1,721,072 research outputs found
"Le monde [n'] est [pas] en ordre": l'atmosfera fantastica in Kamouraska di Anne Hébert
No full textL'articolo prende in esame l'atmosfera fantastica nel romanzo Kamouraska di A. Hébert, atmosfera la cui evocazione permette all'autrice di scardinare le basi culturali del lettore per sovvertire i valori di una società soffocante - quella del Québec del diciannovesimo secolo così come quella del Québec degli anni '50 - e riaffermare la rivendicazione di un'alterità vitale che sovverte il senso tradizionale del mondo
Radio-Guided Localization and Resection of Small or Ill-Defined Pulmonary Lesions
No full textBackground: Screening programs have increased the identification of small or indistinct pulmonary lesions that are difficult to localize. We report our experience in their preoperative localization by radiotracer and resection. Methods: Patients with pulmonary nodules of subsolid morphology or smaller than 1 cm, deeper 1 cm below the visceral pleura, or both underwent computed tomography (CT)-guided injection of radiotracer technetium 99m macroaggregates in the vicinity of the lesion. During the operation, a handheld gamma probe was used to detect the hot spot where the radioactive tracer was localized, and this area was resected. Results: From November 2007 to May 2013, 112 patients (58 men; median age 62 years) underwent preoperative radiotracer injection with a successful marking in all patients. Adverse events included 33 (29.4%) pneumothoraces (one requiring chest tube placement), 23 (20.5%) parenchymal hemorrhage suffusions, and 1 (0.9%) allergic reaction to contrast medium. In all cases except two, the gamma probe revealed pulmonary lesions. Overall, 123 pulmonary nodules were localized and resected. The mean distance from the pleura was 12 mm (range, 0 to 39 mm). Pulmonary resection was performed by thoracoscopy in 70 (62.5%) cases, thoracotomy in 36 (32.1%), and conversion of thoracoscopy to thoracotomy in 6 (5.4%). The mean nodule size was 9 mm (range, 3 to 24 mm). Histology showed 14 (11.4%) benign lesions and 109 (88.6%) malignant lesions (85 primary lung cancers and 24 metastases). Conclusions: Radiotracer localization of pulmonary lesions is a simple and feasible procedure with a high rate of success. Optimal candidates are patients with suspicious-looking nodules detected by screening or incidental CT resulting frm the high rate of nonsolid morphology and small size
Semantic Transcoding of Videos by using Adaptive Quantization
No full textThis paper proposes the use of an approach of video transcoding driven by the video content and providedwith the adaptive quantization of MPEG standards.Computer vision techniques can extract semanticsfrom videos according with user's interests: the videosemantics is exploited to adapt the video in order tomeet the device's capabilities and the user'srequirements and preserve the best quality possible. Well assessed video analysis techniques are used to segment the video into objects grouped in classes ofrelevance to which the user can assign a weight proportional to their relevance. This weight is used todecide the quantization values to be applied in theMPEG-2 encoding to each macroblock. A modified version of the PSNR (Peak Signal-to-Noise Ratio) is used as performance metric and comparativeevaluation is reported with respect to other codingstandards such as JPEG, JPEG 2000, (basic) MPEG-2, and MPEG-4. Experimental results are provided on different situations, one indoor and oneoutdoor. Keywords:Videotranscoding, adaptive quantization, motion detectio
FREE Surveillance in a pRivacy respectFul way
No full textThe FREE SURF project aims at proposing new technologies for the next generations of video surveillance systems oriented to the automatic real-time control of the presence and actions undertaken by people in the environment, without the direct control of a human operator. The FREE SURF project is born with a twofold aim: first, innovative scientific research in the field of Computer Vision and Pattern Recognition, second, innovative applied research for the development of new generations of video surveillance systems, both effective and socially acceptable with respect to privacy concerns.The first objective is to conduct a thoughtful research activity in the field of Computer Engineering for video surveillance of people in "structural constraint FREE" systems, that is in systems free from structural and environmental constraints. The automatic visual control of human presence and actions in a given environment is, indeed, one of the most studied problems in the last decade. Nowadays, a very large literature exists, which presents algorithms and robust implementations for the recognition of single persons, in structured environments: closed environments with controlled illumination, open environments with large field of view (in order to consider people as small rigid moving objects), with few people, with only partially occluded fields of view, controlled by fixed cameras (to segment objects as different from the background), and installed with a precise manual calibration (for an exact 3D reconstruction).The final objective of the project is to study innovative methodologies and techniques for going further on: the final targets are environments free from structural constraints, in scenes with more people that live together and interact each other, as in parks or tourist areas. The foreseen activities are devoted to the study of new ways to extract visual data, from distributed camera systems, from hybrid systems with active cameras, capable to automatically move toward a target, from moving cameras, and coordinated with networks of sensors. New algorithms will be studied and working prototypes developed for people segmentation and tracking in videos acquired by multiple auto-calibrated cameras, by exploiting geometrical information and appearance (color and texture). Approaches for active camera control and mosaicing of the scene from moving cameras will be studied. Moreover, mobile agents systems will be studied to coordinate cameras and sensor networks in large scenes like archaeological sites. These techniques will all implemented in separated modules by each RU, but they will be coordinated in a single architecture to provide a common interface for the reasoning modules.All the previous modules have the common objective to extract visual data on the people in the scene. In particular, trajectory computation with invariants independent of the point of view, people posture analysis and soft biometries are the main data that will be extracted. Differently from projects dealing with biometric analysis, the FREE SURF project is oriented to the automatic visual analysis of the presence and behavior of people independently of their identities, which are not easy to assess in noisy, low-resolution videos with large filed of view, like those typical of distributed video surveillance systems. As a further support, hybrid system with PTZ and mobile cameras can provide, if needed, information with more details, which can be used in "posterity logging" by the experts. The visual data are provided to modules for dual activities: to monitor dangerous situations in real time, and to annotate interesting situations for future off-line queries. The first is a strategic tool to help the human operator in the prevention and fast responsiveness to facts regarding security, the second provides a valid support to investigations and a-posteriori analysis. These solutions may enable the many existing surveillance systems to provide effective support in a predictive way.The second objective of the project is to define new solutions to answer to the social requirements of safety and security both for places and people with solutions made "in a privacy-respectful way". In Italy, as well as in the whole world, cameras are spreading everywhere. This is not a social problem by itself if the cameras were only intelligent sensors, such as fire sensors, capable to simply process videos and generate alarms. The social awkwardness comes from the fact that behind a camera there is a human operator that controls and watches, prejudicing the individual's privacy. While it is acceptable to use cameras by the public officers for security reasons in public places, the diffusion of private closed-circuit TV systems in department stores, shopping centers or even the diffusion of web-accessible webcams in public tourist places are not. The current laws on privacy are (rightly) very restrictive, but currently there is no technological mean to guarantee that such laws are respected: many installed systems, without video processing, are either not compliant with these laws or simply unusable and used only as a deterrent for criminality since they declare to have a such low resolution or a such deep field of view to prevent people identification. The aim of this project is, instead, to provide automatic tools for extracting visual information on people that can be, on the one side, used by authorized systems to automatically monitor the scene, and, on the other side, used to guarantee the removal of biometric data and, thus, the compatibility with privacy laws. In particular, robust algorithms for people tracking and face and head detection will be useful to obscure biometric data in real time.The reported objectives of the project are for sure ambitious, but they are also feasible in the timeframe of the project. Besides the limited funding requests to MIUR, the RUs have made available many man-months of people with already a great experience on the field and can benefit of the resources, both hardware and software, in their laboratories. The consortium is composed of three very active RUs at national level, in particular in the GIRPR (www.girpr.it): all the three RUs have organized both the International Conf. of GIRPR (ICIAP), and the school for PhD students (VISMAC) that has been/will be held in Firenze, Palermo and Modena, in year 1999, 2001 and 2007 (ICIAP) and 1992, 2006 and 2000 (VISMAC). They are, moreover, very active at international level, with frequent PhD students and researchers with research centers in USA and other countries (such as the University of Technology, Sydney, Australia), and they have many active projects in the field.A very important aspect of the project is that it already contributes to the creation of a network of expressions of interest and collaborations. In particular, ITC-iRST of Trento, one of the most important non-university research centers in video surveillance, will participate to the project; big national companies such as SIRTI and ALCATEL have indicated their interest. Public entities such as Regione Emilia-Romagna and Parco Valle dei Templi di Agrigento have declared their interest in the project, as final users
DELOS: a Network of Excellence on Digital Libraries
No full textDigital libraries represent a new infrastructure and environment that has been made possible by the integration and use of a number of IC technologies, the availability of digital content on a global scale and a strong demand from users who are now online. They are destined to become an essential part of the information infrastructure in the 21st century.On the basis of these considerations, our 10-year grand vision for digital libraries is the following: digital libraries should enable any citizen to access all human knowledge any time and anywhere, in a friendly, multi-modal, efficient and effective way, by overcoming barriers of distance, language, and culture and by using multiple Internet-connected devices. The new generation digital libraries should not just be seen as static information repositories but as growing, interactively, and collaboratively used nuclei of what will be, at some stage, a good part of human knowledge that depends as much on information as on communication.The challenges and opportunities that motivate advanced digital library initiatives are associated with this view of the digital library environment.In recent years, a large number of digital library systems have been developed. However, each system is typically built from scratch and develops its own techniques, focusing on a specific type of information or services, and addressing the needs of a specific application domain. After this first experience, it has become clear that the future of digital libraries goes beyond what these initial efforts may indicate individually.It is time for generic digital library technology to be developed and incorporated into industrial-strength Digital Library Management Systems (DLMSs), offering advanced functionality through reliable and extensible services.The main objective of the DELOS network is thus to define and conduct a joint program of activities (JPA) in order to integrate and coordinate the ongoing research activities of the major European research teams in the field of digital libraries for the purpose of developing the next generation digital library technologies. The implementation of an integrated programme of this type will make the accomplishment of our grand vision for digital libraries feasible.Another main objective of the DELOS network is to integrate research activities carried out in a number of related fields crucial for the development of the next generation of digital libraries with ongoing research activities in the digital library field itself
Semantic video transcoding using classes of relevance
No full textIn this work we present a framework for on-the-fly video transcoding that exploits computer vision-based techniques to adapt the Web access to the user requirements. Theproposed transcoding approach aims at coping with both user bandwidth and resources capabilities, and with user interests in the video's content. We propose an object-basedsemantic transcoding that, according to the user-dened classes of relevance, applies different transcoding techniques to the objects segmented in a scene. Object extraction is provided by on-the-fly video processing, without manual annotation. Multiple transcoding policies are reviewed and a performance evaluation metric based on the Weighted Mean Square Error (and corresponding PSNR), that takes into account the perceptual user requirements by means of classes of relevance, is dened. Results are analyzed by varying transcoding techniques, bandwidth requirements and video types (with indoor and outdoor scenes), showing that the use of semantics can dramatically improve the bandwidth to distortion ratio
Regional cerebral metabolism of glucose in comatose and vegetative state patients
No full textRegional cerebral metabolism of glucose (rCMRglu) was evaluated in patients who were in a coma and vegetative state to determine the level of brain function during these conditions. rCMRglu was measured in 17 discrete brain regions with (/-) [18F] -fluoro-2-deoxy-D-glucose (FDG) and positrn emission tomography (PET) in 15 patients with ;brain pathology subsequent to cardiorespiratory arrest (CA), head trauma (HT), or brain ischemia (BI) resulting from cerebrovascular accident or brain surgery. Five comatose patients (Coma group, n = 5), and 10 vegetative state patients (VS, patients awake but not aware) were studied. The VA patients were subdivided, according to the length of their VS condition, into a VS group (n = 6, 3 months if CA or BI patients of > 12 months if HT patients.) Ten normal age-matched subjects served as control. Global CMRglu was 6.72 +/- 0.93 (+/-SD) mg/100 g/min in control subjects. It was significantly (p < - 0.001) reduced to 3.70 +/- 61 in coma, to 3.45 +/- in VS, and to 2.33 +/- 0.34 mg/100 g/min in PVS patients. rCMRglu was significantly reduced (p < - 01001) from control values in all the 17 structures surveyed in every patient. In the Coma and VS groups, there was an overlapping of rCMRglu in the majority of the brain structures. (ABSTRACT TRUNCATED AT 250 WORDS
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