cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Εφαρμογή της θεωρίας των τεχνητών νευρωνικών δικτύων στον εντοπισμό βλαβών σε συστήματα υαλοπετασμάτων αλουμινίου
Creators: name: Ευσταθιάδης, Χρίστος Ο.
Publisher: name: Aristotle University of Thessaloniki
Year: 2008
Subjects: Αλουμίνιο
Εντοπισμός βλαβών
Ανάστροφη διάδοση σφάλματος
Μέθοδος πεπερασμένων στοιχείων
Damage detection
Back propagation
Finite element method

description: Η διατριβή εντάσσεται στο γνωστικό πεδίο της παρακολούθησης της δομικής συμπεριφοράς κατασκευών με τη χρήση μεθόδων τεχνητής νοημοσύνης. Εξετάζεται ο τρόπος στήριξης του υαλοπετάσματος στο φέρον κτίριο και με τη χρήση λογισμικού πραγματοποιείται παραμετρική προσομοίωση της κατασκευής και μορφώνεται βάση αποτελεσμάτων. Υλοποιούνται διάφορα ΤΝΔ και μέσα από επαναληπτικές εφαρμογές εξετάζεται η καταλληλότητα τους
description: The thesis deals with the health monitoring in order to identify imperfections in typical curtain-wall systems. Several F.E. Models were developed, a parametric analysis was curried out and a patterns database was created. A wide variety of neural networks were studied and several parameters were investigated. The results showed that NN's can be an efficient method for the identification and localization of imperfections in curtain-wall systems
Statistical models for the effect of length on the strength of lumber
Creators: name: Williamson, Justin Andrew
Publisher: name: University of British Columbia
Year: 2009

description: This thesis concerns the problem of modelling the effect of length on the strength of lumber. The length effect manifests as a shift to lower values of the strength distribution from shorter to longer boards. This effect is also noticeable for other materials. It is usually attributed to a statistical effect: a longer member has a greater chance of having a serious defect. This effect is not currently allowed for in design codes, which results in boards of different length having different reliability. A method is needed to find adjustment factors that will provide equal reliability. It has been modelled with the Weibull model, which significantly over-predicts the length effect. It is deduced that the over-prediction is due to the dependence between elements of the board, which is not allowed by the Weibull model. The presence of this dependence has been found experimentally. Two classes of alternative model are developed. One requires input of the magnitude of the dependence and the strength distribution. The other requires only the strength distribution and gives an estimate of the dependence. A simulation study of 100,000 boards shows with considerable certainty that both classes of model work better than the currently accepted models on data which contains dependence. Real lumber strength data from bending and tension tests of 3000 boards from 4 sources are used to validate the proposed models. Using a wide variety of measures it is shown with a high degree of certainty that the proposed models are superior to the existing models. Theory is developed which shows that this model-based approach has much less uncertainty than a purely data-based approach, and this is confirmed from the data. Machine graded lumber may be better fitted by a model developed from the Gumbel distribution. It is shown that equal reliability adjustment factors can be obtained from the model parameters very easily. The average factor proposed to be applied to design strength for halving the length is 1.14. It appears that this factor is lower for high grade lumber. The tools used for the length effect in single members have been extended to computing the reliability of weakest link structures. This is a useful class of structures, and this method appears to be superior to existing methods. This can be used to show that the different length adjustments make a considerable difference to the calculated reliability of structural systems such as trusses. Two truss types were considered and found to have effective lengths of up to 7.3m, for a β = 3. These required a (downward) adjustment to the single member strength of up to 24%.
Στατιστικά μοντέλα ανάλυσης και εκτίμησης δεδομένων διοίκησης λογισμικού
Creators: name: Σέντας, Παναγιώτης Γ.
Publisher: name: Aristotle University of Thessaloniki
Year: 2007
Subjects: Διατεταγμένη παλινδρόμηση
Πολυωνυμική λογιστική παλινδρόμηση
Ανάλυση επιβίωσης
Εκτίμηση κόστους έργων λογισμικού
Ordinal regression
Multinomial logistic regression
Survival analysis
Software cost estimation

description: Η εκτίμηση του κόστους ή της διάρκειας ενός έργου λογισμικού αποτελούν σημαντικά ζητήματα στην επιστημονική περιοχή της τεχνολογίας λογισμικού. Η εκτίμηση αυτή γίνεται ως επί το πλείστον με στατιστά μοντέλα που εφαρμόζονται σε ιστορικές βάσεις. Από την στιγμή που τα περισσότερα από τα σύνολα δεδομένων κόστους λογισμικού περιέχουν χαμένες τιμές, προκύπτει παράλληλα και το πρόβλημα της συμπλήρωσή τους. Η παρούσα διατριβή ασχολείται τόσο με την εκτίμηση του κόστους ή της διάρκειας, όσο και με την διαχείριση των χαμένων τιμών, αντιμετωπίζοντάς τα με στατιστικές μεθόδους και μοντέλα που κατασκευάζονται πάνω σε δεδομένα κόστους λογισμικού
description: Estimating the cost or the duration of a software project is an important issue in software engineering. This estimation is usually made with statistical models which are based on historical databases, Since most of the software cost datasets include missing values, the problem of their competion arises. The present dissertation deals with the estimation of the cost or the duration and also with the handling of missing data, using statistical methods and models which are build on software cost data
Επίδραση διαχειριστικών πρακτικών στην ποιότητα νερού και στην οικολογία των ποταμών της Ελλάδας: ο Πηνειός (Θεσσαλίας) ως ειδική περίπτωση μελέτης
Creators: name: Χατζηνικολάου, Γιώργος Τ.
Publisher: name: Aristotle University of Thessaloniki
Year: 2007
Subjects: Βενθικά μακροασπόνδυλα
Αποκατάσταση ποταμών
Benthic macroinvertebrates
River restoration

description: Ο ποταμός Πηνειός ως ειδική περίπτωση μελέτης των μεγάλων ποταμών της Ελλάδας χρησιμοποιήθηκε για να δοκιμασθούν οι μέχρι τώρα διαχειριστικές πρακτικές στην οικολογία του. Η περιγραφή της υφιστάμενης κατάστασης αρχίζει με την ανάλυση των μεταφερόμενων και των παραγόμενων ρυπαντικών φορτίων στη λεκάνη απορροής. Στη συνέχεια ερευνήθηκε η οικολογική ποιότητα του Πηνειού από τα βενθικά μακροσπόνδυλα, τα φυσικοχημικά στοιχεία και άλλα αβιοτικά χαρακτηριστικά. Ο βαθμός τροποποίησης του ποταμού βρέθηκε πως επιδρά αρνητικά στην ικανότητα αυτοκαθαρισμού. Τέλος, εξετάστηκαν 2 διαφορετικές μέθοδοι δειγματοληψίας της απόχης και των τεχνητών υποστρωμάτων. Σε πολλά δείγματα η ποιότητα είναι σχεδόν ίδια
description: The Pinios River as a case study for large Greek rivers was used in order to test the managerial practises on its ecology. The current status begins with the transported to emitted pollution loads analysis at the river basin. next, the ecological quality of Pinios based on beathic macroinvertebrates, physichochemical and more found abiotic characteristics was studied. The river habitat modification level was found to impact the self-purification capacity. Finally, 2 different samplingmethods were tested : the sweep-net sampling and the artificial substrates. The water quality when based on multiple samples is raughly equal
Lepton Scattering off Few-Nucleon Systems at Medium and High Energies
Creators: name: Atti, C. Ciofi degli
name: Kaptari, L. P.
name: Morita, H.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The interpretation of recent Jlab experimental data on the exclusive process A(e,e'p)B off few-nucleon systems are analyzed in terms of realistic nuclear wave functions and Glauber multiple scattering theory, both in its original form and within a generalized eikonal approximation. The relevance of the exclusive process 4He(e,e'p)^3H for possible investigations of QCD effects is illustrated.
description: 6 pages, 3 figures. Plenary talk given by C. Ciofi degli Atti at the XX European Conference "Few Body Problems in Physics", Pisa, Italy, September 2007. To appear in Few-Body Systems
Tachyon condensation and off-shell gravity/gauge duality
Creators: name: Myung, Yun Soo
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We investigate quasilocal tachyon condensation by using gravity/gauge duality. In order to cure the IR divergence due to a tachyon, we introduce two regularization schemes: AdS space and a d=10 Schwarzschild black hole in a cavity. These provide stable canonical ensembles and thus are good candidates for the endpoint of tachyon condensation. Introducing the Cardy-Verlinde formula, we establish the on-shell gravity/gauge duality. We propose that the stringy geometry resulting from the off-shell tachyon dynamics matches onto the off-shell AdS black hole, where "off-shell" means non-equilibrium configuration. The instability induced by condensation of a tachyon behaves like an off-shell black hole and evolves toward a large stable black hole. The off-shell free energy and its derivative ($β$-function) are used to show the off-shell gravity/gauge duality for the process of tachyon condensation. Further, d=10 Schwarzschild black hole in a cavity is considered for the Hagedorn transition as a possible explanation of the tachyon condensation.
description: 28 pages, 13 eps figures, version to appear in IJMPA
Deconfinement of classical Yang-Mills color fields in a disorder potential
Creators: name: Ermann, Leonardo
name: Shepelyansky, Dima L.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Theory (hep-th)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: We study numerically and analytically the behavior of classical Yang-Mills color fields in a random one-dimensional potential described by the Anderson model with disorder. Above a certain threshold the nonlinear interactions of Yang-Mills fields lead to chaos and deconfinement of color wavepackets with their subdiffusive spreading in space. The algebraic exponent of the second moment growth in time is found to be in a range of 0.3 to 0.4. Below the threshold color wavepackets remain confined even if a very slow spreading at very long times is not excluded due to subtle nonlinear effects and the Arnold diffusion for the case when initially color packets are located in a close vicinity. In a case of large initial separation of color wavepackets they remain well confined and localized in space. We also present comparison with the behavior of the one-component field model of discrete Anderson nonlinear Schrödinger equation with disorder.
description: 9 pages, 9 figures
Double beta decay to the first $2^+$ state within a boson expansion formalism with a projected spherical single particle basis
Creators: name: Raduta, A. A.
name: Raduta, C. M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The Gamow-Teller transition operator is written as a polynomial in the dipole proton-neutron and quadrupole charge conserving QRPA boson operators, using the prescription of the boson expansion technique of Belyaev-Zelevinski type. Then, the $2νββ$ process ending on the first $2^+$ state in the daughter nucleus is allowed via one, two and three boson states describing the odd-odd intermediate nucleus. The approach uses a single particle basis which is obtained by projecting out the good angular momentum from an orthogonal set of deformed functions. The basis for mother and daughter nuclei have different deformations. The GT transition amplitude as well as the half lives were calculated for ten transitions. Results are compared with the available data as well as with some predictions obtained with other methods.
description: 12 pages
Estimation and Inference for Nonparametric Expected Shortfall Regression over RKHS
Creators: name: Yu, Myeonghun
name: Wang, Yue
name: Xie, Siyu
name: Tan, Kean Ming
name: Zhou, Wen-Xin
Publisher: name: Taylor & Francis
Year: 2025
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: Biotechnology
subject: Ecology
subject: Sociology
subject: FOS: Sociology
subject: Science Policy

description: Expected shortfall (ES) has emerged as an important metric for characterizing the tail behavior of a random outcome, specifically associated with rarer events that entail severe consequences. In climate science, the threats of flooding and heatwaves loom large, impacting natural environments and human communities. In actuarial studies, a key observation in modeling insurance claim sizes is that features exhibit distinct effects in explaining small and large claims. This article concerns nonparametric expected shortfall regression as a class of statistical methods for tail learning. These methods directly target upper/lower tail averages and will empower practitioners to address complex questions that are beyond the reach of mean regression-based approaches. Using kernel ridge regression, we introduce a two-step nonparametric ES estimator that involves a plugged-in quantile function estimate without sample-splitting. We provide non-asymptotic estimation and Gaussian approximation error bounds, depending explicitly on the effective dimension, sample size, regularization parameters, and quantile estimation error. To construct pointwise confidence bands, we propose a fast multiplier bootstrap procedure and establish its validity. We demonstrate the finite-sample performance of the proposed methods through numerical experiments and an empirical study aimed at examining the heterogeneous effects of different air pollutants and meteorological factors on average and high PM2.5 concentration. Supplementary materials for this article are available online, including a standardized description of the materials available for reproducing the work.
Weak-strong uniqueness property for models of compressible viscous fluids near vacuum
Creators: name: Feireisl, Eduard
name: Novotny, Antonin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: We extend the weak-strong uniqueness principle to general models of compressible viscous fluids near/on the vacuum. In particular, the physically relevant case of positive density with polynomial decay at infinity is considered.
A novel wide-angle Compton Scanner setup to study bulk events in germanium detectors
Creators: name: Abt, I.
name: Gooch, C.
name: Hagemann, F.
name: Hauertmann, L.
name: Aguilar, D. Hervas
name: Liu, X.
name: Schulz, O.
name: Schuster, M.
name: Zsigmond, A. J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: A novel Compton Scanner setup has been built, commissioned and operated at the Max-Planck-Institute for Physics in Munich to collect pulses from bulk events in high-purity germanium detectors for pulse shape studies. In this fully automated setup, the detector under test is irradiated from the top with 661.660 keV gammas, some of which Compton scatter inside the detector. The interaction points in the detector can be reconstructed when the scattered gammas are detected with a pixelated camera placed at the side of the detector. The wide range of accepted Compton angles results in shorter measurement times in comparison to similar setups where only perpendicularly scattered gammas are selected by slit collimators. In this paper, the construction of the Compton Scanner, its alignment and the procedure to reconstruct interaction points in the germanium detector are described in detail. The creation of a first pulse shape library for an n-type segmented point-contact germanium detector is described. The spatial reconstruction along the beam axis is validated by a comparison to measured surface pulses. A first comparison of Compton Scanner pulses to simulated pulses is presented to demonstrate the power of the Compton Scanner to test simulation inputs and models.
description: 15 pages, 18 figures
Generating ultrafilters in a reasonable way
Creators: name: Roslanowski, Andrzej
name: Shelah, Saharon
Publisher: name: arXiv
Year: 2006
Subjects: subject: Logic (math.LO)
subject: FOS: Mathematics

description: We continue investigations of reasonable ultrafilters on uncountable cardinals defined in Shelah math.LO/0407498 and studied also in math.LO/0605067. We introduce a general scheme of generating a filter on lambda from filters on smaller sets and we investigate the combinatorics of objects obtained this way.
Text Classification Using Hybrid Machine Learning Algorithms on Big Data
Creators: name: Asogwa, D. C.
name: Anigbogu, S. O.
name: Onyenwe, I. E.
name: Sani, F. A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Information Retrieval (cs.IR)
subject: Artificial Intelligence (cs.AI)
subject: Computation and Language (cs.CL)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Recently, there are unprecedented data growth originating from different online platforms which contribute to big data in terms of volume, velocity, variety and veracity (4Vs). Given this nature of big data which is unstructured, performing analytics to extract meaningful information is currently a great challenge to big data analytics. Collecting and analyzing unstructured textual data allows decision makers to study the escalation of comments/posts on our social media platforms. Hence, there is need for automatic big data analysis to overcome the noise and the non-reliability of these unstructured dataset from the digital media platforms. However, current machine learning algorithms used are performance driven focusing on the classification/prediction accuracy based on known properties learned from the training samples. With the learning task in a large dataset, most machine learning models are known to require high computational cost which eventually leads to computational complexity. In this work, two supervised machine learning algorithms are combined with text mining techniques to produce a hybrid model which consists of Naïve Bayes and support vector machines (SVM). This is to increase the efficiency and accuracy of the results obtained and also to reduce the computational cost and complexity. The system also provides an open platform where a group of persons with a common interest can share their comments/messages and these comments classified automatically as legal or illegal. This improves the quality of conversation among users. The hybrid model was developed using WEKA tools and Java programming language. The result shows that the hybrid model gave 96.76% accuracy as against the 61.45% and 69.21% of the Naïve Bayes and SVM models respectively.
description: 8 pages, 2 figures, 8 tables, Journal
Text: History of the Iñapari
Creators: name: Trigoso Silvano, Jorge
name: Parker, Stephen
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2020
Subjects: subject: inp

description: This research was carried out by Steve Parker (Dallas International University; SIL International) under the auspices of SIL International. This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

One WAV file. Originally recorded on cassette, digitized by depositor. See related file bundle for transcription, glossing, and translation.
World-making with extended gravity black holes for cosmic natural selection in the multiverse scenario
Creators: name: Barrau, A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Physics is facing contingency. Not only in facts but also in laws (the frontier becoming extremely narrow). Cosmic natural selection is a tantalizing idea to explain the apparently highly improbable structure of our Universe. In this brief note I will study the creation of Universes by black holes in -string inspired- higher order curvature gravity.
description: 5 pages, 1 figure. Proceedings of the Eleventh Marcel Grossmann Meeting on General Relativity, edited by H. Kleinert, R.T. Jantzen and R. Ruffini, World Scientific, Singapore, 2007
Response of reinforced concrete to reverse cyclic loading
Creators: name: Fronteddu, Luciano Fabio
Publisher: name: University of British Columbia
Year: 2008

description: This thesis investigates the response of cracked reinforced concrete subjected to reverse cyclic loading with particular emphasize on the contribution from tensile stresses in cracked concrete. An iterative strain compatibility approach using a nonlinear bond stress-slip relationship was implemented into a computer program. The program indicated that monotonic tension stiffening does not decay with increasing strain. Analyses also demonstrated that the variation of slip along a reinforcing bar is approximately linear, which allowed the development of a simple transparent tension stiffening model that could be presented in equation form. This model indicated that in addition to being proportional to the square root of the concrete strength, the reinforcement ratio, and inversely proportional to the bar diameter, tension stiffening is directly proportional to the crack spacing. To better understand tension stiffening under reverse cyclic loading, the bond model was enhanced by adding a reverse cyclic bond stress-slip relationship. An empirical reverse cyclic tension stiffening model was developed, based on the data obtained from an experimental program. This involved testing 5 large-scale reinforced concrete elements under reverse cyclic axial load. The parameters which were investigated were the amount of concrete surrounding the reinforcement, as well as the load history. A model for reinforcing steel, which was selected from the literature, was modified in order to generalize the model for different types of steel. A simple model for the concrete in compression was also selected from the literature. The analytical models were combined into a computer program which can predict the complete reverse cyclic axial response of reinforced concrete.
ปัจจัยบ่งชี้และอัตราการมีงานทำของผู้พิการบาดเจ็บไขสันหลัง
Creators: name: ไปยดา วงศ์ภากร
name: อภิชนา โฆวินทะ
Publisher: name: ราชวิทยาลัยแพทย์เวชศาสตร์ฟื้นฟู แห่งประเทศไทย
Year: 2557
Subjects: การทำงาน, บาดเจ็บไขสันหลัง, อาชีพ,

description: 1, 24, เวชศาสตร์ฟื้นฟูสาร
Text: History of the Iñapari in Spanish
Creators: name: Trigoso Silvano, Jorge
name: Parker, Stephen
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2020
Subjects: subject: inp

description: This research was carried out by Steve Parker (Dallas International University; SIL International) under the auspices of SIL International. This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

One WAV file. Originally recorded on cassette, digitized by depositor.
Z2 topological order and first-order quantum phase transitions in systems with combinatorial gauge symmetry
Creators: name: Wu, Kai-Hsin
name: Yang, Zhi-Cheng
name: Green, Dmitry
name: Sandvik, Anders W.
name: Chamon, Claudio
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study a generalization of the two-dimensional transverse-field Ising model, combining both ferromagnetic and antiferromagnetic two-body interactions, that hosts exact global and local Z2 gauge symmetries. Using exact diagonalization and stochastic series expansion quantum Monte Carlo methods, we confirm the existence of the topological phase in line with previous theoretical predictions. Our simulation results show that the transition between the confined topological phase and the deconfined paramagnetic phase is of first-order, in contrast to the conventional Z2 lattice gauge model in which the transition maps onto that of the standard Ising model and is continuous. We further generalize the model by replacing the transverse field on the gauge spins with a ferromagnetic XX interaction while keeping the local gauge symmetry intact. We find that the Z2 topological phase remains stable, while the paramagnetic phase is replaced by a ferromagnetic phase. The topological-ferromagnetic quantum phase transition is also of first-order. For both models, we discuss the low-energy spinon and vison excitations of the topological phase and their avoided level crossings associated with the first-order quantum phase transitions.
A Supersymmetric Twin Higgs
Creators: name: Chang, Spencer
name: Hall, Lawrence J.
name: Weiner, Neal
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present a supersymmetric realization of the twin Higgs mechanism, which cancels off all contributions to the Higgs mass generated above a scale f. Radiative corrections induced by the top quark sector lead to a breaking of the twin sector electroweak symmetry at a scale f ~ TeV. In our sector, below the scale f, these radiative corrections from the top quark are present but greatly weakened, naturally allowing a Z boson mass an order of magnitude below f, even with a top squark mass of order 1 TeV and a messenger scale near the Planck mass. A sufficient quartic interaction for our Higgs boson arises from the usual gauge contribution together with a radiative contribution from a heavy top squark. The mechanism requires the presence of an SU(2)-adjoint superfield, and can be simply unified. Naturalness in these theories is usually associated with light winos and sleptons, and is largely independent of the scale of the colored particles. The assumption of unification naturally predicts the existence of many exotic fields. The theory often has particles which may be stable on collider timescales, including an additional color octet superfield. In the limit that m_SUSY >> f, the mechanism yields a UV completion of the non-supersymmetric twin Higgs, but with the notable improvement of a tree-level quartic for the standard model Higgs. In this framework, a successful UV completion requires the existence of new charged fields well below the scale f.
description: 20 pages
Most Descriptive Soil Health Indicators Across a Conversion Gradient from Forests to Agriculture in the Boreal Region
Creators: name: Kolka, Randall
name: BENALCAZAR VERGARA, PAUL
name: McLaren, Brian
name: Diochon, Amanda
name: Sahota, Tarlok
Publisher: name: Zenodo
Year: 2023
Subjects: subject: Agriculture

description: Goal: Test a suite of soil health metrics from the comprehensive assessment of soil health (CASH) on time since conversion from the forest to agricultural lands in northwest Ontario.
Περιστρεφόμενοι σχετιστικοί αστέρες
Creators: name: Βαβουλίδης, Μιλτιάδης Μ.
Publisher: name: Aristotle University of Thessaloniki
Year: 2008
Subjects: Ταλαντώσεις
Μαγνητικό πεδίο
Στερεός φλοιός
Oscillations
Magnetic field
Solid crust

description: Στη διατριβή αυτή μελετούνται περιστρεφόμενοι σχετιστικοί αστέρες(αστέρες νετρονίων) και σχετιστικοί αστέρες με μαγνητικό πεδίο. Πιο συγκεκριμένα, μελετάται η επίδραση του στερεού φλοιού στη δυναμική(μη-ακτινικές ταλαντώσεις) τέτοιου είδους αστέρων
description: In this dissertation, rotating relavistic stars (neutron stars) and relativistic stars with a magnetic field are studied. More specifically, the influence of the solid crust in the dynamics (non-radial oscillations) of such stars is studied
Neutron stars with a crossover equation of state
Creators: name: Kapusta, J. I.
name: Welle, T.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The question of whether quark matter exists in neutron stars is a long standing one. Generally one finds that a first order phase transition from baryons to quarks softens the equation of state so much that the star would collapse into a black hole. We consider a crossover equation of state, similar to the crossover that is found in lattice QCD studies at finite temperature and zero or small baryon chemical potentials. We find that with reasonable parameters it may be possible to support neutron stars up to about 2.2 solar masses. In that case 1 to 10% of the pressure would be contributed by quark matter in the central core of the highest mass stars.
description: 4 pages, 5 figures
Text: How I Killed a Jaguar
Creators: name: Trigoso Silvano, Jorge
name: Parker, Stephen
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2020
Subjects: subject: inp

description: This research was carried out by Steve Parker (Dallas International University; SIL International) under the auspices of SIL International. This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

One WAV file. Originally recorded on cassette, digitized by depositor. See related file bundle for transcription, glossing, and translation.
Magnetothermal study of Dy Stuffed Spin Ice: Dy2(DyxTi2-x)O7-x/2
Creators: name: Ueland, B. G.
name: Lau, G. C.
name: Freitas, R. S.
name: Snyder, J.
name: Dahlberg, M. L.
name: Muegge, B. D.
name: Duncan, E. L.
name: Cava, R. J.
name: Schiffer, P.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We have studied the thermodynamics of the stuffed spin ice material, Dy2(DyxTi2-x)O7-x/2, in which additional Dy3+ replace Ti4+ in the pyrochlore Dy2Ti2O7. Heat capacity measurements indicate that these materials lose the spin ice zero point entropy for x >= 0.3, sharply contrasting with results on the analogous Ho materials. A finite ac susceptibility is observed as T ~ 0 in both the Ho and Dy materials with x = 0.67, which suggests that spin fluctuations persist down to T ~ 0. We propose that both the entropy and susceptibility data may be explained as a result of domains of local pyrochlore type structural order in these materials.
description: Accepted to Phys. Rev. B
Kinetics of the long-range spherical model
Creators: name: Baumann, Florian
name: Dutta, Sreedhar B.
name: Henkel, Malte
Publisher: name: arXiv
Year: 2007
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: The kinetic spherical model with long-range interactions is studied after a quench to $T < T_c$ or to $T = T_c$. For the two-time response and correlation functions of the order-parameter as well as for composite fields such as the energy density, the ageing exponents and the corresponding scaling functions are derived. The results are compared to the predictions which follow from local scale-invariance.
description: added "fluctuation-dissipation ratios"; fixed typos
Growth and magnetism of self-organized arrays of Fe(110) wires formed by deposition on kinetically grooved W(110)
Creators: name: Borca, Bogdana
name: Fruchart, Olivier
name: Cheynis, Fabien
name: Hasegawa, Manabu
name: Meyer, Claire
Publisher: name: arXiv
Year: 2006
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: Homoepitaxy of W(110) and Mo(110) is performed in a kinetically-limited regime to yield a nanotemplate in the form of a uniaxial array of hills and grooves aligned along the [001] direction. The topography and organization of the grooves were studied with RHEED and STM. The nanofacets, of type {210}, are tilted 18° away from (110). The lateral period could be varied from 4 to 12nm by tuning the deposition temperature. Magnetic nanowires were formed in the grooves by deposition of Fe at 150°C on such templates. Fe/W wires display an easy axis along [001] and a mean blocking temperature Tb=100K
description: Proceedings of ECOSS 2006 (Paris)
Identifiability-Guaranteed Simplex-Structured Post-Nonlinear Mixture Learning via Autoencoder
Creators: name: Lyu, Qi
name: Fu, Xiao
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Signal Processing (eess.SP)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: This work focuses on the problem of unraveling nonlinearly mixed latent components in an unsupervised manner. The latent components are assumed to reside in the probability simplex, and are transformed by an unknown post-nonlinear mixing system. This problem finds various applications in signal and data analytics, e.g., nonlinear hyperspectral unmixing, image embedding, and nonlinear clustering. Linear mixture learning problems are already ill-posed, as identifiability of the target latent components is hard to establish in general. With unknown nonlinearity involved, the problem is even more challenging. Prior work offered a function equation-based formulation for provable latent component identification. However, the identifiability conditions are somewhat stringent and unrealistic. In addition, the identifiability analysis is based on the infinite sample (i.e., population) case, while the understanding for practical finite sample cases has been elusive. Moreover, the algorithm in the prior work trades model expressiveness with computational convenience, which often hinders the learning performance. Our contribution is threefold. First, new identifiability conditions are derived under largely relaxed assumptions. Second, comprehensive sample complexity results are presented -- which are the first of the kind. Third, a constrained autoencoder-based algorithmic framework is proposed for implementation, which effectively circumvents the challenges in the existing algorithm. Synthetic and real experiments corroborate our theoretical analyses.
The origin of the soft excess in high L/L_Edd AGN
Creators: name: Done, Chris
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We discuss the origin of the soft X-ray excess seen in AGN. There are clear advantages to models where this arises from atomic processes in partially ionised material rather than where it is a true continuum component. However, current data cannot distinguish between models where this material is seen in reflection or absorption, even for the archetypal 'reflection dominated' AGN MCG-6-30-15. Instead, we give physical arguments on the ionisation structure of X-ray illuminated material which exclude a reflection origin if the disc is in hydrostatic equilibrium. The same physical processes strongly favour an absorption origin for the soft excess, giving a more messy picture of the accretion environment. This implies that these apparently 'reflection dominated' AGN are not good places to test GR, but they do give insight into the spectra expected from the first QSO's in the early Universe.
description: 4 pages, 2 figures, for the conference proceedings of "The Extreme Universe in the Suzaku Era",(Progress of Theoretical Physics, Supplement)
Computational Fermi level engineering and doping-type conversion of Ga2O3 via three-step synthesis process
Creators: name: Goyal, Anuj
name: Zakutayev, Andriy
name: Stevanović, Vladan
name: Lany, Stephan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Ga2O3 is being actively explored for high-power and high-temperature electronics, deep-ultraviolet optoelectronics, and other applications. Efficient n-type doping of Ga2O3 has been achieved, but p-type doping faces fundamental obstacles due to compensation, deep acceptor levels, and the polaron transport mechanism of free holes. However, aside from achieving p-type conductivity, plenty of opportunity exists to engineer the position of the Fermi level for improved design of Ga2O3 based devices. We use first-principles defect theory and defect equilibrium calculations to simulate a 3-step growth-annealing-quench synthesis protocol for hydrogen assisted Mg doping in beta-Ga2O3, taking into account the gas phase equilibrium between H2, O2 and H2O, which determines the H chemical potential. We predict Ga2O3 doping-type conversion to a net p-type regime after growth under reducing conditions in the presence of H2 followed by O-rich annealing, which is a similar process to the Mg acceptor activation by H removal in GaN. For equilibrium annealing there is an optimal temperature that maximizes the Ga2O3 net acceptor density for a given Mg doping level, which is further increased in the non-equilibrium annealing scenario without re-equilibration. After quenching to operating temperature, the Ga2O3 Fermi level drops below mid-gap down to about +1.5 eV above the valence band maximum, creating a significant number of uncompensated neutral MgGa0 acceptors. The Fermi level reduction down to +1.5 eV and suppression of free electron density in this doping type converted (NA > ND) Ga2O3 material is of significance and impact for the design of Ga2O3 power electronics devices.
Jacobi Theta-functions and Discrete Fourier Transforms
Creators: name: Ruzzi, M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mathematical Physics (math-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences
subject: 33E05 42A16

description: Properties of the Jacobi Theta3-function and its derivatives under discrete Fourier transforms are investigated, and several interesting results are obtained. The role of modulo N equivalence classes in the theory of Theta-functions is stressed. An important conjecture is studied.
description: 10 pages, to appear on the Journal of Mathematical Physics. V3 with additional references
title: Spontaneous, otogenic intraventricular pneumocephalus
Creators: name: Girdhar, Sachin
Publisher: name: EURORAD
Year: 2024
Subjects: subject: Neuroradiology
subject: CNS
subject: Neuroradiology brain
subject: CT
subject: MR
subject: Clinical Case

description: Clinical History: A 62-year-old male presented to the neurology outpatient department with progressive complaints of walking difficulty, memory disturbances, restricted eye movements and urinary incontinence of three months duration. There was no history of overt trauma, headache or recent surgical intervention. His vital signs were unremarkable. Clinical examination revealed bradykinesia and upper limb rigidity.

description: 62 years, male
Tip-Induced $β$-Hydrogen Dissociation in an Alkyl Group Bound on Si(001)
Creators: name: Adamkiewicz, A.
name: Bohamud, T.
name: Reutzel, M.
name: Höfer, U.
name: Dürr, M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Atomic-scale chemical modification of surface-adsorbed ethyl groups on Si(001) was induced and studied by means of scanning tunneling microscopy. Tunneling at sample bias > +1.5V leads to tip-induced C-H cleavage of a $β$-hydrogen of the covalently bound ethyl configuration. The reaction is characterized by the formation of an additional Si-H and a Si-C bond. The reaction probability shows a linear dependence on the tunneling current at 300 K; the reaction is largely suppressed at 50 K. The observed tip-induced surface reaction at room temperature is thus attributed to a one-electron excitation in combination with thermal activation.
description: 5 pages, 5 figures, and Supporting Information
Onset of Deconfinement in Pb+Pb Collisions at the Cern SPS
Creators: name: Seyboth, Peter
Publisher: name: arXiv
Year: 2006
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: The NA49 fixed-target experiment studied high energy-density matter produced in nucleus-nucleus reactions at the CERN SPS. In central Pb+Pb collisions at 158A GeV the energy density at the early stage substantially exceeds the threshold for quark deconfinement predicted by lattice QCD. The produced matter shows strong transverse and longitudinal flow. Ratios of yields of produced particles are approximately consistent with statistical equilibration. An energy scan through the SPS range revealed structure in the energy dependence of pion and kaon yields as well as of the inverse slopes of transverse mass distributions. These features suggest that a deconfined phase starts to be produced at around 30A GeV in central Pb+Pb collisions. The analysis of fluctuations and correlations has not yet provided evidence for the predicted critical point of QCD.
description: Invited talk given at the XVLVI Cracow School of Theoretical Physics
Qantum theory of optomechanical cooling
Creators: name: Marquardt, Florian
name: Clerk, A. A.
name: Girvin, S. M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We review the quantum theory of cooling of a mechanical oscillator subject to the radiation pressure force due to light circulating inside a driven optical cavity. Such optomechanical setups have been used recently in a series of experiments by various groups to cool mechanical oscillators (such as cantilevers) by factors reaching $10^{5}$, and they may soon go to the ground state of mechanical motion. We emphasize the importance of the sideband-resolved regime for ground state cooling, where the cavity ring-down rate is smaller than the mechanical frequency. Moreover, we illustrate the strong coupling regime, where the cooling rate exceeds the cavity ring-down rate and where the driven cavity resonance and the mechanical oscillation hybridize.
description: 12 pages, 3 figures, brief review submitted to Journal of Modern Optics, for the proceedings of the "Physics of Quantum Electronics" conference (Snowbird, 2008)
Characteristics of tidally-forced pollutant transport in narrow channels
Creators: name: Cole, Michael J. B.
Publisher: name: University of British Columbia
Year: 2008

description: Physical and numerical model studies have been conducted to lend insight to the subject of transport and dispersion of a neutrally buoyant effluent released instantaneously from a point source into a one-dimensional tidal body. Closedform expressions are obtained for the fluid velocity and free surface elevation due to tidal forcing in a one-dimensional channel. Physical experiments were conducted in the Hydraulics Laboratory of the Department of Civil Engineering at the University of British Columbia, and measurements of both effluent concentration and velocity along the test channel were recorded. A numerical model based on the Finite Difference Method was developed for computing the time-varying effluent concentration within the channel. The influence of grid size and time step used in the numerical model was examined. The following parameters were varied: effluent discharge location, release time within the tidal cycle, average water depth, tidal amplitude, and tidal period. The experimental measurements and numerical predictions were correlated to derive an effective one-dimensional diffusion coefficient for the numerical model. The numerical results suggest that the fluid velocity at the instant and location of pollutant release is of primary importance to the mixing of the pollutant cloud into the surrounding waters.
Text: How to Build a House
Creators: name: Trigoso Silvano, Jorge
name: Parker, Stephen
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2020
Subjects: subject: inp

description: This research was carried out by Steve Parker (Dallas International University; SIL International) under the auspices of SIL International. This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

One WAV file. Originally recorded on cassette, digitized by depositor. See related file bundle for transcription, glossing, and translation.
The Metal-Poor Metallicity Distribution of the Ancient Milky Way
Creators: name: Chiti, Anirudh
name: Mardini, Mohammad K.
name: Frebel, Anna
name: Daniel, Tatsuya
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present a low metallicity map of the Milky Way consisting of $\sim$111,000 giants with $-3.5 \lesssim$ [Fe/H] $\lesssim -$0.75, based on public photometry from the second data release of the SkyMapper survey. These stars extend out to $\sim$7kpc from the solar neighborhood and cover the main Galactic stellar populations, including the thick disk and the inner halo. Notably, this map can reliably differentiate metallicities down to [Fe/H] $\sim -3.0$, and thus provides an unprecedented view into the ancient, metal-poor Milky Way. Among the more metal-rich stars in our sample ([Fe/H] $> -2.0$), we recover a clear spatial dependence of decreasing mean metallicity as a function of scale height that maps onto the thick disk component of the Milky Way. When only considering the very metal-poor stars in our sample ([Fe/H] $< -$2), we recover no such spatial dependence in their mean metallicity out to a scale height of $|Z|\sim7$ kpc. We find that the metallicity distribution function (MDF) of the most metal-poor stars in our sample ($-3.0
description: 9 pages, 5 figures; accepted for publication in ApJL. Minor corrections after acceptance addressing referee report for Chiti et al. ApJS submitted