Search results for "DIRECTION"
showing 10 items of 343 documents
Nonparametric statistics for DOA estimation in the presence of multipath
2002
This paper is concerned with array signal processing in nonGaussian noise and in the presence of multipath. Robust and fully nonparametric high resolution algorithms for direction of arrival (DOA) estimation are presented. The algorithms are based on multivariate spatial sign and rank concepts. Spatial smoothing of the multivariate rank and sign based covariance matrices is employed as a preprocessing step in order to deal with coherent sources. The performance of the algorithms is studied using simulations. The results show that almost optimal performance is obtained in wide variety of different noise conditions.
Robust subspace DOA estimation for wireless communications
2002
This paper is concerned with array signal processing in non-Gaussian noise typical in urban and indoor radio channels. Robust and fully nonparametric high resolution algorithms for direction of arrival (DOA) estimation are presented. The algorithms are based on multivariate spatial sign and rank concepts. The performance of the algorithms is studied using simulations. The results show that almost optimal performance is obtained in wide variety of noise conditions.
Microphones’ Directivity for the Localization of Sound Sources
2011
In a recent paper [P. Rizzo, G. Bordoni, A. Marzani, and J. Vipperman, "Localization of Sound Sources by Means of Unidirectional Microphones, Meas. Sci. Tech., 20, 055202 (12pp), 2009] the proof-of-concept of an approach for the localization of acoustic sources was presented. The method relies on the use of unidirectional microphones and amplitude-based signals' features to extract information about the direction of the incoming sound. By intersecting the directions identified by a pair of microphones, the position of the emitting source can be identified. In this paper we expand the work presented previously by assessing the effectiveness of the approach for the localization of an acoustic…
The embodied sources of purpose expressions in Latin
2016
This chapter examines the phrasal means of encoding the semantic role of purpose in Latin. After discussing the notion of semantic role and its use in cognitive linguistics, we illustrate the conceptual relation between the notional domains of space and causation. On this basis, we analyze the source of purpose expressions in Latin, which are mainly based on direction (bare dative and the allative markers, i.e. ad / in + accusative), but also include prepositional phrases metaphorically derived from location (e.g. per + accusative, prō + ablative, propter + accusative), or metonymically spreading from reason to purpose (as in the case of causal markers such as genitive + causā and gratiā ).
A directional spectral mixture analysis method: application to multiangular airborne measurements
2006
This study aims at developing an operational approach-namely, directional spectral mixture analysis (DISMA)-for retrieving vegetation parameters like fractional vegetation cover (FVC) and leaf area index (LAI) from multispectral and multiangular data. The approach attempts to highlight the consistency of one-dimensional models and linear mixture approaches. DISMA combines spectral signatures of soil and vegetation components with an analytical approximation of the radiative transfer equation, giving rise to a fast invertible bidirectional reflectance distribution function (BRDF) model of discontinuous canopies. Both the forward model and its inversion using a simple technique based on looku…
Modeling and Experimental Validation of a Voltage-Controlled Split-Pi Converter Interfacing a High-Voltage ESS with a DC Microgrid
2023
The Split-pi converter can suitably interface an energy storage system (ESS) with a DC microgrid when galvanic isolation is not needed. Usually, the ESS voltage is lower than the grid-side voltage. However, limitations in terms of the ESS current make the use of a high-voltage ESS unavoidable when high power levels are required. In such cases, the ESS voltage can be higher than the microgrid voltage, especially with low microgrid voltages such as 48 V. Despite its bidirectionality and symmetry, the Split-pi exhibits a completely different dynamic behavior if its input and output ports are exchanged. Thus, the present work aims to model the Split-pi converter operating with an ESS voltage hi…
Evidence of stochastic resonance in the mating behavior of Nezara viridula (L.)
2008
We investigate the role of the noise in the mating behavior between individuals of Nezara viridula (L.), by analyzing the temporal and spectral features of the non-pulsed type female calling song emitted by single individuals. We have measured the threshold level for the signal detection, by performing experiments with the calling signal at different intensities and analyzing the insect response by directionality tests performed on a group of male individuals. By using a sub-threshold signal and an acoustic Gaussian noise source, we have investigated the insect response for different levels of noise, finding behavioral activation for suitable noise intensities. In particular, the percentage…
La storia degli orientamenti teorici: una sintesi
2015
Ampia sintesi di storia dell'antropologia socioculturale dalle origini ad oggi scritta appositamente per la seconda edizione italiana di R. Robbins, Antropologia culturale. Un approccio per problemi, UTET. Il testo del capitolo è una versione significativamente rielaborata di quella pubblicata nella prima edizione del manuale. Broad synthesis of the history of socio-cultural anthropology from its origins to the present written specifically for the second Italian edition of R. Robbins, Cultural Anthropology. A problem-solving approach, UTET. The text of the chapter is a significantly revised version of that published in the first edition of the manual.
The Dual Pandemics of COVID-19 and Obesity: Bidirectional Impact
2022
: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the COVID-19 pandemic, has been shown to disrupt many organ systems in the human body. Though several medical disorders have been affected by this infection, a few illnesses in addition may also play a role in determining the outcome of COVID-19. Obesity is one such disease which is not only affected by the occurrence of COVID-19 but can also result in a worse clinical outcome of COVID-19 infection. This manuscript summarizes the most recent evidence supporting the bidirectional impact of COVID-19 and obesity. It highlights how the presence of obesity can be detrimental to the outcome of COVID-19 in a given …
La stereotomia nella cattedra di Architettura statica di Carlo Giachery
2014
La scuola di architettura di Palermo, sin dalla sua fondazione nel 1779, con la creazione della cattedra di Architettura civile affidata a Giuseppe Venanzio Marvuglia, era divenuta inevitabilmente il luogo di verifica e talvolta di esplorazione dei temi legati alla pratica professionale e, quindi, all’arte del costruire. Giachery, Professore di Architettura statica e civile dal 1837 al 1865, è il primo ad avvertire, da docente, la crisi profonda del sistema didattico della scuola di architettura di Palermo isterilita dalla ricerca di astratte idealità neoclassiche e straniatasi dal processo evolutivo della cultura architettonica europea dopo la morte dei “maestri” Marviglia e Gentile. Secon…