cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Soft billiards with corners
Creators: name: Turaev, Dmitry
name: Rom-Kedar, Vered
Publisher: name: Weierstrass Institute
Year: 2002
Subjects: subject: singular Hamiltonians
subject: scattering potentials
subject: elliptic islands
subject: 58F15
subject: 82C05
subject: 34C37
subject: 58F05
subject: 58F13
subject: 58F14

description: We develop a framework for dealing with smooth approximations to billiards with corners in the two-dimensional setting. Let a polygonal trajectory in a billiard start and end up at the same billiard's corner point. We prove that smooth Hamiltonian flows which limit to this billiard have a nearby periodic orbit if and only if the polygon angles at the corner are "acceptable". The criterion for a corner polygon to be acceptable depends on the smooth potential behavior at the corners, which is expressed in terms of a scattering function. We define such an asymptotic scattering function and prove the existence of it, explain how it can be calculated and predict some of its properties. In particular, we show that it is non-monotone for some potentials in some phase space regions. We prove that when the smooth system has a limiting periodic orbit it is hyperbolic provided the scattering function is not extremal there. We then prove that if the scattering function is extremal, the smooth system has elliptic periodic orbits limiting to the corner polygon, and, furthermore, that the return map near these periodic orbits is conjugate to a small perturbation of the Henon map and therefore has elliptic islands. We find from the scaling that the island size is typically algebraic in the smoothing parameter and exponentially small in the number of reflections of the polygon orbit.
A digitális átalakulás a közép- és kelet-európai régióban az ellátási láncok mentén
Creators: name: Szegedi, Zoltán
name: Ulechla, Gergely
name: Miskolcziné Gábriel, Mónika
Publisher: name: BI-KA LOGISZTIKA Kft.
Year: 2021

description: Logisztikai trendek és legjobb gyakorlatok (Nyomtatott ISSN: 2416-0555, Online ISSN: 2560-0362), 2021. december, VII. évfolyam, 2. szám
To count and be counted: quantification in the age of American slavery
Creators: name: Wierda, Meagan
Publisher: name: No Publisher Supplied
Year: 2022

description: This dissertation, which spans the period between the 1820s and the Civil War, uses debates about slavery and citizenship to explore how and to what end African Americans incorporated quantification within their activism. It argues that numbers were an important site of empowerment for Black activists, and that when deployed by the latter, quantification became an anti-racist tool. “To Count and Be Counted” challenges us to think of antebellum African Americans not just as the objects of quantification, but as quantifying subjects in their own right. Black activists mobilized numerical data to critique the demographic fearmongering of the white-led American Colonization Society; used population figures to convey the insurrectionary potential of the African diaspora; marshalled statistics to communicate fitness for citizenship in the face of disenfranchisement; and produced statistical tables to quantify the fatal violence of slavery. By drawing from the Black intellectual tradition as well as from feminist and postcolonial interventions within the field of science and technology studies, both of which challenge narrow parameters of knowledge production, my dissertation deepens our understandings of a vibrant culture of anti-racist protest by asking “who counted?”
Generic uniqueness conditions for the canonical polyadic decomposition and INDSCAL
Creators: name: Domanov, Ignat
name: De Lathauwer, Lieven
Publisher: name: arXiv
Year: 2014
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 15A69, 15A23

description: We find conditions that guarantee that a decomposition of a generic third-order tensor in a minimal number of rank-$1$ tensors (canonical polyadic decomposition (CPD)) is unique up to permutation of rank-$1$ tensors. Then we consider the case when the tensor and all its rank-$1$ terms have symmetric frontal slices (INDSCAL). Our results complement the existing bounds for generic uniqueness of the CPD and relax the existing bounds for INDSCAL. The derivation makes use of algebraic geometry. We stress the power of the underlying concepts for proving generic properties in mathematical engineering.
description: 23 pages
Non-neuronal computational principles for increased performance in brain-inspired networks
Creators: name: Ivanov, Vladimir Alexandrovich
Publisher: name: No Publisher Supplied
Year: 2022

description: Brain-inspired neural networks promise to bring human-like machine learning and intelligence by exploiting our understanding of how the brain computes. Yet, current theories of brain information processing are solely focused on neuronal cells as the fundamental unit of computation, which is contradicted by increasing experimental evidence indicating that non-neuronal cells play a key role in brain computation. In this thesis, we used computational methods to investigate the role of two ubiquitous non-neuronal cells, oligodendrocytes and astrocytes, in neuronal network information processing. Our results suggest that oligodendrocytic impact on connection delays can significantly alter network synchrony and oscillation frequency. We propose experimentally testable hypotheses suggesting that astrocytes can signal when network dynamics deviate away from a computationally optimal regime and regulate network activity by modulating synaptic plasticity. Translating these findings to a brain-inspired learning framework that uses local learning unlike backpropagation methods, we present the neuron-astrocyte liquid state machine as a biologically plausible learning method that achieves comparable performance to feed-forward multi-layer spiking neural networks trained via backpropagation. Overall, these works explore non-neuronal computation in the brain and translate these insights to biologically plausible machine learning.
Poisson polyhedra in high dimensions
Creators: name: Hoerrmann, Julia
name: Hug, Daniel
name: Reitzner, Matthias
name: Thaele, Christoph
Publisher: name: arXiv
Year: 2014
Subjects: subject: Metric Geometry (math.MG)
subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 52A22, 52A23, 52B05, 60D05, 52A39, 52C45

description: The zero cell of a parametric class of random hyperplane tessellations depending on a distance exponent and an intensity parameter is investigated, as the space dimension tends to infinity. The model includes the zero cell of stationary and isotropic Poisson hyperplane tessellations as well as the typical cell of a stationary Poisson Voronoi tessellation as special cases. It is shown that asymptotically in the space dimension, with overwhelming probability these cells satisfy the hyperplane conjecture, if the distance exponent and the intensity parameter are suitably chosen dimension-dependent functions. Also the high dimensional limits of the mean number of faces are explored and the asymptotic behaviour of an isoperimetric ratio is analysed. In the background are new identities linking the $f$-vector of the zero cell to certain dual intrinsic volumes.
Solid Oxide Cell Modelling
Creators: name: BIANCHI, FIAMMETTA RITA
Publisher: name: Universit� degli studi di Genova
Year: 2022

description: The present work of thesis focuses on reversible Solid Oxide Cell (rSOC) modelling through a multiscale approach aiming at performance prediction, considering both the reference initial state and the degradation phenomena. All obtained results have been presented in the framework of two research projects, HERMES (High Efficiency Reversible technologies in fully renewable Multi-Energy System) receiving funds as Project of National Interest and AD ASTRA (HArnessing Degradation mechanisms to prescribe Accelerated Stress Tests for the Realization of SOC lifetime prediction Algorithms) under European Horizon 2020 ? Research and Innovation Framework program. Depending on the system scale and the requested phenomenological level, both a lumped-parameter and a higher-level model were developed to forecast the global cell behaviour and the local variations of main physicochemical features on the cell plane respectively. Following a physical based approach, a compromise was reached among a rigorous formulation, effective outcomes and reduced computational efforts, making proposed simulation codes competitive with commercially available tools. Models were applied and validated on several samples, starting from button cell scale until short stack one, referring to two state-of-the-art planar configurations: fuel electrode and electrolyte supported cells. Potentialities and application examples of developed simulation tools were discussed within several case studies, focusing on design, optimization and control of rSOC operation. Careful analysis was devoted, above all, to evaluate degradation effects on global performance, proposing the modelling activity as a key point to reach a better knowledge of occurring phenomena, overcoming experimental constraints.
Novel methods of measuring star formation burstiness
Creators: name: Broussard, Adam
Publisher: name: No Publisher Supplied
Year: 2022

description: Galaxies' star formation is tightly coupled with the myriad internal and external physical processes that affect their cool gas. In particular, measurements of star formation burstiness (short timescale stochasticity) are important for understanding how galaxies assemble their stellar populations over time as well as the feedback mechanisms that regulate star formation on ≲ 100 Myr timescales. We define a burst state indicator η = log₁₀(SFRʜα/SFRɴᴜᴠ) that compares a galaxy's star formation rate over the past ∼ 10 Myr and ∼ 100 Myr. Because η indicates whether a galaxy's star formation rate is rising, falling, or constant, the width of the η distribution for an ensemble of galaxies can be used to infer star formation burstiness. We first measure burstiness for observed 3D-HST galaxies and compare against mock catalogs created from Santa Cruz Semi-Analytic Models and MUFASA hydrodynamical simulations designed to replicate measurement uncertainties and selection effects for 3D-HST and upcoming JWST surveys. This analysis finds an unexpected trend between η and M⁎ in observations that was not present in the mocks, but which can be partially resolved by assuming that dust has a similar magnitude of effect on nebular emission lines and stellar light. To better understand how dust affects measurements of η, we extend our initial analysis by adding MOSDEF spectroscopy allowing for independent dust corrections for nebular and stellar light, as well as FMOS-COSMOS spectroscopy to expand our sample. Using a similar mock catalog approach, we find decent agreement between the mock catalogs and their respective surveys; however, the FMOS-COSMOS and MOSDEF mocks show a systematically lower median and scatter in η in comparison to observations. This work also presents the novel approach of analytically deriving the relationship between the intrinsic scatter in η, scatter added by measurement uncertainties, and observed scatter, resulting in an intrinsic burstiness measurement for galaxies at z ∼ 1 of 0.06 – 0.16 dex.
MetaReVision: Meta-Learning with Retrieval for Visually Grounded Compositional Concept Acquisition
Creators: name: Xu, Guangyue
name: Kordjamshidi, Parisa
name: Chai, Joyce
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computation and Language (cs.CL)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Humans have the ability to learn novel compositional concepts by recalling and generalizing primitive concepts acquired from past experiences. Inspired by this observation, in this paper, we propose MetaReVision, a retrieval-enhanced meta-learning model to address the visually grounded compositional concept learning problem. The proposed MetaReVision consists of a retrieval module and a meta-learning module which are designed to incorporate retrieved primitive concepts as a supporting set to meta-train vision-anguage models for grounded compositional concept recognition. Through meta-learning from episodes constructed by the retriever, MetaReVision learns a generic compositional representation that can be fast updated to recognize novel compositional concepts. We create CompCOCO and CompFlickr to benchmark the grounded compositional concept learning. Our experimental results show that MetaReVision outperforms other competitive baselines and the retrieval module plays an important role in this compositional learning process.
b-coloring is NP-hard on co-bipartite graphs and polytime solvable on tree-cographs
Creators: name: Bonomo, Flavia
name: Schaudt, Oliver
name: Stein, Maya
name: Valencia-Pabon, Mario
Publisher: name: arXiv
Year: 2013
Subjects: subject: Computational Complexity (cs.CC)
subject: Discrete Mathematics (cs.DM)
subject: Combinatorics (math.CO)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: A b-coloring of a graph is a proper coloring such that every color class contains a vertex that is adjacent to all other color classes. The b-chromatic number of a graph G, denoted by χ_b(G), is the maximum number t such that G admits a b-coloring with t colors. A graph G is called b-continuous if it admits a b-coloring with t colors, for every t = χ(G),\ldots,χ_b(G), and b-monotonic if χ_b(H_1) \geq χ_b(H_2) for every induced subgraph H_1 of G, and every induced subgraph H_2 of H_1. We investigate the b-chromatic number of graphs with stability number two. These are exactly the complements of triangle-free graphs, thus including all complements of bipartite graphs. The main results of this work are the following: - We characterize the b-colorings of a graph with stability number two in terms of matchings with no augmenting paths of length one or three. We derive that graphs with stability number two are b-continuous and b-monotonic. - We prove that it is NP-complete to decide whether the b-chromatic number of co-bipartite graph is at most a given threshold. - We describe a polynomial time dynamic programming algorithm to compute the b-chromatic number of co-trees. - Extending several previous results, we show that there is a polynomial time dynamic programming algorithm for computing the b-chromatic number of tree-cographs. Moreover, we show that tree-cographs are b-continuous and b-monotonic.
Kontsevich-Zagier Integrals for Automorphic Green's Functions. I
Creators: name: Zhou, Yajun
Publisher: name: arXiv
Year: 2013
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: Number Theory (math.NT)
subject: FOS: Mathematics

description: In the framework of Kontsevich-Zagier periods, we derive integral representations for weight-$k$ automorphic Green's functions invariant under modular transformations in $\varGamma_0(N)$ ($N\in\mathbb Z_{\geq1} $), provided that there are no cusp forms on the respective Hecke congruence groups with an even integer weight $k\geq4$. These Kontsevich-Zagier integral representations for automorphic Green's functions give explicit formulae for certain Eichler-Shimura maps connecting Eichler cohomology to Maaß cusp forms. We construct integral representations for weight-4 Gross-Zagier renormalized Green's functions (automorphic self-energy) from limit scenarios of the respective Kontsevich-Zagier integrals. We reduce the weight-4 automorphic self-energy on $ X_0(4)(\mathbb C)=\varGamma_0(4)\setminus\mathfrak H^*$ to an explicit form, which supports an algebraicity conjecture of Gross and Zagier.
description: i+69 pages, 1 figure. Minor clarifications and notational changes. Numerical supplement (NumSuppAGF1.nb) downloadable from http://arxiv.org/format/1312.6352
Cramer-Rao Lower Bound and Information Geometry
Creators: name: Nielsen, Frank
Publisher: name: arXiv
Year: 2013
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: This article focuses on an important piece of work of the world renowned Indian statistician, Calyampudi Radhakrishna Rao. In 1945, C. R. Rao (25 years old then) published a pathbreaking paper, which had a profound impact on subsequent statistical research.
description: To appear in Connected at Infinity II: On the work of Indian mathematicians (R. Bhatia and C.S. Rajan, Eds.), special volume of Texts and Readings In Mathematics (TRIM), Hindustan Book Agency, 2013
Transformation of pedestrian route schemes in the parking – air terminal zones in the course of airport reconstruction
Creators: name: , Agieieva
name: , Kriveljov
Publisher: name: Zenodo
Year: 2022
Subjects: airpotr
urban planning
parking
reconstruction

description: The paper covers the results of the study of pedestrian route schemes on the terminal square, including multi-story parkings. Design decisions on compliance with regulatory requirements at Boryspil International Airport are analyzed. Principle solutions to reduce the length of pedestrian routes and travel time are presented.
Efficient Nonnegative Tucker Decompositions: Algorithms and Uniqueness
Creators: name: Zhou, Guoxu
name: Cichocki, Andrzej
name: Zhao, Qibin
name: Xie, Shengli
Publisher: name: arXiv
Year: 2014
Subjects: subject: Machine Learning (cs.LG)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: Nonnegative Tucker decomposition (NTD) is a powerful tool for the extraction of nonnegative parts-based and physically meaningful latent components from high-dimensional tensor data while preserving the natural multilinear structure of data. However, as the data tensor often has multiple modes and is large-scale, existing NTD algorithms suffer from a very high computational complexity in terms of both storage and computation time, which has been one major obstacle for practical applications of NTD. To overcome these disadvantages, we show how low (multilinear) rank approximation (LRA) of tensors is able to significantly simplify the computation of the gradients of the cost function, upon which a family of efficient first-order NTD algorithms are developed. Besides dramatically reducing the storage complexity and running time, the new algorithms are quite flexible and robust to noise because any well-established LRA approaches can be applied. We also show how nonnegativity incorporating sparsity substantially improves the uniqueness property and partially alleviates the curse of dimensionality of the Tucker decompositions. Simulation results on synthetic and real-world data justify the validity and high efficiency of the proposed NTD algorithms.
description: appears in IEEE Transactions on Image Processing, 2015
Search strategies-Characteristics, treatment, and outcomes of Othello syndrome- A systematic review of case report and case series.
Creators: name: Báez Villagómez, Ana Emilia
name: Araúz, Alison
name: Meza, Daniela
name: Pillajo Tigse, Edgar Ismael
name: Tandazo, Mateo
name: Yupanqui, Michael
Publisher: name: figshare
Year: 2023
Subjects: Mental health services

description: Othello syndrome is a rare psychiatric condition characterized by the false belief that a spouse or partner is unfaithful. This can lead to aggressive behavior and intense jealousy. It's commonly seen in older men and is associated with Parkinson's disease and other neurological conditions. Treatment typically involves a combination of medication and therapy.
Model-dependent estimate on the connection between fast radio bursts and ultra-high energy cosmic rays
Creators: name: Li, Xiang
name: Zhou, Bei
name: He, Hao-Ning
name: Fan, Yi-Zhong
name: Wei, Da-Ming
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The existence of fast radio bursts (FRBs), a new type of extragalatic transients, has been established recently and quite a few models have been proposed. In this work we discuss the possible connection between the FRB sources and ultra-high energy ($>10^{18}$ eV) cosmic rays. We show that in the blitzar model and the model of merging binary neutron stars, the huge energy release of each FRB central engine together with the rather high rate of FRBs, the accelerated EeV cosmic rays may contribute significantly to the observed ones. In other FRB models including for example the merger of double white dwarfs and the energetic magnetar radio flares, no significant EeV cosmic ray is expected. We also suggest that the mergers of double neutron stars, even if they are irrelevant to FRBs, may play a non-ignorable role in producing EeV cosmic ray protons if supramassive neutron stars were formed in a good fraction of mergers and the merger rate is $\gtrsim 10^{3}~{\rm yr^{-1}~ Gpc^{-3}}$. Such a possibility will be unambiguously tested in the era of gravitational wave astronomy.
description: Fig.1 is added to show the possibility distribution, as a function of maximal gravitational mass, of forming supramassive neutron stars in the double neutron star mergers. Major conclusions are unchanged
A Multiplierless Pruned DCT-like Transformation for Image and Video Compression that Requires 10 Additions Only
Creators: name: Coutinho, V. A.
name: Cintra, R. J.
name: Bayer, F. M.
name: Kulasekera, S.
name: Madanayake, A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Multimedia (cs.MM)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: A multiplierless pruned approximate 8-point discrete cosine transform (DCT) requiring only 10 additions is introduced. The proposed algorithm was assessed in image and video compression, showing competitive performance with state-of-the-art methods. Digital implementation in 45 nm CMOS technology up to place-and-route level indicates clock speed of 288 MHz at a 1.1 V supply. The 8x8 block rate is 36 MHz.The DCT approximation was embedded into HEVC reference software; resulting video frames, at up to 327 Hz for 8-bit RGB HEVC, presented negligible image degradation.
description: 13 pages, 4 figures, 5 tables
On the Electride Nature of Na-hP4
Creators: name: Racioppi, Stefano
name: Storm, Christian V.
name: McMahon, Malcolm I.
name: Zurek, Eva
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Early quantum mechanical models suggested that pressure drives solids towards free-electron metal behavior where the ions are locked into simple close-packed structures. The prediction and subsequent discovery of high-pressure electrides (HPEs), compounds assuming open structures where the valence electrons are localized in interstitial voids, required a paradigm shift. Our quantum chemical calculations on the iconic insulating Na-hP4 HPE show that increasing density causes a 3s -> 3pd electronic transition due to Coulomb repulsion between the 1s2s and 3s states, and orthogonality of the 3pd states to the core. The large lobes of the resulting Na-pd hybrid orbitals point towards the center of an 11-membered penta-capped trigonal prism and overlap constructively, forming multi-centered bonds, which are responsible for the emergence of the interstitial charge localization in Na-hP4. These multi-centered bonds facilitate the increased density of this phase, which is key for its stabilization under pressure.
The watering of tall trees - Embolization and recovery
Creators: name: Gouin, Henri
Publisher: name: arXiv
Year: 2014
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We can propound a thermo-mechanical understanding of the ascent of sap to the top of tall trees thanks to a comparison between experiments associated with the cohesion-tension theory and the disjoining pressure concept for liquid thin-films. When a segment of xylem is tight-filled with crude sap, the liquid pressure can be negative although the pressure in embolized vessels remains positive. Examples are given that illustrate how embolized vessels can be refilled and why the ascent of sap is possible even in the tallest trees avoiding the problem due to cavitation. However, the maximum height of trees is limited by the stability domain of liquid thin-films.
description: Extended introduction and additive comments removed from the Journal of Theoretical Biology.22 pages
Graph classes with and without powers of bounded clique-width
Creators: name: Bonomo, Flavia
name: Grippo, Luciano N.
name: Milanič, Martin
name: Safe, Martín D.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Combinatorics (math.CO)
subject: Discrete Mathematics (cs.DM)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences

description: We initiate the study of graph classes of power-bounded clique-width, that is, graph classes for which there exist integers $k$ and $\ell$ such that the $k$-th powers of the graphs are of clique-width at most $\ell$. We give sufficient and necessary conditions for this property. As our main results, we characterize graph classes of power-bounded clique-width within classes defined by either one forbidden induced subgraph, or by two connected forbidden induced subgraphs. We also show that for every positive integer $k$, there exists a graph class such that the $k$-th powers of graphs in the class form a class of bounded clique-width, while this is not the case for any smaller power.
description: 23 pages, 4 figures
Photometric Classification of quasars from RCS-2 using Random Forest
Creators: name: Carrasco, D.
name: Barrientos, L. F.
name: Pichara, K.
name: Anguita, T.
name: Murphy, D. N. A.
name: Gilbank, D. G.
name: Gladders, M. D.
name: Yee, H. K. C.
name: Hsieh, B. C.
name: López, S.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Aims. Construction of a new quasar candidate catalog from the Red-Sequence Cluster Survey 2 (RCS-2), identified solely from photometric information using an automated algorithm suitable for large surveys. The algorithm performance is tested using a well-defined SDSS spectroscopic sample of quasars and stars. Methods. The Random Forest algorithm constructs the catalog from RCS-2 point sources using SDSS spectroscopically-confirmed stars and quasars. The algorithm identifies putative quasars from broadband magnitudes (g, r, i, z) and colours. Exploiting NUV GALEX measurements for a subset of the objects, we refine the classifier by adding new information. An additional subset of the data with WISE W1 and W2 bands is also studied. Results. Upon analyzing 542,897 RCS-2 point sources, the algorithm identified 21,501 quasar candidates, with a training-set-derived precision (the fraction of true positives within the group assigned quasar status) of 89.5% and recall (the fraction of true positives relative to all sources that actually are quasars) of 88.4%. These performance metrics improve for the GALEX subset; 6,530 quasar candidates are identified from 16,898 sources, with a precision and recall respectively of 97.0% and 97.5%. Algorithm performance is further improved when WISE data are included, with precision and recall increasing to 99.3% and 99.1% respectively for 21,834 quasar candidates from 242,902 sources. We compile our final catalog (38,257) by merging these samples and removing duplicates. An observational follow up of 17 bright (r < 19) candidates with long-slit spectroscopy at DuPont telescope (LCO) yields 14 confirmed quasars. Conclusions. The results signal encouraging progress in the classification of point sources with Random Forest algorithms to search for quasars within current and future large-area photometric surveys.
description: Accepted for publication in A&A. 20 pages, 16 figures, 6 tables. Tables 1, 2 and 3 with the quasar candidates are only available in electronic format http://www.aanda.org/
Polygraphs of finite derivation type
Creators: name: Guiraud, Yves
name: Malbos, Philippe
Publisher: name: arXiv
Year: 2014
Subjects: subject: Category Theory (math.CT)
subject: FOS: Mathematics
subject: 68Q42, 03D05, 18D05

description: Craig Squier proved that, if a monoid can be presented by a finite convergent string rewriting system, then it satisfies the homological finiteness condition left-FP3. Using this result, he constructed finitely presentable monoids with a decidable word problem, but that cannot be presented by finite convergent rewriting systems. Later, he introduced the condition of finite derivation type, which is a homotopical finiteness property on the presentation complex associated to a monoid presentation. He showed that this condition is an invariant of finite presentations and he gave a constructive way to prove this finiteness property based on the computation of the critical branchings: being of finite derivation type is a necessary condition for a finitely presented monoid to admit a finite convergent presentation. This survey presents Squier's results in the contemporary language of polygraphs and higher-dimensional categories, with new proofs and relations between them.
Controllable single spin evolution at sub-harmonics of electric dipole spin resonance enhanced by four-level Landau-Zener-St{ü}ckelberg-Majorana interference
Creators: name: Khomitsky, D. V.
name: Bastrakova, M. V.
name: Munyaev, V. O.
name: Zaprudnov, N. A.
name: Studenikin, S. A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Sub-harmonics of electric dipole spin resonance (EDSR) mediated by Landau-Zener-St{ü}ckelberg-Majorana (LZSM) tunneling transitions are studied numerically and analytically in a Zeeman-split four level system with strong spin-orbit coupling that can be realized, for example, in a GaAs-based double quantum dot in a single-hole regime. The spin qubit is formed in one of the dots and the second dot is used as an auxiliary element to enhance functionality of the spin qubit. In particular, it is found that the spin rotation rate can be essentially enhanced due to the tunnel coupling with the auxiliary dot on both the main EDSR frequency and at its high sub-harmonics allowing the coherent spin $π$-rotations on a 10-ns time scale. Spin manipulation on high sub-harmonics is promising for new time-efficient schemes of the spin control and readout in qubit devices operating at high magnetic fields where the main harmonic is inaccessible due to hardware limitations.
description: 14 pages, 6 figures, published version
title: Microbially promoted calcite precipitation in the pelagic redoxcline: Elucidating the formation of the turbid layer
Creators: name: Leberecht, Kerstin M.
name: Ritter, Simon M.
name: Lapp, Christian J.
name: Klose, Lukas
name: Eschenröder, Julian
name: Scholz, Christian
name: Kühnel, Sebastian
name: Stinnesbeck, Wolfgang
name: Kletzin, Arnulf
name: Isenbeck‐Schröter, Margot
name: Gescher, Johannes
Publisher: name: John Wiley & Sons
Year: 2022

description: Large bell‐shaped calcite formations called "Hells Bells" were discovered underwater in the stratified cenote El Zapote on the Yucatán Peninsula, Mexico. Together with these extraordinary speleothems, divers found a white, cloudy turbid layer into which some Hells Bells partially extend. Here, we address the central question if the formation of the turbid layer could be based on microbial activity, more specifically, on microbially induced calcite precipitation. Metagenomic and metatranscriptomic profiling of the microbial community in the turbid layer, which overlaps with the pelagic redoxcline in the cenote, revealed chemolithoautotrophic Hydrogenophilales and unclassified β‐Proteobacteria as the metabolic key players. Bioinformatic and hydrogeochemical data suggest chemolithoautotrophic oxidation of sulfide to zero‐valent sulfur catalyzed by denitrifying organisms due to oxygen deficiency. Incomplete sulfide oxidation via nitrate reduction and chemolithoautotrophy are both proton‐consuming processes, which increase the pH in the redoxcline favoring authigenic calcite precipitation and may contribute to Hells Bells growth. The observed mechanism of microbially induced calcite precipitation is potentially applicable to many other stagnant sulfate‐rich water bodies.
Better 3-coloring algorithms: excluding a triangle and a seven vertex path
Creators: name: Bonomo-Braberman, Flavia
name: Chudnovsky, Maria
name: Goedgebeur, Jan
name: Maceli, Peter
name: Schaudt, Oliver
name: Stein, Maya
name: Zhong, Mingxian
Publisher: name: arXiv
Year: 2014
Subjects: subject: Combinatorics (math.CO)
subject: Discrete Mathematics (cs.DM)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences

description: We present an algorithm to color a graph $G$ with no triangle and no induced $7$-vertex path (i.e., a $\{P_7,C_3\}$-free graph), where every vertex is assigned a list of possible colors which is a subset of $\{1,2,3\}$. While this is a special case of the problem solved in [Combinatorica 38(4):779--801, 2018], that does not require the absence of triangles, the algorithm here is both faster and conceptually simpler. The complexity of the algorithm is $O(|V(G)|^5(|V(G)|+|E(G)|))$, and if $G$ is bipartite, it improves to $O(|V(G)|^2(|V(G)|+|E(G)|))$. Moreover, we prove that there are finitely many minimal obstructions to list 3-coloring $\{P_t,C_3\}$-free graphs if and only if $t \leq 7$. This implies the existence of a polynomial time certifying algorithm for list 3-coloring in $\{P_7,C_3\}$-free graphs. We furthermore determine other cases of $t, \ell$, and $k$ such that the family of minimal obstructions to list $k$-coloring in $\{P_t,C_{\ell}\}$-free graphs is finite.
description: This version includes some new results and additional authors
Products of independent elliptic random matrices
Creators: name: O'Rourke, Sean
name: Renfrew, David
name: Soshnikov, Alexander
name: Vu, Van
Publisher: name: arXiv
Year: 2014
Subjects: subject: Probability (math.PR)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: For fixed $m > 1$, we study the product of $m$ independent $N \times N$ elliptic random matrices as $N$ tends to infinity. Our main result shows that the empirical spectral distribution of the product converges, with probability $1$, to the $m$-th power of the circular law, regardless of the joint distribution of the mirror entries in each matrix. This leads to a new kind of universality phenomenon: the limit law for the product of independent random matrices is independent of the limit laws for the individual matrices themselves. Our result also generalizes earlier results of Götze-Tikhomirov and O'Rourke-Soshnikov concerning the product of independent iid random matrices.
description: 31 pages, 2 figures; minor corrections, added a reference
WIN MR Protocol: FORECAST
Creators: name: Aikin, Nicola
name: Campbell, Jon
name: Clare, Stuart
name: Koushesh, Soraya
name: Parker, David
name: Ridgway, Lucy
name: Sanders, Michael
name: Schmid, Annina
name: Semple, Juliet
name: Tachrount, Mohamed
Publisher: name: Zenodo
Year: 2023
Subjects: Pain, Spinal cord, Lumbar nerve roots, Sciatica

description: Protocol for the acquisition of MRI data for the study "FORECAST". Conducted at the Wellcome Centre for Integrative Neuroimaging (WIN), University of Oxford. Please see the FORECAST protocol in the WIN MR Protocols Database to ensure this is the latest version. Authors' list and CRediT roles: Aikin, Nicola (ORCID: 0009-0009-7097-5683): MR protocol optimisation, Data acquisition Campbell, Jon (ORCID: 0000-0003-4757-1655): Ethics and MR safety protocols reviewing/editing, MR protocol optimisation, Scanning procedure editing/reviewing, Data acquisition Clare, Stuart (ORCID: 0000-0001-6421-9990): Funding acquisition, Conceptualisation, MR protocol optimisation Koushesh, Soraya (ORCID: 0009-0002-9998-5120): Patients' recruitment, MR protocol optimisation, Data acquisition Parker, David: MR protocol optimisation, Data acquisition Ridgway, Lucy(ORCID: 0009-0009-0242-701X): Ethics and MR safety protocols reviewing/editing, Patients' recruitment, Conceptualisation, MR protocol optimisation, Data acquisition Sanders, Michael: Ethics and MR safety protocols reviewing/editing, MR protocol optimisation, Scanning procedure editing/reviewing, Data acquisition Schmid, Annina (ORCID: 0000-0001-7759-0211): Funding acquisition, Ethics and MR safety protocols reviewing/editing, Conceptualisation, MR protocol optimisation, Project management Semple, Juliet (ORCID: 0000-0001-5752-3572): MR protocol optimisation, Scanning procedure editing/reviewing, Data acquisition Tachrount, Mohamed (ORCID: 0000-0003-1147-3412): Funding acquisition, Conceptualisation, Scanning procedure editing/reviewing, MR protocol optimisation, Data analysis Acknowledgements: This project is funded by the Advanced Pain Discovery Platform (UK Research and Innovation (UKRI) and Versus Arthritis)
title: The Effects of Flood Warning Information on Driver Decisions in a Driving Simulator Scenario
Creators: name: Garcia, Katherine Rose
Publisher: name: Old Dominion University Libraries
Year: 2022

description:
Flood warnings are a type of risk communication that alerts the public of potential floods. Flood warnings can be communicated through mobile devices and should convey enough information to keep the user safe during a flood situation. However, the amount of detail included in the warning, such as the depth of the flood, may vary. The purpose of this study was to: (a) extend our prior research on flood warnings by recreating the written driving scenarios into the driving simulator; (b) deepen the understanding of human decision-making in risky situations; and (c) investigate how to best inform drivers of floods by design to keep them protected. We examined the effects of flood warning information on the actions taken by drivers in various driving scenarios in a driving simulator. Participants were tasked to drive to a restaurant after receiving instructions and a type of flood information warning during each scenario (flood, no flood, flood of 6 inches, flood of 6 inches maximum). Their actions taken, trust in the navigation system, understanding of the situation and scenario, and perceived risk were measured for each type of flood information warning. We found that participants accepted the alternate route more when in a scenario with a flood present compared to the no-flood scenario. The level of detail of the warning did not influence the actions taken. These results deepened the understanding of human decision-making and can guide future flood warning designs to keep drivers protected from flooded roadways.
title: SimAnMo — A parallelized runtime model generator
Creators: name: Burger, Michael
name: Nguyen, Giang Nam
name: Bischof, Christian
Publisher: name: John Wiley & Sons
Year: 2022

description: In this article, we present the novel features of the recent version of SimAnMo, the Simulated Annealing Modeler. The tool creates models that correlate the size of one input parameter of an application to the corresponding runtime and thus SimAnMo allows predictions for larger input sizes. A focus lies on applications whose runtime grows exponentially in the input parameter size. Such programs are, for example, of high interest for cryptanalysis to analyze practical security of traditional and post‐quantum secure schemes. However, SimAnMo also generates reliable models for the widespread case of polynomial runtime behavior and also for the important case of factorial runtime increase. SimAnMo's model generation is based on a parallelized simulated annealing procedure and heuristically minimizes the costs of a model. Those may rely on different quality metrics. Insights into SimAnMo's software design and its usage are provided. We demonstrate the quality of SimAnMo's models for different algorithms from various application fields. We show that our approach also works well on ARM architectures.
Self-dual road to noncommutative gravity with twist: a new analysis
Creators: name: Di Grezia, Elisabetta
name: Esposito, Giampiero
name: Vitale, Patrizia
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The field equations of noncommutative gravity can be obtained by replacing all exterior products by twist-deformed exterior products in the action functional of general relativity, and are here studied by requiring that the torsion 2-form should vanish, and that the Lorentz-Lie-algebra- valued part of the full connection 1-form should be self-dual. Other two conditions, expressing self-duality of a pair 2-forms occurring in the full curvature 2-form, are also imposed. This leads to a systematic solution strategy, here displayed for the first time, where all parts of the connection 1-form are first evaluated, hence the full curvature 2-form, and eventually all parts of the tetrad 1-form, when expanded on the basis of γ-matrices. By assuming asymptotic expansions which hold up to first order in the noncommutativity matrix in the neighbourhood of the vanishing value for noncommutativity, we find a family of self-dual solutions of the field equations. This is generated by solving first a inhomogeneous wave equation on 1-forms in a classical curved spacetime (which is itself self-dual and solves the vacuum Einstein equations), subject to the Lorenz gauge condition. In particular, when the classical undeformed geometry is Kasner spacetime, the above scheme is fully computable out of solutions of the scalar wave equation in such a Kasner model.
description: 37 pages, Revtex. Appendix A is a recollection of mathematical tools used in the paper. In the final version, Appendix C and some valuable References have been added. arXiv admin note: text overlap with arXiv:hep-th/0703014 by other authors. Misprints in Eq. (10.23) and (10.25) have been amended, as well as their propagation in Sec. X
Algorithms for optimized Hybrid Power Plant operation through ME4HP implementation
Creators: name: Aparicio, Rubén De Arriba
name: García, Daniel Rayo
Publisher: name: Zenodo
Year: 2020
Subjects: hybrid power plant
optimization
RES-DU
CROSSBOW
PV
Wind farm
battery
storage
renewable
ancillary services

description: This document presents the main algorithms developed in the framework of the ME4HP tool as part of CROSSBOW project. These algorithms are focused on providing different strategies for supporting the Hybrid Power Plant (HPP) operation according to the following objectives: i) to supply the power according to different power demand curves, ii) to increment the revenues of the HPP due to energy sale, iii) to demonstrate the capacity of HPP to provide ancillary services, and iv) to demonstrate the functionalites of HPP after a zero voltage event. This document also includes a detailed explanation of the methodology and its implementation in Matlab, considering as main inputs: the weather, energy prices and energy demand forecast, as well as the power system operator constrains. In addition, the results of the tool demonstrate these functionalities and highlights the adaptability of the tool against different plant configurations and operation modes.
On the bend number of circular-arc graphs as edge intersection graphs of paths on a grid
Creators: name: Alcón, L.
name: Bonomo, F.
name: Durán, G.
name: Gutierrez, M.
name: Mazzoleni, M. P.
name: Ries, B.
name: Valencia-Pabon, M.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics

description: Golumbic, Lipshteyn and Stern \cite{Golumbic-epg} proved that every graph can be represented as the edge intersection graph of paths on a grid (EPG graph), i.e., one can associate with each vertex of the graph a nontrivial path on a rectangular grid such that two vertices are adjacent if and only if the corresponding paths share at least one edge of the grid. For a nonnegative integer $k$, $B_k$-EPG graphs are defined as EPG graphs admitting a model in which each path has at most $k$ bends. Circular-arc graphs are intersection graphs of open arcs of a circle. It is easy to see that every circular-arc graph is a $B_4$-EPG graph, by embedding the circle into a rectangle of the grid. In this paper, we prove that every circular-arc graph is $B_3$-EPG, and that there exist circular-arc graphs which are not $B_2$-EPG. If we restrict ourselves to rectangular representations (i.e., the union of the paths used in the model is contained in a rectangle of the grid), we obtain EPR (edge intersection of path in a rectangle) representations. We may define $B_k$-EPR graphs, $k\geq 0$, the same way as $B_k$-EPG graphs. Circular-arc graphs are clearly $B_4$-EPR graphs and we will show that there exist circular-arc graphs that are not $B_3$-EPR graphs. We also show that normal circular-arc graphs are $B_2$-EPR graphs and that there exist normal circular-arc graphs that are not $B_1$-EPR graphs. Finally, we characterize $B_1$-EPR graphs by a family of minimal forbidden induced subgraphs, and show that they form a subclass of normal Helly circular-arc graphs.
Particle optimization by modifying chemical composition
Creators: name: Benameur, Nassira
name: Marlin, Samuel
name: Sutter, Florian
name: Wiesinger, Florian
name: Oskay, Ceyhun
name: Alkan, Gözde
name: Menichetti, Emanuela
Publisher: name: Zenodo
Year: 2022

description: Different generations of fused and granulated particles with improved mechanical properties were developed by Saint-Gobain and proposed to the partners. The granulated particles GEN4 present the best compromise in terms of performance versus cost.
Exel's crossed product and crossed products by completely positive maps
Creators: name: Kwaśniewski, B. K.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Operator Algebras (math.OA)
subject: FOS: Mathematics
subject: 46L05, 46L55

description: We introduce crossed products of a $C^*$-algebra $A$ by a completely positive map $\varrho:A\to A$ relative to an ideal in $A$. They generalize various crossed products by endomorphisms when $\varrho$ is multiplicative. When $A$ is commutative they include $C^*$-algebras associated to Markov operators by Ionescu, Muhly, Vega, and to topological relations by Brenken, but in general they are not modeled by topological quivers popularized by Muhly and Tomforde. We show that Exel's crossed product $A\rtimes_{α,L} \mathbb{N}$, generalized to the case where $A$ is not necessarily unital, is the crossed product of $A$ by the transfer operator $L$ relative to the ideal generated by $α(A)$. We give natural conditions under which $α(A)$ is uniquely determined by $L$, and hence $A\rtimes_{α,L} \mathbb{N}$ depends only on $L$. Moreover, the $C^*$-algebra $\mathcal{O}(A,α,L)$ associated to $(A,α,L)$ by Exel and Royer always coincides with our unrelative crossed product by $L$. As another non-trivial application of our construction we extend a result of Brownlowe, Raeburn and Vittadello, by showing that the $C^*$-algebra of an arbitrary infinite graph $E$ can be realized as a crossed product of the diagonal algebra $\mathcal{D}_E$ by a `Perron-Frobenious' operator $L$. The important difference is that in general there is no endomorphism $α$ of $\mathcal{D}_E$ making $(\mathcal{D}_E,α,L)$ an Exel system.
description: 45 pages, this is the version accepted to Houston J. Math. Univ (subsections on universal representations and relative Cuntz-Pimsner algebras are added)