recently, a large amount of studies have been related to nonlinear systems with multi-degrees of freedom as well as continuous systems. the purpose of this paper is to optimize passive vibration absorbers in linear and nonlinear states for an euler-bernoulli beam with a nonlinear vibratory behavior under concentrated moving load. the goal parameter in the optimization is maximum deflection of t...

effects of binary mixtures of ionic/nonionic (sodium dodecyl sulfate/2-heptanol or 1-decanol) and nonionic/nonionic surfactants (2-heptnol/1-decanol) on drop/interface coalescence of water drops in a continuous n-heptane phase were examined. the drop size reduced appreciably and the multi-step coalescence was suppressed finally as the concentration of each of the constituting components of surf...

The focus of this paper is on multi-user multi-input multi-output (MIMO) transmissions for millimeter wave systems with a hybrid precoding architecture at the base-station. To enable multi-user transmissions, the base-station uses a cell-specific codebook of beamforming vectors over an initial beam alignment phase. Each user uses a user-specific codebook of beamforming vectors to learn the top-...

A method for precise multi-spot parallel ultrafast laser material structuring is presented based on multi-beam interference generated by dynamic spatial phase engineering. A Spatial Light Modulator (SLM) and digitally programming of phase masks are used to accomplish the function of a multi-facet pyramid lens, so that the laser beam can be spatially modulated to create beam multiplexing and des...

Traditional multi-beam Geostationary (GEO) satellite communication systems provide broadband coverage using a regular grid of fixed spot-beams with uniform 4-colour frequency (4CR) reuse scheme. However, user distribution is non-uniform on ground and, consequently, the demand varies geographically. One potential solution to address high-demand regions enhance beam gain only in those areas. In t...