cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Approaching optimality in blow-up results for Keller-Segel systems with logistic-type dampening
Creators: name: Fuest, Mario
Publisher: name: arXiv
Year: 2020
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35B44 (primary), 35B33, 35K65, 92C17 (secondary)

description: Nonnegative solutions of the Neumann initial-boundary value problem for the chemotaxis system \begin{align}\label{prob:star}\tag{$\star$} \begin{cases} u_t = Δu - \nabla \cdot (u \nabla v) + λu - μu^κ, \\\\ 0 = Δv - \overline m(t) + u, \quad \overline m(t) = \frac1{|Ω|} \int_Ωu(\cdot, t) \end{cases} \end{align} in smooth bounded domains $Ω\subset \mathbb R^n$, $n \ge 1$, are known to be global-in-time if $λ\geq 0$, $μ> 0$ and $κ> 2$. In the present work, we show that the exponent $κ= 2$ is actually critical in the four- and higher dimensional setting. More precisely, if \begin{alignat*}{3} \qquad n &\geq 4, &&\quad κ\in (1, 2) \quad &&\text{and} \quad μ> 0 \\\\ \text{or}\qquad n &\geq 5, &&\quad κ= 2 \quad &&\text{and} \quad μ\in \left(0, \frac{n-4}{n}\right), \end{alignat*} for balls $Ω\subset \mathbb R^n$ and parameters $λ\geq 0$, $m_0 > 0$, we construct a nonnegative initial datum $u_0 \in C^0(\overline Ω)$ with $\int_Ωu_0 = m_0$ for which the corresponding solution $(u, v)$ of \eqref{prob:star} blows up in finite time. Moreover, in 3D, we obtain finite-time blow-up for $κ\in (1, \frac32)$ (and $λ\geq 0$, $μ> 0$). As the corner stone of our analysis, for certain initial data, we prove that the mass accumulation function $w(s, t) = \int_0^{\sqrt[n]{s}} ρ^{n-1} u(ρ, t) \,\mathrm dρ$ fulfills the estimate $w_s \le \frac{w}{s}$. Using this information, we then obtain finite-time blow-up of $u$ by showing that for suitably chosen initial data, $s_0$ and $γ$, the function $ϕ(t) = \int_0^{s_0} s^{-γ} (s_0 - s) w(s, t)$ cannot exist globally.
description: 13 pages
UNDERPINNINGS FOR PROSPECTIVE, NET REVENUE FORECASTING IN HOG FINISHING: CHARACTERIZING THE JOINT DISTRIBUTION OF CORN, SOYBEAN MEAL AND LEAN HOGS TIME SERIES
Creators: name: Shao, Renyuan
name: Roe, Brian E.
name: Shao, Renyuan
name: Roe, Brian E.
Publisher: name: Unknown
Year: 2001
Subjects: Livestock Production/Industries

description: This research focuses on developing a biannual net revenue forecasting model for hog producers based on Monte Carlo simulation of the joint distribution of hog, corn and soybean meal price series. The relative forecasting power of historical volatility, implied volatility and GARCH-based volatility is examined. Consistent with recent research, the performance of these three methods is both commodity and horizon specific, which means there is no single best predictor. However, implied volatility often performs well. Thus, implied volatility is used to forecast variance. Historical covariance is introduced to capture the co-movement of the three price series. Our forecasting model performs well out of sample; most of the realized net revenues fall in 95 percent prediction interval. Based on this forecasting model and the assumption of a utility function, we compare our prospective evaluation with retrospective evaluation of risk management strategies. Though prospective evaluation is not significantly superior to retrospective evaluation for this particular dataset, it is useful because all the market information has been incorporated in this model and because it did protect producers from adverse price movements.
Ubiquitylome data
Creators: name: Touming Liu
Publisher: name: figshare
Year: 2021
Subjects: subject: 60109 Proteomics and Intermolecular Interactions (excl. Medical Proteomics)
subject: FOS: Biological sciences

description: According to a previous study on the microscopic examination of stem barks in ramie, bast fibers from different parts of stem bark showed distinct differences at the developmental level: specifically, the barks in the top part of stem (TPS) did not initiate fiber growth, whereas barks in the middle part of stem (MPS) had a large number of fibers with thickening secondary walls. These datasets represent the raw UHPLC spectra for ubiquitylome of ramie TPS and MPS.
Unobserved Heterogeneity: Evidence and Implications for SMEs' Hedging Behavior
Creators: name: Pennings, Joost M.E.
name: Garcia, Philip
name: Pennings, Joost M.E.
name: Garcia, Philip
Publisher: name: Unknown
Year: 2001
Subjects: subject: Marketing
subject: FOS: Economics and business

description: Financial research indicates that several firm characteristics are related to the use of derivatives. Less attention has been paid to the role of the characteristics of managers, which are particularly important when studying derivative usage of small and medium sized enterprises (SMEs). In this paper we focus on the influence of manager's level of education, the manager's decision-making unit, and the fundamental determinants of risk management - managerial risk attitude and managerial risk perception - on SMEs' commodity derivative usage. In empirical studies to date, the heterogeneity of derivative users has been neglected. We propose a generalized mixture regression model that estimates the relationship between commodity derivative usage and a set of explanatory variables across segments of an industry. Accounting for unobserved heterogeneity reveals that segments of the industry have different determinants of derivative use. Moreover, the heterogeneity at the segment level appears to mask significant effects at the aggregate level, most notably the effects of risk attitude and risk perception.
Non-equilibrium and Irreversible Simulation of Competition among Languages
Creators: name: Stauffer, D.
name: Schulze, C.
name: Lima, F. W. S.
name: Wichmann, S.
name: Solomon, S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: The bit-string model of Schulze and Stauffer (2005) is applied to non-equilibrium situations and then gives better agreement with the empirical distribution of language sizes. Here the size is the number of people having this language as mother tongue. In contrast, when equilibrium is combined with irreversible mutations of languages, one language always dominates and is spoken by at least 80 percent of the population.
description: 9 pages including 4 figures
On the applicability of the equations-of-motion technique for quantum dots
Creators: name: Kashcheyevs, Vyacheslavs
name: Aharony, Amnon
name: Entin-Wohlman, Ora
Publisher: name: arXiv
Year: 2005
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The equations-of-motion (EOM) hierarchy satisfied by the Green functions of a quantum dot embedded in an external mesoscopic network is considered within a high-order decoupling approximation scheme. Exact analytic solutions of the resulting coupled integral equations are presented in several limits. In particular, it is found that at the particle-hole symmetric point the EOM Green function is temperature-independent due to a discontinuous change in the imaginary part of the interacting self-energy. However, this imaginary part obeys the Fermi liquid unitarity requirement away from this special point, at zero temperature. Results for the occupation numbers, the density of states and the local spin susceptibility are compared with exact Fermi liquid relations and the Bethe ansatz solution. The approximation is found to be very accurate far from the Kondo regime. In contrast, the description of the Kondo effect is valid on a qualitative level only. In particular, we find that the Friedel sum rule is considerably violated, up to 30%, and the spin susceptibility is underestimated. We show that the widely-used simplified version of the EOM method, which does not account fully for the correlations on the network, fails to produce the Kondo correlations even qualitatively.
description: 16 pages, 5 figures
A practical criterion of irreducibility of multi--loop Feynman integrals
Creators: name: Baikov, P. A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A practical criterion for the irreducibility (with respect to integration by part identities) of a particular Feynman integral to a given set of integrals is presented. The irreducibility is shown to be related to the existence of stable (with zero gradient) points of a specially constructed polynomial.
Reconfigurable intelligent surface (RIS): Eigenvalue Decomposition-Based Separate Channel Estimation
Creators: name: Zegrar, Salah Eddine
name: Afeef, Liza
name: Arslan, Huseyin
Publisher: name: arXiv
Year: 2020
Subjects: subject: Signal Processing (eess.SP)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Reconfigurable intelligent surface (RIS) has recently drawn significant attention in wireless communication technologies. However, identifying, modeling, and estimating the RIS channel in multiple-input multiple-output (MIMO) systems are considered challenging in recent studies. In this paper, a disassembled channel estimation framework for the RIS-MIMO system is proposed based on the eigenvalue decomposition (EVD) concept to separate the cascaded channel links and estimate each link separately. This estimation is based on modeling the RIS-MIMO channel as a keyhole MIMO system model. Numerical results show that the proposed estimation method has a low estimation time overhead while providing less estimation error.
description: Published in: 2021 IEEE 32nd Annual International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)
Why Don't Country Elevators Pay Less for Low Quality Wheat? Information, Producer Preferences and Prospect Theory
Creators: name: Adam, Brian D.
name: Hong, Seung Jee
name: Adam, Brian D.
name: Hong, Seung Jee
Publisher: name: Unknown
Year: 2001
Subjects: Crop Production/Industries
Demand and Price Analysis

description: Previous research found that country elevators that are the first in their area to grade wheat and pay quality-adjusted prices would receive above-normal profits at the expense of their competitors. Because of spatial monopsony, these early-adopting elevators would pass on to producers only 70% of the quality-based price differentials received from next-in-line buyers. If competing elevators also adopted these practices, profits for all elevators would return to near normal, and elevators would pass on to producers nearly all price differentials received from next-in-line buyers. However, that research could not explain why more elevators were not becoming "early adopters" by paying quality-adjusted prices. More recent research found that producers' risk aversion and lack of information about the quality of their wheat could explain more of the failure of country elevators to pass on premiums and discounts. If producers are risk averse, an elevator that imposes discounts for lower quality wheat, even while paying a higher price for high quality wheat, risks losing business if producers believe that a competing elevator may be more likely to pay them a higher price net of discounts. However, even more important is the level of information producers have about the quality of their wheat before selling it to an elevator. Still, these explanations account for only part of elevators' apparent reluctance to pay quality-adjusted prices. Since inconsistencies have been observed between expected utility and individuals' behavior, this research considers the case where producers' preferences can be more appropriately modeled by prospect theory, and whether such preferences can explain more of elevators' reluctance to pay quality-adjusted prices. A simulation model is used to measure the effects of risk-averse producers (in both expected utility and prospect theory frameworks) and limited quality information on profits that can be earned by an elevator that pays quality-adjusted prices. Results indicate that prospect theory helps to explain part, but not all, of the reluctance to pay quality-adjusted prices.
Estimating Actual Bid-Ask Spreads in Commodity Futures Markets
Creators: name: Bryant, Henry L.
name: Haigh, Michael S.
name: Bryant, Henry L.
name: Haigh, Michael S.
Publisher: name: Unknown
Year: 2001
Subjects: subject: Marketing
subject: FOS: Economics and business

description: Various bid-ask spread estimators are applied to transaction data from LIFFE cocoa and coffee futures markets, and the resulting estimates are compared to observed actual bid-ask spreads. Results suggest that actual bid-ask spreads, which are not reported by most open-outcry futures markets, can be reasonably estimated using readily available transaction data. This is especially important since recent research seems to indicate that efforts to estimate effective spreads using data commonly available from futures markets have not been successful. Thus estimates of actual spreads can give market participants and researchers some idea of potential transaction costs. Accurate estimates of bid-ask spreads will also be needed to assess the relative efficiency of electronic versus open-outcry trading. Results indicate that estimators using averages of absolute price changes perform significantly better at estimating actual bid-ask spreads in futures markets than estimators using the covariance of successive price changes.
Tidal coupling of a Schwarzschild black hole and circularly orbiting moon
Creators: name: Fang, Hua
name: Lovelace, Geoffrey
Publisher: name: arXiv
Year: 2005
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We describe the possibility of using LISA's gravitational-wave observations to study, with high precision, the response of a massive central body to the tidal gravitational pull of an orbiting, compact, small-mass object. Motivated by this application, we use first-order perturbation theory to study tidal coupling for an idealized case: a massive Schwarzschild black hole, tidally perturbed by a much less massive moon in a distant, circular orbit. We investigate the details of how the tidal deformation of the hole gives rise to an induced quadrupole moment in the hole's external gravitational field at large radii. In the limit that the moon is static, we find, in Schwarzschild coordinates and Regge-Wheeler gauge, the surprising result that there is no induced quadrupole moment. We show that this conclusion is gauge dependent and that the static, induced quadrupole moment for a black hole is inherently ambiguous. For the orbiting moon and the central Schwarzschild hole, we find (in agreement with a recent result of Poisson) a time-varying induced quadrupole moment that is proportional to the time derivative of the moon's tidal field. As a partial analog of a result derived long ago by Hartle for a spinning hole and a stationary distant companion, we show that the orbiting moon's tidal field induces a tidal bulge on the hole's horizon, and that the rate of change of the horizon shape leads the perturbing tidal field at the horizon by a small angle.
description: 14 pages, 0 figures, submitted to Phys. Rev. D
Wilson loops in 5d long quiver gauge theories
Creators: name: Uhlemann, Christoph F.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Quiver gauge theories with a large number of nodes host a wealth of Wilson loop operators. Expectation values are obtained, using supersymmetric localization, for Wilson loops in the antisymmetric representations associated with each individual gauge node, for a sample of 5d long quiver gauge theories whose UV fixed points have holographic duals in Type IIB. The sample includes the $T_N$ theories and the results are uniformly given in terms of Bloch-Wigner functions. The holographic representation of the Wilson loops is identified. It comprises, for each supergravity solution, a two-parameter family of D3-branes which exactly reproduce the field theory results and identify points in the internal space with the faces of the associated 5-brane web. The expectation values of (anti)fundamental Wilson loops exhibit an enhanced scaling for many operators, which matches between field theory and supergravity.
description: 43 pages, 7 figures
Emerging Issues and Challenges in Applied Commodity Price Analysis
Creators: name: Hayenga, Marvin L.
name: Hayenga, Marvin L.
Publisher: name: Unknown
Year: 2001
Subjects: Demand and Price Analysis

description: This organization (NCR-134) began 20 years ago to serve as a meeting ground for applied commodity price analysts in academic, business and government positions. The primary objective was to foster interaction, and discuss recent applied research and extension applications, and emerging related issues that might warrant attention. The interchange of ideas has continued for 20 years, and your participation over the years has made it the success that it is today. My focus today will not be on history, however. Rather, it is a set of observations about how I see the world in which we operate, and some challenges and opportunities that deserve more thought and attention as we serve our various customers for our professional expertise. My goal is to provide one useful idea to each of you.
AN ECONOMIC ANALYSIS OF COCA ERADICATION POLICY IN COLOMBIA
Creators: name: Moreno-Sanchez, Rocio Del Pilar
name: Kraybill, David S.
name: Thompson, Stanley R.
name: Moreno-Sanchez, Rocio Del Pilar
name: Kraybill, David S.
name: Thompson, Stanley R.
Publisher: name: Unknown
Year: 2002
Subjects: Political Economy

description: We estimate an econometric model of coca production in Colombia. Our results indicate that coca eradication is an ineffective means of supply control as farmers compensate by cultivating the crop more extensively. The evidence further suggests that incentives to produce legal substitute crops may have greater supply-reducing potential than eradication.
The intersection of race and party: voter perceptions and candidate selection in U.S. Senate elections
Creators: name: Meyer, Chase B.
name: Boyle, Kaitlin M.
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Neuroscience
subject: Sociology
subject: FOS: Sociology
subject: 111714 Mental Health
subject: FOS: Health sciences

description: Previous literature suggests that Democratic candidates of color receive less support than white Democrats on Election Day. It has been suggested that this reduced support is due to voters’ ideological perceptions of people of color being more liberal than whites, which translates into perceptions of candidates. However, these studies are frequently limited to white voters’ perceptions of Democratic candidates of color, and the full relationship linking race/ethnicity, to ideological placement, to vote choice has rarely been tested. In the current study, we examine how both the race/ethnicity and party affiliation of Senate candidates shape perceptions of their ideology and vote choice among people of all race and ethnicities. Using the 2006–2018 Cooperative Congressional Election Study, we find support for our hypothesis that Black Democrats are generally perceived as more liberal than white Democrats. These perceptions have real consequences, resulting in fewer votes. Conversely, Black Republican candidates are perceived to be just as conservative—and Hispanic Republicans even more conservative—than white Republican candidates. Findings suggest that the link between race/ethnicity, perceptions of ideology, and electoral success vary according to the race/ethnicity and party of candidates.
Performance of Linear Coding and Transmission in Low-Latency Computer Vision Offloading -- Supplementary Material
Creators: name: Žádník, Jakub
name: Trioux, Anthony
name: Kieffer, Michel
name: Mäkitalo, Markku
name: Coudoux, François-Xavier
name: Corlay, Patrick
name: Jääskeläinen, Pekka
Publisher: name: Zenodo
Year: 2024

description: Supplementary material to the paper “Performance of Linear Coding and Transmission in Low-Latency Computer Vision Offloading” accepted for IEEE Wireless Communications and Networking Conference (WCNC) 2024 conference.
PROTECTING CONTRACT GROWERS OF BROILER CHICKEN INDUSTRY
Creators: name: Helal, Uddin
name: Helal, Uddin
Publisher: name: Unknown
Year: 2002
Subjects: Livestock Production/Industries

description: In case of the tournament based pay-structure, the regulator may be able to increase the welfare of the growers regulating the average performance standard upward. Since she cares about the welfare of the growers, her optimal is to leave part of the surplus to the growers. She does this through setting the relative standard at all others' average inflated by some function of the weight. If there is budgetary constraint then the regulator may not be able to implement this inflated standard.
B-type supergiants in the SMC: Rotational velocities and implications for evolutionary models
Creators: name: Dufton, P. L.
name: Ryans, R. S. I.
name: Simon-Diaz, S.
name: Trundle, C.
name: Lennon, D. J.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: High-resolution spectra for 24 SMC and Galactic B-type supergiants have been analysed to estimate the contributions of both macroturbulence and rotation to the broadening of their metal lines. Two different methodologies are considered, viz. goodness-of-fit comparisons between observed and theoretical line profiles and identifying zeros in the Fourier transforms of the observed profiles. The advantages and limitations of the two methods are briefly discussed with the latter techniques being adopted for estimated projected rotational velocities (\vsini) but the former being used to estimate macroturbulent velocities. Only one SMC supergiant, SK 191, shows a significant degree of rotational broadening (\vsini $\simeq$ 90 \kms). For the remaining targets, the distribution of projected rotational velocities are similar in both our Galactic and SMC samples with larger values being found at earlier spectral types. There is marginal evidence for the projected rotational velocities in the SMC being higher than those in the Galactic targets but any differences are only of the order of 5-10 \kms, whilst evolutionary models predict differences in this effective temperature range of typically 20 to 70 \kms. The combined sample is consistent with a linear variation of projected rotational velocity with effective temperature, which would imply rotational velocities for supergiants of 70 \kms at an effective temperature of 28 000 K (approximately B0 spectral type) decreasing to 32 \kms at 12 000 K (B8 spectral type). For all targets, the macroturbulent broadening would appear to be consistent with a Gaussian distribution (although other distributions cannot be discounted) with an $\frac{1}{e}$ half-width varying from approximately 20 \kms at B8 to 60 \kms at B0 spectral types.
description: 4 figures, 8 pages, submitted to Astronomy and Astrophysics
Diamagnetic d-orbitals Drive Magnetic Structure Selection in the Double Perovskite Ba$_2$MnTeO$_6$
Creators: name: Mustonen, Otto H. J.
name: Pughe, Charlotte E.
name: Walker, Helen C.
name: Mutch, Heather M.
name: Stenning, Gavin B. G.
name: Coomer, Fiona C.
name: Cussen, Edmund J.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: B-site ordered A$_2$B'B''O$_6$ double perovskites have a variety of applications as magnetic materials. Here we show that diamagnetic $d^{10}$ and $d^0$ B'' cations have a significant effect on the magnetic interactions in these materials. We present a neutron scattering and theoretical study of the Mn$^{2+}$ double perovskite Ba$_2$MnTeO$_6$ with a $4d^{10}$ Te$^{6+}$ cation on the B''-site. It is found to be a Type I antiferromagnet with a dominant nearest-neighbor $J_1$ interaction. In contrast, the $5d^0$ W$^{6+}$ analogue Ba$_2$MnWO$_6$ is a Type II antiferromagnet with a significant next-nearest-neighbor $J_2$ interaction. This is due to a $d^{10}$/$d^0$ effect, where the different orbital hybridization with oxygen 2p results in different superexchange pathways. We show that $d^{10}$ B'' cations promote nearest neighbor and $d^0$ cations promote next-nearest-neighbor interactions. The $d^{10}$/$d^0$ effect could be used to tune magnetic interactions in double perovskites.
description: 21+4 pages
First detection of 13CH in the interstellar medium
Creators: name: Jacob, Arshia M.
name: Menten, Karl M.
name: Wiesemeyer, Helmut
name: Guesten, Rolf
name: Wyrowski, Friedrich
name: Klein, Bernd
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: In recent years, a plethora of high spectral resolution observations of sub-mm and FIR transitions of methylidene (CH), have demonstrated this radical to be a valuable proxy for H2, that can be used for characterising molecular gas within the interstellar medium (ISM) on a Galactic scale, including the CO-dark component. Here we report the discovery of the 13CH isotopologue in the ISM using the upGREAT receiver on board SOFIA. We have detected the three hyperfine structure components of the 2THz frequency transition from its ground-state toward four high-mass star-forming regions and determine 13CH column densities. The ubiquity of molecules containing carbon in the ISM has turned the determination of the ratio between the abundances of carbon's two stable isotopes, 12C/13C, into a cornerstone for Galactic chemical evolution studies. Whilst displaying a rising gradient with Galactocentric distance, this ratio, when measured using observations of different molecules (CO, H2CO, and others) shows systematic variations depending on the tracer used. These observed inconsistencies may arise from optical depth effects, chemical fractionation or isotope-selective photo-dissociation. Formed from C+ either via UV-driven or turbulence-driven chemistry, CH reflects the fractionation of C+, and does not show any significant fractionation effects unlike other molecules previously used to determine the 12C/13C isotopic ratio which make it an ideal tracer for the 12C/13C ratio throughout the Galaxy. Therefore, by comparing the derived column densities of 13CH with previously obtained SOFIA data of the corresponding transitions of the main isotopologue 12CH, we derive 12C/13C isotopic ratios toward Sgr B2(M), G34.26+0.15, W49(N) and W51E. Adding our values derived from 12/13CH to previous calculations of the Galactic isotopic gradient we derive a revised value of 12C/13C = 5.85(0.50)R_GC + 15.03(3.40).
PRODUCTIVITY AND EFFICIENCY OF INDIVIDUAL FARMS IN POLAND: A CASE FOR LAND CONSOLIDATION
Creators: name: Lerman, Zvi
name: Lerman, Zvi
Publisher: name: Unknown
Year: 2002
Subjects: Productivity Analysis

description: The article examines productivity and efficiency of Polish individual farms, contributing to the policy debate on excessive fragmentation and the need for land consolidation. Data of a rural household survey conducted in the spring of 2000 show that Polish individual farms in the size range of up to 100 hectares have positive marginal productivity of land and increasing returns to scale. Among the individual farms surveyed, larger farms report higher household incomes from farm and non-farm sources combined. Rural families cultivating larger land holdings are observed to be substantially better off than families with relatively small allotments.
IMPACTS OF UNIVERSITY FINANCIAL AND ACADEMIC SUPPORT ON STUDENT PERFORMANCE AT THE SS-AAEA QUIZBOWL COMPETITION AND IN THE CLASSROOM
Creators: name: Popp, Jennie S. Hughes
name: Popp, Jennie S. Hughes
Publisher: name: Unknown
Year: 2002
Subjects: Teaching/Communication/Extension/Profession

description: A 2001 survey of SS-AAEA Quizbowl participants suggested potential benefits of the SS-AAEA Quizbowl Competition to students' academic performance. A new survey of quizbowl advisers is used with the previous data to determine the impact of a university's academic and/or financial support of participants on students' performances at the competition.
Hypervirial Models of Stellar Systems
Creators: name: Evans, N. W.
name: An, J.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: A family of cusped potential-density pairs is presented for modelling galaxies and dark haloes. The density profile is cusped like 1/r^(2-p) at small radii. The distribution function is simple and takes the form L^(p-2) E^[(3p+1)/2] where E is the binding energy and L is the angular momentum. The models all possess the remarkable property that the virial theorem holds locally, from which they earn their name as the hypervirial family. Famously, this property was first discovered by Eddington to hold for the Plummer model in 1916. In fact, the seductive properties of the Plummer model extend to the whole hypervirial family, including the members possessing the cosmologically important cusps of 1/r or 1/r^1.5 or 1/r^1.33. The intrinsic and projected properties of the family of models are discussed in some detail.
description: essentially identical to the published version with an additional appendix
Did the party system change from 2012–2016?
Creators: name: Santucci, Jack
Publisher: name: Taylor & Francis
Year: 2020
Subjects: subject: Neuroscience
subject: Sociology
subject: FOS: Sociology
subject: Science Policy
subject: 111714 Mental Health
subject: FOS: Health sciences

description: We test the implications of the spatial realignment framework against data from the 2012–2016 electoral cycle. The data, which come from the 2011–2016 Voter Study Group survey, include 19 items asked of the same 4705 respondents in two periods. Social issues improved in their ability to separate liberals from conservatives, as well as Republican from Democratic voters. There was limited but statistically significant decline in polarization on some economic items (except trade). Decreased inter-party division on economic items has come with increased intra-party division, albeit asymmetrically between parties and across issues. Increased intra-party divisions are due to vote-switchers not having adopted their new parties’ positions. The changes we find are small and mostly consistent with spatial realignment. Overall, they amount to diminution of class-based politics, including on some social issues with redistributive implications.
Finite-dimensional representations of the symmetry algebra of the dihedral Dunkl--Dirac operator
Creators: name: De Bie, Hendrik
name: Langlois-Rémillard, Alexis
name: Oste, Roy
name: Van der Jeugt, Joris
Publisher: name: arXiv
Year: 2020
Subjects: subject: Representation Theory (math.RT)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: The Dunkl--Dirac operator is a deformation of the Dirac operator by means of Dunkl derivatives. We investigate the symmetry algebra generated by the elements supercommuting with the Dunkl--Dirac operator and its dual symbol. This symmetry algebra is realised inside the tensor product of a Clifford algebra and a rational Cherednik algebra associated with a reflection group or root system. For reducible root systems of rank three, we determine all the irreducible finite-dimensional representations and conditions for unitarity. Polynomial solutions of the Dunkl--Dirac equation are given as a realisation of one family of such irreducible unitary representations.
description: v3 40p. Final version accepted in J. Algebra. See v2 for proof of Thm 4.1
title: Origin of the mid-temperature transition in vinylidenefluoride-based ferro-, pyro- and piezoelectric homo-, co- and ter-polymers
Creators: name: Venkatesan, Thulasinath Raman
name: Gerhard, Reimund
Publisher: name: Universität Potsdam
Year: 2020

description: The existence of an intermediate transition between the glass and the Curie/melting temperatures in Poly(vinylidene fluoride) (PVDF) and some of its co- and ter-polymers has been reported by several authors. In spite (or because?) of various different explanations in the literature, the origins of the transition are still not clear. Here, we try to understand the extra transition in more detail and study it with thermal and dielectric methods on PVDF, on its co-polymers with trifluoroethylene (P(VDF-TrFE)) and tetrafluoroethylene (P(VDF-TFE)), and on its ter-polymer with trifluoroethylene and chlorofluoroethylene (P(VDF-TrFE-CFE). Based on interpretations from the literature and our experimental studies, we propose the new hypothesis that the intermediate transition should have several interrelated origins. Especially since the relevant range is not far above room temperature, better understanding and control of their properties may also have practical implications for the use of the respective polymer materials in devices.
description: Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe, 977
THE ROLES OF BELIEFS, INFORMATION, AND CONVENIENCE IN THE AMERICAN DIET
Creators: name: Mancino, Lisa
name: Mancino, Lisa
Publisher: name: Unknown
Year: 2002
Subjects: Food Consumption/Nutrition/Food Safety

description: This study's objective is to explicitly assume that time pressures and perceived hunger lead to greater demand for convenience. In turn, this leads to an increased consumption of fat. As such, estimated demand will be a function of prices, income, time constraints, health information, sensitivity to time delay and the convenience of the meal.
description: Replaced with revised version of paper 08/02.
A fast method for computing strong-lensing cross sections: Application to merging clusters
Creators: name: Fedeli, C.
name: Meneghetti, M.
name: Bartelmann, M.
name: Dolag, K.
name: Moscardini, L.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Strong gravitational lensing by irregular mass distributions, such as galaxy clusters, is generally not well quantified by cross sections of analytic mass models. Computationally expensive ray-tracing methods have so far been necessary for accurate cross-section calculations. We describe a fast, semi-analytic method here which is based on surface integrals over high-magnification regions in the lens plane and demonstrate that it yields reliable cross sections even for complex, asymmetric mass distributions. The method is faster than ray-tracing simulations by factors of $\sim30$ and thus suitable for large cosmological simulations, saving large amounts of computing time. We apply this method to a sample of galaxy cluster-sized dark matter haloes with simulated merger trees and show that cluster mergers approximately double the strong-lensing optical depth for lens redshifts $z_\mathrm{l}\gtrsim0.5$ and sources near $z_\mathrm{s} = 2$. We believe that this result hints at one possibility for understanding the recently detected high arcs abundance in clusters at moderate and high redshifts, and is thus worth further studies.
description: 12 pages, 18 figures, accepted for publication on Astronomy and Astrophysics. Added the subsection "Source Properties" and 3 figures
THE DETERMINANTS OF COUPON DISCOUNTS FOR BREAKFAST CEREALS
Creators: name: Price, Gregory K.
name: Connor, John M.
name: Price, Gregory K.
name: Connor, John M.
Publisher: name: Unknown
Year: 2002
Subjects: subject: Marketing
subject: FOS: Economics and business

description: This study identifies the determinants of coupon values at the brand level using a framework developed from price discrimination theory and the principles of demand. Couponing is considered within the context of a complex marketing program in which it is coordinated with other non-price promotional strategies. A simultaneous, two-equation, fixed-effects, panel-data model is specified and fitted with data on household purchases of ready-to-eat (RTE) breakfast cereals between 1992 and 1997. The empirical model accounts for the bi-directional causality between brand prices and discount levels and captures the retail effects of the major cereal maker's price cuts and discount reductions that occurred in 1996. Higher brand prices cause coupon values to rise, supporting the hypothesis that cereal makers price discriminate among consumers. Other non-price promotions, including advertising, store flyers, and in-store displays, appear to be coordinated with couponing. Specifically, coupon values fall with more intense advertising and in-store displays but rise when the couponed products are featured in store flyers. Discount levels are positively related to brand market share and the size of discounts that are redeemed for rival cereals. Moreover, coupon values fall with increasing brand loyalty among RTE cereal purchasers. Cereal prices are positively affected by coupon values, advertising expenditures, food-ingredient and packaging costs, and the prices of competing brands. Inventory levels are negatively correlated with brand price. Employee wages were not found to significantly influence cereal prices.
On the leading terms of Zeta isomorphisms and p-adic L-functions in non-commutative Iwasawa theory
Creators: name: Burns, David
name: Venjakob, Otmar
Publisher: name: arXiv
Year: 2005
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11G40

description: We discuss the formalism of Iwasawa theory descent in the setting of the localized K_1-groups of Fukaya and Kato. We then prove interpolation formulas for the `leading terms' of the global Zeta isomorphisms that are associated to certain Tate motives and of the p-adic L-functions that are associated to certain critical motives.
description: 38 pages; added references and corrected typos
Linearized Quantum Gravity Using the Projection Operator Formalism
Creators: name: Bomstad, Wayne R.
name: Klauder, John R.
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The theory of canonical linearized gravity is quantized using the Projection Operator formalism, in which no gauge or coordinate choices are made. The ADM Hamiltonian is used and the canonical variables and constraints are expanded around a flat background. As a result of the coordinate independence and linear truncation of the perturbation series, the constraint algebra surprisingly becomes partially second-class in both the classical and quantum pictures after all secondary constraints are considered. While new features emerge in the constraint structure, the end result is the same as previously reported: the (separable) physical Hilbert space still only depends on the transverse-traceless degrees of freedom.
description: 30 pages, no figures, enlarged and corrected version
Bremsstrahlung in GRMHD models of accreting black holes
Creators: name: Yarza, R.
name: Wong, G. N.
name: Ryan, B. R.
name: Gammie, C. F.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The role of bremsstrahlung in the emission from hot accretion flows around slowly accreting supermassive black holes is not thoroughly understood. In order to appraise the importance of bremsstrahlung relative to other radiative processes, we compute spectral energy distributions (SEDs) of accretion disks around slowly accreting supermassive black holes including synchrotron radiation, inverse Compton scattering, and bremsstrahlung. We compute SEDs for (i) four axisymmetric radiative general relativistic magnetohydrodynamics (RadGRMHD) simulations of $10^{8}M_{\odot}$ black holes with accretion rates between $10^{-8}\dot{M}_{\text{Edd}}$ and $10^{-5}\dot{M}_{\text{Edd}}$, (ii) four axisymmetric RadGRMHD simulations of M87$^\ast$ with varying dimensionless spin $a_\ast$ and black hole mass, and (iii) a 3D GRMHD simulation scaled for Sgr A$^\ast$. At $10^{-8}\dot{M}_{\text{Edd}}$, most of the luminosity is synchrotron radiation, while at $10^{-5}\dot{M}_{\text{Edd}}$ the three radiative processes have similar luminosities. In most models, bremsstrahlung dominates the SED near $512\text{ keV}$. In the M87$^\ast$ models, bremsstrahlung dominates this part of the SED if $a_{\ast} = 0.5$, but inverse Compton scattering dominates if $a_{\ast}= 0.9375$. Since scattering is more variable than bremsstrahlung, this result suggests that $512\text{ keV}$ variability could be a diagnostic of black hole spin. In the appendix, we compare some bremsstrahlung formulae found in the literature.
description: 10 pages, 5 figures, accepted for publication in ApJ
Galaxy Models with Tangentially Anisotropic Velocity Distributions
Creators: name: an, J. H.
name: Evans, N. W.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: This paper provides two families of flexible and simple galaxy models. Representatives of many of the families possess the important cosmological cusps, with the density behaving like 1/r or 1/r^1.33 or 1/r^1.5 at small radii. The density falls off between 1/r^3 and 1/r^5 at large radii. We provide analytic and anisotropic distribution functions for all the models. Unlike many existing methods, our algorithm can yield tangentially anisotropic velocity dispersions in the outer parts, and so is useful for modeling populations of satellite galaxies and substructure in host galaxy halos. As an application, we demonstrate the degeneracy between mass and anisotropy for the satellite galaxy population of the Milky Way. This can introduce a factor of ~3 uncertainty in the mass of the Milky Way as inferred from the kinematics of the satellite population.
description: to appear in AJ, extended appendix, typo corrected from the 2nd version (completely rewritten from the 1st version, see also astro-ph/0508419 for some materials split from the 1st version)
Economic vote and globalization before and during the Great Recession
Creators: name: Giuliani, Marco
Publisher: name: Taylor & Francis
Year: 2019
Subjects: subject: Ecology
subject: FOS: Biological sciences
subject: Sociology
subject: FOS: Sociology
subject: Science Policy

description: The Great Recession undoubtedly reduced the electoral prospects of incumbent parties, coherently with the expectations of the economic vote theory. Yet, the exceptionality of the period may have displaced other elements of that theory, such as, for instance, the moderating impact that globalization is supposed to have on the retrospective mechanism. By using an original dataset comparing 168 elections in 38 democratic countries in the period 2000–2015, we detail how the crisis modified and even reversed that conditional effect. Furthermore, we differentiate our results by separating the impact of economic openness from that of political globalization. In so doing, we improve our understanding of the mechanisms that trigger the conditional effect on the economic vote in normal and exceptional times.
ARE HOUSEHOLD PRODUCTION DECISIONS COOPERATIVE? EVIDENCE ON MIGRATION AND MILK SALES FROM NORTHERN KENYA
Creators: name: McPeak, John G.
name: Doss, Cheryl R.
name: McPeak, John G.
name: Doss, Cheryl R.
Publisher: name: Unknown
Year: 2002
Subjects: Consumer/Household Economics

description: Among the Gabra of Northern Kenya, men decide where to migrate with the household herds while women decide whether to sell milk. We test three models of household decision-making. The results suggest that household decisions are contested. Husbands appear to use migration decisions to resist their wive's access to income.
description: Replaced with revised version of paper 08/29/02.
Current scaling of the topological quantum phase transition between a quantum anomalous Hall insulator and a trivial insulator
Creators: name: Kawamura, Minoru
name: Mogi, Masataka
name: Yoshimi, Ryutaro
name: Tsukazaki, Atsushi
name: Kozuka, Yusuke
name: Takahashi, Kei S.
name: Kawasaki, Masashi
name: Tokura, Yoshinori
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We report a current scaling study of a quantum phase transition between a quantum anomalous Hall insulator and a trivial insulator on the surface of a heterostructure film of magnetic topological insulators. The transition was observed by tilting the magnetization while measuring the Hall conductivity $σ_{xy}$. The transition curves of $σ_{xy}$ taken under various excitation currents cross each other at a single point, exemplifying a quantum critical behavior of the transition. The slopes of the transition curves follow a power law dependence of the excitation current, giving a scaling exponent. Combining with the result of the previous temperature scaling study, critical exponents $ν$ for the localization length and $p$ for the coherence length are separately evaluated as $ν$ = 2.8 $\pm$ 0.3 and $p$ = 3.3 $\pm$ 0.3.
description: 6 pages, 4 figures
Galaxy Bias and $σ_8$ from Counts in Cells from the SDSS Main Sample
Creators: name: Repp, Andrew
name: Szapudi, István
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The counts-in-cells (CIC) galaxy probability distribution depends on both the dark matter clustering amplitude $σ_8$ and the galaxy bias $b$. We present a theory for the CIC distribution based on a previous prescription of the underlying dark matter distribution and a linear volume transformation to redshift space. We show that, unlike the power spectrum, the CIC distribution breaks the degeneracy between $σ_8$ and $b$ on scales large enough that both bias and redshift distortions are still linear; thus we obtain a simultaneous fit for both parameters. We first validate the technique on the Millennium Simulation and then apply it to the SDSS Main Galaxy Sample. We find $σ_8 = 0.94^{+.11}_{-.10}$ and $b = 1.36^{+.14}_{-.11}$, consistent with previous complementary results from redshift distortions and from Planck.
description: 5 pages, 3 figures; submitted to MNRAS
Addendum to the discussion of "Breakdown and groups"
Creators: name: Davies, P. Laurie
name: Gather, Ursula
Publisher: name: arXiv
Year: 2005
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics
subject: 62G35 (Primary) 62H11 (Secondary)

description: In his discussion of Davies and Gather [Ann. Statist. 33 (2005) 977--1035] [math.ST/0508497] Tyler pointed out that the theory developed there could not be applied to the case of directional data. He related the breakdown of directional functionals to the problem of definability. In this addendum we provide a concept of breakdown defined in terms of definability and not in terms of bias. If a group of finite order $k$ acts on the sample space we show that the breakdown point can be bounded above by $(k-1)/k$. In the case of directional data there is a group of order $k=2$ giving an upper bound of 1/2.
description: Published at http://dx.doi.org/10.1214/009053606000000399 in the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org)
No-go limitations on UV completions of the Neutrino Option
Creators: name: Brivio, Ilaria
name: Talbert, Jim
name: Trott, Michael
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We discuss the possible origin of the Majorana mass scale(s) required for the "Neutrino Option" where the electroweak scale is generated simultaneously with light neutrino masses in a type-I seesaw model, by common dimension four interactions. We establish no-go constraints on the perturbative generation of the Majorana masses required due to global symmetries of the seesaw Lagrangian.
description: 6 pages, 3 figures. Matches published version