cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Quantum Simulation of Chiral Phase Transitions
Creators: name: Czajka, Alexander M.
name: Kang, Zhong-Bo
name: Ma, Henry
name: Zhao, Fanyi
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Lattice (hep-lat)
subject: Nuclear Theory (nucl-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The Nambu-Jona-Lasinio (NJL) model has been widely studied for investigating the chiral phase structure of strongly interacting matter. The study of the thermodynamics of field theories within the framework of Lattice Field Theory is limited by the sign problem, which prevents Monte Carlo evaluation of the functional integral at a finite chemical potential. Using the quantum imaginary time evolution (QITE) algorithm, we construct a quantum simulation for the $(1+1)$ dimensional NJL model at finite temperature and finite chemical potential. We observe consistency among digital quantum simulation, exact diagonalization, and analytical solution, indicating further applications of quantum computing in simulating QCD thermodynamics.
description: 25 pages, 6 figures, published version
Aligning Goals for Certification and Professional Growth: Building Cooperation Among Bachelor of Education Programs in Alberta
Creators: name: Burns, Amy
name: Danyluk, Patricia
name: Nickel, Jodi
name: Kendrick, Astrid
name: Kapoyannis, Theodora
name: McNeilly, Elizabeth
Publisher: name: Alberta Journal of Educational Research
Year: 2022

description: This article chronicles a provincial collaboration between ten Bachelor of Education degree-granting universities in Alberta, Canada. This collaboration focused on the newly implemented Teaching Quality Standard (2018) in Alberta and its impact on preservice teacher practicums. Data were collected through curriculum mapping and interviews at each institution. Each institution analyzed their own data and shared themes at a number of group meetings. Two common themes arose: (a) the interconnectedness of practicum and teacher education courses and (b) the role of the Teaching Quality Standard as a development tool within practicum. Key words: teacher education, practicum, teaching quality standard, postsecondary collaboration Cet article relate une collaboration provinciale entre dix universités de l'Alberta, au Canada, qui décernent des baccalauréats en éducation. Cette collaboration s'est concentrée sur la nouvelle norme de qualité de l'enseignement (2018) en Alberta et son impact sur les stages des enseignants en formation initiale. Les données ont été recueillies par le biais de la cartographie des programmes d'études et d'entretiens dans chaque établissement. Chaque établissement a analysé ses propres données et a partagé les thèmes lors de plusieurs réunions de groupe. Deux thèmes communs sont apparus : (a) l'interconnexion des stages et des cours de formation des enseignants et (b) le rôle de la norme de qualité de l'enseignement comme outil de développement dans le cadre des stages. Mots clés: formation des enseignants, stage, norme de qualité de l'enseignement, collaboration postsecondaire
description: Alberta Journal of Educational Research, Vol. 68 No. 1 (2022): Spring
Computing with B-series
Creators: name: Ketcheson, David I.
name: Ranocha, Hendrik
Publisher: name: arXiv
Year: 2021
Subjects: subject: Numerical Analysis (math.NA)
subject: Mathematical Software (cs.MS)
subject: Symbolic Computation (cs.SC)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences

description: We present BSeries.jl, a Julia package for the computation and manipulation of B-series, which are a versatile theoretical tool for understanding and designing discretizations of differential equations. We give a short introduction to the theory of B-series and associated concepts and provide examples of their use, including method composition and backward error analysis. The associated software is highly performant and makes it possible to work with B-series of high order.
Fano resonance in Raman scattering of graphene
Creators: name: Yoon, Duhee
name: Jeong, Dongchan
name: Lee, Hu-Jong
name: Saito, Riichiro
name: Son, Young-Woo
name: Lee, Hyun Cheol
name: Cheong, Hyeonsik
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Fano resonances and their strong doping dependence are observed in Raman scattering of single-layer graphene (SLG). As the Fermi level is varied by a back-gate bias, the Raman G band of SLG exhibits an asymmetric line shape near the charge neutrality point as a manifestation of a Fano resonance, whereas the line shape is symmetric when the graphene sample is electron or hole doped. However, the G band of bilayer graphene (BLG) does not exhibit any Fano resonance regardless of doping. The observed Fano resonance can be interpreted as interferences between the phonon and excitonic many-body spectra in SLG. The absence of a Fano resonance in the Raman G band of BLG can be explained in the same framework since excitonic interactions are not expected in BLG.
description: 18 pages, 3 figures, to appear in Carbon
Optimal Thresholds for Fracton Codes and Random Spin Models with Subsystem Symmetry
Creators: name: Song, Hao
name: Schönmeier-Kromer, Janik
name: Liu, Ke
name: Viyuela, Oscar
name: Pollet, Lode
name: Martin-Delgado, M. A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Fracton models provide examples of novel gapped quantum phases of matter that host intrinsically immobile excitations and therefore lie beyond the conventional notion of topological order. Here, we calculate optimal error thresholds for quantum error correcting codes based on fracton models. By mapping the error-correction process for bit-flip and phase-flip noises into novel statistical models with Ising variables and random multi-body couplings, we obtain models that exhibit an unconventional subsystem symmetry instead of a more usual global symmetry. We perform large-scale parallel tempering Monte Carlo simulations to obtain disorder-temperature phase diagrams, which are then used to predict optimal error thresholds for the corresponding fracton code. Remarkably, we found that the X-cube fracton code displays a minimum error threshold ($7.5\%$) that is much higher than 3D topological codes such as the toric code ($3.3\%$), or the color code ($1.9\%$). This result, together with the predicted absence of glass order at the Nishimori line, shows great potential for fracton phases to be used as quantum memory platforms.
description: 6+10 pages, 4+4 figures, Fig 1 selected for PRL cover. v2: minor changes to introduction, more quantum error correction details added to supplementary materials, typos corrected, published version
A Novel Tropical Geometry-based Interpretable Machine Learning Method: Application in Prognosis of Advanced Heart Failure
Creators: name: Yao, Heming
name: Derksen, Harm
name: Golbus, Jessica R.
name: Zhang, Justin
name: Aaronson, Keith D.
name: Gryak, Jonathan
name: Najarian, Kayvan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: A model's interpretability is essential to many practical applications such as clinical decision support systems. In this paper, a novel interpretable machine learning method is presented, which can model the relationship between input variables and responses in humanly understandable rules. The method is built by applying tropical geometry to fuzzy inference systems, wherein variable encoding functions and salient rules can be discovered by supervised learning. Experiments using synthetic datasets were conducted to investigate the performance and capacity of the proposed algorithm in classification and rule discovery. Furthermore, the proposed method was applied to a clinical application that identified heart failure patients that would benefit from advanced therapies such as heart transplant or durable mechanical circulatory support. Experimental results show that the proposed network achieved great performance on the classification tasks. In addition to learning humanly understandable rules from the dataset, existing fuzzy domain knowledge can be easily transferred into the network and used to facilitate model training. From our results, the proposed model and the ability of learning existing domain knowledge can significantly improve the model generalizability. The characteristics of the proposed network make it promising in applications requiring model reliability and justification.
Entanglement phase transition with spin glass criticality
Creators: name: Côté, Jeremy
name: Kourtis, Stefanos
Publisher: name: arXiv
Year: 2021
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We define an ensemble of random Clifford quantum circuits whose output state undergoes an entanglement phase transition between two volume-law phases as a function of measurement rate. Our setup maps exactly the output state to the ground space of a spin glass model. We identify the entanglement phases using an order parameter that is accessible on a quantum chip. We locate the transition point and evaluate a critical exponent, revealing spin glass criticality. Our work establishes an exact statistical mechanics theory of an entanglement phase transition.
description: Updated to reflect published version
Metastability in a stochastic neural network modeled as a velocity jump Markov process
Creators: name: Bressloff, Paul C.
name: Newby, Jay M.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: One of the major challenges in neuroscience is to determine how noise that is present at the molecular and cellular levels affects dynamics and information processing at the macroscopic level of synaptically coupled neuronal populations. Often noise is incorprated into deterministic network models using extrinsic noise sources. An alternative approach is to assume that noise arises intrinsically as a collective population effect, which has led to a master equation formulation of stochastic neural networks. In this paper we extend the master equation formulation by introducing a stochastic model of neural population dynamics in the form of a velocity jump Markov process. The latter has the advantage of keeping track of synaptic processing as well as spiking activity, and reduces to the neural master equation in a particular limit. The population synaptic variables evolve according to piecewise deterministic dynamics, which depends on population spiking activity. The latter is characterised by a set of discrete stochastic variables evolving according to a jump Markov process, with transition rates that depend on the synaptic variables. We consider the particular problem of rare transitions between metastable states of a network operating in a bistable regime in the deterministic limit. Assuming that the synaptic dynamics is much slower than the transitions between discrete spiking states, we use a WKB approximation and singular perturbation theory to determine the mean first passage time to cross the separatrix between the two metastable states. Such an analysis can also be applied to other velocity jump Markov processes, including stochastic voltage-gated ion channels and stochastic gene networks.
GRB 130606A as a Probe of the Intergalactic Medium and the Interstellar Medium in a Star-forming Galaxy in the First Gyr After the Big Bang
Creators: name: Chornock, Ryan
name: Berger, Edo
name: Fox, Derek B.
name: Lunnan, Ragnhild
name: Drout, Maria R.
name: Fong, Wen-fai
name: Laskar, Tanmoy
name: Roth, Katherine C.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We present high signal-to-noise ratio Gemini and MMT spectroscopy of the optical afterglow of the gamma-ray burst (GRB) 130606A at redshift z=5.913, discovered by Swift. This is the first high-redshift GRB afterglow to have spectra of comparable quality to those of z~6 quasars. The data exhibit a smooth continuum at near-infrared wavelengths that is sharply cut off blueward of 8410 Angs due to absorption from Ly-alpha at redshift z~5.91, with some flux transmitted through the Ly-alpha forest between 7000-7800 Angs. We use column densities inferred from metal absorption lines to constrain the metallicity of the host galaxy between a lower limit of [Si/H]>-1.7 and an upper limit of [S/H] 6.4). This is comparable to the lowest-redshift Gunn-Peterson troughs found in quasar spectra. We set a 2-sigma upper limit of 0.11 on the neutral fraction of the IGM at the redshift of the GRB from the lack of a Ly-alpha red damping wing, assuming a model with a constant neutral density. Some Ly-beta and Ly-gamma transmission is detected in this redshift window, indicating that it is not completely opaque, and hence that the IGM is nonetheless mostly ionized at these redshifts. GRB 130606A thus for the first time realizes the promise of GRBs as probes of the first galaxies and cosmic reionization.
description: Minor revisions to match version accepted by ApJ. 11 pages, 8 figures, 2 tables
Goal Orientation and Learning Readiness: Evidence Among Freshmen in Selected Kenyan Universities
Creators: name: Mose, Evelyne Kwamboka
name: Aloka, Peter JO
name: Mwebi, Benard
Publisher: name: Alberta Journal of Educational Research
Year: 2022

description: This study, which adopted an ex post facto research design, investigated the relationship between goal orientation and learning readiness among first year students in three public universities in Kenya. A sample size of 372 first years from the three universities were obtained using both stratified and simple random sampling techniques. The Goal Questionnaire for Students (GQS) and the Learning Readiness Questionnaire (LRQ) were used to collect data. The findings reported Eta squared (.547) which implied that a fairly large proportion (54.7%) of variance in he learning readiness index among the first year students is explained by goal orientation of the students. Results from the study determined that universities should emphasize techniques of performance approach in their guidance programs. Key words: Goal Orientation, Learning Readiness, first year, students, universities, Kenya Cette étude, qui a adopté une conception de recherche ex post facto, a examiné la relation entre l'orientation vers un objectif et la préparation à l'apprentissage chez les étudiants de première année dans trois universités publiques du Kenya. Un échantillon de 372 étudiants de première année des trois universités a été obtenu en utilisant des techniques d'échantillonnage aléatoire simple et stratifié. Le Goal Questionnaire for Students (GQS) et le Learning Readiness Questionnaire (LRQ) ont été utilisés pour collecter les données. Les résultats font état d'un coefficient Eta carré (.547) qui implique qu'une proportion assez importante (54,7%) de la variance de l'indice de préparation à l'apprentissage chez les étudiants de première année s’explique par l'orientation des objectifs des étudiants. Les résultats de l'étude ont déterminé que les universités devraient mettre l'accent sur les techniques d'approche de la performance dans leurs programmes d'orientation. Mots clés: orientation vers un but, préparation à l'apprentissage, première année, étudiants, universités, Kenya
description: Alberta Journal of Educational Research, Vol. 68 No. 1 (2022): Spring
Dynamical metasurfaces: electromagnetic properties and instabilities
Creators: name: Oue, Daigo
Publisher: name: Imperial College London
Year: 2021

description: In this thesis, I analyse the electromagnetic properties of dynamical metasurfaces and find two critical phenomena. The first is the Casimir-induced instability of a deformable metallic film. In general, two charge-neutral interfaces attract with or repel each other due to the contribution from the zero-point fluctuation of the electromagnetic field between them, namely, the Casimir effect. The effects of perturbative interface corrugation on the Casimir energy in the film system is studied by the proximity force approximation with dispersion correction. If the corrugation period exceeds a critical value, the Casimir effect dominates the surface tension and brings about structural instability. The second is Čerenkov radiation in the vacuum from a time-varying, corrugated surface. Travelling faster than light brings about electromagnetic shock waves, Čerenkov radiation. Since light is the fastest object in a vacuum, it has been considered that Čerenkov radiation is emitted only in the presence of some refractive index. Here, I propose mimicking a series of particles travelling faster than light in a vacuum by dynamical surface corrugation to find Čerenkov radiation in a vacuum from the surface. The dynamical corrugation induces an effective current source on the surface with an external electrostatic field applied. When the corrugation profile is of travelling wave type, the source can be regarded as a series of dipoles virtually travelling along the surface. If the phase velocity of the travelling wave profile exceeds the speed of light, and so do the dipoles, they emit Čerenkov radiation in a vacuum.
Machine Learning-based Prediction of Porosity for Concrete Containing Supplementary Cementitious Materials
Creators: name: Cao, Chong
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Computational Engineering, Finance, and Science (cs.CE)
subject: FOS: Computer and information sciences

description: Porosity has been identified as the key indicator of the durability properties of concrete exposed to aggressive environments. This paper applies ensemble learning to predict porosity of high-performance concrete containing supplementary cementitious materials. The concrete samples utilized in this study are characterized by eight composition features including w/b ratio, binder content, fly ash, GGBS, superplasticizer, coarse/fine aggregate ratio, curing condition and curing days. The assembled database consists of 240 data records, featuring 74 unique concrete mixture designs. The proposed machine learning algorithms are trained on 180 observations (75%) chosen randomly from the data set and then tested on the remaining 60 observations (25%). The numerical experiments suggest that the regression tree ensembles can accurately predict the porosity of concrete from its mixture compositions. Gradient boosting trees generally outperforms random forests in terms of prediction accuracy. For random forests, the out-of-bag error based hyperparameter tuning strategy is found to be much more efficient than k-Fold Cross-Validation.
Two-particle entanglement in capacitively coupled Mach-Zehnder interferometers
Creators: name: Vyshnevyy, A. A.
name: Lebedev, A. V.
name: Lesovik, G. B.
name: Blatter, G.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We propose and analyze a mesoscopic device producing on-demand entangled pairs of electrons. The system consists of two capacitively coupled Mach-Zehnder interferometers implemented in a quantum Hall structure. A pair of electron wave-packets is injected into the chiral edge states of two (of the four) incoming arms; scattering on the incoming interferometers splits the wave-packets into four components of which two interact. The resulting interaction phase associated with this component leads to the entanglement of the state; the latter is scattered at the outgoing beam splitter and analyzed in a Bell violation test measuring the presence of particles in the four outgoing leads. We study the two-particle case and determine the conditions to reach and observe full entanglement. We extend our two-particle analysis to include the underlying Fermi seas in the quantum Hall device; the change in shape of the wave-function, the generation of electron-hole pairs in the interaction regime, and a time delay between the pulses all reduce the degree of visible entanglement and the violation of the Bell inequality, effects which we analyze quantitatively. We determine the device settings optimizing the entanglement and the Bell test and find that violation is still possible in the presence of the Fermi seas, with a maximal Bell parameter reaching ${\cal B} = 2.18 > 2$ in our setup.
description: 14 pages, 8 figures
Main Sequence Star Populations in the Virgo Overdensity Region
Creators: name: Jerjen, H.
name: Da Costa, G. S.
name: Willman, B.
name: Tisserand, P.
name: Arimoto, N.
name: Okamoto, S.
name: Mateo, M.
name: Saviane, I.
name: Walsh, S.
name: Geha, M.
name: Jordán, A.
name: Olszewski, E.
name: Walker, M.
name: Zoccali, M.
name: Kroupa, P.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present deep CMDs for two Subaru Suprime-Cam fields in the Virgo Stellar Stream(VSS)/Virgo Overdensity(VOD) and compare them to a field centred on the highest concentration of Sagittarius (Sgr) Tidal Stream stars in the leading arm, Branch A of the bifurcation. A prominent population of MS stars is detected in all three fields and can be traced as faint as g~24 mag. Using theoretical isochrone fitting we derive an age of 9.1(+1.0;-1.1)Gyr, a median abundance of [Fe/H]=-0.70 (+0.15; -0.20)dex and d_helio of 30.9+-3.0kpc for the MS of the Sgr Stream Branch A. The dominant main sequence populations in the two VSS/VOD fields (Lsun ~265 deg, Bsun ~13 deg) are located at a mean distance of 23.3+-1.6kpc and have an age ~8.2Gyr and an abundance [Fe/H]=-0.67(+0.16;-0.12)dex similar to the Sgr Stream stars. These parameters are also in good agreement with the age of the main population in the Sagittarius dwarf (8.0+-1.5Gyr). They also agree with the peak in the metallicity distribution of 2-3Gyr old M-giants, [Fe/H] ~ -0.6dex, in the Sgr leading arm north. We then compare the results from the VSS/VOD fields with the Sgr Tidal Stream model by Law & Majewski based on a triaxial Galactic halo that is calibrated with SDSS Sgr A-branch and 2MASS M-giant stars. We find that the most prominent feature in the CMDs, the MS population at 23kpc, is not explained by the model. Instead the model predicts in these directions a low density filamentary structure of Sgr debris stars at ~9kpc and a slightly higher concentration of Sgr stars spread from 42-53kpc. At best there is only marginal evidence for the presence of these populations in our data. Our findings then suggest that while there are probably some Sgr debris stars present, the dominant stellar population in the VOD originates from a different halo structure that has almost identical age and metallicity as some sections of the Sgr tidal stream.
description: 11 pages, 8 figures, 5 tables, accepted for publication in ApJ
Dynamical metasurfaces: electromagnetic properties and instabilities
Creators: name: Oue, Daigo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: In this thesis, I analyse the electromagnetic properties of dynamical metasurfaces and find two critical phenomena. The first is the Casimir-induced instability of a deformable metallic film. In general, two charge-neutral interfaces attract with or repel each other due to the contribution from the zero-point fluctuation of the electromagnetic field between them, namely, the Casimir effect. The effects of perturbative interface corrugation on the Casimir energy in the film system is studied by the proximity force approximation with dispersion correction. If the corrugation period exceeds a critical value, the Casimir effect dominates the surface tension and brings about structural instability. The second is Čerenkov radiation in the vacuum from a time-varying, corrugated surface. Travelling faster than light brings about electromagnetic shock waves, Čerenkov radiation. Since light is the fastest object in a vacuum, it has been considered that Čerenkov radiation is emitted only in the presence of some refractive index. Here, I propose mimicking a series of particles travelling faster than light in a vacuum by dynamical surface corrugation to find Čerenkov radiation in a vacuum from the surface. The dynamical corrugation induces an effective current source on the surface with an external electrostatic field applied. When the corrugation profile is of travelling wave type, the source can be regarded as a series of dipoles virtually travelling along the surface. If the phase velocity of the travelling wave profile exceeds the speed of light, and so do the dipoles, they emit Čerenkov radiation in a vacuum.
description: Submitted in part fulfilment of the requirements for the degree of Doctor of Philosophy in Physics at Imperial College London
Drag Reduction, from Bending to Pruning
Creators: name: Lopez, Diego
name: Eloy, Christophe
name: Michelin, Sébastien
name: de Langre, Emmanuel
Publisher: name: arXiv
Year: 2013
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Most plants and benthic organisms have evolved efficient reconfiguration mechanisms to resist flow-induced loads. These mechanisms can be divided into bending, in which plants reduce their sail area through elastic deformation, and pruning, in which the loads are decreased through partial breakage of the structure. In this work, we show by using idealized models that these two mechanisms or, in fact, any combination of the two, are equally efficient to reduce the drag experienced by terrestrial and aquatic vegetation.
description: 5 pages, 5 figures
Non-existence of an invariant measure for a homogeneous ellipsoid rolling on the plane
Creators: name: García-Naranjo, Luis C.
name: Marrero, Juan C.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 37C40, 37J60, 70F25, 70G45, 70G65

description: It is known that the reduced equations for an axially symmetric homogeneous ellipsoid that rolls without slipping on the plane possess a smooth invariant measure. We show that such an invariant measure does not exist in the case when all of the semi-axes of the ellipsoid have different length.
description: v2: Minor changes after journal review. This text uses the theory developed in arXiv:1304.1788 for the specific example of a homogeneous ellipsoid rolling on the plane
Target estimands for population-adjusted indirect comparisons
Creators: name: Remiro-Azócar, Antonio
Publisher: name: arXiv
Year: 2021
Subjects: subject: Methodology (stat.ME)
subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: Disagreement remains on what the target estimand should be for population-adjusted indirect treatment comparisons. This debate is of central importance for policy-makers and applied practitioners in health technology assessment. Misunderstandings are based on properties inherent to estimators, not estimands, and on generalizing conclusions based on linear regression to non-linear models. Estimators of marginal estimands need not be unadjusted and may be covariate-adjusted. The population-level interpretation of conditional estimates follows from collapsibility and does not necessarily hold for the underlying conditional estimands. For non-collapsible effect measures, neither conditional estimates nor estimands have a population-level interpretation. Estimators of marginal effects tend to be more precise and efficient than estimators of conditional effects where the measure of effect is non-collapsible. In any case, such comparisons are inconsequential for estimators targeting distinct estimands. Statistical efficiency should not drive the choice of the estimand. On the other hand, the estimand, selected on the basis of relevance to decision-making, should drive the choice of the most efficient estimator. Health technology assessment agencies make reimbursement decisions at the population level. Therefore, marginal estimands are required. Current pairwise population adjustment methods such as matching-adjusted indirect comparison are restricted to target marginal estimands that are specific to the comparator study sample. These may not be relevant for decision-making. Multilevel network meta-regression (ML-NMR) can potentially target marginal estimands in any population of interest. Such population could be characterized by decision-makers using increasingly available "real-world" data sources. Therefore, ML-NMR presents new directions and abundant opportunities for evidence synthesis.
description: 14 pages (the main text is 9 pages), 1 figure. Conditionally accepted by Statistics in Medicine (conditional on the changes made in this revision)
THE RELATIONSHIP BETWEEN INTERNAL MARKETING PRACTICES AND EMPLOYEES' ORGANIZATIONAL COMMITMENT, THE CASE OF AWASH INSURANCE COMPANY S.C.
Creators: name: HABTAMU ERTIRO
Publisher: name: Zenodo
Year: 2017

description: The objective of this study is to investigate the relationship between internal marketing and employees’ organizational commitment in Awash Insurance Company (AIC). This research uses a cross-sectional study to survey the relationship between internal marketing and employees’ organizational commitment. The population of interest in this study was professional staff of AIC. One hundred and twenty three questionnaires were distributed and 106 questionnaires were returned, yielding a response rate of 86.16%. The findings reveal that there is significant relationship between internal marketing and employees’ organizational commitment. It is recommended that there is need for AIC to sensitized of their role in spearheading internal marketing initiatives, for a more proactive approach and for effective implementation of internal marketing strategies. The study will be of value to future scholars by stimulating further research to develop a better understanding of internal marketing best practices applied in Ethiopian insurance industry.
Longitudinal interlayer magnetoresistance in quasi-2D metals
Creators: name: Grigoriev, P. D.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The longitudinal interlayer magnetoresistance $R_{zz}(B_{z})$ is calculated in strongly anisotropic layered metals, when the interlayer band width $4t_{z}$ is less than the Landau level separation $\hbar ω_{c}$. The impurity scattering has much stronger effect in this regime than in 3D metals and leads to a linear longitudinal interlayer magnetoresistance $R_{zz}\propto B_{z}$ in the interval $\hbar ω_{c}>4t_{z}>>\sqrt{Γ_{0}\hbar ω_{c}}$ changing to a square-root dependence $R_{zz}\propto B_{z}^{1/2}$ at higher field or smaller $t_{z}$. The crossover field allows to estimate the interlayer transfer integral as $t_{z}\sim \sqrt{Γ_{0}\hbar ω_{c}}$. Longitudinal interlayer magnetoresistance, being robust to the increase of temperature or long-range disorder, is easy for measurements and provides a useful tool to investigate the electronic structure of quasi-two-dimensional compounds.
description: 6 pages, 6 figures
A comparison of different methods of identifying publications related to the United Nations Sustainable Development Goals: Case Study of SDG 13: Climate Action
Creators: name: Purnell, Philip James
Publisher: name: arXiv
Year: 2022
Subjects: subject: Digital Libraries (cs.DL)
subject: FOS: Computer and information sciences

description: As sustainability becomes an increasing priority throughout global society, academic and research institutions are assessed on their contribution to relevant research publications. This study compares four methods of identifying research publications related to United Nations Sustainable Development Goal 13: climate action. The four methods, Elsevier, STRINGS, SIRIS, and Dimensions have each developed search strings with the help of subject matter experts which are then enhanced through distinct methods to produce a final set of publications. Our analysis showed that the methods produced comparable quantities of publications but with little overlap between them. We visualised some difference in topic focus between the methods and drew links with the search strategies used. Differences between publications retrieved are likely to come from subjective interpretation of the goals, keyword selection, operationalising search strategies, AI enhancements, and selection of bibliographic database. Each of the elements warrants deeper investigation to understand their role in identifying SDG-related research. Before choosing any method to assess the research contribution to SDGs, end users of SDG data should carefully consider their interpretation of the goal and determine which of the available methods produces the closest dataset. Meanwhile data providers might customise their methods for varying interpretations of the SDGs.
On the HI column density - radio source size anti-correlation in compact radio sources
Creators: name: Curran, S. J.
name: Allison, J. R.
name: Glowacki, M.
name: Whiting, M. T.
name: Sadler, E. M.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Existing studies of the atomic hydrogen gas content in distant galaxies, through the absorption of the 21-cm line, often infer that the total column density is anti-correlated with the linear extent of the background radio source. We investigate this interpretation, by dissecting the various parameters from which the column density is derived, and find that the relationship is driven primarily by the observed optical depth, which, for a given absorber size, is anti-correlated with the linear size. Therefore, the inferred anti-correlation is merely the consequence of geometry, in conjunction with the assumption of a common spin temperature/covering factor ratio for each member of the sample, an assumption for which there is scant observational justification. While geometry can explain the observed correlation, many radio sources comprise two radio lobes and so we model the projected area of a two component emitter intercepted by a foreground absorber. From this, the observed optical depth/linear size relationship is best reproduced through models which approximate either of the two Fanaroff & Riley classifications, although the observed scatter in the sample cannot be duplicated using a single deprojected radio source size. Furthermore, the trend is best reproduced using an absorber of diameter ~100 - 1000 pc, which is also the range of values of linear sizes at which the 21-cm detection rate peaks. This may indicate that this is the characteristic linear size of the absorbing gas structure.
description: Accepted by MNRAS
Critical behavior and magnetic relaxation dynamics of Nd0.4Sr0.6MnO3 nanoparticles
Creators: name: Kundu, S.
name: Nath, T. K.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Detailed dc and ac magnetic properties of chemically synthesized Nd0.4Sr0.6MnO3 with different particle size (down to 27 nm) have been studied in details. We have found ferromagnetic state in the nanoparticles, whereas, the bulk Nd0.4Sr0.6MnO3 is known to be an A-type antiferromagnet. A Griffiths-like phase has also been identified in the nanoparticles. Further, critical behavior of the nanoparticles has been studied around the second order ferromagnetic-paramagnetic transition region (|(T-TC)/TC|£ 0.04) in terms of modified Arrott plot, Kouvel-Fisher plot and critical isotherm analysis. The estimated critical exponents (b,g,d) are quite different from those predicted according to three-dimensional mean-field, Heisenberg and Ising models. This signifies a quite unusual nature of the size-induced ferromagnetic state in Nd0.4Sr0.6MnO3. The nanoparticles are found to be interacting and do not behave like ideal superparamagnet. Interestingly, we find spin glass like slow relaxation of magnetization, aging and memory effect in the nanometric samples. These phenomena have been attributed to very broad distribution of relaxation time as well as to inter-particle interaction. Experimentally, we have found out that the dynamics of the nanoparticle systems can be best described by hierarchical model of spin glasses.
description: Philosophical Magazine (2013)
Water vapour induced structural flexibility in a square lattice coordination network
Creators: name: Koupepidou, Kyriaki
name: Bezrukov, Andrey
name: Castell, Dominic
name: SENSHARMA, DEBOBROTO
name: Mukherjee, Soumya
name: ZAWOROTKO, MICHAEL
Publisher: name: University of Limerick
Year: 2023
Subjects: classificationCode: 34
subject: Chemical sciences
subject: FOS: Chemical sciences

description: Herein, we introduce a new square lattice topology coordination network, sql-(1,3-bib)(ndc)-Ni, with three types of connection and detail its gas and vapour induced phase transformations. Exposure to humidity resulted in an S-shaped isotherm profile, suggesting potential utility of such materials as desiccants.
Unified Question Generation with Continual Lifelong Learning
Creators: name: Yuan, Wei
name: Yin, Hongzhi
name: He, Tieke
name: Chen, Tong
name: Wang, Qiufeng
name: Cui, Lizhen
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computation and Language (cs.CL)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Question Generation (QG), as a challenging Natural Language Processing task, aims at generating questions based on given answers and context. Existing QG methods mainly focus on building or training models for specific QG datasets. These works are subject to two major limitations: (1) They are dedicated to specific QG formats (e.g., answer-extraction or multi-choice QG), therefore, if we want to address a new format of QG, a re-design of the QG model is required. (2) Optimal performance is only achieved on the dataset they were just trained on. As a result, we have to train and keep various QG models for different QG datasets, which is resource-intensive and ungeneralizable. To solve the problems, we propose a model named Unified-QG based on lifelong learning techniques, which can continually learn QG tasks across different datasets and formats. Specifically, we first build a format-convert encoding to transform different kinds of QG formats into a unified representation. Then, a method named \emph{STRIDER} (\emph{S}imilari\emph{T}y \emph{R}egular\emph{I}zed \emph{D}ifficult \emph{E}xample \emph{R}eplay) is built to alleviate catastrophic forgetting in continual QG learning. Extensive experiments were conducted on $8$ QG datasets across $4$ QG formats (answer-extraction, answer-abstraction, multi-choice, and boolean QG) to demonstrate the effectiveness of our approach. Experimental results demonstrate that our Unified-QG can effectively and continually adapt to QG tasks when datasets and formats vary. In addition, we verify the ability of a single trained Unified-QG model in improving $8$ Question Answering (QA) systems' performance through generating synthetic QA data.
description: Paper accepted in The Web Conference (WWW) 2022
Dissipative superradiant spin amplifier for enhanced quantum sensing
Creators: name: Koppenhöfer, Martin
name: Groszkowski, Peter
name: Lau, Hoi-Kwan
name: Clerk, A. A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Quantum metrology protocols exploiting ensembles of $N$ two-level systems and Ramsey-style measurements are ubiquitous. However, in many cases excess readout noise severely degrades the measurement sensitivity; in particular in sensors based on ensembles of solid-state defect spins. We present a dissipative "spin amplification" protocol that allows one to dramatically improve the sensitivity of such schemes, even in the presence of realistic intrinsic dissipation and noise. Our method is based on exploiting collective (i.e., superradiant) spin decay, an effect that is usually seen as a nuisance because it limits spin-squeezing protocols. We show that our approach can allow a system with a highly imperfect spin readout to approach SQL-like scaling in $N$ within a factor of two, without needing to change the actual readout mechanism. Our ideas are compatible with several state-of-the-art experimental platforms where an ensemble of solid-state spins (NV centers, SiV centers) is coupled to a common microwave or mechanical mode.
description: equivalent to published version, 21+9 pages, 10+7 figures
Nonsingular Promises from Born-Infeld Gravity
Creators: name: Fiorini, Franco
Publisher: name: arXiv
Year: 2013
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Born-Infeld determinantal gravity formulated in Weitzenbock spacetime is discussed in the context of Friedmann-Robertson-Walker (FRW) cosmologies. It is shown how the standard model big bang singularity is absent in certain spatially flat FRW spacetimes, where the high energy regime is characterized by a de Sitter inflationary stage of geometrical character, i.e., without the presence of the inflaton field. This taming of the initial singularity is also achieved for some spatially curved FRW manifolds where the singularity is replaced by a de Sitter stage or a big bounce of the scale factor depending on certain combinations of free parameters appearing in the action. Unlike other Born-Infeld-like theories in vogue, the one here presented is also capable of deforming vacuum general relativistic solutions.
description: 5 pages, no figures. Accepted for publication in Physical Review Letters
Disorder-dominated quantum criticality in moiré bilayers
Creators: name: Tan, Yuting
name: Tsang, Pak Ki Henry
name: Dobrosavljević, V.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Moiré bilayer materials have recently attracted much attention following the discovery of various correlated insulating states at specific band fillings. Here we discuss the metal-insulator transitions (MITs) that have been observed in the same devices, but at fillings far from the strongly correlated regime dominated by Mott-like physics, displaying many similarities to other examples of disorder-dominated MITs. We propose a minimal theoretical model describing the interplay of interactions and disorder, which able to capture most experimental trends observed on several devices.
N-Omniglot, a large-scale neuromorphic dataset for spatio-temporal sparse few-shot learning
Creators: name: Li, Yang
name: Dong, Yiting
name: Zhao, Dongcheng
name: Zeng, Yi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Neural and Evolutionary Computing (cs.NE)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Few-shot learning (learning with a few samples) is one of the most important cognitive abilities of the human brain. However, the current artificial intelligence systems meet difficulties in achieving this ability. Similar challenges also exist for biologically plausible spiking neural networks (SNNs). Datasets for traditional few-shot learning domains provide few amounts of temporal information. and the absence of neuromorphic datasets has hindered the development of few-shot learning for SNNs. Here, to the best of our knowledge, we provide the first neuromorphic dataset for few-shot learning using SNNs: N-Omniglot, based on the Dynamic Vision Sensor. It contains 1,623 categories of handwritten characters, with only 20 samples per class. N-Omniglot eliminates the need for a neuromorphic dataset for SNNs with high spareness and tremendous temporal coherence. Additionally, the dataset provides a powerful challenge and a suitable benchmark for developing SNNs algorithms in the few-shot learning domain due to the chronological information of strokes. We also provide the improved nearest neighbor, convolutional network, SiameseNet, and meta-learning algorithm in the spiking version for verification.
D4.1 - Hybrid Federated Learning model
Creators: name: Uribe, Silvia
name: Serrano, Javier
name: Río, Alberto Del
name: Piscia, Davide
name: Planat, Vincent
Publisher: name: Zenodo
Year: 2022

description: The main aim of this deliverable is to define GenoMed4All’s hybrid federated learning model specification expressed in terms of platform requirements, which have been acquired by analyzing in details the project’s objectives as well as by decomposing the stakeholders’ needs through the different use cases’ definition. It includes a description of the requirements elicitation methodology together with the set of technical requirements regarding the federated learning approach of the project’s platform. Moreover, it includes an extensive analysis of the most important federated learning framework solutions already available, and it finally defines the evaluation criteria that have helped in the selection of the most appropriate one for the project’s purposes and needs.
Social Selectivity in Higher Education: A Case Study of Canada and the Czech Republic
Creators: name: Hellingman, Sean
name: Mazouch, Petr
name: Vltavská, Kristýna
name: Ryckenberg, Samuel
Publisher: name: Alberta Journal of Educational Research
Year: 2022

description: This work examines the choices of individuals with respect to higher education in the Czech Republic and Canada. Specifically, how do the students’ socioeconomic backgrounds influence their study decisions. Data from the Czech edition of The European Union Statistics on Income and Living Conditions survey and the Canadian Survey of Labour and Income Dynamics was used to identify influences of students’ entry to university. Individuals from households with higher socioeconomic status were more likely to enter university than people who were less well off in both countries. Social selectivity is much more present in higher education in the Czech Republic than in Canada. Key words: Higher Education, Czech Republic, Canada, Social Selectivity, Logistic Regression, Ordered Statistics Ce travail examine les choix des personnes en matière d'enseignement supérieur en République tchèque et au Canada, notamment comment les antécédents socio-économiques des étudiants influencent leurs décisions relatives aux études. Les données de l'édition tchèque de l'enquête Statistiques sur le revenu et les conditions de vie de l'Union européenne et de l'Enquête canadienne sur la dynamique du travail et du revenu ont été utilisées pour identifier les influences sur l'entrée des étudiants à l'université. Dans les deux pays, les personnes issues de ménages ayant un statut socio-économique élevé étaient plus susceptibles d'entrer à l'université que les personnes moins bien loties. La sélectivité sociale est beaucoup plus présente dans l'enseignement supérieur en République tchèque qu'au Canada. Mots clés: enseignement supérieur, République tchèque, Canada, sélectivité sociale, régression logistique, statistiques ordonnées
description: Alberta Journal of Educational Research, Vol. 68 No. 1 (2022): Spring