In this paper, we assess the performance of the slotted ALOHA protocol with capture in a mobile communications environment with Rayleigh and Log-normal fading when used with switched-beam smart antennas. We consider the configuration where one receiver is present at each base station and calculate the capture probability, its asymptotic value as the number of colliding packets tends to infinity...

The ex situ lift out (EXLO) adhesion forces are reviewed and new applications of EXLO for focused ion beam (FIB)-prepared specimens are described. EXLO is used to manipulate electron transparent specimens on microelectromechanical systems carrier devices designed for in situ electron microscope analysis. A new patented grid design without a support film is described for EXLO. This new slotted g...

-A slotted waveguide providing a two dimensional near-field focused beam is presented in this paper. This antenna focuses the beam in the E-plane and provides a wide beam in the H-plane in order to illuminate a linear array, as reflector transmit-array antenna with a small width (100mm) and a very large length (1530mm) located in the near-field region. The simulated field distribution on the ar...

The Butler matrix [1] is a beam-forming network for a multi-beam array antenna. The main-beam direction can be switched according to the input port. Conventional Butler matrix suffers from high crossover levels between adjacent main beams of -3.7dB and high sidelobe levels of -11.4dB independent on the number of ports, theoretically. In order to solve these problems, the configuration of a circ...

Presented here is a slotted-quad-beam structure sensor for the measurement of friction in micro bearings. Stress concentration slots are incorporated into a conventional quad-beam structure to improve the sensitivity of force measurements. The performance comparison between the quad-beam structure sensor and the slotted-quad-beam structure sensor are performed by theoretical modeling and finite...

In this study, the behavior characteristics of I beam-to-concrete filled tube (CFT) column connection is studied through experiment and finite element models under the monotonic loading. To validate the finite element modeling, at first, an experimental model is made and experimented. After validation of the finite element modeling, different models were created in the software. The studied par...

A system-level shake-table test of a two-story low-damage concrete wall building was conducted in 2019. The consisted unbonded post-tensioned (UPT) walls with perimeter frames and different wall-to-floor connections to provide deformation compatibility. results highlighted that the measured lateral strength notably exceeded design value. This over-strength largely attributed compatibility defor...

Moment-resisting frames have extensive usage in earthquake-prone areas and high ability in energy dissipation.After the earthquake in Northridge 1994,Kobe 1995 fixed connections of steel structures have shown poor performance and generally they were caught brittle fracture of beam flange weld to the column.In order to remedy to avoid similar situations in future earthquakes,researchers introduc...

the present study is concerned with the simultaneous optimization of the size of components and the arrangement of connections for performance-based seismic design of low-rise spsws. design variables include the size of beams and columns, the thickness of the infill panels, the type of each beam-to-column connection and the type of each infill-to-boundary frame connection. the objective functio...