cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Spontaneous parity breaking of graphene in the quantum Hall regime
Creators: name: Fuchs, Jean-Noël
name: Lederer, Pascal
Publisher: name: arXiv
Year: 2006
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We propose that the inversion symmetry of the graphene honeycomb lattice is spontaneously broken via a magnetic field dependent Peierls distortion. This leads to valley splitting of the $n=0$ Landau level but not of the other Landau levels. Compared to quantum Hall valley ferromagnetism recently discussed in the literature, lattice distortion provides an alternative explanation to all the currently observed quantum Hall plateaus in graphene.
description: 4 pages, to appear in Phys. Rev. Lett
Small noise asymptotic of the timing jitter in soliton transmission
Creators: name: Debussche, Arnaud
name: Gautier, Eric
Publisher: name: arXiv
Year: 2006
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60F10, 60H15 (Primary); 35Q55 (Secondary)

description: We consider the problem of the error in soliton transmission in long-haul optical fibers caused by the spontaneous emission of noise inherent to amplification. We study two types of noises driving the stochastic focusing cubic one dimensional nonlinear Schrödinger equation which appears in physics in that context. We focus on the fluctuations of the mass and arrival time or timing jitter. We give the small noise asymptotic of the tails of these two quantities for the two types of noises. We are then able to prove several results from physics among which the Gordon--Haus effect which states that the fluctuation of the arrival time is a much more limiting factor than the fluctuation of the mass. The physical results had been obtained with arguments difficult to fully justify mathematically.
description: Published in at http://dx.doi.org/10.1214/07-AAP449 the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Contextuality, decoherence and quantum trajectories
Creators: name: Sanz, A. S.
name: Borondo, F.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Here we analyze the relationship between quantum contextuality and decoherence in interference experiments with matter particles by means of a simple reduced quantum-trajectory model, which attempts to simulate the behavior of the projections of multi-dimensional, system-plus-environment Bohmian trajectories onto the subspace of the reduced system. This model allows us to understand the crossing of the subsystem trajectories as a combined effect of interference quenching and erasure of ``which-way'' information, which can be of utility to interpret decoherence effects in many-dimensional systems where full Bohmian treatments become prohibitive computationally.
description: 15 pages, 3 figures
Severed texts : aspects of aestheticization in Roland Barthes’ post-structural writings
Creators: name: Blais, Joann M.
Publisher: name: University of British Columbia
Year: 2008

description: This thesis contributes to a discussion of the specificity of Roland Barthes' post-structural theorizing by examining some of the themes and techniques of aestheticization running through his writing--reverie, pleasure, "perversion," and the hyper-textualization of the human subject and culture. Following this thread/hypothesis of aestheticization, the thesis focuses upon changing notions of the human subject and textuality presented in Barthes' writings from "The Death of the Author" (1968) until Camera Lucida (1980). The opening chapter discusses aestheticizing and decadent discourses in nineteenth century French and English literary traditions, identifies relevant intertexts, and proposes a set of key themes in aestheticizing discourses--the rejection of the natural, the quest for separation and mediation expressed in a valorization of artifice, aesthetic pleasure, private experience, and anti-utilitarian, anti-bourgeois values. The second chapter lays out the myth of an alienated literary modernity underwriting Barthes' later theorizing. Subsequent chapters follow shifts in notions of subjectivity, textuality, and aestheticizing strategies in most of the major texts produced by Barthes during this period: S/Z, The Empire of Signs, Pleasure of the Text, Roland Barthes, Fragments of a Lover's Discourse, Camera Lucida, and essays collected in The Rustle of Language and The Responsibility of Forms. The last two chapters follow Barthes' half-ludic struggle with his earlier construction of the subject as public intertext. He dramatically moves away from conventional forms of theorizing into the cultivation of subjectivity, affectivity, and personal culture to escape being captured in the public texts of the cultural Imaginary. Finally, the thesis will consider some of the contributions and consequences of his theories, including whether the cultural skepticism and pose of fatal belatedness underwriting his positions can be maintained.
Disordered locality in loop quantum gravity states
Creators: name: Markopoulou, Fotini
name: Smolin, Lee
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We show that loop quantum gravity suffers from a potential problem with non-locality, coming from a mismatch between micro-locality, as defined by the combinatorial structures of their microscopic states, and macro-locality, defined by the metric which emerges from the low energy limit. As a result, the low energy limit may suffer from a disordered locality characterized by identifications of far away points. We argue that if such defects in locality are rare enough they will be difficult to detect.
description: 11 pages, 4 figures, revision with extended discussion of results
The cosmological behavior of Bekenstein's modified theory of gravity
Creators: name: Bourliot, F.
name: Ferreira, P. G.
name: Mota, D. F.
name: Skordis, C.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We study the background cosmology governed by the Tensor-Vector-Scalar theory of gravity proposed by Bekenstein. We consider a broad family of potentials that lead to modified gravity and calculate the evolution of the field variables both numerically and analytically. We find a range of possible behaviors, from scaling to the late time domination of either the additional gravitational degrees of freedom or the background fluid.
description: 10 pages, 8 figures, A few typos corrected in the text and figures. Version published in PRD
Επιχειρηματικό Πλάνο για Εταιρείες Ανοικτού Λογισμικού
Creators: name: Ζιώγας, Αγγελος Γεωργίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2016
Subjects: Ελεύθερο Λογισμικό
Λογισμικό Ανοικτού Κώδικα
Υπηρεσίες Πληροφορικής
Free Software
Open Source Software
IT Services

description: Βασικός σκοπός της παρούσας διπλωματικής είναι η σύνταξη επιχειρηματικού πλάνου για νεοφυείς εταιρείες που θα προσφέρουν υπηρεσίες πληροφορικής σε Ελεύθερα Λογισμικά/Λογισμικά Ανοικτού Κώδικα στην Ελληνική αγορά. Αρχικά, περιγράφονται τα χαρακτηριστικά, τα πλεονεκτήματα και τα προβλήματα αυτών των λογισμικών. Στη συνέχεια, αναφέρονται τα χαρακτηριστικά και τα πλεονεκτήματα των Συστημάτων Διαχείρισης Επιχειρησιακών Πόρων και των Συστημάτων Διαχείρισης Πελατειακών Σχέσεων. Επιπρόσθετα, πραγματοποιείται η κατηγοριοποίηση του κλάδου Τεχνολογίας Πληροφοριών και Επικοινωνίας και γίνεται αναφορά στις υπηρεσίες πληροφορικής. Στην πορεία, διερευνώνται, μέσα από εμπειρική έρευνα, πιθανές ελλείψεις στην Ελλάδα σε παρεχόμενες υπηρεσίες και λογισμικά ανοικτού κώδικα σε σύγκριση με το εξωτερικό. Επίσης, γίνεται αναφορά στα χαρακτηριστικά και τις εκδόσεις του λογισμικού Odoo και τέλος συντάσσονται δύο επιχειρηματικά πλάνα για νεοφυείς εταιρείες παροχής υπηρεσιών σε λογισμικά ανοικτού κώδικα.
description: The main objective of this thesis is to draft a business plan for startup companies that will provide IT services to Free Software/Open Source Software in the Greek market. Initially, the features, benefits and disadvantages of these software solutions are described. Subsequently, the features and advantages of Enterprise Resource Planning Systems and Customer Relationship Management Systems are described. Additionally, the categorization of the Information and Communications Technology sector is made and IT services are referred. Potential shortages in Greece over services and open source software compared to abroad are looked into through empirical research and reference is made to the characteristics and versions of the Odoo software. Finally, two business plans for startup service companies in open source software are drafted.
Comment on "New Mean-Field Theory of the tt't"J Model Applied to the High-Tc Superconductors"
Creators: name: Ferraz, Alvaro
name: Kochetov, Evgueny
name: Uchoa, Bruno
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Comment on "New Mean-Field Theory of the tt't"J Model Applied to the High-Tc Superconductors" by T. C. Ribeiro and X.-G. Wen [cond-mat/0410750; Physical Review Letters 95, 057001 (2005)].
description: 1 page
Additional file 3 of Therapeutic potential of an intestinotrophic hormone, glucagon-like peptide 2, for treatment of type 2 short bowel syndrome rats with intestinal bacterial and fungal dysbiosis
Creators: name: Hu, Xiuting
name: Cheng, Wei
name: Fan, Shengxian
name: Huang, Yuhua
name: Chen, Xi
name: Jiang, Zhiwei
name: Wang, Jian
Publisher: name: figshare
Year: 2021
Subjects: subject: Biochemistry
subject: Microbiology
subject: FOS: Biological sciences
subject: Physiology
subject: Pharmacology
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: Cancer

description: Additional file 3:
Muon spin relaxation and rotation study on the solid solution of the two spin-gap systems (CH3)2CHNH3-CuCl3 and (CH3)2CHNH3-CuBr3
Creators: name: Saito, T.
name: Oosawa, A.
name: Goto, T.
name: Suzuki, T.
name: Watanabe, I.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Muon-spin-rotation and relaxation studies have been performed on (CH$_3$)$_2$CHNH$_3$Cu(Cl$_x$Br$_{1-x}$)$_3$ with $x$=0.85 and 0.95, which are solid solutions of the two isomorphic spin-gap systems (CH$_3$)$_2$CHNH$_3$CuCl$_3$ and (CH$_3$)$_2$CHNH$_3$CuBr$_3$ with different spin gaps. The sample with $x$=0.85 showed a clear muon spin rotation under zero-field below $T_{\rm N}$=11.65K, indicating the existence of a long-range antiferromagnetic order. A critical exponent of the hyperfine field was obtained to be $β$=0.33, which agrees with 3D-Ising model. In the other sample with $x$=0.95, an anomalous enhancement of the muon spin relaxation was observed at very low temperatures indicating a critical slowing down due to a magnetic instability of the ground state.
Simulating gas giant exoplanet atmospheres with Exo-FMS: Comparing semi-grey, picket fence and correlated-k radiative-transfer schemes
Creators: name: Lee, Elspeth K. H.
name: Parmentier, Vivien
name: Hammond, Mark
name: Grimm, Simon L.
name: Kitzmann, Daniel
name: Tan, Xianyu
name: Tsai, Shang-Min
name: Pierrehumbert, Raymond T.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Radiative-transfer (RT) is a fundamental part of modelling exoplanet atmospheres with general circulation models (GCMs). An accurate RT scheme is required for estimates of the atmospheric energy transport and for gaining physical insight from model spectra. We implement three RT schemes for Exo-FMS: semi-grey, non-grey `picket fence', and real gas with correlated-k. We benchmark the Exo-FMS GCM using these RT schemes to hot Jupiter simulation results from the literature. We perform a HD 209458b-like simulation with the three schemes and compare their results. These simulations are then post-processed to compare their observable differences. The semi-grey scheme results show qualitative agreement with previous studies in line with variations seen between GCM models. The real gas model reproduces well the temperature and dynamical structures from other studies. After post-processing our non-grey picket fence scheme compares very favourably with the real gas model, producing similar transmission spectra, emission spectra and phase curve behaviours. Exo-FMS is able to reliably reproduce the essential features of contemporary GCM models in the hot gas giant regime. Our results suggest the picket fence approach offers a simple way to improve upon RT realism beyond semi-grey schemes.
description: MNRAS accepted 22 June 2021 - V2, typos fixed
Ferroelectric polarization flop in a frustrated magnet MnWO$_4$ induced by magnetic fields
Creators: name: Taniguchi, K.
name: Abe, N.
name: Takenobu, T.
name: Iwasa, Y.
name: Arima, T.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The relationship between magnetic order and ferroelectric properties has been investigated for MnWO$_4$ with long-wavelength magnetic structure. Spontaneous electric polarization is observed in an elliptical spiral spin phase. The magnetic-field dependence of electric polarization indicates that the noncollinear spin configuration plays a key role for the appearance of ferroelectric phase. An electric polarization flop from the b direction to the a direction has been observed when a magnetic field above 10T is applied along the b axis. This result demonstrates that an electric polarization flop can be induced by a magnetic field in a simple system without rare-earth f-moments.
description: 9 pages, 4 figures
The nature and role of oxidation state dependent conformational differences in cytochrome c
Creators: name: Berghuis, Albert M.
Publisher: name: University of British Columbia
Year: 2008

description: The objective of the work described in this thesis was to study the nature and role of conformational differences between the oxidation states of cytochrome c. Using x-ray crystallographic techniques, the oxidized form of yeast iso-l-cytochrome c was solved and compared to the previously determined reduced state. The following differences between the oxidation states were identified. Three segments of polypeptide chain, located for the most part on the Met80 side of the protein, were shown to display an increase in mobility in the oxidized state. A conserved internal water molecule, Wat166, was observed to shift 1.7 A towards the heme iron atom and reorient its dipole moment in the oxidized state. As part of this movement several hydrogen bonds were broken including the interaction between Tyr67 OH and the Met80 SD heme ligand. Finally, differences between the two oxidation states were also observed for the conformation of the pyrrole A propionate and its associated hydrogen bond network, the distortion of the porphyrin ring plane, and the orientation of the imidazole plane of the His18 ligand. In order to assess the function of the observed conformational differences between the two oxidation states of cytochrome c, the three dimensional structures of five mutants (N52A, N521,Y67F, N52I-Y67F and 175M) were determined, of which three were completed in both oxidation states. Correlation of wild-type and variant protein structures with functional studies suggested that Wat166 was a central feature in oxidation state dependent differences, and three roles for this water molecule could be identified. First, the oxidation state dependent positioning and orientation of Wat166 appears to be particularly important for modulating the interaction between Tyr67 OH and Met80 SD. This hydrogen bond was shown to influence the electron withdrawing power of the Met80 ligand and therefore is a factor in controlling the midpoint reduction potential of cytochrome c. Secondly, the presence of Wat166 is necessary to maintain the spatial and hydrogen bonding relationships between residues in this region of the protein. Finally, Wat166 also appears to mediate the oxidation state dependent flexibility of selected polypeptide chain segments. The biological function of this phenomenon is still unclear, but our results suggest that it might play a role in interactions between cytochrome c and its redox partners. In conclusion, the work described in this thesis gives insight into the structure-function relationships in cytochrome c and provides a basis for future studies aimed at understanding the mechanism of electron transfer carried out by this protein.
Vacuum instability in time-dependent electric fields. New example of exactly solvable case
Creators: name: Breev, A. I.
name: Gavrilov, S. P.
name: Gitman, D. M.
name: Shishmarev, A. A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A new exactly solvable case in strong-field quantum electrodynamics with a time-dependent external electric field is presented. The corresponding field is given by an analytic function, which is asymmetric (in contrast to Sauter-like electric field) with respect to the time instant, where it reaches its maximum value, that is why we call it the analytic asymmetric electric field. We managed to exactly solve the Dirac equation with such a field, which made it possible to calculate characteristics of the corresponding vacuum instability nonperturbatively. We construct the so-called in- and out-solutions and with their help calculate mean differential and total numbers of created charged particles, probability of the vacuum to remain a vacuum, vacuum mean values of current density and energy-momentum tensor of the particles. We study the vacuum instability in regimes of rapidly and slowly changing analytic asymmetric electric field, and compare the obtained results with corresponding ones obtained earlier for the case of the symmetric Sauter-like electric field. We also compare exact results in the regime of slowly changing field with corresponding results obtained within the slowly varying field approximation recently proposed by two of the authors, thus demonstrating the effectiveness of such an approximation.
description: 27 pages, 7 figures, some minor changes introduced
Green Function Method for Nonlinear Systems
Creators: name: Frasca, Marco
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We show that a Green function solution can be given for a class of non-homogeneous nonlinear systems having relevance in quantum field theory. This in turn means that a quantum field theory in the strong coupling limit can be formulated and the spectrum obtained.
description: 5 pages, 3 figures. Corrected typos. Accepted for publication in Modern Physics Letters A
Οικονομετρική ανάλυση της μεταβλητότητας και των συσχετίσεων των αναδυόμενων κεφαλαιαγορών της Λατινικής Αμερικής
Creators: name: Ανδρέου, Αλέξανδρος Χριστάκη
Publisher: name: Aristotle University of Thessaloniki
Year: 2016
Subjects: Αναδυόμενες κεφαλαιαγορές
Οικονομετρική ανάλυση DCC-GARCH
Λατινική Αμερική
Emerging markets
DCC-GARCH model econometric analysis
Latin America

description: Η χρηματοπιστωτική κρίση του 2007 αποτέλεσε αντικείμενο μελέτης για πολλούς ερευνητές, όσον αφορά τη μετάδοσή της στον υπόλοιπο κόσμο. Ιδιαίτερο ενδιαφέρον αποτελεί η μετάδοσή της στις αναδυόμενες κεφαλαιαγορές που απασχολούν τους επενδυτές με τη συμπεριφορά τους. Η παρούσα εργασία επικεντρώνεται στις κεφαλαιαγορές της Λατινικής Αμερικής και μελετά την εξέλιξη της μεταβλητότητάς των αποδόσεων των αντίστοιχων δεικτών κατά την περίοδο 1/1/2008-1/10/2015, καθώς και τη συσχέτιση τους με τον αμερικανικό δείκτη S&P 500. Η ίδια ανάλυση γίνεται και μεταξύ των αποδόσεων των MSCI δεικτών, των χωρών αυτών, με τον αμερικανικό δείκτη. Τα αποτελέσματα που προέκυψαν από το υπόδειγμα του εκθετικού σταθμισμένου κινητού μέσου (EWMA) και από το μοντέλο DCC-GARCH δείχνουν την αλληλεξάρτηση μεταξύ των γενικών δεικτών με τον S&P 500 και δεν επιβεβαιώνουν την υπόθεση για μετάδοση της κρίσης. Το αντίθετο προκύπτει μεταξύ των MSCI δεικτών της Λατινικής Αμερικής με τον αμερικανικό δείκτη. Τα αποτελέσματα μπορούν να ληφθούν υπόψη από τους επενδυτές για τη διαμόρφωση των χαρτοφυλακίων τους και να αποτελέσουν αντικείμενο για περαιτέρω ανάλυση με πιο εξελιγμένες μεθόδους.
description: This thesis empirically investigates the contagion effect of global financial crisis to the emerging markets in Latin America and specifically to Brazil, Chile and Mexico. The study contains analysis of the volatilities and correlations of these countries during the period 1/1/2008-1/10/2015. The results are arisen by comparing the general stock indexes of emerging markets with the S&P 500 American index and by comparing the MSCI emerging markets’ indexes with the S&P 500. Both the results of econometric DCC-GARCH model and the exponentially weighted moving average (EWMA) model showed a continued correlation between the general indexes and the S&P 500, which does not confirm the contagion effect but the existence of connection and inderdependence. The opposite results occurred between the MSCI and American index. During the period of crisis the correlations increased rapidly and after 2011 they returned to negative pro-crisis levels, confirming the contagion effect to emerging markets of Latin America. These findings could be taken into consideration by the investors who aim to the effective portfolio through the risk diversification.
Shape invariance approach to exact solutions of the Klein-Gordon equation
Creators: name: Jana, T.
name: Roy, P.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Using the shape invariance property we obtain exact solutions of the (1+1)dimensional Klein-Gordon equation for certain types of scalar and vector potentials. We also discuss the possibility of obtaining real energy spectrum with non-Hermitian interaction within this framework.
Combining Text Mining and Visualization Techniques to Study Teams' Behavioral Processes
Creators: name: Licorish, Sherlock A.
name: MacDonell, Stephen G.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: There is growing interest in mining software repository data to understand, and predict, various aspects of team processes. In particular, text mining and natural-language processing (NLP) techniques have supported such efforts. Visualization may also supplement text mining to reveal unique multi-dimensional insights into software teams' behavioral processes. We demonstrate the utility of combining these approaches in this study. Future application of these methods to the study of teams' behavioral processes offers promise for both research and practice.
description: Conference paper, 6 pages, 3 figures, 1 table
Random Vortex-Street Model for a Self-Similar Plane Turbulent Jet
Creators: name: L'vov, Victor
name: Pomyalov, Anna
name: Procaccia, Itamar
name: Govindarajan, Rama
Publisher: name: arXiv
Year: 2008
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: We ask what determines the (small) angle of turbulent jets. To answer this question we first construct a deterministic vortex-street model representing the large scale structure in a self-similar plane turbulent jet. Without adjustable parameters the model reproduces the mean velocity profiles and the transverse positions of the large scale structures, including their mean sweeping velocities, in a quantitative agreement with experiments. Nevertheless the exact self similar arrangement of the vortices (or any other deterministic model) necessarily leads to a collapse of the jet angle. The observed (small) angle results from a competition between vortex sweeping tending to strongly collapse the jet and randomness in the vortex structure, with the latter resulting in a weak spreading of the jet.
description: 4 pages, 3 figures, submitted to PRL
Solar-like oscillations in open cluster stars
Creators: name: Stello, D.
name: Bruntt, H.
name: Arentoft, T.
name: Gilliland, R. L.
name: Nuspl, J.
name: Kim, S. -L.
name: Kang, Y. B.
name: Koo, J. -R.
name: Lee, J. -A.
name: Lee, C. -U.
name: Sterken, C.
name: Jacob, A. P.
name: Frandsen, S.
name: Dind, Z. E.
name: Jensen, H. R.
name: Szabo, R.
name: Csubry, Z.
name: Kiss, L. L.
name: Bouzid, M. Y.
name: Dall, T. H.
name: Bedding, T. R.
name: Kjeldsen, H.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Asteroseismology of stellar clusters is potentially a powerful tool. The assumption of a common age, distance, and chemical composition provides constraints on each cluster member, which significantly improves the asteroseismic output. Driven by this great potential, we carried out multi-site observations aimed at detecting solar-like oscillations in the red giant stars in the open cluster M67 (NGC 2682) (Stello et al. 2006). Here we present the first analysis of our data, which show evidence of excess power in the Fourier spectra, shifting to lower frequencies for more luminous stars, consistent with expectations from oscillations. If the observed power excesses were due to stellar oscillations, this result would show great prospects for asteroseismology in stellar clusters.
description: 2 pages, 2 figures. Accepted for publication in CoAst
SSHOC D9.1 Challenges that user communities face when attempting to contribute to SSHOC
Creators: name: Van Der Eijk, Cees
Publisher: name: Zenodo
Year: 2019
Subjects: SSHOC
Social Sciences and Humanities Open Cloud
European Open Science Cloud
EOSC
User Communities
Data Communities
SSHOC infrastructure
user communities contributing to SSHOC

description: This report analyses obstacles that user- and data-communities and their members are likely to experience when attempting to engage with, make use of the products and services provided by, and contribute to the evolving EOSC/SSHOC infrastructure. This remit is described in section 1. The report then analyses (in section 2) the concept of user-communities, in order to subsequently distinguish different kinds of user-communities and different kinds of members. The reason for these distinctions is that the kinds of obstacles to be experienced cannot be expected to be uniform, but to vary because of the characteristics of communities and members. With respect to user-communities an important difference is whether they are included in the SSHOC Consortium (many SSH user communities are not, or not yet, yet SSHOC aspires to be also relevant for them). Additional differences relate to their organisational strength. With respect to members of user communities, the most relevant distinction is between ‘leading’ members (who occupy a role or position in the organisations of user communities) and ‘regular’ members. The report then distinguishes (in section 3) different ways in which user-communities and their members can interact with the evolving EOSC/SSHOC infrastructure, and describes three of such ways: ‘engaging with’ (mainly in the form of attentiveness), which is seen as a first step towards ‘using’ (which consists of drawing on the infrastructure to acquire data, tools, and other products and services for use in research). The third way of interaction consists of ‘contributing to’ (which involves making one’s own research, its data, tools, outcomes and publications available to others via the EOSC/SSHOC infrastructure). In section 4 a bounded rationality perspective and a socialisation perspective are used to analyse factors that create obstacles for user-communities and their members to productively interact with the EOSC/SSHOC infrastructure. This results in the identification of the following four generic obstacles: (1) unfamiliarity; (2) expense (in terms of money, time, attention and training); (3) low priority (as a consequence of opportunity costs); and (4) inability (in the form of insufficient relevant skills and competence). Section 5 discusses how each of these obstacles impinges on different kinds of user-communities and different kinds of their members, a discussion that is summarised in the form of low, medium or high relevance of each of the four identified obstacles for the various kinds of user-communities and members that were distinguished earlier, in section 2.
description: This deliverable has been accepted by the European Commission on - 03 November 2020
Έρευνα για την απόσταση περπατήματος προς στάσεις λεωφορείων: Η περίπτωση του φοιτητικού πληθυσμού του Α.Π.Θ.
Creators: name: Τσιουλάνος, Χρήστος Απόστολου
Publisher: name: Aristotle University of Thessaloniki
Year: 2016
Subjects: Απόσταση περπατήματος προς στάσεις λεωφορείων
Περιγραφική στατιστική
Επαγωγική στατιστική
Walking distance to bus stops
Descriptive statistics
Inferential statistics

description: Ο γενικός στόχος της Μεταπτυχιακής Διπλωματικής Εργασίας είναι να προσδιοριστεί η επιθυμητή απόσταση περπατήματος προς στάσεις λεωφορείων με αναφορά στον φοιτητικό πληθυσμό του Α.Π.Θ. Η προσέγγιση του θέματος έγινε μέσω της υλοποίησης έρευνας ερωτηματολογίων. Η ανάλυση των ερωτηματολογίων έγινε με όρους περιγραφικής και επαγωγικής στατιστικής. Η Μεταπτυχιακή Διπλωματική Εργασία αποτελείται από έξι κεφάλαια. Το Πρώτο Κεφάλαιο περιλαμβάνει τον στόχο, την μεθοδολογία και την δομή του τεύχους. Το Δεύτερο Κεφάλαιο περιλαμβάνει τα αφορούντα στην προσέγγιση του θέματος μέσα από την βιβλιογραφία καθώς και τις μελέτες εφαρμογής όπου παρουσιάζονται παραδείγματα για διάφορες χώρες. Το τρίτο κεφάλαιο αφορά στον σχεδιασμό και στον τρόπο υλοποίησης της έρευνας ερωτηματολογίου. Το Τέταρτο και το Πέμπτο Κεφάλαιο περιλαμβάνει την ανάλυση των αποτελεσμάτων της Μεταπτυχιακής Διπλωματικής Εργασίας με όρους περιγραφικής και επαγωγικής στατιστικής αντίστοιχα. Η Μεταπτυχιακή Διπλωματική Εργασία ολοκληρώνεται με το Έκτο Κεφάλαιο όπου παρουσιάζεται η ανασκόπηση της έρευνας και τα αποτελέσματα
description: The overall objective of this Master Thesis is to determine the desired walking distance from bus stops with reference to the students of the Aristotle University of Thessaloniki. The approach of the Thesis was made through the implementation of questionnaire-based survey. The analysis of the questionnaires was done in terms of descriptive and inferential statistics. The Master Thesis consists of six chapters. The first chapter includes the objective, methodology and structure of the Thesis. The second chapter concerns the approach through the literature review and the case studies where examples of different countries are presented. The third chapter covers the design and actualization of the questionnaire-based survey. The Fourth and Fifth Chapter include the analysis of the results of the Thesis in terms of descriptive and inferential statistics respectively. Finally, the Sixth Chapter presents the research results.
The electronic pseudogap in optimally doped NCCO
Creators: name: Sunko, D. K.
name: Barisic, S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We study the effect of antiferromagnetic correlations in the three-band Emery model, in comparison with the experimental angle-resolved photoemission (ARPES) spectra in optimally doped NCCO. The same calculation, formerly used to describe BSCCO, is relevant here, but in contrast to BSCCO, where quantum paramagnon fluctuations are important, the characteristic energy of the dispersive paramagnons in NCCO is of the order of Tc. The wide dispersing features of the single-electron spectrum in NCCO are analogous to the BSCCO hump. The Fermi surface is pseudogapped in both the nodal and antinodal directions, although the detailed features differ, being dominated by loss of intensity in the nodal direction, and loss of coherence in the antinodal one. Direct oxygen-oxygen hopping is important in NCCO as well as in BSCCO, in order to obtain overall agreement with the measured ARPES spectra.
description: Final version as accepted in PRB(RC), one paragraph added, 4 pages, 3 figures
A Compiler Infrastructure for Accelerator Generators
Creators: name: Nigam, Rachit
name: Thomas, Samuel
name: Li, Zhijing
name: Sampson, Adrian
Publisher: name: arXiv
Year: 2021
Subjects: subject: Programming Languages (cs.PL)
subject: Hardware Architecture (cs.AR)
subject: FOS: Computer and information sciences

description: We present Calyx, a new intermediate language (IL) for compiling high-level programs into hardware designs. Calyx combines a hardware-like structural language with a software-like control flow representation with loops and conditionals. This split representation enables a new class of hardware-focused optimizations that require both structural and control flow information which are crucial for high-level programming models for hardware design. The Calyx compiler lowers control flow constructs using finite-state machines and generates synthesizable hardware descriptions. We have implemented Calyx in an optimizing compiler that translates high-level programs to hardware. We demonstrate Calyx using two DSL-to-RTL compilers, a systolic array generator and one for a recent imperative accelerator language, and compare them to equivalent designs generated using high-level synthesis (HLS). The systolic arrays are $4.6\times$ faster and $1.1\times$ larger on average than HLS implementations, and the HLS-like imperative language compiler is within a few factors of a highly optimized commercial HLS toolchain. We also describe three optimizations implemented in the Calyx compiler.
description: To appear at ASPLOS 2021
Translation equivalent elements in free groups
Creators: name: Lee, Donghi
Publisher: name: arXiv
Year: 2006
Subjects: subject: Group Theory (math.GR)
subject: FOS: Mathematics
subject: Primary 20E05, 20E36, 20F10

description: Let F_n be a free group of rank n>1. Two elements g, h in F_n are said to be translation equivalent in F_n if the cyclic length of ϕ(g) equals the cyclic length of ϕ(h) for every automorphism ϕof F_n. Let F(a, b) be the free group generated by {a, b} and let w(a,b) be an arbitrary word in F(a,b). We prove that w(g, h) and w(h, g) are translation equivalent in F_n whenever g, h \in F_n are translation equivalent in F_n, which hereby gives an affirmative solution to problem F38b in the online version (http://www.grouptheory.info) of [1].
description: 7pages
Discussion of "Equi-energy sampler" by Kou, Zhou and Wong
Creators: name: Atchadé, Yves F.
name: Liu, Jun S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics

description: We congratulate Samuel Kou, Qing Zhou and Wing Wong [math.ST/0507080] (referred to subsequently as KZW) for this beautifully written paper, which opens a new direction in Monte Carlo computation. This discussion has two parts. First, we describe a very closely related method, multicanonical sampling (MCS), and report a simulation example that compares the equi-energy (EE) sampler with MCS. Overall, we found the two algorithms to be of comparable efficiency for the simulation problem considered. In the second part, we develop some additional convergence results for the EE sampler.
description: Published at http://dx.doi.org/10.1214/009053606000000489 in the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Inference and Optimization of Real Edges on Sparse Graphs - A Statistical Physics Perspective
Creators: name: Wong, K. Y. Michael
name: Saad, D.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Inference and optimization of real-value edge variables in sparse graphs are studied using the Bethe approximation and replica method of statistical physics. Equilibrium states of general energy functions involving a large set of real edge-variables that interact at the network nodes are obtained in various cases. When applied to the representative problem of network resource allocation, efficient distributed algorithms are also devised. Scaling properties with respect to the network connectivity and the resource availability are found, and links to probabilistic Bayesian approximation methods are established. Different cost measures are considered and algorithmic solutions in the various cases are devised and examined numerically. Simulation results are in full agreement with the theory.
description: 21 pages, 10 figures, major changes: Sections IV to VII updated, Figs. 1 to 3 replaced
Expression of leukocyte-endothelial adhesion molecules during acute inflammation in the lung
Creators: name: Burns, Alan R.
Publisher: name: University of British Columbia
Year: 2008

description: Neutrophil (PMN)-endothelial cell adhesion is a critical step in the response of PMNsto inflammation. In the systemic circulation, the leukocyte adhesion molecule, L-selectin, facilitates PMN adhesion to inflamed endothelium while CD11/CD18 is required for PMN emigration into extravascular tissues. An inducible endothelial ligand for CD18 is intercellular adhesion molecule-1 (ICAM-1). In the pulmonary circulation, PMNs emigrate by either a CD 18-independent or CD 18-dependent mechanism. The objective of this thesis was to quantitate and compare the surface expression of L-selectin, CD 18, and ICAM-1 during CD18-independent and CD 18-dependent emigration. Rabbits and mice received airway instillates of Streptococcus pneumoniae or Escherichia coil endotoxin to induce CD 18-independent or CD18-dependent emigration, respectively. Ultra thin cryosections of frozen lung were immunogold labeled for L-selectin, CD 18, and ICAM-1. Gold particles on the plasma membranes were quantitated by transmission electron microscopy. In rabbits, CD 18-independent emigration was associated with L-selectin down modulation and CD18 up modulation on intravascular PMNs.A similar alteration of L-selectin and CD18 expression was observed during CD 18-dependent emigration but only after PMNs emigrated into the interstitium. Alterations in L-selectin and CD18 expression were only observed on PMNs within the inflammatory focus. In mice, capillary endothelial ICAM-1 expression was unchanged during CD 18-independent emigration. During CD 18-dependent emigration, ICAM-1 expression increased 4.2-fold and this increase bordered on statistical significance, suggesting that the mechanism of adhesion may be regulated by the expression of endothelial rather than PMN adhesion molecules. ICAM-1 was also constitutively expressed on alveolar Type I but not Type II pneumocytes, the precursors of Type I cells. During pneumonia, Type II but not Type I pneumocytes showed increasedICAM-1 expression, suggesting that ICAM-1 expression represents an early event in differentiation preceding proliferation. In vitro studies of unstimulated human PMNs showed that L-selectin was preferentially expressed on the PMN surface microvilli that mediate initial contact with endothelium. During transendothelial migration, L-selectin down modulation is temporally correlated with PMN-endothelial contact. These studies describe the ultrastructural localization of adhesion molecules in normal and inflamed lungs and increase our understanding of the correlation between expression and function of adhesion molecules.
Τρισδιάστατη αποτύπωση του Ιερού Ναού του Όσιου Δαυίδ Θεσσαλονίκης
Creators: name: Καρούμπης, Ευάγγελος Αντωνίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2016
Subjects: Τρισδιάστατη αποτύπωση
Θεσσαλονίκη
Ιερός Ναός Όσιου Δαυίδ
3D survey
Thessaloniki
Saint David church

description: Ο Ιερός Ναός του Όσιου Δαυίδ γνωστός και με την ονομασία Μονή Λατόμου βρίσκεται στην περιοχή της άνω πόλης και είναι το παλαιότερο χριστιανικό μνημείο της Θεσσαλονίκης. Χρονολογείται στα τέλη του 5ου ή αρχές του 6ου αιώνα. Είναι μοναδικής αρχαιολογικής και ιστορικής αξίας. Στο τετρατοσφαίριο της κόγχης του ιερού βήματος υπάρχει το περίφημο εντοίχειο ψηφιδωτό του «Οράματος του Ιεζεκιήλ» ένα από τα αρχαιότερα ψηφιδωτά της παλαιοχριστιανικής τέχνης και ένα από τα αριστουργήματα της παγκόσμιας τέχνης. Αντικείμενο της παρούσας μεταπτυχιακής διατριβής είναι η τρισδιάστατη αποτύπωση με σαρωτή laser στο Ιερό Ναό του Όσιου Δαυίδ. Παράλληλα γίνεται μία σύντομη αναφορά στο βίο του Αγίου. Επίσης παρουσιάζονται οι μέθοδοι γεωμετρικής τεκμηρίωσης των μνημείων και συγκεκριμένα η μέθοδος της τρισδιάστατης αποτύπωσης, περιγράφοντας τα είδη των σαρωτών, την αρχή λειτουργίας τους, τη μεθοδολογία και την επεξεργασία των μετρήσεων. Μέσα από την περιγραφή όλων των σταδίων της αποτύπωσης του μνημείου αλλά και της επεξεργασίας των δεδομένων γίνεται μια προσπάθεια ανάδειξης των πλεονεκτημάτων και της χρησιμότητας της μεθόδου. Αποτέλεσμα της εν λόγω εργασίας αποτελούν οι ορθοεικόνες των κατόψεων, όψεων, άνοψης και τομών με υπολογισμένα τα σχετικά υψόμετρα και τις διαστάσεις.
description: The sacred temple of Blessed David also known as Latomou Abbey is located in the area of Apper town and it is the oldest Christian monument of Thessaloniki. It is dated back to the end of the fifth or the early sixth century. It's of a unique archaeological and historical value. In the conch of the niche sacred altar, there is the famous mosaic "the vision of Ezekiel", one of the oldest mosaics of early Christian art and one of the worldwide' art, masterpieces. The purpose of the present postgraduate study is the three-dimensional plot with a laser scanner of the sacred temple of Blessed David. At the same time, there is a short report of the Saints' life. In addition, the geometrical documentation methods of the monuments, are presented and specifically the method of the three-dimensional imprinting by describing the different kinds of the scanners, their principle of operation methodology, methodology and the process of the measurements. Through the description of the stages, of the monuments' imprinting, but also through the process of the data, has been an effort of highlighting the benefits and the methods' usefulness. The results of this project are the orthoimage of the floor plans, facades, sections and top view, calculated with the relevant altitudes and dimensions.
Perturbations of the orbital elements due to the magnetic-like part of the field of a plane gravitational wave
Creators: name: Iorio, Lorenzo
name: Ruggiero, Matteo Luca
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We focus on the secular changes of the orbital elements of a planet in the solar system, determined by the magnetic-like part of a gravitational wave field. Using Fermi coordinates we show that the total force acting on a test particle is made of two contributions: a gravito-electric one and a gravito-magnetic one. While the electric-like force has been thoroughly discussed in the past, the effect of the gravito-magnetic force, which depends on the velocity of the test particle, has not been considered yet. We obtain approximated results to some orders in the orbital eccentricity and show that these effects are much smaller than the corresponding gravito-electric ones.
description: 10 pages, to appear in International Journal of Modern Physics D
A New Deep HST/ACS CMD of I Zw 18: Evidence for Red Giant Branch Stars
Creators: name: Aloisi, A.
name: Annibali, F.
name: Mack, J.
name: Tosi, M.
name: van der Marel, R.
name: Clementini, G.
name: Contreras, R.
name: Fiorentino, G.
name: Marconi, M.
name: Musella, I.
name: Saha, A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present results from new deep HST/ACS photometry of I Zw 18, the most metal-poor blue compact dwarf galaxy in the nearby universe. It has been previously argued that this is a very young system that started forming stars only < 500 Myr ago, but other work has hinted that older (> 1 Gyr) red giant branch (RGB) stars may exist in this galaxy. Our deeper data indeed reveal evidence for an RGB. Underlying old (> 1 Gyr) populations are therefore present in even the most metal-poor systems, implying that star formation started at z > 0.1. The RGB tip (TRGB) magnitude and the properties of Cepheid variables identified from our program indicate that I Zw 18 is farther away (D = 19.0 +/- 1.8 Mpc) than previously believed.
description: 4 pages, 2 figures. Typos corrected. Proceedings of the IAU Symp. 241 "Stellar Populations as Building Blocks of Galaxies", held in La Palma in December 2006, eds. R. F. Peletier & A. Vazdekis
Machine learning of mirror skin effects in the presence of disorder
Creators: name: Araki, Hiromu
name: Yoshida, Tsuneya
name: Hatsugai, Yasuhiro
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Non-Hermitian systems with mirror symmetry may exhibit mirror skin effect which is the extreme sensitivity of the spectrum and eigenstates on the boundary condition due to the non-Hermitian topology protected by mirror symmetry. In this paper, we report that the mirror skin effect survives even against disorder which breaks the mirror symmetry. Specifically, we demonstrate the robustness of the skin effect by employing the neural network which systematically predicts the presence/absence of the skin modes, a large number of localized states around the edge. The trained neural network detects skin effects in high accuracy, which allows us to obtain the phase diagram. We also calculate the probability by the neural network for each of states. The above results are also confirmed by calculating the inverse participation ratio.
description: 6 pages, 5 figures