1,720,967 research outputs found
Experimental Reconstructions of Dielectric Targets with Metallic Inclusions by Microwave Imaging
No full textReconstruction of metallic inclusions inside dielectric targets by means of a microwave tomographic system
No full textExperimental results concerning the inspection at microwave frequencies of wood material with metallic inclusions are reported. They have been obtained by inverting samples of the scattered electromagnetic field collected by a prototype of an imaging system. The system is able to acquire multi-illumination multiview data in a tomographic arrangement. The retrieved maps of the dielectric permittivity and electric conductivity of the cross sections of unknown targets are obtained by applying the distorted-wave Born approximation to the electric field integral equation governing the scattering phenomenon
Electromagnetic imaging of dielectric targets by using a tomographic systems
No full textThe reconstruction of plastic targets by using an electromagnetic imaging system working at microwave frequencies is considered. A prototype of a tomograph is used to measure field scattered data in a multi-illumination multi-view arrangement. The samples of the field are used to retrieve the two-dimensional distributions of the dielectric parameters of the target under test. Experimental results are provided and the overall reconstruction quality is evaluated
A multistatic tomographic approach to microwave imaging of dielectric targets
No full textIn the last years, the development of microwave imaging systems, aimed at reconstructing images of the dielectric properties of unknown targets from measures of the scattered field, has been a continuously pursued target. There are mainly two topics that must be faced. First of all, it is necessary to create fast and efficient measurement setups for obtaining the samples of the scattered electric field. Secondly, it is necessary to develop numerical methods able to extract from such measured values the needed information. In this paper, a multistatic measurement setup and an efficient reconstruction procedure are presented. Experimental results are provided in order to demonstrate the effectiveness of the proposed system
Nondestructive Inspection of Wood Materials by a Microwave Imaging Approach – Experimental Results
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Imaging of dielectric targets with metallic inclusions by means of a prototype of microwave axial tomograph
No full textMicrowave systems are becoming powerful tools for imaging applications. In fact, when designed by taking into account the full scattering phenomena, they are able to directly provide information about the physical properties of the target under test. In this paper, the possibility of detecting metallic inclusions inside dielectric objects is assessed by using a prototype of a microwave axial tomograph, which is able to create images of the dielectric permittivity and of the electric conductivity of the inspected target
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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