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Face Video Competition

RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
  • Poh, N
  • Chan, CH
  • Kittler, J
  • Marcel, S
  • Mc Cool, C
  • Rua, EA
  • Alba Castro, JL
  • Villegas, Mauricio
  • Paredes Palacios, Roberto
  • Struc, V
  • Pavesic, N
  • Salah, AA
  • Fang, H
  • Costen, N
Person recognition using facial features, e.g., mug-shot images, has long been used in identity documents. However, due to the widespread use of web-cams and mobile devices embedded with a camera, it is now possible to realise facial video recognition, rather than resorting to just still images. In fact, facial video recognition offers many advantages over still image recognition; these include the potential of boosting the system accuracy and deterring spoof attacks. This paper presents the first known benchmarking effort of person identity verification using facial video data. The evaluation involves 18 systems submitted by seven academic institutes., The work of NPoh is supported by the advanced researcher fellowship PA0022121477of the Swiss NSF; NPoh, CHC and JK by the EU-funded Mobio project grant IST-214324; NPC and HF by the EPSRC grants EP/D056942 and EP/D054818; VS andNP by the Slovenian national research program P2-0250(C) Metrology and Biomet-ric System, the COST Action 2101 and FP7-217762 HIDE; and, AAS by the Dutch BRICKS/BSIK project.




An evaluation of video-to-video face verification

RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
  • Poh, Norman
  • Chan, Chi Ho
  • Kittler, Josef
  • Marcel, Sébastien
  • McCool, Christopher
  • Aragonés Rúa, Enrique
  • Alba Castro, Jose Luis
  • Villegas, Mauricio
  • Paredes Palacios, Roberto
  • Struc, Vitomir
  • Pavesic, Nikola
  • Salah, Albert Ali
  • Fang, Hui
  • Costen, Nicholas
[EN] Person recognition using facial features, e.g., mug-shot images, has long been used in identity documents. However, due to the widespread use of web-cams and mobile devices embedded with a camera, it is now possible to realize facial video recognition, rather than resorting to just still images. In fact, facial video recognition offers many advantages over still image recognition; these include the potential of boosting the system accuracy and deterring spoof attacks. This paper presents an evaluation of person identity verification using facial video data, organized in conjunction with the International Conference on Biometrics (ICB 2009). It involves 18 systems submitted by seven academic institutes. These systems provide for a diverse set of assumptions, including feature representation and preprocessing variations, allowing us to assess the effect of adverse conditions, usage of quality information, query selection, and template construction for video-to-video face authentication., Manuscript received September 30, 2009; revised August 18, 2010; accepted August 23, 2010. Date of publication September 20, 2010; date of current version November 17, 2010. The work of N. Poh was supported by the Advanced Researcher Fellowship PA0022 121477 of the Swiss NSF. The work of N. Poh, C. H. Chan, and J. Kittler was supported by the EU-funded Mobio project grant IST-214324. The work of N. Costen and H. Fang was supported by the EPSRC Grant EP/D056942 and Grant EP/D054818. The work of N. Pavesic and V. Struc was supported by the Slovenian National Research Program P2-0250(C) Metrology and Biometric System, the COST Action 2101 and FP7-217762 HIDE. The work of E. A. Rua was supported by the Spanish Project TEC2008-05894. The work of M. Villegas and R. Paredes was supported by the Spanish MEC/MICINN under the MIPRCV "Consolider Ingenio 2010" program (CSD2007-00018). The work of A. A. Salah was supported by the Dutch BRICKS/BSIK project. The associate editor coordinating the review of this manuscript and approving it for publication was Dr. Patrick J. Flynn. N. Poh, C. H. Chan, and J. Kittler are with the Centre for Vision, Speech and Signal Processing (CVSSP), School of Electronics and Physical Sciences, University of Surrey, Guildford, GU2 7XH, Surrey, U. K. (e-mail: n.poh@surrey.ac.uk; normanpoh@ieee.com).




Microwave calorimetry using X-rays

RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
  • Nicula, R.
  • Stir, M.
  • Wurm, A.
  • Catalá Civera, José Manuel|||0000-0002-0617-1762
  • Ishizaki, K.
  • Vaucher, S.
  • Zhuravlev, E.
  • Schick, C.
An alternative approach for microwave calorimetry is proposed which relies on the synchrotron radiation powder diffraction technique as well as on the Grüneisen formalism for the analysis of thermal expansion. Cobalt was selected as suitable magnetic material for the present evaluation of the method. First results are reported concerning the calorimetric assessment of the HCP (hexagonal close-packed) to FCC (face centered cubic) transition of cobalt from in situ time-resolved X-ray diffraction experiments performed during magnetic (H-field) microwave heating. The X-ray calorimetry method yields specific heat capacity estimations that compare well with results from conventional differential scanning calorimetry measurements. In the presence of the 2.45 GHz microwave H-field, an 'anomalous' behaviour of the heat capacity across the structural phase transition is detected, which can be correlated with the magnetic spin reorientation transition of cobalt in the same temperature range. © 2011 Elsevier B.V. All rights reserved., We kindly acknowledge the help of Fabia Gozzo, Antonio Cervellino and the team at the MS X04SA beamline at the Swiss Light Source. This work was jointly supported by the Swiss National Science Foundation (SNSF) and by the German Science Foundation (DFG), Project "Calorimetry of phase transitions in ultrafast conventional and electromagnetic heating", SNSF Grant 20PA21-129123 and DFG Grant SCHI331/21-1.




Reactive synthesis of Ti-Al intermetallics during microwave heating in an E-field maximum

RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
  • Vaucher, S.
  • Stir, M.
  • Ishizaki, K.
  • Catalá Civera, José Manuel|||0000-0002-0617-1762
  • Nicula, R.
The time-resolved X-ray diffraction synchrotron radiation technique was used in combination with E-field microwave heating to study in situ the kinetics of intermetallic phase formation in the Ti-Al system. The reaction of Ti with Al is triggered by the melting and spreading of Al onto the surface of Ti particles. The tetragonal TiAl 3 phase is the primary reaction product, formed by instantaneous nucleation at the interface between the unreacted Ti cores and the Al melt. The growth of TiAl 3 layers is diffusion-controlled. These preliminary results demonstrate that microwave heating can be used to rapidly synthesise intermetallic phases from high-purity elemental powders. © 2010 Elsevier B.V. All rights reserved., This work has been supported by the Swiss National Science Foundation (Grant 20PA21E-129193).




Accelerating distributed deep neural network training with pipelined MPI allreduce

RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
  • Castelló, Adrián|||0000-0002-8576-8451
  • Quintana-Ortí, Enrique S.|||0000-0002-5454-165X
  • Duato Marín, José Francisco
[EN] TensorFlow (TF) is usually combined with the Horovod (HVD) workload distribution package to obtain a parallel tool to train deep neural network on clusters of computers. HVD in turn utilizes a blocking Allreduce primitive to share information among processes, combined with a communication thread to overlap communication with computation. In this work, we perform a thorough experimental analysis to expose (1) the importance of selecting the best algorithm in MPI libraries to realize the Allreduce operation; and (2) the performance acceleration that can be attained when replacing a blocking Allreduce with its non-blocking counterpart (while maintaining the blocking behaviour via the appropriate synchronization mechanism). Furthermore, (3) we explore the benefits of applying pipelining to the communication exchange, demonstrating that these improvements carry over to distributed training via TF+HVD. Finally, (4) we show that pipelining can also boost performance for applications that make heavy use of other collectives, such as Broadcast and Reduce-Scatter., Project TIN2017-82972-R of the Spanish Ministerio de Ciencia, Innovacion y Universidades. Agencia Valenciana de la Innovacion. Juan de la Cierva-Formacion project FJC2019-039222-I of the Ministerio de Ciencia, Innovacion y Universidades PRACE Preparatory Access project #2010PA5531.




Datos de biomasa e índices de diversidad en aulas forestales de Valdepoza (Palencia) y Llano de San Marugán (Valladolid), Biomass and diversity indices dataset from Valdepoza (Palencia) and Llano de San Marugán (Valladolid) marteloscopes

UVaDOC. Repositorio Documental de la Universidad de Valladolid
  • Bravo Oviedo, Felipe
  • Martín Ariza, Ana
  • Dugarsuren, Narangarav
  • Ordoñez Alonso, Ángel Cristobal
A partir de los datos dendrométricos (diámetro y alturas), medidos en el año 2014 en dos parcelas permanentes de superficie una ha situadas en el Llano de San Marugán (Valladolid) y en Valdepoza (Palencia). Todos los árboles se georreferenciaron y se identifico su especie (Pinus sylvestris, Pinus nigra, Pinus pinea, Quercus pyrenaica, Quercus ilex, Quercus faginea y Juniperus thurifera). A partir de estos, se calcularon diez índices de diversidad que se clasifican en tres categorías (índices de riqueza de especies, índices de composición/mezcla de especies e índices de estructura), Based on dendrometric data (diameter and heights), measured in 2014 in two permanent plots of one ha located in Llano de San Marugán (Valladolid) and in Valdepoza (Palencia). All trees were georeferenced and their species identified (Pinus sylvestris, Pinus nigra, Pinus pinea, Quercus pyrenaica, Quercus ilex, Quercus faginea and Juniperus thurifera). From these, ten diversity indices were calculated and classified into three categories (species richness indices, species composition/mixture indices and structural indices)., Departamento de Producción Vegetal y Recursos Forestales, Universidad de Valladolid, Ministerio de Ciencia PCIN-2017-027. Mixed species forest management. Lowering risk, increasing resilience, REFORM: REsilience of FORest Mixtures, Fondo Europeo de Desarrollo Regional: SOE4/PA/E1012 COMFOR-SUDOE: Integrated and intelligent management of complex forests and mixed-species plantations in Southwest Europe.
Proyecto: EC/SOE4/PA




Caracterización probabilística de vidrio mediante diferentes tipos de ensayos

Archivo Digital UPM
  • Ramos, Alberto
  • Pelayo, F.
  • Lamela, María Jesús
  • Pryzbilla, C.
  • Fernández-Canteli, Alfonso
  • Huerta Gómez de Merodio, María Consuelo
  • Pacios Álvarez, Antonia
El vidrio no puede ser tratado como un material estructural convencional desde el punto de vista de la resistencia mecánica. Su naturaleza, como material frágil, junto con la inevitable presencia de microfisuras en su superficie y las consecuencias de accidentes por posibles fallos, exigen métodos rigurosos que garanticen un cálculo seguro de los elementos estructurales de vidrio, cuya resistencia a rotura depende en gran medida del tamaño del elemento y del tipo de carga a la que está sometido. Por lo tanto, su cálculo debe basarse en conceptos probabilísticos y en criterios de mecánica de la fractura, en sustitución de un cálculo convencional de vidrio según tablas deducidas de programas experimentales y posterior aplicación del concepto de tensiones admisibles. Con el fin de analizar y comparar las características mecánicas de vidrios templados, termoendurecidos y recocidos, se realizó un amplio programa experimental de ensayos de flexión a cuatro puntos y de anillos concéntricos de pequeña superficie, seguido de un ajuste de los resultados mediante una función de distribución triparamétrica de Weibull.

Glass cannot be handled as a conventional structural material from the point of view of the mechanical strength. Its nature as brittle material, together with the inevitable presence of micro-cracks on its surface and the consequences of eventual failures, demand rigorous methods to achieve a safe design for glass elements, whose stress resistance is very much dependent on the integrity of its surface, element size and loading pattern. Thus, its design must rely on probabilistic concepts and fracture mechanics criteria, substitutive of the conventional glass design based on charts derived from experimental programs and subsequent application of the admissible stress concept. In order to analyze and compare the strength characteristics of tempered, heat-strengthened and annealed glass, a large experimental programme based on four-point bending and coaxial double ring tests was performed and the results were fitted using a three-parameter Weibull cumulative distribution function.




Dispersive transmission line modeling in the Z-domain-application to the transient analysis of solid state microstrip circuits

Archivo Digital UPM
  • Alonso Montes, José Ignacio
  • Pérez Martínez, Félix
A technique for the modeling of microstrip transmission lines is presented. It is based on the simulation of line propagation characteristics by means of IIR (infinite-impulse-response) digital filters and allows the simulation of solid-state circuits constructed on dispersive microstrip lines. The distortion of Gaussian and square pulses when they are propagated along a line is studied by the stated technique.




Inclusion of dispersive effects of microstrip lines in formulation using state-space approach of nonlinear microwave circuits

Archivo Digital UPM
  • Alonso Montes, José Ignacio
  • Pérez Martínez, Félix
A method is presented to include the dispersive effects of transmission lines in microwave circuits in a formulation using a state space approach. The starting point are the IIR digital filter which approximate the forward impulse response and characteristic impedance




How to keep your information secure? Toward a better understanding of users security behavior

Archivo Digital UPM
  • Arenas, Álvaro E.
  • Ray, Gautam
  • Hidalgo Nuchera, Antonio
  • Urueña López, Alberto
Use of computers and the Internet is an integral part of our lives, with business becoming more digital. As a result, individuals are using their home computers to perform diverse tasks and to store sensitive data. This paper investigates the relative efficacy of two strategies to protect home computers from security threats: security tools and security activities. For the analysis, we collected data from over 1900 individuals in Spain, following an approach combining self- reported data, via an online survey, with actual data collected directly from home users' computers. The main contribution of the paper is to provide a model, based on routine activity theory, explaining the role of security tools and security activities in protecting personal computers from malware infection, thus offering an in-depth understanding of users' security behavior. Using multivariate, logit and probit regressions, our study reveals that having security tools is positively related with higher risk activities and more infections, while pursuing security activities reduces malware infections. These results have important implications for policy makers and organizations, reinforcing the view that security tools are not sufficient to protect users from malware infection, and the need to develop security education and awareness programs for computer users.




Addendum to: Improved global fit to non-standard neutrino interactions using COHERENT energy and timing data

Digital.CSIC. Repositorio Institucional del CSIC
  • Coloma, Pilar
  • Esteban, Iván
  • González-García, M. C.
  • Maltoni, Michele
In this addendum we re-assess the constraints on Non-Standard Interactions (NSI) from the combined analysis of data from oscillation experiments and from COHERENT after including the new data released since the publication of ref. [1]., This work was supported by the spanish grants FPA2016-76005-C2-1-P, FPA2016-78645-P,
PID2019-105614GB-C21 and PID2019-110058GB-C21, by USA-NSF grant PHY-1915093,
– 5 –
JHEP12(2020)071
by AGAUR (Generalitat de Catalunya) grant 2017-SGR-929, by EU ITN project H2020-
MSCA-ITN-2019/870881-HIDDeN, and by the Spanish Agencia Estatal de Investigación
through the grant “IFT Centro de Excelencia Severo Ochoa SEV-2016-0597”. IE acknowledges
support from the FPU program fellowship FPU15/0369. The authors acknowledge
use of the HPC facilities at the IFT (Hydra cluster)




Disentangling the relationship between tree biomass yield and tree diversity in mediterranean mixed forests

Digital.CSIC. Repositorio Institucional del CSIC
  • Bravo, Felipe
  • Ariza, Ana Martín
  • Dugarsuren, Narangarav
  • Ordóñez, Cristóbal
16 Pág.
Instituto de Ciencias Forestales (ICIFOR), Tree biomass and the diversity relationship in mixed forest have an impact on forest ecosystem services provisions. Tree biomass yield is driven by several aspects such as species identity, site condition, stand density, tree age and tree diversity expressed as species mingling and structural diversity. By comparing diverse degrees of tree mixtures in natural forests, we can gain insight into the ecosystem services provision level and dynamic. Two monitoring sites in the Castilian Northern Plateau (Spain) have been analyzed to disentangle the relationships between biodiversity levels and tree biomass yield. Two permanent one hectare (ha) squared plots were established at Llano de San Marugán and Valdepoza. In each plot, all individual trees were measured (diameter and height), georeferenced and its species identity defined. Tree species in the two sites were Pinus sylvestris, Pinus nigra, Pinus pinea, Quercus pyrenaica, Quercus ilex, Quercus faginea and Juniperus thurifera. From these datasets, ten diversity indices that fall in three categories (species richness indices, species compositional/mingling indices and vertical structural indices) were used as predictor variables to fit several candidate models. By merging the trees by site (without considering the species identity) selected models include individual tree basal area as an explanatory variable combining by addition or interaction with diversity indices. When species are analyzed independently, structural diversity impacts on biomass yield in combination (additive or multiplicative) with tree size is negative for Pinus nigra and positive for the other species., This paper has been funded partly by the projects PCIN-2017-027 (Mixed species forest management. Lowering risk, increasing resilience, REFORM: REsilience of FORest Mixtures funded by the Spanish Ministry of Science under the EU ERA-NET Sumforest: Sustainable forest management, multifunctional forestry, European Forest Policy) and COMFOR-SUDOE: Integrated and intelligent management of complex forests and mixed-species plantations in Southwest Europe (Project Code: SOE4/PA/E1012) through the European Regional Development Fund (ERDF) Narangarav Dugarsuren was funded by the EJMD MEDFOR (Erasmus +) The APC was funded by Universidad de Valladolid trough COMFOR-SUDOE funds., Peer reviewed




SPT analysis of hydrogen embrittlement in CrMoV welds

Repositorio Institucional de la Universidad de Burgos (RIUBU)
  • Álvarez, G.
  • Zafra, A.
  • Rodríguez, C.
  • Belzunce, J.
  • Cuesta Segura, Isidoro Iván
In this paper Small Punch Tests (SPT) are used to determine the mechanical properties of the heat affected zone (HAZ) of CrMoV welded joints and to evaluate the embrittlement caused by the presence of internal hydrogen. Hydrogen permeation tests were carried out to determine the effective diffusion coefficients of the different regions of welded joints, whose hydrogen contents were measured using a hydrogen analyser.

The paper demonstrates that SPTs can be used to estimate the tensile properties and the toughness of small areas, such as the subzones of a welded joint which are not thick enough for machining standard specimens. In cases where it is not possible to determine the fracture toughness of brittle regions using standard SPT samples, tests using longitudinally notched SPT samples were conducted. The normalized energy at failure,
, was selected as the most appropriate SPT parameter to estimate the fracture toughness regardless of the fracture behaviour of the material (ductile or brittle). It was seen that the fracture toughness of the fine grained HAZ (FG-HAZ) is similar to that of the Base Metal (BM), while the fracture toughness of the coarse grained HAZ (CG-HAZ) is more similar to that of the Weld Metal (WM). The effect of hydrogen on BM and FG-HAZ is low, with embrittlement indexes of about 20%. However, a strong effect of hydrogen was observed in CG-HAZs and WMs, with embrittlement indexes of 60–80%. and a clear change from ductile to brittle behaviour in their fracture surfaces., The authors would like to acknowledge the Spanish Ministry of Economy and Competitiveness and the Principality of Asturias government for the financing support given to the RTI2018-096070-B-C31 and IDI/2018/000134 projects, respectively. G. Álvarez (PA-20-PF-BP19-087) and A. Zafra (PA-18-PF-BP17-038) would also thank the Principality of Asturias for the financial support through the Severo Ochoa Scholarship Programme. Finally, the authors thank the Scientific and Technical Service, University of Oviedo, for the use of the SEM JEOL-JSM5600 scanning electron microscope.




Glutathione metabolism is essential for self-renewal and chemoresistance of pancreatic cancer stem cells

Zaguán. Repositorio Digital de la Universidad de Zaragoza
  • Jagust, P.
  • Alcalá, S.
  • Jr, B.S.
  • Heeschen, C.
  • Sancho, P.
BACKGROUND
Cellular metabolism regulates stemness in health and disease. A reduced redox state is essential for self-renewal of normal and cancer stem cells (CSCs). However, while stem cells rely on glycolysis, different CSCs, including pancreatic CSCs, favor mitochondrial metabolism as their dominant energy-producing pathway. This suggests that powerful antioxidant networks must be in place to detoxify mitochondrial reactive oxygen species (ROS) and maintain stemness in oxidative CSCs. Since glutathione metabolism is critical for normal stem cell function and CSCs from breast, liver and gastric cancer show increased glutathione content, we hypothesized that pancreatic CSCs also rely on this pathway for ROS detoxification. AIM To investigate the role of glutathione metabolism in pancreatic CSCs.
METHODS
Primary pancreatic cancer cells of patient-derived xenografts (PDXs) were cultured in adherent or CSC-enriching sphere conditions to determine the role of glutathione metabolism in stemness. Real-time polymerase chain reaction (PCR) was used to validate RNAseq results involving glutathione metabolism genes in adherent vs spheres, as well as the expression of pluripotency-related genes following treatment. Public TCGA and GTEx RNAseq data from pancreatic cancer vs normal tissue samples were analyzed using the webserver GEPIA2. The glutathione-sensitive fluorescent probe monochlorobimane was used to determine glutathione content by fluorimetry or flow cytometry. Pharmacological inhibitors of glutathione synthesis and recycling [buthionine-sulfoximine (BSO) and 6-Aminonicotinamide (6-AN), respectively] were used to investigate the impact of glutathione depletion on CSC-enriched cultures. Staining with propidium iodide (cell cycle), Annexin-V (apoptosis) and CD133 (CSC content) were determined by flow cytometry. Self-renewal was assessed by sphere formation assay and response to gemcitabine treatment was used as a readout for chemoresistance.
RESULTS
Analysis of our previously published RNAseq dataset E-MTAB-3808 revealed up-regulation of genes involved in the KEGG (Kyoto Encyclopedia of Genes and Genomes) Pathway Glutathione Metabolism in CSC-enriched cultures compared to their differentiated counterparts. Consistently, in pancreatic cancer patient samples the expression of most of these up-regulated genes positively correlated with a stemness signature defined by NANOG, KLF4, SOX2 and OCT4 expression (P < 10-5). Moreover, 3 of the upregulated genes (MGST1, GPX8, GCCT) were associated with reduced disease-free survival in patients [Hazard ratio (HR) 2.2-2.5; P = 0.03-0.0054], suggesting a critical role for this pathway in pancreatic cancer progression. CSC-enriched sphere cultures also showed increased expression of different glutathione metabolism-related genes, as well as enhanced glutathione content in its reduced form (GSH). Glutathione depletion with BSO induced cell cycle arrest and apoptosis in spheres, and diminished the expression of stemness genes. Moreover, treatment with either BSO or the glutathione recycling inhibitor 6-AN inhibited self-renewal and the expression of the CSC marker CD133. GSH content in spheres positively correlated with intrinsic resistance to gemcitabine treatment in different PDXs r = 0.96, P = 5.8 × 1011). Additionally, CD133+ cells accumulated GSH in response to gemcitabine, which was abrogated by BSO treatment (P < 0.05). Combined treatment with BSO and gemcitabine-induced apoptosis in CD133+ cells to levels comparable to CD133- cells and significantly diminished self-renewal (P < 0.05), suggesting that chemoresistance of CSCs is partially dependent on GSH metabolism.
CONCLUSION
Our data suggest that pancreatic CSCs depend on glutathione metabolism. Pharmacological targeting of this pathway showed that high GSH content is essential to maintain CSC functionality in terms of self-renewal and chemoresistance.




Deciphering pyramidanes: a quantum chemical topology approach

Zaguán. Repositorio Digital de la Universidad de Zaragoza
  • Vidal, Lucía
  • Barrena-Espés, Daniel
  • Echeverría, Jorge
  • Munárriz, Julen
  • Pendás, Ángel Martín
C[C4H4], the simplest compound of the [4]‐pyramidane family, has so far eluded experimental characterization, although several of its analogs, E[C4(SiMe3)4] in which the E apex atom is a tetrel group element, have been successfully prepared. The non‐classical bonding mode of E, similar to that found in propellanes, has prompted a considerable number of theoretical studies to unravel the nature of the apex‐base interaction. Here, we contribute to this knowledge by analyzing the electron localization function (ELF) and classical QTAIM descriptors; as well the statistical distribution of electrons in atomic regions by means of the so‐called electron distribution functions (EDFs), calculation of multicenter indices (MCI) as aromaticity descriptors and by performing orbital invariant energy decompositions with the interacting quantum atoms (IQA) approach on a series of E[C4(SiMe3)4] compounds. We find that the bonding evolves from covalent to electrostatic as E changes from C to Pb, with an anomaly when E=Si, which is shown to be the most charged moiety, compatible with an aromatic [C4(SiMe3)4]2− scaffold in the pyramidane base.