We explore the relationship between evolved neural network structure and function, by applying graph theoretical tools to the analysis of the topology of artificial neural networks known to exhibit evolutionary increases in dynamical neural complexity. Our results suggest a synergistic convergence between network structures emerging due to physical constraints, such as wiring length and brain v...

We consider a function-valued trait z(t) whose pre-selection distribution is Gaussian, and a fitness function W that models optimizing selection, subject to certain natural assumptions. We show that the post-selection distribution of z(t) is also Gaussian, compute the selection differential, and derive an equation that expresses the selection gradient in terms of the parameters of W and of the ...

A visionary Darwinian ahead of his time, George C. Williams developed in his 1966 book Adaptation and Natural Selection the essentials of a unifying theory of adaptation that remains robust today and has inspired immense progress in understanding how natural selection works.

Recent research on growth empirics has been focused on resolving model and variable uncertainty. The conventional approach has been to assume a linear growth process and then to proceed with investigating the relevant variables that determine cross-country growth. This paper questions the linearity assumption underlying the vast majority of such research and uses recently-developed nonparametri...

W consider the Bayesian ranking and selection problem, in which one wishes to allocate an information collection budget as efficiently as possible to choose the best among several alternatives. In this problem, the marginal value of information is not concave, leading to algorithmic difficulties and apparent paradoxes. Among these paradoxes is that when there are many identical alternatives, it...

Introduction: Beam-angle optimization (BAO) is a computationally intensive problem for a number of reasons. First, the search space of the solutions is huge, requiring enumeration of all possible beam orientation combinations. For example, when choosing 4 angles out of 36 candidate beam angles, C36 = 58905 possible combinations exist.  Second, any change in a   beam 4 config...

It is common practice in statistical data analysis to perform datadriven variable selection and derive statistical inference from the resulting model. Such inference enjoys none of the guarantees that classical statistical theory provides for tests and confidence intervals when the model has been chosen a priori. We propose to produce valid “post-selection inference” by reducing the problem to ...