We derive a multifractal model for the velocity probability density distribution function (PDF), which is valid from the inertial range to the viscous range. The model gives a continuous evolution of velocity PDFs from large to small scales. It also predicts the asymptotic form of the PDF of velocity gradients. More importantly, the model captures the crossover range behavior and thus allows us...

Precise lateral jet interaction models are required for missiles’ blending control strategies. Because of the complicated flow field, the interaction models are multivariable, complex and coupled. Traditional aerodynamics coefficients model identification used Maximum-likelihood estimation to adjust the parameters of the postulation model, but it is not good at dealing with complex nonlinear mo...

Distribution of the goods from a producer to a customer is one of the most important tasks of transportation. This paper focuses on the usage of genetic algorithms (GA) for optimizing problems in transportation, namely vehicle routing problem (VRP). VRP falls in the field of NP-hard problems, which cannot be solved in polynomial time. The problem was solved using genetic algorithm with two type...

A theoretical and experimental analysis is made of the effects of self-adaptation in a simple evolving system. Specifically, we consider the effects of coding the mutation and crossover probabilities of a genetic algorithm evolving in certain model fitness landscapes. The resultant genotype-phenotype mapping is degenerate in fitness space, there being no direct selective advantage for one proba...

ROSSING OVER, the exchange of chromatin between homologous chroC mosomes, is of utmost importance in genetic studies. Although little is known about the mechanism which is responsible for this exchange, a number of facts on this subject have been fairly well established: (1) Crossing over is produced by breakage and reunion of broken end's (even on BELLING'S hypothesis, breakage and reunion hav...

The herd behavior of returns is investigated in Korean futures exchange market. It is obtained that the probability distribution of returns for three types of herding parameter scales as a power law R with the exponents β = 3.6(KTB203) and 2.9(KTB209) in two kinds of Korean treasury bond. For our case since the active state of transaction exists to decrease lesser than the herding parameter h =...

In this study, we propose to use an Adaptive Genetic Algorithm (AGA) aimed to enhance the performance of information retrieval under Vector Space Model (VSM) in both (Cosine and Dice similarity). Using the algorithm is aimed to improve the quality of the results of user's query and generate improved queries that fit searcher’s needs. Furthermore, we investigate and evaluate different fitness fu...

Motivated by the diffusion-reaction kinetics on interstellar dust grains, we study a first-passage problem of mortal random walkers in a confined two-dimensional geometry. We provide an exact expression for the encounter probability of two walkers, which is evaluated in limiting cases and checked against extensive kinetic Monte Carlo simulations. We analyze the continuum limit which is approach...

We introduce a new parameter to discuss the behavior of a genetic algorithm. This parameter is the mean number of exact copies of the best fit chromosomes from one generation to the next. We argue that the genetic algorithm should operate efficiently when this parameter is slightly larger than 1. We consider the case of the simple genetic algorithm with the roulette–wheel selection mechanism. W...

The ensemble averaged power scattered in and out of lossless chaotic cavities decays as a power law in time for large times. In the case of a pulse with a finite duration, the power scattered from a single realization of a cavity closely tracks the power-law ensemble decay initially, but eventually transitions to an exponential decay. In this paper, we explore the nature of this transition in t...