cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Gap winds in a fjord : Howe Sound, British Columbia
Creators: name: Jackson, Peter L.
Publisher: name: University of British Columbia
Year: 2008

description: Gap, outflow, or Squamish wind, is the cold low level seaward flow of air through fjords which dissect the coastal mountain barrier of northwestern North America. These flows, occurring mainly during winter, can be strong, threatening safety, economic activity and comfort. Howe Sound gap winds were studied using a combination of observations and several types of models. Observations of winds in Howe Sound showed that gap wind strength varied considerably along the channel, across the channel and vertically. Generally, winds increase down the channel, are strongest along the eastern side, and are below 1000 m depth. Observations were unable to answer all questions about gap winds due to data sparseness, particularly in the vertical direction. Therefore, several modelling approaches were used. The modelling began with a complete 3-dimensional quasi-Boussinesq model (CSURAMS) and ended with the creation and testing of models which are conceptually simpler, and more easily interpreted and manipulated. A gap wind simulation made using RAMS was shown to be mostly successful by statistical evaluation compared to other mesoscale simulations, and by visual inspection of the fields. The RAMS output, which has very high temporal and spatial resolution, provided much additional information about the details of gap flow. In particular, RAMS results suggested a close analogy between gap wind and hydraulic channel flow, with hydraulic features such as supercritical flow and hydraulic jumps apparent. These findings imply gap wind flow could potentially be represented by much simpler models. The simplest possible models containing pressure gradient, advection and friction but not incorporating hydraulic effects, were created, tested, and found lacking. A hydraulic model, which in addition incorporates varying gap wind height and channel geometry, was created and shown to successfully simulate gap winds. Force balance analysis from RAMS and the hydraulic model showed that pressure gradient and advection are the most important forces, followed by friction which becomes an important force in fast supercritical flow. The sensitivity of gap wind speed to various parameters was found from sensitivity tests using the hydraulic model. Results indicated that gap wind speed increases with increasing boundary layer height and speed at the head of channel, and increasing synoptic pressure gradient. Gap wind speed decreases with increasing friction, and increasing boundary layer height at the seaward channel end. Increasing temperature dilterences between the cold gap wind air and the warmer air aloft was found to increase the variability of the flow — higher maximum but lower mean wind speeds.
The phenomenology of nuclear scattering for a WIMP of arbitrary spin
Creators: name: Gondolo, Paolo
name: Jeong, Injun
name: Kang, Sunghyun
name: Scopel, Stefano
name: Tomar, Gaurav
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We provide a first systematic and quantitative discussion of the phenomenology of the non-relativistic effective Hamiltonian describing the nuclear scattering process for a Weakly Interacting Massive Particle (WIMP) of arbitrary spin $j_χ$. To this aim we obtain constraints from a representative sample of present direct detection experiments assuming the WIMP-nucleus scattering process to be driven by each one of the 44 effective couplings that arise for $j_χ\le$ 2. We find that a high value of the multipolarity $s\le 2 j_χ$ of the coupling, related to the power of the momentum transfer $q$ appearing in the scattering amplitude, leads to a suppression of the expected rates and pushes the expected differential spectra to large recoil energies $E_R$. For $s\le$ 4 the effective scales probed by direct detection experiments can be suppressed by up to 5 orders of magnitude compared to the case of a standard spin-independent interaction. For operators with large $s$ the expected differential spectra can be pushed to recoil energies in the MeV range, with the largest part of the signal concentrated at $E_R\gtrsim$ 100 keV and a peculiar structure of peaks and minima arising when both the nuclear target and the WIMP are heavy. As a consequence the present bounds on the effective operators can be significantly improved by extending the recoil energy intervals to higher recoil energies. Our analysis assumes effective interaction operators that are irreducible under the rotation group. Such operators drive the interactions of high-multipole dark matter candidates, i.e. states that possess only the highest multipole allowed by their spin. As a consequence our analysis represents also the first phenomenological study of the direct detection of quadrupolar, octupolar, and hexadecapolar dark matter.
description: 33 pages, 8 figures, 2 tables
Stochastic Gravity: Beyond Semiclassical Gravity
Creators: name: Verdaguer, E.
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The back-reaction of a classical gravitational field interacting with quantum matter fields is described by the semiclassical Einstein equation, which has the expectation value of the quantum matter fields stress tensor as a source. The semiclassical theory may be obtained from the quantum field theory of gravity interacting with N matter fields in the large N limit. This theory breaks down when the fields quantum fluctuations are important. Stochastic gravity goes beyond the semiclassical limit and allows for a systematic and self-consistent description of the metric fluctuations induced by these quantum fluctuations. The correlation functions of the metric fluctuations obtained in stochastic gravity reproduce the correlation functions in the quantum theory to leading order in an 1/N expansion. Two main applications of stochastic gravity are discussed. The first, in cosmology, to obtain the spectrum of primordial metric perturbations induced by the inflaton fluctuations, even beyond the linear approximation. The second, in black hole physics, to study the fluctuations of the horizon of an evaporating black hole.
description: 12 pages, no figures, proceedings of the XXIX Spanish Relativity Meeting
Multi-wavelength flare observations of the blazar S5 1803+784
Creators: name: Nesci, R.
name: Cutini, S.
name: Stanghellini, C.
name: Martinelli, F.
name: Maselli, A.
name: Lipunov, V. M.
name: Kornilov, V.
name: Lopez, R. R.
name: Siviero, A.
name: Giroletti, M.
name: Orienti, M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The radio, optical, and $γ$-ray light curves of the blazar S5 1803+784, from the beginning of the {\it Fermi} Large Area Telescope (LAT) mission in August 2008 until December 2018, are presented. The aim of this work is to look for correlations among different wavelengths useful for further theoretical studies. We analyzed all the data collected by {\it Fermi} LAT for this source, taking into account the presence of nearby sources, and we collected optical data from our own observations and public archive data to build the most complete optical and $γ$-ray light curve possible. Several $γ$-ray flares ($\mathrm{F>2.3~10^{-7} ph(E>0.1 GeV)~cm^{-2}~s^{-1}}$) with optical coverage were detected, all but one with corresponding optical enhancement; we also found two optical flares without a $γ$-ray counterpart. We obtained two {\it Swift} Target of Opportunity observations during the strong flare of 2015. Radio observations performed with VLBA and EVN through our proposals in the years 2016-2020 were analyzed to search for morphological changes after the major flares. The optical/$γ$-ray flux ratio at the flare peak varied for each flare. Very minor optical V-I color changes were detected during the flares. The X-ray spectrum was well fitted by a power law with photon spectral index $α$=1.5, nearly independent of the flux level: no clear correlation with the optical or the $γ$-ray emission was found. The $γ$-ray spectral shape was well fitted by a power law with average photon index $α$= 2.2. These findings support an Inverse Compton origin for the high-energy emission of the source, nearly co-spatial with the optically emitting region. The radio maps showed two new components originating from the core and moving outwards, with ejection epochs compatible with the dates of the two largest $γ$-ray flares.
description: Twelve pages, 12 figures, accepted for MNRAS
Superconductivity in a model of two Hubbard chains coupled with ferromagnetic exchange interaction
Creators: name: Shirakawa, T.
name: Nishimoto, S.
name: Ohta, Y.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We study the ground-state properties of the double-chain Hubbard model coupled with ferromagnetic exchange interaction by using the weak-coupling theory, density-matrix renormalization group technique, and Lanczos exact-diagonalization method. We determine the ground-state phase diagram in the parameter space of the ferromagnetic exchange interaction and band filling. We find that, in high electron density regime, the spin gap opens and the spin-singlet $d_{xy}$-wave-like pairing correlation is most dominant, whereas in low electron density regime, the fully-polarized ferromagnetic state is stabilized where the spin-triplet $p_{y}$-wave-like pairing correlation is most dominant.
description: 11 pages, 10 figures
Influence of the microstructure on the magnetism of Co-doped ZnO thin films
Creators: name: Fouchet, A.
name: Prellier, W.
name: Mercey, B.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The prediction of ferromagnetism at room temperature in Co-ZnO thin films has generated a large interest in the community due to the possible applications. However, the results are controversial, going from ferromagnetism to non-ferromagnetism, leading to a large debate about its origin (secondary phase, Co clusters or not). By carefully studying the micro-structure of various Co-ZnO films, we show that the Co2+ partly substitutes the ZnO wurtzite matrix without forming Co clusters. Surprisingly, the ferromagnetism nature of the films disappears as the Co content increases. In addition, our results suggest that the observed ferromagnetism is likely associated to a large amount of defects- close to the interface and strongly depending on the growth temperature- which may explained the spreading of the results.
description: 4 pages, 4 figures, to be published in Journal of Applied Physics (2006)
Superconductivity in the Topological Nodal-line Semimetal NaAlSi
Creators: name: Yamada, Takahiro
name: Hirai, Daigorou
name: Yamane, Hisanori
name: Hiroi, Zenji
Publisher: name: arXiv
Year: 2021
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: NaAlSi is an sp electron superconductor crystallizing in a layered structure of the anti-PbFCl type with a relatively high transition temperature Tc of ~7 K. Recent electronic state calculations revealed the presence of topological nodal lines in the semimetallic band structure, which attracted much attention owing to the superconductivity. However, experimental investigation remained limited because of the lack of single crystals. Here, we successfully prepared single crystals of NaAlSi by a Na-Ga flux method and characterized their superconducting and normal-state properties through electrical resistivity, magnetization, and heat capacity measurements. A sharp superconducting transition with a Tc of 6.8 K is clearly observed, and heat capacity data suggest an anisotropic superconducting gap. Surprisingly, despite the sp electron system, the normal state is governed by the electron correlations, which is indicated by a T2 resistivity and a Wilson ratio of 2.0. The origin of the electron correlation may be related to the orthogonal saddle-shaped Fermi surfaces derived from the Si px and py states, which intersect with the light Al s bands to form the nodal lines near the Fermi level. These results strongly suggest that the superconductivity of NaAlSi is not caused by a simple phonon mechanism but involves a certain unconventional aspect, although its relevance to the nodal lines is unclear.
Thermodynamic electric quadrupole moments of nematic phases from first-principles calculation
Creators: name: Kitamura, Taisei
name: Ishizuka, Jun
name: Daido, Akito
name: Yanase, Youichi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The electronic nematic phase emerging with spontaneous rotation symmetry breaking is a central issue of modern condensed matter physics. In particular, various nematic phases in iron-based superconductors and high-$T_{\rm c}$ cuprate superconductors are extensively studied recently. Electric quadrupole moments (EQMs) are one of the order parameters characterizing these nematic phases in a unified way, and elucidating EQMs is a key to understanding these nematic phases. However, the quantum-mechanical formulation of the EQMs in crystals is a nontrivial issue because the position operators are non-periodic and unbound. Recently, the EQMs have been formulated by local thermodynamics, and such {\it thermodynamic EQMs} may be used to characterize the fourfold rotation symmetry breaking in materials. In this paper, we calculate the thermodynamic EQMs in iron-based superconductors LaFeAsO and FeSe as well as a cuprate superconductor La$_2$CuO$_4$ by a first-principles calculation. We show that owing to the orbital degeneracy the EQMs in iron-based superconductors are mainly determined by the geometric properties of wave functions. This result is in sharp contrast to the cuprate superconductor, in which the EQMs are dominated by distortion of the Fermi surface.
description: 13 pages, 18 figures
Η εναρμόνιση των ειδικών φόρων κατανάλωσης
Creators: name: Αραμπατζή, Ευαγγελία Λάμπρου
Publisher: name: Aristotle University of Thessaloniki
Year: 2016
Subjects: Ειδικοί Φόροι Κατανάλωσης
Εναρμόνιση
Ευρωπαϊκή Οδηγία
Excise duties
Harmonization
European Directive

description: Σκοπός της διπλωματικής ήταν η μελέτη της εναρμόνισης των ειδικών φόρων κατανάλωσης. Αρχικά, εξέτασα την έννοια των φόρων κατανάλωσης και τα βασικά χαρακτηριστικά των ειδικών φόρων κατανάλωσης. Στη συνέχεια παρουσίασα τους λόγους για τους οποίους πραγματοποιήθηκε η εναρμόνιση των ειδικών φόρων κατανάλωσης. Ακόμη, αναφέρθηκα αναλυτικά στην Οδηγία 2008/118/ΕΚ η οποία ρυθμίζει το γενικό καθεστώς της κατοχής, κυκλοφορίας και ελέγχου των προϊόντων που υπόκεινται σε ειδικούς φόρους κατανάλωσης. Κατόπιν των ανωτέρω, έθιξα τα ειδικά καθεστώτα των εναρμονισμένων προς το ενωσιακό δίκαιο ειδικών φόρων κατανάλωσης, ήτοι τα ενεργειακά προϊόντα και την ηλεκτρική ενέργεια, την αλκοόλη και τα αλκοολούχα ποτά, καθώς και τα βιομηχανοποιημένα καπνά. ‘Έπειτα, αναφέρομαι στους μη εναρμονισμένους προς το ενωσιακό δίκαιο ειδικούς φόρους κατανάλωσης, όπως το τέλος ταξινόμησης των αυτοκινήτων και ο ειδικός φόρος κατανάλωσης στις μπανάνες. Τέλος, με απασχόλησε η νομολογία του Δικαστηρίου της Ευρωπαϊκής Ένωσης, η οποία αφορά τόσο το γενικό όσο και το ειδικό καθεστώς των ειδικών φόρων κατανάλωσης.
description: The aim of the present thesis was to study the harmonization of excise duties. Initially, the meaning of the consumption taxes and the basic features of excise duties were examined. Afterwards, I presented the reasons that the harmonization of excise duties was held. Furthermore, a thorough analysis of the Directive 2008/118/EC which regulates the general regime of possession, movement and monitoring of products which are subjected to the excise duties was undertaken. Furthermore, I examined the special procedures of the harmonized with the European Union’s law excise duties, and particularly the energy products and the electricity market; the alcohol and the alcoholic beverages; and the manufactured tobacco. Additionally, I examined the non-harmonized with the European Union law excise duties, such as the cars’ registration fee and the excise duty on bananas. Finally, this study dealt with the jurisprudence of the Court of Justice of the European Union, which concerns both the general and the special arrangements of excise duties.
The patience of concurrent stochastic games with safety and reachability objectives
Creators: name: Chatterjee, Krishnendu
name: Ibsen-Jensen, Rasmus
name: Hansen, Kristoffer
Publisher: name: IST Austria
Year: 2015
Subjects: 000 Computer science, knowledge & general works
510 Mathematics

description: We consider finite-state concurrent stochastic games, played by k>=2 players for an infinite number of rounds, where in every round, each player simultaneously and independently of the other players chooses an action, whereafter the successor state is determined by a probability distribution given by the current state and the chosen actions. We consider reachability objectives that given a target set of states require that some state in the target set is visited, and the dual safety objectives that given a target set require that only states in the target set are visited. We are interested in the complexity of stationary strategies measured by their patience, which is defined as the inverse of the smallest non-zero probability employed. Our main results are as follows: We show that in two-player zero-sum concurrent stochastic games (with reachability objective for one player and the complementary safety objective for the other player): (i) the optimal bound on the patience of optimal and epsilon-optimal strategies, for both players is doubly exponential; and (ii) even in games with a single non-absorbing state exponential (in the number of actions) patience is necessary. In general we study the class of non-zero-sum games admitting epsilon-Nash equilibria. We show that if there is at least one player with reachability objective, then doubly-exponential patience is needed in general for epsilon-Nash equilibrium strategies, whereas in contrast if all players have safety objectives, then the optimal bound on patience for epsilon-Nash equilibrium strategies is only exponential.
Groupoids and an index theorem for conical pseudo-manifolds
Creators: name: Debord, Claire
name: Lescure, Jean-Marie
name: Nistor, Victor
Publisher: name: arXiv
Year: 2006
Subjects: subject: Operator Algebras (math.OA)
subject: FOS: Mathematics
subject: 46L80, 58B34, 19K35, 19K58, 58H05

description: We define an analytical index map and a topological index map for conical pseudomanifolds. These constructions generalize the analogous constructions used by Atiyah and Singer in the proof of their topological index theorem for a smooth, compact manifold $M$. A main ingredient is a non-commutative algebra that plays in our setting the role of $C_0(T^*M)$. We prove a Thom isomorphism between non-commutative algebras which gives a new example of wrong way functoriality in $K$-theory. We then give a new proof of the Atiyah-Singer index theorem using deformation groupoids and show how it generalizes to conical pseudomanifolds. We thus prove a topological index theorem for conical pseudomanifolds.
Εισαγωγή Μεταδεδομένων στο Σύστημα Διαχείρισης Περιεχομένου Wordpress
Creators: name: Σκαρλατοπούλου, Χριστίνα Δημητρίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2016
Subjects: Μεταδεδομένα
Πρόσθετα
Σύστημα Διαχείρισης Περιεχομένου
Metadata
Plugin
Content Management System

description: Το αντικείμενο αυτής της διπλωματικής εργασίας είναι η παρουσίαση, η εισαγωγή και η χρήση πρόσθετων (plugins) του Συστήματος Διαχείρισης Περιεχομένου (ΣΔΠ) WordPress, σχετικών με την εισαγωγή μεταδεδομένων σε ιστοσελίδες. Αρχικά εισάγεται ο αναγνώστης στις βασικές έννοιες για την κατανόηση των μεταδεδομένων και του σημασιολογικού ιστού. Στη συνέχεια, παρουσιάζεται η περιγραφή, η διαδικασία εγκατάστασης και η διαδικασία χρήσης μίας ποικιλίας από πρόσθετα (plugins), τα οποία καλύπτουν ένα ευρύ φάσμα διαχείρισης μεταδεδομένων στο WordPress. Εφαρμόζεται μία σειρά από επιλεγμένα πρόσθετα και ένα ειδικά κατασκευασμένου πρόσθετου για την δημιουργία και ενσωμάτωση μεταδεδομένων στην ιστοσελίδα του Διατμηματικού Προγράμματος Μεταπτυχιακών Σπουδών (ΔΠΜΣ) στην ≪ Πληροφορική και Διοίκηση ≫ των Τμημάτων Πληροφορικής και Οικονομικών Επιστημών του Αριστοτελείου Πανεπιστημίου Θεσσαλονίκης. Τέλος, η εργασία κλείνει συνοψίζοντας τα αποτελέσματά και προτείνοντας κάποιες μελλοντικές εργασίες για την περαιτέρω εισαγωγή μεταδεδομένων στην ιστοσελίδα του ΔΠΜΣ .
description: The object of this thesis is the presentation and the use of plugins in a Content Management System (CMS) and particularly at WordPress, for the enrichment of websites with metadata. First, the reader is introduced to the basic concepts of metadata and the basic issues of the Semantic Web. Thereafter, various plugins are described, along with the installation process and the process of using those plugins that cover a wide range of putting metadata to WordPress. Furthermore a number of selected plugins are applied on the website of the Interdisciplinary MSc Course on "Informatics and Management" of the Departments of Informatics and Economics of the Aristotle University of Thessaloniki, along with a custom-made plugin to generate and embed metadata into the above site. Finally, the thesis concludes with summarizing the results.
Reconstructing robust phylogenies of metastatic cancers
Creators: name: Reiter, Johannes
name: Makohon-Moore, Alvin
name: Gerold, Jeffrey
name: Bozic, Ivana
name: Chatterjee, Krishnendu
name: Iacobuzio-Donahue, Christine
name: Vogelstein, Bert
name: Nowak, Martin
Publisher: name: IST Austria
Year: 2015
Subjects: 000 Computer science, knowledge & general works
570 Life sciences; biology

description: A comprehensive understanding of the clonal evolution of cancer is critical for understanding neoplasia. Genome-wide sequencing data enables evolutionary studies at unprecedented depth. However, classical phylogenetic methods often struggle with noisy sequencing data of impure DNA samples and fail to detect subclones that have different evolutionary trajectories. We have developed a tool, called Treeomics, that allows us to reconstruct the phylogeny of a cancer with commonly available sequencing technologies. Using Bayesian inference and Integer Linear Programming, robust phylogenies consistent with the biological processes underlying cancer evolution were obtained for pancreatic, ovarian, and prostate cancers. Furthermore, Treeomics correctly identified sequencing artifacts such as those resulting from low statistical power; nearly 7% of variants were misclassified by conventional statistical methods. These artifacts can skew phylogenies by creating illusory tumor heterogeneity among distinct samples. Importantly, we show that the evolutionary trees generated with Treeomics are mathematically optimal.
Σύγκριση μη καταστροφικών ελέγχων σε συγκολλήσεις εξοπλισμού διυλιστηρίου
Creators: name: Πυξαράς, Μαρίνος Αναστασίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2016
Subjects: Μη καταστροφικοί έλεγχοι
Συγκολλήσεις
Διυλιστήριο
Non-destructive testings
Welds
Refinery

description: Η συγκεκριμένη εργασία καλύπτει την περιοχή των μη καταστροφικών ελέγχων (ΜΚΕ - NDT) που πραγματοποιούνται σε κατασκευές που χρησιμοποιούνται σε διυλιστήρια, αλλά ασχολείται και με τα είδη και τις τεχνικές των συγκολλήσεων. Οι μέθοδοι που αναπτύσσονται είναι τα Διεισδυτικά Υγρά, τα Μαγνητικά Σωματίδια, η Ραδιογραφία, ο Υπέρηχος και οι Phased Arrays. Στο πρώτο μέρος παρουσιάζεται η κάθε μέθοδος ξεχωριστά σε ότι αφορά τους τρόπους εφαρμογής, τις δυνατότητες και τους περιορισμούς τους. Στο δεύτερο μέρος αναφέρονται τα είδη συγκολλήσεων και τα σφάλματα τα οποία μπορούν να εμφανιστούν σε μία διαδικασία συγκόλλησης. Τέλος στο τρίτο μέρος γίνεται σύγκριση όλων των μεθόδων σε τμήμα συγκόλλησης ηλεκτροδίου σε δοχείου πίεσης χάλυβα ASTM A516 Grade 70 που χρησιμοποιείται για διανομή υδρόθειου σε διυλιστήρια πετρελαίου συνδέονται τα πειραματικά αποτελέσματα με τη θεωρία που αναλύθηκε και παρουσιάζονται συμπεράσματα λαμβάνοντας υπόψη και οικονομοτεχνικά δεδομένα σε ότι αφορά το κόστος κάθε μεθόδου και των επιλογών των κατασκευαστριών εταιριών καθώς και τα πρότυπα και προδιαγραφές που έχουν συμφωνηθεί μεταξύ του κατασκευαστή και του διυλιστηρίου.
description: This thesis covers the area of non-destructive testings (NDT) conducted in structures used in refineries, but also deals with the types and weld techniques. The methods explained are Penetrant Testing, Magnetic Particle Testing, the Radiography, Ultrasound and Phased Arrays. The first part presents each method individually with regards the methods of implementation, the possibilities and limitations. In the second part mentioned types of welds and the errors that can occur in a welding process. Finally the third part is a comparison of all methods in electrode welding portion to a steel pressure vessel ASTM A516 Grade 70 used for distribution of hydrogen sulfide in oil refineries. The experimental results with theory analyzed and presented conclusions given and-economic data with regard to cost of each method combined with the standards and specifications that have been agreed between the manufacturer and the refinery.
Intervening or associated? Machine learning classification of redshifted H I 21-cm absorption
Creators: name: Curran, S. J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: In a previous paper we presented the results of applying machine learning to classify whether an HI 21-cm absorption spectrum arises in a source intervening the sight-line to a more distant radio source or within the host of the radio source itself. This is usually determined from an optical spectrum giving the source redshift. However, not only will this be impractical for the large number of sources expected to be detected with the Square Kilometre Array, but bright optical sources are the most ultra-violet luminous at high redshift and so bias against the detection of cool, neutral gas. Adding another 44, mostly newly detected absorbers, to the previous sample of 92, we test four different machine learning algorithms, again using the line properties (width, depth and number of Gaussian fits) as features. Of these algorithms, three gave a some improvement over the previous sample, with a logistic regression model giving the best results. This suggests that the inclusion of further training data, as new absorbers are detected, will further increase the prediction accuracy above the current 80%. We use the logistic regression model to classify the z = 0.42 absorption towards PKS 1657-298 and find this to be associated, which is consistent with a previous study which determined a similar redshift from the K-band magnitude-redshift relation.
description: Accepted by MNRAS
Microwave-Induced Cooling of a Superconducting Qubit
Creators: name: Valenzuela, S. O.
name: Oliver, W. D.
name: Berns, D. M.
name: Berggren, K. K.
name: Levitov, L. S.
name: Orlando, T. P.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We demonstrated microwave-induced cooling in a superconducting flux qubit. The thermal population in the first-excited state of the qubit is driven to a higher-excited state by way of a sideband transition. Subsequent relaxation into the ground state results in cooling. Effective temperatures as low as Teff~ 3 millikelvin are achieved for bath temperatures Tbath = 30 - 400 millikelvin, a cooling factor between 10 and 100. This demonstration provides an analog to optical cooling of trapped ions and atoms and is generalizable to other solid-state quantum systems. Active cooling of qubits, applied to quantum information science, provides a means for qubit-state preparation with improved fidelity and for suppressing decoherence in multi-qubit systems.
description: Comments Article plus Supplementary Online Material. 19 pages, 6 figures
Model-independent resonance parameter extraction using the trace of K and T matrices
Creators: name: Ceci, S.
name: Svarc, A.
name: Zauner, B.
name: Manley, M.
name: Capstick, S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A model-independent method for the determination of Breit-Wigner resonance parameters is presented. The method is based on eliminating the dependence on the choice of channel basis by analyzing the trace of the K and T matrices in the coupled-channel formalism, rather than individual matrix elements of the multichannel scattering matrix.
description: 6 pages, 16 figures
Εκκλησία και τεχνολογία κατά την περίοδο της Βυζαντινής αυτοκρατορίας.
Creators: name: Λάμπρος, Χρήστος Αθανασίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2016
Subjects: Εκκλησία
Τεχνολογία
Church
Technology
Byzantine empire

description: Σκοπός της διατριβής ήταν η αναμφισβήτητη προσφορά του Βυζαντίου στην διαφύλαξη όσων είχαν επιτευχθεί κατά την αρχαιότητα ως την εποχή που εμφανίστηκαν οι φυσικομαθηματικές επιστήμες των νεότερων χρόνων. Οι Βυζαντινοί δεν διακρίθηκαν μόνο για τις επιδόσεις τους στην θεωρία αλλά και στην πρακτική χρήση και εφαρμογή των επιστημονικών γνώσεων στον καθημερινό βίο, πράγμα που γίνεται ιδιαίτερα αντιληπτό στην ιατρική και στην τεχνική. Γενικότερα η επιστημονική παρατήρηση της φύσης και η περιγραφή των παρατηρούμενων ήταν πράγματα που είχαν απασχολήσει τους Έλληνες και στην αρχαιότητα. Ειδικά από τον Αριστοτέλη έχουμε πολλά έργα που ασχολούνται με την ερμηνεία των φυσικών φαινομένων, ενώ επίσης έχουμε προσωπικότητες που διακρίθηκαν σε πολλές επιστήμες όπως στην ιατρική, την βοτανική, την αρχιτεκτονική. Το σπουδαιότερο κατόρθωμα της επιστήμης εκείνη την περίοδο έγκειται στον τονισμό της αναγκαιότητας της συνέχισης της ανάπτυξης των θετικών επιστημών όπως αυτή είχε ξεκινήσει αιώνες νωρίτερα και που επιτεύχθηκε στην υστεροβυζαντινή περίοδο. Τα τεχνολογικά ευρήματα του Βυζαντίου αποτελούν αντιπροσωπευτικό δείγμα της εξελίξεως της μηχανικής στην εποχή τους και μαρτυρούν την μεγάλη ανάπτυξη της τεχνολογίας στο Βυζάντιο.
description: The aim of the present thesis was the contribution of Byzantium to preserve what had been achieved all these years due to modern times. The Byzantines not only stood out through their performance in theory but also from the application of all these in everyday life. It was something that appreciated in the medical and technical science. General scientific observation of nature and description of all these that had been observed, were things that had already succeed from the Greeks. Especially since Aristotle have several projects dealing with the interpretation of natural phenomena. Byzantium have met scientists that excelled in many disciplines such as medicine, botany, architecture. The greatest achievement of science at that time lies in emphasizing the necessity of continuing the development of science as it had begun centuries earlier and reached in the late Byzantine period. The technological discoveries of Byzantium constitute a representative sample of the development of engineering in their time and witness the great development of technology in Byzantium.
Superconducting FeSe monolayer with milli-electron volt Fermi energy
Creators: name: Huang, Wantong
name: Lin, Haicheng
name: Zheng, Cheng
name: Yin, Yuguo
name: Chen, Xi
name: Ji, Shuai-Hua
Publisher: name: arXiv
Year: 2021
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Iron selenide (FeSe) is an iron-based superconductor which shows unique properties, including strongly anisotropic superconducting gap, paramagnetism in undoped compound and extremely small Fermi pocket size. In this work, we demonstrate that the sizes of electron and hole pockets in FeSe monolayer become much smaller than those in bulk. The Fermi energy is in the order of a few meV and can be fine-tuned by the thickness of graphene layers underneath. Despite the low carrier density, the FeSe monolayers grown on trilayer or multi-layer graphene are superconducting. The superconducting gap size is sensitive to the Fermi energy of the hole band. Remarkably, the FeSe monolayer provides the opportunity to study the physics in the crossover regime where the Fermi energy and superconducting gap are comparable to each other.
Uses and abuses of QALY analysis
Creators: name: Holmes, Ann M.
Publisher: name: University of British Columbia
Year: 2008

description: A major contribution of economics to health services research has been the development of QALYs (quality adjusted life years) as a measure of health status. This thesis investigates, in three essays, the use of QALYs in health care project evaluation and as an indicator of societal health. The first essay examines the validity (defined as consistency with preferences) and feasibility of various QALY construction methods. Conditions for validity, derived from welfare principles, are used to assess the different methods. A new QALY instrument is devised that has interpersonal content (i.e. is valid for choices involving different individuals). Bias is shown to depend on various independence relationships within preferences. A number of these conditions are tested using data from the General Social Survey of 1985 (Canada. Statistics Canada [1987]). The second essay examines the welfare properties of the QALY-based index as it is commonly employed to make health policy decisions. A comparison with alternative economic-based health indexes (human capital and willingness-to-pay) is provided. The QALY-based measure does indicate which treatment is best for an individual. In choosing patients for treatment, however, QALY-based measures probably discriminate against certain types of individuals, including those who are risk averse with respect to health and in poor health. In choosing between health programs, aggregate QALY-based measures do order community health profiles sensibly (except where people endure states worse than death), unlike the other measures considered. The QALY-based index may, however, favour unequal distributions of health. The final essay assesses the appropriateness and feasibility of QALYs as a foundation for an index of societal health. Results suggest that, theoretically, the QALY serves as an imperfect measure of societal health, but that these problems are endemic to any index based on individual preferences. Using the best available data, a QALY based index is calculated to measure the level and distribution of ill-health in Canada and indicate where health policy can be most effectively targeted. The essay concludes with a discussion of what improvements in data collection are required to obtain more accurate figures.
Moving frames applied to shell elasticity
Creators: name: Sondergaard, Niels
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 53B21;74K25

description: Exterior calculus and moving frames are used to describe curved elastic shells. The kinematics follow from the Lie-derivative on forms whereas the dynamics via stress-forms.
description: 20 pages, 1 figure
Στάσεις και απόψεις των ξενόγλωσσων εκπαιδευτικών και των μαθητών Γυμνασίων του νομού Πιερίας για την πρώτη και δεύτερη ξένη γλώσσα στο σχολείο
Creators: name: Ζερβουδάκη, Κυπαρισσία Γεωργίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2016
Subjects: Ξένη Γλώσσα
Ξενόγλωσση Εκπαιδευτική Πολιτική
Αναλυτικά Προγράμματα
Foreign Language
Foreign Language Education Policy
Curricula

description: Η εκμάθηση μιας ή περισσότερων ξένων γλωσσών έχει γίνει ιδιαίτερα επιτακτική στη χώρα μας τα τελευταία χρόνια, καθώς στα πλαίσια της κοινωνίας της πληροφορίας και των ηλεκτρονικών μέσων αναζητούνται από τους πολίτες της Ελλάδας νέοι τρόποι και στρατηγικές επικοινωνίας. Παράλληλα στο εκπαιδευτικό σύστημα της χώρας μας είναι προφανής η μέριμνα για την παροχή διδασκαλίας και την εξασφάλιση εκμάθησης τουλάχιστον δύο ξένων γλωσσών. Η παρούσα έρευνα επικεντρώνεται στη διερεύνηση των στάσεων και των απόψεων των ξενόγλωσσων εκπαιδευτικών και των μαθητών των Γυμνασίων για το μάθημα της πρώτης και δεύτερης ξένης γλώσσας στο σχολείο.
description: Learning one or more foreign languages has become particularly urgent in our country in recent years, as in the context of the information society and electronic media, new ways of communication strategies are sought by citizens of Greece. At the same time in our country's education system it is obvious the concern for the provision of teaching and learning to ensure at least two foreign languages. This research focuses on exploring the attitudes and opinions of foreign language teachers and of secondary school students for the course of the first and second foreign language at school
Unconditional privacy over channels which cannot convey quantum information
Creators: name: Horodecki, Karol
name: Horodecki, Michal
name: Horodecki, Pawel
name: Leung, Debbie
name: Oppenheim, Jonathan
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: By sending systems in specially prepared quantum states, two parties can communicate without an eavesdropper being able to listen. The technique, called quantum cryptography, enables one to verify that the state of the quantum system has not been tampered with, and thus one can obtain privacy regardless of the power of the eavesdropper. All previous protocols relied on the ability to faithfully send quantum states. In fact, until recently, they could all be reduced to a single protocol where security is ensured though sharing maximally entangled states. Here we show this need not be the case -- one can obtain verifiable privacy even through some channels which cannot be used to reliably send quantum states.
description: Related to quant-ph/0608195 and for a more general audience
Physiologic and Other Effects of Silicone Mask Respirator N99 in the Coronavirus 2019 Outbreaks
Creators: name: Yutthana Apichatbutr
Publisher: name: Text and Journal Publication
Year: 2021
Subjects: silicone mask respiration N99
oxygenation
carbondioxide
airway resistance

description: Vajira Medical Journal, 65, 1, 1-12
A coordinated control to improve performance for a building cluster with energy storage, electric vehicles, and energy sharing considered
Creators: name: Huang, Pei
name: Lovati, Marco
name: Zhang, Xingxing
name: Bales, Chris
Publisher: name: arXiv
Year: 2021
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Distributed renewable energy systems are now widely installed in many buildings, transforming the buildings into electricity prosumers. Existing studies have developed some advanced building side controls that enable renewable energy sharing and that aim to optimise building-cluster-level performance via regulating the energy storage charging/ discharging. However, the flexible demand shifting ability of electric vehicles is not considered in these building side controls. For instance, the electric vehicle charging will usually start once they are plugged into charging stations. But, in such charging period the renewable generation may be insufficient to cover the EV charging load, leading to grid electricity imports. Consequently, the building-cluster-level performance is not optimised. Therefore, this study proposes a coordinated control of building prosumers for improving the cluster-level performance, by making use of energy sharing and storage capability of electricity batteries in both buildings and EVs. An EV charging/discharging model is first developed. Then, based on the predicted future 24h electricity demand and renewable generation data, the coordinated control first considers the whole building cluster as one integrated building and optimises its operation as well as the EV charging/discharging using genetic algorithm. Next, the operation of individual buildings in the future 24h is coordinated using nonlinear programming. For validation, the developed control has been tested on a real building cluster in Ludvika, Sweden. The study results show that the developed control can increase the cluster-level daily renewable self-consumption rate by 19% and meanwhile reduce the daily electricity bills by 36% compared with the conventional controls.
Assessment of Personal Exposure to Particulate Emissions in Urban Microenvironments
Creators: name: Balasubramanian, Rajasekhar
Publisher: name: Karlsruhe
Year: 2019

description: The levels of fine (PM2.5), derived from combustion sources, in both outdoor and indoor environments within cities can be very high and are therefore of health concern. In recent years, the focus of several air pollution studies has shifted from PM2.5 to other urban pollutants such as Black Carbon (BC) and ultrafine particles (UFP) due to their association with negative health effects. BC is a light-absorbing component of PM, and a good indicator of exposure to harmful particulate-bound chemical substances such as polycyclic aromatic hydrocarbons (PAHs) emitted from combustion sources such as urban vehicular traffic. UFP (those with aerodynamic diameter less than 0.1 μm) may be more toxic than PM2.5 due to their enhanced pulmonary deposition efficiency and much higher surface area. We assessed the personal exposure to PM2.5, UFPs and BC in diverse outdoor and indoor microenvironments (MEs) in Singapore. Since individuals are always on the move, it is important to follow their activity patterns, which determine their actual exposure. Consequently, a GPS was used to track individual’s movement and exposure across MEs. Potential health risks associated with inhalation exposure to airborne particles were estimated. The findings obtained from the study can be useful for citizens to make informed choices to reduce their exposures to particulate pollution in both outdoor and indoor environments. In addition, the study outcomes provide a scientific basis for the government to implement effective mitigation measures to lower people’s exposure to airborne particles at the city scale, contributing to improved urban air quality and enhanced health benefits.
Phase Transitions and Pairing Signature in Strongly Attractive Fermi Atomic Gases
Creators: name: Guan, X W
name: Batchelor, M T
name: Lee, C
name: Bortz, M
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We investigate pairing and quantum phase transitions in the one-dimensional two-component Fermi atomic gas in an external field. The phase diagram, critical fields, magnetization and local pairing correlation are obtained analytically via the exact thermodynamic Bethe ansatz solution. At zero temperature, bound pairs of fermions with opposite spin states form a singlet ground state when the external field $H < H_{c1}$. A completely ferromagnetic phase without pairing occurs when the external field $H > H_{c2}$. In the region $H_{c1} < H < H_{c2}$ we observe a mixed phase of matter in which paired and unpaired atoms coexist. The phase diagram is reminiscent of that of type II superconductors. For temperatures below the degenerate temperature and in the absence of an external field, the bound pairs of fermions form hard-core bosons obeying generalized exclusion statistics.
description: 9 pages, 5 figures, expanded version with additional text, references and figures
Large-time asymptotic of heavy tailed renewal processes
Creators: name: Horii, Hiroshi
name: Lefevere, Raphael
name: Nemoto, Takahiro
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mathematical Physics (math-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Probability (math.PR)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We study the large-time asymptotic of renewal-reward processes with a heavy-tailed waiting time distribution. It is known that the heavy tail of the distribution produces an extremely slow dynamics, resulting in a singular large deviation function. When the singularity takes place, the bottom of the large deviation function is flattened, manifesting anomalous fluctuations of the renewal-reward processes. In this article, we aim to study how these singularities emerge as the time increases. Using a classical result on the sum of random variables with regularly varying tail, we develop an expansion approach to prove an upper bound of the finite-time moment generating function for the Pareto waiting time distribution (power law) with an integer exponent. We perform numerical simulations using Pareto (with a real value exponent), inverse Rayleigh and log-normal waiting time distributions, and demonstrate similar results are anticipated in these waiting time distributions.
description: discussion of the finite-time asymptotic of the rate function
A Comparative Study between Semi-Quantitative Analysis in [F-18]FDG Brain PET/ CT Scan using Two Different Software Packages in the Diagnosis of Alzheimer's Disease
Creators: name: Maneerat Jubjitt
name: Tanyaluck Thientunyakit
name: Chakmeedaj Sethanandha
Publisher: name: Text and Journal Publication
Year: 2021
Subjects: Alzheimer
Semi-quantitative analysis
dementia
PET
PET/CT

description: Vajira Medical Journal, 65, 1, 13-26
Minimal Flavour Violation and Beyond
Creators: name: Feldmann, Th.
name: Mannel, Th.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Starting from the effective-theory framework for Minimal Flavour Violation, we give a systematic definition of next-to-minimal (quark) flavour violation in terms of a set of spurion fields exhibiting a particular hierarchy with respect to a small (Wolfenstein-like) parameter. A few illustrative examples and their consequences for charged and neutral decays with different quark chiralities are worked out in some detail. Our framework can be used as a model-independent classification scheme for the parameterization of flavour structure from physics beyond the Standard Model.
description: 17 pages, no figures, phenomenological discussion extended, references added