23 research outputs found
Pattern Reification as the Basis for Description-Driven Systems
One of the main factors driving object-oriented software development for
information systems is the requirement for systems to be tolerant to change. To
address this issue in designing systems, this paper proposes a pattern-based,
object-oriented, description-driven system (DDS) architecture as an extension
to the standard UML four-layer meta-model. A DDS architecture is proposed in
which aspects of both static and dynamic systems behavior can be captured via
descriptive models and meta-models. The proposed architecture embodies four
main elements - firstly, the adoption of a multi-layered meta-modeling
architecture and reflective meta-level architecture, secondly the
identification of four data modeling relationships that can be made explicit
such that they can be modified dynamically, thirdly the identification of five
design patterns which have emerged from practice and have proved essential in
providing reusable building blocks for data management, and fourthly the
encoding of the structural properties of the five design patterns by means of
one fundamental pattern, the Graph pattern. A practical example of this
philosophy, the CRISTAL project, is used to demonstrate the use of
description-driven data objects to handle system evolution.Comment: 20 pages, 10 figure
Managing Evolving Business Workflows through the Capture of Descriptive Information
Business systems these days need to be agile to address the needs of a
changing world. In particular the discipline of Enterprise Application
Integration requires business process management to be highly reconfigurable
with the ability to support dynamic workflows, inter-application integration
and process reconfiguration. Basing EAI systems on model-resident or on a
so-called description-driven approach enables aspects of flexibility,
distribution, system evolution and integration to be addressed in a
domain-independent manner. Such a system called CRISTAL is described in this
paper with particular emphasis on its application to EAI problem domains. A
practical example of the CRISTAL technology in the domain of manufacturing
systems, called Agilium, is described to demonstrate the principles of
model-driven system evolution and integration. The approach is compared to
other model-driven development approaches such as the Model-Driven Architecture
of the OMG and so-called Adaptive Object Models.Comment: 12 pages, 4 figures. Presented at the eCOMO'2003 4th Int. Workshop on
Conceptual Modeling Approaches for e-Busines
Meta-Data Objects as the Basis for System Evolution
One of the main factors driving object-oriented software development in the Web- age is the need for systems to evolve as user requirements change. A crucial factor in the creation of adaptable systems dealing with changing requirements is the suitability of the underlying technology in allowing the evolution of the system. A reflective system utilizes an open architecture where implicit system aspects are reified to become explicit first-class (meta-data) objects. These implicit system aspects are often fundamental structures which are inaccessible and immutable, and their reification as meta-data objects can serve as the basis for changes and extensions to the system, making it self- describing. To address the evolvability issue, this paper proposes a reflective architecture based on two orthogonal abstractions - model abstraction and information abstraction. In this architecture the modeling abstractions allow for the separation of the description meta-data from the system aspects they represent so that they can be managed and versioned independently, asynchronously and explicitly. A practical example of this philosophy, the CRISTAL project, is used to demonstrate the use of meta-data objects to handle system evolution
Using Self-Description to Handle Change in Systems
In the web age systems must be flexible, reconfigurable and adaptable in
addition to being quick to develop. As a consequence, designing systems to
cater for change is becoming not only desirable but required by industry.
Allowing systems to be self-describing or description-driven is one way to
enable these characteristics. To address the issue of evolvability in designing
self-describing systems, this paper proposes a pattern-based, object-oriented,
description-driven architecture. The proposed architecture embodies four
pillars - first, the adoption of a multi-layered meta-modeling architecture and
reflective meta-level architecture, second, the identification of four data
modeling relationships that must be made explicit such that they can be
examined and modified dynamically, third, the identification of five design
patterns which have emerged from practice and have proved essential in
providing reusable building blocks for data management, and fourth, the
encoding of the structural properties of the five design patterns by means of
one pattern, the Graph pattern. In this paper the fundamentals of the
description-driven architecture are described - the multi-layered architecture
and reflective meta-level architecture, remaining detail can be found in the
cited references. A practical example of this architecture is described,
demonstrating the use of description-driven data objects in handling system
evolution.Comment: 9 pages, 5 figures, Object Oriented Information Systems Conference,
Montpellier 200
The MammoGrid Project Grids Architecture
The aim of the recently EU-funded MammoGrid project is, in the light of
emerging Grid technology, to develop a European-wide database of mammograms
that will be used to develop a set of important healthcare applications and
investigate the potential of this Grid to support effective co-working between
healthcare professionals throughout the EU. The MammoGrid consortium intends to
use a Grid model to enable distributed computing that spans national borders.
This Grid infrastructure will be used for deploying novel algorithms as
software directly developed or enhanced within the project. Using the MammoGrid
clinicians will be able to harness the use of massive amounts of medical image
data to perform epidemiological studies, advanced image processing,
radiographic education and ultimately, tele-diagnosis over communities of
medical "virtual organisations". This is achieved through the use of
Grid-compliant services [1] for managing (versions of) massively distributed
files of mammograms, for handling the distributed execution of mammograms
analysis software, for the development of Grid-aware algorithms and for the
sharing of resources between multiple collaborating medical centres. All this
is delivered via a novel software and hardware information infrastructure that,
in addition guarantees the integrity and security of the medical data. The
MammoGrid implementation is based on AliEn, a Grid framework developed by the
ALICE Collaboration. AliEn provides a virtual file catalogue that allows
transparent access to distributed data-sets and provides top to bottom
implementation of a lightweight Grid applicable to cases when handling of a
large number of files is required. This paper details the architecture that
will be implemented by the MammoGrid project.Comment: Talk PSN MOAT0005 from the 2003 Computing in High Energy and Nuclear
Physics (CHEP03), La Jolla, Ca, USA, March 2003, 6 pages, 4 figure
ScienceSoft: Open software for open science
Most of the software developed today by research institutes, university, research projects, etc. is typically stored in local source and binary repositories and available for the duration of a project lifetime only. Finding software based on given functional characteristics is almost impossible and binary packages are mostly available from local university or project repositories rather than the open source community repositories like Fedora/EPEL or Debian. Furthermore general information about who develops, contributes to and most importantly uses a given software program is very difficult to find out and yet the widespread availability of such information would give more visibility and credibility to the software products. The creation of links or relationships not only among pieces of software, but equally among the people interacting with the software across and beyond specific project and communities would foster a more active community and create the conditions for sharing ideas and skills, a more rapid improvement of the software quality and the creation of more sustainable open source communities. This paper presents the work performed as part of the EMI project in collaboration with other partners in setting up an open community dedicated to the development of software for scientific research. The community goals and the benefits for developers and users are outlined. A conceptual prototype of the community portal, the services and the collaboration tools are described