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Gaussian concentration graph models and covariance graph models are two classes of graphical models that are useful for uncovering latent dependence structures among multivariate variables. In the Bayesian literature, graphs are often determined through the use of priors over the space of positive definite matrices with fixed zeros, but these methods present daunting computational burdens in large problems. Motivated by the superior computational efficiency of continuous shrinkage priors for regression analysis, we propose a new framework for structure learning that is based on continuous spike and slab priors and uses latent variables to identify graphs. We discuss model specification, computation, and inference for both concentration and covariance graph models. The new approach produces reliable estimates of graphs and efficiently handles problems with hundreds of variables.

Gaussian concentration graph models and covariance graph models are two classes of graphical models that are useful for uncovering latent dependence structures among multivariate variables. In the Bayesian literature, graphs are often determined through the use of priors over the space of positive definite matrices with fixed zeros, but these methods present daunting computational burdens in large problems. Motivated by the superior computational efficiency of continuous shrinkage priors for regression analysis, we propose a new framework for structure learning that is based on continuous spike and slab priors and uses latent variables to identify graphs. We discuss model specification, computation, and inference for both concentration and covariance graph models. The new approach produces reliable estimates of graphs and efficiently handles problems with hundreds of variables.

Graphical models provide powerful tools to uncover complicated patterns in multivariate data and are commonly used in Bayesian statistics and machine learning. In this paper, we introduce an R package BDgraph which performs Bayesian structure learning for general undirected graphical models with either continuous or discrete variables. The package efficiently implements recent improvements in the Bayesian literature. To speed up computations, the computationally intensive tasks have been implemented in C++ and interfaced with R. In addition, the package contains several functions for simulation and visualization, as well as two multivariate datasets taken from the literature and are used to describe the package capabilities. The paper includes a brief overview of the statistical methods which have been implemented in the package. The main body of the paper explains how to use the package. Furthermore, we illustrate the package's functionality in both real and artificial examples, as well as in an extensive simulation study.

This research project investigates how an interactive learning environment can support students learning and acquisition of mental models when acquiring a target cognitive skill. In this project, we have constructed GIL, an intelligent tutoring system for LISP programming, and have used GIL to conduct pedagogical experiments on skill acquisition. Progress in the current year includes extensions to GIL's graphical representation and model tracing capabilities. The experiments run this year include a study of how GIL's graphical representations facilitate learning for complex programming skills and how GIL enables students to engage in a more natural resoning than the traditional text-based representation of the programming language.

Human-level visual performance has remained largely beyond the reach of engineered systems despite decades of research and significant advances in problem formulation, algorithms and computing power. We posit that significant progress can be made by combining existing technologies from machine vision, insights from theoretical neuroscienee and large-scale distributed computing. Such claims have been made before and so it is quite reasonable to ask what are the new ideas we bring to the,table that might make a difference this time around. From a theoretical standpoint, our primary point of departure from current practice is our reliance on exploiting time in order to turn an otherwise intractable unsupervised problem into a locally semi-supervised, and plausibly tractable, learning problem. From a pragmatic perspective, our system architecture follows what we know of conical neuroanatomy and provides a solid foundation for scalable hierarchical inference. This combination of features provides the framework for implementing a wide range of robust object-recognition capabilities.

1Majesty of Calmness

By William George Jordan

Change your life by changing your thoughts. <em>The Majesty of Calmness</em> is your guide to attracting prosperity, manifesting opportunities, and managing stress—all while discovering the values most precious to you. (Summary by Andrea Fiore)

2Life's Enthusiasms

By David Starr Jordan

The words in this essay on positive thought sing like those in Whitman's "Leaves of Grass." The author praises joyous living and recommends certain routes to its attainment. He explores schooling (public secondary and the university), travel, and the study of nature as ways to stay buoyant during life's trials. He also praises the power of the arts (literature, music, painting, sculpture) to keep spirits soaring. (Summary by Bill Boerst)

3Different Girls

By Elizabeth Jordan and Richard le Gallienne

This is a collection of the best short stories about girls published in Harper's Magazine from 1895 to 1906. The girls in these stories are not the typical 'girl' from late 19th century novels. They are..different. They are actually [gasp] real people! Not necessarily shy, not necessarily bold, not necessarily well read and mostly, not waiting around to be rescued and most definitely not heroines but all of them are completely human. These stories by some of the best authors of the time are about girls in a different light, they are all American girls (except for one, Katie's Sister Josephene), some Irish-American, some older, some younger but all seeing life from a girl's perspective and with a girl's zest for life. So let's go back a hundred years to see what 'different' girls were like then. - Summary by Phil chenevert

Escape into another exciting issue of the influential pulp magazine The Thrill Book! In this issue, beware the "Vengeance of Vishnu", an exotic mystery! Feel your blood chill to the ghost story "The Unseen Seventh"! Cast off for adventure in the sea stories "This Way Out" and "The Sargasso Sea"! Gaze in awe to the weird experiment in soul transference of "The Borderland Bridge"! Also in this issue is the second part of the World War I spy thriller "Strasbourg Rose"! All this and more await you! - Summary by Ben Tucker