Brian S. Logan

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In this paper we describe an adaptive, optimistic synchronisation mechanism for the parallel discrete event simulation of agent-based systems. The mechanism uses the Sphere of Influence (SoI) of an event (the region of the shared simulation state read or written to by the event) to define an adaptive metric which can be used with a throttling mechanism such(More)
The paper presents a load management mechanism for distributed simulations of multi-agent systems. The mechanism minimises the cost of accessing the shared state in the distributed simulation by dynamically redistributing shared state variables according to the access pattern of the simulation model. To evaluate the effectiveness and performance of the(More)
In this paper we present a throttling mechanism for optimistic simulations of multi-agent systems, which delays read accesses to the shared simulation state that are likely to be rolled back. We develop a decision-theoretic model of rollback and show how this can be used to derive the optimal time to delay a read event so as to minimise the expected overall(More)
In this paper we present a detailed analysis of the performance of the Decision Theoretic Read Delay (DTRD) optimistic synchronisation algorithm for simulations of Multi- Agent Systems. We develop an abstract characterisation of the access patterns found in MAS simulations based on the simulation's degree of coupling and skew. Using this characterisation,(More)
We present an agent-based model of the key activities of a troop of chacma baboons (Papio hamadryas ursinus) based on the data collected at De Hoop Nature Reserve in South Africa. We analyse the predictions of the model in terms of how well it is able to duplicate the observed activity patterns of the animals and the relationship between the parameters that(More)
Distributed simulation has emerged as an important instrument for studying large-scale complex systems. Such systems inherently consist of a large number of components, which operate in a large shared state space interacting with it in highly dynamic and unpredictable ways. Optimising access to the shared state space is crucial for achieving efficient(More)
The efficient simulation of a multi-agent system presents particular challenges which are not addressed by standard parallel discrete event simulation (PDES) models and techniques. While the modelling and simulation of agents, at least at a coarse grain, is relatively straightforward, it is harder to apply conventional PDES approaches to the simulation of(More)