Abstract

Abstract
We present a process calculus that models the communication and computational aspects of sensor network applications. The calculus focuses on a basic set of primitives for programming sensor networks that support code deployment, communication and local processing, and provides a very expressive core-language. The calculus and its associated theory provide the tools to verify the robustness of sensor network applications and protocols. © 2007 IEEE.

Abstract

Abstract
A consequence of ILP systems being implemented in Prolog or using Prolog libraries is that, usually, these systems use a Prolog internal database to store and manipulate data. However, in real-world problems, the original data is rarely in Prolog format. In fact, the data is often kept in Relational Database Management Systems (RDBMS) and then converted to a format acceptable by the ILP system. Therefore, a more interesting approach is to link the ILP system to the RDBMS and manipulate the data without converting it. This scheme has the advantage of being more scalable since the whole data does not need to be loaded into memory by the ILP system. In this paper we study several approaches of coupling ILP systems with RDBMS systems and evaluate their impact on performance. We propose to use a Deductive Database (DDB) system to transparently translate the hypotheses to relational algebra expressions. The empirical evaluation performed shows that the execution time of ILP algorithms can be effectively reduced using a DDB and that the size of the problems can be increased due to a non-memory storage of the data.

Abstract
Most of the recent proposals in tabling technology were designed as a means to improve some practical deficiencies of current tabling execution models that reduce their applicability in particular applications. The discussion we address in this paper was also motivated by practical deficiencies we encountered, in particular, on the table storage mechanisms used for tabling support. To improve such mechanisms, we propose two new implementation techniques that make tabling models more efficient when dealing with incomplete tables and more robust when recovering memory from the table space. To validate our proposals, we have implemented them in the YapTab tabling system as an elegant extension of the original design.

Abstract