cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Lifting the spin-momentum locking in ultra-thin topological insulator films
Creators: name: Leis, Arthur
name: Schleenvoigt, Michael
name: Cherepanov, Vasily
name: Lüpke, Felix
name: Schüffelgen, Peter
name: Mussler, Gregor
name: Grützmacher, Detlev
name: Voigtländer, Bert
name: Tautz, F. Stefan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Three-dimensional (3D) topological insulators (TIs) are known to carry 2D Dirac-like topological surface states in which spin-momentum locking prohibits backscattering. When thinned down to a few nanometers, the hybridization between the topological surface states at the top and bottom surfaces results in a topological quantum phase transition, which can lead to the emergence of a quantum spin Hall phase. Here, we study the thickness-dependent transport properties across the quantum phase transition on the example of (Bi$_{0.16}$Sb$_{0.84}$)$_2$Te$_3$ films, with a four-tip scanning tunnelling microscope. Our findings reveal an exponential drop of the conductivity below the critical thickness. The steepness of this drop indicates the presence of spin-conserving backscattering between the top and bottom surface states, effectively lifting the spin-momentum locking and resulting in the opening of a gap at the Dirac point. Our experiments provide crucial steps towards the detection of quantum spin Hall states in transport measurements.
The rise of unemphatic negation: two standard negation constructions in Oji-Cree and their patterns of use
Creators: name: Windsor, Matthew
Publisher: name: Linguistic Typology at the Crossroads
Year: 2022

description: Oji-Cree (Algonquian) makes use of two negation constructions which overlap in non-future environments and differ subtly in their pragmatic contexts of use. Ci-negation is used for neutral, descriptive negation whereas hsii-negation is associated with polemic, emphatic-like uses within stronger assertions. While hsii-negation dates to Proto-Ojibwe, I show that ci-negation developed more recently from indirect irrealis expressions as a way to downplay the inherent abruptness of negation. This represents an opposite pathway from Jespersen’s Cycle, which is partly motivated by the desire to emphasize negatives. Oji-Cree ci-negation instead arose as a new unemphatic expression, motivated by the desire to avoid social tension. Though many languages of the world feature multiple standard negation constructions, the development of these systems remain to be investigated in relation to their diachrony and social contexts. This study contributes to our knowledge of why and how such systems might arise
description: Linguistic Typology at the Crossroads, Vol. 2 No. 2 (2022)
Homogenization of a nonlinear monotone problem in a locally periodic domain via unfolding method
Creators: name: Aiyappan, S.
name: Cardone, G.
name: Perugia, C.
name: Prakash, R.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 80M35, 80M40, 35B27

description: In this paper, the asymptotic behavior of the solutions of a monotone problem posed in a locally periodic oscillating domain is studied. Nonlinear monotone boundary conditions are imposed on the oscillating part of the boundary whereas the Dirichlet condition is considered on the smooth separate part. Using the unfolding method, under natural hypothesis on the regularity of the domain, we prove the weak $L^2$-convergence of the zero-extended solutions of the nonlinear problem and their flows to the solutions of a limit distributional problem.
description: 16 pages, 2 figures
Principal Schottky Bundles over Riemann surfaces
Creators: name: Casimiro, A. C.
name: Ferreira, S.
name: Florentino, C.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Differential Geometry (math.DG)
subject: Algebraic Geometry (math.AG)
subject: Complex Variables (math.CV)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: 14H70 30F10 32CXX

description: We introduce and study (strict) Schottky G-bundles over a compact Riemann surface X, where G is a connected reductive algebraic group. Strict Schottky representations are shown to be related to branes in the moduli space of G-Higgs bundles over X, and we prove that all Schottky $G$-bundles have trivial topological type. Generalizing the Schottky moduli map introduced in Florentino to the setting of principal bundles, we prove its local surjectivity at the good and unitary locus. Finally, we prove that the Schottky map is surjective onto the space of flat bundles for two special classes: when G is an abelian group over an arbitrary X, and the case of a general G-bundle over an elliptic curve.
description: 28 pages, 2 figures, some corrections and accepted for publication in Geometriae Dedicata
Methods and Instruments
Creators: name: Steenberghs, Nina
name: Colpin, Hilde
name: Spilt, Jantine
name: Lubon, Anouck
name: Verschueren, Karine
name: Demol, Karlien
Publisher: name: OSF Registries
Year: 2023

description: The operationalization of the vignettes and variables can be found in the document attached to this component. Composite scores are also given in this document.
(500436) James Dores
Creators: name: Professions, Victorian
Publisher: name: University of Oxford
Year: 2022
Subjects: subject: 220201 Business and Labour History
subject: FOS: Philosophy, ethics and religion
subject: History
subject: 140203 Economic History
subject: FOS: Economics and business

description: This three-year research project began in January 2014 and investigated whether, during the Victorian period, the professions formed a distinct self-sustaining social group with its own mores and values. The project looked at 16,000 individuals drawn from census data for Alnwick, Brighton, Bristol, Dundee, Greenock, Leeds, Merthyr Tydfil, Morpeth, and Winchester. The research project was funded by the UK Economic & Social Research Council and was based at the Universities of Oxford and Northumbria.
Person alignment in reported speech and thought: the distribution and typology of participant roles (based on six Finno-Ugric languages)
Creators: name: Teptiuk, Denys
Publisher: name: Linguistic Typology at the Crossroads
Year: 2022

description: This paper investigates how person alignment is arranged in discourse reporting. I focus on participant roles appearing in narrated and speech events (Jakobson [1957] 1971) and how they are linguistically encoded in (re)presentations of speech and thought. Besides the (re)presentations of speech and thought attributed to other speakers, I include two other types of report: self-quotations (Reported Speaker = Reporter) and quotations with an unknown source (Reported Speaker = ?). For illustrative purposes, I use data from internet communications of six Finno-Ugric languages: Hungarian, Estonian, Finnish, Erzya, Udmurt, Komi. The results show that three types of reports exhibit idiosyncrasies regarding the participant distribution in the narrated event. These idiosyncrasies affect how the linguistic encoding of participants is arranged and how different perspectives are highlighted in reported speech and thought. In addition to two canonical perspectives, i.e. Reported Speaker’s and Reporter’s, there are some ambiguous cases where person marking does not index only one type of perspective. Such ambiguity is characterized by the overlap between different roles carried out by one participant or subsumption of participants from different events under one formal reference. Furthermore, ambiguous cases often contain a generic reference equally suitable for participants in the narrated and current speech event.
description: Linguistic Typology at the Crossroads, Vol. 2 No. 2 (2022)
Non-local Potts model on random lattice and chromatic number of a plane
Creators: name: Shevchenko, V.
name: Tanashkin, A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: Statistical models are widely used for the investigation of complex system's behavior. Most of the models considered in the literature are formulated on regular lattices with nearest-neighbor interactions. The models with non-local interaction kernels have been less studied. In this article, we investigate an example of such a model - the non-local q-color Potts model on a random d=2 lattice. Only the same color spins at a unit distance (within some small margin $δ$) interact. We study the vacuum states of this model and present the results of numerical simulations and discuss qualitative features of the corresponding patterns. Conjectured relation with the chromatic number of a plane problem is discussed.
description: 11 pages, 9 figures
From log-determinant inequalities to Gaussian entanglement via recoverability theory
Creators: name: Lami, Ludovico
name: Hirche, Christoph
name: Adesso, Gerardo
name: Winter, Andreas
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Many determinantal inequalities for positive definite block matrices are consequences of general entropy inequalities, specialised to Gaussian distributed vectors with prescribed covariances. In particular, strong subadditivity (SSA) yields \begin{equation*} \ln\det V_{AC} + \ln\det V_{BC} - \ln\det V_{ABC} - \ln\det V_C \geq 0 \end{equation*} for all $3\times 3$-block matrices $V_{ABC}$, where subscripts identify principal submatrices. We shall refer to the above inequality as SSA of log-det entropy. In this paper we develop further insights on the properties of the above inequality and its applications to classical and quantum information theory. In the first part of the paper, we show how to find known and new necessary and sufficient conditions under which saturation with equality occurs. Subsequently, we discuss the role of the classical transpose channel (also known as Petz recovery map) in this problem and find its action explicitly. We then prove some extensions of the saturation theorem, by finding faithful lower bounds on a log-det conditional mutual information. In the second part, we focus on quantum Gaussian states, whose covariance matrices are not only positive but obey additional constraints due to the uncertainty relation. For Gaussian states, the log-det entropy is equivalent to the Rényi entropy of order $2$. We provide a strengthening of log-det SSA for quantum covariance matrices that involves the so-called Gaussian Rényi-$2$ entanglement of formation, a well-behaved entanglement measure defined via a Gaussian convex roof construction. We then employ this result to define a log-det entropy equivalent of the squashed entanglement, which is remarkably shown to coincide with the Gaussian Rényi-$2$ entanglement of formation. This allows us to establish useful properties of such measure(s), like monogamy, faithfulness, and additivity on Gaussian states.
description: 17 pages; v2 has many typos corrected and it is close to the published version (IEEE)
Cross-linguistic sources of anticausative markers
Creators: name: Inglese, Guglielmo
Publisher: name: Linguistic Typology at the Crossroads
Year: 2022

description: The (anti)causative alternation, that is, the alternation whereby languages contrast intransitive verbs expressing spontaneous events with transitive ones expressing externally caused events, has been the object of extensive language-specific and cross-linguistic studies. Within this type of alternation, marking on the intransitive member goes under the name of anticausative marking, while marking on the transitive member is causative marking. Historical research has mostly focused on causatives, while the diachrony of anticausative markers has largely been neglected. In the literature, only two possible cross-linguistic sources of anticausatives are mentioned: reflexives and passives. By looking at a sample of 97 languages, in this paper I show that sources of anticausativization are much more varied than what currently reported in the literature. Taking this richer diachronic evidence into account also sheds light on some yet controversial aspects concerning the relationship between anticausativization and reflexivity.
description: Linguistic Typology at the Crossroads, Vol. 2 No. 2 (2022)
A New Voltage Stability-Constrained Optimal Power Flow Model: Sufficient Condition, SOCP Representation, and Relaxation
Creators: name: Cui, Bai
name: Sun, Xu Andy
Publisher: name: arXiv
Year: 2017
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: A simple characterization of the solvability of power flow equations is of great importance in the monitoring, control, and protection of power systems. In this paper, we introduce a sufficient condition for power flow Jacobian nonsingularity. We show that this condition is second-order conic representable when load powers are fixed. Through the incorporation of the sufficient condition, we propose a voltage stability-constrained optimal power flow (VSC-OPF) formulation as a second-order cone program (SOCP). An approximate model is introduced to improve the scalability of the formulation to larger systems. Extensive computation results on Matpower and NESTA instances confirm the effectiveness and efficiency of the formulation.
description: Accepted for publication in IEEE Transactions on Power Systems
The Persistence of Memory in Ionic Conduction Probed by Nonlinear Optics
Creators: name: Poletayev, Andrey D.
name: Hoffmann, Matthias C.
name: Dawson, James A.
name: Teitelbaum, Samuel W.
name: Trigo, Mariano
name: Islam, M. Saiful
name: Lindenberg, Aaron M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Chemical Physics (physics.chem-ph)
subject: Computational Physics (physics.comp-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Predicting practical rates of ion transport from atomistic descriptors enables the rational design of materials, devices, and processes, which is especially critical to developing low-carbon energy technologies such as rechargeable batteries. The correlated mechanisms of ionic conduction, variation of conductivity with timescale and confinement, and ambiguity in the vibrational origin of translation, the attempt frequency, call for a direct atomic probe of the most fundamental steps of ionic diffusion: ion hops. However, such hops are rare-event large-amplitude translations, and are challenging to excite and detect. Here we use single-cycle terahertz pumps to impulsively trigger ionic hopping in battery solid electrolytes. This is visualized by an induced transient birefringence enabling direct probing of anisotropy in ionic hopping on the picosecond timescale. The relaxation of the transient signal measures the decay of orientational memory, and the production of entropy in diffusion. We extend experimental results using in silico transient birefringence to identify attempt frequencies for ion hopping. Using nonlinear optical methods, we probe ion transport at its fastest limit, distinguish correlated conduction mechanisms from a true random walk at the atomic scale, and demonstrate the connection between activated transport and the thermodynamics of information.
description: 41 pages, 22 figures
Neural-network-powered pulse reconstruction from one-dimensional interferometric cross-correlation traces
Creators: name: Kolesnichenko, Pavel V.
name: Zigmantas, Donatas
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: Any ultrafast optical spectroscopy experiment is usually accompanied by the necessary routine of ultrashort-pulse characterisation. The majority of pulse characterisation approaches solve either a one-dimensional (e.g. via interferometry) or a two-dimensional (e.g. via frequency-resolved measurements) problem. Solution of the two-dimensional pulse-retrieval problem is generally more consistent due to problem's over-determined nature. In contrast, the one-dimensional pulse-retrieval problem is impossible to solve unambiguously as ultimately imposed by the fundamental theorem of algebra. In cases where additional constraints are involved, the one-dimensional problem may be possible to solve, however, existing iterative algorithms lack generality, and often stagnate for complicated pulse shapes. Here we use a deep neural network to unambiguously solve a constrained one-dimensional pulse-retrieval problem and show the potential of fast, reliable, and complete pulse characterisation using interferometric cross-correlation time traces (determined by the pulses with partial spectral overlap).
description: 24 pages, 4 figures
Stabilization and Variations to the Adaptive Local Iterative Filtering Algorithm: the Fast Resampled Iterative Filtering Method
Creators: name: Barbarino, Giovanni
name: Cicone, Antonio
Publisher: name: arXiv
Year: 2021
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 94A12, 68W40, 15A18, 47B06, 15B05

description: Non-stationary signals are ubiquitous in real life. Many techniques have been proposed in the last decades which allow decomposing multi-component signals into simple oscillatory mono-components, like the groundbreaking Empirical Mode Decomposition technique and the Iterative Filtering method. When a signal contains mono-components that have rapid varying instantaneous frequencies, we can think, for instance, to chirps or whistles, it becomes particularly hard for most techniques to properly factor out these components. The Adaptive Local Iterative Filtering technique has recently gained interest in many applied fields of research for being able to deal with non-stationary signals presenting amplitude and frequency modulation. In this work, we address the open question of how to guarantee a priori convergence of this technique, and propose two new algorithms. The first method, called Stable Adaptive Local Iterative Filtering, is a stabilized version of the Adaptive Local Iterative Filtering that we prove to be always convergent. The stability, however, comes at the cost of higher complexity in the calculations. The second technique, called Resampled Iterative Filtering, is a new generalization of the Iterative Filtering method. We prove that Resampled Iterative Filtering is guaranteed to converge a priori for any kind of signal. Furthermore, in the discrete setting, by leveraging on the mathematical properties of the matrices involved, we show that its calculations can be accelerated drastically. Finally, we present some artificial and real-life examples to show the powerfulness and performance of the proposed methods.
The finite dual coalgebra as a quantization of the maximal spectrum
Creators: name: Reyes, Manuel L.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Rings and Algebras (math.RA)
subject: Algebraic Geometry (math.AG)
subject: Category Theory (math.CT)
subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics
subject: 14A22, 16B50, 16T15 (Primary), 16G30, 16P40, 16R20, 16S80 (Secondary)

description: In pursuit of a noncommutative spectrum functor, we argue that the Heyneman-Sweedler finite dual coalgebra can be viewed as a quantization of the maximal spectrum of a commutative affine algebra, integrating prior perspectives of Takeuchi, Batchelor, Kontsevich-Soibelman, and Le Bruyn. We introduce fully residually finite-dimensional algebras $A$ as those with enough finite-dimensional representations to let $A^\circ$ act as an appropriate depiction of the noncommutative maximal spectrum of $A$; importantly, this class includes affine noetherian PI algebras. In the case of prime affine algebras that are module-finite over their center, we describe how the Azumaya locus is represented in the finite dual. This is used to describe the finite dual of quantum planes at roots of unity as an endeavor to visualize the noncommutative space on which these algebras act as functions. Finally, we discuss how a similar analysis can be carried out for other maximal orders over surfaces.
description: 35 pages, 2 figures. Final version
Infinite Mixtures of Infinite Factor Analysers
Creators: name: Murphy, Keefe
name: Viroli, Cinzia
name: Gormley, Isobel Claire
Publisher: name: arXiv
Year: 2017
Subjects: subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: Factor-analytic Gaussian mixture models are often employed as a model-based approach to clustering high-dimensional data. Typically, the numbers of clusters and latent factors must be specified in advance of model fitting, and remain fixed. The pair which optimises some model selection criterion is then chosen. For computational reasons, models in which the number of latent factors differ across clusters are rarely considered. Here the infinite mixture of infinite factor analysers (IMIFA) model is introduced. IMIFA employs a Pitman-Yor process prior to facilitate automatic inference of the number of clusters using the stick-breaking construction and a slice sampler. Furthermore, IMIFA employs multiplicative gamma process shrinkage priors to allow cluster-specific numbers of factors, automatically inferred via an adaptive Gibbs sampler. IMIFA is presented as the flagship of a family of factor-analytic mixture models, providing flexible approaches to clustering high-dimensional data. Applications to a benchmark data set, metabolomic spectral data, and a manifold learning handwritten digit example illustrate the IMIFA model and its advantageous features. These include obviating the need for model selection criteria, reducing the computational burden associated with the search of the model space, improving clustering performance by allowing cluster-specific numbers of factors, and quantifying uncertainty in the numbers of clusters and cluster-specific factors.
description: Published in Bayesian Analysis
Battery-operated mid-infrared diode laser frequency combs
Creators: name: Sterczewski, Lukasz A.
name: Fradet, Mathieu
name: Frez, Clifford
name: Forouhar, Siamak
name: Bagheri, Mahmood
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Mid-wave infrared (MIR, 3--5 $μ$m) optical frequency combs (OFC) are of critical importance for spectroscopy of fundamental molecular absorption features in space and terrestrial applications. Although in this band OFCs can be obtained via supercontinuum or difference frequency generation using optical pumping schemes, unprecedented source miniaturization and monolithic design are unique to electrically-pumped semiconductor laser structures. To date, high-brightness OFC generation in this region has been demonstrated in quantum- and interband cascade lasers (QCL/ICL), yet with sub-optimal spectral properties. Here, we show a MIR quantum well diode laser (QWDL) OFC, whose excellent spectral uniformity, narrow optical linewidths, and milliwatt optical power are obtained at a fraction of a watt of power consumption. The continuously tunable source offers ~1 THz of optical span centered at 3.04 $μ$m, and a repetition rate of 10 GHz. As a proof-of-principle, we show a directly-battery-operated MIR dual-comb source with almost 0.5 THz of optical coverage accessible in the electrical domain in microseconds. These results indicate the high suitability of QWDL OFCs for future chip-based real-time sensing systems in the mid-infrared.
description: 9 pages, 5 figures
Explainable Deep Machine Learning for Medical Image Analysis
Creators: name: Gaudio, Alex
Publisher: name: Carnegie Mellon University
Year: 2023
Subjects: Artificial Intelligence and Image Processing not elsewhere classified

description: Explanations justify the development and adoption of algorithmic solutions for prediction problems in medical image analysis. This thesis introduces two guiding principles for creating and exploiting explanations of deep networks and medical image data. The first guiding principle is to use explanations to expose inefficiencies in the design of models and image datasets. The second principle is to leverage tools of compression and fixed-weight methods that minimize learning to make more efficient and effective models and more usable medical image datasets. The outcome is more effective deep learning in medical image analysis. Application of these guiding principles in different settings results in five main contributions: (a) improved understanding of biases present in deep networks and medical images, (b) improved predictive and computational performance of predictive models, (c) creation of ante-hoc models that are interpretable by design, (d) creation of smaller image datasets, and (e) improved visual privacy. This thesis falls within the scope of the TAMI project for Transparent Artificial Machine Intelligence and focuses on explainable artificial intelligence (XAI) for medical image data.
Anisotropic Universe in $f(\mathcal{G},\textit{T})$ Gravity
Creators: name: Shamir, M. Farasat
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: This paper is devoted to investigate the recently introduced $f(\mathcal{G},\textit{T})$ theory of gravity, where $\mathcal{G}$ is the Gauss-Bonnet term, and ${\textit{T}}$ is the trace of the energy-momentum tensor. For this purpose, anisotropic background is chosen and a power law $f(\mathcal{G},\textit{T})$ gravity model is used to find the exact solutions of field equations. In particular, a general solution is obtained which is further used to reconstruct some important solutions in cosmological contexts. The physical quantities like energy density, pressure, and equation of state parameter are calculated. A Starobinsky Like $f_2(\textit{T})$ model is proposed which is used to analyze the behavior of universe for different values of equation of state parameter. It is concluded that presence of term $\textit{T}$ in the bivariate function $f(\mathcal{G},\textit{T})$ may give many cosmologically important solutions of the field equations.
description: 20 pages, 10 figures, minor changes
A note on commutation relations and finite dimensional approximations
Creators: name: Lledó, Fernando
name: Martínez, Diego
Publisher: name: arXiv
Year: 2021
Subjects: subject: Operator Algebras (math.OA)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 81T05, 46L05, 47L90

description: In this article we show that the main C*-algebras describing the canonical commutation relations of quantum physics, i.e., the Weyl and resolvent algebras, are in the class of Følner C*-algebras, a class of C*-algebras admitting a kind of finite approximations of Følner type. In particular, we show that the tracial states of the resolvent algebra are uniform locally finite dimensional.
description: 11 pages, minor revision, accepted for publication in Expo. Math
(500437) John Cairns
Creators: name: Professions, Victorian
Publisher: name: University of Oxford
Year: 2022
Subjects: subject: 220201 Business and Labour History
subject: FOS: Philosophy, ethics and religion
subject: History
subject: 140203 Economic History
subject: FOS: Economics and business

description: This three-year research project began in January 2014 and investigated whether, during the Victorian period, the professions formed a distinct self-sustaining social group with its own mores and values. The project looked at 16,000 individuals drawn from census data for Alnwick, Brighton, Bristol, Dundee, Greenock, Leeds, Merthyr Tydfil, Morpeth, and Winchester. The research project was funded by the UK Economic & Social Research Council and was based at the Universities of Oxford and Northumbria.
Cardioid Geometry as the Underpinning of Measurement-Induced Wave-Particle Transitions in the Higgs-Zeno Framework
Creators: name: Chatterjee, Dristi
Publisher: name: Zenodo
Year: 2025

description: Recent advances in the Higgs-Zeno framework have proposed that quantum measurement ac-tively constructs reality by regulating wave-particle transitions and energy distributions. Previouswork utilized Fibonacci-sequence recurrences to model measurement intervals; here, we present analternative approach that demonstrates how modular angular sampling and conformal mappingsnaturally yield a cardioid geometry in the measurement operator’s eigenvalue spectrum. This car-dioid structure provides new insight into the dynamics of decoherence, energy renormalization, andthe emergence of localized matter from quantum waves. Numerical simulations of decay rate sup-pression and modular phyllotaxis further validate the theoretical predictions.
Generalised Linear Model Trees with Global Additive Effects
Creators: name: Seibold, Heidi
name: Hothorn, Torsten
name: Zeileis, Achim
Publisher: name: arXiv
Year: 2016
Subjects: subject: Computation (stat.CO)
subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: Model-based trees are used to find subgroups in data which differ with respect to model parameters. In some applications it is natural to keep some parameters fixed globally for all observations while asking if and how other parameters vary across subgroups. Existing implementations of model-based trees can only deal with the scenario where all parameters depend on the subgroups. We propose partially additive linear model trees (PALM trees) as an extension of (generalised) linear model trees (LM and GLM trees, respectively), in which the model parameters are specified a priori to be estimated either globally from all observations or locally from the observations within the subgroups determined by the tree. Simulations show that the method has high power for detecting subgroups in the presence of global effects and reliably recovers the true parameters. Furthermore, treatment-subgroup differences are detected in an empirical application of the method to data from a mathematics exam: the PALM tree is able to detect a small subgroup of students that had a disadvantage in an exam with two versions while adjusting for overall ability effects.
Broadband DOA estimation using Convolutional neural networks trained with noise signals
Creators: name: Chakrabarty, Soumitro
name: Habets, Emanuël. A. P.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Sound (cs.SD)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: A convolution neural network (CNN) based classification method for broadband DOA estimation is proposed, where the phase component of the short-time Fourier transform coefficients of the received microphone signals are directly fed into the CNN and the features required for DOA estimation are learnt during training. Since only the phase component of the input is used, the CNN can be trained with synthesized noise signals, thereby making the preparation of the training data set easier compared to using speech signals. Through experimental evaluation, the ability of the proposed noise trained CNN framework to generalize to speech sources is demonstrated. In addition, the robustness of the system to noise, small perturbations in microphone positions, as well as its ability to adapt to different acoustic conditions is investigated using experiments with simulated and real data.
description: Published in Proceedings of IEEE Workshop on Applications of Signal Processing to Audio and Acoustics (WASPAA) 2017
Breathing Modes of Skyrmion Strings in a Synthetic Antiferromagnet
Creators: name: Barker, Christopher E. A.
name: Haltz, Eloi
name: Moore, Thomas A.
name: Marrows, Christopher H.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Skyrmions are small topologically protected magnetic structures that hold promise for applications from data storage to neuromorphic computing and they have been shown to possess internal microwave frequency excitations. Skyrmions in a synthetic antiferromagnet have been predicted to be smaller and faster than their ferromagnetic equivalents, and also shown to possess more internal modes. In this work we consider the breathing modes of skyrmions in a four repetition synthetic antiferromagnetic multilayer by means of micromagnetic simulations and examine the further splitting of the modes into different arrangements of out-of-phase and in-phase modes. This results in a lowering of frequencies which is promising for skyrmion sensing applications in a synthetic antiferromagnet.
description: 6 pages, 4 figures
(500438) Thomas Smith
Creators: name: Professions, Victorian
Publisher: name: University of Oxford
Year: 2022
Subjects: subject: 220201 Business and Labour History
subject: FOS: Philosophy, ethics and religion
subject: History
subject: 140203 Economic History
subject: FOS: Economics and business

description: This three-year research project began in January 2014 and investigated whether, during the Victorian period, the professions formed a distinct self-sustaining social group with its own mores and values. The project looked at 16,000 individuals drawn from census data for Alnwick, Brighton, Bristol, Dundee, Greenock, Leeds, Merthyr Tydfil, Morpeth, and Winchester. The research project was funded by the UK Economic & Social Research Council and was based at the Universities of Oxford and Northumbria.
Quantum symmetric pairs
Creators: name: Wang, Weiqiang
Publisher: name: arXiv
Year: 2021
Subjects: subject: Representation Theory (math.RT)
subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics

description: This is a survey of some recent progress on quantum symmetric pairs and applications. The topics include quasi K-matrices, $\imath$Schur duality, canonical bases, super Kazhdan-Lusztig theory, $\imath$Hall algebras, current presentations for affine $\imath$quantum groups, and braid group actions.
description: v2, 22 pages, a corrupted diagram corrected, journal references updated
Green-Blue Stripe Pattern for Range Sensing from a Single Image
Creators: name: Je, Changsoo
name: Choi, Kyuhyoung
name: Lee, Sang Wook
Publisher: name: arXiv
Year: 2017
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Graphics (cs.GR)
subject: FOS: Computer and information sciences
subject: I.2.10; I.4.8

description: In this paper, we present a novel method for rapid high-resolution range sensing using green-blue stripe pattern. We use green and blue for designing high-frequency stripe projection pattern. For accurate and reliable range recovery, we identify the stripe patterns by our color-stripe segmentation and unwrapping algorithms. The experimental result for a naked human face shows the effectiveness of our method.
description: 7 pages, 5 figures. Updated version of a conference paper
Cardioid Geometry as the Underpinning of Measurement-Induced Wave-Particle Transitions in the Higgs-Zeno Framework
Creators: name: Chatterjee, Dristi
Publisher: name: Zenodo
Year: 2025

description: Recent advances in the Higgs-Zeno framework have proposed that quantum measurement ac-tively constructs reality by regulating wave-particle transitions and energy distributions. Previouswork utilized Fibonacci-sequence recurrences to model measurement intervals; here, we present analternative approach that demonstrates how modular angular sampling and conformal mappingsnaturally yield a cardioid geometry in the measurement operator’s eigenvalue spectrum. This car-dioid structure provides new insight into the dynamics of decoherence, energy renormalization, andthe emergence of localized matter from quantum waves. Numerical simulations of decay rate sup-pression and modular phyllotaxis further validate the theoretical predictions.

 

AcknowledgementsThe author acknowledges the use of OpenAI's ChatGPT and DeepSeek as assistive tools in the development of ideas, refinement of theoretical models, and support in drafting and editing the manuscript. The AI was employed for brainstorming, language polishing, diagram suggestions, and exploring mathematical formulations, with all conceptual direction and final interpretations guided by the author.
(500439) James McDonald
Creators: name: Professions, Victorian
Publisher: name: University of Oxford
Year: 2022
Subjects: subject: 220201 Business and Labour History
subject: FOS: Philosophy, ethics and religion
subject: History
subject: 140203 Economic History
subject: FOS: Economics and business

description: This three-year research project began in January 2014 and investigated whether, during the Victorian period, the professions formed a distinct self-sustaining social group with its own mores and values. The project looked at 16,000 individuals drawn from census data for Alnwick, Brighton, Bristol, Dundee, Greenock, Leeds, Merthyr Tydfil, Morpeth, and Winchester. The research project was funded by the UK Economic & Social Research Council and was based at the Universities of Oxford and Northumbria.
Optimal trend following portfolios
Creators: name: Valeyre, Sebastien
Publisher: name: arXiv
Year: 2022
Subjects: subject: Portfolio Management (q-fin.PM)
subject: FOS: Economics and business

description: This paper derives an optimal portfolio that is based on trend-following signal. Building on an earlier related article, it provides a unifying theoretical setting to introduce an autocorrelation model with the covariance matrix of trends and risk premia. We specify practically relevant models for the covariance matrix of trends. The optimal portfolio is decomposed into four basic components that yield four basic portfolios: Markowitz, risk parity, agnostic risk parity, and trend following on risk parity. The overperformance of the proposed optimal portfolio, applied to cross-asset trading universe, is confirmed by empirical backtests. We provide thus a unifying framework to describe and rationalize earlier developed portfolios.
Electronic band gaps of confined linear carbon chains ranging from polyyne to carbyne
Creators: name: Shi, Lei
name: Rohringer, Philip
name: Wanko, Marius
name: Rubio, Angel
name: Waßerroth, Sören
name: Reich, Stephanie
name: Cambré, Sofie
name: Wenseleers, Wim
name: Ayala, Paola
name: Pichler, Thomas
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Ultra long linear carbon chains of more than 6000 carbon atoms have recently been synthesized within double-walled carbon nanotubes, and they show a promising new route to one--atom--wide semiconductors with a direct band gap. Theoretical studies predicted that this band gap can be tuned by the length of the chains, the end groups, and their interactions with the environment. However, different density functionals lead to very different values of the band gap of infinitely long carbyne. In this work, we applied resonant Raman excitation spectroscopy with more than 50 laser wavelengths to determine for the first time the band gap of long carbon chains encapsulated inside DWCNTs. The experimentally determined band gaps ranging from 2.253 to 1.848 eV follow a linear relation with Raman frequency. This lower bound is the smallest band gap of linear carbon chains observed so far. The comparison with experimental data obtained for short chains in gas phase or in solution demonstrates the effect of the DWCNT encapsulation, leading to an essential downshift of the band gap. This is explained by the interaction between the carbon chain and the host tube, which greatly modifies the chain's bond length alternation.
description: 7 pages, 5 figures
Advances in Nonlinear Model Predictive Control and Their Applications in Chemical Engineering
Creators: name: Lin, Kuan-han
Publisher: name: Carnegie Mellon University
Year: 2023
Subjects: Chemical Engineering not elsewhere classified

description: Model Predictive Control (MPC) has emerged as a promising optimization-based controller in various industrial applications because of its nature of coping with variable bounds and multiple-input-multiple-output (MIMO) dynamic processes. Non-linear MPC (NMPC) is the nonlinear branch of MPC that makes use of the nonlinear model and constraints to achieve higher accuracy for systems with complicated dynamics. However, the performance of NMPC is influenced by process uncertainty and computational delays. In addition, it faces stability challenges when considering economically oriented objectives. This thesis aims to enhance the performance of NMPC by developing advanced features that improve robustness, stability, and economic efficiency while maintaining reasonable online computation by leveraging both control and optimization theory. First, we consider the well pumping period in hydraulic fracturing and propose a robust control strategy aimed at addressing the constraint violations on operating pressure and terminal requirements resulted from the uncertainty in the rock layer. A comprehensive dynamic model that captures the process is constructed and incorporated into the predictive model of the robust multistage NMPC, which uses a scenario tree to depict the evolution of states with respect to uncertain parameters. The results demonstrate the promising robustness of the controller, as it satisfies all constraints in the face of the rock uncertainty that changes in time. Next, we develop a strategy to alleviate the online computational burden associated with solving Moving Horizon Estimation (MHE) problems, which is essential for NMPC when the process information is incomplete. We propose to solve an extended horizon MHE within a specified number of delayed sampling steps. This approach uses predicted future measurements in background and nonlinear programming (NLP) sensitivity to execute online corrections once the true measurements are available. The proposed algorithm is applied to a large-scale distillation column to show satisfactory estimation performance with negligible online computational effort. Finally, we propose two stable economic NMPC (eNMPC) formulations that achieve dual objectives of optimizing the economic goal and ensuring closed-loop stability. The proposed formulations track the optimality conditions of the real-time optimization problem instead of the exact setpoint, which eliminates the requirement of solving for the new setpoint when updating parameters related to the economic objective or system. We demonstrate the developed controllers on benchmark examples from the literature, including a continuous stirred-tank reactor and the aforementioned distillation column with improved economic results and guaranteed stability.
title: Modelling oceanic transport of planktonic species in the Southern Ocean
Creators: name: Mori, M
Publisher: name: University of Tasmania
Year: 2018

description: The Southern Ocean ecosystem is unique on a global scale because of complex ocean dynamics (e.g. fronts, eddies and their interaction with topography), seasonal sea ice advance and retreat, and biochemical cycles relating to all these physical factors. These ecosystems have been a↵ected by climate change over at least the last three decades and the assessment and evaluation of these changes - both at present, and for the future - are urgently required tasks. A key element in understanding and managing Southern Ocean ecosystem change is a better understanding of the physical processes that influence oceanic transport and spatial patterns of recruitment. Simulation models provide a powerful approach to address questions regarding transport processes, including testing alternative theories and predicting conditions under future climate change scenarios. This thesis develops methods for dispersal modelling to investigate transport of larval - juvenile stages of two important species: Patagonian toothfish and Antarctic krill. These approaches treat larval - juvenile stages as passive particles whose transport by ocean currents can be modelled using Lagrangian particle tracking. Key datasets used to inform this work are: i) remotely sensed surface geostrophic velocity data, ii) ocean model output and iii) physical parameters such as oceanic front position, topography and sea ice concentration. This thesis is composed of general introduction (Chapter 1), three main dispersal modelling works (Chapter 2–4) and discussion & conclusion (Chapter 5). The second chapter focuses on egg and larval transport of Patagonian toothfish on the Kerguelen Plateau, with results suggesting that successful spawning grounds and transport patterns are coincident with in situ observed data. The second and third chapters focus on Antarctic krill. In particular, Chapter 3 develops a biologically relevant measure of retention time and the results indicate a significant relationship between the length of retention time and observed krill population size. Here retention time is defined as the time that a particle remains in a particular region. Chapter 4 develops a model to test hypotheses for the formation of the observed phenomenon of surface krill patches. Such surface patches are composed mainly of young krill. Results from this chapter support the hypothesis that surfaces patches can form as a result of the release and transport of juvenile krill from the sea ice edge zone during spring and that the distribution of these patches may have shifted to the south due to reductions in sea ice extent over the last 80 years. The tools and methods developed in this thesis have broader applications for other biological particles and will be made available for use by other researchers as an R package.
(500440) Robert Swan
Creators: name: Professions, Victorian
Publisher: name: University of Oxford
Year: 2022
Subjects: subject: 220201 Business and Labour History
subject: FOS: Philosophy, ethics and religion
subject: History
subject: 140203 Economic History
subject: FOS: Economics and business

description: This three-year research project began in January 2014 and investigated whether, during the Victorian period, the professions formed a distinct self-sustaining social group with its own mores and values. The project looked at 16,000 individuals drawn from census data for Alnwick, Brighton, Bristol, Dundee, Greenock, Leeds, Merthyr Tydfil, Morpeth, and Winchester. The research project was funded by the UK Economic & Social Research Council and was based at the Universities of Oxford and Northumbria.
Thermoelectric Transport through SU(N) Kondo Impurity
Creators: name: Karki, D. B.
name: Kiselev, M. N.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We investigate thermoelectric transport through a SU(N) quantum impurity in the Kondo regime. The strong coupling fixed point theory is described by the local Fermi-liquid paradigm. Using Keldysh technique we analyse the electric current through the quantum impurity at both finite bias voltage and finite temperature drop across it. The theory of a steady state at zero-current provides a complete description of the Seebeck effect. We find pronounced non-linear effects in temperature drop at low temperatures. We illustrate the significance of the non-linearities for enhancement of thermopower by two examples of SU(4) symmetric regimes characterized by a filling factor m: i) particle-hole symmetric at m=2 and ii) particle-hole non-symmetric at m=1. We analyse the effects of potential scattering and coupling asymmetry on the transport coefficients. We discuss connections between the theory and transport experiments with coupled quantum dots and carbon nanotubes.
description: 8 pages including supplement, 3+1 figure, published at PRB (RAPID COMMUNICATIONS)