分布式多通道计算机视觉测量系统

提出了一种新颖的分布式多通道计算机视觉测量系统 ,并成功地解决了钢卷尺自动检测问题。讨论了系统的原理、HUB控制器的设计、图像自动识别与自动检测以及定时器编程等核心技术。实践证明 ,分布式多通道计算机视觉测量系统可以实现工业领域中多目标的高速视觉测量与在线质量监控     

基于三模冗余设计的低成本高可信微纳通用计算机

引入商用现货技术成为微纳卫星设计的发展趋势。针对微纳卫星电子系统低成本、小型化、高可靠的应用发展需求,分析对比国内外微纳卫星星载计算机设计特点,提出一种基于三模冗余设计的低成本、高可信微纳通用计算机体系架构,利用接口标准化、软件分层化设计和三模冗余、硬件看门狗等加固设计,构建了一套通用、稳定、可靠的电子系统,并展望了其在科学实验与新技术演示验证、分布式空间系统、军事等方面良好的应用前景。     

近场分布式光度计的研究进展及应用

亮度计成像精度、存储器数据容量和计算机运算能力决定了近场分布式光度计的探测能力。随着成像技术和计算机技术的发展,近场分布式光度计的测量性能有了革命性的提升。介绍了近场分布式光度计的工作原理,归纳了近场分布式光度计相对于远场分布式光度计的优势。综述了国内外近场分布式光度计的研究进展,对比了部分国内外产品的性能指标。针对近场分布式光度计元数据精度不足、扫描重构速度偏慢和溯源装置适应性受限的现状,从部件、软件和系统等方面归纳了相应的解决方案。结合近场分布式光度计的特点和优势,展望了其在照明显示、交通运输、工业视觉和文物保护等领域的应用。     

基于MAS的分布式控制软件系统模型

神光Ⅲ激光器实验装置计算机集中控制系统是一个大型分布式控制系统，被控设备类型复杂，控制点众多，控制要求高，需要对信息与资源共享、控制系统与物理环境协调一致等问题进行优化。传统的分布式控制难以实现大范围内信息和资源共享，不能较好地解决动态问题复杂性和不确定性。分布式智能Agent控制系统不仅能减少网络负担，取代许多远程调用，还能实时调整控制方式，配合被控制对象的变化，实现系统资源的充分利用。     

分布式并行计算在光谱学信号处理领域中的应用

将分布式并行计算引入光谱学信号处理领域。用傅里叶红外光谱仪FTIR-4100获得白砂糖、木糖醇、麦芽糖和葡萄糖4类糖各39个样本的光谱曲线作为测试数据。在两台软硬件配置相同的计算机平台上运行分布式并行算法。先运用分布式并行方法读取FTIR-4100生成的文本文件中的原始数据,然后进行分布式并行数据预处理,包括最大峰值标准化校正,Savitzky-Golay平滑降噪算法等,再运用分布式并行遗传算法抽取糖特征波数共24个,最后将提取到的24个特征波数作为用BP神经网络输入,建立3层人工神经网络。实验结果表明,分布式并行计算运行结果与单机顺序计算结果比对一致,在两台计算机并行工作模式下的计算效率比传统的单机顺序计算处理效率高33.6%,为光谱学信号处理研究领域进行复杂科学计算和提高计算效率提供了新的方法。     

双路热动力试验台集散控制系统设计与实现

自行设计了基于串行总线结构的双路热动力试验台集散控制系统 ,采用RS -4 2 2协议进行管理站与现场控制台的分布式智能仪表的远距离通讯和控制。管理站还设计了一套独立的高精度的数据采集系统 ,它由IEEE -4 88接口与管理站计算机通讯 ,管理站计算机以此为标准修正智能仪表及协调现场控制台控制。实现了对温度、压力、流量等的集散控制。     

分布式光纤温度传感技术在隧道监测中的应用

介绍了分布式光纤温度传感检测原理及采用拉曼散射型分布式光纤温度传感器并将其与高速采集处理电路集成的检测方式。分析了分布式光纤温度传感技术应用于隧道火情监控的优越性。结合计算机及现场Modbus网络构建了隧道监测网络，同时还介绍了开发隧道监测网络的软硬件设计过程。现场实验表明，分布式光纤温度传感技术具有良好的应用前景和较高的推广价值。     

一种分布式内存环境下的并行二分网格加密算法

给出了一个基于ALBERT(Adaptive multi-Level finite element toolbox using Bisection refinement and Error control by Residual Techniques)的并行二分网格加密算法.其目的是开发基于ALBERT的、适合于分布式内存计算机的并行自适应有限元软件包.首先给出了针对ALBERT的并行化策略,然后重点介绍并行网格加密算法,并证明了并行算法和原有串行算法在加密结果上完全等效.最后,数值实验证明该并行算法能有效地在分布式内存的计算机上执行.     

高光谱图像的分布式近无损压缩

星载高光谱图像的有效压缩已经成为高光谱遥感领域亟待解决的难题。分布式信源编码具有较低的编码复杂度与良好的抗误码性,在高光谱图像压缩领域具有广阔的应用前景。提出了一种基于多元陪集码的高光谱图像分布式近无损压缩算法。根据多元陪集码的Slepian-Wolf无损编码的压缩过程,提出了面向高光谱图像分布式近无损压缩的最优量化方案,使得高光谱图像在给定目标码率条件下的失真达到最小,在此基础上对量化值进行Slepian-Wolf无损编码,从而实现了高光谱图像的分布式近无损压缩。实验结果表明,与典型的传统算法相比,该算法取得了较好的近无损压缩性能和较低的编码复杂度。     

水声信号数据融合系统的性能研究

给出了一种多传感器水声信号数据融合的数学模型和融合算法,并将该方法用于分布式水声信号检测系统中多部声呐的信息综合。计算机仿真结果表明,该分布式数据融合系统的检测概率和作用距离均有较大的提高。     

Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide

Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.     

Hybrid Wavelength and Code Division Multiple Access in Optical Networks

A review of schemes for multiple access in fiber optic networks shows that a hybrid of wavelength and code division multiple access (WCDMA) combines the best features of both. In particular, the hybrid scheme retains the large information carrying capacity of wavelength division multiple access (WDMA) and flexibility of code division multiple access (CDMA). In this paper WDMA, optical CDMA (OCDMA), and WCDMA networks are discussed. In OCDMA networks, concept of incoherent and coherent coding including inverse decoding and matched filter is introduced. The delay performance of both WDMA and WCDMA networks, under the simple suboptimum access protocols based on cyclic search, is computed. It has been shown quantitatively that tuning delay significantly affects the delay performance of both WDMA and WCDMA networks. Futhermore, delay performance of WCDMA networks is always better than the WDMA networks for the same tuning delay, load, and number of users.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·10⁴ Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.     

Femtosecond Transform-Limited Pulse Generation by Compensating for the Linear Chirp of SPM Spectra in Dispersion Shifted Fibers

A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.     

Measurement of nonlinear coefficient of optical fiber based on small chirped soliton transmission

We measure the waveform and phase curves of short optical pulses before and after transmission over different lengths of fibers by use of the pulse analyzer with the frequency-resolved optical gating (FROG),and numerically simulate pulse evolution under the experimental conditions.The nonlinear coefficient of the fiber is given by comparing the experimental results with the numerical ones.Difference between the experiment and numerical simulation is analyzed.     

Resonance scattering of canonical elastic shells in absorbing fluid medium

Resonance scattering of elastic spherical shell and cylindrical shell while the surrounding fluid medium has absorption is studied. The normal mode solution derived using exact elastic theory and the separation of variables is still applicable. However, the scattering form function has to be modified for the absorbing medium, otherwise the unreasonable result would be obtained. The backscattering form function in the absorbing medium is redefined, and the form function of elastic spherical and cylindrical shell with vacuum or solid matter filled is calculated in various absorption conditions. The results show that the absorption of surrounding fluid leads to notable attenuation of the coincidence resonances in the mid-frequency, but it has a little influence on the low-frequency resonance scattering induced by the filler inside the shell.     

Single-beam self-referenced phase-sensitive surface plasmon resonance sensor with high detection resolution

A versatile and low-cost single-beam self-referenced phase-sensitive surface plasmon resonance(SPR)sensing system with ultra-high resolution performance is presented.The system exhibits a root-mean-square phase fluctuation of ±0.0028.over a period of 45 min.i.e.a resolution of±5.2×10-9 refractive index units.The enhanced performance has been achieved through the incorporation of three design elements:a true single-beam configuration enabling complete self-referencing so that only the phase change associated with SPR gets detected,a differential measurement scheme to eliminate spurious signals not related to the sensor response,and the elimination of retardation drifts by incorporating temperature stabilization in the liquid crystal phase modulato .Our design should bring the detection sensitivity of non-labeling SPR biosensing closer to that achievable by conventional fluorescence-based techniques.     

Influences of SiO2 protective layers and annealing on the laser-induced damage threshold of Ta2O5 films

Ta2O5 films are prepared on BK7 substrates with conventional electron beam evaporation deposition.The effects of SiO2 protective layers and annealing on the laser-induced damage threshold (LIDT) of the films are investigated.The results show that SiO2 protective layers exert little influence on the electric field intensity(EFI)distribution,microstructure and microdefect density but increase the absorption slightly.Annealing iS effective on decreasing the microdefect density and the absorption of the films.Both SiO2 protective layers and annealing are beneficial to the damage resistance of the films and the latter is more effective to improve the LIDT.Moreover,the maximal LIDT of Ta2O5 films is achieved by the combination of SiO2 protective layers and annealing.