Neural Wave Representation in Early Vision

The neural wave representation which describes spatiotemporal information in early vision is proposed in terms of extended Gabor functions in this paper. Its reasonability, completeness and uncertainty in spatiotemporal domains and their frequency domains were investigated. The ranges of these parameters in this representation were estimated on electrophysiological and psychophysical data. We derived the partial differential equations which the neural wave satisfied. The general significance of 3D neural wave representation has been explored.     

基于无人机智能视觉的输电线路全息全景重建

针对当前重建方法不能精确展现输电线路实际情况的问题,提出基于无人机智能视觉的输电线路全息全景重建方法。通过分析输电线路全息全景重建原理,采用无人机智能视觉技术对输电线路进行拍照,对输电线路全息全景图像进行采集和特征提取等预处理,跟踪图像特征,引入立体匹配算法,实现输电线路全息全景的重构。实验结果表明,所提方法输电线路重建精度高,视觉效果与实际相符,更具实用性及可行性。     

Automatic Debye–Scherrer elliptical ring extraction via a computer vision approach

The accurate calibration of powder diffraction data acquired from area detectors using calibration standards is a crucial step in the data reduction process to attain high‐quality one‐dimensional patterns. A novel algorithm has been developed for extracting Debye–Scherrer rings automatically using an approach based on computer vision and pattern recognition techniques. The presented technique requires no human intervention and, unlike previous approaches, makes no restrictive assumptions on the diffraction setup and/or rings. It can detect complete rings as well as portions of them, and works on several types of diffraction images with various degrees of ring graininess, textured diffraction patterns and detector tilt with respect to the incoming beam.     

RGB pattern of images allows rapid and efficient prediction of antioxidant potential in Calycophyllum spruceanum barks

The use of fast and low-cost methods to optimize the total phenolic compounds (TPC) extraction has been gaining attention in ethnopharmacological research. Extraction conditions of the bioactive compounds from Calycophyllum spruceanum barks were established through multivariate regression models. In this sense, fractional factorial design (FFD) and central rotational composite design (CCRD) were developed using partial least squares regression (PLSR) combined with the information from the color images and spectrophotometry tools to evaluate the antioxidant activity from C. spruceanum barks. In fact, was possible to optimize the extraction of TPC with AA (ethanol 10% v/v, 1 h extraction time at 75 °C temperature). Besides, the precision and performance of generated models were established for the three response variables (TPC, AA by ABTS and FRAP methods) with R² above 0.98 in the PLSR and residual predictive value (RPD) above 3. Thus, the approaches suggested in this study, with emphasis on the use of image analysis, proved to be potential and promising as simple, fast, non-destructive methods for quantifying TPC and antioxidant activity in C. spruceanum barks.     

Online self-calibration for mobile vision based on laser imaging and computer algorithms

A self-calibration technique for mobile three-dimensional vision is presented. This technique determines the vision parameters during the vision task based on computer algorithms and image processing. The three-dimensional vision is performed by a Bezier network based on laser line projection. This network provides the data to perform the online self-calibration when the vision system is modified. Here, the changes of the extrinsic and intrinsic parameters are determined. The structure of the network is performed by the line shifting provided by the surface depth. From this structure, the data for the initial calibration and online self-calibration are deduced. In this manner, the calibrated references and physical measurements are avoided to perform the online self-calibration. Therefore, calibration limitations caused by online modifications are overcome to perform the mobile vision. Thus, the proposed self-calibration improves the accuracy and performance of the mobile vision. It is because online data of calibrated references are not passed to the vision system. This procedure represents a contribution in the field of the online recalibration, which is performed based on calibrated references. To elucidate this contribution, an evaluation is performed based on the self-calibration methods, which are reported in the recent years. Also, the time processing is described.     

A new method for circular grid analysis in the sheet metal forming test

Computer vision systems are employed to determine the major and minor lengths of deformed elliptic grids while determining a sheet metal's workability. The existing method identifies the ellipse using the least squares analysis. It suffers two drawbacks: assumptions in direct conflict with the observed real-world processes and an undesirable property of orientation dependence. For the remedy, this paper presents a new method that, in addition to achieving the desired property of orientation invariance, discards assumptions that conflict with real-world processes. The proposed method is implemented and tested using simulated and real-world data. Results are reported and compared with those obtained by the existing method.     

太阳能帆板平面度测量系统中光斑图像处理方法研究

太阳能帆板的平面度测量是卫星生产制造过程中的一个关键技术，现有的测量方法存在着精度差，效率低的问题。该文在基于实际工程课题的太阳能帆板平面度测量系统基础上，针对测量系统中光斑图像处理这一关键技术进行了详细的研究。对现有测量方法进行了比较与分析，介绍了测量系统的基本原理、图像采集系统设计过程中采取的主要措施、图像处理的具体方法与步骤和测量系统的基本组成。提出了一种新的快速滤波算法和光斑图像能量中心求取算法，大大提高了光斑图像能量中心的求取精度和实时性，提高了太阳能帆板平面度的测量精度。给出了光斑图像处理结果、静态测量重复性误差以及实际帆板的测量结果与分析，实验结果证明所采用的光斑图像处理方法可以满足对实际帆板测量精度的要求。     

论化学学科在世界一流大学建设中的作用*

化学是世界科学发展史上的中心科学,是人类探索未知世界的基本手段,是人类的核心素养和知识体系中必不可少的组成部分。化学学科推动了人类文明进程和科学的形成演化,在世界一流大学形成进程中发挥了至关重要的作用。在新一轮科技革命和高等教育新工科建设的背景下,化学将继续发挥四大基础科学的支柱作用,因此在建设世界一流大学的过程中应不断加强和完善化学学科建设和人才培养体系。世界高等教育的发展证明:一流大学必须有强大的化学学科,能够提供一流的化学相关课程和培养体系,这对人才培养质量起着至关重要的作用。世界一流大学建设中,无论出现什么样的新趋势、新理念,无论评价导向如何变化,化学为基础科学和中心科学的地位不容撼动,在人才培养质量中的核心课程地位不容撼动。     

一种改进的微光夜视系统视距探测方程

视距是评估微光夜视成像系统性能的一个重要参数。随着微光夜视探测技术的发展,经典视距模型的视距仿真结果与实测结果出现了一些偏差,特别是在10-3 lx低照度条件下视距仿真结果不甚理想,这对微光夜视仪在实际应用中造成了很大的阻碍。针对这一问题,从微光成像系统成像链路的三个环节对经典视距模型进行修正：考虑大气透过率对微光夜视系统视距的影响并对经典视距模型中的大气透过率因子进行修正;基于像增强器噪声因子对视距模型进行修正;考虑人眼视觉传递特性对微光夜视系统视距的影响,在系统的传递函数模型中加入了简化的人眼视觉模型。进而推导出改进的视距模型。结合野外试验数据,验证了改进视距模型的有效性和实用性,这对于微光夜视系统的设计、评估和应用具有一定的指导性意义。     

基于DETR的道路环境下双目测量系统

DETR(detection transformer)算法是一个基于Transformer的目标检测算法,具有检测速度快、检测效果好的优势。介绍了一种利用DETR算法及双目视觉原理对道路环境下的人、车、自行车、信号灯等目标进行构建的测量系统。分析了双目测距、相机标定、目标检测以及目标匹配的原理,并以此为基础构建了测量系统。采用目标检测算法检测视野中的目标,利用双目视觉原理对检测到的目标进行测距,同时分析了测量系统中测量误差的来源,并计算其对结果的影响。该算法在KITTI数据集及现实环境中进行测试,测量系统基线为45 cm,对15 m～80 m的指定目标检出率高于90.6%,测距误差小于5.8%,在RTX 2080Ti平台上能够实时运行。