Hasso-Plattner-Institut
Hasso-Plattner-Institut
  
Login
  • de
 

Winter Semester 2018/2019

24.10.2018 - Christopher Weyand

Analysis and Engineering of Scale-Free Network Models

Many real-world networks, although from fundamentally different domains, exhibit common properties such as a high clustering coefficient, large hubs, a power law degree distribution (also referred to as scale-freeness), a giant component, small average distances, and a small diameter.Numerous models were proposed to produce a subset or all properties of real-world networks. Unfortunately, models that generate all properties lack a convincing explanation and do not relate to their observed emergence in the real world. On the other hand, the intuitive explanatory power inherent in the field of Game Theory inspired recent research in this direction. The main questions of my research are: 1. How do formal models provide insights and explanations about real-world networks? 2. Is there a mechanism that guides the creation of real-world networks and is easily expressible by game-theoretic means? 3. To which extend does such a model help in the creation of tools or concepts to further improve real networks

31.10.2018 - no meeting (Reformationstag)

07.11.2018 - Francesco Quinzan

Escaping Large Deceptive Basins of Attraction with Heavy Mutation Operators

In many Evolutionary Algorithms (EAs), a parameter that needs to be tuned is that of the mutation rate, which determines the probability for each decision variable to be mutated. Typically, this rate is set to 1/n for the duration of the optimization, where n is the number of decision variables. This setting has the appeal that the expected number of mutated variables per iteration is one. In a recent theoretical study, it was proposed to sample the number of mutated variables from a power-law distribution. This results into a significantly higher probability on larger numbers of mutations, so that escaping local optima becomes more probable. In this paper, we propose another class of non-uniform mutation rates. We study the benefits of this operator in terms of average-case black-box complexity analysis and experimental comparison. We consider both pseudo-Boolean artificial landscapes and combinatorial problems (the Minimum Vertex Cover and the Maximum Cut). We observe that our non-uniform mutation rates significantly outperform the standard choices, when dealing with landscapes that exhibit large deceptive basins of attraction.

14.11.2018 - no meeting (SAP / Gebäudesperrung)

21.11.2018 - Johannes Wolf

Techniques for Multi-source Data Visualization and Analysis in Geospatial Applications

Cadastral offices and companies responsible for infrastructure such as roads or railway networks usually deal with many different data sources for planning and preservation purposes. Ground-penetrating 2D radar scans are captured in road environments for examination of pavement condition and below-ground variations such as lowerings and developing pot-holes. 3D point clouds captured above ground provide a precise digital representation of the road’s surface and the surrounding environment. If both data sources are captured for the same area, a combined visualization and analysis can be used for infrastructure maintenance tasks. The combination of 2D ground radar scans with 3D point cloud data improves data interpretation by giving context information, e.\,g., about manholes in the street, that can be directly accessed during manual and automated data evaluation. This talk will highlight individual use cases for the combined data analysis of the aforementioned sources.

28.11.2018 - Lan Jiang / Christiane Hagedorn

Title tbd

abstract tbd

Title tbd

abstract tbd

05.12.2018 - Christian Adriano / Johannes Henning

Title tbd

abstract tbd

Title tbd

abstract tbd

12.12.2018 - Konrad Felix Krentz / Diba Kiarash

Title tbd

abstract tbd

Title tbd

abstract tbd

19.12.2018 - Sven Köhler

Ttile tbd

abstract tbd

09.01.2018 - Lukas Pirl / Sumit Shekhar

Title tbd

abstract tbd

Title tbd

abstract tbd

16.01.2019 - Norman Kluge / He Xu (preliminary)

Title tbd

abstract tbd

Title tbd

abstract tbd

23.01.2019 - Fabio Niephaus / Bjarne Pfitzner (preliminary)

Title tbd

abstract tbd

Title tbd

abstract tbd

30.01.2019 - Robert Kovács / Robert Schmid (preliminary)

Title tbd

abstract tbd

Title tbd

abstract tbd

06.02.2019 - (no speaker yet)

Title tbd

abstract tbd