11 research outputs found
Probabilistic Model Checking for Energy Analysis in Software Product Lines
In a software product line (SPL), a collection of software products is
defined by their commonalities in terms of features rather than explicitly
specifying all products one-by-one. Several verification techniques were
adapted to establish temporal properties of SPLs. Symbolic and family-based
model checking have been proven to be successful for tackling the combinatorial
blow-up arising when reasoning about several feature combinations. However,
most formal verification approaches for SPLs presented in the literature focus
on the static SPLs, where the features of a product are fixed and cannot be
changed during runtime. This is in contrast to dynamic SPLs, allowing to adapt
feature combinations of a product dynamically after deployment. The main
contribution of the paper is a compositional modeling framework for dynamic
SPLs, which supports probabilistic and nondeterministic choices and allows for
quantitative analysis. We specify the feature changes during runtime within an
automata-based coordination component, enabling to reason over strategies how
to trigger dynamic feature changes for optimizing various quantitative
objectives, e.g., energy or monetary costs and reliability. For our framework
there is a natural and conceptually simple translation into the input language
of the prominent probabilistic model checker PRISM. This facilitates the
application of PRISM's powerful symbolic engine to the operational behavior of
dynamic SPLs and their family-based analysis against various quantitative
queries. We demonstrate feasibility of our approach by a case study issuing an
energy-aware bonding network device.Comment: 14 pages, 11 figure
Scanning X-ray nanodiffraction: from the experimental approach towards spatially resolved scattering simulations
An enhancement on the method of X-ray diffraction simulations for applications using nanofocused hard X-ray beams is presented. We combine finite element method, kinematical scattering calculations, and a spot profile of the X-ray beam to simulate the diffraction of definite parts of semiconductor nanostructures. The spot profile could be acquired experimentally by X-ray ptychography. Simulation results are discussed and compared with corresponding X-ray nanodiffraction experiments on single SiGe dots and dot molecules
Statistical Model Checking for Product Lines
International audienceWe report on the suitability of statistical model checking forthe analysis of quantitative properties of product line models by an extendedtreatment of earlier work by the authors. The type of analysis thatcan be performed includes the likelihood of specific product behaviour,the expected average cost of products (in terms of the attributes of theproducts’ features) and the probability of features to be (un)installed atruntime. The product lines must be modelled in QFLan, which extendsthe probabilistic feature-oriented language PFLan with novel quantitativeconstraints among features and on behaviour and with advancedfeature installation options. QFLan is a rich process-algebraic specifi-cation language whose operational behaviour interacts with a store ofconstraints, neatly separating product configuration from product behaviour.The resulting probabilistic configurations and probabilistic behaviourconverge in a discrete-time Markov chain semantics, enablingthe analysis of quantitative properties. Technically, a Maude implementationof QFLan, integrated with Microsoft’s SMT constraint solver Z3,is combined with the distributed statistical model checker MultiVeStA,developed by one of the authors. We illustrate the feasibility of our frameworkby applying it to a case study of a product line of bikes
X-ray Nanodiffraction on a Single SiGe Quantum Dot inside a Functioning Field-Effect Transistor
For advanced electronic, optoelectronic, or mechanical nanoscale devices a detailed understanding of their structural properties and in particular the strain state within their active region is of utmost importance. We demonstrate that X-ray nanodiffraction represents an excellent tool to investigate the internal structure of such devices in a nondestructive way by using a focused synchotron X-ray beam with a diameter of 400 nm. We show results on the strain fields in and around a single SiGe island, which serves as stressor for the Si-channel in a fully functioning Si-metal-oxide semiconductor field-effect transistor
Family-Based Model Checking with mCRL2
\u3cp\u3eFamily-based model checking targets the simultaneous verfication of multiple system variants, a technique to handle feature-based variability that is intrinsic to software product lines (SPLs). We present an approach for family-based verification based on the feature μ-calculus μL\u3csub\u3ef\u3c/sub\u3e, which combines modalities with feature expressions. This logic is interpreted over featured transition systems, a well-accepted model of SPLs, which allows one to reason over the collective behavior of a number of variants (a family of products). Via an embedding into the modal μ-calculus with data, underpinned by the general-purpose mCRL2 toolset, off-the-shelf tool support for μLf becomes readily available. We illustrate the feasibility of our approach on an SPL benchmark model and show the runtime improvement that family-based model checking with mCRL2 offers with respect to model checking the benchmark product-by-product.\u3c/p\u3
Selected Synchrotron Radiation Techniques
International audienceSynchrotron radiation is produced when highly energetic charged particles are deviated in a magnetic field. The generated spectrum consists of a large energy range from infrared to gamma X-rays. Harder X-ray ranges require larger synchrotron storage rings. Recent rings offer simultaneously energy tunability for photons with high brightness, high photon fluxes, and low divergence [1]. Photon energy tunability and variable polarization provide chemical, electronic structure and/or magnetic sensitivity. The tunable penetration depth using glancing incident and/or exit scattering angles enables the study of buried interfaces. Importantly, X-ray techniques, especially at high photon energies, can be used with various sample environments including (and not limited to) high pressure, ..