236 research outputs found
What is coordination theory?
"February 1988."Includes bibliogaphical references (p. 22-28).Thomas W. Malone
Operator interfaces for the lifecycle support of component based automation systems
Current manufacturing automation systems (specifically the powertrain sector)
have been facing challenges with constant pressures of globalisation,
environmental concerns and ICT (Information and Communication Technology)
innovations. These challenges instigate new demands for shorter product
lifecycles and require customised products to be manufactured as efficiently as
possible. Manufacturing systems must therefore be agile to remain competitive
by supporting frequent reconfigurations involving distributed engineering
activities. [Continues.
Web service control of component-based agile manufacturing systems
Current global business competition has resulted in significant challenges for
manufacturing and production sectors focused on shorter product lifecyc1es, more diverse
and customized products as well as cost pressures from competitors and customers. To
remain competitive, manufacturers, particularly in automotive industry, require the next
generation of manufacturing paradigms supporting flexible and reconfigurable production
systems that allow quick system changeovers for various types of products. In addition,
closer integration of shop floor and business systems is required as indicated by the
research efforts in investigating "Agile and Collaborative Manufacturing Systems" in
supporting the production unit throughout the manufacturing lifecycles.
The integration of a business enterprise with its shop-floor and lifecycle supply partners
is currently only achieved through complex proprietary solutions due to differences in
technology, particularly between automation and business systems. The situation is
further complicated by the diverse types of automation control devices employed.
Recently, the emerging technology of Service Oriented Architecture's (SOA's) and Web
Services (WS) has been demonstrated and proved successful in linking business
applications. The adoption of this Web Services approach at the automation level, that
would enable a seamless integration of business enterprise and a shop-floor system, is an
active research topic within the automotive domain. If successful, reconfigurable
automation systems formed by a network of collaborative autonomous and open control
platform in distributed, loosely coupled manufacturing environment can be realized
through a unifying platform of WS interfaces for devices communication.
The adoption of SOA- Web Services on embedded automation devices can be achieved
employing Device Profile for Web Services (DPWS) protocols which encapsulate device
control functionality as provided services (e.g. device I/O operation, device state
notification, device discovery) and business application interfaces into physical control
components of machining automation. This novel approach supports the possibility of
integrating pervasive enterprise applications through unifying Web Services interfaces
and neutral Simple Object Access Protocol (SOAP) message communication between
control systems and business applications over standard Ethernet-Local Area Networks
(LAN's). In addition, the re-configurability of the automation system is enhanced via the
utilisation of Web Services throughout an automated control, build, installation, test,
maintenance and reuse system lifecycle via device self-discovery provided by the DPWS
protocol...cont'd
Development of a toolkit for component-based automation systems
From the earliest days of mass production in the automotive industry there has been a
progressive move towards the use of flexible manufacturing systems that cater for
product variants that meet market demands. In recent years this market has become
more demanding with pressures from legislation, globalisation and increased
customer expectations. This has lead to the current trends of mass customisation in
production.
In order to support this manufacturing systems are not only becoming more flexibleâ€
to cope with the increased product variants, but also more agile‡ such that they may
respond more rapidly to market changes. Modularisation§ is widely used to increase
the agility of automation systems, such that they may be more readily reconfigured¶.
Also with globalisation into India and Asia semi-automatic machines (machines that
interact with human operators) are more frequently used to reduce capital outlay and
increase flexibility. There is an increasing need for tools and methodologies that
support this in order to improve design robustness, reduce design time and gain a
competitive edge in the market.
The research presented in this thesis is built upon the work from
COMPAG/COMPANION (COMponent- based Paradigm for AGile automation, and
COmmon Model for PArtNers in automatION), and as part of the BDA (Business
Driven Automation), SOCRADES (Service Oriented Cross-layer infrastructure for
Distributed smart Embedded deviceS), and IMC-AESOP (ArchitecturE for Service-
Oriented Process – monitoring and control) projects conducted at Loughborough
University UK.
This research details the design and implementation of a toolkit for building and
simulating automation systems comprising components with behaviour described
using Finite State Machines (FSM). The research focus is the development of the
engineering toolkit that can support the automation system lifecycle from initial
design through commissioning to maintenance and reconfiguration as well as the
integration of a virtual human. This is achieved using a novel data structure that
supports component definitions for control, simulation, maintenance and the novel
integration of a virtual human into the automation system operation
Intelligent real-time train rescheduling management for railway system
The issue of managing a large and complex railway system with continuous traffic flows and mixed train services in a safe and punctual manner is very important, especially after disruptive events. In the first part of this thesis an analysis method is introduced which allows the visualisation and measurement of the propagation of delays in the railway network. The BRaVE simulator and the University of Birmingham Single Train Simulator (STS) are also introduced and a train running estimation using STS is described. A practical single junction rescheduling problem is then defined and it investigates how different levels of delays and numbers of constraints may affect the performance of algorithms for network-wide rescheduling in terms of quality of solution and computation time. In order to deal with operational dynamics, a methodology using performance-based supervisory control is proposed to provide rescheduling decisions over a wider area through the application of different rescheduling strategies in appropriate sequences.
Finally, an architecture for a real-time train rescheduling framework, based on the distributed artificial intelligence system, is designed in order to handle railway traffic in a large-scale network intelligently. A case study based on part of the East Coast Main Line is followed up to demonstrate the effectiveness of adopting supervisory control to provide the rescheduling options in the dynamic situation
Fifth Conference on Artificial Intelligence for Space Applications
The Fifth Conference on Artificial Intelligence for Space Applications brings together diverse technical and scientific work in order to help those who employ AI methods in space applications to identify common goals and to address issues of general interest in the AI community. Topics include the following: automation for Space Station; intelligent control, testing, and fault diagnosis; robotics and vision; planning and scheduling; simulation, modeling, and tutoring; development tools and automatic programming; knowledge representation and acquisition; and knowledge base/data base integration
HIERARCHICAL-GRANULARITY HOLONIC MODELLING
This thesis aims to introduce an agent-based system engineering approach,
named Hierarchical-Granularity Holonic Modelling, to support intelligent
information processing at multiple granularity levels. The focus is especially
on complex hierarchical systems.
Nowadays, due to ever growing complexity of information systems and
processes, there is an increasing need of a simple self-modular computational
model able to manage data and perform information granulation at different
resolutions (i.e., both spatial and temporal). The current literature lacks to
provide such a methodology. To cite a relevant example, the object-oriented
paradigm is suitable for describing a system at a given representation level;
notwithstanding, further design effort is needed if a more synthetical of more
analytical view of the same system is required.
In the literature, the agent paradigm represents a viable solution in complex
systems modelling; in particular, Multi-Agent Systems have been applied with
success in a countless variety of distributed intelligence settings. Current
agent-oriented implementations however suffer from an apparent dichotomy
between agents as intelligent entities and agents\u2019 structures as superimposed
hierarchies of roles within a given organization. The agents\u2019 architectures are
often rigid and require intense re-engineering when the underpinning ontology
is updated to cast new design criteria.
The latest stage in the evolution of modelling frameworks is represented by
Holonic Systems, based on the notion of \u2018holon\u2019 and \u2018holarchy\u2019 (i.e.,
hierarchy of holons). A holon, just like an agent, is an intelligent entity able to
interact with the environment and to take decisions to solve a specific
problem. Contrarily to agent, holon has the noteworthy property of playing the
role of a whole and a part at the same time. This reflects at the organizational
level: holarchy functions first as autonomous wholes in supra-ordination to
their parts, secondly as dependent parts in sub-ordination to controls on higher
levels, and thirdly in coordination with their local environment.
These ideas were originally devised by Arthur Koestler in 1967. Since then,
Holonic Systems have gained more and more credit in various fields such as
Biology, Ecology, Theory of Emergence and Intelligent Manufacturing.
Notwithstanding, with respect to these disciplines, fewer works on Holonic
Systems can be found in the general framework of Artificial and
Computational Intelligence. Moreover, the distance between theoretic models
and actual implementation is still wide open.
In this thesis, starting from the Koestler\u2019s original idea, we devise a novel
agent-inspired model that merges intelligence with the holonic structure at
multiple hierarchical-granularity levels. This is made possible thanks to a rule-based
knowledge recursive representation, which allows the holonic agent to
carry out both operating and learning tasks in a hierarchy of granularity levels.
The proposed model can be directly used in terms of hardware/software
applications. This endows systems and software engineers with a modular and
scalable approach when dealing with complex hierarchical systems. In order
to support our claims, exemplar experiments of our proposal are shown and
prospective implications are commented
Integrative (Synchronisations-)Mechanismen der (Neuro-)Kognition vor dem Hintergrund des (Neo-)Konnektionismus, der Theorie der nichtlinearen dynamischen Systeme, der Informationstheorie und des Selbstorganisationsparadigmas
Der Gegenstand der vorliegenden Arbeit besteht darin, aufbauend auf dem (Haupt-)Thema, der Darlegung und Untersuchung der Lösung des Bindungsproblems anhand von temporalen integrativen (Synchronisations-)Mechanismen im Rahmen der kognitiven (Neuro-)Architekturen im (Neo-)Konnektionismus mit Bezug auf die Wahrnehmungs- und Sprachkognition, vor allem mit Bezug auf die dabei auftretende Kompositionalitäts- und Systematizitätsproblematik, die Konstruktion einer noch zu entwickelnden integrativen Theorie der (Neuro-)Kognition zu skizzie-ren, auf der Basis des Repräsentationsformats einer sog. „vektoriellen Form“, u.z. vor dem Hintergrund des (Neo-)Konnektionismus, der Theorie der nichtlinearen dynamischen Systeme, der Informationstheorie und des Selbstorganisations-Paradigmas
Implementation methodology for using concurrent and collaborative approaches for theorem provers, with case studies of SAT and LCF style provers
Theorem provers are faced with the challenges of size and complexity, fueled by the increasing range
of applications. The use of concurrent/ distributed programming paradigms to engineer better theorem
provers merits serious investigation, as it provides: more processing power and opportunities for
implementing novel approaches to address theorem proving tasks hitherto infeasible in a sequential setting.
Investigation of these opportunities for two diverse theorem prover settings with an emphasis on
desirable implementation criteria is the core focus of this thesis.
Concurrent programming is notoriously error prone, hard to debug and evaluate. Thus, implementation
approaches which promote easy prototyping, portability, incremental development and effective isolation
of design and implementation can greatly aid the enterprise of experimentation with the application
of concurrent techniques to address specific theorem proving tasks. In this thesis, we have explored one
such approach by using Alice ML, a functional programming language with support for concurrency
and distribution, to implement the prototypes and have used programming abstractions to encapsulate
the implementations of the concurrent techniques used. The utility of this approach is illustrated via
proof-of-concept prototypes of concurrent systems for two diverse case studies of theorem proving: the
propositional satisfiability problem (SAT) and LCF style (first-order) theorem proving, addressing some
previously unexplored parallelisation opportunities for each, as follows:.
SAT: We have developed a novel hybrid approach for SAT and implemented a prototype for the same:
DPLL-Stalmarck. It uses two complementary algorithms for SAT, DPLL and Stalmarck’s. The two
solvers run asynchronously and dynamic information exchange is used for co-operative solving. Interaction
of the solvers has been encapsulated as a programming abstraction. Compared to the standalone
DPLL solver, DPLL-Stalmarck shows significant performance gains for two of the three problem classes
considered and comparable behaviour otherwise. As an exploratory research effort, we have developed a
novel algorithm, Concurrent Stalmarck, by applying concurrent techniques to the Stalmarck algorithm.
A proof-of-concept prototype for the same has been implemented. Implementation of the saturation
technique of the Stalmarck algorithm in a parallel setting, as implemented in Concurrent Stalmarck, has
been encapsulated as a programming abstraction.
LCF: Provision of programmable concurrent primitives enables customisation of concurrent techniques
to specific theorem proving scenarios. In this case study, we have developed a multilayered approach to
support programmable, sound extensions for an LCF prover: use programming abstractions to implement
the concurrent techniques; use these to develop novel tacticals (control structures to apply tactics),
incorporating concurrent techniques; and use these to develop novel proof search procedures. This
approach has been implemented in a prototypical LCF style first-order prover, using Alice ML. New
tacticals developed are: fastest-first; distributed composition; crossTalk: a novel tactic which uses dynamic,
collaborative information exchange to handle unification across multiple sub-goals, with shared
meta-variables; a new tactic, performing simultaneous proof-refutation attempts on propositional (sub-
)goals, by invoking an external SAT solver (SAT case study), as a counter-example finder. Examples of
concrete theorem proving scenarios are provided, demonstrating the utility of these extensions. Synthesis
of a variety of automatic proof search procedures has been demonstrated, illustrating the scope of
programmability and customisation, enabled by our multilayered approach
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