198,396 research outputs found
Optimization of difference patterns for monopulse antennas by a hybrid real/integer-coded differential evolution method
No full textOptimization of the difference patterns for monopulse antennas by a hybrid real/integer-coded differential evolution method
Author(s): Caorsi, S (Caorsi, S); Massa, A (Massa, A); Pastorino, M (Pastorino, M); Randazzo, A (Randazzo, A)
Source: IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION Volume: 53 Issue: 1 Pages: 372-376 DOI: 10.1109/TAP.2004.838788 Part: Part 2 Published: JAN 2005
Times Cited: 46 (from Web of Science)
Cited References: 9 [ view related records ] Citation Map
Abstract: The optimization of difference patterns of monopulse antennas is considered. The synthesis problem is recast as an optimization problem by defining a suitable cost function. In particular, in this paper, the cost function is based on constraints on the side-lobe levels. A subarray configuration is adopted and the excitations of the difference pattern are approximately determined. The optimization problem isefficiently solved by a differential evolution algorithm, which is able to contemporarily handle real and integer unknowns. Numerical results are reported concerning classical array configurations previously considered in the literature.
Accession Number: WOS:000226261600014
Document Type: Article
Language: English
Author Keywords: array antennas; evolutionary algorithm; monopulse antennas; sum and difference patterns
KeyWords Plus: SUM; ARRAYS
Reprint Address: Caorsi, S (reprint author), Univ Pavia, Dept Elect, Via Palestro 3, I-27100 Pavia, Italy
Addresses:
1. Univ Pavia, Dept Elect, I-27100 Pavia, Italy
E-mail Address: [email protected]
Publisher: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
Web of Science Category: Engineering, Electrical & Electronic; Telecommunications
Subject Category: Engineering; Telecommunications
IDS Number: 886VT
ISSN: 0018-926
Reconstruction of velocity profiles of two-dimensional targets by an inverse scattering procedure based on a numerical forward solver
No full textIn this contribution we investigate the capabilities of inverse scattering procedures for electromagnetic problems involving axially moving cylinders, without any restriction on their number, their shapes and their profiles of relative dielectric permittivity and axial velocity. As usual, the inverse scattering problems of interest are recast as optimization problems. An Ant Colony Optimization procedure is adopted to numerically solve these problems. It exploits a proprietary finite element code for the solution of forward scattering problems involving objects in motion. When the maximum magnitude of the axial speed is limited to one-hundredth of the speed of light in vacuum, it has been shown that it could be convenient to split the inverse problem into two parts (M. Pastorino, M. Raffetto, and A. Randazzo, IEEE Trans. Geosci. Remote Sens., 53, 2015, pp. 1452-1462): the first one related to the reconstruction of the geometrical and dielectric unknowns while the second part has to deal with the determination of the velocity profile. In this work we focus, in particular, on the latter one
Survey of clinicians with specialization in CAS (Randazzo, 2019)
No full textPurpose: Little is known about how clinicians develop expertise in childhood apraxia of speech (CAS), a rare speech disorder with heterogeneous presentation. The purpose of this survey study was to examine the beliefs and practices of clinicians specializing in CAS.Method: Speech-language pathologists who self-identify as having expertise in CAS (n = 165) completed an online survey regarding influences on clinical practice and beliefs about CAS. Practice patterns and perspectives regarding CAS were analyzed for respondents who self-identify as having expertise in CAS, across 4 experience bands (1–5, 6–10, 11–15, and 15+ years).Results: A majority of the respondents to this survey provide treatment to preschool-age children with CAS. Respondents report features used in differential diagnosis aligned with the American Speech-Language-Hearing Association’s (2007) technical report, with inconsistency as a key feature. Results suggest that continuing education courses are highly influential in the perceived development of expertise and perspectives regarding CAS. Respondents expressed uncertainty about comorbidity of CAS with other communication disorders. Overall, beliefs and practices are relatively uniform across levels of clinical experience.Conclusions: Practices and perspectives of clinicians who self-identify as having expertise with CAS are influenced by factors noted in previous literature. Results of this survey highlight the need for research on the development of expertise in the clinical management of CAS, updated consensus statements that reflect advances in current research, clarification regarding comorbidity of CAS with other communication disorders, and evaluation of continuing education opportunities.Supplemental Material S1. Cross-tabulation of all responses by years of experience to Item 13: Check how frequently you have used the following approaches to treat CAS. Supplemental Material S2. Cross-tabulation of responses by years of experience for Item 16: How indicative are these characteristics and considerations CAS over other pediatric speech sound disorders? Supplemental Material S3. Cross-tabulation of responses by years of experience to Item 17: Please rate the degree to which the following influence your perspective on pediatric speech sound disorders. Supplemental Material S4. Cross-tabulation of responses by years of experience to Item 18: For the following statements please rate your level of agreement. Randazzo, M. (2019). A survey of clinicians with specialization in childhood apraxia of speech. American Journal of Speech-Language Pathology, 28(4), 1659–1672. https://doi.org/10.1044/2019_AJSLP-19-0034</div
Bioenergy an food security in developing countries perspectives
No full textHaving emerged for the first time during the energy crisis of the ’70s, the interest towards bioenergy and renewable energy sources in general has been recently increased by the
global concern on climate change. Beside its contribution to the
reduction of polluting emissions, the promotion of bioenergy
can play an important role in the way to the achievement of
energy security and also as an instrument of agricultural policy,
due to its tight linkages with the rural sector. This last aspect becomes particularly relevant in developing countries, where the
majority of the population (especially the poorest and the most
food insecure) lives in rural areas. Given this framework, biomass
production for energy purposes (in particular, energy crops
cultivation to produce biofuels) can have different impacts on
food security in developing countries, since it can affect in different ways all the determinants of food security. A comprehensive assessment of this phenomenon is thus required
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