cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Monteiro spaces and rough sets determined by quasiorder relations: Models for Nelson algebras
Creators: name: Järvinen, Jouni
name: Radeleczki, Sándor
Publisher: name: arXiv
Year: 2014
Subjects: subject: Logic (math.LO)
subject: FOS: Mathematics
subject: 06B15 (Primary), 06D30, 08A05, 68T37, 06D10 (Secondary)

description: Rough sets induced by quasiorders appear in several constructions using binary relations in computer science. In this paper, a structural characterisation of rough sets induced by quasiorders is given. These rough sets form Nelson algebras defined on algebraic lattices. We prove that any Nelson algebra can be represented as a subalgebra of an algebra defined on rough sets induced by a suitable quasiorder. We also show that Monteiro spaces, rough sets induced by quasiorders and Nelson algebras defined on $\rm T_0$-spaces that are Alexandrov topologies can be considered as equivalent structures, because they determine each other up to isomorphism.
description: 10 pages, 1 figure; an example added
Wie kommen Seerosen und Sumpferz auf den Markt?
Creators: name: Meurers-Balke, Jutta
name: Zerl, Tanja
name: Gerlach, Renate
name: Eckmeier, Eileen
name: Kalis, Arie J.
Publisher: name: Archäologie im Rheinland
Year: 2022

description: Archäologie im Rheinland, 2013(2014)
The weak decays of $Ξ^{(')}_{c}\toΞ$ in the light-front quark model
Creators: name: Ke, Hong-Wei
name: Kang, Qing-Qing
name: Liu, Xiao-Hai
name: Li, Xue-Qian
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Without contamination from the final state interactions, the calculation of the branching ratios of semileptonic decays $Ξ^{(')}_{c}\toΞ+e^+ν_e$ may provide us more information about the inner structure of charmed baryons. Moreover, by studying those processes, one can better determine the form factors of $Ξ_c\toΞ$ which can be further applied to relevant estimates. In this work, we use the light-front quark model to carry out the computations where the three-body vertex functions for $Ξ_c$ and $Ξ$ are employed. To fit the new data of the Belle II, we re-adjust the model parameters and obtain $β_{s[sq]}=1.07$ GeV which is 2.9 times larger than $β_{s\bar s}=0.366$ GeV. This value may imply that the $ss$ pair in $Ξ$ constitutes a more compact subsystem. Furthermore, we also investigate the non-leptonic decays of $Ξ^{(')}_c\to Ξ$ which will be experimentally measured soon, so our model would be tested by consistency with the new data.
description: 10 pages, 3 figures and 6 tables. arXiv admin note: text overlap with arXiv:1912.01435
Equivalence between simulability of high-dimensional measurements and high-dimensional steering
Creators: name: Jones, Benjamin D. M.
name: Uola, Roope
name: Cope, Thomas
name: Ioannou, Marie
name: Designolle, Sébastien
name: Sekatski, Pavel
name: Brunner, Nicolas
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The effect of quantum steering arises from the judicious combination of an entangled state with a set of incompatible measurements. Recently, it was shown that this form of quantum correlations can be quantified in terms of a dimension, leading to the notion of genuine high-dimensional steering. While this naturally connects to the dimensionality of entanglement (Schmidt number), we show that this effect also directly connects to a notion of dimension for measurement incompatibility. More generally, we present a general connection between the concepts of steering and measurement incompatibility, when quantified in terms of dimension. From this connection, we propose a novel twist on the problem of simulating quantum correlations. Specifically, we show how the correlations of certain high-dimensional entangled states can be exactly recovered using only shared randomness and lower-dimensional entanglement. Finally, we derive criteria for testing the dimension of measurement incompatibility, and discuss the extension of these ideas to quantum channels.
description: 10 pages, 2 figures
Highly Dispersed Networks
Creators: name: Gabel, Alan
name: Krapivsky, P. L.
name: Redner, S.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: We introduce a new class of networks that grow by enhanced redirection. Nodes are introduced sequentially, and each either attaches to a randomly chosen target node with probability 1-r or to the ancestor of the target with probability r, where r an increasing function of the degree of the ancestor. This mechanism leads to highly-dispersed networks with unusual properties: (i) existence of multiple macrohubs---nodes whose degree is a finite fraction of the total number of network nodes N, (ii) lack of self averaging, and (iii) anomalous scaling, in which N_k, the number of nodes of degree k scales as N_k N^{nu-1}/k^{nu}, with 1
description: 4 pages, 6 figures, 2-column revtex4 format
Two 6d origins of 4d SCFTs: class $\mathcal{S}$ and 6d (1,0) on a torus
Creators: name: Baume, Florent
name: Kang, Monica Jinwoo
name: Lawrie, Craig
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider all 4d $\mathcal{N}=2$ theories of class $\mathcal{S}$ arising from the compactification of exceptional 6d $(2,0)$ SCFTs on a three-punctured sphere with a simple puncture. We find that each of these 4d theories has another origin as a 6d $(1,0)$ SCFT compactified on a torus, which we check by identifying and comparing the central charges and the flavor symmetry. Each 6d theory is identified with a complex structure deformation of $(\mathfrak{e}_n,\mathfrak{e}_n)$ minimal conformal matter, which corresponds to a Higgs branch renormalization group flow. We find that this structure is precisely replicated by the partial closure of the punctures in the class $\mathcal{S}$ construction. We explain how the plurality of origins makes manifest some aspects of 4d SCFTs, including flavor symmetry enhancements and determining if it is a product SCFT. We further highlight the string theoretic basis for this identification of 4d theories from different origins via mirror symmetry.
description: 54 pages + references, 10 tables, 8 figures, Journal published version
Economic Dispatch of an Integrated Microgrid Based on the Dynamic Process of CCGT Plant
Creators: name: Lin, Zhiyi
name: Song, Chunyue
name: Zhao, Jun
name: Yang, Chao
name: Yin, Huan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Intra-day economic dispatch of an integrated microgrid is a fundamental requirement to integrate distributed generators. The dynamic energy flows in cogeneration units present challenges to the energy management of the microgrid. In this paper, a novel approximate dynamic programming (ADP) approach is proposed to solve this problem based on value function approximation, which is distinct with the consideration of the dynamic process constraints of the combined-cycle gas turbine (CCGT) plant. First, we mathematically formulate the multi-time periods decision problem as a finite-horizon Markov decision process. To deal with the thermodynamic process, an augmented state vector of CCGT is introduced. Second, the proposed VFA-ADP algorithm is employed to derive the near-optimal real-time operation strategies. In addition, to guarantee the monotonicity of piecewise linear function, we apply the SPAR algorithm in the update process. To validate the effectiveness of the proposed method, we conduct experiments with comparisons to some traditional optimization methods. The results indicate that our proposed ADP method achieves better performance on the economic dispatch of the microgrid.
description: This paper has won the Zhang Si-Ying (CCDC) Outstanding Youth Paper Award in the 33 rd Chinese Control and Decision Conference (CCDC 2021)
Framework for the Application of Robust Design Methods and Tools
Creators: name: Göhler, Moritz
name: Howard, Thomas J.
Publisher: name: Technical University of Denmark, DTU : International Symposium on Robust Design
Year: 2014

description: Robust Design Methods (RDM) have become a powerful concept to design more reliable products. However, even though there are many tools available and have been discussed widely in academia, there is still confusion and doubts in the industry about the use and effectiveness of these methods. Mostly the problems experienced in industry are related to a poor application or knowledge of the methods by the companies (Hasenkamp, et Al, 2007). Based on the authors� experiences in working in development engineering, it has shown that also the phase of application of the specific tools and methods and what those can deliver are not always clear. Expectations to the output are sometimes misleading and imply the incorrect utilization of tools.
A categorization of tools, methods and techniques typically associated with robust design methodology in the literature is provided in this paper in terms of purpose and deliverables of the individual tool or method. The majority of tools aims for optimizing an existing design solution or give an indication of how robust a design is, which requires a somewhat settled design. Furthermore, the categorization presented in this paper shows a lack in the methodology for tools in the area of robustness prediction in early design.
This categorization clarifies the underlying premises and deliverables of RDM tools for professionals working with design processes and can serve as guidance for an organization how to structure its development process and how to make most efficient use of the existing tools. When to apply, what tool or method, for which purpose can be concluded.
The paper also contributes with a framework for researchers to derive a generic landscape or database for RDM build upon the main premises and deliverables of each method.
Existence results for systems with nonlinear coupled nonlocal initial conditions
Creators: name: Bolojan-Nica, Octavia
name: Infante, Gennaro
name: Precup, Radu
Publisher: name: arXiv
Year: 2013
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: Primary 34A34, secondary 34A12, 34B10, 47H10

description: The purpose of the present work is to study the existence of solutions to initial value problems for nonlinear first order differential systems with nonlinear nonlocal boundary conditions of functional type. The existence results are established by means of the Perov, Schauder and Leray-Schauder fixed point principles combined with a technique based on vector-valued metrics and convergent to zero matrices.
description: 12 pages
Experimental validation of fluid inertia models for a cylinder settling in a quiescent flow
Creators: name: Cabrera, F.
name: Sheikh, M. Z.
name: Mehlig, B.
name: Plihon, N.
name: Bourgoin, M.
name: Pumir, A.
name: Naso, A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: The precise description of the motion of anisotropic particles in a flow rests on the understanding of the force and torque acting on them. Here, we study experimentally small, very elongated particles settling in a fluid at small Reynolds number. In our experiments, we can, to a very good approximation, relate the rate of rotation of cylindrical tungsten rods, of aspect ratios β= 8 and β= 16, settling in pure glycerol to the torque they are experiencing. This allows us to compare the measured torque with expressions obtained either in the slender-rod limit, or in the case of spheroids. Both theories predict a simple angle dependence for the torque, which is found to capture very well the experimental results. Surprisingly, the slender-rod approximation predicts much better the results for β= 8, than for β= 16. In the latter case, the expression obtained for a spheroid provides a better approximation. The translational dynamics is shown to be in qualitative agreement with the slender-rod and spheroid models, the former one being found to represent better the experimental data.
description: 15 pages, 7 figures
title: Der Bulldogg und die aristokratischen Hunde; [1848?]
title: Ui! Da schaut's her, itzt hat der 's Boan.
titleType: Subtitle
Creators: name: Ranftl, Matthias
Publisher: name: Universitätsbibliothek der Ludwig-Maximilians-Universität München
Year: 2018

description: Vorlageform der Veröffentlichungsangabe: Druck von Jos. Keck und Sohn. Das Blatt kostet 3 kr. Conv. Münze.
Stein Variational Gradient Descent with Multiple Kernel
Creators: name: Ai, Qingzhong
name: Liu, Shiyu
name: He, Lirong
name: Xu, Zenglin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: Stein variational gradient descent (SVGD) and its variants have shown promising successes in approximate inference for complex distributions. In practice, we notice that the kernel used in SVGD-based methods has a decisive effect on the empirical performance. Radial basis function (RBF) kernel with median heuristics is a common choice in previous approaches, but unfortunately this has proven to be sub-optimal. Inspired by the paradigm of Multiple Kernel Learning (MKL), our solution to this flaw is using a combination of multiple kernels to approximate the optimal kernel, rather than a single one which may limit the performance and flexibility. Specifically, we first extend Kernelized Stein Discrepancy (KSD) to its multiple kernels view called Multiple Kernelized Stein Discrepancy (MKSD) and then leverage MKSD to construct a general algorithm Multiple Kernel SVGD (MK-SVGD). Further, MKSVGD can automatically assign a weight to each kernel without any other parameters, which means that our method not only gets rid of optimal kernel dependence but also maintains computational efficiency. Experiments on various tasks and models demonstrate that our proposed method consistently matches or outperforms the competing methods.
Parameters of the brightest star formation regions in the two principal spiral arms of NGC 628
Creators: name: Gusev, Alexander S.
name: Egorov, Oleg V.
name: Sakhibov, Firouz
Publisher: name: arXiv
Year: 2013
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We study photometric properties, chemical abundances and sizes of star formation regions in the two principal arms of the galaxy NGC 628 (M74). The GALEX ultraviolet, optical UBVRI, and H-alpha? surface photometry data are used, including those obtained with the 1.5-m telescope of the Maidanak Observatory. The thirty brightest star formation regions in ultraviolet light located in the spiral arms of NGC 628 are identified and studied. We find that the star formation regions in one (longer) arm are systematically brighter and larger than the regions in the other (shorter) arm. However, both luminosity and size distribution functions have approximately the same slopes for the samples of star formation regions in both arms. The star formation regions in the longer arm have a higher star formation rate density than the regions in the shorter arm. The regions in the shorter arm show higher N/O ratio at a higher oxygen abundance, but they have lower ultraviolet and H-alpha? luminosities. These findings can be explained if we assume that star formation regions in the shorter arm had higher star formation rate in the past, but now it is lower than for those in the opposite arm. Results of stellar evolutionary synthesis show that the brightest regions in the longer arm are slightly younger than the ones in the shorter arm (3.5+-2.2 Myr versus 6.0+-1.1 Myr). Our results demonstrate that there is a difference in the inner structures and parameters of the interstellar medium between the spiral arms of NGC 628, one of which is long and hosts a regular chain of bright star formation complexes and the other, shorter one does not.
description: 15 pages, 12 figures, 5 tables. Accepted for publication in MNRAS
Neue Untersuchungen zur Siedlungs- und Landschaftsarchäologie in Vilich-Müldorf
Creators: name: El-Kassem, Marcel
name: Maass, Carsten
name: Sambale, Tom
Publisher: name: Archäologie im Rheinland
Year: 2022

description: Archäologie im Rheinland, 2013(2014)
Data synthesis and adversarial networks: A review and meta-analysis in cancer imaging
Creators: name: Osuala, Richard
name: Kushibar, Kaisar
name: Garrucho, Lidia
name: Linardos, Akis
name: Szafranowska, Zuzanna
name: Klein, Stefan
name: Glocker, Ben
name: Diaz, Oliver
name: Lekadir, Karim
Publisher: name: arXiv
Year: 2021
Subjects: subject: Image and Video Processing (eess.IV)
subject: Artificial Intelligence (cs.AI)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Despite technological and medical advances, the detection, interpretation, and treatment of cancer based on imaging data continue to pose significant challenges. These include inter-observer variability, class imbalance, dataset shifts, inter- and intra-tumour heterogeneity, malignancy determination, and treatment effect uncertainty. Given the recent advancements in Generative Adversarial Networks (GANs), data synthesis, and adversarial training, we assess the potential of these technologies to address a number of key challenges of cancer imaging. We categorise these challenges into (a) data scarcity and imbalance, (b) data access and privacy, (c) data annotation and segmentation, (d) cancer detection and diagnosis, and (e) tumour profiling, treatment planning and monitoring. Based on our analysis of 164 publications that apply adversarial training techniques in the context of cancer imaging, we highlight multiple underexplored solutions with research potential. We further contribute the Synthesis Study Trustworthiness Test (SynTRUST), a meta-analysis framework for assessing the validation rigour of medical image synthesis studies. SynTRUST is based on 26 concrete measures of thoroughness, reproducibility, usefulness, scalability, and tenability. Based on SynTRUST, we analyse 16 of the most promising cancer imaging challenge solutions and observe a high validation rigour in general, but also several desirable improvements. With this work, we strive to bridge the gap between the needs of the clinical cancer imaging community and the current and prospective research on data synthesis and adversarial networks in the artificial intelligence community.
description: v2, 51 pages, 15 Figures, 9 Tables, accepted for publication in Medical Image Analysis
$U_{\mathfrak{q}}(\mathfrak{sl}_3)$ web models: Locality, phase diagram and geometrical defects
Creators: name: Lafay, Augustin
name: Gainutdinov, Azat M.
name: Jacobsen, Jesper Lykke
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: Quantum Algebra (math.QA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We continue investigating the generalisations of geometrical statistical models introduced in [13], in the form of models of webs on the hexagonal lattice H having a U_q(sl_n) quantum group symmetry. We focus here on the n=3 case of cubic webs, based on the Kuperberg A_2 spider, and illustrate its properties by comparisons with the well-known dilute loop model (the n=2 case) throughout. A local vertex-model reformulation is exhibited, analogous to the correspondence between the loop model and a three-state vertex model. The n=3 representation uses seven states per link of H, displays explicitly the geometrical content of the webs and their U_q(sl_3) symmetry, and permits us to study the model on a cylinder via a local transfer matrix. A numerical study of the central charge reveals that for each q $\in \mathbb{C}$ in the critical regime, |q|=1, the web model possesses a dense and a dilute critical point, just like its loop model counterpart. In the dense $q=-e^{i π/4}$ case, the n=3 webs can be identified with spin interfaces of the critical three-state Potts model defined on the triangular lattice dual to H. We also provide another mapping to a $\mathbb{Z}_3$ spin model on H itself, using a high-temperature expansion. We then discuss the sector structure of the transfer matrix, for generic q, and its relation to defect configurations in both the strip and the cylinder geometries. These defects define the finite-size precursors of electromagnetic operators. This discussion paves the road for a Coulomb gas description of the conformal properties of defect webs, which will form the object of a subsequent paper. Finally, we identify the fractal dimension of critical webs in the $q=-e^{i π/3}$ case, which is the n=3 analogue of the polymer limit in the loop model.
IJMTE_Spicejet_SudeepChandramana_Nov2018.pdf
Creators: name: Sudeep B Chandramana
Publisher: name: figshare
Year: 2020
Subjects: subject: 150701 Air Transportation and Freight Services
subject: FOS: Economics and business
subject: 150503 Marketing Management (incl. Strategy and Customer Relations)
subject: 150504 Marketing Measurement
subject: 150604 Tourism Marketing

description: Aviation in India is the fastest-growing aviation market in the world according to International Air TransportAssociation (IATA) data. IndiGo, Jet Airways, Air India, Spicejet and GoAir are the major carriers in the Indianaviation industry.India is the world's third-largest domestic and overall civil aviation market. This case studyanalyses the airline industry structure till the year 2013 in general, and the performance of one of the playerSpicejet in particular, during this period. It also provides certain pointers for improving the functioning andoperations of Spicejet
The Separation Capacity of Random Neural Networks
Creators: name: Dirksen, Sjoerd
name: Genzel, Martin
name: Jacques, Laurent
name: Stollenwerk, Alexander
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Statistics Theory (math.ST)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: Neural networks with random weights appear in a variety of machine learning applications, most prominently as the initialization of many deep learning algorithms and as a computationally cheap alternative to fully learned neural networks. In the present article, we enhance the theoretical understanding of random neural networks by addressing the following data separation problem: under what conditions can a random neural network make two classes $\mathcal{X}^-, \mathcal{X}^+ \subset \mathbb{R}^d$ (with positive distance) linearly separable? We show that a sufficiently large two-layer ReLU-network with standard Gaussian weights and uniformly distributed biases can solve this problem with high probability. Crucially, the number of required neurons is explicitly linked to geometric properties of the underlying sets $\mathcal{X}^-, \mathcal{X}^+$ and their mutual arrangement. This instance-specific viewpoint allows us to overcome the usual curse of dimensionality (exponential width of the layers) in non-pathological situations where the data carries low-complexity structure. We quantify the relevant structure of the data in terms of a novel notion of mutual complexity (based on a localized version of Gaussian mean width), which leads to sound and informative separation guarantees. We connect our result with related lines of work on approximation, memorization, and generalization.
description: The current version of the manuscript has been accepted to Journal of Machine Learning Research
Convergence analysis for image interpolation in terms of the cSSIM
Creators: name: Marchetti, Francesco
name: Santin, Gabriele
Publisher: name: arXiv
Year: 2021
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: Assessing the similarity of two images is a complex task that attracts significant efforts in the image processing community. The widely used Structural Similarity Index Measure (SSIM) addresses this problem by quantifying a perceptual structural similarity. In this paper we consider a recently introduced continuous SSIM (cSSIM), which allows one to analyze sequences of images of increasingly fine resolutions, and further extend the definition of the index to encompass the locally weighted version that is used in practice. For both the local and the global versions, we prove that the continuous index includes the classical SSIM as a special case, and we provide a precise connection between image similarity measured by the cSSIM and by the $L_2$ norm. Using this connection, we derive bounds on the cSSIM by means of bounds on the $L_2$ error, and we even prove that the two error measures are equivalent in certain circumstances. We exploit these results to obtain precise rates of convergence with respect to the cSSIM for several concrete image interpolation methods, and we further validate these findings by different numerical experiments. This newly established connection paves the way to obtain novel insights into the features and limitations of the SSIM, including on the effect of the local weighted window on the index performances.
Mixing Energy Models in Genetic Algorithms for On-Lattice Protein Structure Prediction
Creators: name: Rashid, Mahmood A.
name: Newton, M. A. Hakim
name: Hoque, Md. Tamjidul
name: Sattar, Abdul
Publisher: name: arXiv
Year: 2013
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: Neural and Evolutionary Computing (cs.NE)
subject: FOS: Computer and information sciences

description: Protein structure prediction (PSP) is computationally a very challenging problem. The challenge largely comes from the fact that the energy function that needs to be minimised in order to obtain the native structure of a given protein is not clearly known. A high resolution 20x20 energy model could better capture the behaviour of the actual energy function than a low resolution energy model such as hydrophobic polar. However, the fine grained details of the high resolution interaction energy matrix are often not very informative for guiding the search. In contrast, a low resolution energy model could effectively bias the search towards certain promising directions. In this paper, we develop a genetic algorithm that mainly uses a high resolution energy model for protein structure evaluation but uses a low resolution HP energy model in focussing the search towards exploring structures that have hydrophobic cores. We experimentally show that this mixing of energy models leads to significant lower energy structures compared to the state-of-the-art results.
description: Volume 2013, 15 pages, BioMed Research International, 2013
New Quantum Invariants of Planar Knotoids
Creators: name: Moltmaker, Wout
name: van der Veen, Roland
Publisher: name: arXiv
Year: 2022
Subjects: subject: Geometric Topology (math.GT)
subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics
subject: 57K10, 57K12, 57K16, 16T99

description: In this paper we discuss the applications of knotoids to modelling knots in open curves and produce new knotoid invariants. We show how invariants of knotoids generally give rise to well-behaved measures of how much an open curve is knotted. We define biframed planar knotoids, and construct new invariants of these objects that can be computed in polynomial time. As an application of these invariants we improve the classification of planar knotoids with up to five crossings by distinguishing several pairs of prime knotoids that were conjectured to be distinct by Goundaroulis et al.
description: 29 pages, 21 figures, comments are welcome
Time-resolved PhotoEmission Spectroscopy on a Metal/Ferroelectric Heterostructure
Creators: name: Rault, J. E.
name: Agnus, G.
name: Maroutian, T.
name: Pillard, V.
name: Lecoeur, Ph.
name: Niu, G.
name: Vilquin, B.
name: Bendounan, A.
name: Silly, M. G.
name: Sirotti, F.
name: Barrett, N.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In thin film ferroelectric capacitor the chemical and electronic structure of the electrode/FE interface can play a crucial role in determining the kinetics of polarization switching. We investigate the electronic structure of a Pt/BaTiO3/SrTiO3:Nb capacitor using time-resolved photoemission spectroscopy. The chemical, electronic and depth sensitivity of core level photoemission is used to probe the transient response of different parts of the upper electrode/ferroelectric interface to voltage pulse induced polarization reversal. The linear response of the electronic structure agrees quantitatively with a simple RC circuit model. The non-linear response due to the polarization switch is demonstrated by the time-resolved response of the characteristic core levels of the electrode and the ferroelectric. Adjustment of the RC circuit model allows a first estimation of the Pt/BTO interface capacitance. The experiment shows the interface capacitance is at least 100 times higher than the bulk capacitance of the BTO film, in qualitative agreement with theoretical predictions from the literature.
description: 7 pages, 10 figures. Submitted to Phys. Rev. B
Clustering acoustic emission data streams with sequentially appearing clusters using mixture models
Creators: name: Ramasso, Emmanuel
name: Denoeux, Thierry
name: Chevallier, Gael
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (stat.ML)
subject: Machine Learning (cs.LG)
subject: Sound (cs.SD)
subject: Applications (stat.AP)
subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: The interpretation of unlabeled acoustic emission (AE) data classically relies on general-purpose clustering methods. While several external criteria have been used in the past to select the hyperparameters of those algorithms, few studies have paid attention to the development of dedicated objective functions in clustering methods able to cope with the specificities of AE data. We investigate how to explicitly represent clusters onsets in mixture models in general, and in Gaussian Mixture Models (GMM) in particular. By modifying the internal criterion of such models, we propose the first clustering method able to provide, through parameters estimated by an expectation-maximization procedure, information about when clusters occur (onsets), how they grow (kinetics) and their level of activation through time. This new objective function accommodates continuous timestamps of AE signals and, thus, their order of occurrence. The method, called GMMSEQ, is experimentally validated to characterize the loosening phenomenon in bolted structure under vibrations. A comparison with three standard clustering methods on raw streaming data from five experimental campaigns shows that GMMSEQ not only provides useful qualitative information about the timeline of clusters, but also shows better performance in terms of cluster characterization. In view of developing an open acoustic emission initiative and according to the FAIR principles, the datasets and the codes are made available to reproduce the research of this paper.
Rediscovering a Little Known Fact about the t-test and the F-test: Algebraic, Geometric, Distributional and Graphical Considerations
Creators: name: Sinnott, Jennifer A.
name: MacEachern, Steven N.
name: Peruggia, Mario
Publisher: name: Statistica
Year: 2023

description: We discuss the role that the null hypothesis should play in the construction of a test statistic used to make a decision about that hypothesis. To construct the test statistic for a point null hypothesis about a binomial proportion, a common recommendation is to act as if the null hypothesis is true. We argue that, on the surface, the one-sample t -test of a point null hypothesis about a Gaussian population mean does not appear to follow the recommendation. We show how simple algebraic manipulations of the usual t-statistic lead to an equivalent test procedure consistent with the recommendation. We provide geometric intuition regarding this equivalence and we consider extensions to testing nested hypotheses in Gaussian linear models. We discuss an application to graphical residual diagnostics where the form of the test statistic makes a practical difference. By examining the formulation of the test statistic from multiple perspectives in this familiar example, we provide simple, concrete illustrations of some important issues that can guide the formulation of effective solutions to more complex statistical problems.
description: Statistica, Vol. 82 No. 2 (2022)
Fractals of graphene quantum dots in photoluminescence of shungite
Creators: name: Razbirin, B. S.
name: Rozhkova, N. N
name: Sheka, E. F.
name: Nelson, D. K.
name: Starukhin, A. N.
name: Goryunov, A. S.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Photoluminescence of graphene quantum dots (GQDs) of shungite, attributed to individual fragments of reduced graphene oxide (rGO), has been studied for the frozen rGO colloidal dispersions in water, carbon tetrachloride, and toluene. Morphological study shows a steady trend of GQDs to form fractals and a drastic change in the colloids fractal structure caused by solvent was reliably established. Spectral study reveals a dual character of emitting centers: individual GQDs are responsible for the spectra position while fractal structure of GQD colloids provides high broadening of the spectra due to structural inhomogeneity of the colloidal dispersions and a peculiar dependence on excitation wavelength. For the first time, photoluminescence spectra of individual GQDs were observed in frozen toluene dispersions which pave the way for a theoretical treatment of GQD photonics.
description: 10 pages, 8 figures
Network Regression with Graph Laplacians
Creators: name: Zhou, Yidong
name: Müller, Hans-Georg
Publisher: name: arXiv
Year: 2021
Subjects: subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: Network data are increasingly available in various research fields, motivating statistical analysis for populations of networks where a network as a whole is viewed as a data point. Due to the non-Euclidean nature of networks, basic statistical tools available for scalar and vector data are no longer applicable when one aims to relate networks as outcomes to Euclidean covariates, while the study of how a network changes in dependence on covariates is often of paramount interest. This motivates to extend the notion of regression to the case of responses that are network data. Here we propose to adopt conditional Fréchet means implemented with both global least squares regression and local weighted least squares smoothing, extending the Fréchet regression concept to networks that are quantified by their graph Laplacians. The challenge is to characterize the space of graph Laplacians so as to justify the application of Fréchet regression. This characterization then leads to asymptotic rates of convergence for the corresponding M-estimators by applying empirical process methods. We demonstrate the usefulness and good practical performance of the proposed framework with simulations and with network data arising from resting-state fMRI in neuroimaging, as well as New York taxi records.
description: 41 pages, 13 figures
Michelsberg, Metallzeiten, Mittelalter und mehr – Siedlungsbefunde in Rommerskirchen
Creators: name: Husmann, Horst
name: Jürgens, Sabine
name: Krieger, Elisabeth
name: Weiler-Rahnfeld, Ivonne
Publisher: name: Archäologie im Rheinland
Year: 2022

description: Archäologie im Rheinland, 2013(2014)
A remarkable recurrent nova in M31 - The optical observations
Creators: name: Darnley, M. J.
name: Williams, S. C.
name: Bode, M. F.
name: Henze, M.
name: Ness, J. -U.
name: Shafter, A. W.
name: Hornoch, K.
name: Votruba, V.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Context: In late November 2013 a fifth eruption in five years of the M31 recurrent nova M31N 2008-12a was announced. Aims: In this Letter we address the optical lightcurve and progenitor system of M31N 2008-12a. Methods: Optical imaging data of the 2013 eruption from the Liverpool Telescope, La Palma, and Danish 1.54m Telescope, La Silla, and archival Hubble Space Telescope near-IR, optical and near-UV data are astrometrically and photometrically analysed. Results: Photometry of the 2013 eruption, combined with three previous eruptions, enabled construction of a template light curve of a very fast nova, t2(V)~4 days. The archival data allowed recovery of the progenitor system in optical and near-UV data, indicating a red-giant secondary with bright accretion disk, or alternatively a system with a sub-giant secondary but dominated by a disk. Conclusions: The eruptions of M31N 2008-12a, and a number of historic X-ray detections, indicate a unique system with a recurrence timescale of ~1 year. This implies the presence of a very high mass white dwarf and a high accretion rate. The recovered progenitor system is consistent with such an elevated rate of accretion.We encourage additional observations, especially towards the end of 2014.
description: 4 pages, 4 figures, accepted for publication in Astronomy & Astrophysics Letters (updated to mirror accepted version)
Norm principle for even K-groups of number fields
Creators: name: Lim, Meng Fai
Publisher: name: arXiv
Year: 2021
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics

description: We investigate the norm maps of algebraic even $K$-groups of finite extensions of number fields. Namely, we show that they are surjective in most situations. In the event that they are not surjective, we give a criterion in determining when an element in the even $K$-group of the base field comes from a norm of an element from the even $K$-groups of the extension field. This latter criterion is only reliant on the real primes of the base field.
description: Slight change in Title and abstract as recommended by referees (basically replace "$K_{2n}$" by "even K-groups"); some minor corrections and changes in the body of the paper
Hopping Transport through Defect-induced Localized States in Molybdenum Disulfide
Creators: name: Qiu, Hao
name: Xu, Tao
name: Wang, Zilu
name: Ren, Wei
name: Nan, Haiyan
name: Ni, Zhenhua
name: Chen, Qian
name: Yuan, Shijun
name: Miao, Feng
name: Song, Fengqi
name: Long, Gen
name: Shi, Yi
name: Sun, Litao
name: Wang, Jinlan
name: Wang, Xinran
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Molybdenum disulfide is a novel two-dimensional semiconductor with potential applications in electronic and optoelectronic devices. However, the nature of charge transport in back-gated devices still remains elusive as they show much lower mobility than theoretical calculations and native n-type doping. Here we report transport study in few-layer molybdenum disulfide, together with transmission electron microscopy and density functional theory. We provide direct evidence that sulfur vacancies exist in molybdenum disulfide, introducing localized donor states inside the bandgap. Under low carrier densities, the transport exhibits nearest-neighbor hopping at high temperatures and variable-range hopping at low temperatures, which can be well explained under Mott formalism. We suggest that the low-carrier-density transport is dominated by hopping via these localized gap states. Our study reveals the important role of short-range surface defects in tailoring the properties and device applications of molybdenum disulfide.
description: 35 pages, 4 figures. To appear in Nature Communications
Analyzing territorial governance to prevent occupational risks in the sector of waste management
Creators: name: BOUDRA, Leïla
name: BEGUIN, Pascal
Publisher: name: CPH Conference : 11th International Symposium on Human Factors in Organisational Design and Management
Year: 2014

description: Waste recycling management, in France, depends on numerous decisions made
between policy makers acting at different levels. Focusing on research carried out in four waste sorting centers, we analyze the dimensions of the territory that impact on working conditions for operators. System performance in terms of sustainable development raises the essential question of sectors and flows of waste collected. However, it also appears that the latter and the collection process are central issues for prevention (in terms of employee health, safety and welfare). We examine the design process and seek disconnections between the sorting center and its territory that impact work activity. Our goal is therefore to identify margins of maneuver for safeguarding occupational health and preventing risks.
Mathematical structures of non-perturbative topological string theory: from GW to DT invariants
Creators: name: Alim, Murad
name: Saha, Arpan
name: Teschner, Joerg
name: Tulli, Iván
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: Algebraic Geometry (math.AG)
subject: Differential Geometry (math.DG)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We study the Borel summation of the Gromov-Witten potential for the resolved conifold. The Stokes phenomena associated to this Borel summation are shown to encode the Donaldson-Thomas invariants of the resolved conifold, having a direct relation to the Riemann-Hilbert problem formulated by T. Bridgeland. There exist distinguished integration contours for which the Borel summation reproduces previous proposals for the non-perturbative topological string partition functions of the resolved conifold. These partition functions are shown to have another asymptotic expansion at strong topological string coupling. We demonstrate that the Stokes phenomena of the strong-coupling expansion encode the DT invariants of the resolved conifold in a second way. Mathematically, one finds a relation to Riemann-Hilbert problems associated to DT invariants which is different from the one found at weak coupling. The Stokes phenomena of the strong-coupling expansion turn out to be closely related to the wall-crossing phenomena in the spectrum of BPS states on the resolved conifold studied in the context of supergravity by D. Jafferis and G. Moore.
description: 65 pages, 1 figure. Typos fixed and references added. Discussion in Section 2.2 and 6.1 expanded. Definition 4.7 (Def. 28 in v1) slightly modified, strengthening the previous Prop. 40 of v1 to the new Prop. 4.20 of v2. Corollary 3.13, 4.8 and Lemma B.2 added
CCTV supervision or surveillance - what's in a name ?
Creators: name: SCHREIBERS, Kirsten
name: LANDMAN, Renske
name: JANSEN, Jorrit
name: Van Der WEIDE, Richard
name: De BRUIJN, David
Publisher: name: CPH Conference : 11th International Symposium on Human Factors in Organisational Design and Management
Year: 2014

description: Extensive literature search revealed poorly evidenced Human Factors guidelines
for CCTV systems. Case studies were done to get more insight in relevant Human Factors issues. A task taxonomy was found on surveillance. Do CCTV tasks in process control significantly differ from surveillance tasks? And is this so distinctive that it requires different Human Factors guidelines for CCTV system design? This study shows it is distinctive when looking at tasks. A task related concept of 'scene' is introduced instead of other workload measures covering image content or complexity.
Dynamical parity selection in superconducting weak links
Creators: name: Ackermann, Nico
name: Zazunov, Alex
name: Park, Sunghun
name: Egger, Reinhold
name: Yeyati, Alfredo Levy
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Excess quasiparticles play a crucial role in superconducting quantum devices ranging from qubits to quantum sensors. In this work we analyze their dynamics for phase-biased finite-length weak links with several Andreev subgap states, where the coupling to a microwave resonator allows for parity state (even/odd) readout. Our theory shows that almost perfect dynamical polarization in a given parity sector is achievable by applying a microwave pulse matching a transition in the opposite parity sector. Our results qualitatively explain key features of recent experiments on hybrid semiconducting nanowire Josephson junctions and provide theoretical guidelines for efficiently controlling the parity state of Andreev qubits.
description: 14 pages, 7 figures, accepted for publication in Phys. Rev. B
Counting and correcting thermodynamically infeasible flux cycles in genome-scale metabolic networks
Creators: name: De Martino, Daniele
name: Capuani, Fabrizio
name: Mori, Matteo
name: De Martino, Andrea
name: Marinari, Enzo
Publisher: name: arXiv
Year: 2013
Subjects: subject: Molecular Networks (q-bio.MN)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Biological Physics (physics.bio-ph)
subject: Quantitative Methods (q-bio.QM)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: Thermodynamics constrains the flow of matter in a reaction network to occur through routes along which the Gibbs energy decreases, implying that viable steady-state flux patterns should be void of closed reaction cycles. Identifying and removing cycles in large reaction networks can unfortunately be a highly challenging task from a computational viewpoint. We propose here a method that accomplishes it by combining a relaxation algorithm and a Monte Carlo procedure to detect loops, with ad hoc rules (discussed in detail) to eliminate them. As test cases, we tackle (a) the problem of identifying infeasible cycles in the E. coli metabolic network and (b) the problem of correcting thermodynamic infeasibilities in the Flux-Balance-Analysis solutions for 15 human cell-type specific metabolic networks. Results for (a) are compared with previous analyses of the same issue, while results for (b) are weighed against alternative methods to retrieve thermodynamically viable flux patterns based on minimizing specific global quantities. Our method on one hand outperforms previous techniques and, on the other, corrects loopy solutions to Flux Balance Analysis. As a byproduct, it also turns out to be able to reveal possible inconsistencies in model reconstructions.
description: 10 pages; see http://chimera.roma1.infn.it/SYSBIO/ for supporting files