Verificaciónn de firma y gráficos manuscritos: Características discriminantes y nuevos escenarios de aplicación biométrica

Tesis doctoral inédita leída en la Escuela Politécnica Superior, Departamento de Tecnología Electrónica y de las Comunicaciones. Fecha de lectura: Febrero 2015The proliferation of handheld devices such as smartphones and tablets brings a new scenario for biometric authentication, and in particular to automatic signature verification. Research on signature verification has been traditionally carried out using signatures acquired on digitizing tablets or Tablet-PCs. This PhD Thesis addresses the problem of user authentication on handled devices using handwritten signatures and graphical passwords based on free-form doodles, as well as the effects of biometric aging on signatures. The Thesis pretends to analyze: (i) which are the effects of mobile conditions on signature and doodle verification, (ii) which are the most distinctive features in mobile conditions, extracted from the pen or fingertip trajectory, (iii) how do different similarity computation (i.e. matching) algorithms behave with signatures and graphical passwords captured on mobile conditions, and (iv) what is the impact of aging on signature features and verification performance. Two novel datasets have been presented in this Thesis. A database containing free-form graphical passwords drawn with the fingertip on a smartphone is described. It is the first publicly available graphical password database to the extent of our knowledge. A dataset containing signatures from users captured over a period 15 months is also presented, aimed towards the study of biometric aging. State-of-the-art local and global matching algorithms are used, namely Hidden Markov Models, Gaussian Mixture Models, Dynamic Time Warping and distance-based classifiers. A large proportion of features presented in the research literature is considered in this Thesis. The experimental contribution of this Thesis is divided in three main topics: signature verification on handheld devices, the effects of aging on signature verification, and free-form graphical password-based authentication. First, regarding signature verification in mobile conditions, we use a database captured both on a handheld device and digitizing tablet in an office-like scenario. We analyze the discriminative power of both global and local features using discriminant analysis and feature selection techniques. The effects of the lack of pen-up trajectories on handheld devices (when the stylus tip is not in contact with the screen) are also studied. We then analyze the effects of biometric aging on the signature trait. Using three different matching algorithms, Hidden Markov Models (HMM), Dynamic Time Warping (DTW), and distance-based classifiers, the impact in verification performance is studied. We also study the effects of aging on individual users and individual signature features. Template update techniques are analyzed as a way of mitigating the negative impact of aging. Regarding graphical passwords, the DooDB graphical password database is first presented. A statistical analysis is performed comparing the database samples (free-form doodles and simplified signatures) with handwritten signatures. The sample variability (inter-user, intra-user and inter-session) is also analyzed, as well as the learning curve for each kind of trait. Benchmark results are also reported using state of the art classifiers. Graphical password verification is afterwards studied using features and matching algorithms from the signature verification state of the art. Feature selection is also performed and the resulting feature sets are analyzed. The main contributions of this work can be summarized as follows. A thorough analysis of individual feature performance has been carried out, both for global and local features and on signatures acquired using pen tablets and handheld devices. We have found which individual features are the most robust and which have very low discriminative potential (pen inclination and pressure among others). It has been found that feature selection increases verification performance dramatically, from example from ERRs (Equal Error Rates) over 30% using all available local features, in the case of handheld devices and skilled forgeries, to rates below 20% after feature selection. We study the impact of the lack of trajectory information when the pen tip is not in contact with the acquisition device surface (which happens when touchscreens are used for signature acquisitions), and we have found that the lack of pen-up trajectories negatively affects verification performance. As an example, the EER for the local system increases from 9.3% to 12.1% against skilled forgeries when pen-up trajectories are not available. We study the effects of biometric aging on signature verification and study a number of ways to compensate the observed performance degradation. It is found that aging does not affect equally all the users in the database and that features related to signature dynamics are more degraded than static features. Comparing the performance using test signatures from the first months with the last months, a variable effect of aging on the EER against random forgeries is observed in the three systems that are evaluated, from 0.0% to 0.5% in the DTW system, from 1.0% to 5.0% in the distance-based system using global features, and from 3.2% to 27.8% in the HMM system. A new graphical password database has been acquired and made publicly available. Verification algorithms for finger-drawn graphical passwords and simplified signatures are compared and feature analysis is performed. We have found that inter-session variability has a highly negative impact on verification performance, but this can be mitigated performing feature selection and applying fusion of different matchers. It has also been found that some feature types are prevalent in the optimal feature vectors and that classifiers have a very different behavior against skilled and random forgeries. An EER of 3.4% and 22.1% against random and skilled forgeries is obtained for free-form doodles, which is a promising performance

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

Graphical Password-Based User Authentication with Free-Form Doodles

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. M. Martinez-Diaz, J. Fierrez and J. Galbally, "Graphical Password-Based User Authentication With Free-Form Doodles," in IEEE Transactions on Human-Machine Systems, vol. 46, no. 4, pp. 607-614, Aug. 2016. doi: 10.1109/THMS.2015.2504101User authentication using simple gestures is now common in portable devices. In this work, authentication with free-form sketches is studied. Verification systems using dynamic time warping and Gaussian mixture models are proposed, based on dynamic signature verification approaches. The most discriminant features are studied using the sequential forward floating selection algorithm. The effects of the time lapse between capture sessions and the impact of the training set size are also studied. Development and validation experiments are performed using the DooDB database, which contains passwords from 100 users captured on a smartphone touchscreen. Equal error rates between 3% and 8% are obtained against random forgeries and between 21% and 22% against skilled forgeries. High variability between capture sessions increases the error rates.This work was supported by projects Contexts (S2009/TIC-1485) from CAM, Bio-Shield (TEC2012-34881) from Spanish MINECO, and BEAT (FP7-SEC-284989) from EU

Teaching in service systems: new challenges through Services Science Management and Engineering

Objeto: Los servicios dominan las sociedades desarrolladas. Al despliegue de los mismos han contribuido los procesos de servitización, que supone añadir servicios a los productos que tradicionalmente ofrece la empresa. Así, el objetivo del presente trabajo es vincular el desarrollo de los servicios y la servitización con las necesidades formativas en este ámbito, y analizar las experiencias formativas en Ciencia, Gestión e Ingeniería de los servicios a nivel internacional, ofreciendo un análisis del interés académico y profesional de esta nueva disciplina. Diseño/metodología: Se presenta una revisión de la oferta formativa a nivel internacional en la disciplina Ciencia, Gestión e Ingeniería de Servicios, cuyo objeto de estudio es el Servicio, entendido como el proceso interactivo de creación de valor entre el proveedor y el usuario. Aportaciones y resultados: Se pone de manifiesto la omnipresencia de los sistemas de servicios y el proceso de servitización en las economías desarrolladas. Se detecta la necesidad de una formación específica en el ámbito de los servicios. Se identifica la oferta formativa disponible en forma de títulos de Grado y Máster en distintos países. Se relaciona el desarrollo de titulaciones en estos países con el grado de desarrollo del sector servicios, en cuanto a su contribución al PIB. Implicaciones prácticas: Este trabajo ofrece evidencia práctica sobre la forma en la que se puede encontrar el proceso de servitización dentro de la esfera educativa, al presentar una nueva disciplina denominada Ciencia, Gestión e Ingeniería de Servicios. Diferentes actores sociales están profundamente interesados en su desarrollo (academia, empresas, administraciones). Valor añadido: La formación en la disciplina Ciencia, Gestión e Ingeniería de Servicios tiene notable interés académico y profesional. Se detecta que la formación específica en Ciencia de servicios es un tema a abordar a la hora de entender y promover el proceso de servitización.Purpose: Services dominate developed societies. The deployment of these processes has contributed servitization, adding services to products traditionally offered by the company. Thus, the aim of this paper is to link the services development and servitization with instruction needs in this area and to analyze the educational experiences in Science, Management and Engineering Services internationally, offering an analysis of academic and professional interest. Design/methodology/approach: An international review of Science, Management and Engineering Services discipline is established. The object of study of this discipline is the service, understood as the interactive process of value creation between the supplier and the user Findings and Originality/value: The work shows services and servitization omnipresence in developed economies. It detects the need for specific teaching in the services field. It identifies the educational offer in form of Degree and Master in different countries. It relates the development of Service Science, Management and Engineering courses in these countries with the development degree of the services sector in terms of contribution to GDP. Practical implications: This work provides practical evidence about the way in which servitization process is into academia, introducing a new discipline named Science, Management and Engineering Services. Different stakeholders are deeply interested in its development (academia, business, and governments). Originality/value: The course in the Science, Management and Engineering Services has outstanding academic and professional interest. It detects that specific courses in Service Science is an issue to be tackled in order to understand and promote servitization process.Peer Reviewe

Synthetic generation of handwritten signatures based on spectral analysis

Javier Galbally ; Julian Fierrez ; Marcos Martinez-Diaz ; Javier Ortega-Garcia; "Synthetic generation of handwritten signatures based on spectral analysis", Optics and Photonics in Global Homeland Security V and Biometric Technology for Human Identification VI, Proc. SPIE 7306 (May 05, 2009); doi:10.1117/12.817928. Copyright 2009 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 V Optics and Photonics in Global Homeland Security; and VI Biometric Technology for Human Identification (Orlando, Florida, United States)A new method to generate synthetic online signatures is presented. The algorithm uses a parametrical model to generate the synthetic Discrete Fourier Transform (DFT) of the trajectory signals, which are then refined in the time domain and completed with a synthetic pressure function. Multiple samples of each signature are created so that synthetic databases may be produced. Quantitative and qualitative results are reported, showing that, in addition to presenting a very realistic appearance, the synthetically generated signatures have very similar characteristics to those that enable the recognition of real signatures.This work was supported by Spanish MEC under project TEC2006-13141-C03-03

Alt-Right: Origen y proyección comunicativa. Nacimiento, expansión e influencia en España de la derecha alternativa estadounidense.

El presente trabajo aborda el origen de la Alt-Right o derecha alternativa estadounidense. El movimiento cuenta con la particularidad de desarrollarse, casi en su totalidad, a través de las redes sociales. Primero, en portales más marginales, que actuaban a modo de cámaras de eco y después migrando hacia otras plataformas convencionales, caso de Twitter o Facebook. Partiendo de aquí, la investigación trata también las diferentes ramificaciones ideológicas de la derecha alternativa, su evolución, periodo de auge de la mano de Donald Trump y llegada a Europa gracias a Steve Bannon. España, en el contexto de las elecciones madrileñas del 4 de mayo, es el objeto concreto de estudio para determinar, de forma cualitativa y cuantitativa, la influencia de la Alt-Right en las comunidades formadas en redes sociales. Sobre todo, entre los seguidores de Vox.<br /

Template protection for HMM-based on-line signature authentication

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. E. Maiorana, P. Campisi, M. Martínez-Díaz, J. Ortega-García, A. Neri, "Template protection for HMM-based on-line signature authentication" in IEEE Computer Society Conference on Computer Vision and Pattern Recognition Workshops CVPRW, Anchorage, AK (USA), 2008, pp. 1-6.The security of biometric data is a very important issue in the deployment of biometric-based recognition systems. In this paper, we propose a signature-based biometric authentication system, where signal processing techniques are applied to the acquired on-line signature in order to generate protected templates, from which retrieving the original data is computationally as hard as randomly guessing them. A hidden Markov model (HMM)-based matching strategy is employed to compare the transformed signatures. The proposed protected authentication system generates a score as the result of the matching process, thus allowing to implement protected multibiometric recognition systems, through the application of score-fusion techniques. The experimental results show that, at the cost of only a slight performance reduction, the desired protection for the employed biometric templates can be properly achieved

Inmunonutrición: una potente herramienta para evaluar situaciones nutricionales y beneficios de nutrientes, compuestos bioactivos y alimentos

© 2012 Kellogg Company.El texto está disponible para cualquiera que se registre previamente en http://www.katedrakelloggs.com .- 8.Inmunonutrición: una potente herramienta para evaluar situaciones nutricionales y beneficios de nutrientes, compuestos bioactivos y alimentos119-130; 12 páginas,3 figuras, 3 tablas--Manual Práctico de Nutrición y Salud Kellogg’s, obra colectiva de visión multidisciplinar que surge a propuesta del colectivo médico ante la necesidad de recibir formación en materia de nutrición. Existen numerosos manuales de nutrición, pero en esta ocasión se ofrece una edición de consulta rápida, fácil acceso y manejo para utilizar durante la atención al paciente. Se trata de una herramienta práctica, dirigida a profesionales de la salud que en su día a día tienen contacto directo con la población, para transmitir una recomendación adaptada a cada individuo, a su edad, sexo, estado fisiológico y a las diferentes situaciones patológicasPeer reviewe

The La Luna/Río Negro(.) Petroleum system at the Urdaneta West Field, lake Maracaibo basin, NW Venezuela: ID basin modelling and secondary oil migration

This paper investigates the timing of hydrocarbon generation in the northern part of the Urdaneta West field in the NW of the Lake Maracaibo Basin, NW Venezuela, based on ID basin modelling at three wells referred to as wells X, Y and Z. Kitchen areas were identified and secondary migration directions were inferred based on analyses of the thermal and burial history of the Upper Cretaceous La Luna Formation source rock and the geochemistry of 20 oil samples from the Río Negro Formation reservoir. Aliphatic hydrocarbons in the oil samples were analysed by gas chromatography - mass spectrometry (GC-MS) while the vanadium- nickel and sulphur contents were determined by energy dispersive X-ray spectrometry and inductively coupled plasma optical emission spectroscopy, respectively. Bulk and molecular characterizations indicated that the oils originated from a marine carbonate source rock containing oil-prone Type II kerogen, consistent with generation by the La Luna Formation. Burial and thermal history modelling in the study area indicated that the La Luna source rock at wells X, Y and Z reached the oil window during the late Eocene, mid-Eocene and early Paleocene respectively. ID model results from the three wells showed that hydrocarbon generation began in the early Eocene. The transformation ratio of the La Luna Formation source rock in the modelled wells reached values of 35%, 98% and 100% by the end of the Eocene. In the Urdaneta West field, two different oil charges appear to have mixed in the Río Negro reservoir. Both oil charges were generated by the La Luna Formation source rock but at different times. A first charge of less mature oil occurred in the middle-late Eocene (Phase 1 generation), and a second, more mature oil charge took place in the Miocene - Quaternary (Phase 2 generation). The kitchen area for the first oil charge is inferred to have been located to the north and NE of Urdaneta West; that for the second oil charge to the south of the field. This migration model is supported by observed variations in the geochemical compositions of the oil samples analysed from different wells in the Urdaneta West field.J.G. Diaz acknowledges the support of the PDVSA Western Exploration Project Management and the University of Zulia. The authors are grateful to Iván Chirino and Patricia Marín for their scientific assistance. We are also grateful to the JPG referees (Karla Quintero-Bonilla, Katya Reategui and anonymous) whose comments helped to improve the original version of this manuscript. Carlos Boente obtained a post-doctoral contract within the program PAIDI 2020 (Ref 707 DOC 01097), co-financed by the Junta de Andalucía (Andalusian Government) and the EU