We improve on some recent results on lower bounds for conversion problems for regular expressions. In particular we consider the conversion of planar deterministic finite automata to regular expressions, study the effect of the complementation operation on the descriptional complexity of regular expressions, and the conversion of regular expressions extended by adding intersection or interleavi...

Dynamic voltage scaling (DVS) has become a well-known and effective technique to exploit energyperformance trade-off in real-time embedded systems where energy imposes a major constraint. We focus on frame-based real-time systems that execute variable workloads with the goal of minimizing expected energy consumption in the system while still meeting the deadlines. In our previous publication [1...

How do you encourage or facilitate on-line participation? What constitutes effective participation? The paper firstly examines selected theories about encouraging effective on-line participation and secondly, reviews a range of qualitative and quantitative methods for assessing the effectiveness of students' on-line participation. The author aims to make informed recommendations on strategies t...

Recently, it has been shown that every recursively enumerable language can be generated by a scattered context grammar with no more than three nonterminals. However, in that construction, the maximal number of nonterminals simultaneously rewritten during a derivation step depends on many factors, such as the cardinality of the alphabet of the generated language and the structure of the generate...

In a classic digital signature scheme, the global community is capable of verifying a signature. In a designated verifier scheme (DVS), only the designated verifier has this capability. In a classic DVS scheme the signer themselves “designates” the entity that will have the capability of verifying their signature. In a pure identity-based signature scheme a Trusted Authority is introduced, and ...

In this work, we present a new bottom-up algorithm for decision tree pruning that is very e cient (requiring only a single pass through the given tree), and prove a strong performance guarantee for the generalization error of the resulting pruned tree. We work in the typical setting in which the given tree T may have been derived from the given training sample S, and thus may badly over t S. In...

We show that descriptive complexity’s result extends in High Order Logic to capture the expressivity of Turing Machine which have a finite number of alternation and whose time or space is bounded by a finite tower of exponential. Hence we have a logical characterisation of ELEMENTARY. We also consider the expressivity of some fixed point operators and of monadic high order logic. Finally, we sh...

The growing number of video servers resulted in desperate need for eeective method to deliver data to users in a timely fashion. Centralized servers are not a cost-eeective solution because of geographical distribution of users. This paper addresses issues related to design of distributed video server (DVS) to support video-on-demand application for a large number of users. We present a hierarc...

This paper proposes a real-time embedded fall detection system using a DVS(Dynamic Vision Sensor)(Berner et al. [2014]) that has never been used for traditional fall detection, a dataset for fall detection using that, and a DVSTN(DVS-Temporal Network). The first contribution is building a DVS Falls Dataset, which made our network to recognize a much greater variety of falls than the existing da...

In this work the dynamic descriptive complexity of the kclique query is studied in a framework introduced by Patnaik and Immerman. It is shown that when edges may only be inserted then k-clique can be maintained by a quantifier-free update program of arity k − 1, but it cannot be maintained by a quantifier-free update program of arity k−2 (even in the presence of unary auxiliary functions). Thi...