Virtual Instrument Technology and Its Application in Humidity Testing

In recent years,Virtual Instrument technology has been concerned in the arena of information technology and instrument manufacture.The authors propose the Virtual Instrument's concept,characteristics and configuration of both hardware and software.They apply Virtual Instrument to the humidity testing and brings forward the method to solute the problem,which traditional dry-humid balls humidity-testing instrument can not test several objects.By putting the emphasis on data acquisition,data processing,data storage and data display,the software design of virtual humidity test is discussed.     

Great Capacity of Data Logger Based on Virtual Instrument Technology

The Data Logger is an important secondary-instrument,which can be applied to automatic monitor and control system,and high speed local data acquisition for later analysis.The Virtual Great Capacity of Data Logger based on virtual instrument technology is a new instrument which has more advantages than the traditional Data Logger.The design method has been introduced from three ways,which includes system principle, hardware configuration and programming design, and an application example is given.This Data Logger is low cost,easy to take,also easy to operate.It can be widely used in many of actual applications.     

ZOOM FFT Technology Based on Analytic Signal and Band Pass Filter

This paper deals on the method of ZOOM FFT based on analytic signal and band pass filter, which is different from other methods of ZOOM FFT. It is used on computer with larger zoom ratio; higher compute speed and so on than other ways for offline testing. It provides a new method for the development of Virtual Instruments on ZOOM FFT analysis.     

Virtual Sound Intensity Analyzer

The Virtual Sound Intensity Analyzer is a new instrument which has more advantages than the traditional Sound Analyzer. This Analyzer is based on fast Fourie transformation and virtual instrument technique.As an application, combining software and hardware, all kinds of weight noise sound level measurement and real-time noise octave analyzes realized synchronously. The design method has been introduced from three ways, which includes hardware, software and panel. An applied example and error analyze of Virtual Sound Intensity Analyzer are given.This Analyzer is low cost, small volume. and it is also easy to operate. It can be widely used in actual applications.     

X3D-a Next Generation Standard for Web3D and Its Application

With the development of Web application,virtual reality technology based on Web is popular.In Web3D field,the old standard of VRML(Virtual Reality Modeling Language)has many problems and is not fit for the development.So the Web3D Consortium provides a next generation standard for Web3DX3D(Extensible 3D specification).X3D,using multiple file encodings describing the same abstract model including XML,has a modular architecture allowing a range of levels of adoption and support for many different market types.It also has a unified application programming model and an expanded specification structure.The technology character of X3D is mainly analyzed.Also the background,development and supporting tools of X3D are introduced.And then an example of application using X3D is given.     

Digit Weight and Development of a Virtual Noise Analyzer

Traditional noise octave analyzers consist of filter network and weight network based on hardware. In order to realize a noise octave analysis by software, a digit weight method based on FFT is proposed. Using the method, digit weight and digit system error modification for virtual noise octave analyzer can be realized. Because of digit weight and digit system error modification, precision and stability of the instrument can be improved greatly. As an application, which combines the method of digit weight with the technique of digit system error modification, a low cost and high precision virtual real time noise octave analyzer is developed.     

Applying of the DSP Technology in the Virtual Instrument System

The hardware architecture and instruction set of the digital signal processor leads to its high speed and precision in processing data. Aiming at the virtual instrument's deficiency in speed and precision resulting from the limit of the computers' development, the author brings forward a method to promote the performance of the virtual instruments using the DSP technology. Implementing the complex algorithms in DSP and using the principal and subordinate DSP structure or DMA technology in the data acquisition card of the virtual instrument can promote the virtual instrument's real-time characteristic greatly. Several key technologies are introduced in realizing the data acquisition and processing card. The experiment shows that the digital signal processors have higher speed and precision than the computers when implementing complex algorithms, and that using the DSP to implement the algorithms is an effective method to promote the virtual instrument's performance.     

A Virtual Wavelet Transform Analyzer for the Signal Analysis Based on the Direct Algorithm

A virtual wavelet transform analyzer for the signal analysis based on the direct algorithm is introduced so that the discrete wavelet transform and continuous wavelet transform is maken to signal in the direct algorithm. The authors first introduce the direct algorithm of the WT, which is numerical algorithm obtained from the original formula of the wavelet transform by directly numericalizing. Then some conclusions are drawn on the direct algorithm. The examples are the sampling principle and technology for the wavelets, the limitation of the scale range of the wavelets and the measures to solve the edge phenomenal in the direct algorithm of the discrete wavelet transform, and some conclusions in the direct algorithm of the continuous wavelet transform. The virtual wavelet transform analyzer for the signal analysis based on the direct algorithm explored based on these studies and combined with virtual instrument technique can make the discrete wavelet transform and continuous wavelet transform to signal with any basic wavelet. It can be applied in studying the property of any basic wavelet and learning the theory on the wavelet transform, and also in making some engineering signal analysis. In the end, the authors give some typical examples for the application of the virtual analyzer. These examples show that the analyzer can be applied in many situations.     

Virtual Studio System Technology

Virtual studio system (VSS), a new technology based on virtual reality, develops fast in recent years. Virtual studio concept replaces real background sets with computer generated 3D synthetic and combines real foreground action, with computer generated backgrounds. As VSS need not construct real background sets and has little limitness of time and space, it is regarded as a revolution in TV programs. This paper mainly discusses about the background, technology feature, application and future.     

Error Analysis and Modification of Virtual Instrument System

The errors of each parts of virtual instrument system, which are produced in the signals transfer process, are introduced. These errors include sensor error, signal conditioning error, data acquisition error and data dealing error, etc. The main error can be found by analyzing the influence of these errors on different virtual instrument system. The methods of errors modification are also discussed. It's an effective method that modifying system errors, especially nonlinear errors, by software. At last, as a good example, the error analysis and modification of Virtual Noise Analysis Instrument is given.     

Twist and Rotate Speed Measurement Oriented Virtual Instrument Based on Qin''s Model

The paper introduces concepts and the general idea of Intelligent Virtual Controls based on Qin's Model,and advances a new instrumental mode ,that is Virtual Intelligent Twist and Rotate Speed Measurer ,which can be used in measuring the frequently used physical parameters in the rotate mechanical systems ,including twist ,rotate speed ,power and the axes-oriented force. The three-layered hiberarchy ,including the interface layer ,the testing and service layer and the hardware driving layer, is brought forward to design the Virtual Intelligent Twist and Rotate Speed Measurer ,which is a new creative method .In the hiberarchy, the lower layers provide the service and support to the upper ones, and the upper layers realize the functions of instruments with call-back of the lower ones .In the framework the three ones divide the work and cooperate well. An Virtual Instrument based on IVC-based-VI is successfully developed which is used in the twist and rotate speed measurement of the mechanical area.     

Research of Real-time Computer Network Protocol Based on UDP Protocol and Virtual Token

Aiming at the urge demand of a large amount of real-time data transmit in industry and academy fields, the authors analyze the advantages and disadvantages of many kinds of present protocols, take advantage of UDP protocol and standard 802.4 of Token Bus. The real-time network protocol is presented based on UDP protocol and virtual token. And this paper illuminates the principle of real-time quality and reliability about the protocol, giving the frame format of the protocol and the format of Virtual Token. It demonstrates the capability of the protocol with a point-to-point transmit example that constructed according to this protocol.     

Virtual Signal Analyzer Based on Hilbert-Huang Transform

Hilbert-Huang transform(HHT) is a new method for signal analysis developed by Norden.E.Huang et al in 1998.The concepts for main contents,Empirical mode decomposition,Hilbert spectrum and marginal spectrum of Hilbert-Huang transform(HHT) are introduced.Based on the characteristics of VI's development and application,combining software and hardware,the designed method,which includes hardware,software and panel for the Virtual Signal Analyzer Based on Hilbert-Huang Transform are introduced.Based on the HHT,combined with virtual instrument technology,a Virtual Signal Analyzer is developed successfully.It has provided a new method for signal test and analysis.     

PDA Based Virtual Instrument

Test and Measurement task can be done without limit of time and space by PDA with virtual instrument technology. The structure of PDA based virtual instrument is described firstly. Then PMDS(PDA Measurement Develop System) which can construct virtual instruments efficiently using component technology is introduced, it can enhance quality and efficiency of instruments. Finally, portable spectrum analyzer and mobile temperature monitor is built with PMDS to illuminate the usage of PMDS.     

SPR生物传感技术在农产品安全检测中的应用

表面等离子共振作为近几年在国内发展起来的一种检测技术,具备检测样品用量少、灵敏度高、检测速度快等优点,已被用于环境检测、医疗诊断、药物筛选、蛋白质组学、基因组学等诸多领域。随着技术的发展,广大学者将其与生物技术结合起来,在传感芯片表面修饰不同的特异性抗原抗体及信号放大因子,将表面等离子共振技术不断应用到农产品安全的检测中。通过介绍该技术在农产品中农残药残、动物疾病、微生物、食品添加剂、重金属及转基因检测的应用情况,以期使读者深入了解表面等离子共振技术在食品安全检测的发展现状,为其在该领域的进一步发展提供可以借鉴的资料。     

Product Modeling in Virtual Manufacture

The competition among enterprises becomes more and more drastic. In order to win the market, so as to put itself in a stead station, the enterprise put forward many advanced manufacturing modes. Virtual manufacture is put forward by American as a wholly new concept under this situation. It is thought as advanced manufacturing technology of the 21st century. Based on the analysis to the prior, the author expatiated the concept of virtual manufacture and put forward the three demands which the product model suited for the virtual manufacture must satisfy. On the bases the author set up the product model which is composed by product function express and product definition and expatiated the product function and product definition at detail.     

Application of Sound Intensity Technique to Measure the Noise of Electromotor

This paper has explained the characteristics,virtue of sound intensity measurement and the principle. And compare with traditional sound pressure measurement. The principle and composing of virtual sound intensity measurement system based on two-channel FFT analysis are researched. The sound power of large turbogeneratorin operating site is determined by means of sound intensity measurement and sound pressuremeasurement. Itis demonstrated that the method of sound intensity measurement of engine is practicable and the measuring data are valid and the method conquers the problems of traditional method of sound pressure measurement which is apt to environmentinfluence and sound power measurement need to especially acoustic environment. It is proved that the sound intensity method is especially suited to determine highaccuratelythe sound Power level of the electrical machines operating in situated conditions especially in case of acoustically worst environments or on loadand themethod is so superiorityin noise measurement.     

基于3G和VPN的温室远程监控系统的设计与实现

根据温室环境的特点提出一种基于3G无线通信技术和VPN（Virtual Private Network）虚拟专网技术的温室远程监控系统。该系统在温室现场设备和中心服务器之间建立无线的虚拟专网,采用Linux操作系统、ARM9处理器作为软硬件平台,能够对温室环境因子数据的进行自动采集、远程传输、存储管理、网络发布、分析处理,同时实现对温室辅助控制设备的远程控制。试验结果表明：该系统设计方案合理、可靠,能满足各种环境因子的数据采集及多种温室辅助设备的远程控制。鉴于设计方案中采用了通用型技术构架,本系统已经扩展应用于其他农业领域中,如农情监测、气象灾害监测预警等,应用前景非常广阔。     

Development of Virtual Sweep Signal Source

A new kind of virtual sweep signal source which can be used to output specific sweep signal according to(users') configuration and can be widely applied to frequency characteristics measurement in the field of mechanics,electrics and electronics,is developed by using Dot Net software engineering technique,C/S architecture and general data acquisition platform.The virtual instruments not only make up the intrinsic defect of traditional instruments based on hardware components in high performance,remote control and data processing,but also indicate the powerful life and nice future of virtual instrument technologies.