A Robust Real-Time Automatic License Plate Recognition Based on the YOLO Detector

Automatic License Plate Recognition (ALPR) has been a frequent topic of research due to many practical applications. However, many of the current solutions are still not robust in real-world situations, commonly depending on many constraints. This paper presents a robust and efficient ALPR system based on the state-of-the-art YOLO object detector. The Convolutional Neural Networks (CNNs) are trained and fine-tuned for each ALPR stage so that they are robust under different conditions (e.g., variations in camera, lighting, and background). Specially for character segmentation and recognition, we design a two-stage approach employing simple data augmentation tricks such as inverted License Plates (LPs) and flipped characters. The resulting ALPR approach achieved impressive results in two datasets. First, in the SSIG dataset, composed of 2,000 frames from 101 vehicle videos, our system achieved a recognition rate of 93.53% and 47 Frames Per Second (FPS), performing better than both Sighthound and OpenALPR commercial systems (89.80% and 93.03%, respectively) and considerably outperforming previous results (81.80%). Second, targeting a more realistic scenario, we introduce a larger public dataset, called UFPR-ALPR dataset, designed to ALPR. This dataset contains 150 videos and 4,500 frames captured when both camera and vehicles are moving and also contains different types of vehicles (cars, motorcycles, buses and trucks). In our proposed dataset, the trial versions of commercial systems achieved recognition rates below 70%. On the other hand, our system performed better, with recognition rate of 78.33% and 35 FPS.Comment: Accepted for presentation at the International Joint Conference on Neural Networks (IJCNN) 201

Magnetic-field effects in defect-controlled ferromagnetic Ga_{1-x}Mn_xAs semiconductors

We have studied the magnetic-field and concentration dependences of the magnetizations of the hole and Mn subsystems in diluted ferromagnetic semiconductor Ga_{1-x}Mn_xAs. A mean-field approximation to the hole-mediated interaction is used, in which the hole concentration p(x) is parametrized in terms of a fitting (of the hole effective mass and hole/local moment coupling) to experimental data on the Tc critical temperature. The dependence of the magnetizations with x, for a given temperature, presents a sharply peaked structure, with maxima increasing with applied magnetic field, which indicates that application to diluted-magnetic-semiconductor devices would require quality-control of the Mn-doping composition. We also compare various experimental data for Tc(x) and p(x) on different Ga_{1-x}Mn_xAs samples and stress the need of further detailed experimental work to assure that the experimental measurements are reproducible.Comment: RevTeX 4, 3 two-column pages, 4 colour figures; to appear in J Appl Phy

Hopf and zip bifurcation in a specific (n+1)-dimensional competitive system

In this work we study the occurrence of Andronov-Hopf and zip bifurcation in a concrete (n + 1)-dimensional predator-prey system modelling the competition among n species of predators for one species of prey. This is a generalization of results by Farkas (1984

STM probing of local oscillations of the Fano-Kondo effect: a Doniach-Sunjic approach for the Kondo peak

The use of the scanning tunneling microscope (STM) for the investigation of Kondo adatoms on normal metallic surfaces reveals a Fano-Kondo behavior of the conductance as a function of the tip bias. In this work, the Doniach-Sunjic expression is used to describe the Kondo peak and we analyze the effect of a complex Fano phase, arising from an external magnetic field, on the conductance pattern. It is demonstrated that such phase generates local oscillations of the Fano-Kondo line shape and can lead to the suppression of anti-resonances.CNPqFAPESPIBEM Brazilian agencie

Nanoarte e a fluidez da temporalidade construída: Durée - 200 Milhões de Anos

Consideramos que houve uma migração das textualidades tradicionais para o ciberespaço, o qual, além de abrigar tais textualidades, produz constantemente, pela sua própria dinâmica, novas arquiteturas textuais em permanente transformação. Em certa medida, as diferentes vertentes das inovações tecnológicas são responsáveis por essas transformações tendo em vista as novas linguagens que lhes deram materialidade. A nanoarte constitui–se em uma vertente recente e, por conta das dificuldades de acesso aos microscópios que produzem o material de base para a construção de signos que servirão ao processo de construção de novas criações, não é, ainda, de fácil acesso aos criadores. Entretanto, encontramos trabalhos em nanoarte disponíveis na Rede que apontam para textualidades criadas a partir de nano-partículas. nosso objetivo nesse estudo se constituirá na análise da obra de Anna Barros 200 Milhões de Anos: Durée nas implicações interdisciplinares que as relações entre Arte, Ciência e Tecnologia produzem.We believe that there was a migration from traditional textualities to cyberspace, which, besides hosting such textualities, constantly produces, by its own dynamics, new textual architectures constantly changing. To some extent, the different slopes of technological innovations are responsible for these changes in view of the new languages , which gave materiality. The nanoarte consists in a recent slope and because of the difficulties of access to microscopes that produce the basic material for the construction of signs that will serve the construction of new creations process is not yet easily accessible to creators. however, there are nanoarte works available in the network pointing to textualities created from nanoparticles. Our goal in this study will consist in analyzing the work of Anna Barros 200 Million Years: Durée in the interdisciplinary implications of the relationship between Art, Science and Technology produce

Distribution of lipid compounds in sediments from Conceição Lagoon, Santa Catarina Island, Brazil

Lipid compounds from five sediment-water interface samples and a sediment core with 75 cm depth were used to assess sources of organic matter in Conceição Lagoon, located on Santa Catarina Island. The results which were based on the molar C:N:P ratios, relative abundance of sterols (dominated by the C27 sterols), n-alkanols (0.2-1.2 µg g-1), n-alkanes (0.4-5.0 µg g-1) and the Carbon Preference Index (CPI), indicated that the organic matter is predominantly of terrestrial origin (C/N > 10 and CPI > 2). Total phosphorus (TP, average 5.20 µmol g-1) and organic carbon (TOC, average 2.90 mmol g-1) contents were well correlated with the silt and clay fractions at all locations. In the sediment core, chronologically dated with the radionuclide 210Pb, the depth interval from 55 to 75 cm was dominated by the sand fraction (> 50%). However, parameters such as TOC, TP and n-alkane contents increased considerably at this depth suggesting a change in organic matter input sources

Polymer Nanocomposites for Hydrogen Storage

Hydrogen is considered to be a clean, economical and safe renewable energy source that would be ideal to replace fossil fuels, because it is light, highly abundant and its oxidation product (water) is environmentally benign. However, hydrogen is easy to burn (the chemical energy per mass of hydrogen is at least three times larger than that of other chemical fuels), which has the risk of fire and explosion. The problems of transportation and storage restrict the application of hydrogen energy, which has become a key factor in the development and utilization of hydrogen energy. This gas adsorbs at solid surfaces depending on the applied pressure and temperature. For storage purposes in mobile applications, the adsorption of hydrogen has been studied mainly on carbon species, but light and reasonably cheap materials of high surface area should prove to be attractive as well. Porous material is a very promising hydrogen storage material, which stores the gas in the form of molecules at low temperatures and compresses hydrogen into the holes effectively. The purpose of this work was to develop a hybrid porous materials consisting of sulfonated polyetherimide matrix with aluminum nanoparticles and faujasite type zeolite. Dilute solutions were first prepared under stirring at room temperature and the solutions were dried under vacuum. The hybrids were analyzed by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), transmission electron microscopy (TEM) and hydrogen sorption measurements. The addition of aluminum decreased the glass transition temperature of the hybrids when compared to the sulfonated polymer and the TEM images showed that simply physically mixture occurred between polymer and metallic nanoparticles. Hydrogen sorption tests showed an increase in the amount of hydrogen in the presence of zeolite.CNPq (Brazilian Counsel of Technological and Scientific Development)FAPESP (Sao Paulo Research Foundation)Univ Fed Sao Carlos, Dept Mat Engn, Sao Carlos, SP, BrazilUniv Fed Pelotas, Ctr Technol Dev, Pelotas, RS, BrazilUniv Fed Sao Paulo, Inst Sci & Technol, Sao Jose Dos Campos, SP, BrazilUniv Fed Sao Paulo, Inst Sci & Technol, Sao Jose Dos Campos, SP, BrazilCNPq: 159187/2014-1FAPESP: 2013/23586-0Web of Scienc