Search results for "Simulation"

Enhancing the performance of HSDPA communication with multipoint transmission techniques

2015

The evolution of mobile phones, tablets and other mobile communication devices has led to a significant increase in the amount of data delivered over mobile networks. In order to satisfy the climbing data rate demands of customers, existing mobile broadband networks are being expanded with new features that allow ubiquitous and consistent networking experience. This research presents three multipoint transmission techniques for Wideband Code Division Multiple Access (WCDMA) based High-Speed Downlink Packet Access (HSDPA) communication protocol. Multiflow, High-Speed Single-Frequency Network (HS-SFN) and Multipoint-to-Point Single-Frequency Network (M2P-SFN) enable transmission of user-dedicat…

Performance Enhancement of a Small Animal Positron Emission Tomograph based on Continuous Crystals and Silicon Photomultipliers

2017

La tomografía por emisión de positrones (PET, por sus siglas en inglés) es una técnica de Medicina Nuclear que permite obtener de manera no invasiva imágenes funcionales “in vivo” marcando un compuesto orgánico con un emisor de positrones. Los tomógrafos PET requieren un alta resolución espacial y sensibilidad para estimar con precisión la distribución del radiotrazador en el animal. Frente a los bloques pixelados comúnmente utilizados en PET, los detectores que consisten en la combinación de cristales continuos acoplados a fotodetectores segmentados pueden ofrecer una mayor eficiencia y una alta resolución espacial. Esta última depende de la precisión de los algoritmos de determinación de …

Représentation, analyse et caractérisation de surfaces rugueuses

2020

Nous présentons un projet de recherche dans lequel, nous proposons d’aborder la problématique de la représentation numérique, de l’analyse et de la caractérisation de surfaces rugueuses. La rugosité est un concept complexe, par nature multi-échelle et reposant sur l’étude du comportement local d’une surface dans un voisinage donné. Son évaluation sur les surfaces est essentielle pour de nombreux problèmes expérimentaux. Cela explique les nombreuses études réalisées dans les domaines applicatifs liés à la physique et la mécanique, là où le contrôle et la maîtrise de l’état des surfaces constituent un besoin majeur pour les industriels. Un grand nombre de paramètres conventionnels normalisés …

Conditional predictive inference for online surveillance of spatial disease incidence

2011

This paper deals with the development of statistical methodology for timely detection of incident disease clusters in space and time. The increasing availability of data on both the time and the location of events enables the construction of multivariate surveillance techniques, which may enhance the ability to detect localized clusters of disease relative to the surveillance of the overall count of disease cases across the entire study region. We introduce the surveillance conditional predictive ordinate as a general Bayesian model-based surveillance technique that allows us to detect small areas of increased disease incidence when spatial data are available. To address the problem of mult…

Highly-parallelized simulation of a pixelated LArTPC on a GPU

2023

The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The alg…

Multipoint transmission scheme for HSDPA

2013

Spatial Cognition 2020/1: Book of abstracts : August 2-4, 2021, University of Latvia

2021

Spatial Cognition is concerned with the acquisition, development, representation, organization, and use of knowledge about spatial objects in real, virtual or hybrid environments and processed by human or artificial agents. Spatial Cognition includes research from different fields insofar as they are concerned with cognitive agents and space, such as cognitive and developmental psychology, linguistics, computer science, geography, cartography, philosophy, neuroscience, and education. Research issues in the field range from the investigation of human spatial cognition to mobile robot navigation, including topics such as wayfinding, spatial planning, spatial learning, internal and external re…

STUDY OF LARGE PELAGIC FISH LIFE-HISTORY TRAITS IN THE CENTRAL MEDITERRANEAN SEA AND PROJECTION UNDER FUTURE CLIMATE CHANGE SCENARIOS

2022

One of the most sensitive life periods for each species is the first life stages (larval and juvenile). The survival rates of pelagic fish larvae in these phases are usually very low and subject to fluctuations, consequently affecting the recruitment of new generations. From historical Tuna landing data, the stock's abundance is fluctuating, especially for Atlantic Bluefin Tuna (ABT) (Thunnus thynnus, Linnaeus, 1758) Eastern stock. It is the largest Mediterranean Tuna and one of the most expensive species in the world. Some studies hypothesized that the fluctuations are dictated by environmental factors, particularly in the early life stages. Therefore, it appears necessary to better unders…

Redesign of a Reverse Shoulder Prosthesis: Kinematic and Mechanical Study

2014

In this work a commercial reverse shoulder prosthesis has been redesigned to improve performances in terms of range of movements of the implant and stability to dislocation. A kinematic and mechanic study has been performed using a realistic solid model of the prothesised shoulder: in particular, all the components of the prosthesis have been acquired via a 3D laser scanner and inserted in a virtual humerus-glenoid system by reproducing the common surgical procedure. The final model has been used to measure the maximum angles of abduction and rotation of the arm and the shear forces that cause dislocation. Modifications proposed to the commercial prosthesis are: a different orientation of t…

Kinematics of the patellofemoral joint. Investigations on a computer model with reference to patellar fractures.

1990

Patellofemoral kinematics were studied on a computer model. The articulating point of the patella moves from distal to proximal during flexion, until the quadriceps tendon starts to turn around the femur tendo-femoral gliding. The pattern of patellofemoral movement consists of a gliding and rolling component, the latter at its maximum at the beginning of flexion. The pathway of the instant centers of motion moves from dorsal to ventral during flexion. Stress analysis shows that the contact area is at all times the area of maximum bending stress. The distal part of the patella is the part with mechanical stress at all angles of flexion. The conclusions to be drawn for treatment are that frac…