bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization design of electric field potential for high-speed EMU high voltage box
Authors: Zhao Ming
Published: April 2021

Establish the three-dimensional model of high-voltage box and its internal main electrical equipment of EMU. Under the lightning overvoltage condition, through modeling and analyzing the electric field potential distribution of high-voltage components of EMU, understand the insulation weak links of high-voltage components, optimize the insulation gap of high-voltage components, local structure of components and system layout, and systematically master the layout design of high-voltage equipment of EMU method. The research results show that under the lightning overvoltage condition, the areas with higher electric field strength are mainly concentrated in the inlet port of the cable and the outlet port of the circuit breaker, the maximum electric field intensity is concentrated near the electrode of the electromagnetic voltage transformer, and the maximum field strength in the high voltage box is 21.5kv/cm, which meets the air breakdown standard, has certain safety margin and meets the insulation requirements.
Optimizing Research on Solar Cell Semiconductor Materials in Optoelectronic Materials and Devices
Authors: Ma Dinghan
Published: April 2021

Organic solar cells are considered to be a promising new generation of optoelectronic devices. Electrode materials are one of the most important parts of organic solar cells and have a direct impact on battery performance. The research of organic electronics is mainly concentrated in the field of organic semiconductors, and the research and development of related materials and devices have made rapid progress, including organic light-emitting diode display technology, organic thin film transistors, organic solar cells, organic memories, organic sensors, organic lasers, etc. A large number of research results have been obtained in the research of related organic semiconductor materials and devices. The paper analyses some common solar semiconductor battery materials, and prospects the application of the above-mentioned materials in solar cells in the future.
Research on the Bearing capacity of aircraft metal skin with pit damage
Authors: Zhao Luchun , Zhao Zhiqin
Published: April 2021

Pit is a kind of damage form that often occurs in the daily operation process of aircraft. It is formed by permanent plastic deformation due to the impact of foreign objects. In addition to the stress concentration caused by structural geometric changes, it will also produce local residual stress in the interior. Its impact on fatigue cannot be evaluated only through the stress concentration analysis of structural geometric changes. In this paper, the bearing capacity of the damaged metal skin dent is studied. By establishing the finite element model, the stress of the intact structure and the dent with different width depth ratio is compared and analysed.
Numerical simulation of mechanical properties of recycled concrete based on characterization of interfacial transition zone characteristics
Authors: Zhang Yichao , Lin Xuelian , Zhou Jinghai , Sun Hong , Ding Zhaoyang
Published: April 2021

Recycled concrete is the recycling of concrete waste materials. Making full use of recycled concrete can effectively reduce the consumption of natural energy and protect the environment. The interface transition zone of recycled concrete is complex and changeable, which leads to the instability of mechanical properties of recycled concrete. This paper summarizes the numerical simulation of recycled concrete and its interface transition zone, analyses the existing problems, and prospects the future development trend.
Research and Application of Spacecraft Pipeline Digital Development Mode Based on MBD Technology
Authors: Gao XiuHui , Jiang Hao , Zhang He
Published: April 2021

With the increasingly complex types, functions and structures of spacecraft, the requirements for the quality and cycle of spacecraft pipeline design are becoming higher and higher. By summarizing and analyzing the shortcomings of the traditional development mode of relying on drawings and documents as the carrier, and fully combining with the advanced technology of Model-Based Definition (MBD), the digital development mode of spacecraft pipeline based on MBD technology is proposed. Through the built-in pipeline design rules, the construction of standard parts database and CNC elbow, etc., and relying on the Virtual Product Management (VPM) management platform, with a set of pipeline digital model as the information carrier, runs through the design, process and welding work, shorten the spacecraft pipeline development cycle, improves the design quality, and significantly improves the quality control level.
Assessment of Grasp Ability for An End-effecter with Fin-ray Structure
Authors: Bu Lingxin , Hu Guangrui , Chen Jun
Published: April 2021

In this article, a flexible three-finger end-effector based on fin ray effect (FRE) was performed to evaluate the ability to resist dynamic loads during apple picking. A finite element method (FEM) simulation was performed to predict the FRE gripper’s tensile force using Abaqus software. The results of response surface analysis (RSM) showed the significant effects of TPU stiffness, grasp distance and fruit size on the vertical tension of the end-effector. Moreover, there is a good correlation between the test results and the regression model. The findings in the present study provide a reference for the application of the FRE gripper in fruit harvesting.
Structural Design and Thermodynamic Analysis of a Missile Borne RF Module
Authors: Li Jia , Jiang Shouli , Leng Tongtong
Published: April 2021

The volume, weight and heat dissipation resources of missile borne SAR seeker are seriously limited, and the working environment is extremely harsh. Therefore, more stringent requirements are put forward on the structural design and thermal design of the electronic module on the missile borne SAR seeker. In this paper, the modular structure design and passive thermal control of a missile borne RF module are studied. In order to improve the interchangeability of products and simplify the design, a universal RF module based on JVPX connector is designed in this paper. In view of the high-speed and high-temperature physical working environment of the SAR seeker, the structure of phase-change heat sink is adopted in the module, which solves the thermal control problem of short-term reliable operation of the heating chip on the module. Finally, the effectiveness of the passive heat dissipation is verified by simulation analysis.
Research on the application of technology of replacing bridge Bearings without interrupting traffic
Authors: Qiao Guodong , Gao Xin , Ren Kan , Tao Jiangjiang
Published: April 2021

This article determines the bridge jacking plan and proposes a construction organization design without interruption of traffic, based on the research of bearing disease and cause analysis, bearing technical condition evaluation, jacking plan, traffic control, safety technical plan, quality acceptance and other related technologies. According to the evaluation result of the bearing technical condition, an implementation plan for replacing the support without interruption is established, whose rationality and necessity are verified by the support project.
A kind of new “dust-free” rice thresher
Authors: Li Jiacheng , Cui Yue , Han Wenyu
Published: April 2021

The project was designed based on air curtain dust control of novel small rice threshing apparatus, mainly involves dust reduction in the working process of agricultural machinery, specifically belongs to the field of agricultural machinery emission reduction. The apparatus is designed feeding modules, threshing modules, dust module, the control module total four modules, means by using a vertical multi-feeding port semi-feeding type of structure, in the while maintaining efficiency reduction rolling straw produced powder dust and realizes dust removal from the source. By adopting the air curtain dust control technology, the dust produced is restrained within the specified range at the first time of diffusion, and further dust control is realized.
A Design of Intelligent Wardrobe Imitating Labyrinth
Authors: Zhang Wenze , Chen Yijing , Xu Feilong
Published: April 2021

This paper presents a new type of intelligent wardrobe based on the application of family daily life. Through the innovation of mechanism combination and electronic control, the device realizes the imitation labyrinth design of the wardrobe, and realizes the user’s intelligent access to clothes. The upper cabinet lattice is lowered to a position suitable for users to access clothes through a series of movable pulley structure in coordination with the horizontal movement of the lower cabinet lattice, so as to make rational use of the high space. The addition of intelligent electronic control module makes it easier for users to get the clothes they want. The device has excellent performance, simple operation process, low cost in space and economy, wide target audience and good market prospect.
Design and Analysis of A Novel Handcuffs with Two Locks
Authors: Zhang Jie , Gong Xianhong
Published: April 2021

The locking mechanism of raditional handcuff ring is simple with lower reliability. A noval handcuffs was designed. Besides the traditional ratchet locking structure, a magnetic locking structure was added to ensure the security. The appearence and structure of the novel handcuffs were designed and validated with FEM analysis. Meanwhile, the handcuffs were smoothly contoured.
Effect of grain size refinement on microstructure and mechanical properties of AZ31 magnesium alloy
Authors: Wang Xin , Li Mingda , Ma Songyuan , Zang Ji , Li Dongping
Published: April 2021

In this paper, microstructure and mechanical properties of ultra-grain size and coarse-grain size bulk AZ31 magnesium alloy were evaluated using tensile testing. The ultra-grain size (200nm) bulk AZ31 magnesium alloy showed well mechanical properties with stronger tensile strength (315MPa), typical ductile fracture surface and deep dimples, which can be attributed to grain size refinement of bulk AZ31 magnesium alloy.
Research on Enterprise Trust Relationship of Jilin Province Agricultural Products Supply Chain Based on Big Data Blockchain Logistics
Authors: Yang Jisheng , Wang Haiwen , Li Zhenzhen , Chen Haonan
Published: April 2021

Relationship and trust are essential factors to aggregate the agricultural product supply chain’s central bodies and maintain the agricultural product supply chain’s dynamic flexibility. Especially for the agricultural product supply chain dominated by e-commerce with many atomic farmers, relationships and trust are even more critical. The basic premise to ensure its effective operation. Big data blockchain has high security, distributed storage, publicity mechanism, anonymity, openness, transparency, etc. It is of great significance to apply it to the supply chain of agricultural products. Based on the analysis of the significant data blockchain logistics and the relationship between big data and the supply chain, this article discusses the construction and coordinated decision-making of the big data-based supply chain of agricultural products in Jilin Province provides references for relevant personnel.
Research on Injury of Different Percentile Dummies Based on Vehicle Angle Collision
Authors: Wu Yongqiang , Meng Lingxu , Yan Deyou
Published: April 2021

Angle collision has a high incidence in traffic accidents, but there are few researches on angle collision in the field of automotive safety. The 50th dummy is the main protection object in vehicle safety design, and the 5th dummy and 95th dummy are not paid enough attention. In this paper, based on the 18 ° sled collision platform of interior fittings, the injury characteristics of 5th dummy, 50th dummy and 95th dummy under the condition of angle collision are studied. The results show that the 5th dummy’s chest injury index is the largest; the 50th dummy’s pelvis and right thigh force injury index is the largest; the 95th dummy’s left thigh force injury index is the largest; which indicate that different percentile dummies are injured in different degrees in the 18 ° angle collision. Based on the test results, it is also suggested that the chest, thigh and other injury of the dummy should be appropriately considered in the evaluation of the interior fittings test
Mechanical simulation optimization of RTG prototype
Authors: Wu Chunyu , Liu Yang , Yang Shuaifei , Li Yang , Wang Shuyang , Gao Ke , Liu Shichao , Jin Yang
Published: April 2021

The thermocouple energy converter in the radioisotope thermoelectric genera tor (RTG) requires a long time work under high temperature and large temperature diff erence, and needs to withstand the harsh service conditions of heat, force, electricity an d other external fields during the launch process. In order to understand the dynamic p urchase response and dynamic strain of various parts of the structure when the thermoe lectric module is under dynamic load under different conditions, this paper uses softwa re to simulate the vibration and shock scenarios of the thermoelectric module in the RT G prototype. According to the existing conditions, a three-direction impact spectrum a nalysis was carried out. It was found that in the three-direction random vibration, from the root mean square stress result, the risk of damage is small; while during the impac t, the shell and the thermoelectric The displacement in the in-plane direction between t he module furnishing surfaces will cause the thermoelectric material in the thermoelect ric module to produce a large shear stress, which will cause the risk of shear damage to the structure. The imitation result provides a reference for the further optimization des ign of RTG prototype.
Design of Testing Device for Mechanical Property Testing System of Tai Lake Shield
Authors: Weng Yunxian , Zhao Yaping , Ni Xuewen
Published: April 2021

According to the requirements of testing the mechanical properties of water s hield from Tai Lake the corresponding testing system was designed by adopting the id ea of open structure. The test system includes the detection device, the upper computer operation unit and the connected control unit. The testing device adopts a vertical fram e suitable for testing materials in water, USES a stepper motor to drive the lead screw t o achieve the basic tensile movement, and can achieve other testing functions through the addition of shear, friction and other expansion modules. The upper computer USES Kingview7.5 to develop the test interface corresponding to each test function, which c an carry out manual debugging and automatic test operations, and input the measurem ent data and process parameters into the MySQL database to provide real-time display and historical query functions. The main controller is realized by Arduino Mega2560 c ircuit board, which communicates with the HX711 conversion module through the sin gle bus protocol to collect the stress data of materials. By monitoring the running proc ess of stepping motor, the material deformation data is calculated. Through communic ation with Modbus RTU protocol of upper computer, operation command and test data transmission are realized.
Overview of Obstacle Avoidance Algorithms for UAV Environment Awareness
Authors: Zuo Kuijun , Cheng Xuan , Zhang Heng
Published: April 2021

In complex indoor and outdoor environment, obstacle avoidance of UAV (Unmanned Aerial Vehicles) is a challenging problem. In order to realize the obstacle detection, autonomous positioning and trajectory planning of UAV flight mission in large outdoor scene, there are three main technical problems: Firstly, UAV needs to have the ability to quickly detect a variety of obstacles in outdoor scene. Secondly, in order to realize the autonomous navigation of UAV, it needs to establish the coordinates of obstacles in three-dimensional space. Thirdly, based on the above two conditions, UAV can independently plan flight path to avoid obstacles. This paper mainly introduces the use of RGB-D camera, lidar, monocular camera and binocular camera in UAV obstacle avoidance, and compares them from the sensor types, advantages disadvantages and application range. Secondly, the path planning strategy of UAV is discussed, and the existing problems and current research results of UAV trajectory planning strategy are described. Finally, it is pointed out that real-time computing, multi-sensor fusion and integrated obstacle avoidance between multi aircraft should be the research direction of autonomous obstacle avoidance navigation for UAV in the future.
A gravitational search algorithm based on levy flight
Authors: Zhao Jing , Zhu Haidong , Hu Yinhua , Hu Enjun , Huang Baole , Zhang Tingyu , Zhang Pan
Published: April 2021

A gravitational search algorithm based on levy flight is proposed to solve the problem that the gravitational search algorithm falls into the local optimal solution. Firstly, the dynamic adjustment strategy of gravitational constant is introduced to increase the diversity of particles and improve the convergence speed and accuracy of the algorithm. Then, on the basis of gravitation search algorithm, levy flight is introduced, and the particle search range is increased by using levy flight search mode combining small step and long stride search, so as to improve the global search capability of the algorithm. Finally, six standard test functions are used for simulation analysis. The results show that the improved algorithm has obvious advantages in both convergence speed and convergence precision, and it is more advantageous in multi-peak function optimization.
A Positioning System on Robot for Agricultural Environment
Authors: Bi Xiaoming , Tang Wenjie , Gao Zihang
Published: April 2021

Focus on the complex environment in the wild, we designed a positioning system for agricultural environment. This system has multiple parts such as SLAM robot, remote console, mobile monitoring terminal, cloud monitoring platform, which fully fulfills the requirements of the dynamic positioning system. The system takes into account the characteristics of wide positioning range and large coverage area of the SLAM robot, which can greatly reduce the positioning complexity of the system and reduce the required positioning equipment, while reducing operating costs and increasing the coverage area.
RETRACTED: Research on Short Video Photography Technology Under the Integration of Computer Editing in The New Media Era
Authors: Qiang Fu
Published: April 2021

with the development of new media technology and the popularity of mobile devices, the short video platform has become one of the standing applications in the public’s mobile phones, and the short video tool has added a new color to the development of video shooting technology while enriching the spiritual and cultural life of the public. In the era of new media convergence, short video shooting technology has become an indispensable part of video shooting, in view of this, this paper mainly focuses on the analysis and research of short video photography technology under the integration of computer editing in the new media era.
Remote Sensing Image Zero Watermarking Algorithm Based on DFT
Authors: Jing Liang , Sun Zhentao , Chen Kexin , Wen Xue , Cheng Xinyi
Published: April 2021

This paper proposes a remote sensing image zero-watermark algorithm based on DFT, which can be used to protect the rights and interests of digital image copyright owners. First, the high frequency part after DCT transformation is binarized to obtain the characteristic image. Second, block DFT processing the host image. The high frequency part after DFT and the characteristic image are XORed to complete the watermark embedding. In order to test the performance of the watermark, an attack was carried out on the image embedded with the watermark. In order to extract the watermark from the attacked image, the high-frequency part of the data extracted from the attacked image is XORed again with the result of the first XOR. Compare the extracted watermark with the embedded watermark, and calculate its NC value. Most of the NC values are close to 1, indicating that the algorithm is robust. In addition, the PSNR values of the attacked image and the original image are also calculated. The experimental results show that the watermark obtained by the algorithm in this paper has strong invisibility and robustness.
Research on the Application of Computer Network Technology in the Training of Talents in Vocational Education
Authors: Deng Lin
Published: April 2021

With the continuous deepening of education reform, the processing and analysis of teaching information in higher vocational colleges is increasing. Traditional teaching management methods can no longer meet the needs of higher vocational colleges. Computer technology is more suitable for the needs of education reform, and the modern development of teaching management with computer technology as the core promotes the comprehensive level of teaching management in higher vocational colleges. This article analyzes the impact of computer technology on the training of talents in higher vocational education; the current situation of talent training in higher vocational education at this stage, and discusses how to innovate and reform the talent training model in higher vocational colleges under the background of computer technology.
Research on the application of crawler technology in machine learning
Authors: Zhang Lei , Chen Zening , Yang Shufeng
Published: April 2021

With the rapid development of the Internet, the world wide web has become the carrier of a large number of information, and the search engine has entered the public life. In order to help search engines capture related web resources, web crawlers emerge as the times require. Web crawler is a program that automatically extracts web pages. Some malicious web crawlers will not only steal the information of the website, but also cause irreparable damage to the website. Along with it, anti-crawler, the enemy of web crawler, comes into our life. This paper studies the use of machine learning for crawler recognition, so as to make a better anti crawler strategy, use machine recognition instead of manual recognition, reduce the workload of manual recognition of crawler, reduce the loss of human and material resources, and improve the recognition rate of crawler, so as to protect the website information and website equipment.
A recommendation method of teaching resources based on similarity and ALS
Authors: Geng Chuanwei , Zhang Jian , Guan Lianzheng
Published: April 2021

This paper provides a collaborative filtering recommendation algorithm based on the combination of item similarity and alternating least square collaborative filtering based on the Spark platform. This is a recommended method to improve the efficiency of prediction calculations and reduce system response time. In order to solve the problem of model inaccuracy caused by the sparse data of the existing collaborative filtering recommendation scheme, which leads to the inaccuracy of recommending suitable online education and teaching resources to different users, the present invention uses the least squares collaborative filtering recommendation algorithm on the Spark big data analysis platform Optimize and use, and then use parallel methods to increase the amount of work completed per unit time and the accuracy of recommendations, and solve the problem of inaccurate recommendation of teaching resources.
Making Sales Strategies Based on the Existing Shopping Reviews
Authors: Shi Jingcheng , Yang Yan , Qiu Shi
Published: April 2021

With the popularization of mobile Internet technology, people are increasingly inclined to choose to use the internet to purchase products. Consumers’ evaluation of products after online shopping will directly affect the future sales of the products, so many online shopping platforms are committed to the research of intelligent evaluation and analysis models, so as to improve their sales strategies in a timely manner. We take the evaluation of three kinds of goods on Amazon as the research object. The platform allows purchasers to give star-rating and text-based review of products, and also lets them vote for the helpfulness of the former reviews. Therefore, we need to figure out the relation between these factors. We construct an innovative Maximum-Relation-Minimum-Redundancy Feature Selecting Model to analyze how the text-based measures and ratings-based measures affect the reviews, especially on some occacsions at whichthe review has significant positive changes. We also discuss the connection between the specific quality descriptions of text-based reviews and the level of star-ratings. We use an innovative model, Bi-LSTM model to calculate the rate of different emotions contained in the review texts. Then we can find out a remarkably high correlation between certain descriptors and the star-ratings. This paper puts forward an intelligent and constructive scheme for e-commerce platform to adjust its own sales strategy based on customer’s reviews on products.
Research on Precise Demand Forecast of Retail Commodities Based on LSTM-ARIMA Joint Model
Authors: Song Haoran , Du Dengyu , Li Yao
Published: April 2021

Aiming at the retail forecasting problem, this article uses software such as MATLAB, SPSS, and Python as tools, and uses dual correlation analysis, LSTM neural network-ARIMA joint model, and BP neural network-based subclass-skc fusion model, etc., to get an impact on skc sales. The importance of the factors and accurate forecasts of sales.
A study on the Application of Computer Music in Mass Music Tutoring
Authors: Liu Jie , Liang Liang
Published: April 2021

Computer music occupies an important place in the field of musical art, a highly expressive and creative genre that opens up a whole new path for innovation in music production. With the continuous improvement of people’s living standard nowadays, more and more people begin to pay attention to the improvement of spiritual needs, and mass music culture is loved and recognized by people in this environment, and has been vigorously promoted. For the implementation of mass music tutoring, the application of computer music technology has an important role to play, not only to break the limitations of traditional culture, but also to enhance the musical ability and music literacy of the masses. This paper makes an in-depth study on this, firstly, it elaborates the concept of computer music, introduces the specific composition of computer music system, and finally discusses the application ways of computer music in the process of mass music tutoring with the actual situation.
Channel Estimation Based on Compressive Sensing for Multi-User Massive MIMO Systems
Authors: Chen Qiang , Su Sunqing , Lei Guowei
Published: April 2021

Massive multiple-input multiple-output (MIMO) is becoming a key technology for future wireless communications. Channel feedback for massive MIMO is a challenging task due to the increased dimension of MIMO channel matrix. By exploiting the channel sparsity, channel estimation based on compressive sensing (CS) aims to reduce the feedback overhead in massive MIMO systems. In this paper, various CS algorithms for channel estimation in massive MIMO systems are summarized, and a novel CS algorithm, i.e. modified sparsity adaptive matching pursuit (MSAMP), is proposed hereupon. Moreover, various measurement matrices are introduced in the CS scheme. The performances of channel estimation and recovery are simulated and compared. It is inferred from simulation that, SAMP is very appropriate for reconstructing sparse channel information in massive MIMO system, especially the modified SAMP can give higher reconstruction, and some measurement matrix is suitable for certain optimal CS algorithms.
Design of parallel Computing based on Web Technology in Soil Moisture and Thermal process Simulation system
Authors: Hui Kong
Published: April 2021

Most of the traditional simulation software of soil water, soil and crops are based on the C-paw S model, and the efficiency of the simulation and calculation is relatively underground, and the organization and management of the data is slightly inferior, most of them are more powerful on the model. From the point of view of the early organization and management of the data, the simulation and optimization of the medium-term data, the visualization of the late platform and the efficiency of calculation, this project completes a new simulation platform with the help of the classical WHCNS model. At the same time, the innovation is to simulate and optimize the data with the help of big data technology, multi-thread technology, Web technology and the classical WHCNS soil-crop management model, so that the system has become an important experimental means of pilot-scale experiment, which can solve the problems of long experimental period, high cost and regional differences in the pilot-scale experiment of soil organic reconstruction. The simulation platform of the pilot test is constructed, and the relevant mechanism models and research models involved in the experimental research are coupled and integrated into the platform system to form a simulation process of data input-model simulation-calculation output and visual display. Used to assist the pilot test.
Simulation and Implementation of SLAM Drawing Based on ROS Wheeled Mobile Robot
Authors: Cui Yufan , Niu Zijie
Published: April 2021

In order to realize the establishment of the unknown terrain map in the indoor environment of the ROS wheeled mobile robot, this article uses Lidar, Raspberry Pi and other hardware to build the wheeled mobile robot, in the ROS environment, the robot is built by the URDF model, and the robot model is configured. Differential controller, keyboard control node, etc. Establish the simulation environment, use different simulation environments to visually simulate the robot, and simulate the two optimization algorithms in the SLAM algorithm to simulate the construction of the map. In order to explore the effect of SLAM’s different optimization algorithms on the construction of graphics, the SLAM algorithm based on filter and the SLAM algorithm based on graph optimization are introduced respectively. The robot is selected. After the robot is built, three different experimental environments are selected. A variety of map-building algorithms are used to experiment, comparing the effects of G-mapping algorithm and Cartographer algorithm to build maps in a small-scale, large-scale and multi-obstacle environment. Use the image processing software under the Linux system to analyse the map created by the robot in the experimental environment, measure the coordinates of the robot feature points in the created map by the number of pixels, and compare the actual coordinates of the location of the special point in the actual environment to evaluate Construction effect. By comparing the effects of the two algorithms on the contours of various obstacles when building a map, the effect of mapping in a multi-obstacle environment is evaluated. The results show that the SLAM graph-building algorithm based on graph optimization has a more stable graph-building effect.
Research on Energy Consumption Optimization Technology of Heterogeneous Network in Computer Communication Industry
Authors: Xiao Gengyi
Published: April 2021

In the environment of heterogeneous network nodes, the virtual network mapping problem of energy consumption optimization is not to minimize the number of working nodes and links. In order to study the energy consumption analysis of multi-mode terminals in wireless heterogeneous networks, by investigating the working mechanism of the terminal, using the energy-aware virtual network mapping heuristic algorithm to describe the communication state of the terminal, the energy consumption analysis equation of the terminal is obtained. The analysis results show that terminal energy consumption increases with the increase of call arrival intensity and call duration; the ratio of terminal energy consumption to voice services and the probability of discovering heterogeneous networks are in an approximately linear relationship; the heterogeneous network modules enter low energy consumption the waiting state does not save terminal energy consumption.
MCMC impute missing values and Bayesian variable selection for logistic regression model to predict Pima Indian Diabetes
Authors: Li Gongli , Liu Yueze , Li Han , Yao Ruikuan , Li Chenyang
Published: April 2021

Diabetes mellitus is a metabolic disease that causes high blood sugar. The risk factor of diabetes can be reduced significantly by early precise prediction. Lots of literatures published for diabetes prediction, but nearly all of them proposed frequentist Machine learning algorithm to classify and build models. Besides, their data pre-processing methods are not professional. In this literature, we are proposing MCMC filling missing values and Bayesian variable selection for logistic regression model to classify diabetes patients. It shows great performance (AUC = 0.884, sensitivity = 0.805, specificity = 0.875).
Research on Wireless Sensor Network Technology Based on Particle Swarm Algorithm
Authors: Wang Guanghui
Published: April 2021

The paper proposes a positioning method based on random particle swarm optimization algorithm. It is assumed that there are some anchor nodes in the wireless sensor network, and the distance information between adjacent nodes can be obtained. After the positioning node obtains enough distance and location information of the adjacent anchor nodes or the located nodes, the random particle swarm optimization algorithm is used Achieve positioning. Simulation shows that this method has higher performance than multilateral measurement method and positioning method based on standard particle swarm optimization algorithm.
Research on Key Technologies of VR based on MEC
Authors: Jiang Yuhao
Published: April 2021

Multi access edge computing (MEC) is an extension of 5G network on the edge side. Its network characteristics of high bandwidth and low delay provide necessary guarantee for the extreme user experience of VR (virtual reality). At the same time, the distributed architecture of 5g MEC network and the fast data exchange capability between nodes provide the hardware foundation for VR application marginalization deployment and equipment mobility access. Considering the cost and experience of VR, this paper first analyzes the advantages and disadvantages of VR based on traditional hardware architecture, and then describes the benefits of MEC on VR cost and experience. Finally, taking VR live video scene as an example, the key technologies of VR based on MEC are described.
Research on Mathematical Methods of Improving Fama and French Three-factor Model Based on ETF Factors
Authors: Wu Yanqing , Mo Xiaochong , Wang Yuanxin , Gan Fuwen
Published: April 2021

Will ETF factors help to improve Fama and French 3 factor Model? Research has examined the Fama French model in different countries and its risk premium in different mathematical ways. This paper reconstructs the Fama-French model by replacing market capitalization size index (SMB) and book-to-market ratio index (HML) to other Exchange Traded Fund (ETF) factors to investigate whether ETF factors will improve the Fama French model. After comparing 15 ETFs, Factors EMD (GDP growth index) and SMG (factor IYC minus factor IYK) are chosen for our adapted risk model because of a relatively low rate of correlation and covariance. 20 sample stocks are selected form various industries and market capitalization size, and used to test to the performance of FFM and the new FFM. The result has been analyzed from 3 different ways: correlation and covariance, R squared, and p value. Although the new model fails to perform better than a traditional FFM, it may be improved by adding more factors or choosing factors which are more representative of the market.
Basic structure and mathematical model of integrated energy system in ecological park
Authors: Song Qianqian , Liu Yongfu , Zhang Limei , Yang Tongxu , Zhen Linteng
Published: April 2021

The ecological parks are rich in available resources and have various types of energy. The reasonable utilization of the available resources in the park can promote the healthy development of the park. This paper analysed the wind and solar energy resources and their output in the ecological park, and gave mathematical models of typical energy production, conversion, and storage equipment. According to the energy consumption characteristics of the park, the ecological parks were classified based on the characteristics of wind and solar power generation, and the basic structure of the integrated energy system of the ecological park was given.
Research on the flow field of variable head water flow standard facility based on numerical simulation method
Authors: Li Haiyang , Zhang Liang , Hong Bian , Li Xuejing , Chen Yuyang
Published: April 2021

This paper introduces a basic method of using numerical simulation to calculate the internal flow field of variable head water flow standard facility. The content includes the procedure of 3D geometric modeling, mesh gridding and boundary condition setting. The numerical results visually shows the flow filed in the facility, of which proved the correctness and feasibility of the method. The simulation results provide constructive suggestions for the design and manufacture of variable head water flow standard facility.
Research on Credit Strategy Based on XGBoost Algorithm and Optimization Problem
Authors: Cheng Yunke
Published: April 2021

Small and medium-sized enterprises are the important foundation of national economic and social development, and play an important role in expanding employment, increasing income, improving people’s livelihood and national taxation. In this paper, the credit decision-making of small and medium-sized enterprises is deeply studied, and reasonable credit risk quantification results and targeted credit strategies are given. To solve the first problem, this paper establishes a multi-index scoring model based on XGBoost algorithm. According to the extracted features, the credit risk of 123 enterprises is quantitatively analyzed, and the enterprises are scored according to the quantitative results. Prioritize them by score and enterprise credit rating, take interest rate and loan amount as decision variables, and bank profit as objective function, establish a multivariate and single-objective credit strategy optimization model, and get the optimal credit strategy for each enterprise when the annual total credit is fixed. In view of the second question, this paper takes the data in Annex 1 as the training set based on the first question, and extracts the features of the relevant data in Annex 2. Using the enterprise multi-index classification scoring model based on XGBoost algorithm, the credit rating of 302 enterprises is predicted and their credit risks are quantitatively analyzed, and the enterprises are scored according to the quantitative results. Prioritize them by score and enterprise reputation grade, establish the same optimization model as the first one, and formulate specific credit rules to make the results meet the limit conditions of total credit, thus determining the interest rate and loan amount of each enterprise, and obtaining specific credit strategies. In view of the third question, this paper takes the epidemic situation in SARS-CoV-2 as an example, and comprehensively considers the impact of this sudden factor on different industries and different types of enterprises on the basis of the second question. Based on the impact of corporate profits, the data are updated, the indicators are extracted again, and the XGBoost enterprise multi-index classification scoring model is used to predict the credit rating of 302 enterprises again and quantitatively analyze the credit risk, and the enterprises are scored according to the quantitative results. Once again, they are prioritized according to the score and the reputation level of the enterprise. Use the optimization model in question 2 to adjust the corresponding credit strategy. The model established in this paper considers more indicators, and the quantitative and prediction results are reasonable. The algorithm and model can comprehensively consider the impact of unexpected factors and adjust the credit strategy in time. In addition to being applied to credit decision-making of small and medium-sized enterprises, it can also be extended to other types of financial fields, providing ideas for solving related problems.
Design of High Precision Image Measurement System for Small Workpiece
Authors: Zhang Xuelin , Fu Fengzhi , Fan JunPeng , Fan Hua
Published: April 2021

At present, there are many problems in the measurement of small machined parts (size ⩽ 70mm, such as micro circuit board, small non-standard parts, etc.), such as the difficulty and low efficiency of detection, the large data of sizes to be detected, and mainly rely on manual work. A high-precision image measurement system based on machine vision is designed in this paper, and the systematic error and random error of the machine vision measurement system are improved from hardware and software. Experiments show that size measurement of small workpiece with high efficiency and high accuracy can be realized by the system successfully. The measurement accuracy reaches micron level, which fully meets the testing requirements of production line, and has great value of industrialization promotion.
Hematology of Pangasionodon hypopthalmus Reared Under Controlled Photoperiod
Authors: Windarti  , Amin B , Simarmata A H.
Published: April 2021

Manipulated photoperiod has been used to improve the growth of cultured Pangasionodon hypopthalmus. Photoperiod length affects the fish physiology in general and thus reflected in its hematological condition. The hematology of P. hypopthalmus reared in short photoperiod was studied in May–August 2020. There were three treatments applied, namely natural photoperiod (P-Nat, fish tanks were placed under clear plastic tent), 18 hours dark (P-18D, the tanks were placed under dark tarp tent for 18 hours) and 24 hours dark (P-24D, the tanks were placed under dark tarp tent continuously). The fish (3 inches TL, 4 grams BW) were reared in circular tanks ( 100 L) at a density of 30 fishes/tank and fed with commercial fish feed pellets twice a day,, ad libitum. Blood samples were obtained prior to the experiment and at the 8th week. Results showed no significant differences in hematological parameters of the fishes among treatments. The number of erythrocytes and leucocytes in the pre-treated fish was approximately 1,850,000 and 55,200 cells/ml, respectively. While those of the treated fish was 1,760,000 and 54,600 cells/ml (P-Nat); 1.760.000 and 55,000 cells/ml (P-18D) and 1,790,000 and 55,000 cells/ml (P-24D). In pre-treated fish as well as all treated fishes, hemoglobin was around 10 g/dL and glucose was around 110 mg/dL. The percentage of leucocyte type cells were as follows: lymphocyte 65%, monocyte 24%, thrombocyte 6%, neutrophil 3%, eosinophil 1% and basophile 1%. The value of hematological parameters indicate that the fish was in normal and healthy condition and thus it is proved that shortened photoperiod do not affects P. hypopthalmus health in general.
Influence of Phytogenic Feed Additives on The Health Status in The Gut and Disease Resistance of Cultured Fish
Authors: Caipang C M A , Suharman I , Avillanosa A L , Gonzales-Plasus M M
Published: April 2021

Phytogenics are plant-derived natural compounds in the diets that aim to improve animal production. Several of these plant-derived substances have been tested in various aquaculture fish species particularly on their effects on growth and systemic immune response. Most of the previous studies demonstrated positive effects in improving growth, lowering the feed conversion ratio (FCR) and modulating the various immune response parameters in fish. While nutritional strategies are mostly designed towards the use of plant-based materials as feed ingredients or partial substitutions for the more expensive fish meal in the fish diets, recent initiatives have been targeting the use of these phytogenics as feed additives. The tissues and organs of the digestive system are the ones that have close contact with the phytogenic additives once these are ingested by the fish. Once, digested and absorbed, these substances are distributed throughout the body where they affect the physiological conditions of the fish, including its ability to provide resistance against various infectious diseases. The present work provides a short review on the effects during dietary administration with these phytogenics on gut health and disease resistance in fish. A synthesis of available information on these biological aspects in fish will provide a platform towards developing functional feeds in aquaculture.
Estimation of Growth Parameter on Sailfin Catfish (Pterygoplichthys pardalis) in Bengawan Solo River, Central Java Province
Authors: Aida S. N. , Ridho R. , Saleh E. , Utomo A. D. , Nurhayati
Published: April 2021

Bengawan Solo river 548.53 km is the longest river in Java Island Indonesia, which crosses provinces of Central Java and East Java. Bengawan Solo river is heavily polluted by agricultural, industrial and domestic wastes, especially in Surakarta Residence, Central Java. The impacts of pollution in Bengawan Solo river are poor water quality, the population of native fish has declined sharply and some were almost extinct. The fish that develop was Sailfin catfish (Pterygoplichthys pardalis) because these fish were resistant to pollution. The study aimed to determine the growth parameters of Sailfin catfish (P. pardalis) in Bengawan Solo river. Estimation of growth parameter using length frequency data analysis was done using the FISAT program package. The results of growth parameters of Sailfin catfish (P. pardalis) showed that infinity length (L∞) = 41.75 cm; acceleration of growth (K) = 0.48 cm/year. Natural mortality (M) = 1,1; fishing mortality (F) = 2.47; and total mortality (Z) = 3.57. Exploitation rate (E) = 0.69. The conclusion is the fishing mortality of Sailfin catfish is quite high, while natural mortality is low because the fish are resistant to pollution.
Green Catfish (Hemibagrus nemurus) Seeds Cannibali at Different Stocking Densities
Authors: Heltonika B , Zairin M , Widanarni  , Suprayudi M A , Manalu W , Hadiroseyani Y
Published: April 2021

Green catfish is a high economic value commodity in Riau. However, cannibalism in green catfish seeds is still an obstacle in its hatchery, and so far there has been no specific study of cannibalism in green catfish. The purpose of this research was to study the cannibalism of the green catfish seeds at different stocking densities. The research used a completely randomized design with four treatments, namely stocking density 1 (A), 2 (B), 3 (C) and 4 (D) indvidual/liter with five replications. A feed with 40% protein was given four times a day at satiation. The results indicated that the cannibalism index increased with the increase in stocking density, namely 32, 34.5, 53.33 and 51.50%, respectively. The highest incidence of cannibalism was at stocking density of 3 individuals/l, but it was not different from that of 4 individuals/l. The dominant cannibalisms are type 1 cannibalism, namely 26, 27.5, 50.67 and 43.75% respectively; however, type 2 cannibalism did not differ among treatments. There was no difference in growth performance among treatments. It could be concluded that there is a link between cannibalism and an increase in stocking density in the green catfish seeds.