Hot carrier and hot phonon coupling during ultrafast relaxation of photoexcited electrons in graphene

We study, by means of a Monte Carlo simulator, the hot phonon effect on the relaxation dynamics in photoexcited graphene and its quantitative impact as compared to considering an equilibrium phonon distribution. Our multi-particle approach indicates that neglecting the hot phonon effect significantly underestimates the relaxation times in photoexcited graphene. The hot phonon effect is more important for a higher energy of the excitation pulse and photocarrier densities between $1$ and $3\times 10^{12} \mathrm{~cm}^{-2}$. Acoustic intervalley phonons play a non-negligible role, and emitted phonons with wavelengths limited up by a maximum (determined by the carrier concentration) induce a slower carrier cooling rate. Intrinsic phonon heating is damped in graphene on a substrate due to additional cooling pathways, with the hot phonon effect showing a strong inverse dependence with the carrier density.Comment: 12 pages, 5 figure

A Speech Recognizer based on Multiclass SVMs with HMM-Guided Segmentation

Automatic Speech Recognition (ASR) is essentially a problem of pattern classification, however, the time dimension of the speech signal has prevented to pose ASR as a simple static classification problem. Support Vector Machine (SVM) classifiers could provide an appropriate solution, since they are very well adapted to high-dimensional classification problems. Nevertheless, the use of SVMs for ASR is by no means straightforward, mainly because SVM classifiers require an input of fixed-dimension. In this paper we study the use of a HMM-based segmentation as a mean to get the fixed-dimension input vectors required by SVMs, in a problem of isolated-digit recognition. Different configurations for all the parameters involved have been tested. Also, we deal with the problem of multi-class classification (as SVMs are initially binary classifers), studying two of the most popular approaches: 1-vs-all and 1-vs-1

Evolución del contenido de macro conidios de Fusarium en el aire de la ciudad de Ourense (NW España).

MÉNDEZ, J., SEIJO, M. C. & IGLESIAS, I. 2001. Evolución del contenido de macroconidios de Fusarium en el aire de la ciudad de Ourense (NW España). Bot. Complutensis 25: 73-82. En este trabajo se presentan los resultados obtenidos para el tipo conidial Fusarium, en la atmósfera de la ciudad de Ourense tras el muestreo aerobiológico realizado durante los años 1993-1996 utilizando para ello un captador volumétrico tipo Hirst, modelo Lanzoni VPPS 2000. Se analiza tanto el comportamiento estacional como intradiario así como su relación con los diferentes parámetros meteorológicos. Las mayores concentraciones se han registrado durante los meses de mayo y junio, exceptuando el año 1996 que tienen lugar en el mes de septiembre y entre la 01:00 y las 07:00 de la mañana, habiéndose observado diferencias cuantitativas importantes entre el año 1993 y el resto de los años de estudio. Las correlaciones obtenidas entre las concentraciones medias diarias y los diferentes parámetros meteorológicos demuestran que, para este tipo conidial tanto la precipitación como la humedad relativa, resultan siempre significativa y positivamente correlacionadas mientras que la temperatura máxima, media, mínima y las horas de sol varían según los años tanto en el signo como en el grado de significación de las correlaciones obtenidas.MÉNDEZ, J., SEIJO, M. C. & IGLESIAS, I. 2001. Evolution of the content of macroconidia of Fusarium in the air of Ourense (NW Spain) Bot. Complutensis 25: 73-82. In this work, we present the results obtained for the spore-type Fusarium in the atmosphere of the city Ourense during 199-1996, period in which a volumetric spore-trap VPPS 2000 was used. Beside seasonal and intradiurnal variations, the relationships between meteorological parameters and spore concentrations have been also analysed. The maximun values for airborne spores were always registered during May and June only in the year 1996 the maximum values are registered during September, especially between 01:00 and 07:00 (Spanish official time). On spite of the fact that important quantitative differences were observed between 1993 and the rest of the years, the correlations obtained between 73 José Méndez et al. Evolución del contenido de macroconidios de Fusarium... daily mean spore concentrations and the different meteorological parameters showed that rainfall and relative humidity were always positively correlated, whereas the correlations with maximun, minimum and mean temperature and sunshine hours were variable during the different years in sing and signification level

Clupiter: a Raspberry Pi mini-supercomputer for educational purposes

© 2024 IEEE. This version of the paper has been accepted for publication. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.[Abstract]: The main objective of this work is to bring supercomputing and parallel processing closer to non-specialized audiences by building a Raspberry Pi cluster, called Clupiter, which emulates the operation of a supercomputer. It consists of eight Raspberry Pi devices interconnected to each other so that they can run jobs in parallel. To make it easier to show how it works, a web application has been developed. It allows launching parallel applications and accessing a monitoring system to see the resource usage when these applications are running. The NAS Parallel Benchmarks (NPB) are used as demonstration applications. From this web application a couple of educational videos can also be accessed. They deal, in a very informative way, with the concepts of supercomputing and parallel programming.Clupiter has been supported by grants EDC431C 2021/30 (Xunta de Galicia, Consolidation Program of Competitive Reference Groups) and PID2022-136435NB-I00, funded by MCIN/AEI/ 1 0.13039/501100011033 and by “ERDF A wayof making Europe”, EU.Xunta de Galicia; EDC431C 2021/3

SVMs for Automatic Speech Recognition: a Survey

Hidden Markov Models (HMMs) are, undoubtedly, the most employed core technique for Automatic Speech Recognition (ASR). Nevertheless, we are still far from achieving high-performance ASR systems. Some alternative approaches, most of them based on Artificial Neural Networks (ANNs), were proposed during the late eighties and early nineties. Some of them tackled the ASR problem using predictive ANNs, while others proposed hybrid HMM/ANN systems. However, despite some achievements, nowadays, the preponderance of Markov Models is a fact. During the last decade, however, a new tool appeared in the field of machine learning that has proved to be able to cope with hard classification problems in several fields of application: the Support Vector Machines (SVMs). The SVMs are effective discriminative classifiers with several outstanding characteristics, namely: their solution is that with maximum margin; they are capable to deal with samples of a very higher dimensionality; and their convergence to the minimum of the associated cost function is guaranteed. These characteristics have made SVMs very popular and successful. In this chapter we discuss their strengths and weakness in the ASR context and make a review of the current state-of-the-art techniques. We organize the contributions in two parts: isolated-word recognition and continuous speech recognition. Within the first part we review several techniques to produce the fixed-dimension vectors needed for original SVMs. Afterwards we explore more sophisticated techniques based on the use of kernels capable to deal with sequences of different length. Among them is the DTAK kernel, simple and effective, which rescues an old technique of speech recognition: Dynamic Time Warping (DTW). Within the second part, we describe some recent approaches to tackle more complex tasks like connected digit recognition or continuous speech recognition using SVMs. Finally we draw some conclusions and outline several ongoing lines of research

How Is Functional Food Advertising Understood? An Approximation in University Students

In functional food advertising, messages are not always easily understandable for the target audience. Current European legislation, enforced through Regulation 1924/2006, specifies that such messages should be clear and precise so as not to mislead the consumer. The objective of this study was to observe consumers’ understanding of messages in functional food advertisements. The methodology used was a self-administered survey filled out by 191 students enrolled in a Degree in Advertising and Public Relations at the University of Alicante (Spain). The results suggest that a large number of students do not know what functional food is and obtain information about these products mainly from labelling/packaging. The major means of communication through which they learn about health benefits via advertising is the internet, followed by television. Most respondents indicated that they understood related advertisements and found it helpful to be given additional information on health benefits. Worthy of note, the greater their level of understanding of the messages, the higher their level of distrust of advertising messages, which they considered to be deceptive or misleading.This research was conducted under the R&D&i project “Reclamos de salud en la publicidad de alimentos y comprensión del consumidor” (“Health claims in food advertising and consumer understanding”-GV/2016/088), funded by the Generalitat Valenciana, Spain and directed by Cristina González Díaz

Preliminary results of a Exploratory Fishing targeting deep-water species off Uruguay

A Pilot Action of Exploratory Fishing was carried out in the second half of 2001 by two Spanish bottom-longline commercial fishing vessels within the Uruguayan Economic Exclusive Zone (EEZ) targeting deep-water species. Trap fishing gears were also utilised as another alternative fishing gears.The main objective of the exploratory survey was to improve the knowledge of the distribution and the population structure of the species target of the survey: Groupers (Epinephelus spp.), Kingclip (Genypterus blacodes), Brazilian sandperch (Pinguipes spp.) and other accompanying species. Some preliminary results of this exploratory survey are shown in this current work. Fishery and biological data were collected by scientific observers on board of the two vessels which took part in the exploratory fishing. The collected data were date, time, position, depth, SST, SBT, weather condition, catches, discards, length distributions, sex, maturity, stomach fullness… among others. Length distributions, sex ratio and maturity stage of the most abundant species in the catch are also shown. Catch, effort and CPUE by area, gear and depth strata were analysed. Regarding bottom longline gear, the most abundant species were Dogfish shark (Squalus sp), Wreckfish (Polyprion americanus), Tope shark (Galeorhinus galeus) and Argentine hake (Merluccius hubbsi) in waters shallower than 200 m depth. Regarding Traps fishing gears, the most abundant species were crabs (Family Geryonidae) and Argentine conger (Conger orbignyanus)

A Novel Strategy for Improving the Quality of Embedded Zerotree Wavelet Images Transmitted over Alamouti Coding Systems

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-21501-8[Abstract] This work deals with the transmission of images, previously coded using the Embedded Zerotree Wavelet (EZW) transform, over wireless systems in which Space-Time Coding (STC) is used. It is shown how the system performance, measured in terms of Peak Signal to Noise Ratio (PSNR), can be improved using bit allocation strategies that take into account the special structure of the EZW bitstream, where the bits firstly allocated are associated to the lowest frequency subbands, and therefore, an error–free transmission of such bits will be crucial to appropriately recover the transmitted image.Galicia. Consellería de Economía e Industria; 10TIC105003PRGalicia. Consellería de Economía e Industria; 09TIC008105PRMinisterio de Ciencia e Innovación; TEC2010-19545-C04-01Ministerio de Ciencia e Innovación; CSD2008-0001

Behavioral valuation of welfare in the milking parlor for dairy cows

Oral session 2[EN] Milking cows is one of the most important tasks on dairy farms. Poorly performed milking can lead to animal welfare problems manifested by increased aversive behaviour. Kicking is defined as the cow's behaviour as she shifts her weight from one leg to the other (Rousing et al., 2006). Several factors are associated with stepping behaviour during milking, such as the quality of the human-animal relationship, lameness, teat injuries, milk production, and number of parturitions, among others

Topic tacrolimus, alternative treatment for oral erosive lichen planus resistant to steroids : a case report

The lichen planus is a mucocutaneous disease with unknown etiology and auto-immune pathogenia. There have been three variants of lichen planus: the reticular, the plaque-like and the atrophic-erosive lesions. It?s a chronic disease with acute relapses that generally affects more frecuently to women from the fourties. The diagnostic is based on the clinic identification of the lesions joined with the histopathologic study (basal cells hidropic degeneration, linfoplasmocitic infiltration and absence of displasy signs). The great number of therapeutic options are explained for its high prevalency (0.5-2%), its recurrence and its risk for malignant transformation. We present a case of oral erosive lichen planus, refractory to numerous treatments, mainly corticosteroids. During 15 days the lesion responded to the administration of a 0.1% tacrolimus in topic application. This article tries to show the new indication of tacrolimus, a calcineurin inhibitor immunosuppressor, that it is effective in the erosive lesions treatment