DaKS - University of Kassel's research data repository

DaKS is the institutional repository of the University of Kassel for research data. It offers structured storage of research data alongside with descriptive metadata, long-term archiving for at least 10 years and – if requested – the publication of the dataset with a DOI.

DaKS is managed by the university library and the IT Service Centre of the University of Kassel. It is hosted at Philipps-Universität Marburg. We are happy to advise you via daks@uni-kassel.de.

Recent Submissions

Absolute measuring interferometric high-speed profilometer [Dataset]
(Universität Kassel) Eckhardt, Tim; Ziosnki, David; Lehmann, Peter
This dataset contains experimental measurement data obtained for the investigation of high-speed profilometer measurements and absolute surface topography measurement. The dataset comprises measurements acquired with different experimental configurations, including a depth scan with a velocity of 10 µm/s, a lateral scan of a chirp normal, and a measurement of the chirp normal using the GD25 measurement system. The high-speed measurements were recorded with sampling frequencies of 5 MHz and 10 MHz and excitation frequencies of 20 kHz and 19.5 kHz, respectively. The data are provided in HDF5 and text-based formats and include the raw measurement signals as well as example Python scripts for reading and processing the data. The dataset is intended to support the analysis and further development of high-speed profilometry methods, as well as the reproducibility and further investigation of the results presented in the corresponding publication. IMPORTANT: If you use these data, please cite the corresponding article mentioned below.
Navigating the Remanufacturing Trilemma: Balancing Customer, Manufacturer, and Legislator Interests [Repository]
(Universität Kassel, 2025-02-25) Reintanz, Lisa; Wittine, Nicolas; Lange, Kirsten; Wenzel, Sigrid; Refflinghaus, Robert
The associated paper explores the trilemma between different circular economy stakeholders (customer, manufacturer and legislator). The overview database (2019-2024) contains 84 relevant papers (out of 880), which were reduced to 27 through analysis. In addition, findings from expert interviews are used to uncover conflicts and synergies.

The provided Excel file contains the researched literature and documents the process and findings. The main content is found in "References". Each PDF contains an interview protocol, numbered according to the paper’s Table 3. Each protocol contains a description of the expert and a discussion summary.

The provided presentation was used as a guide to conduct the interviews.
Research data from field trials and data analysis, comparing recurrent haploid selection, mass selection, full-sib selection, S2 selection and doubled haploid line selection in a sweet corn population
(Universität Kassel) Aichholz, Charlotte; Becker, Heiko C.; Horneburg, Bernd; Backes, Gunter
This dataset contains the research data underlying the dissertation “Comparison of selection methods in a sweet corn population”. The dissertation investigated the effects of different selection methods on marketable yield, plant development traits, ear quality traits and related agronomic traits in an open-pollinated sweet corn population.

The data were generated in field trials and selection experiments conducted over several years. The dataset includes raw data, cleaned datasets, R scripts, statistical outputs, graphical data and additional photographic documentation. The selection methods covered include recurrent haploid selection, positive mass selection, full-sib selection, S2 line selection, selection of doubled haploid lines produced via colchicine-induced chromosome doubling, and selection of spontaneously doubled haploid lines.

For Chapter 2, the dataset contains data from five cycles of recurrent haploid selection and five cycles of positive mass selection. The initial population and the selected cycles were evaluated in multiple environments under organic and conventional management conditions. Recorded traits include plant development traits such as plant number and vigour, ear quality traits such as ear length, ear diameter, tip fill, ear shape, colour and row number, as well as yield traits such as total yield, marketable yield, total number of ears and number of marketable ears.

For Chapters 3 and 4, the dataset contains data from the evaluation of one cycle of full-sib selection, one cycle of S2 line selection, and selection based on doubled haploid and spontaneously doubled haploid lines. The data include selection-year data, evaluation-year data, cleaned datasets from different trial locations, adjusted datasets, means used for graphical outputs, and R scripts used for data preparation, data cleaning and statistical analysis.

The analyses were carried out mainly in R. Statistical methods included analysis of variance, estimation of variance components, Tukey tests, calculation of heritability, adjustment of data for experimental design or environmental effects where applicable, and identification of influential outliers using Cook’s distance. The R scripts included in the archive document the main steps of data preparation and analysis and indicate which data files were used for the respective analyses.

The dataset is intended to make the results of the dissertation transparent, reproducible and verifiable. It provides the basis for the tables, figures and conclusions presented in the dissertation and associated publications. No personal or sensitive data are included.
[Dataset] Maturity model for assessing the sustainability of a production network
(Universität Kassel) Sutherland, Robin; Bohn, Sebastian; Wenzel, Sigrid
This dataset contains the supplementary material for the paper "Maturity model for assessing the sustainability of a production network".
In response to increasing resource scarcity and global societal trends, this research develops a feature-based maturity model to holistically assess the environmental, economic, and social sustainability of geographically dispersed production networks. The model provides a practical method for companies to determine their current maturity level, identify strategic weaknesses, and derive targeted recommendations to achieve long-term sustainability goals.

Contents:
- The complete maturity model, including dimensions, indicators, and levels (English and German versions).
- Detailed documentation of the selection process of the 24 specific indicators used in the model.
- The questionnaire used for the expert-based evaluation (available in German only).
- Anonymized data and results from the empirical evaluation (available in German only).
Georeferenced dataset on agroecological practices (2011–2020), NDVI, and rainfall in the Maradi Region, Niger (2001–2025)
(Universität Kassel) Abdoulkader, Djibo Amadou; Fastner, Kira; Wiehle, Martin; DIOUF, Abdoulaye
This dataset compiles georeferenced information on agroecological practices implemented in the Maradi Region of Niger between 2011 and 2020. It includes the geographic coordinates of intervention sites, types of agroecological practices, and implementation years. It also contains maximum Normalized Difference Vegetation Index (NDVImax) and Rainfall mean values calculated for the three years before and the three years after interventions for intervention sites and control sites.
The dataset also includes annual regional time series of NDVImax and rainfall for the Maradi Region, covering the period 2001–2025.

Dataset objectives
This dataset was compiled to:
- Assess annual rainfall and NDVImax trends in the Maradi Region between 2001 and 2025;
- Evaluate the contribution of agroecological practices to vegetation recovery using a Before–After Control–Impact (BACI) approach;
- Quantify the relative and interactive contributions of rainfall variability and agroecological interventions to NDVImax using regression-based attribution analysis.
Main variables
- Geographic coordinates of intervention sites.
- Year of implementation of agroecological interventions.
- Type of agroecological practice (Farmer Managed Natural Regeneration (FMNR), Zaï, half-moons, benches, dune fixation, development of grazing land, forage seeding)
- NDVImax mean values calculated for the three years before and the three years after interventions for intervention sites and control sites.
- Rainfall mean values calculated for the three years before and the three years after interventions for intervention sites and control sites.
- Annual regional NDVImax time series for the Maradi Region (2001–2025).
- Annual regional rainfall time series for the Maradi Region (2001–2025).

Data collection
Data on agroecological practices were obtained from records and databases provided by the Regional Directorate of Environment and the Regional Directorate of Agriculture of Maradi (Niger). These data were complemented with remote sensing data from Moderate-resolution Imaging Spectroradiometer (MODIS) and Landsat satellites for NDVImax derivation, as well as rainfall data from the Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) product extracted using Google Earth Engine.

Data analysis
Analyses were conducted in the R environment to assess vegetation and rainfall trends. The Before–After Control–Impact (BACI) approach was applied to evaluate the effects of agroecological practices on vegetation dynamics. Multiple regression analyses were subsequently performed to quantify the relationships between vegetation dynamics, rainfall variability, and agroecological interventions.

Data notes and limitations
The technical characteristics associated with agroecological practices (e.g., structure dimensions, spacing, or other implementation parameters) correspond to general specifications reported in the scientific literature. They do not necessarily represent site-specific measurements, as detailed implementation parameters were not systematically recorded for all intervention sites.
Repository content
The repository includes:
- Georeferenced data on agroecological practices;
- NDVI max mean and rainfall mean datasets for intervention and control sites, as well as annual regional NDVI max and rainfall time series;
- Datasets prepared for trend analyses and multiple regression analyses, BACI results (including NDVI before and after intervention, NDVI, relative NDVI increase, BACI index, and p-value)
- Files required for understanding the agroecological practices and analysis codes.

Data availability on request: The agroecological intervention data used in this study were compiled from information provided by the Regional Directorate of Environment and the Regional Directorate of Agriculture of Maradi (Niger) for scientific research purposes, complemented by data from the IRD/DataSuds dataset on degraded land reclamation actions (Sadda et al., 2024; DOI: 10.23708/ACJTAW). The compiled dataset is not publicly available. Access to the data may be possible upon reasonable request to Djibo Amadou Abdoulkader, subject to the applicable conditions established by the Regional Directorate of Environment and the Regional Directorate of Agriculture of Maradi (Niger), as well as the terms of use applicable to the IRD/DataSuds dataset.