Mohamed T. Ibrahim

Rule and Knowledge Management in an Active Database System

Todays new applications require that reasonable inferences be made on the data within the database i.e. knowledge of the application domain is required. Knowledge is a higher level abstraction than the data or facts alone. Active databases strive to encapsulate an application domain’s knowledge within the database. REFLEX is an active database research prototype. It’s main tenet is that it provides knowledge management facilities for traditional existing database management systems. This short paper discusses the knowledge management facilities and the unique features that REFLEX provides such as its novel concurrency mechanism, self-activity, its non-destructive knowledge model, and its graphical user-interface.

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.

EECA: An Active Knowledge Model

General purpose triggers are central to active database management systems, along with knowledge in the form of production rules. The predominant knowledge model is based on Event-Condition-Action (ECA) triples. Our research has found this model to be limiting and inefficient in both operation and declaration clarity as it causes unnecessary replication of rules. An extension is proposed to the ECA knowledge model to permit a semantically concise and precise declaration of the knowledge. This extension (EECA) has been integrated into the REFLEX active database prototype.

Formal Specification, Object-Oriented Design, and Implementation of an Ephemeral Logger for Database Systems

Recent attempts to relax the ACID rules of transaction processing in order to support Long-Lived Transactions (LLTs) have produced a number of systems which incorporate a meta-transactional framework to store the context of simple atomic transactions. Such a system creates problems for logger design, as a small number of very long transactions can fill the log leading to the premature termination of other transactions. Ephemeral Logging (EL) is a logging algorithm which performs generational garbage collection on the log, thus optimising disk space usage. Its claimed advantage over traditional loggers is most marked in a situation where there are a few long transactions amongst many short ones. This paper describes the formal specification of a transactional logger based on the EL algorithm, its modelling using Object-oriented design (OMT) and implementation. The application of the EL logger to new, emerging applications is also considered. At present the published performance data for this algorithm have been derived using a simulator. This report attempts to examine and scrutinise those results, and asks whether EL could be the logging method of choice in systems that support LLTs.

REFLEX Active Database Model: Application of Petri-Nets

REFLEX is an active database research prototype, designed to provide a flexible and adaptive active database extension to an existing database system. This paper reviews the REFLEX model and its architecture. Some of the main contributions of the research are discussed, such as the notion of self-activity and of enabling investments in legacy systems to be preserved. Some current applications of petri-nets to rule management are described before the design and modelling of REFLEX using petri-nets.

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.

Metadata integration framework for managing forest heterogeneous information resources

Managing a large number of heterogeneous information sources and repositories, including databases, knowledge bases, file systems, digital library is a general problem faced by many organizations today. In this context, forest Web data sources provide complex query and analysis capabilities such as sequence similarity search engines that need to be integrated as well as the data. In this paper we introduce a framework to provide abilities for accessing and managing, in a metadata integrated manner, multiple forest information resources. Afterwards, the MIFOR (metadata integration for managing forest information resources) prototype is studied and developed as a resource discovery tool to map, convert and harvest metadata from structured and semistructured sources.

Exploring Adaptation a Self-Adaptation in Autonomic Computing Systems

This panel paper sets out to discuss what self-adaptation means, and to explore the extent to which current autonomic systems exhibit truly self-adaptive behaviour. Many of the currently cited examples are clearly adaptive, but debate remains as to what extent they are simply following prescribed adaptation rules within preset bounds, and to what extent they have the ability to truly learn new behaviour. Is there a standard test that can be applied to differentiate? Is adaptive behaviour sufficient anyway? Other autonomic computing issues are also discussed.

GFIS Pro – A Tool for Managing Forest Information Resources

The Global Forest Information Service (GFIS), an initiative of internationally recognized forestry institutions lead by the International Union of Forest Research Organizations (IUFRO), primarily aims as an electronic system that utilises the Internet to facilitate forest information resource discovery. For describing the content of resources, the GFIS metadata has been designed and implemented as a generalization of the Dublin Core metadata element set. In this context, a set of multilingual controlled forest vocabularies has been established that allows GFIS to focus on a forest special application domain. Hereafter, we have studied and implemented the GFIS prototype, which supports interoperability search among a class of GFIS nodes by means of GFIS-Dublin Core Metadata and the multi host search (MS) tool.