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

Pension Politics in the 21st Century - Supplementary Materials
(Universität Kassel) Grauel, Carsten
This dataset (file "country_reform_tables.xlsx") covers pension reforms in 24 OECD countries during the period 1980-2020, which forms the basis of the dissertation “Pension Politics in the 21st Century” (https://doi.org/10.17170/kobra-2026021711925). The dataset differentiates pension reforms according to their classification in the categories
- “insurance,”
- “capitalization,”
- “targeting,”
- “recalibration,”
- “women's compensation,”
- “harmonization,”
- “education compensation,”
- “military service compensation,”
- “partial retirement,” and
- “public pension coverage extension.”

It also differentiates reforms according to whether they expand (“expansionary”) or restrict (“contractionary”) the social entitlements of beneficiaries. The categorization scheme is based on an earlier conceptualization developed by Silja Häusermann, but has been modified and further expanded. The recording of reforms was also based on preceding work by Ward Romp.

Details on the categorization and coding of pension reforms can be found in chapters 3 and 4 of the aforementioned dissertation “Pension Politics in the 21st Century” (pp. 25-179).

Abstract to "Pension Politics in the 21st Century" (english):
"The possibility of examining the influence of governments and parties on pension policies has so far been limited by the dependent variable problem in comparative welfare state research in general, and by the lack of valid indicators for capturing pension policies in particular. This study presents a newly created comprehensive dataset on multidimensional pension reforms in 24 developed OECD countries in the period from 1980 to 2020. The pension reforms recorded are arranged according to a modified categorization scheme earlier developed by Silja Häusermann. The present data collection indicates a high incidence of pension reforms that strengthen both the funded and the redistributive nature of pension systems, but also reduce insurance benefits and privileged status rights of public-sector employees. Furthermore, the shortcomings of previous theoretical approaches to the empirical relationship between political actors and pension policies are criticized, in particular in the form of traditional partisan theory, as well as the previous neglect of the authoritarian-libertarian cleavage as a potential conflict structure also underlying and permeating contemporaneous pension politics.
The influence of governments and parties on categorical pension reform regimes is then modeled and estimated. Results show that there is no consistent evidence lending support to detectable effects of party family variables or authoritarian and libertarian government positions on various dimensions of pension policy. However, there is robust evidence lending support to socioeconomically right and left governments influencing at least some dimensions of pension policy. The general assessment regularly expressed in recent studies in comparative welfare state research that government and party effects have completely disappeared can therefore not be followed on the basis of the present empirical findings."

In addition, the other documents (Dataset.dta, Do-File.do) document the referenced dissertation's estimation procedure in Stata (“Pension Politics in the 21st Century”, chapter 7, pp. 224-296).
Brownian motion of DNA-functionalized magnetic nanoparticles as a function of DNA length for conformation analysis beyond the optical resolution limit
(Universität Kassel) Janzen, Christian; Ehresmann, Arno; Hütten, Andreas
Brownian motion provides access to hydrodynamic properties of nanoscale objects independent of their optical resolvability. Here, we present a diffusion-based approach to infer effective particle size distributions of DNA-functionalized magnetic nanoparticles (MNPs), consisting of a magnetic core and a polystyrene shell, in a regime where direct geometric sizing is limited by optical diffraction. Using multi-particle tracking microscopy, we analyze the Brownian dynamics of MNPs grafted with double-stranded DNA (dsDNA) of varying contour length under low-salt conditions. A physically motivated model is introduced that relates dsDNA contour length to an effective hydrodynamic diameter via an attenuated corona description. The measured diffusion coefficient distributions exhibit a systematic and monotonic dependence on dsDNA length in quantitative agreement with the model. While the tracked objects are predominantly dsDNA-mediated agglomerates rather than isolated nanoparticles, clustering does not obscure the length-dependent signal. Instead, the dsDNA corona determines the hydrodynamic scaling, whereas agglomeration mainly introduces an offset and distribution broadening. These results demonstrate that Brownian dynamics enables robust readout of biomolecular length scales even far below the optical resolution limit. The distribution-based approach is inherently tolerant to polydispersity and aggregation, making diffusion-based tracking a simple and promising strategy for future biotechnological and biomedical assays.
Digitale Zwillinge in Produktion und Logistik – Modellfabriken und Reifegradmodelle
(Universität Kassel) Gliem, Deike; Wenzel, Sigrid
Die Dokumentation umfasst zum einen eine systematische Literaturrecherche zur Identifikation bestehender Modellfabriken für Digitale Zwillinge. Insgesamt werden 17 Modellfabriken herangezogen, um eine Handlungsempfehlung zur Anschaffung einer Modellfabrik für Digitale Zwillinge in Produktion und Logistik am Fachgebiet pfp der Universität Kassel auszusprechen. Die Ergebnisse entstanden in Zusammenarbeit mit Luca Rehs (Rehs, Luca-Joshua: Konzeptionierung einer Modellfabrik zur Untersuchung Digitaler Logistikzwillinge. Bachelorarbeit, Universität Kassel, Studiengang Maschinenbau, 05/2024 (Prof. Wenzel / Gliem, FB 15, Universität Kassel)).

Die Dokumentation umfasst zum anderen eine weitere systematische Literaturrecherche zur Identifikation bestehender Reifegradmodelle für Digitale Zwillinge. Insgesamt werden 31 Modelle herangezogen, um ein eigenes Reifegradmodell für Digitale Zwillinge in Produktion und Logistik abzuleiten. Das entwickelte Modell ist speziell auf die Anforderungen und Rahmenbedingungen von kleinen und mittleren Unternehmen (KMU) zugeschnitten. Die Struktur des Reifegradmodells wird vollständig beschrieben und umfasst vier Dimensionen mit jeweils vier Indikatoren, anhand derer die Reife eines Digitalen Zwillings bewertet werden kann. Zusätzlich wird die praktische Anwendung des Modells anhand von drei Use Cases demonstriert, die mögliche Einsatzszenarien in industriellen Umgebungen abbilden.
Der Titel der Publikation wurde am 20.02.2026 geändert. Vorheriger Titel: Modellfabrik und Reifegradmodell für Digitale Zwillinge in Produktion und Logistik
Kartierungsergebnisse der krautigen Vegetation der Park-/Grünanlagen der Stadt Freiburg i. Br. [Daten]
(Universität Kassel, 2025) Barthelmes, Beatrice
Kartierungsergebnisse der krautigen Vegetation der Park-/Grünanlagen der Stadt Freiburg i. Br. Insgesamt wurden in elf untersuchten Park-/Grünanlagen der Stadt Freiburg i. Br. 127 Aufnahmequadrate für die Vegetationserfassung etabliert. Es wurden extensiv gepflegte (Wiesen und Langgrasflächen) und intensiv gepflegte Bereiche (Rasen) untersucht.

Die Kategorien der untersuchten Flächen sind dabei folgende:
Wiesen: Bereiche, die in der Regel mit 1-2 Mahdvorgängen im Jahr extensiv gepflegt werden. Das Mahdgut wird abgeräumt.
Langgrasflächen: Bereiche, die in der Regel mit 1-2 Mahdvorgängen im Jahr extensiv gepflegt werden. Das Mahdgut verbleibt auf der Fläche.
Gebrauchsrasen/Spielrasen: Bereiche, die in regelmäßigen Abständen während der Vegetationsperiode gemulcht werden.

Zusätzlich zur Artenvielfalt wurden nach der international verwendeten Aufnahmen-Skala von Braun-Blanquet die Artmächtigkeiten (Menge) und die Mächtigkeiten der blühenden Arten erfasst. Hierbei wurde die ursprüngliche Schätzskala von Braun-Blanquet verwendet.
Die Kartierungsjahre waren 2020 und 2021.
Mechanical Properties of Normal Concrete
(Universität Kassel) Rezazadeh, Farzad; Dürrbaum, Axel; Abrishambaf, Amin; Zimmermann, Gregor; Kroll, Andreas
Normal concrete is the most widely used form of concrete, and its mechanical properties can vary due to variations in raw-material quality, dosage errors, and changes in material storage, mixing, and curing conditions, even when a fixed reference mix design is used. This variability constitutes a reproducibility challenge for concrete production under fixed formulations. This dataset examines the effects of variations in raw-material condition and process parameters on the mechanical properties of normal concrete produced from a base mix design targeting a 65 MPa compressive strength. The dataset comprises 32 systematically designed experiments. Compressive strength was measured at 1 day (24 hours), 7 days, and 28 days after mixing. Where available, the reported values represent the average of three specimens per experiment. In addition, five fresh-state properties were measured immediately after each mixing process (temperature, electrical conductivity sensor reading, slump-flow, V-funnel flow time, and air content). All experiments were conducted in the laboratory of G.tecz Engineering GmbH under controlled conditions using the same mixer, mixing tools, and personnel. The dataset provides high-dimensional experimental data with a limited number of observations and is suitable for developing and evaluating regression models in sparse scenarios.