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991.
992.
考虑到蔡氏电路受周围电路的影响,故将受周围影响的蔡氏电路做了等效处理,并将其等效为电流激励蔡氏电路。这里首次用解析的方法对三阶非线性微分方程能够产生混沌的参数范围进行预测,利用该方法得出电流激励蔡氏电路产生混沌的必要参数条件。通过数值仿真证明了该等效电路具有极其丰富的混沌动力学行为,仿真结果与解析预测结果有较好的吻合性。 相似文献
993.
We propose a multi-task learning framework for video anomaly detection based on a novel pipeline. Our model contains two crossing streams, one stream employs the backbone of Attention-R2U-net for future frame prediction, while the other is designed based on an encoder–decoder network to reconstruct the input optical flow maps. In addition, the latent layers of the two streams are merged together and assigned with a Deep SVDD-based loss at each location individually. Through the combination of these three tasks, the two-stream-crossing pipeline can be trained end-to-end to provide a comprehensive evaluation for the anomaly targets. Experimental results on several popular benchmark datasets show that our model outperforms the state-of-the-art competing models, which can be applied to different types of anomalous targets and meanwhile achieves remarkable precision. 相似文献
994.
Thanks to its flexible coding structure, high-efficiency video coding (HEVC) can save more coding bit rates than the previous standard, H.264. However, it also increases the complexity of integer-pixel motion estimation (IME). To speed up the encoding process, we propose a parallel spiral search (PSS) algorithm, which features the following characteristics and advantages. First, the proposed algorithm is hardware-friendly. PSS has both a fix search order that cuts the correlation between search points and a high data reuse level that facilitates the pipeline application in hardware implementation. Second, the PSS algorithm processes all prediction units (PU) blocks in parallel, which speeds up the RD calculation. Finally, the early termination strategy is proposed to end the search for unnecessary search points and further reduce search time. Experimental results show that the proposed algorithm outperforms other popular hardware-oriented IME algorithms in terms of coding speed, with the same loss of RD performance. Compared with the default full search algorithm (FSA) in the HEVC test model HM-16.7, the proposed algorithm achieves average time saving ratio of up to 92.55%, with BD-PSNR loss of 0.056 dB and an increase by 1.38% in terms of BD-BR. 相似文献
995.
To reduce the computational complexity of screen content video coding (SCC), a fast algorithm based on gray level co-occurrence matrix and Gabor feature model for HEVC-SCC, denoted as GGM, is proposed in this paper. By studying the correlation of non-zero number in gray level co-occurrence matrix with different partitioning depth, the coding unit (CU) size of intra coding can be prejudged, which selectively skips the intra prediction process of CU in other depth. With Gabor filter, the edge information reflecting the features of screen content images to the human visual system (HVS) are extracted. According to Gabor feature, CUs are classified into natural content CUs (NCCUs), smooth screen content CUs (SSCUs) and complex screen content CUs (CSCUs), with which, the calculation and judgment of unnecessary intra prediction modes are skipped. Under all-intra (AI) configuration, experimental results show that the proposed algorithm GGM can achieve encoding time saving by 42.13% compared with SCM-8.3, and with only 1.85% bit-rate increasement. 相似文献
996.
997.
Emad Abd‐Elrady Li Gan Gernot Kubin 《International Journal of Communication Systems》2013,26(5):651-661
Digital predistortion of nonlinear systems is an important topic in many practical applications. This paper considers direct predistortion of a Volterra system by connecting in tandem an adaptive Volterra predistorter. The coefficients of the predistorter can be recursively estimated using the nonlinear filtered‐x least mean squares (NFxLMS) algorithm. In this paper, the prediction error method (PEM) is used to derive a novel nonlinear filtered‐x PEM (NFxPEM) algorithm. A simulation study on Volterra systems shows that the NFxPEM algorithm more significantly suppresses spectral regrowth and converges much faster than the NFxLMS algorithm. Also, the NFxPEM algorithm is used in this paper to design more efficient digital predistorter—as compared with the NFxLMS algorithm—for digital subscriber line systems. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
998.
充填料浆配合比的选择直接决定了充填体的强度及运行成本。根据两种骨料混合堆积密实度试验,得到废石风砂最优配比。利用Design-Expert软件中的Box-Behnken中心组合试验设计及响应面法(RSM)研究了料浆质量分数、水泥用量和骨料配比对充填体不同龄期内无侧限抗压强度的影响规律,建立了以粗骨料胶结体3,7,28 d强度为响应值的三元二次回归模型,并对该模型的适用性进行了验证。试验结果表明,充填体强度不仅受单一因素影响,而且两因素之间的交互作用对强度影响显著。由模型的响应曲面可知,质量分数与骨料配比的交互作用对充填体早期强度影响显著,水泥用量与骨料配比的交互作用对充填体中期强度影响显著,质量分数与水泥用量的交互作用对充填体后期强度显著。通过回归模型及建立的充填材料成本函数,优选出一组料浆配合比,经现场试验满足生产要求。 相似文献
999.
由于公交客流量是公交系统发展规划的基础依据,因此提高公交客流量预测的准确性有利于城市公交的发展。利用粒子群算法优化参数的良好性能和灰色预测法适合预测不确定因素影响系统的优势,提出用灰色变异粒子群组合预测模型来预测公交客流量,提高公交客流量预测精度,并通过实例对组合预测模型的预测精度和有效性进行了分析。结果表明,此组合预测模型的预测精度优于单一的灰色预测模型,也优于其他几种常用预测算法,能很好地预测公交客流量,为公交系统的决策规划提供了可靠的科学数据。 相似文献
1000.
针对Kalman预测在非线性系统故障预报中预测误差较大的问题.提出一种基于支持向量机预测新息的Kalman预测方法.根据未知非线性系统的典型变量分析子空间模型进行Kalman预测.采用支持向量机时间序列预测算法预测未来时刻的新息,利用新息进行Kalman单步和多步预报.在连续搅拌反应器上的仿真研究表明:所提出方法能准确地预测较长时间段内故障过程的劣化趋势,预知可能发生的故障,使操作人员有时间采取必要措施消除故障隐患. 相似文献