Unreinforced masonry structures, particularly façade walls, are seismically vulnerable due to their weak connections with adjacent floors, and/or roofs. During an earthquake, such walls formulate local mechanisms prone out-of-plane collapse. This behavior has been largely investigated using classical rocking theory, which assumes the structure responds as a rigid body undergoing motion, energy ...

The response of a bridge tower-pier system resting on elastic soil, with a sliding foundation obeying Coulomb's friction law, is studied. The stiffness and damping of the supporting soil is fully taken into account. The action of the suspension bridge cables is equivalent to a horizontal elastic restraint at the top of the tower. The differential equations of motion of the pier are formulated f...

Purpose: This study aimed to investigate radiographic outcomes after posterior spinal fusion (PSF) for pediatric patients younger than 10 years with upper cervical disorders. Methods: Thirteen patients (mean age at surgery, 5.9 years; range, 1 to 9 years) who underwent PSF with a minimum of 2 years of follow-up (mean, 5.8 years) were included. Diagnoses were atlanto-axial instability due to con...

The influence of the vertical component ground motion is investigated for assessing distribution seismic response unanchored rigid blocks. Multiple stripes site-hazard-consistent motions are employed calculating rocking blocks with and without inclusion component. comparison resulting being made both single records full suites, employing a paired record versus an ensemble-statistics comparison,...

The results of three experiments demonstrated that the visual system calibrates motion parallax according to absolute-distance information in processing depth. The parallax was created by yoking the relative movement of random dots displayed on a cathode-ray tube to the movements of the head. In Experiment 1, at viewing distances of 40 cm and 80 cm, observers reported the apparent depth produce...

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...