cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Real-time 3D Facial Tracking via Cascaded Compositional Learning
Creators: name: Lou, Jianwen
name: Cai, Xiaoxu
name: Dong, Junyu
name: Yu, Hui
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: We propose to learn a cascade of globally-optimized modular boosted ferns (GoMBF) to solve multi-modal facial motion regression for real-time 3D facial tracking from a monocular RGB camera. GoMBF is a deep composition of multiple regression models with each is a boosted ferns initially trained to predict partial motion parameters of the same modality, and then concatenated together via a global optimization step to form a singular strong boosted ferns that can effectively handle the whole regression target. It can explicitly cope with the modality variety in output variables, while manifesting increased fitting power and a faster learning speed comparing against the conventional boosted ferns. By further cascading a sequence of GoMBFs (GoMBF-Cascade) to regress facial motion parameters, we achieve competitive tracking performance on a variety of in-the-wild videos comparing to the state-of-the-art methods, which require much more training data or have higher computational complexity. It provides a robust and highly elegant solution to real-time 3D facial tracking using a small set of training data and hence makes it more practical in real-world applications.
RDCNet: Instance segmentation with a minimalist recurrent residual network
Creators: name: Ortiz, Raphael
name: de Medeiros, Gustavo
name: Peters, Antoine H. F. M.
name: Liberali, Prisca
name: Rempfler, Markus
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Instance segmentation is a key step for quantitative microscopy. While several machine learning based methods have been proposed for this problem, most of them rely on computationally complex models that are trained on surrogate tasks. Building on recent developments towards end-to-end trainable instance segmentation, we propose a minimalist recurrent network called recurrent dilated convolutional network (RDCNet), consisting of a shared stacked dilated convolution (sSDC) layer that iteratively refines its output and thereby generates interpretable intermediate predictions. It is light-weight and has few critical hyperparameters, which can be related to physical aspects such as object size or density.We perform a sensitivity analysis of its main parameters and we demonstrate its versatility on 3 tasks with different imaging modalities: nuclear segmentation of H&E slides, of 3D anisotropic stacks from light-sheet fluorescence microscopy and leaf segmentation of top-view images of plants. It achieves state-of-the-art on 2 of the 3 datasets.
description: Accepted at MICCAI-MLMI 2020 workshop
Resonant reflection at magnetic barriers in quantum wires
Creators: name: Xu, Hengyi
name: Heinzel, T.
name: Evaldsson, M.
name: Ihnatsenka, S.
name: Zozoulenko, I. V.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The conductance of a quantum wire containing a single magnetic barrier is studied numerically by means of the recursive Greens function technique. For sufficiently strong and localized barriers, Fano - type reflection resonances are observed close to the pinch-off regime. They are attributed to a magnetoelectric vortex-type quasibound state inside the magnetic barrier that interferes with an extended mode outside. We furthermore show that disorder can substantially modify the residual conductance around the pinch-off regime.
description: 7 pages, 5 figures
Wavefunctions for topological quantum registers
Creators: name: Ardonne, Eddy
name: Schoutens, Kareljan
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We present explicit wavefunctions for quasi-hole excitations over a variety of non-abelian quantum Hall states: the Read-Rezayi states with k\geq 3 clustering properties and a paired spin-singlet quantum Hall state. Quasi-holes over these states constitute a topological quantum register, which can be addressed by braiding quasi-holes. We obtain the braid properties by direct inspection of the quasi-hole wavefunctions. We establish that the braid properties for the paired spin-singlet state are those of `Fibonacci anyons', and thus suitable for universal quantum computation. Our derivations in this paper rely on explicit computations in the parafermionic Conformal Field Theories that underly these particular quantum Hall states.
description: 36 pages; v2: reference added and minor changes
Negative refraction in nonlinear wave systems
Creators: name: Cao, Zhoujian
name: Zhang, Hong
name: Hu, Gang
Publisher: name: arXiv
Year: 2007
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: People have been familiar with the phenomenon of wave refraction for several centuries. Recently, a novel type of refraction, i.e., negative refraction, where both incident and refractory lines locate on the same side of the normal line, has been predicted and realized in the context of linear optics in the presence of both right- and left-handed materials. In this work, we reveal, by theoretical prediction and numerical verification, negative refraction in nonlinear oscillatory systems. We demonstrate that unlike what happens in linear optics, negative refraction of nonlinear waves does not depend on the presence of the special left-handed material, but depends on suitable physical condition. Namely, this phenomenon can be observed in wide range of oscillatory media under the Hopf bifurcation condition. The complex Ginzburg-Landau equation and a chemical reaction-diffusion model are used to demonstrate the feasibility of this nonlinear negative refraction behavior in practice.
Welsh Wreck Web Research Project (North Cardigan Bay). On-line research into the wreck of the: Phoebe
Creators: name: Van Hecke, Alexia
Publisher: name: Archaeology Data Service
Year: 2024

description: Welsh Wreck Web Research Project unpublished report series, 1
description: Research report on the Phoebe, which has been reported in the MADU data-base (MADU ref.93) as a schooner built in Newport in 1839, and having sank on 14th January 1843.
On-line programming in simple movement sequences : An application of the probe reaction in time paradigm
Creators: name: Ketelaars, Maria Adriana Catharina
Publisher: name: University of British Columbia
Year: 2009

description: The main goal of this experiment was to detect on-line programming as it occurred during the execution of forearm extension movements by including a probe reaction time paradigm within an extension-flexion movement task. The experiment included a primary and a secondary task condition and subjects performed these tasks in both single and dual-task situations. For the primary task in the single task condition, subjects performed forearm extension (E), and two types of extension-flexion movements for which the time between successive extension and flexion movements was varied (i.e., this time period was 50-100 msec (EFS) or 250-300 msec (EFL)). For the secondary task in the single task condition, subjects wore headphones through which an auditory stimulus (i.e., probe) was delivered at seven positions, either before or after the primary task stimulus. The onset of this probe was determined by either an absolute time interval, or by on-line analysis of EMG and acceleration profile data. Subjects closed their jaw as quickly as possible following the probe. In the dual task condition, the forearm movement and the jaw clench response were performed simultaneously. The reaction times were comparable for E, EFS and EFL movements in the dual task condition, suggesting that subjects programmed the flexion movement during the execution of the extension movement. By combining probe reaction time measures with those from the initial latency period, a more accurate description could be given of where in time these on-line control processes took place. Specifically, the probe reaction times were lengthened when the probe occurred at the end of the extension movement for EFL movements. It appeared that subjects delayed the execution of the jaw clench response until the programming of the flexion movement had been completed and hence the jaw clench and flexion response were initiated concurrently at this probe position (evidenced by EMG activity of the Masseter and Biceps muscles). Subjects appeared to use this same strategy for probes occurring during the pause time for EFL movements and at the point at which peak velocity was obtained for EFS movements.
Dependences of the Transport Scattering Time and Quantum Lifetime on the Two-Dimensional Electron Gas Density in Modulation-Doped Single GaAs Quantum Wells with AlAs/GaAs Short-Period Superlattice Barriers
Creators: name: Bykov, A. A.
name: Strygin, I. S.
name: Goran, A. V.
name: Nomokonov, D. V.
name: Bakarov, A. K.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The dependences of the transport scattering time τt, quantum lifetime τq, and their ratio τt/τq on the density ne of the electron gas in modulation-doped single GaAs quantum wells with AlAs/GaAs short-period super-lattice barriers are investigated. The experimental dependences are explained in terms of electron scattering by remote ionized donors with an effective two-dimensional concentration n*R and background impurities with a three-dimensional concentration nB. An expression for n*R(ne) is obtained including the contribution of X-valley electrons localized in AlAs layers to the suppression of scattering by the random potential of remote donors. It is shown that the experimentally observed abrupt increase in τt and τq with an increase in ne above a certain critical value nec is related to a decrease in n*R. It is established that the drop in τt/τq observed for electron densities ne > nec occurs because scattering by the random potential of background impurities in this two-dimensional system with a decrease in n*R limits an increase in τt more considerably than an increase in τq.
description: 9 pages, 5 figures
MADRaS : Multi Agent Driving Simulator
Creators: name: Santara, Anirban
name: Rudra, Sohan
name: Buridi, Sree Aditya
name: Kaushik, Meha
name: Naik, Abhishek
name: Kaul, Bharat
name: Ravindran, Balaraman
Publisher: name: arXiv
Year: 2020
Subjects: subject: Robotics (cs.RO)
subject: Machine Learning (cs.LG)
subject: Multiagent Systems (cs.MA)
subject: FOS: Computer and information sciences

description: In this work, we present MADRaS, an open-source multi-agent driving simulator for use in the design and evaluation of motion planning algorithms for autonomous driving. MADRaS provides a platform for constructing a wide variety of highway and track driving scenarios where multiple driving agents can train for motion planning tasks using reinforcement learning and other machine learning algorithms. MADRaS is built on TORCS, an open-source car-racing simulator. TORCS offers a variety of cars with different dynamic properties and driving tracks with different geometries and surface properties. MADRaS inherits these functionalities from TORCS and introduces support for multi-agent training, inter-vehicular communication, noisy observations, stochastic actions, and custom traffic cars whose behaviours can be programmed to simulate challenging traffic conditions encountered in the real world. MADRaS can be used to create driving tasks whose complexities can be tuned along eight axes in well-defined steps. This makes it particularly suited for curriculum and continual learning. MADRaS is lightweight and it provides a convenient OpenAI Gym interface for independent control of each car. Apart from the primitive steering-acceleration-brake control mode of TORCS, MADRaS offers a hierarchical track-position -- speed control that can potentially be used to achieve better generalization. MADRaS uses multiprocessing to run each agent as a parallel process for efficiency and integrates well with popular reinforcement learning libraries like RLLib.
The Origin of the Decoupling of Oxygen and Silicon Dynamics in Liquid Silica as Expressed by its Potential Energy Landscape
Creators: name: Saksaengwijit, A.
name: Heuer, A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The oxygen and silicon dynamics in silica is compared via computer simulations. In agreement with experimental data and previous simulations a decoupling of oxygen and silicon dynamics is observed upon cooling. The origin of this decoupling is studied in the framework of the potential energy landscape. From analysis of the transition features between neighboring superstructures of minima, denoted metabasins, the differences between the oxygen and the silicon dynamics can be quantified. The decoupling can be explicitly related to the presence of generalized rotational processes, giving rise to oxygen but not to silicon displacement. Closer analysis of these processes yields important insight into the nature of the potential energy landscape of silica. The physical picture of relaxation processes in silica, obtained in previous work for the oxygen dynamics, is consistent with the decoupling effects, elucidated here.
Variability of Critical Rotational Speeds of Gearbox by Misalignement and Manufacturing Errors
Creators: name: Driot, N.
name: Rigaud, Emmanuel
name: Perret-Liaudet, Joël
Publisher: name: arXiv
Year: 2007
Subjects: subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: Noise measurement on a population of gearbox manufactured in large number often reveals high variability due to tolerances on each gear design parameter (manufacturing errors). Gearbox noise results mainly from housing vibration induced by the gear meshing process. High acoustic levels correspond to excitation in a resonant manner of some critical modes. All gearbox modes and especially these critical modes depend on tolerances related to gear design parameters through the meshing stiffness. Tolerances are considered on shaft misalignment errors, teeth profile errors and teeth longitudinal errors. We introduce these tolerances as geometric random gaussian parameters. The critical modes are extracted using an efficient procedure. The retained "statistical" method to treat tolerances is the Taguchi's method. We illustrate this methodology considering two different gearbox dynamic models fitted out with a single spur gear. Obtained dispersion results are validated by comparison with Monte-Carlo simulations.
Solar neutrino measurements in Super-Kamiokande-II
Creators: name: Kamiokande Collaboration
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The results of the second phase of the Super-Kamiokande solar neutrino measurement are presented and compared to the first phase. The solar neutrino flux spectrum and time-variation as well as oscillation results are statistically consistent with the first phase and do not show spectral distortion. The time-dependent flux measurement of the combined first and second phases coincides with the full period of solar cycle 23 and shows no correlation with solar activity. The measured boron 8 total flux is 2.38 +/-0.05(stat.) +0.16-0.15(sys.) X 10^6 cm^-2 sec^-1 and the day-night difference is found to be -6.3 +/-4.2(stat.) +/-3.7(sys.) %. There is no evidence of systematic tendencies between the first and second phases.
Steps towards a map of the nearby universe
Creators: name: d'Abrusco, R.
name: Longo, G.
name: Staiano, A.
name: de Filippis, E.
name: Paolillo, M.
name: Brescia, M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present a new analysis of the Sloan Digital Sky Survey data aimed at producing a detailed map of the nearby (z < 0.5) universe. Using neural networks trained on the available spectroscopic base of knowledge we derived distance estimates for about 30 million galaxies distributed over ca. 8,000 sq. deg. We also used unsupervised clustering tools developed in the framework of the VO-Tech project, to investigate the possibility to understand the nature of each object present in the field and, in particular, to produce a list of candidate AGNs and QSOs.
description: 3 pages, 1 figure. To appear in Nucl Phys. B, in the proceedings of the NOW-2006 (Neutrino Oscillation Workshop - 2006), R. Fogli et al. eds
Ανάπτυξη Αλγορίθμου Ταχείας Αντιστροφής Γεωηλεκτρικών Δεδομένων
Creators: name: Καλομοίρης, Ευθύμιος Γρηγορίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2015
Subjects: subject: Γεωφυσική
subject: Ηλεκτρική Αντίσταση
subject: PERTI
subject: Geophysics
subject: FOS: Earth and related environmental sciences
subject: Electric Resistivity

description: Οι ηλεκτρικές μέθοδοι γεωφυσικής διασκόπησης είναι αρκετά δημοφιλείς για ένα πλήθος εφαρμογών. Οι σύγχρονοι αλγόριθμοι αντιστροφής δίνουν ικανοποιητικά αποτελέσματα για κάθε έρευνα. Παρ’ όλα αυτά, σε περιπτώσεις με μεγάλο αριθμό δεδομένων χρειάζονται τεχνικές γρηγορότερης αντιστροφής. Το βασικό αντικείμενο της συγκεκριμένης εργασίας είναι ο έλεγχος μιας νέας γρήγορης μεθόδου αντίστροφης που βασίζεται στις αρχές της τομογραφίας πιθανοτήτων και ονομάζεται PERTI ( new Probability based Electric Resistivity Tomography Inversion). Σε προγραμματιστικό περιβάλλον MATLAB δημιουργήθηκε ο PERTI και στη συνέχεια έγινε επεξεργασία πλήθους συνθετικών όσο και πραγματικών δεδομένων. Τέλος, προέκυψαν τα συμπεράσματα όπως η γρήγορη ποιοτική αναπαράσταση του πεδίου, η αδυναμία του PERTI στην εκτίμηση των πραγματικών τιμών αντίστασης, η αστοχία του για τα επιφανειακά δεδομένα και η μεγέθυνση αγώγιμων δόμων.
description: Electric resistivity methods are quite popular for a number of applications. The current inversion algorithms give satisfactory results for any given research. Nevertheless, in cases with large datasets faster inversion techniques are needed. The main subject of the present thesis is the study of a new rapid method reverse based on the principles of probability tomography called PERTI (new Probability based Electric Resistivity Tomography Inversion). The PERTI algorithm is developed in MATLAB programming environment and a number of synthetic as well as real examples are studied. Finally, the conclusions that result are the fast qualitative representation of the field, the lack of PERTI for real resistivity estimation, the failure for the near-surface data and the enlargement of the conductive parts.
Equivariant $A$-Theory
Creators: name: Malkiewich, Cary
name: Merling, Mona
Publisher: name: Deutsche Mathematiker-Vereinigung
Year: 2019

description: We give a new construction of the equivariant $K$-theory of group actions (cf. Barwick et al.), producing an infinite loop $G$-space for each Waldhausen category with $G$-action, for a finite group $G$. On the category $R(X)$ of retractive spaces over a $G$-space $X$, this produces an equivariant lift of Waldhausen's functor $A(X)$, and we show that the $H$-fixed points are the bivariant $A$-theory of the fibration $X_{hH}\to BH$. We then use the framework of spectral Mackey functors to produce a second equivariant refinement $A_G(X)$ whose fixed points have tom Dieck type splittings. We expect this second definition to be suitable for an equivariant generalization of the parametrized $h$-cobordism theorem.
description: DOCUMENTA MATHEMATICA, Vol 24 (2019), p. 815-855
Hamiltonian chaos and differential geometry of configuration space-time
Creators: name: Di Cairano, Loris
name: Gori, Matteo
name: Pettini, Giulio
name: Pettini, Marco
Publisher: name: arXiv
Year: 2021
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: This paper tackles Hamiltonian chaos by means of elementary tools of Riemannian geometry. More precisely, a Hamiltonian flow is identified with a geodesic flow on configuration space-time endowed with a suitable metric due to Eisenhart. Until now, this framework has never been given attention to describe chaotic dynamics. A gap that is filled in the present work. In a Riemannian-geometric context, the stability/instability of the dynamics depends on the curvature properties of the ambient manifold and is investigated by means of the Jacobi--Levi-Civita (JLC) equation for geodesic spread. It is confirmed that the dominant mechanism at the ground of chaotic dynamics is parametric instability due to curvature variations along the geodesics. A comparison is reported of the outcomes of the JLC equation written also for the Jacobi metric on configuration space and for another metric due to Eisenhart on an extended configuration space-time. This has been applied to the Hénon-Heiles model, a two-degrees of freedom system. Then the study has been extended to the 1D classical Heisenberg XY model at a large number of degrees of freedom. Both the advantages and drawbacks of this geometrization of Hamiltonian dynamics are discussed. Finally, a quick hint is put forward concerning the possible extension of the differential-geometric investigation of chaos in generic dynamical systems, including dissipative ones, by resorting to Finsler manifolds.
Integrodifference master equation describing actively growing blood vessels in angiogenesis
Creators: name: Bonilla, L. L.
name: Carretero, M.
name: Terragni, F.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Tissues and Organs (q-bio.TO)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Dynamical Systems (math.DS)
subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Biological sciences
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We study a system of particles in a two-dimensional geometry that move according to a reinforced random walk with transition probabilities dependent on the solutions of reaction-diffusion equations for the underlying fields. A birth process and a history-dependent killing process are also considered. This system models tumor-induced angiogenesis, the process of formation of blood vessels induced by a growth factor released by a tumor. Particles represent vessel tip cells, whose trajectories constitute the growing vessel network. New vessels appear and may fuse with existing ones during their evolution. Thus, the system is described by tracking the density of active tips, calculated as an ensemble average over many realizations of the stochastic process. Such density satisfies a novel discrete master equation with source and sink terms. The sink term is proportional to a space-dependent and suitably fitted killing coefficient. Results are illustrated studying two influential angiogenesis models.
description: 11 pages, 6 figures, final version to appear in Int. J. Nonlin. Sci. Numer. Simulation
Welsh Wreck Web Research Project (North Cardigan Bay). On-line research into the wreck of the yacht Phoebe, also referred to as the Hebe
Creators: name: Holden, Chris
Publisher: name: Archaeology Data Service
Year: 2024

description: Welsh Wreck Web Research Project unpublished report series, 1
description: Research report on the yacht 'Phoebe' (or Hebe), lost in September, 1833, with all aboard.
Understanding the Predictability of Gesture Parameters from Speech and their Perceptual Importance
Creators: name: Ferstl, Ylva
name: Neff, Michael
name: McDonnell, Rachel
Publisher: name: arXiv
Year: 2020
Subjects: subject: Human-Computer Interaction (cs.HC)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Gesture behavior is a natural part of human conversation. Much work has focused on removing the need for tedious hand-animation to create embodied conversational agents by designing speech-driven gesture generators. However, these generators often work in a black-box manner, assuming a general relationship between input speech and output motion. As their success remains limited, we investigate in more detail how speech may relate to different aspects of gesture motion. We determine a number of parameters characterizing gesture, such as speed and gesture size, and explore their relationship to the speech signal in a two-fold manner. First, we train multiple recurrent networks to predict the gesture parameters from speech to understand how well gesture attributes can be modeled from speech alone. We find that gesture parameters can be partially predicted from speech, and some parameters, such as path length, being predicted more accurately than others, like velocity. Second, we design a perceptual study to assess the importance of each gesture parameter for producing motion that people perceive as appropriate for the speech. Results show that a degradation in any parameter was viewed negatively, but some changes, such as hand shape, are more impactful than others. A video summarization can be found at https://youtu.be/aw6-_5kmLjY.
description: To be published in the Proceedings of the 20th ACM International Conference on Intelligent Virtual Agents (IVA 20)
A Spitzer White Dwarf Infrared Survey
Creators: name: Mullally, F.
name: Kilic, Mukremin
name: Reach, William T.
name: Kuchner, Marc J.
name: von Hippel, Ted
name: Burrows, Adam
name: Winget, D. E.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present mid-infrared photometry of 124 white dwarf stars with Spitzer Space Telescope. Objects were observed simultaneously at 4.5 and 8.0um with sensitivities better than 1 mJy. This data can be used to test models of white dwarf atmospheres in a new wavelength regime, as well as to search for planetary companions and debris disks.
description: 24 pages. Accepted by Astrophysical Journal Supplement Series
Υπολείμματα γεωργικών φαρμάκων στο νερό της βροχής επιλεγμένης περιοχής του νομού Δράμας
Creators: name: Γρηγοριάδου, Σοφία Δημητρίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2015
Subjects: Νερό βροχής
Υπολείμματα γεωργικών φαρμάκων
Αέρια Υγρή Χρωματογραφία
Όρια Ποσοτικού Προσδιορισμού
Όρια Ανίχνευσης
Rainwater
Pesticides Residues
Gas Liquid Chromatography
Limit of Quantification
Limit of Detection

description: Στο νομό Δράμας, όπου αποτελεί και την λεκάνη απορροής του ποταμού Αγγίτη, τόσο η γεωργία όσο και η κτηνοτροφία είναι ιδιαίτερα ανεπτυγμένες. Δείγματα βροχής από συνολικά 274 βροχοπτώσεις, συλλέχθηκαν την χρονική περίοδο Απρίλιο 2013 με Απρίλιο 2014 από δέκα σταθμούς δειγματοληψίας, και αναλύθηκαν για την ανίχνευση υπολειμμάτων γεωργικών φαρμάκων και καφεϊνης. Στις 50 βροχοπτώσεις (18,24%) ανιχνεύθηκε τουλάχιστον μία δραστική ουσία. Από τις 351 δραστικές ουσίες που προορίζονταν για την ανάλυση, συμπεριλαμβανομένων και κάποιων κύριων προϊόντων μεταβολής τους, όπου και ανακτήθηκαν με την μέθοδο της εκχύλισης υγρής στερεής φάσης και αναλύθηκαν με το σύστημα της αέριας και υγρής χρωματογραφίας, ανιχνεύθηκαν στα δείγματα τουλάχιστον μία φορά οι 41. Οι δραστικές ουσίες που ανιχνεύθηκαν με μεγαλύτερη συχνότητα ήταν η καφεϊνη (48,9%), chlorpyrifos-ethyl (44,89%), propoxur (31,75%) και alachlor (24,81%). Η ύπαρξη των fluometuron, terbuthylazine, phosmet, c-HCH (lindane) και s-metolachlor εμφανίστηκαν στο 10 – 15% των δειγμάτων που αναλύθηκαν. Οι υπόλοιπες δραστικές ουσίες παρουσιάζονται σε λιγότερο από το 10% των δειγμάτων που αναλύθηκαν. Οι συγκεντρώσεις μεμονωμένων ουσιών κυμάνθηκαν από 0,001 έως 12,6 ppb. Υψηλότερες συγκεντρώσεις γεωργικών φαρμάκων προέκυψαν κατά την περίοδο των ψεκασμών. Η εκτιμώμενη ετήσια εναπόθεση για το σύνολο των γεωργικών φαρμάκων σε όλες τις ερευνώμενες περιοχές κυμάνθηκε από 17,81 έως 266,1 mg/m2 επιφάνειας εδάφους.
description: In Drama, which is also the Basin of Aggitis River, both agriculture and livestock farming is highly developed. Samples from a total of 274 rain events collected from ten sampling stations during April 2013 – April 2014. Τhey were analyzed for pesticide residues of which 50 events (18.24%) yielded at least one positive detection. Of the 351 active substances, including some major conversion productsof pesticides and caffeine, which were intended for analysis, recovered by solid-phase extraction (SPE) and analyzed by gas and liquid chromatography (GLC) 41 compounds were found in at least one rain event. The most frequently found pesticides including caffeine, were caffeine(48.9%), chlorpyrifos-ethyl (44.89%), propoxur (31.75%) and alachlor (24.81%).Occurrences offluometuron, terbuthylazine, phosmet, c-HCH (lindane) and s-metolachloraccounted for 10 – 15%of the samples analyzed. The remaining target analytes were present in less than the 10% of the analyzed samples. Concentrations of individual compound ranged from 0.001 to 12.6 ppb.Greater pesticide concentrations occurred during application seasons.The estimated annual deposition rates for the sum of the pesticides ranged from 17.81 to 266.1μg/m2 of soil surface.
Constraining temperature distribution inside LIGO test masses from frequencies of their vibrational modes
Creators: name: Blair, Carl D
name: Levin, Yuri
name: Thrane, Eric
Publisher: name: arXiv
Year: 2020
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Thermal distortion of test masses, as well as thermal drift of their vibrational mode frequencies, present a major challenge for operation of the Advanced LIGO and Advanced VIRGO interferometers, reducing optical efficiency, which limits sensitivity and potentially causing instabilities which reduce duty-cycle. In this paper, we demonstrate that test-mass vibrational mode frequency data can be used to overcome some of these difficulties. First, we derive a general expression for the change in a mode frequency as a function of temperature distribution inside the test mass. Then we show how the mode frequency dependence on temperature distribution can be used to identify the wavefunction of observed vibrational modes. We then show how monitoring the frequencies of multiple vibrational modes allows the temperature distribution inside the test mass to be strongly constrained. Finally, we demonstrate using simulations, the potential to improve the thermal model of the test mass, providing independent and improved estimates of important parameters such as the coating absorption coefficient and the location of point absorbers.
description: 12 pages 16 figures
Welsh Wreck Web Research Project (North Cardigan Bay). On-line research into the wreck of the: Pioneer
Creators: name: Perks, Graeme
Publisher: name: Archaeology Data Service
Year: 2024

description: Welsh Wreck Web Research Project unpublished report series, 1
description: The Pioneer was built at Tatamagouche, Nova Scotia by Edward Kent in 1856, sailed to Liverpool and advertised for sale. Hobley and Co the new owners registered Pioneer at Caernarfon and after voyages to the Caribbean started trading with the Eastern Mediterranean and Black sea ports. Pioneer in January 1862 left Queenstown for Rotterdam with a cargo of linseed from Galatz when she became water logged in a gale off Cardigan and all but one of the crew abandoned her and perished in a ships boat. The remaining crew man was rescued by the RNLI and the drifting Pioneer grounded later on the Bar at Aberyon and was towed in. The Pioneer had some minor repairs and continued trading with the Eastern Mediterranean and Black Sea until November 1863. When after putting in at Milford Pioneer continued her voyage from Cardiff to Constantinople and disappeared.
Magnetic torques on T Tauri stars: accreting vs. non-accreting systems
Creators: name: Pantolmos, G.
name: Zanni, C.
name: Bouvier, J.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Classical T Tauri stars (CTTs) magnetically interact with their surrounding disks, a process that is thought to regulate their rotational evolution. In this work, we compute torques acting onto the stellar surface of CTTs arising from different accreting (accretion funnels) and ejecting (stellar winds and magnetospheric ejections) flow components. Furthermore, we compare the magnetic braking due to stellar winds in two different systems: isolated and accreting stars. 2.5D magnetohydrodynamic, time-dependent, axisymmetric simulations are employed. For both systems the stellar wind is thermally driven. In the star-disk-interaction (SDI) simulations the accretion disk is Keplerian, viscous, and resistive. Two series of simulations are presented, one for each system. We find that in classical T Tauri systems the presence of magnetospheric ejections confines the stellar-wind expansion, resulting in an hourglass-shaped geometry of the outflow. In addition, the formation of the accretion columns modifies the amount of open magnetic flux exploited by the stellar wind. These effects have a strong impact on the stellar wind properties and we show that the stellar-wind braking is more efficient in the star-disk-interacting systems than in the isolated ones. We also derive torque scalings, over a wide range of magnetic field strengths, for each flow component in a SDI system that directly applies a torque on the stellar surface. In all the performed SDI simulations the stellar wind extracts less than 2% of the mass accretion rate and the disk is truncated up to 66% of the corotation radius. All the simulations show a net spin-up torque. In order to achieve a stellar-spin equilibrium we need either more massive stellar winds or disks being truncated closer to the corotation radius, which increases the torque efficiency by the magnetospheric ejections.
description: 18 pages, 11 figures, accepted for publication in A&A
Welsh Wreck Web Research Project (North Cardigan Bay). On-line research into the wreck of the: Pluvier of Aberystwith
Creators: name: Perks, Graeme
Publisher: name: Archaeology Data Service
Year: 2024

description: Welsh Wreck Web Research Project unpublished report series, 1
description: The Pluvier was a schooner built in Plymouth by W. S. Kelly and sold to a local commissioning agent, W.G. Crinks and his business partner. It entered the Newfoundland salt fish trade, before it was sold and reregistered at Aberystwyth. Pluvier then mainly sailed from Porthmadog to Germany and the Baltic with slates. The Pluvier was involved in the usual mishaps of a sailing vessel including a series of collisions and groundings, and on one approach to Bristol a series of such, involving seven vessels. The Pluvier was involved in a collision while anchored in St Tudwal's Roads involving two other vessels where her foremast fell and the crew were rescued by lifeboat. Pluvier was later sold again and entered the salt fish trade, foundering in a gale off Cork, Ireland on her return journey, all the crew perished.
3-Dimensional QCD Phase Diagrams for Strange Matter
Creators: name: Dexheimer, V.
name: Aryal, K.
name: Constantinou, C.
name: Peterson, J.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: In this work, we examine in detail the difference between constraining the electric charge fraction and isospin fraction when calculating the deconfinement phase transition in the presence of net strangeness. We present relations among charge and isospin fractions and the corresponding chemical potentials and draw 3-dimensional QCD phase diagrams for matter out of weak equilibrium. Finally, we briefly discuss how our results can be applied to comparisons of matter created in heavy ion collisions and binary neutron star mergers.
description: arXiv admin note: text overlap with arXiv:2004.03039
Lifshitz point at commensurate melting of 1D Rydberg atoms
Creators: name: Chepiga, Natalia
name: Mila, Frédéric
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The recent investigation of chains of Rydberg atoms has brought back the problem of commensurate-incommensurate transitions into the focus of current research. In 2D classical systems, or in 1D quantum systems, the commensurate melting of a period-p phase with p larger than 4 is known to take place through an intermediate floating phase where correlations between domain walls or particles decay only as a power law, but when p is equal to 3 or 4, it has been argued by Huse and Fisher that the transition could also be direct and continuous in a non-conformal chiral universality class with a dynamical exponent larger than 1. This is only possible however if the floating phase terminates at a Lifshitz point before reaching the conformal point, a possibility debated since then. Here we argue that this is a generic feature of models where the number of particles is not conserved because the exponent of the floating phase changes along the Pokrovsky-Talapov transition and can thus reach the value at which the floating phase becomes unstable. Furthermore, we show numerically that this scenario is realized in an effective model of the period-3 phase of Rydberg chains in which hard-core bosons are created and annihilated three by three: The Luttinger liquid parameter reaches the critical value $p^2/8=9/8$ along the Pokrovsky-Talapov transition, leading to a Lifshitz point that separates the floating phase from a chiral transition. Implications beyond Rydberg atoms are briefly discussed.
description: 10 pages, 9 figures
Spectator detection for the measurement of proton neutron interactions at ANKE
Creators: name: Lehmann, I.
name: Barsov, S.
name: Schleichert, R.
name: Wilkin, C.
name: Drochner, M.
name: Hartmann, M.
name: Hejny, V.
name: Merzlyakov, S.
name: Mikirtychyants, S.
name: Mussgiller, A.
name: Protic, D.
name: Stroher, H.
name: Trusov, S.
name: Wustner, P.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: A telescope of three silicon detectors has been installed close to the internal target position of the ANKE spectrometer, which is situated inside the ultra-high vacuum of the COSY-Juelich light-ion storage ring. The detection and identification of slow protons and deuterons emerging from a deuterium cluster-jet target thus becomes feasible. A good measurement of the energy and angle of such a spectator proton (p_sp) allows one to identify a reaction as having taken place on the neutron in the target and then to determine the kinematical variables of the ion-neutron system on an event-by-event basis over a range of c.m. energies. The system has been successfully tested under laboratory conditions. By measuring the spectator proton in the p d to p_sp d pi^0 reaction in coincidence with a fast deuteron in the ANKE Forward Detector, values of the p n to d pi^0 total cross-section have been deduced. Further applications of the telescope include the determination of the luminosity and beam polarisation which are required for several experiments.
description: 16 pages, 9 figures
The role of functional knee bracing in a dynamic setting
Creators: name: Rishiraj, Neetu
Publisher: name: University of British Columbia
Year: 2009

description: The controversy over functional knee bracing still lingers. Although there is ample literature available on both the possible positive and negative concerns of utilizing a functional knee brace, there is very little information available on functional knee bracing in a dynamic setting. The purposes of this study were to evaluate the effect of functional knee bracing on athletic performance during dynamic testing in a non-injured knee joint and to measure the effects of functional knee bracing (under dynamic testing) on an Anterior Cruciate Ligament (ACL)--deficient knee. A total of 60, 30 non-injured and 30 injured, subjects were tested with and without a functional knee brace. Each subject performed five functional tests—10 meter dash, figure-of-eight run, slalom run, hop test, and running down the stairs test. Each subject performed each test 8 times—two submaximal effort trials, followed by 6 trials (3 trials with and 3 trials without a brace) at maximal effort. A 2X3, repeated measures on both factors, ANOVA was conducted to determine the results during the accommodation phase. A single factor ANOVA analysis was performed on the best performance measures after accommodation had occurred to the functional knee brace. Furthermore, a correlation analysis was conducted between knee joint laxity of injured subjects and their performance levels. During the accommodation phase, the non-injured, braced group had statistically significant inferior performances (when compared to the noninjured, non-braced group) in the 10 meter dash, figure-of-eight, and the slalom tests and statistically superior performance in the hop test. In the running down the stairs test no statistically significant difference was noted between the two groups. However, once the subjects had accommodated to the brace (best performance) no statistically significant difference was noted between the non-injured, braced and the non-injured, non-braced groups for any test. As expected, during the accommodation phase, the injured, braced group performed statistically significantly better than the injured, non-braced group. However, after accommodating to the functional knee brace, an analysis of best performance data found no statistically significant difference between the two groups. A strong correlation was not evident between the injured athlete's knee joint laxity and performance levels. This study provides evidence that performance levels of non-injured, braced individuals is either only marginally hindered or is enhanced during the accommodation period when compared with non-injured, non-braced individuals. Once non-injured, braced individuals have accommodated to a functional knee brace they either perform at the same level or they outperform non-injured, non-braced subjects. These findings are an important consideration when considering a functional knee brace for prophylactic purposes. For injured individuals, performance levels are enhanced when a functional knee brace is utilized.
Production of mirror fermions via $eγ$ and $ep$ collisions in the littlest Higgs model with T-parity
Creators: name: Yue, Chong-Xing
name: Ding, Li
name: Liu, Jin-Yan
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: One of the important features of the littlest Higgs model with T-parity, called the $LHT$ model, is that it introduces the mirror fermions, which are the T-parity partners of the standard model fermions. In this paper, we discuss production of the mirror quark associated with mirror neutrino via $eγ$ and $ep$ collisions. We find that, in wide range of the parameter space, the mirror quark can be copiously produced at the International $e^{+}e^{-}$ Linear Collider $(ILC)$ and $ep$ collider $(THERA)$ experiments. The production rates of certain signal events, which are related the main two-body decay modes of the mirror quark, are also calculated.
description: 19 pages, 11 figures
Image-based Anomaly Detection within Crowds
Creators: name: Golda, Thomas
Publisher: name: Karlsruhe
Year: 2019

description: Authorities and security services have to deal with more and more data collected during events and on public places. Two reasons for that are the rising number of huge events, as well as the expanding coverage with CCTV cameras of areas within cities. Even the number of ground crew teams, that are equipped with mobile cameras, rises continuously. These examples show that modern surveillance and location monitoring systems come with need of suited assistance systems, which help the associated security workers to keep track of the situations. In this report, we present a first idea how such a system using modern machine learning algorithms could look like. Furthermore, a more detailed look on two state-of-the-art methods for human pose estimation is given. These algorithms are then investigated for their performance on the target domain of crowd surveillance scenarios using a small dataset called CrowdPose.
Effective Hamiltonians for large-S pyrochlore antiferromagnet
Creators: name: Hizi, Uzi
name: Henley, Christopher L.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The pyrochlore lattice Heisenberg antiferromagnet has a massive classical ground state degeneracy. We summarize three approximation schemes, valid for large spin length $S$, to capture the (partial) lifting of this degeneracy when zero-point quantum fluctuations are taken into account; all three are related to analytic loop expansions. The first is harmonic order spin waves; at this order, there remains an infinite manifold of degenerate collinear ground states, related by a gauge-like symmetry. The second is anharmonic (quartic order) spin waves, using a self-consistent approximation; the harmonic-order degeneracy is split, but (within numerical precision) some degeneracy may remain, with entropy still of order $L$ in a system of $L^3$ sites. The third is a large-N approximation, a standard and convenient approach for frustrated antiferromagnets; however, the large-N result contradicts the harmonic order at $O(S)$ hence must be wrong (for large $S$).
description: 14pp, 1 figure (Proc. Highly Frust. Mag. 2006, to appear JPCM)