cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A deep Chandra observation of Abell 4059: a new face to radio-mode AGN feedback?
Creators: name: Reynolds, Christopher S.
name: Casper, Elyse A.
name: Heinz, Sebastian
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: A deep Chandra observation of the cooling core cluster Abell 4059 (A4059) is presented. Previous studies have found two X-ray cavities in the central regions of A4059 together with a ridge of X-ray emission 20kpc south-west of the cluster center. These features are clearly related to the radio galaxy PKS2354-35 which resides in the cD galaxy. Our new data confirm these previous findings and strengthen previous suggestions that the south-western ridge is colder and denser than, but in approximate pressure equilibrium with, the surrounding ICM atmosphere. In addition, we find evidence for a weak shock that wraps around the north and east sides of the cavity structure. Our data allow us to map the 2-dimensional distribution of metals in the ICM of A4059 for the first time. We find that the SW ridge possesses an anomalously high (super-solar) metalicity. The unusual morphology, temperature structure and metal distribution all point to significant asymmetry in the ICM atmosphere prior to the onset of radio-galaxy activity. Motivated by the very high metalicity of the SW ridge, we hypothesize that the ICM asymmetry was caused by the extremely rapid stripping of metal enriched gas from a starburst galaxy that plunged through the core of A4059. Furthermore, we suggest that the onset of powerful radio-galaxy activity in the cD galaxy may have been initiated by this starburst/stripping event, either via the tidal-shocking of cold gas native to the cD galaxy, or the accretion of cold gas that had been stripped from the starburst galaxy.
description: Accepted for publication in the Astrophysical Journal. 12 pages, 11 figures. A version of this paper including full resolution figures can be found at http://www.astro.umd.edu/~chris/publications/papers/a4059_2008.pdf
Angular power spectrum of supernova remnants: effects of structure, geometry and diffuse foreground
Creators: name: Choudhuri, Samir
name: Saha, Preetha
name: Roy, Nirupam
name: Bharadwaj, Somnath
name: Dey, Jyotirmoy
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The study of the intensity fluctuation power spectrum of individual supernova remnants (SNRs) can reveal the structures present at sub-pc scales, and also constrain the physical process that generates those structures. There are various effects, such as the remnant shell thickness, projection of a three-dimensional structure onto a two-dimensional observational plane, and the presence of diffuse "foreground" emission, which causes the observed power spectrum to deviate from the intrinsic power spectrum of the fluctuations. Here, we report results from a systematic study of these effects, using direct numerical simulations, in the measured power spectrum. For an input power-law power spectrum, independent of the power-law index, we see a break in the observed power law at a scale which depends on the shell thickness of a shell-type SNR, and the three-dimensional turbulence changes to two-dimensional turbulence beyond that scale. We also report how the estimated power spectrum is expected to deviate from the intrinsic SNR power spectrum in the presence of additional diffuse Galactic synchrotron emission (DGSE) around the remnant shell. For a reasonable choice of the parameters, if the intrinsic SNR power spectrum is shallower than the DGSE power spectrum, the SNR contribution dominates at small angular scales of the estimated power spectra. On the other hand, if the SNR power spectrum is relatively steeper, the original power spectra is recovered only over a small window of angular scales. This study shows how detailed modeling may be used to infer the true power spectrum from the observed SNR intensity fluctuations power spectrum, which in turn can be used to constrain the nature of the turbulence that gives rise to these small scale structures.
description: 8 pages, 5 figures, Accepted for publication in MNRAS
Irreversibility line and low-field grain-boundary pinning in electron-doped superconducting thin films
Creators: name: Sergeenkov, S.
name: Lanfredi, A. J. C.
name: Araujo-Moreira, F. M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: AC magnetic susceptibilities of electron-doped Pr_{1.85}Ce_{0.15}CuO_4 (PCCO) and Sm_{1.85}Ce_{0.15}CuO_4 (SCCO) granular thin films have been measured as a function of temperature and magnetic-field strength. Depending on the level of homogeneity of our films, two different types of the irreversibility line (IL) defined as the intergrain-loss peak temperature in the imaginary part of susceptibility have been found. The obtained results are described via the critical-state model taking into account the low-field grain-boundary pinning. The extracted pinning-force densities in more granular SCCO films turn out to be four times larger than their counterparts in less granular PCCO films.
Multi-timescale reverberation mapping of Mrk 335
Creators: name: Mastroserio, Guglielmo
name: Ingram, Adam
name: van der Klis, Michiel
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Time lags due to X-ray reverberation have been detected in several Seyfert galaxies. The different travel time between reflected and directly observed rays naturally causes this type of lag, which depends directly on the light-crossing timescale of the system and hence scales with the mass of the central black hole. Featureless `hard lags' not associated with reverberation, and often interpreted as propagating mass accretion rate fluctuations, dominate the longer timescale variability. Here we fit our reltrans model simultaneously to the time-averaged energy spectrum and the lag-energy spectra of the Seyfert galaxy Mrk 335 over two timescales (Fourier frequency ranges). We model the hard lags as fluctuations in the slope and strength of the illuminating spectrum, and self-consistently account for the effects that these fluctuations have on the reverberation lags. The resulting mass estimate is $1.1^{+2.0}_{-0.7} \times 10^6~M_\odot$, which is significantly lower than the mass measured with the optical reverberation mapping technique (14 - 26 million $M_\odot$). When we add the correlated variability amplitudes to the time lags by fitting the full complex cross-spectra, the model is unable to describe the characteristic reverberation Fe K$α$ line and cannot constrain the black hole mass. This may be due to the assumption that the direct radiation is emitted by a point-like source.
description: Accepted for publication in MNRAS
Cosmic radiation does not prevent collisional charging in (Pre)-Planetary Atmospheres
Creators: name: Jungmann, Felix
name: Bila, Tetyana
name: Kleinert, Laura
name: Mölleken, Andre
name: Möller, Rolf
name: Schmidt, Lars
name: Schneider, Niclas
name: Teiser, Jens
name: Utzat, Detlef
name: Volkenborn, Victoria
name: Wurm, Gerhard
Publisher: name: arXiv
Year: 2020
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: In (pre)-planetary environments, dust and sand grains regularly collide. They electrically charge and discharge during these events. In this work, we study if cosmic radiation has any influence on the equilibrium charge state on timescales of minutes. We developed an experiment that was carried out during the ascent of a stratospheric balloon. With increasing altitude, the radiation activity increases by a factor of 54. However, we found only a very minor decrease in grain charges of up to 30%. This implies that charge-moderated processes from thunderstorms on Earth, over early phases of planet formation to particle motion on the Martian surface on short timescales essentially proceed unhindered from a direct influence of cosmic radiation.
Fidelity of quantum operations
Creators: name: Pedersen, Line Hjortshoj
name: Molmer, Klaus
name: Moller, Niels Martin
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present a derivation and numerous applications of a compact explicit formula for the average fidelity of a quantum operation on a finite dimensional quantum system. The formula can be applied to averages over particularly relevant subspaces; it is easily generalized to multi-component systems, and as a special result, we show that when the same completely positive trace-preserving map is applied to a large number of qubits with one-bit fidelity F close to unity, the average fidelity of the operation on the full K-bit register scales as $F^{3K/2}$.
description: 5 pages, no figures. The text has been modified to acknowledge that our Eq.(1) has appeared already in quant-ph/0503243 and quant-ph/0512217
Categorical Symmetries at Criticality
Creators: name: Wu, Xiao-Chuan
name: Ji, Wenjie
name: Xu, Cenke
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study the concept of "categorical symmetry" introduced recently, which in the most basic sense refers to a pair of dual symmetries, such as the Ising symmetries of the $1d$ quantum Ising model and its self-dual counterpart. In this manuscript we study discrete categorical symmetry at higher dimensional critical points and gapless phases. At these selected gapless states of matter, we can evaluate the behavior of categorical symmetries analytically. We analyze the categorical symmetry at the following examples of criticality: (1) Lifshit critical point of a $(2+1)d$ quantum Ising system; (2) $(3+1)d$ photon phase as an intermediate gapless phase between the topological order and the confined phase of 3d $Z_2$ quantum gauge theory; (3) $2d$ and $3d$ examples of systems with both categorical symmetries (either 0-form or 1-form categorical symmetries) and subsystem symmetries. We demonstrate that at some of these gapless states of matter the categorical symmetries have very different behavior from the nearby gapped phases.
description: 11 pages, 2 figures
Η Πατερική παράδοση στον Αγιο Αθανάσιο Πάριο:
Creators: name: Πόνος, Χρήστος Κωνσταντίνου
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Κολλυβάδες
Πατερική παράδοση
Μνημόσυνα
Boiled wheat
Patristic tradition
Memorial services

description: Ο Αθανάσιος Πάριος έζησε και έδρασε την εποχή της τουρκοκρατίας και ήταν πρωτοπόρος στο κίνημα των Κολλυβάδων. Υπήρξε μέγας διδάσκαλος του Γένους και διαπρεπής θεολόγος. Κύριο μέλημα του ήταν να μεταλαμπαδευτεί το Ορθόδοξο χριστιανικό ιδεώδες και να αφυπνισθεί το υπόδουλο Γένος από τον πνευματικό λήθαργο. Είναι ο υπερασπιστής των ιερών δογμάτων τα οποία διατύπωσαν εν Αγίω Πνεύματι οι Πατέρες στις Οικουμενικές Συνόδους.
description: Athanasios Parios lived and acted during the Turkish occupation and was a pioneer in the movement of Kollyvades. He was a great teacher of the nation and eminent theologian. The main concern for him was to transfer the Orhodox Christian ideal and to awaken the enslaved race from their spiritual slumber. He is the defender of the sacred doctrines which the Holy Spirit Fathers in Ecumenical Councils.
Perception proximale et distale à l'aide du dispositif de Lenay
Creators: name: Hanneton, Sylvain
name: Taleb-Kachour, Dounia
name: Ramanantsoa, Marie-Martine
name: Hardy, Bianca
name: Roby-Brami, Agnès
Publisher: name: arXiv
Year: 2006
Subjects: subject: Neurons and Cognition (q-bio.NC)
subject: FOS: Biological sciences

description: We present in this article experimental results obtained with the "dispositif de Lenay" : for a localization task (distal perception) and an orientation estimation task (proximal perception of the orientation of a cylinder in a plane). In this last experiment, a "virtual" version of the Lenay device was used. Results are here used to illustrate methodological and theoretical proposals for the study of cognitive and sensori-motor processes involved in perception.
description: 17 pages
Flavorgenesis
Creators: name: Ekstedt, Andreas
name: Fonseca, Renato M.
name: Malinský, Michal
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present a model where all fermions are contained in a single irreducible representation of an SU(19) gauge symmetry group. If there is only one scalar field, Yukawa interactions are controlled by a single number rather than by one or more $3\times3$ matrices of couplings. The low-energy concept of flavor emerges entirely from the scalar-sector parameters; more specifically, entries of the Standard Model Yukawa matrices are controlled by several vacuum expectation values.
description: 9 pages
GeoAgentic Workflows for solving geographic tasks: a new methodology applied to location description recognition
Creators: name: Welscher, Franz
name: Schneidergruber, Thomas
name: Scholz, Johannes
name: Röbl, David
name: Li, Ce
Publisher: name: figshare
Year: 2024
Subjects: classificationCode: 370499
subject: Geoinformatics not elsewhere classified

description: This repository provides code and data supporting the paper "GeoAgentic Workflows for solving geographic tasks: a new methodology applied to location description recognition".
Description of turbulent dynamics in the interstellar medium: multifractal/microcanonical analysis I. Application to Herschel observations of the Musca filament
Creators: name: Yahia, H.
name: Schneider, N.
name: Bontemps, S.
name: Bonne, L.
name: Attuel, G.
name: Dib, S.
name: Ossenkopf, V.
name: Turiel, A.
name: Zebadua, A.
name: Elia, D.
name: Maji, S. K.
name: Schmitt, F. G.
name: Robitaille, J. -F
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Observations of the interstellar medium (ISM) show a complex density and velocity structure which is in part attributed to turbulence. We here present a self-contained introduction to the multifractal formalism in a microcanonical version which allows us for the first time to compute precise turbulence characteristic parameters from a single observational map without the need for averages in a grand ensemble of statistical observables. We focus on studying the 250 mu-m Herschel map of the Musca filament and make use of MHD simulations. We find a clear signature of a multiplicative cascade in Musca with an inertial range from 0.05 to 0.65 pc. We show that the proposed microcanonical approach provides singularity spectra which are truly scale invariant as required to validate any method to analyze multifractality. The obtained, for the first time precise enough, singularity spectrum of Musca is clearly not as symmetric as usually observed in log-normal behavior. We claim that the ISM towards Musca features more a log-Poisson shape of its singularity spectrum. Since log-Poisson behavior is claimed to exist when dissipation is stronger for rare events in turbulent flows in contrast to more homogeneous (in volume and time) dissipation events, we suggest that this deviation from log-normality could trace enhanced dissipation in rare events at small scales, which may explain or is at least consistent with the dominant filamentary structure in Musca. Moreover we find that sub-regions in Musca tends to show different multifractal properties. It strongly suggests that different types of dynamics exist inside the Musca cloud. These differences between sub-regions appear only after eliminating noise features which have the tendency to "log-normalize" an observational map. Our study sets up fundamental tools which will be applied to other galactic clouds and simulations in forthcoming studies.
description: 25 pages. 27 figures. Submitted to Astronomy & Astrophysics, November 2020
The Origin of the Dust Extinction Curve in Milky Way-like Galaxies
Creators: name: Li, Qi
name: Narayanan, Desika
name: Torrey, Paul
name: Davé, Romeel
name: Vogelsberger, Mark
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We develop a cosmological model for the evolution of dust grains in galaxies with a distribution of sizes in order to understand the origin of the Milky Way dust extinction curve. Our model considers the formation of active dust in evolved stars, growth by accretion and coagulation, and destruction processes via shattering, sputtering, and astration in the ISM of galaxies over cosmic time. Our main results follow. Galaxies in our cosmological model with masses comparable to the Milky Way's at z~0 exhibit a diverse range of extinction laws, though with slopes and bump strengths comparable to the range observed in the Galaxy. The progenitors of the Milky Way have steeper slopes, and only flatten to slopes comparable to the Galaxy at $z \approx 1$. This owes to increased grain growth rates at late times/in high-metallicity environments driving up the ratio of large to small grains, with a secondary dependence on the graphite to silicate ratio evolution. The UV bump strengths depend primarily on the graphite to silicate ratio, and remain broadly constant in MW-like galaxies between z=3 and z=0, though show slight variability. Our models span comparable regions of bump-slope space as sightlines in the Galaxy do, though there is a lack of clear relationship between the model slopes and bump strengths owing to small scale fluctuations in the bump strength. Our models naturally produce slopes for some non-Milky Way analogs as steep as those of the LMC and SMC in metal poor galaxies, though notably the bump strengths are, on average, too large when comparing to the Magellanic clouds. This owes to the fact that we evolve the grain size distributions of graphites and silicates simultaneously, which is an oversimplification. Our model provides a novel framework to study the origins and variations of dust extinction curves in galaxies over cosmic time.
description: 12 pages, 6 figures, MNRAS submitted
The imprint of massive black hole formation models on the LISA data stream
Creators: name: Sesana, Alberto
name: Volonteri, Marta
name: Haardt, Francesco
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The formation, merging, and accretion history of massive black holes along the hierarchical build--up of cosmic structures leaves a unique imprint on the background of gravitational waves at mHz frequencies. We study here, by means of dedicated simulations of black hole build--up, the possibility of constraining different models of black hole cosmic evolution using future gravitational wave space--borne missions, such as LISA. We consider two main scenarios for black hole formation, namely, one where seeds are light (~10^2 \msun, remnant of Population III stars), and one where seeds are heavy (>~10^4 \msun, direct collapse). In all the models we have investigated, massive black hole binary coalescences do not produce a stochastic GW background, but rather, a set of individual resolved events. Detection of several hundreds merging events in 3 year LISA mission will be the sign of a heavy seed scenario with efficient formation of black hole seeds in a large fraction of high redshift halos. On the other extreme, a low event rate, about few tens in 3 years, is peculiar of scenarios where either the seeds are light, and many coalescences do not fall into the LISA band, or seeds are massive, but rare. In this case a decisive diagnostic is provided by the shape of the mass distribution of detected events. Light binaries (m<10^4\msun) are predicted in a fairly large number in Population III remnants models, but are totally absent in direct collapse models. Finally, a further, helpful diagnostic of black hole formation models lies in the distribution of the mass ratios in binary coalescences. While heavy seed models predict that most of the detected events involve equal mass binaries, in the case of light seeds, mass ratios are equally distributed in the range 0.1-1.
description: 7 pages, 5 figures, minor changes, accepted for publication in MNRAS
GeoAgentic Workflows for solving geographic tasks: a new methodology applied to location description recognition
Creators: name: Welscher, Franz
name: Schneidergruber, Thomas
name: Scholz, Johannes
name: Ce, Li
name: Röbl, David
Publisher: name: figshare
Year: 2024
Subjects: classificationCode: 370499
subject: Geoinformatics not elsewhere classified

description: This repository provides code and data supporting the paper "GeoAgentic Workflows for solving geographic tasks: a new methodology applied to location description recognition".
The Use of Generative Artificial Intelligence for Upper Secondary Mathematics Education Through the Lens of Technology Acceptance
Creators: name: Setälä, Mika
name: Heilala, Ville
name: Sikström, Pieta
name: Kärkkäinen, Tommi
Publisher: name: arXiv
Year: 2025
Subjects: subject: Computers and Society (cs.CY)
subject: Artificial Intelligence (cs.AI)
subject: Human-Computer Interaction (cs.HC)
subject: FOS: Computer and information sciences
subject: K.3.1; I.2

description: This study investigated the students' perceptions of using Generative Artificial Intelligence (GenAI) in upper-secondary mathematics education. Data was collected from Finnish high school students to represent how key constructs of the Technology Acceptance Model (Perceived Usefulness, Perceived Ease of Use, Perceived Enjoyment, and Intention to Use) influence the adoption of AI tools. First, a structural equation model for a comparative study with a prior study was constructed and analyzed. Then, an extended model with the additional construct of Compatibility, which represents the alignment of AI tools with students' educational experiences and needs, was proposed and analyzed. The results demonstrated a strong influence of perceived usefulness on the intention to use GenAI, emphasizing the statistically significant role of perceived enjoyment in determining perceived usefulness and ease of use. The inclusion of compatibility improved the model's explanatory power, particularly in predicting perceived usefulness. This study contributes to a deeper understanding of how AI tools can be integrated into mathematics education and highlights key differences between the Finnish educational context and previous studies based on structural equation modeling.
description: Published in the Proceedings of the 40th ACM/SIGAPP Symposium on Applied Computing (SAC'25), March 31--April 4, 2025, Catania, Italy
Tunable dipolar magnetism in high-spin molecular clusters
Creators: name: Evangelisti, M.
name: Candini, A.
name: Ghirri, A.
name: Affronte, M.
name: Powell, G. W.
name: Gass, I. A.
name: Wood, P. A.
name: Parsons, S.
name: Brechin, E. K.
name: Collison, D.
name: Heath, S. L.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We report on the Fe17 high-spin molecular cluster and show that this system is an exemplification of nanostructured dipolar magnetism. Each Fe17 molecule, with spin S=35/2 and axial anisotropy as small as D=-0.02K, is the magnetic unit that can be chemically arranged in different packing crystals whilst preserving both spin ground-state and anisotropy. For every configuration, molecular spins are correlated only by dipolar interactions. The ensuing interplay between dipolar energy and anisotropy gives rise to macroscopic behaviors ranging from superparamagnetism to long-range magnetic order at temperatures below 1K.
description: Replaced with version accepted for publication in Physical Review Letters
Resolving the Stellar Populations in the Circumnuclear Ring of NGC 7469
Creators: name: Diaz-Santos, Tanio
name: Alonso-Herrero, Almudena
name: Colina, Luis
name: Ryder, Stuart D.
name: Knapen, Johan H.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We investigate the stellar populations in the star forming ring of the luminous infrared galaxy NGC 7469. We use Hubble Space Telescope multi-wavelength (UV through NIR) imaging complemented with new K-band ground-based long-slit spectroscopy, and mid-IR and radio maps. Spectral energy distributions (SEDs) and evolutionary synthesis models have been used to characterize the star formation at different scales from those of individual star clusters (tens of pc) to that of the entire star-forming ring (kpc scale). At the smallest scales two different populations of massive (1-10 x 10^6 Msun) clusters are identified. About 25% of the clusters are young (1-3 Myr) and extincted (A_V ~ 3 mag), whereas the vast majority are of intermediate age (~9 to 20 Myr) and less obscured (A_V ~ 1 mag). At larger (hundreds of pc) scale, an analysis of the integrated SED and spectroscopic data of the ring indicates the presence of two stellar populations. The young (5-6 Myr) and obscured stellar population accounts for the Br_gamma emission and most of the IR luminosity, and about one-third of the stellar mass of the ring. The much less obscured intermediate-age population has properties similar to those of the majority of the (older) 1.1um-selected star clusters. These two populations are spatially anti-correlated. The UV-optical-NIR continuum (including the majority of the clusters) of the ring traces mostly the mildly obscured intermediate-age population, while the MIR and radio peaks mark the location of the youngest and obscured star-forming regions. This study emphasizes the need for multi-wavelength, high-angular resolution observations to characterize the star formation in the dust-obscured regions commonly present in LIRGs.
description: 17 pages, 10 figures. Accepted for publication in ApJ. Paper with high resolution images can be found at http://damir.iem.csic.es/extragalactic/publications/publications.html
Ανακάλυψη Γνώσης από Ιατρικά Δεδομένα:
Creators: name: Τσονίδης, Γεώργιος Χρήστου
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Ανακάλυψη γνώσης
Ιατρικά δεδομένα
Εξόρυξη δεδομένων
Knowledge Discovery
Medical data
Data mining

description: Η σημαντική εξέλιξη της τεχνολογίας και η αλματώδης πρόοδος στην επικοινωνία έχει οδηγήσει στην δημιουργία μιας κοινωνίας ικανής να παρέχει σε πολλούς τομείς διαρκώς νέες πληροφορίες. Ένας τομέας που επωφελείται σε μεγάλο βαθμό είναι αυτός της Υγείας, καθώς με την ψηφιακή αποθήκευση υπάρχει η δυνατότητα συλλογής αρκετών δεδομένων τα οποία με την βοήθεια της Ανακάλυψης Γνώσης μπορεί να οδηγήσουν σε σημαντικά συμπεράσματα. Η παρούσα διπλωματική εργασία ασχολείται με την εφαρμογή μεθόδων ανακάλυψης γνώσης σε πραγματικά ιατρικά δεδομένα, των οποίων τα αποτελέσματα μπορούν να αξιολογηθούν από άτομα που είναι ειδικοί στους τομείς της Υγείας. Για την μελέτη των δεδομένων χρησιμοποιήθηκε το WEKA, μια πλατφόρμα εξόρυξης γνώσης από δεδομένα, που περιέχει μια ευρεία συλλογή αλγορίθμων μηχανικής μάθησης.
description: The breakthrough technology and the rapid advances in communication has led to the creation of a society able to provide consistently new information in many fields. One field that benefits greatly is the Health, with digital storage there is the opportunity of gathering enough data, which with the help of knowledge discovery can lead to important conclusions. This thesis deals with the application knowledge discovery methods on real medical data, whose results can be enaluated by people who are experts in the fields of Health. WEKA was used in order to study the data, a platform for mining knowledge from data, which contains an extensive collection of machine learning algorithms.
Ο θεσμός της υφ’ όρον απόλυσης καταδίκου από τις φυλακές και οι ουσιαστικές/προσωπικές προϋποθέσεις εφαρμογής του:
Creators: name: Μαρκοπούλου, Παγώνα Αθανασίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Υφ'όρον
Απόλυση
Ουσιαστικές
Conditional
Release
Substantial

description: Σκοπός της παρούσας μελέτης ήταν η συνοπτική παρουσίαση της υφ’ όρον απόλυσης καταδίκου από τις φυλακές ως θεσμού του Ποινικού Δικαίου και η εξέταση των ουσιαστικών/προσωπικών προϋποθέσεων εφαρμογής της. Αναπτύχθηκαν ζητήματα ορολογίας και εκτέθηκαν η ιστορία του θεσμού, η δογματική του θεμελίωση, ο σκοπός του και η φύση του. Τέλος, παρουσιάστηκαν οι ουσιαστικές/προσωπικές προϋποθέσεις και τα ερμηνευτικά ζητήματα που προκύπτουν στην πράξη.
description: The aim of the present thesis was to briefly present the conditional release of a convict from incarceration, as an institution of the Penal Law and to examine the substantial/personal conditions for its implementation. Issues of terminology were analyzed and the history of the institution, its doctrinal foundation, its purpose and its nature were displayed. Lastly, the substantial/personal conditions and the issues of interpretation that arise in practice were presented.
Deconfined quantum criticality driven by Dirac fermions in SU(2) antiferromagnets
Creators: name: Nogueira, Flavio S.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Quantum electrodynamics in 2+1 dimensions is an effective gauge theory for the so called algebraic quantum liquids. A new type of such a liquid, the algebraic charge liquid, has been proposed recently in the context of deconfined quantum critical points [R. K. Kaul {\it et al.}, Nature Physics {\bf 4}, 28 (2008)]. In this context, we show by using the renormalization group in $d=4-ε$ spacetime dimensions, that a deconfined quantum critical point occurs in a SU(2) system provided the number of Dirac fermion species $N_f\geq 4$. The calculations are done in a representation where the Dirac fermions are given by four-component spinors. The critical exponents are calculated for several values of $N_f$. In particular, for $N_f=4$ and $ε=1$ ($d=2+1$) the anomalous dimension of the Néel field is given by $η_N=1/3$, with a correlation length exponent $ν=1/2$. These values change considerably for $N_f>4$. For instance, for $N_f=6$ we find $η_N\approx 0.75191$ and $ν\approx 0.66009$. We also investigate the effect of chiral symmetry breaking and analyze the scaling behavior of the chiral holon susceptibility, $G_χ(x)\equiv$.
description: 13 pages, 3 figures; published version
Herschel and Odin observations of H2O, CO, CH, CH+, and NII in the barred spiral galaxy NGC 1365. Bar-induced activity in the outer and inner circumnuclear tori
Creators: name: Sandqvist, Aa.
name: Hjalmarson, AA.
name: Larsson, B.
name: Frisk, U.
name: Lundin, S.
name: Rydbeck, G.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The Odin satellite is now into its twentieth year of operation, much surpassing its design life of two years. One of its major pursuits was the search for and study of H2O in the Solar System and the Milky Way galaxy. Herschel has observed the central region of NGC 1365 in two positions, and both its SPIRE and PACS observations are available in the Herschel Science Archive. Herschel PACS images have been produced of the 70 and 160 micron infrared emission from the whole galaxy, and also of the cold dust distribution as obtained from the ratio of the 160 to 70 micron images. The Herschel SPIRE observations have been used to produce maps of the 557 GHz o-H2O, 752 GHz p-H2O, 691 GHz CO(6-5), 1037 GHz CO(9-8), 537 GHz CH, 835 GHz CH+, and the 1461 GHz NII lines; however, these observations have no effective velocity resolution. Odin has recently observed the 557 GHz o-H2O ground state line in the central region with high (5 km/s) spectral resolution. The emission and absorption of H2O at 557 GHz, with a velocity resolution of 5 km/s, has been marginally detected in NGC 1365 with Odin. The H2O is predominantly located in a shocked 15" (1.3 kpc) region near some central compact radio sources and hot-spot HII regions, close to the northeast component of the molecular torus surrounding the nucleus. An analysis of the H2O line intensities and velocities indicates that a shock-region is located here. This is corroborated by a statistical image deconvolution of our SEST CO(3-2) observations, yielding 5" resolution, and a study of our VLA HI absorption observations. Additionally, an enticing 20" HI ridge is found to extend south-southeast from the nucleus, coinciding in position with the southern edge of an OIII outflow cone, emanating from the nucleus. The molecular chemistry of the shocked central region is analyzed with special emphasis on the CO, H2O and CH, CH+ results.
description: 25 pages, 11 figures
The stellar populations of high-redshift dwarf galaxies
Creators: name: Gelli, V.
name: Salvadori, S.
name: Pallottini, A.
name: Ferrara, A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We use high-resolution ($\approx 10$ pc), zoom-in simulations of a typical (stellar mass $M_\star\simeq10^{10}M_\odot$) Lyman Break Galaxy (LBG) at $z\simeq 6$ to investigate the stellar populations of its six dwarf galaxy satellites, whose stellar [gas] masses are in the range $\log (M_\star/M_\odot) \simeq 6-9$ [$\log (M_{gas}/M_\odot) \simeq4.3-7.75$]. The properties and evolution of satellites show no dependence on the distance from the central massive LBG ($< 11.5$ kpc). Instead, their star formation and chemical enrichment histories are tightly connected their stellar (and sub-halo) mass. High-mass dwarf galaxies ($\rm M_\star \gtrsim 5\times 10^8 M_\odot$) experience a long history of star formation, characterised by many merger events. Lower-mass systems go through a series of short star formation episodes, with no signs of mergers; their star formation activity starts relatively late ($z\approx 7$), and it is rapidly quenched by internal stellar feedback. In spite of the different evolutionary patterns, all satellites show a spherical morphology, with ancient and more metal-poor stars located towards the inner regions. All six dwarf satellites experienced high star formation rate ($\rm >5\,M_\odot yr ^{-1}$) bursts, which can be detected by JWST while targeting high-$z$ LBGs.
description: 17 pages, 14 figures. To be published in MNRAS
Οι πολιτικές για τις μειονότητες στα Βαλκάνια: μια συγκριτική μελέτη υπό το φώς των αντίστοιχων πολιτικών στην Δυτική Ευρώπη
Creators: name: Πισιώτης, Αριστείδης Αργυρίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Μειονότητες
Βαλκάνια
Δυτική Ευρώπη
Minorities
Balkans
Western Europe

description: Σκοπός της διατριβής είναι η συγκριτική μελέτη του μειονοτικού φαινομένου στις χώρες της Βαλκανικής Χερσονήσου. Πιο συγκεκριμένα, επειδή πολύς λόγος έχει γίνει τελευταία για την ευρωπαϊκή πορεία των βαλκανικών κρατών, απώτερος στόχος είναι να καταδειχθεί το κατά πόσο οι βαλκανικοί λαοί είναι σε θέση σήμερα να αποδεχθούν τα ευρωπαϊκά πρότυπα μειονοτικής προστασίας. Ο χρονικός ορίζοντας της μελέτης είναι η περίοδος της πτώσης του κομμουνισμού το 1989 μέχρι και σήμερα, με συχνές όμως αναφορές και σε παλαιότερα γεγονότα. Αρχικά, εξετάζονται οι θεωρητικές προσεγγίσεις που αφορούν τόσο την μειονοτική προστασία όσο και την ποιότητα των κοινωνικών σχέσεων και πολιτικής στην βαλκανική χερσόνησο. Στην συνέχεια παρουσιάζονται οι πολιτικές που ακολούθησαν οι χώρες των Βαλκανίων ως προς τις μειονότητες, χρησιμοποιώντας σαν σημείο αναφοράς την Αλβανία, την Βουλγαρία, την Κροατία, την ΠΓΔΜ, την Ρουμανία και την Σερβία. Στο αμέσως επόμενο κεφάλαιο γίνεται μια προσπάθεια οριοθέτησης των Ευρωπαϊκών προτύπων, μέσα από την μελέτη των αρχών και πολιτικών των ευρωπαϊκών υπερεθνικών οργανισμών (ΕΕ, Συμβούλιο της Ευρώπης και ΟΑΣΕ), αλλά και την διαχρονική πολιτική των ευρωπαϊκών χωρών, με ιδιαίτερη αναφορά στην Ιταλία. Τέλος, στο τελευταίο κεφάλαιο, μέσα από μία πιο συγκεντρωτική και συγκριτική μελέτη, καταλήγουμε στα συμπεράσματα της έρευνας.
description: The aim of this thesis is the comparative analysis of the minority phenomenon in the Balkan countries. More particularly, the principal goal is to be shown whether the Balkan countries are in the position today to accept the European models of minority protection or not. The time horizon of the analysis consists of the period from the fall of communism in 1989 until today. In many cases, however, there are also references in events before the period under examination. At first, the theoretical approaches that concern the minority protection and the quality of the social relations and politics in the Balkan countries are examined. Then, there are presented, the policies that the Balkan countries applied, concerning the minorities. The countries under examination are Albania, Bulgaria, Croatia, FYROM, Romania and Serbia. In the following chapter, an effort of marking out the European models occurs by studying the policies of the European organizations (E.U. Council of Europe, O.S.C.E. ).Finally, in the last chapter, after a comparative analysis that is held, the results of the research are illustrated.
Prospects of Medium Tomography using 2-,3- and 4-Particle Correlations for a (semi-)hard Trigger
Creators: name: Renk, Thorsten
name: Ruppert, Jorg
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Hard partons propagating through hot and dense matter lose energy, leading to the observed depletion of hard hadron spectra in nucleus nucleus collision as compared to scaled proton proton collisions. This lost energy has to be redistributed in the medium due to the conservation of energy, which is manifest in the p_T dependence of the angular correlation pattern of hadrons associate with a (semi-) hard trigger. While at low p_T a splitting of a broad peak is observed, at high p_T the structure shows vacuum width, albeit with reduced yield. This sugests a transfer of energy from hard partons to a collectively recoiling medium. We present a systematic study of these phenomena using a realistic medium evolution and a Monte-Carlo simulation of the experimental trigger and show what information about the medium can be derived from multiparticle correlations.
description: Talk given at the XI International Workshop on Correlation and Fluctuation in Multiparticle Production, Hangzhou, China, 21-24 Nov. 2006
The Atacama Large Millimeter/submillimeter Array: Overview & status
Creators: name: Beasley, A. J.
name: Murowinski, R.
name: Tarenghi, M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The Atacama Large Millimeter/submillimeter Array (ALMA) is an international radio telescope under construction in the Atacama Desert of northern Chile. ALMA will be situated on a high-altitude site at 5000 m elevation which provides excellent atmospheric transmission over the instrument wavelength range of 0.3 to 3 mm. ALMA will be comprised of two key observing components: an array of up to sixty-four 12-m diameter antennas arranged in a multiple configurations ranging in size from 0.15 to ~14 km, and a set of four 12-m and twelve 7-m antennas operating in closely-packed configurations ~50m in diameter (known as the Atacama Compact Array, or ACA), providing both interferometric and total-power astronomical information. High-sensitivity dual-polarization 8 GHz-bandwidth spectral-line and continuum measurements between all antennas will be available from two flexible digital correlators.
Elemental Abundances of M Dwarfs Based on High-Resolution Near-Infrared Spectra: Verification by Binary Systems
Creators: name: Ishikawa, Hiroyuki Tako
name: Aoki, Wako
name: Kotani, Takayuki
name: Kuzuhara, Masayuki
name: Omiya, Masashi
name: Reiners, Ansgar
name: Zechmeister, Mathias
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: M dwarfs are prominent targets of planet search projects, and their chemical composition is crucial to understanding the formation process or interior of orbiting exoplanets. However, measurements of elemental abundances of M dwarfs have been limited due to difficulties in the analysis of their optical spectra. We conducted a detailed chemical analysis of five M dwarfs (T_eff ~3200--3800 K), which form binary systems with G/K-type stars, by performing a line-by-line analysis based on high-resolution (R ~80,000) near-infrared (960--1710 nm) spectra obtained with CARMENES. We determined the chemical abundances of eight elements (Na, Mg, K, Ca, Ti, Cr, Mn, and Fe), which are in agreement with those of the primary stars within measurement errors (~0.2 dex). Through the analysis process, we investigated the unique behavior of atomic lines in a cool atmosphere. Most atomic lines are sensitive to changes in abundance not only of the corresponding elements but also of other elements, especially dominant electron donors such as Na and Ca. The Ti I lines show a negative correlation with the overall metallicity at T_eff < 3400 K due to the consumption of neutral titanium by the formation of TiO molecules. These findings indicate that to correctly estimate the overall metallicity or the abundance of any element, we need to determine the abundances of other individual elements consistently.
description: 19 pages, 11 figures, accepted for publication in PASJ
The NederDrone: A hybrid lift, hybrid energy hydrogen UAV
Creators: name: De Wagter, Christophe
name: Remes, Bart
name: Smeur, Ewoud
name: van Tienen, Freek
name: Ruijsink, Rick
name: van Hecke, Kevin
name: van der Horst, Erik
Publisher: name: arXiv
Year: 2020
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: A lot of UAV applications require vertical take-off and landing (VTOL) combined with very long-range or endurance. Transitioning UAVs have been proposed to combine the VTOL capabilities of helicopters with the efficient long-range flight properties of fixed-wing aircraft. But energy is still a bottleneck for many electric long endurance applications. While solar power technology and battery technology have improved a lot, in rougher conditions they still respectively lack the power or total amount of energy required for many real-world situations. In this paper, we introduce the NederDrone, a hybrid lift, hybrid energy hydrogen-powered UAV which can perform vertical take-off and landings using 12 propellers while flying efficiently in forward flight thanks to its fixed wings. The energy is supplied from a mix of hydrogen-driven fuel-cells to store large amounts of energy and battery power for high power situations. The hydrogen is stored in a pressurized cylinder around which the UAV is optimized. This paper analyses the selection of the concept, the implemented safety elements, the electronics and flight control and shows flight data including a 3h38 flight at sea, starting and landing on a small moving ship.
The inverse spectral problem for the discrete cubic string
Creators: name: Kohlenberg, Jennifer
name: Lundmark, Hans
name: Szmigielski, Jacek
Publisher: name: arXiv
Year: 2006
Subjects: subject: Spectral Theory (math.SP)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 34B05 (Primary); 34A55, 34B20, 41A28 (Secondary)

description: Given a measure $m$ on the real line or a finite interval, the "cubic string" is the third order ODE $-ϕ'''=zmϕ$ where $z$ is a spectral parameter. If equipped with Dirichlet-like boundary conditions this is a nonselfadjoint boundary value problem which has recently been shown to have a connection to the Degasperis-Procesi nonlinear water wave equation. In this paper we study the spectral and inverse spectral problem for the case of Neumann-like boundary conditions which appear in a high-frequency limit of the Degasperis--Procesi equation. We solve the spectral and inverse spectral problem for the case of $m$ being a finite positive discrete measure. In particular, explicit determinantal formulas for the measure $m$ are given. These formulas generalize Stieltjes' formulas used by Krein in his study of the corresponding second order ODE $-ϕ''=zmϕ$.
description: 24 pages. LaTeX + iopart, xypic, amsthm. To appear in Inverse Problems (http://www.iop.org/EJ/journal/IP)
Μοντέλα μαρκοβιανών αλυσίδων στα βιομηχανικά συστήματα:
Creators: name: Ίτσιος, Απόστολος Κωνσταντίνου
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Μαρκοβιανές αλυσίδες
Αλγόριθμος
Πιθανότητες μετάβασης
Πιθανότητες σταθερής κατάστασης
Markov chain
Algorithm
Transition probability matrix
Steady-state probabilities

description: Σκοπός της διατριβής ήταν η μελέτη μοντέλων Μαρκοβιανών αλυσίδων στα βιομηχανικά συστήματα, παρουσιάστηκαν οι σημαντικότερες επιστημονικές έρευνες στον τομέα αυτό και έγινε εισαγωγή στη θεωρία των στοχαστικών διαδικασιών και των μαρκοβιανών αλυσίδων. Η συνεισφορά της εργασίας ήταν η δημιουργία μιας εφαρμογής για ηλεκτρονικούς υπολογιστές όπου υπολογίζονται για μια Μαρκοβιανή αλυσίδα, οι πιθανότητες μετάβασης μετά από ν βήματα (n-step transition probability matrix), οι πιθανότητες σταθερής κατάστασης (stedy-state probabilities) και οι μέσοι χρόνοι επιστροφής (mean return times) χωρίς να απαιτούνται εξωτερικές βιβλιοθήκες ή χρήση εμπορικών εφαρμογών για την λειτουργιά της.
description: The aim of the present thesis was the study of Markov chain model in manufacturing systems. Then we presented the most popular scientific research in this field. Furthermore we analyzed the stochastic process theory and the necessary background about Markov chains. The contribution of this thesis was the creation of a stand-alone application for windows operation system which computes in a user-friendly environment the n-step transition probability matrix, the steady-state probabilities and the mean return times for a Markov chains and does not require 3rd party commercial applications or libraries for its function.
Harmonic analysis on a finite homogeneous space
Creators: name: Scarabotti, Fabio
name: Tolli, Filippo
Publisher: name: arXiv
Year: 2007
Subjects: subject: Representation Theory (math.RT)
subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 43A95, 20C15, 20C30, 20E2, 43A90

description: In this paper, we study harmonic analysis on finite homogeneous spaces whose associated permutation representation decomposes with multiplicity. After a careful look at Frobenius reciprocity and transitivity of induction, and the introduction of three types of spherical functions, we develop a theory of Gelfand Tsetlin bases for permutation representations. Then we study several concrete examples on the symmetric groups, generalizing the Gelfand pair of the Johnson scheme; we also consider statistical and probabilistic applications. After that, we consider the composition of two permutation representations, giving a non commutative generalization of the Gelfand pair associated to the ultrametric space; actually, we study the more general notion of crested product. Finally, we consider the exponentiation action, generalizing the decomposition of the Gelfand pair of the Hamming scheme; actually, we study a more general construction that we call wreath product of permutation representations, suggested by the study of finite lamplighter random walks. We give several examples of concrete decompositions of permutation representations and several explicit 'rules' of decomposition.
description: 69 pages