We present an abstraction of the probabilistic semantics of Multiset Rewriting to formally express systems of reactions with uncertain kinetic rates. This allows biological systems modelling when the exact rates are not known, but are supposed to lie in some intervals. On these (abstract) models we perform probabilistic model checking obtaining lower and upper bounds for the probabilities of reaching states satisfying given properties. These bounds are under- and over-approximations, respectively, of the probabilities one would obtain by verifying the models with exact kinetic rates belonging to the intervals.

XML is an important standard of data exchange and representation. XML database also becomes important as web database. As a mature database system, using relational database to support XML data may bring some advantages. In this paper, based on a relational storage structure support XPath query effectively, an optimized query translation strategy is presented as well as optimization techniques. This method converts XQuery to variable forest. Optimization operations are applied on the variable forest. The optimization is based on the semantics of XML document such as schema of original XML document. The VF can be converted to SQL easily. This method translates XQuery to a set of SQL statements and generates final result through the result of them. Our method adapts to the XML database with relational storage supporting effective query process to XML documents with various schemas and size.

Email communication is growing as a main method for individuals and organizations to communicate. Sadly, this is also an emerging means of conducting crime in the cyber world, e.g. identity theft, virus attacks etc. The need for improving awareness to these threats amongst employees is evident in media reports. Information security is as much a people issue as a technology one. This paper presents a description and results of an email awareness experiment that was performed amongst staff from a South African university. It is shown how management can use these results to focus and improve ICT awareness.

In this paper, we present a HMM based system that is used to recognize ultra low resolution text such as those frequently embedded in images available on the web. We propose a system that takes specifically the challenges of recognizing text in ultra low resolution images into account. In addition to this, we show in this paper that word models can be advantageously built connecting together sub-HMM-character models and inter-character state. Finally we report on the promising performance of the system using HMM topologies which have been improved to take into account the presupposed minimum length of each character.

Statecharts is a visual formalism suitable for high-level system specification, while Verilog is a hardware description language that can be used for both behavioural and structural specification of (hardware) systems. This paper implements a semantics-preserving mapping from Graphical Statecharts to Verilog programs, which, to the best of our knowledge, is the first algorithm to bridge the gap between Statecharts and Verilog, and can be embedded into the hardware/software co-specification process [19] as a front-end.

We present the problem of enforcing a Digital Rights Management (DRM) system that needs to consider location-dependent licensing policies and operates on top of existing conditional access standards. A major application for location-dependent DRM is Pay-TV broadcasting as rightsholders require different business models in different regions. A global provider’s enduser equipment needs to validate the user location in some way in order to enforce DRM in this scenario. We will depict several solutions to the problem and compare their security qualities. The main result is that trusted computing hardware may not be the most appropriate solution given reasonable conditions.

We consider a private zero-bit watermark (WM) system in which an unauthorized removal of the WM is restricted by a linear filtering of the watermarked message combined with additive noise attack. It is assumed that a WM detector knows both the original cover message (CM) and the pulse (or frequency) response of the attack filter. The formulas to calculate the WM-missing and WM-false alarm probabilities are developed and proved. We conclude that whenever some filtering of the watermarked message is yet acceptable with respect to CM quality then there results in a degradation of the WM system even if the designer of the WM uses an optimal signal. This fact is different than most that can be found at current WM literature. The main properties of a WM system under a filtering and additive noise attack condition are confirmed by simulations of the watermarked images.