9,486 research outputs found
AN EFFICIENT MULTI-CRITERIA DECISION-MAKING APPROACH BASED ON HYBRIDIZING DATA MINING TECHNIQUES AN EFFICIENT MULTI-CRITERIA DECISION-MAKING APPROACH BASED ON HYBRIDIZING DATA MINING TECHNIQUES
Multiple-criteria decision-making (MCDM) that deals with multiple criteria in decision-making environments has been explicitly applied to various decision-making fields. Nevertheless, the critical issues of uncertainty and inaccuracy generally and gradually exists in the majority of the MCDM processes because of (1) prejudice and preference of decision-makers or experts as well as (2) the insufficiency information of the input and output. Therefore, this research efficiently proposed a novel method, FVM-index method, to resolve the limitations happened when MCDM is applied. The FVM-index approach, which consists of the fuzzy set theory (FST), the variable precision rough set (VPRS), and the cluster validity index (CVI) function, not only provides optimized classification results for the datasets but also filters out the uncertainty and inaccuracy instances from surveyed datasets by VPRS theory. Because the datasets are refined by the proposed FVM-index method, the decision makers will be able to effectively obtain the suitable results of MCD
Could be a molecular state?
We investigate whether the newly observed narrow resonance can
be described as a molecular state with quantum numbers
. Using QCD sum rules, we consider contributions up to dimension
six in the operator product expansion and work at leading order of
. The mass obtained for this state is (4.05\pm 0.28) \mbox{GeV}.
It is concluded that molecular state is a possible candidate
for .Comment: 7 pages, 4 figures.Published in Eur.Phys.J. C73 (2013) 2661. arXiv
admin note: text overlap with arXiv:1304.185
Higher order light-cone distribution amplitudes of the Lambda baryon
The improved light-cone distribution amplitudes (LCDAs) of the
baryon are examined on the basis of the QCD conformal partial wave expansion
approach. The calculations are carried out to the next-to-leading order of
conformal spin accuracy with consideration of twist 6. The next leading order
conformal expansion coefficients are related to the nonperturbative parameters
defined by the local three quark operator matrix elements with different
Lorentz structures with a covariant derivative. The nonperturbative parameters
are determined with the QCD sum rule method. The explicit expressions of the
LCDAs are provided as the main results.Comment: 17pages,10figures. arXiv admin note: text overlap with
arXiv:1311.596
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Fabrication and Characterization of Nanoscale Pillar Arrays With Engineered Phononic and Photonic Properties
This dissertation reports the results of the investigation of nanoscale pillar structures with engineered phononic and photonic properties. It has been proven that phonon states in semiconductors can be tuned by external boundaries, either as a result of phonon confinement effects in individual nanostructures or as a result of artificially induced external periodicity, e.g., phononic crystals. The possibility of engineering acoustic phonon spectrum is of ultimate importance from scientific and application perspectives since they are the main heat carriers in nonmagnetic semiconductor and insulator materials. The change in acoustic phonon dispersion would affect the heat transport properties, alter the electron-phonon interactions, and affect the optical properties of the material system. It has been recently suggested that periodic structures with properly tuned dimensions can act simultaneously as phononic and photonic crystals, strongly affecting the light-matter interactions. In this dissertation research, I prepared nanoscale pillar structure samples and investigated their properties. The “pillar with hat” structures were fabricated using electron beam lithography on silicon substrates followed by inductively-coupled plasma cryogenic dry etching. The hats of the pillars were created with a unique design to have exactly the same orientation plane as the substrate. The structures were inspected with scanning electron microscopy. I used Brillouin-Mandelstam spectroscopy to measure the dispersion of acoustic phonons with energies in the range from 2 GHz up to 20 GHz through the entire second and higher order Brillouin zones. I analyzed the spectral signatures resulting from the surface ripple mechanism which dominates the light scattering in these specific samples. I found clear signatures of the phonon spectrum modification in the appearance of localized phonon sub-bands at energies between 2˗20 GHz. The variable angle ellipsometry measurements indicated modification of light scattering due to nanostructuring. The experimental data confirmed the dual functionality of the structure with engineered phononic-photonic properties. The results obtained in this dissertation research have important implications for the next generation of photonic and optoelectronic device technologies
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