Search results for "Arrival"

Time-of-arrival, angle-of-arrival, and angle-of-departure statistics of a novel simplistic disk channel model

2011

This paper introduces a novel simplistic geometrical disk scattering model in which the local scatterers are uniformly distributed in polar coordinates within a disk centered on the mobile station (MS). The proposed joint uniform distribution in polar coordinates results in a higher concentration of scatterers around the disk center and a lower concentration far from it. Furthermore, it is assumed that the base station (BS) is elevated to a non-scattering region and that a wave transmitted from the BS reaches the MS after a single bounce by one of the randomly distributed scatterers. Under the above-mentioned assumptions, we derive closed-form expressions for the joint probability density f…

Ship Roll Motion under Stochastic Agencies Using Path Integral Method

2009

The response of ship roll oscillation under random ice impulsive loads modeled by Poisson arrival process is very important in studying the safety of ships navigation in cold regions. Under both external and parametric random excitations the evolution of the probability density function of roll motion is evaluated using the path integral (PI) approach. The PI method relies on the Chapman-Kolmogorov equation, which governs the response transition probability density functions at two close intervals of time. Once the response probability density function at an early close time is specified, its value at later close time can be evaluated. The PI method is first demonstrated via simple dynamica…

Characterization of the atmospheric muon flux in IceCube

2015

Muons produced in atmospheric cosmic ray showers account for the by far dominant part of the event yield in large-volume underground particle detectors. The IceCube detector, with an instrumented volume of about a cubic kilometer, has the potential to conduct unique investigations on atmospheric muons by exploiting the large collection area and the possibility to track particles over a long distance. Through detailed reconstruction of energy deposition along the tracks, the characteristics of muon bundles can be quantified, and individual particles of exceptionally high energy identified. The data can then be used to constrain the cosmic ray primary flux and the contribution to atmospheric …

Analysis of Cardiac Pulse Arrival Time Series at Rest and during Physiological Stress

2022

The study of cardiovascular dynamics is pivotal in the prevention and monitoring of cardiovascular diseases. Pulse Arrival Time (PAT) series contain information concerning not only the dynamics of the Autonomic Nervous System (ANS), but of all the systems involved in the regulation of cardiovascular homeostasis. This study aims to highlight how indexes extracted from PAT series in time-, frequency- and information-domain allow to discriminate among different physiological conditions. Analyses were carried out on 76 young healthy subjects, at rest and during orthostatic or mental stress. Our results show that PAT indexes vary according to the ANS condition, and may thus be useful parameters …

RSS-eye: Human-assisted Indoor Localization without Radio Maps

2015

The pervasive diffusion of smartphones is boosting indoor positioning solutions and location-based services. We propose a novel methodology to perform indoor positioning of mobile users by the estimation of angles of arrival from access points whose locations are known. Angles of arrival are estimated by correlating WiFi RSSI measurements with data coming from a digital compass, which is provided by most current handsets. Our system has minimal requirements in terms of infrastructure and mobile hardware. The system neither needs calibration, nor radio maps but requires the user to perform a gesture when an estimation is needed. The resulting on-demand localization has advantages in terms of…

Modelling the frequency distribution of inter-arrival times from daily precipitation time-series in North-West Italy

2018

Abstract The discrete three-parameter Lerch distribution is used to analyse the frequency distribution of inter-arrival times derived from 26 daily precipitation time-series, collected by stations located throughout a 28,000 km2 area in North-West Italy (altitudes ranging from 113 m to 2,170 m a.s.l.). The precipitation regime of these Alpine regions is very different (latitude 44.5 to 46.5 N) from the typical Mediterranean precipitation regime of the island of Sicily (latitude 37 to 38 N), where the Lerch distribution has already been tested and whose results are compared. In order to verify the homogeneity of the precipitation time series, the Pettitt test was preliminarily performed. In …

An ergodic wideband MIMO channel simulator based on the geometrical T-junction scattering model for vehicle-to-vehicle communications

2010

In this paper, a wideband multiple-input multiple-output (MIMO) simulation model for vehicle-to-vehicle (V2V) channels in T-junction propagation environments is proposed. This simulation model takes the exact relationship between the angle-of-arrival (AOA) and the angle-of-departure (AOD) into account. In order to determine the parameters of the simulation model, the Riemann sum method (RSM) is applied. Furthermore, the statistical and ergodic properties of the simulation model are studied. Closed-form solutions are derived for the space-time-frequency cross-correlation function (STF-CCF), the two-dimensional (2D) spatial cross-correlation function (CCF), the temporal autocorrelation functi…

Trends of some high quantiles of average and extremes inter-arrival timesand rainfall depths at daily scale for an Italian Sub-Alpine area

2015

Modeling of rainfall statistical structure represents an important research area in hydrology, meteorology, atmospheric physics and climatology, because of the several theoretical and practical implications. The statistical inference of the alternation of wet periods (WP) and dry periods (DP) in daily rainfall records can be achieved through the modelling of inter-arrival time-series (IT), defined as the succession of times elapsed from a rainy day and the one immediately preceding it. It has been shown previously that the statistical structure of IT can be well described by the 3-parameter Lerch distribution (Lch). In this work, Lch was successfully applied to IT data belonging to a sub-al…

About time of occurrence of rainy days for Mediterranean and (sub)-Alpine areas

2012

WMPS: A Positioning System for Localizing Legacy 802.11 Devices

2012

The huge success of location-aware applications calls for the quick development of a positioning system alternative to GPS for indoor localization based on existing technologies such as 802.11 wireless networks. In this paper we propose WMPS, the Wireless MAC Processor Positioning System, that is a localization system running on off-the-shelf 802.11 Access Points and based on time-of-flight ranging of users’ standard terminals. We prove through extensive experiments that propagation delays can be measured with the accuracy required by indoor applications despite the different noise components that can affect the result, like latencies of the hardware transreceivers, multi- path, ACK jitters…