Abstract:The Statute of an educational institution is the basic system that regulates the ground rules of the institution’s educational and training activities. Echoing the national and military laws and regulations, it plays a guiding role in the formulation of the institution’s internal rules and regulations. In the process of formulation, a holistic approach should be taken to promote the unity of the top-level design and specific measures,higher education and military education, requirements of the times and the function and mission, historical inheritance and long-term planning, and common requirements and individual development. Only in this way can the statutes effectively square with the development direction, pool the will and strength, stimulate the driving force, demonstrate the enterprising attitude, and therefore to support the high-quality development.

Abstract:Aimed at the problems that structure and function of aero-engine are complex, construction of Bayesian network is difficult, and it is difficult to obtain the exact value of node conditional probability, in this paper, a knowledge graph with fuzzy Bayesian network (KG-FBN) inference fault diagnosis method is proposed. Firstly, on the basis of large-scale historical fault data, an aero-engine fault knowledge graph is constructed by using the knowledge graph technology. Secondly, a mapping method of “knowledge graph-Bayesian network” is proposed to rapidly construct Bayesian network, and introduce fuzzy set theory to solve the uncertainty problem of probability parameters in engineering practice. Finally, an example is given to verify the feasibility of the proposed method. The results show that the proposed method can improve the efficiency of Bayesian network construction and achieve uncertain inference in fault diagnosis, can be also used for optimizing diagnostic strategies, and can improve equipment reliability, and is strong in engineering application value.

Abstract:In order to meet the different requirements of aerodynamic performance for Tailless Aerial Vehicle at different flight stages, this paper proposes a multi-objective control allocation method. Firstly, a TAV non-affine rudder effect model is established to mathematically describe the TAV control allocation problem, an incremental nonlinear control allocation method is proposed and its convergence is proved out. And then, the incremental form of the secondary performance indicators. Finally, the multi-objective nonlinear control allocation problem is solved by the effective set quadratic programming method, and simulated for verification. In the simulation scenario of this paper, compared with the minimum rudder deflection case, the average drag coefficient of the minimum drag case is reduced by 36.96%, and the average lift coefficient of the maximum lift case is increased by 7.76%.The experimental results show that the control allocation method can effectively achieve different sub-objectives such as minimum rudder deflection, minimum drag and maximum lift under conditions of minimum moment allocation error.

Abstract:In order to obtain the characteristics of gliding arc plasma ignition in the combustion chamber of aero-engine, the gliding arc plasma ignition simulation of aero-engine single dome model combustor is studied by numerical simulation. The gliding arc plasma is simplified as a dynamic heat source, gliding arc plasma ignition is compared to electric spark ignition, a rule of temperature distribution and flame evolution in combustion chamber is made by the two ignition methods, and the characteristics of gliding arc plasma ignition are summed up. The calculation results show that the average temperature peaks of the two ignition methods are basically the same. For the gliding arc plasma ignition, when the discharge power is 200 W under conditions of air flow being 25 m3/h, the residual air coefficient is 1, and the ignition delay time is 224.6 ms. When the air coefficient is 2, the ignition delay time is 324.9 ms. And when the residual air coefficient is 4, the ignition delay time is 878.7 ms. In addition, when the discharge power is 200 W under conditions of the air coefficient being 1, and the air flow being 15 m3/h, the ignition delay time is 194 8 ms. When the air flow is 35 m3/h, the ignition delay time is 298 9 ms.

Abstract:Lightning breakdown voltage is a significant parameter in judging whether lightning spark is enabled to generate in the fuel tank when an aircraft is struck by lightning. To investigate the lightning breakdown voltage of small gaps in aircraft fuel pipes installation, a test setup is built, and an adjustable impulse voltage generator is adopted to generate the lightning voltage waveform in accordance to the standard SAE ARP5412B. The test results show that the minimum value of critical withstood breakdown voltage measured in the laboratory environment is 9.0 kV at the installation gap of 3 mm. The types of components around the fuel pipes in fuel tank and the installation forms of the fuel pipes are almost not affected by the lightning breakdown voltage of the installation gap. The effects of the lightning breakdown voltage on the fuel pipes in diameter and on the surface of fuel pipes paint layer are negligible. The installation gap of 3 mm should be in good keep. The withstood breakdown voltage value increases from 9.9 kV to 22.5 kV by applying 1 mm thick sealant on the component surface, showing that the voltage amplitude required for gap lightning breakdown is greatly increased. The researches indicate that coating sealant on the surface of fuel pipes is an effective measure to reduce the risk of lightning breakdown in small gaps. The tests results and research conclusions of this paper are available for reference and basis.

Abstract:Terahertz scattering characteristic acquisition of targets by radar imaging is an important way of scattering measurement, and its premise is to obtain the high resolution and fine imaging results.Aimed at the problems that measurement of imaging in terahertz radar system is difficult to guarantee a complete consistency between the target center and the turntable center during measurement,and the results of imaging are sensitive to position error of targets for the near field terahertz radar system, in this paper, a corresponding accurate imaging model is deduced and established, a method of distance error compensation based on prior information is presented, and a realization of imaging algorithm is proposed, achieving the target’s high resolution fine image acquisition under condition of near field and large rotation angle. The experimental results show that the proposed imaging method can accurately correct the image distortion and defocus caused by the positioning error and near-field factors of the target, and is not subject to the coincidence of the center of the target coordinate system and the radar coordinate system. The study could pave the way for image-based target scattering feature extraction and scattering center diagnosis in terahertz band.

Abstract:In order to achieve simultaneously excellent multiple moving target imaging quality and imaging efficiency, a SAR multiple moving target imaging method based on alternating direction method of multipliers (ADMM) is proposed by utilizing the multi-component linear frequency modulation signal form and sparse prior knowledge of synthetic aperture radar (SAR) multiple moving target signals, First, a sparse observation model of SAR multiple moving targets is established to formulate the multiple moving target imaging task into an inverse problem with the sparse feature constraint. Then the adaptive Chirplet decomposition method is applied to realize the estimation of target Doppler modulation frequencies for the observation matrix construction. The well-focused SAR image of multiple moving targets can be sparsely reconstructed based on ADMM decomposing the complex convex optimization problem into several simple subproblems which can be alternately solved. Finally, the simulations and the experiments on airborne SAR data show that the proposed method is superior to the existing moving target imaging methods in terms of imaging quality and imaging efficiency.

Abstract:In joint operation planning, there is an input information whose scientific nature, rationality and operability of joint operation conception should be fully verified. A qualitative verification mode of joint operation conception is formed based on the hierarchical DEMATEL algorithm and combined with “Wuli-Shili-Renli” methodology suitable for dealing with complex giant system problems. The essential characteristic, verification needs and verification methods of joint operation conception are analyzed, the qualitative evaluation index system of joint operation conception is set up, the analysis framework based on the three-attributes criteria of “Wuli-Shili-Renli” is constructed, and the analysis framework based on the five-dimension criteria of purpose, rationality, feasibility, coordination and risk are built. The case calculation and result analysis are made. Finally，the method is provided for the qualitative verification mode of joint operation conception.

Abstract:In view of the fidelity issue of moving target tracking simulation and RCS characteristics, a target tracking and RCS simulation method is proposed based on the improved particle swarm algorithm (PSO). Firstly, the basic principle of simulating the tracking of moving targets is analyzed by unmanned aerial vehicles (UAV), the motion model and coupling relationship between UAVs and simulated targets are discussed, and the coupling factors and control quantities are determined. And then, the constraint conditions for simulating the target tracking are analyzed, and the target optimization fitness function is given in consideration of UAV performance and energy consumption, and an optimal control model is established for simulating the target tracking. To improve the accuracy and practicality of the model solution, the particle swarm optimization algorithm is improved and embedded in the model solution, achieving an effective simulation of the target tracking. Finally, based on the simulated target tracking, the angle of altitude in simulating flight target is calculated through flight dynamics principles and coordinate system transformation, and the RCS of the simulated flight target is simulated by the electromagnetic calculation software. The simulation results show that this method is wide applicable for achieving tracking simulation of moving targets and RCS simulation.

Abstract:In this paper, we propose and implement a time-domain finite integral technique (TDFIT) for modeling thermal deformations and variable structures of any complexity. By employing a rapid 3D interpolation technology, we simultaneously solve the deformation mapping of diverse thermoelectric mesh models and parametric surfaces. Our approach ensures the accurate integrated simulation of thermoelectric properties, arbitrary thermal distributions, and minor shape variations. The proposed method is particularly suitable for materials characterized by electrically large scales, non-uniform temperature changes, and deformations. This study presents a thermoelectric integrated modeling approach and a practical simulation tool for analyzing the electromagnetic scattering and radiation properties of radomes and aircraft under high-temperature and high-pressure conditions.

Abstract:Ranking importance in nodes is a commonly used analysis method for identifying key nodes in complex networks, and importance of analyzing nodes in the network is a great help to a deeper understanding network characteristics. In order to further improve the accuracy of node evaluation based on existing methods, this paper introduces the concept of Binomial Entropy to quantify the importance of nodes in the network, measures the mutual influence between nodes through neighborhood similarity, and simultaneously uses Van der Waals force to abstract the interaction between nodes. Therefore, a key node identification method based on binomial entropy and Van der Waals force between neighboring nodes is proposed. This method is a comprehensive consideration of the local and global characteristics of nodes from the overall information flow of the network and the location and interaction relationship between adjacent nodes, and a selection from three similar algorithms to verify the performance through three evaluation indicators. The experimental results show that the algorithm in this paper is good in performance in judging important nodes.

Abstract:In the process of multi-body separation of sub-mother UAV, the analysis of aerodynamic interference characteristics is an important research direction in swarm UAV launch technology. In this paper, based on the dynamic nested unstructured polyhedral mesh technology, the unsteady N-S equation of the flow field and the six-degree-of-freedom motion equation of the rigid body are coupled to realize the accurate simulation of the multi-body separation process of the sub-mother UAV. Firstly, the aerodynamic interference zone of the parent UAV and the separation mode of the child UAV are analyzed. Secondly, the aerodynamic interference characteristics of the sub-mother UAV and between the sub-UAV and the sub-UAV and the sub-UAV in the overall state are calculated. Finally, according to the change of the motion state of the sub-UAV in the process of multi-body separation, the safety characteristics were evaluated. The results show that compared with deceleration separation, accelerated separation can get out of the aerodynamic interference region faster and has higher safety. Moreover, with the increase of the number of sub-UAVs, the distance of the wings of the sub-UAV decreases continuously, and this also weakens the influence of the wingtip vortex on the wing surface of the sub-UAV to a certain extent and increases the lift of the sub-UAV.

Abstract:Mission being changeable in the process of flight for UAVs formations, a trajectory online planning method is proposed for unmanned aerial vehicle formation based on improved consensus theory. Firstly, the consensus algorithm is improved，and by introducing the artificial potential field method, a collision avoidance strategy is proposed in consideration of inter-vehicle distance and relative velocity. Additionally, a turning strategy is proposed in consideration of the UAV’s relative position, state, turning radius, and speed . Furthermore, an online trajectory planning method is presented based on the concept of formation disassembly and the RRT* algorithm. The simulation results show that the collision avoidance strategy can make the intervals of UAVs a safe distance between UAVs before formation is made, preventing collisions, and the turning strategy makes the formation integral in the process of turning, and the trajectory planning method online for formation recombination can handle the execution of new tasks.

Abstract:Rapid and accurate identification of unknown malware and its variants is one of the important research directions in the field of cyberspace security. Based on a brief description of the significant research value of malware detection, the existing deep learning-based malware detection techniques and methods are summarized in consideration of the current situation of domestic and foreign research. Firstly, the traditional detection techniques are sorted out from static, dynamic and hybrid detection methods respectively. Secondly, the malware classification and identification methods based on deep learning are summarized from the malware feature extraction methods based on sequence features, image visualization and data enhancement. Finally, the technical difficulties and future development trends of malware feature extraction and identification based on deep learning are analyzed and foreseen.

Abstract:Aimed at the problems that user’s business is different in demand for partiality and single defense strategy is limited in real network services, a virus propagation model and mixed defense strategy is proposed in operating system. First of all, the network is split into different subnets by adopting link interrupt and operating system migration strategies. In synthetic consideration of the correlation of the virus infection between subnets and virus propagation, an operating system virus propagation model is constructed, and the equilibrium solution and the stability analysis of the system are given. Secondly, by introducing the network service evaluation index and the definition of negative cost, a hybrid defense strategy is proposed to suppress the spread of operating system virus. The calculation method of optimal policy configuration, execution process and parameter identification algorithm are designed. The theoretical and experimental results show that the proposed virus propagation model and the hybrid defense strategy can effectively supplement the gap period of the traditional defense means in short supply.

Abstract:Aimed at the problems that generative adversarial network is incomplete in structure, unreal in content and poor in quality of images generated, an attention mechanism text-to-image generation model combined with semantic segmentation graph (SSA-GAN) is proposed. First, taking global sentence vectors as input conditions, a simple and effective deep fusion module is utilized for fully fusing text information while generating images are generating simultaneously. Second, the semantically segmented images are combined to extract their edge profile features to provide additional generative and constraint conditions for the model, and the attention mechanism is used to provide fine-grained word-level information for the model to enrich the details of the generated images. Finally, a multimodal similarity computation model is used to compute fine-grained image-text matching loss to further train the generator. The model is tested and validated by CUB-200 and Oxford-102 Flowers datasets, and the results show that the proposed model (SSA-GAN) improves the quality of the final generated images. Compared to the models such as StackGAN, AttnGAN, DF-GAN, and RAT-GAN, the IS increases in metrics values by 13.7% and 43.2%, respectively. And the FID in metric values is reduced to 34.7% and 74.9%, respectively.