the vibrations produced by trains include two parts which are deterministic and random vibrations. due to variation of dynamic loads and patterns of load-time, the random vibration of moving train is one of the most important issues in the field of railway engineering. one of the important sources in producing the train vibrations is rail roughness and irregularities. in this paper, responses o...

newell's learning stages model is a learning model based on dynamic systems theory which is divided to three stages based on the relationship among learners' degree of freedom. the aim of this study was to investigate the effect of attention focus of instruction on learning a simple skill (throwing darts) and a complex skill (non-dominant foot chip shot). thestudyconsistedoftwoexperim...

This paper addresses both dynamic modelling and dynamic parameter identification of a permanent magnet spherical actuator, which is capable of performing three-degree-of-freedom (DOF) motion in one single joint. The dynamic model of the spherical actuator is derived from Lagrange’s equations, but the parameters, called dynamic parameters, in the model are usually uncertain. Then the dynamic mod...

A simulation model for a two degrees of freedom industrial manipulator where an accelerometer is attached to the robot arm is presented. An overview of the kinematic and dynamic models as well as a thorough description of the accelerometer model are given. The simulation model can be run with di erent types of properties, e.g. model errors and disturbances. Di erent types of suggested simulatio...

This paper presents the simplest walking model with an upper body. The model is a passive dynamic walker, i.e. it walks down a slope without motor input or control. The upper body is confined to the midway angle of the two legs. With this kinematic constraint, the model has only two degrees of freedom. The model achieves surprisingly successful walking results: it can handle disturbances of 8% ...

a new dynamic friction model for modeling of elliptical vibration assisted turning (evat) was developed in this research. the periodic change of the friction force direction is known to be one of the most important causes of this phenomenon. in modeling of machining processes (including the evat process), static coulomb friction model was employed by most of the researchers. because of the peri...

We derive the complete set of macroscopic dynamic equations for ferrogels under an external magnetic field, including the magnetization as an independent dynamic degree of freedom. The magnetoelasticity comes in the form of magnetostriction and through the magnetic part of the Maxwell stress. Various dynamic couplings of the elastic degree of freedom with the magnetization and the magnetic fiel...

The well-known electro-mechanical analogy that equates current, voltage, resistance, inductance and capacitance to force, velocity, damping, spring constant and mass has a shortcoming in that mass can only be used to simulate a capacitor which has one terminal connected to ground. A new model that was previously proposed by the authors that combines a mass with a pulley (MP) is shown to simulat...

dynamic analysis of two-dimensional elasticity problems using the isogeometric analysis method and its comparison with the finite element method is the subject of this research. for this purpose, formulation of the governing differential equation is obtained by using the b-spline basis functions. some numerical examples employing consistent and lumped mass matrices are presented in order to com...

To realize maximum throughput, tight control of the bottleneck unit(s) is necessary. Dynamic degrees of freedom can be used to obtain tighter bottleneck control. Here, “dynamic” means that the degree of freedom has no steady-state effect on plant operation, like most inventories (levels). Nevertheless, temporary changes of inventories can allow for dynamic changes in the flow through the bottle...