The measurement algorithms applied in power quality measurement systems are based on Fast Fourier Transformation. That one-dimension frequency analysis is sufficient in many cases. However, to illustrate the character of the signal in a more comprehensive manner, it is crucial to represent the investigated signal on time-frequency plane. There are a lot of time-frequency representations (TFR) f...

Metamodels are a key concept in Model-Driven Engineering. Any artifact in a modeling ecosystem has to be defined in accordance to a metamodel prescribing its main qualities. One of the most important artifact is model transformation that are considered to be the heart and soul of MDE and as such advanced techniques and tools are needed for supporting the development, quality assurance, maintena...

The fractal image coding technique has attracted a degree of interest for its low bit rate. But the reconstructed image is of medium quality. This problem has prevented the fractal technique from being practically used. In order to improve the compression fidelity, a new affine transformation is proposed in this paper. Meanwhile, its contractivity requirement is analyzed, and the optimal parame...

In this paper we present the results of a rst empirical investigation on how the quality of non-uniform variates is innuenced by the underlying uniform RNG and the transformation method used. We use well known standard RNGs and transformation methods to the normal distribution as examples. We nd that except for transformed density rejection methods, which do not seem to introduce any additional...

We explore the application of genetic algorithms in model transformations that can be understood as pattern-based refinements. In MDA (Model Driven Architecture), such transformations can be exploited for deriving a PIM model from a CIM model. The approach uses design patterns as the basis of mutations and exploits various quality metrics for deriving a fitness function. A genetic representatio...

Multi-dimensional look up tables (LUTs) are widely employed for color transformations due to its high accuracy and general applicability. Using the LUT model generally involves the color measurement of a large number of samples. The precision and uncertainty of the color measurement will be mainly represented in the LUTs, and will affect the smoothness of the color transformation. This, in turn...

In this paper, we study the problem of video quality prediction over the wireless 4G network. Video transmission data is collected from a real 4G SCM testbed for investigating factors that affect video quality. After feature transformation and selection on video and network parameters, video quality is predicted by solving as regression problem. Experimental results show that the dominated fact...

Business analytics systems can potentially create value and provide competitive advantage to organisations. We argue that business analytics systems can also enable alignment between business strategy and IT strategy and support organisational transformation. We explain how a data warehouse, standardised metrics and global reporting supported the strategic transformation of a diversified and mu...

Since the finite element approximations of microstructures are strongly mesh dependent, the use of the mesh transformation method based on the energy minimizing principle is considered a natural approach in the finite element computation of microstructures. However, without a control on the mesh quality, the mesh can become increasingly irregular in the process of energy minimization and thus j...