39,361 research outputs found
Evolutionary L∞ identification and model reduction for robust control
An evolutionary approach for modern robust control oriented system identification and model reduction in the frequency domain is proposed. The technique provides both an optimized nominal model and a 'worst-case' additive or multiplicative uncertainty bounding function which is compatible with robust control design methodologies. In addition, the evolutionary approach is applicable to both continuous- and discrete-time systems without the need for linear parametrization or a confined problem domain for deterministic convex optimization. The proposed method is validated against a laboratory multiple-input multiple-output (MIMO) test rig and benchmark problems, which show a higher fitting accuracy and provides a tighter L�¢���� error bound than existing methods in the literature do
The Chiral Extension of Lattice QCD
The chiral extension of Quantum Chromodynamics (XQCD) adds to the standard
lattice action explicit pseudoscalar meson fields for the chiral condensates.
With this action, it is feasible to do simulations at the chiral limit with
zero mass Goldstone modes. We review the arguments for why this is expected to
be in the same universality class as the traditional action. We present
preliminary results on convergence of XQCD for naive fermions and on the
methodology for introducing counter terms to restore chiral symmetry for Wilson
fermions.Comment: 7 pages, LATTICE 94 talk by R. Brower: Latex file with 2 postscript
figures for encapsulatio
Digital Heritage Gamification: An Augmented-Virtual Walkthrough to Learn and Explore Tangible Cultural Heritage
In the last decade, cultural heritage including historical sites are reconstructed into digital heritage. Based on UNESCO , digital heritage defines as “cultural, educational, scientific and administrative resources, as well as technical, legal, medical and other kinds of information created digitally, or converted into digital form from existing analogue resources”. In addition, the digital heritage is doubling in size every two years and expected will grow tenfold between 2013 and 2020. In order to attract and stir the interest of younger generations about digital heritage, gamification has been widely promoted. In this research, a virtual walkthrough combine with gamifications are proposed for learning and exploring historical places in Malaysia by using mobile device. In conjunction with Visit Perak 2017 Campaign, this virtual walkthrough is proposed for Kellie’s Castle at Perak. The objectives of this research are two folds 1) modelling and design of innovative mobile game for virtual walkthrough application, and 2) to attract tourist to explore and learn historical places by using sophisticated graphics from Augmented Reality. The efficiency and effectiveness of the mobile virtual walkthrough will be accessed by the International and local tourists. In conclusion, this research is speculated to be pervasively improve the cultural and historical knowledge of the learners
Enhancement of Copper Sorption through Acid Blue 29 Treated Oil Palm Pressed Fibres
The removal of cupric ions from aqueous solution by natural and dyecoated palm pressed fibres was studied. Sorption was both pH and concentration dependent. The equilibrium data followed the Langmuir isotherm model with maximum copper sorption capacities of 2.41 and 7.71 mg/g for natural and dye-treated fibres respectively. The presence of
other metal ions inhibited copper uptake in the following order Pb> Zn > Ni. The suppressing effects of chelators correspond to their log K values. Column studies showed that bed-depth had a more pronounced
effect on copper sorption than flow rate
Magnetic Monopole Content of Hot Instantons
We study the Abelian projection of an instanton in as a
function of temperature (T) and non-trivial holonomic twist () of the
Polyakov loop at infinity. These parameters interpolate between the circular
monopole loop solution at T=0 and the static 't Hooft-Polyakov
monopole/anti-monopole pair at high temperature.Comment: 3 pages, LATTICE98(confine), LaTeX, PostScript figures include
Stray field signatures of N\'eel textured skyrmions in Ir/Fe/Co/Pt multilayer films
Skyrmions are nanoscale spin configurations with topological properties that
hold great promise for spintronic devices. Here, we establish their N\'eel
texture, helicity, and size in Ir/Fe/Co/Pt multilayer films by constructing a
multipole expansion to model their stray field signatures and applying it to
magnetic force microscopy (MFM) images. Furthermore, the demonstrated
sensitivity to inhomogeneity in skyrmion properties, coupled with a unique
capability to estimate the pinning force governing dynamics, portends broad
applicability in the burgeoning field of topological spin textures.Comment: 6 pages, 4 figures, significantly revised and upgraded. For the
updated supplementary material please contact one of the corresponding
author
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