Investigating BSM Models with Large Scale Separation

Coupled oscillator models with no scale separation

We consider a class of spatially discrete wave equations that describe the motion of a system of linearly coupled oscillators perturbed by a nonlinear potential. We show that the dynamical behavior of this system cannot be understood by considering the slowest modes only: there is an ‘‘inverse cascade’’ in which the effects of changes in small scales are felt by the largest scales and the mean-...

Simulating Large-scale Networks with Analytical Models

Discrete-event simulation of computer networks has significant scalability issues, which makes simulating large-scale networks problematic. We propose a high-level abstraction modeling network domains, interdomain links and traffic with highly scalable analytical models, which is much more efficient but slightly less accurate than node-by-node models. Thus, simulation scenarios containing sever...

Large-Scale Charge Separation in Thunderclouds

Currently available evidence for the mechanisms thought to be responsible for large-scale charge separation in thunderclouds is reviewed. The evidence suggests that electrically charged precipitation particles are basic to the electrification process but that convective motions are essential in accounting for the electrical energy of active thunderstorms. The relative contributions of air and p...

The application of DEA and queuing models to large scale computer networks

Large-Scale Hierarchical Topic Models

In the past decade, a number of advances in topic modeling have produced sophisticated models that are capable of generating hierarchies of topics. One challenge for these models is scalability: they are incapable of working at the massive scale of millions of documents and hundreds of thousands of terms. We address this challenge with a technique that learns a hierarchy of topics by iterativel...