cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Comments on the Quantum Field Theory of the Coulomb Gas Formalism
Creators: name: Kapec, Daniel
name: Mahajan, Raghu
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The holomorphic Coulomb gas formalism is a set of rules for computing minimal model observables using free field techniques. We attempt to derive and clarify these rules using standard techniques of QFT. We begin with a careful examination of the timelike linear dilaton. Although the background charge $Q$ breaks the scalar field's continuous shift symmetry, the exponential of the action is invariant under a discrete shift because $Q$ is imaginary. Gauging this symmetry makes the dilaton compact and introduces winding modes into the spectrum. One of these winding operators corresponds to the BRST current first introduced by Felder. The cohomology of this BRST charge isolates the irreducible representations of the Virasoro algebra within the linear dilaton Fock space, and the supertrace in the BRST complex reproduces the minimal model partition function. The model at the radius $R=\sqrt{pp'}$ has two marginal operators corresponding to the Dotsenko-Fateev screening charges. Deforming by them, we obtain a model that might be called a "BRST quotiented compact timelike Liouville theory." The Hamiltonian of the zero-mode quantum mechanics is not Hermitian, but it is $PT$-symmetric and exactly solvable. Its eigenfunctions have support on an infinite number of plane waves, suggesting an infinite reduction in the number of independent states in the full QFT. Applying conformal perturbation theory to the exponential interactions reproduces the Coulomb gas calculations of minimal model correlators. In contrast to spacelike Liouville, these resonance correlators are finite because the zero mode is compact. We comment on subtleties regarding the reflection operator identification, as well as naive violations of truncation in correlators with multiple reflection operators inserted. This work is part of an attempt to understand the relationship between JT gravity and the $(2,p)$ minimal string.
description: 67 pages. v2: Added a summary section and fixed typos. Matches published version
Rapid Formation of Gas Giant Planets around M Dwarf Stars
Creators: name: Boss, Alan P.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Extrasolar planet surveys have begun to detect gas giant planets in orbit around M dwarf stars. While the frequency of gas giant planets around M dwarfs so far appears to be lower than that around G dwarfs, it is clearly not zero. Previous work has shown that the core accretion mechanism does not seem to be able to form gas giant planets around M dwarfs, because the time required for core formation scales with the orbital period, which lengthens for lower mass stars, resulting in failed (gas-poor) cores unless the gaseous protoplanetary disk survives for > 10 Myr. Disk instability, on the other hand, is rapid enough (~ 1000 yrs) that it should be able to form gas giant protoplanets around even low mass stars well before the gaseous disk disappears. A new suite of three dimensional radiative, gravitational hydrodynamical models is presented that calculates the evolution of initially marginally gravitationally unstable disks with masses of 0.021 to 0.065 solar masses orbiting around stars with masses of 0.1 and 0.5 solar masses, respectively. The models show that gas giant planets are indeed likely to form by the disk instability mechanism in orbit around M dwarf stars, the opposite of the prediction for formation by the core accretion mechanism. This difference offers another observational test for discriminating between these two theoretical end members for giant planet formation. Ongoing and future extrasolar planet searches around M dwarfs by spectroscopy, microlensing, photometry, and astrometry offer the opportunity to help decide between the dominance of the two mechanisms.
description: 22 pages, 8 figures, 1 table. ApJ, accepted
Theory of Cosmological Perturbations and Applications to Superstring Cosmology
Creators: name: Brandenberger, Robert H.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The theory of cosmological perturbations is the main tool which connects theories of the early universe (based on new fundamental physics such as string theory) with cosmological observations. In these lectures, I will provide an introduction to this theory, beginning with an overview of the Newtonian theory of fluctuations, moving on to the analysis of fluctuations in the realm of classical general relativity, and culminating with a discussion of the quantum theory of cosmological perturbations. I will illustrate the formalism with applications to inflationary cosmology. I will review the basics of inflationary cosmology and discuss why - through the evolution of fluctuations - inflation may provide a way of observationally testing Planck-scale physics.
description: Writeup of lectures delivered at the 2004 Cargese Summer School on String Theory, 49 pages, 3 figures
Limbic-striatal interactions and their modulation by dopamine : electrophysiological, neurochemical and behavioral analyses
Creators: name: Floresco, Stanley Bogdan
Publisher: name: University of British Columbia
Year: 2009

description: Excitatory glutamatergic inputs from limbic regions such as the hippocampus and the basolateral amygdala (BLA), and dopaminergic inputs from the ventral tegmental area converge in the nucleus accumbens (NAc). It has been proposed that interactions between these glutamatergic and dopaminergic pathways play an important role in adaptive behaviors. The present thesis employed a multidisciplinary approach to study these interactions, with a specific emphasis on the importance of mesoaccumbens dopamine (DA) transmission, in order to obtain a better understanding of the neural mechanisms by which the NAc transforms signals from the temporal lobes into behavior. The experiments of Chapter 2 utilized extracellular single-unit recordings of individual NAc neurons in combination with electrochemical measures of DA efflux in the NAc. Recordings from NAc neurons which received input from the hippocampus but not the BLA revealed that increased efflux of mesoaccumbens DA, evoked by tetanic stimulation of the fimbria, potentiated hippocampal-evoked neural activity in these cells. These effects were mediated by both DA and NMDA receptors. Similar recordings from neurons which received converging input from both the hippocampus and the BLA revealed tetanic stimulation of the fimbria again potentiated hippocampal evoked spiking activity, while concurrently suppressing BLA-evoked spiking activity in the same neurons. The suppression of BLA-evoked spiking activity was activity-dependent, and was mediated by both D, and adenosine A, receptors. Chapter 3 showed that random foraging on a radial-arm maze, which is dependent on a neural circuit linking the hippocampus to the NAc, was correlated with an increase in mesoaccumbens DA extracellular levels, as measured with microdialysis. In Chapter 4, pharmacological blockade of DA or NMDA receptors in the NAc, or selective disruption of dopaminergic modulation of ventral subicular inputs to the NAc (using an asymmetrical infusion procedure) significantly disrupted random foraging. These effects were mediated by the Dl receptor. In Chapter 5, the present data are integrated with previous research to formulate a model of ventral striatal function. It is proposed that the NAc mediates behavior through distinct patterns of activity and inactivity driven by excitatory limbic input projecting to different groups of neural ensembles. Mesoaccumbens DA transmission plays an essential role in regulating the synchrony ensemble activity, augmenting activity in one ensemble while suppressing activity in another. It is argued that the modulatory effects of DA appears to be essential when an organism must switch from one form of adaptive behavior to another in response to a constantly changing environment.
Radio Observations and Spectrum of the SNR G127.1+0.5 and its Central Source 0125+628
Creators: name: Leahy, Denis A.
name: Tian, Wenwu
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present new images of the Supernova Remnant (SNR) G127.1+0.5 (R5), based on the 408 MHz and 1420 MHz continuum emission and the HI-line emission data of the Canadian Galactic Plane Survey (CGPS). The radio spectrum of the central compact source (0125+628) is analyzed in the range 178 MHz - 8.7 GHz, indicating a flat spectrum with synchrotron self-absorption below 800 MHz. The SNR's flux density at 408 MHz is 17.1$\pm$1.7 Jy and at 1420 MHz is 10.0$\pm$0.8 Jy, corrected for flux densities from compact sources within the SNR. The SNR's integrated flux density based spectral index (S$_ν$$\propto$$ν$$^{-α}$) is 0.43$\pm$0.10. The respective T-T plot spectral index (derived from the relative size of brightness temperature variations between two frequencies, see text for details) is 0.46$\pm$0.01. There is no evidence at 1$σ$ for spatial variations in spectral index within G127.1+0.5. In particular, we compared the northern shell, southern shell and central diffuse region. HI observations show structures associated with the SNR in the radial velocity range of -12 to -16 km$/$s, suggesting G127.1+0.5's distance is 1.15 kpc. The estimated Sedov age is 2 - 3 $\times$$10^{4}$ yr.
description: 13 pages, 5 figures, 5 tables, accepted by A&A
Extensions of Lieb's concavity theorem
Creators: name: Hansen, Frank
Publisher: name: arXiv
Year: 2005
Subjects: subject: Mathematical Physics (math-ph)
subject: Operator Algebras (math.OA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: The operator function (A,B)\to\tr f(A,B)(K^*)K, defined on pairs of bounded self-adjoint operators in the domain of a function f of two real variables, is convex for every Hilbert Schmidt operator K, if and only if f is operator convex. As a special case we obtain a new proof of Lieb's concavity theorem for the function (A,B)\to\tr A^pK^*B^{q}K, where p and q are non-negative numbers with sum p+q\le 1. In addition, we prove concavity of the operator function (A,B)\to \tr(A(A+μ_1)^{-1}K^* B(B+μ_2)^{-1}K) on its natural domain D_2(μ_1,μ_2), cf. Definition 4.1
description: The format of one reference is changed such that CiteBase can identify it
Effects of the QCD phase transition on hadronic observables in relativistic hydrodynamic simulations of heavy-ion reactions in the FAIR/NICA energy regime
Creators: name: Spieles, Christian
name: Bleicher, Marcus
Publisher: name: arXiv
Year: 2020
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We investigate hadronic particle spectra and flow characteristics of heavy-ion reactions in the FAIR/NICA energy range of $1\ A{\rm GeV} \le E_{\rm lab} \le 10\ A{\rm GeV}$ within a relativistic ideal hydrodynamic one-fluid approach. The particlization is realized by sampling the Cooper-Frye distribution for a grand canonical hadron gas on a hypersurface of constant energy density. Results of the hydrodynamic calculations for different underlying equations of state are presented and compared with experimental data and microscopic transport simulations. The sensitivity of the approach to physical model inputs concerning the initial state and the particlization is studied.
description: Submitted to EPJ ST
Influence of a dynamical gluon mass in the $pp$ and $\bar{p}p$ forward scattering
Creators: name: Luna, E. G. S.
name: Martini, A. F.
name: Menon, M. J.
name: Mihara, A.
name: Natale, A. A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We compute the tree level cross section for gluon-gluon elastic scattering taking into account a dynamical gluon mass, and show that this mass scale is a natural regulator for this subprocess cross section. Using an eikonal approach in order to examine the relationship between this gluon-gluon scattering and the elastic $pp$ and $\bar{p}p$ channels, we found that the dynamical gluon mass is of the same order of magnitude as the {\it ad hoc} infrared mass scale $m_{0}$ underlying eikonalized QCD-inspired models. We argue that this correspondence is not an accidental result, and that this dynamical scale indeed represents the onset of non-perturbative contributions to the elastic hadron-hadron scattering. We apply the eikonal model with a dynamical infrared mass scale to obtain predictions for $σ_{tot}^{pp,\bar{p}p}$, $ρ^{pp,\bar{p}p}$, slope $B^{pp,\bar{p}p}$, and differential elastic scattering cross section $dσ^{\bar{p}p}/dt$ at Tevatron and CERN-LHC energies.
description: 20 pages, 5 figures; misprints corrected and comments added. To appear in Phys. Rev. D
Khovanov homology detects the figure-eight knot
Creators: name: Baldwin, John A.
name: Dowlin, Nathan
name: Levine, Adam Simon
name: Lidman, Tye
name: Sazdanovic, Radmila
Publisher: name: arXiv
Year: 2020
Subjects: subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 57K18

description: Using Dowlin's spectral sequence from Khovanov homology to knot Floer homology, we prove that reduced Khovanov homology (over $\mathbb{Q}$) detects the figure-eight knot.
Ground State Properties of one-dimensional Antiferromagnetic Spin-1 Chain with Single-ion Anisotropy
Creators: name: Aydiner, Ekrem
name: Akyuz, Cenk
Publisher: name: arXiv
Year: 2005
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: In this study, we have investigated ground state properties of one-dimensional antiferromagnetic spin-1 chain with single-ion anisotropy at very low temperatures using the Transfer Matrix method. Magnetic plateaus, phase diagram, specific heat, susceptibility of the spin chain have been evaluated numerically from the free energy. Results are in good agreement with the experimental data for the spin-1 compounds [Ni$_2$(Medpt)$_2$($μ$-ox)(H$_2$O)$_2$](ClO$_4$)$_2$2H$_2$O, [Ni$_{2}$(Medpt)$_{2}$($μ$-ox)($μ$-N$_{3}$)](ClO$_{4}$)0.5H$_{2}$O, Ni(C$_2$H$_8$N$_2$)Ni(CN)$_4$ and Ni(C$_{10}$H$_8$N$_2$)$_2$Ni(CN)$_4$.H$_2$O. However, spin-Peierls transition have not been observed in the temperature dependence of specific heat and magnetic susceptibility.
description: RevTex, 9 pages, 7 figures: one reference added
On the Littlewood conjecture in fields of power series
Creators: name: Adamczewski, Boris
name: Bugeaud, Yann
Publisher: name: arXiv
Year: 2005
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11J69, 11J70, 13F25, 68R15

description: Let $\k$ be an arbitrary field. For any fixed badly approximable power series $Θ$ in $\k((X^{-1}))$, we give an explicit construction of continuum many badly approximable power series $Φ$ for which the pair $(Θ, Φ)$ satisfies the Littlewood conjecture. We further discuss the Littlewood conjecture for pairs of algebraic power series.
Scalable designs for quantum computing with rare-earth-ion-doped crystals
Creators: name: Wesenberg, Janus H.
name: Moelmer, Klaus
name: Rippe, Lars
name: Kroell, Stefan
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Due to inhomogeneous broadening, the absorption lines of rare-earth-ion dopands in crystals are many order of magnitudes wider than the homogeneous linewidths. Several ways have been proposed to use ions with different inhomogeneous shifts as qubit registers, and to perform gate operations between such registers by means of the static dipole coupling between the ions. In this paper we show that in order to implement high-fidelity quantum gate operations by means of the static dipole interaction, we require the participating ions to be strongly coupled, and that the density of such strongly coupled registers in general scales poorly with register size. Although this is critical to previous proposals which rely on a high density of functional registers, we describe architectures and preparation strategies that will allow scalable quantum computers based on rare-earth-ion doped crystals.
description: Submitted to Phys. Rev. A
Spontaneous CP violation and symplectic modular symmetry in Calabi-Yau compactifications
Creators: name: Ishiguro, Keiya
name: Kobayashi, Tatsuo
name: Otsuka, Hajime
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We explore the geometrical origin of CP and the spontaneous CP violation in Calabi-Yau compactifications. We find that the CP symmetry is identified with an outer automorphism of the symplectic modular group in the large complex structure regime of Calabi-Yau threefolds, thereby enlarging the symplectic modular group to their semidirect product group. The spontaneous CP violation is realized by the introduction of fluxes, whose effective action is invariant under CP as well as the discrete $\mathbb{Z}_2$ symmetry or $\mathbb{Z}_4$ R-symmetry. We explicitly demonstrate the spontaneous CP violation on a specific Calabi-Yau threefold.
description: 23 pages, v2:published version
The Concept of Article, Manuscript and/or Journal and the reason Why Nurses have to learn about it
Creators: name: Dias, Maria Frani Ayu Andari
Publisher: name: Zenodo
Year: 2021
Subjects: article
manuscript
journal

description: Presentasi ini adalah presentasi yang disiapkan bagi Mahasiswa/i keperawatan, dengan tujuan agar mereka dapat memahami perbedaan antara artikel, manuskrip atau junal.
Numeric Spectrum of Relic Gravitational Waves in Accelerating Universe
Creators: name: Zhang, Yang
name: Zhao, Wen
name: Yuan, Yefei
name: Xia, Tianyang
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The accelerating expansion of the Universe at the present stage is a process that will change the spectrum of relic gravitational waves. Here we present a numerical calculation for the power spectrum of relic gravitational waves in the accelerating Universe. The results show that although the overall features of the power spectrum is similar to that in the non-accelerating models, the amplitude is smaller by an order of $10^{-1}$. We also find that the spectrum is very sensitive to the index $β$ of the inflationary expansion with the scale factor $a(τ) \propto |τ|^{1+β}$. With increase of $β$, the resulting spectrum is tilted to be flatter with more power on high frequencies, and the sensitivity of the second science run of the LIGO detectors puts a restriction on the parameter $β< -1.8$. The influence of reheating following the inflation has been examined.
description: 7 pages, 4 figures, minor typos corrected
Nonlinear Model Predictive Control of Robotic Systems with Control Lyapunov Functions
Creators: name: Grandia, Ruben
name: Taylor, Andrew J.
name: Singletary, Andrew
name: Hutter, Marco
name: Ames, Aaron D.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Systems and Control (eess.SY)
subject: Robotics (cs.RO)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: The theoretical unification of Nonlinear Model Predictive Control (NMPC) with Control Lyapunov Functions (CLFs) provides a framework for achieving optimal control performance while ensuring stability guarantees. In this paper we present the first real-time realization of a unified NMPC and CLF controller on a robotic system with limited computational resources. These limitations motivate a set of approaches for efficiently incorporating CLF stability constraints into a general NMPC formulation. We evaluate the performance of the proposed methods compared to baseline CLF and NMPC controllers with a robotic Segway platform both in simulation and on hardware. The addition of a prediction horizon provides a performance advantage over CLF based controllers, which operate optimally point-wise in time. Moreover, the explicitly imposed stability constraints remove the need for difficult cost function and parameter tuning required by NMPC. Therefore the unified controller improves the performance of each isolated controller and simplifies the overall design process.
A Machine-Independent port of the MPD language run time system to NetBSD
Creators: name: Souvatzis, Ignatios
Publisher: name: arXiv
Year: 2005
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: Programming Languages (cs.PL)
subject: FOS: Computer and information sciences
subject: D.1.3; D.3.4

description: SR (synchronizing resources) is a PASCAL - style language enhanced with constructs for concurrent programming developed at the University of Arizona in the late 1980s. MPD (presented in Gregory Andrews' book about Foundations of Multithreaded, Parallel, and Distributed Programming) is its successor, providing the same language primitives with a different, more C-style, syntax. The run-time system (in theory, identical, but not designed for sharing) of those languages provides the illusion of a multiprocessor machine on a single Unix-like system or a (local area) network of Unix-like machines. Chair V of the Computer Science Department of the University of Bonn is operating a laboratory for a practical course in parallel programming consisting of computing nodes running NetBSD/arm, normally used via PVM, MPI etc. We are considering to offer SR and MPD for this, too. As the original language distributions were only targeted at a few commercial Unix systems, some porting effort is needed. However, some of the porting effort of our earlier SR port should be reusable. The integrated POSIX threads support of NetBSD-2.0 and later allows us to use library primitives provided for NetBSD's phtread system to implement the primitives needed by the SR run-time system, thus implementing 13 target CPUs at once and automatically making use of SMP on VAX, Alpha, PowerPC, Sparc, 32-bit Intel and 64 bit AMD CPUs. We'll present some methods used for the impementation and compare some performance values to the traditional implementation.
description: 6 pages
THE EFFECTS OF THE INTEREST RATE CEILINGS ON THE MICRO LENDING MARKET IN SOUTH AFRICA
Creators: name: Mohane, Happy
name: Coetzee, Gerhard K.
name: Grant, William
name: Mohane, Happy
name: Coetzee, Gerhard K.
name: Grant, William
Publisher: name: Unknown
Year: 2002
Subjects: Financial Economics

description: Interest rates are a topical subject in the micro lending industry in South Africa. The micro lending industry has been accused of charging usurious interest and exploitating the consumers. This has led to the Department of Trade and Industry passing a Usury Act with an aim of protecting the consumers. The Act imposes interest rate ceilings on loan finance provided by money lending institutions. These ceilings are proposed to be linked to the prime rate. Given this, it is not possible for micro lenders to charge full-cost recovery interest rates. This paper tries to highlight the effects of interest rate ceilings on the micro finance market. It argues that the biggest cost component of microlenders is administration costs and not the cost of capital, thus linking ceilings to the prime rate is illogic.
Thermal Entanglement between Alternate Qubits of a Four-qubit Heisenberg XX Chain in a Magnetic Field
Creators: name: Cao, M.
name: Zhu, S.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The concurrence of two alternate qubits in a four-qubit Heisenberg XX chain is investigated when a uniform magnetic field B is included. It is found that there is no thermal entanglement between alternate qubits if B is close to zero. Magnetic field can induce entanglement in a certain range both for the antiferromagnetic and ferromagnetic cases. Near zero temperature, the entanglement undergoes two sudden changes with increasing value of the magnetic field B. This is due to the changes in the ground state. This novel property may be used as quantum entanglement switch. The anisotropy in the system can also induce the entanglement between two alternate qubits.
description: 10 pages, 3 figures
Mengenal Emosi dan Cara Menghargai Diri Sendiri
Creators: name: Dias, Maria Frani Ayu Andari
Publisher: name: Zenodo
Year: 2021
Subjects: Mengenal Emosi
Emosi
Menghargai diri sendiri

description: Presentasi "Menghargai Emosi dan Cara Menghargai Diri Sendiri" ini disampaikan pada acara "Meet the Authors: Gender, Seksualitas dan Psikologi" #Diskusi4 pada hari Jumat, 12 Maret 2021 secara daring. Penyelenggara acara, rumah produksi EaBooks, dan Buku Mojok Group.
EVALUATING THE EFFICIENCY OF THE WHEAT TARIFF REGIME IN SOUTH AFRICA
Creators: name: Meyer, Ferdinand H.
name: Meyer, Ferdinand H.
Publisher: name: Unknown
Year: 2002
Subjects: Crop Production/Industries
International Relations/Trade

description: A drastic change in the marketing system of wheat in South Africa has taken place over the past decade. For the first time an important tariff on wheat was implemented in the form of a variable import levy. Traditionally, countries have implemented variable import levy schemes in order to protect domestic price guarantees by means of determining a reference price, which was generally above the domestic guaranteed price, below which imports were not allowed into the country. In this paper the efficiency of the Wheat Tariff Regime in South Africa is examined, after it has been operational for the past seven years.
The Viscosity Bound Conjecture and Hydrodynamics of M2-Brane Theory at Finite Chemical Potential
Creators: name: Saremi, Omid
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Kovtun, Son and Starinets have conjectured that the viscosity to entropy density ratio $η/s$ is always bounded from below by a universal multiple of $\hbar$ i.e., $\hbar/(4πk_{B})$ for all forms of matter. Mysteriously, the proposed viscosity bound appears to be saturated in all computations done whenever a supergravity dual is available. We consider the near horizon limit of a stack of M2-branes in the grand canonical ensemble at finite R-charge densities, corresponding to non-zero angular momentum in the bulk. The corresponding four-dimensional R-charged black hole in Anti-de Sitter space provides a holographic dual in which various transport coefficients can be calculated. We find that the shear viscosity increases as soon as a background R-charge density is turned on. We numerically compute the few first corrections to the shear viscosity to entropy density ratio $η/s$ and surprisingly discover that up to fourth order all corrections originating from a non-zero chemical potential vanish, leaving the bound saturated. This is a sharp signal in favor of the saturation of the viscosity bound for event horizons even in the presence of some finite background field strength. We discuss implications of this observation for the conjectured bound.
description: LaTeX, 26+1 Pages, 4 Figures, Version 2: references added
An Implementation of Partial Transmit Sequences to Design Energy Efficient Underwater Acoustic OFDM Communication System
Creators: name: Raza, Waleed
name: Ma, Xuefei
name: Ali, Amir
name: Shah, Zubair Ali
name: Mehdi, Ghazanfar
Publisher: name: arXiv
Year: 2020
Subjects: subject: Signal Processing (eess.SP)
subject: Computational Engineering, Finance, and Science (cs.CE)
subject: Information Theory (cs.IT)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: In this article we research about underwater acoustics transceivers. As Underwater acoustic transceivers consume more power than Radio frequency transceivers. The techniques which are being utilized in radio frequency cannot be implemented directly in underwater acoustic system it needs to be re investigated to design new methods. To achieve reliable acoustic data transmission new techniques should be achieved or the traditional Orthogonal frequency divisional multiplexing techniques should be revised. The power consumption also relies upon underwater acoustic signal propagation and transmission distances. Several underwater acoustic applications require long-term monitoring of the sea. For the battery powered modems, it becomes very serious problem. By designing an Energy efficient OFDM Communication system we can solve this problem. We study about peak to average power ratio in an Orthogonal frequency divisional multiplexing system by reducing the major draw-back of OFDM system. The PAPR reduction utilized in this paper is Partial Transmit Sequences for underwater acoustic OFDM communication system which has lesser complexity. The results have provided better performance in underwater acoustic OFDM communication system.
HOW COMPETITIVE IS AGRIBUSINESS IN THE SOUTH AFRICAN FOOD COMMODITY CHAIN?
Creators: name: Van Rooyen, C.J.
name: Esterhuizen, Dirk
name: Doyer, Ockert T.
name: Van Rooyen, C.J.
name: Esterhuizen, Dirk
name: Doyer, Ockert T.
Publisher: name: Unknown
Year: 1999
Subjects: Agribusiness

description: The competitiveness of sixteen selected food commodity chains in South Africa was calculated using the Revealed Comparative Advantage method of Balassa. The majority of commodity chains are marginally competitive. Except for the maize, pineapple, and apple chains, the competitiveness index generally decreases when moving from primary to processed products. This implies that benification or "value adding" opportunities in South Africa are restricted. To compete in a global economy strategies should be followed that improve the competitiveness of the whole food supply chain. It is i.e. not good enough for farmers to be able to compete globally at farm gate level, whilst the locally processed commodities that is sold to the consumer is not competitive in the world market.
Valence instability of cerium under pressure in the Kondo-like perovskite La$_{0.1}$Ce$_{0.4}$Sr$_{0.5}$MnO$_3$
Creators: name: Eto, T.
name: Sundaresan, A.
name: Honda, F.
name: Oomi, G.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Effect of hydrostatic pressure and magnetic field on electrical resistance of the Kondo-like perovskite manganese oxide, La$_{0.1}$Ce$_{0.4}$Sr$_{0.5}$MnO$_3$ with a ferrimagnetic ground state, have been investigated up to 2.1 GPa and 9 T. In this compound, the Mn-moments undergo double exchange mediated ferromagnetic ordering at $T_{\rm C}$ $\sim$ 280 K and there is a resistance maximum, $T_{\rm max}$ at about 130 K which is correlated with an antiferromagnetic ordering of {\it cerium} with respect to the Mn-sublattice moments. Under pressure, the $T_{\rm max}$ shifts to lower temperature at a rate of d$T_{max}$/d$P$ = -162 K/GPa and disappears at a critical pressure $P_{\rm c}$ $\sim$ 0.9 GPa. Further, the coefficient, $m$ of $-logT$ term due to Kondo scattering decreases linearly with increase of pressure showing an inflection point in the vicinity of $P_{\rm c}$. These results suggest that {\it cerium} undergoes a transition from Ce$^{3+}$ state to Ce$^{4+}$/Ce$^{3+}$ mixed valence state under pressure. In contrast to pressure effect, the applied magnetic field shifts $T_{\rm max}$ to higher temperature presumably due to enhanced ferromagnetic Mn moments.
description: to be published in Phys. Rev. B (rapid commun)
Thermal emission from Isolated Neutron Stars and their surface magnetic field: going quadrupolar?
Creators: name: Zane, Silvia
name: Turolla, Roberto
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: In the last few years considerable observational resources have been devoted to study the thermal emission from isolated neutron stars. Detailed XMM and Chandra observations revealed a number of features in the X-ray pulse profile, like asymmetry, energy dependence, and possible evolution of the pulse profile over a time scale of months or years. Here we show that these characteristics may be explained by a patchy surface temperature distribution, which is expected if the magnetic field has a complex structure in which higher order multipoles contribute together with the dipole. We reconsider these effects from a theoretical point of view, and discuss their implications to the observational properties of thermally emitting neutron stars.
description: 6 pages, 1 TeX file, 6 postscript figures; macro: elsart.cls. Accepted for publication in Advances in Space Research. Manuscript Number: JASR-D-04-00405R1
THE URUGUAY ROUND AGREEMENT ON AGRICULTURE: A REVIEW OF PROGRESS AND CHALLENGES IN THE SADC REGION
Creators: name: Ngqangweni, Simphiwe
name: Kandiero, Tonia
name: Gebrehiwet, Yemane
name: Kirsten, Johann F.
name: Ngqangweni, Simphiwe
name: Kandiero, Tonia
name: Gebrehiwet, Yemane
name: Kirsten, Johann F.
Publisher: name: Unknown
Year: 2004
Subjects: International Relations/Trade

description: Through the Uruguay Round Agreement on Agriculture (URAA), the multilateral trade negotiations saw a turning point in the inclusion of agriculture in the trade liberalization debate. This development bears important implications for developing countries, including those of SADC, who have agricultural as a critical element of their economic growth, poverty alleviation, and food security. This article reviews the progress of SADC countries towards implementation of the URAA. We find that the extent of SADC countries support to the agricultural sector is still within the URAA provisions. However, despite certain preferential trade agreements in place between SADC and the developed world, trade barriers are still high in many developed countries. A barrier-free access to developed country markets has important growth and poverty alleviation implications for SADC countries.
STUDYING THE LOCAL DIVERSITY OF RURAL LIVELIHOODS SYSTEMS: AN APPLICATION OF TYPOLOGICAL TECHNIQUES FOR INTEGRATED RURAL DEVELOPMENT SUPPORT IN THE EASTERN CAPE (SOUTH AFRICA)
Creators: name: Perret, Sylvain R.
name: Kirsten, Johann F.
name: Perret, Sylvain R.
name: Kirsten, Johann F.
Publisher: name: Unknown
Year: 2000
Subjects: Community/Rural/Urban Development
Labor and Human Capital

description: This paper presents briefly the principles and procedure of typology schemes, which aim at describing and representing the local diversity of rural households, through the analysis of their modes of operation, strategies and prospects, activities and livelihoods' systems. This approach departs from both strict economic analysis and social participatory approaches, which often overlook the diversity that exists among rural households at local level. It basically combines the respective principles and advantages of both approaches. Through a case study, which was carried out in a rural community of the Eastern Cape Province of South Africa, the paper highlights this local diversity, its representation through a typology scheme, and the issues related to livelihood systems: complementarity between on-farm and off-farm activities and sources of income, the key role of women, significance of subsistence farming activities, existence of productive and potentially profitable activities (wool). Some key questions for the close future are also raised: ageing process at household level (pensions are currently instrumental in livelihood build-up), transmission process to youngsters in a context of PTO land access system, sustainability of farming systems in a fragile and constraining natural environment, weaknesses in the agribusiness environment, basic needs in development support as expressed by people, the worrying situation of certain very poor households, problems and constraints as expressed by farmers. The paper finally discusses the significance of such tools for integrated rural development planning and management purposes. They may be responses to the increasing need for proper diagnosis, in a context of persistent poverty in South-Africa's rural areas and of public willingness to tackle it in an integrated manner.
BWCNN: Blink to Word, a Real-Time Convolutional Neural Network Approach
Creators: name: Ramli, Albara Ah
name: Liu, Rex
name: Krishnamoorthy, Rahul
name: B, Vishal I
name: Wang, Xiaoxiao
name: Tagkopoulos, Ilias
name: Liu, Xin
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease of the brain and the spinal cord, which leads to paralysis of motor functions. Patients retain their ability to blink, which can be used for communication. Here, We present an Artificial Intelligence (AI) system that uses eye-blinks to communicate with the outside world, running on real-time Internet-of-Things (IoT) devices. The system uses a Convolutional Neural Network (CNN) to find the blinking pattern, which is defined as a series of Open and Closed states. Each pattern is mapped to a collection of words that manifest the patient's intent. To investigate the best trade-off between accuracy and latency, we investigated several Convolutional Network architectures, such as ResNet, SqueezeNet, DenseNet, and InceptionV3, and evaluated their performance. We found that the InceptionV3 architecture, after hyper-parameter fine-tuning on the specific task led to the best performance with an accuracy of 99.20% and 94ms latency. This work demonstrates how the latest advances in deep learning architectures can be adapted for clinical systems that ameliorate the patient's quality of life regardless of the point-of-care.
description: 8 pages, 4 figures
The importance of tides for the Local Group dwarf spheroidals
Creators: name: Read, J. I.
name: Wilkinson, M. I.
name: Evans, N. Wyn
name: Gilmore, G.
name: Kleyna, Jan T.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: There are two main tidal effects which can act on the Local Group dwarf spheroidals (dSphs): tidal stripping and tidal shocking. Using N-body simulations, we show that tidal stripping always leads to flat or rising projected velocity dispersions beyond a critical radius; it is $\sim 5$ times more likely, when averaging over all possible projection angles, that the cylindrically averaged projected dispersion will rise, rather than be flat. In contrast, the Local Group dSphs, as a class, show flat or falling projected velocity dispersions interior to $\sim 1$ kpc. This argues for tidal stripping being unimportant interior to $\sim 1$ kpc for most of the Local Group dSphs observed so far. These results have important implications for the formation of the dSphs and for cosmology. A tidal origin for the formation of these Local Group dSphs (in which they contain no dark matter) is strongly disfavoured. In the cosmological context, a naive solution to the missing satellites problem is to allow only the most massive substructure dark matter halos around the Milky Way to form stars. It is possible for dSphs to reside within these halos ($\sim 10^{10}$M$_\odot$) and have their velocity dispersions lowered through the action of tidal shocks, but only if they have a central density core in their dark matter, rather than a cusp. dSphs can reside within cuspy dark matter halos if their halos are less massive ($\sim 10^{9}$M$_\odot$) and therefore have smaller central velocity dispersions initially (abridged).
description: 15 pages, 9 figures. Accepted for publication in MNRAS. No change from previous version
THE FINANCIAL PERFORMANCE OF FARMING CO-OPERATIVES: ECONOMIC VALUE ADDED VS TRADITIONAL MEASURES
Creators: name: Hall, John H.
name: Geyser, J.M.
name: Hall, John H.
name: Geyser, J.M.
Publisher: name: Unknown
Year: 2004
Subjects: Agribusiness

description: The profitability measures have limitations for examining wealth creation. Economic Value Added (EVA) is being used by businesses to measure wealth creation. EVA has some advantages over other financial ratios because it fully accounts for the resources used by co-operatives and it includes both realized and unrealized capital gains in the calculation. This article examines the EVA metric for four years of co-operative financial data to determine if it provides additional information about wealth creation and profitability than do the other ratios.
First scattered light images of debris disks around HD 53143 and HD 139664
Creators: name: Kalas, Paul
name: Graham, James R.
name: Clampin, Mark C.
name: Fitzgerald, Michael P.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the first scattered light images of debris disks around a K star (HD 53143) and an F star (HD 139664) using the coronagraphic mode of the Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope (HST). With ages 0.3 - 1 Gyr, these are among the oldest optically detected debris disks. HD 53143, viewed ~45 degrees from edge-on, does not show radial variation in disk structure and has width >55 AU. HD 139664 is seen close to edge-on and has belt-like morphology with a dust peak 83 AU from the star and a distinct outer boundary at 109 AU. We discuss evidence for significant diversity in the radial architecture of debris disks that appears unconnected to stellar spectral type or age. HD 139664 and possibly the solar system belong in a category of narrow belts 20-30 AU wide. HD 53143 represents a class of wide disk architecture with characteristic width >50 AU.
description: 7 pages, 3 figures
USDA Production Forecasts for Pork, Beef, and Broilers: A Further Evaluation
Creators: name: Sanders, Dwight R.
name: Manfredo, Mark R.
name: Sanders, Dwight R.
name: Manfredo, Mark R.
Publisher: name: Unknown
Year: 2001
Subjects: Livestock Production/Industries

description: This paper examines USDA one-step ahead forecasts of quarterly beef, pork, and poultry production. The forecasts are evaluated based on traditional criteria for optimality-efficiency and unbiasedness-as well as their performance versus an univariate time series model. The results suggest that the USDA forecasts are unbiased; however, they are generally not efficient. That is, they do not fully incorporate the information contained in past forecasts. Moreover, the USDA predictions do not encompass all the information contained in forecasts generated by simple time series models.
Tantric Influences on Indo-Aryan Civilization
Creators: name: Gauthier, Richard
Publisher: name: Zenodo
Year: 2020
Subjects: tantra, indo-aryan

description: As the founder of a global movement of spiritually-oriented and socially-minded intellectuals, artists and writers called Renaissance Universal, Prabhat Rainjan Sarkar (1922-1990), a spiritual teacher (also known as Shrii Shrii Anandamurti) and social philosopher, describes the interrelationship, clashes and inter-mixing between the indigenous people of early India with their Tantra-based civilization and the Aryans who migrated into India bringing their Vedic civilization. This discourse is one of a series of remarkable semi-annual Renaissance Universal discourses given by P. R. Sarkar after the founding of the Renaissance Universal movement. The discourse presents a strong challenge to traditional thinking about this important topic.
MARKET-MAKING BEHAVIOR IN FUTURES MARKETS
Creators: name: Liu, Holly
name: Williams, Jeffrey C.
name: Jorda, Oscar
name: Liu, Holly
name: Williams, Jeffrey C.
name: Jorda, Oscar
Publisher: name: Unknown
Year: 2001
Subjects: subject: Marketing
subject: FOS: Economics and business
subject: Liquidity
subject: Market-Making
subject: Futures Markets
subject: Scalpers
subject: Autoregressive Conditional Intensity (ACI)
subject: Volatility

description: This paper examines voluntary market-making behavior, namely scalping, in futures markets. Specifically, this paper studies what factors determine scalpers' entry and exit, and how scalping affects market liquidity and price volatility. The data used for the analysis are time-stamped electronic transaction data marked with traders' identities from the Dalian Futures Exchanges in China. The contributions of this paper are: (1) to give detailed analysis of scalping behavior and its impact on market liquidity; (2) to develop new econometric tools for analyzing time-series count data; (3) to propose a new measure of liquidity.
Eruption of Solar Magnetic Flux Ropes Caused by Flux Feeding
Creators: name: Zhang, Quanhao
name: Wang, Yuming
name: Liu, Rui
name: Zhang, Jie
name: Hu, Youqiu
name: Wang, Wensi
name: Zhuang, Bin
name: Li, Xiaolei
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Large-scale solar eruptions are believed to have a magnetic flux rope as the core structure. However, it remains elusive as to how the flux rope builds up and what triggers its eruption. Recent observations found that a prominence erupted following multiple episodes of "flux feeding". During each episode, a chromospheric fibril rose and merged with the prominence lying above. In this letter, we carried out 2.5-dimensional magnetohydrodynamic (MHD) numerical simulations to investigate whether the flux-feeding mechanism can explain such an eruption. The simulations demonstrate that the discrete emergence of small flux ropes can initiate eruptions by feeding axial flux into the preexistent flux rope until its total axial flux reaches a critical value. The onset of the eruption is dominated by an ideal MHD process. Our simulation results corroborate that the flux feeding is a viable mechanism to cause the eruption of solar magnetic flux ropes.
description: This paper has been accepted by ApJL
Gravitationally lensed radio emission associated with SMM J16359+6612, a multiply imaged submillimeter galaxy behind A2218
Creators: name: Garrett, M. A.
name: Knudsen, K. K.
name: van der Werf, P. P.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report the detection of discrete, lensed radio emission from the multiply imaged, z=2.516 submillimetre selected galaxy, SMM J16359+6612. All three images are detected in deep WSRT 1.4 GHz and VLA 8.2 GHz observations, and the radio positions are coincident with previous sub-mm SCUBA observations of this system. This is the widest separation lens system to be detected in the radio so far, and the first time that multiply imaged lensed radio emission has been detected from a star forming galaxy -- all previous multiply-lensed radio systems being associated with radio-loud AGN. Taking into account the total magnification of ~45, the WSRT 1.4 GHz observations suggest a star formation rate of 500 Solar mass/yr. The source has a steep radio spectrum (alpha -0.7) and an intrinsic flux density of just 3 microJy at 8.2 GHz. Three other SCUBA sources in the field are also detected by the WSRT, including SMMJ16359+66118, a singly imaged (and magnified) arclet at z=1.034. Higher resolution radio observations of SMMJ16359+6612 (and other highly magnified star forming galaxies) provide a unique opportunity to study the general properties and radio morphology of intrinsically faint, distant and obscured star forming galaxies. They can also help to constrain the technical specification of next generation radio telescopes, such as the Square Kilometre Array.
description: 5 pages, 2 figures, to appear in A&A letters