1,766 research outputs found
Some thesis about laicity
En este artículo se expresa que la laicidad indica una condición de la polis, esa
condición que se funda en la separación operativa entre religión, moral y derecho. Aquello
que distingue la laicidad, como modelo de vida civil de una sociedad, es que la separación
entre las esferas religiosa, moral y jurídica es elevada a principio de organización primario,
con el reconocimiento de una autonomía decisoria “soberana” a la sociedad civil, a través de
sus representantes. No es preciso ser ateos para aceptar y sostener este modelo de laicidad,
basado en la libertad de conciencia. Como tampoco supone ser agnósticos hacia lo trascendente,
escépticos en lo cognitivo o indiferentistas en ética. Significa tan sólo admitir que todo
hombre puede incurrir en error, sin por ello caer en el relativismo extremo. Así, la laicidad es
la salvaguardia de la libertad también para las iglesias, en especial cuando son minoritarias.This article says that laicity indicates a condition of the polis, that condition is based
on the operational separation between religion, morality and law. That which distinguishes
laicity as a model of civic life in a society, is that the separation between the religious, moral
and legal is high primary organizing principle, the recognition of a decision-making autonomy
“sovereign” civil society, through their representatives. No one should be atheist to accept
and support this model of laicity, based on freedom of conscience. Nor does it mean to be
agnostic towards the transcendent, cognitive skeptical or indifferent ethics. It just means that
every man can admit making an error, without falling into extreme relativism. Thus, laicity is
the safeguarding of freedom also for the churches, especially when they are minority
Analytic description of the image to patient torso registration problem in image guided interventions
Objective: The accurate registration of virtual pre-operative information of the human body anatomy, obtained as images
with imaging devices, with real intra-operative information is one of the key aspects on which effective Image Guided
Surgery (IGS) is based. The registration of pre-operative images on the real patient, during abdominal and thoracic
interventions, is influenced by many parameters, which in many cases are influenced each other, thus making it often
difficult to define the problem and consequently to solve it for each specific kind of intervention. The objective of this
paper is to obtain an analytic description of the 3D image to patient registration problem, which can be more intuitive than
the traditional textual descriptions.
Methods: The problem is formalized and various parameters affecting the registration are macro-classified in function of
their nature.
Results: The problem is analytically described discussing for each macro-category of parameters potential solutions to
avoid or to reduce their contribution to the registration error.
Conclusions: The availability of an analytic description of the image to patient torso registration problem can be
beneficial for teaching IGS, to describe existing registration strategies, and to search new ones for each kind of surgery
using a systematic approach
The role of camera convergence in stereoscopic video see-through augmented reality displays
In the realm of wearable augmented reality (AR) systems, stereoscopic video see-through displays raise issues related to the user's perception of the three-dimensional space. This paper seeks to put forward few considerations regarding the perceptual artefacts common to standard stereoscopic video see-through displays with fixed camera convergence. Among the possible perceptual artefacts, the most significant one relates to diplopia arising from reduced stereo overlaps and too large screen disparities. Two state-of-the-art solutions are reviewed. The first one suggests a dynamic change, via software, of the virtual camera convergence, whereas the second one suggests a matched hardware/software solution based on a series of predefined focus/vergence configurations. Potentialities and limits of both the solutions are outlined so as to provide the AR community, a yardstick for developing new stereoscopic video see-through systems suitable for different working distances
Perspective Preserving Solution for Quasi-Orthoscopic Video See-Through HMDs
In non-orthoscopic video see-through (VST) head-mounted displays (HMDs), depth perception through stereopsis is adversely affected by sources of spatial perception errors. Solutions for parallax-free and orthoscopic VST HMDs were considered to ensure proper space perception but at expenses of an increased bulkiness and weight. In this work, we present a hybrid video-optical see-through HMD the geometry of which explicitly violates the rigorous conditions of orthostereoscopy. For properly recovering natural stereo fusion of the scene within the personal space in a region around a predefined distance from the observer, we partially resolve the eye-camera parallax by warping the camera images through a perspective preserving homography that accounts for the geometry of the VST HMD and refers to such distance. For validating our solution; we conducted objective and subjective tests. The goal of the tests was to assess the efficacy of our solution in recovering natural depth perception in the space around said reference distance. The results obtained showed that the quasi-orthoscopic setting of the HMD; together with the perspective preserving image warping; allow the recovering of a correct perception of the relative depths. The perceived distortion of space around the reference plane proved to be not as severe as predicted by the mathematical models
Comparison of measurement methods of the front velocity of small-scale debris flows
Debris flow is a gravity-driven process, which is characterized by a travelling dense surge including large boulders, and it is followed by a more fluid tail. These characteristics make difficult the measurement of the mean flow velocity by means of common hydraulic techniques. Different methods can be used at real scale and small-scale to measure the front velocity but a dedicate comparison between available methods is still lacking. This research aims to compare the front velocity measurements in the transport zone of a miniature debris flow using three devices: i) a common digital video camera (29 frames per second); ii) a high speed thermo camera (60 fps); and iii) a laser photoelectric sensors system. The statistical analysis of data has highlighted no significant differences exist between front velocities obtained by means of the video camera and the thermo camera, whereas photocells data statistically differ from those achieved via the other systems. Some lack of data recorded by photocell was documented, while the thermo camera technique did not show significant loss of information being also helpful to detect the kinematic behaviour of single particles. Finally, the tests confirmed the influence of the solid volumetric concentration in the debris-flow mechanics, which promotes, ceteris paribus, the debris-flow slowing down
Augmented reality in open surgery
Augmented reality (AR) has been successfully providing surgeons an extensive visual information of surgical anatomy to assist them throughout the procedure. AR allows surgeons to view surgical field through the superimposed 3D virtual model of anatomical details. However, open surgery presents new challenges. This study provides a comprehensive overview of the available literature regarding the use of AR in open surgery, both in clinical and simulated settings. In this way, we aim to analyze the current trends and solutions to help developers and end/users discuss and understand benefits and shortcomings of these systems in open surgery. We performed a PubMed search of the available literature updated to January 2018 using the terms (1) “augmented reality” AND “open surgery”, (2) “augmented reality” AND “surgery” NOT “laparoscopic” NOT “laparoscope” NOT “robotic”, (3) “mixed reality” AND “open surgery”, (4) “mixed reality” AND “surgery” NOT “laparoscopic” NOT “laparoscope” NOT “robotic”. The aspects evaluated were the following: real data source, virtual data source, visualization processing modality, tracking modality, registration technique, and AR display type. The initial search yielded 502 studies. After removing the duplicates and by reading abstracts, a total of 13 relevant studies were chosen. In 1 out of 13 studies, in vitro experiments were performed, while the rest of the studies were carried out in a clinical setting including pancreatic, hepatobiliary, and urogenital surgeries. AR system in open surgery appears as a versatile and reliable tool in the operating room. However, some technological limitations need to be addressed before implementing it into the routine practice
Lo scavo preventivo per l’ampliamento del cimitero di Pieve Dugliara (PC). Relazione preliminare
The paper presents the data from the preventive excavation carried out in the area adjacent to the cemetery of Pieve Dugliara (PC) in the first months of 2012. The study, while including all the structures investigated, focuses on the large pit located in the southeastern corner. It shows two main phases of utilization, dated on the basis of the few materials found: a first phase around the passage between the 6th and the 5th century B.C. and a second one referable to the Roman Republican period (early 1st century B.C.). The paper provides, through comparisons, an interpretation regarding the use of the structure in the two periods and to integrate it within the local topography.L’articolo presenta i dati provenienti dallo scavo preventivo eseguito nell’area adiacente al cimitero di Pieve Dugliara (PC) nei primi mesi del 2012. Lo studio, pur comprendendo tutte le strutture indagate, analizza in particolare la grande fossa situata nell’angolo sud-est. Essa rivela due fasi di frequentazione principali, datate sulla base dei pochi materiali presenti: una prima fase intorno al passaggio tra VI e V sec. a.C. e una seconda riferibile al periodo romano repubblicano (inizio I sec. a. C.). Si fornisce inoltre, tramite confronti, un’interpretazione riguardo l’utilizzo della struttura nei due periodi ed un suo inquadramento nella topografia locale
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