We exhibit an explicit list of nine graphs such that a graph drawn in the Klein bottle is 5-colorable if and only if it has no subgraph isomorphic to a member of the list. This answers a question of Thomassen [J. Comb...
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Superconductivity in Mo3Sb7 is analyzed using the combined electronic structure and phonon calculations, and the electron-phonon coupling constant λph=0.54 is determined from first principles. This value explains the...
Superconductivity in Mo3Sb7 is analyzed using the combined electronic structure and phonon calculations, and the electron-phonon coupling constant λph=0.54 is determined from first principles. This value explains the experimental value of the superconducting critical temperature Tc=2.2 K. The possible influence of spin fluctuations and spin gap on the superconductivity in Mo3Sb7 is discussed, and electron-paramagnon interaction is found to be weak.
In the complex metallic alloys (CMA) it is often found that some parts of the unit cell form well-defined nanoscale building blocks, called clusters, which are characterized by a specific local symmetry and separated ...
Meta-heuristics are general frameworks of heuristics methods for solving combinatorial optimization problems, where exploring the exact solutions for these problems becomes very hard due to some limitations like extre...
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ISBN:
(纸本)9781605580463
Meta-heuristics are general frameworks of heuristics methods for solving combinatorial optimization problems, where exploring the exact solutions for these problems becomes very hard due to some limitations like extremely large running time. In this paper, new local searches over tree space are defined. Using these local searches, various meta-heuristics can be generalized to deal with tree data structures to introduce a more general framework of meta-heuristics called Meta-Heuristics Programming (MHP) as general machine learning tools. As an alternative to Genetic Programming (GP) algorithm, Memetic Programming (MP) algorithm is proposed as a new outcome of the MHP framework. The efficiency of the proposed MP Algorithm is examined through comparative numerical experiments. Copyright 2008 ACM.
We take advantage of natural induction methods to build classifiers of the pigmented skin lesion images. This methodology can be treated as a non-invasive approach to early diagnosis of melanoma. We use the AQ21 appli...
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We take advantage of natural induction methods to build classifiers of the pigmented skin lesion images. This methodology can be treated as a non-invasive approach to early diagnosis of melanoma. We use the AQ21 application, which is based on the attributional calculus, to discover patterns in the skin images. Our classifier has good efficiency and may potentially be an important diagnostic aid.
We study an electron-hole pair in a stack of multiple quantum dots in the presence of an external electric field using the configuration-interaction approach. We find that the bright energy levels can be grouped into ...
We study an electron-hole pair in a stack of multiple quantum dots in the presence of an external electric field using the configuration-interaction approach. We find that the bright energy levels can be grouped into families which are associated with the hole localized in a specific dot of the stack. The exciton energy levels undergo avoided crossings as function of the external electric field with different patterns for each family. We show that the variation of the depths of the dots along the stack can be deduced from the exciton spectrum. For stronger coupling the families are mixed by a weak electric field due to hole tunneling. This results in a characteristic multiple avoided crossing of energy levels belonging to different families with an accompanying modulation of the recombination probabilities and an appearance of a single particularly bright state. Discussion of a simple modeling of these avoided crossings is provided.
We have engineered the magnetic properties of 1–8 nm Co films epitaxially grown on an Au-buffered bifacial W(110)/W(540) single crystal. The surface of Au/W(110) was atomically flat, whereas the Au/W(540) followed th...
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We have engineered the magnetic properties of 1–8 nm Co films epitaxially grown on an Au-buffered bifacial W(110)/W(540) single crystal. The surface of Au/W(110) was atomically flat, whereas the Au/W(540) followed the morphology of the vicinal W surface, showing a regular array of monoatomic steps. For Co grown on Au/W(540), the existence of the out-of-plane magnetization component extended strongly to a thickness d of about 8 nm, which was accompanied by an anomalous increase of the out-of-plane switching field with increasing d. In addition, the process of up-down magnetization switching could be realized with both a perpendicular and in-plane external magnetic field.
Correlations between magnetic properties and electronic structure of rare earth based intermetallics of the ZrNiAl-type crystal structure have been analysed. The analysis has been supported by results of magnetometric...
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Correlations between magnetic properties and electronic structure of rare earth based intermetallics of the ZrNiAl-type crystal structure have been analysed. The analysis has been supported by results of magnetometric, neutron diffraction and photoelectron spectroscopy measurements. It has been demonstrated that structure of the valence band and crystal electric field effects are the most important factors affecting the magnetic behaviour of the discussed compounds.
In this paper, by employing bivariate cubic C- 1 B-splines, a bivariate B-spline finite element method is presented to solve bending problems of rectangular plates. In comparison with analytical solutions, it is foun...
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In this paper, by employing bivariate cubic C- 1 B-splines, a bivariate B-spline finite element method is presented to solve bending problems of rectangular plates. In comparison with analytical solutions, it is found that, for various boundary conditions and different loading conditions, the accuracy of the present numerical method is very satisfactory.
We studied tetragonally distorted Fe1−xCox alloy films on Rh(001), which show a strong perpendicular anisotropy in a wide thickness and composition range. Analyzing x-ray magnetic circular dichroism spectra at the L3,...
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We studied tetragonally distorted Fe1−xCox alloy films on Rh(001), which show a strong perpendicular anisotropy in a wide thickness and composition range. Analyzing x-ray magnetic circular dichroism spectra at the L3,2 edges we found a dependence of the Co magnetic orbital moment on the chemical composition of the Fe1−xCox alloy films, with a maximum at x=0.6. For this composition, we observed an out-of-plane easy axis of magnetization at room temperature for film thickness up to 15 monolayers. Since both the magnetic orbital moment and the anisotropy energy show similar composition dependence, it confirms that both quantities are directly related. Our experiments show that the adjustment of the Fermi level by a proper choice of the alloy composition is decisive for the large magnetic orbital moment and for a large magnetic anisotropy in a tetragonally distorted lattice.
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