Most of watermarking techniques are based on Wide Spread Spectrum (WSS). Security of such schemes is studied here in adopting a cryptanalysis point of view. The security is proportional to the difficulty the opponent has to recover the secret parameters, which are, in WSS watermarking scheme, the private carriers. Both theoretical and practical points of view are investigated when several piece...

A 2D (6x6) fiber collimator array with a telescope beam expander is incorporated into a 1xN2 wavelengthselective switch ( W S S ) to achieve high port count. The 1xN2 WSS is realized using two cross-scanning 1-axis analog micromirror arrays in a 4-foptical system. We have achieved a 1x9 WSS with a channel spacing of 160 GHz, a fiber-to-fiber insertion loss of 14 dB and a switching time of < 1 m...

OBJECTIVE To determine whether selectin-mediated leukocyte-rolling velocity in inflamed venules in vivo is determined by wall shear rate (WSR) or by wall shear stress (WSS). METHODS WSS was manipulated independently of WSR by altering the viscosity of blood plasma in mice with an isovolemic exchange of blood for low- or high-viscosity dextran solutions. Rolling of neutrophils or beads coated ...

The capabilities and limitations of various molecular viscosity models, when testing Left Coronary Artery (LCA) tree, were analyzed via: molecular viscosity, local and global non-Newtonian importance factors, Wall Shear Stress (WSS) and Wall Shear Stress Gradient (WSSG). Seven non-Newtonian molecular viscosity models, plus the Newtonian one, were compared. Dense grid of 620000 nodes located, mo...

Mice are widely used to investigate atherogenesis, which is known to be influenced by stresses related to blood flow. However, numerical characterization of the haemodynamic environment in the commonly studied aortic arch has hitherto been based on idealizations of inflow into the aorta. Our purpose in this work was to numerically characterize the haemodynamic environment in the mouse aortic ar...

It has recently been shown that using battery storage systems (BSSs) to provide reactive power provision in a medium-voltage (MV) active distribution network (ADN) with embedded wind stations (WSs) can lead to a huge amount of reverse power to an upstream transmission network (TN). However, unity power factors (PFs) of WSs were assumed in those studies to analyze the potential of BSSs. Therefor...

PURPOSE To compare pulmonary artery flow using Cartesian and radially sampled four-dimensional flow-sensitive (4D flow) MRI at two institutions. METHODS Nineteen healthy subjects and 17 pulmonary arterial hypertension (PAH) subjects underwent a Cartesian 4D flow acquisition (institution 1) or a three-dimensional radial acquisition (institution 2). The diameter, peak systolic velocity (Vmax), ...

BACKGROUND Atherosclerotic plaque in the descending thoracic aorta (dAo) is related to altered wall shear stress (WSS) for normal patients. Resection with end-to-end anastomosis (RWEA) is the gold standard for coarctation of the aorta (CoA) repair, but may lead to altered WSS indices that contribute to morbidity. METHODS Computational fluid dynamics (CFD) models were created from imaging and ...

The wall shear stress (WSS) of flowing blood and the circumferential strain (CS) driven by the pressure pulse interact to impose a dynamic force pattern on endothelial cells (ECs) which can be characterized by the temporal phase angle between WSS and CS, a quantity which varies significantly throughout the circulation. To study the interaction of WSS and CS on endothelial production of vasodila...

We investigate whether blebs in cerebral aneurysms form in regions of low or high wall shear stress (WSS), and how the intraaneurysmal hemodynamic pattern changes after bleb formation. Seven intracranial aneurysms harboring well defined blebs were selected from our database and subject-specific computational models were constructed from 3D rotational angiography. For each patient, a second anat...