Degradation and passivation of CuInSe2

in Applied Physics Letters (2012), 101

An RLL-Constrained LDPC Coded Recording System Using Deliberate Flipping and Flipped-Bit Detection

in IEEE Transactions on Communications (2012)

Shear Stresses in Honeycomb Sandwich Plates: Analytical Solution, Finite Elemente Method and Experimental Verification

in Journal of Sandwich Structures & Materials (2012), 14(4), 449-468

Honeycomb composite structures are used in airplanes, railway cars and vehicles. The sandwich panels consist of two stiff face sheets of aluminium, which are bonded to a very lightweight honeycomb core of ... [more ▼]

Honeycomb composite structures are used in airplanes, railway cars and vehicles. The sandwich panels consist of two stiff face sheets of aluminium, which are bonded to a very lightweight honeycomb core of aluminium. Compared to normal plates, sandwich panels have a very high stiffness and simultaneously a low weight. The core of these structures is mainly subjected to shear stresses. The shear stresses depend strongly on the angle of the load application. The distribution and the level of the shear stresses are investigated using analytical calculations. The load direction which induces highest stresses in the honeycomb core is derived. This direction is not the W-direction, which is the most compliant one. When doing finite element simulations of honeycomb cores, often the core is homogenized in order to reduce the calculation time. In this article, some equations are derived in order to calculate the real shear stresses from the shear stresses of the homogeneous core. The equations are validated by finite element simulations and partially by tests. Three-point bending tests and additionally some Food Cart Roller Tests were conducted in order to test the panels in different angles. [less ▲]

Modeling default correlation in a US retail loan portfolio

E-print/Working paper (2012)

Using rule-based machine learning for candidate disease gene prioritization and sample classification of cancer gene expression data

in PLoS ONE (2012), 7(7), 39932-39932

Microarray data analysis has been shown to provide an effective tool for studying cancer and genetic diseases. Although classical machine learning techniques have successfully been applied to find ... [more ▼]

Microarray data analysis has been shown to provide an effective tool for studying cancer and genetic diseases. Although classical machine learning techniques have successfully been applied to find informative genes and to predict class labels for new samples, common restrictions of microarray analysis such as small sample sizes, a large attribute space and high noise levels still limit its scientific and clinical applications. Increasing the interpretability of prediction models while retaining a high accuracy would help to exploit the information content in microarray data more effectively. For this purpose, we evaluate our rule-based evolutionary machine learning systems, BioHEL and GAssist, on three public microarray cancer datasets, obtaining simple rule-based models for sample classification. A comparison with other benchmark microarray sample classifiers based on three diverse feature selection algorithms suggests that these evolutionary learning techniques can compete with state-of-the-art methods like support vector machines. The obtained models reach accuracies above 90% in two-level external cross-validation, with the added value of facilitating interpretation by using only combinations of simple if-then-else rules. As a further benefit, a literature mining analysis reveals that prioritizations of informative genes extracted from BioHEL’s classification rule sets can outperform gene rankings obtained from a conventional ensemble feature selection in terms of the pointwise mutual information between relevant disease terms and the standardized names of top-ranked genes. [less ▲]

History of working-life non-employment spells predicts later cognitive function in middle- and older-aged Europeans

in Psychology and Health (2012), 27(S1), 79-79

Regional distribution of thermal sensitivity to cold at rest and during mild exercise in males

in Journal of Thermal Biology (2012), 37(7), 517-523

Higher trace and Berezinian of matrices over a Clifford algebra

in Journal of Geometry and Physics (2012), 62(11), 22942319

We define the notions of trace, determinant and, more generally, Berezinian of matrices over a (Z_2)^n-graded commutative associative algebra A. The applications include a new approach to the classical ... [more ▼]

We define the notions of trace, determinant and, more generally, Berezinian of matrices over a (Z_2)^n-graded commutative associative algebra A. The applications include a new approach to the classical theory of matrices with coefficients in a Clifford algebra, in particular of quaternionic matrices. In a special case, we recover the classical Dieudonné determinant of quaternionic matrices, but in general our quaternionic determinant is different. We show that the graded determinant of purely even (Z_2)^n-graded matrices of degree 0 is polynomial in its entries. In the case of the algebra A = H of quaternions, we calculate the formula for the Berezinian in terms of a product of quasiminors in the sense of Gelfand, Retakh, and Wilson. The graded trace is related to the graded Berezinian (and determinant) by a (Z_2)^n-graded version of Liouville’s formula. [less ▲]

Op Zoek naar Televisie (1925-1960)

in Een Eeuw van Beeld en Geluid. Cultuurgeschiedenis van Radio en Televisie in Nederland. (2012)

EFSF, ESM, nouveau pacte budgétaire : le droit européen mis à l’épreuve

in Revue de Droit Bancaire et Financier (2012), (2, mars-avril 2012), 2-2