Incremental semantic analysis for OCL compilers

In software engineering, modeling with unified modeling language and object constraint language became industry standards and are supported by many computer-aided software engineering tools. The increasing number of the modeled functionalities results in complex models that need more and more textual constraints to express the hidden restrictions applied to the systems. During the metamodel development, rebuilding all the constraints is unnecessary when only a few changes have been applied due to the iterative, incremental manner of modifications. In this paper, we present a family of algorithms that handles the changes in constraints incrementally on the expression level; thus, the required rebuilds are kept to a minimum. Incremental variable reference resolving and type checking are performed as a part of the incremental semantic analysis. Balancing between the incremental and standard compilation is also considered, heuristics are given to select the faster method of compilation at each iteration. With the achieved results the duration of metamodel development can be decreased; thus, the efficiency of the environment is improved.     

Optimal Monotonicity-Preserving Perturbations of a Given Runge–Kutta Method

We propose a fast algorithm for evaluating the moments of Bingham distribution. The calculation is done by piecewise rational approximation, where interpolation and Gaussian integrals are utilized. Numerical tests show that the algorithm reaches the maximum absolute error less than \(5\times 10^{-8}\) remarkably faster than adaptive numerical quadrature. We apply the algorithm to a model for liquid crystals with the Bingham distribution to examine the defect patterns of rod-like molecules confined in a sphere, and find a different pattern from the Landau-de Gennes theory.     

Supporting domain-specific model patterns with metamodeling

Metamodeling is a widely applied technique in the field of graphical languages to create highly configurable modeling environments. These environments support the rapid development of domain-specific modeling languages (DSMLs). Design patterns are efficient solutions for recurring problems. With the proliferation of DSMLs, there is a need for domain-specific design patterns to offer solutions to problems recurring in different domains. The aim of this paper is to provide theoretical and practical foundations to support domain-specific model patterns in metamodeling environments. In order to support the treatment of premature model parts, we weaken the instantiation relationship. We provide constructs relaxing the instantiation rules, and we show that these constructs are appropriate and sufficient to express patterns. We provide the necessary modifications in metamodeling tools for supporting patterns. With the contributed results, a well-founded domain-specific model pattern support can be realized in metamodeling tools.

---

Manual and automated performance optimization of model transformation systems

Model-based development is one of the most promising solutions for several problems of industrial software engineering. Graph transformation is a proven method for processing domain-specific models. However, in order to be used by domain experts without graph transformation experts, it must be fast even if not tweaked for speed manually based on knowledge available only to the implementers of the transformation system. In this paper, we compare the performance of such manual optimizations with a solution using automated optimization based on sharing of matches between overlapping left-hand-sides of sequentially independent rules. This yields a 11% improvement in our scenario, although our prototypical implementation only exploits overlapping between, at most, two rules, and the analyzed benchmark does not contain many cases where the optimization is applicable.