cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Fully Automatic Gym Exercises Recording: An IoT Solution
Creators: name: Bian, Sizhen
name: Rupp, Alexander
name: Magno, Michele
Publisher: name: arXiv
Year: 2023
Subjects: subject: Systems and Control (eess.SY)
subject: Signal Processing (eess.SP)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: In recent years, working out in the gym has gotten increasingly more data-focused and many gym enthusiasts are recording their exercises to have a better overview of their historical gym activities and to make a better exercise plan for the future. As a side effect, this recording process has led to a lot of time spent painstakingly operating these apps by plugging in used types of equipment and repetitions. This project aims to automate this process using an Internet of Things (IoT) approach. Specifically, beacons with embedded ultra-low-power inertial measurement units (IMUs) are attached to the types of equipment to recognize the usage and transmit the information to gym-goers and managers. We have created a small ecosystem composed of beacons, a gateway, smartwatches, android/iPhone applications, a firebase cloud server, and a dashboard, all communicating over a mixture of Bluetooth and Wifi to distribute collected data from machines to users and gym managers in a compact and meaningful way. The system we have implemented is a working prototype of a bigger end goal and is supposed to initialize progress toward a smarter, more efficient, and still privacy-respect gym environment in the future. A small-scale real-life test shows 94.6\% accuracy in user gym session recording, which can reach up to 100\% easily with a more suitable assembling of the beacons. This promising result shows the potential of a fully automatic exercise recording system, which enables comprehensive monitoring and analysis of the exercise sessions and frees the user from manual recording. The estimated battery life of the beacon is 400 days with a 210 mAh coin battery. We also discussed the shortcoming of the current demonstration system and the future work for a reliable and ready-to-deploy automatic gym workout recording system.
On hyperbolic 3-manifolds realizing the maximal distance between toroidal Dehn fillings
Creators: name: Goda, Hiroshi
name: Teragaito, Masakazu
Publisher: name: arXiv
Year: 2005
Subjects: subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 57M25, 57M50

description: For a hyperbolic 3-manifold M with a torus boundary component, all but finitely many Dehn fillings on the torus component yield hyperbolic 3-manifolds. In this paper, we will focus on the situation where M has two exceptional Dehn fillings, both of which yield toroidal manifolds. For such situation, Gordon gave an upper bound for the distance between two slopes of Dehn fillings. In particular, if M is large, then the distance is at most 5. We show that this upper bound can be improved by 1 for a broad class of large manifolds.
description: Published by Algebraic and Geometric Topology at http://www.maths.warwick.ac.uk/agt/AGTVol5/agt-5-21.abs.html
A model for a non-minimally coupled scalar field interacting with dark matter
Creators: name: Binder, J. B.
name: Kremer, G. M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this work we investigate the evolution of a Universe consisted of a scalar field, a dark matter field and non-interacting baryonic matter and radiation. The scalar field, which plays the role of dark energy, is non-minimally coupled to space-time curvature, and drives the Universe to a present accelerated expansion. The non-relativistic dark matter field interacts directly with the dark energy and has a pressure which follows from a thermodynamic theory. We show that this model can reproduce the expected behavior of the density parameters, deceleration parameter and luminosity distance.
description: 3 pages, 4 figures. To appear in Brazilian Journal of Physics
GW190814: Impact of a 2.6 solar mass neutron star on nucleonic equations of state
Creators: name: Fattoyev, F. J.
name: Horowitz, C. J.
name: Piekarewicz, J.
name: Reed, Brendan
Publisher: name: arXiv
Year: 2020
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: Is the secondary component of GW190814 the lightest black hole or the heaviest neutron star ever discovered in a double compact-object system [R. Abbott et al., ApJ Lett., 896, L44 (2020)]? This is the central question animating this letter. Covariant density functional theory provides a unique framework to investigate both the properties of finite nuclei and neutron stars, while enforcing causality at all densities. By tuning existing energy density functionals we were able to: (a) account for a 2.6 Msun neutron star, (b) satisfy the original constraint on the tidal deformability of a 1.4 Msun neutron star, and (c) reproduce ground-state properties of finite nuclei. Yet, for the class of models explored in this work, we find that the stiffening of the equation of state required to support super-massive neutron stars is inconsistent with either constraints obtained from energetic heavy-ion collisions or from the low deformability of medium-mass stars. Thus, we speculate that the maximum neutron star mass can not be significantly higher than the existing observational limit and that the 2.6 Msun compact object is likely to be the lightest black hole ever discovered.
description: 6 pages and 3 figures
Risk-Aware Motion Planning for a Limbed Robot with Stochastic Gripping Forces Using Nonlinear Programming
Creators: name: Shirai, Yuki
name: Lin, Xuan
name: Tanaka, Yusuke
name: Mehta, Ankur
name: Hong, Dennis
Publisher: name: arXiv
Year: 2020
Subjects: subject: Robotics (cs.RO)
subject: Systems and Control (eess.SY)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: We present a motion planning algorithm with probabilistic guarantees for limbed robots with stochastic gripping forces. Planners based on deterministic models with a worst-case uncertainty can be conservative and inflexible to consider the stochastic behavior of the contact, especially when a gripper is installed. Our proposed planner enables the robot to simultaneously plan its pose and contact force trajectories while considering the risk associated with the gripping forces. Our planner is formulated as a nonlinear programming problem with chance constraints, which allows the robot to generate a variety of motions based on different risk bounds. To model the gripping forces as random variables, we employ Gaussian Process regression. We validate our proposed motion planning algorithm on an 11.5 kg six-limbed robot for two-wall climbing. Our results show that our proposed planner generates various trajectories (e.g., avoiding low friction terrain under the low risk bound, choosing an unstable but faster gait under the high risk bound) by changing the probability of risk based on various specifications.
description: IEEE Robotics and Automation Letters (RA-L). Pre-print Version. The video of this paper is: https://youtu.be/ZDqvf1J4nS4
Partial Counterfactual Identification of Continuous Outcomes with a Curvature Sensitivity Model
Creators: name: Melnychuk, Valentyn
name: Frauen, Dennis
name: Feuerriegel, Stefan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (stat.ML)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Counterfactual inference aims to answer retrospective "what if" questions and thus belongs to the most fine-grained type of inference in Pearl's causality ladder. Existing methods for counterfactual inference with continuous outcomes aim at point identification and thus make strong and unnatural assumptions about the underlying structural causal model. In this paper, we relax these assumptions and aim at partial counterfactual identification of continuous outcomes, i.e., when the counterfactual query resides in an ignorance interval with informative bounds. We prove that, in general, the ignorance interval of the counterfactual queries has non-informative bounds, already when functions of structural causal models are continuously differentiable. As a remedy, we propose a novel sensitivity model called Curvature Sensitivity Model. This allows us to obtain informative bounds by bounding the curvature of level sets of the functions. We further show that existing point counterfactual identification methods are special cases of our Curvature Sensitivity Model when the bound of the curvature is set to zero. We then propose an implementation of our Curvature Sensitivity Model in the form of a novel deep generative model, which we call Augmented Pseudo-Invertible Decoder. Our implementation employs (i) residual normalizing flows with (ii) variational augmentations. We empirically demonstrate the effectiveness of our Augmented Pseudo-Invertible Decoder. To the best of our knowledge, ours is the first partial identification model for Markovian structural causal models with continuous outcomes.
Westernization of the Asian Diet: The Case of Rising Wheat Consumption in Indonesia
Creators: name: Fabiosa, Jacinto F.
name: Fabiosa, Jacinto F.
Publisher: name: Unknown
Year: 2006
Subjects: subject: Food Consumption/Nutrition/Food Safety
subject: double-hurdle demand
subject: trade
subject: Westernization of diet

description: With sustained income growth and fast urbanization, Indonesia will see a major shift in the growth of grain consumption from rice to wheat products. New demand estimates from consumption survey data give a relatively high income elasticity of demand for wheat-based products, in the range of 0.44 to 0.84, with 26% to 34% of this response coming from the impact of income on the probability of consumption for non-consuming households and the remaining impact coming from the response on the level of consumption for households currently consuming wheat products. Urban location of households also contributes an increase of 0.11% to 0.13% to consumption. In contrast, elasticities in rice show a negative impact of income and urbanization on the probability of consumption and a positive but small impact on the unconditional mean. A partial liberalization scenario shows the domestic wheat flour price declining by 13.66%, inducing consumption to increase by 7.06%, which translates into 7.04% growth in imports. This exerts an upward pressure on the world price, increasing it by 0.23%. A faster income growth scenario shows higher consumption (2.60%), imports (2.59%), and prices (0.09%). Countries with a proximity advantage such as Australia, China, and India will benefit from the growth in this market. But, with dependable supply, product quality assurance, and credit availability, North American suppliers may still remain in this market.
Near-field spectroscopy of bimodal size distribution of InAs/AlGaAs quantum dots
Creators: name: Yu, Young-Jun
name: Jeong, I. T.
name: Woo, J. C.
name: Jhe, Wonho
Publisher: name: arXiv
Year: 2005
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We report on high-resolution photoluminescence (PL) spectroscopy of spatial structure of InAs/AlGaAs quantum dots (QDs) by using a near-field scanning optical microscope (NSOM). The double-peaked distribution of PL spectra is clearly observed, which is associated with the bimodal size distribution of single QDs. In particular, the size difference of single QDs, represented by the doublet spectral distribution, can be directly observed by the NSOM images of PL.
description: 3pages, 3figues
CARBON SEQUESTRATION, CO-BENEFITS, AND CONSERVATION PROGRAMS
Creators: name: Feng, Hongli
name: Kling, Catherine L.
name: Gassman, Philip W.
name: Feng, Hongli
name: Kling, Catherine L.
name: Gassman, Philip W.
Publisher: name: Unknown
Year: 2004
Subjects: subject: Environmental Economics and Policy
subject: carbon sequestration
subject: co-benefits
subject: Conservation Reserve Program

description: Land use changes to sequester carbon also provide "co-benefits," some of which (for example, water quality) have attracted at least as much attention as carbon storage. The non-separability of these co-benefits presents a challenge for policy design. If carbon markets are employed, then social efficiency will depend on how we take into account co-benefits, that is, externalities, in such markets. If carbon sequestration is incorporated into conservation programs, then the weight given to carbon sequestration relative to its co-benefits will partly shape these programs. Using the Conservation Reserve Program (CRP) as an example, we show that CRP has been sequestering carbon, which was not an intended objective of the program. We also demonstrate that more carbon would have been sequestered had CRP targeted this objective, although the "co-benefits" would have increased or decreased.
Surface transitions of the semi-infinite Potts model II: the low bulk temperature regime
Creators: name: Dobrovolny, Christophe
name: Laanait, Lahoussine
name: Ruiz, Jean
Publisher: name: arXiv
Year: 2005
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We consider the semi-infinite (q)-state Potts model. We prove, for large (q), the existence of a first order surface phase transition between the ordered phase and the the so-called "new low temperature phase" predicted in \cite{Li}, in which the bulk is ordered whereas the surface is disordered.
Quantum fluctuations in atomic Josephson junctions: the role of dimensionality
Creators: name: Bardin, Andrea
name: Lorenzi, Francesco
name: Salasnich, Luca
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We investigate the role of quantum fluctuations in the dynamics of a bosonic Josephson junction in $D$ spatial dimensions, by using beyond mean-field Gaussian corrections. We derive some key dynamical properties in a systematic way for $D=3, 2, 1$. In particular, we compute the Josephson frequency in the regime of low population imbalance. We also obtain the critical strength of the macroscopic quantum self-trapping. Our results show that quantum corrections increase the Josephson frequency in spatial dimensions $D=2$ and $D=3$, but they decrease it in the $D=1$ case. The critical strength of macroscopic quantum self-trapping is instead reduced by quantum fluctuations in $D=2$ and $D=3$ cases, while it is enhanced in the $D=1$ configuration. We show that the difference between the cases of D = 2 and D = 3 on one side, and D = 1 on the other, can be related to the qualitatively different dependence of the interaction strength on the scattering length in the different dimensions.
description: 25 pages, 9 figures, 2 tables
Correlated Energy Uncertainties in Reaction Rate Calculations
Creators: name: Longland, Richard
name: de Séréville, Nicolas
Publisher: name: arXiv
Year: 2020
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Context. Monte Carlo methods can be used to evaluate the uncertainty of a reaction rate that arises from many uncertain nuclear inputs. However, until now no attempt has been made to find the effect of correlated energy uncertainties in input resonance parameters. Aims. To investigate the impact of correlated energy uncertainties on reaction rates. Methods. Using a combination of numerical and Monte Carlo variation of resonance energies, the effect of correlations are investigated. Five reactions are considered: two fictional, illustrative cases and three reactions whose rates are of current interest. Results. The effect of correlations in resonance energies depends on the specific reaction cross section and temperatures considered. When several resonances contribute equally to a reaction rate, and are located either side of the Gamow peak, correlations between their energies dilute their effect on reaction rate uncertainties. If they are both located above or below the maximum of the Gamow peak, however, correlations between their resonance energies can increase the reaction rate uncertainties. This effect can be hard to predict for complex reactions with wide and narrow resonances contributing to the reaction rate.
description: 9 pages, 9 figures, accepted to Astronomy and Astrophysics
Nucleation properties of isolated shear bands
Creators: name: Yadav, Shwetabh
name: Sagapuram, Dinakar
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Shear banding, or localization of intense strains along narrow bands, is a plastic instability in solids with important implications for material failure in a wide range of materials and across length-scales. In this paper, we report on a series of experiments on the nucleation of single isolated shear bands in three model alloys. Nucleation kinetics of isolated bands and characteristic stresses are studied using high-speed in situ imaging and parallel force measurements. The results demonstrate the existence of a critical shear stress required for band nucleation. The nucleation stress bears little dependence on the normal stress and is proportional to the shear modulus. These properties are quite akin to those governing the onset of dislocation slip in crystalline solids. A change in the flow mode from shear banding to homogeneous plastic flow occurs at stress levels below the nucleation stress. Phase diagrams delineating the strain, strain rate and temperature domains where these two contrasting flow modes occur are presented. Our work enables interpretation of shear band nucleation as a crystal lattice instability due to (stress-assisted) breakdown of dislocation barriers, with quantitative experimental support in terms of stresses and the activation energy.
description: 20 pages, 10 figures, 2 tables
Engineering the Cost Function of a Variational Quantum Algorithm for Implementation on Near-Term Devices
Creators: name: Premaratne, Shavindra P.
name: Matsuura, A. Y.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Variational hybrid quantum-classical algorithms are some of the most promising workloads for near-term quantum computers without error correction. The aim of these variational algorithms is to guide the quantum system to a target state that minimizes a cost function, by varying certain parameters in a quantum circuit. This paper proposes a new approach for engineering cost functions to improve the performance of a certain class of these variational algorithms on today's small qubit systems. We apply this approach to a variational algorithm that generates thermofield double states of the transverse field Ising model, which are relevant when studying phase transitions in condensed matter systems. We discuss the benefits and drawbacks of various cost functions, apply our new engineering approach, and show that it yields good agreement across the full temperature range.
description: 8 pages, 4 figures
The Effect of Consumption Based Taxes on Agriculture in the United States
Creators: name: Marcu, Mihaela
name: Moss, Charles B.
name: Marcu, Mihaela
name: Moss, Charles B.
Publisher: name: Unknown
Year: 2005
Subjects: Public Economics

description: Recently several proposals have arisen to replace the current income tax system in the United States with a consumption based or Fair Tax. This study investigates the effect of such a consumption based tax on agricultural investment decisions using stochastic optimal control to model the investment decision at the farm level. The results indicate that a consumption tax rate of 25.9 percent would be equivalent to the income tax rate paid by very large producers in the United States.
Bound states in Andreev billiards with soft walls
Creators: name: Libisch, F.
name: Rotter, S.
name: Burgdoerfer, J.
name: Kormanyos, A.
name: Cserti, J.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The energy spectrum and the eigenstates of a rectangular quantum dot containing soft potential walls in contact with a superconductor are calculated by solving the Bogoliubov-de Gennes (BdG) equation. We compare the quantum mechanical solutions with a semiclassical analysis using a Bohr--Sommerfeld (BS) quantization of periodic orbits. We propose a simple extension of the BS approximation which is well suited to describe Andreev billiards with parabolic potential walls. The underlying classical periodic electron-hole orbits are directly identified in terms of ``scar'' like features engraved in the quantum wavefunctions of Andreev states determined here for the first time.
description: 8 pages, 6 figures, submitted to Phys. Rev
Canonical Approach to Ginsparg-Wilson Fermion
Creators: name: Matsui, Kosuke
name: Okamoto, Tomohiro
name: Fujiwara, Takanori
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: Based upon the lattice Dirac operator satisfying the Ginsparg-Wilson relation, we investigate canonical formulation of massless fermion on the spatial lattice. For free fermion system exact chiral symmetry can be implemented without species doubling. In the presence of gauge couplings the chiral symmetry is violated. We show that the divergence of the axial vector current is related to the chiral anomaly in the classical continuum limit.
description: 19 pages, 1 figure, final version
Matched photometric catalogs of GALEX UV sources with Gaia DR2 and SDSS DR14 databases (GUVmatch)
Creators: name: Bianchi, Luciana
name: Shiao, Bernard
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We have matched the ultraviolet (UV) sources in GUVcat_AIS (Bianchi et al.2017) with optical databases having similar depth and wide sky coverage. GUVcat_AIS has GALEX far-UV (FUV, lambda-eff ~1528Å) and near-UV (NUV, lambda-eff ~2310Å) photometry of approx 83~million sources, covering 24,788 square degrees of the sky, with typical depth of FUV=19.9, NUV=20.8~ABmag. Matches with Gaia and SDSS databases are presented here. Gaia data release 2 (DR2), covering the entire GUVcat footprint (Bianchi et al. 2019), detected about one third of the $GUVcat\_AIS$ sources. We found 31,925,294 Gaia~DR2 counterparts to 30,024,791 GUVcat_AIS unique sources, with photometry in $Gaia$~$G$ band, and often also in $Gaia$~$BP$ and $RP$ bands; 26,275,572 matches have a parallax measurement, 21,084,628/18,588,140/16,357,505 with parallax error less than 50%/30%/20%. The match with SDSS data release 14 (DR14) yields 23,310,532 counterparts to 22,207,563 unique GUVcat_AIS sources, 10,167,460 of which are point-like, over a total overlap area of $\approx$11,100~square~degrees (Bianchi et al. 2019)}. SDSS adds to the UV photometry five optical magnitudes: $u,g,r,i,z$, and optical spectra of 860,224 matched sources. We used a match radius of 3arcsec, consistent with previous works (e.g., Bianchi et al. 2011a), although the positions agree to $\lesssim$1.5arcsec for the majority of [point-like] matched-sources, in order to identify possible multiple matches whose UV flux could be unresolved in GALEX imaging. The catalogs can be trimmed to a tighter match radius using the provided separation. The multi-band photometry is used to identify classes of astrophysical objects that are prominent in UV, to characterise the content of the $GUVmatch$ catalogs, where stars in different evolutionary stages, QSOs, and galaxies can be separated.
description: accepted for ApJS
Subsurface Boundary Geometry Modeling: Applying Computational Physics, Computer Vision and Signal Processing Techniques to Geoscience
Creators: name: Leung, Raymond
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: FOS: Computer and information sciences
subject: J.2; I.3.5

description: This paper describes an interdisciplinary approach to geometry modeling of geospatial boundaries. The objective is to extract surfaces from irregular spatial patterns using differential geometry and obtain coherent directional predictions along the boundary of extracted surfaces to enable more targeted sampling and exploration. Specific difficulties of the data include sparsity, incompleteness, causality and resolution disparity. Surface slopes are estimated using only sparse samples from cross-sections within a geological domain with no other information at intermediate depths. From boundary detection to subsurface reconstruction, processes are automated in between. The key problems to be solved are boundary extraction, region correspondence and propagation of the boundaries via contour morphing. Established techniques from computational physics, computer vision and signal processing are used with appropriate modifications to address challenges in each area. To facilitate boundary extraction, an edge map synthesis procedure is presented. This works with connected component analysis, anisotropic diffusion and active contours to convert unordered points into regularized boundaries. For region correspondence, component relationships are handled via graphical decomposition. FFT-based spatial alignment strategies are used in region merging and splitting scenarios. Shape changes between aligned regions are described by contour metamorphosis. Specifically, local spatial deformation is modeled by PDE and computed using level-set methods. Directional predictions are obtained using particle trajectories by following the evolving boundary. However, when a branching point is encountered, particles may lose track of the wavefront. To overcome this, a curvelet backtracking algorithm has been proposed to recover information for boundary segments without particle coverage to minimize shape distortion.
description: Keywords: Interdisciplinary research, active contours, backtracking, contour morphing, directional prediction, particle trajectories, spatial correspondence, subsurface boundaries, wavefront propagation. 23 page article, 17 figures
Primordial magnetic fields and CMB anisotropies
Creators: name: Subramanian, Kandaswamy
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Possible signatures of primordial magnetic fields on the Cosmic Microwave Background (CMB) temperature and polarization anisotropies are reviewed. The signals that could be searched for include excess temperature anisotropies particularly at small angular scales below the Silk damping scale, B-mode polarization, and non-Gaussian statistics. A field at a few nG level produces temperature anisotropies at the 5 micro Kelvin level, and B-mode polarization anisotropies 10 times smaller, and is therefore potentially detectable via the CMB anisotropies. An even smaller field, with B_0 < 0.1 nG, could lead to structure formation at high redshift z > 15, and hence naturally explain an early re-ionization of the Universe.
description: 6 pages, 4 figures, talk given in Bologna, August 2005, proceedings of "The Origin and Evolution of Cosmic Magnetism", Astron. Nachr. (in press)
Strongly Correlated Chern Insulators in Magic-Angle Twisted Bilayer Graphene
Creators: name: Nuckolls, Kevin P.
name: Oh, Myungchul
name: Wong, Dillon
name: Lian, Biao
name: Watanabe, Kenji
name: Taniguchi, Takashi
name: Bernevig, B. Andrei
name: Yazdani, Ali
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Interactions among electrons and the topology of their energy bands can create novel quantum phases of matter. Most topological electronic phases appear in systems with weak electron-electron interactions. The instances where topological phases emerge only as a result of strong interactions are rare, and mostly limited to those realized in the presence of intense magnetic fields. The discovery of flat electronic bands with topological character in magic-angle twisted bilayer graphene (MATBG) has created a unique opportunity to search for new strongly correlated topological phases. Here we introduce a novel local spectroscopic technique using a scanning tunneling microscope (STM) to detect a sequence of topological insulators in MATBG with Chern numbers C = $\pm$ 1, $\pm$ 2, $\pm$ 3, which form near $ν$ = $\pm$ 3, $\pm$ 2, $\pm$ 1 electrons per moiré unit cell respectively, and are stabilized by the application of modest magnetic fields. One of the phases detected here (C = +1) has been previously observed when the sublattice symmetry of MATBG was intentionally broken by hexagonal boron nitride (hBN) substrates, with interactions playing a secondary role. We demonstrate that strong electron-electron interactions alone can produce not only the previously observed phase, but also new and unexpected Chern insulating phases in MATBG. The full sequence of phases we observed can be understood by postulating that strong correlations favor breaking time-reversal symmetry to form Chern insulators that are stabilized by weak magnetic fields. Our findings illustrate that many-body correlations can create topological phases in moiré systems beyond those anticipated from weakly interacting models.
description: 17 pages, 4 figures
Young children’s historical understanding
Creators: name: Weinert, Stella Rose
Publisher: name: University of British Columbia
Year: 2009

description: This study investigated young children's historical understanding, as little research has been done in this area. It described and analyzed first and second grade children's historical understanding before and after they were involved in a local history project. Specifically, it looked at how primary children understand history and what historians do; their understanding of the historical elements of evidence, interpretation and empathy and how the teaching of these concepts can develop their thinking. This information is important in considering appropriate history curriculum for young children. The study took place in my classroom of 18 students in a small, rural, public elementary school in British Columbia. I had the roles of both teacher and researcher in this case study. The data consists of interviews with the students, writing samples and transcribed video and audio-taped class discussions, as well as detailed classroom notes. The data were analyzed using qualitative research methodology. The study's findings revealed the children involved in the study developed an understanding of history and what historians do and engaged in historical methodology, including the use of evidence and interpretation. Although empathetic thinking proved difficult for most, a few considered its nature. All showed an interest in and engagement with the subject of history. Explicit teaching, as well as engaging students in historical methodology, at a level appropriate to their age, furthered their development. In light of these findings, the thesis proposes that history is an appropriate subject for young children and one in which they can become meaningfully engaged. This study is intended to inform and support the work of curriculum developers, elementary school teachers and teacher educators.
IS PRICING ABOVE MARGINAL COST AN INDICATION OF MARKET POWER IN THE U.S. MEATPACKING INDUSTRY?
Creators: name: Panagiotou, Dimitrios
name: Panagiotou, Dimitrios
Publisher: name: Unknown
Year: 2005
Subjects: Demand and Price Analysis

description: There have been concerns about the increasing concentration in the meat packing industry. But this increased concentration may be due to various types of cost economies. In this paper we prove the existence of scale economies that might justify the increased consolidation in the industry.
Field-induced bound-state condensation and spin-nematic phase in SrCu$_2$(BO$_3$)$_2$ revealed by neutron scattering up to 25.9 T
Creators: name: Fogh, Ellen
name: Nayak, Mithilesh
name: Prokhnenko, Oleksandr
name: Bartkowiak, Maciej
name: Munakata, Koji
name: Soh, Jian-Rui
name: Turrini, Alexandra A.
name: Zayed, Mohamed E.
name: Pomjakushina, Ekaterina
name: Kageyama, Hiroshi
name: Nojiri, Hiroyuki
name: Kakurai, Kazuhisa
name: Normand, Bruce
name: Mila, Frédéric
name: Rønnow, Henrik M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Bose-Einstein condensation (BEC) underpins exotic forms of order ranging from superconductivity to superfluid 4 He. In quantum magnetic materials, ordered phases induced by an applied magnetic field can be described as the BEC of magnon excitations. With sufficiently strong magnetic frustration, exemplified by the system SrCu$_2$(BO$_3$)$_2$ , no clear magnon BEC is observed and the complex spectrum of multi-magnon bound states may allow a different type of condensation, but the high fields required to probe this physics have remained a barrier to detailed investigation. Here we exploit the first purpose-built high-field neutron scattering facility to measure the spin excitations of SrCu$_2$(BO$_3$)$_2$ up to 25.9 T and use cylinder matrix-product-states (MPS) calculations to reproduce the experimental spectra with high accuracy. Multiple unconventional features point to a condensation of $S = 2$ bound states into a spin-nematic phase, including the gradients of the one-magnon branches, the presence of many novel composite two- and three-triplon excitations and the persistence of a one-magnon spin gap. This gap reflects a direct analogy with superconductivity, suggesting that the spin-nematic phase in SrCu$_2$(BO$_3$)$_2$ is best understood as a condensate of bosonic Cooper pairs. Our results underline the wealth of unconventional states yet to be found in frustrated quantum magnetic materials under extreme conditions.
Technical Efficiency among Organic and Conventional Farms in Sweden 2000-2002: A Counterfactual and Self-Selection Analysis
Creators: name: Larsen, Karin
name: Foster, Kenneth A.
name: Larsen, Karin
name: Foster, Kenneth A.
Publisher: name: Unknown
Year: 2005
Subjects: subject: Farm Management
subject: technical efficiency
subject: self-selection
subject: organic farming

description: Technical efficiency and its determinants among organic and conventional farms in Sweden are analyzed for time-period 2000-2002. In addition, we address the issues that arise when comparing performance measures among the two groups of producers (conventional and organic) due differences in their technologies and the potential presence of self-selection in the farmer's choice of using conventional or organic production methods. If the choice of production method is based on, or at least in part based on, the farms expected productivity in organic and conventional farming respectively there is self-selection present that must be considered. We apply an endogenous switching regression model suggested by Lee (1978) to compare efficiency measures between the two groups that also allows for testing for the presence of self-selection. The results suggest that organic producers have a lower average technical efficiency which is expected because they use a more restricted technology. Moreover, the results suggest that the organic farmers are on average more efficient in organic production than the average conventional would have been in organic production.
Dysgonia algira
Creators: name: Joos, R Enato
name: Fritsch, Dieter
name: Bryner, Rudolf
name: Billen, Wolfgang
name: Wicki, Christoph
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Lepidoptera
Noctuidae
Dysgonia
Dysgonia algira

description: 8904 Dysgonia algira (Linnaeus, 1767)
Münchenstein (BL), Merian Gärten, 25.6.2014. Die Art ist im Raum Pratteln–Birsfelden seit 1986 bekannt und galt als südlicher Zuwanderer. Heute wird sie als bodenständig betrachtet und kann regelmässig nachgewiesen werden.
description: Published as part of Joos, R Enato, Fritsch, Dieter, Bryner, Rudolf, Billen, Wolfgang & Wicki, Christoph, 2018, Vielfalt der nachtaktiven Gross- und Kleinschmetterlinge in zwei Parkanlagen bei Basel, pp. 57-71 in Entomo Helvetica 11 on page 63, DOI: 10.5169/seals-986024, http://zenodo.org/record/8034307
Berezinskii-Kosterlitz-Thouless localization-localization transitions in disordered two-dimensional quantized quadrupole insulators
Creators: name: Wang, C.
name: He, Wenxue
name: Ren, Hechen
name: Wang, X. R.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: Anderson localization transitions are usually referred to as quantum phase transitions from delocalized states to localized states in disordered systems. Here we report an unconventional ``Anderson localization transition'' in two-dimensional quantized quadrupole insulators. Such transitions are from symmetry-protected topological corner states to disorder-induced normal Anderson localized states that can be localized in the bulk, as well as at corners and edges. We show that these localization-localization transitions (transitions between two different localized states) can happen in both Hermitian and non-Hermitian quantized quadrupole insulators and investigate their criticality by finite-size scaling analysis of the corner density. The scaling analysis suggests that the correlation length of the phase transition, on the Anderson insulator side and near critical disorder $W_c$, diverges as $ξ(W)\propto \exp[α/\sqrt{|W-W_c|}]$, a typical feature of Berezinskii-Kosterlitz-Thouless transitions. A map from the quantized quadrupole model to the quantum two-dimensional $XY$ model motivates why the localization-localization transitions are Berezinskii-Kosterlitz-Thouless type.
description: 6 pages, 3 figures
X-Ray Spectra of the Narrow-Line Seyfert 1 Galaxy Ton S180 in Comparison with Galactic Black Holes
Creators: name: Murashima, Mio
name: Kubota, Aya
name: Makishima, Kazuo
name: Kokubun, Motohide
name: Hong, Soojing
name: Negoro, Hitoshi
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: An analysis was made of 0.3-15 keV X-ray spectra of a Narrow-Line Seyfert 1 Galaxy, Ton S180, using archival data from ASCA, RXTE, and XMM-Newton. At energies above 2.5 keV, a power-law with a photon index of ~ 2.3 successfully and consistently reproduced the spectra from all of these observatories. Assuming this power-law component to extend toward lower energies, a soft excess, which is one of the most remarkable features of Narrow-Line Seyfert 1 Galaxies, is explained by another power-law multiplied by a thermal cutoff at ~ 0.4 keV. Some similarities have been observed between this object and Galactic black hole binaries in very high state, the latter being realized under high accretion rates. Attempts have been made to interpret the soft excess in terms of Comptonization of the disk photons by an electron cloud surrounding the accretion disk, like BHBs in a very high state.
description: 7 pages, 7 figures
Probabilistic-based Feature Embedding of 4-D Light Fields for Compressive Imaging and Denoising
Creators: name: Lyu, Xianqiang
name: Hou, Junhui
Publisher: name: arXiv
Year: 2023
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: The high-dimensional nature of the 4-D light field (LF) poses great challenges in achieving efficient and effective feature embedding, that severely impacts the performance of downstream tasks. To tackle this crucial issue, in contrast to existing methods with empirically-designed architectures, we propose a probabilistic-based feature embedding (PFE), which learns a feature embedding architecture by assembling various low-dimensional convolution patterns in a probability space for fully capturing spatial-angular information. Building upon the proposed PFE, we then leverage the intrinsic linear imaging model of the coded aperture camera to construct a cycle-consistent 4-D LF reconstruction network from coded measurements. Moreover, we incorporate PFE into an iterative optimization framework for 4-D LF denoising. Our extensive experiments demonstrate the significant superiority of our methods on both real-world and synthetic 4-D LF images, both quantitatively and qualitatively, when compared with state-of-the-art methods. The source code will be publicly available at https://github.com/lyuxianqiang/LFCA-CR-NET.
Perturbation approach to ab initio effective mass calculations
Creators: name: Rubel, Oleg
name: Tran, Fabien
name: Rocquefelte, Xavier
name: Blaha, Peter
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: A degenerate perturbation $k\cdot p$ approach for effective mass calculations is implemented in the all-electron density functional theory (DFT) package WIEN2k. The accuracy is tested on major group IVA, IIIA-VA, and IIB-VIA semiconductor materials. Then, the effective mass in graphene and CuI with defects is presented as illustrative applications. For states with significant Cu-d character additional local orbitals with higher principal quantum numbers (more radial nodes) have to be added to the basis set in order to converge the results of the perturbation theory. Caveats related to a difference between velocity and momentum matrix elements are discussed in the context of application of the method to non-local potentials, such as Hartree-Fock/DFT hybrid functionals and DFT+U.
description: 27 pages, 1 table, 5 figures
The Equivalence Principle as a Stepping Stone from Special to General Relativity: A Socratic Dialog
Creators: name: Drake, S. P.
Publisher: name: arXiv
Year: 2005
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this paper we show how the student can be led to an understanding of the connection between special relativity and general relativity by considering the time dilation effect of clocks placed on the surface of the Earth. This paper is written as a Socratic dialog between a lecturer Sam and a student Kim.
description: 8 pages, 1 figure, uses the revtex4 documentclass. Submitted to the American Journal of Physics. Minor modification and corrections following referees' comments
Dynamics of chiral oscillations - A comparative analysis with spin-flipping
Creators: name: Bernardini, Alex E.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Chiral oscillation as well as spin flipping effects correspond to quantum phenomena of fundamental importance in the context of particle physics and, in particular, of neutrino physics. From the point of view of first quantized theories, we are specifically interested in appointing the differences between chirality and helicity by obtaining their dynamic equations for a fermionic Dirac-type particle (neutrino). We also identify both effects when the non-minimal coupling with an external (electro)magnetic field in the neutrino interacting Lagrangian is taken into account. We demonstrate that, however, there is no constraint between chiral oscillations, when it takes place in vacuum, and the process of spin flipping related to the helicity quantum number, which does not take place in vacuum. To conclude, we show that the origin of chiral oscillations (in vacuum) can be interpreted as position very rapid oscillation projections onto the longitudinal direction of momentum.
description: 14 pages, no figures
Study of QGP signatures with the phi->K+K- signal in Pb-Pb ALICE events
Creators: name: Akindinov, A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The phi->K+K- decay channel in Pb-Pb collisions at LHC is studied through a full simulation of the ALICE detector. The study focuses on possible signatures in this channel of quark-gluon plasma (QGP) formation. On a basis of 10^6 collisions at high centrality some proposed QGP signatures are clearly visible both in K+K- invariant mass and transverse mass distributions. The high significance of this observation appears to reside heavily on the use of the TOF (Time Of Flight) system of ALICE in addition to its central tracking detectors.
description: 9 pages, 7 figures, to appear in EPJ C
Comment on the article ``UCN anomalous losses and the UCN capture cross section on material defects'' by A. Serebrov et al
Creators: name: Barabanov, A. L.
name: Protasov, K. V.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We present correct solution of the problem about a scattering of the neutron on a point-like defect existing in a medium and show that this mechanism cannot explain anomalous losses of UCN in storage bottles.
description: 4 pages
Health vs. Environmental Motivation in Organic Preferences and Purchases
Creators: name: Durham, Catherine A.
name: Andrade, Diego
name: Durham, Catherine A.
name: Andrade, Diego
Publisher: name: Unknown
Year: 2005
Subjects: Health Economics and Policy

description: Economic analyses generally incorporate environmental motivations in examining the factors that determine whether consumers will buy organic and ecolabeled foods, but have not typically considered health and wellness motivations. Market research studies, using both focus groups and surveys, have found that many consumers believe that organic foods are healthier to eat, and have segmented consumers using health and wellness concerns as a factor associated with organic buying behavior. These findings have been widely interpreted in the press as indicating that health and wellness concerns are a primary motivator for buying organic. This study compares the impact of these motivators, as well as demographic and economic factors, in determining how dedicated a consumer is to organic buying as measured by whether more than 50 percent of the consumer's produce purchases are organic. The buying level results are compared to a model of stated preferences.
High-impedance surface acoustic wave resonators
Creators: name: Kandel, Yadav P.
name: Magar, Suraj Thapa
name: Iyer, Arjun
name: Renninger, William H.
name: Nichol, John M.
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: Because of their small size, low loss, and compatibility with magnetic fields and elevated temperatures, surface acoustic wave resonators hold significant potential as future quantum interconnects. Here, we design, fabricate, and characterize GHz-frequency surface acoustic wave resonators with the potential for strong capacitive coupling to nanoscale solid-state quantum systems, including semiconductor quantum dots. Strong capacitive coupling to such systems requires a large characteristic impedance, and the resonators we fabricate have impedance values above 100 $Ω$. We achieve such high impedance values by tightly confining a Gaussian acoustic mode. At the same time, the resonators also have low loss, with quality factors of several thousand at millikelvin temperatures. These high-impedance resonators are expected to exhibit large vacuum electric-field fluctuations and have the potential for strong coupling to a variety of solid-state quantum systems.