cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Time-domain anyon interferometry in Kitaev honeycomb spin liquids and beyond
Creators: name: Klocke, Kai
name: Aasen, David
name: Mong, Roger S. K.
name: Demler, Eugene A.
name: Alicea, Jason
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Motivated by recent experiments on the Kitaev honeycomb magnet $α\text{-RuCl}_3$, we introduce time-domain probes of the edge and quasiparticle content of non-Abelian spin liquids. Our scheme exploits ancillary quantum spins that communicate via time-dependent tunneling of energy into and out of the spin liquid's chiral Majorana edge state. We show that the ancillary-spin dynamics reveals the edge-state velocity and, in suitable geometries, detects individual non-Abelian anyons and emergent fermions via a time-domain counterpart of quantum-Hall anyon interferometry. We anticipate applications to a wide variety of topological phases in solid-state and cold-atoms settings.
Anisotropic Decay Dynamics of Photoexcited Aligned Carbon Nanotube Bundles
Creators: name: Hashimoto, Y.
name: Murakami, Y.
name: Maruyama, S.
name: Kono, J.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We have performed polarization-dependent ultrafast pump-probe spectroscopy of a film of aligned single-walled carbon nanotube bundles. By taking into account imperfect nanotube alignment as well as anisotropic absorption cross sections, we quantitatively determined distinctly different photo-bleaching dynamics for polarizations parallel and perpendicular to the tube axis. For perpendicular polarization, we observe a slow (1.0-1.5 ps) relaxation process, previously unobserved in randomly-oriented nanotube bundles. We attribute this slower dynamics to the excitation and relaxation of surface plasmons in the radial direction of the nanotube bundles.
description: 4 pages, 3 figures
Radion stabilization with(out) Gauss-Bonnet interactions and inflation
Creators: name: Konikowska, D.
name: Olechowski, M.
name: Schmidt, M. G.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Radion stabilization is analyzed in 5-dimensional models with branes in the presence of Gauss-Bonnet interactions. The Goldberger-Wise mechanism is considered for static and inflating backgrounds. The necessary and sufficient conditions for stability are given for the static case. The influence of the Gauss-Bonnet term on the radion mass and the inter-brane distance is analyzed and illustrated by numerical examples. The interplay between the radion stabilization and the cosmological constant problem is discussed.
description: 25 pages, 4 figures, references added, to appear in Physical Review D
Psychoacoustic Calibration of Loss Functions for Efficient End-to-End Neural Audio Coding
Creators: name: Zhen, Kai
name: Lee, Mi Suk
name: Sung, Jongmo
name: Beack, Seungkwon
name: Kim, Minje
Publisher: name: arXiv
Year: 2021
Subjects: subject: Sound (cs.SD)
subject: Machine Learning (cs.LG)
subject: Audio and Speech Processing (eess.AS)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Conventional audio coding technologies commonly leverage human perception of sound, or psychoacoustics, to reduce the bitrate while preserving the perceptual quality of the decoded audio signals. For neural audio codecs, however, the objective nature of the loss function usually leads to suboptimal sound quality as well as high run-time complexity due to the large model size. In this work, we present a psychoacoustic calibration scheme to re-define the loss functions of neural audio coding systems so that it can decode signals more perceptually similar to the reference, yet with a much lower model complexity. The proposed loss function incorporates the global masking threshold, allowing the reconstruction error that corresponds to inaudible artifacts. Experimental results show that the proposed model outperforms the baseline neural codec twice as large and consuming 23.4% more bits per second. With the proposed method, a lightweight neural codec, with only 0.9 million parameters, performs near-transparent audio coding comparable with the commercial MPEG-1 Audio Layer III codec at 112 kbps.
Τεχνικές και συστήματα ψηφιοποίησης και επεξεργασίας αρχειακού οπτικοακουστικού υλικού (Φιλμ:
Creators: name: Απέργης, Χρήστος Μιχαήλ
name: Κούτρος, Μενέλαος
Publisher: name: Aristotle University of Thessaloniki
Year: 2014
Subjects: Φιλμ
Ψηφιοποίηση
Οπτικοακουστικά μέσα
Film
Digitalization
Audiovisual

description: Σκοπός της διατριβής ήταν η μελέτη των τεχνικών μεθόδων καθώς και των συστημάτων ψηφιοποίησης αρχειακού οπτικοακουστικού υλικού (Φιλμ). Εξετάσαμε στην ελληνική και ξένη βιβλιογραφία τους τύπους, τα χαρακτηριστικά του φιλμ, την ιστορική εξέλιξη καθώς και τους τρόπους συντήρησης, αποθήκευσης και της ανάγκης για διάσωσης αυτής της πολιτιστικής κληρονομιάς. Στη συνέχεια παρουσιάσαμε αναλυτικά τις μεθόδους με τις οποίες γίνεται σήμερα η ψηφιοποίηση ενός οπτικοακουστικού μέσου όπως το φιλμ. Ακόμη αναφερθήκαμε αναλυτικά στα συστήματα που χρησιμοποιήσαμε στην παρούσα διατριβή για να ψηφιοποιήσουμε υλικό από φιλμ super 8mm ,στην κατασκευή ενός απλού συστήματος telecine και την συντήρηση μιας μηχανής προβολής ενός τέτοιου υλικού. Ένα άλλο θέμα που θίξαμε ήταν η αξιολόγηση του ψηφιοποιημένου υλικού που προέκυψε με τα συστήματα που αναφέραμε παραπάνω χρησιμοποιώντας ειδικό λογισμικό μέτρησης της ποιότητας βίντεο. Τέλος ασχοληθήκαμε επιπλέον με την επεξεργασία των ψηφιοποιημένων αρχείων ως προς την αποθορυβοποίηση και την χρωματική διόρθωση τους μέσω κατάλληλου λογισμικού.
description: The aim of the present thesis was the study of the techniques and systems of digitalization archival copy audiovisual material (film). We have looked at the Greek and foreign literature, types, the characteristics of the film, the historical development and the ways to maintain, storage and the need to rescue this culture heritage. Then we presented in detail the methods by which it is today the digitization of audiovisual media such as film. Yet we discussed in detail the systems used in this thesis to move believably material from film super 8mm ,the construction of a simple system telecine box and the maintenance of a camera viewing of such material. Another issue that we discussed was the evaluation of digital material obtained from the systems mentioned above using special software measurement of quality video. Finally we have looked at in addition to the processing of digitized files to noise reduction and color correction through appropriate software.
title: Statistisches Jahrbuch der Stadt Zürich 1939
title: Stat. Jahrb. Stadt Zür.
titleType: AlternativeTitle
Creators: name: (:Unkn) Unknown
Publisher: name: Buchdruckerei Berichthaus
Year: 1940
Subjects: subject: 314 Allgemeine Statistiken zu Europa
subject: Amtliche Statistik
subject: Bevölkerungsstatistik
subject: Wirtschaftsstatistik
subject: Stadtleben
subject: Zürich
subject: Baustatistik

description: Die in dieser Ausgabe publizierten Daten beziehen sich zum grössten Teil auf folgenden Zeitabschnitt : 1939
description: Seit 1929 fehlte in der Eheschliessungskarte die Berufsangabe der Frauen. Diese Lücke konnte in der 35. Ausgabe des Statistischen Jahrbuchs der Stadt Zürich wieder gefüllt werden. Ferner sind alle Gemeindeabstimmungen seit der Stadtvereinigung von 1893 aufgeführt worden. Ansonsten blieb das Jahrbuch zum Vorjahr unverändert.
High-Resolution Mid-Infrared Spectroscopy of GV Tau N: Surface Accretion and Detection of Ammonia in a Young Protoplanetary Disk
Creators: name: Najita, Joan R.
name: Carr, John S.
name: Brittain, Sean D.
name: Lacy, John H.
name: Richter, Matthew J.
name: Doppmann, Greg W.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Physical processes that redistribute or remove angular momentum from protoplanetary disks can drive mass accretion onto the star and affect the outcome of planet formation. Despite ubiquitous evidence that protoplanetary disks are engaged in accretion, the process(es) responsible remain unclear. Here we present evidence for redshifted molecular absorption in the spectrum of a Class I source that indicates rapid inflow at the disk surface. High resolution mid-infrared spectroscopy of GV Tau N reveals a rich absorption spectrum of individual lines of C2H2, HCN, NH3, and water. From the properties of the molecular absorption, we can infer that it carries a significant accretion rate (~ 1e-8 to 1e-7 Msun/yr), comparable to the stellar accretion rates of active T Tauri stars. Thus we may be observing disk accretion in action. The results may provide observational evidence for supersonic "surface accretion flows," which have been found in MHD simulations of magnetized disks. The observed spectra also represent the first detection of ammonia in the planet formation region of a protoplanetary disk. With ammonia only comparable in abundance to HCN, it cannot be a major missing reservoir of nitrogen. If, as expected, the dominant nitrogen reservoir in inner disks is instead N2, its high volatility would make it difficult to incorporate into forming planets, which may help to explain the low nitrogen content of the bulk Earth.
description: 55 pages, 18 figures, accepted for publication in the Astrophysical Journal
Surface imaging of cool evolved stars in the era of the ELT
Creators: name: Wittkowski, Markus
name: Chiavassa, A.
name: Höfner, S.
name: Climent, J. B.
Publisher: name: Zenodo
Year: 2019

description: Cool evolved stars are the main source of chemical enrichment of the interstellar medium, and understanding their mass loss offers a unique opportunity to study the cycle of matter. We discuss interferometric studies and their comparison to latest state-of-the-art dynamic model atmospheres. They show broad agreement for asymptotic giant branch stars. For red supergiants, however, current models cannot explain observed extensions by far, pointing to missing physical processes in their models, and uncertainties in our general understanding of mass loss. We present ongoing imaging and time-series observations that provide the strongest constraints, and may help to identify missing dynamic processes. VLTI studies will remain the highest spatial resolution observations at ESO into the ELT era, complemented by ALMA observations. We discuss crucial improvements in both instrumental and operational areas for surface imaging of cool evolved stars in the era of the ELT.
Discovering relationships between patient phenotypes and gene functions in large-scale transcriptomic data
Creators: name: Urban, Lara
name: Remmele, Christian W
name: Schwarz, Roland F
name: Liò, Pietro
name: Dittrich, Marcus
name: Müller, Tobias
Publisher: name: F1000Research
Year: 2015

description: A current challenge for transcriptomic analysis is the extraction of biological meaning. We assessed and adapted multivariate ecological methods for transcriptomic data, which are widely used to discover associations between species and sample covariates: RLQ visualizes associations within and between covariates whereas the fourth-corner analysis (4CA) identifies significance of the associations. We used these methods to discover associations between patient phenotypes and gene functions and demonstrated their high potential to unravel complex relationships in large-scale transcriptomic data.
A Global 86GHz VLBI Survey of Compact Radio Sources
Creators: name: Lee, Sang-Sung
name: Lobanov, Andrei P.
name: Krichbaum, Thomas P.
name: Witzel, Arno
name: Zensus, J. Anton
name: Bremer, Michael
name: Greve, Albert
name: Grewing, Michael
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present results from a large 86GHz global VLBI survey of compact radio sources. The main goal of the survey is to increase by factors of 3--5 the total number of objects accessible for future 3-mm VLBI imaging. The survey observations reach the baseline sensitivity of 0.1Jy and image sensitivity of better than 10 mJy/beam. The total of 127 compact radio sources have been observed. The observations have yielded images for 109 sources, extending the database of the sources imaged at 86GHz with VLBI observation by a factor of 5, and only 6 sources have not been detected. The remaining 12 objects have been detected but could not be imaged due to insufficient closure phase information. Radio galaxies are less compact than quasars and BL Lacs on sub-milliarcsecond scale. Flux densities and sizes of core and jet components of all imaged sources have been estimated using Gaussian model fitting. From these measurements, brightness temperatures have been calculated, taking into account resolution limits of the data. The cores of 70% of the imaged sources are resolved. The core brightness temperatures of the sources peak at $\sim 10^{11}$ K and only 1% have brightness temperatures higher than $10^{12}$ K. Cores of Intraday Variable (IDV) sources are smaller in angular size than non-IDV sources, and so yield higher brightness temperatures.
description: 72 pages, 12 figures, accepted for publication in the Astronomical Journal
The Contribution of Alpha Particles to the Solar Wind Angular Momentum Flux in the Inner Heliosphere
Creators: name: Finley, Adam J.
name: McManus, Michael D.
name: Matt, Sean P.
name: Kasper, Justin C.
name: Korreck, Kelly E.
name: Case, Anthony W.
name: Stevens, Michael L.
name: Whittlesey, Phyllis
name: Larson, Davin
name: Livi, Roberto
name: Bale, Stuart D.
name: de Wit, Thierry Dudok
name: Goetz, Keith
name: Harvey, Peter R.
name: MacDowall, Robert J.
name: Malaspina, David M.
name: Pulupa, Marc
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: An accurate assessment of the Sun's angular momentum (AM) loss rate is an independent constraint for models that describe the rotation evolution of Sun-like stars. In-situ measurements of the solar wind taken by Parker Solar Probe (PSP), at radial distances of $\sim 28-55R_{\odot}$, are used to constrain the solar wind AM-loss rate. For the first time with PSP, this includes a measurement of the alpha particle contribution. The mechanical AM flux in the solar wind protons (core and beam), and alpha particles, is determined as well as the transport of AM through stresses in the interplanetary magnetic field. The solar wind AM flux is averaged over three hour increments, so that our findings more accurately represent the bulk flow. During the third and fourth perihelion passes of PSP, the alpha particles contain around a fifth of the mechanical AM flux in the solar wind (the rest is carried by the protons). The proton beam is found to contain $\sim 10-50\%$ of the proton AM flux. The sign of the alpha particle AM flux is observed to correlate with the proton core. The slow wind has a positive AM flux (removing AM from the Sun as expected), and the fast wind has a negative AM flux. As with previous works, the differential velocity between the alpha particles and the proton core tends to be aligned with the interplanetary magnetic field. In future, by utilising the trends in the alpha-proton differential velocity, it may be possible to estimate the alpha particle contribution when only measurements of the proton core are available. Based on the observations from this work, the alpha particles contribute an additional $10-20\%$ to estimates of the solar wind AM-loss rate which consider only the proton and magnetic field contributions. Additionally, the AM flux of the proton beam can be just as significant as the alpha particles, and so should not be neglected in future studies.
description: 12 pages + 8 figures, accepted for publication in A&A
Torsion Phenomenology at the LHC
Creators: name: Belyaev, A. S.
name: Shapiro, I. L.
name: Vale, M. A. B. do
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We explore the potential of the CERN Large Hadron Collider (LHC) to test the dynamical torsion parameters. The form of the torsion action can be established from the requirements of consistency of effective quantum field theory. The most phenomenologically relevant part of the torsion tensor is dual to a massive axial vector field. This axial vector has geometric nature, that means it does not belong to any representation of the gauge group of the SM extension or GUT theory. At the same time, torsion should interact with all fermions, that opens the way for the phenomenological applications. We demonstrate that LHC collider can establish unique constraints on the interactions between fermions and torsion field considerably exceeding present experimental lower bounds on the torsion couplings and its mass. It is also shown how possible non-universal nature of torsion couplings due to the renormalization group running between the Planck and TeV energy scales can be tested via the combined analysis of Drell-Yan and $t\bar{t}$ production processes.
title: Statistisches Jahrbuch der Stadt Zürich 1940
title: Stat. Jahrb. Stadt Zür.
titleType: AlternativeTitle
Creators: name: (:Unkn) Unknown
Publisher: name: Buchdruckerei Berichthaus
Year: 1941
Subjects: subject: 314 Allgemeine Statistiken zu Europa
subject: Amtliche Statistik
subject: Bevölkerungsstatistik
subject: Wirtschaftsstatistik
subject: Stadtleben
subject: Zürich
subject: Baustatistik

description: Die in dieser Ausgabe publizierten Daten beziehen sich zum grössten Teil auf folgenden Zeitabschnitt : 1940
description: Die 36. Ausgabe des Statistischen Jahrbuchs der Stadt Zürich erfuhr keinerlei Anpassungen gegenüber dem Vorjahr. Besonders hervorgehoben wurde aber der frühzeitige Versand, trotz den durch die Kriegszeit verursachten Schwierigkeiten in Materialbeschaffung und Verarbeitung.
GTP-dependent K-Ras dimerization
Creators: name: Muratcioglu, Serena
name: Tanmay S. Chavan
name: Freed, Benjamin C.
name: Hyunbum Jang
name: Khavrutskii, Lyuba
name: R. Natasha Freed
name: Dyba, Marzena A.
name: Stefanisko, Karen
name: Tarasov, Sergey G.
name: Tarasova, Nadya I.
name: Gursoy, Attila
name: Gaponenko, Vadim
name: Nussinov, Ruth
name: Ozlem Keskin
Publisher: name: F1000Research
Year: 2015

description: Ras proteins recruit and activate effectors, including Raf, that transmit receptor-initiated signals. Monomeric Ras can bind Raf; however, activation of Raf requires its dimerization. It has been suspected that dimeric Ras may promote dimerization and activation of Raf. Here we show that the GTP-bound catalytic domain of K-Ras4B, a highly oncogenic splice variant of the K-Ras isoform, forms stable homodimers. We observe two major dimer interfaces. The first, highly populated β-sheet dimer interface is at the Switch I and effector binding regions, overlapping Raf’s, PI3K’s, RalGDS’ and additional effectors’ binding surfaces. This interface has to be inhibitory to such effectors. The second, helical interface also overlaps some effectors’ binding sites. This interface may promote Raf‘s activation. Our data reveal how Ras self-association can regulate effector binding and activity, and suggest that disruption of the helical dimer interface by drugs may abate Raf’s signaling in cancer.
Small instantons and the strong CP problem in composite Higgs models
Creators: name: Gupta, R. S.
name: Khoze, V. V.
name: Spannowsky, M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We show that QCD instantons can generate large effects at small length scales in the ultraviolet in standard composite Higgs models that utilise partial compositeness. This has important implications for possible solutions of the strong CP problem in these models. First we show that in the simplest known UV completions of composite Higgs models, if an axion is also present, it can have a mass much larger than the usual QCD axion. Even more remarkable is the case where there are no axions, but the strong CP problem can be solved by generating the up quark mass entirely from the contribution of instantons thus reviving the massless up-quark solution for these models. In both cases no additional field content is required apart from what is required to realise partial compositeness.
description: 8 pages, 3 figures
The Role of the Exchange-Correlation Potential in ab initio Electron Transport Calculations
Creators: name: Ke, San-Huang
name: Baranger, Harold U.
name: Yang, Weitao
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The effect of the exchange-correlation potential in ab initio electron transport calculations is investigated by constructing optimized effective potentials (OEP) using different energy functionals or the electron density from second-order perturbation theory. We calculate electron transmission through two atomic chain systems, one with charge transfer and one without. Dramatic effects are caused by two factors: changes in the energy gap and the self-interaction error. The error in conductance caused by the former is about one order of magnitude while that caused by the latter ranges from several times to two orders of magnitude, depending on the coupling strength and charge transfer. The implications for accurate quantum transport calculations are discussed.
description: 4 pages, published version, substantially revised discussion and revisions for clarity
Higher Schl{ä}fli Formulas and Applications II. Vector-valued differential relations
Creators: name: Schlenker, Jean-Marc
name: Souam, Rabah
Publisher: name: arXiv
Year: 2006
Subjects: subject: Differential Geometry (math.DG)
subject: Geometric Topology (math.GT)
subject: FOS: Mathematics

description: The classical Schläfli formula, and its ``higher'' analogs given in [SS03], are relations between the variations of the volumes and ``curvatures'' of faces of different dimensions of a polyhedra (which can be Euclidean, spherical or hyperbolic) under a first-order deformation. We describe here analogs of those formulas which are vector-valued rather than scalar. Some consequences follow, for instance constraints on where cone singularities can appear when a constant curvature manifold is deformed among cone-manifolds.
description: 26 pages, no figure. v2: added 2 refs, improved intro. v3: added section on low dim examples
Photoionization feedback in turbulent molecular clouds
Creators: name: Sartorio, Nina S.
name: Vandenbroucke, Bert
name: Falceta-Goncalves, Diego
name: Wood, Kenneth
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present a study of the impact of photoionization feedback from young massive stars on the turbulent statistics of star-forming molecular clouds. This feedback is expected to alter the density structure of molecular clouds and affect future star formation. Using the AMUN- Rad code, we first generate a converged isothermal forced turbulent density structure inside a periodic box. We then insert an ionizing source in this box and inject photoionization energy using a two-temperature pseudo-isothermal equation of state. We study the impact of sources at different locations in the box and of different source luminosities. We find that photoionization has a minor impact on the 2D and 3D statistics of turbulence when turbulence continues to be driven in the presence of a photoionizing source. Photoionization is only able to disrupt the cloud if the turbulence is allowed to decay. In the former scenario, the presence of an HII region inside our model cloud does not lead to a significant impact on observable quantities, independent of the source parameters.
description: 10 pages, 7 figures
Η ανταγωνιστικότητα των ελληνικών εξαγωγών ροδάκινων στην Ευρώπη:
Creators: name: Γραπατσά, Ευαγγελία Γεωργίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2014
Subjects: Ανταγωνιστικότητα
Διεθνές εμπόριο
Ροδάκινο
Competitiveness
International trade
Peach

description: Στην παρούσα εργασία γίνεται μια προσπάθεια μελέτης της ανταγωνιστικότητας των ελληνικών εξαγωγών ροδάκινων στην Ευρωπαϊκή αγορά. Πιο συγκεκριμένα, η εργασία περιλαμβάνει γενικά χαρακτηριστικά για τα ροδάκινα, στατιστικά στοιχεία παραγωγής, εισαγωγών και εξαγωγών. Παράλληλα, γίνεται αναφορά στην πολιτική που ακολουθείται από την Ευρωπαϊκή Ένωση, στην κοινή Αγροτική Πολιτική και στις μεταρρυθμίσεις της, καθώς και στην πολιτική που επικρατεί για τη ροδακινοκαλλιέργεια. Στην πορεία, γίνεται σύγκριση της ανταγωνιστικότητας των ελληνικών εξαγωγών ροδάκινων στην Ευρώπη με την αντίστοιχη των ισπανικών, ιταλικών και γαλλικών εξαγωγών. Για τη μελέτη της ανταγωνιστικότητας, χρησιμοποιήθηκαν οι εξής οικονομικοί δείκτες: Δείκτης Κάλυψης Εισαγωγών, Δείκτης Εισαγωγικής Διείσδυσης, Δείκτης Συγκριτικού Πλεονεκτήματος (Balassa), Δείκτης Ανταγωνιστικότητας – Εξειδίκευσης και ο Δείκτης Ενδοκλαδικού Εμπορίου. Τέλος, εκτιμώνται οι παραπάνω δείκτες, συγκρίνονται και σχολιάζονται τα αποτελέσματα. Λέξεις – κλειδιά: ροδάκινα, νεκταρίνια, ανταγωνιστικότητα, εμπόριο, εξαγωγές, δείκτες ανταγωνιστικότητας, συγκριτικό πλεονέκτημα.
description: This research paper is an attempt to study the competitiveness of the Greek exports of peaches in the European market. More specifically, this paper includes general information concerning peaches and nectarines, statistic data on their production, imports and exports. Furthermore, a reference is made to the policy pursued by the European Union and to the process and reform of the Common Agricultural Policy. There is also a reference to the prevailing policy for peach production. In addition, a comparison of trade competitiveness of peach exports is made, between Greece, Spain, Italy and France. The competitiveness was measured by using the following economic indicators: Import Coverage Ratio, Import Penetration Rate, Comparative Advantage Index (Balassa Index), the Net Export Index and the Intra – Industry Trade Index. Last but not least, the indices of export and external trade are estimated and compared and the final results are discussed. Keywords: peaches, nectarines, competitiveness, trade, exports, indicators of competitiveness, comparative advantage.
Seismoelectric responses from sulphide orebodies
Creators: name: Kepic, Anton
Publisher: name: University of British Columbia
Year: 2009

description: In the early 1980's a group of Russian researchers reported finding a new seismoelectric phenomenon associated with sulphide minerals. They asserted that strong bursts of broadband electromagnetic emissions appeared when a seismic wave passed through a sulphide orebody. This discovery has aroused considerable commercial interest because of the economic importance of mining sulphide minerals for zinc, copper, lead, gold, and other metals. However, there have been no reported follow-up studies of their findings, and no evaluation of the exploration potential of this phenomenon. This thesis reports a number of field experiments designed to examine the Russian claims and explore the properties of the phenomenon. These field trials have confirmed the existence of this relatively unknown seismoelectric phenomenaon and have substantially increased our knowledge of its charcteristics. In the tests 0.2-0.5 kg explosive charges were detonated to provide a strong source of seismic energy. When the seismic disturbance passed through a zone of sulphide mineralization, high frequency electromagnetic emissions were produced. The electromagnetic emissions appear in the form of brief pulses, 2 to 5 microseconds in duration. Typical peak amplitudes, measured 80 to 120 m from the zones of sulphide mineralization, are 10 mV/m and 2 nT. The spectrum of the electromag netic pulses spans a very wide range of frequencies, from 1 kHz to 3 MHz. Fourier analysis of the digital records from one of our sites shows a peak in the emission spectrum, at 1.1-1.4 MHz. This spectral peak was consistently reproduced from various portions of the sulphide orebody. New measurement and interpretion techniques were developed to study the electromagnetic signals. These techniques were applied to data from each field trial to demonstrate the potential of seismoelectric techniques for exploration. The results show that the high frequency seismoelectric phenomenon can be used to locate massive sulphides in underground mines. A physical framework to describe the field measurements has been developed. It is proposed that the seismic wave induces electrification via crack formation in the orebody. The electrified surfaces of the crack recombine rapidly in a gas discharge to produce the observed range of electromagnetic frequencies.
Τοπικό και περιφερειακό ραδιόφωνο στην Ευρώπη: ταυτότητα-πολιτικές προοπτικές
Creators: name: Παπαθανασίου, Ευαγγελία Αθανασίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2014
Subjects: Κοινοτικό, δημόσιο εμπορικό ραδιόφωνο
Ευρωπαϊκή περιφερειακή πολιτική-πολιτική ραδιοφώνου
Πολιτιστική ποικιλομορφία-πλουραλισμός
Community public business municipality digital radio
European regional policy-radio policty
Cultural diversity-pluralism

description: Η εργασία διερευνά την κατάσταση του τοπικού και περιφερειακού ραδιοφώνου στην Ευρώπη, την ταυτότητά του, τις πολιτικές που ακολουθούνται και τις προοπτικές που διανοίγονται για αυτόν τον τομέα, στην εποχή της παγκοσμιοποίησης και της ψηφιακής τεχνολογίας. Υποστηρίζει ότι, παρά τα βήματα προόδου που έχουν γίνει και τον προσανατολισμό της Ευρώπης προς την ανάπτυξη των περιφερειών, οι εθνικές πολιτικές και οπτικές και τα κατά τόπους συμφέροντα εξακολουθούν να παίζουν πρωτεύοντα ρόλο στην κατάσταση του τοπικού και περιφερειακού ραδιοφώνου. Σε αυτό συντελεί η απουσία ενός ενιαίου ευρωπαϊκού πλαισίου για τον τομέα των τοπικών μέσων, όπως αυτού για τα μέσα εθνικής εμβέλειας. Καταδεικνύει, παράλληλα ότι το διαδίκτυο, τα μέσα κοινωνικής δικτύωσης και οι νέες τεχνολογικές δυνατότητες μπορούν να διαδραματίσουν πολύ σημαντικό ρόλο για το παρόν και το μέλλον του μέσου, να απελευθερώσουν δυνάμεις και να οδηγήσουν το βηματισμό του με πιο σίγουρο και σταθερό τρόπο, μετατρέποντας τη δύσκολη οικονομική συγκυρία σε ευκαιρία για δημιουργικές καινοτομίες. Σε αυτό το πλαίσιο, εντοπίζονται τα προβλήματα που υπάρχουν για την ψηφιακή μετάβαση και οι προσπάθειες που καταβάλλονται για να ξεπεραστούν, ώστε να μπορέσει το τοπικό και περιφερειακό ραδιόφωνο να συνεχίσει να εκπληρώνει το ρόλο του εκφραστή της φυσιογνωμίας και των αναγκών των τοπικών κοινωνιών.
description: This paper explores the state of local and regional radio in Europe, its identity, the policies followed and the opportunities provided for this field, in the era of globalization and digital technology. He argues that, despite the progress made and the orientation of Europe to regional development, national policies and perspectives and local interests still play a major role in the local and regional radio's state. Τhe lack of a single European framework for the field of local media, such as that for nationwide range media contributes to this. It also demonstrates that the internet, social media and new technological capabilities can play a very important role in the present and future of the medium, unleash forces and lead it in a more secure and stable manner, turning the hard economic situation into an opportunity for creative innovations. In this context, the paper identifies the problems that exist for the digital switchover and the efforts made to overcome in order to enable local and regional radio to continue to fulfil the role of spokesman of physiognomy and the needs of local communities.
Cloud-by-cloud, multiphase, Bayesian modeling: Application to four weak, low ionization absorbers
Creators: name: Sameer
name: Charlton, J. C.
name: Norris, J. M.
name: Gebhardt, M.
name: Churchill, C. W.
name: Kacprzak, G. G.
name: Muzahid, S.
name: Narayanan, Anand
name: Nielsen, N. M.
name: Richter, Philipp
name: Wakker, Bart P.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present a new method aimed at improving the efficiency of component by component ionization modeling of intervening quasar absorption line systems. We carry out cloud-by-cloud, multiphase modeling making use of CLOUDY and Bayesian methods to extract physical properties from an ensemble of absorption profiles. Here, as a demonstration of method, we focus on four weak, low ionization absorbers at low redshift, because they are multi-phase but relatively simple to constrain. We place errors on the inferred metallicities and ionization parameters for individual clouds, and show that the values differ from component to component across the absorption profile. Our method requires user input on the number of phases and relies on an optimized transition for each phase, one observed with high resolution and signal-to-noise. The measured Doppler parameter of the optimized transition provides a constraint on the Doppler parameter of HI, thus providing leverage in metallicity measurements even when hydrogen lines are saturated. We present several tests of our methodology, demonstrating that we can recover the input parameters from simulated profiles. We also consider how our model results are affected by which radiative transitions are covered by observations (for example how many HI transitions) and by uncertainties in the b parameters of optimized transitions. We discuss the successes and limitations of the method, and consider its potential for large statistical studies. This improved methodology will help to establish direct connections between the diverse properties derived from characterizing the absorbers and the multiple physical processes at play in the circumgalactic medium.
description: Accepted for Publication in MNRAS
Extremal black holes in D=4 Gauss-Bonnet gravity
Creators: name: Chen, Chiang-Mei
name: Gal'tsov, Dmitri V.
name: Orlov, Dmitry G.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We show that four-dimensional Einstein-Maxwell-Dilaton-Gauss-Bonnet gravity admits asymptotically flat black hole solutions with a degenerate event horizon of the Reissner-Nordström type $AdS_2\times S^2$. Such black holes exist for the dilaton coupling constant within the interval $0\leq a^2
description: New material and references added, errors corrected including higher decimals in a_cr, figures improved
Renormalization of Quantum Electrodynamics and Hopf Algebras
Creators: name: Prokhorenko, D. V.
name: Volovich, I. V.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: In 1999, A. Connes and D. Kreimer have discovered the Hopf algebra structure on the Feynman graphs of scalar field theory. They have found that the renormalization can be interpreted as a solving of some Riemann -- Hilbert problem. In this work a generalization of their scheme to the case of quantum electrodynamics is proposed. The action of the gauge group on the Hopf algebra of diagrams are defined and the proof that this action is consistent with the Hopf algebra structure is given.
Use of DC resistivity and induced polarization methods in acid mine drainage research at the Copper Cliff mine tailings impoundments
Creators: name: Zudman, Yuval
Publisher: name: University of British Columbia
Year: 2009

description: Oxidation of sulphide minerals contained in the mine tailings impoundments at Copper Cliff, Ontario generates acidic conditions and elevated concentrations of dissolved constituents in the pore water. The tailings groundwater migrates radially outwards and might pose an environmental hazard if reaches the nearby water systems. There is a need to estimate the dimension of the current problem and assess future prospects. That need prompted a combined DC resistivity and Induced Polarization (IP) survey along one of the major flowpaths in the tailings. The DC resistivity and IP data were inverted to produce the detailed electric conductivity and chargeability structures of the cross section below the survey Une. Problems, generic of the inversion methodology and specific to the inversion of data from the tailings, are discussed and solutions are elaborated and demonstrated. The conductivity structure can be directly translated, through theoretical or empirical relations, to a map of the concentration of dissolved solids along the cross section and thereby provide insight about the current pore water quality. The sulphide minerals are the source of the IP response and thus the chargeability model can be used to estimate the amount and distribution of the sulphides. A new methodology to construct and invert IP decay curve information was developed. Assuming Cole-Cole relaxation to model the IP phenomenon, data sets constructed through the inversion of IP data of different time windows were inverted using a damped least squares algorithm. Values of the resultant Cole-Cole parameters might contribute additional insight about the sulphides in the tailings. Lack of time and laboratory verifications prevented full development and comprehensive conclusions. The research in this thesis concentrated along one line of the survey data with the intention of showing the capability of the DC resistivity and IP methods and their potential contribution to estimation of location and concentrations of the sulphide minerals and their oxidation products. The conclusions should assist designers of a large scale survey and prompt investigations of the relations between the physical properties mapped by these methods and the chemical parameters which are considered while assessing the damage and contemplating solutions.
White dwarf - main sequence star collisions from wide triples in the field
Creators: name: Michaely, Erez
name: Shara, Michael
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Multiple star systems interact strongly with Galactic field stars when the outer semi-major axis of a triple or multiple star is > 10 3 AU. Stable triples composed of two white-dwarfs (WD) and a low mass main sequence (MS) star in a wide outer orbit can thus be destabilized by gravitational interactions with random field stars. Such interactions excite the eccentricity of the distant third star sufficiently so that it begins to interact significantly with the inner binary. When this occurs the triple undergoes multiple binary-single resonant encounters. These encounters may result either in a collision between the nondegenerate component and a WD, or the breakup of the triple into a compact binary and a third object which is ejected. The compact binary can be either a MS-WD pair which survives, or collides, or a double WD which may inspiral through gravitational wave emission. We calculate the collision rate between a MS and WD star, and the merger rate of double WDs. Additionally, we describe the prospects of detectability of such a collision, which may resemble a sub-luminous SN event.
description: Comments are welcomed
Στρατηγικές μάθησης σε παιδιά με μαθησιακές δυσκολίες:
Creators: name: Ταπουρίδου, Δήμητρα Γεωργίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2014
Subjects: Στρατηγικές μάθησης
Μαθησιακές δυσκολίες
Παράφραση
Learning strategies
Learning disabilities
Parafrasis

description: Ελληνική Περίληψη Σκοπός της διατριβής ήταν η μελέτη των στρατηγικών μάθησης σε παιδιά με μαθησιακές δυσκολίες. Η παρούσα εργασία αποτελείται από δύο μέρη, ένα θεωρητικό και ένα ερευνητικό. Στο πρώτο μέρος εξετάσαμε τις μαθησιακές δυσκολίες και τα χαρακτηριστικά των ατόμων με μαθησιακές δυσκολίες. Στη συνέχεια, παρουσιάσαμε τους διαφορετικούς ορισμούς που υπάρχουν για τις στρατηγικές μάθησης, αναλύσαμε τις βασικές κατηγορίες τους και αναφερθήκαμε αναλυτικά στη διδασκαλία των στρατηγικών μάθησης. Επιπλέον, παρουσιάσαμε διεξοδικά το μοντέλο παρέμβασης στρατηγικών από το πανεπιστήμιο του Κάνσας. Επίσης, εστιάσαμε στην ανταπόκριση των μαθητών στη στρατηγική της παράφρασης και πόσο αυτή βοηθάει στην κατανόηση ενός κειμένου. Στο δεύτερο μέρος παρουσιάζεται η έρευνα που διεξήχθη σε δημοτικά σχολεία της Θεσσαλονίκης, στην οποία διερευνήσαμε τις διαφορές στον τρόπο που απαντούν σε συγκεκριμένα ερωτήματα ενός κειμένου οι μαθητές με μαθησιακές δυσκολίες και οι μαθητές χωρίς μαθησιακές δυσκολίες. Στο τέλος, παρουσιάζονται τα αποτελέσματα και τα συμπεράσματα της έρευνας.
description: The aim of the thesis was the study of learning strategies in children with learning disabilities . This thesis consists of two parts. The first one is theoretical whereas the other part is mainly based on research. The first part examined the learning difficulties and characteristics of people with learning disabilities. Then, we presented different definitions exist for learning strategies, we analyzed the basic categories and talked in detail the teaching of learning strategies. Furthermore, we presented in detail the model of intervention strategies from the University of Kansas. Also, we focused on the response of students to the strategy of paraphrase and how it helps to understand a text. The second part presents the research carried out in primary schools in Thessaloniki, in which we investigated the differences in the way they respond to specific questions of a text, students with learning disabilities and students without learning disabilities. In the end, presented the results and conclusions of the investigation.
CrowdEst: A Method for Estimating (and not Simulating) Crowd Evacuation Parameters in Generic Environments
Creators: name: Testa, Estevso
name: Barros, Rodrigo C.
name: Musse, Soraia Raupp
Publisher: name: arXiv
Year: 2020
Subjects: subject: Multiagent Systems (cs.MA)
subject: Graphics (cs.GR)
subject: FOS: Computer and information sciences

description: Evacuation plans have been historically used as a safety measure for the construction of buildings. The existing crowd simulators require fully-modeled 3D environments and enough time to prepare and simulate scenarios, where the distribution and behavior of the crowd needs to be controlled. In addition, its population, routes or even doors and passages may change, so the 3D model and configurations have to be updated accordingly. This is a time-consuming task that commonly has to be addressed within the crowd simulators. With that in mind, we present a novel approach to estimate the resulting data of a given evacuation scenario without actually simulating it. For such, we divide the environment into smaller modular rooms with different configurations, in a divide-and-conquer fashion. Next, we train an artificial neural network to estimate all required data regarding the evacuation of a single room. After collecting the estimated data from each room, we develop a heuristic capable of aggregating per-room information so the full environment can be properly evaluated. Our method presents an average error of 5% when compared to evacuation time in a real-life environment. Our crowd estimator approach has several advantages, such as not requiring to model the 3D environment, nor learning how to use and configure a crowd simulator, which means any user can easily use it. Furthermore, the computational time to estimate evacuation data (inference time) is virtually zero, which is much better even when compared to the best-case scenario in a real-time crowd simulator.
Algebraic reduction of the Ising model
Creators: name: Baxter, R. J.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We consider the Ising model on a cylindrical lattice of L columns, with fixed-spin boundary conditions on the top and bottom rows. The spontaneous magnetization can be written in terms of partition functions on this lattice. We show how we can use the Clifford algebra of Kaufman to write these partition functions in terms of L by L determinants, and then further reduce them to m by m determinants, where m is approximately L/2. In this form the results can be compared with those of the Ising case of the superintegrable chiral Potts model. They point to a way of calculating the spontaneous magnetization of that more general model algebraically.
description: 25 pages, one figure, last reference completed. Various typos fixed. Changes on 12 July 2008: Fig 1, 0 to +1; before (2.1), if to is; after (4.6), from to form; before (4.46), first three to middle two; before (4.46), last to others; Conclusions, 2nd para, insert how ; renewcommand \i to be \rm i
Lack-of-correlation anomaly in CMB large scale polarisation maps
Creators: name: Chiocchetta, Caterina
name: Gruppuso, Alessandro
name: Lattanzi, Massimiliano
name: Natoli, Paolo
name: Pagano, Luca
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present an assessment of the CMB large scale anomalies in polarisation using the two-point correlation function as a test case. We employ the state of the art of large scale polarisation datasets: the first based on a Planck 2018 HFI 100 and 143 GHz cross-spectrum analysis, based on SRoll2 processing, and the second from a map-based approach derived through a joint treatment of Planck 2018 LFI and WMAP-9yr. We consider the well-known $S_{1/2}$ estimator, which measures the distance of the two-point correlation function from zero at angular scales larger than $60^{\circ}$, and rely on realistic simulations for both datasets to assess confidence intervals. By focusing on the pure polarisation field described by either the $Q$ and $U$ Stokes parameters or by the local $E-$modes, we show that the first description is heavily influenced by the quadrupole (which is poorly constrained in both datasets) while the second one is more suited for an analysis containing higher multipoles up to $\ell \sim 10$, limit above which both datasets become markedly noise dominated. We find that both datasets exhibit a lack-of-correlation anomaly in pure polarisation, similar to the one observed in temperature, which is better constrained by the less noisy Planck HFI 100$\times$143 data, where its significance lies at about $99.5\%$. We perform our analysis using realizations that are either constrained or non-constrained by the observed temperature field, and find similar results in the two cases.
description: 19 pages, 15 figures
Stable remnants and quantum gravity effects in non linear electric source Culetu black hole
Creators: name: Khan, Yawar H.
name: Ganai, Prince A.
name: Upadhyay, Sudhaker
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this paper, we discuss remnants and quantum gravity effects on thermodynamics of new kind of regular black hole known as Culetu black hole. The black hole results in coupling of gravity to non linear electrodynamic source. We first derive various thermodynamic quantities of interest. We then discuss in detail the existence and stability of remnants. The stability of remnants is analyzed in presence of thermal fluctuations and we observe that thermal fluctuations tend to increase the entropy at the horizon radius which is exactly the remnant radius. We then investigate non perturbative quantum gravity effects on the thermodynamics of Culetu black hole up to leading order terms.
description: 13 pages, 11 figures, published in EPJP