cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Measurement of the Sky Photon Background Flux at the Auger Observatory
Creators: name: Caruso, R.
name: Insolia, A.
name: Petrera, S.
name: Privitera, P.
name: Salamida, F.
name: Verzi, V.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The sky photon background flux has been measured at the southern Auger site in Malargue, Argentina, using the observatory's fluorescence detectors (FD). The analysis is based on ADC variances of pixels not triggered by the First Level Trigger. Photon fluxes are calculated for each individual pixel at each telescope. The statistics from each night of data taking allows a study of local variations in the photon flux. Results show a clear dependence of the flux on elevation angle. Time variations, possibly related to different atmospheric conditions, do not mask this dependence. In particular the flux excess above the horizon shows a rather stable and reproducible behaviour with elevation. Correlation of this dependence with atmospheric parameters can be of interest as it offers the promise of extracting those parameters directly from FD data, thus allowing cross checks with independent methods based on different monitoring devices.
description: contribution to the 29th International Cosmic Ray Conference, Pune, India, 3-10 August 2005
The Discovery of Tidal Tails Around NGC 5466
Creators: name: Belokurov, V.
name: Evans, N. W.
name: Irwin, M. J.
name: Hewett, P. C.
name: Wilkinson, M. I.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report the discovery of tidal tails around the high-latitude Galactic globular cluster NGC 5466 in Sloan Digital Sky Survey (SDSS) data. Neural networks are used to reconstruct the probability distribution of cluster stars in u,g,r,i and z space. The tails are clearly visible, once extra-galactic contaminants and field stars have been eliminated. They extend roughly 4 degrees on the sky, corresponding to about 1 kpc in projected length. The orientation of the tails is in good agreement with the cluster's Galactic orbit, as judged from the proper motion data.
description: 4 pages, 4 figures, submitted to The Astrophysical Journal (Letters)
THE TERM STRUCTURE OF IMPLIED FORWARD VOLATILITY: RECOVERY AND INFORMATIONAL CONTENT IN THE CORN OPTIONS MARKET
Creators: name: Egelkraut, Thorsten M.
name: Garcia, Philip
name: Sherrick, Bruce J.
name: Egelkraut, Thorsten M.
name: Garcia, Philip
name: Sherrick, Bruce J.
Publisher: name: Unknown
Year: 2003
Subjects: subject: Marketing
subject: FOS: Economics and business
subject: corn options
subject: implied forward volatility
subject: informational content
subject: term structure

description: Options with different maturities can be used to generate volatility estimates for non-overlapping future time intervals. This paper develops the term structure of volatility implied by corn futures options, and evaluates the informational content of the implied forward volatility as a predictor of subsequent realized volatility. Using data from 1987-2001 and employing a flexible method to obtain the implied forward volatilities, two types of information are examined: 1) the market's estimate of future realized volatility for the nearby interval of the term structure and, 2) the market's expectation of the direction and magnitude of change of future realized volatility over time. In contrast to previous research, the results indicate that the implied forward volatilities anticipate the realized volatilities provide unbiased forecasts and capture a larger portion of the systematic variability in the realized volatilities than forecasts based on historical volatilities. Using information on the direction and magnitude of change in volatility over time, we find that the early-year options forecast volatility about as well as the three-year moving average and better than the naive forecast, while later-year options and alternative forecasts are less able to predict the direction and magnitude of changing volatility. During this later-year period, the implied forward volatilities tend to over-predict the magnitude of actual volatility. Overall, we find that the term structure of volatility implied by corn futures options contains information on future realized volatility.
LoopReg: Self-supervised Learning of Implicit Surface Correspondences, Pose and Shape for 3D Human Mesh Registration
Creators: name: Bhatnagar, Bharat Lal
name: Sminchisescu, Cristian
name: Theobalt, Christian
name: Pons-Moll, Gerard
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: We address the problem of fitting 3D human models to 3D scans of dressed humans. Classical methods optimize both the data-to-model correspondences and the human model parameters (pose and shape), but are reliable only when initialized close to the solution. Some methods initialize the optimization based on fully supervised correspondence predictors, which is not differentiable end-to-end, and can only process a single scan at a time. Our main contribution is LoopReg, an end-to-end learning framework to register a corpus of scans to a common 3D human model. The key idea is to create a self-supervised loop. A backward map, parameterized by a Neural Network, predicts the correspondence from every scan point to the surface of the human model. A forward map, parameterized by a human model, transforms the corresponding points back to the scan based on the model parameters (pose and shape), thus closing the loop. Formulating this closed loop is not straightforward because it is not trivial to force the output of the NN to be on the surface of the human model - outside this surface the human model is not even defined. To this end, we propose two key innovations. First, we define the canonical surface implicitly as the zero level set of a distance field in R3, which in contrast to morecommon UV parameterizations, does not require cutting the surface, does not have discontinuities, and does not induce distortion. Second, we diffuse the human model to the 3D domain R3. This allows to map the NN predictions forward,even when they slightly deviate from the zero level set. Results demonstrate that we can train LoopRegmainly self-supervised - following a supervised warm-start, the model becomes increasingly more accurate as additional unlabelled raw scans are processed. Our code and pre-trained models can be downloaded for research.
description: NeurIPS'20 (Oral)
Heisenberg saturation of the Froissart bound from AdS-CFT
Creators: name: Kang, Kyungsik
name: Nastase, Horatiu
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In a previous paper, we have analyzed high energy QCD from AdS-CFT and proved the saturation of the Froissart bound (a purely QCD proof of which is still lacking). In this paper we describe the calculation in more physical terms and map it to QCD language. We find a remarkable agreement with the 1952 Heisenberg description of the saturation (pre-QCD!) in terms of shockwave collisions of pion field distributions. It provides a direct map between gauge theory physics and the gravitational physics on the IR brane of the Randall-Sundrum model. Saturation occurs through black hole production on the IR brane, which is in QCD production of a nonlinear pion field soliton of a Born-Infeld action in the hadron collision, that decays into free pions.
description: 16 pages, 1 figure, latex, references added, typos corrected
SPATIAL COMPETITION AND PRICING IN THE AGRICULTURAL CHEMICAL INDUSTRY: EMPIRICAL EVIDENCE FROM GEORGIA
Creators: name: Hall, R. Lee
name: Dorfman, Jeffrey H.
name: Gunter, Lewell F.
name: Hall, R. Lee
name: Dorfman, Jeffrey H.
name: Gunter, Lewell F.
Publisher: name: Unknown
Year: 2003
Subjects: subject: Industrial Organization
subject: agricultural chemicals
subject: market power
subject: spatial competition

description: Three models of spatial competition are tested on retail price data for the agricultural chemical industry. Three empirical tests find no evidence of any spatial competition using data from sixty-five retailers and twelve different chemicals. Demand and supply-side variables have statistically significant, but economically trivial impacts on retail chemical prices. These results point to a virtually complete control of retail prices by the chemical manufacturers, likely through the rebate program they offer retailers. The oligopoly structure of the chemical manufacturing industry makes such control possible. The results suggest that consolidation of retailers or distributors will not have anti-competitive effects since price competition is essentially absent from this market already.
RISK MANAGEMENT TECHNIQUES FOR AGRICULTURAL COOPERATIVES: AN EMPIRICAL EVALUATION
Creators: name: Manfredo, Mark R.
name: Richards, Timothy J.
name: McDermott, Scott
name: Manfredo, Mark R.
name: Richards, Timothy J.
name: McDermott, Scott
Publisher: name: Unknown
Year: 2003
Subjects: Agribusiness

description: While not ignoring risk, agricultural cooperatives tend to accommodate risk through the holding of internal capital reserves rather than engage in active risk management. A lack of information regarding the risk, returns, and the effect on cooperative financial performance of both traditional and innovative risk management strategies is likely a constraint to the adoption of active risk management by cooperatives. In this research, we examine the influence of alternative risk management strategies on cooperative financial performance, namely the return on assets (ROA) of grain merchandising cooperatives of various sizes. Strategies include traditional exchange traded futures and options strategies, an over-the-counter revenue swap, throughput insurance, and combinations of price and throughput strategies. Each of these strategies, for small, medium, and large size firms, are evaluated using a range of procedures including techniques which rely on mean-variance efficiency as well as evaluation procedures which help determine the ability of a strategy to mitigate downside risk. The results of the simulation exercise provide considerable support for the routine buying of at-the-money put options in setting a commodity floor price. The results also support the use, and perhaps the development, of insurance on cooperative throughput if the insurance product is used in conjunction with a price risk management strategy, in essence providing a hedge against downfalls in revenue. Over-the-counter revenue swaps, while intuitively appealing, did not perform well on average relative to more traditional exchange traded products. This result is especially important given the added counter party risk associated with such contracts. However, in some cases, the revenue swap, as well routine hedging with futures, performed better under a Value-at-Risk evaluation criteria than with a mean-variance criteria. Hence, it is important for cooperative managers to consider these results in the context of the risk management goals.
Equilibrium points of logarithmic potentials induced by positive charge distributions. I. Generalized de Bruijn-Springer relations
Creators: name: Borcea, Julius
Publisher: name: arXiv
Year: 2006
Subjects: subject: Complex Variables (math.CV)
subject: Functional Analysis (math.FA)
subject: Spectral Theory (math.SP)
subject: FOS: Mathematics
subject: Primary 31A15; Secondary 30C15, 47A55, 60E15

description: A notion of weighted multivariate majorization is defined as a preorder on sequences of vectors in Euclidean space induced by the Choquet ordering for atomic probability measures. We characterize this preorder both in terms of stochastic matrices and convex functions and use it to describe the distribution of equilibrium points of logarithmic potentials generated by discrete planar charge configurations. In the case of $n$ positive charges we prove that the equilibrium points satisfy $\binom{n}{2}$ weighted majorization relations and are uniquely determined by $n-1$ such relations. It is further shown that the Hausdorff geometry of the equilibrium points and the charged particles is controlled by the weighted standard deviation of the latter. By using finite-rank perturbations of compact normal Hilbert space operators we establish similar relations for infinite charge distributions. We also discuss a hierarchy of weighted de Bruijn-Springer relations and inertia laws, the existence of zeros of Borel series with positive $l^1$-coefficients, and an operator version of the Clunie-Eremenko-Rossi conjecture.
description: To appear in Trans. Amer. Math. Soc., 27 pages, no figures, LaTeX2e
MODELLING THE CAP ARABLE CROP REGIME UNDER UNCERTAINTY
Creators: name: Sckokai, Paolo
name: Moro, Daniele
name: Sckokai, Paolo
name: Moro, Daniele
Publisher: name: Unknown
Year: 2002
Subjects: subject: Agricultural and Food Policy
subject: Risk effects
subject: Common Agricultural Policy
subject: Decoupling
subject: Duality.

description: In this paper we evaluate empirically the absolute and relative size of risk-related effects of a farm policy change, with specific reference to the CAP arable crop regime. We adopt a dual framework under non linear mean-variance risk preferences, which incorporates the impact of price uncertainty in the specific decision-making structure of EU arable crop producers. A system of output supply, input demand and land allocation equations has been estimated on a sample of Italian specialised arable crop farms, which allows us to derive elasticities with respect to all the relevant exogenous variables, including those related to risk. The simulation of the impact of an Agenda 2000-type of shock confirms that the size of risk effects is important in evaluating farmer's output responses. This may have important implications for the revision of "green box" criteria in the context of the current WTO negotiations. Keywords: Risk effects; Common Agricultural Policy; Decoupling; Duality.
THE VALUE OF AGRICULTURAL ECONOMICS EXTENSION PROGRAMMING: AN APPLICATION OF CONTINGENT VALUATION
Creators: name: Roe, Brian E.
name: Haab, Timothy C.
name: Sohngen, Brent
name: Roe, Brian E.
name: Haab, Timothy C.
name: Sohngen, Brent
Publisher: name: Unknown
Year: 2002
Subjects: Teaching/Communication/Extension/Profession

description: We use the contingent valuation method to estimate participant willingness to pay for agricultural economics extension programming. The data, collected as part of standard evaluation forms for the Ohio State University's 2001 Agricultural Outlook and Policy program series, and subsequent analysis suggest participant benefits exceeded departmental costs of conducting the program (benefit-cost ratios of 1.07 under conservative assumptions and 1.74 under moderate assumptions). We also use the data to explore the revenue generation potential from alternative program pricing and discuss the potential for developing differentiated programs to reach distinct audience segments. Additional research necessary before implementing alternative pricing or program differentiation plans is also discussed.
The Two-Dimensional Fractional Discrete Nonlinear Schrodinger Equation
Creators: name: Molina, Mario I.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: We study a fractional version of the two-dimensional discrete nonlinear Schrödinger (DNLS) equation, where the usual discrete Laplacian is replaced by its fractional form that depends on a fractional exponent $s$ that interpolates between the case of an identity operator ($s=0$) and that of the usual discrete 2D Laplacian ($s=1$). This replacement leads to a long-range coupling among sites that, at low values of $s$, decreases the bandwidth and leads to quasi-degenerate states. The mean square displacement of an initially-localized excitation is shown to be ballistic at all times with a `speed' that increases monotonically with the fractional exponent $s$. We also compute the nonlinear modes and their stability for both, bulk and surface modes. The modulational stability is seen to increase with an increase in the fractional exponent. The trapping of an initially localized excitation shows a selftrapping transition as a function of nonlinearity strength, whose threshold increases with the value of $s$. In the linear limit, there persists a linear trapping at small $s$ values. This behavior is connected with the decrease of the bandwidth and its associated increase in quasi-degeneracy.
description: 6 pages, 6 figures
ROLE OF INFORMATION IN THE DECISION TO ADOPT GENETICALLY MODIFIED SEED
Creators: name: Alexander, Corinne E.
name: Alexander, Corinne E.
Publisher: name: Unknown
Year: 2002
Subjects: Crop Production/Industries
Research and Development/Tech Change/Emerging Technologies

description: We examine the role of information in farmers' decisions to adopt GM corn, and find that the set of influential information sources is substantially different in 1997 and 1998. Further, our results suggest that one high quality information source is more influential than the quantity of information.
Stochastic model for Soj relocation dynamics in Bacillus subtilis
Creators: name: Doubrovinski, Konstantin
name: Howard, Martin
Publisher: name: arXiv
Year: 2005
Subjects: subject: Subcellular Processes (q-bio.SC)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: The Bacillus subtilis Spo0J/Soj proteins, implicated in chromosome segregation and transcriptional regulation, show striking dynamics: Soj undergoes irregular relocations from pole to pole or nucleoid to nucleoid. Here we report on a mathematical model of the Soj dynamics. Our model, which is closely based on the available experimental data, readily generates dynamic Soj relocations. We show that the irregularity of the relocations may be due to the stochastic nature of the underlying Spo0J/Soj interactions and diffusion. We propose explanations for the behavior of several Spo0J/Soj mutants including the "freezing" of the Soj dynamics observed in filamentous cells. Our approach underlines the importance of incorporating stochastic effects when modelling spatiotemporal protein dynamics inside cells.
description: 45 pages
ENVIRONMENTAL AMENITIES AND COMMUNITY CHARACTERISTICS: AN EMPIRICAL STUDY OF PORTLAND, OREGON
Creators: name: Cho, Seong-Hoon
name: Wu, JunJie
name: Cho, Seong-Hoon
name: Wu, JunJie
Publisher: name: Unknown
Year: 2002
Subjects: Environmental Economics and Policy

description: This paper examines equilibrium properties of local jurisdictions implied by the Tiebout-style model. A set of equilibrium conditions are derived from a general equilibrium model of local jurisdictions. The conditions are parameterized and empirically estimated in a two-stage procedure. The method is applied to communities in a Portland metropolitan area with an extension of public-good provision to include environmental amenities. The results suggest that the model can replicate many of the empirical regularities observed in the data. For example, the predicted income distributions across communities closely matched the observed distribution. The estimated income elasticity of housing demand is consistent with previous findings. One important finding of this paper is that the parameter estimates would be biased if environmental amenities are not considered.
Suppressed reflectivity due to spin-controlled localization in a magnetic semiconductor
Creators: name: Mena, F. P.
name: DiTusa, J. F.
name: van der Marel, D.
name: Aeppli, G.
name: Young, D. P.
name: Damascelli, A.
name: Mydosh, J. A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The narrow gap semiconductor FeSi owes its strong paramagnetism to electron-correlation effects. Partial Co substitution for Fe produces a spin-polarized doped semiconductor. The spin-polarization causes suppression of the metallic reflectivity and increased scattering of charge carriers, in contrast to what happens in other magnetic semiconductors, where magnetic order reduces the scattering. The loss of metallicity continues progressively even into the fully polarized state, and entails as much as a 25% reduction in average mean-free path. We attribute the observed effect to a deepening of the potential wells presented by the randomly distributed Co atoms to the majority spin carriers. This mechanism inverts the sequence of steps for dealing with disorder and interactions from that in the classic Al'tshuler Aronov approach - where disorder amplifies the Coulomb interaction between carriers - in that here, the Coulomb interaction leads to spin polarization which in turn amplifies the disorder-induced scattering.
description: 6 figures Submitted to PRB
CALIFORNIA WINE WINNERS: A HEDONIC ANALYSIS OF REGIONAL AND WINERY REPUTATION INDICATORS
Creators: name: Schamel, Guenter
name: Schamel, Guenter
Publisher: name: Unknown
Year: 2002
Subjects: subject: Marketing
subject: FOS: Economics and business

description: We hypothesize that quality signals improve over time with the quality performance of a wine producer, and that spillovers will affect other producers within the same region. For this purpose, we estimate a hedonic pricing model for premium California wine. Data source is the annual publication "California Wine Winners" accumulated over the judging years 1990-2001. Quality indicators for 19,583 wines are medals awarded during nine annual wine competitions, variety, regional origin, judging age as well as derived producer (brand) and regional reputation indicators. The data confirms that a wine's price is related to its own quality and to producer/regional reputation for quality.
Generalization of the Schott energy in electrodynamic radiation theory
Creators: name: Heras, Jose A.
name: O'Connell, R. F.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Optics (physics.optics)
subject: General Physics (physics.gen-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We discuss the origin of the Schott energy in the Abraham-Lorentz version of electrodynamic radiation theory and how it can be used to explain some apparent paradoxes. We also derive the generalization of this quantity for the Ford-O'Connell equation, which has the merit of being derived exactly from a microscopic Hamiltonian for an electron with structure and has been shown to be free of the problems associated with the Abraham-Lorentz theory. We emphasize that the instantaneous power supplied by the applied force not only gives rise to radiation (acceleration fields), but it can change the kinetic energy of the electron and change the Schott energy of the velocity fields. The important role played by boundary conditions is noted.
THE IMPACT OF GOVERNMENT POLICIES ON AGRICULTURAL PRODUCTIVITY AND STRUCTURE: PRELIMINARY RESULTS
Creators: name: Ahearn, Mary Clare
name: Yee, Jet
name: Huffman, Wallace E.
name: Ahearn, Mary Clare
name: Yee, Jet
name: Huffman, Wallace E.
Publisher: name: Unknown
Year: 2002
Subjects: Agricultural and Food Policy
Productivity Analysis

description: Our paper begins with a consideration of the causal relationships among productivity, farm structure, government farm payments and public investments in research and extension. We then empirically test key relationships for a relatively recent period (1960-96) in the history of agricultural structural adjustment using a simultaneous equations econometric model. Future work will expand and refine the measurement of variables thought to explain the relationship between productivity and structure.
Mating-type-associated vegetative incompatibility in Neurospora crassa
Creators: name: Shiu, Patrick Ka Tai
Publisher: name: University of British Columbia
Year: 2009

description: The mating-type locus in Neurospora crassa controls mating and sexual development. The fusion of reproductive structures of opposite mating-type, A and a, is required to initiate sexual reproduction. However, the fusion of hyphae of opposite mating-type during vegetative growth results in growth inhibition and cell death, a process that is mediated by the tol locus. Mutations in tol are recessive and suppress mating-type associated heterokaryon incompatibility; heterokaryon incompatibility is a mechanism that prevents the formation of vigorous heterokaryons between genetically dissimilar individuals. In this study, the functional domain for heterokaryon incompatibility in the A mating-type protein, specifically MAT A-l, is mapped to a leucine-rich repeat. The tol gene encodes a putative 1011-amino acid polypeptide with a coiled-coil domain and a leucine-rich repeat (both essential for heterokaryon incompatibility). It contains a region of similarity with two het genes (HET-6 and HET-E). Repeat-induced point mutations in tol result in mutants that are wild-type during vegetative growth and sexual reproduction, but which allow opposite mating-type individuals to form a vigorous heterokaryon. Transcript analyses show that tol mRNA is present during vegetative growth but absent during a cross. These data suggest that tol transcription could be repressed in order to allow the co-existence of opposite mating-type nuclei during the sexual reproductive phase, tol is expressed in a mat A, mat a, A/a partial diploid and in a mating-type deletion strain, indicating that M AT A - l and MAT a-l are not absolutely required for transcription or repression of tol. These data suggest that TOL may interact with MAT A-l and/or MAT a-l to form a death-triggering complex. To understand how tol may mediate mating-type incompatibility, attempts have been made to isolate TOL-interacting proteins {top) by yeast 2-hybrid system. Five N. crassa mycelial cDNA-pGAL4 AD clones are shown to have plasmid-dependent interaction with TOL in yeast. One of them is a homologue of Schizosaccharomyces pombe vip-1, which is a p53- related protein. The tol gene is apparently conserved in many different Neurospora species. One particular allele, tol7 from N. tetrasperma, is of special interest. tol[sub T] is a natural tot in the regard that it does not mediate mating-type incompatibility. Evidence provided in this thesis suggests that two loci closely linked to tol[sub T] may mediate non-allelic vegetative incompatibility and sexual incompatibility, respectively.
Photometric Confirmation of MACHO Large Magellanic Cloud Microlensing Events
Creators: name: Bennett, David P.
name: Becker, Andrew C.
name: Tomaney, Austin
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present previously unpublished photometry of three Large Magellanic Cloud (LMC) microlensing events and show that the new photometry confirms the microlensing interpretation of these events. These events were discovered by the MACHO Project alert system and were also recovered by the analysis of the 5.7 year MACHO data set. This new photometry provides a substantial increase in the signal-to-noise ratio over the previously published photometry and in all three cases, the gravitational microlensing interpretation of these events is strengthened. The new data consist of MACHO-Global Microlensing Alert Network (GMAN) follow-up images from the CTIO 0.9 telescope plus difference imaging photometry of the original MACHO data from the 1.3m "Great Melbourne" telescope at Mt. Stromlo. We also combine microlensing light curve fitting with photometry from high resolution HST images of the source stars to provide further confirmation of these events and to show that the microlensing interpretation of event MACHO-LMC-23 is questionable. Finally, we compare our results with the analysis of Belokurov, Evans & Le Du who have attempted to classify candidate microlensing events with a neural network method, and we find that their results are contradicted by the new data and more powerful light curve fitting analysis for each of the four events considered in this paper. The failure of the Belokurov, Evans & Le Du method is likely to be due to their use of a set of insensitive statistics to feed their neural networks.
description: 29 pages with 8 included postscript figures, accepted by the Astrophysical Journal
On minimal presentations of shifted affine semigroups with few generators
Creators: name: O'Neill, Christopher
name: White, Isabel
Publisher: name: arXiv
Year: 2020
Subjects: subject: Combinatorics (math.CO)
subject: Commutative Algebra (math.AC)
subject: FOS: Mathematics

description: An affine semigroup is a finitely generated subsemigroup of $(\mathbb Z_{\ge 0}^d, +)$, and a numerical semigroup is an affine semigroup with $d = 1$. A growing body of recent work examines shifted families of numerical semigroups, that is, families of numerical semigroups of the form $M_n = \langle n + r_1, \ldots, n + r_k \rangle$ for fixed $r_1, \ldots, r_k$, with one semigroup for each value of the shift parameter $n$. It has been shown that within any shifted family of numerical semigroups, the size of any minimal presentation is bounded (in fact, this size is eventually periodic in $n$). In this paper, we consider shifted families of affine semigroups, and demonstrate that some, but not all, shifted families of 4-generated affine semigroups have arbitrarily large minimal presentations.
THE MEASUREMENT OF INEQUALITY IN CANADIAN AND U.S. AGRICULTURAL INCOME BY COMPONENTS OF NET VALUE ADDED
Creators: name: Erickson, Kenneth W.
name: Moss, Charles B.
name: Mishra, Ashok K.
name: Erickson, Kenneth W.
name: Moss, Charles B.
name: Mishra, Ashok K.
Publisher: name: Unknown
Year: 2002
Subjects: Agricultural Finance

description: This paper examines changes in net value added generated through Canadian and U.S. farm production, 1970-2000. We consider how the structural changes in Canadian and U.S. agriculture have affected the size and distribution of net value added and its components: rent, capital, labor, and to net farm income. We use the Theil Measure of Inequality (TMI) to compare and explain changes in 1) the between and within-region distribution of net value added, and 2) changes in the distribution of factor shares of net value added in Canada and in the U.S. Results show that in Canada (1960-2000), net value added has become somewhat more equally distributed relative to the number of farms per province, but has varied widely from 1972-1988. Between-region inequality in net value added accounted for from 0.5 to 85.5 percent of this inequality from 1960-2000. In the U.S. (1949-2000), net value added has become more unequally distributed. About half of the variation in net value added in the U.S. is due to between-region variation and about half to within-region variation in net value added. We find that most of the variation in the components of net value added (returns to capital, labor, nonoperator landlords, and to farm operators) in Canada and the United States is due to variations across regions, rather than to variations in the components of net value added themselves. These variations have generally been due to macroeconomic differences in regions, such as shifts in enterprise specialization, urbanization, changes in government programs, and to other structural changes in agriculture.
D4.1 – Guidelines on planned actions for recruitment and retention
Creators: name: Migalska, Aleksandra
name: Sekuła, Paulina
name: Stoecker, Ewa
name: Ní Fhlatharta, Aoife
name: Macmahon, Helena
Publisher: name: Zenodo
Year: 2024

description: In this deliverable, which is based on a combination of desk research, our own expertise, MTG partners’ experiences, in addition to existing guidelines, we have prepared a set of overall recommendations supporting academic and non-academic organisations to foster the awareness of gender issues in the field of recruitment, retention and career progression. Our guidelines on planned actions are developed to help to understand and prepare organisational change, which should improve gender equality in an institution. The overall objectives of the deliverable are...

Implementing policy actions to raise awareness at both the bottom and the top of gendered organizational practices in recruitment, retention and career progression;

Supporting scientific research excellence by searching for and hiring the best candidates without the effect of unconscious gender bias;

Supporting women researchers in the development of their careers;

Fostering dialogue, relevant cooperation and professional exchange among recruitment-promotion teams;

Facilitating the uptake of gender equal practices in the implementing institutions, through internal and external dissemination;

Favouring self-reflexivity through participative evaluation efforts
Quantum magnetism of topologically-designed graphene nanoribbons
Creators: name: Zhu, Xingchuan
name: Guo, Huaiming
name: Feng, Shiping
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Based on the Hubbard models, quantum magnetism of topologically-designed graphene nanoribbons (GNRs) is studied using exact numerical simulations. We first study a two-band Hubbard model describing the low-energy topological bands using density matrix renormalization group (DMRG) and determinant quantum Monte Carlo (DQMC) methods. It is found the spin correlations decay quickly with the distance, and the local moment is extrapolated to zero in the presence of symmetry-breaking terms. The results show that the two-band Hubbard chain is nonmagnetic, which is in contrast to the mean-field calculation predicting a critical interaction for the magnetic transition. We then include the Hubbard interaction to the topological-designed GNRs. For large interactions, the spin correlations keep finite for all distances, and the magnetic order develops. The local moment is extrapolated to almost zero for weak interactions, and begins to increase rapidly from a critical interaction. The estimated critical value is much larger than the realistic value in graphene, and we conclude the experimentally relevant GNRs is nonmagnetic, which is consistent with the experimental results.
description: 7 pages, 9 figures; Appear in Journal of Physics: Condensed Matter
Concentration of toroidal magnetic field in the solar tachocline by eta-quenching
Creators: name: Gilman, Peter A.
name: Rempel, Matthias
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We show that if the turbulent magnetic diffusivity used in solar dynamos is assumed to be 'quenched' by increasing toroidal fields, much larger amplitude and more concentrated toroidal fields can be induced by differential rotation from an assumed poloidal field than if there is no quenching. This amplification and concentration mechanism is weakened and bounded by j x B feedbacks on the differential rotation. Nevertheless, it is strong enough to contribute to the creation of ~100 kG toroidal fields near the base of the convection zone, perhaps in conjunction with the 'exploding flux tube' process. Such high fields are necessary for sunspots to occur in low solar latitudes.
description: 8 pages, 6 figures, added references, corrected typos, accepted by ApJ
OPEN ACCESS AND MISSING MARKETS IN ARTISANAL FISHING
Creators: name: Liese, Christopher
name: Smith, Martin D.
name: Kramer, Randall A.
name: Liese, Christopher
name: Smith, Martin D.
name: Kramer, Randall A.
Publisher: name: Unknown
Year: 2002
Subjects: subject: Marketing
subject: FOS: Economics and business

description: This paper combines a model of open access fisheries exploitation with a distance-based approach to missing labor and product markets. The model generates predictions about the circumstances under which exploitation increases or decreases with distance. An econometric model is estimated with survey data from artisanal fishing households in Minahasa, Indonesia. The results can be used to assess the impacts of improved transportation infrastructure on fishery exploitation.
The Entanglement of Superpositions
Creators: name: Linden, Noah
name: Popescu, Sandu
name: Smolin, John A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Given a bipartite quantum state (in arbitrary dimension) and a decomposition of it as a superposition of two others, we find bounds on the entanglement of the superposition state in terms of the entanglement of the states being superposed. In the case that the two states being superposed are bi-orthogonal, the answer is simple, and, for example, the entanglement of the superposition cannot be more than one e-bit more than the average of the entanglement of the two states being superposed. However for more general states, the situation is very different.
description: 4 pages
Observation of a cusp-like structure in the pizero-pizero invariant mass distribution from K+- ==> pi+- pizero pizero decay and determination of the pi-pi scattering lengths
Creators: name: 2 Collaboration
name: Lazzeroni, C.
name: Munday, D. J.
name: Slater, M. W.
name: Wotton, S. A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We report the results from a study of ~23 Million K+- ==> pi+- pizero pizero decays recorded by the NA48/2 experiment at the CERN SPS, showing an anomaly in the pizero pizero invariant mass distribution in the region around 2m+, where m+ is the charged pion mass. This anomaly, never observed in previous experiments, can be interpreted as an effect due mainly to the final state charge exchange scattering process pi+ pi- ==> pizero pizero in K+- ==> pi+- pi+ pi- decay. It provides a precise determination of a0 - a2, the difference between the pi-pi scattering lengths in the isospin I=0 and I=2 states.
description: 16 pages, 7 figures Accepted for publication in Physics Letters B
Implementing a microphysics model in hydrodynamic simulations to study the initial plasma formation in dielectric ablator materials for direct-drive implosions
Creators: name: Kar, Arnab
name: Hu, S. X.
name: Duchateau, G.
name: Carroll-Nellenback, J.
name: Radha, P. B.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: A microphysics model to describe the photoionization and impact ionization processes in dielectric ablator materials like plastic has been implemented into the one-dimensional hydrodynamic code LILAC for planar and spherical targets. At present, the initial plasma formation during the early stages of a laser drive is modeled in an ad hoc manner, until the formation of a critical surface. Implementation of the physics-based models predicts higher values of electron temperature and pressure than the ad hoc model. Moreover, the numerical predictions are consistent with previous experimental observations of the shine-through mechanism in plastic ablators. For planar targets, a decompression of the rear end of the target was observed that is similar to recent experiments. An application of this model is to understand the laser-imprint mechanism that is caused by nonuniform laser irradiation due to a single beam speckle.
AGENDA SETTING, INFLUENCE, AND VOTING RULES: THE INFLUENCE OF THE EUROPEAN COMMISSION AND STATUS QUO BIAS IN THE COMMON AGRICULTURAL POLICY OF THE EU
Creators: name: Pokrivcak, Jan
name: Swinnen, Johan F.M.
name: Pokrivcak, Jan
name: Swinnen, Johan F.M.
Publisher: name: Unknown
Year: 2002
Subjects: Agricultural and Food Policy

description: We develop a two-stage political economy model that explicitly models the complexity of decision-making in the European Union on the Common Agricultural Policy, and we derive how the institutional design affects the outcome and the influence of the various agents involved, and the likelihood of political stalemate.
Forum on using and sharing research data about child well-being [Webinar, Presentation]
Creators: name: Bezjak, Sonja
name: Tuominen, Markus
name: Sieben, Inge
name: Sedmak, Mateja
name: Vipavc Brvar, Irena
Publisher: name: Zenodo
Year: 2023
Subjects: children
children in Europe
child well-being
child centric approach
data management
quality research data
research data
data lifecycle

description: Research data is an important element for advancing scientific knowledge. In this CESSDA webinar, we were putting the spotlight on data on children in the EU. 

With experienced researchers and representatives from social science data archives, we presented: important resources for discovering quality research data on child well-being, opportunities for re-using such data, and how to make your data on children FAIR.
Ionizing radiation from hydrogen recombination strongly suppresses the lithium scattering signature in the CMB
Creators: name: Switzer, Eric R.
name: Hirata, Christopher M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: It has been suggested that secondary CMB anisotropies generated by neutral lithium could open a new observational window into the universe around the redshift z ~ 400, and permit a determination of the primordial lithium abundance. The effect is due to resonant scattering in the allowed LiI doublet (2s ^2S_{1/2} - 2p ^2P_{1/2,3/2}), so its observability depends on the formation history of neutral lithium. Here we show that the ultraviolet photons produced during hydrogen recombination are sufficient to keep lithium in the LiII ionization stage in the relevant redshift range and suppress the neutral fraction by ~3 orders of magnitude from previous calculations, making the lithium signature unobservable.
description: 9 pages, 6 figures
MICROECONOMETRIC MODELING OF HOUSEHOLD FOOD DEMAND: THE CASE OF TRANSITION BULGARIA
Creators: name: Goodwin, Barry K.
name: Phaneuf, Daniel J.
name: Goodwin, Barry K.
name: Phaneuf, Daniel J.
Publisher: name: Unknown
Year: 2001
Subjects: Consumer/Household Economics
Demand and Price Analysis

description: Considerable optimism has been expressed about the outlook for increased exports of food products to Central and Eastern Europe. A clear understanding of the potential for increased exports to this region requires comprehension of consumers' demands for food products. This analysis resents detailed elasticity estimate for food commodities in transition Bulgaria. The analysis is conducted in two segments. The first considers demand for five aggregate food commodities---cereals, fruits and vegetables, meats, dairy products, other foods (including food consumed away from home and prepared foods), and all other goods. The estimates suggest relatively price inelastic demands. We find that cereals and dairy products tend to be income-inelastic while meats and other foods are income-elastic. We also consider a Kuhn-Tucker model of demand for individual meats. These results indicate that the demands for individual meat products are very price and income elastic.
Progress in computing inclusive B decay spectra
Creators: name: Gardi, Einan
name: Andersen, Jeppe R.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We review the progress in the QCD calculation of inclusive decay spectra. It was recently shown that the inherent infrared finiteness of inclusive spectra extends beyond the level of logarithms. Dressed Gluon Exponentiation makes practical use of this property by computing the Sudakov exponent as a Borel sum. Based on renormalon analysis, infrared sensitivity in the exponent is reflected in power corrections that are inversely proportional to the third power of the mass. Therefore, the parametric enhancement of non-perturbative corrections near the phase--space boundary is effective only in a small region. Consequently, the on-shell decay spectrum provides a good approximation to the meson decay. In particular, it facilitates a precise determination of V_ub from present measurements of inclusive charmless semileptonic widths without involving a non-perturbative ``shape function''.
description: 8 pages, 5 figures; To appear in the proceedings of the 7th International Symposium on Radiative Corrections: Application of Quantum Field Theory to Phenomenology (RADCOR 2005), Shonan Village, Kanagawa, Japan, 2-7 Oct 2005
FACTORS INFLUENCING PARTICIPATION IN AGRICULTURAL LAND PRESERVATION PROGRAMS
Creators: name: Lynch, Lori
name: Lovell, Sabrina J.
name: Lynch, Lori
name: Lovell, Sabrina J.
Publisher: name: Unknown
Year: 2001
Subjects: Land Economics/Use

description: We analyze the factors influencing participation in Maryland's farmland preservation programs using data from a survey of agricultural landowners and spatial data on individual parcels. Factors influencing participation included distance from a major city, proximity to preserved parcels, length of family ownership, whether a child plan to continue farming and share of income from farming.
Intrinsic bulk quantum oscillations in a bulk unconventional insulator SmB$_6$
Creators: name: Hartstein, Mate
name: Liu, Hsu
name: Hsu, Yu-Te
name: Tan, Beng S.
name: Hatnean, Monica Ciomaga
name: Balakrishnan, Geetha
name: Sebastian, Suchitra E.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The finding of bulk quantum oscillations in the bulk Kondo insulator SmB$_6$, which has been proposed to be a correlated topological insulator, proved a considerable surprise. The subsequent measurement of bulk quantum oscillations in other correlated insulators including YbB$_{12}$ have lent support to our discovery of a class of unconventional insulators that are host to bulk quantum oscillations, of which SmB$_6$ was the first example. Here we perform a series of experiments to examine evidence for the intrinsic character of bulk quantum oscillations in floating zone-grown single crystals of SmB$_6$ that have been the subject of our quantum oscillation studies thus far. We present results of experiments including chemical composition analysis, magnetisation, thermal conductivity, electrical transport, and heat capacity on floating zone-grown single crystals of SmB$_6$, and a series of quantum oscillation experiments as a function of magnetic field, temperature, and magnetic field-orientation on single crystals of floating-zone grown SmB$_6$, LaB$_6$, and elemental Aluminium. Results of these experimental studies establish the intrinsic origin of quantum oscillations from the bulk of pristine floating zone-grown single crystals of SmB$_6$. The origin of the underlying bulk Fermi surface that bears close similarity with the unhybridised Fermi surface in metallic hexaborides despite the bulk insulating character of SmB$_6$ is thus at the heart of a theoretical mystery.
title: Toetsing kunstwerken in kusthavens: deelrapport 3. Golfbelasting Mercatorsluis
Creators: name: Vanneste, Dieter
name: Nguyen, Duc Anh
name: De Roo, Sieglien
Publisher: name: Flanders Hydraulics Research
Year: 2023

description: Title : WL Rapporten. Waterbouwkundig Laboratorium: Antwerpen.
Volume : 20_025_3
Issue :
Pagination : IX, 47 + 12 p. bijl.
WHY ADOPT INTEGRATED CROP PRODUCTION? A PERSPECTIVE FROM THE FRENCH FRUIT SECTOR
Creators: name: Sterns, James A.
name: Codron, Jean-Marie
name: Sterns, James A.
name: Codron, Jean-Marie
Publisher: name: Unknown
Year: 2001
Subjects: Crop Production/Industries

description: Are changes in consumer demand and concentration in food retail altering market structures so that integrated production practices like IPM and ICM will become not only widely adopted but essential if growers want to maintain access to markets? Data on the European fresh produce sector are analyzed, applying Randall Bartlett's economic theory of power. The authors conclude that if current trends continue, then the answer to the question posed could soon be, "yes."