30,383 research outputs found
Principles and Concepts of Agent-Based Modelling for Developing Geospatial Simulations
The aim of this paper is to outline fundamental concepts and principles of the Agent-Based Modelling (ABM) paradigm, with particular reference to the development of geospatial simulations. The paper begins with a brief definition of modelling, followed by a classification of model types, and a comment regarding a shift (in certain circumstances) towards modelling systems at the individual-level. In particular, automata approaches (e.g. Cellular Automata, CA, and ABM) have been particularly popular, with ABM moving to the fore. A definition of agents and agent-based models is given; identifying their advantages and disadvantages, especially in relation to geospatial modelling. The potential use of agent-based models is discussed, and how-to instructions for developing an agent-based model are provided. Types of simulation / modelling systems available for ABM are defined, supplemented with criteria to consider before choosing a particular system for a modelling endeavour. Information pertaining to a selection of simulation / modelling systems (Swarm, MASON, Repast, StarLogo, NetLogo, OBEUS, AgentSheets and AnyLogic) is provided, categorised by their licensing policy (open source, shareware / freeware and proprietary systems). The evaluation (i.e. verification, calibration, validation and analysis) of agent-based models and their output is examined, and noteworthy applications are discussed.Geographical Information Systems (GIS) are a particularly useful medium for representing model input and output of a geospatial nature. However, GIS are not well suited to dynamic modelling (e.g. ABM). In particular, problems of representing time and change within GIS are highlighted. Consequently, this paper explores the opportunity of linking (through coupling or integration / embedding) a GIS with a simulation / modelling system purposely built, and therefore better suited to supporting the requirements of ABM. This paper concludes with a synthesis of the discussion that has proceeded. The aim of this paper is to outline fundamental concepts and principles of the Agent-Based Modelling (ABM) paradigm, with particular reference to the development of geospatial simulations. The paper begins with a brief definition of modelling, followed by a classification of model types, and a comment regarding a shift (in certain circumstances) towards modelling systems at the individual-level. In particular, automata approaches (e.g. Cellular Automata, CA, and ABM) have been particularly popular, with ABM moving to the fore. A definition of agents and agent-based models is given; identifying their advantages and disadvantages, especially in relation to geospatial modelling. The potential use of agent-based models is discussed, and how-to instructions for developing an agent-based model are provided. Types of simulation / modelling systems available for ABM are defined, supplemented with criteria to consider before choosing a particular system for a modelling endeavour. Information pertaining to a selection of simulation / modelling systems (Swarm, MASON, Repast, StarLogo, NetLogo, OBEUS, AgentSheets and AnyLogic) is provided, categorised by their licensing policy (open source, shareware / freeware and proprietary systems). The evaluation (i.e. verification, calibration, validation and analysis) of agent-based models and their output is examined, and noteworthy applications are discussed.Geographical Information Systems (GIS) are a particularly useful medium for representing model input and output of a geospatial nature. However, GIS are not well suited to dynamic modelling (e.g. ABM). In particular, problems of representing time and change within GIS are highlighted. Consequently, this paper explores the opportunity of linking (through coupling or integration / embedding) a GIS with a simulation / modelling system purposely built, and therefore better suited to supporting the requirements of ABM. This paper concludes with a synthesis of the discussion that has proceeded
Tangible user interfaces : past, present and future directions
In the last two decades, Tangible User Interfaces (TUIs) have emerged as a new interface type that interlinks the digital and physical worlds. Drawing upon users' knowledge and skills of interaction with the real non-digital world, TUIs show a potential to enhance the way in which people interact with and leverage digital information. However, TUI research is still in its infancy and extensive research is required in or- der to fully understand the implications of tangible user interfaces, to develop technologies that further bridge the digital and the physical, and to guide TUI design with empirical knowledge. This paper examines the existing body of work on Tangible User In- terfaces. We start by sketching the history of tangible user interfaces, examining the intellectual origins of this field. We then present TUIs in a broader context, survey application domains, and review frame- works and taxonomies. We also discuss conceptual foundations of TUIs including perspectives from cognitive sciences, phycology, and philoso- phy. Methods and technologies for designing, building, and evaluating TUIs are also addressed. Finally, we discuss the strengths and limita- tions of TUIs and chart directions for future research
A GRID-BASED E-LEARNING MODEL FOR OPEN UNIVERSITIES
E-learning has grown to become a widely
accepted method of learning all over the world. As a
result, many e-learning platforms which have been
developed based on varying technologies were faced
with some limitations ranging from storage
capability, computing power, to availability or access
to the learning support infrastructures. This has
brought about the need to develop ways to
effectively manage and share the limited resources
available in the e-learning platform. Grid computing
technology has the capability to enhance the quality
of pedagogy on the e-learning platform.
In this paper we propose a Grid-based e-learning
model for Open Universities. An attribute of such
universities is the setting up of multiple remotely
located campuses within a country.
The grid-based e-learning model presented in
this work possesses the attributes of an elegant
architectural framework that will facilitate efficient
use of available e-learning resources and cost
reduction, leading to general improvement of the
overall quality of the operations of open universities
Steering in computational science: mesoscale modelling and simulation
This paper outlines the benefits of computational steering for high
performance computing applications. Lattice-Boltzmann mesoscale fluid
simulations of binary and ternary amphiphilic fluids in two and three
dimensions are used to illustrate the substantial improvements which
computational steering offers in terms of resource efficiency and time to
discover new physics. We discuss details of our current steering
implementations and describe their future outlook with the advent of
computational grids.Comment: 40 pages, 11 figures. Accepted for publication in Contemporary
Physic
Simulation Application for the LHCb Experiment
We describe the LHCb detector simulation application (Gauss) based on the
Geant4 toolkit. The application is built using the Gaudi software framework,
which is used for all event-processing applications in the LHCb experiment. The
existence of an underlying framework allows several common basic services such
as persistency, interactivity, as well as detector geometry description or
particle data to be shared between simulation, reconstruction and analysis
applications. The main benefits of such common services are coherence between
different event-processing stages as well as reduced development effort. The
interfacing to Geant4 toolkit is realized through a facade (GiGa) which
minimizes the coupling to the simulation engine and provides a set of abstract
interfaces for configuration and event-by-event communication. The Gauss
application is composed of three main blocks, i.e. event generation, detector
response simulation and digitization which reflect the different stages
performed during the simulation job. We describe the overall design as well as
the details of Gauss application with a special emphasis on the configuration
and control of the underlying simulation engine. We also briefly mention the
validation strategy and the planing for the LHCb experiment simulation.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics
(CHEP03), La Jolla, Ca, USA, March 2003, 6 pages, LaTeX, 9 eps figures. PSN
TUMT00
GART: The Gesture and Activity Recognition Toolkit
Presented at the 12th International Conference on Human-Computer Interaction, Beijing, China, July 2007.The original publication is available at www.springerlink.comThe Gesture and Activity Recognition Toolit (GART) is
a user interface toolkit designed to enable the development of gesture-based
applications. GART provides an abstraction to machine learning
algorithms suitable for modeling and recognizing different types of
gestures. The toolkit also provides support for the data collection and
the training process. In this paper, we present GART and its machine
learning abstractions. Furthermore, we detail the components of the
toolkit and present two example gesture recognition applications
PortisHEad: portfolios in successful Higher Education admissions
The PortisHEad project developed tools to support applications to UK higher education through learner-owned e-portfolios; including the ability to target unique e-portfolios to different institutions. The original demonstration tool helped address the recommendations of the Schwartz report for fairer admissions to higher education. However, despite good learner feedback and a strong sectoral imperative, the tool was not implemented by UCAS, the application service. Despite the withdrawal of UCAS from the project the remaining partners developed a generic application toolkit which allows any e-portfolio user to auto-complete educational or employment-related ‘application-type’ forms using learner-owned data from their e-portfolio. The toolkit is consistent with the ‘thin e-portfolio model’ propounded by the JISC-funded e-Portfolio Reference Model project. It uses an ‘open standard’ web-service which is easily implementable by ‘form-owners’; access to data is managed by the learners and remains secure. The toolkit is easy to deploy and has already generated significant interest not only from admissions tutors but also for its utility to teachers and staff developers. This paper points to how learner-controlled technologies, and learner-owned data, can be meaningfully utilized to engage with intra- and extra-institutional systems using open standards and web services. It also illustrates that technological difficulties are less critical than organisational ones
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