On the non-existence of an R-labeling

We present a family of Eulerian posets which does not have any R-labeling. The result uses a structure theorem for R-labelings of the butterfly poset.Comment: 6 pages, 1 figure. To appear in the journal Orde

The relationship of interpersonal perception to effectiveness in basketball teams / report No. 3

Caption title."Study performed under Contract N6ori-07135 with the Office of Naval Research"--Cover.Includes bibliographical references (leaf 23

Some empirical studies of the reliability of interpersonal perception scores

Study performed under contract N6ori-07135 with the Office of Naval Research. Project on Social Perception, and Group Effectiveness

Geometric Applications of the Split Bregman Method: Segmentation and Surface Reconstruction

Variational models for image segmentation have many applications, but can be slow to compute. Recently, globally convex segmentation models have been introduced which are very reliable, but contain TVregularizers, making them difficult to compute. The previously introduced Split Bregman method is a technique for fast minimization of L1 regularized functionals, and has been applied to denoising and compressed sensing problems. By applying the Split Bregman concept to image segmentation problems, we build fast solvers which can out-perform more conventional schemes, such as duality based methods and graph-cuts. We also consider the related problem of surface reconstruction from unorganized data points, which is used for constructing level set representations in 3 dimensions