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International Journal of Agricultural and Biological Engineering 2024年第1期17卷 49-58页

作者： Wenbo Wei Jianchang Li Jianjun Hao maohua xiao Huiju Zhang College of Mechanical and Electrical Engineering Hebei Agricultural UniversityBaoding 071001HebeiChina College of Engineering Nanjing Agricultural UniversityNanjing 210032China The Higher Educational Key Laboratory for Flexible Manufacturing Equipment Integration of Fujian Province Xiamen Institute of TechnologyXiamen 361000FujianChina

The behavior of oil sunflower seeds penetrating screen holes is an important factor that affects the screening performance of oil sunflower seeds.In this study,a double-deck reverse-motion vibrating screening device for oil sunflower seed screening was designed.The force condition and motion law of the oil sunflower seeds on the screen surface were analyzed.This study compared the effect of particle filling amount of discrete element model of oil sunflower seeds on the simulation effects.The screening process was numerically simulated using the coupled Discrete Element Method and Multibody Dynamics(DEM-MBD)technique with the screening percentage of oil sunflower seeds as the index.The influence of the operating parameters of the vibrating screen on the screening effect was analyzed using a multiparameter collaborative optimization scheme.The results of this study can provide a reference for the numerical simulation of crop screening behavior and the development of screening devices.

关键词： oil sunflower seeds screening analysis DEM-MBD discrete element method response surface analysis

CMAES-WFD:Adversarial Website Fingerprinting Defense Based on Covariance Matrix Adaptation Evolution Strategy

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Computers, Materials & Continua 2024年第5期79卷 2253-2276页

作者： Di Wang Yuefei Zhu Jinlong Fei maohua Guo School of Cyberspace Security Information Engineering UniversityZhengzhou450000China

Website fingerprinting,also known asWF,is a traffic analysis attack that enables local eavesdroppers to infer a user’s browsing destination,even when using the Tor anonymity network.While advanced attacks based on deep neural network(DNN)can performfeature engineering and attain accuracy rates of over 98%,research has demonstrated thatDNNis vulnerable to adversarial samples.As a result,many researchers have explored using adversarial samples as a defense mechanism against DNN-based WF attacks and have achieved considerable success.However,these methods suffer from high bandwidth overhead or require access to the target model,which is unrealistic.This paper proposes CMAES-WFD,a black-box WF defense based on adversarial samples.The process of generating adversarial examples is transformed into a constrained optimization problem solved by utilizing the Covariance Matrix Adaptation Evolution Strategy(CMAES)optimization algorithm.Perturbations are injected into the local parts of the original traffic to control bandwidth overhead.According to the experiment results,CMAES-WFD was able to significantly decrease the accuracy of Deep Fingerprinting(DF)and VarCnn to below 8.3%and the bandwidth overhead to a maximum of only 14.6%and 20.5%,respectively.Specially,for Automated Website Fingerprinting(AWF)with simple structure,CMAES-WFD reduced the classification accuracy to only 6.7%and the bandwidth overhead to less than 7.4%.Moreover,it was demonstrated that CMAES-WFD was robust against adversarial training to a certain extent.

关键词： Traffic analysis deep neural network adversarial sample Tor website fingerprinting

Small-scale fire tests in the underwater tunnel section model with new sidewall smoke extraction

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Deep Underground Science and Engineering 2024年第2期3卷 247-254页

作者： Shunyu Yue Ruifeng Miao Huihang Cheng maohua Zhong Xiujun Yang Department of Engineering Physics Institute of Public Safety ResearchTsinghua UniversityBeijingChina Shanxi Province Expressway Group Limited Liability Company Shanxi Expressway Group Shuoshen Co. LtdShuozhouChina Research Institute of Highway Ministry of Transport RIOH Transport ConsultantsLtdBeijingChina

The Shenzhen–Zhongshan Bridge is a 24‐km‐long bridge and tunnel system,including a 6.8-km-long super cross section subsea tunnel.To solve the smoke exhaust problem of a super large cross-section subsea tunnel,the tunnel has a new smoke exhaust system that combines a horizontal smoke exhaust cross section at the top and sidewall smoke exhaust holes.In order to evaluate the potential fire hazards of this type of tunnel,a 1:30 tunnel model was established and 140 smallscale experiments on underwater tunnel fires were conducted.By changing the fire power,fire location,and fan operation mode,different scenarios of submarine immersed tunnel fire were simulated and the related key parameters such as fire smoke diffusion behavior and smoke temperature distribution were studied.On this basis,the optimal smoke control strategy was proposed for different fire scenarios.The research results indicate that the new smoke exhaust system can fully utilize the smoke flow characteristics,significantly improve smoke exhaust efficiency,and increase available evacuation time,thus further enhancing the fire safety of super large cross-section subsea tunnels.

关键词： sidewall smoke extraction system small‐scale fire tests smoke control

Dynamic simulation of the tractor HMCVT under typical working conditions based on AMESim

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International Journal of Agricultural and Biological Engineering 2022年第2期15卷 102-110页

作者： maohua xiao Yuanfang Zhao Xianhua Li Ghulam Hussain Shengjie Wang Yejun Zhu College of Engineering Nanjing Agricultural UniversityNanjing 210031China Key Laboratory of Modern Manufacturing Technology Guizhou UniversityGuiyang 550025China Faculty of Mechanical Engineering Ghulam Ishaq Khan Institute of Engineering Sciences&TechnologyTopi23460Pakistan Jiangsu Yueda Intelligent Agricultural Equipment Co. Ltd.Yancheng 224004JiangsuChina

In order to study the dynamic characteristics of hydro-mechanical continuously variable transmission(HMCVT)under ploughing and sowing conditions,a complete simulation model of HMCVT is established based on AMESim software,including mechanical transmission model,pump controlled hydraulic motor speed control model and section changing hydraulic system model.In addition,the dynamic model of tractor is established.In order to verify the correctness of the simulation model,a test-bed is established.The test of tractor running speed and the test of pump controlled hydraulic motor system were carried out on the test-bed.The test results show that the simulation model of pump control hydraulic system can correctly reflect the change of transmission ratio of pump controlled hydraulic motor,and the simulation model can reflect the actual working condition change of clutch.Thus,the correctness of the previous simulation model based on AMESim is verified.Based on the simulation model established by AMESim,the dynamic characteristics of HMCVT under ploughing and sowing conditions are studied.The results show that:Under ploughing condition,the planetary platoon will have strong impact at the moment of throttle opening and changing section.Under sowing condition,the HMCVT will have a great impact at the time of variable cross section,but the variation range of rodent force decreases and the changing trend tends to be stable.

关键词： tractor HMCVT AMESim dynamics simulation test

Design and experiment of fuzzy-PID based tillage depth control system for a self-propelled electric tiller

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International Journal of Agricultural and Biological Engineering 2023年第4期16卷 116-125页

作者： maohua xiao Ye Ma Chen Wang Junyun Chen Yejun Zhu Petr Bartos Guosheng Geng College of Engineering Nanjing Agricultural UniversityNanjing 210031China Faculty of Agriculture University of South BohemiaStudentska 1668Czech

The research on the self-propelled electric tiller is vital for further improving the quality and efficiency of greenhouse rotary tillage operation,reducing the work intensity and operation risk of operators,and achieving environmentally friendly characteristics.Most of the existing self-propelled tillers rely on manual adjustment of the tillage depth.Moreover,the consistency and stability of the tillage depth are difficult to guarantee.In this study,the automatic control method of tillage depth of a self-propelled electric tiller is investigated.A method of applying the fuzzy PID(Proportional Integral Derivative)control method to the tillage depth adjustment system of a tiller is also proposed to realize automatic control.The system uses the real-time detection of the resistance sensor and angle sensor.The controller runs the electronically controlled hydraulic system to adjust the force and position comprehensively.The fuzzy control algorithm is used in the operation error control to realize the double-parameter control of the tillage depth.The simulation and experimental verification of the system are conducted.Results show that the control system applying fuzzy PID can improve the soil breaking rate by 3%in the operation process based on reducing the stability variation of tillage depth by 24%.The control strategy can reach the set value of tillage depth quickly and accurately.It can also meet the requirement of tillage depth consistency during the operation.

关键词： Fuzzy PID Self-propelled electric tiller Tillage depth Electro-controlled hydraulic system Comprehensive adjustment of force and position

Novel multiple object tracking method for yellow feather broilers in a flat breeding chamber based on improved YOLOv3 and deep SORT

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International Journal of Agricultural and Biological Engineering 2023年第5期16卷 44-55页

作者： Xiuguo Zou Zhengling Yin Yuhua Li Fei Gong Yungang Bai Zhonghao Zhao Wentian Zhang Yan Qian maohua xiao College of Artificial Intelligence Nanjing Agricultural UniversityNanjing 210095China College of Engineering Nanjing Agricultural UniversityNanjing 210095China Faculty of Engineering and Information Technology University of Technology SydneySydneyNSW 2007Australia

Aiming at the difficulties of the health status recognition of yellow feather broilers in large-scale broiler farms and the low recognition rate of current models,a novel method based on machine vision to achieve precise tracking of multiple broilers was proposed in this paper.Broilers’behavior in the breeding environment can be tracked to analyze their behaviors and health status further.An improved YOLOv3(You Only Look Once v3)algorithm was used as the detector of the Deep SORT(Simple Online and Realtime Tracking)algorithm to realize the multiple object tracking of yellow feather broilers in the flat breeding chamber,which replaced the backbone of YOLOv3 with MobileNetV2 to improve the inference speed of the detection module.The DRSN(Deep Residual Shrinkage Network)was integrated with MobileNetV2 to enhance the feature extraction capability of the network.Moreover,in view of the slight change in the individual size of the yellow feather broiler,the feature fusion network was also redesigned by combining it with the attention mechanism to enable the adaptive learning of the objects’multi-scale features.Compared with traditional YOLOv3,improved YOLOv3 achieves 93.2%mAP(mean Average Precision)and 29 fps(frames per second),representing high-precision real-time detection performance.Furthermore,while the MOTA(Multiple Object Tracking Accuracy)increases from 51%to 54%,the IDSW(Identity Switch)decreases by 62.2%compared with traditional YOLOv3-based objective detectors.The proposed algorithm can provide a technical reference for analyzing the behavioral perception and health status of broilers in the flat breeding environment.

关键词： yellow feather broiler flat breeding chamber multiple object tracking improved YOLOv3 Deep SORT

Fault Diagnosis Based on BP Neural Network Optimized by Beetle Algorithm

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Chinese Journal of Mechanical Engineering 2021年第6期34卷 252-261页

作者： maohua xiao Wei Zhang Kai Wen Yue Zhu Yilidaer Yiliyasi College of Engineering Nanjing Agricultural UniversityNanjing210031China College of Mechanical and Electrical Engineering Xinjiang Agricultural UniversityUrumqi830052China

In the process of Wavelet Analysis,only the low-frequency signals are re-decomposed,and the high-frequency signals are no longer decomposed,resulting in a decrease in frequency resolution with increasing frequency.Therefore,in this paper,firstly,Wavelet Packet Decomposition is used for feature extraction of vibration signals,which makes up for the shortcomings of Wavelet Analysis in extracting fault features of nonlinear vibration signals,and different energy values in different frequency bands are obtained by Wavelet Packet Decomposition.The features are visualized by the K-Means clustering method,and the results show that the extracted energy features can accurately distinguish the different states of the bearing.Then a fault diagnosis model based on BP Neural Network optimized by Beetle Algo-rithm is proposed to identify the bearing faults.Compared with the Particle Swarm Algorithm,Beetle Algorithm can quickly find the error extreme value,which greatly reduces the training time of the model.At last,two experiments are conducted,which show that the accuracy of the model can reach more than 95%,and the model has a certain anti-interference ability.

关键词： Rolling bearing BP neural network Beetle algorithm Wavelet packet transform

中小学课程思政的研究现状和发展趋势——基于知识图谱的分析

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天津师范大学学报（基础教育版） 2024年第3期25卷 54-57页

作者：孙茂华天津市教育科学研究院天津300191

“课程思政”日益成为中小学学科育人的重要课题。通过CiteSpace生成的知识图谱可对中小学课程思政研究的年度发文趋势和关键主题进行可视化分析。研究发现,目前中小学课程思政研究呈现出如下热点:遵循政策导向,聚焦核心素养;立足学科特... 详细信息

“课程思政”日益成为中小学学科育人的重要课题。通过CiteSpace生成的知识图谱可对中小学课程思政研究的年度发文趋势和关键主题进行可视化分析。研究发现,目前中小学课程思政研究呈现出如下热点:遵循政策导向,聚焦核心素养;立足学科特性,开发思政资源;着眼育人价值,探究有效策略。研究认为,未来中小学课程思政研究要推进理论体系向教学体系转化的研究,关注一体化育人体系建设研究,重视“教学评一致性”研究。

关键词：中小学课程思政课程育人核心素养知识图谱分析法

Fuel economy of multiple conditions self-adaptive tractors with hydro-mechanical CVT

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International Journal of Agricultural and Biological Engineering 2018年第3期11卷 102-109页

作者： maohua xiao Jing Zhao Yuewen Wang Haijun Zhang Zhixiong Lu Weihua Wei College of Engineering Nanjing Agricultural UniversityNanjing 210031China College of Mechanical and Electronic Engineering Nanjing Forestry UniversityNanjing 210037China

Fuel economy is one of the most important properties of wheeled tractors.To improve the fuel economy,it is necessary to improve the engine fuel economy and the tractive efficiency of the driving mechanism.By analyzing the fuel economy evaluation index of wheeled tractors,the correlation among the tractor specific fuel consumption,the engine effective specific fuel consumption and the tractive efficiency of the driving mechanism were clarified in this paper.A tractor with a new type of hydro-mechanical continuously variable transmission(HMCVT)was designed and its whole model was established too.On the basis of each module’s simulation model,the binary speed ratio matching simulation model of the gearbox-engine system was obtained by the control system reconstruction,and the fuel economy simulation analysis of the wheeled tractor with HMCVT was carried out under the two typical working conditions of plowing and sowing.Compared with the current national standard,the fuel economy of the newly designed wheeled tractors with the power of 130 kW was 380 g/(kW·h),specific fuel consumption was reduced by 21.1%.The results showed that the new tractor fuel economy was greatly improved.Further,automatic navigation technology can be combined with the self-adaptive tractors to adapt to different working conditions and achieve the optimal fuel economy,which can be applied in precision agriculture.

关键词： high power wheeled tractor self-adaptive tractor HMCVT fuel economy navigation

Design of a straw picking and cutting device

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International Journal of Agricultural and Biological Engineering 2021年第6期14卷 93-98页

作者： Kai Xu Yanyan Ge maohua xiao Min Kang Jie Ni Jinwu Wang College of Engineering Nanjing Agricultural UniversityNanjing 211800China Shandong Daye Co. Ltd.Zhucheng 262218ShandongChina

In order to improve the effective recovery of straw,a new type of straw picking and cutting device was designed.A new type of roller moving knife mechanism was used which can realize simultaneous picking and cutting.A hammer claw was used to pick up and cut straw for the first time,and a roller moving knife was used to cut straw for the second time.ANSYS software was used to conduct static and modal analyses of the moving roller shaft and optimize the structure of the cutting part and the staggered arrangement of hammer claw.The first-order resonance frequency of the hammer claw shaft is 205.84 Hz,and the first-order natural frequency of the pulling roller moving knife mechanism is 214.35 Hz,which can avoid resonance and realize efficient picking and cutting of straw.

关键词： straw hammer claw roller moving knife mechanism fixed knife