Search results for " Soft"
showing 10 items of 1710 documents
Formal Modeling and Discrete-Time Analysis of BPEL Web Services
2008
International audience; Web services are increasingly used for building enterprise information systems according to the Service Oriented Architecture (SOA) paradigm. We propose in this paper a tool-equipped methodology allowing the formal modeling and analysis of Web services described in the BPEL language. The discrete-time transition systems modeling the behavior of BPEL descriptions are obtained by an exhaustive simulation based on a formalization of BPEL semantics using the Algebra of Timed Processes (ATP). These models are then analyzed by model checking value-based temporal logic properties using the CADP toolbox. The approach is illustrated with the design of a Web service for GPS na…
Learning Pros and Cons of Model-Driven Development in a Practical Teaching Experience
2016
Current teaching guides on Software Engineering degree focus mainly on teaching programming languages from the first courses. Conceptual modeling is a topic that is only taught in last courses, like master courses. At that point, many students do not see the usefulness of conceptual modeling and most of them have difficulty to reach the level of abstraction needed to work with them. In order to make the learning of conceptual modeling more attractive, we have conducted an experience where students compare a traditional development versus a development using conceptual models through a Model-Driven Development (MDD) method. This way, students can check on their own pros and cons of working w…
Extending and validating gestUI using technical action research
2017
gestUI is a model-driven method with tool support to define custom gestures and to include gesture-based interaction in existing user software system interfaces. So far, gestUI had been limited to the definition of the same gesture catalogue for all users of the software system. In this paper, we extend gestUI to permit individual users to define their own custom gesture catalogue and redefine some custom gestures in case of difficulty in using or remembering them. After extending gestUI, we applied technical action research from the FP7 CaaS project's Capability Design Tool with the aim of assessing its acceptance in an industrial setting. We also analysed its perceived ease-of-use and use…
Data Quality Model-based Testing of Information Systems
2020
This paper proposes a model-based testing approach by offering to use the data quality model (DQ-model) instead of the program’s control flow graph as a testing model. The DQ-model contains definitions and conditions for data objects to consider the data object as correct. The study proposes to automatically generate a complete test set (CTS) using a DQmodel that allows all data quality conditions to be tested, resulting in a full coverage of DQ-model. In addition, the possibility to check the conformity of the data to be entered and already stored in the database is ensured. The proposed alternative approach changes the testing process: (1) CTS can be generated prior to software developmen…
A Bond Graph Approach to Modeling and Simulation of Nonlinear Wind Turbine System
2013
This chapter addresses the problem of bond graph methodology as a graphical approach for modeling of wind turbine generating systems. The purpose of this chapter is to show some of the benefits of the bond graph approach in contributing a model for wind turbine systems. We will present a nonlinear model of a wind turbine generating system, containing pitch, drive train, tower motion and generator. All which will be modeled by means of bond graph. We will especially focus on the drive train, and show the difference between modeling with a classical mechanical method and by using bond graph. The model consists of realistic parameters, but we are not trying to validate a specific wind turbine …
Gyrification from constrained cortical expansion
2014
The exterior of the mammalian brain - the cerebral cortex - has a conserved layered structure whose thickness varies little across species. However, selection pressures over evolutionary time scales have led to cortices that have a large surface area to volume ratio in some organisms, with the result that the brain is strongly convoluted into sulci and gyri. Here we show that the gyrification can arise as a nonlinear consequence of a simple mechanical instability driven by tangential expansion of the gray matter constrained by the white matter. A physical mimic of the process using a layered swelling gel captures the essence of the mechanism, and numerical simulations of the brain treated a…
Monte Carlo Tests of Nucleation Concepts in the Lattice Gas Model
2013
The conventional theory of homogeneous and heterogeneous nucleation in a supersaturated vapor is tested by Monte Carlo simulations of the lattice gas (Ising) model with nearest-neighbor attractive interactions on the simple cubic lattice. The theory considers the nucleation process as a slow (quasi-static) cluster (droplet) growth over a free energy barrier $\Delta F^*$, constructed in terms of a balance of surface and bulk term of a "critical droplet" of radius $R^*$, implying that the rates of droplet growth and shrinking essentially balance each other for droplet radius $R=R^*$. For heterogeneous nucleation at surfaces, the barrier is reduced by a factor depending on the contact angle. U…
Statistics of reversible transitions in two-state trajectories in force-ramp spectroscopy
2014
A possible way to extract information about the reversible dissociation of a molecular adhesion bond from force fluctuations observed in force ramp experiments is discussed. For small loading rates the system undergoes a limited number of unbinding and rebinding transitions observable in the so-called force versus extension (FE) curves. The statistics of these transient fluctuations can be utilized to estimate the parameters for the rebinding rate. This is relevant in the experimentally important situation where the direct observation of the reversed FE-curves is hampered, e.g. due to the presence of soft linkers. I generalize the stochastic theory of the kinetics in two-state models to the…
Field theoretic study of bilayer membrane fusion: I. Hemifusion mechanism
2003
Self-consistent field theory is used to determine structural and energetic properties of metastable intermediates and unstable transition states involved in the standard stalk mechanism of bilayer membrane fusion. A microscopic model of flexible amphiphilic chains dissolved in hydrophilic solvent is employed to describe these self-assembled structures. We find that the barrier to formation of the initial stalk is much smaller than previously estimated by phenomenological theories. Therefore its creation it is not the rate limiting process. The barrier which is relevant is associated with the rather limited radial expansion of the stalk into a hemifusion diaphragm. It is strongly affected by…
How molecular knots can pass through each other
2014
We propose a mechanism in which two molecular knots pass through each other and swap positions along a polymer strand. Associated free energy barriers in our simulations only amount to a few $k_{B}T$, which may enable the interchange of knots on a single DNA strand.