cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Fermi liquid instabilities in the spin channel
Creators: name: Wu, Congjun
name: Sun, Kai
name: Fradkin, Eduardo
name: Zhang, Shou-Cheng
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We study the Fermi surface instabilities of the Pomeranchuk type in the spin triplet channel with high orbital partial waves ($F_{l}^a ~(l>0)$). The ordered phases are classified into two classes, dubbed the $α$ and $β$-phases by analogy to the superfluid $^3$He-A and B-phases. The Fermi surfaces in the $α$-phases exhibit spontaneous anisotropic distortions, while those in the $β$-phases remain circular or spherical with topologically non-trivial spin configurations in momentum space. In the $α$-phase, the Goldstone modes in the density channel exhibit anisotropic overdamping. The Goldstone modes in the spin channel have nearly isotropic underdamped dispersion relation at small propagating wavevectors. Due to the coupling to the Goldstone modes, the spin wave spectrum develops resonance peaks in both the $α$ and $β$-phases, which can be detected in inelastic neutron scattering experiments. In the p-wave channel $β$-phase, a chiral ground state inhomogeneity is spontaneously generated due to a Lifshitz-like instability in the originally nonchiral systems. Possible experiments to detect these phases are discussed.
description: 26 pages, 14 figures
Transfer Learning with Convolutional Networks for Atmospheric Parameter Retrieval
Creators: name: Malmgren-Hansen, David
name: Nielsen, Allan Aasbjerg
name: Laparra, Valero
name: Valls, Gustau Camps-
Publisher: name: arXiv
Year: 2020
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Machine Learning (cs.LG)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: The Infrared Atmospheric Sounding Interferometer (IASI) on board the MetOp satellite series provides important measurements for Numerical Weather Prediction (NWP). Retrieving accurate atmospheric parameters from the raw data provided by IASI is a large challenge, but necessary in order to use the data in NWP models. Statistical models performance is compromised because of the extremely high spectral dimensionality and the high number of variables to be predicted simultaneously across the atmospheric column. All this poses a challenge for selecting and studying optimal models and processing schemes. Earlier work has shown non-linear models such as kernel methods and neural networks perform well on this task, but both schemes are computationally heavy on large quantities of data. Kernel methods do not scale well with the number of training data, and neural networks require setting critical hyperparameters. In this work we follow an alternative pathway: we study transfer learning in convolutional neural nets (CNN s) to alleviate the retraining cost by departing from proxy solutions (either features or networks) obtained from previously trained models for related variables. We show how features extracted from the IASI data by a CNN trained to predict a physical variable can be used as inputs to another statistical method designed to predict a different physical variable at low altitude. In addition, the learned parameters can be transferred to another CNN model and obtain results equivalent to those obtained when using a CNN trained from scratch requiring only fine tuning.
Expanding World Views: Can SETI expand its own horizons and that of Big History too?
Creators: name: Garrett, Michael A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Popular Physics (physics.pop-ph)
subject: FOS: Physical sciences

description: The Search for Extraterrestrial Intelligence (SETI) is a research activity that started in the late 1950s, predating the arrival of "Big History" and "Astrobiology" by several decades. Many elements first developed as part of the original SETI narrative are now incorporated in both of these emergent fields. However, SETI still offers the widest possible perspective, since the topic naturally leads us to consider not only the future development of our own society but also the forward trajectories (and past histories) of many other intelligent extraterrestrial forms. In this paper, I present a provocative view of Big History, its rapid convergent focus on our own planet and society, its oversimplified and incomplete view of events in cosmic history, and its limited appreciation of how poorly we understand some aspects of the physical world. Astrophysicists are also not spared - in particular those who wish to understand the nature of the universe in "splendid isolation", only looking outwards and upwards. SETI can help re-expand all of our horizons but the discovery of extraterrestrial intelligence may also require its own practitioners to abandon preconceptions of what constitutes intelligent, sentient, thinking minds.
description: 10 pages, 5 figures, Chapter 4 of Expanding Worldviews: Astrobiology, Big History and Cosmic Perspectives (to be published by Springer, ed. Ian A. Crawford), based on a presentation made at a meeting of the same title, organised by Ian Crawford at Birkbeck College (19-20 September 2019)
Stereo-photography of point-plane streamers in air
Creators: name: Nijdam, S.
name: Moerman, J. S.
name: Briels, T. M. P.
name: van Veldhuizen, E. M.
name: Ebert, U.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Standard photographs of streamer discharges show a two-dimensional projection. We here present stereo-photographic images that resolve their three-dimensional structure. We describe the stereoscopic set-up and evaluation, and we present results for positive streamer discharges in air at 0.2 - 1 bar in a point plane geometry with a gap distance of 14 cm and a voltage pulse of 47 kV. In this case an approximately Gaussian distribution of branching angles of 43 degrees is found; these angles do not significantly depend on the distance from the needle or on the gas pressure.
description: 5 pages, 5 figures, accepted by Applied Physics Letters for publication on March 10th 2008
Transcription of the Questionnaire on Information Structure
Creators: name: Parker, Verdena
name: Newbold, Lindsey
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2022
Subjects: subject: hup

description: Audio file VP-211211-09: Transcription of responses to the Questionnaire on Information Structure (file VP-151011-05), from 22:00 to 30:00.
Statistical Approach of Modulational Instability in the Class of Derivative Nonlinear Schroedinger Equations
Creators: name: Grecu, A. T.
name: Grecu, D.
name: Visinescu, Anca
Publisher: name: arXiv
Year: 2006
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences

description: The modulational instability in the class of NLS equations is discussed using a statistical approach. A kinetic equation for the two-point correlation function is studied in a linear approximation, and an integral stability equation is found. The modulational instability is associated with a positive imaginary part of the frequency. The integral equation is solved for different types of initial distributions (delta-function, Lorentzian) and the results are compared with those obtained using a deterministic approach. The differences between modulation instability of the normal NLS equation and derivative NLS equations is emphasized.
description: 16 pages, 4 figures, accepted for publication in Int. J. Theor. Phys
Design of Efficient Deep Learning models for Determining Road Surface Condition from Roadside Camera Images and Weather Data
Creators: name: Carrillo, Juan
name: Crowley, Mark
name: Pan, Guangyuan
name: Fu, Liping
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Artificial Intelligence (cs.AI)
subject: Image and Video Processing (eess.IV)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Road maintenance during the Winter season is a safety critical and resource demanding operation. One of its key activities is determining road surface condition (RSC) in order to prioritize roads and allocate cleaning efforts such as plowing or salting. Two conventional approaches for determining RSC are: visual examination of roadside camera images by trained personnel and patrolling the roads to perform on-site inspections. However, with more than 500 cameras collecting images across Ontario, visual examination becomes a resource-intensive activity, difficult to scale especially during periods of snowstorms. This paper presents the results of a study focused on improving the efficiency of road maintenance operations. We use multiple Deep Learning models to automatically determine RSC from roadside camera images and weather variables, extending previous research where similar methods have been used to deal with the problem. The dataset we use was collected during the 2017-2018 Winter season from 40 stations connected to the Ontario Road Weather Information System (RWIS), it includes 14.000 labeled images and 70.000 weather measurements. We train and evaluate the performance of seven state-of-the-art models from the Computer Vision literature, including the recent DenseNet, NASNet, and MobileNet. Moreover, by following systematic ablation experiments we adapt previously published Deep Learning models and reduce their number of parameters to about ~1.3% compared to their original parameter count, and by integrating observations from weather variables the models are able to better ascertain RSC under poor visibility conditions.
description: Source code for experiments is available at https://github.com/jmcarrillog/deep-learning-for-road-surface-condition
When and how an error yields a Dirichlet form
Creators: name: Bouleau, Nicolas
Publisher: name: arXiv
Year: 2006
Subjects: subject: Functional Analysis (math.FA)
subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60Fxx 65Cxx 31C25 60H07

description: We consider a random variable $Y$ and approximations $Y\_n$, defined on the same probability space with values in the same measurable space as $Y$. We are interested in situations where the approximations $Y\_n$ allow to define a Dirichlet form in the space $L^2(P\_Y)$ where $P\_Y$ is the law of $Y$. Our approach consists in studying both biases and variances. The article attempts to propose a general theoretical framework. It is illustrated by several examples.
description: 44p
Cloud detection machine learning algorithms for PROBA-V
Creators: name: Gómez-Chova, Luis
name: Mateo-García, Gonzalo
name: Muñoz-Marí, Jordi
name: Camps-Valls, Gustau
Publisher: name: arXiv
Year: 2020
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Machine Learning (cs.LG)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: This paper presents the development and implementation of a cloud detection algorithm for Proba-V. Accurate and automatic detection of clouds in satellite scenes is a key issue for a wide range of remote sensing applications. With no accurate cloud masking, undetected clouds are one of the most significant sources of error in both sea and land cover biophysical parameter retrieval. The objective of the algorithms presented in this paper is to detect clouds accurately providing a cloud flag per pixel. For this purpose, the method exploits the information of Proba-V using statistical machine learning techniques to identify the clouds present in Proba-V products. The effectiveness of the proposed method is successfully illustrated using a large number of real Proba-V images.
description: Preprint corresponding to the paper published in 2017 IEEE International Geoscience and Remote Sensing Symposium (IGARSS), Fort Worth, TX, USA, pp. 2251-2254
Mixed order parameter symmetries in cuprate superconductors
Creators: name: Bussmann-Holder, A.
name: Khasanov, R.
name: Shengelaya, A.
name: Maisuradze, A.
name: La Mattina, F.
name: Keller, H.
name: Mueller, K. A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The recent observation of an inflection point in the temperature dependence of the in-plane magnetic field dependence (lambda_ab) is investigated within a two-band model with coupled order parameters of different symmetries. While the dominant order parameter has d-wave symmetry, the smaller one is of s-wave symmetry. Superconductivity is robust in the d-wave channel and induced via interband interactions in the s-wave subsystem.
description: 10 pages, 4 figures
Evaporation within and above a boreal aspen forest
Creators: name: Blanken, Peter David
Publisher: name: University of British Columbia
Year: 2009

description: As part of the Boreal Ecosystem-Atmosphere Study, water vapour, heat, CO₂ and momentum exchange between the atmosphere and a southern boreal aspen (Populus tremuloides Michx.) forest in central Saskatchewan, Canada (53.629 °N, 106.200 °W) were measured continuously throughout much of 1994 using the eddy-covariance method. Measurements were made both above the c. 21.5-m tall 70 year-old aspen stand and within the leafless trunk space above a lush c. 2-m tall hazelnut (Corylus cornuta Marsh.) understory. This research focused on the measurements of and processes controlling water vapour exchange within and above the aspen canopy. Above-canopy turbulent exchange was dominated by large, slowly rotating eddies whereas in-canopy exchange was dominated by the intermittent, downward penetration of gusts. A constant flux layer redeveloped beneath the aspen canopy making eddy-covariance measurements possible. Nocturnal eddy fluxes were often underestimated at both heights due to spatial heterogeneity in turbulence statistics caused by low wind speeds. These periods were identified from the height-independent similarity function normalized by that expected from Monin-Obukhov theory and were empirically corrected as a function of friction velocity. Erratic daytime flux behaviour was corrected on the basis of conservation of energy and partitioning of the missing energy using the original eddy fluxes of latent and sensible heat. Evapotranspiration from the forest accounted for 82-91% of the annual precipitation. Aspen, hazelnut transpiration and soil water evaporation were 68%, 27% and 5%, respectively, of the total annual evapotranspiration. Over the growing season. there was no net change in the soil water content and there was little drainage beyond the root zone. Understory radiation levels decreased exponentially with increasing aspen leaf area. Surface conductance to water vapour was a linear function of forest leaf area and was dominated by the aspen canopy. Aspen and hazelnut canopy conductances decreased non-linearly with increasing saturation deficit and were best parameterized by net assimilation divided by the product of the mole fractions of leaf-level saturation deficit and CO₂ concentration. The accommodation of the transpiring vegetation by the atmosphere was quantified using the Priestley and Taylor α and the McNaughton and Jarvis Ω parameters.
Table S1. from Threatened Neotropical seasonally dry tropical forest: evidence of biodiversity loss in sap-sucking herbivores over 75 years
Creators: name: Pinedo-Escatel, J. A.
name: G. Moya-Raygoza
name: C. H. Dietrich
name: J. N. Zahniser
name: L. Portillo
Publisher: name: The Royal Society
Year: 2021
Subjects: subject: Ecology
subject: FOS: Biological sciences

description: Checklist and abundance of Athysanini known in 1920-40s (HD) and during the recent study (RS).
Experiences from Large-Scale Model Checking: Verification of a Vehicle Control System
Creators: name: Fritzsch, Jonas
name: Schmid, Tobias
name: Wagner, Stefan
Publisher: name: arXiv
Year: 2020
Subjects: subject: Software Engineering (cs.SE)
subject: Hardware Architecture (cs.AR)
subject: Systems and Control (eess.SY)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: In the age of autonomously driving vehicles, functionality and complexity of embedded systems are increasing tremendously. Safety aspects become more important and require such systems to operate with the highest possible level of fault tolerance. Simulation and systematic testing techniques have reached their limits in this regard. Here, formal verification as a long established technique can be an appropriate complement. However, the necessary preparatory work like adequately modeling a system and specifying properties in temporal logic are anything but trivial. In this paper, we report on our experiences applying model checking to verify the arbitration logic of a Vehicle Control System. We balance pros and cons of different model checking techniques and tools, and reason about our choice of the symbolic model checker NuSMV. We describe the process of modeling the architecture, resulting in ~1500 LOC, 69 state variables and 38 LTL constraints. To handle this large-scale model, we automate and optimize the model checking procedure for use on multi-core CPUs and employ Bounded Model Checking to avoid the state explosion problem. We share our lessons learned and provide valuable insights for architects, developers, and test engineers involved in this highly present topic.
description: 11 pages, 7 figures
Yangians in Deformed Super Yang-Mills Theories
Creators: name: Ihry, Jay N.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Quantum Algebra (math.QA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We discuss the integrability structure of deformed, four-dimensional N=4 super Yang-Mills theories using Yangians. We employ a recent procedure by Beisert and Roiban that generalizes the beta deformation of Lunin and Maldacena to produce N=1 superconformal gauge theories, which have the superalgebra SU(2,2|1)xU(1)xU(1). The deformed theories, including those with the more general twist, were shown to have retained their integrable structure. Here we examine the Yangian algebra of these deformed theories. In a five field subsector, we compute the two cases of SU(2)xU(1)xU(1)xU(1) and SU(2|1)xU(1)xU(1) as residual symmetries of SU(2,2|1)xU(1)xU(1). We compute a twisted coproduct for these theories, and show that only for the residual symmetry do we retain the standard coproduct. The twisted coproduct thus provides a method for symmetry breaking. However, the full Yangian structure of SU(2|3) is manifest in our subsector, albeit with twisted coproducts, and provides for the integrability of the theory.
description: 17 pages
Table S2. from Threatened Neotropical seasonally dry tropical forest: evidence of biodiversity loss in sap-sucking herbivores over 75 years
Creators: name: Pinedo-Escatel, J. A.
name: G. Moya-Raygoza
name: C. H. Dietrich
name: J. N. Zahniser
name: L. Portillo
Publisher: name: The Royal Society
Year: 2021
Subjects: subject: Ecology
subject: FOS: Biological sciences

description: Geographical coordinates, presence within the seasonally dry tropical forest (SDTF) of Mexico, and historical (HD) and recent (RS) Athysanini taxa included in the study.
Elicitation of modal and evidential particles
Creators: name: Parker, Verdena
name: Begay, Kayla
name: Newbold, Lindsey
name: Spence, Justin
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2022
Subjects: subject: hup

description: Audio file VP-221211-01: Elicitation of modal and evidential sentence particles ('isdo', 'ungya', etc.) and their interactions with light and heavy verb stems. The session ends abruptly due to a technical issue.
On the Inelastic Collapse of a Ball Bouncing on a Randomly Vibrating Platform
Creators: name: Majumdar, Satya N.
name: Kearney, Michael J.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study analytically the dynamics of a ball bouncing inelastically on a randomly vibrating platform, as a simple toy model of inelastic collapse. Of principal interest are the distributions of the number of flights n_f till the collapse and the total time τ_c elapsed before the collapse. In the strictly elastic case, both distributions have power law tails characterised by exponents which are universal, i.e., independent of the details of the platform noise distribution. In the inelastic case, both distributions have exponential tails: P(n_f) ~ exp[-θ_1 n_f] and P(τ_c) ~ exp[-θ_2 τ_c]. The decay exponents θ_1 and θ_2 depend continuously on the coefficient of restitution and are nonuniversal; however as one approches the elastic limit, they vanish in a universal manner that we compute exactly. An explicit expression for θ_1 is provided for a particular case of the platform noise distribution.
description: 32 pages
Pulmonary surfactant inhibition of nanoparticle uptake by alveolar epithelial cells
Creators: name: Radiom, M.
name: Sarkis, M.
name: Brookes, O.
name: Oikonomou, E. K.
name: Baeza-Squiban, A.
name: Berret, J. -F.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Physical sciences

description: Pulmonary surfactant forms a sub-micrometer thick fluid layer that covers the surface of alveolar lumen and inhaled nanoparticles therefore come in to contact with surfactant prior to any interaction with epithelial cells. We investigate the role of the surfactant as a protective physical barrier by modeling the interactions using silica-Curosurf-alveolar epithelial cell system in vitro. Electron microscopy displays that the vesicles are preserved in the presence of nanoparticles while nanoparticle-lipid interaction leads to the formation of mixed aggregates. Fluorescence microscopy reveals that the surfactant decreases the uptake of nanoparticles by up to two orders of magnitude in two models of alveolar epithelial cells, A549 and NCI-H441, irrespective of immersed culture on glass or air-liquid interface culture on transwell. Confocal microscopy corroborates the results by showing nanoparticle-lipid colocalization interacting with the cells. Our work thus supports the idea that pulmonary surfactant plays a protective role against inhaled nanoparticles. The effect of surfactant should therefore be considered in predictive assessment of nanoparticle toxicity or drug nanocarrier uptake. Models based on the one presented in this work may be used for preclinical tests with engineered nanoparticles.
description: 23 pages, 8 figures
Atomic hyperfine resonances in a magnetic quadrupole field
Creators: name: Saeidian, Shahpoor
name: Lesanovsky, Igor
name: Schmelcher, Peter
Publisher: name: arXiv
Year: 2008
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: The quantum resonances of an atom possessing a single valence electron which shows hyperfine interaction with the nucleus is investigated in the presence of a three dimensional magnetic quadrupole field. Particular emphasis is put on the study of the interplay of the hyperfine and quadrupole forces. Analyzing the underlying Hamiltonian a variety of symmetries are revealed which give rise to a two-fold degeneracy of the resonance energies. Our numerical approach employs the complex scaling method and a Sturmian basis set. Several regimes and classes of short-lived and long-lived resonances are identified. The energies and decay widths of the resonances are characterized by their electronic and nuclear spin properties.
End-to-End Learning of Speech 2D Feature-Trajectory for Prosthetic Hands
Creators: name: Jafarzadeh, Mohsen
name: Tadesse, Yonas
Publisher: name: arXiv
Year: 2020
Subjects: subject: Audio and Speech Processing (eess.AS)
subject: Machine Learning (cs.LG)
subject: Robotics (cs.RO)
subject: Sound (cs.SD)
subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences
subject: I.2
subject: 68T40

description: Speech is one of the most common forms of communication in humans. Speech commands are essential parts of multimodal controlling of prosthetic hands. In the past decades, researchers used automatic speech recognition systems for controlling prosthetic hands by using speech commands. Automatic speech recognition systems learn how to map human speech to text. Then, they used natural language processing or a look-up table to map the estimated text to a trajectory. However, the performance of conventional speech-controlled prosthetic hands is still unsatisfactory. Recent advancements in general-purpose graphics processing units (GPGPUs) enable intelligent devices to run deep neural networks in real-time. Thus, architectures of intelligent systems have rapidly transformed from the paradigm of composite subsystems optimization to the paradigm of end-to-end optimization. In this paper, we propose an end-to-end convolutional neural network (CNN) that maps speech 2D features directly to trajectories for prosthetic hands. The proposed convolutional neural network is lightweight, and thus it runs in real-time in an embedded GPGPU. The proposed method can use any type of speech 2D feature that has local correlations in each dimension such as spectrogram, MFCC, or PNCC. We omit the speech to text step in controlling the prosthetic hand in this paper. The network is written in Python with Keras library that has a TensorFlow backend. We optimized the CNN for NVIDIA Jetson TX2 developer kit. Our experiment on this CNN demonstrates a root-mean-square error of 0.119 and 20ms running time to produce trajectory outputs corresponding to the voice input data. To achieve a lower error in real-time, we can optimize a similar CNN for a more powerful embedded GPGPU such as NVIDIA AGX Xavier.
A global Canopy Water Content product from AVHRR/Metop
Creators: name: García-Haro, Francisco Javier
name: Campos-Taberner, Manuel
name: Moreno, Álvaro
name: Tagesson, Håkan Torbern
name: Camacho, Fernando
name: Martínez, Beatriz
name: Sánchez, Sergio
name: Piles, María
name: Camps-Valls, Gustau
name: Yeba, Marta
name: Gilabert, María Amparo
Publisher: name: arXiv
Year: 2020
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: FOS: Physical sciences

description: Spatially and temporally explicit canopy water content (CWC) data are important for monitoring vegetation status, and constitute essential information for studying ecosystem-climate interactions. Despite many efforts there is currently no operational CWC product available to users. In the context of the Satellite Application Facility for Land Surface Analysis (LSA-SAF), we have developed an algorithm to produce a global dataset of CWC based on data from the Advanced Very High Resolution Radiometer (AVHRR) sensor on board Meteorological Operational (MetOp) satellites forming the EUMETSAT Polar System (EPS). CWC reflects the water conditions at the leaf level and information related to canopy structure. An accuracy assessment of the EPS/AVHRR CWC indicated a close agreement with multi-temporal ground data from SMAPVEX16 in Canada and Dahra in Senegal. The present study further evaluates the consistency of the LSA-SAF product with respect to the Simplified Level 2 Product Prototype Processor (SL2P) product, and demonstrates its applicability at different spatio-temporal resolutions using optical data from MSI/Sentinel-2 and MODIS/Terra and Aqua. We conclude that the EPS/AVHRR CWC product is a promising tool for monitoring vegetation water status at regional and global scales.
On non existence of tokamak equilibria with purely poloidal flow
Creators: name: Throumoulopoulos, G. N.
name: Weitzner, H.
name: Tasso, H.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: It is proved that irrespective of compressibility tokamak steady states with purely poloidal mass flow can not exist in the framework of either magnetohydrodynamics (MHD) or Hall MHD models. Non-existence persists within single fluid plasma models with pressure anisotropy and incompressible flows.
description: The conclusion reported in the last sentence of the first paragraph of Sec. V in the version of the paper published in Physics of Plasmas is incorrect. The correct conclusion is given here (15 pages)
Transcription of a story about early encounters with non-Indians
Creators: name: Parker, Verdena
name: Begay, Kayla
name: Spence, Justin
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2022
Subjects: subject: hup

description: Audio file VP-211211-08: Transcription of a story about early encounters between Indian, white, and Chinese people in Hoopa Valley (file VP-091010-04), from 8:29 to 11:34.
Efficient frequency conversion in a degenerate $χ^{(2)}$ microresonator
Creators: name: Wang, Jia-Qi
name: Yang, Yuan-Hao
name: Li, Ming
name: Hu, Xin-Xin
name: Surya, Joshua B.
name: Xu, Xin-Biao
name: Dong, Chun-Hua
name: Guo, Guang-Can
name: Tang, Hong X.
name: Zou, Chang-Ling
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Microresonators on a photonic chip could enhance nonlinear optics effects, thus are promising for realizing scalable high-efficiency frequency conversion devices. However, fulfilling phase matching conditions among multiple wavelengths remains a significant challenge. Here, we present a feasible scheme for degenerate sum-frequency conversion that only requires the two-mode phase matching condition. When the drive and the signal are both near resonance to the same telecom mode, an efficient on-chip photon-number conversion efficiency upto 42% was achieved, showing a broad tuning bandwidth over 250GHz. Furthermore, cascaded Pockels and Kerr nonlinear optical effects are observed, enabling the parametric amplification of the optical signal to a distinct wavelength in a single device. The scheme demonstrated in this work provides an alternative approach to realizing high-efficiency frequency conversion and is promising for future studies on communications, atom clocks, sensing, and imaging.
description: 6 pages, 4 figures
Chromospheric flux-flux relationships of the CARMENES active RV-loud M Dwarfs
Creators: name: Labarga, Fernando
name: Montes, David
name: Lopez-Gallifa, Alvaro
name: Caballero, Jose A.
name: Jeffers, Sandra V.
name: Reiners, Ansgar
name: Ribas, Ignasi
name: Quirrenbach, Andreas
name: Amado, Pedro J.
Publisher: name: Zenodo
Year: 2021
Subjects: Cool Stars on the main sequence

description: The main objective of this work within CARMENES survey is the extraction of all available information on the chromospheric activity and its variability (rotational modulation, flares, etc.) using for that all the chromospheric indicators included in the spectral range of the spectrograph, ranging from visible (VIS), including the Na I D1, D2 He I D3, and H lines to near-infrared (NIR) that include the Ca II IRT, He I 10830 Å, Paschen a, Paschen b and Paschen d lines. We study in detail the behavior of the flux-flux relationships of lines formed at different chromosphere layers in order to a better understanding of the magnetic activity of M-type dwarf stars. For this task we have selected the CARMENES active RV-loud M Dwarfs (Tal-Or et al. 2018) and apply the spectral subtraction technique using iSTARMOD to derive te equivalent width (EW) of the chromospheric excess emission of the different lines that is converted to surface flux using the c factor methodology defined by Walkowicz et al. (2004) and implemented as Reiners & Basri (2008), using the set of BT-Settl-CIFIST [Fe/H] = 0 synthetic spectra as in Cifuentes et al. (2020). The ongoing results extends the frame of the work done for FGK stars in Martinez-Arnáiz et al. (2011) and confirms the non-universality of the flux-flux relationship presented there, with two or more distinct chromospheric emitter populations.
description: {"references": ["Barden, S. C. 1985ApJ...295..162B", "B\u00f6hm-Vitense, E. \u00a02007ApJ...657..486B", "Cifuentes, C. et al. \u00a02020A&A...642A.115C", "Labarga, F. & Montes, D. 2020sea..confE.153L", "L\u00f3pez-Santiago, J., et al. 2010A&A...514A..97L", "Montes et al. \u00a01995A&A...294..165M", "Montes et al. \u00a02000A&AS..146..103M", "Martinez-Arn\u00e1iz et al. \u00a02011MNRAS.414.2629M", "Quirrenbach, A., et al. 2020SPIE11447E..3CQ", "Reiners, A. & Basri, G. 2008ApJ...684.1390R", "Tal-Or, L. et al. 2018A&A...614A.122T", "Walkowicz, L. M., et al. \u00a02004PASP..116.1105W"]}
Tunnel barrier enhanced voltage signals generated by magnetization precession of a single ferromagnetic layer
Creators: name: Moriyama, T.
name: Cao, R.
name: Fan, X.
name: Xuan, G.
name: Nikolic, B. K.
name: Tserkovnyak, Y.
name: Kolodzey, J.
name: Xiao, John Q.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We report the electrical detection of magnetization dynamics in an Al/AlOx/Ni80Fe20/Cu tunnel junction, where a Ni80Fe20 ferromagnetic layer is brought into precession under the ferromagnetic resonance (FMR) conditions. The dc voltage generated across the junction by the precessing ferromagnet is enhanced about an order of magnitude compared to the voltage signal observed when the contacts in this type of multilayered structure are ohmic. We discuss the relation of this phenomenon to magnetic spin pumping and speculate on other possible underlying mechanisms responsible for the enhanced electrical signal.
Population ecology of arctic ground squirrels in the boreal forest during the decline and low phases of a snowshoe hare cycle
Creators: name: Byrom, Andrea Elizabeth
Publisher: name: University of British Columbia
Year: 2009

description: I examined food and predation as factors limiting arctic ground squirrel (Spermophilus parryii plesius) populations during the decline and low phases of a snowshoe hare cycle (1992 - 1995). Food and predator limitation were tested experimentally with large-scale (36-ha) experimental manipulations: two food-supplemented areas, a predator exclosure, and a food-supplemented treatment where predators were also excluded. Predator removal doubled population density, while addition of food resulted in a four-fold density increase. Removal of predators and addition of food together resulted in a 10-fold increase in arctic ground squirrel population densities. Population densities and adult survival rates were lower in 1992 and 1993 (two years after the snowshoe hare population decline) than in 1994 and 1995. Food supply and predation interact to limit arctic ground squirrel population densities in the boreal forest during the decline and low phases of the snowshoe hare cycle. Supplemental food did not affect dispersal distances or dispersal frequency of 172 radio-collared juveniles of either sex in any year. Juveniles that moved farther from their natal burrow were more likely to die. Males moved farther than females and died more frequently. Dispersal tendency was unrelated to population density in males. Females increased their tendency to disperse only on a study site with population densities 17x those of control populations. Male arctic ground squirrels probably disperse to avoid inbreeding, while females may disperse in response to resource limitation at very high densities. Philopatric females had higher fitness than females that dispersed, particularly if survival during dispersal was taken into account. As population density increased from 1992 - 1995, home range overlap of adult females also increased, as daughters survived to reproductive age in contact with their mother's home range. A stage-based simulation model of the annual cycle of activity and hibernation in arctic ground squirrels was strongly sensitive to adult and juvenile female survival. Arctic ground squirrel populations in the boreal forest can sustain a positive rate of population increase during the low phase of the snowshoe hare cycle, facilitated by flexibility of adult female home range overlap and high adult female survival.
Transcription of the Questionnaire on Information Structure
Creators: name: Parker, Verdena
name: Newbold, Lindsey
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2022
Subjects: subject: hup

description: Audio file VP-211211-07: Transcription of responses to the Questionnaire on Information Structure (file VP-151011-05), from 11:18 to 22:00.
Letter from James Goldie to [R.S.] Dormer, January 26, 1928
Creators: name: Goldie, James
Publisher: name: The University of British Columbia
Year: 2017

description: Letter to R.S. Dormer from James Goldie, dated January 26, 1928, regarding the packing of the Salome apples and the Vernon News coverage of the Kelowna Convention.
Some thoughts upon axiomatized languages with estension tools, a focus on probability theory and error calculus with Dirichlet forms
Creators: name: Bouleau, Nicolas
Publisher: name: arXiv
Year: 2006
Subjects: subject: History and Overview (math.HO)
subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 01A61 03D99 31C25 60-03 60A05

description: A comparison of the "theory of random sequences" developed during the twentieth century and the axiomatic approach of probability theory proposed by Kolmogorov shows the importance of sigma-additivity as extension tool. Similarly, the Cauchy criterion appears to be an extension tool for mathematical analysis. The Dirichlet forms theory possesses also such an extension tool. They are the source of the fruitfulness of these languages and the condition of their creativity. A connection is given with the so-called Richard paradox.
A spectral method algorithm for numerical simulations of gravitational fields
Creators: name: Meringolo, Claudio
name: Servidio, Sergio
name: Veltri, Pierluigi
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: A numerical study of the Einstein field equations, based on the 3+1 foliation of the spacetime, is presented. A pseudo-spectral technique has been employed for simulations in vacuum, within two different formalisms, namely the Arnowitt-Deser-Misner (ADM) and the conformal Baumgarte-Shapiro-Shibata-Nakamura (BSSN) approach. The numerical code is based on the Fourier decomposition, accompanied by different filtering techniques. The role of the dealiasing, as well as the influence of the filter type, has been investigated. The algorithms have been stabilized via a novel procedure that controls self-consistently the regularity of the solutions. The accuracy of the model has been validated through standard testbeds, revealing that the filtered pseudo-spectral technique is among the most accurate approaches. Finally, the procedure has been stressed via black hole dynamics and a new strategy, based on hyperviscous dissipation that suppresses spurious boundary problems, has been proposed. The model represents a valid tool of investigation, particularly suitable for the inspection of small scale nonlinear phenomena in gravitational dynamics.
description: 38 pages, 14 figures
High Bias Voltage Effect on Spin-Dependent Conductivity and Shot Noise in Carbon-doped Fe(001)/MgO(001)/Fe(001) Magnetic Tunnel Junctions
Creators: name: Guerrero, R.
name: Herranz, D.
name: Aliev, F. G.
name: Greullet, F.
name: Tiusan, C.
name: Hehn, M.
name: Montaigne, F.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Low temperature (10K) high voltage bias dynamic conductivity (up to 2.7V) and shot noise (up to 1V) were studied in epitaxial Fe(100)/Fe-C/MgO(100)/Fe(100) magnetic tunnel junctions, as a function of the magnetic state. The junctions show large tunnel magnetoresistance (185% at 300K and 330% at 4K). Multiple sign inversion of the magnetoresistance is observed for bias polarity when the electrons scan the electronic structure of the bottom Fe-C interface. The shot-noise shows a Poissonian character. This demonstrates a pure spin dependent direct tunneling mechanism and validates the high structural quality of the MgO barrier.
Micromechanical description of the compaction of soft pentagon assemblies
Creators: name: Cárdenas-Barrantes, Manuel
name: Cantor, David
name: Barés, Jonathan
name: Renouf, Mathieu
name: Azéma, Emilien
Publisher: name: arXiv
Year: 2020
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We analyze the isotropic compaction of assemblies composed of soft pentagons interacting through classical Coulomb friction via numerical simulations. The effect of the initial particle shape is discussed by comparing packings of pentagons with packings of soft circular particles. We characterize the evolution of the packing fraction, the elastic modulus, and the microstructure (particle rearrangement, connectivity, contact force and particle stress distributions) as a function of the applied stresses. Both systems behave similarly; the packing fraction increases and tends asymptotically to a maximum value $ϕ_{max}$, where the bulk modulus diverges. At the microscopic scale we show that particle rearrangements occur even beyond the jammed state, the mean coordination increases as a square root of the packing fraction and, the force and stress distributions become more homogeneous as the packing fraction increases. Soft pentagons present larger particle rearrangements than circular ones, and such behavior decreases proportionally to the friction. Interestingly, the friction between particles also contributes to a better homogenization of the contact force network in both systems. From the expression of the granular stress tensor, we develop a model that describes the compaction behavior as a function of the applied pressure, the Young modulus and the initial shape of the particles. This model, settled on the joint evolution of the particle connectivity and the contact stress, provides outstanding predictions from the jamming point up to very high densities.
Demonstration of optically modulated dispersion forces
Creators: name: Chen, F.
name: Klimchitskaya, G. L.
name: Mostepanenko, V. M.
name: Mohideen, U.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We report the first experiment on the optical modulation of dispersion forces through a change of the carrier density in a Si membrane. For this purpose a high-vacuum based atomic force microscope and excitation light pulses from an Ar laser are used. The experimental results are compared with two theoretical models. The modulation of the dispersion force will find applications in optomechanical micromachines.
description: 7 pages, 3 figures, opex3.sty is used, text has been made in accordance with the final version to appear in Optics express, 3 misprints are corrected
Endoscopic Vision Challenge 2021
Creators: name: Speidel, Stefanie
name: Maier-Hein, Lena
name: Stoyanov, Danail
name: Bodenstedt, Sebastian
name: Wagner, Martin
name: Müller, Beat
name: Chen, Jonathan
name: Müller, Benjamin
name: Mathis-Ullrich, Franziska
name: Scheikl, Paul
name: Bernal, Jorge
name: Histache, Aymeric
name: Fernandes-Esparrach, Gloria
name: Dray, Xavier
name: Bano, Sophia
name: Casella, Alessandro
name: Vasconcelos, Francisco
name: Moccia, Sara
name: Chinedu Nwoye
name: Alapatt, Deepak
name: Vardazaryan, Armine
name: Padoy, Nicolas
name: Huaulme, Arnaud
name: Harada, Kanako
name: Jannin, Pierre
name: Aneeq Zia
name: Bhattacharyya, Kiran
name: Liu, Xi
name: Ziheng Wang
name: Jarc, Anthony
Publisher: name: Zenodo
Year: 2021
Subjects: Surgical Vision
Endoscopy, Classification
Segmentation
Detection

description: Minimally invasive surgery using cameras to observe the internal anatomy is the preferred approach to many surgical procedures. Furthermore, other surgical disciplines rely on microscopic images or use flexible endoscopes for diagnostic purposes. As a result, endoscopic and microscopic image processing as well as surgical vision are evolving as techniques needed to facilitate computer assisted interventions (CAI). Algorithms that have been reported for such images include 3D surface reconstruction, salient feature motion tracking, instrument detection or activity recognition. However, what is missing so far are common datasets for consistent evaluation and benchmarking of algorithms against each other. As a vision CAI challenge at MICCAI, our aim is to provide a formal framework for evaluating the current state of the art, gather researchers in the field and provide high quality data with protocols for validating endoscopic vision algorithms. EndoVis serves as an umbrella for different kinds of sub-challenges that tackle specific problems and applications in endoscopic/microsopic vision.
Symplectic Calabi-Yau manifolds, minimal surfaces and the hyperbolic geometry of the conifold
Creators: name: Fine, Joel
name: Panov, Dmitri
Publisher: name: arXiv
Year: 2008
Subjects: subject: Symplectic Geometry (math.SG)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics

description: Given an SO(3)-bundle with connection, the associated two-sphere bundle carries a natural closed 2-form. Asking that this be symplectic gives a curvature inequality first considered by Reznikov. We study this inequality in the case when the base has dimension four, with three main aims. Firstly, we use this approach to construct symplectic six-manifolds with c_1=0 which are never Kahler; e.g., we produce such manifolds with b_1=0=b_3 and also with c_2.omega <0, answering questions posed by Smith-Thomas-Yau. Examples come from Riemannian geometry, via the Levi-Civita connection on Lambda^+. The underlying six-manifold is then the twistor space and often the symplectic structure tames the Eells-Salamon twistor almost complex structure. Our second aim is to exploit this to deduce new results about minimal surfaces: if a certain curvature inequality holds, it follows that the space of minimal surfaces (with fixed topological invariants) is compactifiable; the minimal surfaces must also satisfy an adjunction inequality, unifying and generalising results of Chen--Tian. One metric satisfying the curvature inequality is hyperbolic four-space H^4. Our final aim is to show that the corresponding symplectic manifold is symplectomorphic to the small resolution of the conifold xw-yz=0 in C^4. We explain how this fits into a hyperbolic description of the conifold transition, with isometries of H^4 acting symplectomorphically on the resolution and isometries of H^3 acting biholomorphically on the smoothing.
description: v1. 52 pages, but not overly technical, so don't let the length put you off! Comments actively encouraged. v2. Typos corrected, addresses included
Der Krieg oder der "Dia-Logos" als Vater von allen?
Creators: name: Vletsis, Athanasios
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 59 Nr. 2 (2010): Ökumenische Rundschau, Band 59, Heft 2
String Theory and The Arrow of Time
Creators: name: Itzhaki, Nissan
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Time-like linear dilaton triggers, at the classical level, the creation of closed folded strings at an instant. We show that in cosmology these instant folded strings induce negative pressure at no energy cost. Hence they seem to allow an era in which the energy density increases (decreases) while the universe is expanding (contracting). This and other aspects of instant folded strings suggest that they might shed new light on the origin of the arrow of time.