震灾应急物资动态需求预测模型研究

为提高应急物资需求预测方法的实用性,同时考虑提前期和需求的不确定性,采用安全库存理论构建震灾应急物资动态需求预测模型,以观测得到的实际到货量、实际消耗量和实时剩余库存量等信息来动态预测当前时刻应急物资的需求量。应用算例表明,所建模型不仅能够准确反映需求量与被保障人员总数的正相关关系,而且还能实时体现被保障人员总数的变化情况。因此,该模型能够为震灾过程中应急物资需求量的确定提供科学决策依据,具有一定的实用价值和应用前景。     

基于改进粒子群优化算法的微电网孤岛选址定容

分析了在重要孤立系统中采用微电网供电的必要性,在此基础上提出了采用由非支配排序法和拥挤距离排序法改进的粒子群算法进行微电网选址定容,其目的是改进多目标微电网规划问题的优化结果。通过改进算法与基本算法算例结果的对比分析,验证了改进算法在求解孤岛选址定容问题上具有较强的寻优能力、较高的收敛精度和较稳定的最优解,为进一步研究微电网孤岛选址定容问题提供了思路。     

科氏流量计信号相位差测量新算法

对科氏流量计信号进行处理时,传统相位差测量算法存在较大误差。为更好地抑制频谱泄露,提高相位差测量精度,在传统DTFT算法的基础上,通过矩形窗和汉宁窗卷积运算构造出一种新窗——RHC窗。计及负频率成分的影响,提出了一种基于RHC窗的DTFT相位差测量新算法。详细阐述了新算法的原理,并与传统DTFT算法进行了对比仿真,验证了新算法的有效性。     

基于伪装理念的建筑表皮设计

建筑表皮展示了建筑视觉造型的综合构想,是建筑与外界环境的界面。建筑伪装理念是指从视觉层面出发,通过改变建筑表皮形态,使建筑融于周围环境或随环境因素变化而灵活应变的表现方式。伪装理念与建筑表皮设计相结合,为实现建筑与环境共生提供了新思路,同时可引导军事建筑伪装设计。通过分析国内外基于伪装理念的建筑表皮设计实例,提炼建筑表皮伪装设计特点,归纳建筑表皮伪装设计类型,总结建筑表皮伪装设计方法,为军事建筑设计提供参考。     

低空接敌战术对机载雷达探测能力影响分析

针对低空接敌战术中机载雷达探测能力的影响问题进行了研究.从装备原理上对其战术机理进行了定性分析;给出了各类分析因素的数学描述,分别建立了雷达发现概率模型、综合信噪比模型、动态RCS模型,以及地杂波强度模型;之后给出了描述分析过程的具体流程.采用两种不同条件下的算例进行验证,结果证明了低空接敌战术对降低机载雷达探测能力具...     

Simulation of the plasticizing behavior of composite modified double-base (CMDB) propellant in grooved calendar based on adaptive grid technology

The frequent occurrence of safety accidents during the calendering process is caused by the flammable and explosive properties of composite modified double-base (CMDB) propellant. Optimization of process parameters with the aid of fluid simulation technology could effectively ensure the safety of the calendering process. To improve the accuracy of the simulation results, material parameters and model structure were corrected based on actual conditions, and adaptive grid technology was applied in the local mesh refinement. In addition, the rheological behavior, motion trajectories and heat transfer mechanisms of CMDB propellant slurry were studied with different gaps, rotational rates and temperatures of two rollers. The results indicated that the refined mesh could significantly improve the contour clarity of boundaries and simulate the characteristics of CMDB propellant slurry reflux movement caused by the convergent flow near the outlet. Compared with the gap, the increased rotational rate of roller could promote the reflux movement and intensify the shear flow of slurry inside the flow region by viscous shear dragging. Meanwhile, under the synergistic effect of contact heat transfer as well as convective heat exchange, heat accumulated near the outlet and diffused along the reflux movement, which led to the countercurrent heat dissipation behavior of CMDB propellant slurry. The plasticizing mechanism of slurry and the safety of calendering under different conditions were explored, which provided theoretical guidance and reference data for the optimization of calendering process conditions. Based on the simulation results, the safety of the CMDB propellant calendering process could be significantly improved with a few tests conducted during a short research and development cycle.     

Polarization visualization for low-irradiance regions by perceptually uniform color space

Currently,polarization visualization strategies are accomplished by mapping polarization information into a perceptually uniform color appearance model CAM02-UCS.However,the deviation of the CAM02-UCS space from the lightness prediction results in an inaccurate match between the polarization in-formation and the perceptual information.In this paper,we propose a novel polarization visualization strategy based on the perceptual uniform space Jzazbz.The polarization visualization be completed by placing the polarization information into the lightness Jz,colorfulness Cz and hue angle hz channels of the Jzazbz space.The experimental results show that the proposed method can significantly improve the lightness of the low irradiance and high polarization region,hence more polarization information can be sensed by human visual system.     

Recursive weighted least squares estimation algorithm based on minimum model error principle

Kalman filter is commonly used in data filtering and parameters estimation of nonlinear system,such as projectile's trajectory estimation and control.While there is a drawback that the prior error covariance matrix and filter parameters are difficult to be determined,which may result in filtering divergence.As to the problem that the accuracy of state estimation for nonlinear ballistic model strongly depends on its mathematical model,we improve the weighted least squares method(WLSM)with minimum model error principle.Invariant embedding method is adopted to solve the cost function including the model error.With the knowledge of measurement data and measurement error covariance matrix,we use gradient descent algorithm to determine the weighting matrix of model error.The uncertainty and linearization error of model are recursively estimated by the proposed method,thus achieving an online filtering estimation of the observations.Simulation results indicate that the proposed recursive esti-mation algorithm is insensitive to initial conditions and of good robustness.     

A new energy efficient management approach for wireless sensor networks in target tracking

This paper mainly studied the problem of energy conserving in wireless sensor networks for target tracking in defensing combats. Firstly, the structures of wireless sensor nodes and networks were illustrated; Secondly, the analysis of existing energy consuming in the sensing layer and its calculation method were provided to build the energy conserving objective function; What's more, the other two indicators in target tracking, including target detection probability and tracking accuracy, were combined to be regarded as the constraints of the energy conserving objective function. Fourthly, the three energy conserving approaches, containing optimizing the management scheme, prolonging the time interval between two adjacent observations, and transmitting the observations selectively, were introduced; In addition, the improved lion algorithm combined with the Logistic chaos sequence was proposed to obtain sensor management schemes. Finally, simulations had been made to prove the effectiveness of the proposed methods and algorithm.     

Experimental investigation on anti-penetration performance of polyurea-coated ASTM1045 steel plate subjected to projectile impact

In this study, the anti-penetration performance of polyurea/ASTM1405-steel composite plate subjected to high velocity projectile was analyzed. Two kinds of modified polyurea material (AMMT-053 and AMMT-055) were selected and a ballistic impact testing system including speed measuring target system and high-speed camera was designed. This experiment was conducted with a rifle and 5.8 mm projectile to explore the effects by the polyurea coating thickness, the polyurea coating position and the glass-fiber cloth on the anti-penetration performance of polyurea/ASTM1405-steel composite plate. The result showed that the effects of polyurea coating position were different between two types of polyurea, and that the effects of glass-fiber position were disparate between two types of polyurea as well. For AMMT-053 polyurea material, it was better to be on front face than on rear face; whereas for AMMT-055 pol-yurea, it was better to be on rear surface although the difference was very subtle. Additionally, formulas had been given to describe the relationship between the effectiveness of polyurea and the thickness of polyurea coating. In general, AMMT-055 had better anti-penetration performance than AMMT-053. Furthermore, five typical damage modes including self-healing, crack, local bulge, spallation and local fragmentation were defined and the failure mechanism was analyzed with the results of SHPB test. Additionally, the bonding strength played an important role in the anti-penetration performance of polyurea/steel composite plate.