1. Analysis and Optimization of Ultra-Low-Power Rectifier with High Efficiency for Applications in Wireless Power Transmission and Energy Harvesting

Abstract The system capable of harvesting RF energy from the environment through an antenna and converting it into direct current energy to deliver to a load is known as rectenna. The rectifier circuit is an important part of the rectenna and its modeling is arduous since it employs a non-linear device working at extremely low power levels. In addition, ther

J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-03

2. A DISCRETE DYNAMICAL SYSTEM AND ITS APPLICATIONS

ABSTRACT The main goal of this manuscript is to introduce a discrete dynamical system defined by symmetric matrices and a real parameter. By construction, we rediscovery the Power Iteration Method from the Projected Gradient Method. Convergence of the discrete dynamical system solution is established. Finally, we consider two applications, the first one cons

Pesqui. Oper.. Publicado em: 02/12/2019

3. Optimization in timetabling in schools using a mathematical model, local search and Iterated Local Search procedures

Resumo Este artigo aborda o problema de otimização na geração da grade horária escolar. Tal problema consiste em definir os dias e horários das disciplinas a serem ministradas por cada um dos professores de instituições de ensino. Para isto foi desenvolvida uma ferramenta que faz uso de técnicas de Pesquisa Operacional (PO), com foco na geração e

Gest. Prod.. Publicado em: 07/10/2019

4. Preliminary investigation of Terahertz spectroscopy to predict pork freshness non-destructively

Abstract Freshness, a very important criterion for pork quality control, is normally assessed by the index of K value. In this paper, Terahertz (THz) spectroscopy was employed to predict K value of pork nondestructively. The THz spectra (0.2~2.0THz) of 80 pork samples with different freshness in the attenuated total reflectance (ATR) mode were acquired. Simu

Food Sci. Technol. Publicado em: 22/07/2019

5. Optimization of Planar Antenna Arrays Using the Firefly Algorithm

Abstract This paper describes the application of the Firefly Algorithm for the optimization of linear and planar antenna arrays. In order to demonstrate the potential of this technique, three applications are reported. The first one is the synthesis of a radiation pattern with isoflux distribution with a non-uniformly spaced linear array composed of isotropi

J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2019-03

6. Strut-and-tie models for linear and nonlinear behavior of concrete based on topological evolutionary structure optimization (ESO)

Resumo A busca por sistemas resistentes representativos para estrutura de concreto requer profundo conhecimento sobre seu comportamento mecânico. Os modelos de bielas e tirantes são procedimentos clássicos utilizados no dimensionamento do concreto armado onde existem concentrações de tensão, as chamadas regiões descontínuas da estrutura. No entanto,

Rev. IBRACON Estrut. Mater.. Publicado em: 2019-02

7. Equine fecal inoculum optimization in in vitro fermentation assays of dehydrated roughage

ABSTRACT This study evaluated the influence of coastcross hay substrate hydration and equine fecal inoculum dilution on the parameters of fermentation and microbiology in in vitro essays. A 2 × 2 factorial block design was used. The first factor was hydration of the coastcross hay substrate 12 h before incubation or at the time of incubation, and the second

R. Bras. Zootec.. Publicado em: 22/10/2018

8. Optimization of reinforced concrete polygonal sections under biaxial bending with axial force

Abstract Concrete is the world’s most utilized material for production of the structural elements employed in civil construction. Due to its low tensile strength and brittle nature it is reinforced with steel bars forming the reinforced concrete (RC structure). Linear elements of reinforced concrete are commonly employed in multi-story buildings, bridges,

Lat. Am. j. solids struct.. Publicado em: 04/10/2018

9. Analysis of a tuned liquid column damper in non-linear structures subjected to seismic excitations

Abstract The behavior of the tuned liquid column damper (TLCD) is analyzed in the control of non-linear structures subjected to random seismic excitations. The structure is modeled as a system of one degree of freedom with incursion in the non-linear range. The Bouc-Wen hysteretic model is used to model the non-linear behavior of the structure. A stationary

Lat. Am. j. solids struct.. Publicado em: 19/07/2018

10. Automatic Identification of Cigarette Brand Using Near-Infrared Spectroscopy and Sparse Representation Classification Algorithm

A cigarette brand automatic classification method using near-infrared (NIR) spectroscopy and sparse representation classification (SRC) algorithm is put forward by the paper. Comparing with the traditional methods, it is more robust to redundancy because it uses non-negative least squares (NNLS) sparse coding instead of principal component analysis (PCA) for

J. Braz. Chem. Soc.. Publicado em: 2018-07

11. Quantum Particle Swarm Optimization for Synthesis of Non-uniformly Spaced Linear Arrays with Broadband Frequency Invariant Pattern

Abstract This paper describes a method using Quantum Particle Swarm Optimization to obtain a broadband frequency invariant pattern for synthesis of nonuniformly spaced linear array of isotropic antennas. Two cases related to this work using QPSO have been studied, namely, in the first case, the generated frequency invariant far-field pattern is broadside in

J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-09

12. Modelling and Optimization for Heat Treatment of Al-Si-Mg Alloy Prepared by Indirect Squeeze Casting Based on Response Surface Methodology

The purpose of the present study is to model and analyze heat treatment process of Al-Si-Mg alloy prepared by indirect squeeze casting. The combined effects of whole heat treatment process, including solution treatment temperature, solution treatment time, ageing temperature and ageing time, on Vickers hardness, were investigated. The non-linear mathematical

Mat. Res.. Publicado em: 20/07/2017