Abstract:As an important part of equipment support,equipment maintenance work can be improved by scientific and effec-tive evaluation.The evaluation of the maintenance work is based on the full consideration of the factors affecting the evaluation work.Firstly,the analytic hierarchy process is applied to determine the evaluation index weight of the evaluation grade of the evaluation work,and the consistency test is carried out.Then,the fuzzy comprehensive evaluation factor set,evaluation set and relation matrix are constructed.Finally,two level fuzzy comprehensive evaluation method is used to determine the four evaluation levels:better,good,average and poor.This combination of qualitative and quantitative methods aims to carry out scientific,accurate and compre-hensive evaluation of the maintenance work,and provide reference for maintenance work optimization and decision.

Abstract:To improve the calibration accuracy and efficiency of the electrical parameter measurement system for inertial MEMS devices,an in-situ calibration technique has been proposed,and a corresponding miniaturized calibration device has been developed.The in-situ calibration technique involves placing a custom-made standard source meter at the test location of the iner-tial MEMS device,ensuring the consistency between the test points and calibration points,and guaranteeing the complete loop cali-bration of the entire electrical parameter measurement system.The accompanying miniaturized calibration device is designed based on a software and hardware testing platform and an embedded computer control platform.By integrating various modules through a stacked structure,the device reduces noise interference and minimizes its volume,allowing it to perform tests in space-constrained environments.Comparative analysis shows that the in-situ calibration technique can significantly improve the calibration accuracy and efficiency of the electrical parameter measurement system for inertial MEMS devices,meeting the requirements of on-site cali-bration and providing reliable assurance for the high-precision application of inertial MEMS devices.

Abstract:The quality and reliability of GaN devices has become a problem of more and more users,and this paper simulates the high input power application scenario of the device,monitors the degradation of GaN devices during the test process,and sum-marizes the degradation mechanism through the analysis of the test results.

Abstract:Existing mobility models are usually applied in application scenarios such as pursuing,striking and rescuing,and simple linear motion is used,while there are certain defects in the research of curved mobility models for multi-obstacle scenarios in real scenarios.Based on this,this paper analyzes the demand of real application scenarios,uses the repulsive force method of re-pulsive force to avoid obstacles,and realizes the curved motion of nodes by transforming the speed of node motion into derivative vector according to the characteristics of Hermite curve,and proposes a movement model based on Hermite curve,which makes up for the defects of curved movement model for complex multi-obstacle scenarios.In order to study the performance of the model in ap-plication scenarios,the spatial probability distribution of the nodes of the model is investigated and compared with the classical SRMM and RWPM models.The experimental results show that the node motion under this model shows a uniform distribution,which can provide a more realistic application scenario for the simulation of Ad hoc networks.

Abstract:In order to solve the problem of interchannel interference and power allocation in visible light communication sys-tem,an optimal power allocation scheme based on intelligent algorithm is proposed.By introducing an adaptive mechanism,this scheme improves the global search ability and convergence speed of salp swarm algorithm,and combines chaotic sequences to ini-tialize the population,enhancing the robustness and optimization accuracy of the algorithm.By constructing a visible light communi-cation system model,the adaptive salp group algorithm is used to optimize power distribution.The simulation results show that the adaptive salp group algorithm has significant performance advantages in visible light communication system,which can effectively reduce the bit error rate of the system,improve the spectral efficiency and user fairness,and provide powerful technical support for the practical application of visible light communication system.

Abstract:In order to build the debugging environment and solve the problem of sensing data which require for equipment de-bugging,a fast memory debugger based on Windows environment is designed.The memory debugger uses the special string grid technology to achieve the protocol data input,which can overload several grid functions to meet the memory editing,and then con-structs the memory debugging data that developers need to use.The memory debugger can modify the memory data by editing the da-ta,and then replace the change data of the business logic module.Dynamic array to store variable memory is used to achieve the pur-pose of debugging by programmers within the team.This memory debugger uses text and binary files to store variable data for other non-team programmers.At the same time,this paper uses broadcast message technology to design message filtering methods that other recipients need to overload,so that other processes can automatically perceive data changes.

Abstract:According to the requirement of magnetic moment test for large equipment,based the research of spot magnetic mo-ment calibration technology,the magnetic moment measuring instrument is measured by combining magnetic flux induction coil and magnetic flux measuring instrument.The magnetic flux induction coil adopts Helmholtz coil structure,and the magnetic moment is measured accurately by substitution and comparison method.

Abstract:For CMUT linear arrays,this paper designs and implements an ultrasonic imaging circuit design scheme based on FPGA for control and processing.The cssircuit has 32 transmitting and receiving channels.With FPGA as the control core,the ultra-sonic transmitting and echo signal receiving are realized by using a finite state machine(FSM)at the register-transfer level(RTL)to control the associated circuitry.The multi-channel data cache and transmission are completed by using the FIFO memory built in FPGA and USB3.0.During the test,the host computer is used to change the circuit parameters,and the computer-side software per-forms the algorithm to process the display image.The experimental results indicate that the circuit satisfies the B-mode imaging re-quirements for the CMUT probe,and can achieve an imaging rate of 20 frames per second.It has the characteristics of miniaturiza-tion and open architecture,This research provides strong support for the development and application of portable ultrasound imaging systems using CMUT arrays.

Abstract:The aim of this study is to develop a remote wireless trigger system for high-speed cameras based on microcon-troller technology,in order to meet the demand for unattended triggering in high-speed photography.This system ensures reliable capture of the motion state of fast-moving objects.The system realizes the remote triggering of the high-speed camera through the combination of microcontroller and wireless communication module.The system has the control mode of"one master,one slave"or"one master,multiple slaves",which can be flexibly selected according to the actual needs.After multiple experimental tests,the trigger signal of the high-speed camera is sent from the host transmitter to the output trigger signal of the slave,the delay is about 50 ms,and the farthest communication distance is 15 km.The system has the advantages of high reliability,strong anti-interfer-ence ability and easy operation,which provides a safe and reliable trigger source for high-speed camera.

Abstract:In addressing the performance and resource utilization deficiencies encountered by high-performance computing tasks and intelligent applications running on cloud-native systems,a heterogeneous resource-aware load balancing scheduling algo-rithm for cloud-native environments is proposed.This algorithm predicts the load of high-performance tasks to implement load bal-ancing for batch task scheduling,which not only balances the utilization of system computing resources but also effectively reduces communication latency between Pods and improves the efficiency of parallel task execution.For intelligent computing tasks requir-ing specific heterogeneous resources,resource reservation is conducted on nodes with idle heterogeneous resources to prevent these tasks from waiting due to CPU resource scarcity.Experimental results show that,compared to the default Kubernetes scheduling al-gorithm,this proposed algorithm reduces the overall runtime of a mixed workload of high-performance and intelligent computing tasks by 8.38%.

Abstract:The emergence of knowledge graphs has brought profound changes to recommender systems,making recommenda-tions interpretable while providing rich semantic information,and human personalities change over time,a factor that extant tech-niques neglect to bring to recommender systems.So this paper proposes a model that fuses time decay and knowledge graph convolu-tional networks(KGCN-TD),which introduces the time decay factor into the knowledge graph convolutional network model(KGCN),which can help the model capture the temporal nature of user behaviors,and takes the time information as an attribute of the edges in the knowledge graph,and converts the time into a weight by defining a decay function,which focuses on mining knowl-edge graph related attributes to capture item relevance,and extends the sensory field to capture the user's potential distant interests by sampling entity neighbor information and computing entity representations in combination with bias.This strategy respects the temporal order and preserves the structural information of the knowledge graph to further improve the prediction performance of KGCN.The model is effectively validated on three datasets,which are movies,books,and music.

Abstract:The high-speed maneuvering of the target will cause a significant Doppler frequency shift in the radar received echo signal,and the linear frequency modulation pulse compression of the radar has a coupling between the Doppler frequency and the measured distance,that is,the Doppler frequency will cause a certain difference between the measured distance and the true distance of the radar,which affects the measurement of the true distance of the target by pulse compression.In order to eliminate this impact,a mathematical model is established to analyze the theoretical reasons for performance degradation,and the correctness of the theoretical analysis is verified through simulation.Finally,two methods,positive and negative frequency modulation method and broadening ratio compensation method,are proposed to eliminate the influence of high-speed target maneuvering on the dis-tance measurement of linear frequency modulation radar,combined with the pulse compression processing process.

Abstract:PM2.5 has serious impact on air quality,whose prediction is affected by pollutants and the weather factors at the same time.And PM2.5 prediction is characterized by nonlinear and uncertain,the traditional prediction method has lower precision.Therefore,an air PM2.5 concentration prediction model based on improved manta rays foraging optimizing SVM is presented.First of all,a population initialization method based on Laplacian distribution is introduced to promote the population diversity.A weight factor adjustment based on Levy flight is used to improve the global optimization ability of the population.An individual disturbance mechanism based on the neighborhood center opposite-learning and Cauchy mutation is designed to avoid the local optimum.Then,improved manta rays foraging optimization algorithm IMRFO is to optimize support vector machine model,and an air quality predic-tion model IMRFO-SVM is constructed.Finally,The pollutant and meteorological data of a place are selected as experimental fea-ture factors,and the prediction factors are determined by Pearson correlation analysis for experimental analysis.The prediction re-sults of IMRFO-SVM is compared with that of traditional SVM,traditional MRFO optimizing SVM MRFO-SVM and traditional PSO optimizing neural network PSO-BP.Experimental results verify that IMRFO-SVM has higher forecasting precision and faster conver-gence rate.

Abstract:In order to solve the requirement of high bandwidth in high-speed data transmission,a data transmission system based on PCIe interface is designed.The system realizes the interconnection between FPGA and CPU through PCIe interface,and uses optical module to realize the communication between the external RapidIO module and FPGA.By designing the top-level DMA transmission architecture,the data is uploaded to the DDR of CPU through PCIe interface.In addition,PCIe hardware design and initialization training process are introduced,and data read and write mode and state transition process in DMA data transmission module are analyzed in detail.Meanwhile,multi-FIFO design can extend multi-channel data transmission and maximize data high-speed transmission on the basis of existing hardware links.

Abstract:Severe weather conditions have a significant impact on the communication systems of satellite-to-ground links,which have drawn considerable attention.Based on the measured results of the particle distribution of sand and dust storms,the elec-tromagnetic wave attenuation and phase shift models in the sand and dust storms along horizontal and ground-to-air paths are de-rived in this paper.Considering the influence of the atmosphere,the total attenuation of sand and storm weather on the Q/V band sat-ellite communication link is obtained,and the influences of elevation angle and frequency on link transmission are analyzed.It is helpful for the link design of satellite communication systems.

Abstract:Aiming at the problem that the subjective weighting method is greatly affected by the experience of decision-mak-ers,while the objective weighting method is less involved,an evaluation method based on the combination weighting method of game theory is proposed.The analytic hierarchy process is used to calculate the subjective weight of the workload index of flight dis-patchers.The entropy weight method is employed for determining the relative importance or weight of objectives,and the game theo-ry method is introduced for combination weighting.By integrating the fuzzy comprehensive evaluation method,a comprehensive eval-uation model is constructed.The results show that the combinatorial weights calculated based on the game theory combinatorial weights method find an ideal combination point between the empirical judgment of subjective weighting method and the data analysis of objective weighting method,giving full play to the advantages of both sides.

Abstract:In order to solve the problem of the combination of multiple AWACS in the persistent reconnaissance and surveil-lance mission in a specified area,this paper presents a multi-aircraft array configuration method based on the monitoring effect.Based on the theory of minimum encircle circle,the no-fly zone of the AWACS is established.Then,according to Bernoulli's theo-rem of large numbers,the surveillance coverage area of the AWACS is quickly estimated by Monte Carlo method,and the patrol po-sition of the AWACS is obtained.The effectiveness and feasibility of the method are proved by an example simulation.

Abstract:Aiming at the problem of poor image quality and large volume of the current embedded image acquisition and stor-age system,a high-performance small system design scheme is proposed.In terms of hardware,the IMX335 CMOS image sensor is used as the image acquisition front-end,the RV1126 SOC is used as the control and processing end,and the large-capacity SD card is used as the storage end to realize the high-definition and large-capacity small image acquisition embedded device.In terms of software,the development of embedded software environment is completed in ubuntu system.The software level of the system and the process of image acquisition,storage and operation are introduced.Through experimental verification,the system is small in size,stable in operation and clear in image imaging.

Abstract:GNSS(Global Navigation Satellite System)timing is the most accurate long-distance timing method at present,but the satellite transmission power is low,long distance and other factors will lead to the satellite timing signal weak,easy to inter-cept and other problems.To solve these problems,Loran-C timing system can be used to improve.The integrated use of Loran-C and satellite timing can enhance the stability of the whole timing system.In this paper,a timing receiver based on Loran-C system is designed.The hardware and software are designed digitally by heterogeneous method of FPGA+ARM,and the software is embedded with adaptive filtering algorithm to enhance the receiver's signal acquisition capability.The accuracy experiment of PPS shows that the timing accuracy of the system is within±1 μs compared with the satellite timing.

Abstract:Aiming at the problems of high starting speed and low output performance of traditional self-powered sensing devic-es for harvesting wind energy,a self-powered sensing device engineered is proposed for low start-up wind speeds.This device not only supplies power to sensors but also detects wind speed in the natural environment.Utilizing the bidirectional rotation structure,the device successfully achieves a low wind speed start-up of 3 m/s,and the output power reaches 23.2 mW when the wind speed is 5 m/s,which can supply power to the temperature and humidity sensor and display it in real time on the computer.At the same time,the output signal of the triboelectric sensing unit is transmitted to the data terminal to display the wind speed in real time.The test results show that the harvester has high output performance and good wind speed detection sensitivity,and it shows good appli-cation prospects in the field of sustainable monitoring of the Internet of Things.