cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
THE ROLE OF SMALL RICE MILLS IN THE RICE SUBSECTOR OF THE OFFICE DU NIGER, MALI
Creators: name: Diarra, Salifou Bakary
name: Diarra, Salifou Bakary
Publisher: name: Unknown
Year: 1994
Subjects: Crop Production/Industries

description: The presence of the small rice mills in the Office du Niger zone has changed the structure of the rice subsector, helping to reduce concentration and changing marketing options of both farmers and retailers. Current proposals call for major initiative to liberalize the rice market further and to shift the principal role of the O.N. toward provision of water and extension. In this context, it is extremely important to investigate the role of small mills in the subsector, their relative costs, and the segments of the market they serve. Budgeting techniques were used to analyze milling cost data. Price data were used to calculate both correlation coefficients and spatial marketing margins. The analyses of correlation and calculation of spatial margins provided indications on the performance of rice subsector in the Office du Niger zone. The financial analyses revealed that the own-mill-sell or buy-mill-sell activity is far more profitable than the custom milling. Moreover, the analyses suggests that most of the millers sampled would be willing to buy paddy at a higher price than the O.N. support price of CFAF 70 per kg.
Tango for three: Sagittarius, LMC, and the Milky Way
Creators: name: Vasiliev, Eugene
name: Belokurov, Vasily
name: Erkal, Denis
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We assemble a catalogue of candidate Sagittarius stream members with 5d and 6d phase-space information, using astrometric data from Gaia DR2, distances estimated from RR Lyrae stars, and line-of-sight velocities from various spectroscopic surveys. We find a clear misalignment between the stream track and the direction of the reflex-corrected proper motions in the leading arm of the stream, which we interpret as a signature of a time-dependent perturbation of the gravitational potential. A likely cause of this perturbation is the recent passage of the most massive Milky Way satellite - the Large Magellanic Cloud (LMC). We develop novel methods for simulating the Sagittarius stream in the presence of the LMC, using specially tailored N-body simulations and a flexible parametrization of the Milky Way halo density profile. We find that while models without the LMC can fit most stream features rather well, they fail to reproduce the misalignment and overestimate the distance to the leading arm apocentre. On the other hand, models with an LMC mass in the range (1.3+-0.3)x10^11 Msun rectify these deficiencies. We demonstrate that the stream can not be modelled adequately in a static Milky Way. Instead, our Galaxy is required to lurch toward the massive in-falling Cloud, giving the Sgr stream its peculiar shape and kinematics. By exploring the parameter space of Milky Way potentials, we determine the enclosed mass within 100 kpc to be (5.6+-0.4)x10^11 Msun, and the virial mass to be (9.0+-1.3)x10^11 Msun, and find tentative evidence for a radially-varying shape and orientation of the Galactic halo.
description: matches published version
Covariant Irreducible Parametrization of Electromagnetic Fields in Arbitrary Spacetime
Creators: name: Sundkvist, David
Publisher: name: arXiv
Year: 2005
Subjects: subject: Classical Physics (physics.class-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We present a new unified covariant description of electromagnetic field properties for an arbitrary space-time. We derive a complete set of irreducible components describing a six-dimensional electromagnetic field from the Maxwell and metric tensors using the symmetry group SL(2,C). For the special case of a flat space-time metric the components are shown to correspond to the scalar invariants of the electromagnetic field, the energy-momentum-stress tensor and in addition, three new tensors expressing physical observables of rank two and four, respectively. We make a physical interpretation of one of the new rank two tensors as describing a classical intrinsic spin of the electromagnetic field.
description: 11 pages, no figures, Will appear in J. Math. Phys., January (2006)
THE DEMAND FOR FOOD IN EGYPT: PROBLEMS AND PROSPECTS
Creators: name: Elnaggar, Salah Y.
name: Elnaggar, Salah Y.
Publisher: name: Unknown
Year: 1974
Subjects: Demand and Price Analysis
Food Consumption/Nutrition/Food Safety

description: In recent years, Egypt has had a very precarious food situation because of limited cultivated area. Effective demand for food is outrunning the available supply. A high population growth rate together with rapid social change and mass movement of labor contribute to the severe food shortages. As the income per capita increases, and the other factors of production continue to shift from rural to urban areas, prices for food are increasing causing obstacles for the economic growth. This study has focused on the problem of the demand for food, and the economic relationship between the demand for food on the one hand and population growth and per capita income on the other. Also discussed is the possibility of increasing the supply of food to meet the large increasing demand, which must be fulfilled through increasing food production, increasing food imports or some combination of the two.
WHAT CAN WE INFER ABOUT FARM-LEVEL CROP YIELD PDF's FROM COUNTY-LEVEL PDF's?
Creators: name: Xu, Zhiying
name: Xu, Zhiying
Publisher: name: Unknown
Year: 2004
Subjects: Crop Production/Industries

description: Accurate estimates of farm-level crop yield probability density functions (PDF's) are crucial for studying various crop insurance programs and production under risk and uncertainty. Unfortunately, farm-level crop yield PDF's are difficult to estimate due to the lack of sufficient farm yield data. County yield data cover much longer time periods than farm yield data, but using county yield distributions to conjecture about farm yield distributions is dangerous. The theoretical reason is that county yield is the average of correlated farm yields, for which there is no recognizable probability density function (PDF). This paper investigates the relationship between farm and county yield distributions using both statistical theory and the Monte-Carlo simulation method. Results show that under suitable farm yield correlation and density structures, the shape of yield distribution at the farm level is similar to that at the county level. A method is then developed for estimating and simulating farm yield distributions based on county yield PDF estimates and information contained in farm yield data. Six candidate yield models: normal, beta, Weibull, inverse hyperbolic sine transformation, a mixture of normals, and kernel density estimators are applied to Branch County corn yields after detrending nonstationary yield data. Goodness-of-fit results for normal, beta and Weibull distributions show that Weibull best fits county yields. The method for simulating farm yields is illustrated using kernel density estimates.
Extending Gravitational Wave Extraction Using Weyl Characteristic Fields
Creators: name: Iozzo, Dante A. B.
name: Boyle, Michael
name: Deppe, Nils
name: Moxon, Jordan
name: Scheel, Mark A.
name: Kidder, Lawrence E.
name: Pfeiffer, Harald P.
name: Teukolsky, Saul A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We present a detailed methodology for extracting the full set of Newman-Penrose Weyl scalars from numerically generated spacetimes without requiring a tetrad that is completely orthonormal or perfectly aligned to the principal null directions. We also describe how to implement an extrapolation technique for computing the Weyl scalars' contribution at asymptotic null infinity in postprocessing. These methods have been used to produce $Ψ_4$ and $h$ waveforms for the Simulating eXtreme Spacetimes (SXS) waveform catalog and now have been expanded to produce the entire set of Weyl scalars. These new waveform quantities are critical for the future of gravitational wave astronomy in order to understand the finite-amplitude gauge differences that can occur in numerical waveforms. We also present a new analysis of the accuracy of waveforms produced by the Spectral Einstein Code. While ultimately we expect Cauchy characteristic extraction to yield more accurate waveforms, the extraction techniques described here are far easier to implement and have already proven to be a viable way to produce production-level waveforms that can meet the demands of current gravitational-wave detectors.
description: 18 pages, 6 figures, 1 table, published in Physical Review D
Suggested magnetic braking prescription derived from field complexity fails to reproduce the cataclysmic variable orbital period gap
Creators: name: Ortúzar-Garzón, Valentina
name: Schreiber, Matthias R.
name: Belloni, Diogo
Publisher: name: arXiv
Year: 2024
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Magnetic wind braking drives the spin-down of low-mass stars and the evolution of most interacting binary stars. A magnetic braking prescription that was claimed to reproduce both the period distribution of cataclysmic variables (CVs) and the evolution of the rotation rates of low-mass stars is based on a relation between the angular momentum loss rate and magnetic field complexity. The magnetic braking model based on field complexity has been claimed to predict a detached phase that could explain the observed period gap in the period distribution of CVs but has never been tested in detailed models of CV evolution. Here we fill this gap. We incorporated the suggested magnetic braking law in MESA and simulated the evolution of CVs for different initial stellar masses and initial orbital periods. We find that the prescription for magnetic braking based on field complexity fails to reproduce observations of CVs. The predicted secondary star radii are smaller than measured, and an extended detached phase that is required to explain the observed period gap (a dearth of non-magnetic CVs with periods between ${\sim}2$ and ${\sim}3$ hours) is not predicted. Proposed magnetic braking prescriptions based on a relation between the angular momentum loss rate and field complexity are too weak to reproduce the bloating of donor stars in CVs derived from observations and, in contrast to previous claims, do not provide an explanation for the observed period gap. The suggested steep decrease in the angular momentum loss rate does not lead to detachment. Stronger magnetic braking prescriptions and a discontinuity at the fully convective boundary are needed to explain the evolution of close binary stars that contain compact objects. The tension between braking laws derived from the spin-down of single stars and those required to explain CVs and other close binaries containing compact objects remains.
description: 5 pages, 4 figures
Dispersion managed mode-locking dynamics in a Ti:Sapphire laser
Creators: name: Tognetti, Marco V.
name: Crespo, Helder M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We present what is to our knowledge the most complete 1-D numerical analysis of the evolution and the propagation dynamics of an ultrashort laser pulse in a Ti:Sapphire laser oscillator. This study confirms the dispersion managed model of mode-locking, and emphasizes the role of the Kerr nonlinearity in generating mode-locked spectra with a smooth and well-behaved spectral phase. A very good agreement with preliminary experimental measurements is found.
description: 11 pages, 4 figures, submitted to Optics Letters
Rheological Response of Asphalts
Creators: name: Allen, David L.
Publisher: name: Kentucky Transportation Center, University of Kentucky
Year: 1972
Subjects: subject: Transportation Engineering

description: The rheological response of asphalt cements to shearing stresses is presented. The behavioral characteristics were measured using a rotating coaxial cylinder viscometer. Little or no development of theory is presented.  The viscoelastic portion of deformation is discussed in terms of the creep function. Plastic deformation is described using the definitions of apparent and plastic viscosities. Curves showing the effects of temperature, stress level and penetration on these two major components of strain are presented and discussed. Analysis indicated that plastic deformation is the predominant component of strain and, thus, should be considered and incorporated in the design of flexible pavements.
PHENIX experimental overview
Creators: name: McGlinchey, Darren
Publisher: name: Zenodo
Year: 2021
Subjects: qm17
phenix
p+p
p+al
p+au
d+au
3he+au
cu+cu
cu+au
au+au
u+u
small systems
flow
correlations
cumulant
hadron
J/Ψ
π0
direct photon
thermal photon
jet
nuclear
modification
raa
η
heavy flavor
quarkonia
dielectron
charm
bottom
b-meson

description: Plenary overview talk presented at the Quark Matter 2017 conference
Weak gravity versus de Sitter
Creators: name: Cribiori, N.
name: Dall'Agata, G.
name: Farakos, F.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We show that one can uncover a Dine-Seiberg problem for de Sitter critical points in supergravity theories by utilizing the magnetic weak gravity conjecture. We present a large variety of N=2 gauged supergravity models that include vector multiplets and in all cases we find that the weak gravity conjecture threatens de Sitter. A common feature in all such examples is a degenerate mass matrix for the gravitini, which we therefore deem a swampland criterion for de Sitter critical points.
description: 29 pages. v2: minor corrections and references added. Published on JHEP
Random sets of isomorphism of linear operators on Hilbert space
Creators: name: Vershynin, Roman
Publisher: name: arXiv
Year: 2006
Subjects: subject: Functional Analysis (math.FA)
subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 46B09, 47D25 (Primary)

description: This note deals with a problem of the probabilistic Ramsey theory in functional analysis. Given a linear operator $T$ on a Hilbert space with an orthogonal basis, we define the isomorphic structure $Σ(T)$ as the family of all subsets of the basis so that $T$ restricted to their span is a nice isomorphism. Our main result is a dimension-free optimal estimate of the size of $Σ(T)$. It improves and extends in several ways the principle of restricted invertibility due to Bourgain and Tzafriri. With an appropriate notion of randomness, we obtain a randomized principle of restricted invertibility.
description: Published at http://dx.doi.org/10.1214/074921706000000815 in the IMS Lecture Notes Monograph Series (http://www.imstat.org/publications/lecnotes.htm) by the Institute of Mathematical Statistics (http://www.imstat.org)
Obermann, H. A. / Ritter, A. M. / Krumwieder, H. W.: Kirchen- und Theologiegeschichte in Quellen ...
Creators: name: Gassmann, Günther
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 30 Nr. 2 (1981): Ökumenische Rundschau, Band 30, Heft 2
The role of cell surface architecture in the HSV-1 lifecycle and in HA binding ability of CD44
Creators: name: Esford, Lesley E.
Publisher: name: University of British Columbia
Year: 2009

description: HSV-1 resistant cell lines derived from murine fibroblast L cells were isolated and found to have various cell surface alterations resulting from abnormal processing of glycosaminoglycans and oligosaccharides. These cell lines are relatively resistant to infection because heparan sulfate, a ubiquitous glycosaminoglycan, is absent in these mutant cells, and HSV uses heparan sulfate as an initial attachment receptor to initiate infection. One such mutant, sog8, harbors defects in both N-glycosylation and glycosaminoglycan synthesis. Surprisingly, sog8 cells were more susceptible to HSV infection than sog9 cells, which are only defective in heparan sulfate biosynthesis. This suggests that the display of cell surface N-linked glycans plays a role in viral infection. Sog8 cells were also completely unable to support HSV egress. Taken together, these results are consistent with the hypothesis that defects in sog8 cells may alter fusion between viral and cellular membranes at multiple stages of the virus life cycle. These mutant cell lines were also used to investigate the ligand binding requirements for an important cell surface adhesion molecule, CD44, which binds hyaluronan. On the basis of the known properties of several cell lines with defects in glycosylation and glycosaminoglycan synthesis, I determined that chondroitin sulfate biosynthesis is required for inducible hyaluronan binding by CD44. Moreover, in the absence of fully processed oligosaccharides, chondroitin sulfate is not essential for hyaluronan binding, indicating that the effect of chondroitin sulfate depends upon the glycosylation state of the cell. I also investigated the expression of a putative tumour suppressor gene, EXT-1 in sog9 cells. Our laboratory determined that EXT-1 encodes a heparan sulfate polymerase enzyme that restores expression of cell surface heparan sulfate in sog9 cells. As expected, EXT-1 expression also rescues HSV infection of sog9 cells. I characterized the initial interaction of HSV with these cells in an attempt to identify the specific heparan sulfate proteoglycans with which HSV interacts. I identified at least three polypeptides that were recognized by the virus. Further characterization of these proteins will be necessary to determine their potential function.
Evidence for fine tuning of fermionic modes in lattice gluodynamics
Creators: name: Gubarev, F. V.
name: Morozov, S. M.
name: Polikarpov, M. I.
name: Zakharov, V. I.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We consider properties of zero and near-zero fermionic modes in lattice gluodynamics. The modes are known to be sensitive to the topology of the underlying gluonic fields in the quantum vacuum state of the gluodynamics. We find evidence that these modes are fine tuned, that is exhibit sensitivity to both physical (one can say, hadronic) scale and to the ultraviolet cutoff. Namely, the density of the states is in physical units while the localization volume of the modes tends to zero in physical units with the lattice spacing tending to zero. We discuss briefly possible theoretical implications and also include some general, review-type remarks.
description: 7 pages, 7 eps figures, uses JETP Letters style (included); substantial stylistic changes, discussions added, conclusions unchanged. Supplementary materials and computer animations are available at http://lattice.itep.ru/overlap
Surface roughness effects in a transonic axial flow compressor operating at near-stall conditions
Creators: name: Godse, Prashant B.
name: Akolekar, Harshal D.
name: Pradeep, A. M.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Surface roughness is a major contributor to performance degradation in gas turbine engines. The fan and the compressor, as the first components in the engine's air path, are especially vulnerable to the effects of surface roughness. Debris ingestion, accumulation of grime, dust, or insect remnants, typically at low atmospheric conditions, over several cycles of operation are some major causes of surface roughness over the blade surfaces. The flow in compressor rotors is inherently highly complex. From the perspective of the component designers, it is thus important to study the effect of surface roughness on the performance and flow physics, especially at near-stall conditions. In this study, we examine the effect of surface roughness on flow physics such as shock-boundary layer interactions, tip and hub flow separations, the formation and changes in the critical points, and tip leakage vortices amongst other phenomena. Steady and unsteady Reynolds Averaged Navier Stokes (RANS) calculations are conducted at near-stall conditions for smooth and rough NASA (National Aeronautics and Space Administration) rotor 67 blades. Surface streamlines, Q-criterion, and entropy contours aid in analyzing the flow physics qualitatively and quantitatively. It is observed that from the onset of stall, to fully stalled conditions, the blockage varies from 21.7\% to 59.6\% from 90\% span to the tip in the smooth case, and from 40.5\% to 75.2\% in the rough case. This significant blockage, caused by vortex breakdown and chaotic flow structures, leads to the onset of full rotor stall.
Foreigners and the City: An Historiographical Exploration for the Early Modern Period
Creators: name: Calabi, Donatella
name: Calabi, Donatella
Publisher: name: Unknown
Year: 2006
Subjects: Labor and Human Capital

description: This paper will focus on the physical traces left by different minorities in the European city of the early modern age. Looking to the urban context in the main important ports and commercial centers we can find violent conflicts, traditional uses, as well as new urban strategies by the governors to keep together (for economic and social purposes) city-dwellers and foreigners. The invention of specific buildings and the effect on the architectural language is often quite visible and a mean of cultural exchanges.
Top, Higgs, Diboson and Electroweak Fit to the Standard Model Effective Field Theory
Creators: name: Ellis, John
name: Madigan, Maeve
name: Mimasu, Ken
name: Sanz, Veronica
name: You, Tevong
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The search for effective field theory deformations of the Standard Model (SM) is a major goal of particle physics that can benefit from a global approach in the framework of the Standard Model Effective Field Theory (SMEFT). For the first time, we include LHC data on top production and differential distributions together with Higgs production and decay rates and Simplified Template Cross-Section (STXS) measurements in a global fit, as well as precision electroweak and diboson measurements from LEP and the LHC, in a global analysis with SMEFT operators of dimension 6 included linearly. We present the constraints on the coefficients of these operators, both individually and when marginalised, in flavour-universal and top-specific scenarios, studying the interplay of these datasets and the correlations they induce in the SMEFT. We then explore the constraints that our linear SMEFT analysis imposes on specific ultra-violet completions of the Standard Model, including those with single additional fields and low-mass stop squarks. We also present a model-independent search for deformations of the SM that contribute to between two and five SMEFT operator coefficients. In no case do we find any significant evidence for physics beyond the SM. Our underlying $\tt{Fitmaker}$ public code provides a framework for future generalisations of our analysis, including a quadratic treatment of dimension-6 operators.
description: 80 pages, 21 Figures. v3: Extended and clarified discussions, added WZ and ttbar+gamma measurements to the fit and minor typos in predictions fixed. Version accepted for publication in JHEP
Passed the Turing Test: Living in Turing Futures
Creators: name: Gonçalves, Bernardo
Publisher: name: arXiv
Year: 2024
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences

description: The world has seen the emergence of machines based on pretrained models, transformers, also known as generative artificial intelligences for their ability to produce various types of content, including text, images, audio, and synthetic data. Without resorting to preprogramming or special tricks, their intelligence grows as they learn from experience, and to ordinary people, they can appear human-like in conversation. This means that they can pass the Turing test, and that we are now living in one of many possible Turing futures where machines can pass for what they are not. However, the learning machines that Turing imagined would pass his imitation tests were machines inspired by the natural development of the low-energy human cortex. They would be raised like human children and naturally learn the ability to deceive an observer. These ``child machines,'' Turing hoped, would be powerful enough to have an impact on society and nature.
description: Author's version. Forthcoming in Intelligent Computing, a Science Partner Journal published in affiliation with Zhejiang Lab (https://spj.science.org/journal/icomputing). First submitted 19 Feb 2024. Revised 16 Jul 2024. Accepted 15 Aug 2024
Spectral and scattering properties of quantum walks on homogenous trees of odd degree
Creators: name: de Aldecoa, Rafael Tiedra
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mathematical Physics (math-ph)
subject: Functional Analysis (math.FA)
subject: Spectral Theory (math.SP)
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: 47A10, 47A40, 81Q10, 81Q12

description: For unitary operators $U_0,U$ in Hilbert spaces ${\mathcal H}_0,{\mathcal H}$ and identification operator $J:{\mathcal H}_0\to{\mathcal H}$, we present results on the derivation of a Mourre estimate for $U$ starting from a Mourre estimate for $U_0$ and on the existence and completeness of the wave operators for the triple $(U,U_0,J)$. As an application, we determine spectral and scattering properties of a class of anisotropic quantum walks on homogenous trees of odd degree with evolution operator $U$. In particular, we establish a Mourre estimate for $U$, obtain a class of locally $U$-smooth operators, and prove that the spectrum of $U$ covers the whole unit circle and is purely absolutely continuous, outside possibly a finite set where $U$ may have eigenvalues of finite multiplicity. We also show that (at least) three different choices of free evolution operators $U_0$ are possible for the proof of the existence and completeness of the wave operators.
description: Revised version (with new title and more general results) to appear in Annales Henri Poincar\'e
Dissipation of Knowledge and the Boundaries of the Multinational Enterprise
Creators: name: Gattai, Valeria
name: Molteni, Corrado
name: Gattai, Valeria
name: Molteni, Corrado
Publisher: name: Unknown
Year: 2005
Subjects: International Relations/Trade

description: This paper provides a theoretical formalisation of the joint-venture contract, as an alternative to Foreign Direct Investment (FDI), within a Dissipation of Intangible Assets framework. In a two-period model, we discuss how the threat of knowledge spillover shapes the boundaries of a Multinational Enterprise. Similarly to the theoretical findings on the FDI-licensing trade off, we show that the integrated solution is more likely to emerge when know-how easily spills over - i.e. when firms are endowed with more Intangible Assets or they belong to high tech industries. Probit estimates, from a new firm-level dataset, show that Japanese manufacturing operations in Europe are in line with these predictions.
The Inside Story: Quasilocal Tachyons and Black Holes
Creators: name: Horowitz, Gary T.
name: Silverstein, Eva
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We analyze the fate of excitations in regions of closed string tachyon condensate, a question crucial for understanding unitarity in a class of black holes in string theory. First we introduce a simple new example of {\it quasilocal} tachyon condensation in a globally stable AdS/CFT background, and review tachyons' appearance in black hole physics. Then we calculate forces on particles and fields in a tachyon phase using a field theoretic model with spatially localized exponentially growing time dependent masses. This model reveals two features, both supporting unitary evolution in the bulk of spacetime. First, the growing energy of fields sourced by sets of (real and virtual) particles in the tachyon phase yields outward forces on them, leaving behind only combinations which do not source any fields. Secondly, requiring the consistency of perturbative string theory imposes cancellation of a BRST anomaly, which also yields a restricted set of states. Each of these effects supports the notion of a black hole final state arising from string-theoretic dynamics replacing the black hole singularity.
description: 32 pages, harvmac big, 2 figures
Trans-ethyl methyl ether in space - A new look at a complex molecule in selected hot core regions
Creators: name: Fuchs, G. W.
name: Fuchs, U.
name: Giesen, T. F.
name: Wyrowski, F.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: An extensive search for the complex molecule trans-ethyl methyl ether towards several hot core regions has been performed. Using the IRAM 30m telescope and the SEST 15m we looked at several frequencies where trans-ethyl methyl ether has strong transitions, as well as lines which are particularly sensitive to the physical conditions in which the molecule can be found. We included G34.26, NGC6334(I), Orion KL, and W51e2 which have previously been proven to have a rich chemistry of complex molecules. Our observations cannot confirm the tentative Orion KL detection made by Charnley et al. (2001) within their stated column density limits, but we confirm the existence of the trans-ethyl methyl ether towards W51e2 with a column density of 2x10^14 cm-2. The dimethyl ether/methanol ratio of 0.6 as well as the newly found ethyl methyl ether/ethanol ratio of 0.13 indicate relative high abundances of ethers toward W51e2. Furthermore, the observation of ethyl methyl ether also confirms the importance of ethanol as a grain mantle constituent. We present new upper limits of around 8x10^13 cm-2 for the column densities of the molecule toward Orion KL, G34.26, NGC6334(I) and estimate the column density towards SgrB2(N) to be of the same order. The W51e2 observations are discussed in more detail.
description: accepted by A&A
Ab initio study of spin-dependent transport in carbon nanotubes with iron and vanadium adatoms
Creators: name: Fürst, Joachim A.
name: Brandbyge, Mads
name: Jauho, Antti-Pekka
name: Stokbro, Kurt
Publisher: name: arXiv
Year: 2008
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We present an ab initio study of spin dependent transport in armchair carbon nanotubes with transition metal adsorbates, iron or vanadium. We neglect the effect of tube curvature and model the nanotube by graphene with periodic boundary conditions. A density functional theory based nonequilibrium Green's function method is used to compute the electronic structure and zero-bias conductance. The presence of the adsorbate causes a strong scattering of electrons of one spin type only. The scattering is shown to be due to coupling of the two armchair band states to the metal 3d orbitals with matching symmetry causing Fano resonances appearing as dips in the transmission function. The spin type (majority/minority) being scattered depends on the adsorbate and is explained in terms of d-state filling. The results are qualitatively reproduced using a simple tight-binding model, which is then used to investigate the dependence of the transmission on the nanotube width. We find a decrease in the width of the transmission dip as the tube-size increases.
description: 7 pages, 7 figures
Spin entanglement via STM current
Creators: name: Horovitz, Baruch
name: Henkel, Carsten
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We consider a system of two spins under a scanning tunneling microscope bias and derive its master equation. We find that the tunneling elements to the electronic contacts (tip and substrate) generate an exchange interaction between the spins, as well as a Dzyaloshinskii-Moriya interaction in the presence of spin-orbit coupling. The tunnel current spectrum then shows additional lines compared to conventional spin resonance experiments. When the spins have degenerate Larmor frequencies and equal tunneling amplitudes (without spin-orbit), there is a dark state with vanishing decay rate. The coupling to the electronic environment generates significant spin-spin entanglement via the dark state, even if the initial state is non-entangled.
description: 5 pages, 3 figures + 20 pages, 4 figures supplementary
Constructing thermodynamically consistent models with a non-ideal equation of state
Creators: name: Tuzel, Erkan
name: Ihle, Thomas
name: Kroll, Daniel M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: A recently introduced particle-based model for fluid dynamics with continuous velocities is generalized to model fluids with excluded volume effects. This is achieved through the use of biased stochastic multi-particle collisions which depend on local velocities and densities and conserve momentum and kinetic energy. The equation of state is derived and criteria for the correct choice of collision probabilities are discussed. In particular, it is shown how a naive implementation can lead to inconsistent density fluctuations.
description: 6 pages including 4 figures
Space Vs. Networks in the Geography of Innovation: A European Analysis
Creators: name: Nosvelli, Mario
name: Maggioni, Mario A.
name: Uberti, Teodora Erika
name: Nosvelli, Mario
name: Maggioni, Mario A.
name: Uberti, Teodora Erika
Publisher: name: Unknown
Year: 2006
Subjects: Research and Development/Tech Change/Emerging Technologies

description: In the last fifteen years, income differences among European Member States have been strongly narrowing while the process has been matched with a widening of the inter-regional variance within single countries. Traditionally, regional economic disparities in Europe have been ascribed to peripherality and/or to a high level of dependence on declining sectors. Nowadays regional disparities can be no longer defined only in terms of statistical differences in the values of standard macroeconomic indicators, but also according to innovative capacities and knowledge endowment. This paper provides an original framework for the interpretation of the existing relationships between innovation process and research activity in Europe and the structural and geographical features shaping the European scientific and technological map. In order to do so, we focus on two knowledge-based relational phenomena: participation in the same research networks (funded by the EU Fifth Framework Programme) and EPO co-patent applications. Using two complementary econometric techniques we try to assess those factors that determine patenting activity, distinguishing structural features, geographical and relational spillovers. Through these variables we measure the intrinsic relational structure of knowledge flows which directly connects people, institutions and, indirectly, regions, across European countries in order to test whether hierarchical relationships based on a-spatial networks between geographically distant excellence centres prevail over diffusive patterns based on spatial contiguity.
Social Capital, Public Spending and the Quality of Economic Development: The Case of Italy
Creators: name: Sabatini, Fabio
name: Sabatini, Fabio
Publisher: name: Unknown
Year: 2006
Subjects: Community/Rural/Urban Development
Public Economics

description: This paper carries out an empirical assessment of the relationship between social capital and the quality of economic development in Italy. The analysis draws on a dataset collected by the author including about two hundred variables representing different aspects of economic development and four 'structural' dimensions of social capital. The quality of development is measured through human development and indicators of the state of health of urban ecosystems, public services, gender equality, and labour markets, while social capital is measured through synthetic indicators representing strong family ties, weak informal ties, voluntary organizations, and political participation. The quality of development exhibits a strong positive correlation with bridging weak ties and a negative correlation with strong family ties. Particularly, the analysis shows a strong correlation between informal ties and an indicator of "social well-being" (synthesizing gender equality, public services and labour markets) and between voluntary organizations and the state of health of urban ecosystems. Active political participation proves to be irrelevant in terms of development and well-being. Finally, the role of public spending for education, health care, welfare work, and the environment protection is analysed, revealing a scarce correlation both with social capital and development indicators.
Story of the reef, Sogo, and Vave
Creators: name: Rudolph, Johnny (Soni)
name: Ding, Lydia
name: Drummond, Emily
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2020
Subjects: subject: nkr

description: One .wav audio file and one .eaf ELAN transcription file for three creation narratives. The first describes the creation of the coral reef of Nukuoro Atoll; the second describes the creation of the islets by the ghost Sogo; and the third describes the migration of Polynesian peoples to the atoll, led by Vave.
The Role of Community in Migration Dynamics
Creators: name: Vergalli, Sergio
name: Vergalli, Sergio
Publisher: name: Unknown
Year: 2006
Subjects: Labor and Human Capital

description: In this paper, we present a theoretical model that, implementing the pioneering work of Burda (1995), based on the Real Option Theory, investigates the roots of the migration dynamics. In the model the decision to migrate of each individual depends not only on the wage differential, but also on a U-shaped benefit function of a community of homogeneous ethnic individuals, modelled according to the "theory of clubs". The theoretical results are able to give an explanation to the observable "jumps" in the migration flows and to describe how the trigger for entry can change depending on the dimension of the district. The analysis of the results also sheds light on the dynamics of the districts' development: some possible rigidities in the adjustment of the district dimension, as regards the optimal levels, could magnify the hysteresis process.
Firm's Intangible Assets and Multinational Activity: Joint-Venture Versus FDI
Creators: name: Gattai, Valeria
name: Gattai, Valeria
Publisher: name: Unknown
Year: 2005
Subjects: International Relations/Trade

description: This paper provides a theoretical formalisation of the joint-venture contract, as an alternative to Foreign Direct Investment (FDI), within a Dissipation of Intangible Assets framework. In a two-period, two-country equilibrium model, we discuss how the threat of knowledge spillover shapes the boundaries of a Multinational Enterprise. Similarly to the theoretical findings on the FDI-licensing trade off, we show that Foreign Direct Investment is more likely to emerge when know-how easily spills over - i.e. when firms are endowed with more intangible assets or they belong to high tech industries. Probit estimates, from an entirely new firm-level dataset, constructed by the author, show that the experience of Italian multinationals in Asia is in line with our theoretical predictions.
รูปแบบการใช้งาน Social Media (Digital Marketing) ที่มีผลต่อการขยายธุรกิจขายตรง ของนักธุรกิจ บริษัท กิฟฟารีน สกายไลน์ ยูนิตี้ จำกัด
Creators: name: พรลภัส ไพบูลย์  และ  สุมาลี สว่าง
Publisher: name: มหาวิทยาลัยรังสิต
Year: 2015
Subjects: รูปแบบใช้งาน Social Media, ผลต่อความสำเร็จ, ธุรกิจขายตรง, กิฟฟารีน

description: 1, 1, วารสารรังสิตบัณฑิตศึกษาในกลุ่มธุรกิจและสังคมศาสตร์
Perturbations of the almost Killing equation and their implications
Creators: name: Chakraborty, Sumanta
name: Feng, Justin C.
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences
subject: 83C99

description: Killing vectors play a crucial role in characterizing the symmetries of a given spacetime. However, realistic astrophysical systems are in most cases only approximately symmetric. Even in the case of an astrophysical black hole, one might expect Killing symmetries to exist only in an approximate sense due to perturbations from external matter fields. In this work, we consider the generalized notion of Killing vectors provided by the almost Killing equation, and study the perturbations induced by a perturbation of a background spacetime satisfying exact Killing symmetry. To first order, we demonstrate that for nonradiative metric perturbations (that is, metric perturbations with nonvanishing trace) of symmetric vacuum spacetimes, the perturbed almost Killing equation avoids the problem of an unbounded Hamiltonian for hyperbolic parameter choices. For traceless metric perturbations, we obtain similar results for the second-order perturbation of the almost Killing equation, with some additional caveats. Thermodynamical implications are also explored.
description: 21 pages. Matches published version
Statistical Properties of Business Firms Structure and Growth
Creators: name: Matia, Kaushik
name: Fu, Dongfeng
name: Buldyrev, Sergey V.
name: Pammolli, Fabio
name: Riccaboni, Massimo
name: Stanley, H. Eugene
Publisher: name: arXiv
Year: 2005
Subjects: subject: Physics and Society (physics.soc-ph)
subject: General Finance (q-fin.GN)
subject: FOS: Physical sciences
subject: FOS: Economics and business

description: We analyze a database comprising quarterly sales of 55624 pharmaceutical products commercialized by 3939 pharmaceutical firms in the period 1992--2001. We study the probability density function (PDF) of growth in firms and product sales and find that the width of the PDF of growth decays with the sales as a power law with exponent $β= 0.20 \pm 0.01$. We also find that the average sales of products scales with the firm sales as a power law with exponent $α= 0.57 \pm 0.02$. And that the average number products of a firm scales with the firm sales as a power law with exponent $γ= 0.42 \pm 0.02$. We compare these findings with the predictions of models proposed till date on growth of business firms.
Lossy Image Compression with Stochastic Quantization
Creators: name: Kozyriev, Anton
name: Norkin, Vladimir
Publisher: name: arXiv
Year: 2024
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics
subject: 90C15

description: Lossy image compression algorithms play a crucial role in various domains, including graphics, and image processing. As image information density increases, so do the resources required for processing and transmission. One of the most prominent approaches to address this challenge is color quantization, proposed by Orchard et al. (1991). This technique optimally maps each pixel of an image to a color from a limited palette, maintaining image resolution while significantly reducing information content. Color quantization can be interpreted as a clustering problem (Krishna et al. (1997), Wan (2019)), where image pixels are represented in a three-dimensional space, with each axis corresponding to the intensity of an RGB channel. However, scaling of traditional algorithms like K-Means can be challenging for large data, such as modern images with millions of colors. This paper reframes color quantization as a three-dimensional stochastic transportation problem between the set of image pixels and an optimal color palette, where the number of colors is a predefined hyperparameter. We employ Stochastic Quantization (SQ) with a seeding technique proposed by Arthur et al. (2007) to enhance the scalability of color quantization. This method introduces a probabilistic element to the quantization process, potentially improving efficiency and adaptability to diverse image characteristics. To demonstrate the efficiency of our approach, we present experimental results using images from the ImageNet dataset. These experiments illustrate the performance of our Stochastic Quantization method in terms of compression quality, computational efficiency, and scalability compared to traditional color quantization techniques.
description: 7 pages, 1 figure, 1 table, to be published in the "Cybernetics and Computer Technologies" (CCTech)
From Statistical to Geolinguistic Data: Mapping and Measuring Linguistic Diversity
Creators: name: Barni, Monica
name: Barni, Monica
Publisher: name: Unknown
Year: 2006
Subjects: Community/Rural/Urban Development

description: The aim of this paper is describing a new methodology for mapping and measuring linguistic diversity in a territory. The three methods that have been created by the Centro di eccellenza della ricerca Osservatorio linguistico permanente dell-italiano diffuso fra stranieri e delle lingue immigrate in Italia at the Università per Stranieri di Siena are the following: - the Toscane favelle model, a procedural application which passes from quantitative statistical data to a demolinguistic paradigm; - the Monterotondo-Mentana model. The surveys of quantitative and qualitative data are carried out using traditional tools (questionnaires, audio and video recordings) as well as advanced technologies; - the Esquilino model. Digital maps are created which present the distribution of the immigrant languages through the presence of signs in linguistic landscape. The final objective is putting together the data surveyed by the three methods in order to have a "speaking" territory, in which each point surveyed identifies the languages spoken and the various linguistic manifestations
Frog story
Creators: name: Rudolph, Johnny (Soni)
name: Ding, Lydia
name: Drummond, Emily
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2020
Subjects: subject: nkr

description: Two .wav audio files of frog stories in Nukuoro and in English, with a corresponding .eaf ELAN transcription file for the Nukuoro version. Both stories were prompted using visual stimuli from the picture book "Frog, Where Are You?" by Mercer Mayer.
DGGS and their potential impact in Geoscience and Geospatial communities - snapshot
Creators: Pangeo Europe
Alexander Kmoch
Publisher: name: Simula Research Laboratory
Year: 2022

description: A Discrete Global Grid Systems (DGGS) is a unique type of spatial
reference system comprising of a hierarchy of uniquely identifiable
discrete grid cells that span the globe at multiple resolutions. A DGGS
can support efficient management, storage, integration, exploration,
mining, and visualisation of large geospatial datasets, and several
systems of tesselation and indexing schemes exist.

The main topic of this session is to introduce the audience to the
theoretical background of Discrete Global Grid Systems (DGGS), current
real-world implementations and exemplary use cases. This includes grid
generation, data indexing and sampling with DGGRID, and some spatial
analysis with with H3 and rHealPix.
DsPCBSD
Creators: name: Ouyang, Bin
Publisher: name: figshare
Year: 2024
Subjects: classificationCode: 460304
subject: Computer vision

description: This work categorized PCB surface defects into 9 distinct categories based on factors such as their causes, locations, and morphologies and developed a dataset of PCB surface defect (DsPCBSD+). In DsPCBSD+, a total of 20,276 defects were annotated manually by bounding boxes on the 10,259 images. This openly accessible dataset is aimed accelerating and promoting further researches and advancements in the field of DL-based detection of PCB surface defect.