汽车室内道路模拟试验系统控制算法的研究

为了有效的进行汽车道路模拟试验，首先要通过系统识别获得整个试验系统的频响函数矩阵[FRF]，之后在目标信号模拟过程中获得满足试验要求的驱动信号。详细叙述了在系统识别过程中，对识别所得模型进行评判的相干函数法及预测法，和为获取更加准确模型而使用的模型平均法；以及为消除整个实验系统的非线性因素而在目标信号模拟过程中采用的迭代算法。最后，通过具体的试验对上述的控制算法进行了验证。     

对目标打击概率的数学模型及分析

通过分析识别跟踪攻击目标的过程，建立了攻击目标打击概率的数学模型和基本算法，通过计算机采用蒙特卡罗法模拟计算了不同条件下对目标的打击概率，以此研究影响打击概率的因素。计算结果表明，武器系统的作战半径和威力半径两个因素对打击概率影响较大，误差因素在一定范围内影响较小，各参数之间存在优化匹配的空间。     

浅析煤焦油加工过程中的安全防护措施

高温条件下油品生产存在很多不安全因素。通过对高温下油品危险性分析，沦述了高温条件下油品在液态储存，运输及混合等操作时应注意的事项，提出了高温下油品生产及加工的安全防护措施。     

改善海空背景下红外弱点目标识别性能的理论方法探讨

针对舰载红外警戒系统的实际需要，对改善海空背景下红外弱点目标识别性能的方法进行了探讨．在对舰载红外警戒系统中弱点目标识别的技术难点及点目标场景图像模型进行分析的基础上，提出了改善海空背景下红外弱点目标识别性能的3种方法．     

船舶舱室某些物理因素对人体工效的影响

文章研究了噪声、温度、湿度及照明对人体工效的影响。试验在模拟船舶舱室内进行，共有4种物理因素6种排列组合。受试者为男性青年，健康，听力正常。研究发现．听阈偏移仅由噪声引起，而统计学分析表明．强噪声、低温度、高温及高湿可引起税对比敏感度函数下降。与低水平的噪声、温度及湿度相比．强噪声、高温及高湿复合因素可使视、听反应时明显延长。     

基于虚拟误差传感的大尺度空间有源降噪性能研究

针对大尺度空间有源降噪系统误差传声器布放位置受限问题,本文使用虚拟误差传感在降噪目标区域放置多个虚拟误差传声器,将静音区由物理误差传声器点转移至虚拟误差传声器点,扩大降噪目标区域中静音区范围。为了对降噪性能及影响因素进行分析与研究,给出多通道虚拟误差传感的原理和算法,对降噪性能及物理与虚拟误差传声器的数量和布放等因素进行仿真分析,在飞机模型舱内进行实验验证。仿真及实验结果表明：使用虚拟误差传感有利于增大降噪目标区域降噪量及静音区;物理与虚拟误差传声器的布放影响静音区的分布;合理的物理与虚拟误差传声器数量及布放可以扩大静音区使其100%覆盖降噪目标区域,最优数量与初级声场频率特性相关。     

目标跟踪方法综述

复杂背景下实时目标的跟踪与识别属于自动目标识别（ATR）研究领域，包括对目标的分割、特征提取和目标识别等几个方面。本文将运动背景目标跟踪方法分为基于运动分析和基于图像匹配两大类，综述了几种典型方法的基本原理、基本属性、存在弊端及发展过程；通过各种方法的多方面比较。提出了改进思想，总结了目标跟踪的选择方法；同时针对目标跟踪的一些具体问题。提出了优化措施，最后探讨了目标跟踪方法中有待进一步研究的问题。     

舰船红外成象目标实时识别跟踪算法研究

对前视海面舰船红外成象目标的实时识别与跟踪技术进行了研究，提出了一种新的海面舰船红外成象目标的识别跟踪算法。重点论述了其中的跟踪算法；同时基于本文算法及实际系统使用性能的要求，设计了一种适合本文算法的舰船红外成象识别跟踪系统，给出了硬件原理框图，对系统的实时性进行了分析。     

高温管道内流体流量及温度识别研究

建立了高温管道稳态导热模型,通过有限体积法进行求解,对管道外表面温度分布随流体温度流量的变化规律进行了研究。根据Levenberg-Marquardt算法,提出了由管道外壁面温度分布同时识别管内流体流量及温度的计算方法,通过数值模拟研究了随机测量误差对识别结果的影响,证明了算法的有效性,给出了减小随机误差对识别结果影响的方法。     

声诱饵对尺度目标的回波模拟方法

潜艇回波可以等效成若干个散射亮点回波相干迭加的结果,现代声自导鱼雷基于这一物理事实,通过辨识目标尺度来识别真假目标。提出使用具备数据通信能力的多个点源声诱饵,通过信息交互实现各声诱饵回波发射延时的有序控制,实现对尺度目标的多亮点回波模拟。具体仿真算例表明,该方法对利用方位走向特征和声成像进行目标尺度识别的鱼雷具有对抗效果。     

White-light spectral interferometric technique to measure the wavelength dependence of the spectral bqandpass of a fibre-optic spectrometer

Abstract

A spectral-domain white-light interferometric technique with channelled spectrum detection is used to measure the wavelength dependence of the spectral bandpass of a fibre-optic spectrometer. In an experimental setup comprising a halogen lamp, a non-dispersive Michelson interferometer and the spectrometer to be measured, spectral interferograms are recorded for different optical path differences (OPDs) between interfering beams. By processing the recorded spectral interferograms using discrete filtering and a fringe amplitude demodulation method, spectral fringe visibilities, first, as a function of the wavelength for given OPDs, and second, as a function of the OPD at given wavelengths, are obtained. It is confirmed, in accordance with theory, that the latter spectral fringe visibility functions are Gaussian functions with maxima and widths dependent on the wavelength. From the widths of the Gaussian spectral fringe visibility functions the wavelength dependence of the spectrometer bandpass is determined over a wide spectral range.     

Spectral changes and spectral switches of partially coherent beams focused by an aperture lens

Starting from the propagation law of partially coherent polychromatic light in the space-frequency domain, detailed numerical results and physical analysis are given to elucidate spectral changes and spectral switches at the geometrical focal plane of Gaussian Schell-model beams focused by an aperture lens. It is found that, in contrast to the aperture-induced spectral anomalies of spatially fully coherent polychromatic light, for partially coherent polychromatic light aperture diffraction plays an important role in spectral switching, but the truncation parameter, spectral correlation, and bandwidth all affect its spectral behavior.     

Femtosecond laser speckles

The concept of femtosecond laser speckles is put forward. The theory of a speckle pattern in light of finite bandwidth is applied to describe femtosecond laser speckles. Basic representations of the contrast and the spectral correlation of femtosecond laser speckles are presented. The relationship between the speckle contrast and the bandwidth of a femtosecond laser is given. Experimental results are given that indicate an obvious difference between the speckle patterns produced by a continuous-wave laser and those produced by a femtosecond laser.     

Spectral shifts and spectral switches of a pulsed Gaussian beam from a rectangular aperture in the far field

The far-field anomalous spectral behaviours of a space–time-dependent Gaussian pulsed beam passing through a rectangular aperture are studied. By expanding a hard aperture function into a finite sum of complex Gaussian functions and starting from the Fresnel diffraction integral, the approximate analytical expression for the spectral intensity of a space–time-dependent Gaussian pulsed beam passing through a rectangular aperture is derived. Meanwhile, the corresponding closed-forms for the slit and the unapertured cases are also given as special cases of the general results. The red and blue shifts and the spectral intensity distribution are studied and illustrated with numerical calculations. Specifically, it is shown that the spectral switch takes place when the truncation parameter is equal to particular values or the observation position is at the critical diffraction angle. The possibility of tunable spectral switching in the far field with an apertured pulsed beam by varying the size of the rectangular aperture is highlighted.     

Fringe-imaging Mach-Zehnder interferometer as a spectral analyzer for molecular Doppler wind lidar

The theoretical performance of a Mach-Zehnder interferometer used as a spectral analyzer for wind-speed measurement by direct-detection Doppler lidar is presented. The interferometer is optimized for the measurement of wind velocity from the signal that is backscattered by the molecules. In the proposed fringe-imaging Mach-Zehnder (FIMZ) interferometer, a pattern of equally spaced linear fringes is formed and detected by two conventional detector linear arrays. Assuming a pure molecular signal with Gaussian spectral profile, an analytic expression for the standard deviation of the measurement error is obtained and compared with the Cramer-Rao lower bound given by an ideal spectral analyzer (ISA) in the case of shot-noise-limited signal. The FIMZ measurement error is shown to be 2.3 times that of the ISA and is comparable with the error given by previously developed multichannel spectral analyzers that are based on Fabry-Perot interferometers that, in contrast, have the disadvantages of producing unequally spaced circular fringes and requiring dedicated detectors. The optimal path difference for a FIMZ operating at 355 nm is approximately 3 cm. The interferometer is shown to match important lidar beam étendues without significant performance reduction.     

一种用间接法推定摄像机光谱特性的误差特性方法

本文提出一种利用间接法来推定摄像机光谱特性的误差特性新方法。介绍了这种方法的原理，给出了误差特性表达式。利用最小二乘法还推出了误差特性的估算公式。     

Designing and deconstructing the Fano lineshape in plasmonic nanoclusters

By varying the relative dimensions of the central and peripheral disks of a plasmonic nanocluster, the depth of its Fano resonance can be systematically modified; spectral windows where the scattering cross section of the nanocluster is negligible can be obtained. In contrast, electron-beam excitation of the plasmon modes at specific locations within the nanocluster yields cathodoluminescence spectra with no Fano resonance. By examining the selection rules for plasmon excitation in the context of a coupled oscillator picture, we provide an intuitive explanation of this behavior based on the plasmon modes observed for optical and electron-beam excitation in this family of nanostructures.     

Tone Reproduction in Colour Scales*

Brightness variatio within the complete scale of a given hue, from black to white, can be expressed as a function of dye Concentration (through the intermediate of its spectral analytical densities) by the “brightness curve” which yields a parameter characteristic of each hue, the “brightness contrast γB”. The brightness contrast furnishes quantitative information on the intrinsic brightness of each hue and thus allows to exploin the variability with hue of the effects of exposure variations on tone reproduction in colour photography.     

使用特征正交分解型谱表示法的汽车受路面激励随机模拟

将特征正交分解型谱表示法用于模拟汽车受路面激励。首先给出了路面不平度对汽车输入的位移随机激励的谱描述。基于路面激励的功率谱矩阵,结合特征正交分解（POD,Proper Orthogonal Decomposition,）型谱表示法的模拟表达式,给出了路面激励的显式POD分解,定义了汽车的“路面激励模态”,推导了路面对汽车输入激励随机模拟的简化计算公式。该方法可用FFT来减少计算量以提高计算速度。它由于完全消除掉了原型谱表示法的Cholesky分解过程而具有较高的计算效率和更明确的物理意义。最后,通过对一个四轮轿车在国标GB7031—87中的A级路面不平度下受到的位移随机激励进行模拟,说明了该方法的有效性。