bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improved Pre-Processing Process of Climate Series Based on Chebyshev Filter
Authors: Zhang Zhenyu , Pan Ziyu 
Published: June 2022

AbstractIn the process of data mining for time series of environmental factors of dendrobium origin, it is difficult to separate the available features because the feature components are too rich and the de-noising method is not feasible, in this paper, we try to improve the pre-processing process of sequence. In this method, we first de centralize the sequence and check the unit root to evaluate the stationarity of the sequence, and then design a band-pass filter to extract the feature components from the sequence in the range of monthly frequency to annual frequency, then, the features of EEMD and correlation coefficients are extracted by using the EEMD Algorithm, which is commonly used in the field of natural sequence decomposition. Finally, the Savitzky-Golay filter is designed to smooth the reconstructed sequence in order to remove the noise introduced by EEMD, the final usable characteristic component is obtained. Compared with EEMD Algorithm, this method is more reasonable in the pre-processing process, and the power distribution in frequency is more concentrated.
Mechanism Study of Bi-Material COPV Structure Based on Composite Structure Design Theory
Authors: ZHAO Ji-peng , YU Bin , OUYANG Rui-jie , MA Tian-ju , GU Sen-dong , YANG Wen-bo , HOU Yan-hui 
Published: June 2022

Abstract
Composite over-wrapped pressure vessels (COPVs) are widely used in aerospace, aviation, army, Navy, nuclear industry and other military and civil fields because of their light weight, high strength, high reliability and safety, leak before burst (LBB) failure mode safety and many other characteristics. Because the aerospace field has very strict requirements on the weight of platform structure products including COPV, it is necessary to improve the mass efficient of COPV and achieve the characteristics of light weight and high strength. In this paper, through the optimization of composite material grid theory algorithm, the relationship between bidirectional stress and internal pressure of cylinder and dome of isotropic material is deduced. On this basis, the grid theory equations of bidirectional stress and internal pressure load of COPV cylinder and dome are deduced, and the wall thickness equations of ordinary rotating curve head, equal tension head and hemispherical head are proposed. According to the grid theory model of membrane stress of COPV cylinder, the author completed the grid theory algorithm derivation of elastic and plastic lined COPV. This paper is the exploration of composite dome structure analysis, which lays a foundation for the subsequent solution of composite dome grid theory.
Moving Object Detection based on Reverse Projection Error Model
Authors: Cao Yang , Yu Hongfei , Yu Meng 
Published: June 2022

Abstract
A novel moving feature point detection method is proposed in this paper in order to solve the problems in existing methods. Firstly, the coordinates of feature points are normalized by using spherical coordinates in order to solve the imaging distortion of the fish-eye camera. Secondly, based on the spherical normalization coordinates of feature points the reverse projection error model of the fish-eye camera is deduced and a moving feature point’s discriminant is derived to improve the detection integrity of moving object. Finally, according to the law of object motion, the detected potential moving feature points are clustered to further remove outliers. Experimental results show the proposed moving feature point detection method has better detection results compared with the commonly used methods.
MORNSUN series DC-DC power module test fixture design
Authors: Wu Han 
Published: June 2022

Abstract
Test fixture is connected with the ATS automatic test system and the power module under test device, is an important component to achieve the power module test, its suitability, precision, opearbility also directly affect the accuracy of the test and the convenience of disassembly. Based on MORNSUN series DC-DC module, this paper aims to design a pin type test fixture with wide applicability, simple structure and convenient operation, and solve the problem of lack of test fixture in the actual test.
Power system fault restoration based on A2C with the consideration of renewables
Authors: Zhang Huanming , Xu Xiaosheng , Li Mengshi , Chen Ziming , Wu Qinghua 
Published: June 2022

Abstract
Although the power system has made great progress in security and stability, it is still difficult to completely avoid the occurrence of large-scale blackouts caused by various accidental factors under the background of high proportion of renewables. In order to improve the rapidity and reliability of power system fault restoration, this paper proposes a power system fault restoration strategy based on the Advantage Actor Critic. Under the premise of ensuring the priority restoration of loads with high demand on the user side, the overall objective function is to take the least total power loss load, the smallest network loss, the smallest restoration cost and the least number of switching operations into consideration. Test results on a modified IEEE39 system have verified the superiority of the model and recovery strategy.
An Active Power Decoupling Topology for Three-phase Four-leg Inverters with Unbalanced Load
Authors: Xie Yuanchao , Wang Fusheng , Liu Heng 
Published: June 2022

Abstract
Traditional three-phase four-leg inverters are widely used in microgrid systems because of their ability to carry unbalanced loads, but unbalanced load currents will cause instantaneous power to contain double-frequency fluctuations, which will affect the normal operation of the microgrid system. In order to solve the above problems, this paper proposes an improved three-phase four-leg topology and its control strategy, so that the secondary pulsating power on the load side can be provided by the decoupling capacitor. Then the working principle of the proposed topology and its control strategy is analyzed, and the relationship between the current stress of the power device and various influencing factors is deduced. Finally, An experimental prototype was built to verify the effectiveness of the proposed solution.
Research on key technologies of multi-source parallel in microgrid
Authors: Zhao You-cheng , Zhu Chang-qing 
Published: June 2022

Abstract
Microgrid system with micro sources with different rated capacity is a research hotspot in the world. This paper aims to discuss the research status of the key technologies of parallel connection between micro sources in microgrid, and briefly introduces the key technologies of parallel connection of micro source inverter with different rated capacity, parallel connection of diesel generator and parallel connection of micro source inverter and diesel generator, which provides a direction for relevant scholars to study the multi-source parallel connection technology in microgrid.
Influence of DC transmission distance on MMC-HVDC stability under weak AC system
Authors: Zhao Caiping , Wang Qiyuan 
Published: June 2022

Abstract
The oscillation problem of MMC-HVDC under weak AC system poses a potential threat to the safe and stable operation of power grid, which is related to both of the AC and DC parameters. By comparing the stability of MMC-HVDC under different AC system strength with different DC transmission distance, it is found that when the AC system strength is too weak, there is a risk of instability under the condition of long DC transmission distance, and the correctness of this conclusion is verified by time-domain simulation. Later, the mechanism analysis of this phenomenon is carried out, the result shows that it is related to the interaction of MMC subsystems when the strength of AC system decreases.
An Active Power Factor Correction Technology for Aircraft
Authors: Pan Liyun , Liu Gang , Sun Qiangang 
Published: June 2022

Abstract
This paper analyzes the influence of harmonics on the system and the importance of power factor correction. According to the requirements of aircraft use, an active power factor correction system based on three phase six switch topology is designed. The article analyzes the working process and control method of the system, then designs a rectifier to convert 220V/400Hz AC power provided by the aircraft to DC power and the power factor of the rectifier is high. Moreover, the performance of the system is tested.
Research on ZigBee Device Recognition Based on Software Defined Radio
Authors: Cheng Kefei , Deng Yujie , Zhang Liang , Cui Xiaotong , Chen Jinghao , Luo Wei 
Published: June 2022

Abstract
In order to solve the problem that ZigBee protocol sniffer analysis is based on proprietary chip platform and cannot obtain radio signal characteristics. A ZigBee protocol packet sniffing recognition method based on software defined radio is proposed. This paper proposes a ZigBee recognition method based on software radio, and analyzes the characteristics of ZigBee protocol messages. The software radio receiving flow diagram is designed to extract the captured message features, and the experimental results of neural network, KNN, decision tree and random forest algorithm are compared. Finally, the decision tree + hybrid classifier achieves 93.1% recognition accuracy, which verifies that the ZigBee recognition method based on software radio proposed in this paper has a good effect.
OLAP analysis of user energy consumption based on multitemporal distribution characteristics
Authors: Liu Bin , Yang Zhengyu , Wu Jiaqing , Gu Jie 
Published: June 2022

Abstract
With the development of databases, online transaction processing (OLTP) can no longer meet the needs of end users for database query and analysis, and the simple query of large databases by SQL can not meet the requirements of end user analysis. Therefore, online analytical processing (OLAP) is proposed. concept. On the one hand, we explained the basic knowledge of OLAP, including OLAP multidimensional data concept, multidimensional data structure, multidimensional data analysis, characteristics, etc. On the other hand, we established an OLAP analysis model of the multi-temporal and spatial distribution characteristics of user energy consumption, which is refined provide support for the analysis of user energy consumption behavior.
Two-dimensional DOA estimation of coherent signals for MIMO Radar Based on tensor decomposition
Authors: Ren Mingjian , Hu Guoping , Zhou Hao , Lin Bin 
Published: June 2022

Abstract
This paper studies the two-dimensional DOA estimation of coherent targets. Subspace algorithm is usually used to solve this problem. Compared with subspace algorithm, tensor decomposition has significant advantages in estimation accuracy and has been widely used in the field of signal processing. However, the research on tensor decomposition algorithm mainly focuses on incoherent targets. Therefore, we study how to use the advantages of tensor decomposition to improve the estimation accuracy of coherent targets. Firstly, we construct the echo signal model corresponding to the “Sum array” of MIMO radar, and then use the spatial smoothing to process the data to solve the problem of covariance rank deficiency. Then a third-order tensor is constructed according to the position relationship of the data. Finally, the DOA can be estimated from the decomposed tensor according to the position relationship of the data. Simulation results show that proposed algorithm has significant advantages in estimation accuracy.
Microgrid Inverter Control Strategy Based on Virtual Synchronous Generator
Authors: Zhang Yuewei , Han Minxiao 
Published: June 2022

Abstract
Study the control strategy of distributed power supply grid-connected based on virtual synchronous generator. Establish the mathematical model of the inverter grid connection and the mathematical model of the virtual synchronous generator control scheme. Study the grid-connected active and reactive power regulation scheme, and analyze the influence of inertia and damping parameters on grid-connected power tracking in detail. A self-synchronous control strategy without phase-locked loop is designed, which simulates the characteristics of synchronous generator’s speed regulation system and excitation system and can seamlessly switch between two operating states of off-grid and on-grid, which is conducive to the improvement of micro-grid stability. Finally, a simple microgrid system is built on the Matlab/Simulink platform. It is verified that the proposed control strategy has good power tracking characteristics and can enable the distributed power supply to switch quickly in different operating modes.
Effects of Tuning Mode on Radiation Performance of VLF Umbrella Transmitting Antenna
Authors: Quan Ying , Xie Hui , Li Haokun , Zhang Xiaoyang 
Published: June 2022

Abstract
In this paper, the tuning principle and two tuning modes of the VLF umbrella transmitting antenna are introduced. The calculation method of radiation resistance and loss resistance in the multi-tuning mode and the calculation formulas of other important radiation parameters are given. FEKO simulation software is used to model and simulate the umbrella-shaped antenna. The radiation parameters of the antenna in different tuning modes are obtained. The effects of different tuning mode on the radiation performance is compared. The results show that the multi-infeed tuning mode can effectively increase the radiation resistance and power capacity of the antenna and improve the radiation efficiency of the VLF antenna.
Establishing the correspondences between 2D UWB positions and image coordinates
Authors: Zhang Qiang , Li Shiqian , Wei Wei , Liu Minchao , Wu Shuang , Qin Xue 
Published: June 2022

Abstract
Ultra wide band (UWB) positioning system and camera are two types of sensors which records positions and images respectively. In many applications, it is expected to fuse the data obtained by the two types of sensors in two different coordinate systems. In this work, we study the problem of establishing the correspondences between 2D UWB positions and image coordinates of a camera. We propose a simple yet effective method which requires simple apparatus and does not need to know in advance the positions of the UWB anchors in camera frame. Experimental results have demonstrated the effectiveness of proposed method.
Design and Implementation of Ultrasonic Gas Leakage Locating System
Authors: Cao Yongle , Wang Dongjian , Zhu Ming , Li Honglie , Peng Taichong , Yuan Xiaojun , Guan Wenyong 
Published: June 2022

Abstract
The leakage of dangerous gas at the gas station may cause explosions and other serious accidents, threatening the safety of workers. This paper designs and implements a gas leakage locating device based on ultrasonic technique. The device can communicate with an intelligent inspection robot which alarms the gas leakage in real time and tracks the leaking sources. This paper first builds a hardware platform, and then realizes a four-channel signal based leak location algorithm by combining decision tree and neural network algorithm of smoothing pre-treatment. Finally, each software module of the gas leak location device is constructed. Testing of the locating capability of the device was completed in practical working environment.
Fault Diagnosis of Transformer Winding Looseness Based on Vibration Signal and GOA-KELM Model
Authors: Wang Chen , Cai Chengming , Du Yanpeng , Ji Zhenglian , Liu Yi , Miao Mingxiang 
Published: June 2022

Abstract
Aiming at the problem that the latent fault of transformer winding looseness is difficult to identify and the diagnosis accuracy is low, a fault diagnosis method based on vibration signal and grasshopper optimization algorithm (GOA) optimization Kernel Extreme Learning Machine (KELM) is proposed in this paper. The method uses the time-domain and frequency-domain characteristics of the vibration signal. First, the time-frequency features of the vibration signals of multiple sensors are extracted, and a multi-sensor time-frequency feature matrix is constructed. Second, the feature matrix is identified and diagnosed by using GOA to optimize the KELM model. Finally, the feasibility and superiority of the proposed method are verified by the experimental data of 110kV transformer. The experimental results show that the method in this paper can successfully identify the looseness of different degrees of windings and the looseness of different phases, and has a higher diagnostic accuracy than the existing algorithms.
Research and Comparative Analysis of Topology Identification Methods
Authors: Yixi Cuomu , Ma Wen , Zhao Yangyang , Chen Yuzhou , Huang Shufan , Xu Zhiwei 
Published: June 2022

Abstract
Topology model is the basis of perceiving power grid state. Wrong topology model will lead to the deviation of state estimation results from the real operation state. Firstly, this paper briefly analyzes the classification and characteristics of topology errors. Secondly, the characteristics of two existing mainstream topology identification methods are compared and analyzed. Then, we analyze the existing topology identification models and methods. Finally, the problems of the existing schemes are summarized. The results show that the mixed integer programming model based on optimization principle can solve topology errors more efficiently.
Design of the five layers large-scale low-orbit communication constellation TT&C system
Authors: Cui Wenhui , Wang Boru , Gan Xi , Gao Yan , Li Nan 
Published: June 2022

Abstract
The large-scale low-orbit constellation TT&C (Telemetry Tracking and Command) requirements are analyzed, and the principles of scalability, low coupling and robustness for the construction of large-scale low-orbit constellation TT&C system are proposed. The five-layer TT&C system framework based on service-oriented and container cloud technology is designed. The resource load balancing and configurability of services of the large-scale constellation TT&C system is realized. The TT&C system model design for the large-scale low-orbit constellation is completed.
An Automatic Aerospace Tracking Data Analysis Method Based on Time Series Curve Shape
Authors: Zhao Shumin , Zhao Mei , Wang Baiyan , Lin Yiyong , Xu Yingchun 
Published: June 2022

Abstract
In the joint test of aerospace tracking, telemetering and command (TT&C) system, the consistency of measured and theoretical data is highly required. How to evaluate the quality of measured data intelligently and efficiently is a hot issue. To address this problem, an automatic data analysis method based on time series curve shape is proposed in this paper. By locating the part of abnormal shape on the curve, the data quality can be quickly evaluated using various pattern recognition algorithms. Finally, several simulation experiments are used to demonstrate the proposed method, which show that the curve shape can be accurately identified and the data quality can be given reasonably.
The online detection system of concentric ring size based on machine vision
Authors: Bu Yakun , Guo Junmei 
Published: June 2022

Abstract
In today’s rapid industrial development, to improve production efficiency and product quality size detection process must be completed in real-time. Aiming at the problems of low production efficiency and large error rate caused by manual detection in the past, this paper proposes an online detection system of concentric ring size based on machine vision and develops a GUI software operation page. This system first processes the image gray level and uses the median filter for image denoising, and further uses Otsu threshold segmentation for image segmentation. Secondly, the Canny edge detection algorithm is used to extract the edge of the ring image. Finally, the radius and coordinates of the ring are measured by the improved Hough transform loop detection. Experiments show that the size measurement error of the measurement system is less than 0.015 mm. This system can meet the requirements of small and medium-sized enterprises for real-time detection of circular products, and improve the accuracy of quality inspection of circular products.
Channel estimation algorithm based on attention mechanism
Authors: An XuDong , Zhao Lei , Wu Han , Zhang QinJuan 
Published: June 2022

Abstract
As the key to wireless communication, channel estimation has become a hot research topic in recent years. In this paper, we propose a deep learning method based on the channel estimation of inverse convolutional network and expanded convolutional network to address the problems that the performance of traditional channel estimation algorithms in orthogonal frequency division multiplexing (OFDM) systems can hardly meet the communication requirements of complex scenarios and are greatly affected by noise. The method constructs a lightweight deconvolutional network using the correlation of channels, and achieves channel interpolation and estimation step by step with a few layers of deconvolutional operations, which achieves channel estimation with low complexity. To improve the estimation performance, an expanded convolutional network is further constructed to suppress the channel noise and improve the accuracy of channel estimation. The simulation results show that the channel estimation can be performed at different signal levels. The simulation results show that the proposed deep learning method based on deconvolution and dilation convolution has lower estimation error and lower complexity than the traditional methods under different signal-to-noise ratios (SNR).
Research on user granularity-level personalized social text generation technology
Authors: Gao Y B , Gao J T , Ma R , Yang L D 
Published: June 2022

Abstract
With the introduction of large-scale pre-trained language models, breakthroughs have been made in text generation technology research. On this basis, in order to assist users to complete personalized creation, this paper proposes a user-level fine-grained control generation model. First, we design the Encoder-Decoder framework based on the GPT2 structure, and model and encode the user’s static personalized information on the Encoder side. Then add a bidirectional independent attention module to receive the personalized feature vector on the Decoder side. The attention module in the original GPT2 structure captures the dynamic personalized features in the user text, namely writing style, expression way, etc. Next, the scores of each attention module are weighted and fused to participate in the subsequent decoding to automatically generate social texts constrained by the user’s personalized feature attributes. However, the semantic sparsity of the user’s basic information will cause occasional conflicts between the generated text and some personalized features. Therefore, we use the Alignment module to perform the secondary enhancement and generation of consistent understanding between the output data of the Decoder and the user’s personalized features, and finally realize the personalized social text generation. Experiments show that compared with the GPT2 baseline model, the fluency of the model is improved by 0.3%-0.6%, and on the basis of no loss of language fluency, the social text generated by the model can have significant user personalization characteristics, among which personalization and consistency the two evaluation indicators of sexuality both increased significantly by 8.4% and 9%.