基于虚拟仪器的温度测量系统

基于虚拟仪器技术,利用热电偶设计了一套温度测量系统,包括硬件和软件设计,硬件包括对热电偶输出信号的放大和滤波,以及对冷端温度的补偿电路,冷端温度通过Pt100热电阻进行测量;软件采用Labview进行编写,界面简洁,可通过图形化的界面对温度进行实时监测。     

Diversity techniques for mobile radio reception

After discussing the nature of the electromagnetic field in urban environments, and the use of diversity techniques in fading media, the paper presents a survey of these techniques as applied to mobile radio, with emphasis on systems designed for analogue communication. It includes a unified approach to systems based on the double-heterodyne phase-stripper principle. The discussion is not restricted to present-day receivers only, but includes considerations which may apply in future designs.     

Anthropomorphic cardiac ultrasound phantom

A new phantom is described which simulates the human cardiac anatomy for applications in ultrasound imaging, ultrasound Doppler, and color-flow Doppler imaging. The phantom consists of a polymer left ventricle which includes a prosthetic mitral and aortic valve and is connected to a mock circulatory loop. Aerated tap water serves as a blood simulating fluid and ultrasound contrast medium within the circulatory loop. The left ventricle is housed in a Lexan ultrasound visualization chamber which includes ultrasound viewing ports and acoustic absorbers. A piston pump connected to the visualization chamber by a single port pumps degassed water within the chamber which in turn pumps the left ventricle. Real-time ultrasound images and Doppler studies measure flow patterns through the valves and within the left ventricle.     

A Hammerstein-based dynamic model for hysteresis phenomenon

The Hammerstein configuration, which includes a nonlinear static block followed by a linear dynamic block, is applied to model the rate-dependent and temperature-dependent hysteresis phenomenon. The nonlinear static block is realized by a modified Preisach model, which includes both the irreversible and reversible components of magnetization. The linear dynamic block is realized by a low-pass filter, which takes into account the rate-dependent effects of hysteresis. Temperature dependencies are incorporated into the model by fitting the model parameters as piecewise-linear functions of temperature. A procedure is described for the extraction of a single set of model parameters over the frequency, amplitude, and temperature ranges of interest. The theory is verified experimentally     

An analytical equation for the oscillation frequency of high-frequency ring oscillators

An analytical equation for the oscillation frequency of a ring oscillator is derived. The derivation is done using a novel method which does not need to find an expression for the delay of each stage. The resulting equation includes the effect of time-varying parasitics. It also includes the effect of the gate resistance, which has a large effect on the oscillation frequency at high frequencies. Measurement results of ring oscillators fabricated in a 0.18-/spl mu/m CMOS process show that the resulting equation has an average error of 8% over a large range of parameter variations.     

Development of a simulated data set for the SeaWiFS mission

A realistic simulated data set is essential for mission readiness preparations and can potentially assist in all phases of ground support for a future mission. Such a data set was created for the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), a global ocean color mission due for launch in 1997. This data set incorporates a representation of virtually every known aspect of the flight mission. Thus, it provides a high fidelity data set for testing most phases of the ground system, including data processing, data transfers, calibration and validation, quality control, and mission operations. The data set is constructed for a seven-day period, March 25-31, 1994. Specific features of the data set: it includes Global Area Coverage (GAC), recorded Local Area Coverage (LAC), and real-time High Resolution Picture Transmission (HRPT) data for the seven-day period; it includes a realistic orbit which is propagated using a Brouwer-Lyddane model with drag; the data correspond to a command schedule based on the orbit for this seven-day period; it includes total (at-satellite) radiances for ocean, land, clouds, and ice; it utilizes a high-resolution land/sea mask; it includes actual SeaWiFS spectral responses; it includes the actual sensor saturation responses; it is formatted according to current onboard data structures; and it includes corresponding telemetry (instrument and spacecraft) data. The methods are described and some examples of the output are given     

A one-chip scalable 8*8 ATM switch LSI employing shared bufferarchitecture

The authors present a one-chip scalable 8×8 shared buffer switch LSI which includes a 256-cell buffer. Speedup, flow control, and input slot rotation functions are provided in order to interconnect LSIs for scaling-up without degrading cell loss rates. Computer simulations show that these functions bring a satisfactory result and can make the cell loss- rate for a Clos three-stage network superior to that for the output buffer switch which includes the same amount of buffer space. A 0.8 μm BiCMOS process is employed for this LSI. The total number of transistors is one million. This LSI has already been fabricated     

基于云计算的矿井无线传感网络火情远程监控系统

针对矿井实际需求情况,提出了一种基于云计算的无线传感网络火情远程监控系统,此系统包括通讯基站、无线传感器网络和云计算平台,其中,无线传感器网络通过通讯基站与云计算平台相连接。它包括用于采集煤矿安全数据的无线传感器、执行器和用于传输煤矿安全数据的无线网关。该系统具备低成本、自组织、低功耗、信息交互方便的特点,具有很好的应用前景。     

La traduction automatique

There exist two main models of translation system : 1) a transfer model which includes a representation of the text in the source language and a transfer module that changes this representation into a representation of the next in the target language, 2) a pivot model which includes a single representation shared by the texts in the source and target languages. The criteria used to choose one of these two models will be described. Then, a transfer system, Eurotra, will be presented in detail. Eurotra, which is an R and D project develop-ped within the European Economic Community, involves the nine official languages of the eec. The large number of transfer modules (i.e. 72) requires that they be simplified as much as possible. This entails to design a syntactico-semantic representation which is abstract enough to reduce transfer to lexical transfer in a significant number of cases.     

The RF toroidal transformer as a heat delivery system for regionalhyperthermia

A novel working principle for a RF (radio-frequency) hyperthermia applicator, suitable for heating large cylindrical volumes of coaxial loads, is described. The system includes a toroidal inductor as an active device producing an almost uniform electric field, which is polarized along the toroidal z axis in the space inside the toroidal ring where the conductive tissue is placed. This electric field produces axial RF currents which, in turn, produce the required heating, provided that a closed loop is formed by electrically connecting the conductive load through capacitive ring (CR) electrodes to form an electric circuit closed externally to the toroidal inductor. This system behaves like a toroidal transformer (TT), the secondary circuit of which includes the dissipative load between the CR electrodes     

基于USB2．0的CMOS图像采集系统的设计

介绍了一种实用的基于USB2．0的高分辨率、快速数字图像实时采集和传输系统的设计,其中包括CMOS图像传感器和USB2．0数据采集板的硬件电路设计以及固件程序、驱动程序和主机上基于MFC的应用软件的开发。最后通过试验测试实现高速,高分辨率的图像采集。     

An open-source compiler and PCB synthesis tool for digital microfluidic biochips

This paper describes a publicly available, open source software framework designed to support research efforts on algorithms and control for digital microfluidic biochips (DMFBs), an emerging laboratory-on-a-chip (LoC) technology. The framework consists of two parts: a compiler, which converts an assay, specified using the BioCoder language, into a sequence of electrode activations that execute out the assay on the DMFB; and a printed circuit board (PCB) layout tool, which includes algorithms to reduce the number of control pins and PCB layers required to drive the chip from an external source. The framework also includes a suite of visualization tools for debugging, and a collection of front-end algorithms that generate mixing/dilution trees for sample preparation.     

A Mathematical Model of the Human Temperature Regulatory System?Transient Cold Exposure Response

A mathematical model of the human temperature regulatory system which utilizes finite difference techniques and includes new anatomical and basal physiological information, with more detail than previous models, is presented. A cold stress control system which includes both a feedback signal based on head core temperature and feedforward signals based on the skin temperature and the skin heat flux is postulated. Model and direct experimental results (seven temperatures, cardiac output, metabolism, and arm blood flow) are compared for a transient cold exposure. The substantial agreement found suggests that the skin heat flux could be an important input to the temperature regulatory system.     

导航雷达图像显示的多线程编程

设计了导航雷达图像在SoPC硬件平台上显示的软件系统,根据雷达图像显示任务和系统的运行工程对代码的任务进行划分,雷达图像显示任务包括雷达圆和文字数据两部分,划分后的代码任务包括硬件初始化、开始数据接收处理、量程设置、窗口显示、关机等5个任务,对应划分后的任务采用了Windows下的多线程方法编写雷达图像显示的软件系统。经过在SoPC硬件平台上调试运行,效果显示能够满足导航雷达图像显示的各项要求。     

Thermal effects on the linear gain in free-electron lasers

The authors develop a self-consistent formulation of the linear gain in both helical and planar wiggler configurations in the presence of an axial energy spread derived from a beam pitch-angle spread. Such a beam may be thought of as monoenergetic but with a non-vanishing emittance. The analysis includes collective Raman effects for both the helical and planar wiggler systems, and describes the gain at harmonics in the case of a planar wiggler. General dispersion equations are derived, and solved numerically, for each wiggler configuration which includes a general thermal function which describes the effect of the pitch-angle spread     

“软件技术基础”中数据结构教学方法研究

数据结构是“软件技术基础”课程的重要组成部分,内容主要包括常用数据结构及其运算.本文探讨了数据结构的教学方法,包括基本教学四步骤和基于典型案例的算法执行法教学方法.与传统数据结构教学方法比较,这种教学方法具有简单、直观和易教易学的特点.实践表明其可操作性强,且行之有效.     

A categorization of multiscale-decomposition-based image fusionschemes with a performance study for a digital camera application

The objective of image fusion is to combine information from multiple images of the same scene. The result of image fusion is a single image which is more suitable for human and machine perception or further image-processing tasks. In this paper, a generic image fusion framework based on multiscale decomposition is studied. This framework provides freedom to choose different multiscale decomposition methods and different fusion rules. The framework includes all of the existing multiscale-decomposition-based fusion approaches we found in the literature which did not assume a statistical model for the source images. Different image fusion approaches are investigated based on this framework. Some evaluation measures are suggested and applied to compare the performance of these fusion schemes for a digital camera application. The comparisons indicate that our framework includes some new approaches which outperform the existing approaches for the cases we consider     

基于达芬奇技术的TD探测终端设计与实现

针对TD终端探测设备对小型化、低功耗和实时性的要求,运用基于嵌入式Linux的达芬奇软件架构和Qt软件架构进行探测设备实时数据采集、高效数据处理、信息显示方案设计。该方案包括算法封装、USB高速数据管理、多线程同步设计和Qt界面设计,并在嵌入式探测设备上得以实现,通过实际场景测试验证设计的有效性和可靠性。     

基于结构标签学习的显著性目标检测

提出了一种基于结构标签学习的显著性目标检测算法,将结构化学习方法应用到显著性目标检测中。首先从含有标记的图像中随机采集固定大小的矩形区域,并记录其结构标签;然后使用含结构标签的区域特征构建决策树集合;最后采用监督学习的方法对图像进行优化预测,得到最终的显著图。实验结果表明,本文方法能较准确地检测出图像库中图像的显著性区域,在数据库MSRA5000和BSD300的AUC值分别为0.891 8、0.705 2,说明本文方法具有较好的显著性检测效果。     

Location-aware access to hospital information and services

Hospital workers are highly mobile; they are constantly changing location to perform their daily work, which includes visiting patients, locating resources, such as medical records, or consulting with other specialists. The information required by these specialists is highly dependent on their location. Access to a patient's laboratory results might be more relevant when the physician is near the patient's bed and not elsewhere. We describe a location-aware medical information system that was developed to provide access to resources such as patient's records or the location of a medical specialist, based on the user's location. The system is based on a handheld computer which includes a trained backpropagation neural-network used to estimate the user's location and a client to access information from the hospital information system that is relevant to the user's current location.