亚洲男人的天堂2018av,欧美草比,久久久久久免费视频精选,国色天香在线看免费,久久久久亚洲av成人片仓井空

Harmonic Balance is one of the most popular methods for computing periodic solutions of nonlinear dynamical systems. In this work, we address two of its major shortcomings: First, we investigate to what extent the computational burden of stability analysis can be reduced by consistent use of Chebyshev polynomials. Second, we address the problem of a rigorous error bound, which, to the authors' knowledge, has been ignored in all engineering applications so far. Here, we rely on Urabe's error bound and, again, use Chebyshev polynomials for the computationally involved operations. We use the error estimate to automatically adjust the harmonic truncation order during numerical continuation, and confront the algorithm with a state-of-the-art adaptive Harmonic Balance implementation. Further, we rigorously prove, for the first time, the existence of some isolated periodic solutions of the forced-damped Duffing oscillator with softening characteristic. We find that the effort for obtaining a rigorous error bound, in its present form, may be too high to be useful for many engineering problems. Based on the results obtained for a sequence of numerical examples, we conclude that Chebyshev-based stability analysis indeed permits a substantial speedup. Like Harmonic Balance itself, however, this method becomes inefficient when an extremely high truncation order is needed as, e.g., in the presence of (sharply regularized) discontinuities.

相關內容

這是一本簡單證明梯度收斂和隨機梯度下降類型方法的手冊。考慮Lipschitz函數、光滑函數、凸函數、強凸函數和/或Polyak- Lojasiewicz函數。我們的重點是簡單的“好的證據”。每個部分可以單獨參考。我們從梯度下降的證明開始,然后是隨機變量,包括minibatching和momentum。然后使用次梯度方法、近端梯度下降法及其隨機變體處理非光滑問題。我們的重點是全局收斂率和復雜度率。這里發現的一些不太常見的證明包括SGD(隨機梯度下降),近端步驟在第11節,動量在第7節,以及mini-batch在第6節。 //arxiv.org/pdf/2301.11235.pdf本文收集了我們最喜歡的基于梯度和隨機梯度方法的收斂性證明。我們的重點是簡單的證明,這些證明易于復制和理解,并且能夠達到最佳的收斂速度。

付費5元查看完整內容
北京阿比特科技有限公司