541 Works

Entwicklung einer Simulationsmethodik zur schnellen Dimensionierung komplexer Materialflusssysteme

Svenja Bahnsen, Harald Köck, Johannes Hinckeldeyn & Jochen Kreutzfeldt
Simulation models play an important role in the planning and development in intralogistics. Especially the layout and dimensioning of order picking processes, warehouses and handling engineering is often based on static estimations and rules of thumb. This leads to inferior planning results, because dynamic effects, such as peaks of orders, and sequential process steps are often neglected. The most common solution at the moment are event discrete simulation models, which create a significant workload for...

The impact of modular product architectures in PSS design: a systematic literature review

Christoph Rennpferdt, Erik Greve & Dieter Krause

Time-variant rule-based reliability of corroded structures by Monte Carlo simulation

Karoline M. Neumann, Bernt J. Leira, Ole Tom Vårdal & Sören Ehlers
General widespread corrosion is of increasing concern for structural reliability of ageing marine structures, particularly for semi-submersible pontoons. Conditional failure rate, also termed hazard function is sought to describe the increasing maintenance required with age. Literature is reviewed connecting corrosion degradation to hazard rate, either through a time degrading limit state function, or statistical data for time to failure. Here, a rule based failure definition is applied based on corrosion tolerance levels, together with a...

Linear kernels and linear-time algorithms for finding large cuts

Michael Etscheid & Matthias Mnich
The maximum cut problem in graphs and its generalizations are fundamental combinatorial problems. Several of these cut problems were recently shown to be fixed-parameter tractable and admit polynomial kernels when parameterized above the tight lower bound measured by the size and order of the graph. In this paper we continue this line of research and considerably improve several of those results: We show that an algorithm by Crowston et al. [ICALP 2012] for (Signed) Max-Cut...

Polynomial kernels for deletion to classes of acyclic digraphs

Matthias Mnich & Erik Jan van Leeuwen
We consider the problem to find a set X of vertices (or arcs) with |X| <= k in a given digraph G such that D = G-X is an acyclic digraph. In its generality, this is DIRECTED FEEDBACK VERTEX SET or DIRECTED FEEDBACK ARC SET respectively. The existence of a polynomial kernel for these problems is a notorious open problem in the field of kernelization, and little progress has been made. In this paper, we...

Joint learning of geometric and probabilistic constellation shaping

Maximilian Stark, Fayçal Ait Aoudia & Jakob Hoydis

Automated selection and assembly of sets of blades for jet engine compressors and turbines

Maik Dammann & Thorsten Schüppstuhl

Bewertung von Power-to-Gas-Anlagen mittels dynamischer Systemsimulation

Lisa Andresen & Gerhard Schmitz
Mittels dynamischer Systemsimulation wird die Kopplung des Hochdruckgasnetzes der Stadt Hamburg mit dem Stromnetz untersucht. Dabei wird das technische Potential der regenerativen Erzeugung, der Speicherung und der Einspeisung von Wasserstoff in das Gasnetz analysiert. Der Modellierungsansatz wird beschrieben. Den Szenariorahmen bildet der geplante Ausbau der fluktuierenden Erneuerbaren Energien im Jahr 2050 und der Strom- und Gasbedarf in 2012. Die Elektrolyseure werden nur dann betrieben, wenn die Residuallast negativ ist. In einer Jahressimulation wird, unter Berücksichtigung...

Optimizing the start-up process of post-combustion capture plants by varying the solvent flow rate

Thomas Marx-Schubach & Gerhard Schmitz

A review of life cycle assessment studies of electric vehicles with a focus on resource use

Iulia Dolganova, Anne Rödl, Vanessa Bach, Martin Kaltschmitt & Matthias Finkbeiner
Changes in the mobility patterns have evoked concerns about the future availability of certain raw materials necessary to produce alternative drivetrains and related batteries. The goal of this article is to determine if resource use aspects are adequately reflected within life cycle assessment (LCA) case studies of electric vehicles (EV). Overall, 103 LCA studies on electric vehicles from 2009 to 2018 are evaluated regarding their objective, scope, considered impact categories, and assessment methods—with a focus...

Parallel-in-time integration of kinematic dynamos

Andrew T. Clarke, Christopher J. Davies, Daniel Ruprecht & Steven M. Tobias

Temperature field due to a moving heat source in machining orthotropic composites with arbitrary fiber orientation

Jan Philipp Mehnen, Wolfgang Hintze, Lars Köttner & Robert von Wenserski
Milling of fiber reinforced plastics (FRP) is challenging with respect to surface integrity and tool wear due to high process temperatures. The maximum temperatures occurring in the workpiece determine the extent of the matrix decomposition area. Improving the workpiece quality therefore requires an understanding of its internal temperature distribution during milling. However, steep temperature gradients and high mechanical stress make measurements of temperature fields in the cutting zone difficult. In addition, thermal properties change depending...

Fabrication of highly filled composites with an innovative miniaturized spouted bed

Hannah Sophia Rothberg, Swantje Pietsch, Gerold A. Schneider & Stefan Heinrich
In nature bio-composites such as nacre show remarkable mechanical properties due to their complex hierarchical structure and high-volume fraction of its hard component. These composites are highly interesting for structural applications in different branches of industries for mechanical engineering and process technology. The aim of this work was to provide a scalable method for the production of highly filled composites by mimicking the structure of bio-composites. Therefore, composites from iron oxide (Fe2O3) and SBC-polymer (styrene-butadiene...

A Collaborative approach for an integrated modeling of urban air transportation systems

Malte Niklaß, Niclas Dzikus, Majed Swaid, Jan Berling, Benjamin Lührs, Alexander Lau, Ivan Terekhov & Volker Gollnick
The current push in automation, communication, and electrical energy storage technologies has the potential to lift urban mobility into the sky. As several urban air mobility (UAM) concepts are conceivable, all relevant physical effects as well as mutual interrelations of the UAM system have to be addressed and evaluated at a sufficient level of fidelity before implementation. Therefore, a collaborative system of systems modeling approach for UAM is presented. To quickly identify physical effects and...

Platform of design method for developing mobility-preserving products

Kristin Paetzold, Sandro Wartzack & Dieter Krause

The misleading use of “enthalpy\" in an energy conversion analysis

Heinz Herwig

Unveiling the potential for an efficient use of nitrogen along the food supply and consumption chain

Sara Corrado, Carla Caldeira, Gema Carmona-Garcia, Ina Körner, Adrian Leip & Serenella Sala

Evaluation der verkehrlichen Umbaumaßnahmen in der Liebigstraße | Industriegebiet Billbrook | Hamburg

Philine Gaffron & Christiane Waßmann-Krohn
Als Teil einer ganzheitlich orientierten Verkehrsplanung, im Kontext der Klimaschutzziele der Stadt Hamburg und auch im Rahmen des Hamburger Bündnis für den Radverkehr, ist es angezeigt, Mobilität auch in Industrie- und Gewerbegebieten zukunftsverträglicher zu gestalten ohne dabei den Wirtschaftsverkehr zu beeinträchtigen. Aspekte dieser Verträglichkeit sind die Minderung von CO2 (und anderen) Emissionen und das Fördern eines Umstiegs auf gesündere und leistbarere Verkehrsmittel im Umweltverbund (Fuß – Rad – Öffentlicher Verkehr). Maßnahmen wie das Projekt KLimafreundliche...

A combined compression and indentation study of mechanical metamaterials based on inverse opal coatings

Jefferson J. do Rosário, Quynh Yen Häntsch, Gerold A. Schneider & Erica Lilleodden
A relatively new class of tailored photonic metamaterials based on the inverse opal (IO) structure shows multifunctionality with exceptional mechanical response due to its periodic porous arch-like structure. Exploiting the smaller is stronger paradigm through varying its pore size and the addition of atomic layer deposition (ALD) films, allow tailorable strength and elastic modulus. Quantification of such properties are achieved through flat punch nanoindentation testing. Results are validated by comparison to microcompression tests, a widely...

MALITUP : machine learning in theory and practice

Marvin Kastner & Tina Scheidweiler
Increasing digitalization, rapid developments in machine learning and exponentially growing accumulation of data lead to new jobs in the areas of data science. In the field of (maritime) logistics, digitalization is becoming increasingly important, resulting in an ever-increasing demand for trained personnel in the field of machine learning.

In-situ testing of a multi-band software-defined radio platform in a mixed-field irradiation environment

Jan Budroweit, Steffen Mueller, Mattis Jaksch, Rubén Garcia Alía, Andrea Coronetti & Alexander Kölpin
This paper presents an in-situ test concept for a multi-band software-defined radio (SDR) platform in a mixed-field radiation environment. Special focus is given to the complex automated test setup with respect to the requirements of the irradiation facility. Additionally, selected test results of a system-level evaluation are presented and discussed. For the verification of the mixed-field radiation environment, the software-defined radio (SDR) was also tested under proton irradiation. The cross-sections for the observed single event...

On the role of member value in cooperatives

Svenja Damberg

The Role of social innovations in platform coops and perceived member value

Svenja Damberg

Automated proximity sensing in small vertebrates: design of miniaturized sensor nodes and first field tests in bats

Simon Ripperger, Darija Josic, Martin Hierold, Alexander Kölpin, Robert Weigel, Markus Hartmann, Rachel A. Page & Frieder Mayer

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