Search results for "Mathematic"
showing 10 items of 24974 documents
Pyrolytic formation of polycyclic aromatic hydrocarbons from sesquiterpenes
2012
Author's version of an article in the journal: Food Chemistry. Also available from the publisher at: http://dx.doi.org/10.1016/j.foodchem.2012.06.033 The products of the pyrolysis of four sesquiterpenes, β-caryophyllene, α-cedrene, longifolene and valencene, have been examined. Pyrolysis was carried out at 300, 400 and 500 °C, the products determined by GC–MS and then examined for similarities and differences using multivariate data analysis. Analysis showed that longifolene was most resistant and caryophyllene least resistant to pyrolysis with cedrene and valencene occupying intermediate positions. While the compounds were largely unchanged at 300 °C, polycyclic aromatic hydrocarbons (PAHs…
Shape identification in inverse medium scattering problems with a single far-field pattern
2016
Consider time-harmonic acoustic scattering from a bounded penetrable obstacle $D\subset {\mathbb R}^N$ embedded in a homogeneous background medium. The index of refraction characterizing the material inside $D$ is supposed to be Holder continuous near the corners. If $D\subset {\mathbb R}^2$ is a convex polygon, we prove that its shape and location can be uniquely determined by the far-field pattern incited by a single incident wave at a fixed frequency. In dimensions $N \geq 3$, the uniqueness applies to penetrable scatterers of rectangular type with additional assumptions on the smoothness of the contrast. Our arguments are motivated by recent studies on the absence of nonscattering waven…
Charged jet cross sections and properties in proton-proton collisions at $\sqrt{s}=7$ TeV
2015
The differential charged jet cross sections, jet fragmentation distributions, and jet shapes are measured in minimum bias proton-proton collisions at centre-of-mass energy $\sqrt{s}=7$ TeV using the ALICE detector at the LHC. Jets are reconstructed from charged particle momenta in the mid-rapidity region using the sequential recombination $k_{\rm T}$ and anti-$k_{\rm T}$ as well as the SISCone jet finding algorithms with several resolution parameters in the range $R=0.2$ to $0.6$. Differential jet production cross sections measured with the three jet finders are in agreement in the transverse momentum ($p_{\rm T}$) interval $20<p_{\rm T}^{\rm jet,ch}<100$ GeV/$c$. They are also consistent w…
Modeling of the Shear Connection Capacity of Hybrid Steel Trussed Composite Beams
2019
Hybrid Steel Trussed Composite Beams represent a technical solution in use in numerous countries since many years. They are able to join the advantages of prefabrication with those of cast in place structures: they are easy to manufacture, fast to realize, monolithic and with no need of formwork. The behavior of these beams has been recently topic of discussion in the scientific community because the knowledge both related to the reinforced concrete structures and that of composite constructions cannot be straightforwardly extended to this typology, which is intermediate between one and another technology. This paper provides a contribution towards a better understanding of the mechanism of…
Predicted gamma-ray image of SN 1006 due to inverse Compton emission
2009
We propose a method to synthesize the inverse Compton (IC) gamma-ray image of a supernova remnant starting from the radio (or hard X-ray) map and using results of the spatially resolved X-ray spectral analysis. The method is successfully applied to SN 1006. We found that synthesized IC gamma-ray images of SN 1006 show morphology in nice agreement with that reported by the H.E.S.S. collaboration. The good correlation found between the observed very-high energy gamma-ray and X-ray/radio appearance can be considered as an evidence that the gamma-ray emission of SN 1006 observed by H.E.S.S. is leptonic in origin, though the hadronic origin may not be excluded.
Deep-learning based reconstruction of the shower maximum X max using the water-Cherenkov detectors of the Pierre Auger Observatory
2021
The atmospheric depth of the air shower maximum $X_{\mathrm{max}}$ is an observable commonly used for the determination of the nuclear mass composition of ultra-high energy cosmic rays. Direct measurements of $X_{\mathrm{max}}$ are performed using observations of the longitudinal shower development with fluorescence telescopes. At the same time, several methods have been proposed for an indirect estimation of $X_{\mathrm{max}}$ from the characteristics of the shower particles registered with surface detector arrays. In this paper, we present a deep neural network (DNN) for the estimation of $X_{\mathrm{max}}$. The reconstruction relies on the signals induced by shower particles in the groun…
ESTIMATING SOIL PARTICLE-SIZE DISTRIBUTION FOR SICILIAN SOILS
2009
The soil particle-size distribution (PSD) is commonly used for soil classification and for estimating soil behavior. An accurate mathematical representation of the PSD is required to estimate soil hydraulic properties and to compare texture measurements from different classification systems. The objective of this study was to evaluate the ability of the Haverkamp and Parlange (HP) and Fredlund et al. (F) PSD models to fit 243 measured PSDs from a wide range of 38 005_Bagarello(547)_33 18-11-2009 11:55 Pagina 38 soil textures in Sicily and to test the effect of the number of measured particle diameters on the fitting of the theoretical PSD. For each soil textural class, the best fitting perf…
How long is the sign?
2015
AbstractThis paper deals with the relative empirical length of signs in sign languages and provides evidence for the view that they are actually longer units than has hitherto been recognized. The evidence is presented from two perspectives: those of sign articulation and sign recognition. Concerning sign articulation, it is suggested that signs are longer units than is currently assumed because most of the structural features of signs are in fact already present before the currently accepted beginnings of signs and they continue after signs' generally accepted endings. Concerning sign recognition, the longer view of the sign is proposed on the grounds that the recognition point of signs is…
Image inpainting using directional wavelet packets originating from polynomial splines
2020
The paper presents a new algorithm for the image inpainting problem. The algorithm is using a recently designed versatile library of quasi-analytic complex-valued wavelet packets (qWPs) which originate from polynomial splines of arbitrary orders. Tensor products of 1D qWPs provide a diversity of 2D qWPs oriented in multiple directions. For example, a set of the fourth-level qWPs comprises 62 different directions. The properties of the presented qWPs such as refined frequency resolution, directionality of waveforms with unlimited number of orientations, (anti-)symmetry of waveforms and windowed oscillating structure of waveforms with a variety of frequencies, make them efficient in image pro…
Testing and implementing a new approach to estimating interregional output multipliers using input-output data for South Korean regions
2020
Flegg's location quotient (FLQ) is a useful tool for estimating intraregional output multipliers. This paper uses it as one component when estimating interregional multipliers. Using statistical information criteria and official data for 16 South Korean regions, it is found that the best approach is to combine the FLQ with a simple trade model. The paper explains how the proposed procedure can be implemented for both multiple and individual regions, and also how a region-specific value for the unknown parameter δ in the FLQ formula can be determined. Finally, an illustrative case study of one of the regions is carried out.