bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aircraft Engine Audio Signal Analysis in Assisting Maintenance Inspections
Authors: Sakai Yukino 
Published: March 2022

Abstract
As the core component of modern commercial aircraft, turbofan engines have long been the center of focus in aircraft maintenance. Being subject to high temperatures and immense pressures causes problems for the engine components, such as the fan blades, as they are frequently burdened with the potential of overhaul and malfunction. Over many years, the industry has seen various methods of engine inspection and maintenance, ranging from manual inspection to computing large quantities of pre-existing data. Within, audio signal analysis has stood out as a productive, non-invasive method, with many alternate studies analyzing sound signals from components such as the combustion chamber. However, many of these methods, despite demonstrating good accuracy, are incredibly complex and require sophisticated apparatus. Therefore, this study begins by investigating the sound generation process of turbofan engines, especially how the features and form of the fan blade characterize its audio signals. This investigation proposes a solution that utilizes a fast Multi-Class Support Vector Machine (SVM) algorithm based on fan-blade-related audio signals from a perspective similar to the classification of music and images through supervised machine learning. Experimental results show that this fast Multi-Class SVM is more effective than traditional machine learning methods in its accuracy, F1-score, and other indicators.
Design of A Novel 1553B Data Communication Board Based on DSP and Integrated 1553B Terminal
Authors: Yang Jinpeng , Liang Dong , Wang Shuaibing , Yang Tao 
Published: March 2022

Abstract
In order to make the communication cables in airborne equipment not as complicated, large and heavy as before, the MIL-STD-1553B standard was released in the 1970s, thus reducing aircraft weight. Application of 1553B bus is becoming wider and wider. In recent years, UAV is a new force in modern battlefields and local conflicts. At the same time, the 1553B bus is prevalent in the domain of UAV for communication between different devices. A novel 1553B data communication board based on DSP and integrated 1553B terminal is designed in this paper. The principle of 1553B bus is introduced at first. And then it presents the hardware design as well as the software design. In the end, the conclusion part summarizes its applications. Undoubtedly, the 1553B board designed in this paper is convenient to be integrated to the whole system, providing a real-time, reliable and flexible communication solution for UAV.
Outage Probability Analysis for Two-Way Amplify-and-Forward Mobile Relay Assisted Device-to-Device Communication in Rayleigh Fading Channel
Authors: Wang Weipeng , Zhao Jihong , Qu Hua 
Published: March 2022

Abstract
Device-to-Device (D2D) communication underlaying cellular network is potential to enhance the spectral efficiency, reduce the energy consumption and improve individual quality-of-service (QoS) experience. But intra-cell orthogonality is impaired due to spectral reusing and severe co-channel interference could be imposed between cellular and D2D links. Besides, the direct links between local communicating pairs may be unfavorable and suffer an unsatisfied QoS experience since the randomness of channel condition. So, we are focused on analyzing the outage probability of D2D links assisted by two-way relays on Rayleigh fading channel. Specifically, we consider an amplify-and-forward relay protocol at relay due to their limited processing ability, and devise power control at both D2D transmitter and relay to maintain the QoS requirement of prioritized cellular links. The simulation results verify the correctness of the outage probability analyses for D2D links, and indicate the performance gain when relays are introduced to facilitate D2D links.
Research on Super-resolution Location Technology of Leakage Source Based on Ultrasonic Array Sensor
Authors: Bian Xu , Tian Biwan , Jin Shijiu 
Published: March 2022

Abstract
Leakage in the pressure structure is a problem that must be paid attention to, especially in some special applications, such as spacecraft, which will have a serious impact on the entire system. This paper presents a new method of leak source location based on a single sensor array. The elastic wave excited by the leakage is collected by an array sensor placed on the wall, and then the frequency-space characteristics of these signals are analyzed to obtain the spatial point that meets these characteristics, that is, the spatial location of the leakage source. At the same time, combining the super-resolution technology and the randomness of the signal, integrating the distribution maps of the positioning results in different time periods, and finally obtaining a high-precision estimation of the location of the leakage source. The experimental results show that, under the conditions considered in this paper, the average value of the absolute positioning error on a square meter board is about 2 cm.
A Pipeline-based Low Complexity Dual Thresholds and Multiresolution Mouth Detection Method
Authors: Lin Jingli , Li Changwei , Lan Xi , Li Jinge 
Published: March 2022

Abstract
Mouth detection is a basic step in the automatic diagnosis of buccal diseases. This paper proposes a method of using FPGA(Field Prog ram mable Gate Array) to detect the human mouth region in images, which adopts a pipelined design for high-speed operating. Thus, it can be applied to mouth motion detection as well. After an original image is processed regularly by median filtering, color conversion is performed to obtain its corresponding H component, which is used to create a partitioned binary image. Each constituent region of the binary image uses two thresholds for regional processing separately, which results in two binary images: one comprises the mouth and some other regions with a color close to that of the mouth, and the other indicates the position of the mouth. A logical AND is performed on these two binary images to calculate the border of mouth region with reduced resolution, which is then superimposed on the buffered original image to confirm the mouth region eventually. An FPGA-based scheme is presented, which shows the method could detect the whole mouth properly, with a maximum clock speed of 150MHz. In addition, processing an image of 200*200 only consumes 2178 Slice LUTs(Look Up Table), which is a relatively low resource consumption.
Research on Network Routing Control Algorithm Based on OpenFlow and IGP
Authors: Tian Xuejun , Wen Lizi , Yang Xingyan , Chen Liangzhe , Min Gang , Shu Zhong 
Published: March 2022

Abstract
Given the coexistence of heterogeneous hybrid networks such as IP network, 4G network and Software Defined Network (SDN) in the application of digital news media system, this paper designs a routing control algorithm based on SDN network architecture, which can realize the compatibility of internal gateway protocol and OpenFlow communication strategies. Through the analysis of OpenFlow communication protocol in SDN network architecture, the relationship between Interior Gateway Protocol (IGP) and OpenFlow routing rules is found out. Based on the existing hardware structure of the OpenFlow router, the configuration parameters of a port table, port address table and routing table are improved, and the adjacent routing relation table and information transmission port are used to realize the connection between routers are designed. The attention of users is considered It can reduce the burden of system operation and is compatible with the forwarding control of route forwarding and routing filtering. The adjacent routing relation table is designed to control the process of data collection, storage and forwarding, and the input and output ports between adjacent routers are defined. The open router designed in this paper integrates Simple Network Management Protocol (SNMP) agent and SDN agent mechanism organically to achieve the goal of SDN network management; the routing control module focuses on the management of key data flow, realizes the control of routing state and data flow at the same time, and provides the visualization function of routing state and routing state data flow. By constructing the experimental platform of routing transmission and control functions based on routing control and interior gateway protocol, the effect of routing state control of the two methods is compared and analysed from three aspects of packet transmission state, packet processing state and packet receiving delay in routing control process. The experimental results verify the correctness of the design results.
The Echo Model and Simulation Method of Impulse Radar Fuze Based on Attribute Scattering Center Model
Authors: Kong Ming , Li Yuzhao , Chen Jichi , Wang Xu , Wei Guohua 
Published: March 2022

Abstract
This article focuses on solving the problem of performance evaluation and algorithm verification of ultra-bandwidth impulse radar fuze. A modeling and simulation method for the scattering echo of an impulse radar target is proposed. We distinguish the scattering center of the extended target and construct its echo based on the attribute scattering center model. Besides, the position variation characteristics of the scattering center, and the azimuth dependence of the scattering amplitude are fully considered. At the same time, the motion information of the target is modulated to obtain the target scattering echo of the impulse radar. We generate the scattering echo of the typical streamlined moving target at different observation angles by calculation. The changes of the echo position and amplitude of each scattering center are consistent with the scattering echo model. We use the generated echo data to image, and the imaging results are basically consistent with the shape of the target, which verifies the effectiveness of the proposed method.
A Blockchain-based Security Framework for Secure and Resilient Smart Grid
Authors: Luo Bin , Xu Guibin , Xie Jinglong , Wang Yufei 
Published: March 2022

Abstract
Smart grid integrates the information and communication technologies with the physical grid. It can not only improve security and efficiency of traditional power grids, but also has advantages in promoting environmental protection and sustainable development. However, the existing smart grid systems suffer some security concerns such as privacy leakage and data tampering. In order to address these security issues, we propose a security framework for smart grid using Blockchain. It protects data privacy through cryptographic tools, and it applies Blockchain technologies to prevent data tampering. Compared with the existing smart grid systems, our proposed system enjoys better security and resilience.
Model of Information System for Application of Blockchain Technologies
Authors: Ishchukova Evgeniya , Romanenko Kirill , Salmanov Vyacheslav 
Published: March 2022

Abstract
This article describes the current security problems of blockchain networks, identifying the least explored area. The concept of an information system for investigating blockchain incidents is presented. An example of stealing bitcoins from a cryptocurrency wallet was taken as input. This example contains a fairly large number of blocks and transactions, and everything needs to be studied. An overview of the existing vulnerabilities in the Ethereum blockchain platform is presented. A brief description of the basic principles of operation of two largest cryptocurrency platforms - Bitcoin and Ether - is given. Examples of possible incidents that are widespread among users of blockchain systems are considered. The architecture of the designed solutions is described. The first experimental results obtained on the basis of the implementation of the designed algorithms are presented. It is concluded that iterating over a large number of transactions takes a lot of time; in the future, it is planned to apply machine learning methods to analyze such a large data array.
A Hand Gesture Recognition Algorithm Based on Multi-scale Hybrid Features
Authors: Tu Pu , Huang Chen , Zhu Jinxia 
Published: March 2022

Abstract
A human hand gesture recognition algorithm based on multi-scale hybrid features is pro-posed. A large number of gesture data images are organized and annotated by automatic im-age annotation algorithm. Based on dense sampling, the multi-scale Gaussian pyramid is taken into account for enhancing the image details; it can realize the recognition of both large and small target gestures. Meanwhile, according to the aggregation and distribution of gestures, statistical analysis is used to optimize the size and aspect ratio of anchors, which can further improve the accuracy of recognition. The experiment results show that the mean average precisions of this algorithm can be improved to 99.7% and 93.3% for the simple gesture and complex gesture, respectively, which are higher than that obtained by these traditional methods, such as faster region-convolution neural network (Faster R-CNN), You Only Look Once (YOLO), and SSD.
Permanent Magnet Synchronous Motor Control Method Based on Fuzzy PI and Sliding Mode Observer
Authors: Sha Linlin , Song Yi , Li Zijin 
Published: March 2022

Abstract
In order to solve the many shortcomings of the current servo system using mechanical position sensors, this article combines the traditional fuzzy PI control and sliding mode observer, and proposes a control method of PMSM based on fuzzy PI and sliding mode observer. Simulink is used for simulation analysis, and the results are compared. It can be seen from the simulation results that the designed control method can efficiently control the permanent magnet synchronous speed control system, so that the system has excellent starting characteristics and dynamic stability.
Permanent Magnet Synchronous Motor Control Based on New Sliding Mode Observer
Authors: Song Yi , Song Zehang , Yao Xiaodong 
Published: March 2022

Abstract
Aiming at the problems of large chattering and slow response time existing in the preexisting sliding mode observer permanent magnet synchronous motor control, this paper proposes a new sliding mode observer control way. The model of the permanent magnet synchronous motor was established, and design a new function to take the place of the preexisting transforming function. And use Lyapunov stability criterion to analyse the system stability. At the same time, Use Matlab/Simulink simulation software to carry out simulation experiments, build simulation experiment models, and obtain the control result waveforms of the integrated sliding mode observer control system and the newly designed sliding mode observer control system. Compared to pre-existing sliding mode observers, it can be known that, constrasted with the pre-existing sliding film observer, better performance and stronger stability are possessed by the new sliding mode observer proposed in this artical.
Statistical Method of Low Efficiency Wind Turbine Generating Wind Power Curve Based on Operating Data
Authors: Chen Zhannan , Wang Jiechang , Guo Jianfei , Dong Yan , Yu Jinglong , Zhou Runan , Xiao Huanxiu 
Published: March 2022

Abstract
Aiming at the low efficiency of wind turbines in service, this paper proposes a statistical method of low efficiency turbines based on wind power curve generated from operating data. According to the data distribution characteristics of the wind-power data scatter diagram, a data preprocessing model was established based on the quartile method and quadratic clustering method, which can effectively mark the data of shutdown, invalidity, undergeneration, overgeneration and power limit, and draw the wind power curve which can accurately represent the fan’s performance. On this basis, a mining method for low efficiency units based on the difference rate of lost electric quantity and power consistency coefficient is established, which can make statistics of high loss electric quantity units, units deviating from the designed power curve and units with degraded performance regularly, and evaluate the generation improvement before and after maintenance. Through the actual operation and maintenance data of all 814 wind turbines of a certain company, the effectiveness of the method is verified.
Electromechanical Actuator Design and Control Strategy for UAV Landing Gear
Authors: Yang Tao , Wu Jiufeng , Cao Xinlei 
Published: March 2022

Abstract
UAV is becoming more and more prevalent not only in the military field but also in the civilian field, whose flight safety and performance is of top concern. The landing gear system is undoubtedly a determining factor in UAV taking off and landing. In recent days, the all-electric trend in UAV design is not irreversible. As a result, the hydraulic actuator is replaced by EMA in the landing system. The electromechanical actuator for UAV landing system is designed in this paper. The detailed actuator system design is introduced in the beginning. And then communication protocol between the actuator system and the flight control computer is presented, serving as the basis of control strategy, which is the main content to study. The control strategy mainly deals with normal landing and emergency landing process. At last, the conclusion part summarizes its applications. The EMA devised in this paper and its corresponding control strategy provide a new idea in the landing system design of UAV.
Experiment and Modelling of Triangular Holes Array by Non-traditional Machining Process
Authors: Wang Panpan , He Yafeng , Yang Tao , Xu Bo , Long Bing 
Published: March 2022

Abstract
Triangular holes array is a common structure of the specially shaped holes that can be used for various products in aerospace vehicles. These are commonly produced in the electrochemical machining (ECM) process. The high-quality and accuracy of a triangular grid are closely related to the processing parameters of cathode structure and sidewall insulation sleeve, power supply, electrolyte flow rate, feed speed, and machining gap. Simulations have been carried out to consider the influence of parameters including structure and dimension of the cathode, initial machining gap, feed speed, and current on the homogeneity of the flow field in the machining gap. Consequently, the modeling can support the design of the cathode. The paper is divided into two parts. Firstly, the tool cathode is simulated and fabricated. Secondly, the triangular holes array is produced by using the designed cathode tool. It was found that higher feed speed and lower machining gap increase the stability, accuracy, and efficiency of the machining process and the quality of the triangular holes array.
Realization of Control System of Automatic Welding Machine for Air Conditioning Flange Based on CANopen
Authors: Ren Kailang , Yan Liangwen , Huang Shan , Dong Xudong , Wei Mingsen , Chen Jiajian 
Published: March 2022

Abstract
The principle of automatic welding machine (AWM) for air conditioning flange is introduced. The architecture of the control system of AWM realizes the multi spindle linkage control. The communication between PLC and servo driver is built based on CANopen protocol, and the communication between PLC and touch screen is set up based on Modbus RTU protocol. To meet the welding machine spindle coordination control requirements, the PLC program is designed by Delta ISPsoft programming software, and simplified by the application of sequential function chart (SFC) and function block. The human machine interaction (HMI) is developed by Xinjie Touchwin. Linear interpolation algorithm (LIA) is used to prevent the welding defects on the air conditioning flange corner thus it improves the welding quality and realizes the straight path of welding torch from the original to starting welding point and from the end welding point to the original simultaneously. The AWM for air conditioning flange can replace the manual welding and has a broad application prospect in many areas.
Research on Thermal Analysis and Thermal Design of a Space Inertial Sensor Using Laser Measurement
Authors: Chen Haowen , Li Zongfeng , Wang Yi 
Published: March 2022

AbstractIn this paper, a new space inertial sensor based on laser interferometry developed by the experimental team is used for temperature simulation analysis of multi-physics coupling. Through the analysis of the noise influence of the inertial sensor, it is calculated that under the index of the acceleration noise level of 1×10−10g/Hz1/2, the temperature fluctuation of the Test Mass (TM) needs to be controlled ≯0.1 °C. The finite element analysis method is used to simulate and calculate the temperature change inside the inertial sensor within 36 hours. In the case of no heat insulation component, the temperature difference between the six surfaces of the TM is maintained within 10−5K, and the temperature of the Electrode Housing (EH) only fluctuates ±0.1K in the stable fluctuation section when the external environment fluctuates ±1K. After 36h, the temperature of the TM decreased by 0.007K compared with the initial value. With the addition of heat insulation components, the fluctuation range of internal temperature decreases, and the temperature of the EH fluctuates within the range of ±0.015K.
Research on high-temperature resistant resin matrix composites of hypersonic aircraft structure
Authors: Fu Xinwei , Wang Jiafu , Ren Yiru 
Published: March 2022

Abstract
The aircraft structure would be suffered high temperature during the hypersonic flight. To solve the problem of high temperature resistance of hypersonic aircraft, the mechanical properties of different structural materials at different temperatures are studied. The tensile strength and tensile modulus of structural steel, aluminum alloy, titanium alloy, resin matrix composites and polyimide composites are analyzed, and the performance of the materials at high temperature is compared. The results show that the properties of typical materials will decrease with the increase of temperature. The high-temperature mechanical properties of structural steel and aluminum alloy are poor, and the titanium alloy can withstand higher temperature. Polyimide resin composites can work at higher temperature for a long time compared with epoxy resin and bismaleimide resin composites, and it has more obvious advantages than titanium alloy at 400 °C. Polyimide resin composite has great potential to replace traditional materials as load-bearing structural material of hypersonic aircraft.
Numerical simulation of a two-dimensional S-shaped inlet
Authors: Zhan Haoran 
Published: March 2022

Abstract
In order to solve the problem that different operation conditions affect the performance of S-shaped inlet, we have carried out a numerical study on a two-dimensional S-shaped inlet and analysed the influences of incoming Mach number, attack of angle α and the outlet pressure on the performance parameters of the inlet, such as the total pressure recovery coefficient, total compression ratio and the steady-state total pressure distortion index at the exit of inlet. The results show that Ma number and the outlet pressure are the main factors affecting inlet performance. With the increase of Ma number, the total pressure recovery coefficient of inlet decreases from 0.975 to 0.793, the total compression ratio decreases from 1.212 to 1.146, and the steady-state total pressure distortion index increases from 0.0536 to 0.377. The flow energy loss in the inlet increases, the flow uniformity decreases, and the inlet performance becomes worse. With the increase of the outlet pressure, the total pressure recovery coefficient of inlet rises from 0.875 to 0.931, the total compression ratio rises from 1.101 to 1.216, and the steady-state total pressure distortion index decreases from 0.219 to 0.123. The mass flow rate of inlet and airflow loss decrease, and the performance of the inlet improves. We study the influence of different operation conditions on the inlet performance, which provides a certain reference for the performance evaluation of S-shaped inlet.