Simple Smooth Function Research Articles

Cautionary tale of mismeasured tails fromq/gbias

Jet substructure techniques such as subjet $p_T$-asymmetry, mass-drop, and grooming have become powerful and widely used tools in experimental searches at the LHC. While these tools provide much-desired handles to separate signal from background, they can introduce unexpected mass scales into the analysis. These scales may be misinterpreted as excesses if these are not correctly incorporated into background modeling. As an example, we study the ATLAS hadronic di-$W/Z$ resonance search. There, we find that the substructure analysis -- in particular the combination of a subjet asymmetry cut with the requirement on the number of tracks within a jet -- induces a mass scale where the dominant partonic subprocess in the background changes from $pp \to g \!+\! q/\bar q$ to $pp \to q\bar{q}$. In light of this scale, modeling the QCD background using a simple smooth function with monotonically decreasing slope appears insufficient.

Edge Curve Scaling and Smoothing with Cubic Spline Interpolation for Image Up-Scaling

In this paper, we propose an edge map up-scaling method. We propose an edge curve scaling method with cubic spline interpolation to up-scale an edge map. If an edge curve is directly applied to the cubic spline interpolation function for edge curve up-scaling, the edge curve scaling results have zigzag artifacts. We also propose a simple smoothing function to avoid the zigzag problems and maintain the contour shape of images. By predicting edge regions of the up-scaled image, we can recover high frequency components of edge regions of the up-scaled image to improve the sharpness and reduce ringing artifacts.

A New State-Dependent of Sliding Mode Control for Three-Phase Induction Motor Drives

Chattering is known as a main obstacle in realizing sliding mode control. In this study, new robust and chattering suppression of sliding mode control method is investigated. First, an integral sliding mode control is developed. Then, a simple smooth function and switching gain with state-dependent based on fast sigmoid function is introduced. This method allows chattering reduction, as well as maintaining the robust characteristics of sliding mode control. The effectiveness of the proposed algorithm is demonstrated using simulation speed control of indirect field-oriented three-phase induction motor drives with regard to external load disturbances

NLO QCD ANALYSIS OF POLARIZED DEEP INELASTIC SCATTERING

We have carried out a next-to-leading order QCD analysis of the experimental data on polarized DIS in the [Formula: see text] scheme. We have studied two models of the parametrizations of the input parton densities — the first due to Brodsky, Burkhardt and Schmidt (BBS), which gives a simultaneous parametrization for the polarized and unpolarized densities and in which the counting rules are strictly imposed; in the second, the input polarized densities are written in terms of the unpolarized ones in the generic form Δq(x)=f(x)q(x), with f(x) some simple smooth function. In both cases a good fit to the polarized data is achieved. As expected, the polarized data do not allow a precise determination of the polarized gluon density. Concerning the polarized sea quark densities, these are fairly well determined in the BBS model because of the interplay of polarized and unpolarized data, whereas in the second model, where only the polarized data are relevant, the polarized sea quark densities are largely undetermined.

Error estimation for natural frequency finite element analysis

The eigenvalue obtained from a finite element analysis of structures to estimate the buckling load factor or natural frequency has been improved by the use of a least-squares interpolation over a patch of elements. The eigenvalue improvement technique is based on the refinement of the finite element model and using the original eigenvector. The method presented in this paper involves solving a set of simultaneous equations for each patch of elements. These equations are based upon the equations of motion of the finite element model as opposed to a relative simple smoothing function used in the least-squares interpolation procedure.

The Angular Power Spectrum of the Four-Year [ITAL]COBE[/ITAL] Data

The angular power spectrum Cℓ is extracted from the 4 yr COBE Differential Microwave Radiometer (DMR) data with a 20° Galactic cut, using the narrowest window functions possible. The average power in eight multipole bands is also computed and plotted together with a compilation of power spectrum measurements from other experiments. The COBE results are found to be consistent with an n = 1 power spectrum with the normalization Qrms, ps = 18 μK reported by the COBE DMR team. Certain nonstandard cosmologies, such as "small universe" models with nontrivial spatial topology, predict power spectra that are not smooth functions. Rather, they contain bumps and wiggles that may not have been detected by other data analysis techniques such as the Hauser-Peebles method, the band-power method, and orthogonalized spherical harmonics, since these methods all give broader window functions that can smear such features out beyond recognition. On the large angular scales probed by COBE, the universe thus appears to be kind to us, presenting a power spectrum that is a simple smooth function.