We present an ecological framework for considering ecosystem degradation and restoration, particularly in rangelands and arid environments. The framework is a synthesis of three conceptual models previously developed by several rangeland and restoration ecologists. We focus first on distinctions and connections between structural and functional components of rangeland ecosystems and then on dis...

Cyclic covers are shown to characterise disjunctive stable models of unstratified deductive databases, and to facilitate top-down query processing, query compilation and view updating under the disjunctive stable model semantics. Such processing is shown to be more complex than comparable processing of stratified databases.

Compositional proof systems not only enable the stepwise development of concurrent processes but also provide a basis to alleviate the state explosion problem associated with model checking. An assume-guarantee style of specification and reasoning has long been advocated to achieve compositionality. However, this style of reasoning is often nontrivial, typically requiring human input to determi...

Local spatial interaction (i.e. neighborhood interaction) between land-use types is an important component in Cellular Automata -based urban geosimulation models. Herein a new method based on the integration of Tobler’s First Law of Geography with Reilly’s gravity model and coupled with logistical regression approach is proposed to model and calibrate the neighborhood interaction. This method i...

Decoding algorithms for syntax based machine translation suffer from high computational complexity, a consequence of intersecting a language model with a context free grammar. Left-to-right decoding, which generates the target string in order, can improve decoding efficiency by simplifying the language model evaluation. This paper presents a novel left to right decoding algorithm for tree-to-st...

We illustrate a model to define information requirements for the whole Enterprise. The key novelty is that the model is a normative one. Actually it assists the analyst in defining the contents data bases should have. The approach is founded on some key ideas. First, an enterprise processes information on domain families, that include stakeholders, products, process and contexts. By specializin...

Attention plays an important role in human processing of sensory information as a mean of focusing resources towards the most important inputs at the moment. In vision it has been argued attentional processes are crucial for dealing with the complexity of real world scenes. The problem has often been posed in terms of visual search tasks. It has been shown that both the use of prior task and co...

In this talk we present the Fluid Concepts cognitive model, developed by Douglas Hofstadter and his students over the last 30 years. Models in the Fluid Concepts tradition aim to provide a psychologically plausible description of perception and analogy-making, incorporating the parallel processing of bottom-up, data-driven percepts and topdown, expectation-driven hypotheses. We discuss these mo...

We have developed a computational model of perceptual attention that interleaves top-down and bottom-up attention processes of an embodied agent in a virtual environment. What has been lacking in our model until now is how it would work when the one of the tasks being performed by the agent is holding a conversation with one or more agents. In this paper, we propose some modifications to our mo...

In the real world, people often have a habit tending to pay more attention to some things usually noteworthy, while ignore others. This phenomenon is associated with the top-down attention. Modeling this kind of attention has recently raised many interests in computer vision due to a wide range of practical applications. Majority of the existing models are based on eye-tracking or object detect...