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Attempts to evaluate heuristic algorithms are often hampered by the lack of known exact solutions with which to compare results. This is true, in particular, in the study of network backbone design-to date, a fairly undeveloped area in mathematical optimisation. This paper uses a Mixed Integer Programming (MIP) approach to find optimal solutions to the(More)
Ambient Intelligence (AmI) characterizes a vision where humans are surrounded by computers. Combining ongoing technological developments (e.g. pervasive computing, wearable devices, sensor networks etc.) with user-centred design methods greatly increases the acceptance of the intelligent system and makes it more capable of providing a better quality of life(More)
(2007) 'Real-time optimisation of access control lists for efficient Internet packet filtering'. ABSTRACT This paper considers an optimisation problem encountered in the implementation of traffic policies on network routers, namely the ordering of rules in an access control list to minimise or reduce processing time and hence packet latency. The problem is(More)
The efficiency of packet filters is discussed, that is the effect on processing time of the order of rules in Access Control Lists (ACLs). The problem is introduced and formulated, and various approaches considered. A current optimisation technique is described and potential difficulties noted. A simpler solution, more appropriate for real-time(More)
The difficulty of efficiently reordering the rules in an Access Control List is considered and the essential optimisation problem formulated. The complexity of exact and sophisticated heuristics is noted along with their unsuitability for real time implementation embedded in the hardware of the network device. A simple alternative is proposed, in which a(More)
This paper considers communication network design problems that arise in the real world, with large numbers of nodes-and link and switch costs dependent upon their traffic capacity. Such costs, in turn, depend upon network topology so are not fixed at the start of, or through, any optimisation process. Realistic topological restrictions are also discussed.(More)
This paper describes an investigation into the potential for remote controlled operation of home automation systems. It considers problems with their implementation, discusses possible solutions through various network technologies and indicates how to optimize the use of such systems. The home is an eternal, heterogeneous, distributed computing environment(More)
This paper considers the effects of dependencies between rules in Access Control Lists (ACLs). Dependent rules may not be reordered in an ACL if the policies of the list are to be preserved. This is an obstacle to the optimisation of rule order intended to reduce the time taken matching packets against rules. In this paper, the concept of rule dependency is(More)
In this paper, we present a case study on the development of interfaces for elderly and disabled users. The domain of the case study was situated in the home environment, where we focused on producing affordable technologies to enable users to interact with and to control home appliances. We have developed ambient user interfaces that are integrated in(More)