There are a number of models that were proposed in recent years for message passing parallel systems. Examples are the postal model and its generalization the LogP model. In the postal model a parameter h is used to model the communication latency of the message-passing system. Each node during each round can send a fixed-size message and, simultaneously, receive a message of the same size. Fur...

XML-relational systems with well defined XML and relational schemas are widely used in industry. In the presence of rapidly changing requirements both schemas of such a model need continuous evolution, which can be performed by a formal framework that describes the evolution of the mutually dependent schema pairs of the system as sequences of elementary schema transformations. There are a numbe...

The size of a Peer-to-Peer (P2P) network is an important parameter for performance tuning of P2P routing algorithms. This paper introduces and evaluates a new efficient method for participants in an unstructured P2P network to establish the size of the overall network. The presented method is highly efficient, propagating information about the current size of the network to all participants usi...

This paper continues the discussion of parallel tool support with an overview of the current state of tools for runtime control and performance tuning. Each is discussed in terms of the programmer needs addressed, the extent to which representative current tools meet those needs, and what new levels of tool support are important if parallel computing is to become more widespread.

This poster describes a visualization tool that uses polar coordinates to create a circular shaped layout of large call trees of Strand programs. Due to the enormous amount of processes which are generated during execution of parallel Strand programs, conventional techniques to display call trees are overcharged. Out of this motives the tool `Polaranimation' was developed and implemented. One o...

We present the AgreementMaker system for matching realworld schemas and ontologies, which may consist of hundreds or even thousands of concepts. The end users of the system are sophisticated domain experts whose needs have driven the design and implementation of the system: they require a responsive, powerful, and extensible framework to perform, evaluate, and compare matching methods. The syst...

Our research is aimed at characterizing, understanding, and exploiting the interactions between hardware and software to improve system performance. We have developed a paradigm for continuous program optimization (CPO) that assists in and automates the challenging task of performance tuning, and we have implemented an initial prototype of this paradigm. At the core of our implementation is a p...

This letter is a response to the comments of Serang (2012) on Huang and He (2012) in Bioinformatics. Serang (2012) claimed that the parameters for the Fido algorithm should be specified using the grid search method in Serang et al. (2010) so as to generate a deserved accuracy in performance comparison. It seems that it is an argument on parameter tuning. However, it is indeed the issue of how t...

We study the behaviour of an algorithm which compresses relational tables by representing common subspaces as Cartesian products. The output produced allows space to be saved while preserving the functionality of many relational operations such as select, project and join. We describe an implementation of an existing algorithm, propose a slight modification which with high probability produces ...

Parallel application development is a very difficult task for non-expert programmers, and therefore support tools are needed for all phases of this kind of application development cycle. This means that developing applications using predefined programming structures (frameworks/skeletons) should be easier than doing it from scratch. We propose to take advantage of the intrinsic knowledge that t...