cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Radio-to-gamma-ray synchrotron and neutrino emission from proton-proton interactions in active galactic nuclei
Creators: name: Neronov, Andrii
name: Semikoz, Dmitry
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We explore possible physical origin of correlation between radio wave and very-high-energy neutrino emission in active galactic nuclei (AGN), suggested by recently reported evidence for correlation between neutrino arrival directions and positions of brightest radio-loud AGN. We show that such correlation is expected if both synchrotron emitting electrons and neutrinos originate from decays of charged pions produced in proton-proton interactions in parsec-scale relativistic jet propagating through circum-nuclear medium of the AGN.
description: 6 pages, 1 figure, accepted to JETP Lett
Multiple solutions of double phase variational problems with variable exponent
Creators: name: Shi, Xiayang
name: Rădulescu, Vicenţiu D.
name: Repovš, Dušan D.
name: Zhang, Qihu
Publisher: name: arXiv
Year: 2020
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: Primary 35J62, 35J70, Secondary 35J20

description: This paper deals with the existence of multiple solutions for the quasilinear equation $-\mathrm{div}\,\mathbf{A}(x,\nabla u)| u| ^{α(x)-2}u=f(x,u)$ in $ \mathbb{R} ^{N}$, which involves a general variable exponent elliptic operator $\mathbf{ A}$ in divergence form. The problem corresponds to double phase anisotropic phenomena, in the sense that the differential operator has behaviors like $ | ξ| ^{q(x)-2}ξ$ for small $| ξ| $ and like $| ξ| ^{p(x)-2}ξ$ for large $ | ξ| $, where $1
Ο ρόλος των εξωδιδακτικών δραστηριοτήτων στην ανάπτυξη διαπολιτισμικής δεξιότητας και επικοινωνίας σε μαθητές Γυμνασίου
Creators: name: Κουπατσάρη, Αικατερίνη Παναγιώτη
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Διαπολιτισμική επικοινωνία
Διαπολιτισμική δεξιότητα
Εξωδιδακτικές δραστηριότητες
Intercultural communication
Intercultural competency
Extracurricular activities

description: Σκοπός της παρούσας εργασίας είναι η καταγραφή και ανάλυση των απόψεων των μαθητών, των εκπαιδευτικών και του διευθυντή ενός διαπολιτισμικού γυμνασίου μεγάλου ελληνικού αστικού κέντρου, σχετικά με τις εξωδιδακτικές δραστηριότητες που υλοποιούνται εκτός του επίσημου αναλυτικού προγράμματος και κατά πόσο αυτές συμβάλλουν ή όχι στην ανάπτυξη διαπολιτισμικής δεξιότητας και επικοινωνίας στους μαθητές. Τα δεδομένα συνελέγησαν μέσω της ποιοτικής μεθόδου της ημιδομημένης συνέντευξης για τους εκπαιδευτικούς και το διευθυντή και μέσω της ομαδικά εστιασμένης συζήτησης για τους μαθητές. Τα αποτελέσματα της έρευνας, έδειξαν ότι οι εξωδιδακτικές δραστηριότητες βοηθούν τους μαθητές να αναπτύξουν κοινωνικές, γνωστικές και συναισθηματικές δεξιότητες, ικανές να διαμορφώσουν πολύπλευρα το χαρακτήρα και τις αντιλήψεις τους και να συμβάλλουν θετικά στην ανάπτυξη διαπολιτισμικής δεξιότητας και επικοινωνίας μεταξύ αλλοδαπών και γηγενών μαθητών.
description: The aim of the present study is to register and analyze the point of view of the teachers, the principal and the students of an intercultural junior high school in a Greek urban city, regarding the role of school- based extracurricular activities in developing intercultural competency and communication in students. Data was collected through the qualitative method of semi- structured interview for the teachers and the principal and through the focus group discussion for the students. The research findings showed that school- based extracurricular activities can contribute to the development of social, cognitive and emotional competencies to students, which are able to mould student’ s personage and perceptions and thus contribute positively to the intercultural competency and communication development among foreign and native students.
Quantum deformed magnon kinematics
Creators: name: Gomez, Cesar
name: Hernandez, Rafael
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The dispersion relation for planar N=4 supersymmetric Yang-Mills is identified with the Casimir of a quantum deformed two-dimensional kinematical symmetry, E_q(1,1). The quantum deformed symmetry algebra is generated by the momentum, energy and boost, with deformation parameter q=e^{2πi/λ}. Representing the boost as the infinitesimal generator for translations on the rapidity space leads to an elliptic uniformization with crossing transformations implemented through translations by the elliptic half-periods. This quantum deformed algebra can be interpreted as the kinematical symmetry of a discrete integrable model with lattice spacing given by the BMN length a=2π/\sqrtλ. The interpretation of the boost generator as the corner transfer matrix is briefly discussed.
description: 7 pages. Latex. v2: Misprint corrected. Added references to the previous elliptic uniformization by N. Beisert and the recent one by I. Kostov, D. Serban and D. Volin
title: Implementation of complex signal processing applications using high level synthesis tools on a VERSAL platform
title: Υλοποίηση πολύπλοκων εφαρμογών ψηφιακής επεξεργασίας σήματος με χρήση εργαλείων σύνθεσης σε υψηλό επίπεδο σε πλατφόρμα VERSAL

Creators: name: Σταυροπουλος Αλεξανδρος-Ανδρεας
Publisher: name: Technical University of Crete
Year: 2024

description: The growing demand for efficient and scalable hardware architectures to support complex machine learning (ML) and signal processing applications has led to the exploration of versatile platforms like the AMD/Xilinx Versal Adaptive Compute Acceleration Platform (ACAP). This thesis investigates the performance of the Versal VCK190, focusing on its Network-on-Chip (NoC) architecture and its potential for accelerating convolutional neural networks (CNNs) and matrix multiplication tasks. By leveraging the Vitis and Vitis AI development environments, benchmarks for CNN models and matrix operations were deployed to evaluate the throughput and efficiency of the NoC. The results demonstrate the strengths of the Versal platform in managing highperformance AI workloads, while also revealing areas where optimizations could improve performance, particularly in real-time applications.
Key contributions of this work include the development of custom benchmarks for CNNs and matrix multiplication, a thorough evaluation of NoC throughput and performance analysis based on real-time AI inference. The findings offer valuable insights into the capabilities and limitations of the Versal architecture for heterogeneous computing applications.

description: Η αυξανόμενη ζήτηση για αποδοτικές και κλιμακούμενες αρχιτεκτονικές υλικού για την υποστήριξη σύνθετων εφαρμογών μηχανικής μάθησης (ΜΜ) και επεξεργασίας σήματος έχει οδηγήσει στην εξερεύνηση ευέλικτων πλατφορμών όπως η πλατφόρμα AMD/Xilinx Versal Adaptive Compute Acceleration Platform (ACAP). Η παρούσα διπλωματική διερευνά τις επιδόσεις του Versal VCK190, εστιάζοντας στην αρχιτεκτονική του Network-on-Chip (NoC) και στις δυνατότητές του για την επιτάχυνση των συνελικτικών νευρωνικών δικτύων (ΣΝΔ) και των εργασιών πολλαπλασιασμού πινάκων. Αξιοποιώντας τα περιβάλλοντα ανάπτυξης Vitis και Vitis AI, αναπτύχθηκαν δείκτες αναφοράς για μοντέλα ΣΝΔ και πράξεις πινάκων για την αξιολόγηση της απόδοσης και της αποδοτικότητας του NoC. Τα αποτελέσματα καταδεικνύουν τα πλεονεκτήματα της πλατφόρμας Versal στη διαχείριση φορτίων εργασίας ΜΜ υψηλής απόδοσης, ενώ παράλληλα αποκαλύπτουν περιοχές όπου οι βελτιστοποιήσεις θα μπορούσαν να βελτιώσουν τις επιδόσεις, ιδίως σε εφαρμογές πραγματικού χρόνου.
Οι βασικές συνεισφορές αυτής της εργασίας περιλαμβάνουν την ανάπτυξη προσαρμοσμένων δοκιμών για ΣΝΔ και πολλαπλασιασμό πινάκων, ενδελεχή αξιολόγηση της απόδοσης του NoC και ανάλυση επιδόσεων με βάση την εξαγωγή συμπερασμάτων σε πραγματικό χρόνο. Τα ευρήματα προσφέρουν πολύτιμες πληροφορίες σχετικά με τις δυνατότητες και τους περιορισμούς της αρχιτεκτονικής Versal για εφαρμογές ετερογενών υπολογιστών.
Λαμβάνοντας τη διάγνωση της ψύχωσης: διερεύνηση του προσωπικού βιώματος
Creators: name: Παναγιωτοπούλου, Μενελάη Ανδρέα
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Ψύχωση
Σχιζοφρένεια
Διάγνωση
Psychosis
Schizophrenia
Diagnosis

description: Η παρούσα έρευνα στοχεύει να μελετήσει τον τρόπο, με τον οποίο, τα άτομα που εκδηλώνουν ψυχωτικά συμπτώματα, βίωσαν την εμπειρία της πρώτης τους επαφής με ψυχιατρικές υπηρεσίες, κατά την οποία τους αποδόθηκε και η διάγνωση της ψύχωσης. Βασική επιδίωξη της έρευνας, είναι να δώσει έμφαση στο προσωπικό βίωμα λήψης της διάγνωσης, ρίχνοντας φως στα θέματα που τα ίδια τα άτομα αναδεικνύουν μέσα από τις περιγραφές τους. Πρόκειται για μια έρευνα ποιοτικά προσανατολισμένη που στηρίζεται στον λόγο των ατόμων με διάγνωση ψύχωσης. Στην έρευνα συμμετείχαν δέκα άτομα, που έχουν λάβει διάγνωση ψύχωσης, ενώ η δομή, μέσω της οποίας προσεγγίσθηκαν, είναι ο Σύλλογος Οικογενειών για τη Ψυχική Υγεία (ΣΟΨΥ). Η συλλογή των δεδομένων επιτεύχθηκε μέσω της διεξαγωγής ημι-δομημένων συνεντεύξεων με τους συμμετέχοντες καi υποβλήθηκε σε ποιοτική ανάλυση κάνοντας χρήση της τεχνικής της Ερμηνευτικής Φαινομενολογίας. Τα ευρήματα της έρευνας ομαδοποιήθηκαν και εντάχθηκαν σε τρεις γενικές κατηγορίες κάτω από τους τίτλους: ¨Βιώνοντας το πρόβλημα¨, ¨Έναρξη της ψυχιατρικής πορείας: η λήψη της διάγνωσης¨ και ¨Η αντίληψη της ψύχωσης¨.
description: The present study aims to consider the way in which, people with psychotic symptoms, meet the experience of their first visit to psychiatric services and the diagnosis of psychosis that they receive. The primary intention of the study is to emphasize on the personal feeling of people when diagnosed, illuminating the themes that derive from their descriptions. It is a qualitative study, which is based on the speech of people diagnosed with psychosis. Ten participants with the diagnosis of psychosis took place, and were recruited from the Union of families for Mental Illness. The data were collected through semi-structured interviews with the participants and were submitted in qualitative analysis, using the method of Interpretative Phenomenological Analysis. The results of the study were grouped and subsumed into three general categories: “Experiencing the problem”, “The beginning of the psychiatry process: The receiving of diagnosis” and “The concept of psychosis”.
The effect of fibre length on passage through narrow apertures
Creators: name: Olson, James Allen
Publisher: name: University of British Columbia
Year: 2009

description: This thesis has examined the factors affecting the passage of fibres through narrow apertures under conditions similar to pulp pressure screening. This was accomplished by developing a theoretical model of fibre passage and verifying the predictions of this model experimentally. The theoretical model was based on earlier observations of a "wall effect" and a "turn-ing effect". These factors were represented in the model as a fibre concentration profile upstream of the aperture, and as the probability of a fibre at a given position entering the aperture. The near-wall, fibre concentration profile was experimentally determined for 1mm, 2mm and 3mm stiff fibres. Fibre concentration was found to increase linearly from zero at the wall to the average suspension concentration at a distance approximately 0.3 of a fibre length. It remained constant beyond this point. For a given initial position and orientation of a fibre upstream-of the slot, the prob-ability of passage was modeled by theoretically determining the trajectories of individual fibres at the entry flow of the aperture, including impacts with the aperture wall. To a first order approximation, fibres passed through the aperture when their centres origi-nated within the fluid layer that was drawn into the aperture. Using these theoretically calculated probabilities of passage with the experimentally measured fibre concentration profiles upstream of the aperture, passage ratios of fibres of different sizes were pre-dicted. The predictions were compared to experimental measurements of passage ratio. The theoretical model was found to give good predictions of average passage ratio.
A principal component analysis for LISA -- the TDI connection
Creators: name: Romano, J. D.
name: Woan, G.
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Data from the Laser Interferometer Space Antenna (LISA) is expected to be dominated by frequency noise from its lasers. However the noise from any one laser appears more than once in the data and there are combinations of the data that are insensitive to this noise. These combinations, called time delay interferometry (TDI) variables, have received careful study, and point the way to how LISA data analysis may be performed. Here we approach the problem from the direction of statistical inference, and show that these variables are a direct consequence of a principal component analysis of the problem. We present a formal analysis for a simple LISA model and show that there are eigenvectors of the noise covariance matrix that do not depend on laser frequency noise. Importantly, these orthogonal basis vectors correspond to linear combinations of TDI variables. As a result we show that the likelihood function for source parameters using LISA data can be based on TDI combinations of the data without loss of information.
description: 7 pages, 3 figures, 1 table
Η ελευθερία της βούλησης στην πλατωνική φιλοσοφία
Creators: name: Μποϊτσης, Ιωάννης Αθανασίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Πλάτωνας
Ελευθερία
Βούληση
Plato
Freedom
Will

description: Σκοπός της διπλωματικής εργασίας ήταν η ανάδειξη των θέσεων της πλατωνικής φιλοσοφίας σχετικά με το ζήτημα της ελευθερίας της βούλησης. Για τον σκοπό αυτό εξετάστηκαν αρχικά οι γενικότερες πεποιθήσεις της αρχαίας ελληνικής σκέψης σχετικά με το ζήτημα αυτό και έπειτα, οι πλατωνικοί διάλογοι που αφορούν στην ελευθερία της βούλησης. Αναλύθηκαν οι πλατωνικές θέσεις σχετικά με την έννοια της αληθινής ελευθερίας, που είναι απόλυτα συνυφασμένη με την έννοια της αλήθειας και της αναζήτησης αυτής. Εξετάστηκαν επίσης οι «επιπτώσεις» της ελεύθερης βούλησης στα επίπεδα της ηθικής και της μεταφυσικής. Τέλος, θίχτηκε το ζήτημα της «ακρασίας» και η προβληματική που γεννά η σωκρατική αυτή θέση.
description: The aim of the present thesis was to highlight the insights of Plato’s philosophy concerning the issue of free choice (freedom of will). In order to fulfill this, I first studied the general tensions in the era of ancient Greece referring to this matter and then, I focused on the platonic dialogues dealing with this. Apart from this, it was equally important to analyze the platonic beliefs regarding the definition of real freedom; a term which not only perfectly coincides with the one of “truth”, but also with the seeking of the actual and real truth. What is more, there is a discussion on the impact that freedom of will may induce in the fields of ethics and metaphysics. Finally, there is a reference to the issue of “akrasia” and the problems that this Socratic theory causes.
Colloquium: Physical properties of group-IV monochalcogenide monolayers
Creators: name: Barraza-Lopez, Salvador
name: Fregoso, Benjamin M.
name: Villanova, John W.
name: Parkin, Stuart S. P.
name: Chang, Kai
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We survey the state-of-the-art knowledge of ferroelectric and ferroelastic group-IV monochalcogenide monolayers. These semiconductors feature remarkable structural and mechanical properties, such as a switchable in-plane spontaneous polarization, soft elastic constants, structural degeneracies, and thermally-driven two-dimensional structural transformations. Additionally, these 2D materials also display selective valley excitations, valley Hall effects, and persistent spin helix behavior. After a description of their Raman spectra, a discussion of optical properties arising from their lack of centrosymmetry---such as an unusually strong second-harmonic intensity, large bulk photovoltaic effects, photostriction, and tunable exciton binding energies---is provided as well. The physical properties observed in these materials originate from (correlate with) their intrinsic and switchable electric polarization, and the physical behavior hereby reviewed could be of use in non-volatile memory, valleytronic, spintronic, and optoelectronic devices: these 2D multiferroics enrich and diversify the 2D materials toolbox.
description: Accepted for publication at Reviews of Modern Physics on September 9, 2020
Cosmological Landscape and Euclidean Quantum Gravity
Creators: name: Barvinsky, A O
name: Kamenshchik, A Yu
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Quantum creation of the universe is described by the {\em density matrix} defined by the Euclidean path integral. This yields an ensemble of universes -- a cosmological landscape -- in a mixed quasi-thermal state which is shown to be dynamically more preferable than the pure quantum state of the Hartle-Hawking type. The latter is suppressed by the infinitely large positive action of its instanton, generated by the conformal anomaly of quantum matter. The Hartle-Hawking instantons can be regarded as posing initial conditions for Starobinsky solutions of the anomaly driven deSitter expansion, which are thus dynamically eliminated by infrared effects of quantum gravity. The resulting landscape of hot universes treated within the cosmological bootstrap (the self-consistent back reaction of quantum matter) turns out to be limited to a bounded range of the cosmological constant, which rules out a well-known infrared catastrophe of the vanishing cosmological constant and suggests an ultimate solution to the problem of unboundedness of the cosmological action in Euclidean quantum gravity.
description: 6 pages, to be published in the Special issue of J. Phys. A dedicated to the Quantum Theories and Renormalization Group in Gravity and Cosmology (IRGAC 2006, Barcelona, Spain, 11-15 July 2006)
Survey: Family language policy of the second-generation Turkish families in the Netherlands (Turkish & Dutch)
Creators: name: Bezcioglu Goktolga, Irem
name: Yagmur, Kutlay
name: Backus, Ad
Publisher: name: Zenodo
Year: 2019
Subjects: Family Language Policy
Sociolinguistics
Turkish/Dutch families

description: This survey was developed to explore the family language policy among second-generation Turkish families in the Netherlands.

It is available in English, Turkish and Dutch. The English version is available in the PhD dissertation of İrem Bezcioğlu-Göktolga in this link: Bezcioglu_Goktolga_Family_03_09_2019.pdf (uvt.nl)

Turkish and Dutch versions are available here.
Unifying Online and Counterfactual Learning to Rank
Creators: name: Oosterhuis, Harrie
name: de Rijke, Maarten
Publisher: name: arXiv
Year: 2020
Subjects: subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences

description: Optimizing ranking systems based on user interactions is a well-studied problem. State-of-the-art methods for optimizing ranking systems based on user interactions are divided into online approaches - that learn by directly interacting with users - and counterfactual approaches - that learn from historical interactions. Existing online methods are hindered without online interventions and thus should not be applied counterfactually. Conversely, counterfactual methods cannot directly benefit from online interventions. We propose a novel intervention-aware estimator for both counterfactual and online Learning to Rank (LTR). With the introduction of the intervention-aware estimator, we aim to bridge the online/counterfactual LTR division as it is shown to be highly effective in both online and counterfactual scenarios. The estimator corrects for the effect of position bias, trust bias, and item-selection bias by using corrections based on the behavior of the logging policy and on online interventions: changes to the logging policy made during the gathering of click data. Our experimental results, conducted in a semi-synthetic experimental setup, show that, unlike existing counterfactual LTR methods, the intervention-aware estimator can greatly benefit from online interventions.
description: Harrie Oosterhuis and Maarten de Rijke. 2021. Unifying Online and Counterfactual Learning to Rank: A Novel Counterfactual Estimator that Effectively Utilizes Online Interventions. In The 14th ACM International Conference on Web Search and Data Mining (WSDM '21), March 8-12, 2021, Jerusalem, Israel. ACM, New York, NY, USA, 9 pages. https://doi.org/10.1145/3437963.3441794
Mixing and $CP$ violation in the charm system
Creators: name: Lenz, Alexander
name: Wilkinson, Guy
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In recent years charm physics has undergone a renaissance, one which has been catalysed by an unexpected and impressive set of experimental results from the $B$-factories, the Tevatron and LHCb. The existence of $D^0\bar{D}{}^0$ oscillations is now well established, and the recent discovery of $CP$ violation in $D^0$ decays has further renewed interest in the charm sector. In this article we review the current status of charm-mixing and $CP$-violation measurements, and assess their agreement with theoretical predictions within the Standard Model and beyond. We look forward to the great improvements in experimental precision that can be expected over the coming two decades, and the prospects for corresponding advances in theoretical understanding.
description: Article submitted to Vol. 71 of Annual Review of Nuclear and Particle Science
Μελέτη των χαλαζοκαταιγίδων στην περιοχή Ημαθίας-Πέλλας
Creators: name: Σφυρή, Ελένη Ευάγγελου
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Χαλαζοκαταιγίδα
Κεντρική Μακεδονία
Μέγιστη Ανακλαστικότητα
Hailstorm
Central Macedonia
Maximum Reflectivity

description: Αντικειμενικός σκοπός στην παρούσα εργασία είναι η μελέτη και η περιγραφή των χαρακτηριστικών των χαλαζοκαταιγίδων καθώς και η μελέτη των μέσης κλίμακας θερμοδυναμικών χαρακτηριστικών τους, πάνω από την περιοχή της Κεντρικής Μακεδονίας κατά την περίοδο 1998 – 2008 (Απρίλιος ως Σεπτέμβριος), με δεδομένα από το ΕΠΧΠ του ΕΛΓΑ. Συγκεκριμένα μελετώνται: η συχνότητα των ημερών χαλαζοκαταιγίδας, των χτυπημένων χαλαζόμετρων, της μέγιστης ανακλαστικότητας, του ύψους της ισόθερμου των -5°C καθώς και της ταχύτητας και της διεύθυνσης κίνησης των χαλαζοκαταιγίδων. Τα δεδομένα αυτά προέρχονται, από τις ετήσιες εκθέσεις του ΕΛΓΑ, το C-band ραντάρ καιρού του Φιλύρου, από τις αντίστοιχες ραδιοβολίσεις και το πρόγραμμα καταγραφής ΤΙΤΑΝ.Μελετάται επίσης η συμβολή της ορεογραφίας στα χαρακτηριστικά των χαλαζοκαταιγίδων, ενώ στο τελευταίο κεφάλαιο αναλύεται μια περίπτωση έντονης χαλαζοκαταιγίδας που έλαβε χώρα στην περιοχή προστασίας Π1 στις 4/7/2008. Από την ανάλυση αυτή προκύπτει ότι ο μήνας με την εντονότερη χαλαζική δραστηριότητα είναι ο Ιούνιος, ότι η πλειονότητα των χαλαζοκαταιγίδων που πλήττουν την περιοχή μελέτης είναι ορεογραφικές και ότι υπάρχει σημαντική θετική συσχέτιση μεταξύ μέγιστης ανακλαστικότητας και ύψους κορυφής των ηχώ. Όσον αφορά τη μελέτη περίπτωσης, είναι θερμική χαλαζοκαταιγίδα πάνω από πεδινή περιοχή και οφείλεται κυρίως στην ατμοσφαιρική αστάθεια που επικρατούσε.
description: The objective of this study is the analysis of the mesoscale thermodynamic characteristics of the hailstorms, which occurred over the region of Central Macedonia where the National Hail Suppression Program is applied, during the period 1998-2008, except for the year 2003. The data used are derived through the C-band weather radar at Filyro and from the representative soundings of the synoptic station of Thessaloniki. The frequency of hailstorms occurrence, their movement, intensity and the maximum development are studied. The radar data are analyzed and studied through the software TITAN (Thunderstorm Identification, Tracking Analysis and Nowcasting), for the period 2006-2008.
Biomechanical models to simulate consequences of maxillofacial surgery
Creators: name: Payan, Yohan
name: Chabanas, Matthieu
name: Pelorson, Xavier
name: Vilain, Coriandre
name: Levy, Patrick
name: Luboz, Vincent
name: Perrier, Pascal
Publisher: name: arXiv
Year: 2006
Subjects: subject: Medical Physics (physics.med-ph)
subject: FOS: Physical sciences

description: This paper presents the biomechanical finite element models that have been developed in the framework of the computer-assisted maxillofacial surgery. After a brief overview of the continuous elastic modelling method, two models are introduced and their use for computer-assisted applications discussed. The first model deals with orthognathic surgery and aims at predicting the facial consequences of maxillary and mandibular osteotomies. For this, a generic three-dimensional model of the face is automatically adapted to the morphology of the patient by the mean of elastic registration. Qualitative simulations of the consequences of an osteotomy of the mandible can thus be provided. The second model addresses the Sleep Apnoea Syndrome. Its aim is to develop a complete modelling of the interaction between airflow and upper airways walls during respiration. Dynamical simulations of the interaction during a respiratory cycle are computed and compared with observed phenomena.
Rede Moara: fomento ao compartilhamento de código fonte de forma livre
Creators: name: Vechi, Bernardo Dionízio
name: Torres Schiessl, Ingrid
name: Macêdo, Diego José
name: dos Santos de Moura, Rebeca
name: Rodrigues Costa, Lucas
name: Shintaku, Milton
Publisher: name: Zenodo
Year: 2024

description: Apresentação realizada na sessão Demos, da 15ª Conferência Lusófona de Ciência Aberta, na Escola Superior de Enfermagem do Porto (ESEP), de 01 a 04 de outubro de 2024.
Intersecting and $2$-intersecting hypergraphs with maximal covering number: the Erdős-Lovász theme revisited
Creators: name: Barát, János
Publisher: name: arXiv
Year: 2020
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics

description: Erdős and Lovász noticed that an $r$-uniform intersecting hypergraph $H$ with maximal covering number, that is $τ(H)=r$, must have at least $\frac{8}{3}r-3$ edges. There has been no improvement on this lower bound for 45 years. We try to understand the reason by studying some small cases to see whether the truth lies very close to this simple bound. Let $q(r)$ denote the minimum number of edges in an intersecting $r$-uniform hypergraph. It was known that $q(3)=6$ and $q(4)=9$. We obtain the following new results: The extremal example for uniformity 4 is unique. Somewhat surprisingly it is not symmetric by any means. For uniformity 5, $q(5)=13$, and we found 3 examples, none of them being some known graph. We use both theoretical arguments and computer searches. In the footsteps of Erdős and Lovász, we also consider the special case, when the hypergraph is part of a finite projective plane. We determine the exact answer for $r\in \{3,4,5,6\}$. For uniformity 6, there is a unique extremal example. In a related question, we try to find $2$-intersecting $r$-uniform hypergraphs with maximal covering number, that is $τ(H)=r-1$. An infinite family of examples is to take all possible $r$-sets of a $(2r-2)$-vertex set. There is also a geometric candidate: biplanes. These are symmetric 2-designs with $λ=2$. We determined that only 3 biplanes of the 18 known examples are extremal.
Quantum Direct Communication with Continuous Variables
Creators: name: Pirandola, Stefano
name: Braunstein, Samuel L.
name: Mancini, Stefano
name: Lloyd, Seth
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We show how continuous variable systems can allow the direct communication of messages with an acceptable degree of privacy. This is possible by combining a suitable phase-space encoding of the plain message with real-time checks of the quantum communication channel. The resulting protocol works properly when a small amount of noise affects the quantum channel. If this noise is non-tolerable, the protocol stops leaving a limited amount of information to a potential eavesdropper.
description: 6 pages, 5 figures, REVTeX
Panorama: A Framework to Support Collaborative Context Monitoring on Co-Located Mobile Devices
Creators: name: Alanezi, Khaled
name: Zhou, Xinyang
name: Chen, Lijun
name: Mishra, Shivakant
Publisher: name: arXiv
Year: 2021
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences

description: A key challenge in wide adoption of sophisticated context-aware applications is the requirement of continuous sensing and context computing. This paper presents Panorama, a middleware that identifies collaboration opportunities to offload context computing tasks to nearby mobile devices as well as cloudlets/cloud. At the heart of Panorama is a multi-objective optimizer that takes into account different constraints such as access cost, computation capability, access latency, energy consumption and data privacy, and efficiently computes a collaboration plan optimized simultaneously for different objectives such as minimizing cost, energy and/or execution time. Panorama provides support for discovering nearby devices and cloudlets/cloud, computing an optimal collaboration plan, distributing computation to participating devices, and getting the results back. The paper provides an extensive evaluation of Panorama via two representative context monitoring applications over a set of Android devices and a cloudlet/cloud under different constraints.
description: Published in MobiCase 2015
Relativistic Dynamics of Non-ideal Fluids: Viscous and heat-conducting fluids II. Transport properties and microscopic description of relativistic nuclear matter
Creators: name: Muronga, Azwinndini
Publisher: name: arXiv
Year: 2006
Subjects: subject: Nuclear Theory (nucl-th)
subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: In the causal theory of relativistic dissipative fluid dynamics, there are conditions on the equation of state and other thermodynamic properties such as the second-order coefficients of a fluid that need to be satisfied to guarantee that the fluid perturbations propagate causally and obey hyperbolic equations. The second-order coefficients in the causal theory, which are the relaxation times for the dissipative degrees of freedom and coupling constants between different forms of dissipation (relaxation lengths), are presented for partonic and hadronic systems. These coefficients involves relativistic thermodynamic integrals. The integrals are presented for general case and also for different regimes in the temperature--chemical potential plane. It is shown that for a given equation of state these second-order coefficients are not additional parameters but they are determined by the equation of state. We also present the prescription on the calculation of the freeze-out particle spectra from the dynamics of relativistic non-ideal fluids.
description: 47 pages, 2 figures, added references, added typos
Flow resistance of screen plate apertures
Creators: name: Gooding, Robert William
Publisher: name: University of British Columbia
Year: 2009

description: Pulp screens remove fibre bundles, plastic specks and other oversize contaminants from pulp suspensions before the pulp is made into paper. Removal efficiency increases as the size of the apertures in the screen plate is reduced. Smaller apertures do, however, increase the hydraulic resistance of the screen plate and may cause an excessive loss of screen capacity. There is considerable incentive to reduce hydraulic resistance so that smaller, more efficient, apertures can be used. The objective of this study was to learn what determines the hydraulic resistance of screen plate apertures, and how resistance can be reduced. Hydraulic resistance was assessed using the nondimensional pressure drop coefficient (K) across the screen plate, and K was studied by three methods. Computational fluid dynamics (CFD) was used to predict how flow variables and aperture geometry affect K in an idealized screening configuration. Experiments with a flow channel were used to confirm the theoretical CFD findings and explore how fibre accumulations at the screen aperture would affect K. Finally, trials with an industrial pulp screen showed how industrial variables influenced K. This study determined that the recirculating zone at the slot entry has a dominant influence on K. Both the size of the recirculating zone and K could be reduced by increasing the ratio of slot velocity to upstream velocity. In one typical case, an increase in this velocity ratio (V[sub]N) from 0.2 to 1.0 caused K to decrease from 10.8 to 2.2. Optimizing the shape of the slot entry was also found to reduce K. When a simple recess was made at the slot entry, the value of K (at V[sub]N = 1) decreased from 2.2 to 1.5. A hydraulic model of a commercial screen was used to assess the relative contribution of the screen plate resistance to the total pressure loss through the screen. For water flowing through a particular screen, the resistance of the screen housing was more than six times that of the screen plate. For pulp flow through the same screen, where apertures may have been partially blocked by fibres, the resistance of the housing was still double that of the screen plate.
A Methodological Approach to Model CBR-based Systems
Creators: name: Oliveira, Eliseu M.
name: Reale, Rafael F.
name: Martins, Joberto S. B.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences
subject: I.2.1; F.4.1

description: Artificial intelligence (AI) has been used in various areas to support system optimization and find solutions where the complexity makes it challenging to use algorithmic and heuristics. Case-based Reasoning (CBR) is an AI technique intensively exploited in domains like management, medicine, design, construction, retail and smart grid. CBR is a technique for problem-solving and captures new knowledge by using past experiences. One of the main CBR deployment challenges is the target system modeling process. This paper presents a straightforward methodological approach to model CBR-based applications using the concepts of abstract and concrete models. Splitting the modeling process with two models facilitates the allocation of expertise between the application domain and the CBR technology. The methodological approach intends to facilitate the CBR modeling process and to foster CBR use in various areas outside computer science.
description: pp 1-16, 3 figures
Παράλληλη επεξεργασία μεγάλων προβλημάτων του υπολογιστικού ηλεκτρομαγνητισμού με γραφικούς επεξεργαστές:
Creators: name: Γούσιος, Γεώργιος Μιχαήλ
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Ηλεκτρομαγνητισμός
Παράλληλη επεξεργασία
Γραφικοί επεξεργαστές
Electromagnetism
Parallel processing
Graphical processing units

description: Σκοπός της εργασίας αυτής ήταν η μετατροπή ενός προβλήματος ηλεκτρομαγνητισμού ,το οποίο ήταν σχεδιασμένο για σειριακή επεξεργασία,σε παράλληλη επεξεργασία με τη χρήση της κάρτας γραφικών.Για τον προγραμματισμό στην κάρτα γραφικών χρησιμοποιήθηκε η γλώσσα Cuda C της Nvidia.Στην αρχή της εργασίας γίνεται μια θεωρητική εισαγωγή στην αρχιτεκτονική των συγχρόνων καρτών γραφικών και έπειτα η οργάνωση του προγραμματισμού στην Cuda.Στο πρακτικό μέρος,αρχικά, παρατίθενται κάποια στοιχεία ηλεκτρομαγνητισμού και γίνεται η επισκόπηση του προβλήματος.Στη συνέχεια παρουσιάζονται τα αποτελέσματα μαζί με τα ανάλογα γραφήματα.Τέλος,δίνονται τα συμπεράσματα και ακολουθεί ο σχολιασμός τους.
description: The aim of the present thesis was the conversion of an electromagnetism problem ,which was designed for serial processing,into parallel processing with the use of a graphical processing unit.For programming on GPU (graphical processing unit) , we used the Cuda C language of Nvidia.At the beginning of this thesis we are making a theoretical introduction to the architecture of modern GPUs and then we are dealing with the programming structure in Cuda.In practical part,initially , can be found some electromagnetism information and the problem overview.Next,the results are presented together with the relevant graphs.Finally,we present the conclusions and their comments.
Theoretical analysis of dynamic chemical imaging with lasers using high-order harmonic generation
Creators: name: Le, Van-Hoang
name: Le, Anh-Thu
name: Xie, Rui-Hua
name: Lin, C. D.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We report theoretical investigations of the tomographic procedure suggested by Itatani {\it et al.} [Nature, {\bf 432} 867 (2004)] for reconstructing highest occupied molecular orbitals (HOMO) using high-order harmonic generation (HHG). Using the limited range of harmonics from the plateau region, we found that under the most favorable assumptions, it is still very difficult to obtain accurate HOMO wavefunction, but the symmetry of the HOMO and the internuclear separation between the atoms can be accurately extracted, especially when lasers of longer wavelengths are used to generate the HHG. We also considered the possible removal or relaxation of the approximations used in the tomographic method in actual applications. We suggest that for chemical imaging, in the future it is better to use an iterative method to locate the positions of atoms in the molecule such that the resulting HHG best fits the macroscopic HHG data, rather than by the tomographic method.
description: 13 pages, 14 figures
A wall function approach in lattice Boltzmann method: algorithm and validation using turbulent channel flow
Creators: name: Han, Mengtao
name: Ooka, Ryozo
name: Kikumoto, Hideki
Publisher: name: arXiv
Year: 2020
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: In the lattice Boltzmann method (LBM), the widely utilized wall boundary is the bounce-back (BB) boundary, which corresponds to the no-slip boundary. The BB boundary prevents the LBM from capturing the accurate shear drag on the wall when addressing high Reynolds number flows using coarse-grid systems. In this study, we proposed a "wall-function bounce (WFB)" boundary that incorporates a wall function into the LBM's boundary condition and overcomes the limitation of the BB. The WFB boundary calculates the appropriate shear drag on the wall using a wall function model, and thereafter modifies distribution functions to reflect the shear drag. The Spalding's law was utilized as the wall function in WFB. Simulations of turbulent channel flow at $Re_τ$=640 and 2003 using the LBM-based large-eddy simulation (LBM-LES) were conducted to validate the effectiveness of the proposed boundary condition. The results indicate that the BB boundary underestimated the time-averaged velocity in the buffer layer at $Re_τ$=640, and the averaged velocity in the entire domain at $Re_τ$=2003, when using coarse-grid systems. However, WFB obtained the proper shear drag on the wall and thus, compensated for the underestimation and agreed better with the experimental or DNS data, especially at the first-layer grid. In addition, WFB improved the Reynolds normal stress in the near-wall region to some extent. The distributions of shear stress on the wall by WFB was analogous to those by the wall model function in the finite volume method.
description: This manuscript is under review by an international journal
Εικόνες γυναικών στην πρώιμη κρητική ποίηση (14ος – 16ος αιώνας)
Creators: name: Βουλγαρίδου, Δέσποινα Αναστασίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Εικόνες γυναικών
Πρώιμη κρητική ποίηση
Στερεότυπα
Μισογυνισμός
Images og women
Early cretan poetry
Stereotypes
Misogyny

description: Η παρούσα διατριβή είχε σκοπό να εξετάσει τις εικόνες των γυναικών όπως εμφανίζονται σε συγκεκριμένα κείμενα της πρώιμης κρητικής ποίησης που ανήκουν στην περίοδο 14ος - 16ος αιώνας. Διερευνήσαμε τις γυναικείες λογοτεχνικές εικόνες και τον τρόπο αναπαράστασης της θηλυκότητας με τη βοήθεια της φεμινιστικής λογοτεχνικής θεωρίας και κριτικής, η οποία μας παρείχε τη δυνατότητα να προσεγγίσουμε από μια ιδιαίτερη οπτική γωνία τα κείμενα, να σχολιάσουμε και να αναλύσουμε τις εικόνες. Επιπλέον, ερευνήσαμε αν οι γυναικείες εικόνες που συναντούμε στα υπό εξέταση ποιήματα είναι στερεοτυπικές. Μια ενδιαφέρουσα ποικιλία γυναικείων λογοτεχνικών τύπων αναδύθηκε από τη μελέτη των ποιημάτων μας: από την Παναγία μέχρι τη γυναίκα φόνισσα.
description: The present thesis had as aim to examine the images of women as they appear in certain texts of the early Cretan poetry which belong to the period 14th to 16th century. We explored the feminine literary images and the representation of femininity with the help of the feminist literary theory and criticism which gave us the possibility to approach the texts from a special point of view, to comment and to analyze the images. Furthermore, we explored whether the feminine images we encounter in the examined poems are stereotypical. An interesting variety of feminine literary types emerged from the study of our poems: from the Virgin to the woman murderess.
High-precision mass measurements of nickel, copper, and gallium isotopes and the purported shell closure at N=40
Creators: name: Guenaut, C.
name: Audi, G.
name: Beck, D.
name: Blaum, K.
name: Bollen, G.
name: Delahaye, P.
name: Herfurth, F.
name: Kellerbauer, A.
name: Kluge, H. -J.
name: Libert, J.
name: Lunney, D.
name: Schwarz, S.
name: Schweikhard, L.
name: Yazidjian, C.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: High-precision mass measurements of more than thirty neutron-rich nuclides around the Z=28 closed proton shell were performed with the triple-trap mass spectrometer ISOLTRAP at ISOLDE/CERN to address the question of a possible neutron shell closure at N=40. The results, for 57,60,64-69Ni (Z=28), 65-74,76Cu (Z=29), and 63-65,68-78Ga (Z=31), have a relative uncertainty of the order of 10^8. In particular, the masses of 72-74,76Cu have been measured for the first time. We analyse the resulting mass surface for signs of magicity, comparing the behavior of N=40 to that of known magic numbers and to mid-shell behavior. Contrary to nuclear spectroscopy studies, no indications of a shell or sub-shell closure are found for N=40.
description: 14 figures
Tunable plasmons in large area WTe2 thin films
Creators: name: Wang, Chong
name: Sun, Yangye
name: Huang, Shenyang
name: Xing, Qiaoxia
name: Zhang, Guowei
name: Song, Chaoyu
name: Wang, Fanjie
name: Xie, Yuangang
name: Lei, Yuchen
name: Sun, Zhengzong
name: Yan, Hugen
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: The observation of the electrically tunable and highly confined plasmons in graphene has stimulated the exploration of interesting properties of plasmons in other two dimensional materials. Recently, hyperbolic plasmon resonance modes are observed in exfoliated WTe2 films, a type-II Weyl semimetal with layered structure, providing a platform for the assembly of plasmons with hyperbolicity and exotic topological properties. However, the plasmon modes were observed in relatively thick and small-area films, which restrict the tunability and application for plasmons. Here, large-area (~ cm) WTe2 films with different thickness are grown by chemical vapor deposition method, in which plasmon resonance modes are observed in films with different thickness down to about 8 nm. Hybridization of plasmon and surface polar phonons of the substrate is revealed by mapping the plasmon dispersion. The plasmon frequency is demonstrated to be tunable by changing the temperature and film thickness. Our results facilitate the development of a tunable and scalable WTe2 plasmonic system for revealing topological properties and towards various applications in sensing, imaging and light modulation.
description: 18 pages, 5 figures
Κοινωνική προέλευση και σχολική επίδοση: μια εμπειρική έρευνα υπό το πρίσμα της κοινωνικής δικαιοσύνης:
Creators: name: Θεοδοσιάδου, Κυριακή Σπυρίδωνος
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Κοινωνική δικαιοσύνη
Σχολική επίδοση
Εκπαιδευτικές και κοινωνικές ανισότητες
Social justice
School achievement
Educational and social inequalities

description: Η διατριβή αφενός μελετά σε θεωρητικό επίπεδο θέματα εφαρμογής της κοινωνικής δικαιοσύνης στην εκπαίδευση και κοινωνικών και εκπαιδευτικών ανισοτήτων και εξετάζει το ρόλο που διαδραματίζει το σχολείο μέσα σε αυτό το πλαίσιο και αφετέρου, σε ερευνητικό επίπεδο, αποσκοπεί στη διερεύνηση των σχέσεων μεταξύ της κοινωνικής προέλευσης των μαθητών και των σχολικών επιδόσεών τους. Καθώς το θέμα συνδέεται άμεσα με την κοινωνική δικαιοσύνη, την έρευνα απασχολούν, επίσης, οι στάσεις και οι απόψεις εκπαιδευτικών και διευθυντών για το ρόλο της κοινωνικής δικαιοσύνης στην εκπαίδευση και το κατά πόσο αυτή βρίσκει εφαρμογή στη διδακτική πράξη. Η έρευνα αποτελεί ένα συνδυασμό ποσοτικών και ποιοτικών μεθόδων∙ με τη χρήση ερωτηματολογίου που απευθύνεται στους μαθητές, στο οποίο περιλαμβάνονται κλειστές και ανοιχτές ερωτήσεις, ερευνώνται θέματα που αφορούν, μεταξύ άλλων, την κοινωνική προέλευσή τους, τη μόρφωση των γονέων τους, τα κίνητρα μάθησης κ.ά. και με δομημένη συνέντευξη από τους εκπαιδευτικούς και τους διευθυντές των σχολείων εξετάζονται οι διδακτικές και εκπαιδευτικές πρακτικές που υιοθετούνται μέσα στη τάξη και το κατά πόσο συμβαδίζουν με την καλλιέργεια της κοινωνικής δικαιοσύνης.
description: The thesis examines, in a theoretical level, the implementation of social justice in education, and social and educational inequalities and examines the role of the school within this framework, and in an empirical level, investigates the relationship between students’ social background and their school performance. This issue is related to social justice, therefore it is also important for the research to examine the attitudes and opinions of teachers and principals about the role of social justice in education, and whether it can be applied into the classroom. The research is a combination of quantitative and qualitative research methods∙ through a questionnaire addressed to the students, which includes closed and open questions, it is examined their social origin, their parents’ education, their motivation etc and through a structured interview to teachers and principals examined the teaching and learning practices adopted in the classroom and whether they cultivate social justice.