Median structures on asymptotic cones and homomorphisms into mapping class groups

The main goal of this paper is a detailed study of asymptotic cones of the mapping class groups. In particular, we prove that every asymptotic cone of a mapping class group has a bi-Lipschitz equivariant embedding into a product of real trees, sending limits of hierarchy paths onto geodesics, and with image a median subspace. One of the applications is that a group with Kazhdan's property (T) can have only finitely many pairwise non-conjugate homomorphisms into a mapping class group. We also give a new proof of the rank conjecture of Brock and Farb (previously proved by Behrstock and Minsky, and independently by Hamenstaedt).Comment: final version, to appear in Proc. LM

Coarse density of subsets of moduli space

Let $\mathcal{M}_g$ be the moduli space of genus $g$ Riemann surfaces. Weshow that an algebraic subvariety of $\mathcal{M}_g$ is coarsely dense withrespect to the Teichm\"uller metric (or Thurston metric) if and only if it isall of $\mathcal{M}_g$. We apply this to projections of$\operatorname{GL}_2(\mathbb{R})$-orbit closures in the space of abeliandifferentials. Moreover, we determine which strata of abelian differentialshave coarsely dense projection to $\mathcal{M}_g$.<br

Acoustic Correlates of “Big” and “Thin” in Kujamutay

Proceedings of the 4th Annual Meeting of the Berkeley Linguistics Society (1978), pp. 293-31

Periodic elements of the free idempotent generated semigroup on a biordered set

We show that every periodic element of the free idempotent generated semigroup on an arbitrary biordered set belongs to a subgroup of the semigroup

New energy-transfer upconversion process in Er(3+):ZBLAN mid-infrared fiber lasers

Abstract not availableOri Henderson-Sapir, Jesper Munch, and David J. Ottawa

Retaining Expression on De-identified Faces

© Springer International Publishing AG 2017The extensive use of video surveillance along with advances in face recognition has ignited concerns about the privacy of the people identifiable in the recorded documents. A face de-identification algorithm, named k-Same, has been proposed by prior research and guarantees to thwart face recognition software. However, like many previous attempts in face de-identification, kSame fails to preserve the utility such as gender and expression of the original data. To overcome this, a new algorithm is proposed here to preserve data utility as well as protect privacy. In terms of utility preservation, this new algorithm is capable of preserving not only the category of the facial expression (e.g., happy or sad) but also the intensity of the expression. This new algorithm for face de-identification possesses a great potential especially with real-world images and videos as each facial expression in real life is a continuous motion consisting of images of the same expression with various degrees of intensity.Peer reviewe

Versatile and widely tunable mid-infrared erbium doped ZBLAN fiber laser

We report on a long wavelength emitting rare earth doped fiber laser with emission centered at 3.5 {\mu}m and tunable across 450 nm. The longest wavelength emission was 3.78 {\mu}m, which is the longest emission from a fiber laser operating at room temperature. In a simple optical arrangement employing dielectric mirrors for feedback, the laser was capable of emitting 1.45 W of near diffraction limited output power at 3.47 {\mu}m. These emission characteristics compliment the emission from quantum cascade lasers and demonstrate how all infrared dual wavelength pumping can be used to access high lying rare earth ion transitions that have previously relied on visible wavelength pumping

Dmitri Shalin Interview with J. David Sapir about Erving Goffman entitled Seeing the Photographs Erving said, Do You Think That Those Pictures Say Anything about Reality? Absolutely not. . .

This memoir is written by Dr. J. David Sapir, Professor Emeritus at the Department of Anthropology, Virginia University, and it posted in the Goffman Archives with his permission. The extended paper from which this excerpt is taken can be found on this page,http://people.virginia.edu/~ds8s/WE-documentarystyle.pdf

Analysis of airplane boarding via space-time geometry and random matrix theory

We show that airplane boarding can be asymptotically modeled by 2-dimensional Lorentzian geometry. Boarding time is given by the maximal proper time among curves in the model. Discrepancies between the model and simulation results are closely related to random matrix theory. We then show how such models can be used to explain why some commonly practiced airline boarding policies are ineffective and even detrimental.Comment: 4 page