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航空运输中时常会受到各种因素的干扰,形成非正常航班。非正常航班若得不到及时有效处理,会给航空公司带来巨大损失,因此航空恢复问题显得十分重要。主要针对航空公司飞机恢复问题进行了研究。利用原时刻表,综合考虑航班时间约束、飞机维护约束、机场容量约束和飞机容量约束,并结合航空公司运行实际,建立了飞机恢复模型。模型中对飞机恢复成本进行了细分,并以成本最小为目标函数。为解决该问题,设计了一个启发式算法。通过使用某航空公司的数据,对模型进行了计算,对算法进行了测试。计算结果表明,启发式算法可以较好解决飞机恢复问题,所得该方案能较好地符合航空公司要求。 相似文献
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基于启发式自适应离散差分进化算法的多UCAV协同干扰空战决策 总被引:2,自引:1,他引:1
研究了多无人作战飞机(UCAV)协同干扰空战决策(MUCJAD)问题,在干扰效能评估指标量化方法的基础上为该问题建立了优化模型。为有效求解该模型,提出一种启发式自适应离散差分进化(H-SDDE)算法。在H-SDDE算法中,设计了包含4种候选解产生策略的候选策略池,引入了候选解产生策略及其参数的自适应学习过程。此外,结合实际问题为算法设计了基于威胁度的扩展型整数编码方案、基于威胁度的启发式个体调整操作、基于约束满足的个体修复操作。在12个测试实例上进行了仿真验证,结果表明,H-SDDE算法与其他同类算法相比在求解质量和求解速度上具有明显优势,能够更好地发挥多UCAV协同干扰整体效果。 相似文献
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智能优化算法在飞机总体设计中的应用 总被引:2,自引:1,他引:1
飞机总体设计在飞机的整个设计过程中是非常关键的步骤,在这个过程中,飞机的总体布局和许多重要参数都被确定下来。但是,飞机的总体设计又是一个复杂和艰难的过程,因为涉及到大型系统的有约束的非线性优化问题,用传统优化方法很难得到满意的结果。本文采用了近年来发展很快的几种智能优化算法--遗传算法、模拟退火算法、禁忌搜索算法、Hopfield神经网络算法解决飞机总体设计优化问题,阐述了各算法的关键步骤及运行过程,并编写了相应的计算程序。通过对各种算法的结果进行比较和讨论,最后的结论是:模拟退火算法最适合求解这类复杂的约束非线性优化问题,禁忌搜索算法和遗传算法次之,Hopfield神经网络算法效果最差,容易陷入局部最优解。 相似文献
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结合国内某飞机复合材料制造车间的实际生产特点,提出了针对复合材料车间计划排产的方法和步骤,并建立了基于启发式规则算法的优化排产模型。该排产方法将生产班组作为相对独立的生产单元,在设计上不仅充分考虑到复合材料生产的特点,而且对生产中出现的突发问题进行了相应的调整处理,使得排产方法更加适应复合材料生产的实际情况,最终提高了车间的生产效率。 相似文献
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提出了一种将小波的尺度函数与SV(support vector)算法相结合的WSK-SV(wavelet scaling kernel-support vector)新算法,并将Daubechies小波以及Shannon小波的尺度函数分别构成尺度核函数,而且分别作为SV算法中一个可容许的支持向量核函数使用.该算法充分利用了Daubechies小波函数的紧支集与正交等特点以及小波的MRA(multi-resolution analysis,多分辨分析),并注意了尺度核函数能够满足Mercer条件.该算法除了具有通常SVM(support vector machine)所具有的优点外,还具有很好的收敛性以及泛化能力,能够有效地提高学习与预测效率.典型算例选取了不同的小波尺度函数,数值计算表明:在一维、二维和三维问题中,这些小波的尺度函数均可以用于WSK-SV算法,进而显示了这个新算法的可行性与通用性. 相似文献
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在传统中心差分离散混合傅里叶变换(DMFT)抛物方程模型基础上,针对传统算法计算动态阻抗边界条件时的数值振荡及忽略后向传播与散射造成计算误差增大的问题,提出基于前-后向混合差分方法的递归双向DMFT(TW-DMFT)模型,以一阶前-后向差分方程代替传统的中心差分方程拟合阻抗边界条件,以递归双向传播模型改进传统单向预测模型.仿真分析了双向DMFT模型计算不同边界及媒介条件下单刃峰和实际地形的电波传播分布特性,与传统算法及几何绕射理论(GTD)进行比较,新算法提高稳定性及精度的同时弥补了传统算法的不足,更具有普适性. 相似文献
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Huang Shunji Wang Jianguo Qiu Hueizhong 《IEEE transactions on aerospace and electronic systems》1991,27(6):865-868
A fast algorithm is presented which computes the two-dimensional Hartley transform. This algorithm is referred to as the split vector radix algorithm. It uses the decimation in frequency decomposition and, due to its in-place property, it does not require midmemory devices or matrix transposition. Its computational structure is simpler than that of the algorithm of L.Z. Chen (1983), and it is easy to program. Compared with the vector radix algorithm of R. Kumaresan and P.K. Gupta (1986), the proposed algorithm saves about 35% of the multiplication and 10% of the additions for the discrete Fourier transform (DFT) of a 4096*4096 real valued input sequence.<> 相似文献
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In this paper, we present a novel and efficient track-before-detect (TBD) algorithm based on multiple-model probability hypothesis density (MM-PHD) for tracking infrared maneuvering dim multi-target. Firstly, the standard sequential Monte Carlo probability hypothesis density (SMC-PHD) TBD-based algorithm is introduced and sequentially improved by the adaptive process noise and the importance re-sampling on particle likelihood, which result in the improvement in the algorithm robustness and convergence speed. Secondly, backward recursion of SMC-PHD is derived in order to ameliorate the tracking performance especially at the time of the multi-target arising. Finally, SMC-PHD is extended with multiple-model to track maneuvering dim multi-target. Extensive experiments have proved the efficiency of the presented algorithm in tracking infrared maneuvering dim multi-target, which produces better performance in track detection and tracking than other TBD-based algorithms including SMC-PHD, multiple-model particle filter (MM-PF), histogram probability multi-hypothesis tracking (H-PMHT) and Viterbi-like. 相似文献
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The continuous growth of air traffic has led to acute airspace congestion and severe delays, which threatens operation safety and cause enormous economic loss. Flight assignment is an economical and effective strategic plan to reduce the flight delay and airspace congestion by reasonably regulating the air traffic flow of China. However, it is a large-scale combinatorial optimization problem which is difficult to solve. In order to improve the quality of solutions, an effective multi-objective parallel evolution algorithm(MPEA) framework with dynamic migration interval strategy is presented in this work. Firstly, multiple evolution populations are constructed to solve the problem simultaneously to enhance the optimization capability. Then a new strategy is proposed to dynamically change the migration interval among different evolution populations to improve the efficiency of the cooperation of populations. Finally, the cooperative co-evolution(CC) algorithm combined with non-dominated sorting genetic algorithm II(NSGA-II) is introduced for each population. Empirical studies using the real air traffic data of the Chinese air route network and daily flight plans show that our method outperforms the existing approaches, multiobjective genetic algorithm(MOGA), multi-objective evolutionary algorithm based on decomposition(MOEA/D), CC-based multi-objective algorithm(CCMA) as well as other two MPEAs with different migration interval strategies. 相似文献
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This paper presents a novel and efficient extrema-mapping algorithm, which we call the roller-coaster algorithm. Two versions of the algorithm, the one-dimensional (1-D) and the two-dimensional (2-D) roller-coaster, are developed. Its applicability to array signal processing is demonstrated. We use it to solve a multiple source direction finding problem using multiple signal classification (MUSIC), beamformer, and minimum variance methods, and for antenna array design. The algorithm is based on heuristic assumptions and its properties are not proved. Yet, its performance was tested in many simulated experiments, yielding favorable results 相似文献
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稀疏、含噪观测条件下周期点过程的周期估计是一个经典的信号处理问题。针对该问题,提出了一种格型线搜索(LLS)算法,该算法通过数值方式搜索似然函数的最大值,但其性能取决于人为预先选取的搜索步长。推导了一个步长计算公式,并利用该公式改进了LLS算法。改进的LLS算法能够自适应选择搜索步长,其达到的克拉美-罗界(CRLB)的信噪比(SNR)门限与最大似然估计(MLE)算法一致,但计算复杂度比后者低一个多的数量级。性能分析与仿真实验表明,所提算法比已有算法能更好地实现估计精度与复杂度的折中。 相似文献