cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
BusTr: Predicting Bus Travel Times from Real-Time Traffic
Creators: name: Barnes, Richard
name: Buthpitiya, Senaka
name: Cook, James
name: Fabrikant, Alex
name: Tomkins, Andrew
name: Xu, Fangzhou
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: We present BusTr, a machine-learned model for translating road traffic forecasts into predictions of bus delays, used by Google Maps to serve the majority of the world's public transit systems where no official real-time bus tracking is provided. We demonstrate that our neural sequence model improves over DeepTTE, the state-of-the-art baseline, both in performance (-30% MAPE) and training stability. We also demonstrate significant generalization gains over simpler models, evaluated on longitudinal data to cope with a constantly evolving world.
description: 14 pages, 2 figures, 5 tables. Citation: "Richard Barnes, Senaka Buthpitiya, James Cook, Alex Fabrikant, Andrew Tomkins, Fangzhou Xu (2020). BusTr: Predicting Bus Travel Times from Real-Time Traffic. 26th ACM SIGKDD Conference on Knowledge Discovery and Data Mining. doi: 10.1145/3394486.3403376"
Signatures of non-trivial band topology in LaAs/LaBi heterostructure
Creators: name: Wadhwa, Payal
name: Kumar, T. J. Dhilip
name: Shukla, Alok
name: Kumar, Rakesh
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In this article, we investigate non-trivial topological features in a heterostructure of extreme magnetoresistance (XMR) materials LaAs and LaBi using density functional theory (DFT). The proposed heterostructure is found to be dynamically stable and shows bulk band inversion with non-trivial Z_{2} topological invariant and a Dirac cone at the surface. In addition, its electron and hole carrier densities ratio is also calculated to investigate the possibility to possess XMR effect. Electrons and holes in the heterostructure are found to be nearly compensated, thereby facilitating it to be a suitable candidate for XMR studies.
description: 5 Figures, 9 pages
Decay of Spin-One Particle into Two Photons in Presence of Uniform External Magnetic Field
Creators: name: Angom, Dilip
name: Bhattacharya, Kaushik
name: Rindani, Saurabh D.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Yang's theorem states that an initial J=1 state cannot decay into two photons. Because of this result some reactions relating to elementary particles or atomic transitions can be ruled out. The theorem is not valid in the presence of background electric or magnetic fields. In this work we show that the decay of a J=1 particle into two photons is permitted by Bose symmetry and rotational invariance when the background of the decay process is not pure vacuum but contains an external classical magnetic/electric field. We also discuss constraints on these amplitudes from {\bf CP} invariance.
description: Tex file
The Bernardi formula for non-transitive deformations of the braid arrangement
Creators: name: Bisain, Ankit
name: Hanson, Eric J.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05A19

description: Bernardi has given a general formula for the number of regions of a deformation of the braid arrangement as a signed sum over boxed trees. We prove that each set of boxed trees which share an underlying (rooted labeled plane) tree contributes 0, +1, or -1 to this sum, and we give an algorithm for computing this value. For Ish-type arrangements, we further construct a sign-reversing involution which reduces Bernardi's signed sum to the enumeration of a set of (rooted labeled plane) trees. We conclude by explicitly enumerating the trees corresponding to the regions of Ish-type arrangements which are nested, recovering their known counting formula.
description: 23 pages, 9 figures. v3: journal version. v2: Level of generality changed in Sections 4-5 to correct an error in v1, additional clarity and examples added throughout
Observation of a new charmonium state in double charmonium production in e+ e- annihilation at \sqrt{s} ~ 10.6 GeV
Creators: name: The Belle Collaboration
name: Abe, K.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We report the first observation of a new charmonium state at a mass of $(3.943 \pm 0.006 \pm 0.006) {GeV}/c^2$. This state, called X(3940), is observed in the process $e^+ e^- \to J/ψX(3940)$ in the spectrum of masses recoiling against a reconstructed $J/ψ$. We also observe the decay of the X(3940) into $D^* \bar{D}$ and measure the intrinsic width of this state to be less than $52 MeV/c^2$ at the 90% C.L. These results are obtained from a $350 fb^{-1}$ data sample collected with the Belle detector near the $Υ(4S)$ resonance, at the KEKB asymmetric energy $e^+ e^-$ collider.
description: BELLE-CONF-0517
Surface declination governed asymmetric sessile droplet evaporation
Creators: name: Dhar, Purbarun
name: Dwivedi, Raghavendra Kumar
name: Harikrishnan, A R
Publisher: name: arXiv
Year: 2020
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: The article reports droplet evaporation kinetics on inclined substrates. Comprehensive experimental and theoretical analyses of the droplet evaporation behaviour for different substrate declination, wettability and temperatures have been presented. Sessile droplets with substrate declination exhibit distorted shape and evaporate at different rates compared to droplets on the same horizontal substrate and is characterized by more often changes in regimes of evaporation. The slip stick and jump stick modes are prominent during evaporation. For droplets on inclined substrates, the evaporative flux is also asymmetric and governed by the initial contact angle dissimilarity. Due to smaller contact angle at the rear contact line, it is the zone of a higher evaporative flux. Particle image velocimetry shows the increased internal circulation velocity within the inclined droplets. Asymmetry in the evaporative flux leads to higher temperature gradients, which ultimately enhances the thermal Marangoni circulation near the rear of the droplet where the evaporative flux is highest. A model is adopted to predict the thermal Marangoni advection velocity, and good match is obtained. The declination angle and imposed thermal conditions interplay and lead to morphed evaporation kinetics than droplets on horizontal heated surfaces. Even weak movements of the TL alter the evaporation dynamics significantly, by changing the shape of the droplet from ideally elliptical to almost spherical cap, which ultimately reduces the evaporative flux. The life time of the droplet is modelled by modifying available models for non-heated substrate, to account for the shape asymmetry. The present findings may find strong implications towards microscale thermo-hydrodynamics.
The Pierre Auger Observatory -Status and Prospects -
Creators: name: Kampert, Karl-Heinz
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The southern Pierre Auger Observatory is presently under construction in Malargue, Mendoza, Argentina. It combines two complementary air shower observation techniques; the detection of particles at ground and the observation of associated fluorescence light generated in the atmosphere above the ground. Experimentally, this is being realised by employing an array of 1600 water Cherenkov detectors, distributed over an area of 3000 km^2, and operating 24 wide-angle Schmidt telescopes, positioned at four sites at the border of the ground array. The Observatory will reach its full size in 2006. However, with the 540 tanks and 12 telescopes presently in operation, the Pierre Auger Observatory has become the largest world-wide cosmic ray experiment already now. This paper sketches the experimental set-up and discusses the current status. In parallel to the ongoing completion of the experiment, a large number of events have been detected with energies above 10^19 eV. The data are used to verify both the performance of the individual detector components as well as to test the quality of the hybrid event reconstruction. All results obtained so far are very promising and they underline the great advantages of the chosen hybrid approach.
description: Invited highlight paper presented at XIII ISVHECRI, Pylos (Greece), Sept. 2004 8 pages, 10 figures, to appear in Nucl. Phys. B (Proc. Suppl.)
Godel-type Metrics in Various Dimensions II: Inclusion of a Dilaton Field
Creators: name: Gurses, Metin
name: Sarioglu, Ozgur
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: This is the continuation of an earlier work where Godel-type metrics were defined and used for producing new solutions in various dimensions. Here a simplifying technical assumption is relaxed which, among other things, basically amounts to introducing a dilaton field to the models considered. It is explicitly shown that the conformally transformed Godel-type metrics can be used in solving a rather general class of Einstein-Maxwell-dilaton-3-form field theories in D >= 6 dimensions. All field equations can be reduced to a simple "Maxwell equation" in the relevant (D-1)-dimensional Riemannian background due to a neat construction that relates the matter fields. These tools are then used in obtaining exact solutions to the bosonic parts of various supergravity theories. It is shown that there is a wide range of suitable backgrounds that can be used in producing solutions. For the specific case of (D-1)-dimensional trivially flat Riemannian backgrounds, the D-dimensional generalizations of the well known Majumdar-Papapetrou metrics of general relativity arise naturally.
description: REVTeX4, 17 pp., no figures, a few clarifying remarks added and grammatical errors corrected
Discrete Lagrangian field theories on Lie groupoids
Creators: name: Vankerschaver, Joris
name: Cantrijn, Frans
Publisher: name: arXiv
Year: 2005
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 58A20; 58H05; 65P10; 70S05

description: We present a geometric framework for discrete classical field theories, where fields are modeled as "morphisms" defined on a discrete grid in the base space, and take values in a Lie groupoid. We describe the basic geometric setup and derive the field equations from a variational principle. We also show that the solutions of these equations are multisymplectic in the sense of Bridges and Marsden. The groupoid framework employed here allows us to recover not only some previously known results on discrete multisymplectic field theories, but also to derive a number of new results, most notably a notion of discrete Lie-Poisson equations and discrete reduction. In a final section, we establish the connection with discrete differential geometry and gauge theories on a lattice.
description: 37 pages, 6 figures, uses xy-pic (v3: minor amendment to def. 3.5; remark 3.7 added)
Crossover behaviours exhibited by fluctuations and correlations in a chain of active particles
Creators: name: Singh, Prashant
name: Kundu, Anupam
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study motion of tagged particles in a harmonic chain of active particles. We consider three models of active particle dynamics - run and tumble particle, active Ornstein-Uhlenbeck particle and active Brownian particle. We investigate the variance, auto correlation, covariance and unequal time cross correlation of two tagged particles. For all three models, we observe that the mean squared displacement undergoes a crossover from the super-diffusive $\sim t^μ$ scaling for $t \ll τ_A$ ($τ_A$ being the time scale arising due to the activity) to the sub-diffusive $\sim \sqrt{t}$ scaling for $t \gg τ_A$, where $μ= \frac{3}{2}$ for RTP, $μ= \frac{5}{2}$ for AOUP. For the $x$ and $y$-coordinates of ABPs we get $μ=\frac{7}{2}$ and $μ=\frac{5}{2}$ respectively. We show that these crossover behaviours in each case can be described by appropriate crossover function that connects these two scaling regimes. We compute these crossover functions explicitly. In addition, we also find that the equal and unequal time auto and cross correlations obey interesting scaling forms in the appropriate limits of the observation time $t$. The associated scaling functions are rigorously derived in all cases. All our analytical results are well supported by the numerical simulations.
description: 47 pages, 34 figures
Modelling Drosophila Motion Vision Pathways for Decoding the Direction of Translating Objects Against Cluttered Moving Backgrounds
Creators: name: Fu, Qinbing
name: Yue, Shigang
Publisher: name: arXiv
Year: 2020
Subjects: subject: Neurons and Cognition (q-bio.NC)
subject: Neural and Evolutionary Computing (cs.NE)
subject: FOS: Biological sciences
subject: FOS: Computer and information sciences

description: Decoding the direction of translating objects in front of cluttered moving backgrounds, accurately and efficiently, is still a challenging problem. In nature, lightweight and low-powered flying insects apply motion vision to detect a moving target in highly variable environments during flight, which are excellent paradigms to learn motion perception strategies. This paper investigates the fruit fly \textit{Drosophila} motion vision pathways and presents computational modelling based on cutting-edge physiological researches. The proposed visual system model features bio-plausible ON and OFF pathways, wide-field horizontal-sensitive (HS) and vertical-sensitive (VS) systems. The main contributions of this research are on two aspects: 1) the proposed model articulates the forming of both direction-selective (DS) and direction-opponent (DO) responses, revealed as principal features of motion perception neural circuits, in a feed-forward manner; 2) it also shows robust direction selectivity to translating objects in front of cluttered moving backgrounds, via the modelling of spatiotemporal dynamics including combination of motion pre-filtering mechanisms and ensembles of local correlators inside both the ON and OFF pathways, which works effectively to suppress irrelevant background motion or distractors, and to improve the dynamic response. Accordingly, the direction of translating objects is decoded as global responses of both the HS and VS systems with positive or negative output indicating preferred-direction (PD) or null-direction (ND) translation. The experiments have verified the effectiveness of the proposed neural system model, and demonstrated its responsive preference to faster-moving, higher-contrast and larger-size targets embedded in cluttered moving backgrounds.
description: 27 pages, 13 figures, been included in a future issue of the journal of Biological Cybernetics
The thermal equilibrium mass loss model and its applications in binary evolution
Creators: name: Ge, Hongwei
name: Webbink, Ronald F
name: Han, Zhanwen
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Binary evolution is indispensable in stellar evolution to understand the formation and evolution of most peculiar and energetic objects, such as binary compact objects, Type Ia supernovae, X-ray binaries, cataclysmic variables, blue stragglers, hot subdwarfs, and central binaries in planetary nebulae. Mass transfer in binary stars can change the evolutionary path and fate of the corresponding objects relative to what is expected from single stellar evolution. What is the critical mass ratio at which unstable mass transfer occurs is an unsolved fundamental problem in binary evolution. To resolve this issue, we construct the thermal equilibrium mass loss model and derive critical mass ratios for both thermal timescale mass transfer and unstable mass transfer, the latter of which occurs when the outer Lagrangian point, L2, is overfilled. Using several 3.2 Msun stellar models as examples, we study the stellar response to thermal equilibrium mass loss and present the thresholds for thermal timescale mass transfer. We study the possible mass transfer channels of binary systems containing a 3.2 Msun donor star, taking into account thermal timescale mass transfer, unstable mass transfer through L2, and dynamical timescale mass transfer. We repeat this simulation for a grid of donor stars with different masses (from 0.1 to 100 Msun with Z = 0.02) and at different evolutionary stages, and present our results. The results show that unstable mass transfer due to the overfilling of the outer Lagrangian point may also play an essential role in the formation of common envelopes for late red giant branch and asymptotic giant branch donors.
description: Accepted for publication in ApJS; 25 pages, 9 figures, 3 tables, analytic formula for outer Lagrangian radius R_L2/3
Tautness for riemannian foliations on non-compact manifolds
Creators: name: Prieto, J. I. Royo
name: Saralegi-Aranguren, M.
name: Wolak, R.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Differential Geometry (math.DG)
subject: Algebraic Topology (math.AT)
subject: FOS: Mathematics
subject: 57R30

description: For a riemannian foliation $\mathcal{F}$ on a closed manifold $M$, it is known that $\mathcal{F}$ is taut (i.e. the leaves are minimal submanifolds) if and only if the (tautness) class defined by the mean curvature form $κ_μ$ (relatively to a suitable riemannian metric $μ$) is zero. In the transversally orientable case, tautness is equivalent to the non-vanishing of the top basic cohomology group $H^{^{n}}(M/\mathcal{F})$, where $n = \codim \mathcal{F}$. By the Poincaré Duality, this last condition is equivalent to the non-vanishing of the basic twisted cohomology group $H^{^{0}}_{_{κ_μ}}(M/\mathcal{F})$, when $M$ is oriented. When $M$ is not compact, the tautness class is not even defined in general. In this work, we recover the previous study and results for a particular case of riemannian foliations on non compact manifolds: the regular part of a singular riemannian foliation on a compact manifold (CERF).
description: 18 pages
Towards Fair Knowledge Transfer for Imbalanced Domain Adaptation
Creators: name: Jing, Taotao
name: Xu, Bingrong
name: Li, Jingjing
name: Ding, Zhengming
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Domain adaptation (DA) becomes an up-and-coming technique to address the insufficient or no annotation issue by exploiting external source knowledge. Existing DA algorithms mainly focus on practical knowledge transfer through domain alignment. Unfortunately, they ignore the fairness issue when the auxiliary source is extremely imbalanced across different categories, which results in severe under-presented knowledge adaptation of minority source set. To this end, we propose a Towards Fair Knowledge Transfer (TFKT) framework to handle the fairness challenge in imbalanced cross-domain learning. Specifically, a novel cross-domain mixup generation is exploited to augment the minority source set with target information to enhance fairness. Moreover, dual distinct classifiers and cross-domain prototype alignment are developed to seek a more robust classifier boundary and mitigate the domain shift. Such three strategies are formulated into a unified framework to address the fairness issue and domain shift challenge. Extensive experiments over two popular benchmarks have verified the effectiveness of our proposed model by comparing to existing state-of-the-art DA models, and especially our model significantly improves over 20% on two benchmarks in terms of the overall accuracy.
The reaction e+e- --> e+e-pi+pi- and the pion form factor measurements via the radiative return method
Creators: name: Czyz, Henryk
name: Nowak-Kubat, Elzbieta
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The role of the reaction e+e- --> e+ e-pi+pi- in the pion form factor measurements via radiative return method without photon tagging is studied in detail. The analysis is based on the developed Monte Carlo program EKHARA, which ingredients are also presented.
COMPETING AT THE "CUTTING EDGE": OPPORTUNITIES FOR AGRIBUSINESS PARTNERSHIPS AND CO-OPERATION IN THE SOUTHERN AFRICAN REGION
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: 2000
Subjects: Agribusiness

description: What are the opportunities for agricultural business, trade and co-operation in Southern Africa and, in particular, South Africa and Zimbabwe - two of the most significant economies in the SADC region? The competitiveness status of agribusiness - from a global viewpoint - in sixteen food and fibre supply chains in Zimbabwe and South Africa is determined in this study using the Revealed Comparative Advantage method of Balassa. Based on this status, there is potential in certain agro-food chains for supply chain integration and cooperation between agribusinesses in South Africa and Zimbabwe. Such partnerships will improve competitiveness and will allow agribusinesses to compete at the "cutting edge" in the global environment.
Representations of Menger $(2,n)$-semigroups by multiplace functions
Creators: name: Dudek, Wieslaw A.
name: Trokhimenko, Valentin S.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: 20N15; 08N05

description: Investigation of partial multiplace functions by algebraic methods plays an important role in modern mathematics were we consider various operations on sets of functions, which are naturally defined. The basic operation for $n$-place functions is an $(n+1)$-ary superposition $[ ]$, but there are some other naturally defined operations, which are also worth of consideration. In this paper we consider binary Mann's compositions $\op{1},...,\op{n}$ for partial $n$-place functions, which have many important applications for the study of binary and $n$-ary operations. We present methods of representations of such algebras by $n$-place functions and find an abstract characterization of the set of $n$-place functions closed with respect to the set-theoretic inclusion.
A Theory of 'Auction as a Search' in speculative markets
Creators: name: Pani, Sudhanshu
Publisher: name: arXiv
Year: 2020
Subjects: subject: Trading and Market Microstructure (q-fin.TR)
subject: FOS: Economics and business

description: The tatonnement process in high frequency order driven markets is modeled as a search by buyers for sellers and vice-versa. We propose a total order book model, comprising limit orders and latent orders, in the absence of a market maker. A zero intelligence approach of agents is employed using a diffusion-drift-reaction model, to explain the trading through continuous auctions (price and volume). The search (levy or brownian) for transaction price is the primary diffusion mechanism with other behavioural dynamics in the model inspired from foraging, chemotaxis and robotic search. Analytic and asymptotic analysis is provided for several scenarios and examples. Numerical simulation of the model extends our understanding of the relative performance between brownian, superdiffusive and ballistic search in the model.
Supermassive Black Holes in Elliptical Galaxies: Switching from Very Bright to Very Dim
Creators: name: Churazov, E.
name: Sazonov, S.
name: Sunyaev, R.
name: Forman, W.
name: Jones, C.
name: Boehringer, H.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Relativistic outflows (mainly observed in the radio) are a characteristic feature of both Galactic stellar mass black holes and supermassive black holes (SMBHs). Simultaneous radio and X-ray observations of Galactic sources have shown that the outflow is strong at low accretion rates, but it weakens dramatically or disappears completely at high accretion rates, manifesting structural changes in the accretion flow. It is reasonable to assume that SMBHs follow the same trend. For low luminosity SMBHs in nearby elliptical galaxies and clusters, recent observations strongly suggest that the outflows play the central role in keeping the gas hot (mechanical feedback). If the outflow is quenched in SMBHs at high accretion rates similarly to the behavior of galactic sources, then the straightforward consequence is a relatively weak feedback of rapidly accreting SMBHs. We argue that elliptical galaxies and their central engines should then evolve through two stages. Early on, the central SMBH rapidly grows by accreting cooling gas at a near-Eddington rate with high radiative efficiency but with weak feedback on the infalling gas. This stage terminates when the black hole has grown to a sufficiently large mass that its feedback (radiative and/or mechanical), despite the low gas heating efficiency, is able to suppress gas cooling. After that the system switches to a stable state corresponding to passively evolving ellipticals, when the accretion rate and radiative efficiency are very low, but the gas heating efficiency is high and energy input from the relativistic outflow keeps the gas hot.
description: MNRAS Letters, accepted, 6 pages, 2 figures
Parity violation in nuclear systems
Creators: name: Desplanques, Bertrand
Publisher: name: arXiv
Year: 2005
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Parity violation in nuclear systems is reviewed. A few ingredients relevant to the description of the parity-violating nucleon-nucleon force in terms of meson exchanges are reminded. Effects in nuclear systems are then considered. They involve pp scattering, some complex nuclei and the deuteron system.
description: 4 pages, to be published in the proceedings of the workshop
TACTO: A Fast, Flexible, and Open-source Simulator for High-Resolution Vision-based Tactile Sensors
Creators: name: Wang, Shaoxiong
name: Lambeta, Mike
name: Chou, Po-Wei
name: Calandra, Roberto
Publisher: name: arXiv
Year: 2020
Subjects: subject: Robotics (cs.RO)
subject: Machine Learning (cs.LG)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: Simulators perform an important role in prototyping, debugging, and benchmarking new advances in robotics and learning for control. Although many physics engines exist, some aspects of the real world are harder than others to simulate. One of the aspects that have so far eluded accurate simulation is touch sensing. To address this gap, we present TACTO - a fast, flexible, and open-source simulator for vision-based tactile sensors. This simulator allows to render realistic high-resolution touch readings at hundreds of frames per second, and can be easily configured to simulate different vision-based tactile sensors, including DIGIT and OmniTact. In this paper, we detail the principles that drove the implementation of TACTO and how they are reflected in its architecture. We demonstrate TACTO on a perceptual task, by learning to predict grasp stability using touch from 1 million grasps, and on a marble manipulation control task. Moreover, we provide a proof-of-concept that TACTO can be successfully used for Sim2Real applications. We believe that TACTO is a step towards the widespread adoption of touch sensing in robotic applications, and to enable machine learning practitioners interested in multi-modal learning and control. TACTO is open-source at https://github.com/facebookresearch/tacto.
description: Accepted to IEEE RAL and ICRA 2022
Soft-core meson-baryon interactions. I. One-hadron-exchange potentials
Creators: name: Polinder, H.
name: Rijken, Th. A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The Nijmegen soft-core model for the pseudoscalar-meson baryon interaction is derived, analogous to the Nijmegen NN and YN models. The interaction Hamiltonians are defined and the resulting amplitudes for one-meson-exchange and one-baryon-exchange in momentum space are given for the general mass case. The partial wave projection is carried through and explicit expressions for the momentum space partial wave meson-baryon potentials are presented.
description: 25 pages, 2 PostScript figures, revtex4, submitted to Phys. Rev. C
LINKING AGRIBUSINESS AND SMALL-SCALE FARMERS IN DEVELOPING COUNTRIES: IS THERE A NEW ROLE FOR CONTRACT FARMING?
Creators: name: Kirsten, Johann F.
name: Sartorius, Kurt
name: Kirsten, Johann F.
name: Sartorius, Kurt
Publisher: name: Unknown
Year: 2002
Subjects: Agribusiness
Farm Management

description: This article examines a new role for contract farming in developing countries in the light of the industrialization of agriculture and the globalization of world markets. A theoretical rationale for contracting in developing countries is developed on the basis of adopting new institutional economic theory for the purpose of matching governance forms to market failure problems and transaction characteristics. The history of contract farming is reviewed, together with the advantages and disadvantages to the various players, for the purpose of developing a list of key success factors, problems and some possible solutions.
INTER-SECTORAL COMPETITION FOR WATER ALLOCATION IN RURAL SOUTH AFRICA: ANALYSING A CASE STUDY THROUGH A STANDARD ENVIRONMENTAL ECONOMICS APPROACH
Creators: name: Farolfi, Stefano
name: Perret, Sylvain R.
name: Farolfi, Stefano
name: Perret, Sylvain R.
Publisher: name: Unknown
Year: 2002
Subjects: Environmental Economics and Policy
Resource /Energy Economics and Policy

description: South Africa has adopted an ambitious new water legislation that promotes equity, sustainability, representativity and economic performance through water management decentralization, new local and regional management institutions, water users' licensing, and the possible emergence of water rights' markets. This paper addresses the diversity of water users and uses that currently exists in rural areas, and especially focuses on the competition for water that may result from such a diversity in a context of water scarcity, and from the diversity of objectives formulated by the public authorities. The paper first briefly describes the current institutional arrangements regarding access to water. It also presents the situation in rural areas where farming communities and the mining sector are interacting on water- and labour-related matters. The paper then presents a case study whereby these two sectors have embarked into a negotiation process on water rights transfer, under the auspices of several public role players. It proposes an analysis of the case study through a standard environmental economics model. The model considers the marginal net private benefit (MNPB) generated by mining activities and the associated marginal returns to water (MRW). The transfer of water from farmers to mines results in a loss in crop production potential by the farmers and the subsequent loss of income and potential for development. Such a loss can be considered the opportunity cost of water for smallholders. If not compensated, it represents a proxy of the externality associated with water transfer. The model first highlights the difference in terms of water productivity in the two sectors, and its consequences if a system of transferable licenses is adopted. Then, some policy options (taxes, standards, subsidies) are tested and discussed.
PROSPECTS FOR RURAL GROWTH? MEASURING GROWTH LINKAGES IN A SOUTH AFRICAN SMALLHOLDER FARMING AREA
Creators: name: Simphiwe, N.
name: Simphiwe, N.
Publisher: name: Unknown
Year: 2001
Subjects: subject: Community/Rural/Urban Development
subject: rural
subject: growth linkages
subject: multipliers
subject: smallholder
subject: South Africa
subject: Africa

description: This paper addresses the possible impact of rising smallholder incomes on local non-agricultural development in a case study area located in the Eastern Cape province of South Africa. It determines how increased rural incomes are spent on a mix of goods and services, and debates the implications of these spending patterns for growth in rural areas through the alleviation of demand constraints. These results make it possible to identify areas of intervention necessary for sustaining growth originating from stimulus to tradable agriculture from economic reforms. This paper thus contributes to an emerging literature on the possible impact of promoting smallholder agriculture in South Africa on rural livelihoods.
The first laws of thermodynamics of the (2+1)-dimensional BTZ black holes and Kerr-de Sitter spacetimes
Creators: name: Shuang, Wang
name: Shuang-Qing, Wu
name: Fei, Xie
name: Lin, Dan
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We investigate the first law of thermodynamics in the case of the (2+1)-dimensional BTZ black holes and Kerr-de Sitter spacetimes, in particular, we focus on the integral mass formulas. It is found that by assuming the cosmological constant as a variable state parameter, both the differential and integral mass formulas of the first law of black hole thermodynamics in the asymptotic flat spacetimes can be directly extended to those of rotating black holes in anti-de Sitter and de Sitter backgrounds. It should be pointed that these formulas come into existence in any dimensions also.
description: 3 pages, no figure, revtex4, references added, to appear in CPL
An improvement of Tusnády's inequality in the bulk
Creators: name: Ouimet, Frédéric
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistics Theory (math.ST)
subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60E15, 62E17, 62E20, 60F99

description: We prove a non-asymptotic generalization of the refined continuity correction developed in Cressie (1978) for the Binomial distribution, which we then use to improve the versions of Tusnády's inequality from Massart (2002) and Carter & Pollard (2004) in the bulk.
description: 18 pages, 1 figure
Bi-large Neutrino Mixing and CP violation in an SO(10) SUSY GUT for Fermion Masses
Creators: name: Dermisek, Radovan
name: Raby, Stuart
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We construct a simple SO(10) SUSY GUT with $D_3$ family symmetry and low energy R parity. The model describes fermion mass matrices with 14 parameters and gives excellent fits to 20 observable masses and mixing angles in both quark and lepton sectors, giving 6 predictions. Bi-large neutrino mixing is obtained with hierarchical quark and lepton Yukawa matrices; thus avoiding the possibility of large lepton flavor violation. The model naturally predicts small 1-3 neutrino mixing, $\sin θ_{13} \simeq 0.05$, and a CP violating phase $δ$ close to $π/2$. Among other interesting predictions is a tiny effective Majorana mass for neutrinoless double-beta decay. Leptogenesis is also possible with the decay of the lightest right-handed neutrino giving an acceptable CP violating asymmetry $ε_1$ of order $10^{-6}$, {\em and with the correct sign for the resultant baryon asymmetry}. We also show how similar models with the non-abelian symmetry groups SU(2) or $D_4$, instead of $D_3$, can be constructed.
description: 16 pages, resubmitted as a PLB letter, appendices were removed
ANALYSING THE LOW ADOPTION OF WATER CONSERVATION TECHNOLOGIES BY SMALLHOLDER FARMERS IN SOUTHERN AFRICA
Creators: name: Perret, Sylvain R.
name: Stevens, Joe B.
name: Perret, Sylvain R.
name: Stevens, Joe B.
Publisher: name: Unknown
Year: 2003
Subjects: subject: Resource /Energy Economics and Policy
subject: adoption
subject: innovation
subject: water conservation
subject: technologies
subject: collective action
subject: property rights
subject: sustainability
subject: livelihoods

description: Natural resource degradation and water scarcity are a global concern, which typically threatens the sustainability of smallholder farmers' livelihoods in semi-arid developing areas. As part of research efforts, a number of water-conservation technologies (WCT) have been developed, yet with low adoption rates in smallholder farming environments. This paper discusses the concepts of adoption and innovation, comparing the perspectives of research operators to the ones of smallholder farmers. Discrepancies are highlighted and ultimately explain low uptake of technologies by farmer. Then it addresses socio-economic factors affecting such adoption. It is argued that WCT show specific traits: (1) diversity and applicability to different time and spatial scales; (2) hence, the dependency upon a context. These traits influence dissemination and adoption of WCT, and should not be ignored, from the early stage of technology development. It is shown that adoption does not only depend on individual farmers willingness, but also upon the role of property rights on resources, and collective action at community level. Other specific issues and factors like the demand for WCT, the role of public sector and research, and related biases are also discusses. It finally draws some recommendations towards rural livelihoods that are more sustainable. Farmers' participation in technology development, taking account of local indigenous knowledge and sound institutional arrangements are among other the pathways that are suggested towards a better integration of technology development and innovation processes.
Essays on dividend policy
Creators: name: Bhattacharyya, Nalinaksha
Publisher: name: University of British Columbia
Year: 2009

description: This model explains dividend policy as a component of a screening contract set up by an uninformed principal. Our model assumes that the manager wants to maximize his net wealth and the principal recognizes this and sets up a screening contract to utilize the skill of the agent in the productive enterprise.This model deals simultaneously with moral hazard and hidden information. We model hidden information in two ways-hidden information about the productivity of agent and hidden information about the initial cash endowment of the agent. We find that when hidden information is about the productivity of the agent then, contrary to the findings of the dividend models based on the signaling paradigm, dividend - conditional on cash availability - bears an inverse relationship to managerial type. That is, for a given level of available cash, the x lower type manager declares a higher dividend than that declared by a manager with higher productivity. Still this particular model can be used to explain many of the empirical findings obtained by other researchers. An interesting corollary of our model is that with costly effort and differences in productivity, the relationship between dividend and managerial type flips from being monotone increasing to monotone decreasing; this corollary extends the result obtained by Miller and Rock (1985). Another interesting implication of this dissertation is that dividends can be shown to be relevant in the presence of moral hazard and hidden information, even when the agency contract is chosen optimally . When the hidden information is about the initial cash endowment of the agent then however we find that the agent with greater cash endowment declares higher dividend. We can therefore see that the nature of the hidden information plays a critical role in determining the relationship between dividends and agent type. When cash available is common knowledge and the asymmetric information is about the productivity of agent then higher dividend -conditioned on cash availability- is an indication of lower agent type. However when productivity of agent is common knowledge and the asymmetric information is about the initial cash endowment of the-agent then higher dividend is an indication of higher agent type. We may note here that the outcome of the model in the second case is in line with the outcome of the signalling models and the free cash flow conjectures by Easterbrook (1984) and Jensen(1986).
EFFICIENCY ANALYSIS OF SMALL SCALE WOOL PRODUCTION IN THE FORMER TRANSKEI, SOUTH AFRICA
Creators: name: Haese, M.D.
name: Calus, Mieke
name: Kirsten, Johann F.
name: Van Huylenbroeck, Guido
name: Bostyn, F.
name: Haese, M.D.
name: Calus, Mieke
name: Kirsten, Johann F.
name: Van Huylenbroeck, Guido
name: Bostyn, F.
Publisher: name: Unknown
Year: 2001
Subjects: Livestock Production/Industries

description: Specialising in wool production could be a good opportunity for farmers in the former Transkei to upgrade to fully commercial and economic viable enterprises. This paper investigates the efficiency of the current practices of wool producers in three villages. Two of those villages are beneficiaries of the LandCare project of the National Department of Agriculture, and receive help on technical matters and marketing. The analysis shows that in the two villages beneficiary of the Land Care project the technical, allocative and economic efficiency of the wool production is higher than in the third village. In the latter, the technical efficiency of some of the farms is still good, but the difference is made in the marketing of the wool.
Image Analysis Based on Nonnegative/Binary Matrix Factorization
Creators: name: Asaoka, Hinako
name: Kudo, Kazue
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Using nonnegative/binary matrix factorization (NBMF), a matrix can be decomposed into a nonnegative matrix and a binary matrix. Our analysis of facial images, based on NBMF and using the Fujitsu Digital Annealer, leads to successful image reconstruction and image classification. The NBMF algorithm converges in fewer iterations than those required for the convergence of nonnegative matrix factorization (NMF), although both techniques perform comparably in image classification.
description: 3 pages, 1 figure
Dark Energy Condensation
Creators: name: Pietroni, Massimo
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The two most popular candidates for dark energy, i.e. a cosmological constant and quintessence, are very difficult to distinguish observationally, mostly because the quintessence field does not have sizable fluctuations. We study a scalar field model for dark energy in which the scalar field is invariant under reflection symmetry, phi -> -phi. Under general assumptions, there is a phase transition at late times (z < 0.5). Before the phase transition, the field behaves as a cosmological constant. After the phase transition, a time-dependent scalar condensate forms, the field couples with dark matter and develops sizable perturbations tracking those of dark matter. The background cosmological evolution is in agreement with existing observations, but might be distinguished from that of a cosmological constant by future Supernovae surveys. The growth of cosmological perturbations carries the imprint of the phase transition, however a non-linear approach has to be developed in order to study it quantitatively.
description: 6 pages, 7 figures. References added. Discussion on the early evolution of the field added. Matches the version to appear on PRD
Phase Separation and an upper bound for $Δ$ for Fermi fluids in the Phase Separation and an upper bound for $Δ$ for Fermi fluids in the unitary regime
Creators: name: Cohen, Thomas D.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Superconductivity (cond-mat.supr-con)
subject: Nuclear Theory (nucl-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: An upper bound is derived for $Δ$ for a cold dilute fluid of equal amounts of two species of fermion in the unitary regime $k_f a \to \infty$ (where $k_f$ is the Fermi momentum and $a$ the scattering length, and $Δ$ is a pairing energy: the difference in energy per particle between adding to the system a macroscopic number (but infinitesimal fraction) of particles of one species compared to adding equal numbers of both. The bound is $δ\leq {5/3} (2 (2 ξ)^{2/5} - (2 ξ))$ where $ξ=ε/ε_{\rm FG}$, $δ= 2 Δ/ε_{\rm FG}$; $ε$ is the energy per particle and $ε_{\rm FG}$ is the energy per particle of a noninteracting Fermi gas. If the bound is saturated, then systems with unequal densities of the two species will separate spatially into a superfluid phase with equal numbers of the two species and a normal phase with the excess. If the bound is not saturated then $Δ$ is the usual superfluid gap. If the superfluid gap exceeds the maximum allowed by the inequality phase separation occurs.
description: This is the version to be publishd. The notation has been improved to match standard useage. An improved discussion on the implication of the nature of the bound and the physical meaning of the parameter Delta
Enhancement in Thermally Generated Spin Voltage at Pd/NiFe$_2$O$_4$ Interfaces by the Growth on Lattice-Matched Substrates
Creators: name: Rastogi, A.
name: Li, Z.
name: Singh, A. V.
name: Regmi, S.
name: Peters, T.
name: Bougiatioti, P.
name: Meier, D. Carsten né
name: Mohammadi, J. B.
name: Khodadadi, B.
name: Mewes, T.
name: Mishra, R.
name: Gazquez, J.
name: Borisevich, A. Y.
name: Galazka, Z.
name: Uecker, R.
name: Reiss, G.
name: Kuschel, T.
name: Gupta, A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Efficient spin injection from epitaxial ferrimagnetic NiFe$_2$O$_4$ thin films into a Pd layer is demonstrated via spin Seebeck effect measurements in the longitudinal geometry. The NiFe$_2$O$_4$ films (60 nm to 1 $μ$m) are grown by pulsed laser deposition on isostructural spinel MgAl$_2$O$_4$, MgGa$_2$O$_4$, and CoGa$_2$O$_4$ substrates with lattice mismatch varying between 3.2% and 0.2%. For the thinner films ($\leq$ 330 nm), an increase in the spin Seebeck voltage is observed with decreasing lattice mismatch, which correlates well with a decrease in the Gilbert damping parameter as determined from ferromagnetic resonance measurements. High resolution transmission electron microscopy studies indicate substantial decrease of antiphase boundary and interface defects that cause strain-relaxation, i.e., misfit dislocations, in the films with decreasing lattice mismatch. This highlights the importance of reducing structural defects in spinel ferrites for efficient spin injection. It is further shown that angle-dependent spin Seebeck effect measurements provide a qualitative method to probe for in-plane magnetic anisotropies present in the films.
description: 18 pages, 6 figures