Modeling load distribution for rural photovoltaic grid areas using image recognition

Expanding photovoltaic(PV)resources in rural-grid areas is an essential means to augment the share of solar energy in the energy landscape,aligning with the“carbon peaking and carbon neutrality”objectives.However,rural power grids often lack digitalization;thus,the load distribution within these areas is not fully known.This hinders the calculation of the available PV capacity and deduction of node voltages.This study proposes a load-distribution modeling approach based on remote-sensing image recognition in pursuit of a scientific framework for developing distributed PV resources in rural grid areas.First,houses in remote-sensing images are accurately recognized using deep-learning techniques based on the YOLOv5 model.The distribution of the houses is then used to estimate the load distribution in the grid area.Next,equally spaced and clustered distribution models are used to adaptively determine the location of the nodes and load power in the distribution lines.Finally,by calculating the connectivity matrix of the nodes,a minimum spanning tree is extracted,the topology of the network is constructed,and the node parameters of the load-distribution model are calculated.The proposed scheme is implemented in a software package and its efficacy is demonstrated by analyzing typical remote-sensing images of rural grid areas.The results underscore the ability of the proposed approach to effectively discern the distribution-line structure and compute the node parameters,thereby offering vital support for determining PV access capability.

The deep spatiotemporal network with dual-flow fusion for video-oriented facial expression recognition

The video-oriented facial expression recognition has always been an important issue in emotion perception.At present,the key challenge in most existing methods is how to effectively extract robust features to characterize facial appearance and geometry changes caused by facial motions.On this basis,the video in this paper is divided into multiple segments,each of which is simultaneously described by optical flow and facial landmark trajectory.To deeply delve the emotional information of these two representations,we propose a Deep Spatiotemporal Network with Dual-flow Fusion(defined as DSN-DF),which highlights the region and strength of expressions by spatiotemporal appearance features and the speed of change by spatiotemporal geometry features.Finally,experiments are implemented on CKþand MMI datasets to demonstrate the superiority of the proposed method.

Human Gait Recognition Based on Sequential Deep Learning and Best Features Selection

Gait recognition is an active research area that uses a walking theme to identify the subject correctly.Human Gait Recognition(HGR)is performed without any cooperation from the individual.However,in practice,it remains a challenging task under diverse walking sequences due to the covariant factors such as normal walking and walking with wearing a coat.Researchers,over the years,have worked on successfully identifying subjects using different techniques,but there is still room for improvement in accuracy due to these covariant factors.This paper proposes an automated model-free framework for human gait recognition in this article.There are a few critical steps in the proposed method.Firstly,optical flow-based motion region esti-mation and dynamic coordinates-based cropping are performed.The second step involves training a fine-tuned pre-trained MobileNetV2 model on both original and optical flow cropped frames;the training has been conducted using static hyperparameters.The third step proposed a fusion technique known as normal distribution serially fusion.In the fourth step,a better optimization algorithm is applied to select the best features,which are then classified using a Bi-Layered neural network.Three publicly available datasets,CASIA A,CASIA B,and CASIA C,were used in the experimental process and obtained average accuracies of 99.6%,91.6%,and 95.02%,respectively.The proposed framework has achieved improved accuracy compared to the other methods.

Study on Local Optical Flow Method Based on YOLOv3 in Human Behavior Recognition

In the process of human behavior recognition, the traditional dense optical flow method has too many pixels and too much overhead, which limits the running speed. This paper proposed a method combing YOLOv3 (You Only Look Once v3) and local optical flow method. Based on the dense optical flow method, the optical flow modulus of the area where the human target is detected is calculated to reduce the amount of computation and save the cost in terms of time. And then, a threshold value is set to complete the human behavior identification. Through design algorithm, experimental verification and other steps, the walking, running and falling state of human body in real life indoor sports video was identified. Experimental results show that this algorithm is more advantageous for jogging behavior recognition.

Monitoring and Recognition of Debris Flow Infrasonic Signals

Low frequency infrasonic waves are emitted during the formation and movement of debris flows, which are detectable in a radius of several kilometers, thereby to serve as the precondition for their remote monitoring.However, false message often arises from the simple mechanics of alarms under the ambient noise interference.To improve the accuracy of infrasound monitoring for early-warning against debris flows, it is necessary to analyze the monitor information to identify in them the infrasonic signals characteristic of debris flows.Therefore, a large amount of debris flow infrasound and ambient noises have been collected from different sources for analysis to sum up their frequency spectra, sound pressures, waveforms, time duration and other correlated characteristics so as to specify the key characteristic parameters for different sound sources in completing the development of the recognition system of debris flow infrasonic signals for identifying their possible existence in the monitor signals.The recognition performance of the system has been verified by simulating tests and long-term in-situ monitoring of debris flows in Jiangjia Gully,Dongchuan, China to be of high accuracy and applicability.The recognition system can provide the local government and residents with accurate precautionary information about debris flows in preparation for disaster mitigation and minimizing the loss of life and property.

Recognition Method for Change Point of Traffic Flow Linear Regressions

Recognition method of traffic flow change point was put forward based on traffic flow theory and the statistical change point analysis of multiple linear regressions. The method was calibrated and tested with the field data of Liantong Road of Zibo city to verify the validity and the feasibility of the theory. The results show that change point method of multiple linear regression can make out the rule of quantitative changes in traffic flow more accurately than ordinary methods. So, the change point method can be applied to traffic information management system more effectively.

Multi Multi-Task Learning with Dynamic Splitting for Open Open-Set Wireless Signal Recognition

Open-set recognition(OSR)is a realistic problem in wireless signal recogni-tion,which means that during the inference phase there may appear unknown classes not seen in the training phase.The method of intra-class splitting(ICS)that splits samples of known classes to imitate unknown classes has achieved great performance.However,this approach relies too much on the predefined splitting ratio and may face huge performance degradation in new environment.In this paper,we train a multi-task learning(MTL)net-work based on the characteristics of wireless signals to improve the performance in new scenes.Besides,we provide a dynamic method to decide the splitting ratio per class to get more precise outer samples.To be specific,we make perturbations to the sample from the center of one class toward its adversarial direction and the change point of confidence scores during this process is used as the splitting threshold.We conduct several experi-ments on one wireless signal dataset collected at 2.4 GHz ISM band by LimeSDR and one open modulation recognition dataset,and the analytical results demonstrate the effective-ness of the proposed method.

PURP: A Scalable System for Predicting Short-Term Urban TrafficFlow Based on License Plate Recognition Data

Accurate and efficient urban traffic flow prediction can help drivers identify road traffic conditions in real-time,consequently helping them avoid congestion and accidents to a certain extent.However,the existing methods for real-time urban traffic flow prediction focus on improving the model prediction accuracy or efficiency while ignoring the training efficiency,which results in a prediction system that lacks the scalability to integrate real-time traffic flow into the training procedure.To conduct accurate and real-time urban traffic flow prediction while considering the latest historical data and avoiding time-consuming online retraining,herein,we propose a scalable system for Predicting short-term URban traffic flow in real-time based on license Plate recognition data(PURP).First,to ensure prediction accuracy,PURP constructs the spatio-temporal contexts of traffic flow prediction from License Plate Recognition(LPR)data as effective characteristics.Subsequently,to utilize the recent data without retraining the model online,PURP uses the nonparametric method k-Nearest Neighbor(namely KNN)as the prediction framework because the KNN can efficiently identify the top-k most similar spatio-temporal contexts and make predictions based on these contexts without time-consuming model retraining online.The experimental results show that PURP retains strong prediction efficiency as the prediction period increases.

Hidden Two-Stream Collaborative Learning Network for Action Recognition

The two-stream convolutional neural network exhibits excellent performance in the video action recognition.The crux of the matter is to use the frames already clipped by the videos and the optical flow images pre-extracted by the frames,to train a model each,and to finally integrate the outputs of the two models.Nevertheless,the reliance on the pre-extraction of the optical flow impedes the efficiency of action recognition,and the temporal and the spatial streams are just simply fused at the ends,with one stream failing and the other stream succeeding.We propose a novel hidden two-stream collaborative(HTSC)learning network that masks the steps of extracting the optical flow in the network and greatly speeds up the action recognition.Based on the two-stream method,the two-stream collaborative learning model captures the interaction of the temporal and spatial features to greatly enhance the accuracy of recognition.Our proposed method is highly capable of achieving the balance of efficiency and precision on large-scale video action recognition datasets.

Network Protocol Recognition Based on Convolutional Neural Network

How to correctly acquire the appropriate features is a primary problem in network protocol recognition field.Aiming to avoid the trouble of artificially extracting features in traditional methods and improve recognition accuracy,a network protocol recognition method based on Convolutional Neural Network(CNN)is proposed.The method utilizes deep learning technique,and it processes network flows automatically.Firstly,normalization is performed on the intercepted network flows and they are mapped into two-dimensional matrix which will be used as the input of CNN.Then,an improved classification model named Ptr CNN is built,which can automatically extract the appropriate features of network protocols.Finally,the classification model is trained to recognize the network protocols.The proposed approach is compared with several machine learning methods.Experimental results show that the tailored CNN can not only improve protocol recognition accuracy but also ensure the fast convergence of classification model and reduce the classification time.

A Statistical Framework for Real-Time Traffic Accident Recognition

Over the past decade, automatic traffic accident recognition has become a prominent objective in the area of machine vision and pattern recognition because of its immense application potential in developing autonomous Intelligent Transportation Systems (ITS). In this paper, we present a new framework toward a real-time automated recognition of traffic accident based on the Histogram of Flow Gradient (HFG) and statistical logistic regression analysis. First, optical flow is estimated and the HFG is constructed from video shots. Then vehicle patterns are clustered based on the HFG-features. By using logistic regression analysis to fit data to logistic curves, the classifier model is generated. Finally, the trajectory of the vehicle by which the accident was occasioned, is determined and recorded. The experimental results on real video sequences demonstrate the efficiency and the applicability of the framework and show it is of higher robustness and can comfortably provide latency guarantees to real-time surveillance and traffic monitoring applications.

泵站过流能力校核系统开发及应用

泵站长期运行阻力加大、出流能力减弱,影响城市排涝。基于Python编程语言和数字图像技术,开发了一套泵站过流能力校核评估系统,运用摄像机实时采集轴流泵电压表、电流表数据,同步采用超声波多普勒剖面仪、雷达水位计实时测量泵站出口流量和扬程。针对复杂流态、环境噪声干扰下流量数据偏差大的问题,建立了移动中值滤波法,并利用贝塞尔插值进行数据填充,有效提升了流量数据的准确性。实践应用于泵站出流能力校核,测得该泵站相同功率和相同扬程条件下出流能力均较理论值下降。

基于改进卷积神经网络的心理状态预警技术

针对传统问卷法难以真实反映被调查者心理状态的问题,基于光流法和卷积神经网络提出了一种微表情判断方法,并将其作为心理状态预警技术的核心模块。对于数据集中人脸数据离散的问题,该方法采用人眼权重法对图像进行预处理,且通过金字塔光流算法提取预处理图像序列的光流特征,再利用三维卷积神经网络对该特征加以训练。与传统算法相比,所提方法在减少模型训练参数与运算时间的同时还具有更优的学习能力。实验测试结果表明,该算法在CASME数据集上的微表情识别准确率为89.2%,F1值为0.6751,均优于其他对比方法。由此证明,该算法可实现对人脸微表情的准确识别,进而为学生心理状态预警提供客观的数据支撑。

航空发动机滑油回油管内的流型识别及含气率预测研究

发动机润滑系统回油管内油气两相介质的流动特性直接影响系统中回油泵及散热器的工作特性。为辨别回油管内油气两相流流型和建立含气率预测关系式,本文搭建了模拟轴承腔回油管流动的实验系统,并依据涡轴发动机回油量及油气比完成了700组不同工况的实验测试。实验空气与滑油流量范围分别为10~200 SL/min与6~37 L/min。本文对实验范围内的管内流型进行了判别,并修正了含气率的预测模型。首先对两种极限工况的压力信号的时序特征、概率密度函数和傅里叶变换进行分析,判定其流型为分层流和弹状流。将流型结果与Mandhane流型图进行对比,显示Mandhane流型图并不能准确预测回油管内的油气两相流流型。其次利用含气率经验关系式进行含气率预测,发现Massena预测模型预测的含气率与实验值更接近,预测结果更准确。分层流的含气率在50%以下,而弹状流的含气率在50%以上。最后根据流型对Nicklin经验关系式进行修正,得到分层流和弹状流对应的分布系数分别为0.848和0.919。

融合三维人脸动态信息和光流信息的人脸表情识别

人脸表情识别在静态图像上取得了卓越的成效,但这些方法应用于视频或图像序列时,准确度和鲁棒性往往会受到影响。传统的方法通常无法基于空间信息和光流信息进行人脸表情的识别,然而这些辅助识别信息都是二维信息,没有考虑到人脸的表情变化是一种三维的变化过程。为充分挖掘人脸表情识别的深层语义信息,提出了一种基于三维人脸动态信息和光流信息相结合的融合表情识别方法。该方法构建基于人脸深度图像、光流图像和RGB图像的多流卷积神经网络,通过融合3种模态的信息进行人脸表情识别。所提方法在CAER,RAVDESS数据集上进行了充分验证,实验结果表明,其在表情识别性能上优于目前的主流方法,证明了其有效性。

基于颜色和光流的多注意力机制微表情识别

针对光流法无法充分利用微表情面部颜色信息,导致识别准确率不高的问题,本文提出一种基于颜色和光流的多注意力双流网络方法。首先,提出以CIE Luv色差图的形式,初步提取人脸情感生理特征,弥补微表情光流特征的单一性和局限性;然后,将PAM模块和ECA block并行组合得到轻量化的双注意力模块,提取空间和通道关键特征;最后,设计一种交叉注意力机制以获取颜色和光流混合特征,将其与空间通道关键特征融合用于分类。本模型在实验中采用留一交叉验证法进行评估,在SAMM数据集上的准确率和F1分数分别达到69.18%和67.04%,在CASMEⅡ数据集上的准确率和F1分数分别达到72.38%和70.85%。实验结果均优于目前主流算法,进一步证明本文模型及其模块在识别微表情方面的有效性。

基于RBF的油气水段塞流流型超声识别方法

石油管道内的多相流流型识别主要集中在气液两相流和油水两相流方向且准确识别流型范围有限,为了解决油气水段塞流流型识别问题,本文提出一种基于RBF神经网络和超声传播规律的油气水段塞流流型识别方法。根据油气水段塞流的相分布特点,建立了流型识别超声测试仿真模型。采用超声透射衰减技术和反射回波技术研究水平管道油气水三相段塞流超声响应特性,提取透射衰减信号区分段塞流液膜区、气泡夹带区和稳定液塞区。利用反射信号时间序列数据中的回波能量等统计特征,通过RBF神经网络对油气水段塞流进行流型识别。结果表明,基于超声传播机理以及RBF神经网络三相段塞流流型识别率为95.7%。基于RBF神经网络的流型识别算法研究为超声技术实现水平管油气水段塞流流型识别提供了理论基础。

基于改进AlexNet网络的泥石流次声信号识别方法

环境干扰噪声是泥石流次声现场监测的主要挑战,极大限制了泥石流次声信号识别的准确率。鉴于深度学习在声学信号识别中的优异表现,本文提出一种基于改进的AlexNet网络的泥石流次声信号识别方法,有效提升泥石流次声信号识别准确率和收敛速度。首先对原始次声数据集进行数据扩充、滤波降噪等预处理,并利用小波变换生成时频谱图像,然后将得到的时频谱图像作为输入,通过减小卷积核、引入批量归一化层和选择Adam优化算法搭建改进的AlexNet网络模型。实验结果表明,改进的AlexNet网络模型识别准确率为91.48%,实现了泥石流次声信号的智能识别,可为泥石流次声监测预警提供高效、可靠的技术支撑。

面向摄像头视频监控的泥石流发生场景智能识别方法

摄像头视频监控在泥石流防灾减灾中的应用较为广泛,但现有的视频检测技术功能有限,无法自动判断出泥石流灾害事件的发生。针对这一问题,本文基于迁移学习策略,改进一种基于卷积神经网络的视频分类方法。首先,借助TSN模型框架,将底层网络架构更改为ResNet-50,用于运动特征提取和泥石流场景识别。然后,通过ImageNet和Kinet-ics-400数据集预训练该模型,使模型具备较强的泛化能力。最后,结合经过预处理的地质灾害视频数据集对模型进行训练和微调,使其能够精准地识别出泥石流事件。通过大量的运动场景视频对该模型进行检验,实验结果表明,该方法对泥石流运动场景视频的识别准确率可达87.73%。因此,本文的研究成果可充分发挥视频监控在泥石流监测预警中的作用。