Coal rock image recognition method based on improved CLBP and receptive field theory

Rapid coal-rock identification is one of the key technologies for intelligent and unmanned coal mining.Currently,the existing image recognition algorithms cannot satisfy practical needs in terms of recognition speed and accuracy.In view of the evident differences between coal and rock in visual attributes such as color,gloss and texture,the complete local binary pattern(CLBP)image feature descriptor is introduced for coal and rock image recognition.Given that the original algorithm oversimplifies local texture features by ignoring imaging information from higher-order pixels and the concave and convex areas between adjacent sampling points,this paper proposes a higher-order differential median CLBP image feature descriptor to replace the original CLBP center pixel gray with a local gray median,and replace the binary differential with a second-order differential.Meanwhile,for the high dimensionality of CLBP descriptor histogram and feature redundancy,deep learning perceptual field theory is introduced to realize data nonlinear dimensionality reduction and deep feature extraction.With relevant experiments conducted,the following conclusion can be drawn:(1)Compared with that of the original CLBP,the recognition accuracy of the improved CLBP algorithm is greatly improved and finally stabilized above 94.3%under strong noise interference;(2)Compared with that of the original CLBP model,the single image recognition time of the coal rock image recognition model fusing the improved CLBP and the receptive field theory is 0.0035 s,a reduction of 71.0%;compared with the improved CLBP model(without the fusion of receptive field theory),it can shorten the recognition time by 97.0%,but the accuracy rate still maintains more than 98.5%.The method offers a valuable technical reference for the fields of mineral development and deep mining.

Detection of the movement direction by the cells with directional receptive fields in the primary visual cortex of the cat

The study was performed on neurons with direction selective (DS) receptive fields (RFs) in the primary visual cortex of the cat. Preferred directions (PDs) of these cells to a single light spot and a system of two identical light spots moving across the RF with a given angle between them were compared. Directional interactions appeared when the angles between the directions of the two moving spots were 30o or 60o. PD for 56% of the cells coincided with bisectors of these angles. These cells responded to a combination of the two moving stimuli as if only one stimulus moved in the RF in an intermediate direction. This direction coincided with PD of the DS neuron to a single spot. Also, the investigation revealed that DS neurons responded to stimuli moving at such angles as 180o (to preferred and opposite directions simultaneously). In the further experiment we investigated responses of the DS cells in the primary visual cortex of RF. The angle between the directions of the two moving spots was 60o. These cells responded to a combination of the two moving stimuli as if only one stimulus moved in RF in an intermediate direction. The more relative luminance of one of spots in pair was, the closer the intermediate direction approached to the direction of this spot).

Dynamic self-adaptive ANP algorithm and its application to electric field simulation of aluminum reduction cell

Region partition(RP) is the key technique to the finite element parallel computing(FEPC),and its performance has a decisive influence on the entire process of analysis and computation.The performance evaluation index of RP method for the three-dimensional finite element model(FEM) has been given.By taking the electric field of aluminum reduction cell(ARC) as the research object,the performance of two classical RP methods,which are Al-NASRA and NGUYEN partition(ANP) algorithm and the multi-level partition(MLP) method,has been analyzed and compared.The comparison results indicate a sound performance of ANP algorithm,but to large-scale models,the computing time of ANP algorithm increases notably.This is because the ANP algorithm determines only one node based on the minimum weight and just adds the elements connected to the node into the sub-region during each iteration.To obtain the satisfied speed and the precision,an improved dynamic self-adaptive ANP(DSA-ANP) algorithm has been proposed.With consideration of model scale,complexity and sub-RP stage,the improved algorithm adaptively determines the number of nodes and selects those nodes with small enough weight,and then dynamically adds these connected elements.The proposed algorithm has been applied to the finite element analysis(FEA) of the electric field simulation of ARC.Compared with the traditional ANP algorithm,the computational efficiency of the proposed algorithm has been shortened approximately from 260 s to 13 s.This proves the superiority of the improved algorithm on computing time performance.

采用感受野优化与渐进特征融合的图像超分辨率算法

针对现有基于深度学习的超分辨率方法存在参数冗余以及难以学习到全局上下文信息、重建图像高频特征能力欠佳的问题,提出一种基于感受野优化与渐进特征融合的超分辨率网络(RPSRnet),其在单幅图像重建方面实现了较高的性能。该网络采用像素注意力机制与大感受野卷积相结合的方式,设计两条渐进路径将输入表征为不同层次的特征抽象,增强网络捕获上下文信息的能力,同时减少了网络参数冗余。通过分层卷积和多重感受野分支,在保持轻量卷积的前提下,于分层的多路径上学习不同尺度的融合特征,增强网络重建边缘细节和复杂纹理特征的能力。实验结果表明:相比于先进算法,所提算法在基准测试集Set5上的峰值信噪比达到32.47 dB,在测试集Set14上达到28.81 dB,优于现有的先进算法,且网络参数更少,实现了9%的参数缩减,从而验证了算法的有效性。

CARFB:即插即用的目标检测模块

针对坐标注意力(CA)在水平和垂直方向特征的平均池化可能丢失目标显著特征,以及使用二维普通卷积对小目标特征学习不足的情况,提出了CARFB(coordinate attention and receptive field block)模块。该模块将CA的平均池化修改为平均+最大池化,以保留输入特征在水平和垂直方向的显著和细节信息;利用RFB具有不同大小感受野的优势,在水平和垂直方向分别使用RFB模块代替CA的融合特征统一卷积,以同时提取不同大小目标的特征;引入包含不同大小卷积核和步长的CBS模块,替换CA的二维普通卷积,进一步提取水平和垂直方向的特征,得到重新加权的输出特征。CARFB模块在水平和垂直方向保存目标位置信息,利用不同感受野提取不同大小目标的强辨别性特征,从而具有更强的特征学习能力。为了验证提出的即插即用模块CARFB的性能,将其嵌入ObjectBox目标检测框架,得到ObjectBox-CARFB模型;用CARFB模块替换RFBnet中的RFB模块,得到CARFBnet目标检测模型。MSCOCO数据集的实验测试表明,ObjectBox-CARFB模型的性能得到全面提升,尤其对小目标的检测性能提升突出;PASCALVOC和MSCOCO数据集的实验结果表明,CARFBnet300和CARFBnet512的目标检测能力分别优于原始RFBnet300和RFBnet512模型,并优于其他同系列对比模型。提出的CARFB模块具有更强的特征学习能力,对不同尺度目标均能取得较好的检测效果,特别是在小目标检测方面,效果提升显著。提出的CARFB模块可以嵌入到任何一个卷积神经网络,能保存更多的目标信息,具有更强的特征学习能力和更高的网络性能,对不同尺度目标均能取得较好的检测效果,尤其对小目标的检测效果提升显著。

Local field potentials,spiking activity,and receptive fields in human visual cortex

The concept of receptive field(RF) is central to sensory neuroscience. Neuronal RF properties have been substantially studied in animals,while those in humans remain nearly unexplored. Here, we measured neuronal RFs with intracranial local field potentials(LFPs) and spiking activity in human visual cortex(V1/V2/V3). We recorded LFPs via macro-contacts and discovered that RF sizes estimated from lowfrequency activity(LFA, 0.5–30 Hz) were larger than those estimated from low-gamma activity(LGA, 30–60 Hz) and high-gamma activity(HGA, 60–150 Hz). We then took a rare opportunity to record LFPs and spiking activity via microwires in V1 simultaneously. We found that RF sizes and temporal profiles measured from LGA and HGA closely matched those from spiking activity. In sum, this study reveals that spiking activity of neurons in human visual cortex could be well approximated by LGA and HGA in RF estimation and temporal profile measurement, implying the pivotal functions of LGA and HGA in early visual information processing.

2-D Current Field Numerical Simulation Integrating Yangtze Estuary with Hangzhou Bay

In this paper, integrating the Yangtze Estuary with the Hangzhou Bay, a 2-D velocity field model is established. In the model, fine self-adaptive grids are employed to adapt to the complicated coastal shape. The hydrodynamic equations satisfied by two contravariant components of velocity vector and surface elevation in non-orthogonal curvilinear coordinates are used. In each momentum equation the coefficients before the two partial derivatives of surface elevation with respect to variables of alternative direction coordinates have different orders of magnitude, i. e., the derivative with the larger coefficient may play a more important role than that with the smaller one. With this advantage, the ADI scheme can be easily employed. The hydrodynamic factors include tidal current, river runoff and wind-induced current. In terms of tidal current, seven main constituents in the area are considered in the open boundaries. The verifications of surface elevation process and current velocity process in the spring tide and in the neap tide show that the model can preferably reflect current fields in the area. Through the simulation of Lagrangian residual current fields in summer and in winter, the paths of the exchange of water and sediment between the Yangtze Estuary and the Hangzhou Bay are elementarily discussed.

Novel high-voltage self-adaptive power device based on interface charge＊

This paper presents a novel high-voltage lateral double diffused metal-oxide semiconductor （LDMOS） with self- adaptive interface charge （SAC） layer and its physical model of the vertical interface electric field. The SAC can be self-adaptive to collect high concentration dynamic inversion holes, which effectively enhance the electric field of dielectric buried layer （EI） and increase breakdown voltage （BV）. The BV and EI of SAC LDMOS increase to 612 V and 600 V/tim from 204 V and 90.7 V/ttm of the conventional silicon-on-insulator, respectively. Moreover, enhancement factors of r/which present the enhanced ability of interface charge on EI are defined and analysed.

基于双通路视觉系统的自适应轮廓检测模型

在轮廓检测领域,背景纹理的干扰容易造成轮廓提取不完整。针对这一问题,本文提出了一种基于双通路视觉系统的自适应轮廓检测模型。首先从皮层下通路的信息采集与评估过程出发,对图像整体的显著性进行评估,以此获得轮廓信息的可能性分布;然后采用自适应尺度的高斯导函数对经典视觉通路中感受野的动态特性进行模拟,加强了模型对轮廓细节的捕获;最后在外周抑制算法的基础上,结合像素的空间分布对所有边缘的稀疏性进行度量,更加准确地区分了轮廓和纹理边缘。实验结果表明,本文模型可以有效抑制背景纹理,提升轮廓连续性,具有较好的轮廓检测性能。

基于改进YOLOv5的遥感图像目标检测

目前目标检测技术虽然已经趋于成熟,但是对遥感图像的检测仍存在不少挑战。针对遥感图像的背景复杂、目标尺度差异大、目标方向任意等特点造成目标检测精度低下的问题,提出一种基于改进YOLOv5的遥感图像目标检测算法。首先,构建一种联合注意力的多尺度特征增强网络,充分融合高低层特征,使特征层具有语义信息的同时包含丰富的细节信息,并在融合过程中利用设计的特征聚焦模块帮助模型选择关键特征,抑制无关信息。其次,使用感受野模块(RFB)对融合后的特征图进行更新,扩大特征图的感受野,减少特征信息损失。最后,对目标增加旋转角度,并采用圆形平滑标签将回归问题转化成分类问题,提高遥感目标定位的准确性。在用于航拍图像目标检测的大规模数据集(DOTA)上的实验结果表明,与YOLOv5算法相比,所提算法的交并比(Io U)为0.5和0.5~0.95时的平均精度均值(m AP@0.5和m AP@0.5∶0.95)分别提高了7.3和3.3个百分点,能够明显提高复杂背景下遥感图像目标的检测精度,并改善对遥感目标的漏检和误检情况。

基于Transformer的多尺度遥感语义分割网络

为了提升遥感图像语义分割效果,本文针对分割目标类间方差小、类内方差大的特点,从全局上下文信息和多尺度语义特征2个关键点提出一种基于Transformer的多尺度遥感语义分割网络(muliti-scale Transformer network,MSTNet)。其由编码器和解码器2个部分组成,编码器包含基于Transformer改进的视觉注意网络(visual attention network,VAN)主干和基于空洞空间金字塔池化(atrous spatial pyramid pooling, ASPP)结构改进的多尺度语义特征提取模块(multi-scale semantic feature extraction module, MSFEM)。解码器采用轻量级多层感知器(multi-layer perception,MLP)配合编码器设计,充分分析所提取的包含全局上下文信息和多尺度表示的语义特征。MSTNet在2个高分辨率遥感语义分割数据集ISPRS Potsdam和LoveDA上进行验证,平均交并比(mIoU)分别达到79.50%和54.12%,平均F1-score(m F1)分别达到87.46%和69.34%,实验结果验证了本文所提方法有效提升了遥感图像语义分割的效果。

基于多尺度特征融合的绝缘子缺陷程度检测

针对绝缘子不同程度缺陷特征相似、像素信息少、不同程度缺陷检测效果不佳的问题,提出了一种基于多尺度特征融合的绝缘子缺陷程度检测网络(multi-scale feature fusion defect degree detection network,MFFD3Net)。该网络采用重构的ResNeSt50架构提高了对绝缘子缺陷程度数据集的特征提取能力。设计了基于反卷积的多尺度特征融合模块,丰富了不同尺寸特征图的表达能力,提高了对不同尺度目标的检测性能。同时,在输入检测模块的浅层特征图后增加多感受野的特征提取模块(receptive field block,RFB),使得更多绝缘子缺陷信息进入有效感受野,对最终特征图产生影响,提升不同程度绝缘子缺陷的检测精度。MFFD3Net在绝缘子缺陷程度数据集上的全类平均精度达到85.02%,其中绝缘子轻微破损与绝缘子轻微闪络小目标的检测精度分别为78.37%、79.98%,能够完成不同程度绝缘子缺陷的识别与定位。因此,该文提出的MFFD3Net对于完善电力系统故障预警、保障电网安全稳定运行具有重要意义。

基于改进YOLOv5s的面向自动驾驶场景的道路目标检测算法

在复杂道路场景中检测车辆、行人、自行车等目标时,存在因多尺度目标及部分遮挡易造成漏检及误检等情况,提出一种基于改进YOLOv5s的面向自动驾驶场景的道路目标检测算法。首先,利用深度可分离卷积替换部分普通卷积,减少模型的参数量以提升检测速度。其次,在特征融合网络中引入基于感受野模块(receptive field block,RFB)改进的RFB-s,通过模仿人类视觉感知,增强特征图的有效感受野区域,提高网络特征表达能力及对目标特征的可辨识性。最后,使用自适应空间特征融合(adaptively spatial feature fusion,ASFF)方式以提升PANet对多尺度特征融合的效果。实验结果表明,在PASCAL VOC数据集上,所提算法检测平均精度均值相较于YOLOv5s提高1.71个百分点,达到84.01%,在满足自动驾驶汽车实时性要求的前提下,在一定程度上减少目标检测时的误检及漏检情况,有效提升模型在复杂驾驶场景下的检测性能。

基于改进U^(2)-Net网络的金属涂层剥落与腐蚀图像分割方法

针对金属涂层缺陷图像分割中存在特征提取能力弱和分割精度低的问题,提出了一种改进的U^(2)-Net分割模型。首先,在U型残差块(RSU)中嵌入改进的增大感受野模块(receptive field block light,RFB_l),组成新的特征提取层,增强对细节特征的学习能力,解决了网络由于感受野受限造成分割精度低的问题;其次,在U^(2)-Net分割模型的解码阶段引入有效的边缘增强注意力机制(contour enhanced attention,CEA),抑制网络中的冗余特征,获取具有详细位置信息的特征注意力图,增强了边界与背景信息的差异性,从而达到更精确的分割效果。实验结果表明,该模型在两个金属涂层剥落与腐蚀数据集上的平均交并比、准确率、查准率、召回率和F_1-measure分别达到80.36%、96.29%、87.43%、84.61%和86.00%,相比于常用的SegNet、U-Net以及U^(2)-Net分割网络的性能都有较大提升。

基于改进SSD模型的柑橘叶片病害轻量化检测模型

针对当前目标检测算法存在模型占比大,对柑橘叶片病害检测速度较慢、精度较低等问题,提出了一种基于改进SSD(single shot multibox detector)的柑橘叶片病害轻量化检测方法。引入了轻量化卷积神经网络MobileNetV2作为SSD网络的骨架,以减小模型规模、提高检测速度。引入感受野模块(receptive field block,RFB)来扩大浅层特征感受野,以提高模型对小目标的检测效果。并引入CA(coordinate attention)注意力机制,以强化不同深度的特征信息,进一步提升柑橘叶片病害的识别精度。结果表明,与VGG16-SSD相比,改进模型(MR-CA-SSD)在柑橘叶片病害检测上平均精度均值(mAP)提升4.4百分点,模型占比减小52.3 MB,每秒检测帧数提升3.15。MR-CA-SSD综合性能也优于YOLOv4、CenterNet、Efficientnet-YoloV3等模型。该改进模型可实现对柑橘叶片病害的快速准确诊断,有助于对病害部位及时精准施药。

基于多元感受野与EResPANet的草莓病害检测算法研究

针对草莓病害图像在检测时存在背景复杂、目标小导致难以被精确检测的问题,本文提出一种基于多元感受野与EResPANet的草莓病害检测算法.首先,该算法使用多元感受野特征标定网络替换YOLOv7-Tiny的主干网络,抑制冗余信息,解决主干网络特征逐层提取时小目标病害丢失问题;最后,通过设计EResPANet网络,避免网络在深层特征提取时,目标信息被复杂背景干扰而导致无法检测的问题.实验结果表明,本文提出的方法相比YOLOv7-Tiny算法在mAP上提高了10.3%,证明本文算法可实现草莓各类病害的准确检测.

多病害并发复杂场景下的道路病害检测RGT-YOLOv7模型

随着我国公路网的不断扩展,道路病害检测已经成为道路养护与行车安全保障必不可少的组成部分,基于深度学习的道路病害检测已经成为该领域的研究热点.针对多种病害并发的复杂场景下道路病害识别精度不高、泛化能力不足的问题,提出了一种复杂场景下的道路病害检测模型RGT-YOLOv7(Receptive Ghost Triplet-YOLOv7).在主干网络部分引入三重注意力机制,提高病害特征在不同通道与空间的相关性,解决了特征提取效率不高的问题;将原有的全连接空间金字塔卷积模块替换为快速全连接空间金字塔卷积模块,并加入幻影卷积模块,提高冗余特征的使用率,将原有的冗余特征与新提取到的特征融合,得到包含不同尺度的特征信息;为了扩大模型感受野,在特征增强部分加入改进的感受野模块,利用不同尺寸的空洞卷积从不同方向对特征图进行提取,加强对横向和纵向特征的提取.实验结果表明,与YOLOv7相比,识别的平均正确率(mean average precision,mAP)和平衡F分数分别提升了6.9、3.9个百分点,尤其是对纵向裂缝危害识别的平均正确率提高了22.3个百分点,与Faster R-CNN、YOLOv5等模型相比也有良好的性能提升,表明RGT-YOLOv7是一种有效的复杂场景下的道路病害检测模型.

基于改进SwiftNet的堆场图像实时分割网络

在堆场环境下,实时图像语义分割可以提供直观的场景类别信息。为节约工控机等边缘设备的硬件资源以及为多源信息融合提供图像语义类别信息,提出一种轻量化的实时语义分割网络模型。首先提出基于空间注意力引导的上采样融合模块,通过引入空间注意力和残差注意力结构设计一种轻量化的解码器,在上采样过程中还原空间细节,抑制冗余信息,进而融合不同来源的特征图;其次提出一种轻量化的级联空洞空间金字塔模块,利用级联的空洞卷积单元增大网络感受野,有效提取多尺度特征;最后使用通道分离、通道混洗、通道池化等操作,降低多尺度聚合过程中的计算开销。在公开数据集Camvid上,该模型的平均交并比(MIoU)为70.1%,推理速度为146.3帧/s,分割精度和推理速度优于ENet、ICNet等模型,消融实验结果也证明了所提各模块的有效性;在实际堆场图像数据集上,该模型的MIoU为93.5%,推理速度为123.8帧/s,证明模型结构具有良好的泛化性能。

一种基于SAM-MSFF网络的低照度目标检测方法

由于低照度图像具有对比度低、细节丢失严重、噪声大等缺点,现有的目标检测算法对低照度图像的检测效果不理想.为此,本文提出一种结合空间感知注意力机制和多尺度特征融合(Spatial-aware Attention Mechanism and Multi-Scale Feature Fusion,SAM-MSFF)的低照度目标检测方法 .该方法首先通过多尺度交互内存金字塔融合多尺度特征,增强低照度图像特征中的有效信息,并设置内存向量存储样本的特征,捕获样本之间的潜在关联性;然后,引入空间感知注意力机制获取特征在空间域的长距离上下文信息和局部信息,从而增强低照度图像中的目标特征,抑制背景信息和噪声的干扰;最后,利用多感受野增强模块扩张特征的感受野,对具有不同感受野的特征进行分组重加权计算,使检测网络根据输入的多尺度信息自适应地调整感受野的大小.在ExDark数据集上进行实验,本文方法的平均精度(mean Average Precision,mAP)达到77.04%,比现有的主流目标检测方法提高2.6%~14.34%.

多感受野特征自适应融合及动态损失调整的初烤烟叶等级检测

初烤烟叶等级的快速准确检测对开发烟叶智能分级设备以促进农产品精细化管理有着重要意义。针对相似度较高但等级不同的初烤烟叶难以区分的问题,本文提出多感受野特征自适应融合及动态损失调整的初烤烟叶等级检测网络(Flue-cured Tobacco Leaf Grade Detection Network,FTGDNet)。首先,FTGDNet采用CSPNet作为特征提取主干网络,采用GhostNet作为辅助特征提取网络以增强模型的特征提取能力;其次,在主干网络末端嵌入显式视觉中心瓶颈模块(Explicit Visual Center Bottleneck module,EVCB)以实现全局特征信息与局部细节特征信息融合;然后,构建多感受野特征自适应融合模块(Multi-Receptive Field Feature Adaptive Fusion module,MRFA_d),利用注意力特征融合机制(Attention Feature Fusion,AFF)将不同感受野特征图进行自适应加权融合,在增强模型局部感受野的同时突出有效通道信息;最后,设计了一种新的定位损失函数(More Complete IoU Loss,MCIoU_Loss),结合预测框与真实框面积损失以解决在回归定位过程中二者宽高比相等且中心点重合时CIoU_Loss性能退化导致定位精度下降问题,此外,引入矩形相似度衰减系数在训练过程中对真实框与预测框的相似度判别项进行动态调整,加快模型拟合。实验结果表明,FTGDNet对十个等级的初烤烟叶的验证精度达到90.0%,测试精度达到87.4%,且推理时间仅为12.6 ms。相较于多种先进目标检测算法,FTGDNet具有更高的检测精度和更快的检测速度,可为高精度初烤烟叶等级检测提供关键技术支撑。