springs are the  mechanical parts which have many application in industries. static and dynamic forces cause relaxation in these parts so that they lose some of their free length and reaction force. springs constant are very important in airplane and vailway industry since constant and variable forces are applied to them in period time, therefore it is necessary to avoid decreasing in spring co...

In this paper static analysis of orthotropic functionally graded material (FGM) cylinders with finite length was carried out by a mesh-free method. MLS shape functions are used for approximation of displacement field in the weak form of equilibrium equation and essential boundary conditions are imposed by transformation method. In this simulation, an ax symmetric model is used. Mechanical prope...

This paper employs nonlinear disturbance observer (NDO) for robust trajectory-free Nonlinear Model Predictive Control (NMPC) of biped robots. The NDO is used to reject the additive disturbances caused by parameter uncertainties, unmodeled dynamics, joints friction, and external slow-varying forces acting on the biped robots. In contrary to the slow-varying disturbances, handling sudden pushing ...

This paper describes an evolutionary approach to the problem of inferring stochastic context-free grammars from nite language samples. The approach employs a genetic algorithm, with a tness function derived from a minimum description length principle. Solutions to the inference problem are evolved by optimizing the parameters of a covering grammar for a given language sample. We provide details...

A linear external perturbation is introduced in the action of the partition function of the random matrix model of RNA [ It is seen that (i). the perturbation distinguishes between paired and unpaired bases in that there are structural changes, from unpaired and paired base structures (0 ≤ α < 1) to completely paired base structures (α = 1), as the perturbation parameter α approaches 1 (α is th...

the developing turbulent flow in an open channel is a complex three-dimensional flow influenced by the secondary currents and free surface effects and is, therefore, not amenable to analytical solution. this paper aims to study the impact of three key hydraulic parameters (relative roughness, the froude number and the reynolds number) on the establishment length using computational fluid dynami...

Abstract Submerged vegetation acts as large-scale roughness element that changes flow structure and promotes subdivision, thereby affecting scalar transport energy transfer in the river. This article explores vertical distributions of both hydrodynamic pressure P D effective mixing length L vegetated free- region through flume experiments. Firstly, formulas have been proposed present study to c...