基于仿真的无人机空袭沙特油田事件探索性分析

以2019 年9 月也门空袭沙特油田事件为例,提出一种基于仿真的危机事件快速分析方法,将仿真与探索性分析相结合,对危机事件进行全面的分析与处理。根据沙特、也门关于事件细节的公开资料,基于仿真推演复盘此次空袭的作战情况,校验各方在事件声明中细节的合理性和真实性,同时可为我国防御“低、小、慢”无人机的发展和作战研究提供借鉴意义。     

An Evolutionary Real-Time 3D Route Planner for Aircraft

Abstract: A novel evolutionary route planner for aircraft is proposed in this paper. In the new planner, individual candi-dates are evaluated with respect to the workspace, thus the computation of the configuration space is not required. By usingproblem-specific chromosome structure and genetic operators, the routes are generated in real time, with different missionconstraints such as minimum route leg length and flying altitude, maximum turning angle, maximum climbing/diving an-gle and route distance constraint taken into account.     

中国社会稳定与安全预警系统的理论设计

简要概述了中国社会稳定与安全预警系统的功能与作用 ;重点介绍了该预警系统设计的理论依据 ,即在预警系统设计过程中 ,综合、集成、借鉴了不同学科的理论与方法 ,其中 ,创造性地应用了社会物理学的思想、理论与方法 ,以此作为研制预警系统的总体理论框架 ;依据研究组独创的社会稳定与安全五大支持系统理论 ,设计出了“四级叠加 ,逐层收敛 ,系统耦合 ,规范权重 ,识别阈值 ,统一排序”的预警指标体系 ;最后 ,就预警系统内部模块的结构、功能与系统运行流程作了一定程度的说明。     

Pre-processing for time domain image formation in SS-BSAR system

A pre-processing procedure is designed for a space-surface bistatic synthetic aperture radar (SS-BSAR) system when a time domain image formation algorithm is employed. Three crucial technical issues relating to the procedure are fully discussed. Firstly, unlike image formation algorithms operating in the frequency domain, a time domain algorithm requires the accurate global navigation satellite system (GNSS) time and position. This paper proposes acquisition of this information using a time-and-spatial transfer with precise ephemeris and interpolation. Secondly, synchronization errors and compensation methods in SS-BSAR are analyzed. Finally, taking the non-ideal factors in the echo and the compatibility of image formation algorithms into account, a matched filter based on the minimum delay is constructed. Experimental result using real data suggest the pre-processing is functioning properly.     

Enhanced self-adaptive evolutionary algorithm for numerical optimization

There are many population-based stochastic search algorithms for solving optimization problems. However, the universality and robustness of these algorithms are still unsatisfactory. This paper proposes an enhanced self-adaptiveevolutionary algorithm (ESEA) to overcome the demerits above. In the ESEA, four evolutionary operators are designed to enhance the evolutionary structure. Besides, the ESEA employs four effective search strategies under the framework of the self-adaptive learning. Four groups of the experiments are done to find out the most suitable parameter values for the ESEA. In order to verify the performance of the proposed algorithm, 26 state-of-the-art test functions are solved by the ESEA and its competitors. The experimental results demonstrate that the universality and robustness of the ESEA out-perform its competitors.     

SEA方法及其在$C^3I$系统效能分析中的应用(Ⅲ)——监视模型

针对ＳＥＡ方法的要求,提出了评估$Ｃ^３Ｉ$系统在执行监视任务时的系统效能的三个性能量度（ＭＯＰ）,通过分析$Ｃ^３Ｉ$系统在执行监视任务时的行为过程和环境特点,结合排队理论,建立了评估$Ｃ^３Ｉ$系统监视效能的ＳＥＡ方法模型．利用该模型计算了一个实际$Ｃ^３Ｉ$系统的监视效能,并对结果进行了简要分析．     

水稻植株生长异常原因经验识别系统研究

在全面分析水稻生长异常症状与原因关系的基础上,以ＷＩＮＤＯＷＳ９５为平台,用ＶｉｓｕａｌＢａｓｉｃ５．０开发多媒体“水稻生长异常经验识别系统”,“系统”根据看,问、摸获取的信息,不仅能快速准确地识别导致水稻生长异常的原因,还可提供相应的防治措施。     

Compressed sensing based channel estimation for fast fading OFDM systems

A compressed sensing (CS) based channel estimation algorithm is proposed by using the delay-Doppler sparsity of the fast fading channel. A compressive basis expansion channel model with sparsity in both time and frequency domains is given. The pilots in accordance with a novel random pilot matrix in both time and frequency domains are sent to measure the delay-Doppler sparsity channel. The relatively nonzero channel coefficients are tracked by random pilots at a sampling rate significantly below the Nyquist rate. The sparsity channels are estimated from a very limited number of channel measurements by the basis pursuit algorithm. The proposed algorithm can effectively improve the channel estimation performance when the number of pilot symbols is reduced with improvement of throughput efficiency.     

Application of improved equivalent edge currents in synthetic aperture radar imaging

Target modeling and scattering function calculating are important prerequisites and groundwork for the synthetic aperture radar (SAR) imaging simulation. According to the difficult problems that normal methods cannot calculate the scattering function of electrically large object under the condition to wideband, an effective method of improved equivalent edge currents is presented and applied to SAR imaging simulation for the first time. This method improves calculating velocity and has relatively high precision. The concrete steps of applying the method are given. By way of the simulation experiment, the effectiveness of the method is verified.     

Fast motion estimation algorithm for H.264/AVC based on centered prediction

H.264/AVC video coding standard can achieve roughly half of the bit-savings over MPEG2 and MPEG4 for a given quality. However, this comes at a cost in considerably increased complexity at the encoder and thus increases the difficulty in hardware implementation. The high redundancy that exists between the successive frames of a video sequence makes it possible to achieve a high data compression ratio. Motion estimation (ME) plays an important role in motion compensated video coding. A fast motion estimation algorithm for H.264/AVC is proposed based on centered prediction, called centered prediction based fast mixed search algorithm (CPFMS). It makes use of the spatial and temporal correlation in motion vector (MV) fields and feature of all-zero blocks to accelerate the searching process. With the initialized searching point prediction, adaptive search window changing and searching direction decision, CPFMS is provided to reduce computation in block-matching process. The experimental results show that the speed of CPFMS is nearly 12 times of FS with a negligible peak signal-noise ratio (PSNR) loss. Also, the efficiency of CPFMS outperforms some popular fast algorithms such as hybrid unsymmetrical cross multi-hexagongrid search and a novel multidirectional gradient descent search evidently.