184 research outputs found
Online Domain Adaptation for Person Re-Identification with a Human in the Loop
No full textSupervised deep learning methods have recently achieved remarkable performance in person re-identification. Unsupervised domain adaptation (UDA) approaches have also been proposed for application scenarios where only unlabelled data are available from target camera views. We consider a more challenging scenario when even collecting a suitable amount of representative, unlabelled target data for offline training or fine-tuning is infeasible. In this context we revisit the human-in-the-loop (HITL) approach, which exploits online the operator's feedback on a small amount of target data. We argue that HITL is a kind of online domain adaptation specifically suited to person re-identification. We then reconsider relevance feedback methods for content-based image retrieval that are computationally much cheaper than state-of-the-art HITL methods for person reidentification, and devise a specific feedback protocol for them. Experimental results show that HITL can achieve comparable or better performance than UDA, and is therefore a valid alternative when the lack of unlabelled target data makes UDA infeasible
Le vicende storiche della sede dell’Accademia di San Luca al Foro di Cesare
No full textLa breve vita dell’incompiuto palazzo dell’Accademia di S. Luca, la cui costruzione venne iniziata nel 1931, è indissolubilmente legata alla lunga storia del Foro di Cesare, sulle cui spoglie si erge, e della chiesa dei Ss. Luca e Martina, sul retro della quale sorse la prima sede storica dell’Accademia realizzata al tempo di papa Urbano VIII (1635-44).
Il nuovo palazzo dell’Accademia dei pittori del quale ancora si conservano le fondazioni riportate alla luce negli scavi condotti dalla Sovraintendenza Comunale di Roma negli anni 1998-2000, doveva infatti essere eretto sul medesimo sito occupato dalla precedente sede. L’importanza dell’edificio è legata, oltre che alla sua prestigiosa ubicazione, anche agli illustri progettisti che furono personalità di spicco del panorama culturale del periodo a cavallo tra gli anni Venti e Trenta dello scorso secolo. I resti del palazzo e i progetti di seguito analizzati sono infatti una eloquente testimonianza tanto dei nuovi fermenti intellettuali quanto delle criticità dell’epoca e palesano pensieri e ripensamenti che furono sottesi alla realizzazione oltre che dell’Accademia stessa anche, e soprattutto, della nascente via dell’Impero.The seat of the ancient, prestigious Academy of San Luca, the leading cultural institution in Roma, was traditionally located by the church of SS. Luca e Martina in the Roman Forum. The first building, which housed the Academy of Painters, was destroyed in 1929-31 when extensive demolitions were carried out in the area, as part of a plan for recovery of the Forum complex. Projects for the new building were submitted by Tullio Passarelli, Gustavo Giovannoni and finally Arnaldo Foschini; after a long debate construction started in 1932, but the project was soon abandoned as the archaeological issue prevailed, and it was decided to excavate the underlying remain of Caesar’s Forum. Passarelli’s and Foschini’s drawings are published here, together with surveys of the present state by the author of the article, and show careful planning in the layout of the interiors, while the exteriors are a remarkable exercise in the academic style, universally adopted in Rome’s official buildings in the Thirties
Le vicende storiche della sede dell’Accademia di San Luca al Foro di Cesare
No full textLa breve vita dell’incompiuto palazzo dell’Accademia di S. Luca, la cui costruzione venne iniziata nel 1931, è indissolubilmente legata alla lunga storia del Foro di Cesare, sulle cui spoglie si erge, e della chiesa dei Ss. Luca e Martina, sul retro della quale sorse la prima sede storica dell’Accademia realizzata al tempo di papa Urbano VIII (1635-44).
Il nuovo palazzo dell’Accademia dei pittori del quale ancora si conservano le fondazioni riportate alla luce negli scavi condotti dalla Sovraintendenza Comunale di Roma negli anni 1998-2000, doveva infatti essere eretto sul medesimo sito occupato dalla precedente sede. L’importanza dell’edificio è legata, oltre che alla sua prestigiosa ubicazione, anche agli illustri progettisti che furono personalità di spicco del panorama culturale del periodo a cavallo tra gli anni Venti e Trenta dello scorso secolo. I resti del palazzo e i progetti di seguito analizzati sono infatti una eloquente testimonianza tanto dei nuovi fermenti intellettuali quanto delle criticità dell’epoca e palesano pensieri e ripensamenti che furono sottesi alla realizzazione oltre che dell’Accademia stessa anche, e soprattutto, della nascente via dell’Impero.The seat of the ancient, prestigious Academy of San Luca, the leading cultural institution in Roma, was traditionally located by the church of SS. Luca e Martina in the Roman Forum. The first building, which housed the Academy of Painters, was destroyed in 1929-31 when extensive demolitions were carried out in the area, as part of a plan for recovery of the Forum complex. Projects for the new building were submitted by Tullio Passarelli, Gustavo Giovannoni and finally Arnaldo Foschini; after a long debate construction started in 1932, but the project was soon abandoned as the archaeological issue prevailed, and it was decided to excavate the underlying remain of Caesar’s Forum. Passarelli’s and Foschini’s drawings are published here, together with surveys of the present state by the author of the article, and show careful planning in the layout of the interiors, while the exteriors are a remarkable exercise in the academic style, universally adopted in Rome’s official buildings in the Thirties
I forti ottocenteschi a Roma: cenni e spunti di approfondimento sulle tecniche costruttive murarie
No full textNel 1877, con Regio Decreto n. 4007, si deliberò la costruzione di un campo trincerato a difesa di Roma. Un sistema nel quale quindici forti di prima linea e tre batterie in posizione arretrata vennero strategicamente distribuiti sulle alture, a difesa delle vie consolari, lungo il perimetro di una circonferenza ideale che inscrive il centro della capitale. La progettazione generale fra il 1871 e il 1877 fu diretta da Luigi Garavaglia e dal suo gruppo, mentre dal 1877 al 1885 subentrò Luigi Durant de la Penne e un nuovo gruppo di lavoro.
Per quanto simili fra di loro, i forti hanno caratteristiche architettoniche e tecnologiche proprie che si evidenziano nell’impiego di differenti tipologie murarie, nella varietà del disegno generale e dei particolari degli alzati, così come nella scelta delle coperture, dei sistemi di smaltimento delle acque e di areazione ecc. Nella definizione, in particolare, delle principali tipologie murarie, per quanto riguarda i componenti costruttivi, è evidente che la natura geologica del sottosuolo romano si riflette nelle strutture fortificate realizzate con il materiale estratto dai siti stessi nei quali vengono costruiti o disponibile nelle immediate vicinanze. Per quanto concerne, poi, la pezzatura degli elementi e l’apparecchiatura muraria, emerge che, al di là di rare eccezioni, nei forti di Roma sono prevalentemente utilizzati i blocchi lapidei rettangolari. Mentre i laterizi o i conci in pietra, sono impiegati nelle piattabande delle aperture di vani di porte e finestre o nei risvolti d’angolo del manufatto edilizio; i laterizi vengono impiegati anche per la costruzione di archi e volte. Si rileva inoltre che in particolare nei forti realizzati nella prima fase sono presenti paramenti realizzati con materiale misto, in blocchi lapidei disposti in filari orizzontali e ricorsi di laterizi. Diversamente nei forti costruiti nella seconda fase le murature presentano per lo più paramenti realizzati con materiale omogeneo: o interamente in pietra o in laterizio.
In estrema sintesi emerge che in un momento di grande fermento culturale, i forti si pongono, per quanto concerne le tecniche costruttive murarie, in una fase intermedia che sembra in buona parte conservare i caratteri del cantiere tradizionale ottocentesco e, per quanto riguarda la progettazione generale, rispondono a logiche e criteri che, come attesta anche la trattatistica dell’epoca, sono codificati e sovralocalistici.19TH CENTURY FORTS IN ROME: SOME NOTES AND AN INITIAL DISCUSSION OF WALL CONSTRUCTION TECHNIQUES
In 1877, Royal Decree n. 4007 sanctioned the construction of an entrenched fortification to defend Rome. The system foresaw fifteen front-line forts and three second-line batteries strategically located in the hills to defend the consular roads and built along the perimeter of an imaginary circumference inscribing the centre of the capital. The general planning was directed by Luigi Garavaglia and his group between 1871 and 1877, while from 1877 to 1885 Luigi Durant de la Penne and a new workgroup took over.
Although the forts are all similar to each other, each has its own architectural and technological features that are noticeable in the use of different types of wall, in their design and elevation, as well as in the choice of roofing, water disposal systems and ventilation, etc. In particular, the decision as to which building materials were to be used in the construction of the main wall types is clearly dependent on the geological nature of the Roman subsoil. The fortified structures are constructed with the material extracted from the very sites on which they were built or available in the immediate vicinity. Then, as regards the size of the stones and the masonry equipment, almost all the Roman forts, with very few exceptions, are built with rectangular stone blocks. While clay-bricks or ashlars are used in the jack arches over the door and window openings or in the corners of buildings, clay-bricks are also used for the construction of arches and vaults. Also worth noting is the fact that a mixture of materials were used for the battlements of forts erected especially in the first phase, which have horizontal rows of stone blocks and also layers of bricks. On the contrary, most of the battlements dating from the second phase were made either in stone or just in brick.
In sum, we could say that in a moment of great cultural ferment, the masonry construction techniques used to build these forts are in an intermediate phase that seems in large part to preserve the characteristics of a traditional nineteenth-century construction site. As far as their general design is concerned, they are subject to reasoning and criteria which, as the treatises of that time also demonstrate, are codified and supra-local
BLUES: Before-reLU-EStimates Bayesian Inference for Crowd Counting
No full textEnsuring the trustworthiness of artificial intelligence and machine learning systems is becoming a crucial requirement given their widespread applications, including crowd counting, which we focus on in this work. This is often addressed by integrating uncertainty measures into their predictions. Most Bayesian uncertainty quantification techniques use a Gaussian approximation of the output, whose variance is interpreted as the uncertainty measure. However, in the case of neural network models for crowd counting based on density estimation, where the ReLU activation function is used for the output units, such a prior may lead to an approximated distribution with a significant mass on negative values, although they cannot be produced by the ReLU activation. Interestingly, we found that this is related to “false positive” pedestrian localisation errors in the density map. We propose to address this issue by shifting the Bayesian Inference Before the reLU EStimates (BLUES). This modification allows us to estimate a probability distribution both on the people density and the people presence in each pixel. This allows us to compute a crowd segmentation map, which we exploit for filtering out false positive localisations. Results on several benchmark data sets provide evidence that our BLUES approach allows for improving the accuracy of the estimated density map and the quality of the corresponding uncertainty measure
On the Evaluation of Video-Based Crowd Counting Models
No full textCrowd counting is a challenging and relevant computer vision task. Most of the existing methods are image-based, i.e., they only exploit the spatial information of a single image to estimate the corresponding people count. Recently, video-based methods have been proposed to improve counting accuracy by also exploiting temporal information coming from the correlation between adjacent frames. In this work, we point out the need to properly evaluate the temporal information's specific contribution over the spatial one. This issue has not been discussed by existing work, and in some cases such evaluation has been carried out in a way that may lead to overestimating the contribution of the temporal information. To address this issue we propose a categorisation of existing video-based models, discuss how the contribution of the temporal information has been evaluated by existing work, and propose an evaluation approach aimed at providing a more complete evaluation for two different categories of video-based methods. We finally illustrate our approach, for a specific category, through experiments on several benchmark video data sets
Lingua araba e identità nazionale in Medio Oriente: il nazionalismo territoriale in Egitto
No full textQualità della vita e demenza: studio empirico longitudinale su un intervento di supporto integrato alle relazioni familiari.
No full textTrustworthy AI in Video Surveillance: The IMMAGINA Project
No full textThe increasing adoption of machine learning and deep learning models in critical applications raises the issue of ensuring their trustworthiness, which can be addressed by quantifying the uncertainty of their predictions. However, the black-box nature of many such models allows only to quantify uncertainty through ad hoc superstructures, which require to develop and train a model in an uncertainty-aware fashion. However, for applications where previously trained models are already in operation, it would be interesting to develop uncertainty quantification approaches acting as lightweight “plug-ins” that can be applied on top of such models without modifying and re-training them. In this contribution we present a research activity of the Pattern Recognition and Applications Lab of the University of Cagliari related to a recently proposed post hoc uncertainty quantification method, we named dropout injection, which is a variant of the well-known Monte Carlo dropout, and does not require any re-training nor any further gradient descent-based optimization; this makes it a promising, lightweight solution for integrating uncertainty quantification on any already-trained neural network. We are investigating a theoretically grounded solution to make dropout injection as effective as Monte Carlo dropout through a suitable rescaling of its uncertainty measure; we are also evaluating its effectiveness in the computer vision tasks of crowd counting and density estimation for intelligent video surveillance, thanks to our participation in a project funded by the European Space Agency
Transição para a parentalidade, trabalho familiar e saúde das mulheres
No full textDuring the transition to parenthood, heterosexual couples adopt traditional gender roles. Women undertake more responsibilities in family work (Katz-Wise, Priess, & Hyde, 2010). Difficulties in balancing paid work and family can influence women's health (Rantanen, 2008). This paper aims to disclose discourses (Billig, 1987) that maintain the gender gap in family work during the transition to parenthood. Twenty couples during the third trimester of pregnancy responded to an in-depth interview on expectations about the division of family work and work-family balance. Data were analysed according to the principles of Discourse Analysis (Potter & Wetherell, 1987), with the aim of identifying the interpretive repertoires that support the greater responsibility of women in family work. Results revealed that couples referred to an essentialist view of gender (Connell, 2009), which considered women as essentially predisposed to mothering. Exclusive maternal responsibility for child-care is associated with women's concerns for work-family balance. Findings evidenced the need for interventions aimed at deconstructing discourses that maintain the unequal distribution of responsibilities, in order to prevent health risks for working mothers
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