cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Horizon Straddling ISCOs in Spherically Symmetric String Black Holes
Creators: name: Pradhan, Parthapratim
Publisher: name: arXiv
Year: 2012
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The causal geodesics in the equatorial plane of a static extremal charged black holes in heterotic string theory are examined with regard to their geodesic stability, and compared with similar geodesics in the non-extremal situation. Extremization of the effective potential for time-like and null circular geodesics implies that in the extremal limit, the radius of ISCO(Inner-most Stable Circular Orbit) $(r_{ISCO})$, circular photon orbit (CPO) $(r_{ph})$ and marginally bound circular orbit (MBCO) $(r_{mb})$ are coincident with the event horizon $(r_{hor})$ i.e. $r_{ISCO}=r_{ph}=r_{mb}=r_{hor}=2M$. Since the proper radial distance on a constant time slice both in Schwarzschild and Painlevé-Gullstrand coordinates become zero, thus these three orbits indeed coincide with the \emph{null geodesic generators of the event horizon}. This strange behavior is quite different from the static, spherically symmetric extremal Reissner Nordstrøm black hole.
description: Accepted for Publication in IJMPD, 26/06/2015
Jets from accretion disk dynamos: consistent quenching modes for dynamo and resistivity
Creators: name: Mattia, Giancarlo
name: Fendt, Christian
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Astrophysical jets are launched from strongly magnetized systems that host an accretion disk surrounding a central object. The origin of the magnetic field, which is a key component of the launching process, is still an open question. Here we address the question of how the magnetic field required for jet launching is generated and maintained by a dynamo process. By carrying out non-ideal MHD simulations (PLUTO code), we investigate how the feedback of the generated magnetic field on the mean-field dynamo affects the disk and jet properties. We find that a stronger quenching of the dynamo leads to a saturation of the magnetic field at a lower disk magnetization. Nevertheless, we find that, while applying different dynamo feedback models, the overall jet properties remain unaffected. We then investigate a feedback model which encompasses a quenching of the magnetic diffusivity. Our modeling considers a more consistent approach for mean-field dynamo modeling simulations, as the magnetic quenching of turbulence should be considered for both, a turbulent dynamo and turbulent magnetic diffusivity. We find that, after the magnetic field is saturated, the Blandford-Payne mechanism can work efficiently, leading to more collimated jets, that move, however, with slower speed. We find strong intermittent periods of flaring and knot ejection for low Coriolis numbers. In particular, flux ropes are built up and advected towards the inner disk thereby cutting off of the inner disk wind, leading to magnetic field reversals, reconnection and the emergence of intermittent flares.
description: 24 pages, 17 figures, accepted for publication in ApJ
Packing and Shipping Mechanically Harvested Lettuce
Creators: name: Hinsch, R. Tom
name: Rij, Roger E.
name: Hinsch, R. Tom
name: Rij, Roger E.
Publisher: name: Unknown
Year: 1976
Subjects: subject: Crop Production/Industries
subject: Labor and Human Capital
subject: Marketing
subject: FOS: Economics and business
subject: Research and Development/Tech Change/Emerging Technologies

description: Excerpts from the report: Western iceberg lettuce accounts for approximately 20 percent of all carlots of fresh fruits and vegetables shipped from California, constituting the largest volume of a single perishable commodity shipped out of State. Lettuce shipments have increased by approximately 17 percent between 1968 and 1972. ARS agricultural engineers have developed a mechanical lettuce harvester, which may be the key element of a handling and marketing system that will enable producers and marketers of lettuce to keep pace with increasing costs. The purpose of this study was to determine if lettuce could be handled in large containers, and the effect of this handling on lettuce quality. A system to increase the product flow from the harvester into a shipping container was investigated. This system was based on jumble filling the lettuce into relatively large containers on the harvester. The containers varied in size, holding from 50 to 240 heads, compared with the present 24-head carton.
Schmitz, Hermann: Stadt und Imperium - Köln in römischer Zeit
Creators: name: Jacob-Friesen, Karl Hermann
Publisher: name: Nachrichten aus Niedersachsens Urgeschichte
Year: 2019

description: Rezension zu: Schmitz, Hermann: Stadt und Imperium - Köln in römischer Zeit. 1. Band: Die Anfänge der Stadt Köln und die Ubier. 8°. 208 S. Köln 1948. Kölner Universitätsverlag Balduin Pick
description: Nachrichten aus Niedersachsens Urgeschichte, Bd. 18 (1949): Nachrichten aus Niedersachsens Urgeschichte
A plethora of inertial products
Creators: name: Edidin, Dan
name: Jarvis, Tyler J.
name: Kimura, Takashi
Publisher: name: arXiv
Year: 2012
Subjects: subject: Algebraic Geometry (math.AG)
subject: Algebraic Topology (math.AT)
subject: FOS: Mathematics
subject: 55N32, 55N15 (Primary), 14N35, 53D45, 57R18, 19L10, 19L47 (Secondary)

description: For a smooth Deligne-Mumford stack X we describe a large number of inertial products on K(IX) and A*(IX) and corresponding inertial Chern characters. We do this by developing a theory of inertial pairs. Each inertial pair determines an inertial product on K(IX) and an inertial product on A*(IX) and Chern character ring homomorphisms between them. We show that there are many inertial pairs; indeed, every vector bundle V on X defines two new inertial pairs. We recover, as special cases, the orbifold products of Chen-Run, Abramovich-Graber-Vistoli, Jarvis-Kaufmann-Kimura, and Edidin-Jarvis-Kimura and the virtual product of Gonzalez-Lupercio-Segovia-Uribe-Xicotencatl. We also introduce an entirely new product we call the localized orbifold product, which is defined on the complexification of K(IX). The inertial products developed in this paper are used in a subsequent paper to describe a theory of inertial Chern classes and power operations in inertial K-theory. These constructions provide new manifestations of mirror symmetry, in the spirit of the Hyper-Kaehler Resolution Conjecture.
description: 20 pages. Several minor errors corrected. To appear in Annals of K-Theory
Spaced Load Patterns for Improved Temperature Control in Export Shipments of Lettuce
Creators: name: Stewart, Joseph K.
name: Bongers, Anton
name: Hinds, Russel H.
name: Stewart, Joseph K.
name: Bongers, Anton
name: Hinds, Russel H.
Publisher: name: Unknown
Year: 1976
Subjects: subject: Crop Production/Industries
subject: International Relations/Trade
subject: Marketing
subject: FOS: Economics and business
subject: Research and Development/Tech Change/Emerging Technologies

description: Excerpt from the report: Exports of Western lettuce have increased during the past several years, but have been limited because of relatively high risks. There is still much to learn before iceberg lettuce can be consistently delivered to overseas markets in good condition. Proper temperature control throughout the load is the most important factor in maintaining the quality of lettuce during transport. In past years, researchers at the U.S. Department of Agriculture laboratory in Rotterdam have observed many loads of lettuce on arrival from the United States in which temperatures were excessively high and decay losses were severe because of tight or improper load patterns. To improve temperature control, we compared two spaced loading patterns and evaluated market quality of lettuce shipped in refrigerated van containers from the Western United States to Europe and the Far East.
Ramsey multiplicity and the Turán coloring
Creators: name: Fox, Jacob
name: Wigderson, Yuval
Publisher: name: arXiv
Year: 2022
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics

description: Extending an earlier conjecture of Erdős, Burr and Rosta conjectured that among all two-colorings of the edges of a complete graph, the uniformly random coloring asymptotically minimizes the number of monochromatic copies of any fixed graph $H$. This conjecture was disproved independently by Sidorenko and Thomason. The first author later found quantitatively stronger counterexamples, using the Turán coloring, in which one of the two colors spans a balanced complete multipartite graph. We prove that the Turán coloring is extremal for an infinite family of graphs, and that it is the unique extremal coloring. This yields the first determination of the Ramsey multiplicity constant of a graph for which the Burr--Rosta conjecture fails. We also prove an analogous three-color result. In this case, our result is conditional on a certain natural conjecture on the behavior of two-color Ramsey numbers.
description: 39 pages, final version to appear in Advances in Combinatorics
Probabilistic Reconciliation of Count Time Series
Creators: name: Corani, Giorgio
name: Azzimonti, Dario
name: Rubattu, Nicolò
Publisher: name: arXiv
Year: 2022
Subjects: subject: Methodology (stat.ME)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: Forecast reconciliation is an important research topic. Yet, there is currently neither formal framework nor practical method for the probabilistic reconciliation of count time series. In this paper we propose a definition of coherency and reconciled probabilistic forecast which applies to both real-valued and count variables and a novel method for probabilistic reconciliation. It is based on a generalization of Bayes' rule and it can reconcile both real-value and count variables. When applied to count variables, it yields a reconciled probability mass function. Our experiments with the temporal reconciliation of count variables show a major forecast improvement compared to the probabilistic Gaussian reconciliation.
Hartwig Zürn, Hallstattzeitliche Grabfunde in Württemberg und Hohenzollern
Creators: name: Joachim, Hans-Eckart
Publisher: name: Bonner Jahrbücher
Year: 2019

description: Rezension zu: Hartwig Zürn, Hallstattzeitliche Grabfunde in Württemberg und Hohenzollern . Forschungen und Berichte zur Vor- und Frühgeschichte in Baden-Württemberg 25. Konrad Theiss Verlag, Stuttgart 1987. Textband mit 230 Seiten und 99 Abbildungen; Tafelband mit 505 Tafeln.
description: Bonner Jahrbücher, Bd. 189.1989: Bonner Jahrbücher
Limits to Quantum Gate Fidelity from Near-Field Thermal and Vacuum Fluctuations
Creators: name: Sun, Wenbo
name: Bharadwaj, Sathwik
name: Yang, Li-Ping
name: Hsueh, Yu-Ling
name: Wang, Yifan
name: Jiao, Dan
name: Rahman, Rajib
name: Jacob, Zubin
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: High-fidelity quantum gate operations are essential for achieving scalable quantum circuits. In spin qubit quantum computing systems, metallic gates and antennas which are necessary for qubit operation, initialization, and readout, also cause detriments by enhancing fluctuations of electromagnetic fields. Therefore evanescent wave Johnson noise (EWJN) caused by thermal and vacuum fluctuations becomes an important unmitigated noise, which induces the decay of spin qubits and limits the quantum gate operation fidelity. Here, we first develop a quantum electrodynamics theory of EWJN. Then we propose a numerical technique based on volume integral equations to quantify EWJN strength in the vicinity of nanofabricated metallic gates with arbitrary geometry. We study the limits to two spin-qubit gate fidelity from EWJN-induced relaxation processes in two experimentally relevant quantum computing platforms: (a) silicon quantum dot system and (b) NV centers in diamond. Finally, we introduce the Lindbladian engineering method to optimize the control pulse sequence design and show its enhanced performance over Hamiltonian engineering in mitigating the influence of thermal and vacuum fluctuations. Our work leverages advances in computational electromagnetics, fluctuational electrodynamics and open quantum systems to suppress the effects of thermal and vacuum fluctuations and reach the limits of two-spin-qubit gate fidelity.
description: 24 pages, 12 figures
Explainable AI Integrated Feature Selection for Landslide Susceptibility Mapping using TreeSHAP
Creators: name: Inan, Muhammad Sakib Khan
name: Rahman, Istiakur
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Landslides have been a regular occurrence and an alarming threat to human life and property in the era of anthropogenic global warming. An early prediction of landslide susceptibility using a data-driven approach is a demand of time. In this study, we explored the eloquent features that best describe landslide susceptibility with state-of-the-art machine learning methods. In our study, we employed state-of-the-art machine learning algorithms including XgBoost, LR, KNN, SVM, and Adaboost for landslide susceptibility prediction. To find the best hyperparameters of each individual classifier for optimized performance, we have incorporated the Grid Search method, with 10 Fold Cross-Validation. In this context, the optimized version of XgBoost outperformed all other classifiers with a Cross-validation Weighted F1 score of 94.62 %. Followed by this empirical evidence, we explored the XgBoost classifier by incorporating TreeSHAP, a game-theory-based statistical algorithm used to explain Machine Learning models, to identify eloquent features such as SLOPE, ELEVATION, TWI that complement the performance of the XGBoost classifier mostly and features such as LANDUSE, NDVI, SPI which has less effect on models performance. According to the TreeSHAP explanation of features, we selected the 9 most significant landslide causal factors out of 15. Evidently, an optimized version of XgBoost along with feature reduction by 40 % has outperformed all other classifiers in terms of popular evaluation metrics with a Cross-Validation Weighted F1 score of 95.01 % on the training and AUC score of 97 %
description: Accepted for publication in SN Computer Science (Springer)
The Community is the Infrastructure: A Short Discussion of the PETSc User Community
Creators: name: Adams, Mark
name: Balay, Satish
name: Brown, Jed
name: Eijkhout, Victor
name: Faibussowitsch, Jacob
name: Kong, Fande
name: Knepley, Matthew
name: Kruger, Scott
name: Marin, Oana
name: Mills, Richard
name: Munson, Todd
name: Sanan, Patrick
name: Smith, Barry
name: Zhang, Hong
name: Zhang, Hong
name: Zhang, Junchao
Publisher: name: figshare
Year: 2021
Subjects: subject: 80306 Open Software
subject: FOS: Computer and information sciences
subject: 80205 Numerical Computation
subject: 80110 Simulation and Modelling
subject: 80204 Mathematical Software

description: Whitepaper submitted to the 2021 Collegeville Workshop Series on Scientific Software, which focused on the theme of "software teams". This paper describes the development community for the Portable, Extensible Toolkit for Scientific Computing (PETSc), a suite of data structures and routines for the scalable (parallel) solution of scientific applications modeled by partial differential equations.
title: What do investors in electric vehicles technologies want?
Creators: name: Kast, Bettina
name: Bortolotti, Eva
name: Noailly, Joëlle
Publisher: name: Graduate Institute of International and Development Studies
publisherIdentifier: https://ror.org/007ygn379
publisherIdentifierScheme: ROR
Year: 2020

description: CIES Policy Brief ; 6
Exploring the limits of safety analysis in complex technological systems
Creators: name: Sornette, D.
name: Maillart, T.
name: Kroeger, W.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: From biotechnology to cyber-risks, most extreme technological risks cannot be reliably estimated from historical statistics. Therefore, engineers resort to predictive methods, such as fault/event trees in the framework of probabilistic safety assessment (PSA), which consists in developing models to identify triggering events, potential accident scenarios, and estimate their severity and frequency. However, even the best safety analysis struggles to account for evolving risks resulting from inter-connected networks and cascade effects. Taking nuclear risks as an example, the predicted plant-specific distribution of losses is found to be significantly underestimated when compared with available empirical records. Using a novel database of 99 events with losses larger than $50'000 constructed by Sovacool, we document a robust power law distribution with tail exponent mu \approx 0.7. A simple cascade model suggests that the classification of the different possible safety regimes is intrinsically unstable in the presence of cascades. Additional continuous development and validation, making the best use of the experienced realized incidents, near misses and accidents, is urgently needed to address the existing known limitations of PSA when aiming at the estimation of total risks.
description: expanded to 25 pages including 5 figures, in press in International Journal of Disaster Risk Reduction
On Controller Tuning with Time-Varying Bayesian Optimization
Creators: name: Brunzema, Paul
name: von Rohr, Alexander
name: Trimpe, Sebastian
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Systems and Control (eess.SY)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Changing conditions or environments can cause system dynamics to vary over time. To ensure optimal control performance, controllers should adapt to these changes. When the underlying cause and time of change is unknown, we need to rely on online data for this adaptation. In this paper, we will use time-varying Bayesian optimization (TVBO) to tune controllers online in changing environments using appropriate prior knowledge on the control objective and its changes. Two properties are characteristic of many online controller tuning problems: First, they exhibit incremental and lasting changes in the objective due to changes to the system dynamics, e.g., through wear and tear. Second, the optimization problem is convex in the tuning parameters. Current TVBO methods do not explicitly account for these properties, resulting in poor tuning performance and many unstable controllers through over-exploration of the parameter space. We propose a novel TVBO forgetting strategy using Uncertainty-Injection (UI), which incorporates the assumption of incremental and lasting changes. The control objective is modeled as a spatio-temporal Gaussian process (GP) with UI through a Wiener process in the temporal domain. Further, we explicitly model the convexity assumptions in the spatial dimension through GP models with linear inequality constraints. In numerical experiments, we show that our model outperforms the state-of-the-art method in TVBO, exhibiting reduced regret and fewer unstable parameter configurations.
description: To appear in the proceedings of the 61st IEEE Conference on Decision and Control
Quality Maintenance of California Strawberries Exported to Far Eastern Markets
Creators: name: Harris, C. Max
name: Harvey, John M.
name: Harris, C. Max
name: Harvey, John M.
Publisher: name: Unknown
Year: 1976
Subjects: subject: Crop Production/Industries
subject: International Relations/Trade
subject: Marketing
subject: FOS: Economics and business
subject: Research and Development/Tech Change/Emerging Technologies

description: Report Summary: Transit times for air shipments of strawberries sent from shipping points in California to wholesale markets in Tokyo and Hong Kong averaged 28 and 37 hours, respectively. These times may vary, however, because of differences in schedules among various airlines serving these areas. Pallet loads of fruit remained cooler during transit when shipped in enclosed airline containers than when shipped on open, netted master pallets. Warming of berries in the top layers was slowed by the use of dry ice and plastic film pallet covers. The covers also provided a gas barrier around the fruit that retained carbon dioxide atmospheres, which retard development of decay.
Non-local double-path Casimir phase in atom interferometers
Creators: name: Impens, François
name: Behunin, Ryan O.
name: Ttira, Claudio Ccapa
name: Neto, Paulo A. Maia
Publisher: name: arXiv
Year: 2012
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Atomic Physics (physics.atom-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present a quantum open system theory of atom interferometers evolving in the quantized electromagnetic field bounded by an ideal conductor. Our treatment reveals an unprecedented feature of matter-wave propagation, namely the appearance of a non-local double-path phase coherence. Such a non-local phase arises from the coarse-graining over the quantized electromagnetic field and internal atomic degrees of freedom, yielding a non-Hamiltonian evolution of the atomic waves moving in presence of correlated quantum dipole and field fluctuations. We develop a diagrammatic interpretation of this phase, and estimate it for realistic experimental parameters.
description: 5 pages, 1 figure. Final version, published in the Europhysics Letters
A non-equilibrium superradiant phase transition in free space
Creators: name: Ferioli, Giovanni
name: Glicenstein, Antoine
name: Ferrier-Barbut, Igor
name: Browaeys, Antoine
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: A class of systems exists in which dissipation, external drive and interactions compete and give rise to non equilibrium phases that would not exist without the drive. There, phase transitions could occur without the breaking of any symmetry, yet with a local order parameter, in contrast with the Landau theory of phase transitions at equilibrium. One of the simplest driven dissipative quantum systems consists of two-level atoms enclosed in a volume smaller than the wavelength of the atomic transition cubed, driven by a light field. The competition between collective coupling of the atoms to the driving field and their cooperative decay should lead to a transition between a phase where all the atomic dipoles are phaselocked and a phase governed by superradiant spontaneous emission. Here, we realize this model using a pencil-shaped cloud of laser cooled atoms in free space, optically excited along its main axis, and observe the predicted phases. Our demonstration is promising in view of obtaining free-space superradiant lasers or to observe new types of time crystals.
description: 9 pages, 8 figures
1-factor and cycle covers of cubic graphs
Creators: name: Steffen, Eckhard
Publisher: name: arXiv
Year: 2012
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05C70

description: Let $G$ be a bridgeless cubic graph. Consider a list of $k$ 1-factors of $G$. Let $E_i$ be the set of edges contained in precisely $i$ members of the $k$ 1-factors. Let $μ_k(G)$ be the smallest $|E_0|$ over all lists of $k$ 1-factors of $G$. Any list of three 1-factors induces a core of a cubic graph. We use results on the structure of cores to prove sufficient conditions for Berge-covers and for the existence of three 1-factors with empty intersection. Furthermore, if $μ_3(G) \not = 0$, then $2 μ_3(G)$ is an upper bound for the girth of $G$. We also prove some new upper bounds for the length of shortest cycle covers of bridgeless cubic graphs. Cubic graphs with $μ_4(G) = 0$ have a 4-cycle cover of length $\frac{4}{3} |E(G)|$ and a 5-cycle double cover. These graphs also satisfy two conjectures of Zhang. We also give a negative answer to a problem of Zhang.
description: final version
Extremely Correlated Fermi Liquids: The Formalism
Creators: name: Shastry, B. Sriram
Publisher: name: arXiv
Year: 2012
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We present the detailed formalism of the extremely correlated Fermi liquid theory, developed for treating the physics of the t-J model. We start from the exact Schwinger equation of motion for the Greens function for projected electrons, and develop a systematic expansion in a parameter λ, relating to the double occupancy. The resulting Greens function has a canonical part arising from an effective Hamiltonian of the auxiliary electrons, and a caparison part, playing the role of a frequency dependent adaptive spectral weight. This adaptive weight balances the requirement at low ω, of the invariance of the Fermi volume, and at high ω, of decaying as c_0/(i ω), with a correlation depleted c_0 <1. The effective Hamiltonian H_{eff} describing the auxiliary Fermions is given a natural interpretation with an effective interaction V_{eff} containing both the exchange J(ij), and the hopping parameters t(ij). It is made Hermitian by adding suitable terms that ultimately vanish, in the symmetrized theory developed in this paper. Simple but important shift invariances of the t-J model are noted with respect to translating its parameters uniformly. These play a crucial role in constraining the form of V_{eff} and also provide checks for further approximations. The auxiliary and physical Greens function satisfy two sum rules, and the Lagrange multipliers for these are identified. A complete set of expressions for the Greens functions to second order in λis given, satisfying various invariances. A systematic iterative procedure for higher order approximations is detailed. A superconducting instability of the theory is noted at the simplest level with a high transition temperature.
description: 33 pages, 6 figures, 4 tables
Uncertainty quantification in mechanistic epidemic models via cross-entropy approximate Bayesian computation
Creators: name: Cunha, Americo
name: Barton, David A. W.
name: Ritto, Thiago G.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Applications (stat.AP)
subject: Computational Engineering, Finance, and Science (cs.CE)
subject: Dynamical Systems (math.DS)
subject: Populations and Evolution (q-bio.PE)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics
subject: FOS: Biological sciences
subject: I.6.5
subject: 37N25

description: This paper proposes a data-driven approximate Bayesian computation framework for parameter estimation and uncertainty quantification of epidemic models, which incorporates two novelties: (i) the identification of the initial conditions by using plausible dynamic states that are compatible with observational data; (ii) learning of an informative prior distribution for the model parameters via the cross-entropy method. The new methodology's effectiveness is illustrated with the aid of actual data from the COVID-19 epidemic in Rio de Janeiro city in Brazil, employing an ordinary differential equation-based model with a generalized SEIR mechanistic structure that includes time-dependent transmission rate, asymptomatics, and hospitalizations. A minimization problem with two cost terms (number of hospitalizations and deaths) is formulated, and twelve parameters are identified. The calibrated model provides a consistent description of the available data, able to extrapolate forecasts over a few weeks, making the proposed methodology very appealing for real-time epidemic modeling.
Maximal Fermi charts and geometry of inflationary universes
Creators: name: Klein, David
Publisher: name: arXiv
Year: 2012
Subjects: subject: Mathematical Physics (math-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Differential Geometry (math.DG)
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: 83F05, 83C10

description: A proof is given that the maximal Fermi coordinate chart for any comoving observer in a broad class of Robertson-Walker spacetimes consists of all events within the cosmological event horizon, if there is one, or is otherwise global. Exact formulas for the metric coefficients in Fermi coordinates are derived. Sharp universal upper bounds for the proper radii of leaves of the foliation by Fermi spaceslices are found, i.e., for the proper radii of the spatial universe at fixed times of the comoving observer. It is proved that the radius at proper time $τ$ diverges to infinity for non inflationary cosmologies as $τ\to\infty$, but not necessarily for cosmologies with periods of inflation. It is shown that any spacelike geodesic orthogonal to the worldline of a comoving observer has finite proper length and terminates within the cosmological event horizon (if there is one) at the big bang. Geometric properties of inflationary versus non inflationary cosmologies are compared, and opposite inequalities for the inflationary and non inflationary cases, analogous to Hubble's law, are obtained for the Fermi relative velocities of comoving test particles. It is proved that the Fermi relative velocities of radially moving test particles are necessarily subluminal for inflationary cosmologies in contrast to non inflationary models, where superluminal relative Fermi velocities necessarily exist.
description: Minor corrections made in this version
Quantum magnetic properties of the SU(2N) Hubbard model in the square lattice: a quantum Monte Carlo study
Creators: name: Cai, Zi
name: Hung, Hsiang-Hsuan
name: Wang, Lei
name: Wu, Congjun
Publisher: name: arXiv
Year: 2012
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We employ the determinant projector quantum Monte-Carlo method to investigate the ground state magnetic properties in the Mott insulating states of the half-filled SU(4) and SU(6) Fermi-Hubbard model in the 2D square lattice, which is free of the sign problem. The long-range antiferromagnetic Neel order is found for the SU(4) case with a small residual Neel moment. Quantum fluctuations are even stronger in the SU(6) case. Numeric results are consistent with either a vanishing or even weaker Neel ordering than that of SU(4).
description: sumbitted to PRB
Nonexistence of motility induced phase separation transition in one dimension
Creators: name: Mukherjee, Indranil
name: Raghu, Adarsh
name: Mohanty, P. K.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We introduce and study a model of hardcore particles obeying run-and-tumble dynamics on a one-dimensional lattice, where particles run in either +ve or -ve $x$-direction with an effective speed $v$ and tumble (change their direction of motion) with a constant rate $ω.$ We show that the coarse-grained dynamics of the system can be mapped to a beads-in-urn model called misanthrope process where particles are identified as urns and vacancies as beads that hop to a neighbouring urn situated in the direction opposite to the current. The hop rate, same as the magnitude of the current, depends on the total number of beads present in the departure and the arrival urn; we calculate it analytically and show that it does not satisfy the criteria required for a phase separation transition. Tumbling is generally detrimental to the stability of jamming; thus, our results for this restricted tumbling model strongly suggest that motility induced phase separation transition can not occur in one dimension.
description: 7 pages, 5 figures
A tower connecting gauge groups to string topology
Creators: name: Malkiewich, Cary
Publisher: name: arXiv
Year: 2012
Subjects: subject: Algebraic Topology (math.AT)
subject: FOS: Mathematics
subject: 55P65, 55P42, 55P50, 55R70

description: We develop a variant of calculus of functors, and use it to relate the gauge group G(P) of a principal bundle P over M to the Thom ring spectrum (P^Ad)^{-TM}. If P has contractible total space, the resulting Thom ring spectrum is LM^{-TM}, which plays a central role in string topology. R.L. Cohen and J.D.S. Jones have recently observed that, in a certain sense, (P^Ad)^{-TM} is the linear approximation of G(P). We prove an extension of that relationship by demonstrating the existence of higher-order approximations and calculating them explicitly. This also generalizes calculations done by G. Arone.
description: 50 pages. Most recent version has a new section on convergence. Accepted for publication in the Journal of Topology
Zwei jungsteinzeitliche Siedlungsplätze am Nordfuß des Hildesheimer Waldes im Landkreis Hildesheim-Marienburg
Creators: name: Baumann, G. E. H.
Publisher: name: Nachrichten aus Niedersachsens Urgeschichte
Year: 2019

description: Nachrichten aus Niedersachsens Urgeschichte, Bd. 34 (1965): Nachrichten aus Niedersachsens Urgeschichte
Henry Clay Lindgren und Frank L. Kovacs, Ancient Bronze Coins of Asia Minor and the Levant from the Lindgren Collection
Creators: name: Ziegler, Ruprecht
Publisher: name: Bonner Jahrbücher
Year: 2019

description: Rezension zu: Henry Clay Lindgren und Frank L. Kovacs, Ancient Bronze Coins of Asia Minor and the Levant from the Lindgren Collection. Chrysopylon Publishers, San Mateo, California 1985. XVIII, 212 Seiten, 135 Tafeln.
description: Bonner Jahrbücher, Bd. 187.1987: Bonner Jahrbücher
Margarete Tempelmann-Maczyńska, Die Perlen der römischen Kaiserzeit und der frühen Phase der Völkerwanderungszeit im mitteleuropäischen Barbaricum
Creators: name: Koch, Ursula
Publisher: name: Bonner Jahrbücher
Year: 2019

description: Rezension zu: Margarete Tempelmann-Maczy´nska, Die Perlen der römischen Kaiserzeit und der frühen Phase der Völkerwanderungszeit im mitteleuropäischen Barbaricum. Römisch- Germanische Forschungen 43. Verlag Philipp von Zabern, Mainz 1985. XII, 339 Seiten, 24 Abbildungen, 16 Tabellen, 14 Farbtafeln, 66 Tafeln, 3 Beilagen.
description: Bonner Jahrbücher, Bd. 187.1987: Bonner Jahrbücher
Systematic strain-induced bandgap tuning in binary III-V semiconductors from density functional theory
Creators: name: Mondal, Badal
name: Tonner-Zech, Ralf
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The modification of the nature and size of bandgaps for III-V semiconductors is of strong interest for optoelectronic applications. Strain can be used to systematically tune the bandgap over a wide range of values and induce indirect-to-direct (IDT), direct-to-indirect (DIT), and other changes in bandgap nature. Here, we establish a predictive ab initio approach, based on density functional theory, to analyze the effect of uniaxial, biaxial, and isotropic strain on the bandgap. We show that systematic variation is possible. For GaAs, DITs were observed at 1.52% isotropic compressive strain and 3.52% tensile strain, while for GaP an IDT was found at 2.63% isotropic tensile strain. We additionally propose a strategy for the realization of direct-indirect transition by combining biaxial strain with uniaxial strain. Further transition points were identified for strained GaSb, InP, InAs, and InSb and compared to the elemental semiconductor silicon. Our analyses thus provide a systematic and predictive approach to strain-induced bandgap tuning in binary III-V semiconductors.
Rapidity Divergences and Deep Inelastic Scattering in the Endpoint Region
Creators: name: Fleming, Sean
name: Labun, Ou Z.
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The deep inelastic scattering cross section in the endpoint region, $x \sim 1$, has been subjected to extensive analysis. We revisit this process, and show that in the endpoint individual factors in the factorized hadronic tensor have rapidity divergences. We regulate these divergences using a recently introduced rapidity regulator, and find that each factor requires a different scale to minimize large rapidity logarithms. Interestingly, in this case running in rapidity is non-perturbative. In addition, we give an operator definition of the parton distribution function in the endpoint region, and remark on the issues that should be considered in constructing this function.
description: 18 pages, 3 figures
Sinaida W. Udalzowa (Hrsg.), Die byzantinische Kultur zwischen dem 4. und 7. Jahrhundert (Russ.)
Creators: name: Wirth, Gerhard
Publisher: name: Bonner Jahrbücher
Year: 2019

description: Rezension zu: Sinaida W. Udalzowa (Hrsg.), Die byzantinische Kultur zwischen dem 4. und 7. Jahrhundert (Russ.). Verlag der Akademie der Wissenschaften, Moskau 1984. 723 Seiten
description: Bonner Jahrbücher, Bd. 187.1987: Bonner Jahrbücher
Local characterization of strongly convex sets
Creators: name: Weber, Alexander
name: Reißig, Gunther
Publisher: name: arXiv
Year: 2012
Subjects: subject: Metric Geometry (math.MG)
subject: Functional Analysis (math.FA)
subject: Optimization and Control (math.OC)
subject: FOS: Mathematics
subject: 52A30, 46C05

description: Strongly convex sets in Hilbert spaces are characterized by local properties. One quantity which is used for this purpose is a generalization of the modulus of convexity δ_Ωof a set Ω. We also show that \lim_{ε\to 0} δ_Ω(ε)/ε^2 exists whenever Ωis closed and convex.
International Prehistoric Conference / Internationale Prähistorische Konferenz
Creators: name: Petrasch, Jörg
Publisher: name: Bonner Jahrbücher
Year: 2019

description: Rezension zu: International Prehistoric Conference / Internationale Prähistorische Konferenz. Szckszárd 9.-12. 5. 1985. A Béri Balogh Ádám Mézeum Évkönyve 13. Kiadja a Béri Balogh Ádám Megyei Múzeum, Szekszárd 1986. 387 Seiten mit zahlreichen Abbildungen und Tabellen.
description: Bonner Jahrbücher, Bd. 189.1989: Bonner Jahrbücher
Visualising highly localised luminescence in GaN/AlN heterostructures in nanowires
Creators: name: Zagonel, L. F.
name: Rigutti, L.
name: Tchernycheva, M.
name: Jacopin, G.
name: Songmuang, R.
name: Kociak, M.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The optical properties of a stack of GaN/AlN quantum discs (QDiscs) in a GaN nanowire have been studied by spatially resolved cathodoluminescence (CL) at the nanoscale (nanoCL) using a Scanning Transmission Electron Microscope (STEM) operating in spectrum imaging mode. For the electron beam excitation in the QDisc region, the luminescence signal is highly localized with spatial extension as low as 5 nm due to the high band gap difference between GaN and AlN. This allows for the discrimination between the emission of neighbouring QDiscs and for evidencing the presence of lateral inclusions, about 3 nm thick and 20 nm long rods (quantum rods, QRods), grown unintentionally on the nanowire sidewalls. These structures, also observed by STEM dark-field imaging, are proven to be optically active in nanoCL, emitting at similar, but usually shorter, wavelengths with respect to most QDiscs.
description: 25 Pages, 18 Figures, manuscript format
Transit Temperatures and Quality of Fresh Vegetables Shipped in an Experimental and a Commercial Van Container to the Far East
Creators: name: Stewart, Joseph K.
name: Stewart, Joseph K.
Publisher: name: Unknown
Year: 1976
Subjects: subject: Crop Production/Industries
subject: International Relations/Trade
subject: Marketing
subject: FOS: Economics and business
subject: Research and Development/Tech Change/Emerging Technologies

description: Report Summary: Transit temperatures and arrival condition of mixed vegetables (cabbage, carrots, celery, and lettuce) were determined in produce shipped in a U.S. Department of Agriculture (USDA) experimental van container and a commercial refrigerated van container from San Francisco, Calif., to Pusan, South Korea. The test was made in cooperation with the U.S. Department of Defense. The USDA experimental van, tightly stacked with packages of produce in a solid load pattern, provided commodity temperatures comparable to those in a commercial refrigerated van that had a spaced load with air channels for air circulation around the packages. Solid load patterns are faster and easier to load than spaced load patterns and allow more packages to be placed in a van container. Solid loads, however, can only be used in vans with refrigeration and air distribution systems designed to force refrigerated air through the package. Otherwise, excessive temperatures would occur within the load, accompanied by deterioration of product. Quality of the cabbage, carrots, and celery shipped in the two vans was good at destination, but lettuce suffered losses from decay in both vans.
An explicit formula for the coefficients in Laplace's method
Creators: name: Nemes, Gergő
Publisher: name: arXiv
Year: 2012
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: Primary: 41A60, Secondary: 41A58

description: Laplace's method is one of the fundamental techniques in the asymptotic approximation of integrals. The coefficients appearing in the resulting asymptotic expansion, arise as the coefficients of a convergent or asymptotic series of a function defined in an implicit form. Due to the tedious computation of these coefficients, most standard textbooks on asymptotic approximations of integrals do not give explicit formulas for them. Nevertheless, we can find some more or less explicit representations for the coefficients in the literature: Perron's formula gives them in terms of derivatives of an explicit function; Campbell, Fröman and Walles simplified Perron's method by computing these derivatives using an explicit recurrence relation. The most recent contribution is due to Wojdylo, who rediscovered the Campbell, Fröman and Walles formula and rewrote it in terms of partial ordinary Bell polynomials. In this paper, we provide an alternative representation for the coefficients, which contains ordinary potential polynomials. The proof is based on Perron's formula and a theorem of Comtet. The asymptotic expansions of the gamma function and the incomplete gamma function are given as illustrations.
description: 14 pages, to appear in Constructive Approximation
Deep Kernel Learning of Dynamical Models from High-Dimensional Noisy Data
Creators: name: Botteghi, Nicolò
name: Guo, Mengwu
name: Brune, Christoph
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: This work proposes a Stochastic Variational Deep Kernel Learning method for the data-driven discovery of low-dimensional dynamical models from high-dimensional noisy data. The framework is composed of an encoder that compresses high-dimensional measurements into low-dimensional state variables, and a latent dynamical model for the state variables that predicts the system evolution over time. The training of the proposed model is carried out in an unsupervised manner, i.e., not relying on labeled data. Our learning method is evaluated on the motion of a pendulum -- a well studied baseline for nonlinear model identification and control with continuous states and control inputs -- measured via high-dimensional noisy RGB images. Results show that the method can effectively denoise measurements, learn compact state representations and latent dynamical models, as well as identify and quantify modeling uncertainties.
Brachyhypopomus Mago-Leccia 1994
Creators: name: Giora, Júlia
name: Burns, John R.
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Actinopterygii
Gymnotiformes
Hypopomidae
Brachyhypopomus

description: Results
Spermatozoa of Brachyhypopomus draco, Brachyhypopomus bombilla and Brachyhypopomus gauderio - Hypopomidae.
The spermatozoa of the three analyzed species are characterized by a well defined head, midpiece, and single flagellum. Both the head and nucleus tend to be spherical in B. draco (head, Fig. 1F; nucleus Fig. 1 G-H-I), but ovoid in B. gauderio (head, Fig. 1A; nucleus, Fig. 1 B-C) and B. bombilla (head, Fig. 1K; nucleus, Fig. 1 M-N). Nuclear diameter is 1.0 µm for B. draco; length and width nuclear measurements are 1.7 x 2.8 µm for B. gauderio and 0.9 x 1.8 µm for B. bombilla. Nuclear chromatin is condensed and granular in all three species, with extensive areas of lighter chromatin seen only in B. bombilla (Fig. 1 M-N).All species undergo nuclear rotation. The proximal centriole is anterior, slightly lateral and perpendicular to the distal. Electron-dense material is associated with both centrioles. The proximal centriole and most of the distal are contained within a deep nuclear fossa (Fig. 1 C-I-M). Only in B. gauderio does the fossa branch extensively throughout the nucleus (Fig. 1B). The midpiece contains several elongate mitochondria and a large number of vesicles, some of which contain stainable material (Fig. 1 B-D-G-H-M).An open cytoplasmic canal is only observed immediately posterior to the centriolar complex in B. gauderio (Fig. 1C) and B. draco (Fig. 1I) but this may close more posteriorly.An open cytoplasmic canal is not apparent in B. bombilla. An area of more organized membranous structures is only observed in the midpiece of B. draco (Fig. 1 G-J). The flagellum has the classic 9 + 2 microtubular pattern and does not show intratubular differentiation, both tubules of each peripheral doublet being electron-lucent (Fig 1 E-J-L). The flagellar membrane does not have lateral projections or fins in any of the species. However, there is substantially more cytoplasm between the axoneme and flagellar membrane in B. bombilla (Fig. 1L).
description: Published as part of Giora, Júlia & Burns, John R., 2011, Sperm ultrastructure in three different families of weakly electric fishes (Teleostei: Gymnotiformes), pp. 881-888 in Neotropical Ichthyology 9 (4) on page 882, DOI: 10.1590/S1679-62252011005000047, http://zenodo.org/record/5756622
Furstenberg entropy realizations for virtually free groups and lamplighter groups
Creators: name: Hartman, Yair
name: Tamuz, Omer
Publisher: name: arXiv
Year: 2012
Subjects: subject: Dynamical Systems (math.DS)
subject: Probability (math.PR)
subject: FOS: Mathematics

description: Let $(G,μ)$ be a discrete group with a generating probability measure. Nevo shows that if $G$ has property (T) then there exists an $ε>0$ such that the Furstenberg entropy of any $(G,μ)$-stationary ergodic space is either zero or larger than $ε$. Virtually free groups, such as $SL_2(\mathbb{Z})$, do not have property (T), and neither do their extensions, such as surface groups. For these, we construct stationary actions with arbitrarily small, positive entropy. This construction involves building and lifting spaces of lamplighter groups. For some classical lamplighters, these spaces realize a dense set of entropies between zero and the Poisson boundary entropy.
description: 27 pages