1,577 research outputs found
La Realidad Aumentada como alternativa a las prácticas de Geología en Educación Primaria
Este trabajo consiste en un análisis sobre la problemática que encontramos en la realización de las prácticas de laboratorio y de campo en el área específica de la enseñanza de la Geología. Esta problemática afecta tanto a alumnos como a docentes. Nuestro objetivo es identificar estas dificultades para, mediante el uso de las nuevas tecnologías, tratar de sugerir posibles soluciones. Para ello proponemos la Realidad Aumentada como herramienta para elaborar nuevos contenidos que mejoren la enseñanza de Geología en el aula. Hemos realizado un búsqueda documental sobre qué se ha realizado en el área de educación utilizando esta tecnología. A partir de los resultado obtenidos, proponemos una serie de ideas factibles de elaborarse en el centro educativo y que tratan de aportar soluciones a dicha problemáticaThis work consists in an analysis about the problems that we find in the realization of laboratory and field practices in the specific area of Geology teaching. This problem affects both students and teachers. Our goal is to identify these difficulties so, through the use of new technologies, try to suggest possible solutions. For this we propose the Augmented Reality as a tool to develop new content that improves the teaching of Geology in the classroom. We have made a documentary search about what has been done in the area of education using this technology. Based on the results obtained, we propose a series of feasible ideas to be developed in the educational center and that try to provide solutions to this problem.Universidad de Sevilla. Grado en Educación Primari
Fusion of facial regions using color information in a forensic scenario
Comunicación presentada en: 18th Iberoamerican Congress on Pattern Recognition, CIARP 2013; Havana; Cuba; 20-23 November 2013The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-41827-3_50This paper reports an analysis of the benefits of using color information on a region-based face recognition system. Three different color spaces are analysed (RGB, YCbCr, lαβ) in a very challenging scenario matching good quality mugshot images against video surveillance images. This scenario is of special interest for forensics, where examiners carry out a comparison of two face images using the global information of the faces, but paying special attention to each individual facial region (eyes, nose, mouth, etc.). This work analyses the discriminative power of 15 facial regions comparing both the grayscale and color information. Results show a significant improvement of performance when fusing several regions of the face compared to just using the whole face image. A further improvement of performance is achieved when color information is consideredThis work has been partially supported by contract with Spanish Guardia Civil and projects BBfor2 (FP7-ITN-238803), bio-Challenge (TEC2009-11186), Bio Shield (TEC2012-34881), Contexts (S2009/TIC-1485), TeraSense (CSD2008-00068) and "Cátedra UAM-Telefónica
Vulnerabilities in biometric systems: Attacks and recent advances in liveness detection
This is an electronic version of the paper presented at the Spanish Workshop on Biometrics 2007, SWB-07 held in Girona (Spain)A review of the state-of-the-art in direct and indirect attacks to fingerprint and iris automatic recognition security systems is presented. A summary of the novel liveness detection methods, which take advantage of different physiological properties to distinguish between real and fake biometric traits, is also reported.This work has been supported by the TIC2006-13141-C03-03 project of the Spanish Ministry of Science and Technology and the BioSecure NoE
Country knowledge and familiarity effects on consumer perceived risk and rejection of foreign-made products
Las preocupaciones de los consumidores por los productos fabricados en el extranjero plantean interrogantes sobre lo que éstos conocen acerca del país de origen y la medida en que ese conocimiento se traduce en su rechazo de los productos extranjeros. El presente estudio examina tres tipos de variables de conocimiento acerca del país de origen que, junto con la experiencia de uso/familiaridad, actúan como antecedentes potenciales del riesgo percibido y, a su vez, de la reticencia de los consumidores españoles a comprar y de la (no) posesión de productos chinos. Los resultados revelan que el conocimiento medioambiental del país genera riesgo de auto-imagen/social, mientras que la experiencia de uso/familiaridad reduce tanto el riesgo de auto-imagen/social como el riesgo de rendimiento. Ambos tipos de riesgo afectan significativamente (positivamente) a la reticencia de los consumidores a comprar y (negativamente) a la posesión de productos extranjeros. Se discuten las implicaciones teóricas.Consumer concerns about foreign-made products raise questions about what consumers know about the COO and the extent to which such knowledge translates into their rejection of foreign products. The present examines three types country knowledge variables, along with familitarity/usage experience, as potential antecedents of perceived risk and, in turn, of Spanish consumers’ reluctance to buy and (non-)ownership of Chinese apparel products. The findings reveal that environmental country knowledge can engender self-image/social risk, whereas familiarity/usage experience reduces both self-image/social and performance risks. As expected, the two distinct risk types considered here significantly contributed to consumers’ reluctance to buy (positively) and product ownership (negatively). Theoretical implications are discussed
Multimodal biometric fusion: A study on vulnerabilities to indirect attacks
The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-41827-3_45Proceedings of 18th Iberoamerican Congress, CIARP 2013, Havana, CubaFusion of several biometric traits has traditionally been regarded as more secure than unimodal recognition systems. However, recent research works have proven that this is not always the case. In the present article we analyse the performance and robustness of several fusion schemes to indirect attacks. Experiments are carried out on a multimodal system based on face and iris, a user-friendly trait combination, over the publicly available multimodal Biosecure DB. The tested system proves to have a high vulnerability to the attack regardless of the fusion rule considered. However, the experiments prove that not necessarily the best fusion rule in terms of performance is the most robust to the type of attack considered.This work has been partially supported by projects Contexts (S2009/TIC-1485) from CAM, Bio-Challenge (TEC2009-11186) and Bio-Shield (TEC2012-34881) from Spanish MINECO, TABULA RASA (FP7-ICT-257289) and BEAT (FP7-SEC-284989) from EU, and Cátedra UAM-Telefónica
Cryptographic key generation using handwritten signature
M. Freire-Santos ; J. Fierrez-Aguilar ; J. Ortega-Garcia; "Cryptographic key generation using handwritten signature", Biometric Technology for Human Identification III, Proc. SPIE 6202 (April 17, 2006); doi:10.1117/12.665875. Copyright 2006 Society of Photo‑Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.Proceedings of the III Biometric Technology for Human Identification (Orlando, Florida, USA)Based on recent works showing the feasibility of key generation using biometrics, we study the application of handwritten signature to cryptography. Our signature-based key generation scheme implements the cryptographic construction named fuzzy vault. The use of distinctive signature features suited for the fuzzy vault is discussed and evaluated. Experimental results are reported, including error rates to unlock the secret data by using both random and skilled forgeries from the MCYT database.This work has been supported by Spanish MCYT TIC2003-08382-C05-01 and by European Commission IST-2002-507634 Biosecure NoE projects
Incorporating signature verification on handheld devices with user-dependent Hidden Markov Models
Proceedings of the International Conference on Frontiers in Hadwriting Recognition (ICFHR 2008)A dynamic signature verification system based on Hidden
Markov Models is presented. For each user model,
the number of states and Gaussian mixtures of the Hidden
Markov Model is automatically set in order to optimize
the verification performance. By introducing this userdependent
structure in the statistical modeling of signatures,
the system error rate is significantly decreased in
the challenging scenario of dynamic signature verification
on handheld devices. Experimental results are given on a
subset of the recently acquired BIOSECURE multimodal
database, using signatures captured with a PDAThis work has been supported by the Spanish Ministry of Education under project TEC2006-13141-C03-03
Feature selection based on genetic algorithms for on-line signature verification
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. J. Galbally, J. Fiérrez, M. R. Freire, J. Ortega-garcía, "Feature Selection Based on Genetic Algorithms for On-Line Signature Verification" in Workshop on Automatic Identification Advanced Technologies, 2007, 198 - 203.Two different genetic algorithm (GA) architectures are applied to a feature selection problem in on-line signature verification. The standard GA with binary coding is first used to find a suboptimal subset of features that minimizes the verification error rate of the system. The curse of dimensionality phenomenon is further investigated using a GA with integer coding. Results are given on the MCYT signature database comprising 330 users (16500 signatures). Signatures are represented by means of a set of 100 features which can be divided into four different groups according to the signature information they contain, namely: i) time, ii) speed and acceleration, iii) direction, and iv) geometry. The GA indicates that features from subsets i and iv are the most discriminative when dealing with random forgeries, while parameters from subsets ii and iv are the most appropriate to maximize the recognition rate with skilled forgeries.This work was supported by Spanish MEC under project TEC2006-13141-C03-03 and the European NoE Biosecure
Sobre cómo varían las firmas manuscritas con el tiempo: una modelización Sigma Lognormal
Comunicación presentada en las Jornadas de Reconocimiento Biométrico de Personas (JRBP 2013)En el presente trabajo se analiza la variación de las firmas
dinámicas con el tiempo usando la Teoría Cinemática, siguiendo un protocolo
general, consistente y completamente reproducible. Los experimentos
se llevan a cabo sobre una nueva base de datos a largo plazo,
capturada, bajo condiciones casi idénticas, en 6 sesiones uniformemente
distribuidas durante un periodo de 15 meses. Las firmas se han representado
con el modelo Sigma Lonormal, el cual tiene en cuenta los efectos
del envejecimiento del cuerpo más relacionados con la escritura, como los
tiempos de respuesta neuromusculares. Tras estudiar la evolución de las
firmas con el tiempo, se ha llevado a cabo un análisis de distintos grupos
de edad basado en los parámetros del modelo.Este trabajo ha sido parcialmente nanciado por los proyectos Contexts (S2009/TIC-1485) de la CAM, Bio-Challenge (TEC2009-11186) y Bio-Shield (TEC2012-34881) del MINECO, Guardia Civil y C atedra UAM-Telef onica
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