The acoustic properties of a periodic rigid frame porous layer with multiple irregularities in the rigid backing and embedded rigid circular inclusions are investigated theoretically and numerically. The theoretical representation of the sound field in the structure is obtained using a combination of multipole method that accounts for the periodic inclusions and multi-modal method that accounts...

SUMMARY The PiSQRD web resource can be used to subdivide protein structures in quasi-rigid dynamical domains. The latter are groups of amino acids behaving as approximately rigid units in the course of protein equilibrium fluctuations. The PiSQRD server takes as input a biomolecular structure and the desired fraction of protein internal fluctuations that must be accounted for by the relative ri...

The general formulation of the dynamics an elastic body undergoing arbitrary motion is revisited with emphasis on orthogonality between rigid and deformation one hand, appropriate definition relative velocities induced by other hand. A mixed displacement–velocity approach adopted, thus allowing a local frame which results in simplification discretization solution steps. proposed applied to mode...

A new design concept in the development of vertical takeoff and landing aircraft with high forward flight speed capability is that of the X-Wing. The X-Wing is a stiff, bearingless helicopter rotor system which can be stopped in flight and the blades used as two forward-swept wings and two aft-swept wings. Because of the unusual configuration in the fixed-wing mode, there is a high potential fo...

The rapid growth of space utilization requires extensive construction, and maintenance of space structures and satellites in orbit. &#10This will, in turn, substantiate application of robotic systems in space. In this paper, a near-minimum-time optimal control law is developed for a rigid space platform with flexible links during an orientating maneuver with large angle of rotation. The time op...

a 42-year-old woman was admitted to the hospital because of odynophagia and neck pain after swallowing a piece of bone. anteroposterior (ap) and lateral neck x-ray showed the foreign body. rigid esophagoscopy under general anesthesia was performed and foreign body extracted by rigid bronchoscopy.

In this paper, a minimum and near-minimum time optimal control laws are developed and compared for a rigid space platform with flexible links during an orientating maneuver with large angle of rotation. The control commands are considered as typical bang-bang with multiple symmetrical switches, the time optimal control solution for the rigid-body mode is obtained as a bang-bang function and app...

A method to identify the transfer function of HDD head/actuator system modes that have gains that are smaller than the rigid-body mode is presented. Prony’s method is used to identify the frequency and damping of the modes, and the measured actuator current and PES in the time-domain are used to identify the gain of the transfer function of the modes. Overall accuracy is verified by comparing t...