time-complexity. In this paper, we present a new permutation method to construct the irreducible like-trinomials of the form (x + 1)^m + (x + 1)ⁿ + 1 for the implementation of efficient bit-parallel multipliers. For implementing the multiplications based on such polynomials, we have defined a like-polynomial basis (LPB) as an alternative to the original polynomial basis of GF(2^m). We have shown further that the modular arithmetic for the binary field based on like-trinomials is equivalent to the arithmetic for the field based on trinomials. In order to design multipliers for composite fields, we have found another permutation polynomial to convert irreducible polynomials into like-trinomials of the forms (x² + x + 1)^m + (x² + x + 1)ⁿ + 1, (x² + x)^m + (x² + x)ⁿ + 1 and (x⁴ + x + 1)^m + (x⁴ + x + 1)ⁿ + 1. The proposed bit-parallel multiplier over GF(2^4m) is found to offer a saving of about 33% multiplications and 42.8% additions over the corresponding existing architectures.     

基于TD SCDMA的虚拟外场测试平台

目前在TD外场测试过程中,存在着设备操作不便、无线环境复杂、测试情景不能再现等诸多难题。为解决这些问题,通过对2G及3G相关理论的研究,给出适合TD网络的业务模型和传输模型。在此基础上提出一种利用软硬件仿真TD网络外场测试环境,在实验室环境中构建虚拟外场测试平台的方法。对该平台的结构和工作原理进行分析论述,利用该平台可使大部分外场测试能方便地在实验室中进行,提高了测试效率。     

面向钢铁集团测量过程的工作流设计

为实现钢铁集团测量过程的流程化管理,提出一种基于扩展有限状态机的工作流元模型,给出元模型的元素定义与迁移原理。根据ISO10012测量过程的受控条件,利用该模型对测量过程进行工作流与角色权限设计,实现基于浏览器/服务器的3层工作流系统。结果表明,该系统能满足测量过程的7个受控条件。     

IEEE 1588精密时钟同步协议2.0版本浅析

在分布式测控系统中,各分布式设备、独立的智能传感器、作动器与系统之间的时钟同步是系统测控数据有效性的关键。IEEE 1588精密时钟同步协议有效地解决了分布式测控系统时间同步问题,也是新测试系统总线标准LXI的核心技术之一。首先介绍了IEEE 1588时钟同步的基本原理,之后主要针对最新发布的IEEE 1588 2.0版本所采用的新技术、新方法进行了分析,为进一步研究打下基础。     

电容式水分仪的研制

介绍了基于单片式电容传感器的电容式水分仪,可实现对被测对象的无损检测。主要用于地暖供热管道渗漏和建筑物渗漏的检测。描述了水分测量系统的测量原理、硬件结构,以及软件设计结构。实践表明,该水分仪具有较高的准确性和应用推广价值。     

基于ANSYS的直流励磁电机电磁场分析与计算

应用有限元数值分析软件（ANSYS）对直流串励电机内部电磁场进行分析计算,获得电动机负载运行时的电枢反应磁场,并通过ANSYS的后处理功能得到负载运行气隙磁密分布图,在此基础上对直流励磁电机的电磁转矩进行了分析计算,通过样机实验验证了计算结果,证明了理论分析的正确性。为直流励磁电机的性能分析及设计提供了一定的参考。