1,721,040 research outputs found
Geometric proposals for faster R-CNN
No full textFaster R-CNN has established itself as the de-facto best object detector but it remains strongly limited in two aspects: (i) it is sensitive to background clutter and its classification performance decreases when it is confronted with more noisy proposals; (ii) it suffers when the objects vary largely in scale and specifically for the small objects. We address both issues with our geometric-proposals for Faster R-CNN (GP-FRCNN), whereby we re-rank the generic object proposals with an approximate geometric estimate of the scene. But the devil is in the details: the simple extension requires involved scale adjustments (e.g. anchors, layer resolution) which we detail in this paper. Finally, our GP-FRCNN performs equally well on smaller and larger objects, a long standing challenge for any object detection algorithm. The application of GP-FRCNN to surveillance videos is straightforward and does not require an explicit geometric formulation. We extensively test the model on the UA-DETRAC dataset, where GP-FRCNN outperforms the standard Faster R-CNN by 19%
Shape from Texture: Fast Estimation of Planar Surface Orientation via {F}ourier Analysis
No full textShape from texture has received much attention in the past few decades. We propose a computationally efficient method to extract 3D planar surface orientation from the spectral variations of a visual texture. Under the assumption of homogeneity, the texture is represented by the novel method of identifying ridges of its Fourier transform. Local spatial frequencies are then computed using a minimal set of selected Gabor filters. Under perspective projection, frequencies are backprojected and orientation is computed so as to minimize the variance of the frequencies' backprojections. A comparative study with two existing methods, and experimentation on simulated and real texture images is given
Castiglioni Chapel in Pavia: A methodological approach for documentation and virtualisation techniques
No full textIn the reuse project of an environment, in order to define the set of residual services provided by the building organization as a whole, both spatial and material analyses of the current state need to be paired with a survey of both environmental and technological systems. In the case study of the Castiglioni Chapel, it is also essential to associate the various diagnostic outputs with the survey, in order to plan specific interventions for the site management project. The presented survey methodology targets the analysis of the alterations and evident cracks in the intrados of the vault. AR/VR systems allow to enhance the representation of the proposed reuse of the Chapel. All the aforementioned are aimed at devising a function that makes the space as a place of knowledge and digital use of the Chapel
Fourier Analysis and {Gabor} Filtering for Texture Analysis and Local Reconstruction of General Shapes
No full textSince the pioneering work of Gibson in 1950, Shape- From-Texture has been considered by researchers as a hard problem, mainly due to restrictive assumptions which often limit its applicability. We assume a very general stochastic homogeneity and perspective camera model, for both deterministic and stochastic textures. A multi-scale distortion is efficiently estimated with a previously presented method based on Fourier analysis and Gabor filters. The novel 3D reconstruction method that we propose applies to general shapes, and includes non-developable and extensive surfaces. Our algorithm is accurate, robust and compares favorably to the present state of the art of Shape-From- Texture. Results show its application to non-invasively study shape changes with laid-on textures, while rendering and retexturing of cloth is suggested for future work
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
Italia e Turchia tra Europa e Medio Oriente (1969-1993)
No full textQuesto lavoro indaga sulle relazioni bilaterali italo-turche negli anni Settanta e Ottanta del Novecento. Il colpo di Stato del settembre 1980 in Turchia ebbe conseguenze negative sui rapporti tra Ankara e la Comunità Europea, ma non sulle relazioni bilaterali con Roma, considerata l’importanza strategica del paese anatolico. Una posizione di convergenza si ebbe anche sulla decisione di non sostenere le sanzioni contro il leader libico Gheddafi, volute dal presidente degli Stati Uniti, Ronald Reagan. Tra la fine degli anni Ottanta e l’inizio degli anni Novanta, si cercarono nuove possibilità di collaborazione tra Italia e Turchia, sia in vista della creazione di un asse mediterraneo, con l’obiettivo di bilanciare l’asse dell’Europa centrale e settentrionale dopo l’unificazione della Germania, sia in funzione della protezione dalla pressione demografica proveniente dalla sponda meridionale del Mediterraneo, percepita come una minaccia
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
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