Hand Image Segmentation by means of Gaussian Multiscale Aggregation for biometric applications

Applying biometrics to daily scenarios involves demanding requirements in terms of software and hardware. On the contrary, current biometric techniques are also being adapted to present-day devices, like mobile phones, laptops and the like, which are far from meeting the previous stated requirements. In fact, achieving a combination of both necessities is one of the most difficult problems at present in biometrics. Therefore, this paper presents a segmentation algorithm able to provide suitable solutions in terms of precision for hand biometric recognition, considering a wide range of backgrounds like carpets, glass, grass, mud, pavement, plastic, tiles or wood. Results highlight that segmentation accuracy is carried out with high rates of precision (F-measure 88%)), presenting competitive time results when compared to state-of-the-art segmentation algorithms time performance

Asymptotically Toeplitz Hessenberg Operators and the Rieman mapping

In a recent work the authors have established a relation between the limits of the elements of the diagonals of the Hessenberg matrix D associated with a regular measure, whenever those limits exist, and the coe?cients of the Laurent series expansion of the Riemann mapping ?(z) of the support supp(?), when this is a Jordan arc or a connected nite union of Jordan arcs in the complex plane C. We extend here this result using asymptotic Toeplitz operator properties of the Hessenberg matriz.

Gaussian Multiscale Aggregation oriented to Hand Biometric Segmentation in Mobile Devices

New trends in biometrics are oriented to mobile devices in order to increase the overall security in daily actions like bank account access, e-commerce or even document protection within the mobile. However, applying biometrics to mobile devices imply challenging aspects in biometric data acquisition, feature extraction or private data storage. Concretely, this paper attempts to deal with the problem of hand segmentation given a picture of the hand in an unknown background, requiring an accurate result in terms of hand isolation. For the sake of user acceptability, no restrictions are done on background, and therefore, hand images can be taken without any constraint, resulting segmentation in an exigent task. Multiscale aggregation strategies are proposed in order to solve this problem due to their accurate results in unconstrained and complicated scenarios, together with their properties in time performance. This method is evaluated with a public synthetic database with 480000 images considering different backgrounds and illumination environments. The results obtained in terms of accuracy and time performance highlight their capability of being a suitable solution for the problem of hand segmentation in contact-less environments, outperforming competitive methods in literature like Lossy Data Compression image segmentation (LDC).

Gaussian Multiscale Aggregation Applied to Segmentation in Hand Biometrics

This paper presents an image segmentation algorithm based on Gaussian multiscale aggregation oriented to hand biometric applications. The method is able to isolate the hand from a wide variety of background textures such as carpets, fabric, glass, grass, soil or stones. The evaluation was carried out by using a publicly available synthetic database with 408,000 hand images in different backgrounds, comparing the performance in terms of accuracy and computational cost to two competitive segmentation methods existing in literature, namely Lossy Data Compression (LDC) and Normalized Cuts (NCuts). The results highlight that the proposed method outperforms current competitive segmentation methods with regard to computational cost, time performance, accuracy and memory usage.

Coronary Artery Tracking in 3D Cardiac CT Images Using Local Morphological Reconstruction Operators

Automatic segmentation and tracking of the coronary artery tree from Cardiac Multislice-CT images is an important goal to improve the diagnosis and treatment of coronary artery disease. This paper presents a semi-automatic algorithm (one input point per vessel) based on morphological grayscale local reconstructions in 3D images devoted to the extraction of the coronary artery tree. The algorithm has been evaluated in the framework of the Coronary Artery Tracking Challenge 2008 [1], obtaining consistent results in overlapping measurements (a mean of 70% of the vessel well tracked). Poor results in accuracy measurements suggest that future work should refine the centerline extraction. The algorithm can be efficiently implemented and its general strategy can be easily extrapolated to a completely automated centerline extraction or to a user interactive vessel extraction

Spatio-temporal filtering with morphological operators for robust cell migration estimation in "in-vivo" images

The understanding of the embryogenesis in living systems requires reliable quantitative analysis of the cell migration throughout all the stages of development. This is a major challenge of the "in-toto" reconstruction based on different modalities of "in-vivo" imaging techniques -spatio-temporal resolution and image artifacts and noise. Several methods for cell tracking are available, but expensive manual interaction -time and human resources- is always required to enforce coherence. Because of this limitation it is necessary to restrict the experiments or assume an uncontrolled error rate. Is it possible to obtain automated reliable measurements of migration? can we provide a seed for biologists to complete cell lineages efficiently? We propose a filtering technique that considers trajectories as spatio-temporal connected structures that prunes out those that might introduce noise and false positives by using multi-dimensional morphological operators.

Aircraft flight trajectory deviation in the standard instrument departures. Operators penalties.

In the recent years many problems are emerging due to the aircraft noise on the airport surrounding areas. The solution to this problem is not easy considering that the neighbourhood asks for the reduction of the number of aircraft operations and the airlines ask for a growing demand in the number of operations in the major airports. So the airport and regulatory authorities try to get a solution imposing a fine to the aircraft which its actual trajectory differs from the nominal one more than a lateral deviation. But, which is the value of this deviation?. The current situation is that many operators have to pay a lot of money for exceeding a deviation which has been established without operational criteria. This paper presents the results of a research program which is being carried out by the authors which aims to determine the "delta" deviation to be used for this purpose. In addition it is proposed a customized method per SID and per airport to be used for determining the maximum allowed lateral deviation by which if the aircraft is within it, then none fine will be imposed.

Analysis of the operating efficiency of mobile operators during the 2002 to 2008 period

This article aims to quantify the efficiency of mobile operators in Spain and other European countries such as France and Germany. The period considered is from 2002 to 2008. Linear regression is used to analyze the relationship between growth in revenue and gross operating margin (EBITDA) generated by the relevant operators and the aggregate industry in each country. At the industry level, it is shown that (i) there is a strong correlation between revenue and margin; and (ii) this correlation weakens when competitive intensity grows. At the operator level, those which achieved larger increases in revenues did not sacrifice their margins, but offset the additional investments and costs required to achieve said growth through economies of scale.

Determining the effectiveness of three software evaluation techniques through informal aggregation

An accepted fact in software engineering is that software must undergo verification and validation process during development to ascertain and improve its quality level. But there are too many techniques than a single developer could master, yet, it is impossible to be certain that software is free of defects. So, it is crucial for developers to be able to choose from available evaluation techniques, the one most suitable and likely to yield optimum quality results for different products. Though, some knowledge is available on the strengths and weaknesses of the available software quality assurance techniques but not much is known yet on the relationship between different techniques and contextual behavior of the techniques. Objective: This research investigates the effectiveness of two testing techniques ? equivalence class partitioning and decision coverage and one review technique ? code review by abstraction, in terms of their fault detection capability. This will be used to strengthen the practical knowledge available on these techniques.

How network operators can enhance ambient assisted living applications through next generation networks

Within the technological framework of Information and Communication Technologies (ICT), consumers are currently requesting multimedia services with simplicity of use, reliability, security and service availability through mobile and fixed access. Network operators are proposing the Next Generation Networks (NGN) to address the challenges of providing both services and network convergence. Apart from these considerations, there is a need to provide social and healthcare assistance services in order to support the progressive aging in the elderly population. In order to achieve this objective, the Ambient Assisted Living (AAL) initiative proposes ICT systems and services to promote autonomy and an independent life among the elderly. This paper describes the design and implementation of a group of services, called “service enablers”, which helps AAL applications to be supported in NGN. The presented enablers are identified to support the teleconsulting applications requirements in an NGN environment, involving the implementation of a virtual waiting room, a virtual whiteboard, a multimedia multiconference and a vital-signs monitoring presence status. A use case is defined and implemented to evaluate the developed enablers' performance.

A genetic algorithm for slope stability analyses with concave slip surfaces using custom operators

Heuristic methods are popular tools to find critical slip surfaces in slope stability analyses. A new genetic algorithm (GA) is proposed in this work that has a standard structure but a novel encoding and generation of individuals with custom-designed operators for mutation and crossover that produce kinematically feasible slip surfaces with a high probability. In addition, new indices to assess the efficiency of operators in their search for the minimum factor of safety (FS) are proposed. The proposed GA is applied to traditional benchmark examples from the literature, as well as to a new practical example. Results show that the proposed GA is reliable, flexible and robust: it provides good minimum FS estimates that are not very sensitive to the number of nodes and that are very similar for different replications

Análisis prospectivo del despliegue de redes de comunicaciones móviles LTE en nuevas bandas de frecuencia mediante el desarrollo de modelos tecnoeconómicos

El estándar LTE se ha posicionado como una de las claves para que los operadores de telecomunicación puedan abordar de manera eficiente en costes el crecimiento de la demanda de tráfico móvil que se prevé para los próximos años, al ser una tecnología más escalable en el núcleo de la red y más flexible en la interfaz radio que sus predecesoras. En este sentido, es necesario también que los reguladores garanticen un acceso al espectro radioeléctrico adecuado, equitativo y no discriminatorio, que permita un entorno estable para el despliegue de redes de comunicaciones móviles avanzadas. Además de la flexibilización del marco regulador del espectro radioeléctrico en Europa, que ha permitido el despliegue de nuevas tecnologías en las bandas de frecuencia históricas de GSM, se ha puesto a disposición espectro adicional para sistemas IMT en nuevas bandas de frecuencia, lo que ha planteando a su vez nuevos retos para la tecnología y la regulación. La fragmentación del espectro disponible para comunicaciones móviles ha impulsado el desarrollo de técnicas de agregación de portadoras en las nuevas versiones del estándar LTE, que permiten explotar mejor los recursos radio en su conjunto. No obstante, el espectro inferior a 1 GHz sigue siendo escaso, ya que el tráfico móvil aumenta y la banda de 900 MHz aún se utiliza para servicios GSM, lo que no ha conseguido sino agravar la disputa entre los servicios de radiodifusión terrestre y de comunicaciones móviles por la parte superior de la banda UHF. En concreto, la banda de 700 MHz se perfila como una de las próximas para aumentar el espectro disponible para los servicios en movilidad, si bien su liberación por parte de las actuales redes de Televisión Digital Terrestre presenta no pocas dificultades en los Estados miembros en los que ésta es la principal plataforma audiovisual de acceso gratuito, abriendo un debate sobre el modelo audiovisual a largo plazo en Europa. Por otro lado, las políticas públicas de promoción del acceso a la banda ancha rápida y ultrarrápida de la presente década han establecido objetivos ambiciosos para el año 2020, tanto en el ámbito europeo como en los diferentes Estados miembros. La universalización del acceso a redes de banda ancha de al menos 30 Mbps constituye uno de los principales retos. Las expectativas generadas por la tecnología LTE y la puesta a disposición de nuevas bandas de frecuencia hace posible que los servicios de acceso fijo inalámbrico adquieran especial relevancia ante los objetivos de política pública establecidos que, como ha sido reconocido en diversas ocasiones, no podrán lograrse sino con un compendio de diferente tecnologías. Para esta Tesis Doctoral se han desarrollado una serie modelos tecnoeconómicos con el objetivo de realizar un análisis prospectivo que evalúa tres casos de especial relevancia en el despliegue de redes LTE: en primer lugar, la valoración económica de la banda de 700 MHz; en segundo lugar, la evaluación de modelos de negocio y reducción de costes considerando tecnologías femtocelulares; y finalmente, la viabilidad de las redes LTE de acceso fijo inalámbrico para el cierre de la brecha digital en el acceso a la banda ancha de 30 Mbps. En relación con la aplicación del análisis tecnoeconómico para la valoración del espectro de 700 MHz, los resultados obtenidos ponen de manifiesto dos cuestiones fundamentales. En primer lugar, la necesidad de asignar a los operadores más espectro para satisfacer las previsiones de demanda de tráfico móvil a medio plazo. En segundo, existe una diferencia notable en los costes de despliegue de una red LTE cuando se dispone de espectro en frecuencias inferiores a 1 GHz y cuando no, pero esta diferencia de costes disminuye a medida que se añade nuevo espectro sub-1GHz. De esta manera, la atribución de la banda de 700 MHz a servicios de comunicaciones móviles supone una reducción relevante en los costes de despliegue si el operador no dispone de espectro en la banda de 800 MHz, pero no así si ya dispone de espectro en bandas bajas para el despliegue. En este sentido, puede concluirse que el precio que los operadores estarán dispuestos a pagar por el espectro de la banda de 700 MHz dependerá de si ya tienen disponible espectro en la banda de 800 MHz. Sin embargo, dado que la competencia por ese espectro será menor, los ingresos esperables en las licitaciones de esta nueva banda serán en general menores, a pesar de que para algunos operadores este espectro sería tan valioso como el de 800 MHz. En segundo lugar, en relación con el despliegue de femtoceldas pueden extraerse algunas conclusiones en términos de ahorro de costes de despliegue y también de cara a la viabilidad de los modelos de negocio que posibilitan. El ahorro que supone la introducción de femtoceldas en el despliegue de una red LTE frente al caso de un despliegue exclusivamente macrocelular se ha demostrado que es mayor cuanto menor es el ancho de banda disponible para la red macrocelular. En esta línea, para un operador convergente el despliegue de femtoceldas tiene sentido económico si el ancho de banda disponible es escaso (en torno a 2x10 MHz), que, en el caso de España, puede reflejar el caso de los operadores del segmento fijo que son nuevos entrantes en el móvil. Por otro lado, los modelos de acceso abierto son interesantes para operadores exclusivamente móviles, porque consiguen flexibilizar los costes sustituyendo estaciones base macrocelulares por el despliegue de femtoceldas, pero necesitan desplegarse en zonas con una densidad de población relativamente elevada para que éstas descarguen tráfico de varios usuarios de la red macrocelular simultáneamente. No obstante, las femtoceldas son beneficiosas en todo caso si es el usuario quien asume los costes de la femtocelda y el backhaul, lo que sólo parece probable si se integran en el modelo de negocio de comercialización de nuevos servicios. Por tanto, el despliegue de femtoceldas en buena parte de la casuística estudiada sólo tiene sentido si consiguen aumentar los ingresos por usuario comercializando servicios de valor añadido que necesiten calidad de servicio garantizada y exploten a la vez de esa forma su principal ventaja competitiva respecto a la tecnología WiFi. Finalmente, en relación con el papel de la tecnología LTE para la provisión de servicios de acceso fijo inalámbrico para la banda ancha de 30 Mbps, se ha desarrollado un modelo TD-LTE y mediante la metodología de análisis tecnoeconómico se ha realizado un estudio prospectivo para el caso de España. Los resultados obtenidos preciden una huella de cobertura de FTTH del 74% para 2020, y demuestran que una red TD-LTE en la banda de 3,5 GHz resulta viable para aumentar la cobertura de servicios de 30 Mbps en 14 puntos porcentuales. Junto con la consideración de la cobertura de otras redes, la cobertura de 30 Mbps de acuerdo a la viabilidad de los despliegues alcanzaría el 95% en España en el año 2020. Como resumen, los resultados obtenidos muestran en todos los casos la capacidad de la tecnología LTE para afrontar nuevos desafíos en relación con el aumento del tráfico móvil, especialmente crítico en las zonas más urbanas, y el cierre de la brecha digital en el acceso a la banda ancha rápida en las zonas más rurales. ABSTRACT The LTE standard has been pointed out as one of the keys for telecom operators to address the demand growth in mobile traffic foreseen for the next years in a cost-efficient way, since its core network is more scalable and its radio interface more flexible than those of its predecessor technologies. On the other hand, regulators need to guarantee an adequate, equitable and non-discriminatory access to radio spectrum, which enable a favorable environment for the deployment of advanced mobile communication networks. Despite the reform of the spectrum regulatory framework in Europe, which allowed for the deployment of new technologies in the historic GSM bands, additional spectrum has been allocated to IMT systems in new frequency bands, what in turn has set out new challenges for technology and regulation. The current fragmentation of available spectrum in very different frequency bands has boosted the development of carrier aggregation techniques in most recent releases of the LTE standard, which permit a better exploitation of radio resources as a whole. Nonetheless, spectrum below 1 GHz is still scarce for mobile networks, since mobile traffic increases at a more rapid pace than spectral efficiency and spectrum resources. The 900 MHz frequency band is still being used for GSM services, what has worsen the dispute between mobile communication services and terrestrial broadcasting services for the upper part of the UHF band. Concretely, the 700 MHz frequency band has been pointed out as one of the next bands to be allocated to mobile in order to increase available spectrum. However, its release by current Digital Terrestrial Television networks is challenging in Member States where it constitutes the main free access audiovisual platform, opening up a new debate around the audiovisual model in the long term in Europe. On the other hand, public policies of the present decade to promote fast and ultrafast broadband access has established very ambitious objectives for the year 2020, both at European and national levels. Universalization of 30 Mbps broadband access networks constitutes one of the main challenges. Expectations raised by LTE technology and the allocation of new frequency bands has lead fixed wireless access (FWA) services to acquire special relevance in light of public policy objectives, which will not be met but with a compendium of different technologies, as different involved stakeholders have acknowledged. This PhD Dissertation develops techno-economic models to carry out a prospective analysis for three cases of special relevance in LTE networks’ deployment: the spectrum pricing of the 700 MHz frequency band, an assessment of new business models and cost reduction considering femtocell technologies, and the feasibility of LTE fixed wireless access networks to close the 30 Mbps broadband access gap in rural areas. In the first place and regarding the application of techno-economic analysis for 700 MHz spectrum pricing, obtained results reveal two core issues. First of all, the need to allocate more spectrum for operators in order to fulfill mobile traffic demand in the mid-term. Secondly, there is a substantial difference in deployment costs for a LTE network when there is sub-1GHz spectrum available and when there is not, but this difference decreases as additional sub-1GHz spectrum is added. Thus, the allocation of 700 MHz band to mobile communication services would cause a relevant reduction in deployment costs if the operator does not count on spectrum in the 800 MHz, but not if it already has been assigned spectrum in low frequencies for the deployment. In this regard, the price operators will be willing to pay for 700 MHz spectrum will depend on them having already spectrum in the 800 MHz frequency band or not. However, since competition for the new spectrum will not be so strong, expected incomes from 700 MHz spectrum awards will be generally lower than those from the digital dividend, despite this spectrum being as valuable as 800 MHz spectrum for some operators. In the second place, regarding femtocell deployment, some conclusions can be drawn in terms of deployment cost savings and also with reference to the business model they enable. Savings provided by a joint macro-femto LTE network as compared to an exclusively macrocellular deployment increase as the available bandwidth for the macrocells decreases. Therefore, for a convergent operator the deployment of femtocells can only have economic sense if the available bandwidth is scarce (around 2x10 MHz), which might be the case of fix market operators which are new entrant in mobile market. Besides, open access models are interesting for exclusively mobile operators, since they make costs more flexible by substituting macrocell base stations by femtocells, but they need to be deployed relatively densely populated areas so that they can offload traffic from several macrocell users simultaneously. Nonetheless, femtocells are beneficial in all cases if the user assumes both femtocell and backhaul costs, which only seems probable if they are integrated in a business model commercializing new services. Therefore, in many of the cases analyzed femtocell deployment only makes sense if they increase revenues per user through new added value services which need from guaranteed quality of service, thus exploiting its main competitive advantage compared to WiFi. Finally, regarding the role of LTE technology in the provision of fixed wireless access services for 30 Mbps broadband, a TD-LTE model has been developed and a prospective study has been carried out through techno-economic methodology for the Spanish case. Obtained results foresee a FTTH coverage footprint of 74% households for 2020, and prove that a TD-LTE network in the 3.5 GHz band results feasible to increase 30 Mbps service coverage in additional 14 percentage points. To sum up, obtained results show LTE technology capability to address new challenges regarding both mobile traffic growth, particularly critical in urban zones, and the current digital divide in fast broadband access in most rural zones.

Co-aggregation ability of cell Wall components of Saccharomyces cerevisiae to pathogenic bacteria

Autoaggregation in bacteria is the phenomenon of aggregation between cells of the same strain, whereas coaggregation is due to aggregation occurring among different species. Aggregation ability of prebiotic bacteria is related to adhesion ability, which is a prerequisite for the colonization and protection of the gastrointestinal tract in all animal species; however, coaggregation ability of prebiotic bacteria offers a possibility of close interaction with pathogenic bacteria.