cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Enhancing the Bernese GNSS Software for multi-technique analysis at BKG - Focus on the VLBI implementation
Creators: name: Flohrer, Claudia
name: Walenta, Anastasiia
name: Thaller, Daniela
name: Gattano, César
name: Dach, Rolf
name: Hugentobler, Urs
Publisher: name: Zenodo
Year: 2023
Subjects: VLBI analysis, Bernese GNSS Software, Combination of space-geodetique techniques

description: The Geodesy Group of the BKG (Federal Agency for Cartography and Geodesy) has been involved in IVS analysis and combination activities for many years. It successfully operates an IVS Analysis Center (using NASA’s software packages νSolve and Calc/Solve) and the IVS combination centre (using the DFGI-TUM software package DOGS CS). BKG also operates an ILRS analysis center and is a partner in the CODE consortium, which operates the IGS analysis center CODE at the AIUB (Astronomical Institute of the University of Bern). Both analysis centers are using the Bernese GNSS Software, which is developed by AIUB and continuously adapted to changing requirements and user needs. Currently, BKG uses different software packages for different space-geodetic techniques. However, our focus is not only on the individual techniques, but also on the combination of the different observation techniques, in particular to improve the Earth rotation parameters. We would like to continue the multi-technique combined analysis using a single software package, namely the Bernese GNSS Software. Ultimately, this will allow us to combine GNSS, VLBI and SLR data not only at SINEX level, but also at the observation level in the near future.
 We present the current status of the Bernese GNSS Software enhancements for the analysis of VLBI data. We also compare the results of the VLBI data analysis derived from Calc/Solve with those derived from the Bernese GNSS Software. For the latter we use the unconstrained normal equations from Calc/Solve as input and discuss different options for constraining station and quasar coordinates.
Understanding INT4 Quantization for Transformer Models: Latency Speedup, Composability, and Failure Cases
Creators: name: Wu, Xiaoxia
name: Li, Cheng
name: Aminabadi, Reza Yazdani
name: Yao, Zhewei
name: He, Yuxiong
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computation and Language (cs.CL)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Improving the deployment efficiency of transformer-based language models has been challenging given their high computation and memory cost. While INT8 quantization has recently been shown to be effective in reducing both the memory cost and latency while preserving model accuracy, it remains unclear whether we can leverage INT4 (which doubles peak hardware throughput) to achieve further latency improvement. In this study, we explore the feasibility of employing INT4 weight and activation (W4A4) quantization for language models. Our findings indicate that W4A4 quantization introduces no to negligible accuracy degradation for encoder-only and encoder-decoder models, but causes a significant accuracy drop for decoder-only models. To materialize the performance gain using W4A4, we develop a highly optimized end-to-end W4A4 encoder inference pipeline supporting different quantization strategies. Our INT4 pipeline is $8.5\times$ faster for latency-oriented scenarios and up to $3\times$ for throughput-oriented scenarios compared to the inference of FP16, and improves the SOTA BERT INT8 performance from FasterTransformer by up to $1.7\times$. We provide insights into the failure cases when applying W4A4 to decoder-only models, and further explore the compatibility of INT4 quantization with other compression methods, like pruning and layer reduction.
Homoclinic orbit and the violation of the chaos bound around a black hole with anisotropic matter fields
Creators: name: Jeong, Soyeon
name: Lee, Bum-Hoon
name: Lee, Hocheol
name: Lee, Wonwoo
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the homoclinic orbit and the violation of chaos bound, which are obtained by particle motions around a black hole that coexist with anisotropic matter fields. The homoclinic one is associated with an unstable local maximum of the effective potential. By perturbing a particle located slightly away from the homoclinic one, we numerically compute Lyapunov exponents indicating the sensitivity of the initial value. Our results demonstrate that the violation of the chaos bound increases with higher angular momentum, and the anisotropic matter gives rise to violating the chaos bound further, even in the case of the nonextremal black hole. We utilize the Hamiltonian-Jacobi formalism to explicitly illustrate how the geodesic motion of a particle can be integrable in the procedure of obtaining our findings.
description: 19 pages, 27 figures, references added, version to appear in PRD
The origin of the eccentricity of the hot Jupiter in CI Tau
Creators: name: Rosotti, Giovanni P.
name: Booth, Richard A.
name: Clarke, Cathie J.
name: Teyssandier, Jean
name: Facchini, Stefano
name: Mustill, Alexander J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Following the recent discovery of the first radial velocity planet in a star still possessing a protoplanetary disc (CI Tau), we examine the origin of the planet's eccentricity (e $\sim 0.3$). We show through long timescale ($10^5$ orbits) simulations that the planetary eccentricity can be pumped by the disc, even when its local surface density is well below the threshold previously derived from short timescale integrations. We show that the disc may be able to excite the planet's orbital eccentricity in $
description: 5 pages, 4 figures. Accepted to MNRAS letters
Effect of interactions on the topological expression for the chiral separation effect
Creators: name: Zubkov, M. A.
name: Abramchuk, R. A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In the absence of interactions the conductivity of chiral separation effect (CSE) in the system of massless fermions is given by topological expression. Interactions might change the pattern drastically. However, we prove that the CSE conductivity is still given by the topological invariant composed of the Green functions at zero temperature as long as the chiral symmetry is present, and if the renormalized axial current is considered. This allows to predict its appearance with the standard value of conductivity per Dirac fermion $σ_{CSE} = \frac{1}{2 π^2}$ in quark - gluon matter at $T = 0$ and sufficiently large baryon chemical potential, in the hypothetical phase with restored chiral symmetry and without color superconductivity. This phase may be realized inside the neutron stars. We also argue that the same topological expression for the CSE may be observed in Weyl semimetals, which realize the system of interacting relativistic fermions in solid state systems. In order to estimate the non - perturbative corrections to $σ_{CSE}$ within QCD at finite temperatures we apply method of field correlators developed by Yu.A.Simonov. As expected, above the deconfinement crossover the topological expression is approached within the quark - gluon plasma phase, when the quark chemical potential is sufficiently large. However, we observe that this occurs only when quark chemical potential is much larger than the thermal (Debye) mass. This range of parameters appears to be far out of the region accessible at the modern colliders.
description: Latex, 21 pages, 4 figures
The LOFAR LBA Sky Survey II. First data release
Creators: name: de Gasperin, F.
name: Edler, H. W.
name: Williams, W. L.
name: Callingham, J. R.
name: Asabere, B.
name: Bruggen, M.
name: Brunetti, G.
name: Dijkema, T. J.
name: Hardcastle, M. J.
name: Iacobelli, M.
name: Offringa, A.
name: Norden, M. J.
name: Rottgering, H. J. A.
name: Shimwell, T.
name: van Weeren, R. J.
name: Tasse, C.
name: Bomans, D. J.
name: Bonafede, A.
name: Botteon, A.
name: Cassano, R.
name: Chyzy, K. T.
name: Cuciti, V.
name: Emig, K. L.
name: Kadler, M.
name: Miley, G.
name: Mingo, B.
name: Oei, M. S. S. L.
name: Prandoni, I.
name: Schwarz, D. J.
name: Zarka, P.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: The Low Frequency Array (LOFAR) is the only existing radio interferometer able to observe at ultra-low frequencies (<100 MHz) with high resolution (<15") and high sensitivity (<1 mJy/beam). To exploit these capabilities, the LOFAR Surveys Key Science Project is using the LOFAR Low Band Antenna (LBA) to carry out a sensitive wide-area survey at 41-66 MHz named the LOFAR LBA Sky Survey (LoLSS). LoLSS is covering the whole northern sky above declination 24 deg with a resolution of 15" and a sensitivity of 1-2 mJy/beam (1 sigma) depending on declination, field properties, and observing conditions. Here we present the first data release. An automated pipeline was used to reduce the 95 fields included in this data release. The data reduction procedures developed for this project have general application and are currently being used to process LOFAR LBA interferometric observations. Compared to the preliminary release, direction-dependent errors have been corrected for during the calibration process. This results in a typical sensitivity of 1.55 mJy/beam at the target resolution of 15". The first data release of the LOFAR LBA Sky Survey covers 650 sqdeg in the HETDEX spring field. The resultant data products released to the community include mosaic images (I and V Stokes) of the region, and a catalogue of 42463 detected sources and related Gaussian components used to describe sources' morphologies. Separate catalogues for 6 in-band frequencies are also released. The first data release of LoLSS shows that, despite the influences of the ionosphere, LOFAR can conduct large-scale surveys in the frequency window 42-66 MHz with unprecedentedly high sensitivity and resolution. The data can be used to derive unique information on the low-frequency spectral properties of many thousands of sources with a wide range of applications in extragalactic and galactic astronomy.
description: 20 pages, 22 figures, images and catalogues available at https://www.lofar-surveys.org/lolss.html
Exploring different methods to describe source position variations
Creators: name: Karbon, Maria
name: Belda, Santiago
name: Escapa, Alberto
name: Ferrandiz, Jose Manuel
Publisher: name: Zenodo
Year: 2023
Subjects: VLBI, CRF, EOP, radio source, astrometry

description: The positions of the radio sources in the ICRF3 catalog, representing the newest realization of the Celestial
 Reference Frame (CRF), are given as a time invariant coordinate pair. However, systematic changes of
 source positions at different spacial and temporal scales are well documented. Failing to acknowledge such
 source behavior might lead to a deterioration in the quality of the frame, and thus in all derived variables, e.g.
 the orientation parameters of the Earth (EOP). One approach to overcome these shortcomings is the
 parametrization of source positions, similar to what is applied to the positions of the station.
 We present a feasible approach to parameterize all the source positions observed within the IVS data
 archive and produce a celestial reference frame based thereon, together with a list of consistent defining
 sources. We compare the resulting frame with the conventional ICRF3 as well as the Gaia frame to uncover
 eventual deformations and their origin. Further we examine the resulting EOP and station positions and give
 an evaluation of the precision and accuracy of the parameters.
An In Vitro 3D Model to Evaluate Behaviour of Breast Cancer Cells and Response to Treatment
Creators: name: Azimi, Tayebeh
Publisher: name: University of Westminster
Year: 2019

description: The field of 3D culture models of disease has started to move towards systems that aim to recapitulate the complexity of human tissues. However, despite recent improvements, current 3D systems remain overly simplistic, lacking the biophysical characteristics and diverse structures found in most organs. In this project, the cellular behaviour of breast cancer and their responsiveness to chemotherapeutic agents were evaluated under different 3D cell culture conditions. MDA-MB231 and SKBR3 cells were prepared as spheroids using ultra-low attachment plates and as 'artificial cancer masses' (ACM) by embedding cells in a dense collagen type-I. The ACMs were maintained under flow (150 μL/min) and flow/pressure (550 μL/min, ~19 mmHg) conditions. A significant reduction in cell viability was observed when cancer cells were grown as ACM compared to 2D culture. Cell viability also declined significantly when ACMs were maintained in flow/pressure condition compared to static condition. Similarly, an increase in the expression levels of markers of EMT was observed when cells were cultured as ACM. However, compared to static 3D incorporation of flow and pressure was associated with decreased expression levels of vimentin, HIF1-α, whilst MMP14 expression increased and snail remained unchanged. HER2 levels were increased in SKBR3 when the cells were cultured under flow/pressure (1.5 fold) compared to static condition. Overall, cells cultured as ACMs exhibited reduced responsiveness to doxorubicin compared to those grown in the conventional 2D culture. A decrease sensitivity was also observed in 3D/flow/pressure and 3D/flow compared to 3D/static condition. The results obtained in this study show that cancer cell behaviour and their response to therapeutic agents are affected by different microenvironments. Therefore, a new generation of 3D in vitro models need to be developed as pre-clinical drug testing platforms.
MUSE Deep-Fields: The Lya Luminosity Function in the Hubble Deep Field South at 2.91 < z < 6.64
Creators: name: Drake, Alyssa B.
name: Guiderdoni, Bruno
name: Blaizot, Jeremy
name: Wisotzki, Lutz
name: Herenz, Edmund Christian
name: Garel, Thibault
name: Richard, Johan
name: Bacon, Roland
name: Bina, David
name: Cantalupo, Sebastiano
name: Contini, Thierry
name: Brock, Mark den
name: Hashimoto, Takuya
name: Marino, Raffaella Anna
name: Pello, Roser
name: Schaye, Joop
name: Schmidt, Kasper B.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present the first estimate of the Lyα luminosity function using blind spectroscopy from the Multi Unit Spectroscopic Explorer, MUSE, in the Hubble Deep Field South. Using automatic source-detection software, we assemble a homogeneously-detected sample of 59 Lyα emitters covering a flux range of -18.0 < log10 (F) < -16.3 (erg s^-1 cm^-2), corresponding to luminosities of 41.4 < log10 (L) < 42.8 (erg s^-1). As recent studies have shown, Lyα fluxes can be underestimated by a factor of two or more via traditional methods, and so we undertake a careful assessment of each object's Lyα flux using a curve-of-growth analysis to account for extended emission. We describe our self-consistent method for determining the completeness of the sample, and present an estimate of the global Lyα luminosity function between redshifts 2.91 < z < 6.64 using the 1/Vmax estimator. We find the luminosity function is higher than many number densities reported in the literature by a factor of 2 - 3, although our result is consistent at the 1σ level with most of these studies. Our observed luminosity function is also in good agreement with predictions from semi-analytic models, and shows no evidence for strong evolution between the high- and low-redshift halves of the data. We demonstrate that one's approach to Lyα flux estimation does alter the observed luminosity function, and caution that accurate flux assessments will be crucial in measurements of the faint end slope. This is a pilot study for the Lyα luminosity function in the MUSE deep-fields, to be built on with data from the Hubble Ultra Deep Field which will increase the size of our sample by almost a factor of 10.
description: 13 pages, 8 figures, submitted to MNRAS
CLEAN imaging systematics of M87 radio jet
Creators: name: Pashchenko, I. N.
name: Kravchenko, E. V.
name: Nokhrina, E. E.
name: Nikonov, A. S.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: The spectral index images of the jet in the nearby radio galaxy M87 have previously been shown with Very Long Baseline Interferometric arrays at 2-43 GHz. They exhibit flattening of the spectra at a location of inner (central) spine and toward outer ridges. This could imply optical depth effects, lower energy cutoff or stratification of the emitting particles energy distribution. In this paper we employ simulations of multifrequency VLBI observations of M87 radio jet with various model brightness distributions. CLEAN deconvolution errors produce significant features in the observed images. For intensity images they result in the appearance of the inner ridge line in the intrinsically edge brightened jet models. For spectral index images they flatten the spectra in a series of stripes along the jet. Another bias encountered in our simulations is steepening of the spectra in a low surface brightness jet regions. These types of the imaging artefacts do not depend on the model considered. We propose a methods for the compensation of the systematics using only the observed data.
description: 23 pages, 19 figures. Accepted by MNRAS 2023 May 16. In original form 2022 April 01
Observational constraints on the formation and evolution of the Milky Way nuclear star cluster with Keck and Gemini
Creators: name: Do, Tuan
name: Ghez, Andrea
name: Morris, Mark
name: Lu, Jessica
name: Chappell, Samantha
name: Feldmeier-Krause, Anja
name: Kerzendorf, Wolfgang
name: Martinez, Gregory David
name: Murray, Norm
name: Winsor, Nathan
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Due to its proximity, the Milky Way nuclear star cluster provides us with a wealth of data not available in other galactic nuclei. In particular, with adaptive optics, we can observe the detailed properties of individual stars, which can offer insight into the origin and evolution of the cluster. We summarize work on the central parsec of the Galactic center based on imaging and spectroscopic observations at the Keck and Gemini telescopes. These observations include stellar positions in two dimension and the velocity in three dimensions. Spectroscopic observations also enable measurements of the physical properties of individual stars, such as the spectral type and in some cases the effective temperature, metallicity, and surface gravity. We present a review of our latest measurements of the density profiles and luminosity functions of the young and old stars in this region. These observations show a complex stellar population with a young (4-6 Myr) compact star cluster in the central 0.5 pc embedded in an older and much more massive nuclear star cluster. Surprisingly, the old late-type giants do not show a cusp profile as long been expected from theoretical work. The solution to the missing cusp problem may offer us insight into the dynamical evolution of the cluster. Finally, we also discuss recent work on the metallicity of stars in this region and how they might be used to trace their origin. The nuclear star cluster shows a large variation in metallicity ([M/Fe]). The majority of the stars have higher than solar metallicity, with about 6\% having [M/Fe] $< -0.5$. These observations indicate that the NSC was not built from the globular clusters that we see today. The formation of the nuclear star cluster is more likely from the inward migration of gas originating in the disk of the Milky Way.
description: 9 pages, 5 figures, 2 tables, IAU 322 The Multi-Messenger Astrophysics of the Galactic Centre
CTD2022: Accelerated graph building for particle tracking graph neural nets
Creators: name: Vage, Liv Helen
name: Tapper, Alex
Publisher: name: Zenodo
Year: 2022

description: The CMS experiment is undergoing upgrades that will increase the average pileup from 50 to 140, and eventually 200. The high level trigger at CMS will experience an increase in data size by a factor of five. With current algorithms, this means that almost 50% of the high level trigger time budget is spent on particle track reconstruction. Graph neural nets have shown promise as an alternative algorithm for particle tracking. They are still subject to several constraints, e.g. momentum cuts, or not allowing for missing hits in a track. The graphs also have several orders of magnitude more fake edges than real, causing slow graph building. Alternative ways of building the graphs are explored to address these limitations. Reinforcement learning and seeded graph building are both introduced as potential alternatives. Some preliminary results suggest that reinforcement learning can result in quicker graph building with fewer physics restrictions.
The scalar exotic resonances X(3915), X(3960), X(4140)
Creators: name: Badalian, A. M.
name: Simonov, Yu. A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The scalar resonances $X(3915), X(3960), X(4140)$ are considered as exotic four-quark states: $cq\bar c \bar q, cs\bar c \bar s, cs\bar c\bar s$, while the $X(3863)$ is proved to be the $c\bar c, 2\,^3P_0$ state. The masses and the widths of these resonances are calculated in the framework of the Extended Recoupling Model, where a four-quark system is formed inside the bag and has relatively small size ($\la 1.0$~fm). Then the resonance $X(3915)$ appears due to the transitions: $J/ψω$ into $D^{*+}D^{*-}$ (or $D^{*0}\bar D^{*0})$ and back, while the $X(3960)$ is created due to the transitions $D_s^+D_s^-$ into $J/ψϕ$ and back, and the $X(4140)$ is formed in the transitions $J/ψϕ$ into $D_s^{*+}D_s^{*-}$ and back. The characteristic feature of the recoupling mechanism is that this type of resonances can be predominantly in the $S$-wave decay channels and has $J^P=0^+$. In two-channel case the resonance occurs to be just near the lower threshold, while due to coupling to third channel (like the $c\bar c$ channel) it is shifted up and lies by (20--30)~MeV above the lower threshold. The following masses and widths are calculated: $M(X(3915))=3920$~MeV, $Γ(X(3915))=20$~MeV; $M(X(3960))=3970$~MeV, $Γ(X(3960)=45(5)$~MeV, $M(X(4140))= 4120(20)$~MeV, $Γ(X(4140))=100$~MeV, which are in good agreement with experiment.
description: 16 pages
Viscoelastic nematodynamics
Creators: name: Turzi, Stefano S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Nematic liquid crystals exhibit both crystal-like and fluid-like features. In particular, the propagation of an acoustic wave shows an unexpected occurrence of some of the solid-like features at the hydrodynamic level, namely, the frequency-dependent anisotropy of sound velocity and acoustic attenuation. The non-Newtonian behavior of nematics also emerges from the frequency-dependent viscosity coefficients. To account for these phenomena, we put forward a viscoelastic model of nematic liquid crystals, and we extend our previous theory to fully include the combined effects of compressibility, anisotropic elasticity and dynamic relaxation, at any shear rate. The low-frequency limit agrees with the compressible Ericksen-Leslie theory, while at intermediate frequencies the model correctly captures the relaxation mechanisms underlying finite shear and bulk elastic moduli. We show that there are only four relaxation times allowed by the uniaxial symmetry.
description: 9 pages, 3 figures
$W$-representations of two-matrix models with infinite set of variables
Creators: name: Wang, Lu-Yao
name: Zhu, Yu-Sen
name: Chen, Ying
name: Kang, Bei
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The Hermitian, complex and fermionic two-matrix models with infinite set of variables are constructed. We show that these two-matrix models can be realized by the $W$-representations. In terms of the $W$-representations, we derive the compact expressions of correlators for these two-matrix models.
description: 12 pages
CTD2022: Software Performance of the ATLAS Track Reconstruction for LHC Run 3
Creators: name: Vessella, Makayla
Publisher: name: Zenodo
Year: 2022

description: This poster summarizes the main changes to the ATLAS experiment's Inner Detector track reconstruction software chain in preparation for LHC Run 3 (2022-2024). The work was carried out to ensure that the expected high-activity collisions (with on average 50 simultaneous proton-proton interactions per bunch crossing, pile-up) can be reconstructed promptly using the available computing resources while maintaining good physics performance. Performance figures in terms of CPU consumption for the key components of the reconstruction algorithm chain and their dependence on the pile-up are shown, as well as physics performance figures of preliminary data from Run-3 commissioning. For the design pile-up value of 60 the updated track reconstruction is a factor of 2 faster than the previous version.
Adaptive hp-Refinement for Spectral Elements in Numerical Relativity
Creators: name: Renkhoff, Sarah
name: Cors, Daniela
name: Hilditch, David
name: Brügmann, Bernd
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: When a numerical simulation has to handle a physics problem with a wide range of time-dependent length scales, dynamically adaptive discretizations can be the method of choice. We present a major upgrade to the numerical relativity code bamps in the form of fully adaptive, physics-agnostic hp-refinement. We describe the foundations of mesh refinement in the context of spectral element methods, the precise algorithm used to perform refinement in bamps, as well as several indicator functions used to drive it. Finally, we test the performance, scaling, and the accuracy of the code in treating several 1d and 2d example problems, showing clear improvements over static mesh configurations. In particular, we consider a simple non-linear wave equation, the evolution of a real scalar field minimally coupled to gravity, as well as nonlinear gravitational waves.
description: 19 pages, 17 figures
What Massive Open Online Course (MOOC) Stakeholders Can Learn From Learning Analytics?
Creators: name: Khalil, Mohammad
name: Ebner, Martin
Publisher: name: arXiv
Year: 2016
Subjects: subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences

description: Massive Open Online Courses (MOOCs) are the road that led to a revolution and a new era of learning environments. Educational institutions have come under pressure to adopt new models that assure openness in their education distribution. Nonetheless, there is still altercation about the pedagogical approach and the absolute information delivery to the students. On the other side with the use of Learning Analytics, powerful tools become available which mainly aim to enhance learning and improve learners performance. In this chapter, the development phases of a Learning Analytics prototype and the experiment of integrating it into a MOOC platform, called iMooX will be presented. This chapter explores how MOOC Stakeholders may benefit from Learning Analytics as well as it reports an exploratory analysis of some of the offered courses and demonstrate use cases as a typical evaluation of this prototype in order to discover hidden patterns, overture future proper decisions and to optimize learning with applicable and convenient interventions.
description: Learning, Design, and Technology, Springer International Publishing. (pp. 1-30) (2016)
D7.1 – TREX Branding and communication kit
Creators: name: Schillaci, Andrea
Publisher: name: Zenodo
Year: 2020
Subjects: QMC
Branding and communication kit

description: This document is therefore intended to report about the TREX Branding and Communication Kit, one of the first online tools developed to pursue an optimal development of the TREX brand and visual identity and to start spreading project recognition among relevant stakeholder groups while unifying the style of the communication revolving around the project. While Chapter 1 of this document is intended to give a brief overview of the rationale behind adopting a communication kit inside a project like TREX, in Chapter 2, each section will present one of the items of the final Communication Kit, focusing on their specificities and features. Examples from the current version of the tool are provided in form of screenshots and references have been added for further information. The conclusions are drawn in Chapter 3.
Trap-Integrated Superconducting Nanowire Single-Photon Detectors with Improved RF Tolerance for Trapped-Ion Qubit State Readout
Creators: name: Hampel, Benedikt
name: Slichter, Daniel H.
name: Leibfried, Dietrich
name: Mirin, Richard P.
name: Nam, Sae Woo
name: Verma, Varun B.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: Superconductivity (cond-mat.supr-con)
subject: Applied Physics (physics.app-ph)
subject: Atomic Physics (physics.atom-ph)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: State readout of trapped-ion qubits with trap-integrated detectors can address important challenges for scalable quantum computing, but the strong rf electric fields used for trapping can impact detector performance. Here, we report on NbTiN superconducting nanowire single-photon detectors (SNSPDs) employing grounded aluminum mirrors as electrical shielding that are integrated into linear surface-electrode rf ion traps. The shielded SNSPDs can be successfully operated at applied rf trapping potentials of up to $\mathrm{54\,V_{peak}}$ at $\mathrm{70\,MHz}$ and temperatures of up to $\mathrm{6\,K}$, with a maximum system detection efficiency of $\mathrm{68\,\%}$. This performance should be sufficient to enable parallel high-fidelity state readout of a wide range of trapped ion species in typical cryogenic apparatus.
description: 6 pages, 4 figures. The following article has been submitted to Applied Physics Letters
Effects of orientational and positional randomness of particles on photonic band gap
Creators: name: Qin, Zichen
name: Liu, Tao
name: Wan, Duanduan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: A recent work [PRL, 126, 208002 (2021)] has explored how thermal noise-induced randomness in a self-assembled photonic crystal affects photonic band gaps (PBGs). For the system of a two-dimensional photonic crystal composed of a self-assembled array of rods with square cross sections, it was found that its PBGs can exist over an extensive range of packing densities. Counterintuitively, at intermediate packing densities, the transverse magnetic (TM) band gap of the self-assembled system can be larger than that of its corresponding perfect system (rods arranged in a perfect square lattice and having identical orientations). Due to shape anisotropicity, the randomness in the self-assembled system contains two kinds of randomness, i.e., positional and orientational randomness of the particles. In this work, we further investigate how PBGs are influenced solely by positional or orientational randomness. We find that compared to the perfect situation, the introduction of only orientational randomness decreases the transverse electric (TE) band gap while having no obvious effects on the transverse magnetic (TM) band gap. In contrast, the introduction of only positional randomness decreases the TE band gap significantly, while it can widen or narrow the TM band gap, depending on the parameter range. We also discuss the thermal (i.e., self-assembled) system where two kinds of randomness are present. Our study contributes to a better understanding of the role orientational randomness and positional randomness play on PBGs, and may benefit the PBG engineering of photonic crystals through self-assembly approaches.
A q-analog of Schläfli and Gould identities on Stirling numbers
Creators: name: Josuat-Vergès, Matthieu
Publisher: name: arXiv
Year: 2016
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics

description: Stirling numbers of both kinds are linked to each other via two combinatorial identities due to Schläfli and Gould. Using q-analogs of Stirling numbers defined as inversion generating functions, we provide q-analogs of the two identities. The proof is computational and we leave open the problem of finding a more combinatorial one.
Allothymoites kumadai Ono 2007
Creators: name: Gao, Cai-Xia
name: Li, Shu-Qiang
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Theridiidae
Allothymoites
Allothymoites kumadai

description: Allothymoites kumadai Ono, 2007 Allothymoites kumadai Ono, 2007: 162, figs 32–44. Material examined. China, Yunnan, 4♂, 1♀, Xishuangbanna, Menglun Nature Reserve, tropical evergreen rainforest (21º56.206'N, 101º16.204'E), 1 December 2009, Guo Tang and Zhi-Yuan Yao leg. Distribution. China (Yunnan); Japan.
description: Published as part of Gao, Cai-Xia & Li, Shu-Qiang, 2014, Comb-footed spiders (Araneae: Theridiidae) in the tropical rainforest of Xishuangbanna, Southwest China, pp. 1-135 in Zoological Systematics 39 (1) on page 2, DOI: 10.11865/zs20140101, http://zenodo.org/record/7475365
CTD2022: Optimizing the Exa.TrkX Inference Pipeline for Manycore CPUs
Creators: name: Lazar, Alina
name: Acharya, Nirajan
name: Liu, Emma
name: Lucas, Alberto
Publisher: name: Zenodo
Year: 2022

description: The reconstruction of charged particle trajectories is an essential component of high energy physics experiments. Recently proposed pipelines for track finding, built based on the Graph Neural Networks (GNNs), provide high reconstruction accuracy, but need to be optimized, in terms of speed, especially for online event filtering. Like other deep learning implementations, both the training and inference of particle tracking methods can be optimized to fully benefit from the GPU's parallelism ability. However, the inference of particle reconstruction could also benefit from multicore parallel processing on CPUs. In this context, it is imperative to explore the impact of the number of cores of a CPU on the speed related performance of running inference. Using PyTorch and Facebook AI Similarity Search (Faiss) library multiple CPU threads capability, multiprocessing for the filtering inference loop and the weakly connected components algorithm for labeling results in faster latency times for the inference pipeline. This tracking pipeline based on the Graph Neural Networks (GNNs) is evaluated on multi-core Intel Xeon Gold 6148s Skylake and Intel Xeon 8268s Cascade Lake CPUs. Computational time is measured and compared using different numbers of cores per task. The experiments show that the multi-core parallel execution outperforms the sequential one.
Pauli-Villars' regularization of ghosts in path-integral string formulation
Creators: name: Makeenko, Yuri
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: I consider Pauli-Villars' regulators for the ghosts in the path-integral string formulation and show how they preserve conformal invariance. I calculate the regulator contributions to the effective action and to the central charge and demonstrate the consistency of the mean-field quantization of the Nambu-Goto string in $2
description: 13 pages, 2 figures; v2: Appendix added; v3: to appear in JHEP
Metallic, Magnetic and Molecular Nanocontacts
Creators: name: Requist, Ryan
name: Baruselli, Pier Paolo
name: Smogunov, Alexander
name: Fabrizio, Michele
name: Modesti, Silvio
name: Tosatti, Erio
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Scanning tunnelling microscopy and break-junction experiments realize metallic and molecular nanocontacts that act as ideal one-dimensional channels between macroscopic electrodes. Emergent nanoscale phenomena typical of these systems encompass structural, mechanical, electronic, transport, and magnetic properties. This Review focuses on the theoretical explanation of some of these properties obtained with the help of first-principles methods. By tracing parallel theoretical and experimental developments from the discovery of nanowire formation and conductance quantization in gold nanowires to recent observations of emergent magnetism and Kondo correlations, we exemplify the main concepts and ingredients needed to bring together ab initio calculations and physical observations. It can be anticipated that diode, sensor, spin-valve and spin-filter functionalities relevant for spintronics and molecular electronics applications will benefit from the physical understanding thus obtained.
The Art of Un-belonging
Creators: name: Sozen, Deniz
Publisher: name: University of Westminster
Year: 2019

description: This practice-based research sets out to explore artistic strategies that destabilise fixed notions of belonging and identity in the context of globalisation and diasporic art. Drawing on Glissant’s concept of Relation ([1990], 1997) in combination with feminist and new materialist theories (Braidotti, Haraway) and an “anthropology beyond the human” (Kohn, 2013), the research challenges a dualistic conception of self/Other and contributes to the decolonisation of contemporary art by opening and reinscribing the concept of belonging and identity beyond the human. The practice element consists of three discrete yet interrelated artworks that challenge an ethnocentric and anthropocentric conception of belonging. The multilingual video-performance Surya Namaz (2018) is a personal investigation of yoga and namaz, the Muslim prayer ritual, exploring the potential of transcultural performance, opacity and multilingualism to undo fixed notions of belonging. Kahvehane Kongresspark (2016), a temporary café, ceramic cups/saucers and a site-specific performance in public space and Trans Plantations (2018), an installation of cups/saucers and coffee beans cast in porcelain in combination with an audio-visual element, are concerned with the colonial history and human entanglements with coffee, taking the exploration of belonging beyond the anthropocentric. The written thesis is composed of three chapters. Chapter 1 contextualises the research by providing a brief overview on the globalisation of art and introduces Glissant’s theory of Relation as guiding framework of the thesis. This part also reflects on feminist art and theory’s relevance for current discourses concerned with belonging and identity, exploring the potential of feminist strategies for the complication of binary thinking. The subsequent chapters are guided by and complement the practice element of the thesis through ways of critical analysis and performative writing, addressing questions posed by the practice in addition to case studies of contemporary artworks. Based on the conception of identity as relational, the research argues that Relation is central to the re-thinking of belonging and identity.
Fine structure of the age-chromospheric activity relation in solar-type stars I: The Ca II infrared triplet: Absolute flux calibration
Creators: name: Lorenzo-Oliveira, Diego
name: de Mello, Gustavo F. Porto
name: Dutra-Ferreira, Letícia
name: Ribas, Ignasi
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Strong spectral lines are useful indicators of stellar chromospheric activity. They are physically linked to the convection efficiency, differential rotation, and angular momentum evolution and are a potential indicator of age. However, for ages > 2 Gyr, the age-activity relationship remains poorly constrained thus hampering its full application. The Ca II infrared triplet (IRT lines) has been poorly studied compared to classical chromospheric indicators. We report in this paper absolute chromospheric fluxes in the three Ca II IRT lines, based on a new calibration tied to up-to-date model atmospheres. We obtain the Ca II IRT absolute fluxes for 113 FGK stars from high signal-to-noise ratio and high-resolution spectra covering an extensive domain of chromospheric activity levels. We perform an absolute continuum flux calibration for the Ca II IRT lines anchored in atmospheric models calculated as an explicit function of effective temperatures, metallicity, and gravities avoiding the degeneracy present in photometric continuum calibrations based solely on color indices. The internal uncertainties achieved for continuum absolute flux calculations are 2\% of the solar chromospheric flux, one order of magnitude lower than photometric calibrations. We gauge the impact of observational errors on the final chromospheric fluxes due to the absolute continuum flux calibration and find that $T_{\rm eff}$ uncertainties are properly mitigated by the photospheric correction leaving [Fe/H] as the dominating factor in the chromospheric flux uncertainty. Across the FGK spectral types, the Ca II IRT lines are sensitive to chromospheric activity. The reduced internal uncertainties reported here enable us to build a new chromospheric absolute flux scale and explore the age-activity relation from the active regime down to very low activity levels and a wide range of $T_{\rm eff}$, mass, [Fe/H], and age.
description: 12 pages, 12 figures, 6 tables, Accepted for publication on A&A. Abstract edited to comply with arXiv standards regarding the number of characters
Ideograms for Physics and Chemistry
Creators: name: García-Risueño, Pablo
name: Syropoulos, Apostolos
name: Verges, Natalia
Publisher: name: arXiv
Year: 2016
Subjects: subject: Physics Education (physics.ed-ph)
subject: FOS: Physical sciences

description: Ideograms (symbols that represent a word or idea) have great communicative value. They refer to concepts in a simple manner, easing the understanding of related ideas. Moreover, ideograms can simplify the often cumbersome notation used in the fields of Physics and physical Chemistry. Nonetheless only a few specific ideograms for these fields have been defined to date. In this work we propose that the scientific community follows the example of Mathematics -as well as that of oriental languages- and bestows a more important role upon ideograms. To support this thesis we propose ideograms for essential concepts in Physics and Chemistry. They are designed to be intuitive, and their goal is to make equations easier to read and understand. Our symbols are included in a publicly available Latex package (svrsymbols).
description: letter, 12 pages
Stellar Populations in the Central 0.5 pc of Our Galaxy III: The Dynamical Sub-structures
Creators: name: Jia, Siyao
name: Xu, Ningyuan
name: Lu, Jessica R.
name: Chu, D. S
name: O'Neil, K. Kosmo
name: Drechsler, W. B.
name: Hosek, M. W.
name: Sakai, S.
name: Do, T.
name: Ciurlo, A.
name: Gautam, A. K.
name: Ghez, A. M.
name: Becklin, E.
name: Morris, M. R.
name: Bentley, R. O.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We measure the 3D kinematic structures of the young stars within the central 0.5 parsec of our Galactic Center using the 10 m telescopes of the W.~M.~Keck Observatory over a time span of 25 years. Using high-precision measurements of positions on the sky, and proper motions and radial velocities from new observations and the literature, we constrain the orbital parameters for each young star. Our results show two statistically significant sub-structures: a clockwise stellar disk with 18 candidate stars, as has been proposed before, but with an improved disk membership; a second, almost edge-on plane of 10 candidate stars oriented East-West on the sky that includes at least one IRS 13 star. We estimate the eccentricity distribution of each sub-structure and find that the clockwise disk has <$e$> = 0.39 and the edge-on plane has <$e$> = 0.68. We also perform simulations of each disk/plane with incompleteness and spatially-variable extinction to search for asymmetry. Our results show that the clockwise stellar disk is consistent with a uniform azimuthal distribution within the disk. The edge-on plane has an asymmetry that cannot be explained by variable extinction or incompleteness in the field. The orientation, asymmetric stellar distribution, and high eccentricity of the edge-on plane members suggest that this structure may be a stream associated with the IRS 13 group. The complex dynamical structure of the young nuclear cluster indicates that the star formation process involved complex gas structures and dynamics and is inconsistent with a single massive gaseous disk.
description: 41 pages, 26 figures, 13 tables, 2 appendices. Accepted for publication in ApJ
CTD2022: Linearized Track-Fitting on an FPGA
Creators: name: Zinsser, Joachim
name: Dittmeier, Sebastian
name: Schoening, Andre
Publisher: name: Zenodo
Year: 2022

description: For the ATLAS experiment at the High-Luminosity LHC, a hardware-based track-trigger was originally envisioned, which performs pattern recognition via AM ASICs and track fitting on an FPGA. A linearized track fitting algorithm is implemented in the Track-Fitter that receives track candidates as well as corresponding fit-constants from a database and performs the $\chi^2$-test of the track as well as calculates the helix-parameters. A prototype of the Track-Fitter has been set-up on a Intel Stratix 10 FPGA. Its firmware was tested in simulation-studies and verified on the hardware. The performance of the Track-Fitter has been evaluated in extensive > simulation studies and these results will be presented in this talk.
Best Proximity Point Theorems for Asymptotically Relatively Nonexpansive Mappings
Creators: name: Rajesh, S.
name: Veeramani, P.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 47H09, 47H10

description: Let $(A, B)$ be a nonempty bounded closed convex proximal parallel pair in a nearly uniformly convex Banach space and $T: A\cup B \rightarrow A\cup B$ be a continuous and asymptotically relatively nonexpansive map. We prove that there exists $x \in A\cup B$ such that $\|x - Tx\| = \emph{dist}(A, B)$ whenever $T(A) \subseteq B$, $T(B) \subseteq A$. Also, we establish that if $T(A) \subseteq A$ and $T(B) \subseteq B$, then there exist $x \in A$ and $y\in B$ such that $Tx = x$, $Ty = y$ and $\|x - y\| = \emph{dist}(A, B)$. We prove the aforesaid results when the pair $(A, B)$ has the rectangle property and property $UC$. In case of $A = B$, we obtain, as a particular case of our results, the basic fixed point theorem for asymptotically nonexpansive maps by Goebel and Kirk.