复杂背景中低对比目标的提取

在复杂背景中提取低对比的目标是电视跟踪、测量系统进一步发展需要解决的重点课题，是提高作用距离、快速、准确地捕获目标和精密跟踪、测量的先决条件。针对如何在复杂背景中提取低对比目标的技术途径，结合实际工程研制和外场实验进行了探讨。     

用模拟方法实现视频信号的背景抵消

在电视跟踪测量中,目标信号的提取是关键性问题。本文介绍了两种视频信号背景抵消方法的设计思想及实验结果。所提取出的目标信号为识别目标同时提供了两种参数——目标的宽度参数及亮度参数,为实时电视跟踪提供了技术基础。     

高分遥感视频改进型时空上下文目标跟踪

针对时空上下文(STC)目标跟踪算法在高分辨率视频卫星影像中目标经过复杂背景时跟踪准确度过低的问题,提出适用于视频卫星影像数据的改进型时空上下文目标跟踪算法。算法结合感知哈希算法对STC目标跟踪算法中置信图模型加以改进以提升跟踪算法的目标定位精度,使用帧间学习率自适应更新方法以提升跟踪算法准确度。另外,对系列视频卫星影像进行了仿真实验,结果表明,所提算法在保证实时跟踪速度的同时克服了视频卫星影像中复杂背景对目标跟踪算法的干扰,实现了针对高分辨率视频卫星影像的精准目标跟踪。     

基于相关准则的磨粒显微图像目标提取

针对磨粒显微图像识别中的目标提取问题 ,应用一种新的阈值分割方法将磨粒目标从复杂背景中分离。该算法以原始图像与分割后图像的相关系数最大为准则 ,选取最优阈值对磨粒图像进行二值化 ,经腐蚀、膨胀等滤波运算后 ,利用跟踪搜索法提取磨粒边界 ,实现了复杂背景下磨粒目标的有效提取。应用实例表明了算法的简洁有效性。     

面向激光跟踪仪跟踪恢复的合作目标视觉检测

为了实现复杂场景下激光跟踪仪跟踪恢复过程中合作目标靶球的检测,本文研究了基于深度学习的靶球检测方法。首先,分析靶球自身特点、应用环境及它在跟踪恢复过程中的作用,然后根据Faster R-CNN模型原理与跟踪恢复应用需求提出基于超特征与浅层高分辨率特征信息复用的改进方法生成新的融合特征图,并优化区域建议提取参数,协同解决图像中目标多尺度变化与小尺寸导致目标漏检率高的问题;同时提出一种基于强背景干扰的困难样本挖掘方法提高模型对外形颜色等与目标近似的干扰物识别能力,解决模型误检测率高的问题。最后,本文构建了目标靶球数据集并进行了对比训练与测试。测试实验结果表明:本文提出的基于强背景干扰困难样本挖掘方法的改进Faster R-CNN模型在目标多尺度、小尺寸检测,以及对复杂背景中相似干扰物的辨别能力都有提升,最终对测试集的检测精度达到了90.11%,能够满足激光跟踪仪跟踪恢复过程对合作目标靶球的视觉检测精度要求。     

复杂背景弱小目标检测技术

本文主要研究论文复杂背景弱小目标检测技术,通过弱目标的提取技术,时空域融合的背景抑制增强滤波技术,可以有效排除杂波干扰,减小背景抑制难度,使目标的搜索跟踪更加准确。本文主要创新点是基于时空域融合滤波的模块化并行背景抑制算法和简化的云层边缘虚景剔除方法,更加简单有效地完成弱小目标检测。     

多目标跟踪算法在水质监测中的应用

针对活鱼水质监测系统中的活鱼跟踪中存在的问题,提出了一种基于视频的多目标跟踪算法,通过采用一种基于统计模型的背景建模方法得到了实验鱼缸的初始背景,并在活鱼目标检测跟踪过程中实时更新背景,在此基础上采用背景相减法和自适应图像二值化实现了活鱼运动目标的提取,并用连通区域分析提取活鱼的大小、质心等特征值,最后将卡尔曼预测器应用于基于运动特征的跟踪技术中,实现了活鱼的轨迹跟踪,提取到了活鱼的运动轨迹,最终达到了为后续的水质预警提供了可靠的轨迹数据的目的,所跟踪得到的活鱼运动轨迹数据是监测系统水质预警的重要基础。研究结果表明,该算法符合系统的实时性和准确性要求,能实现活鱼运动轨迹的准确快速跟踪。     

一种改进的均值移位红外目标跟踪算法

为了增强复杂背景条件下红外目标跟踪的稳健性,提出了一种改进的均值移位目标跟踪算法。该算法融合了均值移位的梯度匹配搜索策略的优势与基于特征分类跟踪算法强鲁棒性的优点,建立了灰度似然比加权的核直方图目标表征模型。模型中加入了目标与局部背景灰度特征的似然比作为原始核直方图的权值,应用该模型的均值移位算法能够进一步提高目标像素灰度的移位权重,有效抑制背景干扰,进而提高低对比度目标跟踪的稳健性。同时,基于跟踪复杂度估计提出了目标遮挡情况下的模型更新判别准则,提高了算法的自适应性能。实测红外目标跟踪实验表明了该算法简单、有效。     

基于均值漂移算法的水下视频目标跟踪

鉴于水下的特殊环境,本文利用均值漂移算法对水下视频中的运动目标进行跟踪.首先对水下视频目标对象和候选目标对象分别建立RGB颜色分布加权直方图模型,将这两个模型进行匹配,匹配度用Bhattacharrya系数来表示,搜索出与目标最匹配的候选目标并且更新目标模型,依此类推,从而在视频序列中实现目标跟踪.仿真实验证明,基于均值漂移算法的目标跟踪能够克服水下视频环境中干扰运动目标跟踪的因素:水波、倒影、气泡、游泳池浮标的遮挡等,进一步与基于Kalman滤波器的水下目标跟踪相比(对比),目标跟踪结果表明本文所用的算法能够对水下这种复杂背景的运动目标进行稳定实时的跟踪.     

基于自适应标签和稀疏学习相关滤波的红外目标跟踪算法研究

针对背景杂乱、遮挡、热交叉以及目标形变等复杂跟踪场景下目标跟踪算法出现性能严重退化问题,提出一种基于自适 应标签和稀疏学习相关滤波的实时红外单目标跟踪算法。 首先,根据目标响应情况自适应地构造样本标签,通过自适应标签训 练提升相关滤波器的分类能力,抑制干扰区域对跟踪模型的污染。 其次,加入稀疏学习策略,通过目标响应 L1 范数抑制复杂跟 踪场景下目标响应多峰分布,提高跟踪算法的鲁棒性;与基线算法相比,该算法精度和 AUC 分别提升了 19. 3% 和 39. 8% 。 在数 据集 GTOT、RGBT234 和 VOT-2016TIR 上的实验结果表明,该算法对上述复杂跟踪场景具有良好的应对能力,运行速度超过 35 fps,综合性能优于对比跟踪算法。     

Estimation of a Bottom Echo-Signal Level Reflected from a Plane Surface of a Cylindrical Article Using a Normal Probe Operating in a Pulsed Mode

The influence of the pulsed operating mode on a bottom echo-signal level reflected from a plane surface of a cylindrical article is studied during variations in the article's radius. It is shown that the pulsed character of a signal smoothens this function significantly as compared to that in the previously computed continuous mode. Numerical estimates of the bottom echo signal have been made for the ultrasonic inspection of wheel-pair axles of railway vehicles.     

Collision between a ring and a beam

With car–parapet collision accidents in mind, a normal collision between a free-flying half ring and a simply supported beam with/without axial constraints is studied, in which an elastic–plastic half ring with an attached mass and the elastic–plastic beam are taken as the simplest models of a car and a parapet, respectively. Particular attention is paid to the energy partitioning between the two structures and the evolution of the contact regions during collision. A mass–spring finite difference (MS–FD) model is employed whilst the large deflection and axial stretching/compression are incorporated. The numerical results show that the less stiff (i.e. softer) structure will dissipate more energy and the contact regions will move away from the initial contact points. With the increase of the relative thickness of the beam to the ring, the final deformation of the half ring will transform from a “U” shape to a “W” shape.     

Diagnostics of a cavity in a prismatic beam

A beam with a cross section in the form of a hollow rectangular box is considered. A method for calculation of the dimensions of a cavity in a beam by two natural bending frequencies that are taken from different spectra is proposed. These are the spectra of vibrations in two mutually perpendicular planes that are chosen in such a way that the neutral axis of the cross section is parallel to the sides in both cases. The dependence of the natural frequency on the cavity’s parameters is studied. It is proven that the frequency values of the beam under investigation and of an identical beam with a solid cross section do not coincide at any size of the cavity and the natural frequency values of the former beam are always higher than those of the latter one.     

Operation of a Dilution Refrigerator in a Micromode

Two design versions of a ³He-in-⁴He dilution refrigerator with ³He pumping out through its condensation on a cold wall are described: a classical refrigerator with a heat exchanger and a refrigerator with a collector that allows for operation in a quasi-single mode. The refrigerator operated stably in both cases when a power of 30 W was fed to the still, i.e., at a circulation rate of ³He of a few micromoles per second. In this case, the mixing chamber was cooled down to a temperature below 0.05 K.     

八关节三动杆蛇形机器人的运动模拟

蛇形机器人是一种高冗余度的机器人,由于其结构可变形,能够通过松软地面以及跨越(或避开)障碍物,能代替人完成某些危险场所如核电厂等维修及城市搜救.本文提出了一种类正弦波形的八关节三动杆蛇形机器人结构,做了运动模拟并给出了结论,该蛇形机器人的研制成功为设计相关类型的机器人提供了参考.     

Imprinting a needle array on a polycarbonate substrate

A micro-needle array was fabricated on a polycarbonate (PC) substrate using an electroformed-Ni mold with a conical concave pattern. The diameter and length of each needle were 50 μm and 135 μm, respectively. The needle array pattern of the electroformed-Ni mold was produced by combining a grayscale mask for X-ray lithography with Ni electroforming technology. The X-ray grayscale mask was composed of Si absorbers and a SU-8 membrane. Each Si absorber had a three-dimensional cone shape rather than a rectangular shape. Threedimensional Si structures were formed to etch an active Si layer in a silicon-on-insulator wafer using a taperedtrench etching technology. Beamline BL-4 in the TERAS synchrotron radiation facility at AIST was used for the Xray lithography experiments. X-rays that penetrated the X-ray grayscale mask irradiated a polymethylmethacrylate (PMMA) sheet. Pt was deposited on the PMMA structure after developing, and Ni was electroformed on it. The electroformed-Ni object was processed by grinding to complete a Ni mold. Finally, the micro-needle array was fabricated by thermal-imprinting on a 0.5-mm thick PC sheet with the electroformed Ni mold.     

集散控制系统在啤酒厂糖化车间的应用

本文简介了工控组态软件 T350 0、欧陆下位机的特点 ,给出了一个在啤酒厂糖化车间应用的实例。     

Solving a new mathematical model for a hybrid flow shop scheduling problem with a processor assignment by a genetic algorithm

This paper presents a new mathematical model for a hybrid flow shop scheduling problem with a processor assignment that minimizes makespan (i.e., C _max) and cost of assigning a number of processors to stages. In this problem, it is assumed that there are a number of parallel identical processors which are assigned to all of the stages with an unlimited intermediate storage between any two successive stages. To solve such a hard problem, first a new heuristic algorithm is proposed to compute the makespan that is embedded in the proposed genetic algorithm in order to find the best sequence of jobs, and then processors are assigned to the stages simultaneously. A number of test problems have been solved and related results are illustrated and analyzed.     

Laminar Flow in a Recess of a Hydrostatic Bearing

The flow in a recess of a hydrostatic journal bearing is studied in detail. The Navier-Stokes equations for the laminar flow of an incompressible liquid are solved numerically in a two-dimensional plane of a typical bearing recess. Pressure- and shear-induced flows, as well as a combination of these two flow conditions, are analyzed. Recess friction, pressure-ram effects at discontinuities in the flow region, and film entrance pressure loss effects are calculated. Entrance pressure loss coefficients over a forward-facing step are presented as functions of the mean flow Reynolds number for pure-pressure and shear-induced laminar flows.     

Analysis of a clutch damper using a discrete model

It is important to have a precise model for the clutch damper in order to simulate the entire powertrain of a vehicle and predict the responses of the system. In this research, we developed a new model in which the spring used in the clutch damper is divided into a finite number of elements. The model takes many unique properties of arc-shaped springs into consideration and is anticipated to be more precise than conventional simple models. With the model, two meaningful results were presented which can be utilized afterwards. One is a simulation concerning the peak torque transmitted via the clutch damper. The other is a simulation that shows the hysteretic characteristics of the clutch damper.