http://hdl.handle.net/2117/3912 Wed, 19 Jun 2013 09:57:30 GMT 2013-06-19T09:57:30Z webmaster.bupc@upc.edu Universitat Politècnica de Catalunya. Servei de Biblioteques i Documentació no http://hdl.handle.net/2117/19474 Title: Biometric applications related to human beings: there is life beyond security Authors: Faúndez Zanuy, Marcos; Hussain, Amir; Mekyska, Jiri; Sesa Nogueras, Enric; Monte Moreno, Enrique; Esposito, Anna; Chetouani, Mohamed; Garre Olmo, Josep; Abel, Andrew; Smékal, Zdenek; Lopez-de-Ipina, Karmele Abstract: The use of biometrics has been successfully applied to security applications for some time. However, the extension of other potential applications with the use of biometric information is a very recent development. This paper summarizes the field of biometrics and investigates the potential of utilizing biometrics beyond the presently limited field of security applications. There are some synergies that can be established within security-related applications. These can also be relevant in other fields such as health and ambient intelligence. This paper describes these synergies. Overall, this paper highlights some interesting and exciting research areas as well as possible synergies between different applications using biometric information. Fri, 31 May 2013 12:50:56 GMT http://hdl.handle.net/2117/19474 2013-05-31T12:50:56Z Faúndez Zanuy, Marcos; Hussain, Amir; Mekyska, Jiri; Sesa Nogueras, Enric; Monte Moreno, Enrique; Esposito, Anna; Chetouani, Mohamed; Garre Olmo, Josep; Abel, Andrew; Smékal, Zdenek; Lopez-de-Ipina, Karmele no Biometrics, Security, Healthcare, Ambient intelligence The use of biometrics has been successfully applied to security applications for some time. However, the extension of other potential applications with the use of biometric information is a very recent development. This paper summarizes the field of biometrics and investigates the potential of utilizing biometrics beyond the presently limited field of security applications. There are some synergies that can be established within security-related applications. These can also be relevant in other fields such as health and ambient intelligence. This paper describes these synergies. Overall, this paper highlights some interesting and exciting research areas as well as possible synergies between different applications using biometric information. http://hdl.handle.net/2117/19454 Title: Exámenes no presenciales Authors: López Álvarez, David; Sánchez Carracedo, Fermín; Cruz Díaz, Josep Llorenç; Fernández Jiménez, Agustín Abstract: Los exámenes tradicionales están orientados a la evaluación sumativa, no a la formativa. Su objetivo es evaluar, no facilitar el aprendizaje, y debido a ello provocan un aprendizaje superficial más que un aprendizaje profundo: los estudiantes perciben que su futuro a corto plazo depende de su nota en un examen, por lo que orientan su estudio a aprobar dicho examen. En este artículo se propone una alternativa: un examen no presencial que realiza tanto evaluación sumativa como formativa. Es un tipo de examen que los estudiantes realizan fuera de clase a lo largo de un periodo de tiempo mucho más largo que el de un examen tradicional, lo que les ayuda a conseguir un aprendizaje profundo. En el artículo se presentan los resultados de una experiencia de 11 semestres utilizando este tipo de exámenes en una asignatura de la Facultat d’Informàtica de Barcelona. Thu, 30 May 2013 09:41:44 GMT http://hdl.handle.net/2117/19454 2013-05-30T09:41:44Z López Álvarez, David; Sánchez Carracedo, Fermín; Cruz Díaz, Josep Llorenç; Fernández Jiménez, Agustín no Modelos de evaluación, Evaluación formativa, Evaluación sumativa, Evaluación de competencias, Modelos de aprendizaje Los exámenes tradicionales están orientados a la evaluación sumativa, no a la formativa. Su objetivo es evaluar, no facilitar el aprendizaje, y debido a ello provocan un aprendizaje superficial más que un aprendizaje profundo: los estudiantes perciben que su futuro a corto plazo depende de su nota en un examen, por lo que orientan su estudio a aprobar dicho examen. En este artículo se propone una alternativa: un examen no presencial que realiza tanto evaluación sumativa como formativa. Es un tipo de examen que los estudiantes realizan fuera de clase a lo largo de un periodo de tiempo mucho más largo que el de un examen tradicional, lo que les ayuda a conseguir un aprendizaje profundo. En el artículo se presentan los resultados de una experiencia de 11 semestres utilizando este tipo de exámenes en una asignatura de la Facultat d’Informàtica de Barcelona. http://hdl.handle.net/2117/19430 Title: Generalized median string computation by means of string embedding in vector spaces Authors: Jiang, Xiaoyi; Wentker, Jöran; Ferrer Sumsi, Miquel Abstract: In structural pattern recognition the median string has been established as a useful tool to represent a set of strings. However, its exact computation is complex and of high computational burden. In this paper we propose a new approach for the computation of median string based on string embedding. Strings are embedded into a vector space and the median is computed in the vector domain. We apply three different inverse transformations to go from the vector domain back to the string domain in order to obtain a final approximation of the median string. All of them are based on the weighted mean of a pair of strings. Experiments show that we succeed to compute good approximations of the median string. Tue, 28 May 2013 16:06:00 GMT http://hdl.handle.net/2117/19430 2013-05-28T16:06:00Z Jiang, Xiaoyi; Wentker, Jöran; Ferrer Sumsi, Miquel no String, Generalized median, Embedding, Vector space, Lower bound In structural pattern recognition the median string has been established as a useful tool to represent a set of strings. However, its exact computation is complex and of high computational burden. In this paper we propose a new approach for the computation of median string based on string embedding. Strings are embedded into a vector space and the median is computed in the vector domain. We apply three different inverse transformations to go from the vector domain back to the string domain in order to obtain a final approximation of the median string. All of them are based on the weighted mean of a pair of strings. Experiments show that we succeed to compute good approximations of the median string. http://hdl.handle.net/2117/19416 Title: Scan detection under sampling: a new perspective Authors: Paredes Oliva, Ignasi; Barlet Ros, Pere; Solé Pareta, Josep Abstract: In tests using the same fraction of packets for comparison, packet sampling outperformed flow sampling for scan detection, while both selective sampling and a proposed extension that uses significantly less resources were superior to either of these techniques. The Web extra at http://youtu.be/Mgf8_a0fRs0 is a slide show that considers how in tests using the same fraction of packets for comparison, packet sampling outperformed flow sampling for scan detection, while both selective sampling and a proposed extension that uses significantly less resources were superior to either technique. Mon, 27 May 2013 15:47:48 GMT http://hdl.handle.net/2117/19416 2013-05-27T15:47:48Z Paredes Oliva, Ignasi; Barlet Ros, Pere; Solé Pareta, Josep no Security of data In tests using the same fraction of packets for comparison, packet sampling outperformed flow sampling for scan detection, while both selective sampling and a proposed extension that uses significantly less resources were superior to either of these techniques. The Web extra at http://youtu.be/Mgf8_a0fRs0 is a slide show that considers how in tests using the same fraction of packets for comparison, packet sampling outperformed flow sampling for scan detection, while both selective sampling and a proposed extension that uses significantly less resources were superior to either technique. http://hdl.handle.net/2117/19410 Title: Guest editorial Authors: Masip Bruin, Xavier; Orda, Ariel; Duhovnikov, Svetoslav Mon, 27 May 2013 13:42:58 GMT http://hdl.handle.net/2117/19410 2013-05-27T13:42:58Z Masip Bruin, Xavier; Orda, Ariel; Duhovnikov, Svetoslav no http://hdl.handle.net/2117/19378 Title: A summary of virtualization techniques Authors: Rodríguez Haro, Fernando; Freitag, Fèlix; Navarro Moldes, Leandro; Hernández Sánchez, Efraín; Farías Mendoza, Nicandro; Guerrero Ibáñez, Juan Antonio; González Potes, Apolinar Abstract: Nowadays, virtualization is a technology that is applied for sharing the capabilities of physical computers by splitting the resources among OSs. The concept of Virtual Machines (VMs) started back in 1964 with a IBM project called CP/CMS system. Currently, there are several virtualization techniques that can be used for supporting the execution of entire operating systems. We classify the virtualization techniques from the OS view. First, we discuss two techniques that executes modified guest OSs: operating system-level virtualization and para-virtualization. Second, we discuss two techniques that executes unmodified guest OSs: binary translation and hardware assisted. Finally, we present a summary of resource management facilities for capacity planning and consolidation of server applications. Thu, 23 May 2013 10:14:43 GMT http://hdl.handle.net/2117/19378 2013-05-23T10:14:43Z Rodríguez Haro, Fernando; Freitag, Fèlix; Navarro Moldes, Leandro; Hernández Sánchez, Efraín; Farías Mendoza, Nicandro; Guerrero Ibáñez, Juan Antonio; González Potes, Apolinar no Virtualization, Capacity planning, Hypervisor, CPU, Tools Nowadays, virtualization is a technology that is applied for sharing the capabilities of physical computers by splitting the resources among OSs. The concept of Virtual Machines (VMs) started back in 1964 with a IBM project called CP/CMS system. Currently, there are several virtualization techniques that can be used for supporting the execution of entire operating systems. We classify the virtualization techniques from the OS view. First, we discuss two techniques that executes modified guest OSs: operating system-level virtualization and para-virtualization. Second, we discuss two techniques that executes unmodified guest OSs: binary translation and hardware assisted. Finally, we present a summary of resource management facilities for capacity planning and consolidation of server applications. http://hdl.handle.net/2117/19211 Title: Median graphs: a genetic approach based on new theoretical properties Authors: Ferrer Sumsi, Miquel; Valveny, Ernest; Serratosa Casanelles, Francesc Abstract: Given a set of graphs, the median graph has been theoretically presented as a useful concept to infer a representative of the set. However, the computation of the median graph is a highly complex task and its practical application has been very limited up to now. In this work we present two major contributions. On one side, and from a theoretical point of view, we show new theoretical properties of the median graph. On the other side, using these new properties, we present a new approximate algorithm based on the genetic search, that improves the computation of the median graph. Finally, we perform a set of experiments on real data, where none of the existing algorithms for the median graph computation could be applied up to now due to their computational complexity. With these results, we show how the concept of the median graph can be used in real applications and leaves the box of the only-theoretical concepts, demonstrating, from a practical point of view, that can be a useful tool to represent a set of graphs. Tue, 14 May 2013 13:20:27 GMT http://hdl.handle.net/2117/19211 2013-05-14T13:20:27Z Ferrer Sumsi, Miquel; Valveny, Ernest; Serratosa Casanelles, Francesc no Median graph, Genetic search, Maximum common subgraph, Graph matching, Structural pattern recognition Given a set of graphs, the median graph has been theoretically presented as a useful concept to infer a representative of the set. However, the computation of the median graph is a highly complex task and its practical application has been very limited up to now. In this work we present two major contributions. On one side, and from a theoretical point of view, we show new theoretical properties of the median graph. On the other side, using these new properties, we present a new approximate algorithm based on the genetic search, that improves the computation of the median graph. Finally, we perform a set of experiments on real data, where none of the existing algorithms for the median graph computation could be applied up to now due to their computational complexity. With these results, we show how the concept of the median graph can be used in real applications and leaves the box of the only-theoretical concepts, demonstrating, from a practical point of view, that can be a useful tool to represent a set of graphs. http://hdl.handle.net/2117/19210 Title: Generalized median graph computation by means of graph embedding in vector spaces Authors: Ferrer Sumsi, Miquel; Valveny, Ernest; Serratosa Casanelles, Francesc; Riesen, Kaspar; Bunke, Horst Abstract: The median graph has been presented as a useful tool to represent a set of graphs. Nevertheless its computation is very complex and the existing algorithms are restricted to use limited amount of data. In this paper we propose a new approach for the computation of the median graph based on graph embedding. Graphs are embedded into a vector space and the median is computed in the vector domain. We have designed a procedure based on the weighted mean of a pair of graphs to go from the vector domain back to the graph domain in order to obtain a final approximation of the median graph. Experiments on three different databases containing large graphs show that we succeed to compute good approximations of the median graph. We have also applied the median graph to perform some basic classification tasks achieving reasonable good results. These experiments on real data open the door to the application of the median graph to a number of more complex machine learning algorithms where a representative of a set of graphs is needed. Tue, 14 May 2013 12:56:41 GMT http://hdl.handle.net/2117/19210 2013-05-14T12:56:41Z Ferrer Sumsi, Miquel; Valveny, Ernest; Serratosa Casanelles, Francesc; Riesen, Kaspar; Bunke, Horst no The median graph has been presented as a useful tool to represent a set of graphs. Nevertheless its computation is very complex and the existing algorithms are restricted to use limited amount of data. In this paper we propose a new approach for the computation of the median graph based on graph embedding. Graphs are embedded into a vector space and the median is computed in the vector domain. We have designed a procedure based on the weighted mean of a pair of graphs to go from the vector domain back to the graph domain in order to obtain a final approximation of the median graph. Experiments on three different databases containing large graphs show that we succeed to compute good approximations of the median graph. We have also applied the median graph to perform some basic classification tasks achieving reasonable good results. These experiments on real data open the door to the application of the median graph to a number of more complex machine learning algorithms where a representative of a set of graphs is needed. http://hdl.handle.net/2117/19184 Title: Median graph: a new exact algorithm using a distance based on the maximum common subgraph Authors: Ferrer Sumsi, Miquel; Valveny, Ernest; Serratosa Casanelles, Francesc Abstract: Median graphs have been presented as a useful tool for capturing the essential information of a set of graphs. Nevertheless, computation of optimal solutions is a very hard problem. In this work we present a new and more efficient optimal algorithm for the median graph computation. With the use of a particular cost function that permits the definition of the graph edit distance in terms of the maximum common subgraph, and a prediction function in the backtracking algorithm, we reduce the size of the search space, avoiding the evaluation of a great amount of states and still obtaining the exact median. We present a set of experiments comparing our new algorithm against the previous existing exact algorithm using synthetic data. In addition, we present the first application of the exact median graph computation to real data and we compare the results against an approximate algorithm based on genetic search. These experimental results show that our algorithm outperforms the previous existing exact algorithm and in addition show the potential applicability of the exact solutions to real problems. Mon, 13 May 2013 18:26:23 GMT http://hdl.handle.net/2117/19184 2013-05-13T18:26:23Z Ferrer Sumsi, Miquel; Valveny, Ernest; Serratosa Casanelles, Francesc no Median graphs have been presented as a useful tool for capturing the essential information of a set of graphs. Nevertheless, computation of optimal solutions is a very hard problem. In this work we present a new and more efficient optimal algorithm for the median graph computation. With the use of a particular cost function that permits the definition of the graph edit distance in terms of the maximum common subgraph, and a prediction function in the backtracking algorithm, we reduce the size of the search space, avoiding the evaluation of a great amount of states and still obtaining the exact median. We present a set of experiments comparing our new algorithm against the previous existing exact algorithm using synthetic data. In addition, we present the first application of the exact median graph computation to real data and we compare the results against an approximate algorithm based on genetic search. These experimental results show that our algorithm outperforms the previous existing exact algorithm and in addition show the potential applicability of the exact solutions to real problems. http://hdl.handle.net/2117/18978 Title: Modeling the routing and spectrum allocation problem for flexgrid optical networks Authors: Velasco Esteban, Luis Domingo; Klinkowski, Miroslaw; Ruiz Ramírez, Marc; Comellas Colomé, Jaume Abstract: Flexgrid optical networks are attracting huge interest due to their higher spectrum efficiency and flexibility in comparison with traditional wavelength switched optical networks based on the wavelength division multiplexing technology. To properly analyze, design, plan, and operate flexible and elastic networks, efficient methods are required for the routing and spectrum allocation (RSA) problem. Specifically, the allocated spectral resources must be, in absence of spectrum converters, the same along the links in the route (the continuity constraint) and contiguous in the spectrum (the contiguity constraint). In light of the fact that the contiguity constraint adds huge complexity to the RSA problem,we introduce the concept of channels for the representation of contiguous spectral resources. In this paper, we show that the use of a pre-computed set of channels allows considerably reducing the problem complexity. In our study, we address an off-line RSA problem in which enough spectrum needs to be allocated for each demand of a given traffic matrix. To this end, we present novel integer lineal programming (ILP) formulations of RSA that are based on the assignment of channels. The evaluation results reveal that the proposed approach allows solving the RSA problem much more efficiently than previously proposed ILP-based methods and it can be applied even for realistic problem instances, contrary to previous ILP formulations. Wed, 24 Apr 2013 11:33:35 GMT http://hdl.handle.net/2117/18978 2013-04-24T11:33:35Z Velasco Esteban, Luis Domingo; Klinkowski, Miroslaw; Ruiz Ramírez, Marc; Comellas Colomé, Jaume no Flexgrid optical networks, Off-line routing, Spectrum allocation Flexgrid optical networks are attracting huge interest due to their higher spectrum efficiency and flexibility in comparison with traditional wavelength switched optical networks based on the wavelength division multiplexing technology. To properly analyze, design, plan, and operate flexible and elastic networks, efficient methods are required for the routing and spectrum allocation (RSA) problem. Specifically, the allocated spectral resources must be, in absence of spectrum converters, the same along the links in the route (the continuity constraint) and contiguous in the spectrum (the contiguity constraint). In light of the fact that the contiguity constraint adds huge complexity to the RSA problem,we introduce the concept of channels for the representation of contiguous spectral resources. In this paper, we show that the use of a pre-computed set of channels allows considerably reducing the problem complexity. In our study, we address an off-line RSA problem in which enough spectrum needs to be allocated for each demand of a given traffic matrix. To this end, we present novel integer lineal programming (ILP) formulations of RSA that are based on the assignment of channels. The evaluation results reveal that the proposed approach allows solving the RSA problem much more efficiently than previously proposed ILP-based methods and it can be applied even for realistic problem instances, contrary to previous ILP formulations. http://hdl.handle.net/2117/18906 Title: The contribution of Type IA supernovae to the galactic iron abundances Authors: Bravo Guil, Eduardo; Isern Vilaboy, Jordi; Canal Corretger, Ramon Abstract: The thermonuclear explosion of a mass-accreting white dwarf in a close binary system is thought to be at the origin of Type Ia supernovae. Standard models, which ignite carbon at densities higher than 2-4 x 10 exp 9 g/cu cm, give, however, a large production of species like Fe-54, Ni-58, and Cr-54, which has been regarded as incompatible with the solar system abundances. In this paper we analyze the weight of the constraints imposed by nucleosynthesis of the Fe-peak nuclides to the aforementioned scenario for Type Ia supernovae when the contribution of Type II and Type Ib supernovae to the galactic iron abundances is also taken into account. We find that the production of the aforementioned nuclides predicted by standard SNIa models is in fact compatible with the solar system abundances when the yields from gravitational-collapse supernovae are adjusted to reproduce the Ni abundances in low-metallicity stars. Fri, 19 Apr 2013 17:11:40 GMT http://hdl.handle.net/2117/18906 2013-04-19T17:11:40Z Bravo Guil, Eduardo; Isern Vilaboy, Jordi; Canal Corretger, Ramon no The thermonuclear explosion of a mass-accreting white dwarf in a close binary system is thought to be at the origin of Type Ia supernovae. Standard models, which ignite carbon at densities higher than 2-4 x 10 exp 9 g/cu cm, give, however, a large production of species like Fe-54, Ni-58, and Cr-54, which has been regarded as incompatible with the solar system abundances. In this paper we analyze the weight of the constraints imposed by nucleosynthesis of the Fe-peak nuclides to the aforementioned scenario for Type Ia supernovae when the contribution of Type II and Type Ib supernovae to the galactic iron abundances is also taken into account. We find that the production of the aforementioned nuclides predicted by standard SNIa models is in fact compatible with the solar system abundances when the yields from gravitational-collapse supernovae are adjusted to reproduce the Ni abundances in low-metallicity stars. http://hdl.handle.net/2117/18905 Title: On the photometric homogeneity of type IA supernovae Authors: Bravo Guil, Eduardo; Domínguez, Inmaculada; Isern, Jordi; Canal Corretger, Ramon; Höflich, P.; Labay, Javier Abstract: The dependence of the characteristics of the light curves of Type Ia supernovae on the ignition density of the progenitor white dwarf is studied with the aid of two models of propagation of the thermonuclear burning front: as a deflagration and as a delayed detonation. The light curve is computed from opacities which take into account the velocity gradients. The results show that in all cases the resulting light curves roughly agree with observations and that they are not sensitive to the ignition density of the white dwarf. Only the model corresponding to a deflagration starting at a density of 8 x 10 exp 9 g/cu cm shows a deviation from the general behavior, having a significantly lower luminosity at maximum. A dispersion of about 1000 km/s is found in the computed expansion velocities at maximum, which compares well with that found in the observations. Fri, 19 Apr 2013 17:02:57 GMT http://hdl.handle.net/2117/18905 2013-04-19T17:02:57Z Bravo Guil, Eduardo; Domínguez, Inmaculada; Isern, Jordi; Canal Corretger, Ramon; Höflich, P.; Labay, Javier no The dependence of the characteristics of the light curves of Type Ia supernovae on the ignition density of the progenitor white dwarf is studied with the aid of two models of propagation of the thermonuclear burning front: as a deflagration and as a delayed detonation. The light curve is computed from opacities which take into account the velocity gradients. The results show that in all cases the resulting light curves roughly agree with observations and that they are not sensitive to the ignition density of the white dwarf. Only the model corresponding to a deflagration starting at a density of 8 x 10 exp 9 g/cu cm shows a deviation from the general behavior, having a significantly lower luminosity at maximum. A dispersion of about 1000 km/s is found in the computed expansion velocities at maximum, which compares well with that found in the observations. http://hdl.handle.net/2117/18785 Title: Chains of trust in vehicular networks: a secure points of interest dissemination strategy Authors: Antolino Rivas, David; Guerrero Zapata, Manel Abstract: This article describes a scheme which to the best of our knowledge is the first one to use user signatures to share information about Points of Interest in Vehicular Ad hoc Networks. In this scheme, users rate restaurants, hotels, etc. and sign those rates with their private key. Then, they broadcast that information and other vehicles store it for future use. When another user needs a Point of Interest recommendation he queries the system for the other users stored reviews and after he visits that Points of Interest for himself, he evaluates it and his level of trust in the reviewers with rates similar to his own increases. In the end, a user will be able to request to his vehicle information on a certain Point of Interest category and itwill respond with the recommendations made by other users, prioritizing the ones in the user’s Web of Trust.poi-Sim is the tool designed to simulate this scheme. It processes a 24 h mobility trace produced by a Multi-Agent Traffic Simulator, which realistically simulates public and private traffic over regional maps of Switzerland. The result is a Chains of Trust simulation with over 260,000 nodes, which shows that the proposed scheme performs satisfactorily in a realistic scenario. Mon, 15 Apr 2013 09:56:22 GMT http://hdl.handle.net/2117/18785 2013-04-15T09:56:22Z Antolino Rivas, David; Guerrero Zapata, Manel no Chains, POI, Reputation, Security, Trust, VANETs This article describes a scheme which to the best of our knowledge is the first one to use user signatures to share information about Points of Interest in Vehicular Ad hoc Networks. In this scheme, users rate restaurants, hotels, etc. and sign those rates with their private key. Then, they broadcast that information and other vehicles store it for future use. When another user needs a Point of Interest recommendation he queries the system for the other users stored reviews and after he visits that Points of Interest for himself, he evaluates it and his level of trust in the reviewers with rates similar to his own increases. In the end, a user will be able to request to his vehicle information on a certain Point of Interest category and itwill respond with the recommendations made by other users, prioritizing the ones in the user’s Web of Trust.poi-Sim is the tool designed to simulate this scheme. It processes a 24 h mobility trace produced by a Multi-Agent Traffic Simulator, which realistically simulates public and private traffic over regional maps of Switzerland. The result is a Chains of Trust simulation with over 260,000 nodes, which shows that the proposed scheme performs satisfactorily in a realistic scenario. http://hdl.handle.net/2117/18501 Title: C3 in UAS as a means for secondary navigation Authors: Ramírez Alcántara, Jorge; Salazar Hernández, Dagoberto José; Prats Menéndez, Xavier; Barrado Muxí, Cristina Abstract: Unmanned Air Systems (UAS) navigate using Global Navigation Satellite Systems (GNSS), but GNSS vulnerability precludes its use as the only means of navigation and requires a secondary means of navigation. A differentiating characteristic of UAS is their periodic communications with the ground station. This paper analyses the adequacy of employing UAS Command, Control and Communications (C3) as a secondary means of navigation. With no additional infrastructure, an Extended Kalman Filter (EKF) is used to process C3 messages and to obtain the positions of the UAS. Navigation accuracy and integrity are calculated in a scenario with three UAS. The obtained results meet the International Civil Aviation Organization (ICAO) Performance-Based Navigation (PBN) requirements. Fri, 22 Mar 2013 13:25:04 GMT http://hdl.handle.net/2117/18501 2013-03-22T13:25:04Z Ramírez Alcántara, Jorge; Salazar Hernández, Dagoberto José; Prats Menéndez, Xavier; Barrado Muxí, Cristina no Unmanned Air Systems (UAS) navigate using Global Navigation Satellite Systems (GNSS), but GNSS vulnerability precludes its use as the only means of navigation and requires a secondary means of navigation. A differentiating characteristic of UAS is their periodic communications with the ground station. This paper analyses the adequacy of employing UAS Command, Control and Communications (C3) as a secondary means of navigation. With no additional infrastructure, an Extended Kalman Filter (EKF) is used to process C3 messages and to obtain the positions of the UAS. Navigation accuracy and integrity are calculated in a scenario with three UAS. The obtained results meet the International Civil Aviation Organization (ICAO) Performance-Based Navigation (PBN) requirements. http://hdl.handle.net/2117/18019 Title: Network convergence and QoS for future multimedia services in the VISION project Authors: Pérez, Luís; Velasco Esteban, Luis Domingo; Rodríguez, Juan; Capelastegui, Pedro; Hernández Sola, Guillem; Calavia, Lorena; Marqués, Antonio; Iribarne, Borja; Pozo, Amador; Poorter, Antoine De Abstract: The emerging use of real-time 3D-based multimedia applications imposes strict quality of service (QoS) requirements on both access and core networks. These requirements and their impact to provide end-to-end 3D videoconferencing services have been studied within the Spanish-funded VISION project, where different scenarios were implemented showing an agile stereoscopic video call that might be offered to the general public in the near future. In view of the requirements, we designed an integrated access and core converged network architecture which provides the requested QoS to end-to-end IP sessions. Novel functional blocks are proposed to control core optical networks, the functionality of the standard ones is redefined, and the signaling improved to better meet the requirements of future multimedia services. An experimental test-bed to assess the feasibility of the solution was also deployed. In such test-bed, set-up and release of end-to-end sessions meeting specific QoS requirements are shown and the impact of QoS degradation in terms of the user perceived quality degradation is quantified. In addition, scalability results show that the proposed signaling architecture is able to cope with large number of requests introducing almost negligible delay. Thu, 28 Feb 2013 11:54:08 GMT http://hdl.handle.net/2117/18019 2013-02-28T11:54:08Z Pérez, Luís; Velasco Esteban, Luis Domingo; Rodríguez, Juan; Capelastegui, Pedro; Hernández Sola, Guillem; Calavia, Lorena; Marqués, Antonio; Iribarne, Borja; Pozo, Amador; Poorter, Antoine De no Network convergence, Multimedia services, Quality of service The emerging use of real-time 3D-based multimedia applications imposes strict quality of service (QoS) requirements on both access and core networks. These requirements and their impact to provide end-to-end 3D videoconferencing services have been studied within the Spanish-funded VISION project, where different scenarios were implemented showing an agile stereoscopic video call that might be offered to the general public in the near future. In view of the requirements, we designed an integrated access and core converged network architecture which provides the requested QoS to end-to-end IP sessions. Novel functional blocks are proposed to control core optical networks, the functionality of the standard ones is redefined, and the signaling improved to better meet the requirements of future multimedia services. An experimental test-bed to assess the feasibility of the solution was also deployed. In such test-bed, set-up and release of end-to-end sessions meeting specific QoS requirements are shown and the impact of QoS degradation in terms of the user perceived quality degradation is quantified. In addition, scalability results show that the proposed signaling architecture is able to cope with large number of requests introducing almost negligible delay.