Abstract

Abstract
Logic programming provides an ideal framework for tackling complex data, such as the multi-dimensional vector-based data used to represent spatial databases. Unfortunately, the usefulness of logic programming systems if often hampered by the fact that most of these systems have to rely on a single unification-based mechanism as the only way to search in the database. While unification can usually take effective advantage of hash-based indexing, it is often the case that queries over more complex and structured data, such as the vectorial terms stored in spatial databases, cannot. We propose a new extension to Prolog indexing: User Defined Indexing (UDI). In this mechanism, the programmer may add extra information to Prolog indices so that only interesting fragments of the database will be selected. UDI provides a general extension of indexing, and can be used for both instantiated and constrained variables. As a test case, we demonstrate how UDI can be combined with a constraint system to provide an elegant and efficient mechanism to generate and execute range queries and spatial queries. Experimental evaluation shows that this mechanism can achieve orders of magnitude speedups on non-trivial datasets.

Abstract
In this piper, we propose a method to broadcast digital video programs in which the channel capacity is dynamically distributed among video programs according to each video program particular complexity. A bit rate control algorithm based on the Structural Similarity Index as the measure of video program complexity is examined. Initial results show that a uniform picture quality among video programs can be obtained.

Abstract
In this paper we present the work in progress on LogCHEM, an ILP based tool for discriminative interactive mining of chemical fragments. In particular, we describe the integration with a molecule visualisation software that allows the chemist to graphically control the search for interesting patterns in chemical fragments. Furthermore, we show how structured information, such as rings, functional groups like carboxyl, amine, methyl, ester, etc are integrated and exploited in LogCHEM.

Abstract
Software development is a knowledge-intensive activity and frequently implies a progressive crystallization of knowledge, towards programming language statements. Although wikis have proved very effective, for both collaborative authoring and knowledge management, it would be useful for knowledge acquisition to better support team awareness and the recognition of knowledge structures, their relations, and their incremental evolution. This paper presents Weaki, a wiki prototype especially designed to support incremental formalization of structured contents that uses weakly-typed pages and type evolution. Weaki was applied in academic settings, by students of Software Engineering Labs. Copyright 2009 ACM.

Abstract
In this work we present a review of all-optical XOR gates based on Mach-Zehnder Interferometer with Semiconductor Optical Amplifiers (MZI-SOA), using NRZ modulated signals driven at 10 Gbit/s. The performance of two alternative schemes for logical XOR gates implementation is demonstrated through numerical simulations and experimentally. The extinction ratio shows high operation performance with low degradation. ©2009 IEEE.