1,720,952 research outputs found
Closed-form solutions for the analysis of artificial dielectric layers under generic field incidence
No full textWe present an analytical method to model artificial dielectric layers (ADLs) of finite height. Starting from the closed-form solution for the scattering from a single layer under plane wave illumination, the formulation is extended to the multi-layer case, by including the higher-order interaction between parallel layers in analytical form. The method can be used to describe the radiation of a source located in the close proximity of the ADL. Experimental data obtained from a prototype demonstrator are presented and show a good agreement with the results of the theoretical analysis.Accepted author manuscriptTera-Hertz Sensin
A Volumetric Method of Moments for Integrated Lens Antennas
No full textA Volumetric Method of Moments accelerated by means of iterative solvers combined with FFT matrix-vector products has been presented. The method allows analyzing small lens antennas with their integrated feeds efficiently since different structures and geometries can be studied with the same discretization, just by adding the material characteristics in post-processing.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Tera-Hertz Sensin
Towards a Flexible Author Name Disambiguation Framework
Full text linksummary:In this paper we propose a flexible, modular framework for author name disambiguation. Our solution consists of the core which orchestrates the disambiguation process, and replaceable modules performing concrete tasks. The approach is suitable for distributed computing, in particular it maps well to the MapReduce framework. We describe each component in detail and discuss possible alternatives. Finally, we propose procedures for calibration and evaluation of the described system
A Planar Wideband Wide-Scan Phased Array: Connected Array Loaded with Artificial Dielectric Layers
No full textWe present a novel concept for wideband, wide-scan phased array applications. The array is composed by connected-slot elements loaded with artificial dielectric superstrates. The proposed solution consists of a single multi-layer planar printed circuit board (PCB) and does not require the typically employed vertical arrangement of multiple PCBs. This offers advantages in terms of complexity of the assembly and cost of the array. We developed an analytical method for the prediction of the array performance, in terms of active input impedance. This method allows to estimate the relevant parameters of the array with a negligible computational cost. A design example with a bandwidth exceeding one octave (VSWR<2 from 6.5 to 14.3 GHz) and scanning up to 50 degrees for all azimuth planes is presented.Accepted author manuscriptTera-Hertz SensingElectronic
[Conto] Diáspora
Full text linkA short story by Angolan writer Carmo Neto, published under the author\u27s permissionCuento del escritor angoleño Carmo Neto, aquí publicado con su autorización.Conto do escritor angolano Carmo Neto, aqui publicado com sua autorização
A Leaky Enhanced Photo-Conductive Connected Array for Broadband Generation of THz Power
No full textPhotoconductive antennas are devices that provide power up to THz frequencies at a relatively low cost. However, the power radiated by each antenna is typically quite low and arrays have been proposed to increase it. In this paper we present the design of a leaky enhanced array architecture that surpasses the state of the art as it operates efficiently for frequencies up to 1THz, without excessive complications in the manufacturing. This architecture is compared with a ‘standard’ array, showing a broader bandwidth and a higher emitted detected signal.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.ElectronicsTera-Hertz SensingEKL Processin
A Wideband Leaky Lens Antenna with Frequency-Stable Beams for DESHIMA Spectrometer
No full textDESHIMA (Deep Spectroscopic High-redshift Mapper) is an instrument aiming at efficiently making spectroscopic redshift measurements of sub-mm wave galaxies (SMGs), thereby providing about the formation and the evolution of stars and galaxies. The aim of this work is to provide a preliminary study into the design of a wideband leaky lens antenna coupled quasi-optical system within a 1:3 bandwidth. We propose a multi-pixel solution where the virtual sources are located on the lens focal plane. The design is able to provide frequency stable beams to achieve high Gaussian coupling efficiency within the entire bandwidth. We will evaluate the performance of the quasi-optical system design in terms of its Gaussicity and scan loss. The design is specifically targeted at the ASTE telescope located in Atacama, Chile.Accepted Author ManuscriptTera-Hertz SensingQN/Quantum Nanoscienc
An Analysis of Author Contribution Patterns in Eclipse Foundation Project Source Code
No full textPart 1: PapersInternational audienceCollaborative development is a key tenet of open source software, but if not properly understood and managed, it can become a liability. We examine author contribution data for the newest revision of 251,633 Java source files in 592 Eclipse projects. We use this observational data to analyze collaboration patterns within files, and to explore relationships between file size, author count, and code authorship. We calculate author entropy to characterize the contributions of multiple authors to a given file, with an eye toward understanding the degree of collaboration and the most common interaction patterns
Cross domain author profiling from texts
No full textNa área de processamento de língua natural, entende-se por caracterização autoral uma tarefa computacional que tem por objetivo extrair informações sociais e psicológicas dos indivíduos, como gênero e faixa etária, por meio de suas produções textuais. Modelos computacionais de caracterização autoral são comumente empregados em áreas como marketing e segurança, dentre outras. Estes modelos geralmente são de domínio único, i.e., são treinados e validados no mesmo gênero textual, o que faz com que sua portabilidade para outros gêneros seja limitada. Em contrapartida aos modelos de domínio único, modelos interdomínio, que são validados em gêneros textuais diferentes dos que foram treinados, podem ser uma alternativa para casos em que não há dados suficientes para o treinamento de um modelo computacional. Um exemplo seria a utilização de dados do Twitter (domínio que dispõem de grande volume de dados) para o desenvolvimento de modelos de caracterização autoral a serem utilizados em e-mails, domínio onde é mais difícil obter um volume de dados suficiente para o treinamento dos modelos. O presente trabalho apresenta uma proposta de pesquisa em nível de mestrado na área de processamento de língua natural, com ênfase em caracterização autoral, com o objetivo geral de desenvolver modelos de aprendizagem de máquina supervisionada baseados em redes neurais artificiais para a tarefa de caracterização autoral interdomínio, de modo a se obter uma alternativa robusta aos modelos de domínio único, com perda de acurácia reduzida se comparada a modelos equivalentes baseados em domínio únicoIn the area of natural language processing, author profiling is a computational task that aims to extract social and psychological information from individuals, such as gender and age group, through their textual productions. Computational models of author profiling are commonly used in areas such as marketing and security, among others. These models are usually based on a single domain, i.e., they are trained and validated in the same domain, which makes their portability to other domains limited. In contrast to single domain models, cross-genre models, which are validated in different domains than those on which they were trained, may be an alternative for cases in which there is not enough data for training a computational model. An example would be the use of Twitter data (a domain that has a large amount of data) for the development of author profiling models to be used in e-mails, a domain in which it is more difficult to obtain a sufficient amount of data for the training of the models. The present work introduces a proposal for a MSc research in the area of natural language processing, focused on author profiling, with the general objective of developing supervised machine learning models based on artificial neural networks for the task of cross-genre author profiling, in order to obtain a robust alternative to single domain models, with reduced loss of precision compared to equivalent cross-genre model
On the Experimental Characterization of Generated and Received Pulses of Photoconductive Antennas
No full textPhotoconductive antennas (PCAs) are promising candidates for sensing and imaging systems. We have investigated their properties under pulsed laser illumination both in transmission and reception. First, a transmitting PCA has been characterized including a power measurement. Then, a Quasi-Optical (QO) link between a transmitter and a receiver was modelled and analyzed. In this work, we characterize this link with measurement. We use bow-tie based PCAs as examples, and measure the radiated power of the transmitter and the detected current of the receiver. The measurement shows very good agreement with the simulation.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Tera-Hertz SensingElectronic
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