cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Superconducting-coil--resistor circuit with electric field quadratic in the current
Creators: name: Poklonski, N. A.
name: Lopatin, S. Yu.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: It is shown for the first time that the observed [Phys. Lett. A 162 (1992) 105] potential difference Phi_t between the resistor and the screen surrounding the circuit is caused by polarization of the resistor because of the kinetic energy of the electrons of the superconducting coil. The proportionality of Phi_t to the square of the current and to the length of the superconducting wire is explained. It is pointed out that measuring Phi_t makes it possible to determine the Fermi quasimomentum of the electrons of a metal resistor.
description: 2 pages, 1 figure
Rapid localization of gravitational wave sources from compact binary coalescences using deep learning
Creators: name: Chatterjee, Chayan
name: Kovalam, Manoj
name: Wen, Linqing
name: Beveridge, Damon
name: Diakogiannis, Foivos
name: Vinsen, Kevin
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The mergers of neutron star-neutron star and neutron star-black hole binaries are the most promising gravitational wave events with electromagnetic counterparts. The rapid detection, localization and simultaneous multi-messenger follow-up of these sources is of primary importance in the upcoming science runs of the LIGO-Virgo-KAGRA Collaboration. While prompt electromagnetic counterparts during binary mergers can last less than two seconds, the time scales of existing localization methods that use Bayesian techniques, varies from seconds to days. In this paper, we propose the first deep learning-based approach for rapid and accurate sky localization of all types of binary coalescences, including neutron star-neutron star and neutron star-black hole binaries for the first time. Specifically, we train and test a normalizing flow model on matched-filtering output from gravitational wave searches. Our model produces sky direction posteriors in milliseconds using a single P100 GPU, which is three to six orders of magnitude faster than Bayesian techniques.
description: 18 pages, 8 figures
RDBNorma: - A semi-automated tool for relational database schema normalization up to third normal form
Creators: name: Dongare, Y. V.
name: Dhabe, P. S.
name: Deshmukh, S. V.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Databases (cs.DB)
subject: FOS: Computer and information sciences

description: In this paper a tool called RDBNorma is proposed, that uses a novel approach to represent a relational database schema and its functional dependencies in computer memory using only one linked list and used for semi-automating the process of relational database schema normalization up to third normal form. This paper addresses all the issues of representing a relational schema along with its functional dependencies using one linked list along with the algorithms to convert a relation into second and third normal form by using above representation. We have compared performance of RDBNorma with existing tool called Micro using standard relational schemas collected from various resources. It is observed that proposed tool is at least 2.89 times faster than the Micro and requires around half of the space than Micro to represent a relation. Comparison is done by entering all the attributes and functional dependencies holds on a relation in the same order and implementing both the tools in same language and on same machine.
description: 22 pages and international journal
Locating PHEV Exchange Stations in V2G
Creators: name: Pan, Feng
name: Bent, Russell
name: Berscheid, Alan
name: Izraelevitz, David
Publisher: name: arXiv
Year: 2010
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: Plug-in hybrid electric vehicles (PHEVs) are an environmentally friendly technology that is expected to rapidly penetrate the transportation system. Renewable energy sources such as wind and solar have received considerable attention as clean power options for future generation expansion. However, these sources are intermittent and increase the uncertainty in the ability to generate power. The deployment of PHEVs in a vehicle-to-grid (V2G) system provide a potential mechanism for reducing the variability of renewable energy sources. For example, PHEV supporting infrastructures like battery exchange stations that provide battery service to PHEV customers could be used as storage devices to stabilize the grid when renewable energy production is fluctuating. In this paper, we study how to best site these stations in terms of how they can support both the transportation system and the power grid. To model this problem we develop a two-stage stochastic program to optimally locate the stations prior to the realization of battery demands, loads, and generation capacity of renewable power sources. We develop two test cases to study the benefits and the performance of these systems.
description: Submitted to IEEE-SmartGridComm2010
A Tax Map of Global Professional Service Firms: Where Expert Services are Located and Why
Creators: name: Murphy, Richard; Seabrooke, Leonard; Stausholm, Saila N.
Publisher: name: Zenodo
Year: 2019
Subjects: Global Professional Service Firms; Big Four; accounting; auditing; professions; globalization; international political economy; organizational sociology; management studies

description: The role of multi-disciplinary Global Professional Service Firms (GPSFs) in the architecture of international tax abuse has been very little studied. Although it has been known that some of these firms operate in many of the world’s secrecy jurisdictions the scale of their activity in these, and other, locations has been little understood. Nor has their own representations of their tax services been appropriately considered. This working paper seeks to redress this deficiency. We locate the activities of these firms in the broader context of their activities around the globe, since it is the boast of many of them that they operate in more than 140 jurisdictions, worldwide. The research has revealed the opacity of the data surrounding these firms, and the unusual nature of their ownership structures. Financial reports of these firms are not available for most jurisdictions in which they work, whilst common control through ownership structures rarely crosses national boundaries. Using global directories of the firms as indication of presence in a location and the number of employees by jurisdiction as an indication of scale, our research indicates the disproportionate activity of particular GPSFs firms, namely the ‘Big Four’ accountancy firms, providing tax based services in secrecy jurisdictions. This suggests that they are major suppliers of offshore financial services.  We consider the evolution of these GPSFs since the 1990s, suggesting they have been conscious participants in this activity but that their behaviour has adapted over time to reflect prevailing taxation morés to preserve the reputations of those supplying these services. As we show, these morés are reflected in their own presentation of their services as promoted on their web sites, which have changed significantly over time to reflect this fact, with little evidence that there has been any real underlying change in behaviour. As a result we suggest that these firms display a form of adaptive behaviour worthy of further study.
Inflating 2D Convolution Weights for Efficient Generation of 3D Medical Images
Creators: name: Liu, Yanbin
name: Dwivedi, Girish
name: Boussaid, Farid
name: Sanfilippo, Frank
name: Yamada, Makoto
name: Bennamoun, Mohammed
Publisher: name: arXiv
Year: 2022
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
subject: I.4; J.3

description: The generation of three-dimensional (3D) medical images has great application potential since it takes into account the 3D anatomical structure. Two problems prevent effective training of a 3D medical generative model: (1) 3D medical images are expensive to acquire and annotate, resulting in an insufficient number of training images, and (2) a large number of parameters are involved in 3D convolution.
 Methods: We propose a novel GAN model called 3D Split&Shuffle-GAN. To address the 3D data scarcity issue, we first pre-train a two-dimensional (2D) GAN model using abundant image slices and inflate the 2D convolution weights to improve the initialization of the 3D GAN. Novel 3D network architectures are proposed for both the generator and discriminator of the GAN model to significantly reduce the number of parameters while maintaining the quality of image generation. Several weight inflation strategies and parameter-efficient 3D architectures are investigated.
 Results: Experiments on both heart (Stanford AIMI Coronary Calcium) and brain (Alzheimer's Disease Neuroimaging Initiative) datasets show that our method leads to improved 3D image generation quality (14.7 improvements on Fréchet inception distance) with significantly fewer parameters (only 48.5% of the baseline method).
 Conclusions: We built a parameter-efficient 3D medical image generation model. Due to the efficiency and effectiveness, it has the potential to generate high-quality 3D brain and heart images for real use cases.
description: Published at Computer Methods and Programs in Biomedicine (CMPB) 2023
Multiscale Metrology and Optimization of Ultra-Scaled InAs Quantum Well FETs
Creators: name: Kharche, Neerav
name: Klimeck, Gerhard
name: Kim, Dae-Hyun
name: del Alamo, Jesús. A.
name: Luisier, Mathieu
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: A simulation methodology for ultra-scaled InAs quantum well field effect transistors (QWFETs) is presented and used to provide design guidelines and a path to improve device performance. A multiscale modeling approach is adopted, where strain is computed in an atomistic valence-force-field method, an atomistic sp3d5s* tight-binding model is used to compute channel effective masses, and a 2-D real-space effective mass based ballistic quantum transport model is employed to simulate three terminal current-voltage characteristics including gate leakage. The simulation methodology is first benchmarked against experimental I-V data obtained from devices with gate lengths ranging from 30 to 50 nm. A good quantitative match is obtained. The calibrated simulation methodology is subsequently applied to optimize the design of a 20 nm gate length device. Two critical parameters have been identified to control the gate leakage magnitude of the QWFETs, (i) the geometry of the gate contact (curved or square) and (ii) the gate metal work function. In addition to pushing the threshold voltage towards an enhancement mode operation, a higher gate metal work function can help suppress the gate leakage and allow for much aggressive insulator scaling.
Spin excitations of the correlated semiconductor FeSi probed by THz radiation
Creators: name: Glushkov, V. V.
name: Gorshunov, B. P.
name: Zhukova, E. S.
name: Demishev, S. V.
name: Pronin, A. A.
name: Sluchanko, N. E.
name: Kaiser, S.
name: Dressel, M.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: By direct measurements of the complex optical conductivity $σ(ν)$ of FeSi we have discovered a broad absorption peak centered at frequency $ν_{0}(4.2 K) \approx 32 cm^{-1}$ that develops at temperatures below 20 K. This feature is caused by spin-polaronic states formed in the middle of the gap in the electronic density of states. We observe the spin excitations between the electronic levels split by the exchange field of $H_{e}=34\pm 6 T$. Spin fluctuations are identified as the main factor determining the formation of the spin polarons and the rich magnetic phase diagram of FeSi.
description: 5 pages, 4 figures
Recovery With Incomplete Knowledge: Fundamental Bounds on Real-Time Quantum Memories
Creators: name: Danageozian, Arshag
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The recovery of fragile quantum states from decoherence is the basis of building a quantum memory, with applications ranging from quantum communications to quantum computing. Many recovery techniques, such as quantum error correction, rely on the apriori knowledge of the environment noise parameters to achieve their best performance. However, such parameters are likely to drift in time in the context of implementing long-time quantum memories. This necessitates using a "spectator" system, which estimates the noise parameter in real-time, then feed-forwards the outcome to the recovery protocol as a classical side-information. The memory qubits and the spectator system hence comprise the building blocks for a real-time (i.e. drift-adapting) quantum memory. In this article, I consider spectator-based (incomplete knowledge) recovery protocols as a real-time parameter estimation problem (generally with nuisance parameters present), followed by the application of the "best-guess" recovery map to the memory qubits, as informed by the estimation outcome. I present information-theoretic and metrological bounds on the performance of this protocol, quantified by the diamond distance between the "best-guess" recovery and optimal recovery outcomes, thereby identifying the cost of adaptation in real-time quantum memories. Finally, I provide fundamental bounds for multi-cycle recovery in the form of recurrence inequalities. The latter suggests that incomplete knowledge of the noise could be an advantage, as errors from various cycles can cohere. These results are illustrated for the approximate [4,1] code of the amplitude-damping channel and relations to various fields are discussed.
description: 42 pages, 10 figures, and 2 tables. Accepted in Quantum (11/12/2023)
Yes-go cross-couplings in collections of tensor fields with mixed symmetries of the type (3,1) and (2,2)
Creators: name: Bizdadea, C.
name: Cioroianu, E. M.
name: Saliu, S. O.
name: Babalic, E. M.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Under the hypotheses of analyticity, locality, Lorentz covariance, and Poincare invariance of the deformations, combined with the requirement that the interaction vertices contain at most two space-time derivatives of the fields, we investigate the consistent cross-couplings between two collections of tensor fields with the mixed symmetries of the type (3,1) and (2,2). The computations are done with the help of the deformation theory based on a cohomological approach in the context of the antifield-BRST formalism. Our results can be synthesized in: 1. there appear consistent cross-couplings between the two types of field collections at order one and two in the coupling constant such that some of the gauge generators and of the reducibility functions are deformed, and 2. the existence or not of cross-couplings among different fields with the mixed symmetry of the Riemann tensor depends on the indefinite or respectively positive-definite behaviour of the quadratic form defined by the kinetic terms from the free Lagrangian.
description: 35 pages
Asymmetric particle-antiparticle Dirac equation: second quantization
Creators: name: Rigolin, Gustavo
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We build the fully relativistic quantum field theory related to the asymmetric Dirac fields. These fields are solutions of the asymmetric Dirac equation, a Lorentz covariant Dirac-like equation whose positive and "negative" frequency plane wave solutions' dispersion relations are no longer degenerate. At the second quantization level, we show that this implies that particles and antiparticles sharing the same wave number have different energies and momenta. In spite of that, we prove that by properly fixing the values of the relativistic invariants that define the asymmetric Dirac free field Lagrangian density, we can build a consistent, fully relativistic, and renormalizable quantum electrodynamics (QED) that is empirically equivalent to the standard QED. We discuss the reasons and implications of this non-trivial equivalence, exploring qualitatively other scenarios in which the asymmetric Dirac fields may lead to beyond the standard model predictions. We conjecture that this non-degeneracy in the energies for particles and antiparticles may lead to a fully relativistic understanding of the asymmetry between matter and antimatter in the present day universe as well as to an alternative way of modeling the gravitational interaction between a particle and an antiparticle. We give a complete account of how the asymmetric Dirac fields and the corresponding annihilation and creation operators transform under improper Lorentz transformations (parity and time reversal operations) and under the charge conjugation operation. We also prove that the present theory respects the CPT theorem.
description: 20 pages, 1 figure, double column, RevTex4; v2: published version
พฤติกรรมการใช้บริการและคุณภาพการให้บริการรถเคลื่อนที่ของธนาคารออมสิน
Creators: name: พัชรี ยวนไธสงค์
name: วิกรานต์ เผือกมงคล
Publisher: name: มหาวิทยาลัยราชภัฏวไลยอลงกรณ์ ในพระบรมราชูปถัมภ์
Year: 2018
Subjects: คุณภาพการให้บริการ
การบริการรถเคลื่อนที่
พฤติกรรมการใช้บริการ

description: วารสารวิชาการและวิจัย มทร.พระนคร สาขามนุษยศาสตร์และสังคมศาสตร์, 3, 2, 1-12
The Fundamental Theorem of Localizing Invariants
Creators: name: Saunier, Victor
Publisher: name: arXiv
Year: 2022
Subjects: subject: K-Theory and Homology (math.KT)
subject: Algebraic Topology (math.AT)
subject: Category Theory (math.CT)
subject: FOS: Mathematics
subject: 18F25, 19D55, 19D50

description: We prove a generalization of the fundamental theorem of algebraic K-theory for Verdier-localizing functors by extending the proof for algebraic K-theory of spaces to the realm of stable $\infty$-categories. The formula behaves much better for Karoubi-localizing functors, the Verdier-localizing invariants which are additionally invariant under idempotent completion. This general fundamental theorem specializes to new formulas in the context of non-connective K-theory, topological Hochschild homology and topological cyclic homology as well as connective K-theory of arbitrary ring spectra, and generalizes several known formulas for algebraic K-theory of spaces or connective K-theory of ordinary rings, schemes and $\mathbb{S}$-algebras.
description: 25 pages, comments welcome; v2: small corrections and added more comparison to other works; v3: improvements after a referee report
An eccentrically perturbed Tonks-Girardeau gas
Creators: name: Goold, J.
name: Krych, M.
name: Idziaszek, Z.
name: Fogarty, T.
name: Busch, Th.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate the static and dynamic properties of a Tonks-Girardeau gas in a harmonic trap with an eccentric $δ$-perturbation of variable strength. For this we first find the analytic eigensolution of the single particle problem and use this solution to calculate the spatial density and energy profiles of the many particle gas as a function of the strength and position of the perturbation. We find that the crystal nature of the Tonks state is reflected in both the lowest occupation number and momentum distribution of the gas. As a novel application of our model, we study the time evolution of the the spatial density after a sudden removal of the perturbation. The dynamics exhibits collapses and revivals of the original density distribution which occur in units of the trap frequency. This is reminiscent of the Talbot effect from classical optics.
description: Comments and suggestions are welcome
Rough ends of infinite primitive groups
Creators: name: Smith, Simon M
Publisher: name: arXiv
Year: 2010
Subjects: subject: Group Theory (math.GR)
subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 20B15, 05C25

description: If $G$ is a group of permutations of a set $Ω$, then the suborbits of $G$ are the orbits of point-stabilisers $G_α$ acting on $Ω$. The cardinalities of these suborbits are the subdegrees of $G$. Every infinite primitive permutation group $G$ with finite subdegrees acts faithfully as a group of automorphisms of a locally-finite connected vertex-primitive directed graph $Γ$ with vertex set $Ω$, and there is consequently a natural action of $G$ on the ends of $Γ$. We show that if $G$ is closed in the permutation topology of pointwise convergence, then the structure of $G$ is determined by the length of any orbit of $G$ acting on the ends of $Γ$. Examining the ends of a Cayley graph of a finitely generated group to determine the structure of the group is often fruitful. B. Kr{ö}n and R. G. M{ö}ller have recently generalised the Cayley graph to what they call a {\it rough Cayley graph}, and they call the ends of this graph the {\it rough ends} of the group. It transpires that the ends of $Γ$ are the rough ends of $G$, and so our result is equivalent to saying that the structure of a closed primitive group $G$ whose subdegrees are all finite is determined by the length of any orbit of $G$ on its rough ends.
Superconducting phase transition in YNiGe3, a non-f-electron reference to the unconventional superconductor CeNiGe3
Creators: name: Pikul, Adam P.
name: Gnida, Daniel
Publisher: name: arXiv
Year: 2011
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: A polycrystalline sample of YNiGe3, being a non-magnetic isostructural counterpart to the unconventional pressure-induced superconductor CeNiGe3, was studied by means of specific heat and electrical resistivity measurements at temperatures down to 360 mK and in magnetic fields up to 500 Oe. The compound was found to exhibit an ambient-pressure superconductivity below Tc = 0.46 K. The superconducting state in YNiGe3 is destroyed by magnetic field of the order of 500 Oe.
description: to appear in Solid State Communications
Coexistence of the long-range and short-range magnetic order components in SrEr$_2$O$_4$
Creators: name: Hayes, T. J.
name: Balakrishnan, G.
name: Deen, P. P.
name: Manuel, P.
name: Chapon, L. C.
name: Petrenko, O. A.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Single crystal neutron diffraction reveals two distinct components to the magnetic ordering in geometrically frustrated SrEr$_2$O$_4$. One component is a long-range ordered ${\bf k}=0$ structure which appears below $T_N = 0.75$ K. Another component is a short-range incommensurate structure which manifests itself by the presence of a strong diffuse scattering signal. On cooling from higher temperatures down to 0.06 K, the partially ordered component does not undergo a pronounced phase transition. The magnetic moments in the long-range commensurate and short-range incommensurate structures are predominantly pointing along the [001] and [100] axes respectively. The unusual coexistence of two magnetic structures is probed using both unpolarised and XYZ-polarised neutron scattering techniques. The observed diffuse scattering pattern can be satisfactorily reproduced with a classical Monte Carlo simulation by using a simple model based on a ladder of triangles.
description: 6 pages, 5 figures
Instituting power : power relations, institutional hybridity, and indigenous self-governance in Bolivia
Creators: name: Tockman, Jason
Publisher: name: University of British Columbia
Year: 2014

description: Scholars have long observed that institutions and power relations are cyclically constitutive, as institutions shape a given polity’s power relations, and the latter influence the design of institutions. This dissertation unveils how indigenous agents interact with each other, and with the state’s bureaucrats and consultants to create divergent institutional trajectories in a new institutional environment: the construction of 11 pilot institutions of indigenous self-governance in Bolivia, as provided by the 2009 Constitution. The combinations of institutional forms have most significantly been shaped by local relations of power among differently identifying indigenous agents, and by the state-determined socio-territorial boundaries that are the site of institutional construction. Each new “indigenous autonomy” combines liberal and indigenous norms, constituting a hybrid model of indigenous autonomy. Within that model we can discern a bifurcation in which some institutions are more liberal and others are more communitarian. These observations contribute to our understanding of democracy and citizenship in contemporary Latin America as states respond to popular pressures for more rights and inclusion, in what many have called “left turns.” In terms of democracy, this study illustrates how electoral representation is complemented by communitarian democratic forms in ways that enhance Bolivia’s historically exclusionary democracy, yet how elaboration of communitarian democracy is also constrained by the party-based system of representation. Meanwhile, the Constitution’s expansion of rights has contributed to what some observers have called “post- liberal” citizenship. This investigation indicates that state-society relations in Bolivia are not well-characterized as populist, liberal or corporatist; rather, they are concomitantly plural, cyclical and reactive – which I conceive of as interest intermediation by “contentious bargaining.” The contradictions in the construction of these “indigenous autonomies” are a consequence the changing character of the ruling party. As the Movement toward Socialism and its leader, Evo Morales, have shifted from an oppositional force to elected government, they have contended with a complex correlation of social forces and pursued a development program of resource nationalism that responds to widespread calls for economic growth and poverty reduction. In Bolivia’s contentious context, the state’s disposition with regard to indigenous self- governance has been contradictory, simultaneously enabling and constraining indigenous rights.
Large atom number dual-species magneto-optical trap for fermionic 6Li and 40K atoms
Creators: name: Ridinger, Armin
name: Chaudhuri, Saptarishi
name: Salez, Thomas
name: Eismann, Ulrich
name: Fernandes, Diogo Rio
name: Wilkowski, David
name: Chevy, Frédéric
name: Salomon, Christophe
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We present the design, implementation and characterization of a dual-species magneto-optical trap (MOT) for fermionic 6Li and 40K atoms with large atom numbers. The MOT simultaneously contains 5.2x10^9 6Li-atoms and 8.0x10^9 40K-atoms, which are continuously loaded by a Zeeman slower for 6Li and a 2D-MOT for 40K. The atom sources induce capture rates of 1.2x10^9 6Li-atoms/s and 1.4x10^9 40K-atoms/s. Trap losses due to light-induced interspecies collisions of ~65% were observed and could be minimized to ~10% by using low magnetic field gradients and low light powers in the repumping light of both atomic species. The described system represents the starting point for the production of a large-atom number quantum degenerate Fermi-Fermi mixture.
Latent-free equivalent mDAGs
Creators: name: Evans, Robin J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics

description: We show that the marginal model for a discrete directed acyclic graph (DAG) with hidden variables is distributionally equivalent to another fully observable DAG model if and only if it does not induce any non-trivial inequality constraints.
description: 13 pages, 6 figures
Teaching Fluid Mechanics for Undergraduate Students in Applied Industrial Biology: from Theory to Atypical Experiments
Creators: name: Absi, Rafik
name: Nalpace, Caroline
name: Dufour, Florence
name: Huet, Denis
name: Bennacer, Rachid
name: Absi, Tahar
Publisher: name: arXiv
Year: 2011
Subjects: subject: Physics Education (physics.ed-ph)
subject: FOS: Physical sciences

description: EBI is a further education establishment which provides education in applied industrial biology at level of MSc engineering degree. Fluid mechanics at EBI was considered by students as difficult who seemed somewhat unmotivated. In order to motivate them, we applied a new play-based pedagogy. Students were asked to draw inspiration from everyday life situations to find applications of fluid mechanics and to do experiments to verify and validate some theoretical results obtained in course. In this paper, we present an innovative teaching/learning pedagogy which includes the concept of learning through play and its implications in fluid mechanics for engineering. Examples of atypical experiments in fluid mechanics made by students are presented. Based on teaching evaluation by students, it is possible to know how students feel the course. The effectiveness of this approach to motivate students is presented through an analysis of students' teaching assessment. Learning through play proved a great success in fluid mechanics where course evaluations increased substantially. Fluid mechanics has been progressively perceived as interesting, useful, pleasant and easy to assimilate. It is shown that this pedagogy which includes educational gaming presents benefits for students. These experiments seem therefore to be a very effective tool for improving teaching/learning activities in higher education.
The Pathfinder Testbed: Exploring Techniques for Achieving Precision Radial Velocities in the Near-Infrared
Creators: name: Ramsey, Larry
name: Mahadevan, Suvrath
name: Redman, Stephen
name: Bender, Chad
name: Roy, Arpita
name: Zonak, Stephanie
name: Sigurdsson, Steinn
name: Wolszczan, Alex
Publisher: name: arXiv
Year: 2010
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: The Penn State Pathfinder is a prototype warm fiber-fed Echelle spectrograph with a Hawaii-1 NIR detector that has already demonstrated 7-10 m/s radial velocity precision on integrated sunlight. The Pathfinder testbed was initially setup for the Gemini PRVS design study to enable a systematic exploration of the challenges of achieving high radial velocity precision in the near-infrared, as well as to test possible solutions to these calibration challenges. The current version of the Pathfinder has an R3 echelle grating, and delivers a resolution of R~50,000 in the Y, J or H bands of the spectrum. We will discuss the on sky-performance of the Pathfinder during an engineering test run at the Hobby Eberly Telescope as well the results of velocity observations of M dwarfs. We will also discuss the unique calibration techniques we have explored, like Uranium-Neon hollow cathode lamps, notch filter, and modal noise mitigation to enable high precision radial velocity observation in the NIR. The Pathfinder is a prototype testbed precursor of a cooled high-resolution NIR spectrograph capable of high radial velocity precision and of finding low mass planets around mid-late M dwarfs.
description: To appear in Proc. SPIE 2010 Vol. 7735
Precision requirements for spin-echo based quantum memories
Creators: name: Heshami, Khabat
name: Sangouard, Nicolas
name: Minar, Jiri
name: de Riedmatten, Hugues
name: Simon, Christoph
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Spin echo techniques are essential for achieving long coherence times in solid-state quantum memories for light because of inhomogeneous broadening of the spin transitions. It has been suggested that unrealistic levels of precision for the radio frequency control pulses would be necessary for successful decoherence control at the quantum level. Here we study the effects of pulse imperfections in detail, using both a semi-classical and a fully quantum-mechanical approach. Our results show that high efficiencies and low noise-to-signal ratios can be achieved for the quantum memories in the single-photon regime for realistic levels of control pulse precision. We also analyze errors due to imperfect initial state preparation (optical pumping), showing that they are likely to be more important than control pulse errors in many practical circumstances. These results are crucial for future developments of solid-state quantum memories.
description: 8 pages, 2 figures
Magnetic coupling of planets and small bodies with a pulsar wind"
Creators: name: Mottez, Fabrice
name: Heyvaerts, J.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We investigate the electromagnetic interaction of a relativistic stellar wind with a planet or a smaller body in orbit around the star. This may be relevant to objects orbiting a pulsar, such as PSR B1257+12 and PSR B1620-26 that are expected to hold a planetary system, or to pulsars with suspected asteroids or comets. We extend the theory of Alfvén wings to relativistic winds. When the wind is relativistic albeit slower than the total Alfvén speed, a system of electric currents carried by a stationary Alfvénic structure is driven by the planet or by its surroundings. For an Earth-like planet around a "standard" one second pulsar, the associated current can reach the same magnitude as the Goldreich-Julian current that powers the pulsar's magnetosphere.
description: ccepted for publication in "Astronomy and Astrophysics"
Mid-infrared supermirrors with finesse exceeding 400 000
Creators: name: Truong, G. -W.
name: Perner, L. W.
name: Bailey, D. M.
name: Winkler, G.
name: Cataño-Lopez, S. B.
name: Wittwer, V. J.
name: Sudmeyer, T.
name: Nguyen, C.
name: Follman, D.
name: Fleisher, A. J.
name: Heckl, O. H.
name: Cole, G. D.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: For trace gas sensing and precision spectroscopy, optical cavities incorporating low-loss mirrors are indispensable for path length and optical intensity enhancement. Optical interference coatings in the visible and near-infrared (NIR) spectral regions have achieved total optical losses below 2 parts per million (ppm), enabling a cavity finesse in excess of 1 million. However, such advancements have been lacking in the mid-infrared (MIR), despite substantial scientific interest. Here, we demonstrate a significant breakthrough in high-performance MIR mirrors, reporting substrate-transferred single-crystal interference coatings capable of cavity finesse values from 200 000 to 400 000 near 4.5 um, with excess optical losses (scatter and absorption) below 5 ppm. In a first proof-of-concept demonstration, we achieve the lowest noise-equivalent absorption in a linear cavity ring-down spectrometer normalized by cavity length. This substantial improvement in performance will unlock a rich variety of MIR applications for atmospheric transport and environmental sciences, detection of fugitive emissions, process gas monitoring, breath-gas analysis, and verification of biogenic fuels and plastics.
description: Sept 21: Minor revisions to conform to 2-page length requirement including abbr. refs.; Figure font sizes increased Jul 24: Major revisions, including hybrid mirrors and spectroscopy
Development and application of proteomic tools to study platelet function in the context of cardiovascular disease
Creators: name: Zhang, Chengcheng
Publisher: name: University of British Columbia
Year: 2015

description: Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Recent evidence suggests that activated platelets play an important role in promoting the recruitment of leukocytes, particularly monocytes, to damaged endothelium, which leads to formation of atherosclerotic plaques. Lysophosphatidic acid (LPA) accumulates in atherosclerotic plaques, activates additional platelets and amplifies immune response. Therefore, understanding the molecular mechanism of how platelets are activated and the effect of platelet-monocyte aggregate (PMA) formation is key to the design of intervention strategies for CVDs. To achieve this, two novel proteomics tools, i.e. in silico protein interaction analysis and quantitative multiplexed small GTPase activity assay, were developed and applied to study platelet functions. Using the former approach, a core network involved in platelet aggregation was identified that consists of integrin αIIb, integrin β3, talin1, fibrinogen α and β chains, Rap1b and other cytoskeletal proteins. Using the latter method, time-resolved activation profiles of ten small GTPases, i.e. Ras, Rho, Rap and Rac isoforms, in platelets in response to thrombin, ADP and LPA were generated. The addition of PI3K inhibitors only reduced the activation levels of Rap1A and Rap1B without affecting other small GTPase isoforms in LPA-induced platelet activation. Moreover, the small GTPase Rac and calcium, but not PI3 kinase or the small GTPase Rho, were found to be key regulators for LPA-induced platelet secretion. Furthermore, PMA formation was significantly increased in THP-1 monocytic cells incubated with thrombin- or LPA-activated platelets. To investigate the signaling changes in this process systematically, a quantitative phosphoproteomics strategy was adapted and optimized for a two-cell system, which revealed several key biological processes in monocytes, including leukocyte activation, small GTPase activation and cytoskeleton organization. In summary, the research in this thesis has furthered our understanding of platelet function in the context of cardiovascular disease, which might serve as a basis for designing more targeted approaches for antiplatelet therapies. In addition, the proteomics tools we have developed and validated now enable the exploration of new avenues of research, as demonstrated by their successful application to study biological systems.
Cox rings of rational complexity one T-varieties
Creators: name: Altmann, Klaus
name: Petersen, Lars
Publisher: name: arXiv
Year: 2010
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14L30, 14M99, 14H30

description: Let X be a Mori dream space together with an effective torus action of complexity one. In this note, we construct a polyhedral divisor on a suitable covering of the projective line P^1 which corresponds to the affine spectrum of the Cox ring of X. This description allows for a detailed study of torus orbits and deformations of the latter. Moreover, we present coverings of P^1 together with an action of a finite abelian group A in terms of so-called A-divisors of degree zero on P^1.
description: 17 pages, 5 figures
X-ray reflected spectra from accretion disk models. I. Constant density atmospheres
Creators: name: Garcia, Javier
name: Kallman, Timothy
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present new models for illuminated accretion disks, their structure and reprocessed emission. We consider the effects of incident X-rays on the surface of an accretion disk by solving simultaneously the equations of radiative transfer, energy balance and ionization equilibrium over a large range of column densities. We assume plane-parallel geometry and azimuthal symmetry, such that each calculation corresponds to a ring at a given distance from the central object. Our models include recent and complete atomic data for K-shell processes of the iron and oxygen isonuclear sequences. We examine the effect on the spectrum of fluorescent K$α$ line emission and absorption in the emitted spectrum. We also explore the dependence of the spectrum on the strength of the incident X-rays and other input parameters, and discuss the importance of Comptonization on the emitted spectrum.
description: Accepted for publication in ApJ. 34 pages, 10 figures
A magnetic thrust action on small bodies orbiting a pulsar
Creators: name: Mottez, Fabrice
name: Heyvaerts, J.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We investigate the electromagnetic interaction of a relativistic stellar wind with small bodies in orbit around the star. Based on our work on the theory of Alfvén wings to relativistic winds presented in a companion paper, we estimate the force exerted by the associated current system on orbiting bodies and evaluate the resulting orbital drift. This Alfvénic structure is found to have no significant influence on planets or smaller bodies orbiting a millisecond pulsar. %influence on the orbit of bodies around a millisecond pulsar. On the timescale of millions of years, it can however affect the orbit of bodies with a diameter of 100 kilometres around standard pulsars with a period $P \sim $1 s and a magnetic field $B \sim 10^{8}$ T. Kilometer-sized bodies experience drastic orbital changes on a timescale of $10^4$ years.
description: accepted for publication in "Astronomy and Astrophysics"
The tight-coupling approximation for baryon acoustic oscillations
Creators: name: Pitrou, Cyril
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The tight-coupling approximation (TCA) used to describe the early dynamics of the baryons-photons system is systematically built to higher orders in the inverse of the interaction rate. This expansion can be either used to grasp the physical effects by deriving simple analytic solutions or to obtain a form of the system which is stable numerically at early times. In linear cosmological perturbations, we estimate numerically its precision, and we discuss the implications for the baryons acoustic oscillations. The TCA can be extended to the second order cosmological perturbations, and in particular we recover that vorticity is not generated at lowest order of this expansion.
description: 4 pages, 1 figure
Lynx D1.3 Technical architecture design
Creators: name: Maganza, Filippo
name: Anagbo, Kennedy Junior
Publisher: name: Zenodo
Year: 2019
Subjects: technical architecture

description: The Lynx project as a compliance service-oriented platform that seeks to address compliance and regulatory related needs of its clients and users, comprises many services ranging from the fields of Information Extraction and Linking, Knowledge Management and Sematic Web; for which there is the need for a high level technical architecture design that integrates these services in order to address the objectives of the project.

This document, therefore, provides a detailed description of the technical architectural design solution for the Lynx platform. Architecture design in any software development project as in the case of Lynx serves as a blueprint that drives the smooth design and implementation of the software system. Once implemented, fundamental structural choices are costly to change.

In this deliverable, standard architectural patterns such as the Monolithic architecture pattern, SOA and MSA are described narrowing down on the choice of the architectural patterns that suites the architectural design needs of the Lynx platform with reference to the functional and technical requirements of the Lynx platform.

For the Lynx platform, we adopted the MSA pattern which supports loose coupling between services; a feature that allows for easy separation of work and which makes this pattern most adaptable to the Lynx platform requirements.

The document also provides detailed description of the logical and physical architectures.

The logical architecture describes the following:

	Access control system
	Microservices coordination system
	Communication system
	Foundational microservices
	How the software microservices are wired together to form a larger software system

The physical architecture describes the type of infrastructures, the platform and the deployment architecture of the software application and how to deliver the deployable system.
Dimensions of Higher Order Factor Analysis Models
Creators: name: Ardiyansyah, Muhammad
name: Sodomaco, Luca
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistics Theory (math.ST)
subject: Algebraic Geometry (math.AG)
subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 62R01, 62H25, 62H22

description: The factor analysis model is a statistical model where a certain number of hidden random variables, called factors, affect linearly the behaviour of another set of observed random variables, with additional random noise. The main assumption of the model is that the factors and the noise are Gaussian random variables. This implies that the feasible set lies in the cone of positive semidefinite matrices. In this paper, we do not assume that the factors and the noise are Gaussian, hence the higher order moment and cumulant tensors of the observed variables are generally nonzero. This motivates the notion of kth-order factor analysis model, that is the family of all random vectors in a factor analysis model where the factors and the noise have finite and possibly nonzero moment and cumulant tensors up to order k. This subset may be described as the image of a polynomial map onto a Cartesian product of symmetric tensor spaces. Our goal is to compute its dimension and we provide conditions under which the image has positive codimension.
description: 16 pages
Hit and Run Sampling from Tropically Convex Sets
Creators: name: Yoshida, Ruriko
name: Miura, Keiji
name: Barnhill, David
Publisher: name: arXiv
Year: 2022
Subjects: subject: Combinatorics (math.CO)
subject: Probability (math.PR)
subject: FOS: Mathematics

description: In this paper we propose Hit and Run (HAR) sampling from a tropically convex set. The key ingredient of HAR sampling from a tropically convex set is sampling uniformly from a tropical line segment over the tropical projective torus, which runs linearly in its computational time complexity. We show that this HAR sampling method samples uniformly from a tropical polytope which is the smallest tropical convex set of finitely many vertices. Finally, we apply this novel method to any given distribution using Metropolis-Hasting filtering over a tropical polytope.