3,513 research outputs found
ES-ENAS: Blackbox Optimization over Hybrid Spaces via Combinatorial and Continuous Evolution
We consider the problem of efficient blackbox optimization over a large
hybrid search space, consisting of a mixture of a high dimensional continuous
space and a complex combinatorial space. Such examples arise commonly in
evolutionary computation, but also more recently, neuroevolution and
architecture search for Reinforcement Learning (RL) policies. Unfortunately
however, previous mutation-based approaches suffer in high dimensional
continuous spaces both theoretically and practically. We thus instead propose
ES-ENAS, a simple joint optimization procedure by combining Evolutionary
Strategies (ES) and combinatorial optimization techniques in a highly scalable
and intuitive way, inspired by the one-shot or supernet paradigm introduced in
Efficient Neural Architecture Search (ENAS). Through this relatively simple
marriage between two different lines of research, we are able to gain the best
of both worlds, and empirically demonstrate our approach by optimizing BBOB
functions over hybrid spaces as well as combinatorial neural network
architectures via edge pruning and quantization on popular RL benchmarks. Due
to the modularity of the algorithm, we also are able incorporate a wide variety
of popular techniques ranging from use of different continuous and
combinatorial optimizers, as well as constrained optimization.Comment: 22 pages. See
https://github.com/google-research/google-research/tree/master/es_enas for
associated cod
Parameterization adaption for 3D shape optimization in aerodynamics
When solving a PDE problem numerically, a certain mesh-refinement process is
always implicit, and very classically, mesh adaptivity is a very effective
means to accelerate grid convergence. Similarly, when optimizing a shape by
means of an explicit geometrical representation, it is natural to seek for an
analogous concept of parameterization adaptivity. We propose here an adaptive
parameterization for three-dimensional optimum design in aerodynamics by using
the so-called "Free-Form Deformation" approach based on 3D tensorial B\'ezier
parameterization. The proposed procedure leads to efficient numerical
simulations with highly reduced computational costs
An EMO Joint Pruning with Multiple Sub-networks: Fast and Effect
The network pruning algorithm based on evolutionary multi-objective (EMO) can
balance the pruning rate and performance of the network. However, its
population-based nature often suffers from the complex pruning optimization
space and the highly resource-consuming pruning structure verification process,
which limits its application. To this end, this paper proposes an EMO joint
pruning with multiple sub-networks (EMO-PMS) to reduce space complexity and
resource consumption. First, a divide-and-conquer EMO network pruning framework
is proposed, which decomposes the complex EMO pruning task on the whole network
into easier sub-tasks on multiple sub-networks. On the one hand, this
decomposition reduces the pruning optimization space and decreases the
optimization difficulty; on the other hand, the smaller network structure
converges faster, so the computational resource consumption of the proposed
algorithm is lower. Secondly, a sub-network training method based on
cross-network constraints is designed so that the sub-network can process the
features generated by the previous one through feature constraints. This method
allows sub-networks optimized independently to collaborate better and improves
the overall performance of the pruned network. Finally, a multiple sub-networks
joint pruning method based on EMO is proposed. For one thing, it can accurately
measure the feature processing capability of the sub-networks with the
pre-trained feature selector. For another, it can combine multi-objective
pruning results on multiple sub-networks through global performance impairment
ranking to design a joint pruning scheme. The proposed algorithm is validated
on three datasets with different challenging. Compared with fifteen advanced
pruning algorithms, the experiment results exhibit the effectiveness and
efficiency of the proposed algorithm
Recent Advances in Graph Partitioning
We survey recent trends in practical algorithms for balanced graph
partitioning together with applications and future research directions
Eliciting Expertise
Since the last edition of this book there have been rapid developments in the use and exploitation of formally elicited knowledge. Previously, (Shadbolt and Burton, 1995) the emphasis was on eliciting knowledge for the purpose of building expert or knowledge-based systems. These systems are computer programs intended to solve real-world problems, achieving the same level of accuracy as human experts. Knowledge engineering is the discipline that has evolved to support the whole process of specifying, developing and deploying knowledge-based systems (Schreiber et al., 2000) This chapter will discuss the problem of knowledge elicitation for knowledge intensive systems in general
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