cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Proxy-SU(3) symmetry in the shell model basis
Creators: name: Martinou, Andriana
name: Bonatsos, Dennis
name: Minkov, N.
name: Assimakis, I. E.
name: Peroulis, S. K.
name: Sarantopoulou, S.
name: Cseh, J.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The proxy-SU(3) symmetry has been proposed for spin-orbit like nuclear shells using the asymptotic deformed oscillator basis for the single particle orbitals, in which the restoration of the symmetry of the harmonic oscillator shells is achieved by a change of the number of quanta in the z-direction by one unit for the intruder parity orbitals. The same definition suffices within the cartesian basis of the Elliott SU(3) model. Through a mapping of the cartesian Elliott basis onto the spherical shell model basis, we translate the proxy-SU(3) approximation into spherical coordinates, proving, that in the spherical shell model basis the proxy-SU(3) approximation corresponds to the replacement of the intruder parity orbitals by their de Shalit--Goldhaber partners. Furthermore it is shown, that the proxy-SU(3) approximation in the cartesian Elliott basis is equivalent to a unitary transformation in the z-coordinate, leaving the x-y plane intact, a result which in the asymptotic deformed oscillator coordinates implies, that the z-projections of angular momenta and spin remain unchanged. The present work offers a microscopic justification of the proxy-SU(3) approximation and in addition paves the way, for taking advantage of the proxy-SU(3) symmetry in shell model calculations.
description: 15 pages, 7 tables, 1 figure
Lorentz Transformation as a 'Complementary Time-Dependent Coordinate Transformation'. The Physical Foundation of Einstein' Special Relativity
Creators: name: Ceapa, A. C. V.
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Physics (physics.gen-ph)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: We here deduce Lorentz transformation (LT) as a member of a class of time-dependent coordinate transformations, complementary to those already known as spatial translations and rotations. This exercise validates the principle of physical determination of equations within special relativity theory (SRT), in accordance with the derivation of the LT in Einstein's original paper on relativity. This validation is possible because our LT deduction also discloses the real physics warranting Einstein's manipulations of several equations in that paper, thus proving the correctness of his derivation of the LT. The essential role of the revelation in the act of science then results. Far from being an arbitrary dogmatic construction, SRT appears to be a revealed dogmatic theory that can be turned into a truly physical one like operational theory. Radically new technological applications of relativistic quantum theory then results.
description: 18 pages, 11 figures, pdf
"Sociologics" as an analytical framework to examine students’ discourse on socioscientific issues
Creators: name: Fountain, Renee-Marie
Publisher: name: University of British Columbia
Year: 2009

description: This study develops and tests the strengths and weaknesses of an analytical framework entitled sociologies to examine students' responses to socioscientific issues. Sociologies (Latour, 1987) is defined as the unpredictable and heterogeneous networks of links and associations that constitute the construction, accumulation, and mobilization of knowledge in the face of controversy. Recognizing the asymmetry of knowledge production, sociologies looks at how some knowledge is rendered more credible, and more powerful, than others. The framework consists of five questions: a) how causes and effects are attributed; b) what points (ideas) are linked to which other; c) what size and strength these links have; d) who the most legitimate spokespersons are; and e) and how all these elements are modified during the controversy. Latour calls the answer to these five questions "sociologies". Under this rubric, the production of knowledge is contentious because knowledge is socially constructed in a world where discourse and politics and knowledge and power are inextricably related. I argue that the framework of sociologies is an improvement upon commonly used analytical frameworks in socioscientific research in education as, unlike previous forms of analysis, it foregrounds the social construction of knowledge (as evidenced in discourse) and highlights the contentious, complex, unpredictable, and dynamic nature of knowledge production prevalent in these issues.
Evolution of spiral galaxies in modified gravity
Creators: name: Tiret, O.
name: Combes, F.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We compare N-body simulations of isolated galaxies performed in both frameworks of modified Newtonian dynamics (MOND) and Newtonian gravity with dark matter (DM). We have developed a multigrid code able to efficiently solve the modified Poisson equation derived from the Lagrangian formalism AQUAL. We take particular care of the boundary conditions that are a crucial point in MOND. The 3-dimensional dynamics of initially identical stellar discs is studied in both models. In Newtonian gravity the live DM halo is chosen to fit the rotation curve of the MOND galaxy. For the same value of the Toomre parameter (Q_T), galactic discs in MOND develop a bar instability sooner than in the DM model. In a second phase the MOND bars weaken while the DM bars continue to grow by exchanging angular momentum with the halo. The bar pattern speed evolves quite differently in the two models: there is no dynamical friction on the MOND bars so they keep a constant pattern speed while the DM bars slow down significantly. This affects the position of resonance like the corotation and the peanut. The peanut lobes in the DM model move radially outward while they keep the same position in MOND. Simulations of (only stellar) galaxies of different types on the Hubble sequence lead to a statistical bar frequency that is closer to observations for the MOND than the DM model.
description: 13 pages, 21 figures, accepted in A&A
Image-based Textile Decoding
Creators: name: Chen, Siqiang
name: Toyoura, Masahiro
name: Terada, Takamasa
name: Mao, Xiaoyang
name: Xu, Gang
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: A textile fabric consists of countless parallel vertical yarns (warps) and horizontal yarns (wefts). While common looms can weave repetitive patterns, Jacquard looms can weave the patterns without repetition restrictions. A pattern in which the warps and wefts cross on a grid is defined in a binary matrix. The binary matrix can define which warp and weft is on top at each grid point of the Jacquard fabric. The process can be regarded as encoding from pattern to textile. In this work, we propose a decoding method that generates a binary pattern from a textile fabric that has been already woven. We could not use a deep neural network to learn the process based solely on the training set of patterns and observed fabric images. The crossing points in the observed image were not completely located on the grid points, so it was difficult to take a direct correspondence between the fabric images and the pattern represented by the matrix in the framework of deep learning. Therefore, we propose a method that can apply the framework of deep learning via the intermediate representation of patterns and images. We show how to convert a pattern into an intermediate representation and how to reconvert the output into a pattern and confirm its effectiveness. In this experiment, we confirmed that 93% of correct pattern was obtained by decoding the pattern from the actual fabric images and weaving them again.
Η κοινωνική απορρύθμιση ως βασικός αιτιολογικός παράγοντας της εξάρτησης
Creators: name: Ρουσόγλου, Κωνσταντίνα-Νεκταρία
name: Μαντζουράνη, Μαρία Θεοφάνη
Publisher: name: Aristotle University of Thessaloniki
Year: 2014
Subjects: Εξάρτηση
Κοινωνική απορρύθμιση
Καπιταλισμός
Addiction
Social dislocation
Capitalism

description: Σκοπός της παρούσας εργασίας ήταν η παρουσίαση και υποστήριξη της θέσης ότι το φαινόμενο της εξάρτησης από ναρκωτικές ουσίες, όπως παρατηρείται στις μέρες μας, οφείλεται σε μεγάλο βαθμό στην κοινωνική απορρύθμιση και τις επιπτώσεις της στον άνθρωπο. Αρχικά, αναφέραμε αναλυτικά τις βασικές ανάγκες του ανθρώπου, όπως αυτές παρουσιάζονται από την υπαρξιακή φιλοσοφία και την ανθρωπιστική ψυχολογία. Στη συνέχεια, μελετήσαμε τη δομή της κοινωνίας, τους μετασχηματισμούς της με την πάροδο των ετών, καθώς και τα παθογόνα για τον άνθρωπο χαρακτηριστικά της. Έπειτα, αναλύσαμε τα χαρακτηριστικά της σύγχρονης κοινωνίας και το πώς αυτά έρχονται σε αντίθεση με τις βασικές ανάγκες του ανθρώπου, καθώς και τις επιπτώσεις που έχει η αντίθεση αυτή στην ψυχική υγεία. Τέλος, εξετάσαμε πιο συγκεκριμένα το φαινόμενο της εξάρτησης και το πώς αυτό έχει τις ρίζες του στην κοινωνική απορρύθμιση, αναφερόμενες και στο παράδειγμα της Ελλάδας.
description: The aim of this study was to present and support the position that the phenomenon of drug addiction as observed nowadays, has its roots largely to social dislocation and its effects on people. Initially, we analytically referred to the basic human needs, as they are presented by existential philosophy and humanistic psychology. Subsequently, we studied the structure of society, its transformations over the years, and its pathogenic for humans characteristics. Then we analyzed the characteristics of modern society and how they conflict with the basic human needs, as well as the implications of this contradiction on mental health. Finally, we examined more specifically the phenomenon of addiction and how it is rooted in social dislocation, also mentioning the example of Greece.
Large deviations of a random walk model with emerging territories
Creators: name: Schawe, Hendrik
name: Hartmann, Alexander K.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study an agent-based model of animals marking their territory and evading adversarial territory in one dimension, with respect to the distribution of the size of the resulting territories. In particular, we use sophisticated sampling methods to determine it over a large part of territory sizes, including atypically small and large configurations, which occur with probability of less than $10^{-30}$. We find hints for the validity of a large deviation principle, the shape of the rate function for the right tail of the distribution and insight into the structure of atypical realizations.
description: 9 pages, 9 figures
Single top production at HERA in the Standard Model and its minimal supersymmetric extension
Creators: name: Hollik, W.
name: Huettmann, A.
name: Kniehl, B. A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The H1 Collaboration at the DESY electron-proton collider HERA has observed, in photoproduction and neutral-current deep-inelastic scattering, an unexpected excess of events with isolated leptons and missing transverse momentum, especially at large values of hadronic transverse momentum - a signature typical for single top-quark production. This observation is being substantiated in the HERA II run. Motivated by this, we evaluate the cross section of single top-quark photo- and electroproduction both in the standard model and its minimal supersymmetric extension, considering both minimal and non-minimal flavour-violation scenarios in the latter case.
description: 20 pages, 14 figures; some formulas rewritten, input parameters updated, references added, matches version to appear in Nucl. Phys. B
Chamaeleon DANCe. Revisiting the stellar populations of Chamaeleon I and Chamaeleon II with Gaia-DR2 data
Creators: name: Galli, P. A. B.
name: Bouy, H.
name: Olivares, J.
name: Miret-Roig, N.
name: Sarro, L. M.
name: Barrado, D.
name: Berihuete, A.
name: Bertin, E.
name: Cuillandre, J. C.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Context: Chamaeleon is the southernmost low-mass star-forming complex within 200 pc from the Sun. Its stellar population has been extensively studied in the past, but the current census of the stellar content is not complete yet and deserves further investigation. Aims: We take advantage of the second data release of the \textit{Gaia} space mission to expand the census of stars in Chamaeleon and to revisit the properties of the stellar populations associated to the Chamaeleon I (Cha I) and Chamaeleon II (Cha II) dark clouds. Methods: We perform a membership analysis of the sources in the \textit{Gaia} catalogue over a field of 100 deg$^{2}$ encompassing the Chamaeleon clouds, and use this new census of cluster members to investigate the 6D structure of the complex. Results: We identify 188 and 41 high-probability members of the stellar populations in Cha I and Cha II, respectively, including 19 and 7 new members. Our sample covers the magnitude range from $G=6$ to $G=20$ mag in Cha I, and from $G=12$ to $G=18$ mag in Cha II. We confirm that the northern and southern subgroups of Cha I are located at different distances ($191.4^{+0.8}_{-0.8}$ pc and $186.7^{+1.0}_{-1.0}$ pc), but they exhibit the same space motion within the reported uncertainties. Cha II is located at a distance of $197.5^{+1.0}_{-0.9}$ pc and exhibits a space motion that is consistent with Cha I within the admittedly large uncertainties on the spatial velocities of the stars that come from radial velocity data. The median age of the stars derived from the Hertzsprung-Russell diagram (HRD) and stellar models is about 1-2 Myr, suggesting that they are somewhat younger than previously thought. We do not detect significant age differences between the Chamaeleon subgroups, but we show that Cha II exhibits a higher fraction of disc-bearing stars compared to Cha I.
description: 22 pages, 13 figures, online material (Tables A.1 - A.7). Accepted for publication in A&A
Annihilation Contributions and CP Asymmetries in $B^+ \to π^+ K^0, K^+ K^0$ and $B^0\to K^0 \bar K^0$
Creators: name: Hao, Xi-Qing
name: He, Xiao-Gang
name: Li, Xue-Qian
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Recently the branching ratios for $B^+\to K^+\bar K^0$ and $B^0 \to K^0 \bar K^0$ have been measured. Data indicate that the annihilation amplitudes in these decays are not zero. A non-zero annihilation amplitude plays an important role in CP violation for $B^+\to π^+ K^0, K^+ \bar K^0$. Using the measured branching ratios for these decays, we show that there is an absolute bound of 5% for the size of CP asymmetry in $B^+\to π^+ K^0$ from a relation between the amplitudes of these decays. The size of CP asymmetry in $B^+ \to K^+\bar K^0$ can, however, be as large as 90%. Future experimental data will test these predictions.
description: 9 pages, 3 figures; version added a few references and corrected a typo; the final version to appear at PRD
Change in schools: Can principals make a difference?
Creators: name: Binkley, Nadine Bonda
Publisher: name: University of British Columbia
Year: 2009

description: Principals come to their current positions with their own beliefs about their role, about their practice, and about other educational issues related to the nature of education: schools, teachers, students, community, and professional growth. These and all other factors that influence how principals think about their job are what I refer to as "principals' professional beliefs." This study demonstrated that principals bring to change initiatives their professional beliefs and those beliefs influence how they interpret the language of the change initiative, how they conceptualize the change, and how they plan for enactment of the policy change. I used a multi-case study approach to examine how eight principals in a school district that was undergoing a district policy change, thought about their enactment of the change at the school level. I identified three groups of principals: (1) supporters of teacher decision making, (2) facilitators of shared values, and (3) promoters of mutual respect. These principals differed in their involvement in the negotiation of the way the change would be carried out in the school, how much and what kinds of support they offered to teachers, and the degree of autonomy they allowed teachers in determining how the change would be implemented. Three questions guided the study: (1) What factors influence principals' responses to a change in school district policy? More specifically, what are the professional and context-specific issues the principals consider as they interpret a school district policy change and plan for their own action in carrying out that change process? (2) How do principals enact the policy changes in their own schools? (3) What impact did the principals perceive that the policy change had on their enactment of their role? This study provides insights into how principals understand and interpret educational policy language, how they work toward the development of collaborative relationships and collegial cultures, and how their professional beliefs inform their practice. The policy change and the language of the policy is mediated through principals' professional belief systems as they determine how they will enact the policy change. This study disputes findings in existing literature and contributes to our understanding of change in schools by recognizing that principals play significant roles in change at the school level.
PIDNet: An Efficient Network for Dynamic Pedestrian Intrusion Detection
Creators: name: Sun, Jingchen
name: Chen, Jiming
name: Chen, Tao
name: Fan, Jiayuan
name: He, Shibo
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Vision-based dynamic pedestrian intrusion detection (PID), judging whether pedestrians intrude an area-of-interest (AoI) by a moving camera, is an important task in mobile surveillance. The dynamically changing AoIs and a number of pedestrians in video frames increase the difficulty and computational complexity of determining whether pedestrians intrude the AoI, which makes previous algorithms incapable of this task. In this paper, we propose a novel and efficient multi-task deep neural network, PIDNet, to solve this problem. PIDNet is mainly designed by considering two factors: accurately segmenting the dynamically changing AoIs from a video frame captured by the moving camera and quickly detecting pedestrians from the generated AoI-contained areas. Three efficient network designs are proposed and incorporated into PIDNet to reduce the computational complexity: 1) a special PID task backbone for feature sharing, 2) a feature cropping module for feature cropping, and 3) a lighter detection branch network for feature compression. In addition, considering there are no public datasets and benchmarks in this field, we establish a benchmark dataset to evaluate the proposed network and give the corresponding evaluation metrics for the first time. Experimental results show that PIDNet can achieve 67.1% PID accuracy and 9.6 fps inference speed on the proposed dataset, which serves as a good baseline for the future vision-based dynamic PID study.
description: Proceedings of the 28th ACM International Conference on Multimedia (MM '20), October 12--16, 2020, Seattle, WA, USA
Probing the strange content of the proton with charm production in charged current at LHeC
Creators: name: Abdolmaleki, Hamed
name: Bertone, Valerio
name: Britzger, Daniel
name: Camarda, Stefano
name: Cooper-Sarkar, Amanda
name: Geiser, Achim
name: Giuli, Francesco
name: Glazov, Alexander
name: Luszczak, Agnieszka
name: Novikov, Ivan
name: Olness, Fred
name: Sapronov, Andrey
name: Zenaiev, Oleksandr
Publisher: name: Deutsches Elektronen-Synchrotron, DESY, Hamburg
Year: 2019

description: We study charm production in charged-current deep-inelastic scattering (DIS) using the xFitter framework. Recent results from the LHC have focused renewed attention on the determination of the strange-quark parton distribution function (PDF) and the DIS charm process provides important complementary constraints on this quantity. We examine the current PDF uncertainty, and use LHeC pseudodata to estimate the potential improvement from this proposed facility. As xFitter implements both fixed-flavor- and variable-flavor-number schemes, we can compare the impact of these different theoretical choices; this highlights some interesting aspects of multi-scale calculations. We find that the high-statistics LHeC data covering a wide kinematic range could substantially reduce the strange PDF uncertainty.
The Irregular Migrant Population of Europe
Creators: name: Kierans, Denis
name: Vargas-Silva, Carlos
Publisher: name: Krems: University for Continuing Education Krems (Danube University Krems)
Year: 2024
Subjects: irregular migration
migration
data
estimates
undocumented migrants
unauthorised immigration
illegal migration
Europe
United Kingdom
United States

description: This paper presents the findings of a multi-country assessment of irregular migration stocks, that is, the assessment of the estimated number of irregular migrants living various countries at a given point in time. 

The analysis covered the period 2008 to 2023 and was undertaken as part of the Measuring Irregular Migration and related Policies (MIrreM) project, which looks at irregular migration in 20 countries. MIrreM is a follow-up to the Clandestino project, which carried out a similar exercise between 2000 and 2008. 

Some of the key findings of the report include:

Based on the most recent estimates in the Database, there were between 2.6 million and 3.2 million estimated irregular migrants living in 12 European countries (Austria, Belgium, Finland, France, Germany, Greece, Ireland, Italy, Netherlands, Poland, Spain and the UK) over the period 2016 and 2023.

This figure represents less than 1% of the total population and between 8% and 10% of the population that was born in countries outside of the Schengen Area (for EU countries) and the Common Travel Area (for Ireland and the UK).

Amongst the countries studied by the MIrreM project, the United States has the largest estimated irregular migration population not only in terms of absolute numbers, but relative to its total and foreign-born populations

Finland, meanwhile, has the smallest estimated irregular migration population in terms of its size and its share of the total and foreign-born populations amongst the countries we covered.  

Taking the 2008 estimates produced under the Clandestino project as a baseline, there was no definitive change in the estimated number of irregular migrants across the 12 European countries.[1]

At the individual country level, however, many of the estimated irregular migration populations in the countries covered by the project appear to have changed: in three countries, estimates suggest greater numbers, in five countries, the estimated irregular migration population remained the same and, in five countries, it declined.

[1] That is, the new estimate’s lower bound is higher than the 2008 estimate and its upper bound is lower; the updated estimate is more finessed but there is still a significant range which remains a numerical black box, within which we cannot say with any confidence whether there was an increase, decrease or no change in the aggregate estimate.
Το νομικό καθεστώς των Προεδρικών δηλώσεων του Συμβουλίου Ασφαλείας:
Creators: name: Δίγκα, Παναγιώτα Πέτρου
Publisher: name: Aristotle University of Thessaloniki
Year: 2014
Subjects: Προεδρικές δηλώσεις
Συμβούλιο Ασφαλείας
Ψηφίσματα
presidential statement
security council
Resolutions

description: Η παρούσα εργασία πραγματεύεται τη φύση και το νομικό καθεστώς των Προεδρικών Δηλώσεων του Συμβουλίου Ασφαλείας του ΟΗΕ και τον γενικότερο ρόλο τους στα πλαίσια του Διεθνούς Δικαίου. Για να καταλήξει σε κάποιο ασφαλές συμπέρασμα ερευνά τη μορφή, το περιεχόμενό τους, την διαδικασία με την οποία υιοθετούνται, την εξέλιξή τους στο πέρασμα του χρόνου, το πεδίο εφαρμογής τους. Τα ως άνω εξετάζονται υπό το πρίσμα του νομικού καθεστώτος του ίδιου του Συμβουλίου Ασφαλείας, καθώς (οι Προεδρικές Δηλώσεις) αποτελούν ένα από τα κύρια όργανα έκφρασής του. Στο πλαίσιο αυτό, και δεδομένης της διαδεδομένης πλέον χρήσης τους από το Συμβούλιο Ασφαλείας, η παρούσα εργασία εξετάζει και τη σχέση τους με τα ψηφίσματα που εκδίδει αυτό και διατυπώνει το εύλογο ερώτημα γιατί έως σήμερα δεν έχουν θεσμοθετηθεί ως επίσημος τρόπος έκφρασης του οργάνου, ενώ παράλληλα υπογραμμίζει την ανάγκη να προωθηθεί αυτή η πρωτοβουλία.
description: This thesis deals with the nature and legal status of Presidential Statements of the Security Council and discusses their general role within the International Law. To reach a definite conclusion (this thesis) investigates the form, content, process in which adopted, their evolution over time, their scope. Those examined in the light of the legal status of the Security Council itself, as they (the Presidential Statements) are one of the main organs of its expression. In this context, and given their now widespread use of the Security Council, this thesis examines their relationship with the Security Council resolutions and makes the question why until now have not been enacted as an official form of expression, while stressing the need to promote this initiative.
Toward Mapping the Detailed Density Structure of Classical Be Circumstellar Disks
Creators: name: Wisniewski, John P.
name: Kowalski, Adam F.
name: Bjorkman, Karen S.
name: Bjorkman, Jon E.
name: Carciofi, Alex C.
name: ;
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The first results from a near-contemporaneous optical and infrared spectroscopic observing program designed to probe the detailed density structure of classical Be circumstellar disks are presented. We report the discovery of asymmetrical infrared emission lines of He I, O I, Fe II, and the Brackett, Paschen, and Pfund series lines of H I which exhibit an opposite V/R orientation (V $>$ R) to that observed for the optical Balmer H$α$ line (V $
description: 13 pages, accepted by ApJL
Great enhancement of Curie temperature and magnetic anisotropy in two-dimensional van der Waals magnetic semiconductor heterostructures
Creators: name: Xuejuan-Dong
name: Jingyang-You
name: Zhang, Zheng
name: Gu, Bo
name: Su, Gang
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In two-dimensional (2D) magnetic systems, large magnetic anisotropy is needed to stabilize the magnetic order according to Mermin-Wagner theorem. Based on density functional theory (DFT) calculations, we propose that the magnetic anisotropic energy (MAE) of 2D ferromagnetic (FM) semiconductors can be strongly enhanced in van der Waals heterostructures by attaching a nonmagnetic semiconductor monolayer with large spin-orbit coupling. We studied Cr2Ge2Te6/PtSe2 bilayer heterostructures, where each layer has been realized in recent experiments. The DFT calculations show that the MAE of Cr2Ge2Te6/PtSe2 is enhanced by 70%, and the Curie temperature TC is increased far beyond room temperature. A model Hamiltonian is suggested to analyze the DFT results, showing that both the Dzyaloshinskii-Moriya interaction and the single-ion anisotropy contribute to the enhancement of the MAE. Based on the superexchange picture, we find that the decreased energy difference between 3d orbitals of Cr and 5p orbitals of Te contributes partially to the increase of TC. Our present work indicates a promising way to enhance the MAE and TC by constructing van der Waals semiconductor heterostructures, which will inspire further studies on the 2D magnetic semiconductor systems.
description: 10 pages, 5 figures
Driven interfaces in random media at finite temperature : is there an anomalous zero-velocity phase at small external force ?
Creators: name: Monthus, Cecile
name: Garel, Thomas
Publisher: name: arXiv
Year: 2008
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: The motion of driven interfaces in random media at finite temperature $T$ and small external force $F$ is usually described by a linear displacement $h_G(t) \sim V(F,T) t$ at large times, where the velocity vanishes according to the creep formula as $V(F,T) \sim e^{-K(T)/F^μ}$ for $F \to 0$. In this paper, we question this picture on the specific example of the directed polymer in a two dimensional random medium. We have recently shown (C. Monthus and T. Garel, arxiv:0802.2502) that its dynamics for F=0 can be analyzed in terms of a strong disorder renormalization procedure, where the distribution of renormalized barriers flows towards some "infinite disorder fixed point". In the present paper, we obtain that for small $F$, this "infinite disorder fixed point" becomes a "strong disorder fixed point" with an exponential distribution of renormalized barriers. The corresponding distribution of trapping times then only decays as a power-law $P(τ) \sim 1/τ^{1+α}$, where the exponent $α(F,T)$ vanishes as $α(F,T) \propto F^μ$ as $F \to 0$. Our conclusion is that in the small force region $α(F,T)<1$, the divergence of the averaged trapping time $\barτ=+\infty$ induces strong non-self-averaging effects that invalidate the usual creep formula obtained by replacing all trapping times by the typical value. We find instead that the motion is only sub-linearly in time $h_G(t) \sim t^{α(F,T)}$, i.e. the asymptotic velocity vanishes V=0. This analysis is confirmed by numerical simulations of a directed polymer with a metric constraint driven in a traps landscape. We moreover obtain that the roughness exponent, which is governed by the equilibrium value $ζ_{eq}=2/3$ up to some large scale, becomes equal to $ζ=1$ at the largest scales.
description: v3=final version
Chiral phase transition in lattice QCD as a metal-insulator transition
Creators: name: Garcia-Garcia, Antonio M.
name: Osborn, James C.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We investigate the lattice QCD Dirac operator with staggered fermions at temperatures around the chiral phase transition. We present evidence of a metal-insulator transition in the low lying modes of the Dirac operator around the same temperature as the chiral phase transition. This strongly suggests the phenomenon of Anderson localization drives the QCD vacuum to the chirally symmetric phase in a way similar to a metal-insulator transition in a disordered conductor. We also discuss how Anderson localization affects the usual phenomenological treatment of phase transitions a la Ginzburg-Landau.
description: 7 pages, 6 figures, references added, typos corrected, journal version
Αυτόματα και μοναδιακή λογική δεύτερης τάξης με βάρη σε πεπερασμένες λέξεις.:
Creators: name: Τσότσου, Χριστίνα Στέφανου
Publisher: name: Aristotle University of Thessaloniki
Year: 2014
Subjects: Αυτόματα
Λογική
Δυναμοσειρές
Automata
Logic
Series

description: Ελληνική Περίληψη Η παρούσα διπλωματική εργασία πραγματεύεται ένα πολύ σημαντικό ζήτημα που αφορά στα πεπερασμένα αυτόματα με βάρη. Γίνεται χρήση των θεωρημάτων του Buchi, του Elgot και του Schutzenberger και παρουσιάζονται τα αποτελέσματά τους. Αποδεικνύεται, λοιπόν, ότι τα πεπερασμένα αυτόματα με βάρη παρουσιάζουν συμπεριφορές οι οποίες ορίζονται από ρητές τυπικές δυναμοσειρές. Το συμπέρασμα αυτό εξάγεται έπειτα από τη μελέτη των ιδιοτήτων και των τυπικών δυναμοσειρών, οι οποίες αποδεικνύονται μέσω της χρήσης των αυτομάτων με βάρη. Παράλληλα, δίνεται η σύνταξη της MSO-λογικής με βάρη, η οποία αποτελεί επέκταση της κλασικής MSO-λογικής. Η σημασιολογία των τύπων φ αυτής επεκτεταμένης λογικής θα εκφραστεί από τυπικές δυναμοσειρές που ορίζονται πάνω σε κάποιο ημιδακτύλιο. Τα δύο αυτά γεγονότα θα μας οδηγήσουν στην απόλυτη ταύτιση των συμπεριφορών των πεπερασμένων αυτομάτων με βάρη και της μοναδιακής λογικής δεύτερης τάξης με βάρη.
description: The present thesis deals with a very important issue related to finite weighted automata. We generalize Buchi’s and Elgot’s fundamental results in the weighted setup for finite words over semirings. We introduce a weighted version of MSO-logic, which is an extension of the classical MSO-logic. The semantics of its formulas are represented as formal power series. The main results show that, for commutative semirings, the behaviors of weighted automata are precisely the formal power series definable with particular sentences of monadic second-order logic, over finite words.
Securing Right Internships for Dream Placements
Creators: name: Garg, Rishabh
Publisher: name: Zenodo
Year: 2022

description: Securing the right internship can be a game-changer for landing your dream placement. Based on my own internship journey and the lessons I’ve learned over the past 3-4 years, I’m excited to share both the smart moves and the mistakes I made along the way. Whether you’re a year away from on-campus placements or exploring off-campus opportunities, this discussion is packed with insights to help you navigate your preparation more effectively. This session is especially valuable for two types of students: those aiming for SDE roles at top product companies and those still figuring out their path between IT, Core, Finance, and Non-core fields.
74 MHz Discrete HII Absorption Regions Towards The Inner Galaxy
Creators: name: Nord, Michael E.
name: Henning, P. A.
name: Rand, R. J.
name: Lazio, T. Joseph W.
name: Kassim, Namir E.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: At low radio frequencies (< 100 MHz), classical HII regions may become optically thick (optical depth > 1) and can be observed as discrete absorption regions against the Galactic nonthermal background emission created by Galactic cosmic ray electrons spiraling around magnetic fields. In this work we present 74 MHz observations in the region 26>l>-15, -5
description: Accepted, The Astronomical Journal
Remarks on compositions of some random integral mappings
Creators: name: Jurek, Zbigniew J.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: Primary 60E07, 60H05, 60B11, Secondary 44A05, 60H05, 60B10

description: The random integral mappings (some type of functionals of Lévy processes) are continuous homomorphisms between convolution subsemigroups of the semigroup of all infinitely divisible measures. Compositions of those random integrals (mappings) can be always expressed as another single random integral mapping. That fact is illustrated by some old and new examples.
description: arXiv admin note: substantial text overlap with arXiv:1210.5990
A String-Inspired Quintom Model Of Dark Energy
Creators: name: Cai, Yi-fu
name: Li, Mingzhe
name: Lu, Jian-Xin
name: Piao, Yun-Song
name: Qiu, Taotao
name: Zhang, Xinmin
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We propose in this paper a quintom model of dark energy with a single scalar field $ϕ$ given by the lagrangian ${\cal L}=-V(ϕ)\sqrt{1-α^\prime\nabla_μϕ\nabla^μϕ+β^\prime ϕ\Boxϕ}$. In the limit of $β^\prime\to$0 our model reduces to the effective low energy lagrangian of tachyon considered in the literature. We study the cosmological evolution of this model, and show explicitly the behaviors of the equation of state crossing the cosmological constant boundary.
description: 6 pages, 4 figures, accepted by PLB
Fault Injection Analytics: A Novel Approach to Discover Failure Modes in Cloud-Computing Systems
Creators: name: Cotroneo, Domenico
name: De Simone, Luigi
name: Liguori, Pietro
name: Natella, Roberto
Publisher: name: arXiv
Year: 2020
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: Cloud computing systems fail in complex and unexpected ways due to unexpected combinations of events and interactions between hardware and software components. Fault injection is an effective means to bring out these failures in a controlled environment. However, fault injection experiments produce massive amounts of data, and manually analyzing these data is inefficient and error-prone, as the analyst can miss severe failure modes that are yet unknown. This paper introduces a new paradigm (fault injection analytics) that applies unsupervised machine learning on execution traces of the injected system, to ease the discovery and interpretation of failure modes. We evaluated the proposed approach in the context of fault injection experiments on the OpenStack cloud computing platform, where we show that the approach can accurately identify failure modes with a low computational cost.
description: IEEE Transactions on Dependable and Secure Computing; 16 pages. arXiv admin note: text overlap with arXiv:1908.11640
Preserving $Z$-sets by Dranishnikov's resolution
Creators: name: Ageev, S. M.
name: Cencelj, M.
name: Repovš, D.
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Topology (math.GN)
subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 54F65; 58B05; 54C55; 57N20

description: We prove that Dranishnikov's $k$-dimensional resolution $d_k\colon μ^k\to Q$ is a UV$^{n-1}$-divider of Chigogidze's $k$-dimensional resolution $c_k$. This fact implies that $d_k^{-1}$ preserves $Z$-sets. A further development of the concept of UV$^{n-1}$-dividers permits us to find sufficient conditions for $d_k^{-1}(A)$ to be homeomorphic to the Nöbeling space $ν^k$ or the universal pseudoboundary $σ^k$. We also obtain some other applications.
Non-activated transport of strongly interacting two-dimensional holes in GaAs
Creators: name: Huang, Jian
name: Novikov, D. S.
name: Tsui, D. C.
name: Pfeiffer, L. N.
name: West, K. W.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We report on the transport measurements of two-dimensional holes in GaAs field effect transistors with record low densities down to 7*10^8 cm^{-2}. Remarkably, such a dilute system (with Fermi wavelength approaching 1 micrometer) exhibits a non-activated conductivity that grows with temperature following a power law. We contrast it with the activated transport obtained from measuring more disordered samples, and discuss possible transport mechanisms in this strongly-interacting regime.
description: 5 pages, 4 figures
Dynamical vacuum energy, holographic quintom, and the reconstruction of scalar-field dark energy
Creators: name: Zhang, Xin
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: When taking the holographic principle into account, the vacuum energy will acquire dynamical property that its equation of state is evolving. The current available observational data imply that the holographic vacuum energy behaves as quintom-type dark energy. We adopt the viewpoint of that the scalar field models of dark energy are effective theories of an underlying theory of dark energy. If we regard the scalar field model as an effective description of such a holographic vacuum theory, we should be capable of using the scalar field model to mimic the evolving behavior of the dynamical vacuum energy and reconstructing this scalar field model according to the fits of the observational dataset. We find the generalized ghost condensate model is a good choice for depicting the holographic vacuum energy since it can easily realize the quintom behavior. We thus reconstruct the function $h(ϕ)$ of the generalized ghost condensate model using the best-fit results of the observational data.
description: 13 pages, 3 figures; references updated, accepted for publication in Phys. Rev. D
Multipole structure and coordinate systems
Creators: name: Burko, Lior M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: Multipole expansions depend on the coordinate system, so that coefficients of multipole moments can be set equal to zero by an appropriate choice of coordinates. Therefore, it is meaningless to say that a physical system has a nonvanishing quadrupole moment, say, without specifying which coordinate system is used. (Except if this moment is the lowest non-vanishing one.) This result is demonstrated for the case of two equal like electric charges. Specifically, an adapted coordinate system in which the potential is given by a monopole term only is explicitly found, the coefficients of all higher multipoles vanish identically. It is suggested that this result can be generalized to other potential problems, by making equal coordinate surfaces coincide with the potential problem's equipotential surfaces.
description: 2 figures
Towards new servo control algorithms at the TNG telescope
Creators: name: Schipani, P.
name: Gonzalez, M.
name: Perrotta, F.
name: Savarese, S.
name: Colapietro, M.
name: Ghedina, A.
name: Diaz, M. Hernandez
name: Ventura, H.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: The servo control algorithms of the TNG, developed in the nineties, have been working for more than 20 years with no major updates. The original hardware was based on a VME-bus based platform running a real time operating system, a rather popular choice for similar applications at the time. Recently, the obsolescence of the hardware and the lack of spares pushed the observatory towards a complete replacement of the electronics that is now being implemented in steps, respecting the basic requirement of never stopping the observatory night operations. Within the framework of this major hardware work, we are taking the opportunity to review and update the existing control schemes. This servo control update, crucial for the telescope performance, envisages a new study from scratch of the controlled plant, including a re-identification of the main axes transfer functions and a re-design of the control filters in the two nested position and speed loops. The ongoing work is described, including preliminary results in the case study of the azimuth axis and our plans for possible further improvements.
description: Proc. SPIE 11445, Ground-based and Airborne Telescopes VIII, 1144552 (2020)
Transaction Pricing for Maximizing Throughput in a Sharded Blockchain Ledger
Creators: name: Riehl, James R.
name: Ward, Jonathan
Publisher: name: arXiv
Year: 2020
Subjects: subject: Systems and Control (eess.SY)
subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: In this paper, we present a pricing mechanism that aligns incentives of agents who exchange resources on a decentralized ledger with the goal of maximizing transaction throughput. Subdividing a blockchain ledger into shards promises to greatly increase transaction throughput with minimal loss of security. However, the organization and type of the transactions also affects the ledger's efficiency, which is increased by wallet agents transacting in a single shard whenever possible while collectively distributing their transactions uniformly across the available shards. Since there is no central authority to enforce these properties, the only means of achieving them is to design the system such that it is in agents' interest to act in a way that benefits overall throughput. We show that our proposed pricing policy does exactly this by inducing a potential game for the agents, where the potential function relates directly to ledger throughput. Simulations demonstrate that this policy leads to near-optimal throughput under a variety of conditions.
Distribution of particles which produces a "smart" material
Creators: name: Ramm, A. G.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 35J05, 35J10, 70F10, 74J25, 81U40, 81V05, 35R30

description: If $A_q(β, α, k)$ is the scattering amplitude, corresponding to a potential $q\in L^2(D)$, where $D\subset\R^3$ is a bounded domain, and $e^{ikα\cdot x}$ is the incident plane wave, then we call the radiation pattern the function $A(β):=A_q(β, α, k)$, where the unit vector $α$, the incident direction, is fixed, and $k>0$, the wavenumber, is fixed. It is shown that any function $f(β)\in L^2(S^2)$, where $S^2$ is the unit sphere in $\R^3$, can be approximated with any desired accuracy by a radiation pattern: $||f(β)-A(β)||_{L^2(S^2)}0$ is an arbitrary small fixed number. The potential $q$, corresponding to $A(β)$, depends on $f$ and $ε$, and can be calculated analytically. There is a one-to-one correspondence between the above potential and the density of the number of small acoustically soft particles $D_m\subset D$, $1\leq m\leq M$, distributed in an a priori given bounded domain $D\subset\R^3$. The geometrical shape of a small particle $D_m$ is arbitrary, the boundary $S_m$ of $D_m$ is Lipschitz uniformly with respect to $m$. The wave number $k$ and the direction $α$ of the incident upon $D$ plane wave are fixed.It is shown that a suitable distribution of the above particles in $D$ can produce the scattering amplitude $A(α',α)$, $α',α\in S^2$, at a fixed $k>0$, arbitrarily close in the norm of $L^2(S^2\times S^2)$ to an arbitrary given scattering amplitude $f(α',α)$, corresponding to a real-valued potential $q\in L^2(D)$.
description: corrected typos
Gamma-ray Burst host galaxy gas and dust
Creators: name: Starling, Rhaana
name: Wijers, Ralph
name: Wiersema, Klaas
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report on the results of a study to obtain limits on the absorbing columns to wards an initial sample of 10 long Gamma-Ray Bursts observed with BeppoSAX, using a new approach to SED fitting to nIR, optical and X-ray afterglow data, in count space and including the effects of metallicity. When testing MW, LMC and SMC extinction laws we find that SMC-like extinction provides the best fit in most cases. A MW-like ext inction curve is not preferred for any of these sources, largely since the 2175A bump, in principle detectable in all these afterglows, is not present in the data. We rule out an SMC-like gas-to-dust ratio or lower value for 4 of the hosts analysed here (assuming SMC metallicity and extinction law) whilst the remainder of the sample have too large an error to discriminate. We provide an accurate estimate of the line-of-sight extinction, improving upon the uncertainties for the majority of the extinction measurements made in previous studies of this sample.
description: 3 pages, 1 figure, MG11 proceedings