cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Economic botany in the Indian Ocean: official and unofficial botanical gardens on Ile de France and Ile de Bourbon under the French regime, 1735-1810
Creators: name: Muir, Stewart John
Publisher: name: University of British Columbia
Year: 2009

description: France was late to enter the European race for empire in Asia, but it was the earliest nation to employ colonial research gardens to organize the push eastward. The French botanical vanguard settled on the Mascarene Islands in the Indian Ocean where, beginning in the 1730s, a series of gardens contributed to France’s imperial fortunes and provided a model for later plant research networks in other European empires. In spite of past interpretations of French colonial science, there emergences a compelling argument that a dynamic interest in practical applications of scientific knowledge was present in the Indian Ocean region during this period. Botanical gardens on Ile de France and lie de Bourbon performed roles central to the direction of overall French colonial activities. Applied botanical gardens helped develop colonial economies. They exchanged plants with other French colonies, notably in the West Indies. They also provided information and plants, for various purposes, to the metropole. The botanical gardeners of the Mascarenes also represented France to other nations, functioning on its behalf as botanical diplomats sharing knowledge and specimens with foreign countries. This period of economic botanizing ended, for France, in 1810 with the loss of its Mascarenes colonies to the British.
Η διερεύνηση της δυναμικής σχέσης μεταξύ του χρηματιστηρίου και της αγοράς ακινήτων: η περίπτωση του Ηνωμένου Βασιλείου
Creators: name: Εμμανουηλίδου, Φωτεινή Χρήστου
Publisher: name: Aristotle University of Thessaloniki
Year: 2013
Subjects: τιμές ακινήτων
χρηματιστήριο
ARDL συνολοκλήρωση
house prices
stock market
ARDL cointegration

description: Αντικείμενο διερεύνησης της παρούσας διπλωματικής εργασίας αποτελεί η σχέση που υπάρχει μεταξύ της αγοράς ακινήτων και του χρηματιστηρίου του Ηνωμένου Βασιλείου. Είναι γεγονός πως μέσα σε μία αναπτυγμένη οικονομία το χρηματιστήριο, αλλά και η αγορά ακινήτων έχουν βαρύνουσα σημασία και οι χαρτογράφηση των σχέσεων μεταξύ τους θα αποτελούσε σημαντικό εργαλείο στα χέρια όχι μόνο των σχεδιαστών της οικονομικής πολιτικής, αλλά και των επενδυτών. Κύριο μέλημα μας λοιπόν είναι το να απαντήσουμε στο ερώτημα του εάν οι δύο αγορές είναι ολοκληρωμένες ή κατατμημένες και να διερευνήσουμε την κατεύθυνση των αιτιωδών σχέσεων που μπορεί να υπάρχουν μεταξύ των τιμών των ακινήτων και των τιμών των μετοχών του χρηματιστηρίου τόσο στη βραχυχρόνια, όσο και στην μακροχρόνια περίοδο. Παράλληλα, μας απασχόλησαν οι μηχανισμοί μετάδοσης αυτών των αιτιωδών επιδράσεων και στόχος μας ήταν η εμπειρική τεκμηρίωση της ύπαρξης wealth & credit effect για τις υπό εξέταση αγορές. Έτσι λοιπόν, στα πλαίσια της εμπειρικής μελέτης, χρησιμοποιήθηκαν μηνιαίες παρατηρήσεις του γενικού δείκτη τιμών του χρηματιστηρίου του Λονδίνου FTSE100 και του δείκτη τιμών των ακινήτων Halifax για την περίοδο 1984:4-2011:9. Η μεθοδολογία που ακολουθήθηκε για την ανίχνευση της ύπαρξης συνολοκλήρωσης μεταξύ των μεταβλητών ήταν η ARDL των Pesaran & Shin (1999). Συνοπτικά, τα εμπειρικά ευρήματα στα οποία καταλήξαμε καταδεικνύουν την ύπαρξη τόσο ενός wealth effect όσο και ενός credit effect για την μακροχρόνια περίοδο, ενώ για την βραχυχρόνια περίοδο εντοπίστηκε μονόδρομη και όχι αμφίδρομη αιτιότητα με κατεύθυνση από τα χρηματιστήρια προς την αγορά ακινήτων.
description: The current thesis attempts to investigate the relationship between the real estate market and the stock market in the UK. Undeniably within a developed economy both the stock market and the housing market play a significant role, hence understanding how the two markets are connected could be an extremely useful tool for investors and policy makers. Therefore, our main concern is to establish whether the two markets are integrated or segmented and explore the direction of causality both in the short-term and in the long-term. At the same time, our goal was to empirically validate the existence of wealth or credit price effect between the aforementioned markets. For the empirical part of our study we used monthly observations of the FTSE100 stock market index and the Halifax house price index over the period 1984:4-2011:9. The employed econometric approach was the ARDL cointegration technique proposed by Pesaran & Shin (1999). Our findings present evidence supporting the existence of both wealth effect and credit effect for the long-run, while in the short-run we detected a unidirectional causal effect running from stock market towards the real estate market.
Warm Dust and Spatially Variable PAH Emission in the Dwarf Starburst Galaxy NGC 1705
Creators: name: Cannon, John M.
name: Smith, John-David T.
name: Walter, Fabian
name: Bendo, George J.
name: Calzetti, Daniela
name: Dale, Daniel A.
name: Draine, Bruce T.
name: Engelbracht, Charles W.
name: Gordon, Karl D.
name: Helou, George
name: Kennicutt,, Robert C.
name: Leitherer, Claus
name: Armus, Lee
name: Buckalew, Brent A.
name: Hollenbach, David J.
name: Jarrett, Thomas H.
name: Li, Aigen
name: Meyer, Martin J.
name: Murphy, Eric J.
name: Regan, Michael W.
name: Rieke, George H.
name: Rieke, Marcia J.
name: Roussel, Helene
name: Sheth, Kartik
name: Thornley, Michele D.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present Spitzer observations of the dwarf starburst galaxy NGC 1705 obtained as part of SINGS. The galaxy morphology is very different shortward and longward of ~5 microns: short-wavelength imaging shows an underlying red stellar population, with the central super star cluster (SSC) dominating the luminosity; longer-wavelength data reveals warm dust emission arising from two off-nuclear regions offset by ~250 pc from the SSC. These regions show little extinction at optical wavelengths. The galaxy has a relatively low global dust mass (~2E5 solar masses, implying a global dust-to-gas mass ratio ~2--4 times lower than the Milky Way average). The off-nuclear dust emission appears to be powered by photons from the same stellar population responsible for the excitation of the observed H Alpha emission; these photons are unassociated with the SSC (though a contribution from embedded sources to the IR luminosity of the off-nuclear regions cannot be ruled out). Low-resolution IRS spectroscopy shows moderate-strength PAH emission in the 11.3 micron band in the eastern peak; no PAH emission is detected in the SSC or the western dust emission complex. There is significant diffuse 8 micron emission after scaling and subtracting shorter wavelength data; the spatially variable PAH emission strengths revealed by the IRS data suggest caution in the interpretation of diffuse 8 micron emission as arising from PAH carriers alone. The metallicity of NGC 1705 falls at the transition level of 35% solar found by Engelbracht and collaborators; the fact that a system at this metallicity shows spatially variable PAH emission demonstrates the complexity of interpreting diffuse 8 micron emission. A radio continuum non-detection, NGC 1705 deviates significantly from the canonical far-IR vs. radio correlation. (Abridged)
description: ApJ, in press; please retrieve full-resolution version from http://www.astro.wesleyan.edu/~cannon/pubs.html
Associations of serotype with characteristics of the spnd39iii locus implicated in phase switching of pneumococci
Creators: name: C I Mendes
name: M P Machado
name: J  Melo-Cristino
name: J A Carriço
name: M Ramirez
Publisher: name: F1000 Research Limited
Year: 2019

description: Background and aims: A type I restriction-modification system (T1RMS, spnD39III) was implicated in phase variation related to virulence in pneumococci.

Method: We developed a method for the analysis of T1RMS based upon short paired-end reads (ivrTyper) and analysed 37,333 public pneumococcal genomic datasets. We tested the association between serotype and T1RMS by Fisher exact test with FDR correction.

Results: The locus is potentially functional in most genomes (95.7%), although 8.7% were locked due to absence of recombinase gene. Some serotypes presented a higher than expected proportion of isolates with non-functional T1RMS: non-typeable (NT), 1,3, 6B, 8 and 37. All PCV7 serotypes, except serotype 6B, were associated with a lower than expected frequency of impaired T1RMS. Most of the isolates with a functional locus (n=35,733) dominantly expressed the 1.1 Target Recognition Domain (TRD, 82%) but some serotypes were associated with expression of the less frequent alternative 1.2 TRD: NT, 1, 3, 7F, 12F, 9N, 32A, 35F. Most of the isolates for which we could determine the dominantly expressed allele (n=19,789) expressed alleles with the 1.1 TRD: A (1.1-2.1) 37%, E (1.1-2.3) 17.5%, B (1.1-2.2) 11.3%, while among 1.2 TRD isolates dominated allele C (1.2-2.2) 9.4%.

Conclusions: Most of the isolates dominantly expressed alleles associated with the opaque phenotype (A and E) shown to be more virulent. However,some serotypes, including the highly virulent serotypes 1 and 3, were associated with alleles responsible for a transparent phenotype or lacked a functional locus. These results highlight the need for further studies to understand virulence modulation in these serotypes.
Field Linkage and Magnetic Helicity Density
Creators: name: Jardine, Moira
name: Lund, Kristin
name: Russell, Alexander
name: Donati, Jean-Francois
name: Fares, Rim
name: Folsom, Colin
name: Jeffers, Sandra
name: Marsden, Stephen
name: Morin, Julien
name: Petit, Pascal
name: See, Victor
Publisher: name: Zenodo
Year: 2021
Subjects: The Sun - Very low mass stars
Young stars

description: The helicity of a magnetic field is a fundamental property that is conserved in ideal MHD. It can be explored in the stellar context by mapping large-scale magnetic fields across stellar surfaces using Zeeman-Doppler imaging. A recent study of 51 stars in the mass range 0.1-1.34 M$_\odot$ showed that the photospheric magnetic helicity density follows a single power law when plotted against the toroidal field energy, but splits into two branches when plotted against the poloidal field energy. These two branches divide stars above and below $\sim$ 0.5 M$_\odot$. We present here a novel method of visualising the helicity density in terms of the linkage of the toroidal and poloidal fields that are mapped across the stellar surface. This approach allows us to classify the field linkages that provide the helicity density for stars of different masses and rotation rates. We find that stars on the lower-mass branch tend to have toroidal fields that are non-axisymmetric and so link through regions of positive and negative poloidal field. A lower-mass star may have the same helicity density as a higher-mass star, despite having a stronger poloidal field. Lower-mass stars are therefore less efficient at generating large-scale helicity.
Condensation phenomena of conserved-mass aggregation model on weighted complex networks
Creators: name: Kwon, Sungchul
name: Yoon, Sooyeon
name: Kim, Yup
Publisher: name: arXiv
Year: 2008
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We investigate the condensation phase transitions of conserved-mass aggregation (CA) model on weighted scale-free networks (WSFNs). In WSFNs, the weight $w_{ij}$ is assigned to the link between the nodes $i$ and $j$. We consider the symmetric weight given as $w_{ij}=(k_i k_j)^α$. In CA model, the mass $m_i$ on the randomly chosen node $i$ diffuses to a linked neighbor of $i$,$j$, with the rate $T_{ji}$ or an unit mass chips off from the node $i$ to $j$ with the rate $ωT_{ji}$. The hopping probability $T_{ji}$ is given as $T_{ji}= w_{ji}/\sum_{} w_{li}$, where the sum runs over the linked neighbors of the node $i$. On the WSFNs, we numerically show that a certain critical $α_c$ exists below which CA model undergoes the same type of the condensation transitions as those of CA model on regular lattices. However for $α\geq α_c$, the condensation always occurs for any density $ρ$ and $ω$. We analytically find $α_c = (γ-3)/2$ on the WSFN with the degree exponent $γ$. To obtain $α_c$, we analytically derive the scaling behavior of the stationary distribution $P^{\infty}_k$ of finding a walker at nodes with degree $k$, and the probability $D(k)$ of finding two walkers simultaneously at the same node with degree $k$. We find $P^{\infty}_k \sim k^{α+1-γ}$ and $D(k) \sim k^{2(α+1)-γ}$ respectively. With $P^{\infty}_k$, we also show analytically and numerically that the average mass $m(k)$ on a node with degree $k$ scales as $k^{α+1}$ without any jumps at the maximal degree of the network for any $ρ$ as in the SFNs with $α=0$.
description: 8 pages, 6 figures
Discovery of Photospheric Calcium Line Strength Variations in the DAZd White Dwarf G29-38
Creators: name: von Hippel, Ted
name: Thompson, Susan E.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Metals in the photospheres of white dwarfs with Teff between 12,000 and 25,000 K should gravitationally settle out of these atmospheres in 1-2 weeks. Temporal variations in the line strengths of these metals could provide a direct measurement of episodic metal accretion. Using archival VLT and Keck spectroscopy, we find evidence that the DAZd white dwarf G29-38 shows significant changes in its Ca II K line strength. At the two best-observed epochs, we find that the Ca line equivalent width (EW) = 165 +- 4 mA (in 1996.885) and 280 +- 8 mA (in 1999.653), which is an increase of 70%. We consider the effect that pulsation has on the Ca EWs for this known variable star, and find that it adds an error of < 1 mA to these measurements. Calcium line strengths at other observational epochs support variations with timescales as short as two weeks. These Ca EW variations indicate that the metal accretion process in G29-38, presumably from its debris disk, is episodic on timescales of a few weeks or less, and thus the accretion is not dominated by Poynting-Robertson drag from an optically thin, continuous disk, which has a timescale of ~1 year.
description: 15 pages, 4 figures, ApJ accepted
Analysis of personality ratings using the social relations model
Creators: name: Reynolds, Shawn Patrick
Publisher: name: University of British Columbia
Year: 2009

description: Three datasets (N=90, 65, and 88) each provided three modes of assessment of the Big Five factors: Questionnaire, self-rating and peer-ratings. All participants completed the questionnaire before meeting in small discussion groups; afterward, participants rated one another and themselves. Kenny's Social Relations Model (SRM) was used (a) to partition target, rater and relationship components of the rating data, and (b) to correlate the three stable component scores with the questionnaire and self-rating measures. For each of the Big Five, such statistics provide measures of reliability and validity as well as indexing projection, reciprocity, and self-enhancement. It was hypothesized that (a) the three assessment modes would converge, (b) target variance would be stronger than in previous research, (c) self-ratings would be more positive than other-ratings, and (d) projection would be significant but reciprocity would not. In general, these hypotheses were confirmed.
Novikov-Veselov Symmetries of the Two-Dimensional $O(N)$ Sigma Model
Creators: name: Krichever, Igor
name: Nekrasov, Nikita
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mathematical Physics (math-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Algebraic Geometry (math.AG)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We show that Novikov-Veselov hierarchy provides a complete family of commuting symmetries of two-dimensional $O(N)$ sigma model. In the first part of the paper we use these symmetries to prove that the Fermi spectral curve for the double-periodic sigma model is algebraic. Thus, our previous construction of the complexified harmonic maps in the case of irreducible Fermi curves is complete. In the second part of the paper we generalize our construction to the case of reducible Fermi curves and show that it gives the conformal harmonic maps to even-dimensional spheres. Remarkably, the solutions are parameterized by spectral curves of turning points of the elliptic Calogero-Moser system.
Refuting the odd number limitation of time-delayed feedback control
Creators: name: Fiedler, B.
name: Flunkert, V.
name: Georgi, M.
name: Hoevel, P.
name: Schoell, E.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: We refute an often invoked theorem which claims that a periodic orbit with an odd number of real Floquet multipliers greater than unity can never be stabilized by time-delayed feedback control in the form proposed by Pyragas. Using a generic normal form, we demonstrate that the unstable periodic orbit generated by a subcritical Hopf bifurcation, which has a single real unstable Floquet multiplier, can in fact be stabilized. We derive explicit analytical conditions for the control matrix in terms of the amplitude and the phase of the feedback control gain, and present a numerical example. Our results are of relevance for a wide range of systems in physics, chemistry, technology,and life sciences, where subcritical Hopf bifurcations occur.
description: 4 pages, 3 figures, in print at Phys Rev Lett
CMDNet: Learning a Probabilistic Relaxation of Discrete Variables for Soft Detection with Low Complexity
Creators: name: Beck, Edgar
name: Bockelmann, Carsten
name: Dekorsy, Armin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Signal Processing (eess.SP)
subject: Artificial Intelligence (cs.AI)
subject: Information Theory (cs.IT)
subject: Machine Learning (cs.LG)
subject: Machine Learning (stat.ML)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Following the great success of Machine Learning (ML), especially Deep Neural Networks (DNNs), in many research domains in 2010s, several ML-based approaches were proposed for detection in large inverse linear problems, e.g., massive MIMO systems. The main motivation behind is that the complexity of Maximum A-Posteriori (MAP) detection grows exponentially with system dimensions. Instead of using DNNs, essentially being a black-box, we take a slightly different approach and introduce a probabilistic Continuous relaxation of disCrete variables to MAP detection. Enabling close approximation and continuous optimization, we derive an iterative detection algorithm: Concrete MAP Detection (CMD). Furthermore, extending CMD by the idea of deep unfolding into CMDNet, we allow for (online) optimization of a small number of parameters to different working points while limiting complexity. In contrast to recent DNN-based approaches, we select the optimization criterion and output of CMDNet based on information theory and are thus able to learn approximate probabilities of the individual optimal detector. This is crucial for soft decoding in today's communication systems. Numerical simulation results in MIMO systems reveal CMDNet to feature a promising accuracy complexity trade-off compared to State of the Art. Notably, we demonstrate CMDNet's soft outputs to be reliable for decoders.
description: Submitted for publication
Norbert Eschbach, Panathenäische Preisamphoren aus dem Kerameikos zu Athen
Creators: name: Moore, Mary B.
Publisher: name: Bonner Jahrbücher
Year: 2021

description: Rezension zu: Norbert Eschbach, Panathenäische Preisamphoren aus dem Kerameikos zu Athen. Kerameikos. Ergebnisse der Ausgrabungen XXI. Publisher Dr. Ludwig Reichert, Wiesbaden 2017. 353 pages; 28 black and white photos in the text; Beilage I, 1–11; II, 1–14; 126 color plates
description: Bonner Jahrbücher, Bd. 217.2017(2018): Bonner Jahrbücher
Ο ρόλος του φωτός στη ζωγραφική του Γ. Μπουζιάνη, του Ν. Χατζηκυριάκου-Γκίκα και του Π. Τετση
Creators: name: Ευαγγελόπουλος, Παναγιώτης Αθανασίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2013
Subjects: Φως
Ζωγραφική
Μπουζιάνης, Γκίκας, Τέτσης
Light
Painting
Bouzianis, Ghikas, Tetsis

description: Στη συγκεκριμένη εργασία εξετάστηκε ο ρόλος του φωτός στη ζωγραφική του Γιώργου Μπουζιάνη, του Νίκου Χατζηκυριάκου–Γκίκα και του Παναγιώτη Τέτση. Στόχος της εργασίας δεν αποτελεί η ποσοτική χρήση του φωτός εν είδει διαγωνισμού ανάμεσα στους τρείς καλλιτέχνες, αλλά η σε βάθος μελέτη αυτού του βασικού ζωγραφικού παράγοντα και του ρόλου που έπαιξε στο έργο τους. Με βάση αυτό το σκεπτικό εξετάστηκε η γεωγραφία του φωτός στη ζωγραφική των τριών αυτών καλλιτεχνών. Κατά πόσο μπορεί να επιδράσει η γεωγραφική περιοχή όπου δρα ένας καλλιτέχνης στο έργο του. Επίσης εξετάστηκαν οι αναζητήσεις των τριών καλλιτεχνών περί ελληνικού φωτός. Με ποιόν τρόπο προβάλλουν μέσα από το έργο τους ορισμένα εθνικά καλλιτεχνικά χαρακτηριστικά και δημιουργούν συγκινησιακές φορτίσεις ή ιδεολογικούς συνειρμούς. Ακόμη εξετάστηκε η λειτουργία και κατανόηση των αξιών του φωτός και της ατμόσφαιρας που αυτό παράγει σε σχέση με το σχέδιο και το χρώμα.
description: This paper examines the role of light in the George Bouzianis', Nikos Chadjikyriakos-Ghikas' and Panagiotis Tetsis' painting. The goal of this paper is not the excess in the use of light as if it were a competition among the three artists but the in-depth study of this basic element in painting as well as the role that served in their work. Based on this reasoning, this paper examines the geography of light in the painting of these three artists and whether the geographic region that an artist acts influences his work. Furthermore, it examines the pursuits of these three artists about greek light. The way in which certain national artistic features creating emotive charge or ideological connotations were displayed through their work. And finally, the function and the understanding of the principles of light as well as the ambience created by it in relation to drawing and colour.
Holographic entanglement entropy of de Sitter braneworld
Creators: name: Iwashita, Yukinori
name: Kobayashi, Tsutomu
name: Shiromizu, Tetsuya
name: Yoshino, Hirotaka
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We study the holographic representation of the entanglement entropy, recently proposed by Ryu and Takayanagi, in a braneworld context. The holographic entanglement entropy of a de Sitter brane embedded in an anti-de Sitter (AdS) spacetime is evaluated using geometric quantities, and it is compared with two kinds of de Sitter entropy: a quarter of the area of the cosmological horizon on the brane and entropy calculated from the Euclidean path integral. We show that the three entropies coincide with each other in a certain limit. Remarkably, the entropy obtained from the Euclidean path integral is in precise agreement with the holographic entanglement entropy in all dimensions. We also comment on the case of a five-dimensional braneworld model with the Gauss-Bonnet term in the bulk.
description: 5 pages, no figures, minor corrections, accepted for publication in Phys. Rev. D
Pixel-reassignment in Ultrasound Imaging
Creators: name: Sommer, Tal I.
name: Katz, Ori
Publisher: name: arXiv
Year: 2021
Subjects: subject: Medical Physics (physics.med-ph)
subject: Image and Video Processing (eess.IV)
subject: FOS: Physical sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: We present an adaptation of the pixel-reassignment technique from confocal fluorescent microscopy to coherent ultrasound imaging. The method, Ultrasound Pixel-Reassignment (UPR), provides a resolution and signal to noise (SNR) improvement in ultrasound imaging by computationally reassigning off-focus signals acquired using traditional plane-wave compounding ultrasonography. We theoretically analyze the analogy between the optical and ultrasound implementations of pixel reassignment, and experimentally evaluate the imaging quality on tissue-mimicking acoustic phantoms. We demonstrate that UPR provides a $25\%$ resolution improvement and a $3dB$ SNR improvement in in-vitro scans, without any change in hardware or acquisition scheme.
Bettina Kreuzer, Panathenäische Preisamphoren und rotfigurige Keramik aus dem Heraion von Samos
Creators: name: Eschbach, Norbert
Publisher: name: Bonner Jahrbücher
Year: 2021

description: Rezension zu: Bettina Kreuzer, Panathenäische Preisamphoren und rotfigurige Keramik aus dem Heraion von Samos. Samos XXIII. Verlag Dr. Ludwig Reichert, Wiesbaden 2017. VIII und 122 Seiten sowie 36 Tafeln.
description: Bonner Jahrbücher, Bd. 217.2017(2018): Bonner Jahrbücher
Mott Insulator-like Bose-Einstein Condensation in a Tight-Binding System of Interacting Bosons with a Flat Band
Creators: name: Katsura, Hosho
name: Kawashima, Naoki
name: Morita, Satoshi
name: Tanaka, Akinori
name: Tasaki, Hal
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We propose a new class of tight-binding systems of interacting bosons with a flat band, which are exactly solvable in the sense that one can explicitly write down the unique ground state. The ground state is expressed in terms of local creation operators, and apparently resembles that of a Mott insulator. Based on an exact representation in terms of a classical loop-gas model, we conjecture that the ground state may exhibit quasi Bose-Einstein condensation (BEC) or genuine BEC in dimensions two and three or higher, respectively, still keeping Mott insulator-like character. Our Monte Carlo simulation of the loop-gas model strongly supports this conjecture, i.e., the ground state undergoes a Kosterlitz-Thouless transition and exhibits quasi BEC in two dimensions.
description: 14 pages, 13 figures. The format has been changed and some discussions has been added in vers. 5. Further improvements and a new figure (Fig.2) in vers. 6. There is a 22.5 minutes video in which the main results of the paper are described. See https://youtu.be/ef9x11C1cVg
A proposal for realising quantum scars in the tilted 1D Fermi-Hubbard model
Creators: name: Desaules, Jean-Yves
name: Hudomal, Ana
name: Turner, Christopher J.
name: Papić, Zlatko
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Motivated by recent observations of ergodicity breaking due to Hilbert space fragmentation in 1D Fermi-Hubbard chains with a tilted potential [Scherg et al., arXiv:2010.12965], we show that the same system also hosts quantum many-body scars in a regime $U\approx Δ\gg J$ at electronic filling factor $ν=1$. We numerically demonstrate that the scarring phenomenology in this model is similar to other known realisations such as Rydberg atom chains, including persistent dynamical revivals and ergodicity-breaking many-body eigenstates. At the same time, we show that the mechanism of scarring in the Fermi-Hubbard model is different from other examples in the literature: the scars originate from a subgraph, representing a free spin-1 paramagnet, which is weakly connected to the rest of the Hamiltonian's adjacency graph. Our work demonstrates that correlated fermions in tilted optical lattices provide a platform for understanding the interplay of many-body scarring and other forms of ergodicity breaking, such as localisation and Hilbert space fragmentation.
description: 13 pages, 15 figures
Gerhard Kuhn, Das Heilige Tor. Kerameikos. Ergebnisse der Ausgrabungen, Band XIX
Creators: name: Sinn, Ulrich
Publisher: name: Bonner Jahrbücher
Year: 2021

description: Rezension zu: Gerhard Kuhn, Das Heilige Tor. Kerameikos. Ergebnisse der Ausgrabungen, Band XIX. Mit einem Anhang von Bettina von Freytag gen. Löringhoff. Verlag Dr. Ludwig Reichert, Wiesbaden 2017. XII und 268 Seiten mit 256 Abbildungen und 7 Beilagen
description: Bonner Jahrbücher, Bd. 217.2017(2018): Bonner Jahrbücher
Novel methods for distributed acoustic sensing data
Creators: name: Wilson, Rebecca
Publisher: name: Lancaster University
Year: 2019

description: In this thesis, we propose novel methods for analysing nonstationary, multivariate time series, focusing in particular on the problems of classification and imputation within this context. Many existing methods for time series classification are static, in that they assign the entire series to one class and do not allow for temporal dependence with the signal. In the first part of this thesis, we propose a computationally efficient extension of an existing dynamic classification method to the online setting. Dependence within the series is captured by adopting the multivariate locally stationary wavelet (mvLSW) framework and the signal is classified at each time point into one of a number of known classes. We apply the method to multivariate acoustic sensing data in order to detect anomalous regions and evaluate the results against alternative methods in the literature. The second part of this thesis considers imputation in multivariate locally stationary time series containing missing values. We first introduce a method for estimating the local wavelet spectral matrix that can be used in the presence of missingness. We then propose a novel method for imputing missing values that uses the local auto and cross-covariance functions of a mvLSW process to perform one step-ahead forecasting and backcasting. The performance of this nonstationary imputation approach is then assessed against competitor methods for simulated examples and a case study involving a dataset from a Carbon Capture and Storage facility. The software that implements this imputation scheme is also described, together with examples of the R package functionality.
Dietmar Kurapkat and Ulrike Wulf-Rheidt (†) (editors), Werkspuren. Materialverarbeitung und handwerkliches Wissen im antiken Bauwesen
Creators: name: Vitti, Paolo
Publisher: name: Bonner Jahrbücher
Year: 2021

description: Rezension zu: Dietmar Kurapkat and Ulrike Wulf-Rheidt (†) (editors), Werkspuren. Materialverarbeitung und handwerkliches Wissen im antiken Bauwesen. Internationales Kolloquium in Berlin vom 13.–16. Mai 2015, veranstaltet vom Architekturreferat des DAI im Henry-Ford-Bau der Freien Universität Berlin. Diskussionen zur Archäologischen Bauforschung, volume 12. Publisher Schnell und Steiner, Regensburg 2017. XIII and 466 pages with 438 illustrations and an overview map.
description: Bonner Jahrbücher, Bd. 217.2017(2018): Bonner Jahrbücher
Quantum scalar field theories with fractional operators
Creators: name: Calcagni, Gianluca
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We study a class of perturbative scalar quantum field theories where dynamics is characterized by Lorentz-invariant or Lorentz-breaking non-local operators of fractional order and the underlying spacetime has a varying spectral dimension. These theories are either ghost free or power-counting renormalizable but they cannot be both at the same time. However, some of them are one-loop unitary and finite, and possibly unitary and finite at all orders.
description: 49 pages, 5 figures. v2: gravity part moved into a separate paper (arXiv:2106.15430), advanced/retarded Green's functions added, unitarity proof with self-interactions added, connection with IR nonlocal gravity models strengthened, references added; v3: minor typos corrected, mistake corrected in equation (119) which propagated to some equations but did not alter any of the conclusions
The outcomes of measurements in the de Broglie-Bohm theory
Creators: name: Tastevin, G.
name: Laloë, F.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Within the de Broglie-Bohm (dBB) theory, the measurement process and the determination of its outcome are usually discussed in terms of the effect of the Bohmian positions of the measured system S. %} This article shows that the Bohmian positions associated with the measurement apparatus M can actually play a crucial role in the determination of the result of measurement. Indeed, in many cases, the result is practically independent of the initial value of a Bohmian position associated with S, and determined only by those of M. The measurement then does not reveal the value of any pre-existing variable attached to S, but just the initial state of the measurement apparatus. Quantum contextuality then appears with particular clarity as a consequence of the dBB dynamics for entangled systems.
description: 21 pages, 10 figures. Two references added, one paragraph in the introduction and another paragraph in the discussion (slow and fast pointers) changed
Crossover between trivial zero modes in Majorana nanowires
Creators: name: Pan, Haining
name: Sarma, Sankar Das
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We consider the superconductor-semiconductor nanowire hybrid Majorana platform ("Majorana nanowire") in the presence of a deterministic spatially slowly varying inhomogeneous chemical potential and a random spatial quenched potential disorder, both of which are known to produce nontopological almost-zero-energy modes mimicking the theoretically predicted topological Majorana zero modes. We study the crossover among these mechanisms by calculating the tunnel conductance while varying the relative strength between inhomogeneous potential and random disorder in a controlled manner. We find that the entire crossover region manifests abundant trivial zero modes, many of which showing the apparent "quantization" of the zero-bias conductance peak at $ 2e^2/h $, with occasional disorder-dominated peaks exceeding $ 2e^2/h $. We present animations of the simulated crossover behavior and discuss experimental implications. Additionally, in order to simulate the realistic disorder in experimental nanowires, we also study in depth the case of disorder arising from random individual static impurities along the wire, and consider crossover associated with such impurity effects. Our results, when compared qualitatively with existing Majorana nanowire experimental results, indicate the dominant role of random disorder in the experiments. It turns out that all three mechanisms may produce trivial zero-bias peaks in the tunnel conductance, and the crossover among these physical mechanisms (i.e., when more than one mechanism is present in the system) is smooth and continuous, making it difficult a priori to conclude which mechanism is dominant in a particular sample just by a casual inspection of the zero-bias conductance peaks.
description: 26 pages, 19 figures
The discursive construction of trolling on British and Hungarian political blogs
Creators: name: Petyko, Marton
Publisher: name: Lancaster University
Year: 2019

description: This thesis looks at how users construct trolling as a negatively marked communicative behaviour and troll as a behaviour-based identity in their comments on British and Hungarian political blogs, thus focusing on the users’ metapragmatic discourses on online trolling. The main aim of the thesis is to identify the perceived actions, motives, and aims that users associate with trolling in their comments. The thesis is also concerned with how these actions, motives, and aims affect the ways in which trolling is depicted and trolls are portrayed in the users’ comments. To answer these questions, the thesis presents a corpus-based analysis of 6,129 British and 1,118 Hungarian comments in which users call someone a troll or refer to someone’s behaviour as trolling or trollkodás. These comments were collected from 1,713 British and 519 Hungarian comment threads, which were posted on 27 British and 28 Hungarian political blogs in 2015. The thesis observes that British and Hungarian commenters attribute the same four activities, five motives, and six aims to the alleged trolls. The perceived trolling activities include spamming, ignoring or withholding information, flaming, and dishonesty, which in total cover sixteen specific actions. The trolls’ perceived motives comprise various emotional, mental health-related, and social reasons, financial gain, political beliefs, being employed by a political body, and unspecified political affiliation. Finally, the trolls’ perceived aims involve diverting others’ attention, triggering unpleasant emotions, eliciting responses, provoking conflict, misleading or confusing others, and disrupting the ongoing discussion. The analysis also shows that, although users construct trolling and trolls in many different ways, trolling is generally conceptualised as a non-normative and manipulative behaviour while trolls are portrayed as bad debaters and uncooperative troublemakers.
Relating spin-foam to canonical loop quantum gravity by graphical calculus
Creators: name: Yang, Jinsong
name: Zhang, Cong
name: Ma, Yongge
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The graphical calculus method is generalized to study the relation between covariant and canonical dynamics of loop quantum gravity. On one hand, a graphical derivation of the partition function of the generalized Euclidean Engle-Pereira-Rovelli-Livine (EPRL) spin-foam model is presented. On the other hand, the action of a Euclidean Hamiltonian constraint operator on certain spin network states is calculated by graphical method. It turns out that the EPRL model can provide a rigging map such that the Hamiltonian constraint operator is weakly satisfied on certain physical states for the Immirzi parameter $β=1$. In this sense, the quantum dynamics between the covariant and canonical formulations are consistent to each other.
description: 19 pages
Τα πρόδηλα σφάλματα των κτηματολογικών εγγραφών και η διόρθωσή τους
Creators: name: Κοτσάνη, Χριστίνα Αθανασίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2013
Subjects: Κτηματολόγιο
Πρόδηλο σφάλμα
Διόρθωση
Real Estate Registry
Manifest error
Amendment

description: Σκοπός της μεταπτυχιακής εργασίας ήταν η μελέτη των πρόδηλων σφαλμάτων των κτηματολογικών εγγραφών και η διόρθωσή τους. Εξετάσαμε το χαρακτήρα και την περιπτωσιολογία των σφαλμάτων αυτών κατά τη διαδικασία της κτηματογράφησης, καθώς και τη διαδικασία διόρθωσής τους. Στη συνέχεια, παρουσιάσαμε την έννοια του πρόδηλου σφάλματος στο στάδιο του λειτουργούντος κτηματολογίου, εκθέτοντας αναλυτικά την περιπτωσιολογία, τη δυνατότητα διόρθωσης των σφαλμάτων αυτών, τους τρόπους διόρθωσης και την ακολουθούμενη διαδικασία. Η παράθεση αυτή έγινε με τη βοήθεια της εξέτασης του θεσμού όπως αυτός διαμορφώθηκε κατόπιν των νομοθετικών τροποποιήσεων που μεσολάβησαν και κατέληξαν να αποδίδουν στη διαδικασία αυτή τη σημερινή του μορφή. Τέλος, για την πληρέστερη και σαφέστερη κατανόηση του αντικειμένου της εργασίας, παραθέσαμε τα πιο αντιπροσωπευτικά νομολογιακά παραδείγματα, φωτίζοντας με τον τρόπο αυτό και τη θέση των ελληνικών δικαστηρίων στη συγκεκριμένη διαδικασία.
description: The aim of the present thesis was the study of manifest errors of registrations in the Real Estate Registry and their amendment. We examined the nature and the casuistry of these errors during the process of land registration, and the procedure to amend them. Then we presented the meaning of the manifest error at the stage of functioning cadastre, specifying in detail the casuistry, the possibility of the amendment of these errors, the methods for that and the following procedure. This issue was quoted through the examination of the ordinance, as it was formed by the legislative amendments that occurred and redounded to attribute to the procedure its current form. Finally, for a fuller and clearer understanding of the thesis’ object, we presented the most representative jurisprudential examples, enlightening the position of the Greek Court upon the issue.
Gefährdungsbeurteilung von Logistiktätigkeiten: Vorstellung des Ergonomie- und Exoskelett-Quick-Checks
Creators: name: Kretschmer, Veronika
name: Kinne, Semhar
name: :Unav
Publisher: name: Fraunhofer-Gesellschaft
Year: 2023
Subjects: Ergonomie-Quick-Check
Gefährdungsbeurteilung
Muskel-Skellet-Erkrankungen
operative Logistik
psychische Belastung

description: Zur Vermeidung und Vorbeugung von betrieblichen Gesundheitsgefahren in der operativen Logistik wurden am Fraunhofer IML zwei Methoden entwickelt. Der Ergonomie-Quick-Check analysiert und bewertet psychische und physische Arbeitsanforderungen und besteht aus subjektiven (schriftliche Befragung, explorative Interviews) und objektiven Messverfahren (Motion-Capture-Sensorik, biomechanisches Messsystem). Unter Teilnahme der Fachkraft für Arbeitssicherheit (Sifa) und eines Prozessverantwortlichen wird ergänzend ein Workshop mit geeigneten Leitmerkmalmethoden durchgeführt. Auf Basis der Ergebnisse werden Maßnahmen zur ergonomischen Arbeitsplatz- und Prozessgestaltung sowie zur Vermeidung von Muskel-Skelett- und psychischen Beschwerden und Erkrankungen in der Logistik abgeleitet. Der Ergonomie-Quick-Check trägt zur Gefährdungsbeurteilung physischer und psychischer Belastungen und Prävention von Gesundheitsrisiken sowie deren Dokumentation bei (§ 5-6 ArbSchG, DGUV 2013). Darauf aufbauend und um den Unternehmensbedarfen zu begegnen, unergonomische Arbeitsplätze in der operativen Logistik durch den Einsatz von Exoskeletten zu verbessern und so Muskel-Skelett-Erkrankungen vorzubeugen, werden Exoskelett-Quick-Checks unter Einbezug von u. a. Betriebsarzt und Sifa durchgeführt. Diese bestehen aus einer Informationsveranstaltung zur Exoskelett-Technologie inklusive Fittings, Probearbeiten sowie Evaluierung mit einer schriftlichen Befragung auf Beschäftigtenebene.
Ο ναυλομεσίτης: έννοια, ρόλος και ευθύνη
Creators: name: Χατζηϊωαννίδου, Λεμόνα Μιχαήλ
Publisher: name: Aristotle University of Thessaloniki
Year: 2013
Subjects: ναυλομεσίτης
ρόλος
ευθύνη
shipbroker
role
liability

description: Η παρούσα διπλωματική εργασία πραγματεύεται την έννοια, τον ρόλο και την ευθύνη του ναυλομεσίτη. Αρχικά, δίνεται η έννοια του ναυλομεσίτη , ο ορισμός , τα είδη και ο κύριος ρόλος του ναυλομεσίτη. Επίσης, γίνεται η διάκριση της έννοιας του ναυλομεσίτη από συγγενείς έννοιες, έτσι ώστε να οριοθετηθεί πιο εύστοχα ο ρόλος του. Έπειτα, γίνεται αναφορά στο αντικείμενο της ναυλομεσιτείας ,όπου αναπτύσσεται πιο αναλυτικά η σύμβαση ναυλομεσιτείας, ποια είναι τα συμβαλλόμενα μέρη και δίνεται η νομική φύση της. Παρακάτω, δίνεται το νομικό πλαίσιο που περιβάλλει τον ναυλομεσίτη ως προς την ευθύνη του, τόσο την συμβατική όσο και την αδικοπρακτική. Μάλιστα, μελετάται η ευθύνη του στην περίπτωση της ανώμαλης εξέλιξης της σύμβασης ναυλομεσιτείας αλλά και όταν υπερβαίνει τα όρια του τόσο απέναντι στον εντολέα του όσο και στους τρίτους.Αντί επιλόγου, εξετάζεται αν ένας ναυλομεσίτης είναι εμπορικός αντιπρόσωπος.
description: This thesis deals with the concept, the role and the liability of the shipbroker. Firstly, there is the concept of the shipbroker, the definition, the types and the main role of the shipbroker. We ,also, distinguish the concept of the shipbroker from related concepts in order to define more accurately its role. Then, we refer to the object of the shipbroking , where the contract of the shipbroking is developed in more detail, who are the parties and is given the legal nature. Below, we provide the legal framework , which is surrounding the shipbroker about his liability of both the contractual and the tortious. Indeed, is studied his liability in the event of abnormal development of the contract of the shipbroking but also when he exceeds his limits ,of both to his principal and third parties. Instead of epilogue, it is be investigated whether a broker is a commercial agent.
Test of the heavy quark-light diquark approximation for baryons with a heavy quark
Creators: name: Hernández, E.
name: Nieves, J.
name: Verde-Velasco, J. M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We check a commonly used approximation in which a baryon with a heavy quark is described as a heavy quark-light diquark system. The heavy quark influences the diquark internal motion reducing the average distance between the two light quarks. Besides, we show how the average distance between the heavy quark and any of the light quarks, and that between the heavy quark and the center of mass of the light diquark, are smaller than the distance between the two light quarks, which seems to contradict the heavy quark-light diquark picture. This latter result is in agreement with expectations from QCD sum rules and lattice QCD calculations. Our results also show that the diquark approximations produces larger masses than the ones obtained in a full calculation.
description: 9 latex pages, 5 figures, 6 tables
On the Complexity of Exact Maximum-Likelihood Decoding for Asymptotically Good Low Density Parity Check Codes
Creators: name: Xu, Weiyu
name: Hassibi, Babak
Publisher: name: arXiv
Year: 2007
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: Since the classical work of Berlekamp, McEliece and van Tilborg, it is well known that the problem of exact maximum-likelihood (ML) decoding of general linear codes is NP-hard. In this paper, we show that exact ML decoding of a classs of asymptotically good error correcting codes--expander codes, a special case of low density parity check (LDPC) codes--over binary symmetric channels (BSCs) is possible with an expected polynomial complexity. More precisely, for any bit-flipping probability, $p$, in a nontrivial range, there exists a rate region of non-zero support and a family of asymptotically good codes, whose error probability decays exponentially in coding length $n$, for which ML decoding is feasible in expected polynomial time. Furthermore, as $p$ approaches zero, this rate region approaches the channel capacity region. The result is based on the existence of polynomial-time suboptimal decoding algorithms that provide an ML certificate and the ability to compute the probability that the suboptimal decoder yields the ML solution. One such ML certificate decoder is the LP decoder of Feldman; we also propose a more efficient $O(n^2)$ algorithm based on the work of Sipser and Spielman and the Ford-Fulkerson algorithm. The results can be extended to AWGN channels and suggest that it may be feasible to eliminate the error floor phenomenon associated with message-passage decoding of LDPC codes in the high SNR regime. Finally, we observe that the argument of Berlekamp, McEliece and van Tilborg can be used to show that ML decoding of the considered class of codes constructed from LDPC codes with regular left degree, of which the considered expander codes are a special case, remains NP-hard; thus giving an interesting contrast between the worst-case and expected complexities.
description: an attempt at exploring the communication complexity limit,5 pages,submitted to 2007 IEEE International Symposium on Information Theory (ISIT 2007)