cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
ENERGY & ENVIRONMENTAL POLICY TRENDS OUR PLANET IN 2040: COMPARING WORLD ENERGY OUTLOOKS
Creators: name: Fellows, G. Kent
name: Goodday, Victoria
name: Ladha, Rabia
name: Winter, Jennifer
Publisher: name: The School of Public Policy Publications
Year: 2019

description: Comparing the predictions of the latest world energy reports gives insights into the world’s progress towards limiting greenhouse gas emissions and meeting the goals of the Paris Agreement. It gives an indication of just how close — or far — we might be from keeping global temperature increases below 2°C by 2100.
description: The School of Public Policy Publications, Vol 12 (2019)
The development of a fibreglass cable bolt
Creators: name: Mah, G. Peter
Publisher: name: University of British Columbia
Year: 2009

description: The development of a fibreglass cable bolt (FCB) as an alternative to steel cable bolts has been presented. The primary objective of the investigation was to develop a working FCB prototype that was cuttable and easily installed in hard rock mines. The FCB was required to be cuttable by a continuous road-header without adverse affects to equipment, personnel or processing circuits. POLYSTAL, an advanced composite with a circular profile, has been used to develop the working prototype. The methods o finvestigation, included: over seventy-five (75) laboratory and in situ pull-tests, five (5) preliminary laboratory shear tests, two (2) trial in situ installations and three (3) preliminary flotation tests. Conclusions have been drawn regarding the selection of a cuttable material, failure modes and mechanisms, axial and shear load/displacement behaviours, immediate and potential applications, design guidelines, mineral processing effects, installation costs and future research directions. In general, it has been proven that the FCB exists as a viable alternative to steel for cable bolt reinforcement. However, the FCB does not currently exist as an optimized, or only, composite support alternative to steel. These aspects remain outstanding to the further development of composites for use as cable bolt reinforcement. Control of the composite manufacturing process is crucial to achieve a more economical product in the future.
Simulating relic gravitational waves from inflationary magnetogenesis
Creators: name: Brandenburg, Axel
name: Sharma, Ramkishor
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We present three-dimensional direct numerical simulations of the production of magnetic fields and gravitational waves (GWs) in the early Universe during a low energy scale matter-dominated post-inflationary reheating era, and during the early subsequent radiative era, which is strongly turbulent. The parameters of the model are determined such that it avoids a number of known physical problems and produces magnetic energy densities between 0.2% and 2% of the critical energy density at the end of reheating. During the subsequent development of a turbulent magnetohydrodynamic cascade, magnetic fields and GWs develop a spectrum that extends to higher frequencies in the millihertz (nanohertz) range for models with reheating temperatures of around 100 GeV (150 MeV) at the beginning of the radiation-dominated era. However, even though the turbulent cascade is fully developed, the GW spectrum shows a sharp drop for frequencies above the peak value. This suggests that the turbulence is less efficient in driving GWs than previously thought. The peaks of the resulting GW spectra may well be in the range accessible to space interferometers, pulsar timing arrays, and other facilities.
description: 20 pages, 15 figures, 4 tables, Astrophys. J. 920, 26 (2021)
Atmospheric Circulation of Brown Dwarfs and Directly Imaged Extrasolar Giant Planets Driven by Cloud Radiative Feedback
Creators: name: Tan, Xianyu
Publisher: name: Zenodo
Year: 2021
Subjects: brown dwarfs, giant planets, clouds, global circulation

description: Observations of brown dwarfs (BDs), free-floating planetary-mass objects, and directly imaged extrasolar giant planets (EGPs) exhibit rich evidence of large-scale weather. Understanding the mechanisms driving the atmospheric circulation of BDs and directly imaged EGPs is crucial to interpret the observed lightcurve variability. We proposed a thermally-driven mechanism linked to cloud radiative feedback. In this poster, we introduce the principle of this mechanism and highlight the properties of the resulting circulation patterns. I will show that this mechanism can generate vigorous atmospheric flows, including turbulence, vortices, waves, and zonal jets under certain circumstances. Implications for observations will also be discussed.
Finite Products are Biproducts in a Compact Closed Category
Creators: name: Houston, Robin
Publisher: name: arXiv
Year: 2006
Subjects: subject: Category Theory (math.CT)
subject: FOS: Mathematics
subject: 18D10 (Primary) 18A30, 18D15, 18E05 (Secondary)

description: If a compact closed category has finite products or finite coproducts then it in fact has finite biproducts, and so is semi-additive.
description: 9 pages. Introduction further expanded, minor errors corrected
Once more about gauge invariance in ϕ\toγ\pi0\pi0
Creators: name: Achasov, N. N.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: It is argued that the realization of gauge invariance condition as a consequent of cancellation between the ϕ\toγf0\toγ\pi0\pi0 resonance contribution and a ϕ\toγ\pi0\pi0 background one, suggested in Ref. [1], is misleading.
description: 4 pages, one reference added
Solving the Catalogue Cross-Match Problem in the Era of LSST: The Effect of Unresolved Contaminant Objects and Proper Motions on Photometric Catalogues
Creators: name: Wilson, Tom J
name: Naylor, Tim
Publisher: name: Zenodo
Year: 2021
Subjects: Catalogue cross-matching
Photometric catalogs
Statistical methods
LSST
Rubin Observatory

description: Traditional photometric catalogue matching will fail for Rubin Obs. LSST, as typical 2” error circles will contain up to 10 random objects. Bayesian cross-matching techniques which include the astrometric uncertainty of the observations ultimately assume that the Astrometric Uncertainty Function of the sources is Gaussian, which will not apply to LSST. The extreme source densities and significant number of objects with no known proper motion mean that systematic effects, not noise-based scatter, dominant the separations of objects between LSST and other surveys. As part of the LSST:UK consortium we have developed and are implementing methods to handle these effects, vital to being able to trust any composite dataset created, and will be producing robust cross-matches between LSST and a wide range of other catalogues.
description: {"references": ["Sutherland & Saunders (1992): On the likelihood ratio for source identification.", "Wright et al. (2010): The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance", "Ricker et al. (2015): Transiting Exoplanet Survey Satellite (TESS)", "Wilson & Naylor (2017): The effect of unresolved contaminant stars on the cross-matching of photometric catalogues", "Wilson & Naylor (2018): Improving catalogue matching by supplementing astrometry with additional photometric information", "Wilson & Naylor (2018): A contaminant-free catalogue of Gaia DR2-WISE Galactic plane matches: including the effects of crowding in the cross-matching of photometric catalogues"]}
Semi-Automated Creation of Density Functional Tight Binding Models Through Leveraging Chebyshev Polynomial-based Force Fields
Creators: name: Goldman, Nir
name: Kweon, Kyoung Eun
name: Sadigh, Babak
name: Heo, Tae Wook
name: Lindsey, Rebecca K.
name: Pham, C. Huy
name: Fried, Laurence E.
name: Aradi, Bálint
name: Holliday, Kiel
name: Jeffries, Jason R.
name: Wood, Brandon C.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Density Functional Tight Binding (DFTB) is an attractive method for accelerated quantum simulations of condensed matter due to its enhanced computational efficiency over standard Density Functional Theory approaches. However, DFTB models can be challenging to determine for individual systems of interest, especially for metallic and interfacial systems where different bonding arrangements can lead to significant changes in electronic states. In this regard, we have created a rapid-screening approach for determining systematically improvable DFTB interaction potentials that can yield transferable models for a variety of conditions. Our method leverages a recent reactive molecular dynamics force field where many-body interactions are represented by linear combinations of Chebyshev polynomials. This allows for the efficient creation of multi-center representations with relative ease, requiring only a small investment in initial DFT calculations. We have focused our workflow on TiH$_2$ as a model system and show that a relatively small training set based on unit-cell sized calculations yields a model accurate for both bulk and surface properties. Our approach is easy to implement and can yield accurate DFTB models over a broad range of thermodynamic conditions, where physical and chemical properties can be difficult to interrogate directly and there is historically a significant reliance on theoretical approaches for interpretation and validation of experimental results.
description: 45 pages, 7 tables, 7 figures. New version contains updated figures and light editorial changes. This version has been submitted as a revision to J Chem. Theory Comput
Properties of Open Clusters With Gaia DR2
Creators: name: Monteiro, Hektor
name: Dias, Wilton
Publisher: name: Zenodo
Year: 2021
Subjects: Stellar systems, clusters, and associations

description: Reliable fundamental parameters of open clusters such as distance, age and extinction are key to our understanding of Galactic structure and stellar evolution. In this work we present recent results for open clusters investigated using Gaia DR2 data. Cluster memberships were determined using a maximum likelihood method applied to {\it Gaia} DR2 astrometry as well as from other authors and methods from the literature. This has allowed us to estimate mean proper motions and mean parallaxes for thousands of investigated clusters. Mean radial velocities were also determined for 47% of the clusters, many of which had no previous published values. We have improved our isochrone fitting code to account for interstellar extinction using an updated extinction polynomial for the Gaia DR2 photometric band-passes. A Galactic abundance gradient has also been introduced as a prior for metallicity along with an AV prior based on the 3D structure of the Local Galaxy. The updated procedure was validated with a sample of clusters with high quality [Fe/H] determinations. A critical review of the literature shows that our cluster parameter determinations represent a substantial improvement in fundamental parameter estimates. In this work we present general statistics of the sample such as the distribution of properties relative to height from the Galactic plane.
description: {"references": ["Monteiro H., Dias W. S., Moitinho A., Cantat-Gaudin T., L\u00e9pine J. R. D.,Carraro G., Paunzen E., 2020, MNRAS, 499, 1874", "Dias W. S., Alessi B. S., Moitinho A., L\u00e9pine J. R. D., 2002b, A&A, 389,871", "Kharchenko N. V., Piskunov A. E., Schilbach E., R\u00f6ser S., Scholz R.-D.,2013, A&A, 558, A53", "Gaia Collaboration et al., 2018a, A&A, 616, A1", "Cantat-Gaudin T., et al., 2018, A&A, 618, A93", "Soubiran C., et al., 2018a, A&A, 619, A155", "Bossini D., et al., 2019, A&A, 623, A108", "Carrera R., et al., 2019, A&A, 623, A80", "Liu L., Pang X., 2019, ApJS, 245, 32", "Sim G., Lee S. H., Ann H. B., Kim S., 2019, Journal of Korean Astronomical Society, 52, 145", "Castro-Ginard A., et al., 2020, A&A, 635, A45", "Ferreira F. A., Corradi W. J. B., Maia F. F. S., Angelo M. S., Santos J. F. C.J., 2020, MNRAS, 496, 2021"]}
Διδασκαλία της ποίησης στο Λύκειο με την αξιοποίηση της δημιουργικής γραφής. Μία έρευνα δράσης.
Creators: name: Παπαγεωργίου, Μαρία Ιωάννη
Publisher: name: Aristotle University of Thessaloniki
Year: 2018
Subjects: Δημιουργική γραφή
Διδασκαλία της ποίησης
Παιχνίδι της γραφής
Creative writing
Teaching poetry
Play of writing

description: Η παρούσα έρευνα πρωταρχικό στόχο έχει να καταγράψει τη στάση των μαθητών και των μαθητριών τμήματος της Α΄ τάξης Λυκείου απέναντι στο ποιητικό φαινόμενο αυτό καθεαυτό, αλλά και στη διδασκαλία της ποίησης στο σχολείο. Παράλληλα, επιχειρεί να διερευνήσει μέσα από τις μεθόδους άντλησης ποιοτικού υλικού και τα εργαλεία που προσφέρει η έρευνα δράσης, πιθανή αλλαγή αυτής της στάσης ή μετατόπιση των αρχικών θέσεών τους μετά την ενσωμάτωση της δημιουργικής γραφής στη διδασκαλία της ενότητας «Παράδοση και μοντερνισμός στη νεοελληνική ποίηση». Το παρόν εγχείρημα εστιάζει στην αποκατάσταση της αποσπασματικής και ελλειμματικής σχέσης του μαθητή με την ποίηση, την ποιητική γραφή και ανάγνωση μέσα από τη δημιουργική και βιωματική ανταπόκρισή του απέναντι στην ποιητική δημιουργία βασισμένη στο «παιχνίδι της γραφής». Για τον λόγο αυτό επιλέχθηκαν οι πρακτικές της δημιουργικής γραφής, γιατί, εκτός των άλλων, διαμορφώνουν μέσα στη σχολική τάξη συνθήκες ευχάριστες και προωθούν ένα κλίμα παιγνιώδες που θεωρείται πρόσφορο για την ενεργοποίηση του μαθητή-αναγνώστη και του μαθητή-δημιουργού.
description: The purpose of this study was to investigate tenth grade students' opinions about poetry, and also about the teaching of poetry at school. At the same time, we used tools offered by the action research in order to trace a possible change of their attitude or a possible shifting of their initial opinions after the incorporation of creative writing exercises during the teaching of the module "Tradition and Modernism in Modern Greek Poetry". This study also focused on the restoration of the students' fragmented and deficient relationship with poetry, poetic writing and reading through their creative and experiential response to poetic creation based on the "play of writing". For this reason we chose to implement creative writing practices, because these practices create pleasant conditions in the classroom and promote a playful climate that is considered the most appropriate for the activation of the student as a reader and also as a creator.
Physically Motivated Recursively Embedded Atom Neural Networks: Incorporating Local Completeness and Nonlocality
Creators: name: Zhang, Yaolong
name: Xia, Junfan
name: Jiang, Bin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Recent advances in machine-learned interatomic potentials largely benefit from the atomistic representation and locally invariant many-body descriptors. It was however recently argued that including three- (or even four-) body features is incomplete to distinguish specific local structures. Utilizing an embedded density descriptor made by linear combinations of neighboring atomic orbitals and realizing that each orbital coefficient physically depends on its own local environment, we propose a recursively embedded atom neural network model. We formally prove that this model can efficiently incorporate complete many-body correlations without explicitly computing high-order terms. This model not only successfully addresses challenges regarding local completeness and nonlocality in representative systems, but also provides an easy and general way to update local many-body descriptors to have a message-passing form without changing their basic structures.
description: This work has been published in Phys. Rev. Lett
Perturbative analysis of generally nonlocal spatial optical solitons
Creators: name: Ouyang, Shigen
name: Guo, Qi
name: Hu, Wei
Publisher: name: arXiv
Year: 2006
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: In analogy to a perturbed harmonic oscillator, we calculate the fundamental and some other higher order soliton solutions of the nonlocal nonlinear Schroedinger equation (NNLSE) in the second approximation in the generally nonlocal case. Comparing with numerical simulations we show that soliton solutions in the 2nd approximation can describe the generally nonlocal soliton states of the NNLSE more exactly than that in the zeroth approximation. We show that for the nonlocal case of an exponential-decay type nonlocal response the Gaussian-function-like soliton solutions can't describe the nonlocal soliton states exactly even in the strongly nonlocal case. The properties of such nonlocal solitons are investigated. In the strongly nonlocal limit, the soliton's power and phase constant are both in inverse proportion to the 4th power of its beam width for the nonlocal case of a Gaussian function type nonlocal response, and are both in inverse proportion to the 3th power of its beam width for the nonlocal case of an exponential-decay type nonlocal response.
description: 13 pages, 16 figures, accepted by Phys. Rev. E
Τελεστές Toeplitz στον χώρο Bergman A2(D) του μοναδιαίου δίσκου του μιγαδικού επιπέδου
Creators: name: Σπαθοπούλου, Δήμητρα Αλέξανδρου
Publisher: name: Aristotle University of Thessaloniki
Year: 2018
Subjects: Τελεστές Toeplitz
Χώρος Bergman
Carleson μέτρα
Toeplitz operators
Bergman space
Carleson measure

description: Στόχος της διατριβής ήταν η μελέτη των τελεστών Toeplitz στο χώρο Bergman του μοναδιαίου δίσκου του μιγαδικού επιπέδου. Παραθέσαμε τον ορισμό του χώρου Bergman και συγκεκριμένα εξετάσαμε διεξοδικά τον αναπαράγων πυρήνα του καθώς και την Bergman προβολή. Ένα άλλο θέμα που θίξαμε ήταν να ορίσουμε και να περιγράψουμε τόσο την έννοια του Carleson μέτρου, όσο και του μηδενιζόμενου Carleson μέτρου στον χώρο A2. Στην συνέχεια, παρουσιάσαμε αναλυτικά τον ορισμό του τελεστή Toeplitz στον A2, καθώς και δόθηκαν οι αποδείξεις των θεωρημάτων πότε ο τελεστής Toeplitz είναι φραγμένος, συμπαγής στον χώρο Bergman A2.
description: The goal of the thesis was the study of Toeplitz operators on the Bergman space of the unit disk of complex plane. We mentioned the definition of Bergman space and specifically we examined its reproducing kernel, as well as the Bergman projection. Additional, another issue we examined was to define and describe both the meaning of the Carleson measure and the vanishing Carleson measure on A2. Then, we presented thoroughly the definition of Toeplitz operator on A2 and given the proof of theorems when the Toeplitz operator is bounded, compact on the Bergman space A2 .
Magnetic activity & prominence behaviour of the binary system V471 Tau
Creators: name: Zaire, Bonnie
name: Donati, JF
name: Klein, Baptiste
Publisher: name: Zenodo
Year: 2021
Subjects: Cool Stars on the main sequence
Magnetic fields
Binaries

description: This poster presents the analysis of spectropolarimetric data of the pre-cataclysmic variable binary system V471 Tau obtained with ESPaDOnS at the Canada-France-Hawaii Telescope in two observational campaigns. We show first reconstructions of the large-scale magnetic field of the K2 dwarf, as well as new brightness maps and the amount of differential rotation by which surface maps are sheared. We compare the differential rotation fluctuations obtained for the K2 dwarf with those of the single-star analogue AB Dor. Finally, we argue that a slingshot mechanism likely sustains the prominence observed in 2004.
description: {"references": ["https://doi.org/10.1093/mnras/stz3173", "https://doi.org/10.1046/j.1365-2966.2003.07101.x", "https://doi.org/10.1111/j.1365-2966.2006.10073.x", "https://doi.org/10.1111/j.1365-2966.2006.11154.x"]}
Dynamical conditions and causal transport of dissipative spherical collapse in $f(R,T)$ gravity
Creators: name: Guha, Sarbari
name: Ghosh, Uttaran
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this paper, we have investigated the non-adiabatic spherical gravitational collapse in the framework of the $f(R,T)$ theory of gravity with a locally anisotropic fluid that undergoes dissipation in the form of heat flux, free-streaming radiation, and shearing viscosity. The dynamical equations are analyzed in detail, both in the Newtonian and post-Newtonian regimes. Finally we couple the dynamical equations to the full causal transport equation in the context of Israel-Stewart theory of dissipative systems. This yields us a better understanding of the collapse dynamics and may be connected to various astrophysical consequences.
description: 22 pages, accepted for publication in EPJP
Codeword stabilized quantum codes: algorithm and structure
Creators: name: Chuang, Isaac L.
name: Cross, Andrew W.
name: Smith, Graeme
name: Smolin, John A.
name: Zeng, Bei
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The codeword stabilized ("CWS") quantum codes formalism presents a unifying approach to both additive and nonadditive quantum error-correcting codes (arXiv:0708.1021). This formalism reduces the problem of constructing such quantum codes to finding a binary classical code correcting an error pattern induced by a graph state. Finding such a classical code can be very difficult. Here, we consider an algorithm which maps the search for CWS codes to a problem of identifying maximum cliques in a graph. While solving this problem is in general very hard, we prove three structure theorems which reduce the search space, specifying certain admissible and optimal ((n,K,d)) additive codes. In particular, we find there does not exist any ((7,3,3)) CWS code though the linear programming bound does not rule it out. The complexity of the CWS search algorithm is compared with the contrasting method introduced by Aggarwal and Calderbank (arXiv:cs/0610159).
description: 11 pages, 1 figure
Probing activity and rotation of M dwarfs with X-rays and photometric timeseries
Creators: name: Magaudda Enza
name: Stelzer Beate
name: Raetz Stefanie
Publisher: name: Zenodo
Year: 2021

description: The activity-rotation relation of M dwarfs provides observational evidence of the stellar dynamo, which is poorly understood for fully convective stars. It is known that the X-ray activity-rotation relation has a two-regime behavior with saturation for faster rotating stars and with a Lx decrease for slower rotation. However, the number of M dwarfs with sensitive X-ray and rotation measure- ments has for a long time been very limited. New XMM-Newton, Chandra and eROSITA X-ray observations with K2 mission and TESS rotation periods analyzed in my work have substantially increased the number of low activity and fast/slow rotation stars that have been dicult to assess in the past. Combining the new data with a systematic update and homogenization of the literature data has enabled me to examine the activity-rotation relation in different mass bins within the M dwarf regime. Several interesting findings emerged, including a non-constant Lx-level in the saturated regime and a mass-dependence of the slope in the unsaturated regime.
description: {"references": ["Magaudda et al. 2020, A&A, 638, A20", "Raetz et al. 2020, A&A, 637, A22", "Reiners et al. 2015, ApJ, 794"]}
Έρευνα ως προς τις προτιμήσεις των καταναλωτών στα δημητριακά πρωϊνού
Creators: name: Αθανασίου, Αλεξάνδρα Δημητρίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2018
Subjects: Δημητριακά
Συμπεριφορά καταναλωτή
Εμπορία αγροτικών προϊόντων
Cereals
Consumer behavior
Marketing of agricultural products

description: Σκοπός της παρούσας μεταπτυχιακής διατριβής ήταν να αποτυπώσει τις σύγχρονες αγοραστικές συμπεριφορές των καταναλωτών ως προς τα δημητριακά πρωινού στο πολεοδομικό συγκρότημα της Θεσσαλονίκης. Η μεθοδολογία της βασίζεται σε πρωτογενή στοιχεία τα οποία συλλέχθηκαν με τη βοήθεια ενός πλήρως δομημένου ερωτηματολογίου (σε δείγμα 400 ατόμων) με τη μέθοδο της στρωματοποιημένης τυχαίας δειγματοληψίας (Stratified Random Sampling). Τα αποτελέσματα της έρευνας φανερώνουν σαφής καταναλωτικές τάσεις όσον αφορά τις προτιμήσεις και τα κριτήρια των καταναλωτών για την αγορά δημητριακών πρωινού.
description: The purpose of this postgraduate dissertation was to capture the current consumer purchasing habits of breakfast cereals in Thessaloniki's urban development complex. Its methodology is based on primary data collected with the help of a fully structured questionnaire (in a sample of 400 individuals) using the stratified random sampling method. The results of the survey reveal clear consumer trends in consumer preferences and criteria for buying breakfast cereals.
Boundary time crystals in collective $d$-level systems
Creators: name: Prazeres, Luis Fernando dos
name: Souza, Leonardo da Silva
name: Iemini, Fernando
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Boundary time crystals (BTC's) are non-equilibrium phases of matter occurring in quantum systems in contact to an environment, for which a macroscopic fraction of the many body system breaks time translation symmetry. We study BTC's in collective $d$-level systems, focusing in the cases with $d=2$, $3$ and $4$. We find that BTC's appear in different forms for the different cases. We first consider the model with collective $d=2$-level systems [presented in Phys. Rev. Lett. $121$, $035301$ ($2018$)], whose dynamics is described by a Lindblad master equation, and perform a throughout analysis of its phase diagram and Jacobian stability for different interacting terms in the coherent Hamiltonian. In particular, using perturbation theory for general (non Hermitian) matrices we obtain analytically how a specific $\mathbb{Z}_2$ symmetry breaking Hamiltonian term destroys the BTC phase in the model. Based on these results we define a $d=4$ model composed of a pair of collective $2$-level systems interacting with each other. We show that this model support richer dynamical phases, ranging from limit-cycles, period-doubling bifurcations and a route to chaotic dynamics. The BTC phase is more robust in this case, not annihilated by the former symmetry breaking Hamiltonian terms. The model with collective $d=3$-level systems is defined similarly, as competing pairs of levels, but sharing a common collective level. The dynamics can deviate significantly from the previous cases, supporting phases with the coexistence of multiple limit-cycles, closed orbits and a full degeneracy of zero Lyapunov exponents.
description: 18 pages, 12 figures
Εκπαιδευτική και συλλογική δραστηριότητα στην εκκλησιαστική επαρχία Σερρών κατά το 2ο μισό του 19ο αιώνα και στις αρχές του 20ου αιώνα
Creators: name: Στεφάνου, Πασχάλης Στέφανου
Publisher: name: Aristotle University of Thessaloniki
Year: 2018
Subjects: Εκπαίδευση
Εκκλησιαστική Επαρχία
Σέρρες
Education
Church County
Serres

description: Η εκκλησιαστική επαρχία των Σερρών αποτελούσε μία επαρχία από τις ευρωπαϊκές επαρχίες του Οικουμενικού Πατριαρχείου στο χώρο της Μακεδονίας, με έντονη εκκλησιαστική, εθνική, κοινωνική, πολιτική και οικονομική δραστηριότητα κυρίως κατά τον 19ο αιώνα. Η δραστηριότητα αυτή και η κίνηση αντικατοπτρίζεται χαρακτηριστικά στο χώρο της εκπαίδευσης και των γραμμάτων, καθώς παρατηρείται ιδιαίτερη άνθηση. Έτσι, αφού πρώτα αναφερθούμε στην πολιτική, διοικητική και οικονομική κατάσταση στην εκκλησιαστική επαρχίας Σερρών, στη συνέχεια θα περιγράψουμε αναλυτικά την εκπαιδευτική και συλλογική δραστηριότητα που αναπτύχθηκε στην ίδια περιοχή, με σκοπό να αναζητήσουμε τους παράγοντες που συνέβαλαν στην ανάπτυξη τους, καθώς και αυτούς που λειτούργησαν ανασταλτικά. Επίσης, ιδιαίτερη επισήμανση θα γίνει όσον αφορά το ρόλο της Εκκλησίας στην ανάπτυξη της εκπαίδευσης στις Σέρρες και την υπόλοιπη επαρχία.
description: The church country of serres was part of the European candies of Ecumenical Patriarchate in the area of Macedonia with intense religious, notional, social, political and economic activity mainly during the 19th century. There had been a profound activity on the field of education which was flourishing at that time. First I will analyze the political, administrative and economic situation of the church county of serres and then I will describe analytically the educational and collective activity which was developed in the area aiming to find out the factors which contributed to their growth as well as those which inhibited it. Finally, I will ouscuss the roll of the church in education in the area of serres and in the rest of the country.
Energy-conserving integrator for conservative Hamiltonian systems with ten-dimensional phase space
Creators: name: Hu, Shiyang
name: Wu, Xin
name: Liang, Enwei
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this paper, an implicit nonsymplectic exact energy-preserving integrator is specifically designed for a ten-dimensional phase-space conservative Hamiltonian system with five degrees of freedom. It is based on a suitable discretization-averaging of the Hamiltonian gradient, with a second-order accuracy to numerical solutions. A one-dimensional disordered discrete nonlinear Schrödinger equation and a post-Newtonian Hamiltonian system of spinning compact binaries are taken as our two examples. We demonstrate numerically that the proposed algorithm exhibits good long-term performance in the preservation of energy, if roundoff errors are neglected. This result is independent of time steps, initial orbital eccentricities, and regular and chaotic orbital dynamical behavior. In particular, the application of appropriately large time steps to the new algorithm is helpful in reducing time-consuming and roundoff errors. This new method, combined with fast Lyapunov indicators, is well suited related to chaos in the two example problems. It is found that chaos in the former system is mainly responsible for one of the parameters. In the latter problem, a combination of small initial separations and high initial eccentricities can easily induce chaos.
description: 27 pages, 14 figures
Εξόρυξη και ανάλυση δεδομένων για την παρακολούθηση της επαγγελματικής πορείας των αποφοίτων του Τμήματος Πληροφορικής του ΑΠΘ
Creators: name: Αλεπλιώτου, Αικατερίνη Παναγιώτη
Publisher: name: Aristotle University of Thessaloniki
Year: 2018
Subjects: Παρακολούθηση επαγγελματικής πορείας
Απόφοιτοι του Τμήματος Πληροφορικής, ΑΠΘ
Εξόρυξη Δεδομένων
Συλλογή Δεδομένων
Ανάλυση Δεδομένων
LinkedIn
Monitoring professional progress
Graduates of the Department of Informatics, AUTH
Data Mining
Data Collecting
Data Analysis

description: Η παρούσα Διπλωματική Εργασία αποτελεί μια μελέτη της επαγγελματικής πορείας των αποφοίτων του Τμήματος Πληροφορικής του ΑΠΘ. Πιο συγκεκριμένα, αρχικά πραγματοποιείται μια έρευνα στο LinkedIn ώστε να συλλεχθεί ένα ικανοποιητικό δείγμα αποφοίτων το οποίο θα πληροί όλες τις προϋποθέσεις και τους κανόνες της Στατιστικής. Αφού προσδιοριστούν 230 άτομα με κοινό χαρακτηριστικό την απόκτηση Πτυχίου Πληροφορικής από το Αριστοτέλειο Πανεπιστήμιο, επιλέγονται τα επιθυμητά πεδία από τα προσωπικά τους προφίλ τα οποία θα αποτελέσουν τις μεταβλητές της στατιστικής ανάλυσης. Την επιλογή των πεδίων ακολουθεί η συλλογή τους και έπειτα η εκκαθάριση του θορύβου που τα συνοδεύει ώστε να μην επηρεαστεί η ακεραιότητα της στατιστικής ανάλυσης που θα ακολουθήσει μετέπειτα. Έπειτα εφαρμόζεται στατιστική ανάλυση των δεδομένων με την χρήση εργαλείων και μεθόδων ώστε να επιτευχθεί η πλήρης κατανόηση και ερμηνεία των μεταβλητών. Όλη η παραπάνω διαδικασία στοχεύει στην εξαγωγή ποιοτικών και ποσοτικών αποτελεσμάτων, ικανών να επεξηγήσουν στον αναγνώστη πλήρως ποιος είναι ο σκοπός της παρούσας διπλωματικής εργασίας.
description: This MA Thesis presents an academic research in the professional career of the graduates of the Department of Informatics, Aristotle University of Thessaloniki. More precisely, the first part of the Thesis involves a research in LinkedIn in order for a sufficient sample of graduates, which will satisfy all the requirements and the rules of a statistical analysis, to be collected. Having been defined 230 people who have graduated from the Department of Informatics, Aristotle University of Thessaloniki, the appropriate fields from their personal profiles are selected which will constitute the variables of this Statistical Analysis. After the appropriate fields from the personal profiles have been successfully defined, the next step is the collection of the fields. Next, the pre-processing procedure takes place in order for the integrity of the statistical analysis to remain unaffected. The following step is the process of the statistical analysis of the data with the use of tools and methods that are essential for a comprehensive understanding and familiarization with the variables. The aim of the aforementioned procedure is the deduction of quality and quantity results, capable of serving as an explanation to the reader with regards to the goals of this MA Thesis.
Class of Baer *-rings Defined by a Relaxed Set of Axioms
Creators: name: Vas, Lia
Publisher: name: arXiv
Year: 2007
Subjects: subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: 16W99, 16W10

description: We consider a class ${\mathcal C}$ of Baer *-rings (also treated in [S. K. Berberian, Baer *-rings, Die Grundlehren der mathematischen Wissenschaften 195, Springer-Verlag, Berlin-Heidelberg-New York, 1972.] and [L. Vaš, Dimension and Torsion Theories for a Class of Baer *-Rings, Journal of Algebra 289 (2005) no. 2, 614--639]) defined by nine axioms, the last two of which are particularly strong. We prove that the ninth axiom follows from the first seven. This gives an affirmative answer to the question of S. K. Berberian if a Baer *-ring $R$ satisfies the first seven axioms, is the matrix ring $M_n(R)$ a Baer *-ring.
Predicting outcome of upper gastrointestinal bleeding without endoscopy using the clinical Rockall score and Blatchford
Creators: name: Vichit Viriyaroj
Publisher: name: Faculty of Medicine,Srinakharinwirot University
Year: 2011
Subjects: Upper gastrointestinal bleeding, clinical Rockall score, Blatchford score, endoscopy, recurrent

description: 1, 18, Journal of Medicine and Health Sciences
A Comment on Technical Naturalness and the Cosmological Constant
Creators: name: Itzhaki, Nissan
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We propose a model of dynamical relaxation of the cosmological constant. Technical naturalness of the model and the present value of the vacuum energy density imply an upper bound on the supersymmetry breaking scale and the reheating temperature at the TeV scale.
description: 10 pages, ref. added
On the effect of boundaries on noninteracting weakly active particles in different geometries
Creators: name: Wang, Michael
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study analytically how noninteracting weakly active particles, for which passive Brownian diffusion cannot be neglected and activity can be treated perturbatively, distribute and behave near boundaries in various geometries. In particular, we develop a perturbative approach for the model of active particles driven by an exponentially correlated random force (active Ornstein-Uhlenbeck particles). This approach involves a relatively simple expansion of the distribution in powers of the Péclet number and in terms of Hermite polynomials. We use this approach to cleanly formulate boundary conditions, which allows us to study weakly active particles in several geometries: confinement by a single wall or between two walls in 1D, confinement in a circular or wedge-shaped region in 2D, motion near a corrugated boundary, and finally absorption onto a sphere. We consider how quantities such as the density, pressure, and flow of the active particles change as we gradually increase the activity away from a purely passive system. These results for the limit of weak activity help us gain insight into how active particles behave in the presence of various types of boundaries.
What can linearized neural networks actually say about generalization?
Creators: name: Ortiz-Jiménez, Guillermo
name: Moosavi-Dezfooli, Seyed-Mohsen
name: Frossard, Pascal
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: For certain infinitely-wide neural networks, the neural tangent kernel (NTK) theory fully characterizes generalization, but for the networks used in practice, the empirical NTK only provides a rough first-order approximation. Still, a growing body of work keeps leveraging this approximation to successfully analyze important deep learning phenomena and design algorithms for new applications. In our work, we provide strong empirical evidence to determine the practical validity of such approximation by conducting a systematic comparison of the behavior of different neural networks and their linear approximations on different tasks. We show that the linear approximations can indeed rank the learning complexity of certain tasks for neural networks, even when they achieve very different performances. However, in contrast to what was previously reported, we discover that neural networks do not always perform better than their kernel approximations, and reveal that the performance gap heavily depends on architecture, dataset size and training task. We discover that networks overfit to these tasks mostly due to the evolution of their kernel during training, thus, revealing a new type of implicit bias.
description: 18 pages, 16 figures
Comparison of analgesic effect of tetracaine ophthalmic solution and lidocaine as a topical anesthesia for intranasal endoscopy
Creators: name: Niran Hunchaisri
Publisher: name: Faculty of Medicine,Srinakharinwirot University
Year: 2011
Subjects: tetracaine, lidocaine, intranasal, endoscopy

description: 1, 18, Journal of Medicine and Health Sciences
Quantal time asymmetry: mathematical foundation and physical interpretation
Creators: name: Bohm, A.
name: Bryant, P.
name: Sato, Y.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: For a quantum theory that includes exponentially decaying states and Breit-Wigner resonances, which are related to each other by the lifetime-width relation $τ=\frac{\hbar}Γ$, where $τ$ is the lifetime of the decaying state and $Γ$ the width of the resonance, one has to go beyond the Hilbert space and beyond the Schwartz-Rigged Hilbert Space $Φ\subset\mathcal{H}\subsetΦ^\times$ of the Dirac formalism. One has to distinguish between prepared states, using a space $Φ_-\subset\mat hcal{H}$, and detected observables, using a space $Φ_+\subset\mathcal{H}$, where $-(+)$ refers to analyticity of the energy wave function in the lower (upper) complex energy semiplane. This differentiation is also justified by causality: A state needs to be prepared first, before an observable can be measured in it. The axiom that will lead to the lifetime-width relation is that $Φ_+$ and $Φ_-$ are Hardy spaces of the upper and lower semiplane, respectively. Applying this axiom to the relativistic case for the variable $\s=p_μp^μ$ leads to semigroup transformations into the forward light cone (Einstein causality) and a precise definition of resonance mass and width.
description: Plenary talk at the 5th International Symposium on Quantum Theory and Symmetries, July 22-28, 2007, Valladolid, Spain
Quenching factor measurements of sodium nuclear recoils in NaI:Tl determined by spectrum fitting
Creators: name: Bignell, L. J.
name: Mahmood, I.
name: Nuti, F.
name: Lane, G. J.
name: Akber, A.
name: Barberio, E.
name: Baroncelli, T.
name: Coombes, B.
name: Dix, W.
name: Dowie, J. T. H.
name: Eriksen, T.
name: Gerathy, M. S. M.
name: Gray, T. J.
name: McCormick, B. P.
name: Mitchell, A. J.
name: Rahman, M. S.
name: Scutti, F.
name: Spinks, N. J.
name: Stuchbery, A. E.
name: Timmers, H.
name: Urquijo, P.
name: Wang, L.
name: Zhong, Y. Y.
name: Zurowski, M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: We have performed measurements of sodium nuclear recoils in NaI:Tl crystals, following scattering by neutrons produced in a $^{7}$Li(p,n)$^{7}$Be reaction. Understanding the light output from such recoils, which is reduced relative to electrons of equivalent energy by the quenching factor, is critical to interpret dark matter experiments that search for nuclear scattering interactions. We have developed a spectrum-fitting methodology to extract the quenching factor from our measurements, and report quenching factors for nuclear recoil energies between 36 and 401 keV. Our results agree with other recent quenching factor measurements that use quasi-monoenergetic neutron sources. The new method will be applied in the future to the NaI:Tl crystals used in the SABRE experiment.
HST search for giant planets around white dwarfs in the Hyades
Creators: name: Brandner, Wolfgang
name: Zinnecker, Hans
name: Kopytova, Taisiya
Publisher: name: Zenodo
Year: 2021
Subjects: Hyades cluster
substellar companions
white dwarfs
planet formation
dynamical evolution of orbits

description: We carried out a deep high-contrast direct imaging search for giant planets around seven single white dwarfs in the nearby (average distance approximately 45 pc) Hyades open cluster (age 625 Myr) using the Hubble Space Telescope and its NICMOS instrument. No planets were found. Compared to a previous search with SPITZER/IRAC using infrared excess in the white dwarfs as an indicator for unresolved very low-mass companions, which derived detection limits of 7 to 11 M_Jup, our detection limits for angular separations ≥500mas are considerably lower, i.e. in the range 5 to 7 M_Jup. The non-detections are in line with radial velocity studies around K-type giants, which do not find any giant planets around stars more massive than 3 solar masses. This might indicate that initially dense cluster environments hinder the formation of massive giant planets, or that the energetic radiation of the host stars effects dust growth and gas evaporation, and hence the planet formation efficiency.
description: Stellar systems, clusters, and associations
description: {"references": ["Brandner et al., 2021, MNRAS 500, 3920; https://doi.org/10.1093/mnras/staa3422"]}
A simplification of Morita's construction of total right rings of quotients for a class of rings
Creators: name: Vas, Lia
Publisher: name: arXiv
Year: 2007
Subjects: subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: 16S90, 16N80, 16E60

description: The total right ring of quotients $Q_{\mathrm{tot}}^r(R),$ sometimes also called the maximal flat epimorphic right ring of quotients or right flat epimorphic hull, is usually obtained as a directed union of a certain family of extension of the base ring $R$. In [K. Morita, Flat modules, injective modules and quotient rings, Math. Z. 120 (1971) 25--40], $Q_{\mathrm{tot}}^r(R)$ is constructed in a different way, by transfinite induction on ordinals. Starting with the maximal right ring of quotients $Q_{\mathrm{max}}^r(R)$, its subrings are constructed until $Q_{\mathrm{tot}}^r(R)$ is obtained. Here, we prove that Morita's construction of $Q_{\mathrm{tot}}^r(R)$ can be simplified for rings satisfying condition (C) that every subring of the maximal right ring of quotients $Q^r_{\mathrm{max}}(R)$ containing $R$ is flat as a left $R$-module. We illustrate the usefulness of this simplification by considering the class of right semihereditary rings all of which satisfy condition (C). We prove that the construction stops after just one step and we obtain a simple description of $Q^r_{\mathrm{tot}}(R)$ in this case. Lastly, we study conditions that imply that Morita's construction ends in countably many steps.
Span design for entry-type excavations
Creators: name: Lang, Brennan Davis Allan
Publisher: name: University of British Columbia
Year: 2009

description: Underground entry-type excavations require higher factors of safety than do non-entry excavations yet not as high as those required for permanent underground structures. A review is made of underground excavation span design techniques and the conditions under which they can be applied. Shortcomings of these existing methods, as they are applied to cut and fill stopes and other entry-type excavations, are highlighted. A design procedure specific to conditions found in entry-type mining is proposed. At the centre of the procedure is an empirical span design chart, called the “Stability Graph for Entry-Type Excavations”, which provides a practical tool for mining engineers to design stable entry-type excavations. The development of this chart and its use as a design tool is a result of the statistical analysis of 172 stoping case histories collected at a large underground gold mine in northern Ontario, The influence of artificial support in maintaining stability and increasing span is investigated. A report is given of a trial support program carried out at the same operation using a concentrated pattern of cable bolts to replace a post pillar in order to increase span.
Fluctuations of a swarm of Brownian bees
Creators: name: Siboni, Maor
name: Sasorov, Pavel
name: Meerson, Baruch
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Probability (math.PR)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: The ``Brownian bees" model describes an ensemble of $N$ independent branching Brownian particles. When a particle branches into two particles, the particle farthest from the origin is eliminated so as to keep a constant number of particles. In the limit of $N\to \infty$, the spatial density of the particles is governed by the solution of a free boundary problem for a reaction-diffusion equation. At long times the particle density approaches a spherically symmetric steady state solution with a compact support. Here we study fluctuations of the ``swarm of bees" due to the random character of the branching Brownian motion in the limit of large but finite $N$. We consider a one-dimensional setting and focus on two fluctuating quantities: the swarm center of mass $X(t)$ and the swarm radius $\ell(t)$. Linearizing a pertinent Langevin equation around the deterministic steady state solution, we calculate the two-time covariances of $X(t)$ and $\ell(t)$. The variance of $X(t)$ directly follows from the covariance of $X(t)$, and it scales as $1/N$ as to be expected from the law of large numbers. The variance of $\ell(t)$ behaves differently: it exhibits an anomalous scaling $\ln N/N$. This anomaly appears because all spatial scales, including a narrow region near the edges of the swarm where only a few particles are present, give a significant contribution to the variance. We argue that the variance of $\ell(t)$ can be obtained from the covariance of $\ell(t)$ by introducing a cutoff at the microscopic time $1/N$ where the continuum Langevin description breaks down. Our theoretical predictions are in good agreement with Monte-Carlo simulations of the microscopic model. Generalizations to higher dimensions are briefly discussed.
description: 8 pages, 4 figures
Self  care behavior of hypertensive patients at out patient department of HRH Princess Maha Chakri Sirindhorn Medical Center
Creators: name: Patayaporn Laloon, Napaporn Madhyamankura
Publisher: name: Faculty of Medicine,Srinakharinwirot University
Year: 2011
Subjects: Self care behavior, Hypertension, Hypertensive patients

description: 1, 18, Journal of Medicine and Health Sciences