cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Single-particle and collective effects of cubic nonlinearity in the beam dynamics of proton synchrotrons
Creators: name: Tran, Hy J.
Publisher: name: University of British Columbia
Year: 2009

description: This thesis describes some new studies of the effects of cubic nonlinearities arising from image-charge forces and octupole magnets on the transverse beam dynamics of proton synchrotrons and storage rings, and also a study of the damping of coherent oscillations using a feed-back damper. In the latter case, various corrective algorithms were modeled using linear one-turn maps. Kicks of fixed amplitude but appropriate sign were shown to provide linear damping and no coherent tune shift, though the rate predicted analytically was somewhat higher than that observed in simulations. This algorithm gave much faster damping (for equal power) than conventional proportional kicks, which damp exponentially. Two single-particle effects of the image-charge force were investigated: distortion of the momentum dispersion function and amplitudedependence of the betatron tunes (resulting in tune spread). The former is calculated using transfer maps and the method of undetermined coefficients, the latter by solving the cubic nonlinear equation of motion with the smooth approximation and time averaging. In the case of the CERN Large Hadron Collider, neither effect was found to be of serious concern. Two collective effects caused by tune spread, decoherence and Landau damping, were studied, using bounded binomial (rather than gaussian) density distributions to make the results valid for proton beams. The spread arises from a cubic term in the restoring force. To study decoherence, the motion of a transversely displaced beam bunch was determined using the Vlasov equation, and its centroid found by ensemble averaging; the displaced density distribution was Taylor-expanded in terms of the original one to simplify the integration boundary. The decoherence rate was found to depend primarily on the average density gradient. The centroid motion is also amplitude modulated at the synchrotron tune. To study Landau damping of the weak head-tail instability, a perturbation technique was applied to the Vlasov equation, and the dispersion-relation concept was augmented to handle many coupled radial modes by equating the inverse of the beam transfer function to the set of eigenvalues of the interaction matrix. The matrix elements are the overlaps of the impedance and the mode spatial spectra, while the eigenvalues are the mode frequencies. A new and rigorous derivation is given for the head-tail mode spectra for binomial distributions. In the case of an LHC-type bunch in the CERN PS, several modes were predicted to be unstable, with growth rates compatible with the rather imprecise measurements. The octupole strength needed to Landau damp these unstable modes was estimated by mapping out the stability region in the complex frequency plane.
Οργανισμοί μάθησης. Διερεύνηση των πληροφοριακών συστημάτων τους. Μία περίπτωση
Creators: name: Καρακολτσίδης, Νικόλαος Χαραλάμπους
Publisher: name: Aristotle University of Thessaloniki
Year: 2007

description: Οι σύγχρονες επιχειρήσεις για να είναι ανταγωνιστικές στο παγκοσμιοποιημένο περιβάλλον θα πρέπει να δώσουν έμφαση στην ανάπτυξη του "διανοητικού τους κεφαλαίου", δηλαδή να γίνουν οργανισμοί μάθησης. Οι οργανισμοί μάθησης οφείλουν να παρέχουν δυνατότητες πληροφόρησης στο προσωπικό τους μέσω των πληροφοριακών συστημάτων αλλά συγχρόνως και δυνατότητες μάθησης και εκπαίδευσης. Στην παρούσα εργασία γίνεται ανάλυση και μέτρηση του βαθμού μάθησης μιας επιχείρησης και παρουσιάζονται τα πληροφοριακά συστήματα που αυτή χρησιμοποιεί για τη σωστή και αποδοτική λειτουργία της
description: The modern enterprises with the aim of being competitive in the globalized environment should focus on the development of their "intellectual asset" that is to become learning organizations. The learning organizations should provide informing opportunities to their staff through information systems and learning and education possibilities. This dissertation aims at analysing and measuring the level of the organizational learning in an enterprise. Furthermore, it presents the information systems the enterprise uses to insure a productive operation
A reaction-diffusion system with cross-diffusion: Lie symmetry, exact solutions and their applications in the pandemic modeling
Creators: name: Cherniha, Roman
name: Davydovych, Vasyl'
Publisher: name: arXiv
Year: 2020
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: A nonlinear reaction-diffusion system with cross-diffusion describing the COVID-19 outbreak is studied using the Lie symmetry method. A complete Lie symmetry classification is derived and it is shown that the system with correctly-specified parameters admits highly nontrivial Lie symmetry operators, which do not occur for all known reaction-diffusion systems. The symmetries obtained are also applied for finding exact solutions of the system in the most interesting case from applicability point of view. It is shown that the exact solutions derived possess all necessary properties for describing the pandemic spread under 1D approximation in space and lead to the distributions, which qualitatively correspond to the measured data of the COVID-19 spread in Ukraine.
The infrared compactness-temperature relation for quiescent and starburst galaxies
Creators: name: Chanial, Pierre
name: Flores, Hector
name: Guiderdoni, Bruno
name: Elbaz, David
name: Hammer, Francois
name: Vigroux, Laurent
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: IRAS observations show the existence of a correlation between the infrared luminosity Lir and dust temperature Td in star-forming galaxies, in which larger Lir leads to higher dust temperature. The Lir-Td relation is commonly seen as reflecting the increase in dust temperature in galaxies with higher star formation rate. Even though the correlation shows a significant amount of dispersion, a unique relation has been commonly used to construct spectral energy distributions of galaxies in distant universe studies, such as source number counting or photometric redshift determination. In this work, we introduce a new parameter, namely the size of the star-forming region Rir and lay out the empirical and modelled relation between the global parameters Lir, Td and Rir of IR-bright non-AGN galaxies. IRAS 60-to-100um color is used as a proxy for the dust temperature and the 1.4GHz radio contiuum emission for the infrared spatial distribution. The analysis has been carried out on two samples. The first one is made of the galaxies from the 60um flux-limited IRAS Revised Bright Galaxy Samples which have a reliable RC size estimate from the VLA follow-ups of the IRAS Bright Galaxy Samples. The second is made of the sources from the 170um ISOPHOT Serendipity Sky Survey which are resolved by the NVSS or FIRST surveys. We show that the dispersion in the Lir-Td diagram can be reduced to a relation between the infrared surface brightness and the dust temperature, a relation that spans 5 orders of magnitude in surface brightness. We explored the physical processes giving rise to the Sir-Td relation, and show that it can be derived from the Schmidt law, which relates the star formation rate to the gas surface density.
description: 13 pages, 7 figures, accepted for publication in A&A
Μέθοδοι πολυμεταβλητής στατιστικής ανάλυσης με εφαρμογές στην ασφάλεια πληροφοριακών συστημάτων
Creators: name: Γεροφώτη, Μαρία Γεωργίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2007
Subjects: Ανίχνευση εισβολών
Συστήματα ανίχνευσης εισβολών
Ασφάλεια
Ανάλυση κυρίων συνιστωσών
Ανάλυση παραγόντων
Λογαριθμική παλινδρόμηση
Ανάλυση διακρίσεων
Intrusion detection
Intrusion detection systems (IDS)
Security
Principal component analysis (PCA)
Factor analysis (FA)
Discriminant analysis (DA)
Logistic regression (LR)

description: Η σημερινή εποχή χαρακτηρίζεται από την ιδιαίτερα μεγάλη ανάπτυξη και τη γενικευμένη χρήση της τεχνολογίας της πληροφορικής και των επικοινωνιών. Οι υπολογιστές χρησιμοποιούνται σήμερα σε όλες σχεδόν τις ανθρώπινες δραστη-ριότητες και σε κάθε είδους εργασίες. Οι δυνατότητες και οι ευκαιρίες είναι αναντίρρητα απεριόριστες. Παράλληλα όμως αυξάνονται οι κίνδυνοι και τα κρούσμα-τα από ηθελημένες ή τυχαίες καταστροφές, αλλοιώσεις ή μη εξουσιοδοτημένη χρήση των δεδομένων και γενικότερα των υπολογιστικών πόρων. [1] Με την εμφάνιση και τη μεγάλη εξάπλωση του Διαδικτύου και του Ηλεκτρονικού Εμπορίου (E-Commerce) σε κάθε γωνιά της γης, τα υπολογιστικά συστήματα εκτίθενται σε εκατοντάδες εισβολές (intrusions) διαφόρων ειδών, προερχόμενες από τον Παγκόσμιο Ιστό (World Wide Web) σε καθημερινή πλέον βάση. [2] Αυτή τη στιγμή υπάρχουν ποικίλες απειλές και ευπάθειες στην ασφάλεια των πληροφοριακών συστημάτων και δικτύων απέναντι σε αυτές τις εισβολές. Παράλληλα με την παγκόσμια διάδοση του Διαδικτύου και την δραματικά αυξανόμενη χρήση και διαθεσιμότητα ασύρματων υπηρεσιών, ο αριθμός και ο αντίκτυπος των επιθέσεων αυτών αυξάνεται ολοένα και περισσότερο και η εξασφάλιση ασφαλών δικτύων προβάλει στον ορίζοντα ως μια δυνητικά επιτακτική ανάγκη.Η παρούσα μελέτη αφορά σε θεωρίες και μεθοδολογίες που αφορούν στις στατιστικές προσεγγίσεις ανίχνευσης εισβολών
description: Computers are nowadays being used in almost all human activities.The opportunities and chances being offered are unlimited indeed. At the same time, however with the advent growth of the internet and the network technology arise many dangers of deliberate intrusions and unauthorised use of data and resources. Information systems are exposed daily to various threats coming from the world wide web mainly. It is important therefore to ensure safe networks and minimum losss in information systems loss. this study focuses on methodologies concerning statistical techniques of intrusion detection
Criptodinero, ¿China toma la delantera?
Creators: name: Jiménez Tellado, Raul
name: Moreno, Luis
Publisher: name: Digital.CSIC
Year: 2021
Subjects: Robots
criptodinero
China

description: El gobierno chino ha comenzado a migrar el Renminbi, su moneda de curso legal (también conocido como Yuan en occidente), a una plataforma de criptomoneda. Esto conlleva que la moneda china no tendrá soporte físico y se moverá en el mundo virtual de la cadena de bloques (blockchain), es decir en una base de datos que no puede ser modificada. Ningún otro país o entidad internacional ha efectuado este tipo de operación. Facebook (uno de los nuevos señores feudales tecnológicos SefTec), intentó crear su propia criptomoneda Libra, iniciativa neutralizada por el gobierno norteamericano. Fue aquella una decisión acertada, desde nuestro punto de vista, tal y como argumentamos en este artículo.
Die 9. Vollversammlung des Lutherischen Weltbundes in Hongkong - theologische Anfragen
Creators: name: Holze, Heinrich
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 46 Nr. 4 (1997): Ökumenische Rundschau, Band 46, Heft 4
Impact of Dynamical Fermions on QCD Vacuum Structure
Creators: name: Moran, Peter J.
name: Leinweber, Derek B.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We examine how dynamical fermions affect both the UV and infrared structure of the QCD vacuum. We consider large $28^3 \times 96$ lattices from the MILC collaboration, using a gluonic definition of the topological charge density, founded on a new over-improved stout-link smearing algorithm. The algorithm reproduces established results from the overlap formalism and is designed to preserve nontrivial topological objects including instantons. At short distances we focus on the topological charge correlator, $$, where negative values at small $x$ reveal a sign-alternating layered structure to the topological-charge density of the QCD vacuum. We find that the magnitudes of the negative dip in the $$ correlator and the positive $$ contact term are both increased with the introduction of dynamical fermion degrees of freedom. This is in accord with expectations based on charge renormalization and the vanishing of the topological susceptibility in the chiral limit. At large distances we examine the extent to which instanton-like objects are found on the lattice, and how their distributions vary between quenched and dynamical gauge fields. We show that dynamical gauge fields contain more instanton-like objects with an average size greater than in the quenched vacuum. Finally, we directly visualize the topological charge density in order to investigate the effects of dynamical sea-quark degrees of freedom on topology.
description: 9 pages, 8 figures
Photon emission as a source of coherent behaviour of polaritons
Creators: name: Vinck-Posada, Herbert
name: Rodriguez, Boris A.
name: Guimaraes, P. S. S.
name: Cabo, Alejandro
name: Gonzalez, Augusto
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We show that the combined effect of photon emission and Coulomb interactions may drive an exciton-polariton system towards a dynamical coherent state, even without phonon thermalization or any other relaxation mechanism. Exact diagonalization results for a finite system (a multilevel quantum dot interacting with the lowest energy photon mode of a microcavity) are presented in support to this statement.
Deciphering the 3-D Orion Nebula-II: A low-ionization region of multiple velocity components southwest of Theta1OriC confounds interpretation of low velocity resolution studies of temperature, density, and abundance
Creators: name: O'Dell, C. R.
name: Abel, N. P.
name: Ferland, G. J.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: We establish that there are two velocity systems along lines-of-sight that contribute to the emission-line spectrum of the the brightest parts of the Orion Nebula. These overlie the Orion-S embedded molecular cloud southwest of the dominant ionizing star (Theta1OriC). Examination of 10x10" samples of high spectral resolution emission-line spectra of this region reveals it to be of low ionization, with velocities and ionization different from the central part of the Nebula. These properties jeopardize earlier determinations of abundance and physical conditions since they indicate that this region is much more complex than has been assumed in analyzing earlier spectroscopic studies and argue for use of very high spectral resolution or known simple regions in future studies.
description: 9 pages, 2 figures
Scalar Field Dark Energy Perturbations and their Scale Dependence
Creators: name: Unnikrishnan, Sanil
name: Jassal, H. K.
name: Seshadri, T. R.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We estimate the amplitude of perturbation in dark energy at different length scales for a quintessence model with an exponential potential. It is shown that on length scales much smaller than hubble radius, perturbation in dark energy is negligible in comparison to that in in dark matter. However, on scales comparable to the hubble radius ($λ_{p}>1000\mathrm{Mpc}$) the perturbation in dark energy in general cannot be neglected. As compared to the $Λ$CDM model, large scale matter power spectrum is suppressed in a generic quintessence dark energy model. We show that on scales $λ_{p} < 1000\mathrm{Mpc}$, this suppression is primarily due to different background evolution compared to $Λ$CDM model. However, on much larger scales perturbation in dark energy can effect matter power spectrum significantly. Hence this analysis can act as a discriminator between $Λ$CDM model and other generic dark energy models with $w_{de} \neq -1$.
description: 12 pages, 13 figures, added new section, accepted for publication in Phys. Rev. D
Γεωχημική μελέτη αδιατάρακτων εδαφών σε περιοχές του δήμου Μελίτης του νομού Φλώρινας
Creators: name: Τρύφων, Αναστασία Γεωργίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2007
Subjects: subject: Γεωχημεία
subject: Ιχνοστοιχεία
subject: Ανθρακες
subject: Geochemistry
subject: FOS: Earth and related environmental sciences
subject: Trace elements
subject: Lignite

description: Για την εκπόνηση της διατριβής ειδίκευσης συλλέχθηκαν συνολικά 25 δείγματα αδιατάρακτων επιφανειακών εδαφών από τις περιοχές του Δήμου Μελίτης του Νομού Φλώρινας. Προσδιορίστηκαν οι περιεκτικότητες 45 στοιχείων. Με την FAAS προσδιορίστηκαν τα στοιχεία Si, Al, Ti, Mn, Fe, Mg, Ca, Na, J, P και με την ICP-MS τα Ag, As, B, Ba, Be, Bi, Cd, Ce, Co, Cr, Cu, Ga, Ge, Hg, La, Li, Mo, Nb, Ni, Pb, Rb, Sb, Sc, Se, Sn, Sr, Ta, Th, Tl, U, V, Y, Zn, Zr. Οι περιεκτικότητες συγκρίθηκαν με το μέσο όρο του φλοιού της γής. Τα Ca, Mn, Ag, As, Bi, CΦ, Co, Hg, Ni, Sb, Se, Te, U βρέθηκαν εμπλουτισμένα στα δείγματα. Οι συντελεστές εμπλουτισμού που προέκυψαν συγκρίθηκαν με τους συντελεστές εμπλουτισμού των ίδιων στοιχείων στα περιβάλλοντα πετρώματα, στο λιγνίτη και την ιπτάμενη τέφρα. Ο εμπλουτισμός των περισσοτέρων από τα παραπάνω στοιχεία, οφείλεται εκτός από τα περιβάλλοντα πετρώματα, κατά πολύ στην εκμετάλλευση του λιγνίτη. Τα δείγματα με εμπλουτισμό στα Ca, Ag, Cd, Hg, Sb, Se έχουν επηρεαστεί από τα περιβάλλοντα, το λιγνίτη και την ιπτάμενη τέφρα. Ο εμπλουτισμός του Mn, Bi, Co οφείλεται κυρίως στα μεταλλεύματα σιδηροπυρίτη, χαλκοπυρίτη, μαγνητοπυρίτη. Ο εμπλουτισμός As, U αποδίδεται κυρίως στις λιγνιτικές δραστηριότητες. Ο εμπλουτισμός του Te, Ni θα μπορούσε ίσως να αποδοθεί στα μεταλλεύματα και στις λιγνιτικές δραστηριότητες της περιοχής μελέτης
description: Twenty five samples of uncultivated topsoils were collected from selected areas of Meliti's municipality of Prefecture Florina. Forty five elements were determined. With FAAS were determined Si, Al, Ti, Mn, Fe, Mg, Ca, Na, K, P and with ICP-MS the elements Ag, As, B, Ba, Be, Bi, Cd, Ce, Co, Cr, Cu, Ga, Ge, Hg, La, Li, Mo, Nb, Ni, Pb, Rb, Sb, Sc, Se, Sn, Sr, Ta, Te, Th, Tl, U, V, Y, Zn, Zr. The results of analysis were compared with the mean values of the Earth's crust. The elements Ca, Mn, Ag, As, Bi, Cd, Co, Hg, Ni, Sb, Se, Te, U were found to be enriched in the samples. The enrichment factors that were found were surrounding rocks and in liguite and fly ash. The enrichment of the most of the above elements, except from the surrounding rocks, is mainly dueo to the coal mine activities. The enrichment of Ca, Ag, Cd, Hg, Sb, Se is atributed mainly by surroundings rocks, liguite and fly ash. The enrichment of Mn, Bi, Co is mainly attributed to the ores(pyrite, chalcopyrite, pyrrhotite). The enrichment of Te, Ni, is mainly attributed to the presence of ores and to the lignite and fly ash
Knotted nodal lines in superpositions of Bessel-Gaussian light beams
Creators: name: Radozycki, Tomasz
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: A simple analytical way of creating superpositions of Bessel-Gaussian light beams with knotted nodal lines is proposed. It is based on the equivalence between the paraxial wave equation and the two-dimensional Schrödinger equation for a free particle. The $2D$ Schrödinger propagator is expressed in terms of Bessel functions, which allows to obtain directly superpositions of beams with a desired topology of nodal lines. Four types of knots are constructed in the explicit way: the unknot, the Hopf link, the Borromean rings and the trefoil. It is also shown, using the example of the figure-eight knot, that more complex structures require larger number of constituent beams as well as high precision both from the numerical and the experimental side. A tiny change of beam's intensity can lead to the knot "switching".
description: REVTEX, 10 pages, 8 figures
Value Assignments to Observables Depending on a History of Context Change
Creators: name: Uchiyama, Satoshi
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The functional composition principle is generalized by taking into account of history of context change. Analysis of Peres' example shows hysteresis of value assignments. It is shown that value assignments which depend on the history of context change are possible in the case that the Hilbert space of state vectors is finite dimensional.
description: 22 pages. Errors in the previous proof of Proposition 5 were corrected. This is the full version of "On Hysteresis of Value Assignments to Observables during Changes of Context" in Foundations of Probability and Physics - 4, eds. A. Yu. Khrennikov et al., AIP Conf. Proc. 889, 2007, pp. 422-426
Acoustic radiation-free surface phononic crystal resonator for in-liquid low-noise gravimetric detection
Creators: name: Gao, Feng
name: Bermak, Amine
name: Benchabane, Sarah
name: Robert, Laurent
name: Khelif, Abdelkrim
Publisher: name: arXiv
Year: 2021
Subjects: subject: Applied Physics (physics.app-ph)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: Acoustic wave resonators are promising for gravimetric biosensing. However, they generally suffer from strong acoustic radiation in liquid, which limits their quality factor and increases their frequency noise. This article presents an acoustic-radiation-free gravimetric biosensor based on a locally-resonant surface phononic crystal (SPC) consisting of periodic high aspect ratio electrodes to ad-dress the above issue. The acoustic wave generated in the SPC is slower than the sound wave in water, hence preventing acoustic propagation in the fluid and resulting in energy confinement near the electrode surface. This energy confinement results in a significant quality factor improvement and thus reduces the frequency noise. The proposed SPC resonator is numerically studied by finite element analysis and experimentally implemented by an electroplating based fabrication process. Experimental results show that the SPC resonator exhibits an in-liquid quality factor 15 times higher than a conventional Rayleigh wave resonator with a similar operating frequency. The proposed radiation suppression method using SPC can also be applied in other types of acoustic wave resonators. It can thus serve as a general technique for boosting the in-liquid quality factor and the sensing performance of many acoustic biosensors.
Energía nuclear para enfriar el Planeta
Creators: name: Jiménez, Raúl
name: Moreno, Luis
Publisher: name: Grupo Prisa
Year: 2021
Subjects: Energía nuclear
Calentamiento global

description: Con autorización del periódico para autores CSIC. El artículo apareció en la sección Agenda Global.
description: El peligro más importante que acecha a la humanidad es el calentamiento global. Para ser más precisos, y como hemos indicado en un reciente artículo, el peligro concierne al calentamiento de la atmósfera debido a la creciente acumulación de gases como el dióxido de carbono y el metano (principalmente). Hace unos años el sociólogo Anthony Giddens ya nos avisaba de la carencia de una política sistemática de gestión del peligro del calentamiento global, el cual se mostraba diferente a los ya conocidos. Y es que el ‘efecto mariposa’ del calentamiento global se manifiesta en las más variadas formas de destrucción ambiental y hasta en la propia proliferación de enfermedades pandémicas. Es desalentador corroborar cómo los humanos rara vez confrontamos la solución de situaciones que no suponen un claro e inminente peligro.
CESAM: a free code for stellar evolution calculations
Creators: name: Morel, Pierre
name: Lebreton, Yveline
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The Cesam code is a consistent set of programs and routines which perform calculations of 1D quasi-hydrostatic stellar evolution including microscopic diffusion of chemical species and diffusion of angular momentum. The solution of the quasi-static equilibrium is performed by a collocation method based on piecewise polynomials approximations projected on a B-spline basis; that allows stable and robust calculations, and the exact restitution of the solution, not only at grid points, even for the discontinuous variables. Other advantages are the monitoring by only one parameter of the accuracy and its improvement by super-convergence. An automatic mesh refinement has been designed for adjusting the localisations of grid points according to the changes of unknowns. For standard models, the evolution of the chemical composition is solved by stiffly stable schemes of orders up to four; in the convection zones mixing and evolution of chemical are simultaneous. The solution of the diffusion equation employs the Galerkin finite elements scheme; the mixing of chemicals is then performed by a strong turbulent diffusion. A precise restoration of the atmosphere is allowed for.
description: 13 pages, 1 figure, accepted for publication in Astrophysics & Space Science, ESTA/CoRoT Volume
Εφαρμογή ποσοτικών διαδικασιών και χρήση των γεωγραφικών συστημάτων πληροφοριών (GIS) στη διαχείριση δασικών οικοσυστημάτων
Creators: name: Κομίλη, Δέσποινα Ιωάννη
Publisher: name: Aristotle University of Thessaloniki
Year: 2007
Subjects: Διαχείριση δασικών οικοσυστημάτων
Ελεγχος λήμματος
Γραμμικός προγραμματισμός
Γεωγραφικά συστήματα πληροφοριών
Αριστοποίηση συγκομιδής
Σταθερότητα συστάδων
Management of forest ecosystems
Control of harvest
Linear programming
GIS
Harvest optimazation
Stability of cluster

description: Στη διαχείριση δασικών οικοσυστημάτων είναι αναγκαίο οι ανρθωπογενείς επιδράσεις σε αυτά να διενεργούνται κατά τέτοιο τρόπο ώστε να διατηρείται η σταθερότητα της δομής τους και παράλληλα να εκπληρώνουν αειφορικά τους οικονομικούς και οικολογικούς σκοπούς τους. Στην εργασία αυτή παρουσιάζεται η εφαρμογή του γραμμικού προγραμματισμού για τον έλεγχο του λήμματος στις συστάδες δασών με διαφορετική δομή με τη βοήθεια και των γεωγραφιών συστημάτων πληροφοριών. Η μέθοδος βασίζεται στην ανάπτυξη γραμμικών εξισώσεων οι οποίες πληρούν τις συνθήκες σταθερότητας, μεγιστοποιούν την παραγωγή αλλά ελέγχουν και το λήμμα των συστάδων.
description: In forest management it is necessary that man made effects on these are carried out in such a manner is maintained so that the stability of their structure and at the same time in order to fullfill sustainable their ecological and economic purposes. This paper presents and develops application of the linear programming technique for the control of harvest in clusters of forest with different structure and be used the GIS. This method is based on the development of the system of linear equations which fulfill the conditions as the maximization of production as much as the control of harvest.
¿Brexit y Scotin?
Creators: name: Moreno, Luis
Publisher: name: Grupo Prisa
Year: 2016
Subjects: Brexit
Reino Unido
Escocia
Unión Europea

description: Con autorización del periódico para autores CSIC. El artículo apareció en la sección Agenda Europea.
description: A pocos días de la celebración en el Reino Unido del referéndum sobre la Unión Europea, el resultado del mismo aparece incierto. Los sondeos no indican una clara ventaja ni de los partidarios por irse ni de los favorables por quedarse en la UE. A la hora de redactar estas líneas, las últimas proyecciones indicarían un voto marginalmente favorable al ‘exit’ en Inglaterra, aunque el mayor apoyo a permanecer en el club europeo en las otras naciones componentes del Reino Unido (Escocia, Irlanda del Norte y País de Gales), haría que la balanza se inclinase muy levemente a la continuidad británica en las instituciones comunitarias. Todo incierto y hasta cabalístico. La Tabla 1 muestra el mayor peso poblacional de Inglaterra en el conjunto británico (84% del total). Según los sondeos, prevalece allí una pequeña predisposición a abandonar la UE. En Escocia, los encuestados eurófilos alcanzan casi los dos tercios de los residentes en la antigua Caledonia. Pero debe tenerse en cuenta que su peso demográfico en el Reino Unido apenas sobrepasa el 8% del total británico. No es de extrañar que, tradicionalmente, tal disparidad poblacional haya alimentado la sinonimia entre los gentilicios de Inglaterra y Reino Unido.
Fermions meet two bosons -- the heteronuclear Efimov effect revisited
Creators: name: Tran, Binh
name: Rautenberg, Michael
name: Gerken, Manuel
name: Lippi, Eleonora
name: Zhu, Bing
name: Ulmanis, Juris
name: Drescher, Moritz
name: Salmhofer, Manfred
name: Enss, Tilman
name: Weidemüller, Matthias
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: In this article, we revisit the heteronuclear Efimov effect in a Bose-Fermi mixture with large mass difference in the Born-Oppenheimer picture. As a specific example, we consider the combination of bosonic $^{133}\mathrm{Cs}$ and fermionic $^6\mathrm{Li}$. In a system consisting of two heavy bosons and one light fermion, the fermion-mediated potential between the two heavy bosons gives rise to an infinite series of three-body bound states. The intraspecies scattering length determines the three-body parameter and the scaling factor between consecutive Efimov states. In a second scenario, we replace the single fermion by an entire Fermi Sea at zero temperature. The emerging interaction potential for the two bosons exhibits long-range oscillations leading to a weakening of the binding and a breakup of the infinite series of Efimov states. In this scenario, the binding energies follow a modified Efimov scaling law incorporating the Fermi momentum. The scaling factor between deeply bound states is governed by the intraspecies interaction, analogous to the Efimov states in vacuum.
description: 8 pages, 5 figures
$β$-decay rates of $^{(115,117)}$Rh into $^{(115,117)}$Pd isotopes in the microscopic IBFM-2
Creators: name: Ferretti, J.
name: Kotila, J.
name: Vsevolodovna, R. I. Magaña
name: Santopinto, E.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The structure of odd-$A$ $^{(115,117)}$Rh and $^{(115,117)}$Pd isotopes is studied by means of the neutron-proton Interacting Boson-Fermion Model (IBFM-2). $J^P = \frac{1}{2}^+$ quantum number assignment for the $^{(115,117)}$Pd ground-states is critically discussed and the predicted energy levels are compared to the existing experimental data. The resulting nuclear wave functions are used to compute the $β$-decay $ft$ values of the transitions from $^{(115,117)}$Rh to $^{(115,117)}$Pd in the microscopic IBFM-2 and the results compared with the data.
Η διάθεση ηρτημένης της αιρέσεως (αρθ. 206 Α.Κ.)
Creators: name: Στεργιούδα, Δήμητρα Ιωακείμ
Publisher: name: Aristotle University of Thessaloniki
Year: 2007
Subjects: Αίρεση
Δικαιοπραξία
Ακυρότητα
Διάθεση
Condition
Transaction
Nullity
Disposal

description: Εισαγωγικά γίνεται αναφορά στην έννοια, το σκοπό και τη λειτουργία της αίρεσης. Αναφέρεται ειδικότερα ο σκοπός και η χρησιμότητα του αρθ. 206 ΑΚ στη σύγχρονη συναλλακτική ζωή και εξετάζονται οι προϋποθέσεις εφαρμογής του, ήτοι η ύπαρξη εκποιητικής δικαιοπραξίας με αναβλητική ή διαλυτική αίρεση, η διάθεση του αντικειμένου της δικαιοπραξίας, η διάθεση να επήλθε ηρτημένης της αιρέσεως, η δεύτερη αυτή διάθεση να βλάπτει ή ματαιώνει το αποτέλεσμα που επέρχεται με την πλήρωση ή ματαίωση της αίρεσης και τέλος η πλήρωση ή ματαίωση της αίρεσης. Επιπλέον γίνεται λόγος για τις συνέπειες από την εφαρμογή του εξεταζόμενου άρθρου, ήτοι την αυτοδίκαιη και απόλυτη ακυρότητα της δεύτερης διάθεσης, για την παράλληλη εφαρμογή των αρθ. 204 και 206 ΑΚ και για τις εξαιρέσεις από την εφαρμογή του εξεταζόμενου άρθρου.
description: In the introduction reference is made to the meaning, the purpose and the function of the condition. Specifically reference is made to the purpose and the utility of the article 206 of the Civil Code according to the contemporary commercial life. We also examine the conditions for the application of the specific article, and the consequences of its application. Moreover reference is made to the collateral application of the articles 204 and 206 of the Civil Code and to the exemptions from the application of the article examined.
A new solution to the curved Ewald sphere problem for 3D image reconstruction in electron microscopy
Creators: name: Chen, J. P. J.
name: Schmidt, K. E.
name: Spence, J. C. H.
name: Kirian, R. A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: We develop an algorithm capable of imaging a three-dimensional object given a collection of two-dimensional images of that object that are significantly influenced by the curvature of the Ewald sphere. These two-dimensional images cannot be approximated as projections of the object. Such an algorithm is useful in cryo-electron microscopy where larger samples, higher resolution, or lower energy electron beams are desired, all of which contribute to the significance of Ewald curvature.
An AI approach to measuring financial risk
Creators: name: Yu, Lining
name: Härdle, Wolfgang Karl
name: Borke, Lukas
name: Benschop, Thijs
Publisher: name: arXiv
Year: 2020
Subjects: subject: Risk Management (q-fin.RM)
subject: FOS: Economics and business

description: AI artificial intelligence brings about new quantitative techniques to assess the state of an economy. Here we describe a new measure for systemic risk: the Financial Risk Meter (FRM). This measure is based on the penalization parameter (lambda) of a linear quantile lasso regression. The FRM is calculated by taking the average of the penalization parameters over the 100 largest US publicly traded financial institutions. We demonstrate the suitability of this AI based risk measure by comparing the proposed FRM to other measures for systemic risk, such as VIX, SRISK and Google Trends. We find that mutual Granger causality exists between the FRM and these measures, which indicates the validity of the FRM as a systemic risk measure. The implementation of this project is carried out using parallel computing, the codes are published on www.quantlet.de with keyword FRM. The R package RiskAnalytics is another tool with the purpose of integrating and facilitating the research, calculation and analysis methods around the FRM project. The visualization and the up-to-date FRM can be found on hu.berlin/frm.
VLT/Flames observations of the star forming region NGC 6530
Creators: name: Prisinzano, L.
name: Damiani, F.
name: Micela, G.
name: Pillitteri, I.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Mechanisms regulating the evolution of pre-main sequence stars can be understood by studying stellar properties such as rotation, disk accretion, internal mixing and binarity. To investigate such properties, we studied a sample of 332 candidate members of the massive and populous star forming region NGC 6530. We want to select cluster members by using different membership criteria,to study the properties of pre-main sequence stars with or without circumstellar disks. We use intermediate resolution spectra including the Li I 6707.8 Angstroms line to derive radial and rotational velocities, binarity and to measure the Equivalent Width of the lithium line; these results are combined with X-ray data to study the cluster membership. Optical-IR data and Halpha spectra, these latter available for a subsample of our targets, are used to classify CTTS and WTTS and to compare the properties of stars with and without disks. We find a total of 237 certain members including 53 binaries. The rotational velocity distributions of stars with IR excesses are statistically different from that of stars without IR excesses, while the fraction of binaries with disks is significantly smaller than that of single stars. Stars with evidence for accretion show circumstellar disks; youth of cluster members is confirmed by the lithium abundance consistent with the initial content. As indicated by the disk-locking picture, stars with disks have in general rotational velocities lower than stars without disks. Binaries in NGC 6530 seem have undergone a significant disk evolution.
description: 18 pages, 17 figures, in press in Astronomy and Astrophysics
Μοντελοποίηση και προσομοίωση μεθόδων ανάθεσης εργασιών σε συστήματα πολλαπλών Clusters
Creators: name: Παπαστεργίου, Γεώργιος Ιωάννη
Publisher: name: Aristotle University of Thessaloniki
Year: 2007
Subjects: Κατανεμημένα συστήματα
Πολιτικές ανάθεσης εργασιών
Πολιτικές διαμοιρασμού φόρτου
Μετανάστευση εργασιών
Distributed systems
Cluster
Task allocation policies
Load sharing policies
Migration

description: Η εργασία αυτή μελετάει την επίδραση που έχει στη συμπεριφορά και την απόδοση ενός κατανεμημένου συστήματος το οποίο αποτελείται από δύο ανεξάρτητα clusters που επικοινωνούν μεταξύ τους η εφαρμογή τριών διαφορετικών μηχανισμών ανάθεσης των tasks στους επεξεργαστές του συστήματος. Ο στόχος των μηχανισμών αυτών είναι η εξισορρόπηση του φόρτου στους επεξεργαστές του συστήματος χρησιμοποιώντας όσο το δυνατόν λιγότερες πληροφορίες για την κατάσταση του συστήματος. Το σύστημα μοντελοποιείται με βάση την θεωρία ουρών και τα αποτελέσματα εξάγονται μέσω της προσομοίωσης διακεκριμένων γεγονότων. Το μοντέλο εξετάζεται κάτω από συνθετικό φόρτο εργασιών και συγκρίνεται η απόδοσή του για τις τρεις πολιτικές δρομολόγησης.
description: This work studies the effects on behaviour and performance of a distributed system which consists of two independent clusters of processors that communicate with each other the application of three different task allocation mechanisms along with a migrative load sharing policy.The objective of these mechanisms is to balance the workload among the processors of the system using as less as possible system state information. The system is modelled according to the queing theory and the results are derived through sicrete-event simulation. The simulation model is examinded under synthetic workload and its performance in the three routing policies case is compared.
Stars in the age of micro-arc-second astrometry
Creators: name: Lebreton, Y.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The understanding and modeling of the structure and evolution of stars is based on statistical physics as well as on hydrodynamics. Today, a precise identification and proper description of the physical processes at work in stellar interiors are still lacking (one key point being that of transport processes) while the comparison of real stars to model predictions, which implies conversions from the theoretical space to the observational one, suffers from uncertainties in model atmospheres. That results in uncertainties on the prediction of stellar properties needed for galactic studies or cosmology (as stellar ages and masses). In the next decade, progress is expected from the theoretical, experimental and observational sides. I illustrate some of the problems we are faced with when modeling stars and the possible tracks towards their solutions. I discuss how future observational ground-based or spatial programs (in particular those dedicated to micro-arc-second astrometry, asteroseismology and interferometry) will provide precise determinations of the stellar parameters and contribute to a better knowledge of stellar interiors and atmospheres in a wide range of stellar masses, chemical compositions and evolution stages.
description: 7 pages; to appear in the proceedings of "IAU Symposium 248 - A Giant Step: from Milli- to Micro-arcsecond Astrometry", held in Shanghai, China, 15-19 Oct. 2007
Ανάλυση του νεκρού σημείου. Βιβλιογραφικη ανασκόπηση σχετικά με την πολυπαραγωγική επιχείρηση-από το 1995 και ύστερα
Creators: name: Ζαρογιάννη Χριστίνα Αστερίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2007
Subjects: Νεκρό σημείο
Ανάλυση του νεκρού σημείου
Πολυπαραγωγική επιχείρηση
Περιθώριο συνεισφοράς
Συνολικό κόστος, σταθερό κόστος, μεταβλητό κόστος
Κέρδος, ζημία
Break-even point
Break-even analysis
Multiproduct firm
Contribution margin
Total cost, fixed cost, variable cost
Profit, loss

description: Εχουν δημοσιευθεί αρκετά αρθρα που εξετάζουν ποικίλες πτυχές των μοντέλων της ανάλυσης του νεκρού σημείου. Αυτές οι δημοσιεύσεις μπορούν να ταξινομηθούν ανάλογα με την ενασχόλησή τους με τα μοντέλα ανάλυσης του Ν. Σ. που σχετίζονται με προβλήματα ενός και πολλαπλών προϊόντων, προβλήματα μιας και πολλαπλών περιόδων.
description: Several articles have been published and many books have been written that deal with various aspects of breakeven models (Horngre, 2001). These publications can be classified as dealing with the breakeven models related to single and multiproducts, deterministic and stochastic, single and multiperiod problems. Some of these publications integrate various factors related to finance, accounting and taxation to make it realistic and valuable to practitioners (Kakumanu, 1998).In this particular project, initially, in Chapter 1, we will deal with the placement of the phenomenon of breakeven analysis into the business world. We will answer questions such as: what the breakeven analysis means, which businesses use it, which economic fields serves and how often it takes part.In Chapter 2, we will analyze the breakeven point of a firm that sells a simple product. We will analytically describe the methods being used for its calculation with the help of examples. Then we will specify the extensions of the breakeven analysis. In the third Chapter, we will refer to the breakeven analysis of a company that sells more than one products. The resemblances and the differences will be pointed out in terms of the breakeven analysis in a simple product’s company. We will discuss issues related to the breakeven point analysis and the substance of a multi-product firm. Finally, Chapter 4 involves a general evaluation of the phenomenon. The advantages and the reasons for which the breakeven point constitutes an important tool for every business will be underlined, as well as its restrictions.
Improved-Sensitivity Integral SQUID Magnetometry of (Ga,Mn)N Thin Films in Proximity to Mg-doped GaN
Creators: name: Gas, Katarzyna
name: Kunert, Gerd
name: Dluzewski, Piotr
name: Jakiela, Rafal
name: Hommel, Detlef
name: Sawicki, Maciej
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Nominally 45 nm GaN:Mg/ 5 nm (Ga,Mn)N / 45 nm GaN:Mg trilayers structures prepared by molecular beam epitaxy on GaN-buffered Al2O3 substrates are investigated to verify whether the indirect co-doping by holes from the cladding layers can alter the spin-spin interaction in (Ga,Mn)N. The four investigated structures, differing with the Mg doping level, are carefully characterized at the nanoscale by HRTEM, EDX, and by SIMS. HRTEM decisively excluded a presence of foreign Mn-rich phases. The structures, up to medium Mg doping, show no Mg over-doping effects. Magnetic studies of these structures are aided by the employment of a dedicated experimental approach of the in situ compensation of the magnetic contribution from the substrate, allowing up to about fifty-fold reduction of this contribution. This technique, dedicated to these structures, simultaneously provides a tenfold reduction of temporal instabilities of the magnetometric unit and lowers the experimental jitter to merely $5 \times 10^{-7}$~emu at 70~kOe, vastly increasing the precision and the credibility of the results of the standard integral SQUID magnetometry in high magnetic fields. The magnetic characteristics of the trilayers structures established here prove identical with the already known properties of the thick (Ga,Mn)N single layers, namely (i) the low temperature ferromagnetism among Mn$^{3+}$ ions driven by superexchange and (ii) purely paramagnetic response at higher temperatures. The possible cause of the lack of any effects brought about by the adjacent Mg-doping is a presence of residual Mn in the cladding layers, resulting in the deactivation of the p-type doping intended there. This finding points out that a more intensive technological effort has to be exerted to promote the co-doping-driven carrier-mediated ferromagnetic coupling in Mn-enriched GaN, especially at elevated temperatures.
description: 16 pages, 6 figures
Mito sobre Crapennanesha’, las gentes que se opusieron a Enc
Creators: name: Quinchuya López, Amador
name: Santos Granero, Fernando
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2021
Subjects: subject: ame

description: Personaje mítico relacionado a la figura histórica del Inca. Transcrito, traducido, mecanografiado y digitalizado.
The magnetic penetration depth and the vortex core radius in type-II superconductors
Creators: name: Sonier, Jeffrey E.
Publisher: name: University of British Columbia
Year: 2009

description: In this thesis, muon spin rotation (μSR) measurements of the internal magnetic field distribution in the vortex state of the high-T[sub c] superconductor YBa₂Cu₃O₇_[sub ⍴] and the conventional type-II superconductor NbSe₂ are presented. From the measured field distributions, the "characteristic length scales of superconductivity" are extracted. It is found that both the a-b plane magnetic penetration depth λ[sub ab] and the vortex-core radius r[sub o] (which is closely related to the coherence length Ɛ[sub ab] vary as functions of temperature and magnetic field in both materials. The behaviour of λ[sub ab](H, T) and r[sub 0](H, T) at low temperatures is found to be substantially different in YBa₂Cu₃0₇_⍴ from what is observed in NbSe₂. This reflects the unconventional nature of the pairing mechanism in this compound. The temperature dependence of λ[sub ab] in the vortex state of YBa₂Cu₃0₇_⍴ agrees well with microwave cavity measurements in the Meissner state. The magnetic field dependence of λ[sub ab], in YBa₂Cu₃0₇_⍴ is found to be considerably stronger than in NbSe₂. This is likely due to both the nonlinear and the nonlocal effects associated with nodes in the superconducting energy gap. However, in NbSe₂ (where nonlocal effects are negligible), it is not clear whether the field dependence of can be explained solely in terms of the nonlinear effects associated with an isotropic s-wave energy gap. The vortex-core radius r[sub 0] is found to decrease with increasing magnetic field in both superconductors. The reduction in the vortex-core size appears to be due to the increased strength of the vortex-vortex interactions. An important consequence of this variation with field is that Ɛ[sub ab] in the vortex state, which is generally regarded to be extremely small i n the high-T[sub c] compounds, is comparatively large at low magnetic fields. The vortex-core radius is also found to increase with increasing temperature. The strength of this variation is considerably weaker in YBa₂Cu₃0₇_⍴ than in NbSe₂. One possible interpretation is that the quantum limit is realized at much higher temperatures in the high-T[sub c] compound. The measured temperature dependence of r[sub 0] in both superconductors is weaker than current theoretical predictions for an isolated vortex. Finally, the effects of vortex pinning and thermal fluctuations of the vortex lines are considered. It is found that the vortex lattice is strongly pinned in YBa₂Cu₃0₇_⍴. The vortex lattice in the underdoped compound YBa₂Cu₃O₆.₆₀ is found to exhibit quasi-2D behaviour. In particular, a field-induced transition of the 3D-vortex lattice to a 2Dvortex lattice is observed—which appears to be due to the small c-axis coherence length and vortex pinning in the Cu0₂ layers of this material. Also, the 3D-solid vortex lattice in YBa₂Cu₃O₆.₆₀ at low temperatures is found to melt and/or undergo a transition to a 2D-vortex lattice as the temperature is increased.