The paper addresses the problem of line-of-sight (LOS) vs. non-line-of-sight (NLOS) propagation link identification in ultrawideband (UWB) wireless networks, which is necessary for improving the accuracy of radiolocation and positioning applications. A LOS/NLOS likelihood hypothesis testing approach is applied based on exploiting distinctive statistical features of the channel impulse response ...

Multipath hemispherical map (MHM) is a kind of multipath mitigation approach that takes advantage of the spatial repeatability of the multipath effect under an unchanged environment. This approach is not only suitable for static environments, but also for some kinematic platforms, such as a moving ship and airplane, where the dominant multipath effects come from the platform itself and the mult...

Al2O3 films were prepared using electron beam evaporation at room temperature. The samples were irradiated with oxygen plasma under different energy. The variations in average surface defect density and root mean square (RMS) surface roughness were characterized using an optical microscope and an atomic force microscope. Surface average defect density increased after plasma treatment. The RMS s...

The periodic impulse feature is the most typical fault signature of the vibration signal from fault rolling element bearings (REBs). However, it is easily contaminated by noise and interference harmonics. In order to extract the incipient impulse feature from the fault vibration signal, this paper presented an autocorrelation function periodic impulse harmonic to noise ratio (ACFHNR) index base...

21 The purpose of this study was to quantify hip and ankle movement strategies during a standing, 22 arm tracking task in people with multiple sclerosis (MS). Full body kinematics and kinetics were 23 assessed using motion analysis cameras and force plates in 9 MS and 9 age-matched controls. 24 While standing, participants used their dominant hand to track a target moving around a large 25 hori...

The topographical features of fractured tensile, flexural, K1C, and impact specimens of monolithic epoxy have been studied and correlated with mechanical properties and surface features of samples before fracture. The topographical features studied include waviness (Wa), roughness average (Ra), root mean square value (Rq), and maximum roughness height (Rmax or Rz). As surface notches generate t...

The objective of this research was to evaluate the properties of the chemically retted kenaf bast fiber impregnated with the inorganic nanoparticles. High quality kenaf bast fibers were obtained from a chemical retting process. An in situ inorganic nanoparticle impregnation (INI) process was used to introduce the CaCO3 nanoparticles into the retted kenaf bast fibers. It was found that some of t...

According to vector scattering and scalar scattering theory, the relationship of BRDF (bidirectional reflectance distribution function) of light scattering from micro-rough surface with TIS (total integrated scattering) is analyzed. Roughness statistical characterization such as RMS (root mean square), PSD (power spectral density) function are deduced by TIS of polished surface. Based on the li...

OBJECTIVES: The purpose of this study was to determine the effectiveness of visual (VF) and vibrotactile (TF) biofeedback obtained from the lower trunk (L5) tilts signal and their combination (VF+TF) in reducing postural sway in young and elderly people. METHODS: Twenty healthy elderly subjects (8 males, mean age 74 years) and 20 healthy young subjects (7 males, mean age 27 years) were tested i...

The radar backscattering coefficient of three types of soil surfaces at observation angles (10°60°) have been calculated using integral equation model (IEM) for different values of root mean square (RMS) roughness heights and correlation lengths. The surfaces are represented by isotropic autocorrelation functions (exponential, 1.5 power and Gaussian). The dielectric constant (ε) of the soil, an...