bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simulation Test Study on Combined Gap Structure of High-speed Railway Catenary
Authors: Kong Jiaqi , Xia Zhijian , Wang Jufeng 
Published: October 2020

Abstract
In order to deal with the lightning damage problem commonly existing in high-speed railway catenary, a combined multi-breakpoint arc-extinguishing and lightning protection gap device (CMALPGD) which can be applied to high-speed railway catenary is proposed in this paper. Based on the principle of gas production and arc quenching of the device, a three-dimensional dynamic (MHD) model of arc in the arc-extinguishing chamber is established. With the help of simulation software to simulate the changes of the temperature, conductivity and high-speed airflow velocity of the arc at the fracture of the arc-extinguishing chamber, it is known that the high-speed air flow generated by the arc-extinguishing device can quickly extinguish the arc and restrain the arc development, and the whole quenching time is about 2.5ms. At the same time, the arc-extinguishing test is carried out by setting up the test circuit under laboratory conditions, and it is found that the arc-extinguishing time of the device is about 3.0ms and the arc is not reignited for a period of time. The conclusions provide a scientific basis for the application of CMALPGD in high-speed railway catenary in the future.
Helmet wear detection based on neural network algorithm
Authors: Cao Ruiyun , Li Hongxiang , Yang Banglie , Feng Ao , Yang Jie , Mu Jiong 
Published: October 2020

Abstract
Wearing safety helmet correctly is an effective means to reduce the accident rate and ensure the safety of construction personnel. But in the complex work site, the helmet detection task will face a variety of challenges. This paper uses YOLOV4’s deep neural network architecture and makes fine-tuning and improvement according to the characteristics and difficulties of this task, proposes a new helmet detection system, and achieves 95.1% accuracy. The application can timely and accurately detect whether the personnel wear the helmet correctly, which is of great significance for ensuring construction safety in practical work.
Research on cultural landscape supported by digital technology
Authors: Lin Yinan , Wang Ting , Han Mengmeng , Liu Siqi , Huang ZhiLiu 
Published: October 2020

Abstract
Cultural landscape is a combined work of both human and nature. The study of cultural landscape in a region is helpful to discover the historical changes and human factors in the region. With the development and maturity of digital technology, there are many kinds of research ways, such as UAV, satellite remote sensing, etc. Firstly, this paper collects and understands the domestic and foreign research examples, then analyzes the application advantages of UAV in cultural landscape research, and then takes Guling, Fujian Province as an example to carry out the landscape culture research using UAV technology, and finally summarizes that UAV technology can provide reliable data sources for Cultural Landscape Archaeology, solve the accessibility problem in Cultural Landscape Archaeology Research, and provide more perspectives for desktop work.
Dynamic Matrix Based Thermal Power Tracking Control of Nuclear Power Reactor
Authors: Shengbao Li , Feng Zhao 
Published: October 2020

Abstract
power control of nuclear power plant is an important technology to ensure the safe and efficient operation of nuclear power unit. Because the power system of nuclear power reactor belongs to nonlinear system, there are many factors affecting the distribution of thermal power, which leads to the uncertainty of the tracking target of thermal power of nuclear power reactor. Therefore, this paper proposes a dynamic matrix-based thermal power tracking control method for nuclear power reactors. The dynamic matrix algorithm is used to establish the prediction model of the controlled object, to determine the tracking target value, to design the dynamic matrix controller, and to formulate the switching strategy combined with the minimum value of the cumulative prediction error, and to realize the thermal power tracking control of the power reactor. Simulation results show that the proposed method has different target values under different working conditions in accordance with the actual control value, it has better engineering value and practical significance for reducing the working intensity of operators and improving the performance of load tracking.
The Study on Suppression Common-mode Voltage Strategy Based on Predictive Control
Authors: Wang Kai , Zhang Yanbing , Shi Shumei 
Published: October 2020

Abstract
The traditional two-level pulse width modulation strategy will generate a higher common-mode voltage and cause common-mode interference to the inverter load-side equipment. This paper uses predictive control to implement current tracking control. The algorithm is simple to implement and can be adjusted by adjusting the value factor to suppress the common-mode voltage output of the inverter, and the simulation verifies the correctness of the algorithm, which has certain reference value for further research on the suppression of the common-mode voltage on the load side of the inverter.
Gear Ratio Distribution of Electric Vehicle Reducer
Authors: Tang Zhihao , Li Xinmin 
Published: October 2020

Abstract
Based on the contact fatigue strength criterion of tooth surface, the mathematical model of gear ratio distribution of the electric vehicle is established. In the process, there are two objective functions. One is the minimum diameter of electric vehicle reducer, the other is the minimum mass of electric vehicle reducer. Through examples, relevant program is compiled with matlab software. It is obtained that there is a distribution method for gear ratio of the electric vehicle reducer.
Research And Practice On Transformation Of 600 MW Turbine Tubular Cooling Unit Into Direct Air Cooling Unit
Authors: Shengxiang Jin , Liuhu Wang , Jinsong Zhang , Qi Zhang , Qianyu li , Wei Bai , Chuan He , Yong Zhou , Daming li , Yu Xiao 
Published: October 2020

Abstract
In response to the government's policy of protecting Daihai Lake, this paper discusses the possible problems in the technical practice of air cooling transformation of Inner Mongolia Daihai Power Generation Company, including the transformation of steam turbine body, auxiliary system of steam turbine body, transformation of thermal system and auxiliary equipment, layout of steam turbine room, etc. The results show that the operation is stable and the energy saving effect is remarkable.
Research of fastener distribution for typical irregular connections of civil aircraft
Authors: Gou Pengpo 
Published: October 2020

Abstract
In this paper, based on the analytical method of calculating simple and regular single shear connector distribution, based on the engineering formula, the flexibility coefficient of different fasteners, pin spacing, plate width and plate thickness is given. The deformation coordination equation between adjacent fasteners is established. The diameter of different fasteners is given by the equilibrium conditions of the binding force. The calculation equations of fastener load distribution under the spacing of fastener, plate width and plate thickness have been calculated. The finite element model for calculating fastener load is established in finite element software based on finite element method. The calculation results of finite element method and analytical method are compared, and the analytical method is proved to be used to calculate plate width, plate thickness, fastener diameter, and the analysis method. The effectiveness of pin load distribution for typical connection structures with constant spacing between Fasteners is also presented.
Design of Weighing Controller for Kiwi Fruit Grading Based on PLC and MCGS
Authors: Ma Baijie , Zhang Tianyu , Guo Ning 
Published: October 2020

Abstract
At present, after picking kiwifruit in China, most areas have used machines to classify them, gradually replacing manual classification. However, machine classification is currently all large-scale machines, with an average of about 150kg, and the cost is high. It cannot be classified immediately after picking. Transportation is inconvenient, which may lead to inaccurate results, thereby affecting efficiency. Therefore, based on this situation, this article simplifies and improves the large-scale sorting machine. On this basis, the design consists of conveyor belt, pressure sensor N340, stepper motor, stepper driver, MCGS HMI touch screen, air cylinder, ID551, ISD1730 language A medium-sized kiwi fruit grading control system composed of broadcast module, photoelectric switch, aluminum alloy bracket, etc. After the system runs, the kiwi fruit senses the weight through the pressure sensor, and then enters the corresponding grade box according to the weight. The fruit quality is measured according to the fruit weight, and the effect is tested better.
Research into Nose Wheel Steering Deviation Angle Calculation of a Civil Aircraft
Authors: Zhou Jia 
Published: October 2020

Abstract
This document, based on a civil aircraft, describes the basic principle of nose wheel steering deviation angle calculation. The taxiing deviation angle of aircraft in ground test can be balanced by adjusting the nose wheel angle, but the deviation angle cannot be read directly, it needs to be calculated according to the field data. In this paper, we research a method to calculate the deviation angle by try three different modelling: simplified point modelling, calculus modelling and trigonometric modelling. Finally, we find the third modelling is more practical, we can rectified the deviation angle by adjusting the nose wheel turning control system pre-set parameters according with the result. We also transform the mathematic modelling into a computer program, to improve the efficiency in practical use.
Design of sensorless high speed BLDCM controller for molecular pump
Authors: Li Qiang , Huang Xiaojing , Li Jian , Liu Guangmin , Tao Jizhong 
Published: October 2020

Abstract
The brushless direct current motor(BLDCM) of the molecular pump needs to run at high speed for a long time, which puts forward the requirements of high reliability, high speed rang and so on. The traditional sensor methods of using hall sensors for BLDCM commutation will reduce the reliability of the system and increase costs. Therefore, sensorless control methods are widely used in the field of molecular pumps. In this paper, a sensorless BLDCM control system of the molecular pump is designed, and the back-EMF zero crossing detection method is used to obtain the motor position information. Based on this method, the hardware and software of the control system are designed. Driven by the controller, the molecular pump speed can reach 90000rpm, and its steady speed fluctuation is ± 60rpm.
Research on the Development Direction of Smart Substations Under the Background of Power Internet of things Technology
Authors: Shouquan Tang , Jungang Wang , Beibei Li , Xiaoli Huang , Tao Zhang , Weihua Zhong , Zhenjie Li , Fan Li 
Published: October 2020

Abstract
As a key support for smart grids, the smart substation has formed a mature technical solutions after long-term development. In recent years, the internet of things technology has been applied in the whole aspects of power system transmission and distribution. Based on the extensive data collection and fusion, it has improved the state awareness, intelligent decision-making, and asset management capabilities of the power system. With the application of the internet of things technology, the development direction and technical architecture changes of smart substations are important topics that need to be considered at present. Based on the analysis of the current substation development route, this paper studies the applicability of electric power internet of things technology in smart substations, and proposes a smart substation technology solution that combines traditional technology routes and internet of things technologies, wishing to provide some reference for the research of smart substations. Chinese Library Classification Number: TM715
Analysis on Defocusing and Astigmatism of Electron Beam Selective Melting Machines
Authors: Sun Botong , Yin Bohua , Wang Pengfei , Xu Guanglu , Liu Junbiao , Han Li 
Published: October 2020

Abstract
Affected by defocusing and astigmatism, the quality of electron beam steadily deteriorated with increasing deflection distance, limiting the processing area of SEBM machines. The relationship among beam spot size, deflection distance and deflection direction are studied by numerical simulation, which explains the cause of decreasing power density. The experimental results show that defocus is the main factor affecting the beam spot size when the deflection distance is less than 100 mm and astigmatism is the main factor at a larger deflection distance. Then, the chessboard electron imaging experiment is carried out to verify that the spot size increases with the deflection distance. Thus, dynamic focusing and astigmatism should be introduced at the same time to minimize beam area.
Nonlinear Finite Element Analysis of Rod String in Rod Pumping System
Authors: Yan Wenhui , Qu Yinan , Xie Dong , Wu Heng , Peng Yong 
Published: October 2020

Abstract
Rod pumping is the main oil recovery method at home and abroad. The corresponding displacement and load of the sucker rod section are important parameters in the system. This paper uses the advantages of the finite element method to solve the three nonlinear problems in the rod string model, and establishes its finite element analysis model. According to the upper and lower boundary conditions and initial conditions, the software is used to program and calculate. The surface dynamometer card of multi-level steel rod columns and glass fiber reinforced plastics-steel hybrid rod string is predicted, and the calculation results with and without considering mass nonlinearity are compared and analyzed. The feasibility of predicting the surface dynamometer card by the finite element method is verified. It is proved that the coupling has a great influence on the mechanical properties of the glass fiber reinforced plastics-steel hybrid rod string.
Research on Application of Improved YOLO V3 Algorithm in Road Target Detection
Authors: Zhao-zhao JIN , Yu-fu ZHENG 
Published: October 2020

Abstract
Due to the lack of average accuracy and missed detection in the process of real road scene target detection through YOLO V3 network, the improvement scheme is put forward. The K-means clustering algorithm is used to replace the K-means clustering algorithm in the original network to analyze the anchor number and aspect ratio of the Udacity data set, in order to make the obtained parameters more suitable; in addition, in order to improve the performance of the road target detection algorithm, the existing network output is upgraded, and a 104 × 104 feature detection layer is added, and the feature map output by 8 times sampling can be output by 2 times up sampling, and 4 the feature maps of down-sampling are stitched together, and the 104 × 104 feature maps obtained can effectively reduce the disappearance of features. Through the experimental results, we can see that compared with the improved YOLOV3 algorithm, the average detection accuracy of the improved algorithm for road target detection is quite high to 3.17%, and the missing detection rate is reduced by 5.62%.
Performance analysis of double-groove cutter based on ABAQUS numerical simulation
Authors: Chen Zhimin , Chen Shunqing 
Published: October 2020

Abstract
In order to study the influence of double-slotted cutter on chip forming, this paper uses the general finite element simulation software ABAQUS, and builds a finite element model based on Johson-cook material model and Johson-cook fracture criterion. This paper analyzes the changes in cutting force and cutting temperature obtained when cutting titanium alloys with three different double-slot structures. This paper draws the cutting force and cutting temperature change curve at the tool tip, and analyzes and compares the post-processing results of the three geometries. The test results show that the double concave arc groove cutter has less cutting force and cutting temperature during cutting, and the cutting process is relatively stable, which is more suitable for cutting than other groove types.
Experiment and simulation research of forklift roof guard dynamic load test based on LS-DYNA
Authors: Liu Jiasheng , Peng Xuefeng , Dai Zongmiao , Wang Qingyuan 
Published: October 2020

Abstract
In order to solve the problems that the driver is threatened by accidental falling objects during forklift operation, according to the requirements of international standard ISO 6055:2004 for dynamic load test of forklift roof guard, the explicit dynamic calculation model of dynamic load simulation test was established based on LS-DYNA, and the dynamic load test was carried out at the same time. The maximum permanent deformation of roof guard is 13.5mm and 11.8mm, respectively, in the simulation and test results of dynamic load. The simulation analysis and test results show that this forklift roof guard has good deformation resistance and safety performance. And the data consistency is good, both of which meet the requirements of test standards. The results provide more design schemes and references for the structure of forklift roof guard.
Study on fuzzy decoupling control system
Authors: Zhao Jing 
Published: October 2020

Abstract
There is a strong coupling effect between the pressure and flow in the industrial process control. In order to eliminate the coupling, an intelligent control called fuzzy decoupling control is proposed. The unit matrix method is used for decoupling design, which makes the pressure and flow coupling system become two independent subsystems. The simulation results show that the fuzzy decoupling control effectively solves the pressure flow. The quantity has strong coupling effect in the control process, and the control effect is satisfactory.
Model-based Simulation and Verification on Typical Function Scenes of High-Speed Maglev Vehicle Operation Control System
Authors: Guodong Wei , Lei Yuan , Lianchuan Ma 
Published: October 2020

Abstract
Under the new situation, high-speed maglev transportation has gradually become the new development direction of the railway field in the future. Its vehicle operation control system (VOCS for short) as a key subsystem has a great impact on the safety and stability of the entire high-speed maglev train control system. The high-speed maglev VOCS has the characteristics of complex system structure and frequent interaction between its modules. Finding hidden safety hazards and design errors in the system design and development process and ensuring the safety and efficiency of system design and development has become an important task of related projects. On this background, modelling and simulation of typical scenarios of high-speed maglev VOCS are absolutely necessary in the early stage of project development, drawing on the traditional wheel-rail vehicle system simulation verification research results, with the help of advanced computer simulation methods. Using Simulink / Stateflow tools for the parking point stepping functional scenario as an example, the validity and correctness of the high-speed maglev VOCS were verified to ensure the operation safety of the high-speed maglev train through.
Comparative analysis of the M-out-of-N structure in EN50129:2018 and IEC61508:2010
Authors: Wang Yiwei , Wang Yixuan , Ma Lianchuan , Wen Jiakun , Zhang Fan 
Published: October 2020

Abstract
By comparing and analysing EN50129:2018 and IEC 61508:2010, it is found that there are differences in the meaning of the M-out-of-N structure between these two standards. The reason for the differences lays in that the M-out-of-N structure definition of EN50129:2018 is based on the required functions, while the M-out-of-N structure definition of IEC 61508:2010 is based on the dangerous failures. The 2 out of 2 structure defined by EN50129:2018 is equivalent to the 1 out of 2 structure defined by IEC 61508:2010. The 2 out of 2 structure defined by IEC 61508:2010 is equivalent to the parallel redundancy or dual hot standby structure. Further, it is found that the formula given by EN50129:2018 is not as conservative as that given by IEC61508:2010.
Research on vehicle camera calibration and ranging technology based on texture features
Authors: Wang Cai , Cui Bifeng , Zhu Yanxu , Zhang Yuhang , Li Qixuan , Wei Zhao 
Published: October 2020

Abstract
In order to realize the ranging function of the vehicle monocular camera on unstructured roads, it is proposed to use the method based on texture features and soft voting to detect the vanishing point of the road and the road edge, and use camera calibration method and tri-linear method to obtain the internal and external parameters of the camera. Obtain the distance information in the image according to the geometric relationship model. Experiments show that this method can measure the distance of an unstructured road image with only the centerline of the road relying only on the vehicle monocular camera. The method has a wider application range and is simpler in actual engineering.
Development of Optical Fiber Strain Calibration Device
Authors: Bo Tao , Hu Jiacheng , Minghao Zhu , Pengfei Cao , Jiejun Lin , Xiaoyan Shen 
Published: October 2020

Abstract
The Brillouin distributed sensing system is sensitive to the crossover between strain and temperature. The temperature and strain can be measured simultaneously through decoupling. However, there is no suitable method to calibrate and trace the strain measurement. Therefore, a method of calibrating fiber strain by grating ruler is proposed, the decoding circuit of grating ruler is designed, and the calibration device of optical fiber strain is built. The experimental results show that the uncertainty reaches 5.90 μm (k = 2) in the range of 0 ∼ 1000 μm, and the measurement of optical fiber strain can be traced back to the national length standard.
Research and Design Based on Smart Street Lights Network and Adaptive Dimming Method
Authors: Hu Yu , Wu Jian , Shi Tiantian , Ding Lei 
Published: October 2020

Abstract
In order to respond to the call of "smart city" and combine the actual demand of urban road lighting, this paper studies and designs a network based on smart streetlights and adaptive dimming algorithm. In order to improve the efficiency of data transmission in the smart street lamp monitoring network, an unequal clustering topology control algorithm based on band network (UCTC-BN) is proposed to establish a band topology for data Communication. When selecting the cluster head nodes, the algorithm adopts the candidate cluster head mechanism, and the candidate cluster head determines the non-uniform competition radius according to the remaining energy of the nodes and the distance from the sink nodes, thus achieving the goal of balancing the network energy consumption. In view of the low intelligence of street lights dimming and poor energy saving effect, an improved self-adaptive dimming algorithm based on K-means++ and DAG-SVM is studied, the light and traffic volume are clustered and six-classification dimming model is constructed to realize the intelligent dimming of street lights. Experimental results show that the system can efficiently transmit environmental data and comprehensively adjust street lamp lights, effectively reducing street lamp power consumption.