scholarly journals Determination of resonances by the optimized spectral approach

2013 ◽  
Vol 46 (8) ◽  
pp. 085303 ◽  
Author(s):  
Arkadiusz Kuroś ◽  
Przemysław Kościk ◽  
Anna Okopińska
Keyword(s):  
Spectral Approach

scholarly journals Bayesian Determination of Parameters for Plasma-Wall Interactions

Proceedings ◽  
2019 ◽  
Vol 33 (1) ◽  
pp. 27
Author(s):  
Roland Preuss ◽  
Rodrigo Arredondo ◽  
Udo von Toussaint
Keyword(s):  
Polynomial Chaos ◽  
Quantitative Measure ◽  
Projectile Energy ◽  
Spectral Approach ◽  
Surface Binding ◽  
Reduced Order ◽  
Surface Binding Energy ◽  
Determination Of Parameters ◽  
Wall Interactions

Within a Bayesian framework we propose a non-intrusive reduced-order spectral approach (polynomial chaos expansion) to assess the uncertainty of ion-solid interaction simulations. The method not only reduces the number of function evaluations but provides simultaneously a quantitative measure for which combinations of inputs have the most important impact on the result. It is applied to the ion-solid simulation program SDTrimSP with several uncertain and Gaussian distributed input parameters, i.e., angle α , projectile energy E 0 and surface binding energy E s b . In combination with recently acquired experimental data the otherwise hardly accessible model parameter E s b can now be estimated.

scholarly journals Identification of Nonparametric Nonlinear Systems

2019 ◽  
Vol 24 ◽  
pp. 02006
Author(s):  
Mohamed Benyassi ◽  
Adil Brouri
Keyword(s):  
Nonlinear Systems ◽  
Infinite Order ◽  
Nonlinear Function ◽  
Identification Problem ◽  
Spectral Approach ◽  
Linear Dynamics ◽  
Hammerstein Models ◽  
Linear Subsystem ◽  
Linear And Nonlinear

Presently, a modelling and identification of nonlinear systems is proposed. This study is developed based on spectral approach. The proposed nonlinear system is nonparametric and can be described by Hammerstein models. These systems consist of nonlinear element followed by a linear block. This latter (the linear subsystem) is not necessarily parametric and the nonlinear function can be nonparametric smooth nonlinearity. This identification problem of Hammerstein models is studied in the presence of possibly infinite-order linear dynamics. The determination of linear and nonlinear block can be done using a unique stage.

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

Distance to SN 1987A and the LMC

1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia
Keyword(s):  
Angular Size ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Distance Modulus ◽  
Absolute Size ◽  
Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

International determination of the total motion of the pole

1961 ◽  
Vol 13 ◽  
pp. 29-41
Author(s):  
Wm. Markowitz
Keyword(s):  
Secular Motion ◽  
The Future

A symposium on the future of the International Latitude Service (I. L. S.) is to be held in Helsinki in July 1960. My report for the symposium consists of two parts. Part I, denoded (Mk I) was published [1] earlier in 1960 under the title “Latitude and Longitude, and the Secular Motion of the Pole”. Part II is the present paper, denoded (Mk II).

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