Machine Vision Based Measurement of Dynamic Contact Angles in Microchannel Flows

When characterizing flows in miniaturized channels, the determination of the dynamic contact angle is important. By measuring the dynamic contact angle, the flow properties of the flowing liquid and the effect of material properties on the flow can be characterized. A machine vision based system to measure the contact angle of front or rear menisci of a moving liquid plug is described in this article. In this research, transparent flow channels fabricated on thermoplastic polymer and sealed with an adhesive tape are used. The transparency of the channels enables image based monitoring and measurement of flow variables, including the dynamic contact angle. It is shown that the dynamic angle can be measured from a liquid flow in a channel using the image based measurement system. An image processing algorithm has been developed in a MATLAB environment. Images are taken using a CCD camera and the channels are illuminated using a custom made ring light. Two fitting methods, a circle and two parabolas, are experimented and the results are compared in the measurement of the dynamic contact angles.

Research on the Development of Chinese Contemporary Literature Trend under the Language and Culture Angle of View

In this paper, we conduct research on the development of Chinese contemporary literature trend under the language and cultureangle of view. Modern Chinese literature “unifi cation”, actually is to point to in traditional forming process, the new literature has alwaysemphasized performance to distinguish it from the old literary value connotation of thoughts, emotional content. Generalization of the contentfor later generations have don’t have much room for doubt, literary revolution advocates some extent is also the founder of Chinese modernliterature “unifi ed” have made clear, they are not only from the modern Chinese literature to argue that the traditional sense. For dealing withthis basic issue, we propose the countermeasures for the further and in-depth implementation that will then optimize the current research result onthe Chinese contemporary literature.

Automated Angle Detection for Industrial Production Lines Using Combined Image Processing Techniques

Angle detection is a crucial aspect of industrial automation,ensuring precise alignment and orientation ofcomponents in manufacturing processes.Despite the widespread application of computer vision in industrialsettings,angle detection remains an underexplored domain,with limited integration into production lines.Thispaper addresses the need for automated angle detection in industrial environments by presenting a methodologythat eliminates training time and higher computation cost on Graphics Processing Unit(GPU)from machinelearning in computer vision(e.g.,Convolutional Neural Networks(CNN)).Our approach leverages advanced imageprocessing techniques and a strategic combination of algorithms,including contour selection,circle regression,polar warp transformation,and outlier detection,to provide an adaptive solution for angle detection.By configuringthe algorithm with a diverse dataset and evaluating its performance across various objects,we demonstrate itsefficacy in achieving reliable results,with an average error of only 0.5 degrees.Notably,this error margin is 3.274times lower than the acceptable threshold.Our study highlights the importance of accurate angle detection inindustrial settings and showcases the reliability of our algorithm in accurately determining angles,thus contributingto improved manufacturing processes.

The Objective Measure of Color Vision in Primary Open Angle Glaucoma

Purpose: To objectively evaluate the clinical application of color pattern reversal visual e-voked potential (CPR-VEP) on primary open angle glaucoma (POAG). Methods: CPR-VEP and FM 100-hue test were performed in 31 eyes with POAG and 33 normal eyes. Color pattern stimulation was presented by color monitor controlled by computer program. The reversal rate of the stimulating pattern was 2 Hz and the spatial frequency of the stimulating was 0.53 cycle/degree. The color stimulating pattern include White /Black , Red/Black , Green/Black , Blue/Black , Yellow /Black , Red/Green and Blue /Yellow . Results : CPR-VEP P1 latencies were obviously prolonged in POAG group in comparison with normal control group in equiluminance. All CPR-VEP P1 amplitudes, except Blue/Black P1 amplitude, show no differences between POAG group and normal control group . Conclusion: P1 latencies of all CPR-VEP and P1 amplitude of Blue/Black CPR-VEP were parameters for identifing acquired dyschromatopsia caused by POAG. The results

Design of Omni-Directional Tilt Sensor Based on Machine Vision

This paper presents a new Omni-Directional Tilt Sensor (ODTS), which consists of the LED light, transparent cone-shaped closed container, mercury, camera, embedded systems and so on. The volume of the mercury in the container is equal to half of the container’s. When the detected surface is horizontal, the shape of mercury in the image captured by the camera is a black disc since the mercury is lightproof. When the detected surface tilts, the mercury flows and the mercury surface always maintains horizontally due to the gravity force of the earth. At this time, some area of the transparent cone-shaped closed container is not shaded by mercury and the border of the mercury’s shape in the captured image is a half circle and a half ellipse. Thus there is a translucent crescent-shaped area in the image. With analyzing this area by the specific algorithm based on machine vision, the tilt angle and directional angle can be obtained. The experimental results show that the ODTS proposed has some advantages, such as simple maintenance, high precision, wide range, low cost, real-time, reliability and high visualization.

Measurement of bullet impact conditions using automated in-flight photography system

Knowledge of impact conditions is critical to evaluating the terminal impact performance of a projectile.For a small caliber bullet,in-flight velocity has been precisely measured for decades using detection screens,but accurately quantifying the orientation of the bullet on a target has been more challenging.This report introduces the Automated Small-Arms Photogrammetry(ASAP)analysis method used to measure,model,and predict the orientation of a small caliber bullet before reaching an impact surface.ASAP uses advanced hardware developed by Sydor Technologies to record a series of infrared digital photographs.Individual images(four orthogonal pairs)are processed using computer vision algorithms to quantify the orientation of the projectile and re-project its precise position and orientation into a three-dimensional muzzle-fixed coordinate system.An epicyclic motion model is fit to the measured data,and the epicyclic motion is extrapolated to the target location.Analysis results are fairly immediate and may be reviewed during testing.Prove-out demonstrations have shown that the impact-angle prediction capability is less than six hundredths of a degree for the 5.56 mm ball round tested.Keywords:Yaw,Terminal ballistics,Exterior ballistics,Test&evaluation,Computer vision,Image processing,Angle of

Rehabilitation of vision disorder and improved quality of life in patients with primary open angle glaucoma

Background Primary open angle glaucoma （POAG） is a common cause of irreversible blindness. The variable etiology of POAG poses significant challenges for treatment and rehabilitation. We analyzed a large POAG patient cohort during treatment to reveal possible causes of vision disorder, assess vision-related quality of life （VRQL）, and to evaluate the efficacy of rehabilitative treatments. Methods We analyzed the visional disturbances in 500 POAG patients （890 eyes） by regular ophthalmic examination and visual field examination using Humphrey 30-o perimetry. Appropriate rehabilitative treatments for POAG were prescribed based on results of clinical examination and included correction of ametropia, health education, counseling, and the fitting of typoscopes. VRQL was assessed before and after treatment by a VRQL self-assessment questionnaire. Results Scores on the VRQL self-assessment were significantly lower compared to healthy controls. The primary cause of the vision disturbances was ametropia （97.99%）, and 51.61% of the ametropia eyes had not received appropriate correction. The secondary causes of visual impairment were glaucomatous neurodegeneration （26.29%）, complicated cataract, or other accompanying eye diseases. The causes of the clinical low vision （44 patients） were glaucomatous neurodegeneration （32 eyes）, fundus diseases （23 eyes）, keratopathy （11 eyes）, and other eye diseases （10 eyes）. The VRQL scores of patients improved significantly after rehabilitation and the correction of ametropia （P 〈0.01）. Twenty-five patients with low vision were provided with typoscopes, and 21 （84%） experienced significant functional recovery, while the remaining low vision patients could see letter lines two or more levels lower （smaller） on visual charts in a near vision test. Conclusions Vision disorders in POAG patients are common and severe. Appropriate rehabilitation, especially the correction of ametropia, can significantly improve VRQL as revealed by the self-assessment of POAG patients.

Acupuncture analgesia and the direction,angle and depth of needle insertion

Literatures on acupuncture analgesia of the recent 30 years are analyzed through the target pain syndromes, points and tools selected for needling as well as the chosen direction, angle and depth of insertion. The relationship between effect of acupuncture analgesia and needling direction, angle as well as depth is initially optimized to enhance the analgesic effect. The result shows that the 3 factors are the key influences. However, studies on the above mentioned relation are still far from enough. Aiming at enhancing the effect of acupuncture analgesia and exploring the relative mechanism, it is held that multivariate analysis should be adopted to do systematic analysis on relationship between effect and mechanism of acupuncture analgesia and direction, angle and depth of the needle insertion.

快速特征金字塔和Soft-Cascade在折角塞门图像故障检测中的应用

为了提升列车折角塞门的故障检测效率,提出了一种基于快速特征金字塔和Soft-Cascade的故障图像检测算法。首先,构建快速特征金字塔模型来提取图像多尺度聚合通道特征;其次,利用向量化后的多尺度聚合通道特征来训练Soft-Cascade故障分类器;最后,利用训练好的分类器来判断待检折角塞门是否含有故障。实验结果表明:该算法的故障检测正确率为97.33%,离线检测速度高达43fps(每张图像仅需23ms),检测效率高于其他算法。该算法训练时间短,检测速度快,硬件要求低,能满足列车折角塞门的故障检测要求。

基于未知地标被动观测的飞航导弹SINS俯仰姿态误差估计方法

针对飞航导弹单独使用时SINS存在姿态估计精度随时间降低的问题,提出了基于未知地标被动观测的SINS俯仰姿态误差估计方法。首先,根据飞航导弹中制导段飞行的特点,把SINS俯仰姿态误差估计问题转化为攻角估计问题。然后,在不改变导弹巡航路径的前提下,利用弹上成像导引头对视场内任意未知地标连续被动观测,分别提出了弹体坐标系和速度坐标系下的攻角估计方法,并分析了观测噪声对量测方程系数的影响。最后,利用平均去噪的思想对估计结果进行处理,提高了SINS俯仰姿态误差的估计精度。仿真结果表明:两种方法都能有效估计出飞航导弹SINS俯仰姿态量测误差。

基于扩展Kalman滤波的轨道线形检测研究

提出一种双目视觉与陀螺仪结合的数据融合模型来计算轨道空间线形参数、并利用扩展卡尔曼滤波算法对轨道空间线形参数进行优化的方案。减小因双目视觉系统受环境变化的影响及陀螺仪随时间的累积误差,提高融合模型对轨道空间线形参数的测量精度,利用Matlab仿真出轨道空间线形。并利用机械手臂进行相应的实验,实验结果表明:双目视觉与陀螺仪结合的数据融合可有效实现轨道线型的空间测量,测量坐标在X、Y、Z三个方向上的位移误差不超过0.381 mm,优于传统的惯性或者视觉检测精度,降低了计算复杂度,具有较好实用性。

基于改进Canny和异常轮廓点搜索的密封圈毛刺检测系统设计

为解决目前橡胶制品行业对O型密封圈人工检测效率低、精度低的问题,设计了一套基于机器视觉的毛刺缺陷检测系统,分为硬件系统和软件系统。针对密封圈尺寸规格繁多、微弱毛刺较难检测的特点,提出一种改进的Canny边缘检测来提高轮廓检测定位精度;提出一种基于切线倾斜角的异常轮廓点搜索定位算法,根据最小二乘法拟合圆识别到的外径自动设置最优的窗口模板和阈值;通过分析轮廓切线倾斜角的变化搜索定位可疑异常点,再经筛选得到真实毛刺点,最后根据毛刺点的最小外接矩形高度判定缺陷。结果表明,该检测系统能准确可靠地检测出外径尺寸范围为?6~?35mm密封圈毛刺缺陷,在实际工业应用中具有良好的可行性。

“热爱可抵岁月漫长”——我的世界文学之缘

众所周知,“世界文学”的定义自歌德以来便一直处于动态的讨论中。但作为一门专业,世界文学以其广阔的视野和多元的文学体系而备受推崇。它从文学入手,对人类、世界、文明等重要命题进行思考和探讨,体现了文学的“人学”本质,也凸显了其“世界性”的格局与视野。

基于深度学习的机理模型与数据混合驱动的视觉转角测量方法

为克服基于视觉的转角测量方法容易受到系统干扰的局限性,提出了一种基于深度学习的机理模型和数据混合驱动的视觉转角测量方法。从数学原理上验证了采用等腰三角形作为轴上花纹的合理性和有效性,构建三角花纹转角计算机理数学模型。引入基于YOLOv8的深度学习模型,采用线性组合将两者结合构建成混合转角测量模型。实验结果显示,这种混合模型在测量准度上有显著提升,相比仅用机理模型,其平均误差降低1.125°,均方根误差降低10.05°,在不同环境测试集上仍保持高效性能。该模型充分利用了深度学习模型对图像随机干扰的学习能力,同时保持了数学模型的约束和稳定性,提高了视觉角度测量的准确性,而且增强了其对环境变化以及系统干扰的适应性。

基于图像比对的螺纹牙形补偿量算法研究

为研究牙形失真对螺纹参数测量精度的影响,在分析现有螺纹牙形失真量计算方法的基础上,提出了一种基于机器视觉螺纹牙型角和中径的补偿量算法。将螺纹参数一致的没有螺旋升角的螺纹环槽与有螺旋升角的螺纹塞规图片进行比对,获取螺纹牙型角补偿量,再利用几何关系计算出相应螺纹牙的中径补偿量。经过研究发现,螺纹大径处螺旋升角相同的一系列螺纹产生的牙侧角误差基本一致,且随着螺旋升角的增大,牙侧角误差也随之增大。以螺纹塞规为对象进行对比实验,数据表明采用所提方法获得补偿后的牙型角平均值为59.999°和补偿后的中径平均值为18.290 mm与接触式螺纹综合测量仪所测牙型角平均值60.015°和中径平均值18.326 mm接近,且补偿后的牙型角方差7.76×10^(-5)与中径方差8.65×10^(-4)均小于综合测量仪所测牙型角方差3.38×10^(-3)和中径方差8.55×10^(-3)。结果表明,所提出的补偿算法可行。

异型结构多视角点云配准方法研究

针对异型结构全体积质量缺陷检测时需要可靠的结构外表面空间位置信息,提出一种高度还原异型结构真实三维场景的方法。该方法首先提取点云数据中的特征点后通过快速点特征直方图(fast point feature histograms,FPFH)描述特征点,接着采用随机采样一致性(random sample consensus,RANSAC)算法对点云进行粗配准,随后采用Iterative Closest Point算法进行精配准,来对采集到的点云数据进行拼接,最终得到完整异型结构承载件外表面点云数据;实验结果显示,所提出的算法和传统ICP配准算法比较精度提升了74.3%,与RANSAC+ICP配准方法提升了29.5%。优化后的算法在点云配准方面表现出很好的鲁棒性,为实际应用提供了极大的指导价值,能够显著提高点云配准的效率。

双矢量定姿在煤矿掘进机姿态测量中的应用

针对现有巷道掘进机的姿态测量手段中普遍存在的高成本和误差累积等问题,文中提出了一种基于双矢量定姿原理的姿态测量算法。通过在巷道掘进环境中分别对重力矢量和光矢量进行构建与感知,利用惯性倾角测量和双目视觉测量技术,基于矢量元素分别在导航坐标系和掘进机载体坐标系中的数学表达,可实现掘进机载体坐标系相对于巷道导航坐标系的姿态解算。利用倾斜仪和双目相机组成的测量装置对指示激光和重力矢量进行测量,结合双矢量定姿算法即可完成掘进机机身的姿态解算。文中设计了静态重复性精度测量实验,结果表明该方法的姿态角重复性测量精度为0.0662°。利用蒙特卡洛方法对可能会引入的误差源进行仿真分析,结果表明误差对方位角、俯仰角以及滚转角的影响分别为0.7864°、0.4548°和0.4765°。

倾斜角度飞机电传电位计自适应检测研究

现有的方法对倾斜角度拍摄的电传电位计图像的圆心坐标及凹槽角度检测存在较大的位置误差与角度误差,无法满足实际的使用需求。针对倾斜角度拍摄电传电位计时测量圆心坐标及凹槽角度偏移量较大的问题,提出倾斜角度飞机电传电位计自适应检测研究方法。通过图像预处理与边缘检测等方法初步得到飞机电传电位计的圆心及角度信息,提出圆心偏移矫正算法与角度偏移矫正算法对电传电位计圆心坐标及凹槽角度进行矫正,进一步提高电传电位计的检测精度。本检测算法与单应性检测算法作对比实验,结果表明:本算法对圆心距离误差最大为0.21 mm,凹槽弧度误差最大为0.72°。相比于单应性变换法在圆心平均误差下下降了0.09 mm,角度平均误差下降了0.38°,满足实际使用要求。

基于单目视觉实时测量桥式起重机负载摆角

针对目前基于视觉的桥式起重机负载摆角测量方法实时性较低,且没有考虑由运动模糊导致的测量精度下降问题,将一个对旋转和倾斜不敏感的球形标识物安装在负载上,设计一种计算灰度概率分布特征余弦相似度的方法,结合卡尔曼滤波器实时跟踪标识物。提出一种基于背景灰度值的局部自适应分割算法,使模糊边缘变清晰。从感兴趣区域(region of interest,ROI)的中心向周围8个方向寻找灰度梯度最大的点作为模糊图像的边缘点,对这些点采用最小二乘法进行拟合确定标识物位置。通过几何关系模型计算负载摆角。实验结果表明,本文方法在图像模糊情况下的测量精度和实时性能更优。

民间文献研究的新视域

民众在日常生活中使用的文字资料,包括族谱、碑刻、契约、账本、日记、书信、唱本、剧本、赋役文书、礼仪文书、诉讼文书、堪舆书、医药书等,是对民间生活的真实反映,也是中国传统文化的有机组成部分,相较于官方制书、正史以及文人文集,它们更具有民间性、草根性和真实性,对复原历史上的乡村民众生活有着无可替代的作用。基于田野调查的民间历史文献研究,能更准确地反映发生在中国大地的过往历史,反映普通百姓视角下的中国历史进程,基于此形成的经验总结、理论概括,有助于推进形成基于中国经验的学术话语体系。