Search results for " Telecom"
showing 10 items of 1269 documents
Semantically-enhanced advertisement recommender systems in social networks
2016
El suministro de recomendaciones en los sistemas sociales lleva ya algún tiempo en el punto de mira tanto de los académicos como de la industria. Los gigantes de las redes sociales como Facebook, LinkedIn, Myspace, etc., están ansiosos por encontrar la bala de plata de la recomendación. Estas aplicaciones permiten a los clientes dar forma a unas determinadas redes sociales a través de sus comunicaciones sociales cooperativas cotidianas. Mientras tanto, la experiencia online actual depende progresivamente de la asociación social. Una de las principales preocupaciones en la red social es establecer un plan de negocio exitoso para obtener más beneficios de la red social. Hacer un negocio en ca…
A low complexity distributed cluster based algorithm for spatial prediction
2017
Los mapas del entorno radioeléctrico (REM) pueden ser una herramienta esencial para numerosas aplicaciones en las futuras redes inalámbricas 5G. En este trabajo, empleamos un popular método geoestadístico llamado kriging ordinario para estimar el REM de un área cubierta por un eNodeB equipado con múltiples antenas. Los sensores inalámbricos se distribuyen por el área de interés y se organizan clústeres adaptativos de sensores para mejorar la calidad de la estimación del canal. En este trabajo, modificamos el algoritmo de clustering distribuido propuesto en un trabajo anterior para reducir la complejidad de la predicción de kriging. Se realizan simulaciones para detallar la técnica de formac…
Distributed channel prediction for multi-agent systems
2017
Los sistemas multiagente (MAS) se comunican a través de una red inalámbrica para coordinar sus acciones e informar sobre el estado de su misión. La conectividad y el rendimiento del sistema pueden mejorarse mediante la predicción de la ganancia del canal. Presentamos un esquema basado en regresión de procesos gaussianos (GPR) distribuidos para predecir el canal inalámbrico en términos de la potencia recibida en el MAS. El esquema combina una máquina de comité bayesiano con un esquema de consenso medio, distribuyendo así no sólo la memoria sino también la carga computacional y de comunicación. A través de simulaciones de Monte Carlo, demostramos el rendimiento del GPR propuesto. RACHEL TEC20…
Conversión de formatos de proyección y codificación basada en campo de visión para streaming adaptativo de videos 360º utilizando DASH
2019
En este trabajo final de grado se ha extendido una plataforma extremo-a-extremo para la preparación, distribución y reproducción de vídeos 360º con tal de poder adoptar proyecciones CMP homogéneas, existentes hasta la fecha, además de otras configuraciones más avanzadas que permiten concentrar la resolución en áreas concretas del video 360º. In this final degree project, an end-to-end platform has been extended for the preparation, distribution and playback of 360º videos in order to be able to adopt homogeneous CMP projections, existing to date, in addition to other more advanced configurations that allow concentrating the resolution in specific areas of the 360º video.
Color constancy in dermatoscopy with smartphone
2017
The recent spread of cheap dermatoscopes for smartphones can empower patients to acquire images of skin lesions on their own and send them to dermatologists. Since images are acquired by different smartphone cameras under unique illumination conditions, the variability in colors is expected. Therefore, the mobile dermatoscopic systems should be calibrated in order to ensure the color constancy in skin images. In this study, we have tested a dermatoscope DermLite DL1 basic, attached to Samsung Galaxy S4 smartphone. Under the controlled conditions, jpeg images of standard color patches were acquired and a model between an unknown device-dependent RGB and a device independent Lab color space h…
Proportional and Preemption-Enabled Traffic Offloading for IP Flow Mobility: Algorithms and Performance Evaluation
2018
IP Flow Mobility (IFOM) enables a user equipment to offload data traffic at the IP flow level. Although the procedure of IFOM-based flow offloading has been specified by 3GPP, how many IP flows should be offloaded and when offloading should be performed are not defined. Consequently, IP flows may be routed to a target access network which has a strong signal strength but with backhaul congestion or insufficient access capability. In this paper, we propose two algorithms, referred to as proportional offloading (PO), and proportional and preemption-enabled offloading (PPO), respectively, for IP flow offloading in hybrid cellular and wireless local area networks. The PO algorithm decides an op…
A Metaheuristic Bandwidth Allocation Scheme for FiWi Networks Using Ant Colony Optimization
2015
Optical-wireless access networks constitute a quite attractive solution to meet the ever-increasing bandwidth requirements of end-users, offering significant benefits such as ubiquitous coverage in the wireless domain and huge bandwidth in the optical domain. However, converging optical and wireless networking technologies, with Passive Optical Networks (PONs) and 4G wireless standards, such as the Worldwide Interoperability for Microwave Access (WiMAX) and the Long Term Evolution (LTE), entails major challenges that need to be addressed. In this context, designing an efficient and fair bandwidth distribution with Quality of Service (QoS) support is a difficult task due to the interdependen…
Cloud-based eHealth video encoding system for real time thermographic streaming: Performance evaluation
2017
Recent studies about the use of cloud platforms indicate that more than three-fourths of healthcare institutions apply these technologies in their daily lives. However, in most cases the cloud is based on “Infrastructure as a Service”, instead of developing new applications using the benefits that can bring us this type of technology. For these reasons, this paper shows a private cloud-based system to provide a new application based on thermographic video streaming. In this case, the cloud architecture is divided into three zones. The first zone is where the patient is under medical supervision through body temperature analysis using a global thermal camera. The second zone is the cloud its…
A Hierarchical Detection and Response System to Enhance Security Against Lethal Cyber-Attacks in UAV Networks
2018
International audience; Unmanned aerial vehicles (UAVs) networks have not yet received considerable research attention. Specifically, security issues are a major concern because such networks, which carry vital information, are prone to various attacks. In this paper, we design and implement a novel intrusion detection and response scheme, which operates at the UAV and ground station levels, to detect malicious anomalies that threaten the network. In this scheme, a set of detection and response techniques are proposed to monitor the UAV behaviors and categorize them into the appropriate list (normal, abnormal, suspect, and malicious) according to the detected cyber-attack. We focus on the m…
Utility-based resource allocations in multi-hop wireless networks
2011
It is well known that CSMA (Carrier Sense Multiple Access) protocols exhibit very poor performance in case of multi-hop transmissions, because of inter-link interference due to imperfect carrier sensing. Since ad-hoc networks based on multihop packet deliveries are becoming more and more common in different application and networking scenarios, different medium access control extensions are currently considered for improving the channel utilization efficiency. In this paper, we propose a simple approach based on preallocating temporal slots in which different sets of nodes are allowed to contend for the channel access, which can significantly improve CSMA performance with limited signaling …