cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Phase retrieval and saddle-point optimization
Creators: name: Marchesini, S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Optics (physics.optics)
subject: Optimization and Control (math.OC)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Iterative algorithms with feedback are amongst the most powerful and versatile optimization methods for phase retrieval. Among these, the hybrid input-output algorithm has demonstrated practical solutions to giga-element nonlinear phase retrieval problems, escaping local minima and producing images at resolutions beyond the capabilities of lens-based optical methods. Here, the input-output iteration is improved by a lower dimensional subspace saddle-point optimization.
description: 8 pages, 4 figures, revtex
Μελέτη Δικτύων, Φίλτρων, Ιδεωδών και η Χρησιμότητά τους σε Διάφορες Έννοιες Συμπαγότητας:
Creators: name: Μποζέλου, Μαρία Θεοφάνη
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Δίκτυα
Φίλτρα
Ιδεώδη
Συμπαγότητα
Αριθμήσιμη συμπαγότητα
Θεώρημα του Tychonoff
Nets
Filters
Ideals
Compactness
Countable Compactness
Tychonoff’s Theorem

description: Σκοπός αυτής της διπλωματικής εργασίας είναι η μελέτη των φίλτρων, των δικτύων και των ιδεωδών και της χρησιμότητάς τους στη συμπαγότητα και την αριθμήσιμη συμπαγότητα. Πιο συγκεκριμένα: Στο πρώτο κεφάλαιο μελετάμε τα φίλτρα, τα δίκτυα και τη μεταξύ τους σχέση. Και οι δύο αυτές έννοιες είναι γενικεύσεις των ακολουθιών, καθώς οι τελευταίες στους τοπολογικούς χώρους δε μας δίνουν τα επιθυμητά αποτελέσματα. Στο δεύτερο κεφάλαιο μελετάμε τα ιδεώδη και τις εφαρμογές τους στη Γενική Τοπολογία και ορίζουμε με τη βοήθεια ενός ιδεώδους και μιας τοπολογίας μια νέα τοπολογία. Στο τρίτο κεφάλαιο μελετάμε τη συμπαγότητα και κάποιες συναφείς έννοιες στους τοπολογικούς χώρους. Πιο συγκεκριμένα, αφού μελετήσουμε τη συμπαγότητα, επεκτεινόμαστε στη I-συμπαγότητα ή συμπαγότητα modulo κάποιο ιδεώδες I και αφού μελετήσουμε την αριθμήσιμη συμπαγότητα, επεκτεινόμαστε στην αριθμήσιμη I-συμπαγότητα. Στο τέταρτο και τελευταίο κεφάλαιο μελετάμε αν διατηρούνται και πώς οι παραπάνω ιδιότητες σε γινόμενα τοπολογικών χώρων.
description: The aim of the present thesis is the study of nets, filters and ideals and their connection with the notions of compactness and countable compactness. In the first chapter we study extensively filters and nets and the relationship between them. They both are generalizations of the concept of sequences and are introduced in General Topology, since the sequences are not the proper tool for the desired results. In the second chapter we study ideals and their applications in Topology and construct a new topology on a set X from a given topology on X and an ideal on X. In the third chapter we study compactness and some other notions relevant to compactness. More precisely, we extended our study of compactness to I-compactness (I is an ideal) or compactness modulo an ideal and of countable compactness to countable I-compactness. Finally, at the last chapter we examine how the above mentioned concepts behave with products of topological spaces.
On the accuracy of dark matter halo merger trees and the consequences for semi-analytic models of galaxy formation
Creators: name: Chandro-Gómez, Ángel
name: Lagos, Claudia del P.
name: Power, Chris
name: Moreno, Victor J. Forouhar
name: Helly, John C.
name: Lacey, Cedric G.
name: McGibbon, Robert J.
name: Schaller, Matthieu
name: Schaye, Joop
Publisher: name: arXiv
Year: 2025
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Galaxy formation and evolution models, such as semi-analytic models, are powerful theoretical tools for predicting how galaxies evolve across cosmic time. These models follow the evolution of galaxies based on the halo assembly histories inferred from large $N$-body cosmological simulations. This process requires codes to identify halos ("halo finder") and to track their time evolution ("tree builder"). While these codes generally perform well, they encounter numerical issues when handling dense environments. In this paper, we present how relevant these issues are in state-of-the-art cosmological simulations. We characterize two major numerical artefacts in halo assembly histories: (i) the non-physical swapping of large amounts of mass between subhalos, and (ii) the sudden formation of already massive subhalos at late cosmic times. We quantify these artefacts for different combinations of halo finder (SUBFIND, VELOCIRAPTOR, HBT-HERONS) and tree builder codes (D-TRESS+DHALO, TREEFROG, HBT-HERONS), finding that in general more than $50\%$ ($80\%$) of the more massive subhalos with $>10^{3}$ ($>10^{4}$) particles at $z=0$ inherit them in most cases. However, HBT-HERONS, which explicitly incorporates temporal information, effectively reduces the occurrence of these artefacts to $5\%$ ($10\%$). We then use the semi-analytic models SHARK and GALFORM to explore how these artefacts impact galaxy formation predictions. We demonstrate that the issues above lead to non-physical predictions in galaxies hosted by affected halos, particularly in SHARK where the modelling of baryons relies on subhalo information. Finally, we propose and implement fixes for the numerical artefacts at the semi-analytic model level, and use SHARK to show the improvements, especially at the high-mass end, after applying them.
description: Accepted for publication in MNRAS (a new section 3.3.3 discussing results in the context of other galaxy formation models and other minor changes). 32 pages (26 of main body and 6 of appendices)
Τα αγιολογικά κείμενα της μεσοβυζαντινής περιόδου ως πηγές για την παιδεία στο Βυζάντιο:
Creators: name: Πεταλιά, Φωτεινή Δημητρίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Παιδεία
Αγιολογία
Βυζάντιο
Education
Byzantine
Hagiography

description: Σκοπός της διατριβής ήταν η μελέτη της παιδείας στη μεσοβυζαντινή περίοδο με βάση τα αγιολογικά κείμενα. Το ζήτημα της παιδείας κατά τη μέση εποχή παρουσιάζει ιδιαίτερο ενδιαφέρον, καθώς ήταν μια εποχή με διαφορετικά δεδομένα από αυτά της εποχής μας. Περίοδος με σημαντικές δυσκολίες στη ζωή των βυζαντινών ανθρώπων. Η εργασία συνίσταται από τρία κεφάλαια. Στο πρώτο κεφάλαιο παρουσιάζονται οι Βίοι των αγίων της μεσοβυζαντινής εποχής, τα κείμενα δηλαδή που εξιστορούν τη ζωή των αγίων, καθώς και όπου είναι εφικτό στοιχεία για τους συγγραφείς των κειμένων. Στο δεύτερο κεφάλαιο περιγράφεται η εκπαίδευση σε όλα τα επίπεδα, στοιχειώδη, μέση και ανώτερη. Παρουσιάζονται στοιχεία για το περιεχόμενο της εκπαίδευσης που λάμβαναν τα παιδιά των βυζαντινών και τη διαδικασία που έπρεπε να ακολουθήσουν ώστε να κατακτήσουν και τα τρία επίπεδα. Η εργασία μας ολοκληρώνεται με το τρίτο κεφάλαιο, όπου γίνεται λόγος για το ρόλο των γονέων στη διαπαιδαγώγηση των παιδιών και τις ευκαιρίες που τους παρείχαν η οικογένεια και η πολιτεία γενικότερα.
description: The purpose of the thesis was the study of education in the Middle Byzantine period based on the hagiographical texts. The issue of education in this period is of particular interest as it was a time with different data than those of our time. Period with significant difficulties in the lives of the Byzantine people. The first chapter presents the biographies of the saints of the Middle Byzantine era. These texts give an account of the lives of saints, and where possible, details about the writers of the texts. The second chapter describes education at all levels, elementary, secondary and tertiary. It gives information on the content of education the children received as well as the procedure to be followed in order to acomplish all three levels. Our paper concludes in the third chapter, which speak of the role of the parents in educating their children and the opportunities provided for the children by the family and the state in general.
The influence of radio-galaxy activity on X-ray absorption lines from the intracluster medium
Creators: name: Koeckert, Franziska
name: Reynolds, Christopher S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present an investigation of the X-ray absorption features predicted by hydrodynamic simulations of radio galaxies interacting with the intracluster medium (ICM) of their host galaxy clusters. We show how these absorption lines can be used as a new diagnostic for the radio-galaxy/ICM interactions. Such interactions have been observed in numerous systems by ROSAT, CHANDRA and XMM-NEWTON, and understanding them has implications for AGN feedback and galaxy formation. Starting from the hydrodynamic simulations of Reynolds, Heinz & Begelman, we calculate the properties of the highly ionized iron and oxygen lines (seen in absorption against the central active galactic nucleus; AGN), predicting line shapes, equivalent widths, column densities and velocity shifts. The main effect of the jet on the absorption lines is a reduction of the line strength from that of the quiescent ICM and the introduction of some velocity structure in the line profile. We investigate whether these features are detectable with current as well as future high-resolution X-ray spectrometers. We conclude that the CHANDRA transmission gratings have insufficient sensitivity to detect these features with high significance, and certainly would not allow a study of the dynamics of the interaction via absorption signatures. CONSTELLATION-X, on the other hand, will allow superb constraints to be derived. We can also use this analysis to assess the idea that radio-galaxy induced ICM outflows give rise to the resonant oxygen X-ray absorption lines that have been claimed as evidence for the warm-hot intergalactic medium (WHIM). We show that these detached, high-velocity oxygen absorption lines cannot result from a radio-galaxy/ICM interaction, thereby strengthening the WHIM interpretation.
description: minor typos corrected to match the version which will be published in MNRAS
Free annotated data for deep learning in microscopy? A hitchhiker's guide
Creators: name: Shajkofci, Adrian
name: Liebling, Michael
Publisher: name: arXiv
Year: 2020
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: In microscopy, the time burden and cost of acquiring and annotating large datasets that many deep learning models take as a prerequisite, often appears to make these methods impractical. Can this requirement for annotated data be relaxed? Is it possible to borrow the knowledge gathered from datasets in other application fields and leverage it for microscopy? Here, we aim to provide an overview of methods that have recently emerged to successfully train learning-based methods in bio-microscopy.
description: Accepted in Photoniques 104
On-the-fly Reduced Order Modeling of Passive and Reactive Species via Time-Dependent Manifolds
Creators: name: Ramezanian, Donya
name: Nouri, Arash G.
name: Babaee, Hessam
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: FOS: Computer and information sciences

description: One of the principal barriers in developing accurate and tractable predictive models in turbulent flows with a large number of species is to track every species by solving a separate transport equation, which can be computationally impracticable. In this paper, we present an on-the-fly reduced order modeling of reactive as well as passive transport equations to reduce the computational cost. The presented approach seeks a low-rank decomposition of the species to three time-dependent components: (i) a set of orthonormal spatial modes, (ii) a low-rank factorization of the instantaneous species correlation matrix, and (iii) a set of orthonormal species modes, which represent a low-dimensional time-dependent manifold. Our approach bypasses the need to solve the full-dimensional species to generate high-fidelity data - as it is commonly performed in data-driven dimension reduction techniques such as the principle component analysis. Instead, the low-rank components are directly extracted from the species transport equation. The evolution equations for the three components are obtained from optimality conditions of a variational principle. The time-dependence of the three components enables an on-the-fly adaptation of the low-rank decomposition to transient changes in the species. Several demonstration cases of reduced order modeling of passive and reactive transport equations are presented.
Reproducing spin lattice models in strongly coupled atom-cavity systems
Creators: name: Kay, Alastair
name: Angelakis, Dimitris G.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In an array of coupled cavities where the cavities are doped with an atomic V-system, and the two excited levels couple to cavity photons of different polarizations, we show how to construct various spin models employed in characterizing phenomena in condensed matter physics, such as the spin-1/2 Ising, XX, Heisenberg, and XXZ models. The ability to construct networks of arbitrary geometry also allows for the simulation of topological effects. By tuning the number of excitations present, the dimension of the spin to be simulated can be controlled, and mixtures of different spin types produced. The facility of single-site addressing, the use of only the natural hopping photon dynamics without external fields, and the recent experimental advances towards strong coupling, makes the prospect of using these arrays as efficient quantum simulators promising.
description: 4 pages, 3 figures. v3: References added
Spherically symmetric solutions of modified field equations in f(R) theories of gravity
Creators: name: Multamaki, Tuomas
name: Vilja, Iiro
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Spherically symmetric static empty space solutions are studied in f(R) theories of gravity. We reduce the set of modified Einstein's equations to a single equation and show how one can construct exact solutions in different f(R) models. In particular, we show that for a large class models, including e.g. the f(R)=R-μ^4/R model, the Schwarzschild-de Sitter metric is an exact solution of the field equations. The significance of these solutions is discussed in light of solar system constraints on $f(R)$ theories of gravity.
description: 5 pages, v2: references added, minor modifications
Scattering of internal waves from small sea bottom inhomogeneities
Creators: name: Zakharenko, A. D.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: The problem of scattering of linear internal waves from small compact sea bottom inhomogeneities is considered from the point of view of mode-to-mode scattering. A simple formula for modal conversion coefficients, quantifying the amount of energy that is scattered into the n-th mode from the incident field m-th mode, is derived. In this formula the representation of inhomogeneities by their expansions into the Fourier and Fourier-Bessel series with respect to angular and radial coordinates respectively are used. Results of calculations, performed in a simple model case, are presented. The obtained formula can be used for a formulation of the inverse problem, as it was done in the acoustic case.
description: 8 pages, 1 figure
Ultraluminous and Hyperluminous Infrared Galaxies in the SDSS, 2dFGRS and 6dFGS
Creators: name: Hwang, Ho Seong
name: Serjeant, Stephen
name: Lee, Myung Gyoon
name: Lee, Kang Hwan
name: White, Glenn
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present a result of cross-correlating the Infrared Astronomical Satellite Faint Source Catalogue (IRAS FSC) with the spectroscopic catalogues of galaxies in the Fourth Data Release of Sloan Digital Sky Survey (SDSS), the Final Data Release of 2dF Galaxy Redshift Survey (2dFGRS) and the Second Data Release of 6dF Galaxy Survey (6dFGS). We have identified 324 ultraluminous infrared galaxies (ULIRGs) including 190 newly discovered ULIRGs, and 2 hyperluminous infrared galaxies (HLIRGs). Adding these new ULIRGs, we increase the number of known ULIRGs by about 30 per cent. The reliability of the cross-correlation is estimated using the likelihood ratio method. The incompleteness of our sample introduced by the identification procedure in this study is estimated to be about 5 per cent. Our sample covers the redshift range of z=0.037$-$0.517 with a median redshift of $\bar{z}$=0.223, which is larger than that ($\bar{z}$=0.184) of the sample of previously known ULIRGs.
description: 14 pages, 13 figures. To appear in MNRAS. The complete versions of Table 1, Table 2, Table 3 & Figure 1 and Appendix A & B will be published in the online version of the journal
Near-Infrared Imaging Polarimetry of the NGC 2071 Star Forming Region with SIRPOL
Creators: name: Tamura, Motohide
name: Kandori, Ryo
name: Hashimoto, Jun
name: Kusakabe, Nobuhiko
name: Nakajima, Yasushi
name: Ssato, Shuji
name: Nagashima, Chie
name: Kurita, Mikio
name: Nagata, Tetsuya
name: Nagayama, Takahiro
name: Hough, Jim
name: Matsumoto, Tomoaki
name: Chrysostomou, Antonio
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We have conducted deep JHKs imaging polarimetry of a ~8' x 8' area of the NGC 2071 star forming region. Our polarization data have revealed various infrared reflection nebulae (IRNe) associated with the central IR young star cluster NGC2071IR and identified their illuminating sources. There are at least 4 IRNe in NGC2071IR and several additional IRNe are identified around nearby young stars in the same field-of-view. Each illuminating source coincides with a known near-IR source except for IRS3, which is only a part of IRN2 and is illuminated by the radio source 1c. Aperture polarimetry of each cluster source is used to detect unresolved circumstellar disk/outflow systems. Aperture polarimetry of the other point-like sources within the field is made in this region for the first time. The magnetic field structures (from ~1 pc down to \~0.1 pc) are derived using both aperture polarimetry of the point-like sources and imaging polarimetry of the shocked H2 emission that is seen as the dominant knotty nebulae in the Ks band image; they are both of dichroic origin and the derived field directions are consistent with each other. The magnetic field direction projected on the sky is also consistent with that inferred from the 850 micron thermal continuum emission polarimetry of the central 0.2 pc region, but running roughly perpendicular (~75 degrees) to the direction of the large scale outflow. We argue that the field strength is too weak to align the outflow in the large scale field direction via magnetic braking.
description: o appear in PASJ, 9 pages, 11 Postscript figures
Η εκπαιδευτική πολιτική από το 1974, ως το 1997: η σύγκριση, η υποδοχή και η αποτίμηση των 309/76, 1566/85 και 2525/97
Creators: name: Ραφαηλίδης, Σάββας Παναγιώτη
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: εκπαιδευτική μεταρρύθμιση
συνδικαλιστικές οργανώσεις
νόμοι
educational reform
educational unions
educational law

description: Σκοπός της παρούσας μεταπτυχιακής εργασίας ήταν η παρουσίαση και η εξέταση της σχέσης της πολιτικής με την εκπαίδευση, όπως αυτή εκφράζεται μέσα από τις εκπαιδευτικές μεταρρυθμίσεις που έλαβαν χώρα από το τέλος της ελληνικής δικτατορίας, ως και το 1997. Στη συγκεκριμένη εργασία, πέρα από τη σχέση αυτή, παρουσιάστηκε και η στάση ορισμένων εφημερίδων, σχετικά μεγάλης κυκλοφορίας, απέναντι στις επιχειρούμενες εκπαιδευτικές αλλαγές. Εκτός από τη στάση των εφημερίδων εξετάστηκε και παρουσιάστηκε και η στάση των συνδικαλιστικών οργανώσεων ΟΛΜΕ και ΔΟΕ απέναντι στις εκπαιδευτικές αλλαγές που πρότεινε το Υπουργείο. Τέλος, εξετάστηκε και η αλληλεπίδραση των μεταρρυθμίσεων και του ΟΟΣΑ.
description: Purpose of this paper was the presentation and the study of the relationship between politics and formal education, as it expresses itself via the educational reforms that took place in Greece, after the latest greek dictatorship and until 1997. In this particular paper, apart from that relationship, the view of some newspapers with many readers, was presented, too. Some magazines were also examined, magazines which were published by the two major educational unions, OLME and DOE, so we could learn their opinion on the educational reforms that ministry of education had suggested. Last but not least, we examined the interaction of OECD and educational reforms.
UESegNet: Context Aware Unconstrained ROI Segmentation Networks for Ear Biometric
Creators: name: Kamboj, Aman
name: Rani, Rajneesh
name: Nigam, Aditya
name: Jha, Ranjeet Ranjan
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Biometric-based personal authentication systems have seen a strong demand mainly due to the increasing concern in various privacy and security applications. Although the use of each biometric trait is problem dependent, the human ear has been found to have enough discriminating characteristics to allow its use as a strong biometric measure. To locate an ear in a 2D side face image is a challenging task, numerous existing approaches have achieved significant performance, but the majority of studies are based on the constrained environment. However, ear biometrics possess a great level of difficulties in the unconstrained environment, where pose, scale, occlusion, illuminations, background clutter etc. varies to a great extent. To address the problem of ear localization in the wild, we have proposed two high-performance region of interest (ROI) segmentation models UESegNet-1 and UESegNet-2, which are fundamentally based on deep convolutional neural networks and primarily uses contextual information to localize ear in the unconstrained environment. Additionally, we have applied state-of-the-art deep learning models viz; FRCNN (Faster Region Proposal Network) and SSD (Single Shot MultiBox Detecor) for ear localization task. To test the model's generalization, they are evaluated on six different benchmark datasets viz; IITD, IITK, USTB-DB3, UND-E, UND-J2 and UBEAR, all of which contain challenging images. The performance of the models is compared on the basis of object detection performance measure parameters such as IOU (Intersection Over Union), Accuracy, Precision, Recall, and F1-Score. It has been observed that the proposed models UESegNet-1 and UESegNet-2 outperformed the FRCNN and SSD at higher values of IOUs i.e. an accuracy of 100\% is achieved at IOU 0.5 on majority of the databases.
การประยุกต์การแปลงเฮาส์โฮลเดอร์กับการแยกเมทริกซ์
Creators: name: ภัทราวุธ จันทร์เสงี่ยม
name: อานนท์ พลอยมุกดา
Publisher: name: กองบริหารการวิจัย มหาวิทยาลัยธรรมศาสตร์
Year: 2558
Subjects: การแปลงเฮาส์โฮลเดอร์, การแยก QR, การทำให้เป็นเมทริกซ์แบบสามเหลี่ยม, เมทริกซ์เฮสเซนเบิร์ก, เมทริกซ์สามแนวเฉียง

description: 4, 23, วารสารวิทยาศาสตร์และเทคโนโลยี
อัตราส่วนที่เหมาะสมของการเกิดเหตุการณ์ที่สนใจต่อตัวแปรสำหรับการวิเคราะห์การถดถอยลอจิสติกทวิภาคในกรณีที่มีความคลาดเคลื่อนในตัวแปรอธิบาย
Creators: name: ศิวพร ภูกองทอง
name: แสงหล้า ชัยมงคล
Publisher: name: กองบริหารการวิจัย มหาวิทยาลัยธรรมศาสตร์
Year: 2558
Subjects: ตัวแบบเชิงเส้นนัยทั่วไป, ความผิดพลาดจากการวัด, การจำแนกผิด

description: 4, 23, วารสารวิทยาศาสตร์และเทคโนโลยี
Cosmological MHD simulation of a cooling flow cluster
Creators: name: Dubois, Y.
name: Teyssier, R.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Various observations of magnetic fields in the Intra-Cluster Medium (ICM), most of the time restricted to cluster cores, point towards field strength of the order of a few microG (synchrotron radiation from radio relics and radio halos, inverse Compton radiation in X-rays and Faraday rotation measure of polarised background sources). Both the origin and the spatial structure of galaxy clusters magnetic fields are still under debate. In particular, the radial profile of the magnetic field, from the core of clusters to their outskirts, is of great importance for cosmic rays propagation within the Cosmic Web. In this letter, we highlight the importance of cooling processes in amplifying the magnetic field in the core of galaxy clusters up to one order of magnitude above the typical amplification obtained for a pure adiabatic evolution. We have performed a "zoom'' cosmological simulation of a 3 keV cluster, including dark matter and gas dynamics, atomic cooling, UV heating and star formation using the newly developed MHD solver in the AMR code RAMSES. Magnetic field amplification proceeds mainly through gravitational contraction. Shearing motions due to turbulence provide additional amplification in the outskirts of the cluster, while magnetic reconnection during mergers causes magnetic field dissipation in the core. Cooling processes have a strong impact on the magnetic field structure in the cluster. First, due to the sharp rise of the gas density in the centre, gravitational amplification is significantly amplified, when compared to the non--radiative run. Second, due to cooling processes, shearing motions are much stronger in the core than in the adiabatic case, leading to additional field amplification and no significant magnetic reconnection.
description: 4 pages, 6 figures, to be published in A&A, correction in one reference
Cold chemistry: a few-body perspective on impurity physics of a single ion in an ultracold bath
Creators: name: Pérez-Ríos, Jesús
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Atomic Physics (physics.atom-ph)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Impurity physics is a traditional topic in condensed matter physics that nowadays is being explored in the field of ultracold gases. Among the different classes of impurities, we focus on charged impurities in an ultracold bath. When a single ion is brought in contact with an ultracold gas it is subjected to different reactive processes that can be understood from a cold chemistry approach. In this work, we present an outlook of approaches for the dynamics of a single ion in a bath of ultracold atoms or molecules, complementing the usual many-body approaches characteristic of impurity physics within condensed matter physics. In particular, we focus on the evolution of a charged impurity in different baths, including external time-dependent trapping potentials and we explore the effect of the external laser sources present in ion-neutral hybrid traps into the lifetime of an impurity.
description: 8 pages, 6 figures
Ανάπτυξη εκπαιδευτικής πολυμεσικής εφαρμογής με θέμα την Ιστορία και τα τεχνικά χαρακτηριστικά ραδιοφώνου για μαθητές Γυμνασίου
Creators: name: Βίλλη, Φωτεινή Δημητρίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Ιστορία Ραδιοφώνου
Τεχνικά Χαρακτηριστικά Ραδιοφώνου
Μουσική Παραγωγή
History Radio
Technical radio
Music Production

description: Σκοπός της διατριβής ήταν η μελέτη της Ιστορίας του ραδιοφώνου καθώς και η Μουσική Παραγωγή έτσι ώστε οι μαθητές να μάθουν, να αντιληφθούν και να κατανοήσουν τις προαναφερθείσες έννοιες. Αρχικά, εξετάσαμε την ιστορική διαδρομή του μέσου και στην πορεία τα τεχνικά χαρακτηριστικά του ραδιοφώνου. Στη συνέχεια αναλύσαμε ποιος ήταν ο ρόλος του μέσου σε κάθε περίοδο που χωρίσαμε την ιστορία του. Ακόμη παρουσιάσαμε αναλυτικά την έννοια της Μουσικής Παραγωγής, δηλαδή, σχεδιάσαμε ένα εικονικό ραδιοφωνικό στούντιο όπου οι μαθητές έχουν την δυνατότητα να πειραματίζονται στο κομμάτι της μίξης ήχων και να φτάνουν κάθε φορά στο ανάλογο επιθυμητό αποτέλεσμα. Βέβαια αναφερθήκαμε αναλυτικά στο τι εξοπλισμό χρειάζεται ώστε να λειτουργήσει ένα ραδιόφωνο αλλά και πως πρέπει να είναι διαμορφωμένος ένας χώρος ώστε να θεωρηθεί κατάλληλος. Ένα άλλο θέμα που θίξαμε ήταν η λειτουργία και τα χαρακτηριστικά του κάθε μηχανήματος που απαιτείται ώστε να εκπέμπει ένας ραδιοφωνικός σταθμός.
description: The aim of the present thesis was to study the history of radio so that the music production student’s learn, to perceive and understand to above concepts. Initially, we examined, the history of the instrument and the way the technical characteristics of radio. Then we analyzed what was the role of media in each period we broke the story. Also presented in detail the concept of musical productions, namely, we designed a virtual radio studio where students have the opportunity to experiment in mixing the sound track and reach each time in a similar desired result. Of course elaborated on what equipment is needed to operate a radio and it should be a landscaped area in order to qualify.
description: Σε συνεργασία με το τμήμα Λογιστικής και Χρηματοοικονομικής (Πανεπιστήμιο Μακεδονίας)
Electrified Fuzzy Spheres and Funnels in Curved Backgrounds
Creators: name: Thomas, Steven
name: Ward, John
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We use the non-Abelian DBI action to study the dynamics of $N$ coincident $Dp$-branes in an arbitrary curved background, with the presence of a homogenous world-volume electric field. The solutions are natural extensions of those without electric fields, and imply that the spheres will collapse toward zero size. We then go on to consider the $D1-D3$ intersection in a curved background and find various dualities and automorphisms of the general equations of motion. It is possible to map the dynamical equation of motion to the static one via Wick rotation, however the additional spatial dependence of the metric prevents this mapping from being invertible. Instead we find that a double Wick rotation leaves the static equation invariant. This is very different from the behaviour in Minkowski space. We go on to construct the most general static fuzzy funnel solutions for an arbitrary metric either by solving the static equations of motion, or by finding configurations which minimise the energy. As a consistency check we construct the Abelian $D3$-brane world-volume theory in the same generic background and find solutions consistent with energy minimisation. In the $NS$5-brane background we find time dependent solutions to the equations of motion, representing a time dependent fuzzy funnel. These solutions match those obtained from the $D$-string picture to leading order suggesting that the action in the large $N$ limit does not need corrections. We conclude by generalising our solutions to higher dimensional fuzzy funnels.
description: 38 pages, Latex; references added
Resolving the Disc-Halo Degeneracy II: NGC 6946
Creators: name: Aniyan, S.
name: Ponomareva, A. A.
name: Freeman, K. C.
name: Arnaboldi, M.
name: Gerhard, O. E.
name: Coccato, L.
name: Kuijken, K.
name: Merrifield, M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The mass-to-light ratio (M/L) is a key parameter in decomposing galactic rotation curves into contributions from the baryonic components and the dark halo of a galaxy. One direct observational method to determine the disc M/L is by calculating the surface mass density of the disc from the stellar vertical velocity dispersion and the scale height of the disc. Usually, the scale height is obtained from near-IR studies of edge-on galaxies and pertains to the older, kinematically hotter stars in the disc, while the vertical velocity dispersion of stars is measured in the optical band and refers to stars of all ages (up to ~10 Gyr) and velocity dispersions. This mismatch between the scale height and the velocity dispersion can lead to underestimates of the disc surface density and a misleading conclusion of the sub-maximality of galaxy discs. In this paper we present the study of the stellar velocity dispersion of the disc galaxy NGC 6946 using integrated star light and individual planetary nebulae as dynamical tracers. We demonstrate the presence of two kinematically distinct populations of tracers which contribute to the total stellar velocity dispersion. Thus, we are able to use the dispersion and the scale height of the same dynamical population to derive the surface mass density of the disc over a radial extent. We find the disc of NGC 6946 to be closer to maximal with the baryonic component contributing most of the radial gravitational field in the inner parts of the galaxy (Vmax(bar) = 0.76($\pm$0.14)Vmax).
description: 17 pages, 14 figures, Accepted for publication in MNRAS. arXiv admin note: text overlap with arXiv:1802.00465
Einstein's mirror revisited
Creators: name: Gjurchinovski, Aleksandar
name: Skeparovski, Aleksandar
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Physics (physics.gen-ph)
subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: We describe a simple geometrical derivation of the formula for reflection of light from a uniformly moving plane mirror directly from the postulates of special relativity.
description: 4 pages, 5 figures, RevTeX4, comments welcome; V2: corrected Fig. 5 and the discussion associated with it, co-author included
การเปรียบเทียบสถิติทดสอบไม่อิงพารามิเตอร์สำหรับการทดสอบ ความแตกต่างของค่าเฉลี่ยระหว่างประชากรสองกลุ่มที่เป็นอิสระกัน เมื่อขนาดตัวอย่างเล็ก
Creators: name: อาภา วงศ์จินดา
name: อภิญญา หิรัญวงษ์
name: บุญอ้อม โฉมที
Publisher: name: กองบริหารการวิจัย มหาวิทยาลัยธรรมศาสตร์
Year: 2558
Subjects: สถิติ Wilcoxon rank sum, สถิติBrunner and Munzel, สถิติBaumgartner-Wei Beta-Schindler, ความน่าจะเป็นของความคลาดเคลื่อนประเภทที่ 1, อำนาจการทดสอบ

description: 4, 23, วารสารวิทยาศาสตร์และเทคโนโลยี
การวิเคราะห์ปัจจัยที่ส่งผลดีต่อการมีชีวิตอยู่รอด และสภาวะของผู้ป่วยโรคเอดส์ด้วยตัวแบบเชิงเส้นนัยทั่วไป
Creators: name: วีรานันท์ พงศาภักดี
name: ปุณยนุช ธัญญกุลสัจจา
name: ลลิตา โพธิ์ทอง
Publisher: name: กองบริหารการวิจัย มหาวิทยาลัยธรรมศาสตร์
Year: 2558
Subjects: ตัวแบบเชิงสถิติ, การพยากรณ์ความน่าจะเป็น, ตัวแบบลอจิตสองกลุ่ม, ตัวแบบลอจิตสะสม

description: 4, 23, วารสารวิทยาศาสตร์และเทคโนโลยี
Detailed low-spin spectroscopy of 65Ni via neutron capture reaction
Creators: name: Porzio, C.
name: Michelagnoli, C.
name: Cieplicka-Orynczak, N.
name: Sferrazza, M.
name: Leoni, S.
name: Fornal, B.
name: Tsunoda, Y.
name: Otsuka, T.
name: Bottoni, S.
name: Costache, C.
name: Crespi, F. C. L.
name: Iskra, L. W.
name: Jentschel, M.
name: Kandzia, F.
name: Kim, Y. -H.
name: Koester, U.
name: Marginean, N.
name: Mihai, C.
name: Mutti, P.
name: Turturica, A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: An extended investigation of the low-spin structure of the $^{65}$Ni nucleus was performed at the Institut Laue-Langevin, Grenoble, via the neutron capture reaction $^{64}$Ni(n,$γ$)$^{65}$Ni, using the FIPPS HPGe array. The level scheme of $^{65}$Ni was significantly expanded, with 2 new levels and 87 newly found transitions. Angular correlation analyses were also performed, allowing us to assign spins and parities for a number of states, and to determine multipolarity mixing ratios for selected $γ$ transitions. The low-energy part of the experimental level scheme (up to about 1.4 MeV) was compared with Monte Carlo Shell Model calculations, which predict spherical shapes for all states, apart from the 9/2$^+$ and the second excited 1/2$^-$ states of oblate deformation.
On the Detectability of Oxygen X-ray Fluorescence and its Use as a Solar Photospheric Abundance Diagnostic
Creators: name: Drake, Jeremy J.
name: Ercolano, Barbara
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Monte Carlo calculations of the O Kalpha line fluoresced by coronal X-rays and emitted just above the temperature minimum region of the solar atmosphere have been employed to investigate the use of this feature as an abundance diagnostic. While quite weak, we estimate line equivalent widths in the range 0.02-0.2 AA, depending on the X-ray plasma temperature. The line remains essentially uncontaminated by blends for coronal temperatures T =< 3e6 K and should be quite observable, with a flux >~ 2 ph/s/arcmin^2. Model calculations for solar chemical mixtures with an O abundance adjusted up and down by a factor of 2 indicate 35-60% changes in O Kalpha line equivalent width, providing a potentially useful O abundance diagnostic. Sensitivity of equivalent width to differences between recently recommended chemical compositions with ``high'' and ``low'' complements of the CNO trio important for interpreting helioseismological observations is less accute, amounting to 20-26% at coronal temperatures T ~< 2e6 K. While still feasible for discriminating between these two mixtures, uncertainties in measured line equivalent widths and in the models used for interpretation would need to be significantly less than 20%. Provided a sensitive X-ray spectrometer with resolving power >= 1000 and suitably well-behaved instrumental profile can be built, X-ray fluorescence presents a viable means for resolving the solar ``oxygen crisis''.
description: To appear in the Astrophysical Journal
QCD equation of state with 2+1 flavors of improved staggered quarks
Creators: name: Bernard, C.
name: Burch, T.
name: DeTar, C.
name: Gottlieb, Steven
name: Levkova, L.
name: Heller, U. M.
name: Hetrick, J. E.
name: Sugar, R.
name: Toussaint, D.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We report results for the interaction measure, pressure and energy density for nonzero temperature QCD with 2+1 flavors of improved staggered quarks. In our simulations we use a Symanzik improved gauge action and the Asqtad $O(a^2)$ improved staggered quark action for lattices with temporal extent $N_t=4$ and 6. The heavy quark mass $m_s$ is fixed at approximately the physical strange quark mass and the two degenerate light quarks have masses $m_{ud}\approx0.1 m_s$ or $0.2 m_s$. The calculation of the thermodynamic observables employs the integral method where energy density and pressure are obtained by integration over the interaction measure.
description: 25 pages, 11 figures, 5 tables; One more figure added. Eq. 11 changed. Some text changes
The evolution of preprint repositories during the Covid-19 pandemic: A temporary glitch?
Creators: name: Biesenbender, Kristin
name: Peters, Isabella
Publisher: name: Zenodo
Year: 2023

description: This research in progress paper investigates, whether the current preprint popularity is a temporary Covid-19 phenomenon. For this, with the help of the Dimensions database, preprints from eight repositories, namely arXiv, Authorea, bioRxiv, JMIR Preprints, medRxiv, Preprints.org, Research Square and SSRN were analyzed.

The paper was presented as poster at ASIS&T's METSTI 2023: Workshop on Informetric, Scientometric, and Scientific and Technical Information Research in London, UK on 27 October 2023. The workshop program is available here: https://www.asist.org/2023/10/07/metrics-2023-program/ 

This work is funded by the German Federal Ministry of Education and Research (BMBF) and conducted in the project Open Access Effects – The Influence of Structural and Author-specific Factors on the Impact of OA (OASE), grant number 16PU17005A/16PU17005B.

You can find more information about the project here: http://www.zbw.eu/de/forschung/web-science/oase/.
Algorithmic Complexity Bounds on Future Prediction Errors
Creators: name: Chernov, A.
name: Hutter, M.
name: Schmidhuber, J.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: We bound the future loss when predicting any (computably) stochastic sequence online. Solomonoff finitely bounded the total deviation of his universal predictor $M$ from the true distribution $mu$ by the algorithmic complexity of $mu$. Here we assume we are at a time $t>1$ and already observed $x=x_1...x_t$. We bound the future prediction performance on $x_{t+1}x_{t+2}...$ by a new variant of algorithmic complexity of $mu$ given $x$, plus the complexity of the randomness deficiency of $x$. The new complexity is monotone in its condition in the sense that this complexity can only decrease if the condition is prolonged. We also briefly discuss potential generalizations to Bayesian model classes and to classification problems.
description: 21 pages
การประมวลผลภาพดาวเทียมเชิงเลขด้วยระบบผู้เชี่ยวชาญ เพื่อหาพื้นที่มีศักยภาพตั้งโรงงานผลิตเอทานอลและ เส้นทางขนส่งมันสำปะหลังของจังหวัดกำแพงเพชร
Creators: name: ณัฐพล จันทร์แก้ว
name: นันธิญา คาอุดม
name: ทัศนีย์ มีศักดิ์ประเสริฐ
Publisher: name: กองบริหารการวิจัย มหาวิทยาลัยธรรมศาสตร์
Year: 2558
Subjects: ระบบผู้เชี่ยวชาญ, พื้นที่มีศักยภาพ, โรงงานผลิตเอทานอล,

description: 4, 23, วารสารวิทยาศาสตร์และเทคโนโลยี
Phenomenological assessment of proton mechanical properties from deeply virtual Compton scattering
Creators: name: Dutrieux, H.
name: Lorcé, C.
name: Moutarde, H.
name: Sznajder, P.
name: Trawiński, A.
name: Wagner, J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A unique feature of generalised parton distributions is their relation to the QCD energy-momentum tensor. In particular, they provide access to the mechanical properties of the proton i.e. the distributions of pressure and shear stress induced by its quark and gluon structure. In principle the pressure distribution can be experimentally determined in a model-independent way from a dispersive analysis of deeply virtual Compton scattering data through the measurement of the subtraction constant. In practice the kinematic coverage and accuracy of existing experimental data make this endeavour a challenge. Elaborating on recent global fits of deeply virtual Compton scattering measurements using artificial neural networks, our analysis presents the current knowledge on this subtraction constant and assesses the impact of the most frequent systematic assumptions made in this field of research. This study will pave the way for future works when more precise data will become available, e.g. obtained in the foreseen electron-ion colliders EIC and EIcC.
description: 16 pages, 5 figures
Γνωστική επάρκεια και ψυχοκοινωνική προσαρμογή παιδιών με διαταραχές επικοινωνίας
Creators: name: Κερανοπούλου-Γκόλιου, Γλυκερία Κορνήλιου
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Γνωστική Επάρκεια
Διαταραχές Επικοινωνίας
Ψυχοκοινωνική προσαρμογή
Cognitive Competence
Communication Disorders
Psychosocial Adjustment

description: Η παρούσα έρευνα διερεύνησε σε ένα ενιαίο πλαίσιο τις γνωστικές διεργασίες, τη σχολική-κοινωνική επάρκεια και τις δυνατότητες και δυσκολίες παιδιών τα οποία παραπέμφθηκαν σε ιατροπαιδαγωγικό κέντρο λόγω των δυσκολιών που παρουσίαζαν στην έκφραση ή/και κατανόηση του προφορικού λόγου. Συγκεκριμένα, στην έρευνα συμμετείχαν 50 παιδιά ηλικίας από τεσσάρων έως οκτώ ετών, οι γονείς και οι εκπαιδευτικοί τους. Στόχος της εργασίας ήταν η σύγκριση ομάδων παιδιών (αρνητικής διάγνωσης και διάγνωσης διαταραχών επικοινωνίας, υποομάδων διαταραχών επικοινωνίας) ως προς τις υπό εξέταση μεταβλητές, η διερεύνηση των σχέσεων μεταξύ των μεταβλητών και η κατανόηση της συνολικής λειτουργικότητας των παιδιών.
description: The present study aimed to investigate the cognitive competence, the school-social competence and the strengths and difficulties of children, who have been referred for difficulties in using and/or understanding of speech to a center for children’s mental health. A sample of 50 children -ranging in age from four to eight years- and their parents and teachers participated in the study. The study focused on the comparison between the group of children who had been diagnosed as having communication disorders and the group of children who received negative diagnosis in regard to the variables under investigation. Moreover, comparisons between the group with phonological disorder and the group with non-phonological type disorders (including children with receptive language disorder, mixed receptive-expressive language disorder and stuttering) were also carried out.
A beta Cephei pulsator and a changing orbital inclination in the high-mass eclipsing binary system VV Orionis
Creators: name: Southworth, John
name: Bowman, D. M.
name: Pavlovski, K.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present an analysis of the high-mass eclipsing binary system VV Ori based on photometry from the TESS satellite. The primary star (B1V, 9.5 Msun) shows beta Cephei pulsations and the secondary (B7V, 3.8 Msun) is possibly a slowly-pulsating B star. We detect 51 significant oscillation frequencies, including two multiplets with separations equal to the orbital frequency, indicating that the pulsations are tidally perturbed. We analyse the TESS light curve and published radial velocities to determine the physical properties of the system. Both stars are only the second of their pulsation type with a precisely-measured mass. The orbital inclination is also currently decreasing, likely due to gravitational interactions with a third body.
description: Accepted for publication as a Letter in MNRAS. 5 pages, 3 colour figures, 1 table
Η δομή των οικογενειακών ρόλων στην ελληνική οικογένεια και οι επιπτώσεις της στην κοινωνικοποίηση:
Creators: name: Δινάκη, Βασιλική Κωνσταντίνου
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: οικογένεια
κοινωνικοποίηση
σύζυγος
family
socialization
spouse

description: Σκοπός της διατριβής ήταν η μελέτη της δομής των οικογενειακών ρόλων στην ελληνική οικογένεια και οι επιπτώσεις της στην κοινωνικοποίηση. Ερευνήθηκε η οικογένεια ως θεσμός, η δομή της και οι λειτουργίες της, ο μετασχηματισμός του θεσμού της οικογένειας και η εμφάνιση νέων οικογενειακών σχημάτων. Η έρευνα βασίστηκε σε ερευνητικά δεδομένα που προέκυψαν από προηγούμενη έρευνα. Αντικείμενο μελέτης αποτέλεσαν οι συνεντεύξεις συζύγων που πραγματοποιήθηκαν χωριστά στον άντρα – σύζυγο και στη γυναίκα – σύζυγο. Από την ποιοτική ανάλυση περιεχομένου των συνεντεύξεων προέκυψαν συμπεράσματα για τη μορφή της ελληνικής οικογένειας, τη διαγενεακή επαγγελματική και εκπαιδευτική εξέλιξη, τις σχέσεις που διαμορφώνονται μεταξύ γονέων και παιδιών, τις προσδοκίες που οδηγούν σε γάμο. Επιπλέον, προέκυψαν σημαντικά στοιχεία για τον καταμερισμό των εργασιών στο πλαίσιο της οικογένειας, τη συναίνεση μεταξύ του ζευγαριού, τη θυσία επαγγελματικών ευκαιριών για την οικογένεια, τη λήψη αποφάσεων στο οικογενειακό πλαίσιο, τη συμμετοχή των γονέων στην εκπαίδευση των παιδιών τους και τις διαφορές στη διαπαιδαγώγηση παιδιών διαφορετικού φύλου.
description: Aim of the present thesis was the study of familial role structure in Greece and its repercussions on socialization. The family was studied as an institution, along with its structure and functions, its transformation as well as the appearance of new familial forms. The study was based on data that resulted from previous research. Object of study was the interviews of married couples that were conducted separately for each spouse. From the interviews’ qualitative content analysis resulted conclusions about the form of the Greek family, the occupational and educational development through generations, the relationship between parents and children, and the expectations that lead to marriage. Moreover, important input arose concerning the distribution of work within a family, the agreement between spouses, the sacrifice of professional opportunities for family’s sake, the domestic decision making, the parents’ involvement in children’s education and the differences in upbringing male and female offspring.