23 research outputs found

    Traffic Profiling for Mobile Video Streaming

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    This paper describes a novel system that provides key parameters of HTTP Adaptive Streaming (HAS) sessions to the lower layers of the protocol stack. A non-intrusive traffic profiling solution is proposed that observes packet flows at the transmit queue of base stations, edge-routers, or gateways. By analyzing IP flows in real time, the presented scheme identifies different phases of an HAS session and estimates important application-layer parameters, such as play-back buffer state and video encoding rate. The introduced estimators only use IP-layer information, do not require standardization and work even with traffic that is encrypted via Transport Layer Security (TLS). Experimental results for a popular video streaming service clearly verify the high accuracy of the proposed solution. Traffic profiling, thus, provides a valuable alternative to cross-layer signaling and Deep Packet Inspection (DPI) in order to perform efficient network optimization for video streaming.Comment: 7 pages, 11 figures. Accepted for publication in the proceedings of IEEE ICC'1

    Heuristic Approaches for Support Vector Machines with the Ramp Loss

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    Recently, Support Vector Machines with the ramp loss (RLM) have attracted attention from the computational point of view. In this technical note, we propose two heuristics, the first one based on solving the continuous relaxation of a Mixed Integer Nonlinear formulation of the RLM and the second one based on the training of an SVM classifier on a reduced dataset identified by an integer linear problem. Our computational results illustrate the ability of our heuristics to handle datasets of much larger size than those previously addressed in the literature

    Strongly agree or strongly disagree? Rating features in support vector machines

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    In linear classifiers, such as the Support Vector Machine (SVM), a score is associated with each feature and objects are assigned to classes based on the linear combination of the scores and the values of the features. Inspired by discrete psychometric scales, which measure the extent to which a factor is in agreement with a statement, we propose the Discrete Level Support Vector Machine (DILSVM) where the feature scores can only take on a discrete number of values, de fined by the so-called feature rating levels. The DILSVM classifier benefits from interpretability as it can be seen as a collection of Likert scales, one for each feature, where we rate the level of agreement with the positive class. To build the DILSVM classifier, we propose a Mixed Integer Linear Programming approach, as well as a collection of strategies to reduce the building times. Our computational experience shows that the 3-point and the 5-point DILSVM classifiers have comparable accuracy to the SVM with a substantial gain in interpretability and sparsity, thanks to the appropriate choice of the feature rating levels.Ministerio de Economía y CompetitividadJunta de AndalucíaFondo Europeo de Desarrollo Regiona

    Heuristic approaches for support vector machines with the ramp loss

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    Recently, Support Vector Machines with the ramp loss (RLM) have attracted attention from the computational point of view. In this technical note, we propose two heuristics, the first one based on solving the continuous relaxation of a Mixed Integer Nonlinear formulation of the RLM and the second one based on the training of an SVM classifier on a reduced dataset identified by an integer linear problem. Our computational results illustrate the ability of our heuristics to handle datasets of much larger size than those previously addressed in the literature.Ministerio de Economía y CompetitividadJunta de AndalucíaEuropean Regional Development Fund

    Clustering categories in support vector machines

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    The support vector machine (SVM) is a state-of-the-art method in supervised classification. In this paper the Cluster Support Vector Machine (CLSVM) methodology is proposed with the aim to increase the sparsity of the SVM classifier in the presence of categorical features, leading to a gain in interpretability. The CLSVM methodology clusters categories and builds the SVM classifier in the clustered feature space. Four strategies for building the CLSVM classifier are presented based on solving: the SVM formulation in the original feature space, a quadratically constrained quadratic programming formulation, and a mixed integer quadratic programming formulation as well as its continuous relaxation. The computational study illustrates the performance of the CLSVM classifier using two clusters. In the tested datasets our methodology achieves comparable accuracy to that of the SVM in the original feature space, with a dramatic increase in sparsity.Ministerio de Economía y CompetitividadJunta de Andalucí

    p-facility Huff location problem on networks

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    The p-facility Huff location problem aims at locating facilities on a competitive environment so as to maximize the market share. While it has been deeply studied in the field of continuous location, in this paper we study the p-facility Huff location problem on networks formulated as a Mixed Integer Nonlinear Programming problem that can be solved by a branch-and-bound algorithm. We propose two approaches for the initialization and division of subproblems, the first one based on the straightforward idea of enumerating every possible combination of p edges of the network as possible locations, and the second one defining sophisticated data structures that exploit the structure of the combinatorial and continuous part of the problem. Bounding rules are designed using DC (difference of convex) and Interval Analysis tools. In our computational study we compare the two approaches on a battery of 21 networks and show that both of them can handle problems for p ≤ 4 in reasonable computing time.Ministerio de Economía y CompetitividadJunta de AndalucíaHungarian National Research, Development and Innovation OfficeInformation and Communication Technologies COS

    Transcriptome profiling of a Sinorhizobium meliloti fadD mutant reveals the role of rhizobactin 1021 biosynthesis and regulation genes in the control of swarming

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    58 pages, 7 figures, 3 tables, 3 additional files.-- Provisional PDF.[Background] Swarming is a multicellular phenomenom characterized by the coordinated and rapid movement of bacteria across semisolid surfaces. In Sinorhizobium meliloti this type of motility has been described in a fadD mutant. To gain insights into the mechanisms underlying the process of swarming in rhizobia, we compared the transcriptome of a S. meliloti fadD mutant grown under swarming inducing conditions (semisolid medium) to those of cells grown under non-swarming conditions (broth and solid medium).[Results] More than a thousand genes were identified as differentially expressed in response to growth on agar surfaces including genes for several metabolic activities, iron uptake, chemotaxis, motility and stress-related genes. Under swarming-specific conditions, the most remarkable response was the up-regulation of iron-related genes. We demonstrate that the pSymA plasmid and specifically genes required for the biosynthesis of the siderophore rhizobactin 1021 are essential for swarming of a S. meliloti wild-type strain but not in a fadD mutant. Moreover, high iron conditions inhibit swarming of the wild-type strain but not in mutants lacking either the iron limitation response regulator RirA or FadD.[Conclusions] The present work represents the first transcriptomic study of rhizobium growth on surfaces including swarming inducing conditions. The results have revealed major changes in the physiology of S. meliloti cells grown on a surface relative to liquid cultures. Moreover, analysis of genes responding to swarming inducing conditions led to the demonstration that iron and genes involved in rhizobactin 1021 synthesis play a role in the surface motility shown by S. meliloti which can be circumvented in a fadD mutant. This work opens a way to the identification of new traits and regulatory networks involved in swarming by rhizobia.JN was supported by a postdoctoral contract (Consejería de Innovación, Ciencia y Empresa, Junta de Andalucía). This work was supported by a FPI fellowship from MICINN to CVA-G, and by grants BIO2007-62988 and CVI 03541 to MJS.Peer reviewe

    SUPLEMENTO DEL XV CONGRESO INTERNACIONAL DE ACTIVIDAD FÍSICA Y DEPORTE. 17,18 y 19 DE OCTUBRE DEL 2018. ENSENADA, BAJA CALIFORNIA, MÉXICO

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    Compendio, en formato artículo, de los mejores trabajos presentados en el XV CONGRESO INTERNACIONAL DE ACTIVIDAD FÍSICA Y DEPORTE celebrado los días  17,18 y 19 de octubre del 2018 en la Universidad Autónoma de Baja California en la ciudad de Ensenada, Baja California, México:La nutrición en la actividad física y deportiva: alimentos funcionales con nanotecnología, aplicaciones potenciales. González González, K.Y.; Huerta Plaza, B.A.; Amaya Parra, G. (118-130)Perfil antropométrico, físico y hábitos alimentarios en escolares indígenas de Tijuana México. Avendaño Cano, D.L.; Gómez Miranda, L.M.; Aburto Corona, J.A. (131-142)Relación entre el clima de aprendizaje en Educación Física y la percepción de los estudiantes en las competencias del profesorado. Baños, R; Ortiz-Camacho, M.M.; Baena-Extremera, A.; Granero-Gallegos, A.; Machado-Parra, J.P.; Rentería, I.; Acosta, I.; Ramírez, L. (143-153)Valoración de capacidades físicas, composición corporal y consumo de vitaminas en una competencia de Crossfit. Cervantes-Hernández, N.; Hernández Nájera, N.; Carrasco Legleu, C.E.; Candia Lujan, R.; Enríquez Del Castillo, L.A. (154-164)Relación de la actividad física, características antropométricas y VO2máx en jóvenes universitarios: características por género. Enríquez-del Castillo, L.A.; Cervantes-Hernández, N.; Carrasco-Legleu, C.E.; Candia Luján, R. (165-174)Entrenamiento vibratorio de cuerpo completo y sus efectos sobre la composición corporal en jóvenes universitarios. Flores-Chico, B.; Bañuelos-Teres, L.E.; Buendía Lozada, E.R.P. (175-183)Actualización curricular, plan 2016 de la Licenciatura en Cultura Física de la BUAP. Flores-Chico, B.; Flores-Flores, A.; López de La Rosa, LE.; Aguilar-Enríquez, R.I.; Caballero Gómez, JM; Villanueva-Huerta, JA. (184-192)Evaluación psicológica y de la musculatura isquiosural de basquetbolistas universitarias en distintas etapas deportivas. Moranchel-Charros, R.; Martínez-Velázquez, E.S. (193-203)Efecto del ejercicio físico sobre la fuerza, resistencia y riesgo de caída en mujeres adultas. Ortiz Ortiz, M; Espinoza Gutiérrez, R; Gómez Miranda, LM.; Guzmán Gutiérrez, EC.; Calleja Núñez, JJ. (204-212)Desigualdad vs igualdad numérica y su efecto en la técnica de jugadores de fútbol infantil. Vega-Orozco, SI; Gavotto Nogales, OI; Bernal Reyes, F; Horta Gim, MA; Sarabia Sainz, HM. (213-224
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