Cancer classification based on direction-basis-function neural networks

Automatic molecular classification of cancer based on DNA microarray has many advantages over conventional classification based on morphological appearance of the tumor. Using artificial neural networks is a general approach for automatic classification. In this paper, Direction-Basis-Function neuron and Priority-Ordered algorithm are applied to neural networks. And the leukemia gene expression dataset is used as an example to testify the classifier. The result of our method is compared to that of SVM. It shows that our method makes a better performance than SVM.

A New Criterion Number for the Boundary Conditions at the Solid/Liquid Interface in Nanoscale

A simple, but important three-atom model was proposed at the solid/liquid interface, leading to a new criterion number, lambda, governing the boundary conditions (BCs) in nanoscale. The solid wall is considered as the face-centered-cubic (fcc) structure. The fluid is the liquid argon with the well-known LJ potential. Based on the concept, the two micro-systems have the same BCs if they have The same criterion number. The degree of the locking BCs is enhanced when lambda equals to 0.757. Such critical criterion number results in the substantial epitaxial ordering and one, two, or even three liquid layers are locked by the solid wall, depending on the coupling energy scale ratio of the solid and liquid atoms. With deviation from the critical criterion number, the flow approaches the slip BCs and there are little ordering structures within the liquid. Always at the same criterion number, the degree of the slip is decreased or the locking is enhanced with increasing the coupling energy scale ratio of the solid and liquid atoms. The above analysis is well confirmed by the molecular dynamics (MD) simulation. The slip length is well correlated in terms of the new criterion number. The future work is suggested to extend the present theory for other microstructures of the solid wall atoms and quasi-LJ potentials.

Using photoluminescence as optimization criterion to achieve high-quality InGaAs/AlGaAs pHEMT structure

The single delta -doped InGaAs/AlGaAs pseudomorphic HEMT structure materials were grown by molecular beam epitaxy. The photoluminescence spectra of the materials were studied. There are two peaks in the photoluminescence spectra of the materials, corresponding to two sub energy levels of InGaAs quantum well. The ratio of the two peak's intensity was used as criterion to optimize the layer structures of the materials. The material with optimized layer ;tructures exhibits the 77 It mobility and two-dimensional electron gas density of 16 500 cm(2)/Vs and 2.58 x 10(12) cm(-2) respectively, and the 300 K mobility and two-dimensional electron gas density of 6800 cm(2)/Vs and 2.55 x 10(12) cm(-2) respectively. The pseudomorphic HEMT devices with gate length of 0.2 mum were fabricated using this material. The maximum transconductance of 650 mS/mm and the cut-off frequency of 81 GHz were achieved. (C) 2001 Elsevier Science B.V. All rights reserved.