1,392 research outputs found

    Tomb number 2 of the Church of St. Michael in Mornago (Varese, Italy). Anthropological and archaeological study of medieval funeral remains

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    The current paper aims to present the archaeological and anthropological results of the investigation conducted on a medieval burial which presents several features that recall the Longobard culture. After the archaeological evaluations on the architectural morphology of the tomb and on the grave goods, we proceeded with the anthropological investigations on human and animal bone remains. These analyses allowed us to formulate a hypothesis related to this particular funeral ritual from ancient Longobard tradition. The tomb number 2 of St. Michael church in Mornago represents a rare evidence of inhumation with bird in Northern Italy

    Including Pitch Accent Optionality in Unit Selection Text-to-Speech Synthesis

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    A significant variability in pitch accent placement is found when comparing the patterns of prosodic prominence realized by different English speakers reading the same sentences. In this paper we describe a simple approach to incorporate this variability to synthesize prosodic prominence in unit selection text-to-speech synthesis. The main motivation of our approach is that by taking into account the variability of accent placements we enlarge the set of prosodically acceptable speech units, thus increasing the chances of selecting a good quality sequence of units, both in prosodic and segmental terms. Results on a large scale perceptual test show the benefits of our approach and indicate directions for further improvements. Index Terms: speech synthesis, unit selection, prosodic prominence, pitch accent

    A CRITICAL NOTE BY ABELE DE BLASIO (1902) ON THE ARCHAEO-ANTHROPOLOGICAL CONJECTURES OF LUIGI PALMIERI (1872)

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    This paper offers a description and explanation of a criticism written by Abel De Blasio in 1902 on the archaeological and anthropological conjectures that Luigi Palmieri had made in the past. In a note presented in 1872 at the Academy of Sciences of Naples, regarding some ancient tombs discovered by chance near the Observatory on Mount Vesuvius, Palmieri presented interpreta- tive observations that were unacceptable for specialists in anthropological studies and funerary archaeology

    How to Make Selective Realism More Selective (and More Realist Too)

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    Selective realism is the thesis that some wisely chosen theoretical posits are essential to science and can therefore be considered as true or approximately true. How to choose them wisely, however, is a matter of fierce contention. Generally speaking, we should favor posits that are effectively deployed in successful prediction. In this paper I propose a refinement of the notion of deployment and I argue that selective realism can be extended to include the analysis of how theoretical posits are actually deployed in symbolic practices

    Binokulare EigenbewegungsschĂ€tzung fĂŒr Fahrerassistenzanwendungen

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    Driving can be dangerous. Humans become inattentive when performing a monotonous task like driving. Also the risk implied while multi-tasking, like using the cellular phone while driving, can break the concentration of the driver and increase the risk of accidents. Others factors like exhaustion, nervousness and excitement affect the performance of the driver and the response time. Consequently, car manufacturers have developed systems in the last decades which assist the driver under various circumstances. These systems are called driver assistance systems. Driver assistance systems are meant to support the task of driving, and the field of action varies from alerting the driver, with acoustical or optical warnings, to taking control of the car, such as keeping the vehicle in the traffic lane until the driver resumes control. For such a purpose, the vehicle is equipped with on-board sensors which allow the perception of the environment and/or the state of the vehicle. Cameras are sensors which extract useful information about the visual appearance of the environment. Additionally, a binocular system allows the extraction of 3D information. One of the main requirements for most camera-based driver assistance systems is the accurate knowledge of the motion of the vehicle. Some sources of information, like velocimeters and GPS, are of common use in vehicles today. Nevertheless, the resolution and accuracy usually achieved with these systems are not enough for many real-time applications. The computation of ego-motion from sequences of stereo images for the implementation of driving intelligent systems, like autonomous navigation or collision avoidance, constitutes the core of this thesis. This dissertation proposes a framework for the simultaneous computation of the 6 degrees of freedom of ego-motion (rotation and translation in 3D Euclidean space), the estimation of the scene structure and the detection and estimation of independently moving objects. The input is exclusively provided by a binocular system and the framework does not call for any data acquisition strategy, i.e. the stereo images are just processed as they are provided. Stereo allows one to establish correspondences between left and right images, estimating 3D points of the environment via triangulation. Likewise, feature tracking establishes correspondences between the images acquired at different time instances. When both are used together for a large number of points, the result is a set of clouds of 3D points with point-to-point correspondences between clouds. The apparent motion of the 3D points between consecutive frames is caused by a variety of reasons. The most dominant motion for most of the points in the clouds is caused by the ego-motion of the vehicle; as the vehicle moves and images are acquired, the relative position of the world points with respect to the vehicle changes. Motion is also caused by objects moving in the environment. They move independently of the vehicle motion, so the observed motion for these points is the sum of the ego-vehicle motion and the independent motion of the object. A third reason, and of paramount importance in vision applications, is caused by correspondence problems, i.e. the incorrect spatial or temporal assignment of the point-to-point correspondence. Furthermore, all the points in the clouds are actually noisy measurements of the real unknown 3D points of the environment. Solving ego-motion and scene structure from the clouds of points requires some previous analysis of the noise involved in the imaging process, and how it propagates as the data is processed. Therefore, this dissertation analyzes the noise properties of the 3D points obtained through stereo triangulation. This leads to the detection of a bias in the estimation of 3D position, which is corrected with a reformulation of the projection equation. Ego-motion is obtained by finding the rotation and translation between the two clouds of points. This problem is known as absolute orientation, and many solutions based on least squares have been proposed in the literature. This thesis reviews the available closed form solutions to the problem. The proposed framework is divided in three main blocks: 1) stereo and feature tracking computation, 2) ego-motion estimation and 3) estimation of 3D point position and 3D velocity. The first block solves the correspondence problem providing the clouds of points as output. No special implementation of this block is required in this thesis. The ego-motion block computes the motion of the cameras by finding the absolute orientation between the clouds of static points in the environment. Since the cloud of points might contain independently moving objects and outliers generated by false correspondences, the direct computation of the least squares might lead to an erroneous solution. The first contribution of this thesis is an effective rejection rule that detects outliers based on the distance between predicted and measured quantities, and reduces the effects of noisy measurement by assigning appropriate weights to the data. This method is called Smoothness Motion Constraint (SMC). The ego-motion of the camera between two frames is obtained finding the absolute orientation between consecutive clouds of weighted 3D points. The complete ego-motion since initialization is achieved concatenating the individual motion estimates. This leads to a super-linear propagation of the error, since noise is integrated. A second contribution of this dissertation is a predictor/corrector iterative method, which integrates the clouds of 3D points of multiple time instances for the computation of ego-motion. The presented method considerably reduces the accumulation of errors in the estimated ego-position of the camera. Another contribution of this dissertation is a method which recursively estimates the 3D world position of a point and its velocity; by fusing stereo, feature tracking and the estimated ego-motion in a Kalman Filter system. An improved estimation of point position is obtained this way, which is used in the subsequent system cycle resulting in an improved computation of ego-motion. The general contribution of this dissertation is a single framework for the real time computation of scene structure, independently moving objects and ego-motion for automotive applications.Autofahren kann gefĂ€hrlich sein. Die Fahrleistung wird durch die physischen und psychischen Grenzen des Fahrers und durch externe Faktoren wie das Wetter beeinflusst. Fahrerassistenzsysteme erhöhen den Fahrkomfort und unterstĂŒtzen den Fahrer, um die Anzahl an UnfĂ€llen zu verringern. Fahrerassistenzsysteme unterstĂŒtzen den Fahrer durch Warnungen mit optischen oder akustischen Signalen bis hin zur Übernahme der Kontrolle ĂŒber das Auto durch das System. Eine der Hauptvoraussetzungen fĂŒr die meisten Fahrerassistenzsysteme ist die akkurate Kenntnis der Bewegung des eigenen Fahrzeugs. Heutzutage verfĂŒgt man ĂŒber verschiedene Sensoren, um die Bewegung des Fahrzeugs zu messen, wie zum Beispiel GPS und Tachometer. Doch Auflösung und Genauigkeit dieser Systeme sind nicht ausreichend fĂŒr viele Echtzeitanwendungen. Die Berechnung der Eigenbewegung aus Stereobildsequenzen fĂŒr Fahrerassistenzsysteme, z.B. zur autonomen Navigation oder Kollisionsvermeidung, bildet den Kern dieser Arbeit. Diese Dissertation prĂ€sentiert ein System zur Echtzeitbewertung einer Szene, inklusive Detektion und Bewertung von unabhĂ€ngig bewegten Objekten sowie der akkuraten SchĂ€tzung der sechs Freiheitsgrade der Eigenbewegung. Diese grundlegenden Bestandteile sind erforderlich, um viele intelligente Automobilanwendungen zu entwickeln, die den Fahrer in unterschiedlichen Verkehrssituationen unterstĂŒtzen. Das System arbeitet ausschließlich mit einer Stereokameraplattform als Sensor. Um die Eigenbewegung und die Szenenstruktur zu berechnen wird eine Analyse des Rauschens und der Fehlerfortpflanzung im Bildaufbereitungsprozess benötigt. Deshalb werden in dieser Dissertation die Rauscheigenschaften der durch Stereotriangulation erhaltenen 3D-Punkte analysiert. Dies fĂŒhrt zu der Entdeckung eines systematischen Fehlers in der SchĂ€tzung der 3D-Position, der sich mit einer Neuformulierung der Projektionsgleichung korrigieren lĂ€sst. Die Simulationsergebnisse zeigen, dass eine bedeutende Verringerung des Fehlers in der geschĂ€tzten 3D-Punktposition möglich ist. Die EigenbewegungsschĂ€tzung wird gewonnen, indem die Rotation und Translation zwischen Punktwolken geschĂ€tzt wird. Dieses Problem ist als „absolute Orientierung” bekannt und viele Lösungen auf Basis der Methode der kleinsten Quadrate sind in der Literatur vorgeschlagen worden. Diese Arbeit rezensiert die verfĂŒgbaren geschlossenen Lösungen zu dem Problem. Das vorgestellte System gliedert sich in drei wesentliche Bausteine: 1. Registrierung von Bildmerkmalen, 2. EigenbewegungsschĂ€tzung und 3. iterative SchĂ€tzung von 3D-Position und 3D-Geschwindigkeit von Weltpunkten. Der erster Block erhĂ€lt eine Folge rektifizierter Bilder als Eingabe und liefert daraus eine Liste von verfolgten Bildmerkmalen mit ihrer entsprechenden 3D-Position. Der Block „EigenbewegungsschĂ€tzung” besteht aus vier Hauptschritten in einer Schleife: 1. Bewegungsvorhersage, 2. Anwendung der Glattheitsbedingung fĂŒr die Bewegung (GBB), 3. absolute Orientierungsberechnung und 4. Bewegungsintegration. Die in dieser Dissertation vorgeschlagene GBB ist eine mĂ€chtige Bedingung fĂŒr die Ablehnung von Ausreißern und fĂŒr die Zuordnung von Gewichten zu den gemessenen 3D-Punkten. Simulationen werden mit gaußschem und slashschem Rauschen ausgefĂŒhrt. Die Ergebnisse zeigen die Überlegenheit der GBB-Version ĂŒber die Standardgewichtungsmethoden. Die StabilitĂ€t der Ergebnisse hinsichtlich Ausreißern wurde analysiert mit dem Resultat, dass der „break down point” grĂ¶ĂŸer als 50% ist. Wenn die vier Schritte iterativ ausgefĂŒhrt, werden wird ein PrĂ€diktor-Korrektor-Verfahren gewonnen.Wir nennen diese SchĂ€tzung Multi-frameschĂ€tzung im Gegensatz zur ZweiframeschĂ€tzung, die nur die aktuellen und vorherigen Bildpaare fĂŒr die Berechnung der Eigenbewegung betrachtet. Die erste Iteration wird zwischen der aktuellen und vorherigen Wolke von Punkten durchgefĂŒhrt. Jede weitere Iteration integriert eine zusĂ€tzliche Punktwolke eines vorherigen Zeitpunkts. Diese Methode reduziert die Fehlerakkumulation bei der Integration von mehreren SchĂ€tzungen in einer einzigen globalen SchĂ€tzung. Simulationsergebnisse zeigen, dass obwohl der Fehler noch superlinear im Laufe der Zeit zunimmt, die GrĂ¶ĂŸe des Fehlers um mehrere GrĂ¶ĂŸenordnungen reduziert wird. Der dritte Block besteht aus der iterativen SchĂ€tzung von 3D-Position und 3D-Geschwindigkeit von Weltpunkten. Hier wird eine Methode basierend auf einem Kalman Filter verwendet, das Stereo, Featuretracking und Eigenbewegungsdaten fusioniert. Messungen der Position eines Weltpunkts werden durch das Stereokamerasystem gewonnen. Die Differenzierung der Position des geschĂ€tzten Punkts erlaubt die zusĂ€tzliche SchĂ€tzung seiner Geschwindigkeit. Die Messungen werden durch das Messmodell gewonnen, das Stereo- und Bewegungsdaten fusioniert. Simulationsergebnisse validieren das Modell. Die Verringerung der Positionsunsicherheit im Laufe der Zeit wird mit einer Monte-Carlo Simulation erzielt. Experimentelle Ergebnisse werden mit langen Sequenzen von Bildern erzielt. ZusĂ€tzliche Tests, einschließlich einer 3D-Rekonstruktion einer Waldszene und der Berechnung der freien Kamerabewegung in einem Indoor-Szenario, wurden durchgefĂŒhrt. Die Methode zeigt gute Ergebnisse in allen FĂ€llen. Der Algorithmus liefert zudem akzeptable Ergebnisse bei der SchĂ€tzung der Lage kleiner Objekte, wie Köpfe und Beine von realen Crash-Test-Dummies

    Notes for a Political Epistemology of Algorithms

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    Algorithms are everywhere they watch us, they give us advice, sometimes they take autonomous decisions. They are agents mediating between reality and us by virtue of their capability to treat huge amounts of data and to see patterns that are invisible to us. It is pretty clear that they are political actors by virtue of their epistemic features. In this article, I try to put together these two points and outline a political epistemology of algorithms. Firstly, I define political epistemology as concerned with epistemic performances that are essentially situated and therefore political all the way down. Secondly, I show that, in this sense, an epistemic analysis of algorithms cannot help being a piece of political epistemology

    UNDERGROUND METEOROLOGY-“What’s the weather underground?”

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    The aim of this work is to provide a synthetic outline of some of the processes of transient nature occurring in caves, focusing on poorly studied general aspects of underground physics and mainly making use of original experimental data. In the first part, the average climatic conditions of a caves, their connection to the external climate, and the general role played by rock, water, air and external morphology are discussed. The variation of the internal temperature withthe altitude is a key parameter for the cave physics: the related energetic consequences are briefly discussed. In the second part, transient processes are considered, and a general overview of main meteorological phenomena occurring underground is given. The physics of thermal sedimentation, of underground temperature ranges, of infrasonic oscillations of cave atmospheres and, above all, of water vapour condensation in caves is synthetically described. The experimental study of these processes is extremely difficult, because they are time dependent and have very small amplitude; the first measurements show, however, that their variability from one cave to another, and from point to point inside a cave, is surprisingly high. To provide a more correct interpretation of underground climatic measurements, for their speleogenetic role and importance in cave environment protection, a better understanding of the processes described here is essential.

    Underground Drainage Systems and Geothermal Flux

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    V članku opiĆĄem pomen interakcije med geotermičnim tokom in mreĆŸo globokega kraĆĄkega odvodnjavanja. Problem geotermičnega toka, ki ga prestreĆŸejo vodni kanali, ki v sploĆĄnem zaheva tudi izračun temperaturnega polja, obravnavam z inĆŸenirskim pristopom, ki pri tem vpelje t.i. faktorje oblike. Tok vode v kraĆĄkih kanalih zmoti celotno temperaturno polje v okoliĆĄkem masivu in sčasoma pritegne nase ves geotermični tok ĆĄirĆĄega območja. Ćœe majhna količina vode, ki teče v masiv, zmoti temperaturno polje masiva vse do povrĆĄja. Vpel­java geotermičnega preseka struktur podzemnega odvodnjavanja, omogoča izboljĆĄanje klasične formule za oceno minimalne globine vira geotermalne vode. Tej dodamo faktor povečave, ki je odvisen od razmerja med povprečnim in kritičnim pretokom Qc, ki ga določa geotermični presek. V članku opiĆĄem tudi geotermične »stoĆŸce senčenja«, ki nastanejo v masivu nad kraĆĄkimi kanali. An analysis of the interaction between the geothermal flux and the water or air- deep drainage networks. The problem of geothermal power intercepted by deep structures and, in general, the temperature field calculations, is converted to classical thermo-engineering problems in terms of shape factors. It is shown that the fluid flow in a conduit perturbs the whole deep rock temperature field until the geothermal flux of a large area is focalised onto the conduit. It is shown that either small water masses flowing into a mountain are able to perturb the rock temperature up to the surface, on sizes that do not depend on water mass dimension, but on its depth, and then on enormous volumes. The introduction of the "geothermal cross section" of an underground drainage structure allows us to improve the classical formula of minimum provenance depth of geothermal water. Enlarging factors are applied to the classical estimation in dependence of the ratio between the actual average discharge and the critical discharge Qc, which depends on the conduit geothermal cross section. The geothermal "umbra cones"created in the overlying rock by deep underground structures are described. It is shown that the geothermal flux can play a significant role in the underground drainage phenomenology.

    The ribbed drapery of the Puerto Princesa Underground River (Palawan, Philippines): morphology and genesis

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    During the 2011 speleological expedition to the Puerto Princesa Underground River (Palawan, Philippines) a drapery characterized by several close-to-horizontal ribs has been noticed. Even without sampling and analyzing its internal growth layers, a detailed morphological study allowed to present a possible genetic model. The presented model helps to explain its evolution, which is mainly controlled by variation in water flow as a consequence of the Palawan climate. When validated by further analyses, the same genetic mechanism could define also the evolution of the very common but still unexplained complex flowstones, which exhibit several close-to-horizontal steps, widenings and narrowings along their growth axis
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