基于对抗模拟的箔条质心干扰决策计算方法

通过分析箔条质心干扰的作战过程,综合考虑了反舰导弹的来袭方向、性能参数、舰艇的物理和运动参数、作战海域的天气情况,建立箔条质心干扰反舰导弹的作战模拟模型,在此基础上提出了箔条质心干扰方案的计算方法.应用实例的过程和结果表明,该方法简易可行,通过真实模拟双方的对抗过程,所得决策方案可信度高,对质心干扰决策具有很好的指导价值.     

潜艇在水面目标位置散布概率密度的计算方法

潜艇声纳在较远距离上发现水面目标时,探测和解算的目标运动要素具有较大的误差.利用泰勒公式,将目标位置计算公式进行简化处理,结合概率论的相关理论,求解目标位置散布概率密度.针对典型战术态势,计算不同时刻目标位置散布概率密度,绘制概率密度图,与目标位置散布仿真图进行对比.     

自行高炮光电火控半实物仿真系统技术实现途径分析

介绍了自行高炮光电火控系统半实物仿真试验的基本原理和技术实现途径,提出了光电火控系统仿真试验的技术实现途径主要取决于目标模拟方式的观点.描述了图像注入式、屏幕反射式和准直投射式等3种目标模拟方式的功能、组成和工作原理.针对光电火控系统性能指标鉴定试验的特点,深入分析了3种方式的优缺点,认为屏幕反射式和准直投射式适用于鉴定试验,根据目前的技术发展水平,可优先发展准直投射式.     

水面舰艇编队反潜作战仿真模型组件化研究

针对目前编队反潜作战仿真领域中模型利用效率和可重用性较低的现状,提出并建立了基于组件技术的编队反潜仿真模型体系结构,依据编队反潜作战实际物理过程对编队反潜作战仿真模型体系进行了组件化层次结构划分和作战仿真模型组件设计,按照J2EE/EJB体系结构,完成了系统配置和不同类型组件及组件间信息交互接口设计,并对仿真系统进行了实现.结果证明该方法能有效提高模型可重用性并提高系统仿真运行效率.     

行波提取型同轴渡越时间振荡器模拟

提出了一种行波提取型同轴渡越时间振荡器,器件的提取腔采用了类膜片加载的扩展互作用腔结构,具有束波作用效率高,电子束空间电势能低等优点。提取腔的电场结构为3π/2模,与传统的类π模结构相比,提高了微波群速度,有利于微波能量的提取。通过引入前置反射腔,提高了调制腔的品质因数,显著降低了起振时间。利用数值模拟软件对所设计的器件进行了模拟和优化,在二极管电压530kV,二极管电流12.8kA,外加导引磁场0.7T的条件下,得到了2.41GW的输出功率,微波频率7.76GHz,束波功率转换效率达到35.5%。     

On fair designs of cross-chain exchange for cryptocurrencies via Monte Carlo simulation

Cryptocurrency is one of the earliest and the most successful applications of blockchain, and it utilizes the distributed ledger, which is a commonly used technique in blockchain, to make a decentralized transaction within the blockchain of a cryptocurrency. However, how to make a decentralized transaction of cryptocurrencies between parties on different blockchains, that is, the cross-chain exchange, is not well-studied. In this paper, we develop a new method to make cross-chain exchanges based on the classical atomic swap. We first study the optionality embedded into the atomic swap and propose to add a premium into the atomic swap, and then design a new procedure with the premium to guarantee the fairness of the cross-chain exchange. We also provide an algorithm based on the least-squares Monte Carlo method to estimate the premium and analyze the convergence of the algorithm. Moreover, we study the cross-chain exchange with margin trading. We propose an adapted exchange procedure to make a fair cross-chain exchange and an algorithm to estimate the fair premium under the margin trading. Numerical experiments are provided to show the effectiveness of the algorithms.     

面向时空交通栅格流量预测的3D通道注意力网络

城市交通流量预测对交通管理和公共安全具有重要意义。然而,交通栅格流量数据中的规律在时刻变化,在城市中存在全局范围的时空间关系,并且不同特征通道在每个城市区域上有不同的重要性。为解决这些挑战并做出更准确的预测,设计了一种新颖的时空神经网络模型——3D通道注意力网络(three-dimensional channel-wise attention networks,3D-CANet)。提出一个3D通道内注意力(three-dimensional inner channel attention,3D-InnerCA)单元来动态捕获各个通道中不同的全局时空相关性,同时设计通道间注意力(inter channel attention,InterCA)单元来自适应地重校准每个区域上不同特征通道的贡献。在3个真实交通栅格流量数据集上的实验结果表明,3D-CANet模型的预测能力优于其他对比方法,证明了模型的有效性。     

Influence of shaped charge structure parameters on the formation of linear explosively formed projectiles

The research of LEFP (linear explosive forming projectile) is of great value to the development of new warhead due to its excellent performance. To further improve the damage ability of the shaped charge warhead, a special shell overhanging structure was designed to increase the charge based on the traditional spherical charge, in which case the crushing energy of LEFP could be guaranteed. LS-DYNA was used to simulate different charge structures obtained by changing the number of detonation points, the length of shell platform, the radius of curvature and the thickness of liner. The RSM (response surface model) between the molding parameters of LEFP and the structural parameters of charge was established. Based on RSM model, the structure of shaped charge was optimized by using multi-objective genetic algorithm. Meanwhile, the formation process of jet was analyzed by pulsed X-ray photography. The results show that the velocity, length-diameter ratio and specific kinetic energy of the LEFP were closely related to the structural parameters of the shaped charge. After the optimization of charge structure, the forming effect and penetration ability of LEPP had been significantly improved. The experimental data of jet velocity and length were consistent with the numerical results, which verifies the reliability of the numerical results.     

Dual-steering mode based on direct yaw moment control for multi-wheel hub motor driven vehicles:Theoretical design and experimental assessment

One of the main challenges for multi-wheel hub motor driven vehicles is the coordination of individual drivetrains to improve mobility and stability in the steering process.This paper proposes a dual-steering mode based on direct yaw moment control for enhancing vehicle steering ability in complex environ-ments.The control system is designed as a hierarchical structure,with a yaw moment decision layer and a driving force distribution layer.In the higher-level layer,the objective optimization function is con-structed to obtain the slip steering ratio,which represents the degree of vehicle slip steering in the dual-steering mode.A yaw moment controller using active disturbance rejection control theory is designed for continuous yaw rate control.When the actual yaw rate of the vehicle deviates from the reference yaw rate obtained by the vehicle reference model and the slip steering ratio,the yaw moment controller is actuated to determine the yaw moment demand for vehicle steering.In the lower-level layer,there is a torque distribution controller based on distribution rules,which meets the requirement of yaw moment demand without affecting the total longitudinal driving force of the vehicle.For verifying the validity and feasibility of the dual-steering mode,simulations were conducted on the hardware-in-loop real-time simulation platform.Additionally,corresponding real vehicle tests were carried out on an eight-wheel prototype vehicle.Test results were generally consistent with the simulation results,thereby demon-strating that the proposed dual-steering mode reduces steering radius and enhances the steering per-formance of the vehicle.     

Novel aluminum-based fuel: Facile preparation to improve thermal reactions

To improve the thermal properties of aluminum (Al) in the energetic system, a coated structure with ammonium perchlorate (AP) was prepared by a facile approach. And N, N-Dimethylformamide (DMF) was chosen as an ideal solvent based on heterogeneous nucleation theory and molecular dynamics simulation. This coated structure could enlarge the contact area and improve the reaction environment to enhance the thermal properties. The addition of AP could accelerate oxidation temperature of Al with around 17.5 °C. And the heat release of 85@15 composition rises to 26.13 kJ/g and the reaction degree is 97.6% with higher peak pressure (254.6 kPa) and rise rate (1.397 MPa/s). An ideal ratio with 15 wt% AP was probed primarily. The high energy laser-induced shockwave experiment was utilized to simulate the reaction behavior in hot field. And the larger activated mixture of coated powder could release more energy to promote the growth of shockwave with higher speed up to 518.7 ± 55.9 m/s. In conclusion, 85@15 composition is expected to be applied in energetic system as a novel metal fuel.