This paper investigates generating symmetric trajectories for an underactuated biped during the stance phase of running. We use a point mass biped (PMB) model for gait analysis that consists of a prismatic force actuator on a massless leg. The significance of this model is its ability to generate more general and versatile running gaits than the spring-loaded inverted pendulum (SLIP) model, mak...

in this paper, the security of a distance bounding protocol is analyzed which has been recently proposed by jannati and falahati (so-called jf). we prove that an adversary can recover key bits of jf protocol with probability of “1” while the complexity of attack is “2n” runs of protocol. in addition, we propose an improved protocol and prove that the improved protocol is resistant to mafia frau...

adhesion level for the proper running of rail wheelset on track is crucial problem in detecting slippage to avoid accidents. the slippage of rail wheels has been observed applying forward and lateral motions to slip velocity and torsion motion. the longitudinal and lateral forces behavior is watched with respect to traction force to note correlation based on angle of attack. the deriving torque...

The sensitization and subsequent intergranular corrosion of Al-5.3 wt.% Mg alloy has been shown to be an important factor in stress corrosion cracking of Al-Mg alloys. Understanding sensitization requires the review of grain boundary character on the precipitation process which can assist in developing and designing alloys with improved corrosion resistance. This study shows that the degree of ...

In this work, the aerodynamic performance and optimization of a vertical-axis wind turbine with high tip-speed ratio are theoretically studied on basis two-dimensional airfoil theory. By dividing rotating plane into upwind downwind areas, relationship among angle attack, azimuth, pitch angle, is derived using quasi-steady model, loads then obtained. applying polynomial approximation to function...

Several approaches for modelling the longitudinal aerodynamic coefficients of a fighter aircraft at high angles of attack, including the unsteady effects are presented. A traditional approach where the model of the coefficient arises in the form of the steady and unsteady effects, the unsteady effect being modelled by means of transfer functions. The second approach uses an internal variable de...