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Hard to Solve Instances of the Euclidean Traveling Salesman Problem
No full textIn our paper Hard to Solve Instances of the Euclidean Traveling Salesman Problem (Mathematical Programming Computation (2021) 13:51-74) we construct a family of Euclidean instances for the Traveling Salesman Problem for which the integrality ratio of the subtour LP converges to 4/3. These instances turn out to be very hard to solve with exact TSP solvers. On a 200 vertex instance from our family, Concorde, the fastest known exact TSP solver, needs more than 1,000,000 times the runtime it needs for TSPLIB instances of similar size. On a 1000 vertex instance the runtime factor is already about 10^27. Here we provide instances with up to 200 vertices
from our family in TSPLIB format. We also provide code for generating these instances for an arbitrary number of vertices. Finally we make all the .log-files available of the runs of Concorde we describe in our paper
Short Implementation of Adaptive Conforming, Nonconforming, Mixed, and Discontinuous Galerkin FEM's
No full textThis software, written for Matlab, contains four different finite element methods to solve the Poisson model problem on a two-dimensional L-shaped domain with homogeneous Dirichlet boundary conditions and a constant right-hand side equal to one
BonnBeetClouds3D
No full textAgricultural production is facing severe challenges
in the next decades induced by climate change and the need
for sustainability, reducing its impact on the environment.
Advancement in field management through non-chemical weed-
ing by robots in combination with monitoring of crops by
autonomous unmanned aerial vehicles (UAVs) and breeding
of novel and more resilient crop varieties are helpful to
address these challenges. The analysis of plant traits is called
phenotyping, and is an essential activity in plant breeding, it
however involves a great amount of manual labor. With this
paper, we address the problem of automatic fine-grained organ-
level geometric analysis needed for precision phenotyping.
However, the availability of real-world data for such fine-
grained perception tasks in this domain is relatively scarce
compared to other domains such as autonomous driving. To
work towards closing this gap, we propose a novel dataset
that was acquired using UAVs capturing high-resolution im-
ages of a real breeding trial. This has the big advantage of
containing a multitude of plant varieties, leading to a great
morphological and appearance diversity covered by our dataset.
This enables the development of approaches for autonomous
phenotyping that generalize well to different varieties. Based
on overlapping high-resolution images from multiple viewing
angles, we compute photogrammetric dense point clouds via
bundle adjustment that capture the geometric structure of
the plants. We provide detailed and accurate point-wise labels
for individual plants, individual leaves, salient points on the
leaves such as the tip and the base. Additionally we include
measurements of phenotypic traits performed by experts from
the German Federal Plant Variety Office (”Bundessortenamt)
on the real plants, allowing to evaluate approaches not only
on segmentation and keypoint detection, but also directly
on the downstream tasks. The provided labeled point clouds
enable fine-grained plant analysis and opens the door for
further progress in the development of automatic phenotyping
approaches, but also enable further research in closely related
application areas such as surface reconstruction, point cloud
completion, and semantic interpretation of point clouds
Dataset on the adoption of organic agriculture
No full textThe here presented dataset provides information on peer-reviewed articles on organic adoption, retrieved through a systematic literature review of 18129 articles, resulting in 120 target studies. It provides information on i) the article, ii) characteristics of the production system, iii) methods used, iv) quality criteria of the article, and v) types of recommendations given by authors for scaling up organic farming
Source code of "KadanoffBaym.jl", an adaptive solver for KadanoffBaym equations
No full textA permanent storage of "KadanoffBaym.jl", a code developed for the PhD thesis titled "Kondo Collapse and Revival by Pulsed Light." This Julia package implements an adaptive solver for the Kadanoff-Baym equations, used to simulate nonequilibrium dynamics in quantum many-body systems. The repository includes well-documented source code, example scripts, and usage instructions
Productivity effects of agroecological practices in Africa - Dataset
No full textThis dataset, used for the meta-analysis, includes detailed information on the agroecological practices that were used as treatment with their corresponding control group (monocrop system)
Identifying spatio-temporal drivers of extreme events [data set]
No full textThis data set allows to systematically evaluate approaches for the task of identifying extreme events in water cycle components by developing deep neural networks that detect anomalies and drivers of extremes in simulated data
Code for Geometry of Needle-Like Microstructures in Shape-Memory Alloys
No full textThis repository contains the code to
Conti, S., Lenz, M., Rumpf, M., Verhülsdonk, J., Zwicknagl, B., Geometry of Needle-Like Microstructures
in Shape-Memory Alloys. Shap. Mem. Superelasticity (2023).
Needle-like microstructures are often observed
in shape memory alloys near macro-interfaces that separate
regions with different laminate orientation. We study their
shape with a two-dimensional model based on nonlinear
elasticity, that contains an explicit parametrization of the
needle profiles. Energy minimization leads to specific
predictions for the geometry of needle-like domains. Our
simulations are based on shape optimization of the needle
interfaces, using a polyconvex energy density with cubic
symmetry for the elastic problem, and a numerical implementation
via finite elements on a dynamically changing
grid
Geometry generation code for "Isogeometric multilevel quadrature for forward and inverse random acoustic scattering"
No full textThis is the code to generate the computational geometries in
Isogeometric multilevel quadrature for forward and inverse random acoustic scattering. J. Dölz, H. Harbrecht, C. Jerez-Hanckes, and M. Multerer. Computer Methods in Applied Mechanics and Engineering, 388:114242, 2022.
https://dx.doi.org/10.1016/j.cma.2021.114242
In combination with the software package Bembel hosted on https://temf.github.io/bembel/ , the geometries allow to replicate the numerical experiments of the paper
Plaster Cast of the Old Drunkard in the Academic Art Museum Bonn (Inv. 2053)
No full textThe plaster cast shows the Old Drunkard, whose original is located in the Glyptothek Munich (Inv. 437). The statue is one of two preserved Roman copies of a lost, Hellenistic original; the other copy is located in the Capitoline Museums in Rome. The copies are made of marble, the same material is also assumed for the original. The exact execution date of the Hellenistic statue is uncertain, but due to stylistic comparisons it is dated to the last third of the 3rd century B. C. The Munich copy is dated to the 1st century A. D. Over time several assumptions were made concerning the interpretation of the Old Trunkard, from the praying lady to the old woman lusting for wine to the hetaerae