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In satellite edge computing networks, when too many ground users access the satellite through the same channel, the resulting co-channel interference will lead to edge computing performance degradation. To address this problem, a multi-user computing offloading strategy based on stochastic game was proposed under the system model of dynamic environment low earth orbit constellation edge computing network. On the premise of considering the selfishness of users, the stochastic characteristics of the satellite-ground channel and the dynamic nature of ground user access, from the perspective of game theory, the offloading decision-making process of ground users in the dynamic environment was formulated as a stochastic game. It was proved that the formulated stochastic game was equivalent to a weighted potential game with at least one Nash Equilibrium (NE), and the NE minimized the system overhead. In order to achieve NE in a distributed manner under dynamic environment, an intelligent stochastic learning algorithm based on the stochastic learning was designed to efficiently achieve NE for the proposed stochastic game. Simulation results show that compared to the benchmark algorithm, the proposed algorithm can significantly reduce the co-channel interference and the system overhead, and achieve near-optimal performance.

A mine intrinsically safe audio and video recorder is designed. The device is based on 5G SOC processor, and adopts the photosensitive sensor + white light/infrared laser fill light + intrinsically safe circuit scheme. Under the environment of low illumination, full black or confined space, it can collect, compress, store and display 4K high-definition video images, and transmit the collected audio and video data in real time. The recorder has the characteristics of high imaging quality, long shooting distance and low power consumption in low illumination environment; it supports TCP/IP, UDP, RTP, ONVIF, GB28181 and other protocols. In addition to serving as an underground information record, it can also assist the emergency headquarters in carrying out rescue operations in time. The test results show that the picture resolution of the recorder is 10 688×6 012, the video resolution is 2 560×1 440, the visual distance is 20 m, the data packet loss rate is about 0.068%, the delay is about 15.85 ms, and it can achieve continuous video recording for 9 hours or continuous video playback for 4 hours.

ObjectiveTo establish an ischemia-reperfusion model in cynomolgus macaques and to analyse the effects of edaravone intervention.MethodsA total of fifteen adult male cynomolgus macaques were randomly divided into three groups: sham operation (Sham group, n=3), ischemia-reperfusion model (Model group, n=6) and edaravone treatment (Edaravone group, n=6). Ischemic-reperfusion model of cynomolgus macaques was established by clamping the M1 branch of the left cerebral artery for 1 h. After 2 h of reperfusion, the animals in Edaravone group were injected with 0.5 mg/kg edaravone intravenously for intervention treatment, while the animals in Sham and Model groups were injected with an equal volume of normal saline intravenously, twice a day, from the 2nd to 7th day. The behavioral video recordings, clinical observations and neurological deficit scores of cynomolgus macaques were obtained, and brain edema volume and cerebral ischemia volume were statistically analyzed.ResultsCompared with the Sham group, the animals in Model group showed typical symptoms of ischemic stroke, with a significant increase in the neurological deficit score， the volumes of edema and infarct of brain tissue (all P＜0.01). Compared with Model group, the neurological deficit score, the volumes of edema and infarct of brain tissue were significantly reduced in Edaravone group (all P＜0.05).ConclusionAn animal model of ischemia-reperfusion in cynomolgus macaques was successfully established, and edaravone was confirmed to alleviate the damage caused by ischemia-reperfusion.

Aim: Our aim in this study was to isolate potentially novel strains of fowl adenovirus serotype-4 (FAdV-4) that is currently circulating in broiler chicken flocks in Guangdong Province, China, and to compare nucleotide and amino acid (AA) sequences of their respective hexon genes. Materials and Methods: The experiment was carried out on poultry farms experiencing outbreaks of FAdV-4-associated hydropericardium syndrome (HPS). Tissue samples from the hearts and livers of deceased chickens were screened for FAdV-4 infection using hexon gene-specific polymerase chain reaction (PCR). Results: New virus isolates were used to infect 7-day-old chicks, which went onto reproduce typical HPS signs. The hypervariable region of the FAdV-4 hexon gene was PCR-amplified and sequenced. The hexon nucleotide and deduced AA sequence identities were 99.8-99.9% and 99.5-99.8%, respectively, among the four novel isolates. In addition, the new isolates were 97-100% and 96.4-99.9% identical to the nucleotide and deduced AA sequences, respectively, of FAdV-4 hexon genes available in the National Center for Biotechnology Information GenBank database. Phylogenetic analyses, based on the hexon gene sequence, revealed that the new isolates, clustered with FAdV-C; the FAdV-A, FAdV-B, FAdV-D, and FAdV-E viruses, were more distantly related. Conclusion: New FAdV-4 isolates from Guangdong Province are similar to those identified in other regions of the world. This information provides critical insight into HPS epidemiology and provides a perspective for monitoring outbreaks and developing strategies for disease prevention.

A mine-used real-time video transmission system was designed to solve problems of low video definition, unstable transmission rate and poor compatibility in existing underground video transmission system. The system uses 960 nm infrared laser as auxiliary light source, and uses MCCD image sensor to collect video signals, which improves video definition in low light intensity or dark environment. The collected PAL analog video signal is converted into YUV digital signal through video decoding module TVP5150, then the digital signal is compressed and encoded by H.264 through multi format codec, and UDP packet header is added for RTP encapsulation, which improves timeliness of video data transmission. The data is streamed through Live555 streaming media server, RTSP video streaming is encapsulated with ONVIF standard, and real-time video streaming data transmission is realized through Socket network programming, which improves system compatibility and transmission rate stability. The test results show that the system has video transmission rate of 2.190 Mbit/s and packet loss rate of about 1.256%, which meets real-time video transmission requirements.

The audio and video system of mine search and rescue robot is designed based on the Linux. The system selects a 1/2.7 inch CMOS USB binocular camera, BH1750 light intensity acquisition and 850 nm infrared compensation light as the video acquisition scheme under low illumination environment, the hardware has intrinsically safe power conversion circuit and wired/wireless communication interface, the system realizes the acquisition of two high-definition audio and video in the low illumination environment of coal mine, and carries out compression, storage, display and transmission for the collected audio and video data.

In view of problems of poor real-time performance and interactivity of data input and backwardness of emergency response message transmission methods in existing emergency rescue management system for mine rescue team,voice interaction technology is applied to emergency rescue management system for mine rescue team to realize functions of intelligent information input of alarm information and voice autoplay of announcements.Voice recognition technology is used to intelligently input alarm information, quickly generate alarm record sheet, and track alarm handling situation in real time; voice synthesis technology is used to remind the user of announcements and to-do items by voice,so as to avoid work delay. The test results show that the average voice recognition rate of the system is more than 90%, and the voice synthesis accuracy rate is 100%,the speed of entering the alarm information by voice recognition is obviously faster than handwritten recording and typing. Field application results verify the effectiveness and stability of the system.

For problems of high power consumption, large volume, close irradiation distance and poor concealment of existing auxiliary light source for low-illumination video acquisition, a design scheme of intrinsically safe laser auxiliary light source for low-illumination video acquisition was proposed. The semiconductor laser diode with 940 nm wavelength of light source is selected, and multi-mode fiber, smoothing glasses and lens are used to realize regular shape and uniform illumination intensity of beam outputted by the semiconductor laser diode. The intrinsically safe driving circuit adopts constant current driving mode with overvoltage, anti-reverse connection and anti-static protection. Working temperature of semiconductor laser diode is reduced through heat dissipation device, so that the laser auxiliary light source can work stably for a long time. The test results show that the laser auxiliary light source with irradiation distance is 20 m, power consumption is less than 3 W and continuous working temperature below 50 ℃.

This paper compared the influence of fused zirconia-corundum (AZ40), monoclinic zirconia (m-ZrO2), and 3 mol% yttria-stabilized zirconia (3Y-ZrO2) on physical properties at room temperature, hot modulus of rupture, and thermal shock resistance of Al2O3 ceramics, and their relationships with microstructure changes were investigated. It was found that m-ZrO2 or 3Y-ZrO2 addition promoted the process of sintering densification and enhanced the room temperature strength and the hot modulus of rupture of Al2O3 ceramics, and the effect of the latter was more distinct, while those of the sample with AZ40 addition decreased. In addition, the three kinds of ZrO2 were beneficial to improving the thermal shock resistance of Al2O3 ceramics. All these changes had close relationships with the changes of corresponding microstructure characteristics (including distribution of particles, degree of contact between crystals, grain boundary solid solution, microcrack density) and phase composition.

With the construction of interconnected power grid and the rapid development of clean energy, the frequency problem of power system is becoming increasingly prominent. The problem of ultra-low frequency oscillation affects the stability of system frequency. In order to analyze the frequency regulation characteristics of the system, it is necessary to study the local active power control link and stability calculation model of the hydropower plant computer monitoring system. In this paper, the influence of the local active power control link of the monitoring system on the system frequency small signal stability is studied, and the model is built in the simulation program. Through the simulation of 4-machine-2 regional power grid, the influence characteristics of local active power control on frequency dynamic damping level are verified. In the example of large power grid, the coordination between the local active power control of the monitoring system and the speed regulation system of hydropower units is comprehensively considered, the suggestion of coordination of multi-level frequency modulation resources to system frequency regulation is put forward.

Aiming at lower accuracy of classification for signal feature extraction of rolling bearing,firstly,some time domain indexes for online simple rapid discrimination are selected. The sensitivity of time domain index of fault is analyzed based on size of bearing fatigue damage and number of local damage. Secondly,based on the traditional time domain index,two more sensitive time domain index ‘TALAF ’and ‘THIKAT ’is searched. Lastly,the data set including two new indicators are trained and tested based on wavelet neural network which has a good real-time. The training and testing results for the traditional time domain indexes kurtosis and BP neural network are compared with results of the data. The simulation results show that TALAF and THIKAT can effectively improve the accuracy of prediction index state bearing.

The central pattern generator (CPG) has been identified in the spinal cords as responsible for locomotion movements. It is difficult to select the appropriate values of parameters in CPG model. In this paper, the Matsuoka oscillator is selected as the rhythm-generation model and the bat algorithm is chosen to search the parameters of CPG model. The paper shows the details of the parameters optimization and the diagram of the convergence performance. In the paper, the CPG includes the main rhythm-generation neuron and the minor pattern-formation neuron, and Rowat's neural model is chosen as the pattern-formation neuron. Then the CPG model is applied to the three-link biped robot and the result shows that the method of parameter optimization is effective.