bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on the Effect of Rare Earth on the Structure and Impact Performance of Armor Steel
Authors: Zhang Mingyi , Gao Ping , Luo Guoping , Geng Wenyuan , Jia Xiaobin
Published: April 2021

In order to study the impact performance of 685 armored steel with different mischmetal content, the impact performance of the steel at room temperature and -40°C was tested, and the impact fracture morphology and microstructure were observed and analyzed. The results show that the addition of mixed rare earth La-Ce to the test steel improves the tempered martensite structure and refines the austenite grains. At the same time, the inclusions in the steel are modified, and the elongated MnS inclusions are modified. It is a spherical composite rare earth inclusion, and the size of the inclusion is reduced from 6 μ m to 2 μ m. Compared with the test steel without rare earth, the room temperature impact performance of the mixed rare earth test steel and the -40 °C low temperature impact performance are improved. When the La-Ce content is 102 × 10−6, the room temperature impact energy of the protective steel increases by 24.5%, and the low temperature impact energy at -40 °C increases by 17. 4%. The results of the shooting test showed that the protection level of rare earth-containing armored steel reached NATO Level 2.
Experimental Investigation on the Damage Characteristics for Light Armored Vehicle by Large Caliber Rifle Projectile
Authors: Li Jinming , Wang Guanghua , Yan Wenmin , Wang Shu , Mai Ruimin
Published: April 2021

Large-caliber multi-function rifle projectile is one of the main weapons used by the army to attack light armored vehicles. The damage of the bullet to light armored targets is not only the direct killing effect of bullets hitting the target, but also the flames and fragments formed by the penetration process. In this paper, the impact effect of a large caliber multi-functional bullet on light armored vehicles with different firing distance is studied by experiments. By reducing the charge to simulate the shooting at different distances, rifle projectiles with different speed penetrate 10 mm armor plate, and the formation process of after-effect fragment and flame is captured by high-speed photography. The flying angle, flame length and flame time can be observed from the high-speed photographic image. Through data processing, the spatial range of the after-effect fragment and flame was obtained. The research results showed that there was a positive correlation between fragment speed and penetration velocity, the after-effect fragment dispersion and the flame length are not very sensitive to the distance, and the flame size at the distance of 100 m is up to about 50% than 400 m, the flame action time at 400 m is 4.62 times that of 100 m, and the flame reached the brightest time at 400 m is 10.29 times that of 100 m.
A Numerical Simulation Study of Sandwich Structure Shield Against Invasion
Authors: Qi Jiawen , Yin Jianping , Wang Zhijun , Duan Conghui , Li Hao
Published: April 2021

Using ANSYS simulation software, the experimental simulation and numerical analysis of anti-12.7 mm tungsten alloy armor-piercing in different mezzanine layers of sandwich structure protection plate were carried out. The upper and lower panels of the sandwich structure are armored steel and the mezzanine is aluminum alloy. The anti-intrusion performance of the protective plate in different mezzanine structures is simulated and analyzed. The results show that the sandwich structure porous shield has excellent performance against kinetic energy, and the protective performance is better than the holeless shield plate structure under the same surface density condition. In the simulated three sets of tests, the porous shield with an aperture of 3 mm has better anti-intrusion protection performance.
Modelling of Bulging Steel-Elastomer Armour Applied Against Long-rod Projectiles
Authors: Fraś T
Published: April 2021

A protection concept, so-called bulging armour, applied to mitigate effects of kinetic-energy penetrators is hereby discussed basing on an experimental and numerical study. The laminated steel-elastomer armours take advantage of the rubber interlayer that deforms rapidly under an impact causing bulging of the side steel plates. Long and slender kinetic-energy projectiles made with a tungsten alloy tend to fracture disturbed by an asymmetric contact with the deforming plates. In the performed experimental study, the laminates with the natural rubber interlayer of different thicknesses are impacted by the kinetic-energy penetrators with the initial velocity above 1500 m/s. The numerical analysis accompanies the ballistic test complementing it by a detailed insight into the defeat mechanism. The performed investigation proves a protective efficiency of the discussed passive armour and explains its physical background.
Orthogonal Analysis of Linear Shaped Charges Jet Penetrating Layered Targets
Authors: Xu Bin , Liu Chunmei
Published: April 2021

This paper reports on the linear shaped charges (LSCs) jet penetrates into double layer spaced targets. The distance between the LSCs and the first layer target is 0.2 times width of the LSCs, the distance between the LSCs and the second layer target is 25 times width of the LSCs. The mechanism of LSCs penetrate into the double layer spaced targets causing less collateral damage in terms of jet residues has been studied by experiment and numerical simulation. After the LSCs has been crashed by detonation wave, a linear metal jet formed and penetrates into the first layer plate, then the jet is separated into jet tip and slug. The jet tip penetrates into the second layer plate and consumed, then a strip pit formed on the surface of the back plate. The slug penetrates into the second layer plate subsequently and consumed. Due to the stress concentration and tensile fracture, the second layer target is broken and less residue of jet pass it. Experiments were made and the results indicated that the numerical simulation results agreed fully with the physical principle. A verification plate was used in the experiment to test the collateral damage of residual jets. When the space between verification plate and back plate of the layered target is 500mm, both of the experimental results and simulation results show that there is no obvious damage to people. The relationship between the performance of jet and the parameters of LSCs has been analyzed by an orthogonal method (significance test and interaction effect analysis). A good teamwork should be done for all the key parameters of LSCs which can break the spaced targets with less collateral damage.
Influence of Angle on Armor Protection Performance of Thin Layer Charge Reaction
Authors: Zhou Pengfei , Li Rujiang , Liu Yang , Jia Mengye
Published: April 2021

In order to explore the protective effect of thin layer charge reactive armor on oblique penetration of jet, the experiment will adopt 0.8mm thin layer charge structure and change the normal Angle to study its protective ability against oblique penetration of jet. Meanwhile, finite element software ANSYS/LS-DYNA will be used to conduct numerical simulation on the process of jet and reactive armor. For 0.8 mm thin layer charge structure, it can be clearly seen that the normal Angle is from unexploded at 50 to half burst at 70 and finally to full burst at 75, and the after-effect penetration depth is also significantly reduced from 12 mm to 3 mm, with a decrease rate of 75%.
Study on Fragmentation Parameters and Similarity Relation of Natural Fragments of Counterattack Projectiles for Active Protection
Authors: Lv Juan , Kang Zhenyu , Yuan Shuqiang , Li Jingwei , Du Juan
Published: April 2021

The purpose of this paper is to explore the fragmentation similarity between small-size cylindrical projectiles and large-size projectiles. On the basis of the modified Payman fragmentation parameter Co, a new fragmentation parameter Cu and the projectile fragmentation similarity relation were derived. Fragmentation tests of large-size projectiles showed that the results of the number and mass distribution of natural fragments were consistent with the theoretical prediction results, which verified the correctness of the fragmentation similarity relation.
Defense Model of Intercepting a High-Velocity Long Rod by Multiple Linear Shaped Charges
Authors: Li Yishu , Cao Hequan , Yang Likun , Qin Chao
Published: April 2021

The interception of high-velocity long rods has always been a difficult problem in defense technology. The existing research lacks the comprehensive analysis on the relationship between the latency, interception position, intercepting velocity, aftereffect damage and other factors in the defense system. In this paper, we first established a time-space rendezvous model of the long rod intercepted by multiple Linear Shaped Charges(LSCs), and then analyzed the fracture model of the long rod, the yaw-ricochet model and the after-effect penetration model of the fractured rods. Finally, the optimal defense model was established. Based on the optimal defense model, the key parameters and their variation rules that affect the defense performance of the protection system were obtained and the key parameters were verified by numerical simulation. It was found that reducing the latency could shorten the length of the front-fractured rod and increasing the number of LSCs could also reduce the average length of the fractured rods. Shortened length of the fractured rods and various attack angles could greatly reduce the penetration depth, and then improve the defense performance. This article has an important significance for the design of the active protection system with LSCs intercepting long rods.
Comparison Study of the Fifth-Order WCNS and WENO Scheme In the Truncation Error, Dissipation and Dispersion Terms
Authors: Zhang Xu , Chen Xun , Jiang Yanqun
Published: April 2021

This paper makes a comparison study of the fifth-order weighted compact nonlinear scheme (WCNS) and weighted essentially non-oscillatory (WENO) scheme in the truncation error, dissipation and dispersion terms. Truncation error analysis on the WCNS shows that numerical discretization leads to dissipation and dispersion terms. The Fourier spectral analysis methods is used to analyze the dissipative and dispersive features of both schemes.
The Design of A Ku-K Band Single-Fed Wideband Circular-Polarized Patch Antenna
Authors: Zhang Meng , Huang Tao , Liu Juan , Gong Dapeng , Shi Liang , Liu Haipeng
Published: April 2021

In this paper, a Ku-K band single-fed broadband circularly polarized microstrip antenna is designed. The antenna is composed of rectangular dielectric substrate and corner patch. The cut-angle patch makes the microstrip antenna work in circular polarization. The impedance bandwidth of 28.7% and the axial ratio bandwidth of 15.6% are obtained by using coaxial line feeding, tangential angle feeding and multi-patch resonance. The overall thickness of the antenna structure is 1.524mm, which meets the requirements of low profile.
Astronomical Analysis on Star Exploration: A Quantitative Research on Luyten’s star based on Proper Motion and Photometric Brightness.
Authors: Qi Wenzhao
Published: April 2021

There are many intrinsic properties for the stars and some of them can be investigated by an astronomical way. Through an investigation on one Luyten’s star (LHS33), this paper presents one basic astronomical analysis method and result about its high proper motion, and brightness for four different filters (RC, V, Blue, Ic). It is an essential element when exploring the target star and obtaining its properties. The method used in this study is a measurement of astrometric position and photometry. All of the measurements require the original CCD (Charge-coupled Device) images obtained from the telescope and a series of software processing. The results obtained mainly are about the value of proper motion, apparent magnitude in these 4 filters above. For instance, the proper motion calculated for right ascension (RA) is 0.59 ± 0.10 arcsecs per year and for declination (Dec) is -3.70 ± 0.11 arcsecs per year. The valued calculations suggest an agreement with current published data. It verifies the correction for both operation procedure and data analysis. It gives a specific interpretation on why such the observation happened based on the quantitative analysis.
Research on Power Cable Operation Fault Alarm System Based on Big Data
Authors: Guo Yun , Xu Minhu , Zhang Jian , Tan Long , Zhang Kexin , Cao Rong
Published: April 2021

With the continuous development of the national economy, in order to meet the needs of industrial and agricultural production and people’s daily use of electricity, the power system has gradually developed in the direction of large capacity and high voltage. The thesis established a high-voltage cable line fault detection and lean management system based on big data technology, and gave a basic introduction to the high-voltage cable line fault diagnosis and lean management system modules. Analysed the system function modules and judgment logic based on big data technology, and the importance of the system to the cable operation and maintenance management unit to improve the management level.
Low-cost optical techniques for detecting and imaging different objects underwater
Authors: Hyiamang Churchill Osei , Guo Yinjing , Wu Qi , Zhang Jianhua , Niu Chenxi
Published: April 2021

The camera has been commonly used in underwater image acquisition experiments, but the image noise is high, and the distance is limited because of the underwater scattering effect. In this paper, the optical detection device of underwater objects, 520 nm continuous laser modulation by PWM pulse modulation (10 Hz, 60% space ratio), was used to scan and detect two completely different objects (such as advanced resin and green leaves). The photodetectors were used to replace cameras, collect and process the received laser echo signals, and image and display the data. The detected objects images can be visually displayed in the form of grayscale images (resolution of 143 x 62), and the corresponding effects have been discussed. In the experiment, we used a 70 cm long ultra-white glass cylinder and detected a distance of 45 cm, and the results were very consistent with the actual situation.
Analysis of the Research and Development Status and Future Development of Porcelain Insulator Fault Detection Equipment Based on a Portable Insulator Detection Device
Authors: Wang Anli
Published: April 2021

Fault detection of porcelain post insulators has always been the research direction of power industry. At present, the insulator testing equipment still has some defects, such as high cost, complex operation and poor effect. For the design and development of fault detection equipment for porcelain insulators, this paper will introduce the design principle and basic structure of an insulator detection equipment based on a portable insulator fault detection equipment. In this paper, combined with modern science and technology, artificial intelligence and UAV technology are combined with insulator detection work to make innovation and prospect for the future development of insulator detection equipment.
Analysis of common faults in Gas Insulated Substation
Authors: Ma Yuhang
Published: April 2021

This paper makes a statistical analysis of the common faults of GIS equipment, and discusses the causes, hazards and maintenance methods of the four common faults: SF6 gas leakage, SF6 gas micro water exceeding standard, partial discharge caused by internal insulation breakdown and component defects.
Research on High precision Yime Measurement and Analysis method Based on Oscilloscope
Authors: Yang Yang , Xia Wei , Han Lu , Ding Fenghai , Xie Jun
Published: April 2021

High precision time measurement technology is of great significance.It is necessary to test and analyze high precision time,whether it is engineering practice such as telecommunication,chip design,or theoretical research such as atomic physics experiment,as well as space technology such as satellite positioning,radar pulse,etc.With the help of oscilloscope,the time and delay information can be obtained with high accuracy on the premise of high accuracy on the premise of high fidelity acquisition of measured signal.In this paper,aiming at how to use oscilloscope for high-precision time test and analysis,several key factors affecting the accuracy of oscilloscope time test are analyzed,and reference methods and test examples are provided for high-precision time test.
Analysis on unbalanced compensation of star - connected Cascade H - bridge inverter
Authors: Fan Lingyun , Jiang Yunhao , Fang Sian
Published: April 2021

In unbalanced compensation current situation, it is necessary to take appropriate control strategies to ensure that the star connection cascade static reactive power generator of the dc side voltage balance, the commonly used methods for injecting zero sequence voltage, this paper introduce current unbalance degree to analyze the compensation ability of plant, gives the scope of compensation is derived, by means of simulation demonstrate the validity of the derived, for the star connection series H bridge the application and selection of multilevel SVG has the significance.
A PDMS Film Structured Optical fiber Ultrasonic Sensor with high Sensitivity and Wide Response Range characteristics
Authors: Li Long , Liu Shuaicheng , Hao Zhiyuan , Song Ming , Wang Guanjun , Huang Mengxing
Published: April 2021

This paper proposes an implementation method of the optical fiber FP pressure ultrasonic sensor with a controllable cavity length and a variable membrane, in order to effectively improve the sensitivity and response range of the optical fiber Fabry-Perot (FP) ultrasonic sensor. The optical fiber FP ultrasonic sensor with PDMS film structure proposed in this paper has obvious advantages in improving sensitivity and response range.
Anti-Interference Test Technology of Transformer Noise
Authors: Chen Wei , Cao Hao , Hu Sheng , Wu Jianli
Published: April 2021

In order to enhance the transformer noise test accuracy, an anti- interference method based on wavelet packet decomposition and spectral subtraction algorithm is proposed in this paper. The tested original noise signal is decomposed with the wavelet packet method. The occurring time and frequency bands of the noisy signals are observed. In these bands, the noisy signals are further processed by spectral subtraction method. Finally, the pure transformer noise is obtained with wavelet packet reconstruction. The anti-interference effects of transformer noises in the conditions of various interference sources and signal to noise ratios are simulated. The result shows that the proposed method is effective in restraining the influence of diverse burst intermittent environmental noises on the transformer noise test result.
Standing Device for Assisting Elderly People Indoors
Authors: Yang Haoming , Yu Jingle , Yang Li
Published: April 2021

The device is mainly to solve the problem of difficulty for the elderly indoors to get up. The coordinated cooperation of the screw rod and the electric push rod is mainly used to realize the fitting of the motion end of the device to the motion curve of the elderly when standing, thereby further improving the comfort of the elderly Make the device more adaptable. In addition, the device is also equipped with a voice drive device, and the operation of the voice control device realizes man-machine coordination.
Promote and Application of Rigid Body Moment of Inertia Experiment on College Students’ Humanistic Quality Ability
Authors: Peng Rongrong
Published: April 2021

In the experiment of rotational inertia of rigid body, there is often a big difference between the experimental value and the theoretical value, and the error source cannot be found accurately, which leads to the failure of the experiment. In this paper, the basic principle and formula derivation of the tri-linear pendulum method for measuring the rotational inertia of rigid body are given. The physical meaning of each character in the expression of moment of inertia and its possible influence on the accuracy of experimental results are clarified. Secondly, through the measurement of the original data, calculate the experimental results, guide students to analyze the source of error independently and put forward measures to reduce the error. Thirdly, the influence of different factors on the experimental results is analyzed, and the factors influencing the moment of inertia of rigid body are summarized. Finally, this paper discusses how to excavate physical thought, research methods and humanistic knowledge in the process of physical experiment course, and gives the measures and countermeasures to cultivate and improve the scientific and technological ability and humanistic quality of college students, so as to realize the purpose of mutual penetration of scientific knowledge and humanistic quality.
Research on the Planning and Design of Leisure Agriculture Industrial Park under the Background of Rural Revitalization
Authors: Yang Guo
Published: April 2021

With the increasing level of socio-economic development in China, the development of the rural economy has touched the hearts of the Central Party and the whole country, and for this reason, the strategy of rural revitalization was born. With the continuous efforts of rural management services and people in various parts of China, we have gradually explored a road of rural specialty industries that integrate agricultural cultivation, product processing, tourism and leisure experience. The paper takes the planning and design of leisure agriculture industrial park as the research object, and explains the corresponding planning and design principles. The current problems in the planning and design of some rural leisure agriculture industrial park projects in China are discussed, and the specific ideas and methods of planning and design are explored based on the research of these problems, hoping to make some contributions to the development of rural revitalization in China.
Research on the Application of Blended Teaching Mode of Computer Technology from the Perspective of Connectivism
Authors: Yu Zhijuan
Published: April 2021

Simmons systematically proposed the idea of connectivity in the article “Connectivism: A Learning Theory for the Digital Age”, pointing out that learning is no longer a person’s activity, but learning is a process of connecting specialized nodes and information sources. This article is to discuss the application of blended teaching mode with the help of computer technology, as well as the relationship with connectivism.
Construction of Milling Force Model of Cycloid Gear
Authors: Xu Jianmin , Liu Kun , Zheng Qingjie , Gong Xiaoyan
Published: April 2021

The change of the milling force during the milling process will directly affect the machining accuracy of the cycloid gear. In this article, the milling force prediction model of the cycloidal gear is used to predict the milling force of the cycloid gear. The results show that when the spindle speed increases, the milling force gradually decreases; the milling force is also closely related to the feed speed, axis milling depth and radial milling width. With the increase of axial milling depth and radial milling width, the milling force gradually increases, but the magnitude of the increase is different.
Effect of Different Tempering Temperature on the Microstructure and Properties of G115 Steel Weld
Authors: Qi Xiangqian , Liu Zhaohua , Li Xin
Published: April 2021

Evolution of microstructure and room-temperature strength of G115 deposited metal after different tempering at 760°C,800°C and 820°C have been experimentally investigated using metallographic microscope, field emission scanning electron microscopy (SEM) and tensile test, charpy impact test. The results show that after tempering at 800 °C, the G115 deposited metal has the best mechanical properties and can obtain obvious tempered martensite structure of lath bundle. Tempering at 760-800°C, the M23C6 precipitates has a tendency to grow up. The main mechanism that produces the above results is the recovery of martensite and the precipitation of carbon during high temperature tempering. Spherical oxide inclusions formed by welding metallurgy were found in the dimples of the impact fracture of the deposited metal and its influence on the high-temperature durability of the deposited metal needs further study.
Numerical simulation of Vortex-induced Vibration of A Top-tensioned Riser
Authors: Cui Peng , Guo Haiyan
Published: April 2021

The objective purpose of the paper is explore the prediction the vortex-induced vibration (VIV) of a top-tensioned riser. The riser model is established based on vector form intrinsic finite element (VFIFE) method. The riser is discretized into a set of mass points whose motion follow the Newton’s second law and the central difference explicit integration method is used to solve the control equation of the mass point at each time. The fluid hydrodynamic forces are simulated by a Landl-modified Rayleigh wake oscillator. The calculation result is compared with the experiment result to validate the accuracy of the model. Time history of the axial displacement indicates that the model is a real three-dimensional model.
Performance analysis of a vapor injection heat pump using ambient air and recovery electric motor waste thermal
Authors: Piao Changhao , Liu Ziyang , Wang Weiwei , Wu Cunxue , Yuan Rongdi
Published: April 2021

A vapor injection heat pump using electric motor exhaust thermal and ambient air is proposed. This system is applied in pure electric vehicles to improve the air conditioning system consumes too much energy when the ambient temperature is lower than -15°C that affects the vehicle mileage. The compressor of two inlets connected with the high-pressure heat exchanger and the outside evaporator. Mathematical models about vapor injection compressor have been built. The performance analysis is carried out under variable conditions. The results show that the vapor injection heat pump using electric motor waste thermal and ambient air has more performance in low ambient. The optimal opening about the high-pressure electronic expansion valve (EXV) is 13%, and the optimal COP for the air conditioning system is 1.75, the car inside outlet temperature higher than 40°C.
Research on vehicle cabin temperature and thermal comfort optimal control based on fuzzy PID
Authors: Piao Changhao , Wang Weiwei , Liu Ziyang , Wu Cunxue , Yuan Rongdi
Published: April 2021

The heat load of the car compartment is complex and difficult to express with mathematical models. Therefore, this paper establishes a compartment physical model of an electric car through Amesim and simulates the heating process of the heat pump air conditioning system. Because the load of the passenger compartment of the car is complex and changeable, and the heat pump air-conditioning is a large inertia, hysteretic system. This study designs fuzzy rules and uses fuzzy PID to control the temperature of the passenger compartment. Fuzzy PID control has 1.6% less overshoot than PID control and 39 seconds less setting time. At the same time, this paper establishes a thermal comfort model of cabin temperature and humidity. It uses PMV (predicted average vote) and PDD (dissatisfied percentage) thermal comfort index to evaluate the passenger cabin’s thermal comfort. The PMV index controlled by fuzzy PID is more stable than the PMV controlled by PID.
Future Ceiling Design Based on Fischer
Authors: Li Yuqi , Yang Chenglong , Liao Yusen , Li Jiacheng
Published: April 2021

This design cleverly integrates modern machinery and control technology into the home system, and cleverly combines intelligent machinery and intelligent life, making family life more intelligent, comfortable and convenient. Use the ceiling as the carrier to realize the three-dimensional home design, make full use of the indoor top space, and solve the problems of small residential space and difficult storage. The main functions contained in this device are stored indoors. The introduction of this design conforms to the trend of intelligent family life and greatly facilitates people’s daily life.
Influence of finite element structural modification on dynamic characteristics of transmission tower
Authors: Jian Mingjian , Li Jidong , Deng Hualing , Zhang Huakai , Yuan Tangqing , Chen Yang
Published: April 2021

Taking a 500kV dry type single circuit angle tower as the research object, the computational modal analysis of the established finite element calculation model is carried out. It is found that local vibration occurs at the bottom of the transmission tower. The weakness of the original structure lies in the intersection of the longest web, the deformation displacement of the joint is the largest, so the structure needs to be strengthened. There are two corresponding strengthening methods: Diamond reinforcement and positive cross reinforcement. Further analysis results show that the regular cross structure has a certain strengthening effect on the original structure.
Fault Diagnosis of Rolling Bearing Based on EEMD and MMTS
Authors: Teng Lehua
Published: April 2021

Aiming at the non-stability of vibration signals and the inaccuracy of signal extraction of motor bearings, a fault diagnosis method based on the ensemble empirical modal decomposition (EEMD) and Multiclass Mahalanobis-Taguchi system (MMTS) is presented. Firstly, the original vibration signal is processed by EEMD and the processed signal is decomposed into a series of IMF with different characteristic time scales. Then select several IMF components in which the signal energy is concentrated to calculate the characteristic parameters of each order of IMF to construct fault eigenvector. Secondly, the fault eigenvector is used as input to construct the MMTS for fault identification. Finally, the accuracy of the method is verified by the bearing data set collected by the Electrical Engineering Laboratory of Case Western Reserve University (CWRU). The results show that the method can diagnose rolling bearing faults quickly and accurately.
Simulation Analysis and Parameter Optimization of The Electronic Controlled Injector
Authors: Nie Tao , Yang Kun , Zhou Lei , Wu Xin
Published: April 2021

In order to improve the dynamic response characteristics of the electronic controlled injector, a simulation model for the response characteristics of the electronic controlled injector was established. By comparing the calculation results of the simulation model with the experimental results, the validity and accuracy of the model are verified. The influence of inlet hole diameter, outlet hole diameter and needle valve diameter on the dynamic response characteristics of the needle valve of the electronic control injector was studied. The results show that the closing delay time of the needle valve decreases with the increase of the inlet hole diameter of the control chamber, the opening delay time of the needle valve decreases with the increase of the oil outlet diameter of the control chamber, and the closing delay time of the increase of the diameter of the needle valve and the opening delay time decreases. An orthogonal experiment with three factors and four levels was designed to optimize the structural parameters of the electronic control injector. The optimized results show that the dynamic response characteristics of the injector are improved.
Solving the Optimal Strategy of “Crossing the Desert” Based on Dynamic Programming
Authors: Chen Zhou , Liu Qingxing , Cai Yuxiang
Published: April 2021

In real life, many practical situations need to maximize the benefits under certain conditions. This paper studies the B problem of the 2020 National College Students Mathematical Modeling Contest. Through the establishment of a mathematical model, a combination of weighted undirected graphs, dynamic programming, computer simulation and multi-person non-cooperative models are used to discuss different conditions. The best decision and maximum benefit. For question one, get the maximum benefit of the first and second levels; for question two, solve the strategies that players should adopt for the third and fourth levels; for question three, it is concluded that players should use under normal circumstances Specific strategies.
Airborne infrared aircraft target detection algorithm based on YOLOv4-tiny
Authors: Hou Xiangguan , Ma Jianwei , Zang Shaofei
Published: April 2021

Aiming at the problem that the current aerial infrared aircraft targets are blurred, low contrast, and susceptible to noise interference, which can lead to inaccurate recognition, an improved YOLOv4-tiny infrared aircraft target detection method based on cavity convolution is proposed. First, in order to make full use of the shallow features, add a parallel branch after the feature layer whose output size of YOLOv4-tiny is; then, after the first network output layer, add three parallel holes of 1, 3 respectively. 5. The depth of 5 can separate the hollow convolution layer to expand the feature map receptive field; finally, the feature fusion network is improved, the final output feature layer of the network, the improved anti-residual block extraction feature, and the size is adjusted after convolution. The prediction result is processed and output by yolo head. Experiments on the aerial infrared aircraft data set show that compared with the original YOLOv4-tiny, the detection accuracy is increased by 4.29% and the detection effect is significantly improved under the premise of less loss of detection frame rate and small weight.
Open VPN Application Under Campus Network
Authors: Zhou Zhengchun , Huang Tongcheng
Published: April 2021

For security and intellectual copyright considerations, colleges and universities generally have the same problem: non-campus residents cannot access many resources on the campus network. OpenVPN is an open source based on the SSL protocol, combined with the actual needs of campus network applications, it describes in detail how to use the open source OpenVPN technology on the LINUX operating platform to build a user access system. Users can quickly access campus resources by establishing a connection with the OpenVPN server through the client program. Without additional investment, the confidentiality of data is ensured. It allows users to break through the limitations of time and space, which not only facilitates users, but also improves the utilization rate of campus network information resources.
Handwriting with Brain Computer Interface
Authors: Xue Jiachi
Published: April 2021

BCI is the acronym for “Brain Computer Interface”, which is now used to help the patients who suffer severe spinal cord injuries to interact with the world. The BCI will record the neuronal activities from the upper motor neurons, and subsequently, the scientists can analyze and decode these neuronal activity signals to enable the patients to interact with their surroundings. R. Wilett et al., conducted a study to use BCI to allow paralyzed patients to perform handwriting, which is one of the most essential steps for the patients to communicate with others. In this essay, the paper written by R. Wilett and his team will be reviewed, and thoughts on the future development of this technology will be given at the end.
Reliable Personnel Positioning in Industrial Environments Based on Improved Adaptive EKF With Random Packet Loss
Authors: Wang Xiaoyan , Wang Wenyan , Bai Xuejiao
Published: April 2021

In the complex industrial environment, random packet loss may occur in the process of sensor data transmission. The traditional Extended Kalman Filter (EKF) algorithm will reduce the estimation accuracy, even lead to the divergence of the estimator. To solve these problems, an improved adaptive extended Kalman filter (IAEKF) is proposed to estimate the covariance matrix of process noise adaptively. At the same time, the forgetting factor of strong tracking filter (STF) is introduced to improve the robustness of the algorithm in the case of random packet loss. Simulation results show that IAEKF algorithm can effectively reduce the personnel positioning error in the case of random packet loss, and has better localization accuracy, meeting the requirements of industrial environment.
Correlation Analysis, Optimization and Computer Simulation of Teaching Efficiency and Blended Learning of Higher Vocational English Based on POA and CoI Algorithm
Authors: Jin Xu
Published: April 2021

Blended learning has become a popular form of teaching. In order to study a more scientific and reasonable learning plan, this paper uses CoI theory and POA theory to design the teaching plan. First of all, the use of POA theory output, input, output of the three stages of pre-class, in-class, after-class design respectively. The main task before class is to assign output tasks, preview the contents of the class and exchange doubts with students. In class, the teacher checks the students’ study before class. According to the students’ learning situation and output results, pertinently explain the knowledge points and summarize the information involved in the students’ independent output. Review the output according to what you have learned after class. At the same time, the corresponding teaching plans are made according to the three elements of CoI theory: social existence, teaching existence and cognitive existence. After that, it analyzes the correlation between teaching efficiency and teaching methods. The experimental results show that blended learning is better than traditional teaching methods. Finally, the optimization scheme is put forward, and the summary and prospect are carried out.
Research and Simple Calculations on Public Transport Card Data
Authors: Yang Yefan
Published: April 2021

Big data is one of the hottest topics nowadays. Under the background of smart city and intelligent public transport, a large number of scholars begin to use big data of public transport in urban transport planning. This paper, combined with dozens of the latest journal papers, combined with their own understanding, focuses on the development of bus IC card big data, application status and research prospects, forming a reading report.
Fluid-cloth coupling algorithm based on PBD and CCD
Authors: Huang Sijie , Zhou Kun
Published: April 2021

In order to simulate the interaction between cloth and fluid, we use Smooth Particle Hydrodynamics (SPH) as a method in fluid simulation, we propose a Continuous collision detection (CCD) and position-based dynamics (PBD) collision constrained iterative flow coupling method. By analyzing the parallelism of the algorithm, we implement a low storage and load balanced fluid and cloth coupling algorithm parallel computing is used to accelerate the simulation. The experimental results show that our method realizes the bidirectional coupling of fluid and cloth, and improves the simulation performance.
Research on the Computer Informatization in Multimedia Public Opinion Monitoring
Authors: Xu Chunshu , Xu Zhongyuan
Published: April 2021

This article designs and implements a Hadoop-based network public opinion monitoring system. The system uses HDFS as the underlying storage system, and builds a distributed database based on HBase on it for unified storage and management of public opinion information. The paper will introduce a Hadoop-based microblog public opinion monitoring system that can mine and analyse large-scale collected data, realize the discovery and tracking of public opinion hot topics, and the social network analysis of Weibo. The analysis results are visualized and presented for the party. Government agencies, large enterprises and other units and organizations discover sensitive information in a timely manner, grasp public opinion hotspots, grasp public opinion trends, and provide automated, systematic and scientific information support in response to public opinion crises.
Calculation of Pollutant Carrying Capacity in Shaanxi Section of Weihe River in China
Authors: Sun Xiaomei , Zhang Haiou , Wang Jian
Published: April 2021

At present, in the calculation of water pollution carrying capacity, only the guarantee rate of the driest month is 90% to calculate it. The water pollution carrying capacity of the water function area is relatively small, so it is more stricter to control the total amount of pollutants on this basis, and the actual water pollution carrying capacity is not fully utilized, which will form a significant constraint on the social and economic development. Moreover, it is inconvenient to assess the actual water environment management by using the annual pollution capacity obtained by this method. Therefore, this paper takes Shaanxi section of Weihe River in China as an example to calculate the pollutant carrying capacity under different guarantee rates, taking COD and NH3-N as the representatives of organic pollutants, and taking the national standard pollutant carrying capacity calculation model as a means to reflect the river’s pollutant carrying capacity under different guarantee rates, so as to provide reference for the comprehensive treatment of water environment in Weihe River basin.
Dynamic Patch Convolution (DPConv)
Authors: Deng Shuchao
Published: April 2021

Lightweight Convolutional Neural Networks (CNNs) due to the small amount of calculation and performance degradation, budget constraints depth (number of convolution layers), and width of CNN (number of channels), resulting in limited representation capabilities. To solve this problem, this paper proposes a new dynamic block convolution design to increase the depth or width of the model complexity without increasing the network. Instead of using a single convolution kernel in each layer, dynamic block convolution dynamically aggregates multiple parallel convolution kernels based on input-related attention. Assembling multiple kernels is not only computationally efficient, but also due to the small size of the kernel, but also has more representation capabilities. These kernels are aggregated in a non-linear manner through attention. The two methods of spatial dimension block and multi-head are used in the traditional CNN attention design. The image is divided into small images and then multiple attention mechanism weights are used for each small image. Compared with the traditional CNN attention, the experimental effect is better.
Parallel Multi-Branch Model with Multi-Resolution Interaction for Human Pose Estiation
Authors: Cai Lingyi , Liu Wei
Published: April 2021

In recent years, human pose estimation has become a research hotspot in the field of computer vision, and has extensive application value in many fields, such as activity recognition [1], action detection, self-drving, etc. This paper tries a novel multi-stage network structure to complete the task of human pose estimation, and focus on improving the loss of spatial accuracy caused by repeated downsampling and upsampling. The network structure contains multiple resolution subnets. After the original resolution is learned in the first stage, a low-resolution branch will be generated in each subsequent stage, and these branches can learn feature representations in parallel. Through continuous multi-scale and multi-resolution fusion, necessary information interaction between subnets of different resolutions can be carried out to obtain richer feature maps and make the predicted key point heat maps more accurate. This paper uses COCO keypoint detection dataset to obtain the relevant results of pose estimation, which verifies the effectiveness of this network.
Research on Computer Intelligent Electronic Information Sharing Platform System
Authors: Tian Rongming
Published: April 2021

With the rapid development of e-government construction, the total amount of government information resources has increased rapidly, and the quality requirements have been continuously improved, initially forming an open and shared environment for information resources. The information sharing and exchange platform is designed to solve the above problems. It aims to build a flexible, safe and reliable transmission system and provide a unified technical support environment for various applications. The information exchange and sharing platform is a basic platform facility for each application system, and the application system can exchange and share data with other application systems through the information exchange and sharing platform. Due to the lack of uniform data standards, specifications and formats, the comprehensive utilization level of information resources is limited. In order to build a computer intelligent e-government information resource sharing platform, this paper explores the establishment of an architecture for the organization, exchange and utilization of e-government information resources from a technical point of view, based on the existing research on the sharing methods and modes of government information resources sharing.
Simulation study on Air Outlet of Data Center
Authors: Liu Fuyi
Published: April 2021

How to reduce the amount of wasted cooling in corridors and gaps is a problem in data center air conditioning design. Modeling the data center airflow data and simulating the temperature distribution are the prerequisites and key points to solve this problem. This paper uses the optimal idea to establish a mathematical model to simulate the location of the air conditioning vent. Determine the layout of the computer cabinet based on the analysis of the internal and external environment of the computer cabinet. The external environment analysis is mainly the analysis of several directions: According to the CFD simulation and simulation, the wind speed and tuyere arrangement of the air supply port are compared and the optimal wind speed of the air supply port is obtained. For the problem of the ceiling height and the spacing of the upper air outlet, discuss the method of determining the air supply spacing on the air duct so that the upper air supply can cover all the air inlets of the cabinet to achieve the most reasonable air supply flow. For the numerical simulation and optimization of the airflow organization in the equipment room, it is easy to know that the farther away from the air conditioner, the higher the temperature is relative to the air conditioner, and the wind speed far from the air conditioner is relatively large, so the temperature in the distance is higher. Also, because the hot aisle has no ventilation slots, its temperature must be higher than the cold aisle. Therefore, the temperature in the hot aisle is higher than the ground and the air conditioner is far away. According to the airflow dynamic equation and the K-ε turbulence model equation, the Fluent software is used, and combined with the data given in the data center room, the airflow data is simulated. Finally, the best solution for setting the position of the air conditioning air outlet is given.
Design of high-order QAM modem algorithm
Authors: Chang Yinghui , Liu Changlong
Published: April 2021

More and more attention has been paid on the issue of bandwidth utilization. Nowadays, with limited frequency spectrum resources, the capacity of traditional communication system has not been able to meet the demands of users. Quadrature Amplitude Modulation (QAM) has become a critical technical solution for broadband wireless access and wireless video communication due to its advantages of high frequency spectrum utilization and high-power spectrum density. In order to further improve the control information transmission performance of high-order QAM, we propose a high-order QAM modulation and demodulation algorithm, which is designed from the aspects of interleave between channels, leading sequence, constellation modulation, frequency domain sampling and (Orthogonal Frequency Division Multiplexing) OFDM generation, etc. The simulation results demonstrate that the algorithm can ensure the reliable reception of control information.