cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Photon capture cones and embedding diagrams of the Ernst spacetime
Creators: name: Stuchlík, Zdeněk
name: Hledík, Stanislav
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The differences between the character of the Schwarzschild and Ernst spacetimes are illustrated by comparing the photon capture cones, and the embedding diagrams of the $t=\mathrm{const}$ sections of the equatorial planes of both the ordinary and optical reference geometry of these spacetimes. The non-flat asymptotic character of the Ernst spacetime reflects itself in two manifest facts: the escape photon cones correspond to purely outward radial direction, and the embedding diagrams of both the ordinary and optical geometry shrink to zero radius asymptotically. Using the properties of the embedding diagrams, regions of these spacetimes which could have similar character are estimated, and it is argued that they can exist for the Ernst spacetimes with a sufficiently low strength of the magnetic field.
description: 12 pages, 7 figures
Fanaroff-Riley classification of radio galaxies using group-equivariant convolutional neural networks
Creators: name: Scaife, Anna M. M.
name: Porter, Fiona
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Weight sharing in convolutional neural networks (CNNs) ensures that their feature maps will be translation-equivariant. However, although conventional convolutions are equivariant to translation, they are not equivariant to other isometries of the input image data, such as rotation and reflection. For the classification of astronomical objects such as radio galaxies, which are expected statistically to be globally orientation invariant, this lack of dihedral equivariance means that a conventional CNN must learn explicitly to classify all rotated versions of a particular type of object individually. In this work we present the first application of group-equivariant convolutional neural networks to radio galaxy classification and explore their potential for reducing intra-class variability by preserving equivariance for the Euclidean group E(2), containing translations, rotations and reflections. For the radio galaxy classification problem considered here, we find that classification performance is modestly improved by the use of both cyclic and dihedral models without additional hyper-parameter tuning, and that a D16 equivariant model provides the best test performance. We use the Monte Carlo Dropout method as a Bayesian approximation to recover epistemic uncertainty as a function of image orientation and show that E(2)-equivariant models are able to reduce variations in model confidence as a function of rotation.
description: 11 pages, 6 figures, accepted MNRAS
Propagation of fluctuations in interaction networks governed by the law of mass action
Creators: name: Maslov, Sergei
name: Sneppen, Kim
name: Ispolatov, Iaroslav
Publisher: name: arXiv
Year: 2006
Subjects: subject: Molecular Networks (q-bio.MN)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Biological Physics (physics.bio-ph)
subject: Genomics (q-bio.GN)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: Using an example of physical interactions between proteins, we study how perturbations propagate in interconnected networks whose equilibrium state is governed by the law of mass action. We introduce a comprehensive matrix formalism which predicts the response of this equilibrium to small changes in total concentrations of individual molecules, and explain it using a heuristic analogy to a current flow in a network of resistors. Our main conclusion is that on average changes in free concentrations exponentially decay with the distance from the source of perturbation. We then study how this decay is influenced by such factors as the topology of a network, binding strength, and correlations between concentrations of neighboring nodes. An exact analytic expression for the decay constant is obtained for the case of uniform interactions on the Bethe lattice. Our general findings are illustrated using a real biological network of protein-protein interactions in baker's yeast with experimentally determined protein concentrations.
description: 4 pages; 2 figures
A photo-ionized canopy for the shock-excited Criss-Cross Nebula
Creators: name: Temporin, S.
name: Weinberger, R.
name: Stecklum, B.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Aims. We study a new broad well-defined arc of optical nebulosity close to the cloud-shock interacting Criss-Cross Nebula, derive the basic physical properties of the former and revise those of the latter, and compare both objects to simulations of cloud-shock interactions from the literature. Methods. Deep optical, partly wide-field, images were used to reveal the intricate morphology and overall extent of the nebulosities. Optical spectroscopy enabled us to uncover their nature. Results. The two nebulosities obviously are physically linked, but are of different type; the Criss-Cross Nebula is, as was shown also in an earlier paper, excited via a slow shock from the expanding Orion-Eridanus Bubble, but the broad arc is definitely photo-ionized. The source for ionizing photons appears to be hot gas in this bubble. Some results of simulations of interactions of SNRs with interstellar clouds available from the literature bear a striking resemblance to our nebulae, which appear to represent an example - unrivalled in closeness and clarity - for an early to medium stage in the destruction of an isolated cloud over-run by a highly evolved SNR. Thereby the Criss-Cross Nebula is, when seen from the SNR, the rear disrupted part of the original small cloud, whereas the arc probably is its yet rather intact front part.
description: 6 pages, 3 figures. Figures degraded because of size constraints. Accepted for publication in A&A
Αξιοποίηση Εθνικών Πολιτικών για τον Περιβαλλοντικό σχεδιασμό οδικών συστημάτων
Creators: name: Γκιουφής, Θωμάς Παναγιώτη
Publisher: name: Aristotle University of Thessaloniki
Year: 2016
Subjects: Περιβάλλον
Οδικό σύστημα
Σχεδιασμός
Enviroment
Road system
Planning

description: Το αντικείμενο της παρούσας διπλωματικής είναι η αξιοποίηση εθνικών πολιτικών για τον περιβαλλοντικό σχεδιασμό των οδικών συστημάτων. Ένα από τα σημαντικότερα προβλήματα που καλείται να αντιμετωπίσει σήμερα η ανθρωπότητα είναι το φαινόμενο της κλιματικής αλλαγής που έχει δυσμενή αποτελέσματα για το περιβάλλον. Η αύξηση των εκπομπών αερίων του θερμοκηπίου αποτελεί ένα από τα βασικά αίτια του προβλήματος. Για την επίτευξη της μείωσης των αερίων του θερμοκηπίου με άμεσα αποτελέσματα στο παρόν αλλά και στο μέλλον πρέπει να χαραχθεί μια στρατηγική βιώσιμης ανάπτυξης σε ποικίλους τομείς της ανθρώπινης δραστηριότητας. Η ανάγκη για την αλλαγή στην πολιτική των μεταφορών έχει γίνει επιτακτική. Ένας από τους τομείς αυτούς είναι και ο τομέας των μεταφορών. Η αλλαγή που χρειάζεται συγκεκριμένα είναι ο στρατηγικός σχεδιασμός των πολιτικών εφαρμογής στα οδικά συστήματα μεταφορών. Οι νέες καινοτόμες τεχνολογίες, τα συμπεριφορικά μέτρα για χρήση σύγχρονων μέσων μεταφορών αλλά και η επαναχρησιμοποίηση ανακυκλώσιμων υλικών για την κατασκευή έργων, αποτελούν κάποιες από τις μεθόδους και τα μέτρα διαχείρισης που εφαρμόζονται σε Ευρωπαϊκό πλαίσιο και όχι μόνο για την βελτίωση των εκπομπών αερίων. Τέλος, ο σκοπός αυτής της διπλωματικής είναι η παρουσίαση κάποιων συμπερασμάτων και προβλέψεων για τις μελλοντικές τάσεις στον σχεδιασμό οδικών συστημάτων, με κατεύθυνση πάντα τον περιβαλλοντικό σχεδιασμό και την αξιοποίηση των πολιτικών για δημιουργία βιώσιμων οδικών συστημάτων.
description: The subject of this thesis is the development of national policies on the environmental design of road systems. One of the major problems that humanity is facing today is the phenomenon of climate change which has adverse effects on the environment. The increase of greenhouse gas emissions is one of the main causes of the problem. In order to achieve the reduction of greenhouse gases with direct effects on the present and the future, the definition of a development strategy in various areas of human activity is necessary. The need for change in transport policy has become imperative. One of these areas is the transport sector. The change needed in particular is the strategic planning of implementation policies in road transport systems. New innovative technologies, behavioral measures to modern means of transport but also the reuse of recyclable materials for construction projects, are some of the methods and management measures applicable in the European frame, and not only to improve emissions. Finally, the aim of this thesis is to present some conclusions and predictions about future trends in the design of road systems, with direction always environmental planning and utilization of policies in order to create sustainable road systems.
Combining Events and Frames using Recurrent Asynchronous Multimodal Networks for Monocular Depth Prediction
Creators: name: Gehrig, Daniel
name: Rüegg, Michelle
name: Gehrig, Mathias
name: Carrio, Javier Hidalgo
name: Scaramuzza, Davide
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Event cameras are novel vision sensors that report per-pixel brightness changes as a stream of asynchronous "events". They offer significant advantages compared to standard cameras due to their high temporal resolution, high dynamic range and lack of motion blur. However, events only measure the varying component of the visual signal, which limits their ability to encode scene context. By contrast, standard cameras measure absolute intensity frames, which capture a much richer representation of the scene. Both sensors are thus complementary. However, due to the asynchronous nature of events, combining them with synchronous images remains challenging, especially for learning-based methods. This is because traditional recurrent neural networks (RNNs) are not designed for asynchronous and irregular data from additional sensors. To address this challenge, we introduce Recurrent Asynchronous Multimodal (RAM) networks, which generalize traditional RNNs to handle asynchronous and irregular data from multiple sensors. Inspired by traditional RNNs, RAM networks maintain a hidden state that is updated asynchronously and can be queried at any time to generate a prediction. We apply this novel architecture to monocular depth estimation with events and frames where we show an improvement over state-of-the-art methods by up to 30% in terms of mean absolute depth error. To enable further research on multimodal learning with events, we release EventScape, a new dataset with events, intensity frames, semantic labels, and depth maps recorded in the CARLA simulator.
Unnatural Oscillon Lifetimes in an Expanding Background
Creators: name: Graham, N.
name: Stamatopoulos, N.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: We consider a classical toy model of a massive scalar field in 1+1 dimensions with a constant exponential expansion rate of space. The nonlinear theory under consideration supports approximate oscillon solutions, but they eventually decay due to their coupling to the expanding background. Although all the parameters of the theory and the oscillon energies are of order one in units of the scalar field mass $m$, the oscillon lifetime is exponentially large in these natural units. For typical values of the parameters, we see oscillon lifetimes scaling approximately as $τ\propto \exp(k E/m)/m$ where $E$ is the oscillon energy and the constant $k$ is on the order of 5 to 15 for expansion rates between $H=0.02m$ and $H=0.01m$.
description: 7 pages, 2 .eps figures; v2: expanded discussion of decay, fixed typos; version to appear in Physics Letters B
Excitation and conversion of electromagnetic waves in pulsar magnetospheres
Creators: name: Gogoberidze, G.
name: Machabeli, G. Z.
name: Usov, V. V.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We demonstrate that nonlinear decay of obliquely propagating Langmuir waves into Langmuir and Alfven waves (L --> L'+A) is possible in a one-dimensional, highly relativistic, streaming, pair plasma. Such a plasma may be in the magnetospheres of pulsars. It is shown that the characteristic frequency of generated Alfven waves is much less than the frequency of Langmuir waves and may be consistent with the observational data on the radio emission of pulsars.
description: 10 pages, 1 figure
Nonlinear propagation of broadband intense electromagnetic waves in an electron-positron plasma
Creators: name: Marklund, M.
name: Eliasson, B.
name: Shukla, P. K.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: A kinetic equation describing the nonlinear evolution of intense electromagnetic pulses in electron-positron (e-p) plasmas is presented. The modulational instability is analyzed for a relativistically intense partially coherent pulse, and it is found that the modulational instability is inhibited by the spectral pulse broadening. A numerical study for the one-dimensional kinetic photon equation is presented. Computer simulations reveal a Fermi-Pasta-Ulam-like recurrence phenomena for localized broadband pulses. The results should be of importance in understanding the nonlinear propagation of broadband intense electromagnetic pulses in e-p plasmas in laser-plasma systems as well as in astrophysical plasma settings.
description: 16 pages, 5 figures, to appear in Phys. Plasmas
DEP bulletin 1989 - July - December
Creators: name: No Name Supplied
Publisher: name: No Publisher Supplied
Year: 1989

description: The DEP bulletin is a semi-monthly publication of the New Jersey Department of Environmental Protection. It contains a list of construction permit applications recently filed or acted upon by the Department along with a calendar of events of interest, a schedule of public hearings, and Environmental Impact Statements acted upon during the period.
Coherent Aharonov Bohm oscillations in type-II (ZnMn)Te quantum dots
Creators: name: Sellers, I. R.
name: Whiteside, V. R.
name: Govorov, A. O.
name: Fan, W. C.
name: Chou, W-C.
name: Khan, I.
name: Petrou, A.
name: McCombe, B. D.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: The magneto-photoluminescence of type-II (ZnMn)Te quantum dots is presented. As a result of the type-II band alignment Aharonov-Bohm (AB) oscillations in the photoluminescence intensity are evident, confirming previous predictions for the suitability of this geometry to control the optical Aharonov-Bohm effect in semiconductor systems. Moreover, the system demonstrates an interesting interplay between the AB effect and the spin polarization in diluted magnetic semiconductor quantum dots. The intensity of the AB oscillations increases with both magnetic field and the degree of optical polarization, indicating the suppression of spin fluctuations improves the coherence of the system.
description: submitted to PRB
GRB 060117: Reverse + forward shock solution
Creators: name: Jelínek, Martin
name: Prouza, Michael
name: Kubánek, Petr
name: Hudec, René
name: Nekola, Martin F.
name: Ridky, Jan
name: Grygar, Jiri
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present a discovery and observation of an extraordinarily bright prompt optical emission of the GRB 060117 obtained by a wide-field camera atop the robotic telescope FRAM of the Pierre Auger Observatory from 2 to 10 minutes after the GRB. We found rapid average temporal flux decay of alpha = -1.7 +/- 0.1 and a peak brightness R = 10.1 mag. We interpret the shape of the lightcurve as a transition between reverse and forward shock emission.
description: 2 pages, 1 figure; Proceedings of "SWIFT and GRBs: Unveiling the Relativistic Universe" June 5-9, 2006 Venice (Italy)
Studies in applied statistics : ship hull design optimization and endogamous group comparisons
Creators: name: Thorne, Anona Elaine
Publisher: name: University of British Columbia
Year: 2008

description: This paper contains two case studies in applied statistics. The first study originated from a series of seakeeping experiments on twenty-seven different ship hull designs. The experimenters sought a method of predicting performance for hull designs different from those included in the study. The results of these experiments had already been analyzed, but we wished to consider the Taguchi method as an alternative method of analysis. In this study, we describe the initial design problem and analyses and provide a critical evaluation of the Taguchi method; we assess its merits to determine its suitability for the ship hull design problem. We find the Taguchi method unsatisfactory in general, and inappropriate for the ship hull design problem. The second study derives from a case which came to the Statistical Consulting and Research Lab (SCARL) in the Department of Statistics at The University of British Columbia. Having lost all her original data, our client wished to know if it were possible to "reconstruct" her data or, in any event, to perform a statistical analysis, using the tables of summary statistics in her possession. She wished to model several different pulmonary functions using various demographic and anthropometric measurements as explanatory variables. For each of the different model variants under consideration, she wanted to see if the same model parameters would be valid for all endogamous groups, or if some groups were sufficiently different that the parameter values would be different for these groups. We were able to develop a new general method for application to her problem; the derivation and application of this methodology are presented in the second study.
On the reductive Borel-Serre compactification, II: Excentric quotients and least common modifications
Creators: name: Zucker, Steven
Publisher: name: arXiv
Year: 2006
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 32J05, 14J99

description: Let X be a locally symmetric variety. Let EBS(X) and TorE(X) denote its excentric Borel-Serre and excentric toroidal compactifications, resp. We determine their least common modification and use it to prove a conjecture of Goresky and Tai concerning canonical extensions of homogeneous vector bundles. In the process, we see that EBS(X) and TorE(X) are homotopy equivalent.
description: 56 pages
Naming Games in Spatially-Embedded Random Networks
Creators: name: Lu, Qiming
name: Korniss, G.
name: Szymanski, Boleslaw K.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Multiagent Systems (cs.MA)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: We investigate a prototypical agent-based model, the Naming Game, on random geometric networks. The Naming Game is a minimal model, employing local communications that captures the emergence of shared communication schemes (languages) in a population of autonomous semiotic agents. Implementing the Naming Games on random geometric graphs, local communications being local broadcasts, serves as a model for agreement dynamics in large-scale, autonomously operating wireless sensor networks. Further, it captures essential features of the scaling properties of the agreement process for spatially-embedded autonomous agents. We also present results for the case when a small density of long-range communication links are added on top of the random geometric graph, resulting in a "small-world"-like network and yielding a significantly reduced time to reach global agreement.
description: We have found a programming error in our code used to generate the results of the earlier version. We have corrected the error, reran all simulations, and regenerated all data plots. While the qualitative behavior of the model has not changed, the numerical values of some of the scaling exponents did. 7 figures
Tamm states in one dimensional photonic crystals containing left-handed materials
Creators: name: Namdar, Abdolrahman
Publisher: name: arXiv
Year: 2006
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We present a theoretical study of electromagnetic surface waves localized at an interface separating a conventional uniform medium and a semi-infinite 1-D photonic crystal made of alternate left-handed metamaterial and right-handed material which we refer to as left-handed photonic crystal. We find novel type of surface mode's structure, the so-called surface Tamm states and demonstrate that the presence of metamaterial in the photonic crystal structure allows for a flexible control of the dispersion properties of surface states, and can support the Tamm states with a backward energy flow and a vortex-like structure.
description: 8pages, 5 figures
Design Principles for High Temperature Superconductors with Hydrogen-based Alloy Backbone at Moderate Pressure
Creators: name: Zhang, Zihan
name: Cui, Tian
name: Hutcheon, Michael J.
name: Shipley, Alice M.
name: Song, Hao
name: Du, Mingyang
name: Kresin, Vladimir Z.
name: Duan, Defang
name: Pickard, Chris J.
name: Yao, Yansun
Publisher: name: arXiv
Year: 2021
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Hydrogen-based superconductors provide a route to the long-sought goal of room-temperature superconductivity, but the high pressures required to metallize these materials limit their immediate application. For example, carbonaceous sulfur hydride, the first room-temperature superconductor, can reach a critical temperature (Tc) of 288 K only at the extreme pressure of 267 GPa. The next recognized challenge is the realization of room-temperature superconductivity at significantly lower pressures. Here, we propose a strategy for the rational design of high-temperature superconductors at low pressures by alloying small-radius elements and hydrogen to form ternary hydride superconductors with alloy backbones. We identify a hitherto unknown fluorite-type backbone in compositions of the form AXH8, which exhibit high temperature superconductivity at moderate pressures. The Fm-3m phase of LaBeH8, with a fluorite-type H-Be alloy backbone, is predicted to be metastable and superconducting with a Tc ~ 191 K at 50 GPa; a substantially lower pressure than that required by the geometrically similar clathrate hydride LaH10 (170 GPa). Our approach paves the way for finding high-Tc ternary hydride superconductors at conditions close to ambient pressures.
description: 11 pages, 4 figures
Το δικαίωμα του παιδιού στην πόλη. Πρόταση μουσειοπαιδαγωγικής προσέγγισης του αστικού πολιτισμού.
Creators: name: Γεωργοπούλου, Αθηνά Γεωργίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2016
Subjects: μουσειπαιδαγωγική
αστικός πολιτισμός-αρχιτεκτονική
museum educational project
architecture-urban culture

description: Τις τελευταίες δεκαετίες η έννοια του μουσείου έχει διευρυνθεί ακολουθώντας τη διεύρυνση που έχει προηγηθεί στις έννοιες του υλικού πολιτισμού και της κουλτούρας. Το πεδίο της πόλης και της πολεοδομίας, που διατηρεί -αναμφίβολα πλέον- πολιτιστικό και κοινωνικό περιεχόμενο, αποδεικνύεται ένα πεδίο πολύ πρόσφορο ώστε να βρει κανείς σε αυτό μουσειολογικό ενδιαφέρον. Παρ΄όλ΄αυτά, οι μέχρι τώρα προσπάθειες διαχειρίζονται κατά βάση το πολιτιστικό απόθεμα, σχεδιάζοντας πολιτιστικές διαδρομές. Στην παρούσα εργασία προσπαθούμε να αξιοποιήσουμε το διδακτικό ρόλο των μουσείων και με γνώμονα τις μουσειοπαιδαγωγικές πρακτικές να προσεγγίσουμε την αρχιτεκτονική στη βάση του αστικού πολιτισμού. Θεωρώντας την πόλη ως ένα ανοιχτό μουσείο και μουσειακή συλλογή τα ίχνη της ανθρώπινης δράσης, φτιάχνουμε ένα παιδαγωγικό με το οποίο αναζητούμε το δικαίωμα των παιδιών στην καθημερινότητα του άστεως.
description: Over the last decades, the concept of museum has widened greatly following the broadening of material culture and civilization. The field of city and of urban planning – that undoubtedly maintains a cultural and social aspect – has proven itself to be a promising field in which one can find a museological interest. However, all the attempts so farare examining mainly the cultural stock and therefore, are designing cultural tours. In the present study, we attempt to emphasize on the education role of the museums. In line with the principles of museum education we try to approach architecture on the basis of urban culture. Recognizing the city as an open museum and the traces of human action as the museological collection, we are designing an educational project through which we are seeking children’s right to the city.
description: Σε συνεργασία με το Παιδαγωγικό Τμήμα Δημοτικής Εκπαίδευσης (Πανεπιστήμιο Δυτικής Μακεδονίας)
The effects of a kappa-distribution in the heliosheath on the global heliosphere and ENA flux at 1 AU
Creators: name: Heerikhuisen, J.
name: Pogorelov, N. V.
name: Florinski, V.
name: Zank, G. P.
name: Roux, J. A. le
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We investigate heliosheath energetic neutral atom (ENA) fluxes at keV energies, by assuming that the heliosheath proton distribution can be approximated by a kappa-distribution. The choice of the kappa parameter derives from observational data of the solar wind (SW). This has direct applications to the upcoming IBEX mission. We will look at all-sky ENA maps within the IBEX energy range (10 eV to 6 keV), as well as ENA energy spectra in several directions. We find that the use of kappa, as opposed to a Maxwellian, gives rise to greatly increased ENA fluxes above 1 keV, while medium energy fluxes are somewhat reduced. We show how IBEX data can be used to estimate the spectral slope in the heliosheath, and that the use of kappa reduces the differences between ENA maps at different energies. We also investigate the effect introducing a kappa-distribution has on the global interaction between the SW and the local interstellar medium (LISM), and find that there is generally an increase in energy transport from the heliosphere into the LISM, due to the modified profile of ENA's energies. This results in a termination shock that moves out by 4 AU, a heliopause that moves in by 9 AU and a bow shock 25 AU farther out, in the nose direction.
Spatial Entanglement From Off-Diagonal Long Range Order in a BEC
Creators: name: Heaney, Libby
name: Anders, Janet
name: Kaszlikowski, Dagomir
name: Vedral, Vlatko
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate spatial entanglement - particle-number entanglement between regions of space - in an ideal Bosonic gas. We quantify the amount spatial entanglement around the transition temperature for condensation by probing the gas with two localised two-level systems. We show that spatial entanglement in the gas is directly related to filling of the ground state energy level and therefore to the off-diagonal long-range order of the system and the onset of condensation.
description: 7 pages, 3 figures. Extended from 4 to 7 pages. More detailed derivations of key formula. Extended introduction and background. Results remain unchanged
The effect of aspherical stellar wind of giant stars on the symbiotic channel of type Ia supernovae
Creators: name: Wu, Chengyuan
name: Liu, Dongdong
name: Wang, Xiaofeng
name: Wang, Bo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The progenitor systems accounting for explosions of type Ia supernovae (SNe Ia) is still under debate. Symbiotic channel is one of the possible progenitor scenarios, in which the WDs in these systems increase in mass through wind accretion from their red giant companions. The mass-loss processes of the giants in the symbiotic systems could produce amount of circumstellar medium (CSM), and the detections of the interaction signals between SN ejecta and CSM can be used as an ideal way to distinguish the different progenitor models. However, the density distribution and geometric structure of the CSM around the symbiotic systems remain highly uncertain. By assuming that the tidal torque from binary interaction can increase the mass-loss rate of the red giant and cause the stellar wind concentrate towards the equatorial plane, we provide a simplified method to estimate the density and the degree of deviation from spherical symmetry of the CSM. Based on the calculations of the binary evolutions of symbiotic systems using stellar evolution code MESA, we obtained the parameter space for producing SNe Ia. We found that SNe Ia could originate from symbiotic systems with massive carbon-oxygen white dwarfs (CO WDs), while the half-opening angle of the stellar wind from red giant towards the WD varies with the binary evolution, resulting in the formation of surrounding CSM with different geometric structures. The corresponding properties of ejecta-CSM interactions may be examined by the spectropolarimetry observations in the future, from which one may find additional relationship between circumstellar environment of SNe Ia and their progenitor systems.
description: 25 pages, 12 figures, submitted to MNRAS, a revised version after referee's comments
Adaptive mesh computation of polycrystalline pattern formation using a renormalization-group reduction of the phase-field crystal model
Creators: name: Athreya, Badrinarayan P.
name: Goldenfeld, Nigel
name: Dantzig, Jonathan A.
name: Greenwood, Michael
name: Provatas, Nikolas
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Pattern Formation and Solitons (nlin.PS)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: We implement an adaptive mesh algorithm for calculating the space and time dependence of the atomic density field during materials processing. Our numerical approach uses the systematic renormalization-group formulation of the phase field crystal model to provide the underlying equations for the complex amplitude of the atomic density field--a quantity that is spatially uniform except near topological defects, grain boundaries and other lattice imperfections. Our algorithm is a hybrid formulation of the amplitude equations, combining Cartesian and polar decompositions of the complex amplitude. We show that this approach leads to an acceleration by three orders of magnitude in model calculations of polycrystalline domain formation in two dimensions.
description: 37 pages, 15 figures. Submitted to Phys. Rev. E
Οι επιδράσεις του διαδικτύου στους εφήβους και η σχολική θρησκευτική αγωγή
Creators: name: Τραμουντάνη, Λεμονιά Γεωργίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2016
Subjects: Διαδίκτυο και θρησκευτική αγωγή
Οι επιδράσεις του διαδικτύου στους εφήβους
Έφηβοι και θρησκευτικό μάθημα
Internet and religious education
Effects of internet in adolescents
Adolescents and religious module

description: Σκοπός της παρούσας εργασίας είναι η θεωρητική προσέγγιση των επιδράσεων του Διαδικτύου στους έφηβους χρήστες. Γίνεται δηλαδή αναφορά τόσο στα πλεονεκτήματα που προκύπτουν από τη χρήση του Διαδικτύου όσο και στις αρνητικές επιδράσεις για τους εφήβους από την προβληματική του χρήση. Ταυτόχρονα, η εργασία επικεντρώνεται στην προσέγγιση μεθόδων και πρακτικών από τους εκπαιδευτικούς, ώστε να προάγουν τη σωστή χρήση του Διαδικτύου ιδιαίτερα για τους εφήβους, οι οποίοι δε μπορούν να αξιολογήσουν τη χρήση του και να την αξιοποιήσουν χωρίς αρνητικές επιπτώσεις. Στόχος αυτής της εργασίας μεταξύ άλλων είναι να επισημάνει κάποιους από τους κινδύνους και να ενημερώσει για τις συνέπειες αλλά και τον τρόπο αντιμετώπισής τους. Η εργασία επικεντρώνεται ειδικότερα στο μάθημα της θρησκευτικής αγωγής και στον ρόλο του θεολόγου παιδαγωγού, διότι το θρησκευτικό μάθημα δεν προσφέρει μόνο γνώσεις στον μαθητή, αλλά του μεταδίδει αξίες, συμβάλλοντας στην ανάπτυξη της προσωπικότητας του. Ειδικότερα θέλουμε να προσεγγίσουμε το θέμα αυτό από την σκοπιά του θεολόγου, ο οποίος καλείται να αναγνωρίσει τις αρνητικές επιδράσεις του Διαδικτύου, όταν αυτές εμφανίζονται στον έφηβο χρήστη, αλλά και να μπορέσει στην συνέχεια να βοηθήσει να ξεπεραστούν και να αντιμετωπιστούν.
description: The purpose of this paper is the theoretical approach of Internet’s effects in adolescent’s users. There is reference both in the advantages arising from the use of the Internet and as well as its negative effect on adolescents by its problematic application. At the same time, this work focuses on approaching methods and practices from teachers in order to promote the correct use of the Internet in particular for adolescents who cannot evaluate its use and utilize it without negative effects. The goal of this paper, among others, is to highlight some of the dangers and to inform about the consequences and how to address them. This paper is focused in particular in module of religious education and the role of religious pedagogue, because religious module does not offer only knowledge to student, but communicates values, contributing in the evolvement of his/her personality. In particular, we want to approach this subject from the angle of theologian, who is called to identify the negative effects of the Internet, when these appear on adolescent user, but continuously he/she will be able to help overcome and deal them.
Tuning the mode-splitting of a semiconductor microcavity with uniaxial stress
Creators: name: Tomm, Natasha
name: Korsch, Alexander R.
name: Javadi, Alisa
name: Najer, Daniel
name: Schott, Rüdiger
name: Valentin, Sascha R.
name: Wieck, Andreas D.
name: Ludwig, Arne
name: Warburton, Richard J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Applied Physics (physics.app-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A splitting of the fundamental optical modes in micro/nano-cavities comprising semiconductor heterostructures is commonly observed. Given that this splitting plays an important role for the light-matter interaction and hence quantum technology applications, a method for controlling the mode-splitting is important. In this work we use an open microcavity composed of a "bottom" semiconductor distributed Bragg reflector (DBR) incorporating an n-i-p heterostructure, paired with a "top" curved dielectric DBR. We measure the mode-splitting as a function of wavelength across the stopband. We demonstrate a reversible in-situ technique to tune the mode-splitting by applying uniaxial stress to the semiconductor DBR. The method exploits the photoelastic effect of the semiconductor materials. We achieve a maximum tuning of $\sim$11 GHz. The stress applied to the heterostructure is determined by observing the photoluminescence of quantum dots embedded in the sample, converting a spectral shift to a stress via deformation potentials. A thorough study of the mode-splitting and its tuning across the stop-band leads to a quantitative understanding of the mechanism behind the results.
description: 7 pages, 5 figures
The dynamics of condensate shells: collective modes and expansion
Creators: name: Lannert, C.
name: Wei, T. -C.
name: Vishveshwara, S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We explore the physics of three-dimensional shell-shaped condensates, relevant to cold atoms in "bubble traps" and to Mott insulator-superfluid systems in optical lattices. We study the ground state of the condensate wavefunction, spherically-symmetric collective modes, and expansion properties of such a shell using a combination of analytical and numerical techniques. We find two breathing-type modes with frequencies that are distinct from that of the filled spherical condensate. Upon trap release and subsequent expansion, we find that the system displays self-interference fringes. We estimate characteristic time scales, degree of mass accumulation, three-body loss, and kinetic energy release during expansion for a typical system of Rb87.
On a Norm Compression Inequality for 2XN Partitioned Block Matrices
Creators: name: Audenaert, Koenraad M. R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 15A60

description: We conjecture the following so-called norm compression inequality for $2\times N$ partitioned block matrices and the Schatten $p$-norms: for $p\ge 2$, $$ ||({array}{cccc} A_1 & A_2 & ... & A_N B_1 & B_2 & >... & B_N {array})||_p \le ||({array}{cccc} ||A_1||_p & ||A_2||_p & ... & ||A_N||_p \ ||B_1||_p & ||B_2||_p & ... & ||B_N||_p {array})||_p $$ while for $1\le p\le 2$ the ordering of the inequality is reversed. This inequality includes Hanner's inequality for matrices as a special case. We prove several special cases of this inequality and give examples for $3\times 3$ and larger partitionings where it does not hold.
description: 22 pages; mistake in section on duality corrected, additional results added
Χωρικός Μουσειολογικός Σχεδιασμός και Προγραμματισμός της έκθεσης με τίτλο:ΚΘΒΕ. 1961-2016, 55 χρόνια. Οι άνθρωποι πίσω από την ιστορία
Creators: name: Βασιλειάδου, Άννα Χαράλαμπου
Publisher: name: Aristotle University of Thessaloniki
Year: 2016
Subjects: έκθεση
θέατρο
σχεδιασμός
exhibition
theatre
design

description: Αντικείμενο της Διπλωματικής Εργασίας είναι ο Νοηματικός και Χωρικός Μουσειολογικός Προγραμματισμός και Σχεδιασμός μιας μόνιμης έκθεσης για το Κρατικό Θέατρο Βορείου Ελλάδος. Στόχος της εργασίας είναι η σύνταξη μιας ολοκληρωμένης μελέτης σε επίπεδο Προμελέτης. Όλο το εγχείρημα στηρίζεται στην πρόθεσή μας να συνδέσουμε την ιστορία του ΚΘΒΕ με τους ανθρώπους που βρέθηκαν πίσω από σημαντικές στιγμές στην πορεία της ιστορίας του Θεάτρου. Γίνεται φανερό ότι στα πλαίσια μιας διπλωματικής εργασίας στόχος είναι να παρουσιαστούν προθέσεις και ιδέες, οι οποίες περισσότερο από μία τελική άποψη, αναδεικνύουν μία μουσειολογική πρόταση.
description: The scope of this particular thesis is the Conceptual and Architectural Museological Planning and Design of a permanent exhibition for the National Theatre of Northern Greece. The thesis’ objective is the production of a comprehensive study as a preliminary design. Our venture relies on our intention to connect the history of the NTNG with the individuals that played a significant role throughout the course of the Theatre. It is evident that in the thesis’ framework the aim is to present our intentions as well as our ideas, which designate, not only an aspect on the matter, but also a museological proposition.
description: Σε συνεργασία με το Παιδαγωγικό Τμήμα Δημοτικής Εκπαίδευσης (Πανεπιστήμιο Δυτικής Μακεδονίας)
Magentic Ordering under Hydrostatic Pressure in Doped Spin Gap Systems ACu$_{1-x}$Mg$_x$Cl$_3$: A$=$Tl and K
Creators: name: Ono, T.
name: Imamura, H.
name: Kawakami, J.
name: Goto, K.
name: Tanaka, H.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Magnetic phase transitions under hydrostatic pressures in spin gap systems TlCu$_{0.988}$Mg$_{0.012}$Cl$_3$ and KCu$_{0.973}$Mg$_{0.027}$Cl$_3$ were investigated by magnetization measurements. The present doped systems exhibit impurity-induced magnetic orderings. With increasing pressure, ordering temperature $T_{\rm N}$ increases. With a further increase in pressure, the present systems undergo phase transitions to uniform antiferromagnetic phases due to the closing of the triplet gap in the intact dimers. The crossover from the impurity-induced ordered phase to the uniform antiferromagnetic phase occurs at $P \simeq 1.3$ kbar for TlCu$_{0.988}$Mg$_{0.012}$Cl$_3$.
description: 2 pages, 3 figures, conference proceeding of International Conference on Magnetism
Κοινωνικά κινήματα. Ενεργή διεκδίκηση του δημόσιου (κοινωνικού) χώρου: Η εμπειρία του κινήματος κατά της εξόρυξης χρυσού στη ΒΑ Χαλκιδική (Σκουριές)
Creators: name: Γεωργιάδου, Μαρία Κωνσταντίνου
Publisher: name: Aristotle University of Thessaloniki
Year: 2016
Subjects: Κοινωνικά κινήματα
Μεταλλουργία χρυσού
Δημόσιος χώρος
Social movement
Gold mining
Public Space

description: Στα πλαίσια της παρούσας διπλωματικής εργασίας μελετήθηκαν οι δράσεις, οι πρακτικές και η πολιτική πλαισίωση του κινήματος κατά της εξόρυξης χρυσού στη B.A. Χαλκιδική. Ένα κίνημα που εναντιώθηκε σθεναρά στις επενδυτικές δραστηριότητες της El dorado gold στην περιοχή, επαναδιεκδίκησε το δημόσιο χώρο (πραγματικά -το βουνό- και συμβολικά -το χώρο δράσης των κοινωνικών κινημάτων-) και δημιούργησε ένα σύνολο πολιτικών περιεχομένων. Η μελέτη του κινήματος προσεγγίσθηκε μέσω της προσωπικής εμπλοκής της γράφουσας στις κινηματικές διαδικασίες και η μεθοδολογία που χρησιμοποιήθηκε ήταν αυτή της συμμετοχικής έρευνας-δράσης (RAR). Στην εργασία παρατίθεται αρχειακό υλικό, σημειώσεις από το προσωπικό ημερολόγιο της γράφουσας, κείμενα τον επιτροπών αγώνα που συμμετέχουν στο κίνημα κατά της εξόρυξης, υλικό από έντυπο και ηλεκτρονικό τύπο. Στα πλαίσια επίσης της εν λόγω εργασίας μελετήθηκαν και παρατίθενται τα ιδοποιά χαρακτηριστικά των νέων κοινωνικών κινημάτων, αυτών δηλαδή που παρουσιάστηκαν από το Μάη του 68 και έπειτα και φαίνεται να εμπεριέχουν κάποια καινούρια νοήματα και στόχους που τα διαφοροποιούν από παλαιότερες κινηματικές διαδικασίες.
description: The actions, practices and political framework of the social movement against gold mining in B.A. Chalkidiki were studied as part of this thesis. This movement strongly opposed the investment activities of El Dorado gold in the area, reclaimed public space (both practically -the mountain itself- and symbolically -the social and political space of the movement-) and through this activity created a new set of political meaning. The study was approached through personal involvement in various facets of the movement and its processes and use of participative research-action (PAR). Resources utilized include listed archives, notes from author’s participation diary, texts written of struggle committees, articles from print and electronic media. The characteristics of the ‘new social movements’ starting from May 1968 were also studied and cited, those which seemed to contain some new meanings and goals that differentiate them from older movements.
Double superconducting dome and triple enhancement of Tc in the kagome superconductor CsV3Sb5 under high pressure
Creators: name: Chen, K. Y.
name: Wang, N. N.
name: Yin, Q. W.
name: Tu, Z. J.
name: Gong, C. S.
name: Sun, J. P.
name: Lei, H. C.
name: Uwatoko, Y.
name: Cheng, J. -G.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: CsV3Sb5 is a newly discovered Z2 topological kagome metal showing the coexistence of a charge density wave (CDW)-like order at T* = 94 K and superconductivity (SC) at Tc = 2.5 K at ambient pressure. Here we study the interplay between CDW and SC in CsV3Sb5 via measurements of resistivity and magnetic susceptibility under hydrostatic pressures. We find that the CDW transition decreases with pressure and experience a subtle modification at Pc1 = 0.6-0.9 GPa before it vanishes completely at Pc2 = 2 GPa. Correspondingly, Tc(P) displays an unusual M-shaped double dome character with two maxima around Pc1 and Pc2, respectively, leading to a tripled enhancement of Tc to about 8 K at 2 GPa. The obtained temperature-pressure phase diagram resembles those of many unconventional superconductors, illustrating an intimated competition between CDW-like order and SC. The competition is found to be particularly strong for the intermediate pressure range Pc1 <= P <= Pc2 as evidenced by the broad superconducting transition and reduced superconducting volume fraction. This work not only demonstrates the potential to raise the Tc of the V-based kagome superconductors, but also offers more insights into the rich physics related to the electronic correlations in this novel family of topological kagome metals.
Equatorial photon motion in the Kerr-Newman spacetimes with a non-zero cosmological constant
Creators: name: Stuchlík, Zdeněk
name: Hledík, Stanislav
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Discussion of the equatorial photon motion in Kerr-Newman black-hole and naked-singularity spacetimes with a non-zero cosmological constant is presented. Both repulsive and attractive cosmological constants are considered. Circular photon orbits are determined, and their stability is established. The spacetimes are divided into separated classes according to the properties of the `effective potential'. There is a special class of Kerr-Newman-de Sitter black-hole spacetimes with so-called `restricted repulsive barrier'. Further, the azimuthal motion is discussed and photon trajectories are given in typical situations. It is shown that for some photons with negative impact parameter turning points of their azimuthal motion can exist.
description: 37 pages, 17 figures
Quantized Nonlinear Thouless Pumping
Creators: name: Jürgensen, Marius
name: Mukherjee, Sebabrata
name: Rechtsman, Mikael C.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Other Condensed Matter (cond-mat.other)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The sharply quantized transport observed in the integer quantum Hall effect can be explained via a simple one-dimensional model with a time-periodic, adiabatically varying potential in which electronic charge is pumped from one side of the system to the other. This so-called `Thouless pump' captures the topological physics of the quantum Hall effect using the notion of dimensional reduction: The time-varying potential mathematically maps onto a momentum coordinate in a conceptual second dimension. Importantly, this assumes an electronic system in equilibrium and in its ground state, that is, with uniformly filled bands below a Fermi energy. Here, we theoretically propose and experimentally demonstrate quantized nonlinear Thouless pumping of photons with a band that is decidedly not uniformly occupied. In our system, nonlinearity acts to quantize transport via soliton formation and spontaneous symmetry breaking bifurcations. Quantization follows from the fact that the instantaneous soliton solutions centered upon a given unit cell are identical after each pump cycle, up to translation invariance; this is an entirely different mechanism from traditional Thouless pumping of fermions in equilibrium. Our result shows that nonlinearity and interparticle interactions can induce quantized transport and topological behavior even where the linear limit does not.