bluuebunny/crossref_metadata_2025 huggingface dataset:
Reconstruction of power fault signal based on big data fusion
Authors: Huijuan Shen , Guoqing Xin , Weiguang Dong , Xiaoqiang LV
Published: August 2020

In order to solve the storage difficulty of power failure signals under big data fusion, which leads to the waste of hardware resources, this paper proposed a Dice-gradient projection for sparse recovery (Dice-GPSR) algorithm based on the compressed sensing theory to reconstruct the fusion signals. Firstly, the algorithm optimizes the support set based on the Dice coefficient measure matching criterion, changes the search direction and iterative search path of the gradient projection sparse reconstruction algorithm, and improves the convergence speed. Secondly, the sparsity of the signal is estimated and the flow of Dice-GPSR algorithm is given. Finally, Dice-GPSR algorithm is used to reconstruct the original signal and compare the reconstruction performance with other reconstruction algorithms. The simulation results show that Dice-GPSR algorithm has higher reconstruction accuracy and reconstruction signal to noise ratio than other reconstruction algorithms.
Research on big data storage and compression method for dual core intelligent meter
Authors: Ming Wei , Xiang You Feng , Qiang Wang , Xiao Feng Shen
Published: August 2020

With the rapid integration and development of cloud computing, big data and smart grid, not only the type and accuracy requirements of the collected data are increasing, but also the storage depth is getting higher and higher. In hardware, the dual port RAM design is used to improve the real-time performance of reading and writing, digital filter is used for preprocessing in software, and “Equivalent Normalization (EN)” is used to improve storage depth. These schemes save hardware storage space and improve data transmission efficiency in practical application. So the advantages of dual-core intelligent power meter will be further exploited and brought into play.
Design and Application Analysis of Intelligent Low-voltage Switchgear Based on Internet of Things
Authors: Qi Jiajin , Wu Feifei , Zhong Hengqiang , Wang Liqun
Published: August 2020

Low-voltage switchgear is a key control device in the power distribution network, which integrates a large number of lines and power electronic components. Once a failure occurs, it will cause serious economic losses. With the continuous upgrade and expansion of the power system construction scale, the traditional low-voltage switchgear can no longer meet the requirements in terms of function or performance, and is replaced by a new type of intelligent switchgear. This paper designs an intelligent low-voltage switchgear based on the Internet of Things, real-time monitoring of temperature and key electrical parameters, and improves the reliability and maintainability of the switchgear.
A Computer Vision Based Detection System for Trash Bins Identification during Trash Classification
Authors: Yu Yue
Published: August 2020

In this study, an image based detection system is designed and applied to identify different trash bins for classification. The CCD industrial camera is used to obtain the RGB format images on the trash disposal line in real time. In order to reduce the effect of environmental brightness, the obtained RGB format images are transformed into HSI color format. According to the calculated saturation and hue values, the threshold of saturation and hue values is set for the following image segmentation, respectively. Then, accurate position information of trash bin is obtained for the subsequent classification processing. This detection system could overcome environmental constraints and improve efficiency for trash classification.
RSS Positioning Algorithm Based on Maximum Likelihood Recursive Estimation and CKF
Authors: Ning Xiao , Shuai Shi
Published: August 2020

In order to improve the positioning accuracy of indoor and dense obstacles, a positioning algorithm based on maximum likelihood recursive estimation and cubature Kalman filter is proposed for the positioning technology based on the received signal strength. The algorithm consists of two steps: initial position estimation and mobile location. Firstly, according to the principle of triangulation, the possible target region of mobile terminal is determined and the region is divided into smaller possible target region step by step. Then, based on the hybrid cooperation of the received signal strength and time of arrival, the nonlinear CKF filter is used to realize the mobile location. Finally, MATLAB is used to simulate the algorithm, and the simulation results show that the proposed method has better positioning performance even in the shadow area.
Simulation analysis of complex electromagnetic environment effect of helicopter engine
Authors: Yan Qiuying , Zhou Xiuqing , Jia Yunfeng , Chen Lei
Published: August 2020

With the improvement of equipment informatization, the adaptability of complex electromagnetic environment of airborne engine equipment is becoming increasingly important. The mechanism and degree of influence of complex electromagnetic environment on engine are quite different, which has seriously threatened flight safety. In order to predict and analyze part of electromagnetic environment faced by airborne engine, FEKO electromagnetic simulation software is used for simulation research. According to the relevant test methods of SAE-ARP5416, SAE-ARP5412, GJB-1389A and other standards of American Society of engineers, the field strength and cable coupling of airborne engine under lightning effect and high field intensity irradiation are predicted by simulation. The conclusion has certain guiding significance for further research on complex electromagnetic field protection of engine.
High efficient polymer solar cell processed by environment-friendly solvent system
Authors: Chen Jinxiang , Zhou Hang
Published: August 2020

In this paper, we fabricate the solution-processed solar cell to investigate the effect of the boiling point of the solvent additive on the performance of the polymer solar cell. We select the non-halogen solvent trimethylbenzene (TMB) as the host solvent and 2,2-(1,2-ethanediyldioxo) diethyl mercaptan (EOS) as the solvent additive to process the solar cell based on the FBT-Th4(1,4): PC71BM. The best power conversion efficiency is over 10%, which is the best result among the solar cells based on FBT-Th4(1,4): PC71BM. It should be noted that EOS can fast remove completely during the film-forming period. In order to investigate the underlying reason that the performance is improved, the TEM and AFM measurement are carried on. At last, we research the air stability and thermal stability of the solar cell processed with the new solvent additive.
Design and Implementation of Container Global Monitoring Device Based on Low-Orbit Satellite Communication Module
Authors: Xu Shibo , Li Jichun , Cao Wensheng , Zhang Shuhui
Published: August 2020

Containers are important equipment for global cargo transportation. After the USA 9/11 terrorist attacksand, safety of container transportation has attracted much attention. The real-time monitoring of containers has become an inevitable trend for future container intelligent development. In this paper, current development status and advantage of application on monitoring container of low-orbit satellites are introduced, and circuit design and development solution based on low-orbit satellite module is elaborated, finally the monitoring device is proved that has great practicability by actual test experiment.
A multi-sensors pure azimuth data fusion method
Authors: Guo Richeng , Wang Ying , Lan Chunyan , Xu Boran
Published: August 2020

Passive detection sensors have the advantages of good concealment, strong viability, strong resistance to electronic interference, wide coverage of airspace, and stronger detection capabilities for low-altitude targets than active detection sensors, and farther detection distances. It has caused more and more research and application attention in various fields. However, passive detection sensors mainly obtain azimuth information, no stable distance information, and stable tracking of only azimuth targets has many uncertainties. In recent years, how to integrate effective and stable passive detection data has become the focus of scholars research and the difficulty of urgent breakthrough. This article proposes a method of fusion of pure azimuth data for systems with multi-source detection sensors, through the filtering of “modified extreme coordinates ”based on the measurement results of each sensor, “based on the Lagrange daily linear interpolation method” time allocation, “m/n logic-based” track association and fusion, obtain more accuracy and track more stable direction measurement results, and improve the comprehensive capabilities of the multi-source detection sensor system.
Mutual Inductance Estimation of Multiple Input Wireless Power Transfer for Charging Electronic Equipment
Authors: Hou Xiaochen , Kang Le , Hu Song , Yang Haodong
Published: August 2020

The transmission performance of wireless power transfer is highly influenced by the mutual inductance (M) between the transmitter and the receiver. This paper proposes a mutual inductance estimation method for the multiple input coils wireless charging system which can be used in low-power portable devices such as mobile phones. The method can estimate M precisely and reliably without using empirical formulas and additional communication system. It simplifies the estimation process and achieves more accurate values of M under any conditions. Simulations and experimental results prove the proposed method has a good performance on estimating M at any circumstance.
Design of Ultra-low Power Consumption Low-dropout Regulator
Authors: Xiao-juan Bai , Wen-Zhuo Shao , Zhi-Gang Han
Published: August 2020

This paper designs a type of ultra-low power consumption LDO with the CSMC 0.5μm technology, which can output the 1.5V voltage. In this LDO, the error amplifier is structed with two-stage operational amplifiers. The input of first stage uses PMOS differential pairs that can decrease the noises and the second stage uses the common-source structure in order to increase the open-loop gain. In addition, the MOS amounts we use are as less as possible over the whole circuit, which decrease the die size to satisfy the trend of product miniaturization. The result of simulator Spectre shows that the LDO proposed can output the 1.5V voltage stably, the PSR is -66dB at 1kHz, and the loop gain is 72.5dB, the lowest dropout voltage is 93mV, the power consumption is only 1mW.
Research of flexible terminal
Authors: Wang Quan , Chen Xuqiong , Liu Qingbo , Wang Liting , Xiong Yue , Yuan Li
Published: August 2020

In recent years, with the rapid development of high-low Earth Orbit Commercial Satellite Communication Technologies and products, and the increasing demand of aviation, navigation and space trunking communication, satellite Communication has entered the stage of satellite Internet development with hybrid application of GEO Satellite and NGSO Constellation. Based on the characteristics of GEO satellite and NGSO satellite, this paper studies the flexible terminal which can access the GEO and NGSO Constellation, designs and analyzes the key technologies such as low cost phased array antenna and flexible waveform, providing some insights and ideas around the development for the mixed application of the terminal in GEO and NGSO satellites.
Comprehensive performance analysis of coil electromagnetic radiator
Authors: Yucheng Jiao , Chunhua Jiang , Hongtao Qi , Xue Ma
Published: August 2020

The coil electromagnetic radiator is widely used in underwater weapon system and underwater active electromagnetic detection, and it’s an essential part of electromagnetic fuze, active electromagnetic detection and other systems. The main parameters to measure the electromagnetic radiator are coil turns, inductance and radiation intensity. In this paper, the relationship between coil turns, inductance and radiation intensity of electromagnetic radiator is analyzed. Through theoretical analysis and experimental test, we can draw the following useful conclusion: Although increasing the number of coil turns can improve the radiation magnetic moment of unit exciting current, too many turns of coil is not good for engineering implementation. Therefore, in practical application, the relationship between coil turns, size, inductance and magnetic moment of the radiator should be considered comprehensively.
The effect of measurement noise on the typical quantum teleportation protocol
Authors: Zhaolei Zhang , Zhiqiang Ma , Lei Shi
Published: August 2020

Quantum teleportation is an important reaseach direction of quantum communication. Quantum meaurement is one of necessary physical implementation for quantum teleportation. Thus, this paper explored the influence of measurement noise on quantum teleportation. The realization steps of quantum teleportation with measurement noise are presented. From the density operation and fidelity value, the performance of quantum teleportation is analyzed. The research results about measurement noise might be utilized for quantum communication.
The improved slime mould algorithm with Levy flight
Authors: Zhao Juan , Gao Zheng-Ming , Sun Wu
Published: August 2020

In this paper, we proposed the Levy flights to replace the random numbers whether it was in Gauss distribution or uniform distribution in the standard slime mould algorithm (SMA). Three kinds of classical benchmark functions such as the unimodal, multimodal benchmark functions and those who have basins which we could see clearly from their three dimensional profiles. Comparisons were made through the average results over 100 Monte Carlo simulation experiments in order to eliminate the influence of randomness. Results showed that the improved SMA with Levy flight might not always perform better. The improved SMA replacing the uniform distributed parameter achieved better performance whereas the improved SMA replacing the Gauss distributed parameter gained nothing in performance, even worse sometimes than the standard SMA.
The hybrid grey wolf optimization-slime mould algorithm
Authors: Gao Zheng-Ming , Zhao Juan , Yang Yu , Tian Xue-Jun
Published: August 2020

In this paper, we hybridize the grey wolf optimization (GWO) algorithm with the newly proposed slime mould algorithm (SMA). Comparisons had been made and three kinds of benchmark functions were introduced to verify the capability. 100 Monte Carlo simulation experiments had been carried on to reduce the influence of randomness as less as possible. Results showed that the performance of hybrid GWO-SMA would base on the given characteristics of problems themselves because of the random threshold parameter p and the multiple branches in the updating equation. The hybridization of the GWO and SMA might be not recommended for steady applications and engineering problems.
A Novel Safety Helmet Wear Detection Method based on Improved RFBnet
Authors: Chen Liu , Xue Zhishuang , Liu Xiaofang , Chen Mingju , Huang Hui
Published: August 2020

In order to solve the problems of error detection and missed detection in complex environments, a helmet wear detection method based on dense connection method and CIou loss is proposed. This method is based on RFBnet-512 neural network, and improves the bankbone network of RFBnet-512 with dense connection to enhance the bankbone network’s ability to extract features. At the same time, in order to avoid errors caused by inconsistent loss function and evaluation index, CIou loss is used to replace the original SmoothL1 loss of RFBnet-512 network, making the calculation of regression loss more close to the evaluation index. The experiment shows that compared with the original RFBnet-512 network, the detection accuracy is improved by 0.018, and the detection speed is significantly improved.
Design and Simulation of a magnetic balance weak current sensor based on TMR
Authors: Song Jiakuo , Zhang Guoqing , Nie Yu , Wang Guizhong , Li Hongbo , Hou Yingwei
Published: August 2020

In this paper, a weak current sensor based on TMR is designed. The system structure, principle and conversion process of the sensor are introduced. The voltage current conversion circuit and feedback block diagram are analyzed emphatically. Then ANSYS Maxwell is used to simulate the electromagnetic field of the iron core and the coil. The results show that when the measured conductor and the secondary coil are connected with the current which is inversely proportional to the number of turns, the magnetic field in the air gap reaches a balance, close to the zero flux state. Finally, Multisim software is used to simulate the driving circuit of the system. The simulation results show that for DC and AC signals, the secondary current can track the primary current quickly, and the accuracy can reach 0.7% when measuring 1∼10mA weak current.
Research on the Preprocessing of Tai Le Character Recognition
Authors: Guo Hai , Yang Doudou , Zhao Jingying , Liu Yifan
Published: August 2020

Tai Le character is a kind of alphabetic writing with a long history, and its character recognition research plays an important role in inheriting and protecting Tai Le. Preprocessing is an key part of the Tai Le character recognition system, the quality of the preprocessing directly affects the recognition rate in the recognition system. Image preprocessing is the premise of feature extraction and recognition, since the directly input image usually contains noise, it affects the recognition effect. Therefore, it is of great application value and far-reaching historical significance to study the preprocessing technology of Tai Le character recognition. This paper proposes the image preprocessing method of Tai Le character, including graying, binarization, de-noise, and edge detection, and achieves good preprocessing results, which lays a foundation for feature extraction and recognition of Tai Le character.
A Novel Method for Sorting Radar Signal Based on Welch Power Spectrum characteristics
Authors: Han Jun , He MingHao , Li MingWei , Gong YuQin
Published: August 2020

The accuracy rate of current sorting methods of radar emitter signal is not high and they are sensitive to the signal-noise-rate (SNR). To solve these problems, a novel sorting method is proposed. Firstly, Welch power spectrum of the received signal is analyzed and its energy is normalized. Then its complexity characteristics are extracted to reduce dimension and sort easily, and are used as the sorting parameters. The last sorting is accomplished by KFCM algorithm. According to simulation results, the Complexity characteristics of Welch Power Spectrum have excellent separability and stability in low SNR.
The Blind Estimation of Carrier Frequency Offset of Non-cooperative Burst Signal
Authors: Ying Wang , Richeng Guo , Kaifeng Guo , Yichen Liu
Published: August 2020

In order to address the challenge of carrier blind synchronization and blind demodulation for non-cooperative burst signals, a modification scheme of carrier frequency offset estimation is proposed in this paper. Due to the existence of carrier frequency offset and phase offset, the received signal constellation is circular. In the absence of prior information, a non-data-aided method is adopted to estimate carrier frequency offset of the received signal. Then the loop processing method is used to compensate and correct the carrier frequency offset and phase offset to complete the carrier recovery. Simulation results show that the proposed method has high accuracy in carrier frequency offset and phase offset correction when the signal to noise ratio is close to or higher than that of demodulation. Moreover, it has wide extension in engineering practice.
Multi-camera Panoramic Stitching with Real-time Chromatic Aberration Correction
Authors: Shen Jue , Qian Fei , Chen Xianfu
Published: August 2020

Due to uneven lighting conditions and differences between camera lenses, in actual engineering applications, there is a difference in brightness of the image collected by the camera, which will cause obvious gaps in video stitching and poor stitching effect of panoramic pictures. This paper designs and implements an algorithm based on the gray statistics of overlapping areas to achieve global correction, and combined with the fade-in and fade-out image fusion algorithm to make the splicing transition natural. The experimental results show that in the Visual Studio 2015 platform environment, real-time stitching of 8-channel cameras has a fast algorithm speed and can achieve a stitching speed of 25 frames per second. The video is smooth and the picture quality is good without obvious color difference.
Research on Microservice Application Performance Monitoring Framework and Elastic Scaling Mode
Authors: Wang Zhihui , Xia Ying , Sun Changhua , Cheng Lei
Published: August 2020

Compared with the traditional monolithic architecture, the microservice architecture style divides a system into different microservices which run in the distributed system. The complex dependencies between services bring new challenges to the monitoring analysis and quality assurance of system performance. According to the characteristics of microservice application, a performance monitoring framework based on big data is designed in this paper. It monitors and controls the microservice performance through data collection, big data storage, elastic scaling management, integrated scheduling and so on. Furthermore, an elastic scaling mode based on time sliding window and scene driven is proposed. Experiments show that this mode could realize resource expansion prediction and resources saving. This research is helpful to real-time monitoring and continuous optimization for microservices, which will effectively promote the integration process of development, testing and maintenance for microservice application in SGCC (State Grid Corporation of China).
Application and Research of Spam Classification Based on Cluster Intelligence Algorithm to Optimize SVM
Authors: Xia Zhennan , Deng Jianzhi
Published: August 2020

With the development of science and technology, the increasing popularity of the Internet, email has been widely used. Because of its convenience and low cost, e-mail has been used by more and more criminals to maliciously spread commercial advertisements, computer viruses and bad information. In order to resist spam, this paper proposes a spam classification method based on swarm intelligence algorithm optimized SVM. It classifies English spam and extracts features with special sensitive word coding. The model and method in this paper have certain reference value for spam classification research.
A TOPS Improved Algorithm Based on Eigenvalue Discrimination
Authors: Jinfeng Zhang , Lichun Li
Published: August 2020

Under low SNR, if the signal subspace estimation of TOPS (Test of orthogonality of projected subspaces, TOPS) algorithm reference frequency point is inaccurate, the error will spread to the whole frequency point, thus causing the problem of algorithm performance degradation. In this paper, a TOPS improved algorithm based on eigenvalue discrimination is proposed. This method selects the optimal reference frequency point by judging the distinguishing degree of characteristic value between signal subspace and noise subspace at each frequency point, and then uses the transfer matrix to project the signal subspace at the optimal reference point to each frequency point, reducing the error of the whole frequency band caused by the inaccurate selection of reference frequency point. This algorithm has higher resolution accuracy under low SNR, and the threshold of 100% resolution probability SNR is about 4dB lower than the original algorithm. Simulation results verify the effectiveness of the proposed algorithm.
Design and application of low power switch IC
Authors: Yang Guangyao
Published: August 2020

Based on PSM (pulse skip modulation) mode, this paper analyzes and optimizes the system, designs a low-power switching power supply chip, and integrates the high-voltage power MOSFET switch and power controller in one device. Different from the traditional PWM (pulse width modulator) controller, the output voltage is regulated by simple on / off control without loop compensation. The controller consists of oscillator, feedback circuit, 5.8V regulator, bypass pin under voltage circuit, over temperature protection, frequency jitter, current limiting circuit and leading edge blanking of integrated 700V power MOSFET. The chip can be applied to mobile phones, digital cameras, and chargers of low-power electrical appliances, etc.
An in-situ Evaluation Method for the Morphology of Large Format Detector Array
Authors: Huang Yue , Lin Chun
Published: August 2020

The morphology, especially the flatness, became more and more crucial for successful flip-chip (FC) bonding for large format detector array. For the first time an in-situ method to evaluate the flatness of bonding samples was established by linking the machine parameter and the sample attribute. The derived collimator correlation was justified by detector array and then it was used as a criterion to examine the accuracy of the bonder’s laser leveling module. The combination of the collimator correlation and the laser leveling results could theoretically show more in-situ details of the morphology and can be utilized as either a selection yardstick or a compensation canon before FC bonding. However, whether or not the vacuum system of the bonder had an impact on the morphology could not be decided at present configuration.
A Novel Big Data Index Architecture for Programming Environment
Authors: Cao Peng , Xu Haitao
Published: August 2020

With the rapid development of computer information technology and the upgrading of programming software, the types and number of project codes are growing rapidly, showing typical characteristics of large data such as massive, instantaneous, diverse and variable. The distributed column storage database HBase based on the Hadoop big data platform, has the characteristics of high reliability, high performance, column-oriented, and scalability. It also has good scalability, can store more than ten billions of data, and is suitable for large-scale data reading and writing, which takes advantages in processing large-scale unstructured and semi-structured software data on the programming site. So, this paper studies the big data index architecture in the programming field. In view of the low efficiency of HBase non-primary key attribute query, the inverted index is a natural platform for cloud-based big data storage and query in this large development site. Based on this advantage, this paper designs and optimizes the secondary index architecture based on the HBase for programming field big data inverted index.
Study on Control Strategy for Series-Parallel Hybrid Electric Vehicles
Authors: Xu Lei , Li Zhe , Sun Hanwen , Fan Jie , Bai Qin , Ou Yang , Wang Peng , Deng Bo
Published: August 2020

This paper proposed a power allocation mechanism and mode switching strategy for the series-parallel hybrid electric vehicles. A test-data based simulation platform for series-parallel plug-in hybrid electric vehicles is established and developed for theoretical verification. The results indicate that the proposed control strategy realized a more reasonable power distribution in the combined power system under various working modes, which means a remarkable improvement in vehicle fuel economy.
Research and Implementation of Digital Twin Heterogeneous Data Exchange System
Authors: Guqi Peng , Hongen Zhong
Published: August 2020

Digital twin is one of the most important technologies to realize system intelligence and automation, and it seamlessly integrates the digital and physical space. So far, the concept of digital twin has been proposed for nearly 15 years, and the importance of digital twin is increasingly recognized by academia and industry, with a large number of digital twin models applied in different industries. The interoperability of different models has become a major challenge for digital twins. In this paper, we propose a system for heterogeneous data exchange of different models, and demonstrates the data interaction prototype of the mechanical and thermal models of the electric box load parts, finally we evaluated the effectiveness of our system.
Application and analysis of interacting multimode Kalman filter in location algorithm
Authors: Ning Xiao
Published: August 2020

Aiming at the non-line-of-sight (NLOS) problem that affects the accuracy of wireless location in cellular networks, the IMM method is introduced. The method based on interactive multimode Kalman filter (IMMKF) is studied and analyzed in detail. A more complex second-order and fourth-order Markov transfer model is established to describe the wireless communication channel. The positioning performance and the factors that affect the performance of IMMKF filter are analyzed by simulation. The simulation results show that IMMKF can adaptively switch between models with the change of channel propagation environment, suppress non line of sight error, and show good positioning performance and filtering performance.
Classification and identification of unknown network protocols based on CNN and T-SNE
Authors: Xue Jingliang , Chen Yingchun , Li Ou , Li Fei
Published: August 2020

With the continuous development of users’ demands and network technology, more and more new network protocols emerge, which poses great challenges to network protocol classification and identification. An artificial intelligence method was used to explore autonomous classification and identification of unknown network protocols in this paper in order to reduce the time and labor cost of network protocol classification and identification. In this paper, firstly, the network traffic was converted into grayscale images, and through transfer learning, the Convolutional Neural Networks (CNN) pre-trained model was used to extract the protocol features, so as to reduce the time and the amount of labeled data needed for the artificial neural network training. Finally, with the improved unsupervised hybrid clustering algorithm based on T-SNE and K-means, the types and number of protocols were autonomously identified and the network traffic was classified simultaneously. In this way, we can identify unknown protocols without prior knowledge and the protocol identification adaptability for big data was also greatly improved. Experimental results show this method has high accuracy and robustness in identifying unknown network protocols.
Simulation analysis of passive intermodulation mechanism of transceiver link
Authors: Sun Fei , Jia Yunfeng , Duan Bo , Liu Yuhan
Published: August 2020

The electromagnetic environment of modern battle-field is complex and the interference intensity is large. Under the influence of high field electromagnetic interference, airborne RF equipment becomes the short board of electromagnetic environment adaptability of aircraft. Because of the wide application of military aircraft platform, the external climate and electromagnetic environment are very complex. At the same time, the interior space of military aircraft is narrow and there are many high-power frequency equipment, which lead to a very complex electromagnetic environment inside the aircraft. Under the irradiation of high-power electromagnetic field, passive intermodulation products will be produced in the receiving antenna, transmission line, connector, filter and even some non-metallic conductive materials and aircraft skin under certain conditions. The passive intermodulation products will cause great interference to the airborne high sensitivity receiving equipment, and even burn the receiving equipment in extreme conditions. Therefore, the research on passive intermodulation products of airborne equipment is very urgent.
Design and Implementation of Pedestrian Flow Monitoring and Warning Platform in Public Area based on Pedestrian Detection
Authors: Zhen Aijun , Wang Qingli , Wang Ancheng , Wu Kai
Published: August 2020

In the traditional public area pedestrian flow monitoring, a lot of manpower and material resources are needed. Only relying on people’s eyes to identify and count the number of people in the video under monitoring is not only inefficient, but also has errors in accuracy and wastes a certain amount of energy and financial resources. In the rapid development trend of artificial intelligence, this system starts from the perspective of real-time monitoring, with the maturity and development of machine vision technology, and creates a cloud monitoring platform based on JavaWeb technology. The pedestrian detection technology is applied to the pedestrian flow monitoring, which provides a feasible scheme for accurate and fast pedestrian flow monitoring and warning, and develops a system to help public area managers and government departments to deal with the crowd gathering situation, analyze and monitor the crowd density, and give a quick warning to the crowd outbreak and gathering place.
Application and Algorithm Analysis of Micro-Expression Recognition
Authors: Cai Zhaoqi , Yan Shaowen
Published: August 2020

Micro-expressions (MEs) are the expressions of real emotion in people’s heart. It usually happens when people want to hide their true emotions. Through the study of MEs, we can correctly speculate on the inner activities of the expressors, which has important application value in the fields of criminal investigation, arrest, psychotherapy, education and teaching. At present, more and more people are paying attention to the research of ME recognition. People try to detect MEs by faster algorithms, but the recognition process is affected by many factors, so it is necessary to optimize related technologies as soon as possible to achieve higher accuracy. Therefore, this paper analyzes the application of ME recognition and related algorithms, and puts forward the development prospects.
Design of the Speech Tone Disorders Intervention System Based on Speech Synthesis
Authors: Xinyi Yang , Boyu Si , Qingyun Meng , Kailin Huang
Published: August 2020

Tone Disorder is a typical performance of speech impediment. It has become an urgent matter because of affecting patients’ common communications. In this paper, a speech tone disorder intervention system is designed on MATLAB GUI. By sampling the patients’ speech, extracting and adjusting the pitch information and synthesizing new speech, the system can help patients do self-intervention and build a ‘speech-hearing feedback chain’ for them during the rehabilitation process. The system is non-invasive for intervention of speech tone disorder from the uncoordinated movement of articulatory organs or psychological disorders. The results of two single-subject experiments prove that the system can improve the intervention effect of speech tone disorders intervention and increase the comprehensibility of users’ speech.
Network Intrusion Detection Model Based on Artificial Intelligence
Authors: Meng Qingchuan , Zhang Youzi , Wu Fengzhi , Chen Xiaoming
Published: August 2020

The Internet occupies a more and more important position in people’s life. The society has become more convenient because of the progress of network technology, and the network security problem has attracted more and more attention. Therefore, the security technology based on network is more and more important. Intrusion detection technology is the main research direction of dynamic security tools. Aiming at the problem of low accuracy of network intrusion detection, this paper proposes a network intrusion detection model based on AI, introduces artificial intelligence neural network and algorithm, extracts data feature information through repeated training of the algorithm, and constructs network intrusion monitoring model based on neural network. According to the design goal of the model, the basic framework of the system is given, which provides accurate detection basis for network intrusion detection. The experimental results show that the detection accuracy of the model is high.
Research of Downhole Instructions Decoding with Variable Drilling Fluid Displacement
Authors: Huo Aiqing , Yang Yuyan
Published: August 2020

This paper studied a downlink communication mode in which the effective downhole control instruction was generated by the use of drilling fluid pump displacement to format three descending and three ascending pulse instruction encoding. The principle of the downlink communication was introduced. The encoding idea of the downlink instruction code with 5-bit pulse was described. This downlink code was used to compose the corresponding control instruction which includes the information of the tool face angle and the guide force percentage. The downhole pulse widths were recognized by using STM32 as a micro control chip. The corresponding control commands were identified through the development of the software in the downhole drilling tool. Laboratory ground experiments demonstrated the feasibility of this downlink transmission mode by using variable drilling fluid displacement and the achievability of instruction decoding software.
Development of Intelligent Agricultural Machinery Control Device
Authors: Jiang Ru , Kasimov Farkhod , Zhang Dong , Kaliyeva Kulyash
Published: August 2020

This article is dedicated to creating a low-cost intelligent agricultural machinery control equipment based on ATmega 328p chip. The created control device is used to directly connect various peripheral sensors and actuators of the intelligent agricultural machinery to the computer. The controller circuit design diagram is given, and the control method is presented. The accuracy of the signal input/output channels of the control device to transmit signals was verified through experiments, and the control device was applied to the intelligent agricultural machinery experiment platform. The experimental results are analyzed and suggestions for further development of the control device are provided.
Design and Realization of Automatic Test System for Anti-Jamming Performance of GNSS Receivers
Authors: Wang Zhiying , Wang Menglan , Wei Heng
Published: August 2020

The performance test is a key part of the anti-jamming the global navigation satellite system (GNSS) receivers in researching and production. To solve the big workload and cumbersome in performance tests, an automatic test system is proposed in this paper. This system, whose core part is software which designs in Microsoft Visual Studio, can automatically control jammer, holder and anti-jamming antenna. The test software can automatically receive data from the navigation receiver and the anti-jamming antenna, can automatically statistics the carrier to noise ratio (CNR) and position information, also can automatically monitor the jam to signal ratio (JSR) in real time. Taking the CNR and the position information as anti-jamming performance test indicators, the software can automatically control the radio frequency (RF) power of jammer by setting the start, stop and step values of the jammer power. The test result shows that it can realize the automatic test after setting the necessary parameter. Also, it can automatically generate test report after completing the test. This system improves the efficiency of the anti-jamming performance test of GNSS receivers.
Investigation into the finger structure capacitor in the micro force measurement device
Authors: Xu Li , Wang Shuxiang , Li Qian , Zheng Peiliang , Huang Zhenyu
Published: August 2020

The finger structure capacitor in the micro force measurement device was investigated by theory model analysis and comparative analysis with traditional parallel plate capacitor. The relationship between the micro force output and the distance variation between the electrodes was analysed. The micro force output of the finger structure capacitor and the traditional parallel plate capacitor were compared. Results show that the finger structure capacitor could produce stable micro force values when the finger structure parameters satisfied with x0/g >5. The output micro force value changed by less than 2% when the distance changed within 1mm in this range. Compared with traditional flat capacitors, the new finger structure capacitor greatly reduced the influence of the measurement and control uncertainty of the distance on the output micro-force values. The new finger structure capacitor device had little change in the output of micro force within 1mm distance variation and its output value changed with 1.7%, under the conditions of different applied voltages.
Research on Non-destructive Testing Method of Coating Thickness of Turbine Blade
Authors: Wu Jie , Li Ye
Published: August 2020

Turbine blades are an important component of the turbine section of a gas turbine engine. High-temperature blade coating is a key technology for the manufacture of turbine engines, and its complex surface structure is currently lacking an effective non-destructive evaluation method for coating thickness. In this paper, the eddy current field is directly exciting in the substrate metal of the turbine blade coating system to achieve non-destructive detection of the coating thickness and substrate material. The results show that a new method of coating non-destructive testing based on the principle of array induction logging three-coil system is proposed. The shielding coil effectively cancels the direct coupling signal and enhances the signal from the coating and the substrate; when the distance between the transmitting coil and the main receiving coil is 8cm and the scale factor α is about 0.7047, the signal-to-noise ratio is increased by 102 times, and when the scale factor α is about 0.9032, the signal-to-noise ratio is increased by 215 times, the focusing effect is obvious while the scale factor α raises, and the sensitivity is also greatly improved; the receiving array is more than 4cm away from the transmitting coil, reflecting the more obvious change of coating thickness. When the distance between the transmitting coil and the main receiving coil is 4∼9cm, and the scale factor α is about 0.9032, the imaginary part of the measurement signal reflects the coating thickness changes more sensitively, and the real part of the measurement signal reflects substrate material changes more sensitively.
Cryogenically printed flexible chitosan/bioglass scaffolds with stable and hierarchical porous structures for wound healing
Authors: Wu Chunxuan , Yu Zehao , Li Yihan , Zhou Kui , Cao Chuanliang , Zhang Peng , Li Wenchao
Published: August 2020

Wound healing is a dynamic and well-orchestrated process that can be promoted by creating an optimal environment with wound dressing. An ideal wound dressing material should possess a suitable matrix, structure and bioactive components, functioning synergistically to accelerate wound healing. Wound dressings that allow reproducibility and customizability are highly desirable in clinical practice. In this study, using chitosan (CS) as the matrix and bioglass (BG) as the biological component, a spatially designed dressing scaffold was fabricated from a home-made cryogenic printing system. The micro- and macro-structures of the scaffold were highly controllable and reproducible. The printed scaffold exhibited interconnected and hierarchical pore structures, as well as good flexibility and water absorption capacity, and these properties were not affected by the content of BG. Nevertheless, when the content of BGs exceeded 20% that of CS, the tension strength and elongation rate reduced, but in vitro antibacterial, cell proliferation and migration performance were enhanced. In vivo examinations revealed that the composite scaffold significantly promoted wound healing process, with the group having 30% bioglass showing better wound closure, neovascularization and collagen deposition than other groups. These results indicate that the 3D printed CS/BG composite scaffold is a promising dressing material that accelerates wound healing.
Riverbank macrolitter in the Dutch Rhine–Meuse delta
Authors: van Emmerik Tim , Roebroek Caspar , de Winter Winnie , Vriend Paul , Boonstra Marijke , Hougee Merijn
Published: August 2020

Anthropogenic litter in aquatic ecosystems negatively impacts ecosystems, species and economic activities. Rivers play a key role in transporting land-based waste towards the ocean. A large portion however is retained within river basins, for example in the estuary, in sediments and on the riverbanks. To effectively identify litter sources, sinks and transport mechanisms, reliable data are crucial. Furthermore, such data can support optimizing litter prevention mitigation and clean-up efforts. This paper presents the results of a 2-year monitoring campaign focused on riverbank macrolitter (>0.5 cm) in the Dutch Rhine–Meuse delta. Between 2017 and 2019, volunteers sampled 152 415 litter items at 212 unique locations. All items were categorized based on the River-OSPAR method (based on the OSPAR beach litter guidelines), which includes 110 specific item categories across ten parent categories. The median litter density was 2060 items/km, and the most observed items were foam, hard, and soft plastic fragments (55.8%). Plastic bottles, food wrappings and packaging, caps, lids and cotton swabs were the most abundant specific items. The litter density and most abundant items vary considerably between rivers, along the river, and over time. For both rivers however, the highest litter density values were found at the Belgian (Meuse) and German (Rhine) borders, and at the Biesbosch National Park, the most downstream location. With this paper, we aim to provide a first scientific overview of the abundance, top item categories, and spatiotemporal variation of anthropogenic litter on riverbanks in the Dutch Rhine–Meuse delta. In addition, we evaluate the used River-OSPAR method and provide suggestions for future implementation in (inter)national long-term monitoring strategies. The results can be used by scientists and policy-makers for future litter monitoring, prevention and clean-up strategies.
Projections of Arctic sea ice conditions and shipping routes in the twenty-first century using CMIP6 forcing scenarios
Authors: Wei Ting , Yan Qing , Qi Wei , Ding Minghu , Wang Chuya
Published: August 2020

The accelerated decline in Arctic sea ice in recent decades suggests the possibility of future trans-Arctic shipping routes linking the Atlantic and Pacific oceans, with significant implications for the global economy. We present a projection of Arctic sea ice conditions and shipping activities during the 21st century based on 16 CMIP6 models calibrated to remove spatial biases. The multimodel ensemble mean shows that the Arctic is likely to be ice-free in September by 2076 and 2055 under the SSP2-4.5 and SSP5-8.5 scenarios, respectively, whereas the extent of sea ice is >2 × 106 km2 throughout the 21st century under the SSP1-2.6 scenario. The Arctic sea ice in September thins over time, leading to a reduction in the area with an ice thickness >120 cm (i.e. the threshold over which sea ice is inaccessible to Type A vessels) by 34–100% by the late 21st century (2086–2100) under the three scenarios. Given the declines in the extent and thickness of sea ice, the most commonly traversed route along the North West Passage tends to migrate from the southern to the northern route during the 21st century. The optimum route along the Northern Sea Route shifts northward with time, with the Transpolar Sea Route becoming available. Quantitatively, the maritime accessibility to Type A vessels via the Transpolar Sea Route increases from ∼6.7, 4.2 and 2.1% in 2021–2035 to 14.7, 29.2 and 67.5% in 2086–2100 under the SSP1-2.6, SSP2-4.5 and SSP5-8.5 scenarios, respectively. The season for trans-Arctic shipping extends from 5 to ∼7.5 (9) months by the late 21st century under the SSP1-2.6 (SSP2-4.5) scenario and the Arctic becomes navigable all year round under the SSP5-8.5 scenario. These findings may aid in developing strategic planning by governments for the Arctic and providing strategic advice for the global maritime industry.