Pairwise testing for software product lines: Comparison of two approaches

in Software Quality Journal (2012), 20(3), 605-643

Software Product Lines (SPL) are difficult to validate due to combinatorics induced by variability, which in turn leads to combinatorial explosion of the number of derivable products. Exhaustive testing in ... [more ▼]

Software Product Lines (SPL) are difficult to validate due to combinatorics induced by variability, which in turn leads to combinatorial explosion of the number of derivable products. Exhaustive testing in such a large products space is hardly feasible. Hence, one possible option is to test SPLs by generating test configurations that cover all possible t feature interactions (t-wise). It dramatically reduces the number of test products while ensuring reasonable SPL coverage. In this paper, we report our experience on applying t-wise techniques for SPL with two independent toolsets developed by the authors. One focuses on generality and splits the generation problem according to strategies. The other emphasizes providing efficient generation. To evaluate the respective merits of the approaches, measures such as the number of generated test configurations and the similarity between them are provided. By applying these measures, we were able to derive useful insights for pairwise and t-wise testing of product lines. [less ▲]

Re-thinking Banking and Finance

Scientific Conference (2012)

Simon Dubnow: Jüdische Geschichte – für Kinder erzählt. Hg. von Marion Aptroot, aus dem Jiddischen von Jutta Schumacher.

Book published by Vandenhoeck & Ruprecht (2012)

Do open-market repurchases supply or demand immediacy?

Scientific Conference (2012)

Do open-market repurchases supply or demand immediacy?

Scientific Conference (2012)

Tuning the spectral sensitivity of vertical InN nanopyramid based photodetectors by means of band gap engineering and/or nanostructure size control

in ASDAM 2012, The Ninth International Conference on Advanced Semiconductor Devices and Microsystems (2012)

Materielle Selektivität von Steuerbeihilfen im Lichte des Gibraltar-Urteils des EuGH

in Jaeger, Thomas; Haslinger, Birgit (Eds.) Jahrbuch Beihilferecht 2012 (2012)

Die Feststellung der Selektivität einer Maßnahme steht typischerweise im Zentrum einer Prüfung im Lichte beihilferechtlicher Vorgaben. Zumal bei steuerlichen Regelungen liegt darin auch die fundamentale ... [more ▼]

Die Feststellung der Selektivität einer Maßnahme steht typischerweise im Zentrum einer Prüfung im Lichte beihilferechtlicher Vorgaben. Zumal bei steuerlichen Regelungen liegt darin auch die fundamentale Schwierigkeit, ein Referenzsystem „normaler Besteuerung“ zu definieren, an deren Maßstab ihr Ausnahmecharakter bestimmt werden kann. In seiner jüngsten Rechtsprechung scheint der EuGH mit einem revolutionären Ansatz zu reagieren, indem er der Qualifikation bestimmter Steuersysteme als „intrinsisch selektiv“ durch die Kommission zustimmt, wodurch der Bezug zu einem Referenzsystem „normaler Besteuerung“ scheinbar redundant wird. Dies wirft die Frage auf, ob die Mitgliedstaaten ihre bisher unangetastete Freiheit, die Grundstruktur ihrer Steuersysteme ungeachtet beihilferechtlicher Überlegungen zu gestalten, bereits verloren haben, und wo gegebenenfalls die Grenzen dieser Freiheit zu ziehen sind. Dieser Beitrag versucht, ausgehend vom jüngst ergangenen Gibraltar-Urteil des EuGH eine Antwort auf diese Frage zu geben. [less ▲]

Towards future III-nitride based THz OEICs in the UV range

in ASDAM 2012, The Ninth International Conference on Advanced Semiconductor Devices and Microsystems (2012)

Size-dependent free flexural vibration behavior of functionally graded nanoplates

in Computational Materials Science (2012), 65

In this paper, size dependent linear free flexural vibration behavior of functionally graded (FG) nanoplates are investigated using the iso-geometric based finite element method. The field variables are ... [more ▼]

In this paper, size dependent linear free flexural vibration behavior of functionally graded (FG) nanoplates are investigated using the iso-geometric based finite element method. The field variables are approximated by non-uniform rational B-splines. The nonlocal constitutive relation is based on Eringen's differential form of nonlocal elasticity theory. The material properties are assumed to vary only in the thickness direction and the effective properties for the FG plate are computed using Mori-Tanaka homogenization scheme. The accuracy of the present formulation is demonstrated considering the problems for which solutions are available. A detailed numerical study is carried out to examine the effect of material gradient index, the characteristic internal length, the plate thickness, the plate aspect ratio and the boundary conditions on the global response of the FG nanoplate. From the detailed numerical study it is seen that the fundamental frequency decreases with increasing gradient index and characteristic internal length. © 2012 Elsevier B.V. All rights reserved. [less ▲]

Error estimation and error bounding in energy norm based on a displacement recovery technique

in ECCOMAS 2012 - European Congress on Computational Methods in Applied Sciences and Engineering, e-Book Full Papers (2012)

Traditionally, recovery based error estimators in linear elasticity have considered the evaluation of an enhanced stress field obtained from the raw Finite Element (FE) stress solution. Instead of that ... [more ▼]

Traditionally, recovery based error estimators in linear elasticity have considered the evaluation of an enhanced stress field obtained from the raw Finite Element (FE) stress solution. Instead of that, one can also obtain a recovered displacement field from the FE displacements. Herein, we describe a superconvergent patch recovery of the displacement field which considers the local fulfilment of boundary and internal equilibrium equations, Dirichlet constraints and, for singular problems, the splitting of the displacement and stress fields into singular and smooth parts. Numerical tests using problems with known analytical solution have been carried out to validate the proposed technique for error estimation and error bounding in energy norm and quantities of interest. [less ▲]