bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Scheduling Algorithms in Uplink of LTE System
Authors: Yang Chuhua , He Jun
Published: April 2020

Downlink scheduling of LTE packet scheduling has been widely studied, while uplink scheduling is rarely studied. Aiming at the problem that uplink scheduling can not guarantee the transmission of real-time traffic packets within the delay period, a new uplink scheduling algorithm is proposed, we establish the target integer linear programming model by the delay constraints of real-time traffic. And aiming at the problem that the bandwidth of low priority traffic is insufficient and the overall QoS is affected when multi-class traffic is processed, a new scheduling algorithm for multi-class traffic is proposed, which includes multi-class traffic scheduling algorithm for eNodeB and priority adjustment algorithm for UE. Through our algorithm, emergency UE is always scheduled first, the algorithm can also maximize MAC throughput and satisfy the minimum QoS constraints. It can also improve the problem that the bandwidth of low priority traffic is insufficient. The experimental results show that the proposed algorithm can significantly improve LTE uplink performance.
SIFT Feature Image Stitching Based on Improved Cuckoo Algorithm
Authors: Li Jie , Liu Dujin
Published: April 2020

Traditional image stitching method based on SIFT algorithm that the stitching time is long and the efficiency is low, and the stitching effect is not ideal. In this paper, the location of the parasitic nest in the cuckoo algorithm is mutated, and an evolutionary reduction function is proposed for the step factor and the probability of discovery. On the basis of this, an improved cuckoo algorithm is proposed, and the edge points of the image are solved by this algorithm, and the comparison between the edge points of the image and the feature points in the SIFT algorithm is made. The results show that the time of image stitching is obviously reduced and the speed and quality of the splicing are improved obviously, and it can fully meet the needs of practical application.
Research on Safety Risk Management and Control of Live Work in Distribution Networks
Authors: Gu Jianwei , Zhang Peng
Published: April 2020

To ensure the power quality and satisfaction of power users, at the same time to reduce power outage losses for power supply companies, live operations are increasingly used in operation and maintenance of the distribution networks, which poses a great challenge to operator safety. This paper systematically studies the safety management and control of live working in the distribution network, analyzes the safety risks in the live working process, proposes corresponding safety protection measures, and calculates the rank member of the index based on the subjective and objective weights, introduces the D-S evidence theory fusion principle to fuse the hierarchical membership of the indicators, and gets security risk assessment results based on the principle of maximum membership.
Research on Energy and Agricultural Alternative Energy Based on Crop Biomass Fuel Power Generation
Authors: Li Zhiyuan , Fu Chaosong , Lv Xing
Published: April 2020

The development and utilization of biomass energy based on crop biomass fuel power generation is of great significance for promoting China’s ecological civilization construction, energy revolution and low-carbon economic development, and responding to the implementation of major national strategies such as global climate change. Based on the analysis of the status and trends of China’s biomass energy development, this paper systematically analyzes the challenges China faces in developing biomass energy, and discusses the strategies and key technical directions for the future development of biomass energy. The research results can be Chinese students. The rapid development of material energy technology provides theoretical support.
Optimal Decision-making of Multi-market Trading of Power Sales Companies Based on Renewable Portfolio Standard on Electricity-Consumption Side
Authors: Mu Yicheng , Yao Hanbing , Du Zhen’an , Hu Yuchuan
Published: April 2020

In the electricity market where the renewable energy quota system is implemented on the electricity selling side, the electricity selling company can complete the quota of consumption and realize profit through electricity trading, consumption trading, green certificate trading and other forms. Based on the all day renewable energy generation curve trading mode, this paper puts forward the corresponding trading rules, which can effectively promote the active consumption of renewable energy in the power selling side. This paper comprehensively compares the trading income of electricity selling companies in electricity market, green certificate market and transferable load market. Aiming at the maximum profit, it studies the operating strategy of electricity selling companies, which can provide reference for multi market trading decision-making of electricity selling companies.
Research on Fault Detection Method of Wind Turbine Generator Based on SCADA Data
Authors: Wang Xin , Guo Pengfei , Liu Weijiang , Li Chao
Published: April 2020

In this paper, a data driven fault detection model of the generator based on improved nonlinear state estimation (INSET) method was established and the residuals of all the relevant parameters were predicted synchronously. According to the residual distribution characteristics the alarm rules were designed. In case studies, the fault was detected timely and exactly for avoiding serious accident. In addition, compared with other conventional algorithms, the results showed higher prediction accuracy and sensitivity and indicated the feasibility of the method.
Research on Lighting and Energy Consumption in Large Space of Railway Station in Hot-Summer and Cold-Winter Zone in China
Authors: Cheng Jiayang , Zhang Hui , Wang Li , Tang Meng
Published: April 2020

Based on surveys and tests of railway stations in hot summer and cold winter zone in China, analyzed the status quo of railway station buildings. A performance analysis model of the Zhengzhou East Railway Station waiting hall was established to analyse the effects of scattered skylights and different aspect ratios on the lighting environment and energy consumption characteristics, provided reference for the design of Railway Stations in hot summer and cold winter zone.
An Improved Content Delivery Technology Based on Genetic Algorithm in Cloud Storage
Authors: Zhao Pu , Shang Jingtao , li Qian , Ma Mingyuan , Sun Xin
Published: April 2020

Compared with the traditional content delivery network (CDN), content delivery based on cloud storage has the advantage of reducing storage costs while providing superior data security over common storage solutions. There has been a lot of research on content delivery technology, but existing research on content delivery technology is rarely used in cloud storage based CDN. In this paper, we analyze the charging and content delivery mechanism of cloud storage, then propose a reasonable network topology and cost model. Based on the analysis of existing heuristic algorithms such as user greedy and server greedy, an improved content delivery technology based on genetic algorithm in cloud storage is proposed, which effectively reduces the content delivery cost.
Research and Implementation of Cross-correlation Symbol Synchronization Algorithm for Long Training Sequence Based on OFDM System
Authors: Wang Guofu , Guoyong Li , Zhang Faquan , Ye Jincai , Guojia Xu
Published: April 2020

Through the analysis of the classic protocol IEEE 802.11a in OFDM system. An OFDM symbol synchronization algorithm based on Long Training Sequence (LTS) is studied. The symbol synchronization estimation using the LTS sequence symbol cross-correlation method can improve the two parameters of the correlation delay D and the synchronization point decision threshold. It reduces the interference of noise on the decision threshold under the Gaussian White Noise (AGWN) channel and the difficulty of FPGA implementation; improves the accuracy of symbol synchronization and the probability of detecting symbol synchronization under a low signal-to-noise ratio. Simulation experiments and FPGA hardware implementation show that compared with conventional algorithms, the system performance is improved.
Research progress on human feel test method of Substation low frequency noise
Authors: Chen Wei , Hu Sheng , Wen Wei , Wu Xiaowen , Cao Hao , Lu Ling , Peng Jiwen
Published: April 2020

Low frequency noise has the characteristics of slow attenuation, strong penetration and long propagation distance. Compared with other types of environmental noise with the same equivalent sound level, the subjective annoyance of low frequency noise in substation is higher, which easily leads to the problem of public complaints. In order to quantify people’s subjective and objective feelings of noise, researchers established the relationship between subjective perception and objective parameters through human perception test. In this paper, the development history of low frequency noise human perception test method and the present situation are investigated, and a feasible human perception test method suitable for substation low frequency noise is put forward.
Research Progress of evaluation method and control limit for Substation low frequency noise
Authors: Hu Sheng , Wen Wei , Wu Xiaowen , Chen Wei , Lu Ling , Peng Jiwen
Published: April 2020

At present, the low frequency noise control limit standards are only suitable for indoor structural noise control, and it is urgent to establish standards or specifications for substation low frequency noise evaluation and limit value. According to the theory of spectrum gauge weight, the equivalent continuous A sound level decays the low frequency part of noise greatly, only from the aspect of loudness, it only considers the feeling of human hearing to noise, and fails to fully consider the subjective feeling of people’s annoyance to low frequency noise. The method of low frequency noise weight correction needs to be further studied. In this paper, the evaluation method of low frequency noise and the control limit standard are fully investigated, which can be used as a reference for the formulation of low frequency noise limit standard in our country.
The Construction of Air Energy Hot Water System in Colleges and Universities Students’ Dormitories
Authors: Huang Kun , Wang Bing , Zeng Qing , Wang Lihua , Guo Xiaoying
Published: April 2020

Hot water entering students’ dormitories is the development direction of school hot water system, and air energy hot water system is one of the main forms of heat supply in colleges and universities hot water system. This paper first describes the composition of air energy hot water system and BOT construction mode, then analyses the main equipment selection and operation mode of the system, and finally shows the construction effect diagram of the system. The results show that it is necessary and feasible to construct the air energy hot water system in colleges and universities students’ dormitories, which is worth popularizing.
Design of Solar Energy Automatic Tracking System Based on STC89C52
Authors: Huang Kun
Published: April 2020

This paper designs a solar energy automatic tracking system based on STC89C52. The photoelectric sensor collects the sunlight signal. After A/D conversion, the collected signal is sent to STC89C52. After data comparison, MCU sends out control signals. The step motor is used to control the level and pitch angle of the solar panel, so that it always faces the direction of sunlight, and realizes the sunlight tracking. The hardware design includes the minimum system of STC89C52 MCU, sunlight signal acquisition circuit, A/D conversion circuit, key circuit, motor drive circuit, etc. The software is written in C language, including main program, data acquisition subroutine, key reading subroutine, data comparison subroutine, etc. Through physical production and operation debugging, the design function is normal.
Design and Implementation of Portable Petrochemical Equipment Vibration Monitor Based on Multi-Layer Architecture
Authors: Zhao Weidong , Wang Shuqiang , Xue Qingjun
Published: April 2020

Current vibration monitors for petrochemical equipment show several problems, such as high cost, inconvenient for use, and so on. To solve these problems, this paper designed a vibration data collector and a data processing App system based on multi-layer architecture. The data communication is realized by Bluetooth. The collector collects the acceleration, the speed and displacement data of the equipment, and the data processing functions such as data storage, analysis, viewing, and uploading are realized by the mobile phone App system. This method not only can simplify the design of the collector but also can enrich the functions of the vibration monitor. Practices show that this vibration monitor has short response time for vibration measurement, works stably which can meet the actual demand for vibration measurement of petrochemical equipment.
Development and Design of Self-Adaptive Variable Diameter Robot for In-Pipe Inspection
Authors: Ling Zhangwei , Chen Yonggui , Tang Jie , Zheng Mulin
Published: April 2020

Pipeline defects such as aging, corrosion and cracks may result in the structural failure of industry pipelines, causing environmental pollution, energy waste and even catastrophic accidents of explosion. In-pipe inspection robots are regarded as an expected non-destructive testing tool of analyzing and evaluating in-pipe defects. This paper built a simple variable-diameter pipeline platform based on real pipeline environment. The movement of robots was analyzed to meet the functional requirements of variable diameter and obstacle-crossing. A design scheme of automated in-pipe robot with self-adaptive various diameter mechanism was developed, where a parallelogram connecting rod mechanism combining spring and feed screw nut pair was employed to adapt the diameter change of pipelines from 200mm to 250mm, actively and forcedly. Moreover, a digital camera device was equipped to perform on-line macro detections and in-pipe image acquirements. The results indicate that designed robot system has good various diameter properties. The work provides a reference for subsequent designs of in-pipe inspection robots.
Theoretical Analysis of a Water Hydraulic Internal Ball Gear Pump
Authors: Yang Yousheng , Yang Feihu , Fan Junqian , Yankey Richmond Polley
Published: April 2020

In view of current volumetric water hydraulic pumps, especially water hydraulic internal gear pumps, a scheme of an internal ball gear pump was proposed. Its working principle was expounded and the calculation methods of its performance parameters such as displacement, flow pulsation and maximum speed were studied. Compared and analysed the advantages and disadvantages of traditional displacement water hydraulic pump with ball gear pump, and its key basic technologies. The results show that (1) by engaging the concave/convex ball gears instead of the gears, it can realize the function of the pump; (2) the arrangement of multiple rows of radial staggered not only ensures the continuity and stability of the transmission, but also solves the phenomenon of water trapping; (3) displacement is proportional to the diameter of the ball (modulus) while flow pulsation is inversely proportional to the number of rows of ball gear. Also, the maximum speed is inversely proportional to the diameter of the concave ball gear and the density of the working medium, which is proportional to the inlet pressure of the ball tooth pump, etc... This study could lay a simple theoretical foundation for the development of high-performance water hydraulic internal ball gear pump.
The Experimental Study of the Influence of Modal to the Noise of the Hydrofoil
Authors: Xu Yingbo , Tang Denghai
Published: April 2020

In order to study the influence of modal to the noise of the blade, the tests of modal and noise are carried out in the cavitation tunnel. The modal of hydrofoil was measured in the water and the noises of the hydrofoil with different inflow velocity were tested. The results show that the frequency of the peak of the noise spectrum is not changed with the inflow speed increasing. The amplitude of the peak increases first and then decreases with the inflow speed increasing. The structural characteristic of the hydrofoil has important influence on the noise and the frequency of the peak is equal to the modal frequency.
Analysis of Construction Settlement of Shield Tunnel Crossing Metro Operating Tunnel
Authors: Zhang Mengheng , Wan Heng , Li Wei , Kang Huixin , Ding Xiuheng , Shen Peng
Published: April 2020

Based on the background of the Suzhou Metro Line 3 crossing the Line 1 operating tunnel, the finite element software MIDAS/GTS was used to perform 3D model and simulate the construction of the shield tunnel. The influence of shield tunnel penetration before and after strengthening on operating tunnels is studied. The research results show that the maximum settlement of the operating tunnel caused by underpass construction without reinforcement is 11.64mm, which exceeds the control value of 10mm, and deformation control measures must be taken. After reinforcement, the maximum settlement of the soil around Line 3 is only 5.65mm, the reduction of settlement about 50%, and the settlement control effect is obvious, which shows that it is feasible to take deformation control measures for pre-reinforcement of the soil around the tunnel.
Digital Life Analysis Based on R
Authors: Guo Yuewen
Published: April 2020

Based on R language ggplot2 and wordcloud2, this paper analyzes, collects and visualizes the collected personal behavior data sets, and completes the interpretation of personal digital life.
A Review of VSLAM Technology Applied in Augmented Reality
Authors: Tang Baihui , Cao Sanxing
Published: April 2020

With the development of the Internet, new technologies such as big data, artificial intelligence, virtual reality, block chains and quantum communications are emerging regularly and progressing. Augmented reality, as one of the important frontier directions of the new generation of information science and technology, integrates multi-media, sensors, new display technology, the Internet and artificial intelligence, and is gradually becoming a new focus of innovative applications in various industries. This paper details the development of VSLAM technology over recent years, and its application in augmented reality. We describe VSLAM’s development status, the classical schemes, and the specific system architecture of each scheme. The schemes are distinguished by their respective approaches to the four basic algorithmic frameworks: visual odometry, optimization, loop closing and mapping. We summarize current developments and existing problems and also consider the prospects.
Identification of Influence Factors on Accuracy Control of Non-Destructive Testing for Embedded Depth of Highway Guardrail Column
Authors: Hui Bing , Li Yubao , Xu Yongli , Ran Deqin , Shang Yong , Guo Qinghui
Published: April 2020

Combined with the project example of column buried depth nondestructive testing, the influence factors of signal-to-noise ratio of column buried depth nondestructive testing are analyzed. At the same time, the control measures to improve the accuracy are put forward according to the influencing factors.
Study on the Effect of Parallel Pipe Jacking Spacing on Surface Subsidence Deformation in the Pre-Construction Method of Tube Curtain
Authors: Zhang Jie , Zhao Xinyue , Li Yue , Zhang Junjie , Ren Guohui
Published: April 2020

In view of the feasibility of the pre-construction method of the tube screen, the paper makes a comprehensive and in-depth study on the law of the ground subsidence and deformation by means of theoretical analysis, numerical simulation and engineering test. The mechanism of parallel pipe jacking distance on surface settlement and the settlement calculation formula of parallel pipe jacking are studied. By means of numerical simulation, the law of surface subsidence with different jacking intervals is analyzed, and the accuracy of simulation is verified by combining with the monitoring of surface subsidence in actual engineering. The main conclusions are as follows: (1) By studying the subsidence mechanism of parallel pipe jacking distance to the surface, the necessity of controlling the surface subsidence by controlling the pipe jacking distance is expounded; (2) By comparing and analyzing the numerical simulation results of different pipe jacking distances, the vertical displacement values of the ground under different working conditions were obtained; (3) By comparing the engineering monitoring data with the numerical simulation results, it is proved that it is feasible to control the surface settlement by adjusting the pipe jacking distance.
Analysis on the Optimization of Agricultural Products Logistics in Huairen City
Authors: Li Dandan , Hou Hanping , Yang Jianliang , Yao Tianhui , Zhang Kexin , Liu Xinlu , Ren Hongzhi , Wang Wenjuan , Wang Liting
Published: April 2020

The essence of agricultural products logistics is the entity flow and information transfer from producer to consumer, which not only meets the needs of customers, but also realizes the value of agricultural products. Huairen city has a huge demand for the modernization of agricultural products logistics because of its natural location advantage and the active guidance of national policies. Although the city has made progress in the construction of transportation facilities and logistics industry, there are still problems such as backward level of cold chain logistics, low level of standardization and informatization, and shortage of talents. Therefore, based on the theory and practice, this paper analyzes the current situation, explores the future development direction of Huairen city’s agricultural products logistics, so as to accelerate the establishment of a modern agricultural products circulation system, promote the rationalization and adjustment of the agricultural structure.
The Evaluation of Logistics Performance of Harbor-Front Station Based on DEA
Authors: Zhang Kexin , Hou Hanping , Yang Jianliang , Yan Xinxin , Ting Jiangmeng , Yu Mingli , Yang Xiqing , wang Yue , Zou Jingyan
Published: April 2020

The evaluation of logistics performance of harbor-front station is conducive to the realization of efficient and coordinated logistics operations at harbor-front station, thereby achieving seamless connection between railways and ports, accelerating the turnover of sea-rail combined transport containers, thereby improving the logistics efficiency of sea-rail combined transport. This paper points out the role and responsibility of harbor-front station in sea-rail combined transportation. It uses C2R model of data envelopment (DEA) analysis method, in consideration of input and output indexes determined on the basis of the logistics evaluation index, then establishes horizontal logistics performance evaluation system to carry out the logistics performance evaluation. According to the results, this paper puts forward specific and constructive measures for the logistics operation and management of the harbor-front station.
Planter Pressure Information Acquisition System Based on STM32
Authors: Liang Xiaoyu , Zhao Jingbo , Wu Youyu
Published: April 2020

This paper introduces a plantar pressure detection and analysis system based on flexible membrane pressure sensor. The system collects and analyzes the data through the wireless Bluetooth module, and transmits the data and results to the upper computer.The performance of the system was tested and analyzed through the upper computer platform written in C ++.The results showed no significant jumps and mutations.
Prediction of Horizontal Displacement of Foundation Pit Based on NAR Dynamic Neural Network
Authors: Sun Zongjun , Li Kai , Li Zhongyi
Published: April 2020

Absrtact. NAR dynamic neural network has the function of feedback and memory, which can be effectively used in time series data modeling. Taking the actual horizontal displacement of a foundation pit in Qingdao as the experimental data, the time series prediction model of the horizontal displacement of the foundation pit is established by NAR dynamic neural network. The model is applied to predict the horizontal displacement of foundation pit, and compared with grey prediction, support vector machine and BP neural network. The results show that the prediction accuracy of NAR dynamic neural network model is high. It has strong stability and can be effectively applied to the prediction of foundation pit displacement.
Road Crack Detection Using Deep Neural Network with Receptive Field Block
Authors: Yang Jing , Fu Qin , Nie Mingxin
Published: April 2020

Cracks are common pavement diseases that affect pavement performance. To maintain the road in good condition, localizing and fixing the cracks is a vital responsibility for transportation maintenance department. However, traditional manual detection methods are considerably tedious and require domain expertise. Therefore, the research on automatic detection and identification of pavement crack is of great significance for ensuring traffic safety and pavement maintenance decisions. In this paper, we propose an automatic pavement crack detection network based on the Single Shot MultiBox Detector(SSD) deep learning framework, and introduce the receptive field module to enhance the feature extraction capability of the network, which ensures real-time crack detection and also improves the performance of accuracy in pavement crack detection.
Accurate Calculation Method for Mechanical Specific Energy of Horizontal Well
Authors: Wang Shuangshuang , Li Qian
Published: April 2020

The existing drilling efficiency-monitoring model based on the theory of mechanical specific energy is only applicable to vertical wells. When it is used to monitor the drilling efficiency of horizontal wells, the impact of high friction in horizontal wells is not considered, so the monitored specific energy of the machine is not real Specific energy of horizontal wells. Based on the previous research results, this dissertation uses the micro-element method to segment the drill string into micro-elements, and considers the influence of the friction torque of the horizontal well. For the existing horizontal wells, rotary drilling, sliding drilling and the characteristics of compound drilling have derived the mechanical specific energy calculation models of horizontal wells based on these three different drilling conditions for real-time monitoring of drilling efficiency of horizontal wells.
An Improved Evaluation of Comprehensive for Mine Fire Risk
Authors: Wang Linlin , Tong Ruigang
Published: April 2020

Because of the uncertainty of the influencing factors of coal mine fire in China, it will lead to the uncertainty of the evaluation results in the comprehensive evaluation of coal mine fire risk. Based on this, the goaf management, ventilation conditions, coal seam geological occurrence, and exploitation technology are used as first level evaluation indexes, and the fuzzy comprehensive evaluation method of fusion Dempster-Shafer evidence theory (D-S) is used to establish a comprehensive evaluation system for coal mine fire risk. The fire risk of Qiuji Coal Mine was comprehensively evaluated. The example shows that the fuzzy comprehensive evaluation method based on D-S can consider the uncertainty of influence factors more accurately and improve the accuracy and reliability of the comprehensive evaluation of coal mine fire risk.
Evaluation of the Compactness of Benefit Coupling of Farmers’ Cooperatives in Poor Areas: Based on the Date in Qinba and Wumeng Areas in Sichuan, China
Authors: Fu Xinhong , Du Zhijing , Zhang Xiyu , Chen Xue , Li Jianqiang
Published: April 2020

As a new type of agricultural management, farmers’ cooperatives play a critical role in the development of rural industries and the promotion of farmers’ poverty alleviation. However, in recent years, the problem of non-standardization and “empty shelling” of farmers’ cooperatives has seriously restricted the common development of their interests with members. Based on the field research of farmers’ cooperatives in the poverty-stricken areas of Qinba and Wumeng in Sichuan, this paper estimates the close relationship of the interests of farmers’ cooperatives in poor areas in Sichuan and summarizes the problems of farmers’ cooperatives in poor areas. The empirical results show that the poverty alleviation funds invested in the cooperatives have a positive effect on the compactness of benefit coupling, that the cooperatives are more closely related to the degree of closeness, and the sales linkage and rebate linkage are mainly semi-closed. The degree of frequency of the looseness of the equity linkage is high, and the tightness of service is mainly loose. Therefore, it is suggested that cooperatives should integrate resources, quantify equity, and clarify property rights to strengthen the close connection with the interests of members, and drive farmers to lift poverty and increase income.
Inverse Kinematics Analysis of Hybrid-Driven Special Five-Bar Mechanism for Shield Machine
Authors: Nie Jianjun , Wu Xiaowei , Yan Hongzhen
Published: April 2020

To simplify the inverse kinematics model of special five-bar mechanism based on Assur group, a inverse kinematics model is proposed by using vector analysis method and Euler’s formula, which is expressed by all explicit equations and establishes a direct relation between the output motion and the input motion. A numerical example and a computer simulation were conducted to verify the mathematical model. Results show that the motion law of control bar l4 obtained directly from the mathematical model is consistent with the result from ADAMS simulation, and the mathematical model of the special five-bar mechanism is correct and can be used to analyze the motion law of the drive bar and the control bar directly according to the motion parameters of the output point.
Characteristics of Tunnel Water Inrush and Progress in Grouting Materials in Mira Mountain Tunnel
Authors: Chen Wei , He Zhihao , Zhang Hao , Huang Teng , Peng Wenbo
Published: April 2020

Mira mountain tunnel is located in high altitude and cold area. Due to the influence of fragile ecological environment such as thin air and complex geological conditions, the tunnel would be liable to cause geological hazards. This paper will analyze the characteristics and causes of geological disasters in Mira mountain tunnel, combined with the research progress of grouting water stop material for tuff tunnel in high altitude and high cold area, so as to further guide the actual grouting construction and reduce the risk of geological disasters.
The Application of Principal Component Analysis in Stability Evaluation of Foundation Pit
Authors: Xia Weiyan , Wang Wei , Yuan Jiaqi
Published: April 2020

The foundation pit stability is the key and difficult point in foundation pit engineering research. The stability and safety of the foundation pit should be ensured not only by its excavation, but also by the surrounding buildings.Because the stability of foundation pit is decided by many complicated factors, it has a certain randomness.This paper adopts the principal component analysis method combined with engineering examples to calculate and analyze the six influencing factors that affect the stability of foundation pit: land subsidence, groundwater level, pile top settlement, horizontal displacement of pile top, reinforced concrete brace and inclination.The results show that inclination and pile top displacement have the most important influence on the stability of foundation pit. According to this study, the principal component analysis method has higher accuracy in the stability evaluation of foundation pit and has certain reference value, which can provide theoretical basis for the stability evaluation of foundation pit in related projects.
Research on Extraction Method of River Water from MODIS Image of Mountainous Areas in Western Sichuan and Optimized by DEM Data
Authors: Li Bo , Wang Meikai , Tang Jun
Published: April 2020

This paper has studied the extraction method of river water in the mountainous area of western Sichuan. We combine the two advantages of higher time resolution of MODIS and digital simulation of DEM surface terrain. This method can remove the shadow of the river and refine the effect of water. We have the advantage of applying MODIS to river monitoring. However, due to the narrow river channel in the western Sichuan Mountains, the region has mountain shadows and mixed snow cover, which makes the river edge areas blurred. We use existing methods to extract water bodies and the real situation is different. In order to apply the advantages of MODIS data to the monitoring of Mountain Rivers in this experiment, we selected the area flowing through the upper reaches of Minjiang River as a typical research area. After sampling and analyzing the typical features in the MODIS data for multiple days, this experiment The NDVI method was improved, and then it was combined with the MODIS band 1 data to obtain the mountain water body enhancement index (MEWI). In the end, this experiment realized the fuzzy treatment of mountain gullies in the image and highlighted the water body. Based on the previous work, we removed the blurred shadows of the edges of the MEWI water body by extracting regions with lower DEM slopes. The results show that after removing the channel shadow based on DEM, the channel water body is refined.
Research on Soil Shear Strength Device Based on Shear Wave Velocity
Authors: Wu Xin , Li Qing
Published: April 2020

The shear strength of soil refers to the ultimate resistance of the shear stress generated by the external load of the soil. The strength problem is one of the most important basic contents of soil mechanics, and shear failure is an important feature of strength damage. At present, the monitoring methods of the soil shear strength device, such as indoor direct shear test, triaxle compression test, large-scale direct shear test on site, and on-site cross shear test, cannot realize real-time measurement in situ in the long-term field. In this paper, a device for measuring the shear strength of soil based on shear wave velocity is proposed, and the shear strength of the soil in situ can be obtained in real time.
A Modified Sequential Method for Solving the Full Composition Model in Numerical Reservoir Simulation
Authors: Hu Xiaodong , Wang Min , Shi Anfeng , Liu Zhifeng , Wang Xiaohong
Published: April 2020

A modified sequential method (MSEQ) is proposed in this article to solve the full composition model in numerical reservoir simulation. During the iterative process, in order to solve the composition equations efficiently, the pressure field is treated as fixed temporarily, then the topological sorting algorithm is employed to update the saturation and mole friction field. Through the topological sorting for the grids from upstream to downstream, the full field coupled composition equations can be decoupled and solved with high efficiency as same as the explicit difference scheme. Numerical tests are performed and the high performance of the proposed MSEQ is illustrated. It can predict the simulation results with the same accuracy, and its computational speed is more than 2 times faster than the fully implicit method (FI) and the traditional sequential method (TSEQ).
A Systematic Review and Meta-analysis of Robotic Gripper
Authors: Long Zhang , Jiang Qian , Shuai Tao , Wen Feijuan , Liang Chunping
Published: April 2020

With the rapid development of robotics, robots gradually replace people to complete various tasks. Grasping is one of the most common tasks in industry and daily life. In addition to typical pick-and-place task, grasping a tool is the basis for performing other tasks, such as grabbing the key to open the door, grabbing a hammer to nail, etc. The robotic grippers are the manipulator in which the robot completes the grasp. Their performance characteristics have a significant impact on work efficiency because they are the parts interacting with the grasping objects directly. Therefore, this paper researches on robotic gripper and its related technology from the following aspects. First of all, the current robotic gripper type is analyzed in detail. Second, the research status of the most promising robotic gripper is reviewed widely. Third, the critical technology of robotic gripper is studied deeply. Finally, the analysis of robotic gripper development trend is performed prospectively.
Optimization of the position layout of in-vehicle central information display based on genetic algorithm
Authors: Xu Wenxia , Tan Jianjie , Ma Jun , Gong Zaiyan , Zhang Jing
Published: April 2020

In-vehicle central information display (CID) has become an essential part in the cockpit. It is of great theoretical significance and application value to optimize the position layout of CID, which help to improve driving safety and operating comfort. In this paper, the ergonomics experiment is designed and the driving simulation test method is used for the experiment. Based on the collected data for genetic algorithm, the fitness function is set, and the process of gene selection, crossover and mutation is simulated to obtain the optimized coordinates of the position layout of the central control screen. According to the results of optimization, ergonomics experiments are carried out again to verify the reliability of the optimization results. This paper has guiding significance for the development of digitalization in the cockpit.
A Range Doppler Imaging Algorithm Based on the MSR Spectrum for the Multi-Aperutre Syntactic Sonar
Authors: Lv Jinhua , Tang Jinsong , Wu Haoran
Published: April 2020

For ignoring the azimuth variation of the “non-hop-go-hop” time, the existing imaging algorithm for multi-aperture have a poor imaging in moderate squint, so this paper proposes a multi-aperture range Doppler imaging algorithm based on the spectrum of method of series reversion. The exact range history is approximated once, and the error can be adjusted by the order of Taylor series expansion. Then, the analytical expression of the two-dimensional spectrum is obtained by the method of series reversion. In signal processing, the signal of the single aperture is handle with the squint range Doppler imaging algorithm, and the azimuth spectrum is superposed to each aperture, to obtain the image. Finally, the effectiveness and correctness of the algorithm is provided by the simulation experiments.
Design of Cantilever Deflection Compensation Mechanism for Three-Stage Cylinder
Authors: Fan Jinwei , Tao Haohao
Published: April 2020

In order to solve the problem of large deflection caused by insufficient rigidity of the existing three-stage cylinder cantilever mechanism, a new design scheme is proposed. By installing lifting hydraulic cylinder at the front end of the first stage cylinder of the multi-stage cylinder and installing hinged structure at the back end of the first stage cylinder, the pitch angle of the whole cantilever is changed to compensate the deflection of the cantilever. The simulation and data fitting are carried out by using ANSYS and MATLAB software, and the measurement mode of the existing laser rangefinder is improved, and the electrical control system of the device is optimized. Finally, the deflection of the device is further reduced by optimizing the structure and control system.
The Effect of Dual-injector on Combustion Process of 396 Series Diesel Engine with Shallow Basin-shaped Combustion Chamber
Authors: Liang Yu , Zhou Liying , Huang Haomin
Published: April 2020

The 396 series diesel engine has high performance and reliability and long service life, and it has been widely used in many areas, especially in the field of military and industrial power plants. By applying shallow basin-shaped combustion chamber, the original fuel injection system of the 396 series diesel engine can be improved easily. With two symmetrical injectors in each cylinder, two injectors can be used to spray diesel at the same time, or one injector can be used to spray ignition diesel and the other injector can be used to spray biodiesel or alcohol fuel. A 3D combustion model of the 396 series diesel engine with shallow basin-shaped combustion chamber was established by using the computational fluid dynamics software FIRE. When 8-hole single-injector and 4-hole dual-injector were respectively adopted, the combustion process was simulated to compare and analyze the fuel spray, ignition start point, combustion pressure, combustion heat release rate, average temperature in cylinder and NO emission, and the impact of injection duration and fuel injection advance angle on the combustion process were discussed. By increasing fuel injection pressure, shortening fuel injection duration and increasing fuel injection advance angle properly, the combustion process of 396 series diesel engine can be improved when an 8-hole single-injector was adopted. When a dual-injector was applied, the fuel spray space distribution area was wide, combustion process was improved, cylinder pressure and temperature became high, combustion was relatively sufficient and thermal efficiency got high. Proper reduction of fuel injection advance angle and extension of injection duration can mitigate the condition of large NO emission and higher cylinder pressure when the dual-injector was adopted. The combustion process of the 396 series diesel engine with shallow basin-shaped combustion chamber can be improved obviously and the thermal efficiency can be improved by adopting the dual-injector and selecting proper injection duration and fuel injection advance angle. This research result is conductive to improve the combustion process of the 396 series diesel engine with shallow basin-shaped combustion chamber and provides a basis for using biodiesel and alcohol fuel in the diesel engine.
Prediction of Explosion Power of Fuel Air Mixture in Coal Mine by Improved BP Neural Network
Authors: Ma Shengxiang , Shi Xunxian , Yu Chenglong
Published: April 2020

In order to improve the feasibility and accuracy of predicting the explosion power of fuel air mixture, a method of BP neural network prediction is proposed by combining factor analysis method with BP neural network. Using factor analysis method, the original data of 9 fuel air mixture explosion power factors were processed by dimensionality reduction data, 2 common factors were obtained, and 2 common factors were substituted for 9 fuel air mixtures as input layer parameters of BP neural network. A prediction model of coal and gas outburst with the combination of factor analysis method and BP Neural network is established to predict the explosion power of fuel air mixture. The prediction model of the explosion power of the fuel air mixture is selected to verify the improved BP neural network prediction models, and the final results are as follows: The relative error range of four prediction samples is 0.16%-7.58%, all less than 10%. The improved BP neural network prediction method is used to solve the problem of the traditional BP neural network because of the excessive number of input layer parameters, low data processing efficiency, slow iteration rate and low precision, which provides a new research way for predicting the explosion power of fuel air mixture.
Research on The Current Situation and Development Measures of Rail-Water Intermodal Transport in Guangzhou Port Group
Authors: Hu Guojie , Sun Wanhua , Jiang Jian
Published: April 2020

The development of rail-water intermodal transport is not only the strategy of national development, but also the inevitable result of the adjustment of national transport structure. The development of rail-water intermodal transport will greatly reduce the logistics cost of the whole society and promote the development of social economy. In this paper, Guangzhou Port Group in Guangdong, Hong Kong, Macao and Pearl River Delta region is the main research object. The problems faced by the development of rail-water intermodal transport are analyzed, and corresponding countermeasures are put forward to promote the development of rail-water intermodal transport in Guangzhou Port Group and increase the proportion of container rail-water intermodal transport.
Research on the Relationship between Highway Trip Demand and Social Economy in the New Normal Economic stage of China Based on Panel Data Analysis
Authors: Sun Zhuoqun , Zhang Yi , Ji Wenbo , Li Shengli , Wang Chao , Ye Zhirui
Published: April 2020

As China entered the new normal of economy, the economic growth rate and industrial structure are undergoing huge changes, which has also profoundly affected the traffic volume of expressways. Therefore, analyzing the relationship between socio-economic and transportation demand is crucial for transportation planning and demand management. This study analyzed the interaction of socio-economic and trip demand from 2008 to 2017, which was a crucial period for Shandong’s industrial transformation and economic development. To achieve this goal, principal component analysis and panel data analysis methods were applied to our issue.
Realization of the Airborne System for Moving Target Detection and Tracking Based on Quadrotor
Authors: Ding Yongfei , Wei Chunyan , Wang Xinhua , Li Jiahuan
Published: April 2020

In this paper, taking quadrotor as the research object, a kind of airborne vision system is presented to detect and track the moving target. Lower cost and better performance are the remarkable characteristics of the system. Firstly, the overall scheme of the detection and tracking system is designed. Secondly, a new image detection algorithm based on HSV color model and template matching is proposed, then according to image principle, the relative distance from quadrotor to target is calculated. In order to solve the time delay caused by image processing, the target position prediction is made by adding Kalman filter. Then, according to the position information of quadrotor and target, a segmented PID controller is designed to improve the tracking effect. Finally, the algorithm is applied to the actual flight of the quadrotor to verify its feasibility.
Population migration and environment reconstruction of Bay Area Urban Agglomeration——Evidence from the Beibu Gulf Megalopolis
Authors: Hu Zhaolian
Published: April 2020

Bay area construction is an important part of regional energy and environment construction and high-quality economic development, and people-oriented is the core of high-quality development, so it is of great significance to re-examine the development of Bay Area Urban Agglomeration and energy and environment structure from the perspective of population migration. Based on the gravity data of Beibu Gulf Urban Agglomerations, this paper uses the social network analysis method to deconstruct the population migration and spatial network structure of urban agglomerations. The results show that the network strength of the Beibu Gulf Urban Agglomeration is gradually increasing, and the network integrity is significantly enhanced; the external radiation effect of the central city is enhanced, showing the spatial characteristics of “gathering and diffusion in one”. The conclusion of this paper is of great significance to the formulation of energy and environmental policies and the promotion of high-quality development of bay area integration.
Autonomous evasion method for drones under static threat
Authors: Dai Chao , He Qian , Liu Yang , Yan Nan
Published: April 2020

In the flight area, it is difficult for drones to have a clear understanding of all threats in advance, that is, there are some sudden static threats, which requires real-time detection and avoidance of drones during flight. This paper proposes an improved RPG method for UAV threat evasion guidance control, and gives the UAV threat evasion guidance law.