2,379 research outputs found
Enhancing the Expressivity of Variational Neural, and Hardware-Efficient Quantum States Through Orbital Rotations
Variational approaches, such as variational Monte Carlo (VMC) or the
variational quantum eigensolver (VQE), are powerful techniques to tackle the
ground-state many-electron problem. Often, the family of variational states is
not invariant under the reparametrization of the Hamiltonian by single-particle
basis transformations. As a consequence, the representability of the
ground-state wave function by the variational ansatz strongly dependents on the
choice of the single-particle basis. In this manuscript we study the joint
optimization of the single-particle basis, together with the variational state
in the VMC (with neural quantum states) and VQE (with hardware-efficient
circuits) approaches. We show that the joint optimization of the
single-particle basis with the variational state parameters yields significant
improvements in the expressive power and optimization landscape in a variety of
chemistry and condensed matter systems. We also realize the first active-space
calculation using neural quantum states, where the single-particle basis
transformations are applied to all of the orbitals in the basis set
Stress vs sputtering effects in the propagation of surface ripples produced by ion-beam sputtering
The proceeding at: 19th International Conference on Ion Beam Modification of Materials
(IBMM 2014). Took place at 2014, September, 14-19, in Bruges (Belgium). The event Web Site in https://iks32.fys.kuleuven.be/indico/event/16/Under low energy ion irradiation, periodic features (ripples) can develop on the surfaces of semiconductor materials, with typical sizes in the nanometric range. Recently, a theory of pattern formation has been able to account for the variability with the ion/target combination of the critical angle value separating conditions on ion incidence that induce the presence or the absence of ripples. Such a theory is based in the accumulation of stress in the damaged irradiated layer and its relaxation via surface-confined viscous flow. Here we explore the role of stress, and its competition with purely erosive mechanisms, to deter-mine the sign of the velocity with which the ripple pattern moves across the target plane. Based on this theory, we discuss different situations and make specific testable predictions for the change of sign in that velocity.Our work has been funded through MINECO (Spain) grants
FIS2012-38866-C05-01, FIS2012-32349, and FIS2013-47949-C2-2.
A.M.-B. acknowledges support from MINECO, through FPI scholarship
BES-2010-036179.Publicad
Applications of Polidocanol in Varicose Vein Treatment Assisted by Exposure to Nd:YAG Laser Radiation
Efficient Floating-Point Representation for Balanced Codes for FPGA Devices
Trabajo premiado con Best paper AwardWe propose a floating–point representation to deal
efficiently with arithmetic operations in codes with a balanced
number of additions and multiplications for FPGA devices. The
variable shift operation is very slow in these devices. We propose
a format that reduces the variable shifter penalty. It is based on
a radix–64 representation such that the number of the possible
shifts is considerably reduced. Thus, the execution time of the
floating–point addition is highly optimized when it is performed
in an FPGA device, which compensates for the multiplication
penalty when a high radix is used, as experimental results have
shown. Consequently, the main problem of previous specific highradix
FPGA designs (no speedup for codes with a balanced
number of multiplications and additions) is overcome with our
proposal. The inherent architecture supporting the new format
works with greater bit precision than the corresponding single
precision (SP) IEEE–754 standard.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. IEEE, IEEE Computer Societ
Federated identity architecture of the european eID system
Federated identity management is a method that facilitates management of identity processes and policies among the collaborating entities without a centralized control. Nowadays, there are many federated identity solutions, however, most of them covers different aspects of the identification problem, solving in some cases specific problems. Thus, none of these initiatives has consolidated as a unique solution and surely it will remain like that in a near future. To assist users choosing a possible solution, we analyze different federated identify approaches, showing main features, and making a comparative study among them. The former problem is even worst when multiple organizations or countries already have legacy eID systems, as it is the case of Europe. In this paper, we also present the European eID solution, a purely federated identity system that aims to serve almost 500 million people and that could be extended in midterm also to eID companies. The system is now being deployed at the EU level and we present the basic architecture and evaluate its performance and scalability, showing that the solution is feasible from the point of view of performance while keeping security constrains in mind. The results show a good performance of the solution in local, organizational, and remote environments
Resource allocation and management techniques for network slicing in WiFi networks
© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Network slicing has recently been proposed as one of the main enablers for 5G networks; it is bound to cope with the increasing and heterogeneous performance requirements of these systems. To "slice" a network is to partition a shared physical network into several self-contained logical pieces (slices) that can be tailored to offer different functional or performance requirements. Moreover, a defining characteristic of the slicing paradigm is to provide resource isolation as well as efficient use of resources. In this context, the thesis described in this paper contributes to the problem of slicing WiFi networks by proposing a solution to the problem of enforcing and controlling slices in WiFi Access Points. The focus of the research is on a variant of network slicing called QoS Slicing, in which slices have specific performance requirements. In this document, we describe the two main contributions of our research, a resource allocation mechanism to assign resources to slices, and a solution to enforce and control slices with performance requirements in WiFi Access Points.This work has been supported by the European Commission and the Spanish Government (Fondo Europeo de Desarrollo Regional, FEDER) by means of the EU H2020 NECOS (777067) and ADVICE (TEC2015-71329) projects.Peer ReviewedPostprint (author's final draft
Gamificación y e-learning: estudio de un contexto universitario para la adecuación de su diseño
Gamification, applied to educational contexts, can increase the motivation and engagement of students. First analysis of the bibliography tells that there is not enough research done in this topic, and there are few guidelines marked to implement gamification. This work aims to generate hypotheses that guide the design of a future pilot study in e-learning high education. Students and teachers from the Master of Education and New Technologies at the Madrid Open University (UDIMA) have been tested. The methodology includes qualitative and quantitative aspects and two different on-line questionnaires. Student’s questionnaire included a translation of the BrainHex test. Conclusions about the gamification characteristics which are more suitable in this e-learning high education context are generated using these results and through a review of existing research: related to the acceptance of gamification by students and teachers; related to the type of gamification elements that are more suitable for use in the context at the UDIMA and related to aspects or behaviors that need to be changed through the motivation of students.La «gamificación», aplicada a la educación, puede afectar positivamente a la motivación e implicación del alumnado, si bien aún existen pocas investigaciones que respalden sus bondades y marquen pautas sobre cómo realizar este proceso. Este trabajo tiene como objetivo generar hipótesis dirigidas a facilitar el diseño de un futuro estudio piloto en el ámbito de la educación superior en modalidad e-learning. Para ello, se estudiaron factores relacionados con el alumnado y el profesorado del Máster de Educación y Nuevas Tecnologías de la Universidad a Distancia de Madrid (UDIMA). La metodología utilizada combina aspectos cualitativos y cuantitativos con una finalidad descriptiva y exploratoria. Para la obtención de datos se utilizaron dos cuestionarios on-line diferentes para el profesorado y el alumnado, incluyéndose en este último una traducción del test BrainHex. A partir de los datos y de la revisión de la literatura existente se generan conclusiones acerca de la aceptación del alumnado y del profesorado respecto a la introducción de la gamificación en la formación, sobre qué tipo de elementos de gamificación son más adecuados para su uso en el contexto de la UDIMA y a la motivación de qué aspectos o conductas deberían dirigirse para su éxito
MOBILE APPLICATION WITH AUGMENTED REALITY FOR THE TOURIST EXPERIENCE: A CASE STUDY IN THE DISTRICT OF CASA GRANDE, PERUVIAN NORTH COAST
When visiting the Casa Grande District, tourists arrive at the Main Square, from where they see around them many buildings to which they only take pictures and then leave, but they do not know about the history and value that each of them represents. Thus, the objective of this research is to value the diverse architectural heritage that the Casa Grande District has and at the same time improve the tourist experience, through the use of a Mobile Application with Augmented Reality. To carry out the experimental research, the agile Mobile-D methodology was used, which has 5 phases: Exploration, Initiation, Production, Stabilization and Testing; in the Research Design, two groups were used: Experimental Group (Ge) and Control Group (Gc), while Student's t-test was used to validate the hypotheses. Finally, the results revealed that the Mobile Application with augmented reality presented better results in the Ge with respect to the Gc in each of the indicators: time and cost of access to information, the number of visits and the satisfaction of tourists
Lagochilascaris minor Leiper, 1909 (Nematoda: Ascarididae) in Mexico: three clinical cases from the Peninsula of Yucatan
Human lagochilascariasis (HL) is a parasite produced by Lagochilascaris minor Leiper 1909 that also can be found in cats and dogs. HL is considered an emerging zoonosis in the Americas, spreading from Mexico to Argentina, and the Caribbean Islands. The present paper describes three HL cases from the Peninsula of Yucatan, Mexico, recorded in the last decade. It describes the characteristics of the lesions and discusses the route of transmission in humans and particularly in the observed patients.La Lagochilascariasis humana (HL) es producida por Lagochilascaris minor Leiper, 1909; el cual es un parásito que puede ser encontrado también en gatos y perros. HL es considerada una zoonosis emergente en América distribuida desde México hasta Argentina y las islas del Caribe. El presente artículo describe tres casos de HL en la Península de Yucatán, México registrados en la última década. Se describen las características de las lesiones y se discute la ruta de transmisión en humanos y particularmente en los pacientes observados
Integración de un Planificador de Trayectorias Parametrizado en la Arquitectura Robótica ROS
En este trabajo se presenta la integración de un nuevo planificador reactivo de movimiento dentro de la arquitectura robótica ROS. Este planificador, desarrollado originalmente como parte de la librería MRPT y basado en el Espacio de Trayectorias Parametrizado (TP-Space), amplia las posibilidades de navegación de las plataformas robóticas actuales mediante la generación de trayectorias tanto circulares como no-circulares, así como la posibilidad de contemplar la geometría 3D del robot (no restringiéndose a formas prismáticas). La integración se ha realizado garantizando la compatibilidad con el stack de navegación autónoma más popular de la plataforma ROS, adaptando el funcionamiento de dicho reactivo a la interfaz de comunicación estándar de ROS, siendo este compatible con los planificadores globales existentes. Para validar este trabajo, se han realizado múltiples pruebas de navegación en entornos de interior (tanto simulados como reales), con presencia de obstáculos y donde la plataforma robótica es equipada con diversas cámaras RGB-D y un escáner láser.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.
Proyecto WISER (DPI2017-84827-R), financiado por el Ministerio de Ciencia e Innovación contando con fondos del Fondo Europeo de Desarrollo Regional (FEDER)
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