1,863 research outputs found
Zukunftsfähige Stallkonzepte für die ökologische Milcherzeugung
Ensuring high animal welfare standards is one of the objectives of organic farming. The combination of modern housing concepts, proper herd management and good
human-animal relationship could be an effective strategy. In this study 14 viable dairy barn concepts were described and evaluated. In nine of these dairy farms the
management and animal welfare situation was examined. The outcome was a documentation of 14 different dairy farming concepts (housing, management) that are suitable to develop individual solutions with regard to animal welfare and the special requirements of organic dairy farms
Signatures of unresolved binaries in stellar spectra: implications for spectral fitting
The observable spectrum of an unresolved binary star system is a
superposition of two single-star spectra. Even without a detectable velocity
offset between the two stellar components, the combined spectrum of a binary
system is in general different from that of either component, and fitting it
with single-star models may yield inaccurate stellar parameters and abundances.
We perform simple experiments with synthetic spectra to investigate the effect
of unresolved main-sequence binaries on spectral fitting, modeling spectra
similar to those collected by the APOGEE, GALAH, and LAMOST surveys. We find
that fitting unresolved binaries with single-star models introduces systematic
biases in the derived stellar parameters and abundances that are modest but
certainly not negligible, with typical systematic errors of in
, 0.1 dex in , and 0.1 dex in for APOGEE-like
spectra of solar-type stars. These biases are smaller for spectra at optical
wavelengths than in the near-infrared. We show that biases can be corrected by
fitting spectra with a binary model, which adds only two labels to the fit and
includes single-star models as a special case. Our model provides a promising
new method to constrain the Galactic binary population, including systems with
single-epoch spectra and no detectable velocity offset between the two stars.Comment: Accept to MNRAS with minor revisions since v1. 7 pages, 5 figure
Classification of graph C*-algebras with no more than four primitive ideals
We describe the status quo of the classification problem of graph C*-algebras
with four primitive ideals or less
Bilinear modulation models for seasonal tables of counts
We propose generalized linear models for time or age-time tables of seasonal counts, with the goal of better understanding seasonal patterns in the data. The linear predictor contains a smooth component for the trend and the product of a smooth component (the modulation) and a periodic time series of arbitrary shape (the carrier wave). To model rates, a population offset is added. Two-dimensional trends and modulation are estimated using a tensor product B-spline basis of moderate dimension. Further smoothness is ensured using difference penalties on the rows and columns of the tensor product coefficients. The optimal penalty tuning parameters are chosen based on minimization of a quasi-information criterion. Computationally efficient estimation is achieved using array regression techniques, avoiding excessively large matrices. The model is applied to female death rate in the US due to cerebrovascular diseases and respiratory diseases
Hemingway and Bullshit
This paper uses Harry Frankfurt\u27s definition of bullshit as a lens to re-examine Ernest Hemingway\u27s aesthetic of factual details and omission. Frankfurt argues that bullshit consists of speech made with indifference to its veracity, and one who makes a habit of bullshitting may lose touch with reality. By studying three works across the author\u27s career, Big Two-Hearted River, The Short Happy Life of Francis Macomber, and The Old Man and the Sea, one sees that Hemingway\u27s prose style evolves and eventually contradicts his artistic statements. Given the fact that he promotes his aesthetic while discarding it, his theory becomes bullshit. Because normative critical interpretation of the author rests largely on his aesthetic theory, it too is inaccurate. Though Hemingway misrepresents how he writes, the success of his work regardless of aesthetics demonstrates that his writing is more complex than many think and deserves a more thorough re-evaluation
Disordered Topological Insulators via -Algebras
The theory of almost commuting matrices can be used to quantify topological
obstructions to the existence of localized Wannier functions with time-reversal
symmetry in systems with time-reversal symmetry and strong spin-orbit coupling.
We present a numerical procedure that calculates a Z_2 invariant using these
techniques, and apply it to a model of HgTe. This numerical procedure allows us
to access sizes significantly larger than procedures based on studying twisted
boundary conditions. Our numerical results indicate the existence of a metallic
phase in the presence of scattering between up and down spin components, while
there is a sharp transition when the system decouples into two copies of the
quantum Hall effect. In addition to the Z_2 invariant calculation in the case
when up and down components are coupled, we also present a simple method of
evaluating the integer invariant in the quantum Hall case where they are
decoupled.Comment: Added detail regarding the mapping of almost commuting unitary
matrices to almost commuting Hermitian matrices that form an approximate
representation of the sphere. 6 pages, 6 figure
Visualization of Genomic Changes by Segmented Smoothing Using an L0 Penalty
Copy number variations (CNV) and allelic imbalance in tumor tissue can show strong segmentation. Their graphical presentation can be enhanced by appropriate smoothing. Existing signal and scatterplot smoothers do not respect segmentation well. We present novel algorithms that use a penalty on the norm of differences of neighboring values. Visualization is our main goal, but we compare classification performance to that of VEGA
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