The complex derivative D^α±jβ, with α, β ∈ R＋ is a generalization of the concept of integer derivative, where α = 1,β = 0. Fractional-order electric elements and circuits are becoming more and more attrac...The complex derivative D^α±jβ, with α, β ∈ R＋ is a generalization of the concept of integer derivative, where α = 1,β = 0. Fractional-order electric elements and circuits are becoming more and more attractive. In this paper, the complexorder electric elements concept is proposed for the first time, and the complex-order elements are modeled and analyzed.Some interesting phenomena are found that the real part of the order affects the phase of output signal, and the imaginary part affects the amplitude for both the complex-order capacitor and complex-order memristor. More interesting is that the complex-order capacitor can do well at the time of fitting electrochemistry impedance spectra. The complex-order memristor is also analyzed. The area inside the hysteresis loops increases with the increasing of the imaginary part of the order and decreases with the increasing of the real part. Some complex case of complex-order memristors hysteresis loops are analyzed at last, whose loop has touching points beyond the origin of the coordinate system.展开更多
文摘The complex derivative D^α±jβ, with α, β ∈ R＋ is a generalization of the concept of integer derivative, where α = 1,β = 0. Fractional-order electric elements and circuits are becoming more and more attractive. In this paper, the complexorder electric elements concept is proposed for the first time, and the complex-order elements are modeled and analyzed.Some interesting phenomena are found that the real part of the order affects the phase of output signal, and the imaginary part affects the amplitude for both the complex-order capacitor and complex-order memristor. More interesting is that the complex-order capacitor can do well at the time of fitting electrochemistry impedance spectra. The complex-order memristor is also analyzed. The area inside the hysteresis loops increases with the increasing of the imaginary part of the order and decreases with the increasing of the real part. Some complex case of complex-order memristors hysteresis loops are analyzed at last, whose loop has touching points beyond the origin of the coordinate system.
文摘目的比较深度森林联合模型、深度森林以及随机森林在医学影像数据分类中的预测性能。方法本研究提出深度森林联合模型,通过Sobol-MDA(Sobol-mean decrease accuracy)结合深度森林级联结构和随机森林的特征提取能力,对模拟实验和真实医学影像数据进行分析。模拟实验涵盖结局变量不均衡、变量间非线性关系、噪声变量、多重共线性及交互作用等场景。实例分析基于腮腺MRI数据,比较各模型在曲线下面积(area under curve,AUC)值等指标上的表现。结果在模拟实验以及实例分析中,深度森林联合模型表现优越,特别是在复杂交互作用场景下,其预测性能显著优于深度森林或随机森林模型。结论深度森林联合模型在应对复杂医学影像数据分类任务中具有显著优势,尤其在处理变量间存在高阶交互作用时,其预测性能优于深度森林。
