6,142 research outputs found
Simulation of networks of spiking neurons: A review of tools and strategies
We review different aspects of the simulation of spiking neural networks. We
start by reviewing the different types of simulation strategies and algorithms
that are currently implemented. We next review the precision of those
simulation strategies, in particular in cases where plasticity depends on the
exact timing of the spikes. We overview different simulators and simulation
environments presently available (restricted to those freely available, open
source and documented). For each simulation tool, its advantages and pitfalls
are reviewed, with an aim to allow the reader to identify which simulator is
appropriate for a given task. Finally, we provide a series of benchmark
simulations of different types of networks of spiking neurons, including
Hodgkin-Huxley type, integrate-and-fire models, interacting with current-based
or conductance-based synapses, using clock-driven or event-driven integration
strategies. The same set of models are implemented on the different simulators,
and the codes are made available. The ultimate goal of this review is to
provide a resource to facilitate identifying the appropriate integration
strategy and simulation tool to use for a given modeling problem related to
spiking neural networks.Comment: 49 pages, 24 figures, 1 table; review article, Journal of
Computational Neuroscience, in press (2007
Analyzing Multiple Product Development Projects Based On Information and Resource Constraints
Product development (PD) and engineering design processes are often characterized by the
information flowing among activities. In PD, this flow forms a complex activity weba process
that can be viewed as a complex system. Most literature on the subject of information flow in
PD focuses on a single project, where precedence information constraints (based solely on
necessary information and possible assumptions) determine the execution sequence for the
activities and the resultant project lead-time. In this paper, we consider multiple PD projects that
share a common set of design resources. Especially in this setting, precedence information
availability is insufficient to assure that activities will execute on time. We extend the
information flow modeling literature by including resource availability. We model several PD
projects as a portfolio, where activity execution is based on both information and resource
availability. We demonstrate the effects of accounting for resource constraints on both
individual projects and portfolio lead-time distributions
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