We study the geometry and topology of Bott towers in the context of toric geometry. We show that any kth stage of a Bott tower is a smooth projective toric variety associated to a fan arising from a crosspolytope; conversely, we prove that any toric variety associated to a fan obtained from a crosspolytope actually gives rise to a Bott tower. The former leads us to a description of the tangent ...

Given two or more parties possessing large, confidential datasets, we consider the problem of securely computing the kth-ranked element of the union of the datasets, e.g. the median of the values in the datasets. We investigate protocols with sublinear computation and communication costs. In the twoparty case, we show that the kth-ranked element can be computed in logk rounds, where the computa...

In this paper, we provide a simple approximation for the distance from an arbitrary location to the kth nearest point. Distance is measured as the Euclidean and the rectilinear distances on a continuous plane. The approximation demonstrates that the kth nearest distance is proportional to the square root of k and inversely proportional to the square root of the density of points. The accuracy o...

This document together with video material constitutes Deliverable 2.3 from the first year of the eRENA project. It is based on work on extended performances within eRENA at EPFL, University of Geneva and KTH and on input from other extended performance work at GMD and ZKM. The characteristics of these performances and experience from production and carrying them out in Geneva, Stockholm, Bonn ...

The paper studies a single-server queueing system with autonomous service and l priority classes. Arrival and departure processes are governed by marked point processes. There are l buffers corresponding to priority classes, and upon arrival a unit of the kth priority class occupies a place in the kth buffer. Let N , k = 1, 2, . . . , l denote the quota for the total kth buffer content. The val...

An algebraic principle for blind source separation is presented in this paper. This separation principle identi"es a (smaller) set of equations whose solutions can blindly extract non-Gaussian signals. The concept of `Mth-order uncorrelatednessa is introduced and it is proven that for Mth-order uncorrelated source signals, signals with nonzero kth-order cumulant (2(k)M) can always be extracted ...

Magnetic Resonance Imaging (MRI) images are frequently corrupted by Rician noise during image gaining or transmission, which makes them worse than original. With the object to remove noise and lessen the loss of details as low as possible at the same time, we proposed a novel image denoising algorithm based on Genetic Algorithm (GA), Partial Differential Equations (PDE) and Total Variation (TV)...

In this paper, we propose a novel spatio-temporal feature which is useful for feature-fusion-based action recognition with Multiple Kernel Learning (MKL). The proposed spatio-temporal feature is based on moving SURF interest points grouped by Delaunay triangulation and on their motion over time. Since this local spatio-temporal feature has different characteristics from holistic appearance feat...

Jenny Tigerholm, Marcus E. Petersson, Otilia Obreja, Angelika Lampert Richard 3 Carr Martin Schmelz, Erik Fransén 4 1 Dept. of Computational Biology, School of Computer Science and Communication, KTH 5 Royal Institute of Technology, Stockholm, Sweden 6 2 Stockholm Brain Institute, KTH Royal Institute of Technology, Stockholm, 7 Sweden 8 3 Dept. of Anaesthesiology Mannheim, Heidelberg University...