In this paper, we present an approach to obstacle avoidance for a group of unmanned vehicles moving in formation. The goal of the group is to move through a partially unknown environment with obstacles and reach a destination while maintaining the formation. We address this problem for a class of dynamic unicycle robots. Using Inputto-State Stability we combine a general class of formationkeepi...

This paper focuses on the delay-dependent robust stability of linear neutral delay systems. The systems under consideration are described by functional differential equations, with norm bounded time varying nonlinear uncertainties in the “state” and norm bounded time varying quasi-linear uncertainties in the delayed “state” and in the difference operator. The stability analysis is performed via...

This thesis is two fold. The first part deals with an existence proof of a formal algorithm that takes a narrative discourse and returns its semantic representation in the Event Calculus (EC from now on) [19]. This algorithm uses Discourse Representation Theory, and takes on the form of a translation from Discourse Representation Structures to Scenarios and Integrity Constraints in EC. The seco...

A political literary discourse is important at this moment, given the political upheavals that have engulfed African countries. The writer is often seen as an emancipator of the masses therefore, the imaginative writer can, through his work, offer critical appraisal of existing political situations in order to mould and redirect the actions of society, its belief and values. Literature can ther...

We propose a functional view of ontologies that emphasises their role in determining answers to queries, irrespective of the formalism in which they are written. A notion of framework is introduced that captures the situation of a global language into which both an ontology language and a query language can be translated, in an abstract way. We then generalise existing notions of robustness fro...

It has been hypothesized that Tree Adjoining Grammar (TAG) is particularly well suited for sentence generation. It is unclear, however, how a sentence generation system based on TAG should choose among the syntactic possibilities made available in the grammar. In this paper we consider the question of what needs to be done to generate with TAGs and explain a generation system that provides the ...

It is important for task-based learning and teaching research to focus on academic content tasks that involve form and meaning, language and content, and academic discourse and disciplinary knowledge. This is needed to address problems such as low academic achievement by English language learners. We argue that the SFL approach to language, particularly in the area of ‘field’ and ideational mea...

Within organisations, business processes are increasingly captured and supported through socio-technical systems, which incorporate both people and technologies. In today's rapidly changing marketplace, such business processes are more and more complex and volatile, and so are the requirements for their supporting systems. In this paper we consider change in organisations, and proposed novel te...

Administrative data are increasingly important in statistics, but, like other types of data, may contain measurement errors. To prevent such errors from invalidating analyses of scientific interest, it is therefore essential to estimate the extent of measurement errors in administrative data. Currently, however, most approaches to evaluate such errors involve either prohibitively expensive audi...

A new functional-based approach is developed for the stability analysis of linear impulsive systems. The new method, which introduces looped-functionals, considers non-monotonic Lyapunov functions and leads to LMIs conditions devoid of exponential terms. This allows one to easily formulate dwell-times results, for both certain and uncertain systems. It is also shown that this approach may be ap...