Search results for "NETWORKS"
showing 10 items of 3260 documents
Development of handcrafted and deep based methods for face and facial expression recognition
2021
The research objectives of this thesis concern the development of new concepts for image segmentation and region classification for image analysis. This involves implementing new descriptors, whether color, texture, or shape, to characterize regions and propose new deep learning architectures for the various applications linked to facial analysis. We restrict our focus on face recognition and person-independent facial expressions classification tasks, which are more challenging, especially in unconstrained environments. Our thesis lead to the proposal of many contributions related to facial analysis based on handcrafted and deep architecture.We contributed to face recognition by an effectiv…
Reduced complexity models in the identification of dynamical networks: Links with sparsification problems
2009
In many applicative scenarios it is important to derive information about the topology and the internal connections of more dynamical systems interacting together. Examples can be found in fields as diverse as Economics, Neuroscience and Biochemistry. The paper deals with the problem of deriving a descriptive model of a network, collecting the node outputs as time series with no use of a priori insight on the topology. We cast the problem as the optimization of a cost function operating a trade-off between accuracy and complexity in the final model. We address the problem of reducing the complexity by fixing a certain degree of sparsity, and trying to find the solution that “better” satisfi…
Estado de la investigación sobre la colaboración en Entornos Virtuales de Aprendizaje
2019
El aprendizaje colaborativo posee una tradición teórica y práctica amplia en la educación general, como en la educación superior. No obstante, la actividad de coordinación entre personas que buscan aprender no es sencilla de gestionar. Esta complejidad aumenta cuando entre la actividad colaborativa surge un nuevo componente, la tecnología. ¿Qué se ha avanzado sobre el aprendizaje colaborativo mediado tecnológicamente? Este trabajo tiene como objetivo analizar el estado de la investigación sobre aprendizaje colaborativo en Educación Superior en los Entornos Virtuales de Aprendizaje (EVA). Para ello se realiza un análisis bibliométrico de las publicaciones indexadas de la base de datos SCOPUS…
Arc routing problems: A review of the past, present, and future
2020
[EN] Arc routing problems (ARPs) are defined and introduced. Following a brief history of developments in this area of research, different types of ARPs are described that are currently relevant for study. In addition, particular features of ARPs that are important from a theoretical or practical point of view are discussed. A section on applications describes some of the changes that have occurred from early applications of ARP models to the present day and points the way to emerging topics for study. A final section provides information on libraries and instance repositories for ARPs. The review concludes with some perspectives on future research developments and opportunities for emergin…
The Vuelo Ruiz de Alda (1929-30): an exceptional cartographic document. Again about Ilici
2015
Se presenta en este artículo una primera valoración de las posibilidades que para la arqueología, y más concretamente para la estratigrafía del paisaje, encierra un soberbio documento como es la serie fotográfica conocida como Vuelo Ruiz de Alda (1929-30), una vez que los fotogramas han sido ampliamente puestos al alcance de la investigación. Para ello se ponen a prueba las imágenes aplicándolas a dos establecimientos de época ibérica antigua (El Oral y El Molar). Igualmente, se ha retomado una línea de investigación a propósito de la red caminera que afecta al enclave de La Alcudia-Ilici, lo que lleva implícitamente a tratar sobre su catastro romano y la trama parcelaria de todo su entorno…
Special Issue “Smart Urban Lighting Systems”
2020
The design and operation of multifunctional infrastructures for public lighting as well as their impact on the urban environment and citizens’ life is today of great interest. The cost of energy for public lighting is often an issue for the budget of municipalities. Furthermore, researchers’ and designers’ attention is increasingly focused on aspects of public lighting not directly valuable through economic factors. Starting from the “quality” of the light environment, looking at citizens’ visual comfort, the light has to be considered as an instrument to improve the urban context and objects therein (including buildings). Indeed, urban degradation (lack of infrastructures, maintenance, ser…
Modeling the insect mushroom bodies: application to a delayed match-to-sample task.
2013
Despite their small brains, insects show advanced capabilities in learning and task solving. Flies, honeybees and ants are becoming a reference point in neuroscience and a main source of inspiration for autonomous robot design issues and control algorithms. In particular, honeybees demonstrate to be able to autonomously abstract complex associations and apply them in tasks involving different sensory modalities within the insect brain. Mushroom Bodies (MBs) are worthy of primary attention for understanding memory and learning functions in insects. In fact, even if their main role regards olfactory conditioning, they are involved in many behavioral achievements and learning capabilities, as …
Artificial Neural Networks to Predict the Power Output of a PV Panel
2014
The paper illustrates an adaptive approach based on different topologies of artificial neural networks (ANNs) for the power energy output forecasting of photovoltaic (PV) modules. The analysis of the PV module’s power output needed detailed local climate data, which was collected by a dedicated weather monitoring system. The Department of Energy, Information Engineering, and Mathematical Models of the University of Palermo (Italy) has built up a weather monitoring system that worked together with a data acquisition system. The power output forecast is obtained using three different types of ANNs: a one hidden layer Multilayer perceptron (MLP), a recursive neural network (RNN), and a gamma m…
Modelling and Analysis of Nonstationary Vehicle-to-Infrastructure Channels with Time-Variant Angles of Arrival
2018
In mobile radio channel modelling, it is generally assumed that the angles of arrival (AOAs) are independent of time. This assumption does not in general agree with real-world channels in which the AOAs vary with the position of a moving receiver. In this paper, we first present a mathematical model for the time-variant AOAs. This model serves as the basis for the development of two nonstationary multipath fading channels models for vehicle-to-infrastructure communications. The statistical properties of both channel models are analysed with emphasis on the time-dependent autocorrelation function (ACF), time-dependent mean Doppler shift, time-dependent Doppler spread, and the Wigner-Ville sp…