477 research outputs found
Analysis of simulation environment
In this paper the requirements for an ALN simulation environment are analysed, as needed in the CATNETS Project. A number of grid and general purpose simulators are evaluated regarding the identified requirements for simulating economical resource allocation mechanisms in ALNs. Subsequently a suitable simulator is chosen for usage in the CATNETS project. --CATNETS simulator,requirements analysis,simulator selection
Analysis and selection of the simulation environment
This document provides the initial report of the Simulation work package (Work Package 4,WP4) of the CATNETS project. It contains an analisys of the requirements for a simulation tool to be used in CATNETS and an evaluation of a number of grid and general purpose simulators with respect to the selected requirements. A reasoned choice of a suitable simulator is performed based on the evaluation conducted. -- Diese Arbeit analysiert die Anforderungen an eine Simulationsumgebung fĂŒr die Analyse der Katallaxie. Anhand von Kennzahlen wird die Auswahl der Simulationsumgebung bestimmt.Grid Computing
A web-based approach to engineering adaptive collaborative applications
Current methods employed to develop collaborative applications have to make
decisions and speculate about the environment in which the application will operate
within, the network infrastructure that will be used and the device type the application
will operate on. These decisions and assumptions about the environment in which
collaborative applications were designed to work are not ideal. These methods produce
collaborative applications that are characterised as being inflexible, working on
homogeneous networks and single platforms, requiring pre-existing knowledge of the
data and information types they need to use and having a rigid choice of architecture.
On the other hand, future collaborative applications are required to be flexible; to work
in highly heterogeneous environments; be adaptable to work on different networks and
on a range of device types. This research investigates the role that the Web and its
various pervasive technologies along with a component-based Grid middleware can
play to address these concerns. The aim is to develop an approach to building adaptive
collaborative applications that can operate on heterogeneous and changing
environments. This work proposes a four-layer model that developers can use to build
adaptive collaborative applications. The four-layer model is populated with Web
technologies such as Scalable Vector Graphics (SVG), the Resource Description
Framework (RDF), Protocol and RDF Query Language (SPARQL) and Gridkit, a
middleware infrastructure, based on the Open Overlays concept. The Middleware layer
(the first layer of the four-layer model) addresses network and operating system
heterogeneity, the Group Communication layer enables collaboration and data sharing,
while the Knowledge Representation layer proposes an interoperable RDF data
modelling language and a flexible storage facility with an adaptive architecture for
heterogeneous data storage. And finally there is the Presentation and Interaction layer
which proposes a framework (Oea) for scalable and adaptive user interfaces. The four layer
model has been successfully used to build a collaborative application, called
Wildfurt that overcomes challenges facing collaborative applications. This research has
demonstrated new applications for cutting-edge Web technologies in the area of
building collaborative applications. SVG has been used for developing superior
adaptive and scalable user interfaces that can operate on different device types. RDF
and RDFS, have also been used to design and model collaborative applications
providing a mechanism to define classes and properties and the relationships between
them. A flexible and adaptable storage facility that is able to change its architecture
based on the surrounding environments and requirements has also been achieved by
combining the RDF technology with the Open Overlays middleware, Gridkit
Recommended from our members
Performance evaluation of information and communications technology infrastructure for smart distribution network applications
This thesis was submitted for the degree of Master of Philosophy and awarded by Brunel University.Current electrical networks require secure, scalable and cost-effective Information and
Communications Technology (ICT) solutions to facilitate the novel functionalities
required by Smart Grids. Countries around the globe are investigating alternative energy sources to mitigate the current energy crisis and environmental issues experienced by many countries due to global warming, rapid growth of population, inefficient energy management, dwindling fossil fuel resources, etc. Therefore, alternative or renewable energy sources, such as wind, solar, hydro, combined heat and power, etc., are required to mitigate such a crisis and such sources will also need to be integrated in to the power grid
in a distributed manner. Such distributed energy sources are mainly connected to the
distribution networks and introduce huge challenges to the distribution network operator (DNO). Many of these challenges cannot be dealt with effectively using existing network operation mechanisms therefore the research and development of novel ICT solutions to support smart distribution network operation is required.
This research investigated suitable ICT solutions to enable the Smart Grid to tackle these challenges and proposes ICT infrastructure models that can be used for simulation studies in order to investigate cost-effective, scalable and secure solutions for the DNOs. Initially, a Quality of Service (QoS) monitoring test-bed was proposed to evaluate the performance of bandwidth intensive applications, such as smart meter data transmission. Simulation studies for different communication technologies, cellular and Power Line
Communication (PLC), were also carried out and the simulation models were verified
using experimental test results. Finally, the modelling and analysis of smart metering
infrastructure was carried out using simulation and extensive studies were performed to evaluate the data transmission rate performance for different configurations of smart meters and concentrators
A lightweight distributed super peer election algorithm for unstructured dynamic P2P systems
Dissertação apresentada na Faculdade de CiĂȘncias e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia ElectrotĂ©cnica e de ComputadoresNowadays with the current growth of information exchange, and the increasing mobility of devices, it becomes essential to use technology to monitor this development. For that P2P networks are used, the exchange of information between agencies is facilitated, these now being applied in mobile networks, including MANETs, where they have special features such as the fact that they are semi-centralized, where it takes peers more ability to make a greater role in the network. But those peer with more capacity, which are used in the optimization of various parameters of these systems, such as optimization\to research, are difficult to identify due to the fact that the network does not have a fixed topology, be constantly changing, (we like to go online and offline, to change position, etc.) and not to allow the exchange of large messages. To this end, this thesis proposes a distributed election algorithm of us greater capacity among several possible goals, enhance research in the network. This includes distinguishing characteristics, such as election without global knowledge network, minimal exchange of messages, distributed decision made without dependence on us and the possibility of influencing the election outcome as the special needs of the network
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