1,354,470 research outputs found
(SEMI)-AUTOMATED ANALYSIS OF MELANOCYTIC LESIONS
No full textMelanoma is a very aggressive form of skin cancer whose incidence has constantly grown in the last 50 years. To increase the survival rate, an early diagnosis followed by a prompt excision is crucial and requires an accurate and periodic analysis of the patient's melanocytic lesions. We have developed an hardware and software solution named Mole Mapper to assist the dermatologists during the diagnostic process. The goal is to increase the accuracy of the diagnosis, accelerating the entire process at the same time. This is achieved through an automated analysis of the dermatoscopic images which computes and highlights the proper information to the dermatologist. In this thesis we present the 3 main algorithms that have been implemented into the Mole Mapper:
A robust segmentation of the melanocytic lesion, which is the starting point for any other image processing algorithm and which allows the extraction of useful information about the lesion's shape and size. It outperforms the speed and quality of other state-of-the-art methods, with a precision that meets a Senior Dermatologist's standard and an execution time that allows for real-time video processing;
A virtual shaving algorithm, which increases the precision and robustness of the other computer vision algorithms and provides the dermatologist with a hair-free image to be used during the evaluation process. It matches the quality of state-of-the-art methods but requires only a fraction of the computational time, allowing for computation on a mobile device in a time-frame compatible with an interactive GUI;
A registration algorithm through which to study the evolution of the lesion over time, highlighting any unexpected anomalies and variations. Since a standard approach to this problem has not yet been proposed, we define the scope and constraints of the problem; we analyze the results and issues of standard registration techniques; and finally, we propose an algorithm with a speed compatible with Mole Mapper's constraints and with an accuracy comparable to the registration performed by a human operator
High count rate InGaAs/InP SPAD system with balanced SPAD-dummy approach running up to 1.4 GHz
No full textThe capability to achieve high count rates has become an imperative in the most areas where near-infrared single-photon counters are required to detect photons up to 1.7 mu m. Hence, afterpulsing mitigation is a dominant theme in recent works concerning systems based on InGaAs/InP SPADs. Given the challenges inherent in reducing the density of defects that give rise to the carrier trapping events causing afterpulsing, the only viable approach is to reduce the potential number of carriers that can be trapped by limiting the charge flow per avalanche event.In this paper we present a sine-wave gating system based on the balanced detector configuration. The gate frequency is programmable in a wide range (1.0 - 1.6 GHz) for allowing synchronization with an external laser system and for exploring the best trade-off between afterpulsing and photon detection efficiency. The long-term stability can be achieved with a stable cancelation of the gate feedthrough. In this work this is guaranteed by a feedback loop that continuously monitors the residual output power at the gate frequency and adjusts the amplitude and phase of the two sinusoids fed to the SPAD-dummy couple
Antigono II Gonata. Percezione e autorappresentazione di un re
No full textLa tesi di dottorato "Antigono II Gonata. Percezione e autorappresentazione di un re" ripercorre le vicende di Antigono Gonata col preciso obiettivo di indagare sulla sua propaganda politica, ovvero sulle prassi della sua autorappresentazione.
La ricerca ha mostrato come il Gonata sia stato un abile sovrano, capace di destreggiarsi tra innovazione e tradizione per affermare la propria immagine politica, per ottenere approvazione tra i propri sudditi e per smentire la fama negativa di tiranno attribuitagli dagli antagonisti.
Convergono su di lui, infatti, due filoni storiografici distinti: da un lato una tradizione negativa sviluppata dai nemici di Antigono che evidenzia i tratti più dispotici del Gonata e che insiste in particolare sul suo intento di soggiogare la Grecia con un dominio di estrema durezza: si consideri ad esempio il ritratto di Antigono come barbaro che emerge dal decreto di Cremonide. Dall’altro lato una tradizione che tende a presentare il Gonata sotto una luce del tutto positiva, elaborata probabilmente da Antigono stesso o dagli scrittori presenti alla sua corte.
Si è mostrato come, fin dall’inizio del suo regno, il Gonata abbia manifestato l’intento di accentuare la propria dimensione dinastica, differenziandola dalla tradizione precedente. Così sono da intendersi l’introduzione come elemento cultuale innovativo del culto di Pan, dio che, stando alla tradizione, avrebbe affiancato Antigono a Lisimachia (277/276 a.C.) permettendogli di vincere i Galli, e l’omaggio per i propri antenati con l’edificazione di un grande monumento celebrativo, a Delo, per i progonoi. Inoltre, per enfatizzare la propria comunione con la casata argeade dei re macedoni, promuove una serie di iniziative in questo senso, che includono la rivitalizzazione dei culti di Eracle e Asclepio e forse, elemento non meno significativo, l’omaggio alla memoria del figlio di Alessandro il Grande, Alessandro IV, eliminato da Cassandro. A proposito di quest’ultima tematica, questo studio discute un aspetto della ricezione di Antigono nel Novecento: dal riesame degli affreschi di Boscoreale è possibile supporre che, a differenza di quanto ipotizzato da Studniczka all’inizio del secolo scorso, Antigono non sia rappresentato in uno degli affreschi, ma sia piuttosto il committente dell’opera.
Si è poi analizzato come, per porsi in linea di diretta continuità con la tradizione argeade, il Gonata abbia consentito all’accettazione, o probabilmente alla diffusione stessa, di un culto in proprio onore.
La ricerca ha confermato l’effettiva propensione filosofica di Antigono, che abbracciò insegnamenti stoici (lo stretto rapporto che sviluppò con i principali filosofi del tempo ne è testimone), e certamente sfruttò tale caratterizzazione per connotare e promuovere e la propria immagine regale; ma al tempo stesso questa autorappresentazione non nasconde il fatto che egli ricorse a qualsiasi, anche spregiudicata, astuzia politica per conservare il potere per una quarantina di anni.
Nella molteplicità degli approcci e dei temi affrontati si sono presi in esame inoltre i modi e gli stili della comunicazione tra Antigono e i sudditi; la spinosa questione relativa alla cronologia del regno del Gonata per come potrebbe riflettere il suo intento di creare una vera e propria era antigonide, nonché una più radicata legittimazione del suo ruolo in Macedonia; e infine il ruolo delle donne antigonidi nella gestione del potere, che risulta centrale anche per la conservazione del carisma familiare: il suicidio della madre di Antigono, Phila, ne è una drammatica controprova.This work (Antigonos II Gonatas. Perception and Auto-Representation of a King) focuses on Antigonos Gonatas’ life with the aim of examining his political propaganda and auto representation as well as his relationship with his subjects.
My research argues that Gonatas was a skillful and clever sovereign, able to juggle through innovation and tradition to oppose a negative portrait as a tyrant developed by his enemies, and to achieve prestige among his subjects. I have demonstrated that two historiographic traditions developed, one influenced by Antigonos’ enemies that represents Gonatas as a tyrant, the other one influenced by Antigonos’ himself or by the historians at his court, that shows the Macedonian king in a positive light. Since the beginning of his political life, Antigonos followed two different line of actions: on the one side, he introduced the cult of the god Pan, to differentiate himself from the previous political and religious tradition and to emphasize his own imagine as a king; on the other side, in order to connect himself with the Argead ghenos, he revitalized the cult of the gods Herakles and Asclepius, he built a monument for his ancestors, the progonoi, in Delos and he revitalized the image of Alexander IV, Alexander the Great’s son. Considering this last point, this study reassesses Antigonos’ reception in the 20th century. In particular, by re-examining the Boscoreale’s frescoes, it shows, against Studniczka’s hypothesis, that it is not possible to demonstrate that Antigonos is represented in these paintings. Moreover, Antigonos accepted, or perhaps sponsored, a cult in his honor (SEG 41, 75). This research confirms that Antigonos followed stoic teachings (as his relationship with the main philosophers of his time shows) to promote his political image; at the same time, he made use of any cunning political strategy to maintain the power for more than forty years.
Considering the different approaches and themes discussed in this study, my research focuses also on the various ways and styles of communication. It considers the thorny issue regarding the chronology of Antigonos’ reign and how it could reflect his aim of creating a real ‘Antigonid era’ and a more rooted legitimation of his role as a king of Macedonia. Furthermore, it discusses the part played by Antigonid women in maintaining and managing the political power. This work demonstrates that Phila I, his mother, had a pivotal role in maintaining the cultural and administrative requirements of the Antigonid court
Clinico-Genetic Characterization of a Large Italian Cohort with Primary Spastic Paraplegia
No full textM1002. Clinico-Genetic Characterization of a Large Italian Cohort with Primary Spastic Paraplegia
Andrea Martinuzzi, Mariateresa Bassi, Grazia D’Angelo, Sara Bonato, Gabriella Paparella, Olimpia Musumeci, Mariagiovanna Rossetto, Marianna Fantin, Francesca Peruch, Alessia Arnoldi, Claudia Crimella, Erika Tenderini, Paolo Bonanni, Vanessa Casanova, Giovanni Meola, Giacomo Comi, Antonio Toscano and Nereo Bresolin; Conegliano, TV, Italy; Bosisio Parini, LC, Italy; Messina, Italy and Milano, Italy
Background: Diagnostic definition of hereditary spastic paraplegias (HSPs) is complicated by the wide genetic heterogeneity.
Objectives: Establish in a large cohort of Italian HSP
patients the relative frequency of the various forms, provid- ing indications for an efficient diagnostic algorhythm.
Methods: 478 index cases (72 familial, 98 pure, 380
complicated) HSP were clinically and molecularly assessed.
Results: 80 cases were molecularly defined. SPG4 was the most frequent form (55%), followed by SPG11 (16.6%) SPG7 (9%), SPG10 (8,8% ) and 5 (5.1%). SPG3a and
SPG31 were rarer (2.5%). No mutations were identified in SPG6, 8, 13, 20, 21, 35, 48. There was wide inter and intrafamilial variation. Neurophysiology showed invariably increased central conduction time at lower limbs. Axonal polyneuropathy was detected in some SPG3a, 5, 10, 11, 17 and SPG4 (15%). MRI showed abnormalities in SPG 5, 10, 11 and 15.
Conclusion: Frequency of SPG forms within this cohort
of Italian HSPs confirms the prevalence of SPG4, reveals the recurrence of SPG11 and 7 and the low frequency of SPG3a and 31. Once SPG4 and SPG11 are excluded, fam- ily history, neurophysiology and neuroimaging may direct the choice of genetic testing.
Study supported by: Italian Ministry of Healt
Cyclic Analyses of Reinforced Concrete Masonry Panels Using a Force-Based Frame Element
No full textThis paper presents the calibration of a frame element that can be used to model the flexural as well as the shear behavior of reinforced masonry panels subjected to monotonic and cyclic loads. The element can be used in the equivalent frame method to analyze masonry wall systems, and is based on a force-based Timoshenko beam element formulation that combines a fiber-section model with a phenomenological nonlinear shear law. The element was originally applied to the analysis of reinforced concrete frames, and has been recently extended to unreinforced masonry structures. Well-established constitutive laws are used for masonry and steel reinforcement. The constitutive law for shear requires special attention in order to correctly predict the shear force-deformation response of masonry walls, accounting for the presence of shear reinforcement. A procedure to calibrate the parameters of the shear law is presented. The effectiveness, accuracy, and simplicity of the force-based Timoshenko frame element and the calibration method are validated by results of experimental tests. Even though the element is general and can model any reinforced masonry panel, the applications of this paper focus on panels made of hollow concrete blocks
Gender structures in forestry organisations. Par. 1.9 Italy.
No full textOn the basis of the available official data and of a preliminary ad hoc survey conducted in 2003 at national level, the paper presents the situation women are facing in the forestry sector in Italy in terms of number, employment conditions and perspectives for the future. The main problems – lower wages, low participation in decision- making and in power positions, preconceptions, etc. – are common to those outlined by specific studies or initiatives carried out in other countries (Croatia, France, Norway, Sweden, Switzerland, among others). However, in the near future, Italian women are expected to enter forestry professions at all levels in increasing numbers, acting as forestry workers, private and public forest companies’ managers, experts and technical advisers, officers and agents of the paramilitary State Forestry Corp (Corpo Forestale dello Stato), and to demand their role, specific contribution and attitude to be more recognized. Social as well as forestry policies and strategies have to take into account this issue, which is part of broader changes throughout the forestry sector
Improving elevation perception with a tool for image-guided head-related transfer function selection
No full textThis paper proposes an image-guided HRTF selection procedure that exploits the relation between features of the pinna shape and HRTF notches. Using a 2D image of a subject's pinna, the procedure selects from a database the HRTF set that best fits the anthropometry of that subject. The proposed procedure is designed to be quickly applied and easy to use for a user without previous knowledge on binaural audio technologies. The entire process is evaluated by means of an auditory model for sound localization in the mid-sagittal plane available from previous literature. Using virtual subjects from a HRTF database, a virtual experiment is implemented to assess the vertical localization performance of the database subjects when they are provided with HRTF sets selected by the proposed procedure. Results report a statistically significant improvement in predictions of localization performance for selected HRTFs compared to KEMAR HRTF which is a commercial standard in many binaural audio solutions; moreover, the proposed analysis provides useful indications to refine the perceptually-motivated metrics that guides the selection
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Applying a Single-notch Metric to Image-guided Head-related Transfer Function Selection for Improved Vertical Localization
No full textThis paper proposes an image-guided HRTF selection procedure that exploits the relation between features of the pinna shape and HRTF notches. Using a 2D image of a user's pinna, the procedure selects from a database the HRTF set that best fits the anthropometry of that user. The proposed procedure is designed to be quickly applied and easy to use for a user without previous knowledge on binaural audio technologies. The entire process is evaluated by means of (i) an auditory model for sound localization in the mid-sagittal plane available from previous literature, and (ii) a short localization test in virtual reality. Using both virtual and real subjects from a HRTF database, predictions and the experimental evaluation aimed to assess the vertical localization performance with HRTF sets selected by the proposed procedure. Our results report a statistically significant improvement in predictions of the auditory model for localization performance with selected HRTFs compared to KEMAR HRTFs, which is a commercial standard in many binaural audio solutions. Moreover, the proposed localization test with human listeners reflect the model's predictions, further supporting the applicability of our perceptually-motivated metrics with anthropometric data extracted by pinna images
Nonlinear analysis of masonry structures using fiber-section line elements
No full textFor seismic analysis of unreinforced masonry (URM) buildings characterized by a box-like behavior, a widely accepted model is based on the equivalent frame idealization of walls. The equivalent frame model uses 1D elements to represent the vertical piers and horizontal spandrels which are connected by rigid nodes. The mechanical characterization of the elements is one of the crucial aspects to predict reasonably the building seismic behavior. Through the comparison with pseudo-static and dynamic experimental tests performed on two-story full-scale buildings, this paper validates the frame modeling in the OpenSees framework, which includes a fiber-section force-based beam element for the axial-flexural behavior, coupled with a cyclic shear-deformation phenomenological law
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