Title : Scholars Journal of Physics, Mathematics and Statistics Abbr. Title : Sch J Phys Math Stat ISSN : 2393-8056 (Print) & 2393-8064 (Online) Discipline : Physics, Mathematics and Statistics Frequency : Monthly Publisher : Scholars Academic and Scientific Publisher Country : India Language : English
Current Issue : Volume-8 - Issue-06 Call for paper ; 2021
Energy prediction for different cluster structures is the basis for finding and predicting the global optimal structure of clusters. The current methods for predicting the energy of the ground state structures of different clusters include theoretical prediction methods and optimized simplified potential energy function methods. The accuracy of the theoretical prediction method is high, but its calculation amount is too large. Therefore, this paper proposes a PSO-BP neural network three-dimensional cluster energy prediction model based on atomic coordinates, and uses different types of Euclidean distances between atoms as input variables, and the energy of clusters with different structures as output variables. Select gold cluster Au20 and boron cluster B45-part of the sample data as the training set to build the model, and predict the rest of the samples, and finally get: the prediction accuracy of the PSO-BP neural network model is higher than that of the traditional BP neural network model. The cluster energy prediction model is feasible.
Consider the existence of a non-autonomous two-dimensional stochastic plate equation with linear memory term pullback the attractor on . Apply the Ornstein-Uhlenbeck process to deal with the random term, transform the original equation into a deterministic equation containing random variables, and then estimate its consistency by replacing the system solution with variables, and prove that the random dynamic system corresponding to the original system equation pullback the absorption set Existence, and finally proves the system's pullback asymptotically compaction , which leads to the existence of the pullback attractor of the original system.
Lot received or units produced are not all perfect items. A time and price dependent demand inventory model is formulated when items produced or lot received are of defective and repairable nature. Three tired pricing is considered. For different situations, expression for total profit is derived to derive optimal solution. For parameter, post-optimality computations are also done.