Closest Pairs in Bounded Doubling Dimension, →recording (32 min), password Bentley+Shamos(1978), →slides.

The number of intersections of two simple polygons: an almost optimal bound
(joint work with Eyal Ackerman and Balázs Keszegh),→paper,→recording, 35 min, the talk itself is from 0:00-1:25 and from 8:00 to the end. The password is Solution:mn-m-n+3. →transcript (xournal file, PDF version with slight text alignment errors).
If you are interested in the techical setup and what happened during the breakdown, see my report (in German).

On the Average Complexity of the k-Level, →recording (34 min, stream, download 59 MByte, password Average=k^2),→stream/download 44 MByte →slides.
The talk was presented with Microsoft OneNote on a tablet computer. 3D Images were prepared with Geogebra. The talk was recorded locally during the Webex Meeting session and then uploaded to the Webex site.

The theory behind MapReduce.

Since the introduction of map-reduce in 2004, this programming model has been adopted by many leading technology companies. The easy-to-use implementations of map-reduce enable extensive data processing and generation "without" a deep understanding of parallel and distributed programming. Nevertheless, reducing the runtime on map-reduce computations can be crucial when processing terabytes of data on clusters with over a thousand machines. In this work, we will identify cost drivers in map-reduce and discuss an approach to designing efficient map-reduce algorithms. In particular, we will focus on the tradeoff between a high degree of parallelism and low communication cost. Furthermore, we will examine different algorithms that solve the Hamming distance problem using map-reduce and analyze them theoretically and experimentally.

GreenGrass: Innovative Nutzung des Grünlands für eine nachhaltige Intensivierung der Landwirtschaft im Landschaftsmaßstab

Extremal rectangle-induced set systems, → recording, 33 min, password At-most-n^1.75

The ε-net lemma and some applications to the wet part, → recording (37 min), password 2*Shatter-function, → transcript, → appendix of paper

Drawing Trees in Small Grids, → recording (32 min), password nxSQRT(logn)xloglogn^2

Routing, → recording (31 min), password Label_is_a_01-string

Growth of replacements, → recording (35 min), password Replace-1-ball-by-2-balls

On Optimal Polyline Simplification Using the Hausdorff and Fréchet Distance, → recording 29 min, password OPT=3vertices, slides

No-Dimensional Tverberg Theorems and Applications, → recording 28 min, password Tverberg:(d+1)(k-1)+1

Distance labeling in graphs, → recording 42 min, 59 MByte

Some basics of quantum computing, → recording 39 min, 43 MByte, password 2Qbits-dimension4

A constant-factor approximation algorithm for vertex guarding a weakly visible polygon, →recording  36 min, password 2+epsilon-Approximation

Targeted Drug Delivery: Collecting Particles with Uniform External Forces, recording 40 min, password Marbles2n

Approximate Curve-Restricted Simplification of Polygonal Curves, recording 39 min, password 2-Approximation-in-n^5logn

Simple Drawings of K_m,n contain shooting stars, recording 34 min, password drawingK2n

On the power of RAMs operating with unit cost measure, recording 30 min, password RAM1cost

Spiroplots, → transcript

Chan's framework for implicit LP-type problems, recording 38 min, password Chan-LP-type-2a

New Results in Sona Drawing: Hardness and TSP Separation, → recording 43 min, password TSP/Sona>1.6366

Forbidden submatrices, recording 35 min, password 37-weight-4-Patterns

Recent news about book embeddings of planar graphs, recording 49 min, password Book-number>=4

An Algebraic Version of the Four Color Theorem, recording 37 min, password cyclically4Colorable

Cops and Robbers [Part VI], recording 40 min, password: outerPlanar3cops

Carathéodory's theorem for some notions of convexity, recording 37 min, password: dimension=2D

Radon and Tverberg numbers. 

Sorting Trucks and Stacking Segments, → recording 30 min, 49 MByte

Plane Spanning Trees in Edge-Colored Simple Drawings of K_n, → recording 37 min, password: Cylinder2lids

List update: deterministic and randomized. recording 41 min, password BIT-is-1.75-competitive

Finding a k-cycle in Minor-Closed Graphs. → Recording 43 min, password: k-Cycle4

The expected longest common subsequence, the Chvátal-Sankoff constant, and Markov decision processes. → recording 34 min, password C-Sankoff~0.81, transcript/slides, result table for k=4, python program

Making Change in 2048. You can play the game here, and the live transcript is linked below. recording 47 min (password: pPJ3JVJx )

On the maximum crossing number in star-simple drawings of the complete graph with no empty lens. → Recording 31 min, password: (n-4)!eCrossings

Introduction to promise problems

Theoretische Untersuchung des Boyer-Myrvold-Algorithmus

Seach trees on trees. → Recording 43 min, password: k-Cycle4

Implementierung und Evaluation von Techniken zur Bestimmung von Extremwerten

The Mittagsseminar is continued in the winter semester 2020/21