3,311 research outputs found
Identification of functional information subgraphs in complex networks
We present a general information theoretic approach for identifying
functional subgraphs in complex networks where the dynamics of each node are
observable. We show that the uncertainty in the state of each node can be
expressed as a sum of information quantities involving a growing number of
correlated variables at other nodes. We demonstrate that each term in this sum
is generated by successively conditioning mutual informations on new measured
variables, in a way analogous to a discrete differential calculus. The analogy
to a Taylor series suggests efficient search algorithms for determining the
state of a target variable in terms of functional groups of other degrees of
freedom. We apply this methodology to electrophysiological recordings of
networks of cortical neurons grown it in vitro. Despite strong stochasticity,
we show that each cell's patterns of firing are generally explained by the
activity of a small number of other neurons. We identify these neuronal
subgraphs in terms of their mutually redundant or synergetic character and
reconstruct neuronal circuits that account for the state of each target cell.Comment: 4 pages, 4 figure
Ethical Considerations Relating to Outsourcing of Legal Services by Law Firms to Foreign Service Providers: Perspectives from the United States
Ethical Considerations Relating to Outsourcing of Legal Services by Law Firms to Foreign Service Providers: Perspectives from the United States
Ethical Considerations Relating to Outsourcing of Legal Services by Law Firms to Foreign Service Providers: Perspectives from the United States
Visualizing classification of natural video sequences using sparse, hierarchical models of cortex.
Recent work on hierarchical models of visual cortex has reported state-of-the-art accuracy on whole-scene labeling using natural still imagery. This raises the question of whether the reported accuracy may be due to the sophisticated, non-biological back-end supervised classifiers typically used (support vector machines) and/or the limited number of images used in these experiments. In particular, is the model classifying features from the object or the background? Previous work (Landecker, Brumby, et al., COSYNE 2010) proposed tracing the spatial support of a classifier’s decision back through a hierarchical cortical model to determine which parts of the image contributed to the classification, compared to the positions of objects in the scene. In this way, we can go beyond standard measures of accuracy to provide tools for visualizing and analyzing high-level object classification. We now describe new work exploring the extension of these ideas to detection of objects in video sequences of natural scenes
How seriously should we take the opinions of academics and experts when it comes to complicated issues like electoral integrity?
The result of the 2015 General Election came as a surprise for most people, but particularly those in the academic and polling community. But what is the appropriate role for academics in an electoral setting, particularly when it comes to complicated issues like the integrity of electoral contests. Ferran Martinez i Coma and Carolien Van Ham seek to answer this question, and conclude that expert surveys are useful even when treating complex and multi-faceted issues, such as electoral integrity; and even when carried out in institutional settings as different as liberal democracies and electoral autocracies
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