952 resultados para Mobile communication system
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We present a system for dynamic network resource configuration in environments with bandwidth reservation. The proposed system is completely distributed and automates the mechanisms for adapting the logical network to the offered load. The system is able to manage dynamically a logical network such as a virtual path network in ATM or a label switched path network in MPLS or GMPLS. The system design and implementation is based on a multi-agent system (MAS) which make the decisions of when and how to change a logical path. Despite the lack of a centralised global network view, results show that MAS manages the network resources effectively, reducing the connection blocking probability and, therefore, achieving better utilisation of network resources. We also include details of its architecture and implementation
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This research work deals with the problem of modeling and design of low level speed controller for the mobile robot PRIM. The main objective is to develop an effective educational tool. On one hand, the interests in using the open mobile platform PRIM consist in integrating several highly related subjects to the automatic control theory in an educational context, by embracing the subjects of communications, signal processing, sensor fusion and hardware design, amongst others. On the other hand, the idea is to implement useful navigation strategies such that the robot can be served as a mobile multimedia information point. It is in this context, when navigation strategies are oriented to goal achievement, that a local model predictive control is attained. Hence, such studies are presented as a very interesting control strategy in order to develop the future capabilities of the system
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This paper is focused on the robot mobile platform PRIM (platform robot information multimedia). This robot has been made in order to cover two main needs of our group, on one hand the need for a full open mobile robotic platform that is very useful in fulfilling the teaching and research activity of our school community, and on the other hand with the idea of introducing an ethical product which would be useful as mobile multimedia information point as a service tool. This paper introduces exactly how the system is made up and explains just what the philosophy is behind this work. The navigation strategies and sensor fusion, where machine vision system is the most important one, are oriented towards goal achievement and are the key to the behaviour of the robot
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This work extends a previously developed research concerning about the use of local model predictive control in differential driven mobile robots. Hence, experimental results are presented as a way to improve the methodology by considering aspects as trajectory accuracy and time performance. In this sense, the cost function and the prediction horizon are important aspects to be considered. The aim of the present work is to test the control method by measuring trajectory tracking accuracy and time performance. Moreover, strategies for the integration with perception system and path planning are briefly introduced. In this sense, monocular image data can be used to plan safety trajectories by using goal attraction potential fields
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We present a system for dynamic network resource configuration in environments with bandwidth reservation and path restoration mechanisms. Our focus is on the dynamic bandwidth management results, although the main goal of the system is the integration of the different mechanisms that manage the reserved paths (bandwidth, restoration, and spare capacity planning). The objective is to avoid conflicts between these mechanisms. The system is able to dynamically manage a logical network such as a virtual path network in ATM or a label switch path network in MPLS. This system has been designed to be modular in the sense that in can be activated or deactivated, and it can be applied only in a sub-network. The system design and implementation is based on a multi-agent system (MAS). We also included details of its architecture and implementation
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One of the things about Apple's walled garden iBooks system is the only way to share what you've created in iBooks Author is via the iPad or a PDF preview... So, for those of you who haven't got an iPad... but don't try clicking on the videos or the slideshows.
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Slide to go with Panopto recording for MA Communication Design on best practice for mobile ui design and some basic JQuery Mobile Customisation. Big thanks to Jonathan Stark Luke Wroblewski Jared Spool Without whom this would not have been made
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El acceso a la telefonía móvil en Colombia evidencia ciertas particularidades con respecto a otros países. En Colombia surgió una nueva alternativa de comunicación que consistía en la venta de minutos de celular en las calles y en pequeños negocios durante los primeros años de ésta década. En este documento se analizan las principales características de quienes usan esta modalidad de comunicación con base en una encuesta dirigida a usuarios y no usuarios de bajos ingresos. Se usa un modelo probabilístico para explicar las características de las personas que lo usan y se encuentra que las personas que están en la modalidad de contrato prepago y que viven en ciudades pequeñas tienen una mayor probabilidad de usar esta alternativa de comunicación. De otro lado se encuentra que quienes están con el operador dominante tienden a usar este servicio también de una forma más notoria. Estos resultados parecen indicar que los diferenciales de precios entre las llamadas off-net y on-net así como entre prepago y postpago son los que alimentaron el surgimiento de esta actividad
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LocalGIS-DOS es la nueva versión oficial de LocalGIS, el Sistema de Información Territorial Software Libre para Entidades Locales que surgió a iniciativa del Ministerio de Industria, Turismo y Comercio y que está englobado dentro del Plan Avanza. La nueva versión LocalGIS-DOS, que estará disponible en marzo de 2010 coincidiendo con las IV Jornadas de SIG Libre de Girona, va a contar con nuevos módulos que dotarán a LocalGIS de importantes mejoras tecnológicas y funcionales de Gestión Municipal. LocalGIS-DOS incluye un nuevo módulo de Enrutamiento y Cálculo de rutas, tanto en el Módulo de Editor GIS como en la Guía Urbana, que permitirá calcular caminos óptimos y zonas de influencia. El nuevo módulo de Movilidad facilitará la gestión de información municipal desde dispositivos móviles, con herramientas para la edición y visualización de la misma y para su correcta replicación con la base de datos central. LocalGIS-DOS permitirá gestionar varios municipios con intereses comunes de forma simultánea, creando el concepto de Entidad Supramunicipal, pudiendo así gestionar de forma conjunta capas, estilos y usuarios. Esta nueva versión incorpora también la Variable Temporal a las capas de información, permitiendo a los usuarios seleccionar por fechas la información que desean visualizar, facilitando así la elaboración de estudios temporales georreferenciados y el versionado histórico de mapas. También incluye un nuevo Módulo de Gestión de la Ciudad, desde donde se gestionarán avisos, mantenimientos y obras ubicadas en el suelo público. Finalmente indicar que a nivel tecnológico LocalGIS-DOS contará, entre otras, con mejoras relativas al acceso a bases de datos externas, al canal cifrado de comunicación, firma digital de documentos y mejoras en la generación de informes
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Eye tracking has become a preponderant technique in the evaluation of user interaction and behaviour with study objects in defined contexts. Common eye tracking related data representation techniques offer valuable input regarding user interaction and eye gaze behaviour, namely through fixations and saccades measurement. However, these and other techniques may be insufficient for the representation of acquired data in specific studies, namely because of the complexity of the study object being analysed. This paper intends to contribute with a summary of data representation and information visualization techniques used in data analysis within different contexts (advertising, websites, television news and video games). Additionally, several methodological approaches are presented in this paper, which resulted from several studies developed and under development at CETAC.MEDIA - Communication Sciences and Technologies Research Centre. In the studies described, traditional data representation techniques were insufficient. As a result, new approaches were necessary and therefore, new forms of representing data, based on common techniques were developed with the objective of improving communication and information strategies. In each of these studies, a brief summary of the contribution to their respective area will be presented, as well as the data representation techniques used and some of the acquired results.
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Mobile internet represents a major new trend in communication technologies use and consumption, but few evidence exists that confirms claims of novelty and social change in association with this technology use. This paper characterizes the use of mobile internet in a southern European country and associated patterns of use, focusing both on users’ profiles, forms of access, motivations to use and most popular activities undertaken via this technology, from a diffusion of innovations and social adoption of technologies perspectives, and tries to compare mobile it with fixed access to the internet in order to validate possible transformations that point to new social configurations. We seek to understand the way stakeholders perceive and characterize the European context of mobile internet. The depicted study involved a qualitative stage consisting of a set of interviews with mobile communications industry representatives and market research community in the country. These interviews were analysed in Nvivo, leading to the following eleven main categories that are explored throughout the paper: smartphones in Europe, mobile internet in Europe, users profiles, obstacles to the spread, forms of access, forms of use, motivations to use mobile internet, limitations of smartphones, apps, digital divide VS digital union and predictions for the future, as well as several subcategories forming a tree categorization. According to the data collected, mobile phones’ sales are decreasing in Europe and worldwide but on the other hand smartphones are having an exponential growth which leads to the democratization of internet access via mobile devices. As a consequence of this, it is believed that mobile internet access will soon exceed the fixed one. Mobile internet users are multiplatform, they exploit all the possibilities of mobility and they are spending less time on computers. The main obstacles to the spread of mobile internet are the high prices of price plans and there is still a lack of information and knowledge regarding the service. Mobile internet users are developing new online surfing behaviours based on apps and less in browsers and social networks represent a very high share of internet traffic through mobile phones. With mobility, “dead time” is turning into useful time and users are more likely to be available to try new services and analyze products. Innovative services concerning geolocation, consumerism, share and relationships are growing and it is necessary to highlight that mobile internet allows calling and texting, which can turn telecommunications companies into the role of Dump Pipes. This exploratory design raises questions in relation with mobile internet access and its social consequences, and provides interesting indicative research results relevant for future research in this area.
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A recent area for investigation into the development of adaptable robot control is the use of living neuronal networks to control a mobile robot. The so-called Animat paradigm comprises a neuronal network (the ‘brain’) connected to an external embodiment (in this case a mobile robot), facilitating potentially robust, adaptable robot control and increased understanding of neural processes. Sensory input from the robot is provided to the neuronal network via stimulation on a number of electrodes embedded in a specialist Petri dish (Multi Electrode Array (MEA)); accurate control of this stimulation is vital. We present software tools allowing precise, near real-time control of electrical stimulation on MEAs, with fast switching between electrodes and the application of custom stimulus waveforms. These Linux-based tools are compatible with the widely used MEABench data acquisition system. Benefits include rapid stimulus modulation in response to neuronal activity (closed loop) and batch processing of stimulation protocols.
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The intelligent controlling mechanism of a typical mobile robot is usually a computer system. Research is however now ongoing in which biological neural networks are being cultured and trained to act as the brain of an interactive real world robot – thereby either completely replacing or operating in a cooperative fashion with a computer system. Studying such neural systems can give a distinct insight into biological neural structures and therefore such research has immediate medical implications. The principal aims of the present research are to assess the computational and learning capacity of dissociated cultured neuronal networks with a view to advancing network level processing of artificial neural networks. This will be approached by the creation of an artificial hybrid system (animat) involving closed loop control of a mobile robot by a dissociated culture of rat neurons. This paper details the components of the overall animat closed loop system architecture and reports on the evaluation of the results from preliminary real-life and simulated robot experiments.
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We present a general Multi-Agent System framework for distributed data mining based on a Peer-to-Peer model. Agent protocols are implemented through message-based asynchronous communication. The framework adopts a dynamic load balancing policy that is particularly suitable for irregular search algorithms. A modular design allows a separation of the general-purpose system protocols and software components from the specific data mining algorithm. The experimental evaluation has been carried out on a parallel frequent subgraph mining algorithm, which has shown good scalability performances.