Hierarchy provides unique opportunities for the design of advanced materials with superior properties that arise from architecture, rather than constitutive material response. Contrary to quasi-static regime, where potential hierarchy has been largely explored, its role in vibration mitigation and wave manipulation remains elusive. So far, majority studies concerning hierarchical elastic metamaterials have proposed a self-similar repetition specific unit cell at multiple scale levels,...

A multistatic radar based on ultra-wideband (UWB), also known as a UWB sensor network, has been shown to represent very promising solution localize an intruder moving within small surveillance area. In this paper, tracking algorithm low-complexity particle filtering is proposed, specifically tailored networks with one transmitter and several receivers. An expression calculate the weights first derived, combining observations from all The filter then modified solve problems caused by blind...

The quest for large and low frequency band gaps is one of the principal objectives pursued in a number engineering applications, ranging from noise absorption to vibration control, seismic wave abatement. For this purpose, plethora complex architectures (including multi-phase materials) multi-physics approaches have been proposed past, often involving difficulties their practical realization. To address issue, work we propose an easy-to-manufacture design able open large, complete Lamb...

A content adaptive, network aware approach for joint optimization of wireless video transmission is presented in this article. The system has been developed the framework IST PHOENIX project (www.ist-phoenix.org). After a description considered cross-layer and information to be exchanged among component blocks, concept "JSCC/D controllers" introduced. Results obtained through demonstrator realized as proof-of-concept described paradigm are then shown, confirming validity

Insufficient information on existing bridge substructures and foundations poses significant challenges for structural condition evaluation can cause uncertainties the safety serviceability of bridges. Characterization bridges substructure will not only help to decrease vulnerability natural hazards but also provide opportunities their reuse with considerable benefits. In this paper, feasibility leveraging identification techniques characterize is investigated. A three-span simply supported...

The study aims at investigating the effect of a generic state prestress on passbands and bandgaps phononic crystal plate. To this end, an Updated Lagrangian scheme is developed, which consists two steps: first, static geometrically nonlinear analysis representative unit cell undergoing action applied external load conducted then Floquet-Bloch decomposition to linearized equations acousto-elasticity for in deformed configuration. In addition, formula calculation energy velocity proposed. case...

In this study, we investigate the effect of a nonuniform Winkler-type elastic foundation on stability pipes conveying fluid fixed at upstream end only. A analysis transverse motion aims determining flutter velocity as function governing control parameters such mass over pipe ratio, or stiffness. The global system is analyzed applying an ad-hoc developed finite-element formulation that leads to discrete state-space equation motion. It shown for uniform foundation, increased stiffness Winkler...

The U.S. currently spends tens of billions dollars annually to inspect infrastructures and collect subjective, qualitative data that can often be unreliable or largely irrelevant. Inspections also require adequate access remote locations, for example, appropriate scaffolding, lifting additional protective equipment, which might increase the associated personal safety risk add costs. use unmanned vehicles has experienced a tremendous growth primarily in military homeland security...

Large scale elastic metamaterials have recently attracted increasing interest in the scientific community for their potential as passive isolation structures seismic waves. In particular, so-called “seismic shields” been proposed protection of large areas where other strategies (e.g. dampers) are not workable solutions. this work, we investigate feasibility an innovative design based on hierarchical unit cell, i.e. a structure with self-similar geometry repeated at different scales. Results...

A radar sensor network (RSN) is a wireless system, typically composed of one transmitting (TX) node and several receiving (RX) nodes, aimed at detecting tracking an intruder (target) moving within given surveillance area. In this paper, RSNs based on impulse radio ultra-wideband (UWB) are investigated. the considered each scanning RX calculates soft image area target-scattered UWB pulses. All images then transferred to fusion where decision about target presence or absence taken. Optimum...

M-health is an emerging area of research and one the key challenges in future this medical video streaming over wireless channels. Contrasting requirements almost lossless compression low available bandwidth have to be tackled quality ultrasound radiology applications. On side, techniques need conservative, order avoid removing perceptively important information; on other error resilience correction should provided, with constraint a limited bandwidth. A quality-driven, network-aware...

A numerical procedure is presented for the computation of dispersive parameters in elastic mechanical waveguides generic cross-section immersed non-viscous fluids. The method uses a semi-analytical finite element formulation to describe solid waveguide, while two-and-a-half dimensional boundary used represent unbounded surrounding fluid. Leaky and trapped guided wave modes are found on appropriate Riemann sheets by enforcing generalized Snell–Descartes law along fluid-structure interface...

Non-destructive testing and structural health monitoring techniques using elastic guided waves are often limited by material inhomogeneity or geometrical irregularities of the tested parts. This is a severe restriction in many fields engineering such as aerospace aeronautics, where typically one needs to monitor composite structures with varying mechanical properties complex ge- ometries. particularly true case multiscale materials, anisotropy gradients may be present. Here, we provide an...

M-health services are expected to become increasingly relevant in the management of emergency situations by enabling real-time support remote medical experts. In this context, transmission multiple health-related video streams from an ambulance a hospital can improve efficacy teleconsultation service, but requires large bandwidth meet desired quality, not always guaranteed mobile network. order deliver over single bandwidth-limited wireless access channel, paper we propose novel optimization...

Future wireless video transmission systems will consider orthogonal frequency division multiplexing (OFDM) as the basic modulation technique due to its robustness and low complexity implementation in presence of frequency-selective channels. Recently, adaptive bit loading techniques have been applied OFDM showing good performance gains cable systems. In this paper a multilayer technique, based on so called "ordered subcarrier selection algorithm," is proposed Hiperlan2-like system at 5 GHz...