Search results for " Informatica"
showing 10 items of 978 documents
Fusion of visual tools in virtual spaces
1996
Virtual space environment may be improved by combining it with graphical and visual tools. This paper analyses an integrated system able to merge fusion techniques, icons tools and a virtual space environment. A virtual space is characterised by a set of dynamic visual icons and by a heterogeneous virtual reality environment. Their integration is supported by virtual icon grammar (VIG) working on dynamic icons and virtual world. VIG allows to test the actions made by dynamic icons on the activated Virtual World metaphors at a time “t”, and a range of different transactions that place between user and VW(visual query, view and browse of under-world,...), moreover, user can define, modify and…
Granger causality analysis of sleep brain-heart interactions
2014
We studied the networks of Granger causality (GC) between the time series of cardiac vagal autonomic activity and brain wave activities, measured respectively as the normalized high frequency (HF) component of heart rate variability and EEG power in the δ, θ, α, Ï, β bands, computed in 10 healthy subjects during sleep. GC analysis was performed by vector autoregressive modeling, and significance of each link in the network was assessed using F-statistics. The whole-night analysis revealed the existence of a fully connected network of brain-heart and brain-brain interactions, with the à EEG power acting as a hub which conveys the largest number of GC links between the heart and brain n…
New Error Measures to Evaluate Features on Three-Dimensional Scenes
2011
In this paper new error measures to evaluate image features in three-dimensional scenes are proposed and reviewed. The proposed error measures are designed to take into account feature shapes, and ground truth data can be easily estimated. As other approaches, they are not error-free and a quantitative evaluation is given according to the number of wrong matches and mismatches in order to assess their validity
A Few Remarks on the Roots of Fuzziness Measures
2012
In the forty years from the introduction of Fuzzy Entropy, fuzziness measures has been employed in many different fields pertaining both hard and soft sciences, from medicine to art, from engineering to linguistics. If we look back at the road traveled, we can safely state that on of the main reasons for this enduring presence, and maybe the most underrated, is the truly uniqueness of the concept of fuzziness. Far from a reminiscence, this consideration is more of a projection on the future of fuzziness: we strongly believe that the innovation implicit in the concept, while having sometime hindered in the past its perception as a powerful paradigm and tool for the hard science community, wi…
Do Uncertainty and Fuzziness Present Themselves (and Behave) in the Same Way in Hard and Human Sciences?
2010
In the present paper the question whether uncertainty and fuzziness present themselves and behave in the same way (or not) in hard and human sciences will be briefly discussed. This problem came out from the attempt to answer the question asked by Lotfi Zadeh on the (apparent) strangeness of a very limited use of fuzzy sets in human sciences.
Synthetic individual binaural audio delivery by pinna image processing
2014
Purpose – The purpose of this paper is to present a system for customized binaural audio delivery based on the extraction of relevant features from a 2-D representation of the listener’s pinna. Design/methodology/approach – The most significant pinna contours are extracted by means of multi-flash imaging, and they provide values for the parameters of a structural head-related transfer function (HRTF) model. The HRTF model spatializes a given sound file according to the listener’s head orientation, tracked by sensor-equipped headphones, with respect to the virtual sound source. Findings – A preliminary localization test shows that the model is able to statically render the elevation of a vi…
Facilitating Access to Health Web Pages with Different Language Complexity Levels
2019
The number of people looking for health information on the Internet is constantly growing. When searching for health information, different types of users, such as patients, clinicians or medical researchers, have different needs and should easily find the information they are looking for based on their specific requirements. However, generic search engines do not make any distinction among the users and, often, overload them with the provided amount of information. On the other hand, specific search engines mostly work on medical literature and specialized web sites are often not free and contain focused information built by hand. This paper presents a method to facilitate the search of he…
Quantification of Different Regulatory Pathways Contributing to Heartbeat Dynamics during Multiple Stimuli: a Proof of the Concept.
2019
The dynamical interplay between brain and heart is mediated by several feedback mechanisms including the central autonomic network and baroreflex loop at a peripheral level, also for a short-term regulation. State of the art focused on the characterization of each regulatory pathway through a single stressor elicitation. However, no studies targeted the actual quantification of different mediating routes leading to the generation of heartbeat dynamics, particularly in case of combined exogenous stimuli. In this study, we propose a new approach based on computational modeling to quantify the contribution of multiple concurrent stimuli in modulating cardiovascular dynamics. In this prelimina…
Towards Disentangling the Contribution of Different Pathways for the Regulation of Cardiac Activity: A Pilot Study
2020
Heartbeat is dynamically regulated through mediating routes associated with central and peripheral feedback mechanisms. Previous studies focused on the quantification of these mechanisms in the presence of a single stressor. In this pilot study we propose a model aimed to quantify the contribution of different heartbeat regulatory routes while multiple stressors are administrated to the subject. The model is tested with Heart rate Variability (HRV) series from 26 subjects undergoing physical and affective stressors. Results show that the physical stressor prevalently (74%) contributes in mediating cardiac vagal control dynamics in case of concurrent affective elicitation. These results may …
Quantifying multidimensional control mechanisms of cardiovascular dynamics during multiple concurrent stressors
2021
Heartbeat regulation is achieved through different routes originating from central autonomic network sources, as well as peripheral control mechanisms. While previous studies successfully characterized cardiovascular regulatory mechanisms during a single stressor, to the best of our knowledge, a combination of multiple concurrent elicitations leading to the activation of different autonomic regulatory routes has not been investigated yet. Therefore, in this study, we propose a novel modeling framework for the quantification of heartbeat regulatory mechanisms driven by different neural routes. The framework is evaluated using two heartbeat datasets gathered from healthy subjects undergoing p…