cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
title: Χρηματοοικονομική ανάλυση της εταιρείας HERTZ AUTOHELLAS ATEE για τις χρήσεις 2018-22
title: Financial analysis of the company HERTZ AUTOHELLAS SA for the period 2018-2022
titleType: AlternativeTitle
Creators: name: Μαραγκού, Βασιλική Δήμητρα
Publisher: name: Πανεπιστήμιο Δυτικής Αττικής
Year: 2023
Subjects: Χρηματοοικονομική ανάλυση
Hertz Autohellas
Αριθμοδείκτες
Χρηματοοικονομικές καταστάσεις
Ισολογισμός
Πανδημία
Οικονομικές κρίσεις
Κλάδος μίσθωσης αυτοκινήτων
Financial analysis

description: Τα οικονομικά στοιχεία, που αποτυπώνονται στις χρηματοοικονομικές καταστάσεις, είναι κρίσιμα στοιχεία για την λήψη όλων των αποφάσεων που σχετίζονται με τις λογιστικές συναλλαγές (αποφάσεις για την παραγωγή αγαθών, μέτρηση δεικτών αγοράς, αξιολόγηση/επιμέτρηση επιδόσεων κ.α.). Σκοπός της παρούσας εργασίας είναι η χρηματοοικονομική ανάλυση της εταιρείας & ομίλου HERTZ – AUTO HELLAS SA, για την περίοδο 2018-2022, που περιλαμβάνει δύο μείζονα γεγονότα (πανδημία & lockdown, ρωσο-ουκρανικό πόλεμο). Από την ανάλυση των στοιχείων των οικονομικών καταστάσεων & ισολογισμών της ΕΤΑΙΡΕΙΑΣ & ΟΜΙΛΟΥ, παρουσιάζεται μια πτώση κατά την περίοδο της Πανδημίας (Lockdown, σημαντική απώλεια λόγω πτώσης του τουρισμού) στα περισσότερα μεγέθη, και κυρίως στο κύκλο εργασιών και στους χρηματοοικονομικούς δείκτες & ΕΔΜΑ. Επίσης, και κατά την Ουκρανική Κρίση, υπάρχει μια σχετική σταθεροποίηση ή και μικρή πτώση (π.χ. κέρδη χρήσης μετά φόρων) σε σχέση στην αύξηση που υπήρξε κατά το 2021 (βάση των οικονομικών αποτελεσμάτων θεωρείται έτος ανάκαμψης). Πρέπει να σημειωθεί ότι η πτώση είναι μεγαλύτερη στην εταιρεία (τουρισμός) και μικρότερη στον όμιλο (αγορά/πώληση/ενοικίαση οχημάτων & ανταλλακτικών). Επιπλέον, παρουσιάζεται μια αύξηση του τραπεζικού δανεισμού, κυρίως τα έτη, 2021 & 2022. Η ερμηνεία για αυτά τα οικονομικά στοιχεία (δανειακές υποχρεώσεις) μπορεί να αποδοθεί στις επιπτώσεις της Πανδημίας (π.χ. αγορά στόλου νέων οχημάτων) και στην ουκρανική κρίση (άνοδος τιμών καυσίμων). Τέλος, στο τρέχον έτος (2023), για το πρώτο τρίμηνο του έτους, σύμφωνα με το πρώτο απολογισμό του ΟΜΙΛΟΥ εμφανίζεται μια θετική Δυναμική λόγω οργανικής Ανάπτυξης και επέκτασης των δραστηριοτήτων του (εξαγορές/συγχωνεύσεις).
Characterization of Tl$_2$NaYCl$_6$:Ce Scintillation Crystals as Gamma-Ray Detectors
Creators: name: Hawrami, R.
name: Ariesanti, E.
name: Burger, A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: In this paper the growth of a 16mm diameter Ce-doped Tl$_2$NaYCl$_6$ and its characterization as a gamma-ray detector are reported. With a 16 mm dia. x 8 mm cylindrical sample, energy resolution of 4.1% (FWHM) at 662 keV and light yield of 27,800ph/MeV are measured. Decay times of 91 ns (34%), 462 ns (52%), and 2.1 microseconds (15%) are calculated. The x-ray excited emission spectrum exhibits bands that are similar to other Tl-based elpasolite scintillators like Tl$_2$NaYCl$_6$:Ce.
description: arXiv admin note: text overlap with arXiv:1911.03611
Penetration test as a fast method to determine yield stress and structural build-up for 3D printing of cementitious materials
Creators: name: Pott, Ursula
name: Stephan, Dietmar
Publisher: name: Elsevier BV
Year: 2021
Subjects: subject: 600 Technik, Medizin, angewandte Wissenschaften::620 Ingenieurwissenschaften::620 Ingenieurwissenschaften und zugeordnete Tätigkeiten
subject: penetration test
subject: 3D printing
subject: yield stress
subject: thixotropic structural build-up

description: 3D printing technology is becoming increasingly important in the construction sector, leading to changes in material requirements compared to traditional manufacturing methods. To characterize the rheological properties (yield stress, viscosity, and structural build-up) of printable mortars, suitable methods are necessary. However, with a rheometer, this is problematic because a time-resolved determination of the properties is complicated, time-consuming, and the torque limitation is often too low. For this reason, a penetration test, and a formula for calculating the yield stress are introduced. To validate the formula, it is determined that the results are comparable with the calculated yield stress based on a rheological test. Furthermore, it is shown that it is possible to extrapolate the data and to determine structural build-up. This paper is intended to give an up-to-date overview of the penetration method and to illustrate the advantages and possibilities of the method in the field of 3D printing. Moreover, it is discussed in which areas improvement and further investigations are needed.
Anomalous Quantum Information Scrambling for $\mathbb{Z}_3$ Parafermion Chains
Creators: name: Zhang, Shun-Yao
name: Deng, Dong-Ling
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Parafermions are exotic quasiparticles with non-Abelian fractional statistics that could be exploited to realize universal topological quantum computing. Here, we study the scrambling of quantum information in one-dimensional parafermionic chains, with a focus on $\mathbb{Z}_3$ parafermions in particular. We use the generalized out-of-time-ordered correlators (OTOCs) as a measure of the information scrambling and introduce an efficient method based on matrix product operators to compute them. With this method, we compute the OTOCs for $\mathbb{Z}_3$ parafermions chains up to $200$ sites for the entire early growth region. We find that, in stark contrast to the dynamics of conventional fermions or bosons, the information scrambling light cones for parafermions can be both symmetric and asymmetric, even for inversion-invariant Hamiltonians involving only hopping terms. In addition, we find a deformed light cone structure with a sharp peak at the boundary of the parafermion chains in the topological regime, which gives a unambiguous evidence of the strong zero modes at infinite temperature.
description: 5 pages, 4 figures, plus Supplementary Materials
First-order intertwining operators with position dependent mass and $η$- weak-psuedo-Hermiticity generators
Creators: name: Mustafa, Omar
name: Mazharimousavi, S. Habib
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A Hermitian and an anti-Hermitian first-order intertwining operators are introduced and a class of $η$-weak-pseudo-Hermitian position-dependent mass (PDM) Hamiltonians are constructed. A corresponding reference-target $η$-weak-pseudo-Hermitian PDM -- Hamiltonians' map is suggested. Some $η$-weak-pseudo-Hermitian PT -symmetric Scarf II and periodic-type models are used as illustrative examples. Energy-levels crossing and flown-away states phenomena are reported for the resulting Scarf II spectrum. Some of the corresponding $η$-weak-pseudo-Hermitian Scarf II- and periodic-type-isospectral models (PT -symmetric and non-PT -symmetric) are given as products of the reference-target map.
description: 11 pages, no figures, Revised/Expanded, more references added. To appear in the Int.J. Theor. Phys
title: Culture Jamming in the Caribbean: A Case of Alternative Media through Double Alternativity in Trinidad and Tobago
Creators: name: Felix, Jonathan J.
Publisher: name: Archipelagos Journal
Year: 2020
Subjects: subject: FOS: Humanities

description: This essay serves as a written counterpart to a previously published visual case study that explored the cultural production of Caribbean creative Warren Le Platte and his creation of an internet meme series in 2016. In a continuation of that analysis here, Le Platte's work is again positioned as an articulation of *alternative media*, a concept defined by subversive, disruptive, or interrogative strategies in response to inequitable relations and power dynamics. Employed as a reflexive critique of his home island of Trinidad, Le Platte's work raises questions regarding the cultural logic of dysfunctionality underscored by his personal experience as a citizen. By employing a visual discourse analysis, this essay continues to explore alternative media in the Caribbean and how activities of "prosumption" (production + consumption) intersect with practices related to language, identity, and cultural memory in this context.
title: Teaching without a Text: Close Listening to Kamau Brathwaite's Digital Audio Archive
Creators: name: Edmond, Jacob
Publisher: name: Archipelagos Journal
Year: 2020
Subjects: subject: FOS: Humanities

description: New media technologies—from the tape recorder to the computer—enabled Kamau Brathwaite's revolutionary poetic approach; digital technologies likewise enable us to study and teach his groundbreaking work in new ways. This essay argues that teaching and studying Brathwaite should begin with the audible word not the written text and that digital audio archives and platforms can play a key role in enabling this approach. Digital audio archives such as PennSound and the Poetry Archive allow students and scholars to approach Brathwaite's work by listening closely to a wide range of sound recordings. This essay demonstrates the utility of this close listening approach by taking advantage of the digital platform of _archipelagos journal_ to interweave its text with Brathwaite's recorded voice. It not only demonstrates the value of approaching Brathwaite's work through digital sound recordings but also argues for a larger overturning of critical, pedagogical, and essayistic conventions in literary studies through a methodological turn away from the page.
A simply connected surface of general type with p_g=0 and K^2=2
Creators: name: Lee, Yongnam
name: Park, Jongil
Publisher: name: arXiv
Year: 2006
Subjects: subject: Algebraic Geometry (math.AG)
subject: Symplectic Geometry (math.SG)
subject: FOS: Mathematics
subject: 14J29, 14J10, 14J17, 53D05

description: In this paper we construct a simply connected, minimal, complex surface of general type with p_g=0 and K^2=2 using a rational blow-down surgery and Q-Gorenstein smoothing theory.
description: 19 pages, 6 figures. To appear in Inventiones Mathematicae
Dipper-like variability of the Gaia alerted young star V555 Ori
Creators: name: Nagy, Zsófia
name: Szegedi-Elek, Elza
name: Ábrahám, Péter
name: Kóspál, Ágnes
name: Bódi, Attila
name: Bouvier, Jérôme
name: Kun, Mária
name: Moór, Attila
name: Cseh, Borbála
name: Farkas-Takács, Anikó
name: Hanyecz, Ottó
name: Hodgkin, Simon
name: Ignácz, Bernadett
name: Kiss, Csaba
name: Könyves-Tóth, Réka
name: Kriskovics, Levente
name: Marton, Gábor
name: Mészáros, László
name: Ordasi, András
name: Pál, András
name: Sarkis, Paula
name: Sárneczky, Krisztián
name: Sódor, Ádám
name: Szabados, László
name: Szabó, Zsófia Marianna
name: Szakáts, Róbert
name: Tarczay-Nehéz, Dóra
name: Vida, Krisztián
name: Zsidi, Gabriella
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: V555 Ori is a T Tauri star, whose 1.5 mag brightening was published as a Gaia science alert in 2017. We carried out optical and near-infrared photometric, and optical spectroscopic observations to understand the light variations. The light curves show that V555 Ori was faint before 2017, entered a high state for about a year, and returned to the faint state by mid-2018. In addition to the long-term flux evolution, quasi-periodic brightness oscillations were also evident, with a period of about 5 days. At optical wavelengths both the long-term and short-term variations exhibited colourless changes, while in the near-infrared they were consistent with changing extinction. We explain the brightness variations as the consequence of changing extinction. The object has a low accretion rate whose variation in itself would not be enough to reproduce the optical flux changes. This behaviour makes V555 Ori similar to the pre-main sequence star AA Tau, where the light changes are interpreted as periodic eclipses of the star by a rotating inner disc warp. The brightness maximum of V555 Ori was a moderately obscured ($A_V$=2.3 mag) state, while the extinction in the low state was $A_V$=6.4 mag. We found that while the Gaia alert hinted at an accretion burst, V555 Ori is a standard dipper, similar to the prototype AA Tau. However, unlike in AA Tau, the periodic behaviour was also detectable in the faint phase, implying that the inner disc warp remained stable in both the high and low states of the system.
description: Accepted to MNRAS
Radio-Loudness of Active Galactic Nuclei: Observational Facts and Theoretical Implications
Creators: name: Sikora, M.
name: Stawarz, L.
name: Lasota, J. -P.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We investigate how the total radio luminosity of AGN-powered radio sources depends on their accretion luminosity and the central black hole mass. Our studies cover about seven orders of magnitude in accretion luminosity and the full range of AGN black hole masses. We find that AGNs form two distinct and well separated sequences on the radio-loudness -- Eddington-ratio plane. The `upper' sequence is formed by radio selected AGNs, the `lower' sequence contains mainly optically selected objects. Whereas an apparent `gap' between the two sequences may be an artifact of selection effects, the sequences themselves mark the real upper bounds of radio-loudness of two distinct populations of AGNs: those hosted respectively by elliptical and disk galaxies. Both sequences show the same dependence of the radio-loudness on the Eddington ratio (an increase with decreasing Eddington ratio), which suggests that the normalization of this dependence is determined by the black hole spin. This implies that central black holes in giant elliptical galaxies have (on average) much larger spins than black holes in spiral/disc galaxies. This galaxy-morphology related radio-dichotomy breaks down at high accretion rates where the dominant fraction of luminous quasars hosted by elliptical galaxies is radio quiet. This led to speculations in the literature that formation of powerful jets at high accretion rates is intermittent and related to switches between two disk accretion modes, as directly observed in some BH X-ray binaries. We argue that such intermittency can be reconciled with the spin paradigm, provided that successful formation of relativistic jets by rotating black holes requires collimation by MHD outflows from accretion disks.
description: 33 pages, 4 figures and 5 tables included. Final version, accepted for publication in ApJ
Evolution of transonicity in an accretion disc
Creators: name: Ray, Arnab K.
name: Bhattacharjee, Jayanta K.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: For inviscid, rotational accretion flows driven by a general pseudo-Newtonian potential on to a Schwarzschild black hole, the only possible fixed points are saddle points and centre-type points. For the specific choice of the Newtonian potential, the flow has only two critical points, of which the outer one is a saddle point while the inner one is a centre-type point. A restrictive upper bound is imposed on the admissible range of values of the angular momentum of sub-Keplerian flows through a saddle point. These flows are very unstable to any deviation from a necessarily precise boundary condition. The difficulties against the physical realisability of a solution passing through the saddle point have been addressed through a temporal evolution of the flow, which gives a non-perturbative mechanism for selecting a transonic solution passing through the saddle point. An equation of motion for a real-time perturbation about the stationary flows reveals a very close correspondence with the metric of an acoustic black hole, which is also an indication of the primacy of transonicity.
description: 18 pages
Morris-Thorne Wormholes in $f(R,T)$ modified theory of gravity
Creators: name: Chanda, A
name: Dey, S
name: Paul, B C
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We study static traversable wormholes obtained by Morris and Thorne in general relativity (GR) in the framework of a modified theory of gravity. The modified gravitational action $f(R,T)$ is a function of the Ricci scalar ($R$) and of the trace of the energy momentum tensor ($T$). For a modified gravity $f(R,T)=R+αR^{2}+λT$, where $α$ and $λ$ are constants, we obtain wormhole solutions (WH) with normal matter for a relevant shape functions. The energy conditions are checked at the throat and away from the throat of the WH. The coupling parameters $α$ and $λ$ in the gravitational action play an important role to accommodate the matter composition. For a given $λ$, WH solutions are found in the presence of exotic matter at the throat for $α<0$. It is shown that WH exists in the modified gravity without exotic matter when $α>0$. We consider two different shape functions to investigate the existence of WH in the presence of exotic or normal matter. A class of WH solutions exist with anisotropic fluid provided $λ\neq - 8 π$. In flat asymptotic regions on both sides of the throat with anisotropic source and $λ= - 8 π$, it does not permit WH as per no go theorem. As $λ\rightarrow 0$ in the gravitational action, all the energy conditions are obeyed with the hybrid shape function indicating existence of WH with normal matter.
description: 23 pages, 15 figures
NSWM Policy Fellows Poster Presentation Webinar Series 3: Beyond the Hackathon: Measuring the Impact of Child Welfare Hackathons, Online Student Wellness: Examples of Technology-Enhanced Activities, Programs, and Services That Can Promote Wellness, and The Next Generation Safety Net: Addressing Barriers to Care for Long-Term Care Services and Supports.
Creators: name: Gaitán, Idalia
name: Wallach, Neva
name: Marquart, Matthea S.
name: Johnson, Kimson
Publisher: name: Columbia University
Year: 2018
Subjects: College students--Health and hygiene
Older people--Long-term care
Social service
Child welfare
Career development
Leadership
Social workers--Training of

description: The Network for Social Work Management Policy Fellows program offers practical training in social work management for emerging and mid-career leaders seeking new experiences and skill sets. The nine month leadership and professional development experience equips participants with core management competencies to inspire, organize, and work effectively with others to advance the public good.

In this webinar series, 2017-2018 Policy Fellows will present their posters from the 29th Annual Management Conference, "Disruptive Leadership: Maximizing Inclusion, Invention and Innovation in Human Services."

- Host and moderator: Idalia G. Gaitán
- Neva Wallach, MSW, "Beyond the Hackathon: Measuring the Impact of Child Welfare Hackathons"
- Matthea Marquart, MSSW, "Online Student Wellness: Examples of Technology-Enhanced Activities, Programs, and Services That Can Promote Wellness"​
- Kimson Johnson, MSW, "The Next Generation Safety Net: Addressing Barriers to Care for Long-Term Care Services and Supports"
Galaxy Clusters in the Line of Sight to Background Quasars: I. Survey Design and Incidence of MgII Absorbers at Cluster Redshifts
Creators: name: Lopez, S.
name: Barrientos, L. F.
name: Lira, P.
name: Padilla, N.
name: Gilbank, D. G.
name: Gladders, M. D.
name: Maza, J.
name: Tejos, N.
name: Vidal, M.
name: Yee, H. K. C.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We describe the first optical survey of absorption systems associated with galaxy clusters at z= 0.3-0.9. We have cross-correlated SDSS DR3 quasars with high-redshift cluster/group candidates from the Red-Sequence Cluster Survey. We have found 442 quasar-cluster pairs for which the MgII doublet might be detected at a transverse (physical) distance d<2 Mpc from the cluster centers. To investigate the incidence (dN/dz) and equivalent-width distribution n(W) of MgII systems at cluster redshifts, two statistical samples were drawn out of these pairs: one made of high-resolution spectroscopic quasar observations (46 pairs), and one made of quasars used in MgII searches found in the literature (375 pairs). The results are: (1) the population of strong MgII systems (W_0>2.0 Ang.) near cluster redshifts shows a significant (>3 sigma) overabundance (up to a factor of 15) when compared with the 'field' population; (2) the overabundance is more evident at smaller distances (d<1 Mpc) than larger distances (d<2 Mpc) from the cluster center; and, (3) the population of weak MgII systems (W_0<0.3 Ang.) near cluster redshifts conform to the field statistics. Unlike in the field, this dichotomy makes n(W) in clusters appear flat and well fitted by a power-law in the entire W-range. A sub-sample of the most massive clusters yields a stronger and still significant signal. Since either the absorber number density or filling-factor/cross-section affects the absorber statistics, an interesting possibility is that we have detected the signature of truncated halos due to environmental effects. Thus, we argue that the excess of strong systems is due to a population of absorbers in an overdense galaxy environment, and the lack of weak systems to a different population, that got destroyed in the cluster environment. (Abridged)
description: Accepted for publication in the Astrophysical Journal
Introduction
Creators: name: Kohl, Martina
Publisher: name: ASJ
Year: 2019

description: In 2011, I introduced our readership to a new American Studies Journal issue titled Women’s Voices from the House of Time: “The American Studies Journal 55 is an unusual edition if we compare it to all its predecessors. It is a collection of memoir pieces, a reflection upon a specific theme, a look back at a significant moment or moments by six women … . All of them were inspired by the topic ‘Women’s Voices from the House of Time,’ which comes from the title of a poem by Moira Roth now serving as the gate through which the reader approaches this journal.”
description: American studies journal; Vol. 67, No. 01, 2019. 2199-7268
description: Special Issue: Women’s Voices from the House of Time (Part II)
Physical and chemical vertical structure of magnetostatic accretion disks of young stars
Creators: name: Khaibrakhmanov, Sergey A.
name: Dudorov, Alexander E.
name: Vasyunin, Anton I.
name: Kiskin, Mikhail Yu.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The vertical structure of the accretion disks of young stars with fossil large-scale magnetic field is studied. The equations of magnetostatic equilibrium of the disk are solved taking into account the stellar gravity, gas and magnetic pressure, turbulent heating, and heating by stellar radiation. The modelled physical structure of the disk is used to simulate its chemical structure, in particular, to study the spatial distribution of CN molecules. The disk of the typical T Tauri star is considered. Simulations show that the temperature within the disk in the region $r<50$ au decreases with height and density profiles are steeper than in the isothermal case. Outside the `dead' zone, vertical profiles of the azimuthal component of the magnetic field are nonmonotonic, and the magnetic field strength maximum is reached within the disk. The magnetic pressure gradient can cause an increase in the disk thickness in comparison with the hydrostatic one. The CN molecule concentration is maximum near the photosphere and in the disk atmosphere where the magnetic field strength at chosen parameters is $\sim 0.01$ G. Measurements of the Zeeman splitting of CN lines in the submm range can be used to determine the magnetic field strength in these regions of accretion disks.
description: 3 pages, 1 figure, published in Bulletin of the Lebedev Physics Institute
Finite element model updating using objective-consistent sensitivity-based parameter clustering and Bayesian regularization
Creators: name: Bartilson, Daniel
name: Jang, Jinwoo
name: Smyth, Andrew W.
Publisher: name: Columbia University
Year: 2019
Subjects: subject: Finite element method--Models
subject: Civil engineering
subject: FOS: Civil engineering
subject: Cluster analysis
subject: Structural analysis (Engineering)--Mathematical models

description: Finite element model updating seeks to modify a structural model to reduce discrepancies between predicted and measured data, often from vibration studies. An updated model provides more accurate prediction of structural behavior in future analyses. Sensitivity-based parameter clustering and regularization are two techniques used to improve model updating solutions, particularly for high-dimensional parameter spaces and ill-posed updating problems. In this paper, a novel parameter clustering scheme is proposed which considers the structure of the objective function to facilitate simultaneous updating of disparate data, such as natural frequencies and mode shapes. In a small-scale updating example with simulated data, the proposed clustering scheme is shown to provide moderate to excellent improvement over existing parameter clustering methods, depending on the accuracy of initial model. A full-scale updating example on a large suspension bridge shows similar improvement using the proposed parametrization scheme. Levenberg-Marquardt minimization with Bayesian regularization is also implemented, providing an optimal regularized solution and insight into parametrization efficiency.
Protocols for Neuromotor Prosthetic to Treat Stroke-Related Paresis
Creators: name: Serruya, Mijail
Publisher: name: Zenodo
Year: 2022
Subjects: Brain Computer Interface
Stroke
BCI for stroke

description: Multiple microelectrode arrays implanted in intact areas adjacent to a stroke will be used to record signals to be decoded into motor commands. The decoding/haptic computer will be physically connected to the patient via percutaneous connectors and will wirelessly interface with the Myomo brace fitted to the patient.
A Portable, Self-Contained Neuroprosthetic Hand with Deep Learning-Based Finger Control
Creators: name: Nguyen, Anh Tuan
name: Drealan, Markus W.
name: Luu, Diu Khue
name: Jiang, Ming
name: Xu, Jian
name: Cheng, Jonathan
name: Zhao, Qi
name: Keefer, Edward W.
name: Yang, Zhi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Robotics (cs.RO)
subject: Artificial Intelligence (cs.AI)
subject: Human-Computer Interaction (cs.HC)
subject: FOS: Computer and information sciences

description: Objective: Deep learning-based neural decoders have emerged as the prominent approach to enable dexterous and intuitive control of neuroprosthetic hands. Yet few studies have materialized the use of deep learning in clinical settings due to its high computational requirements. Methods: Recent advancements of edge computing devices bring the potential to alleviate this problem. Here we present the implementation of a neuroprosthetic hand with embedded deep learning-based control. The neural decoder is designed based on the recurrent neural network (RNN) architecture and deployed on the NVIDIA Jetson Nano - a compacted yet powerful edge computing platform for deep learning inference. This enables the implementation of the neuroprosthetic hand as a portable and self-contained unit with real-time control of individual finger movements. Results: The proposed system is evaluated on a transradial amputee using peripheral nerve signals (ENG) with implanted intrafascicular microelectrodes. The experiment results demonstrate the system's capabilities of providing robust, high-accuracy (95-99%) and low-latency (50-120 msec) control of individual finger movements in various laboratory and real-world environments. Conclusion: Modern edge computing platforms enable the effective use of deep learning-based neural decoders for neuroprosthesis control as an autonomous system. Significance: This work helps pioneer the deployment of deep neural networks in clinical applications underlying a new class of wearable biomedical devices with embedded artificial intelligence.
Stellar populations of massive elliptical galaxies in very rich clusters
Creators: name: Carretero, C.
name: Vazdekis, A.
name: Beckman, J. E.
name: .
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present a detailed stellar population analysis of 27 massive elliptical galaxies within 4 very rich clusters at redshift z~0.2: A115, A655, A963 and A2111. Using the new, high-resolution stellar populations models developed in our group, we obtained accurate estimates of the mean luminosity-weighted ages and relative abundances of CN, Mg and Fe. We have found that [CN/H] and [Mg/H] are correlated with sigma while [Fe/H] and Log(age) are not. In addition, both abundance ratios [CN/Fe] and [Mg/Fe] increase with sigma. Furthermore, the [CN/H]-sigma and [CN/Fe]-sigma slopes are steeper for galaxies in very rich clusters than those in the less dense Virgo and Coma clusters. On the other hand, [Mg/H]-sigma and [Mg/Fe]-sigma slopes keep constant as functions of the environment. Our results are compatible with a scenario in which the stellar populations of massive elliptical galaxies, independently of their environment and mass, had formation timescales shorter than ~1 Gyr. This result implies that massive elliptical galaxies have evolved passively since, at least, as long ago as z~2. For a given galaxy mass the duration of star formation is shorter in those galaxies belonging to more dense environments; whereas the mass-metallicity relation appears to be also a function of the cluster properties: the denser the environment is, the steeper are the correlations. Finally, we show that the abundance ratios [CN/Fe] and [Mg/Fe] are the key "chemical clocks" to infer the star formation history timescales in ellipticals. In particular, [Mg/Fe] provides an upper limit for those formation timescales, while [CN/Fe] apperars to be the most suitable parameter to resolve them in elliptical galaxies with sigma<300 km/s.
description: Accepted for publication in MNRAS
On the Definition of Effective Permittivity and Permeability For Thin Composite Layers
Creators: name: Saenz, Elena
name: Ikonen, Pekka
name: Gonzalo, Ramon
name: Tretyakov, Sergei
Publisher: name: arXiv
Year: 2007
Subjects: subject: Classical Physics (physics.class-ph)
subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: The problem of definition of effective material parameters (permittivity and permeability) for composite layers containing only one-two parallel arrays of complex-shaped inclusions is discussed. Such structures are of high importance for the design of novel metamaterials, where the realizable layers quite often have only one or two layers of particles across the sample thickness. Effective parameters which describe the averaged induced polarizations are introduced. As an explicit example, we develop an analytical model suitable for calculation of the effective material parameters $ε_{\rm{eff}}$ and $μ_{\rm{eff}}$ for double arrays of electrically small electrically polarizable scatterers. Electric and magnetic dipole moments induced in the structure and the corresponding reflection and transmission coefficients are calculated using the local field approach for the normal plane-wave incidence, and effective parameters are introduced through the averaged fields and polarizations. In the absence of losses both material parameters are purely real and satisfy the Kramers-Kronig relations and the second law of thermodynamics. We compare the analytical results to the simulated and experimental results available in the literature. The physical meaning of the introduced parameters is discussed in detail.
description: 6 pages, 5 figures
Connection between accretion disk and superluminal radio jets and the role of radio plateau state in GRS 1915+105
Creators: name: Yadav, J. S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We investigate the association between the accretion disk during radio plateau state and the following superluminal relativistic radio jets with peak intensity varies from 200 mJy to 1000 mJy observed over a period of five years and present the evidences of direct accretion disc-jet connection in microquasar GRS 1915+105. We have analysed RXTE PCA/HEXTE X-ray data and have found that the accretion rate, $\dot{m}_{accr}$, as inferred from the X-ray flux, is very high during the radio plateaux. We suggest that the accretion disk during the radio plateaux always associated with radiation-driven wind which is manifested in the form of enhanced absorption column density for X-ray and the depleted IR emission. We find that the wind density increases with the accretion disk luminosity during the radio plateaux. The wind density is similar to the density of the warm absorber proposed in extragalactic AGNs and Quasars. We suggest a simple model for the origin of superluminal relativistic jets. Finally, We discuss the implications of this work for galactic microquasars and the extragalactic AGNs and Quasars.
description: 9 pages, 6 Figures, Accepted for publication in ApJ
Profile Of Pedestrian Crashes In Nablus City, Palestine
Creators: name: Jaber, Ahmed
name: Al-Sahili, Khaled
Publisher: name: figshare
Year: 2021
Subjects: subject: 90507 Transport Engineering
subject: FOS: Civil engineering

description: Pedestrians are a vulnerable group in terms of road safety. Studies in Nablus City showed a high percentage of pedestrian crashes. The objective of this research is to draw a detailed profile of pedestrian crashes in Nablus City, Palestine. Road crash data involving pedestrians for five years (2012-2016) were collected from Nablus Traffic Police Department. Data were analyzed spatially, temporally, and based on various patterns. Results showed that the highest frequency of pedestrian crashes occurred in year 2015, during the spring season, on Thursday, and in the early afternoon hours. The crashes concentrated in the city center and its perimeter zones. They also concentrated on major streets of the city. Pedestrians with an age group younger than 10 years old were the most vulnerable. A high percentage of pedestrian crashes involved public transportation vehicles. The majority of victims and drivers were males. The results were linked to socio-economic characteristics and behavior of people in the city. The vast majority of pedestrian crashes were slight injuries. Killed or seriously injured (KSI) pedestrian crashes constituted 7% with a concentration on Saturday and in the afternoon hours. The highest age groups involved in KSI crashes were younger than 10 years old and older than 40 years old. The study recommends the traffic police to computerize the data collection and archiving system, and to reallocate the limited human resources to areas with high pedestrian crashes and severity. The relevant authorities should exert awareness efforts among school children and drivers regarding road safety behavior
Physical properties of Brightest Cluster Galaxies up to redshift 1.80 based on HST data
Creators: name: Chu, Aline
name: Durret, Florence
name: Marquez, Isabel
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Brightest cluster galaxies (BCGs) have grown by accreting numerous smaller galaxies and can be used as tracers of cluster formation and evolution in the cosmic web. However, there is still a controversy on the main epoch of formation of BCGs, since some authors believe they have already formed before redshift z=2, while others still find them to evolve at more recent epochs. We aim to analyse the physical properties of a large sample of BCGs covering a wide redshift range up to z=1.8 and analysed in a homogeneous way, to see if their characteristics vary with redshift. As a first step, we also present a new tool to define for each cluster which galaxy is the BCG. For a sample of 137 clusters with HST images in the optical and/or infrared, we analyse the BCG properties by applying GALFIT with one or two Sersic components. For each BCG, we compute the Sersic index, effective radius, major axis position angle, surface brightness. We then search for correlations of these quantities with redshift. We find that BCGs follow the Kormendy relation (between the effective radius and the mean surface brightness), with a slope that remains constant with redshift, but with a variation with redshift of the ordinate at the origin. Although the trends are faint, we find that both the absolute magnitudes and effective radii tend to become respectively brighter and bigger with decreasing redshift. On the other hand, we find no significant correlation of the mean surface brightnesses or Sersic indices with redshift. The major axes of the cluster elongations and of the BCGs agree within 30 degrees for 73% of our clusters at redshift z <= 0.9. Our results agree with the BCGs being mainly formed before redshift z=2. The alignment of the major axes of BCGs with their clusters agree with the general idea that BCGs form at the same time as clusters by accreting matter along the filaments of the cosmic web.
description: Accepted for publication in Astronomy & Astrophysics
Guaranteed and Prospective Galactic TeV Neutrino Sources
Creators: name: Kistler, Matthew D.
name: Beacom, John F.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Recent observations, particularly from the HESS Collaboration, have revealed rich Galactic populations of TeV gamma-ray sources, including a collection unseen in other wavelengths. Many of these gamma-ray spectra are well measured up to ~10 TeV, where low statistics make observations by air Cerenkov telescopes difficult. To understand these mysterious sources, especially at much higher energies--where a cutoff should eventually appear--new techniques are needed. We point out the following: (1) For a number of sources, it is very likely that pions, and hence TeV neutrinos, are produced; (2) As a general point, neutrinos should be a better probe of the highest energies than gamma rays, due to increasing detector efficiency; and (3) For several specific sources, the detection prospects for km^3 neutrino telescopes are very good, about 1-10 events/year, with low atmospheric neutrino background rates above reasonable energy thresholds. Such signal rates, as small as they may seem, will allow neutrino telescopes to powerfully discriminate between models for the Galactic TeV sources, with important consequences for our understanding of cosmic-ray production.
description: 12 pages, 5 figures; minor changes to match published version
The pre-conquest Roman penetration of south-eastern Britain
Creators: name: Millar, Roderick J. O.
Publisher: name: University of British Columbia
Year: 2011

description: This thesis is concerned with an examination of the interaction between a state level society, that of Rome in the period of the Late Republic and Early Empire, and a neighbouring group of chiefdoms, those in the south-eastern part of Britain. In this period the social, economic and political systems in southern Britain appear to have gone through processes of major stress and change. The study tests the general hypothesis that in the period between the expeditions of Caesar in 55 and 54 BC and the final Claudian conquest in AD 43, the south-east of Britain went through an evolution from a number of small independent chiefdoms competing with each, other to a proto-state. This evolution was triggered and accelerated by the interaction with Rome. To test this hypothesis the published archaeological reports on the excavations in three areas of south-eastern Britain were analyzed. The areas around St. Albans, Braughing and Skeleton Green, and Colchester were used. The analysis compares a number of specific types of artifacts, certain features, and burials from all three areas. The general weight of the evidence, despite some minor inconsistencies, shows that in the approximately ninety years between 55 BC and AD 43 power shifted from several centres: the St. Albans area, Braughing, Welwyn and Hertford to one centre at Colchester. Under the dominance of Colchester, St. Albans and probably other formerly independent chiefdoms, became satellite centres to Colchester. This shift in the power centre was accompanied by a marked increase in social stratification, demonstrated in the elite burials, the increasing range of elite goods, and larger and more complex features.
Scattering Rule in Soliton Cellular Automaton associated with Crystal Base of $U_q(D_4^{(3)})$
Creators: name: Yamada, Daisuke
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics
subject: 81R50, 82B23, 37B15

description: In terms of the crystal base of a quantum affine algebra $U_q(\mathfrak{g})$, we study a soliton cellular automaton (SCA) associated with the exceptional affine Lie algebra $\mathfrak{g}=D_4^{(3)}$. The solitons therein are labeled by the crystals of quantum affine algebra $U_q(A_1^{(1)})$. The scatteing rule is identified with the combinatorial $R$ matrix for $U_q(A_1^{(1)})$-crystals. Remarkably, the phase shifts in our SCA are given by {\em 3-times} of those in the well-known box-ball system.
description: 25 pages
title: Knockout of the Cardiac Transcription Factor NKX2-5 Results in Stem Cell-Derived Cardiac Cells with Typical Purkinje Cell-like Signal Transduction and Extracellular Matrix Formation
Creators: name: Disse, Paul
name: Aymanns, Isabel
name: Mücher, Lena
name: Sandmann, Sarah
name: Varghese, Julian
name: Ritter, Nadine
name: Strutz-Seebohm, Nathalie
name: Seebohm, Guiscard Friedrich Aldous
name: Peischard, Stefan
Publisher: name: University of Muenster, Institutional Repository MIAMI
Year: 2023
Subjects: subject: 610 Medicine and health

description: The human heart controls blood flow, and therewith enables the adequate supply of oxygen and nutrients to the body. The correct function of the heart is coordinated by the interplay of different cardiac cell types. Thereby, one can distinguish between cells of the working myocardium, the pace-making cells in the sinoatrial node (SAN) and the conduction system cells in the AV-node, the His-bundle or the Purkinje fibres. Tissue-engineering approaches aim to generate hiPSC-derived cardiac tissues for disease modelling and therapeutic usage with a significant improvement in the differentiation quality of myocardium and pace-making cells. The differentiation of cells with cardiac conduction system properties is still challenging, and the produced cell mass and quality is poor. Here, we describe the generation of cardiac cells with properties of the cardiac conduction system, called conduction system-like cells (CSLC). As a primary approach, we introduced a CrispR-Cas9-directed knockout of the NKX2-5 gene in hiPSC. NKX2-5-deficient hiPSC showed altered connexin expression patterns characteristic for the cardiac conduction system with strong connexin 40 and connexin 43 expression and suppressed connexin 45 expression. Application of differentiation protocols for ventricular- or SAN-like cells could not reverse this connexin expression pattern, indicating a stable regulation by NKX2-5 on connexin expression. The contraction behaviour of the hiPSC-derived CSLCs was compared to hiPSC-derived ventricular- and SAN-like cells. We found that the contraction speed of CSLCs resembled the expected contraction rate of human conduction system cells. Overall contraction was reduced in differentiated cells derived from NKX2-5 knockout hiPSC. Comparative transcriptomic data suggest a specification of the cardiac subtype of CSLC that is distinctly different from ventricular or pacemaker-like cells with reduced myocardial gene expression and enhanced extracellular matrix formation for improved electrical insulation. In summary, knockout of NKX2-5 in hiPSC leads to enhanced differentiation of cells with cardiac conduction system features, including connexin expression and contraction behaviour.
description: Finanziert durch den Open-Access-Publikationsfonds der Universität Münster.
Computation of Electrostatic Field near Three-Dimensional Corners and Edges
Creators: name: Majumdar, N.
name: Mukhopadhyay, S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Computational Physics (physics.comp-ph)
subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: Theoretically, the electric field becomes infinite at corners of two and three dimensions and edges of three dimensions. Conventional finite-element and boundary element methods do not yield satisfactory results at close proximity to these singular locations. In this paper, we describe the application of a fast and accurate BEM solver (which usesexact analytic expressions to compute the effect of source distributions on flatsurfaces) to compute the electric field near three-dimensional corners and edges. Results have been obtained for distances as close as 1$μm$ near the corner/edge and good agreement has been observed between the present results and existing analytical solutions.
description: Presented in International Conference on Computational and Experimental Engineering and Sciences held at IIT Madras, Chennai, India, during 1-6 December, 2005
YARARA: Significant improvement of RV precision through post-processing of spectral time-series
Creators: name: Cretignier, M.
name: Dumusque, X.
name: Hara, N. C.
name: Pepe, F.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Aims: Even the most-precise radial-velocity instruments gather high-resolution spectra that present systematic errors that a data reduction pipeline cannot identify and correct for efficiently. In this paper, we aim at improving the radial-velocity precision of HARPS measurements by cleaning individual extracted spectra using the wealth of information contained in spectra time-series. Methods: We developed YARARA, a post-processing pipeline designed to clean high-resolution spectra from instrumental systematics and atmospheric contamination. Spectra are corrected for: tellurics, interference pattern, detector stitching, ghosts and fiber B contaminations as well as more advanced spectral line-by-line corrections. YARARA uses Principal Component Analysis on spectra time-series with prior information to disentangle contaminations from real Doppler shifts. We applied YARARA on three systems: HD10700, HD215152 and HD10180 and compared our results to the HARPS standard Data Reduction Software and the SERVAL post-processing pipeline. Results: On HD10700, we obtain radial-velocity measurements that present a rms smaller than 1 m/s over the 13 years of the HARPS observations, which is 20 and 10 % better than the HARPS Data Reduction Software and the SERVAL post-processing pipeline, respectively. We also injected simulated planets on the data of HD10700 and demonstrated that YARARA does not alter pure Doppler shifted signals. On HD215152, we demonstrated that the 1-year signal visible in the periodogram becomes marginal after processing with YARARA and that the signals of the known planets become more significant. Finally, on HD10180, the known six exoplanets are well recovered although different orbitals parameters and planetary masses are provided by the new reduced spectra.
description: 23 pages, 19 figures