bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Numerical Study on Plane Contact Problem Involving Inclusions
Authors: Xie D D , Zhu K , An Y H , Li P , Jin X Q 
Published: August 2021

Abstract
Hertz’s contact theory is widely used in elastic solid contact problems. In this paper, the applicability of Hertz’s contact theory in conformal contact problems was examined. Taking deep groove ball bearing and the outer raceway model as an example, both the FEM analyses and the theoretical studies were conducted. It is found that when the radius coefficient of groove curvature is greater than 0.55, Hertz’s theory can be practically applied for conformal contact. Contact problems of rolling bearings are generally solved by Hertz’s contact theory without considering inclusions and inhomogeneities in the material. In this paper, inclusions are presented in the contact analyses, and the corresponding elastic field distribution of the contact-inclusion model is investigated by using the finite element method.
Non-uniform Kirigami Enhances Films Conformability
Authors: Wang Haotian , Han Yafeng 
Published: August 2021

Abstract
Developing films with great conformability has become a research hotspot in many fields. The conventional method to enhance conformability is to make the film thinner and more compliant, which usually compromises the strength of the structure. For example, developing functional medical bandages that can perfectly conform to the skin surface during cyclic bending of the joints is still a considerable challenge. In this paper, we propose a novel non-uniform kirigami to make the film achieve the same non-uniform auxetic (negative Poisson’s ratio) deformation as the skin around the joint area. By mapping the corresponding unit cells to the target surface, the surface can easily achieve the same deformation as the target skin without any alterations in its thickness or adhesion. As the obtained non-uniform kirigami film structure has the same deformation behavior as the target skin surface, the conformability of the structure can be guaranteed during the entire rotation process of the joints. Moreover, the proposed film is also expected to be used in novel biomaterials, such as smart bandages, skin scaffold, etc.
Analysis and Comparative Study on the Pushing Effect of Screw Rod with Different Structural Parameters
Authors: Zhao Keli , Yu Aiwei , Liu Yuqi , Zhao Qingxi , Man Zunhai 
Published: August 2021

Abstract
The computational fluid dynamics software fluent is used to calculate and study the hydrodynamic performance of the rotating screw in the water flow field. First, UG is used to establish different parameter calculation models, and then the slip grid method in the fluent is used to calculate the flow field state, thrust and torque of the simulated screw rod under different blade angles and number of blade turns, calculate through the above data obtain the screw rod’s pushing efficiency, and obtain the best structural parameters of the screw rod when the best pushing effect is achieved through the comparison of experimental data.
Investment Casting Simulation and Analysis of Shell AlSi11 Alloy Part
Authors: Miao Liqin , Tang Zhengwei , Zhang Dashun , Meng Fanjun , Wang Jing , Li Xueguang 
Published: August 2021

Abstract
Shell investment casting of AlSi11 alloy was stimulated in this paper. The shell model of AlSi11 alloy casting was established using UG three-dimensional drawing software, and the solidification process of the inner material of the shell was numerically simulated based on the ProCAST software. The final analysis shows that the entire solidification process is solidified layer by layer, and the filling time of the material inside the shell is 14.70s. After solidification and cooling, the shrinkage volume of the internal defects of the material is 7.80 square centimeters, the average shrinkage rate is 17.90%, and the pore volume is 1.70 square centimeters. Through the simulation and analysis of the solidification process, not only can we find out the shrinkage cavities generated in the solidification process, but also can effectively reduce production costs and improve efficiency.
Factors Affecting the Tooth Surface Finish of the Inner Gear Rings for Coal Cutters
Authors: Zhao Liyuan , Yuan Yuedong , Chen Long , Ma Rui 
Published: August 2021

Abstract
In order to analyze the reason why tooth surface finish of the inner gear rings for coal cutters can not meet the standard requirement, a series of experimental studies are carried out on the gear-shaping cutter and the corresponding cutting parameters. It is found that the tooth surface finish can not reach the standard after machining with each cutting parameter by using a M2 high-speed steel cutter. Using a M42 high-speed steel cutter + Balchas coating, the tooth surface finish under each cutting parameter can meet the standard requirement. Combining with the requirements of machining efficiency and tooth surface finish, the matching cutting parameters are proposed. This study has guiding significance for improving the tooth surface finish of the inner gear rings for the coal cutters.
Design of Automatic Claw Changing Robot for Intelligent Sorting System
Authors: Song Zhilan , Wen Ping , Ran Wenxue 
Published: August 2021

Abstract
In recent years, China’s express business volume has steadily increased, which has greatly increased the operation volume and complexity of sorting operations. However, the current logistics sorting process is still in manual or semi-automatic sorting, and the technology in the process of express sorting cannot match the surging order volume in the express industry. And with the rapid development of e-commerce and the increasing personalized demand, customer orders gradually tend to be multi-variety, small batch, multi-frequency, and then put forward higher requirements for the flexibility of the sorting system. In this paper, aiming at the low sorting efficiency caused by the inconsistent standards of goods in the sorting process, based on the idea of automatic tool changing in machining center, a hand changing grasping robot is designed, which includes the structure of cluster, “claw library” and robot automatic claw changing structure. The design can realize the multi-purpose of one machine and improve the flexibility of the sorting system.
Study on the Control of Micro-Environmental Parameters in Long Distance Laser Interferometry
Authors: He Yan , Zhu Yurong , Nie Hongfei 
Published: August 2021

Abstract
Fluctuation in environmental parameters has become an important factor affecting the performance of ultra precision measurement. Aiming at the long-distance and high-speed laser interferometer measurement system, a method combining structure design and closed-loop control is proposed to reduce the measurement error caused by environmental parameters. The uniform pressure structure is designed, and the control system of micro environmental parameters is established. The simulation and experimental research on the uniformity of temperature and pressure on the optical path measured by laser interferometer are carried out. The simulation and experimental results show that this method can achieve temperature uniformity and stability above 0.01°C and pressure uniformity and stability above 1Pa, and can be widely used in micro environment parameter control of long-distance ultra precision measurement.
Design and Fabrication of a Novel High Power THz Slow Wave Structure Based on MEMS Technology
Authors: Zheng Heng , Yao Jinyuan , Zheng Rui , Zhang Qi , Lu Xichi 
Published: August 2021

Abstract
With the development of TWT in terahertz band, the size of TWT is greatly reduced and the power gain is also reduced. In order to improve the performance of traveling wave tube (TWT), an E-plane and H-plane tapered folded waveguide slow wave structure operating at 0.34THz is designed. In order to reduce the RF loss, a gradual ridge is added to the E-plane ridge. Compared with other ridge loaded structures, the coupling impedance of this structure has been significantly improved, and it has better dispersion characteristics and higher maximum output power. According to the electromagnetic simulation results, under the condition of 16.8kV, 50mA banded electron beam, the maximum output power of the folded waveguide can reach 65.1w, the power gain can reach 31.8db, the 3dB working bandwidth can reach 12GHz, and the electronic efficiency can reach 7.75%. Finally, a complete DRIE process for processing slow wave structure is explored. The slow wave structure is fabricated by combining silicon with non-silicon.
Research on Face Recognition Based on Improved Convolutional Neural Network Using Raspberry Pi
Authors: Ning Lingyi , Huang Zhikai , Xi Xianchang , Zhang Yang 
Published: August 2021

Abstract
In this paper, a face recognition system has been designed using Raspberry Pi based on convolution neural network technology. Convolution neural network that using OpenCV (open source computer vision library) to realize real-time face recognition and feature extraction. The difficult and important problem in deep learning network is that it could be over fitting very easily. In order to alleviate the over fitting phenomenon and improve the accuracy of face recognition, the dropout technology of convolutional neural network had been employed to improve the recognition accuracy and ensure the robustness of face recognition. The results of experiments show that our methods has the advantages in the computer time and recognition rate for the low construction cost, simple structure and strong portability. The accuracy of face detection for static and dynamic images using Raspberry Pi is above 85% in our testament.
X-ray Computed Tomography Method for Measuring Matric Suction of Micro-Sheet Materials Mixed Cs2SO4
Authors: Sun Yinlei , Tang Liansheng 
Published: August 2021

Abstract
In this paper, the X-ray computed tomography method was applied to measure the matric suctions of the glass-sheet samples. With the contributions of Cs2SO4 solution, the distributions of water among glass sheets were distinctly observed. The shape of the liquid bridges between the glass sheets are not simple circular ring, but rings with the triangular or quadrangular projective planes. Cs2SO4 resulted in the coefficient surface tension of the solution decreasing, which is the main reason that the tested values of matric suction were slightly higher than calculated. Overall, the differences between tested and calculated values are less than 3%, which testified that X-ray computed tomography method for measuring matric suction is feasible. The significance of this work is X-ray computed tomography method could be applied in unsaturated clay soil constituted by sheet particles.
Image Classification for Soybean and Weeds Based on ViT
Authors: Liang Jingxin , Wang Dong , Ling Xufeng 
Published: August 2021

Abstract
Abstracts. In this paper, ViT deep neural network based on self-attention mechanism is used in classification for images of soybean and weeds. Firstly, the overall image is split into multiple tiles; with each tile regarded as a word, the whole image is regarded as a sentence, which can be used for image semantic recognition by natural language processing technology. We designed a ViT network with sequence length of 50, embedded dimension of 384, and self-attention module layers of 12. With soybean weed classification dataset, the network is trained, verified and tested. Experimental results showed that ViT network is superior in classification on dataset of soybean and weeds, with excellent generalization capability.
Research on Oblique Penetration of Projectiles into Targets of Different Materials
Authors: Zhang Xiaojing , Yao Wenjin , Li Wenbin , Wang Xiaoming , Zhu Xintao 
Published: August 2021

Abstract
In order to study the trajectory deflection of projectile penetrating obliquely into different materials, the Lagrange algorithm of LS-DYNA was used to simulate the three-dimensional model. The impact angle of projectile is 70°, the concrete target and the soil target are penetrated respectively. The state of the target, the strain nephogram and the stress nephogram of the target under the maximum overload are obtained. The curves of penetration depth, penetration velocity, overload and energy are analyzed. The results show that: in oblique penetration, the projectile’s trajectory deflects more in the process of entering the concrete target, and then deflects less; the trajectory deflection of the projectile is small in the process of entering the soil target and a certain distance after it, but it becomes larger when it is fast out of the target.
Energy Management Control of Fuel Cell Electric Bus Basing on Fuzzy Rule
Authors: Wang Renguang , Hao Dong , Zhang Yanyi , Meng Xiangfei 
Published: August 2021

Abstract
A hybrid fuel cell bus was taken as the research object. Firstly, the structure and characteristics of fuel cell bus power system were introduced, and the power system parameter design was completed according to the vehicle parameters and performance design goals; Secondly, in order to improve the durability of fuel cell and the economy of power system, a three input single output fuzzy energy management control strategy was designed, with the fuel cell power increment selected as the control variable to coordinate control fuel cell power output and change; Finally, the effectiveness of the fuzzy control strategy was verified basing on MATLAB/Simulink platform, the results showed that the fuzzy control strategy can control the SOC of battery reasonably and effectively, while is better than the power-following energy management strategy in terms of power system economy and fuel cell durability.
Research on High Pressure Fine Mist Cultivation Equipment
Authors: Yang Yousheng , Li Xiaoqing , Zheng Yunkai , Wang Yi , Men Daoxin 
Published: August 2021

Abstract
Most of the existing aerosol cultivation equipments are bulky, simple-structured and poor in functional stability. Based on this, the author developed a set of automatic control high-pressure fine mist cultivation device, designed the PLC automatic control circuit, and simulated and tested the temperature and humidity change curves. The test results verify the simulation model and the overall device runs well, among which the spray atomization process, and the temperature field, humidity field and velocity field under three atomization modes are simulated. Three atomization schemes are analyzed, and in the end the optimal one is selected. In comparison, the side-by-side spray is completely covered; the atomization is more sufficient. The results show that the time when the humidity reaches 90% in the same position is different under different initial humidity conditions. The atomization humidity maintenance time in different environments is approximately the same, and can be maintained for 4 to 5 hours. It can be seen from the comparison of the results that the greater the humidity, the shorter the heat exchange time and the faster the heat exchange.
Real-time Pedestrian Detection Algorithm Based on Improved YOLOv3
Authors: Xi Xianchang , Huang Zhikai , Ning Lingyi , Zhang Yang 
Published: August 2021

Abstract
As a research hotspot in the field of current computer vision, pedestrian detection is widely applied to many fields, such as video surveillance and autonomous driving. However, the accuracy of pedestrian detection under video surveillance is poor, and the miss rate of small target pedestrians is high. In this paper, an improves the YOLOv3 algorithm and a YOLOv3-Multi pedestrian detection model had been proposed. First, referring to the residual structure of DarkNet, the shallow features and deep features had been up-sampled and connected to obtain a multi-scale detection layer. Then, according to different special detection categories, the spatial pyramid pool (SPP) is introduced to strengthen the detection of small targets. The experimental results show that our method improves the average accuracy by 2.54%, 6.43% and 8.99%compared with YOLOv3, SSD and YOLOv2 on the VOC dataset.
Retrieval of Suspended Sediment in Songhua River Based on Sentinel-2 Satellite
Authors: Han Xu , Du Chong 
Published: August 2021

Abstract
In view of the current situation that the remote sensing inversion of suspended sediment is mainly based on low spatial resolution satellite data, sentinel-2 satellite data with resolution of up to 10m is used to retrieve the suspended sediment content in Harbin section of Songhua River. And the inversion model is established based on the measured data and remote sensing data. The results show that the fitting degree of b3/(B2 + B4) in the multi band ratio and the measured suspended sediment concentration is the highest, reaching 0.904. The results show that the average relative error between the inversion value and the measured value is 19.88%, and the root mean square error is 0.039g/l. The results show that the suspended sediment content of Songhua River is lower than that of other six rivers in China, and belongs to the less sand river. The sediment content on both sides of the bank is higher than that of the center of the river. In the wide river, the suspended sediment content is low, and the suspended sediment content is higher in the narrow area.
Research on Internet data security and privacy protection
Authors: Ke ZHANG , Yongzhen LI 
Published: August 2021

Abstract
The company's data leakage has always been a very serious problem. Many of the leaked data is the user's personal privacy data, which will bring a lot of trouble to users. In order to improve the security of the storage and use of personal private information in the database, two methods of lightweight private information encryption and social engineering anonymization are proposed to protect database information. We compare the proposed method with the application layer encryption and pre encryption methods. The experimental results show that the proposed method can effectively protect the user's personal privacy data, and can detect and recover the privacy data when managers need it. The storage efficiency of the three methods is close. Therefore, it has good application value in privacy protection.
Research on Kalman Filter for One-dimensional Discrete Data
Authors: Wei Fan , Zhang Zupei , Jia Kunpeng 
Published: August 2021

Abstract
Kalman filter processes the input and observation signals with noise on the basis of linear state space representation to obtain the system state or real signal. In the one-dimensional model, due to the lack of multi-dimensional description of the target, the prior estimate of the state is often the measured value of the previous moment. When the target state changes, the divergence phenomenon will occur. Aiming at the problem that the one-dimensional traditional Kalman filter lacks the target observation dimension, which leads to the divergence or imprecision of the filter, this paper focuses on improving the estimation method of the target state, and proposes a real-time prediction model based on the cascade structure. This model can improve the response of Kalman filter to the change of target state and dynamically adjust the Kalman iterative domain to improve the measurement accuracy. The digital signal filtering simulation is carried out and the performance of the filter is verified based on LabVIEW. Experimental results show that the algorithm can maintain the accuracy and real-time performance of filtering when only one dimension observation results are obtained.
Benefit Analysis of Hydrothermal Processing of Biogas Slurry Applied to Biogas Power Generation Project
Authors: Sun Ke , Liao Dachen , Ye Qiang , Zhang Yuanshang , Chang Xinglan , Xi Shuang , Zhang Tianrong 
Published: August 2021

Abstract
Taking a large-scale anaerobic fermentation biogas power generation project as an example, the biogas slurry was hydrothermal processed and then reused to the anaerobic reactor, so as to reduce the biogas slurry discharge and increase the biogas production. The benefit analysis is carried out on the basis of meeting the requirements of increasing the gas production and the economic benefit as far as possible in the biogas power generation project. Through analyzing the amount of biogas slurry returning to field, the increase of biogas production, and the ammonia nitrogen concentration of the material in the anaerobic reactor, it is concluded that the reasonable amount of hydrothermal processing in this project is 150 t⋅d−1∼200 t⋅d−1 (the ratio of the hydrothermal processing capacity to the material in the anaerobic reactor is 22.4% ∼ 29.9%), which can increase the biogas production to 338.2 Nm3⋅d-1 ∼346.6 Nm3⋅d-1 per ton of dry solid.
Research on Fruit Recognition and Positioning Based on you only look once version4 (YOLOv4)
Authors: Dexiao Kong , Junqiu Li , Jiawen Zheng , Jiale Xu , Qinghui Zhang 
Published: August 2021

Abstract
The recognition and spatial coordinate positioning is an important part of picking equipment of fruits. This paper introduced a method of target detection and pixel learning positioning of fruits based on the Darknet depth framework YOLOv4. We utilized GPU training in Ubuntu 19.10, and used 2000 images of various fruits as the training set for recognition model training, and performed and verified tests in the GPU environment. The results showed that the accuracy of fruit recognition is above 94%, the detection time of a single image is 12.3ms, and the detection rate of the video is 17f/s. The actual test showed that the system has good stability, real-time performance, and correctness of picking objects.
A Survey on Hybrid Energy Systems Market
Authors: Hengtian WU , Hongcai DAI , Weizheng KONG 
Published: August 2021

Abstract
The fast-growing energy needs over the last few years across the world have intensified challenges: how to reduce the generation and operation costs in power systems and, in parallel, to minimize the hydrocarbon emissions. The hybrid energy system (HES) provides overarching opportunities for solutions to aforementioned challenges. The paper starts with the classification of the energy supply and consumer in the market. Next, the HES operations and services are introduced. In the final, the typical market competition relationships of HES energy trading are proposed and analysed.
China Southern Power Grid’s power supply reliability development strategy under digital transformation
Authors: Qiuling Yu 
Published: August 2021

Abstract
Power supply reliability management is a systematic work that requires long-term persistence and continuous improvement. The four factors that restrict the improvement of reliability are: grid, equipment, automation and management. In the long run, the grid structure, equipment quality and automation level of the power grid are the material basis for improving the reliability of power supply. Continuous investment in power grid construction is needed to build a strong and reasonable standardized grid structure, and the application of sturdy and durable high-quality equipment to improve distribution Practical level of electrical automation, improve the ability of the distribution network to transfer power supply, and reduce the failure rate of the distribution network. In view of this, this article mainly analyzes the development strategy of China Southern Power Grid's power supply reliability under the digital transformation.