共查询到20条相似文献,搜索用时 265 毫秒
1.
将虚拟仪器技术应用于电力系统谐波测试,利用美国NI公司功能强大的LabVIEW虚拟仪器开发平台研制了基于虚拟仪器技术的电力谐波测试仪,其总体性能优于传统测试仪.本文论述了谐波测试仪的工作原理、系统组成以及硬软件设计中的技术要点. 相似文献
2.
基于虚拟仪器技术的边界扫描测试仪的设计 总被引:2,自引:2,他引:0
设计了一种基于虚拟仪器技术的边界扫描测试仪,该测试仪采用PC机控制整个测试、诊断过程;首先通过下载电缆将测试指令从打印机端口送往被测PCB,采用边界扫描技术完成测试工作,然后将测试响应上传至PC机,由智能故障诊断软件对响应做相应的分析和运算,获得对PCB的诊断结果。 相似文献
3.
4.
基于LabVIEW的虚拟电力谐波测试仪 总被引:2,自引:0,他引:2
本文利用LabVIEW开发平台研制了基于虚拟仪器的谐波测试装置。该仪器可实现谐波的在线分析,提高了谐波测量的精度,其性能优于传统测试仪。 相似文献
5.
6.
7.
介绍了虚拟仪器技术和电磁干扰(EM I)的含义;阐述了基于虚拟仪器的EM I自动测试系统的设计,用开关电源的传导干扰作为测量实例,在虚拟仪器LabVIEW 7.0(VI)软件平台上,编写了该虚拟仪器程序,并利用该虚拟仪器程序实际测量了3种电子设备中开关电源谐波分量的测量数据;最后,总结了该测试系统的优点。 相似文献
8.
9.
10.
利用最新的虚拟仪器开发平台 ,开发研制了新型的多功能振动测试仪。该仪表将振动软测量技术与虚拟仪器技术相结合 ,集合了多种信号处理算法 ,解决了实验中设备振动参数的测量问题。该仪表信号测量精度高 ,工作稳定 ,环境适应性好 ,并具有良好的功能扩展能力 ,是一种适应实验室特殊要求的高性能测试设备 相似文献
11.
基于GPIB接口的虚拟仪器在接收机测试台的应用 总被引:1,自引:0,他引:1
结合虚拟仪器的特点详细分析了一个基于GPIB接口的虚拟仪器系统——接收机测试台系统,介绍了该系统的硬件组成及其软件设计,展示了虚拟仪器在自动测试系统中的应用。系统的功能模块化设计和用户界面的软件化设计,充分体现了虚拟仪器的优势。最后对虚拟仪器的前景进行了展望。 相似文献
12.
Md. Akram Hossain Mahbub Alam David Yonge Prashanta Dutta 《Computers & Geosciences》2005,31(10):1286-1292
Chromium (VI) (Cr(VI)) contamination of soil and groundwater is considered a major environmental concern. Bioreduction of Cr(VI) to chromium (III) (Cr(III)) can be considered an effective technology in remediating Cr(VI) contaminated sites. Among the Cr(VI) reducing bacteria, Shewanella oneidensis MR-1 (MR-1) is relatively effective. Reduction of Cr(VI) by MR-1 is defined by the dual-enzyme kinetic model. Existing models are not able to simulate bioreduction of Cr(VI) by employing the dual-enzyme kinetic model. The objective of this paper is to present a finite element model capable of simulating bioreduction of Cr(VI) by employing the dual-enzyme kinetic model and compare its prediction with experimental results. The model developed is accurate and can provide oscillation-free results for Peclet number Pn≤20 and Courant number Cn≤1. The model prediction compares well with the experimental results. 相似文献
13.
14.
15.
Alternating direction method (ADM), which decomposes a large-scale original variational inequality (VI) problem into a series of smaller scale subproblems, is very attractive for solving a class of VI problems with a separable structure. This type of method can greatly improve the efficiency, but cannot avoid solving VI subproblems. In this paper, we propose a hybrid splitting method with variable parameters for separable VI problems. Specifically, the proposed method solves only one strongly monotone VI subproblem and a well-posed system of nonlinear equations in each iteration. The global convergence of the new method is established under some standard assumptions as those in classical ADMs. Finally, some preliminary numerical results show that the proposed method performs favourably in practice. 相似文献
16.
17.
18.
植被多分布在复杂地形,不规则的地形会造成遥感影像中同种或相似地物呈现不同的反射率/辐射值,也会使得不同种地物呈现相似的反射率/辐射值,这种反射率的变化会给植被的生物、物理量评估带来误差,所以对地形复杂区域的典型植被指数的评估是十分必要的。选用Landsat卫星影像对复杂地形条件下典型植被指数进行了评估。经过详细的分析,植被指数对由地形引起的红光波段反射率变化敏感,导致它们对地形的变化敏感,所以植被指数受地形的影响总体上是不容忽视的。
相似文献
19.
Chunyang He Yuanyuan Zhao Jie Tian Peijun Shi Qingxu Huang 《International journal of remote sensing》2013,34(4):1127-1145
Time series of vegetation index (VI) information derived from remote sensing is important for land-cover change detection. Although traditional change vector analysis (TCVA) is an effective method for extracting land-cover change information from a time series of VI data, it has the disadvantage of being too sensitive to temporal fluctuations in VI values. The method tends to overestimate the changes and confuse the actual land-cover conversion with the land covers that have not been converted but experience significant VI changes. Cross-correlogram spectral matching (CCSM) can tell the degree of shape similarity between VI profiles and be used to detect land-cover conversion. However, this method may omit some land conversion in which the before and after land-cover types are rather similar in VI profile shape but differ significantly in absolute VI values. This article proposes a new approach that improves TCVA with an adapted use of CCSM. First, TCVA is employed for preliminary detection of land-cover changes. Second, the changes caused by temporal fluctuations of VI values are identified through the CCSM analysis and excluded to only keep the most likely land-cover conversions. Finally, classification is performed to map the different types of land-cover conversions. The improved change vector analysis (ICVA) was applied to detect land-cover conversions from 2000 to 2008, using a time series of Moderate Resolution Imaging Spectroradiometer (MODIS) enhanced VI images for the Beijing–Tianjin–Tangshan urban agglomeration district, China. The results show that ICVA is able to detect land-cover conversion with a significantly higher accuracy (78.00%, κ?=?0.56) than TCVA (64.00%, κ?=?0.35) or CCSM (66.60%, κ?=?0.27). The proposed approach is of particular value in distinguishing actual land-cover conversion from land-cover modifications resulting from phenological changes. 相似文献
20.
面向虚拟检测的测试功能组件研究 总被引:1,自引:1,他引:0
为了解决虚拟仪器软件设计效率低、重复劳动多、通用性及互换性差的问题,提出一种开发面向虚拟检测的测试功能组件的方法,即借鉴成熟的组件技术开发一系列可复用的虚拟测试功能组件。描述了虚拟测试功能组件的方法和开发过程,结合实例介绍了以测试功能组件为单位搭建虚拟仪器的过程。基于虚拟测试功能组件可以快速开发可互换虚拟检测仪器。 相似文献