Alun Butler

Models and tools for an integrated European environmental management and decision support system, (IEEMDSS)

This work proceeds from the assumption that a European environmental information and communication system (EEICS) is already established. In the context of primary users (land-use planners, conservationists, and environmental researchers) we ask what use may be made of the EEICS for building models and tools which is of use in building decision support systems for the land-use planner. The complex task facing the next generation of environmental and forest modellers is described, and a range of relevant modelling approaches are reviewed. These include visualization and GIS; statistical tabulation and database SQL, MDA and OLAP methods. The major problem of noncomparability of the definitions and measures of forest area and timber volume is introduced and the possibility of a model-based solution is considered. The possibility of using an ambitious and challenging biogeochemical modelling approach to understanding and managing European forests sustainably is discussed. It is emphasised that all modern methodological disciplines must be brought to bear, and a heuristic hybrid modelling approach should be used so as to ensure that the benefits of practical empirical modelling approaches are utilised in addition to the scientifically well-founded and holistic ecosystem and environmental modelling. The data and information system required is likely to end up as a grid-based-framework because of the heavy use of computationally intensive model-based facilities.

Requirements and design of an integrated European environmental information communication system, (IEEICS)

The needs for various forms of information systems relating to the European environment and ecosystem are reviewed, and limitations indicated. Existing information systems are reviewed and compared in terms of aims and functionalities. We consider TWO technical challenges involved in attempting to develop an IEEICS. First, there is the challenge of developing an Internet-based communication system which allows fluent access to information stored in a range of distributed databases. Some of the currently available solutions are considered, i.e. Web service federations. The second main challenge arises from the fact that there is general intra-national heterogeneity in the definitions adopted, and the measurement systems used throughout the nations of Europe. Integrated strategies are needed.

On the persistence of computer dreams - an application framework for robust adaptive deployment

The anticipated rewards of adaptive approaches will only be fully realised when autonomic algorithms can take configuration and deployment decisions that match and exceed those of human engineers. Such decisions are typically characterised as being based on a foundation of experience and knowledge. In humans, these underpinnings are themselves founded on the ashes of failure, the exuberance of courage and (sometimes) the outrageousness of fortune. We describe an application framework that will allow the incorporation of similarly risky, error prone and downright dangerous software artifacts into live systems - without undermining the certainty of correctness at application level. We achieve this by introducing the notion of application dreaming.

Layered Autonomic Systems

We adopt a layered approach to autonomic systems to simplify the specification, implementation and evaluation of self-* behaviours. Autonomy is rendered in two dimensions and interfaces suitable for tool based development are incorporated. To exemplify our approach we present an emergent solution for airspace management. This is representative of many problems in which local neighbour interactions can be utilised to give stable and robust global behaviour

Composing Emergent Behaviour in a Fault Intolerant System

We adopt a layered approach to autonomic systems to simplify the specification, implementation and evaluation of self-* behaviours. Our approach is to develop a suite of tools that interoperate in a layered manner to permit generic autonomic behaviours to be incorporated into a wide range of applications. The layered architecture has been designed such that autonomy is achieved in two dimensions. Vertical autonomy exists between the independently functioning layers whilst horizontal autonomy is achieved between nodes, which remain independent while having specific roles in each layer. This paper exemplifies our approach by presenting an emergent solution to the management of air-space. Simulation and visualisation models have been developed for both the cluster and application layers. We analyze performance using these simulations

SOFT – Generating Highly Flexible Object Code from XML Specifications

Many code generation tools exist to aid developers in carrying out common mappings, such as from Object to XML or from Object to relational database. Such generated code tends to possess a high binding between the Object code and the target mapping, making integration into a broader application tedious or even impossible. In this paper we suggest XML technologies and the multiple inheritance capabilities of interface based languages such as Java, offer a means to unify such executable specifications, thus building complete, consistent and useful object models declaratively, without sacrificing component flexibility.