1,721,064 research outputs found
Caratterizzazione Analitica E Sperimentale Di Un Ammortizzatore A Fluido Magnetoreologico
No full textNel presente lavoro si è introdotto un nuovo modello per la rappresentazione matematica degli smorzatori ad effetto magnetoreologico. Il modello si propone di coniugare i pregi e superare i limiti di quelli già preesistenti. Si è utilizzato un approccio di tipo fisico, che è stato declinato in termini puramente analitici; il modello ottenuto è risultato snello a livello computazionale e ben aderente ai valori misurati mediante prove dinamiche, adatto all’implementazione di algoritmi di controllo
CE-VAE: Capsule Enhanced Variational AutoEncoder for Underwater Image Enhancement
No full textUnmanned underwater image analysis for marine monitoring faces two key challenges: (i) degraded image quality due to light attenuation and (ii) hardware storage constraints limiting high-resolution image collection. Existing methods primarily address image enhancement with approaches that hinge on storing the full-size input. In contrast, we introduce the Capsule Enhanced Variational AutoEncoder (CE-VAE), a novel architecture designed to efficiently compress and enhance degraded underwater images. Our attention-aware image encoder can project the input image onto a latent space representation while being able to run online on a remote device. The only information that needs to be stored on the device or sent to a beacon is a compressed representation. There is a dual-decoder module that performs offline, full-size enhanced image generation. One branch reconstructs spatial details from the compressed latent space, while the second branch utilizes a capsule-clustering layer to capture entity-level structures and complex spatial relationships. This parallel decoding strategy enables the model to balance fine-detail preservation with context-aware enhancements. CE- VAE achieves state-of-the-art performance in underwater image enhancement on six benchmark datasets, providing up to 3 × higher compression efficiency than existing approaches. Code available at https://github.com/iN1k1/ce-vae-underwater-image-enhancement
Self-Attention Agreement among Capsules
No full textAt the state of the art, Capsule Networks (CapsNets) have shown to be a promising alternative to Convolutional Neural Networks (CNNs) in many computer vision tasks, due to their ability to encode object viewpoint variations. Network capsules provide maps of votes that focus on entities presence in the image and their pose. Each map is the point of view of a given capsule. To compute such votes, CapsNets rely on the routing-by-agreement mechanism. This computationally costly iterative algorithm selects the most appropriate parent capsule to have nodes in a parse tree for all the active capsules but this behaviour is not ensured by the routing, hence it possibly causes vanishing weights during training. We hypothesise that an attention-like mechanism will help capsules to select the predominant regions among the maps to focus on, hence introducing a more reliable way of learning the agreement between the capsules in a single pass. We propose the Attention Agreement Capsule Networks (AA-Caps) architecture that builds upon CapsNet by introducing a self-attention layer to suppress irrelevant capsule votes thus keeping only the ones that are useful for capsules agreements on a specific entity. The generated capsule attention map is then assigned to classification layer responsible of emitting the predicted image class. The proposed AA-Caps model has been evaluated on five benchmark datasets to validate its ability in dealing with the diverse and complex data that CapsNet often fails with. The achieved results demonstrate that AA-Caps outperforms existing methods without the need of more complex architectures or model ensembles
Collaborative image and object level features for image colourisation
No full textImage colourisation is an ill-posed problem, with multiple correct solutions which depend on the context and object instances present in the input datum. Previous approaches attacked the problem either by requiring intense user-interactions or by exploiting the ability of convolutional neural networks (CNNs) in learning image-level (context) features. However, obtaining human hints is not always feasible and CNNs alone are not able to learn entity-level semantics, unless multiple models pre-trained with supervision are considered. In this work, we propose a single network, named UCapsNet, that takes into consideration the image-level features obtained through convolutions and entity-level features captured by means of capsules. Then, by skip connections over different layers, we enforce collaboration between such the convolutional and entity factors to produce a high-quality and plausible image colourisation. We pose the problem as a classification task that can be addressed by a fully unsupervised approach, thus requires no human effort. Experimental results on three benchmark datasets show that our approach outperforms existing methods on standard quality metrics and achieves state-of-the-art performances on image colourisation. A large scale user study shows that our method is preferred over existing solutions. Code available at https://github.com/Riretta/Image_Colourisation_WiCV_2021
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Caratterizzazione di fluidi magnetoreologici mediante giogo magnetico
No full textNel presente lavoro è esposto un metodo per la ricerca del campo degli spostamenti mediante analisi delle immagini digitali. Il metodo si basa sull’utilizzo dei momenti invarianti di Hu ed ha come scopo di identificare il campo degli spostamenti finiti, ossia non limitati, nel piano. Gli invarianti di Hu godono della proprietà di essere insensibili alle trasformazioni di traslazione, rotazione, ed effetto di scala. In questo lavoro è proposta una metodologia in cui l’immagine da analizzare viene suddivisa, mediante una griglia, in sotto-immagini. La ricerca dei punti è effettuata attraverso un funzionale di comparazione tra gli invarianti, nell’immagine originale e quelli nell’immagine deformata. La soluzione è successivamente affinata imponendo un moto rigido complessivo mediato calcolato ottimizzando i risultati della prima ricerca. La tecnica permette la misurazione del campo degli spostamenti, utile per successive analisi differenziali per la ricerca delle deformazioni
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