particle fall 中文意思是什麼
particle fall
解釋
顆粒沉降-
The result has been that when a relatively mundane particle accelerator called the diamond light source, in oxfordshire, proved to be some ? 80m ( $ 160m ) more expensive than expected, the axe had to fall on other parts of physics
結果，當一個稱為「鉆石光源」的宇宙粒子加速器（位於牛津郡）宣稱獲得多於原計劃的1 . 6億美元的經費時，其他領域的研究經費驟降。 -
The distribution of concentration still obeys the diffusion law, only the efftects of the group particle fall velocity and the dispersive force on the diffusion index z1 shall be considered
懸沙濃度分佈仍遵循擴散定律，但擴散指教z1將受到顆粒群體沉速和離散力的影響， -般為y的函數。 -
A tiny particle of meteoric dust, especially one of many that fall to the surface of the earth or moon
微隕星微小的隕星顆粒，特指大量墜向地球或月球表面的微隕星 -
But, pso convergence ' s speed become slow in latter iterative phase, and pso is easy to fall into local optimization. at present, some scholars improve base pso mostly using 3 methods : disperse algorithm, increase convergence speed, enhance particle ' kinds. in the paper, i put forward 2 methods aiming at local best resutl but not whole best result. i modify base pso using the last method. some scholars put forward times initializations, so i select best result after circulating some times to be a parameter of formula. first, put particle into some small region, and ensure every region having one paticle at least. second, every region ' s particle has probability transfer other regions. although increase running time, enhance particle ' kinds, decrese the probability of convergence far from whole best result. nerms ( network educational resource management system ) is one of the research projects in the science and technology development planning of jilin province. the aim of nerms is to organize and manage various twelve kinds of network educational resources effectively so that people can share and gain them easily and efficiently, so as to quicken the development of network education
但粒子群演算法仍存在如下不足:首先在多峰的情況下，粒子群有可能錯過全局最優解，遠離最優解的空間，最終得到局部最優解;其次在演算法收斂的情況下，由於所有的粒子都向最優解的方向群游，所有的粒子趨向同一，失去了粒子間解的多樣性，使得後期的收斂速度明顯變慢，同時演算法收斂到一定精度時，演算法無法繼續優化，本文對原始粒子群演算法提出了二點改進方案: 1 .演算法迭代到一定代數后，把此時找到的全局最優解當作速度更新公式的另一參數（本文稱之為階段最優解）再進行迭代; 2 .每次迭代過程中除最優解以外的每個粒子都有一定概率「變異」到一個步長以外的區域，其中「變異」的粒子在每一維上都隨機生成一個步長。
分享友人