63,811 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
New Method of Measuring TCP Performance of IP Network using Bio-computing
The measurement of performance of Internet Protocol IP network can be done by
Transmission Control Protocol TCP because it guarantees send data from one end
of the connection actually gets to the other end and in the same order it was
send, otherwise an error is reported. There are several methods to measure the
performance of TCP among these methods genetic algorithms, neural network, data
mining etc, all these methods have weakness and can't reach to correct measure
of TCP performance. This paper proposed a new method of measuring TCP
performance for real time IP network using Biocomputing, especially molecular
calculation because it provides wisdom results and it can exploit all
facilities of phylogentic analysis. Applying the new method at real time on
Biological Kurdish Messenger BIOKM model designed to measure the TCP
performance in two types of protocols File Transfer Protocol FTP and Internet
Relay Chat Daemon IRCD. This application gives very close result of TCP
performance comparing with TCP performance which obtains from Little's law
using same model (BIOKM), i.e. the different percentage of utilization (Busy or
traffic industry) and the idle time which are obtained from a new method base
on Bio-computing comparing with Little's law was (nearly) 0.13%.
KEYWORDS Bio-computing, TCP performance, Phylogenetic tree, Hybridized Model
(Normalized), FTP, IRCDComment: 17 Pages,10 Figures,5 Table
Towards a Maude tool for model checking temporal graph properties
We present our prototypical tool for the verification of graph transformation systems. The major novelty of our tool is that it provides a model checker for temporal graph properties based on counterpart semantics for quantified m-calculi. Our tool can be considered as an instantiation of our approach to counterpart semantics which allows for a neat handling of creation, deletion and merging in systems
with dynamic structure. Our implementation is based on the object-based machinery of Maude, which provides the basics to deal with attributed graphs. Graph transformation
systems are specified with term rewrite rules. The model checker evaluates logical formulae of second-order modal m-calculus in the automatically generated CounterpartModel (a sort of unfolded graph transition system) of the graph transformation system under study. The result of evaluating a formula is a set of assignments for each state, associating node variables to actual nodes
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Forms and processes of information systems evolution
The way in which software evolves over time has been much studied and is now fairly well-understood. What has been less thoroughly studied are the processes by which information systems ā containing software as one component, but also with significant human and organisational aspects ā evolve. In many organisations, few information systems are built at all from scratch, but rather are modified from or built on top of existing ones or bolted together from third-party components. In practice, the old division between design, implementation and maintenance has largely disappeared. In this paper, I discuss the nature of IS evolution. I make a distinction between planned (intentional and strategic) evolution, for which we can formulate a clear process; and unplanned (emergent and externally-driven) evolution, where we can simply study the dynamics of the process and be ready for events
Collaborative design : managing task interdependencies and multiple perspectives
This paper focuses on two characteristics of collaborative design with
respect to cooperative work: the importance of work interdependencies linked to
the nature of design problems; and the fundamental function of design
cooperative work arrangement which is the confrontation and combination of
perspectives. These two intrinsic characteristics of the design work stress
specific cooperative processes: coordination processes in order to manage task
interdependencies, establishment of common ground and negotiation mechanisms in
order to manage the integration of multiple perspectives in design
Technological agglomeration and the emergence of clusters and networks in nanotechnology
Research and development at the nanoscale requires a large degree of
integration, from convergence of research disciplines in new fields of enquiry
to new linkages between start-ups, regional actors and research facilities.
Based on the analysis of two clusters in nanotechnologies (MESA+ (Twente) and
other centres in The Netherlands and Minatec in Grenoble in France), the paper
discusses the phenomenon of technological agglomeration: co-located scientific
and technological fields associated to coordinated technology platforms to some
extent actively shaped by institutional entrepreneurs. Such co-location and
coordination are probably a prerequisite for the emergence of strong
nanocluster
On Agent-Based Software Engineering
Agent-based computing represents an exciting new synthesis both for Artificial Intelligence (AI) and, more generally, Computer Science. It has the potential to significantly improve the theory and the practice of modeling, designing, and implementing computer systems. Yet, to date, there has been little systematic analysis of what makes the agent-based approach such an appealing and powerful computational model. Moreover, even less effort has been devoted to discussing the inherent disadvantages that stem from adopting an agent-oriented view. Here both sets of issues are explored. The standpoint of this analysis is the role of agent-based software in solving complex, real-world problems. In particular, it will be argued that the development of robust and scalable software systems requires autonomous agents that can complete their objectives while situated in a dynamic and uncertain environment, that can engage in rich, high-level social interactions, and that can operate within flexible organisational structures
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