Fak. 5 Verkehrs- und Maschinensysteme

1212 Items

Recent Submissions
Methodische Entwicklung einer modularen Lasersintermaschine zur Herstellung von bioresorbierbaren Implantatmatrizen

Kautz, Clemens Kolja (2019)

Eine aus dem Bereich der regenerativen Medizin stammende visionäre Anwendung der AM-Technologie ist die Fertigung von individuell angepassten Implantaten und Organen. Werden zur Herstellung von Implantatmatrizen, dem Gerüst zum Gewebeaufbau, bioresorbierbare Werkstoffe mittels Lasersintern verarbeitet, verbleibt das erzeugte Implantat nach der Transplantation im Körper des Patienten und wird do...

Adhesive Strength of Contacts of Rough Spheres

Li, Qiang ; Pohrt, Roman ; Popov, Valentin L. (2019-03-26)

The adhesive contact between a parabolic indenter with superimposed roughness and an elastic half space is studied in the JKR-limit (infinitely small range of action of adhesive forces) using the boundary element method with mesh-dependent detachment criterion suggested in 2015. Three types of superimposed roughness are considered: one- and two-dimensional waviness and randomly rough roughness....

Effects of Trust, Self-Confidence, and Feedback on the Use of Decision Automation

Wiczorek, Rebecca ; Meyer, Joachim (2019-03-12)

Operators often fail to rely sufficiently on alarm systems. This results in a joint human-machine (JHM) sensitivity below the one of the alarm system. The ‘confidence vs. trust hypothesis’ assumes the use of the system depends on the weighting of both values. In case of higher confidence, the task is performed manually, if trust is higher, the user relies on the system. Thus, insufficient relia...

Drug Delivery From Polymer-Based Nanopharmaceuticals—An Experimental Study Complemented by Simulations of Selected Diffusion Processes

Macha, Innocent J. ; Ben-Nissan, Besim ; Vilchevskaya, Elena N. ; Morozova, Anna S. ; Abali, Bilen Emek ; Müller, Wolfgang H. ; Rickert, Wilhelm (2019-03-08)

The success of medical therapy depends on the correct amount and the appropriate delivery of the required drugs for treatment. By using biodegradable polymers a drug delivery over a time span of weeks or even months is made possible. This opens up a variety of strategies for better medication. The drug is embedded in a biodegradable polymer (the “carrier”) and injected in a particular position ...

Agent-based modelling of air transport demand

Grether, Dominik ; Nagel, Kai (2013)

Constraints such as opening hours or passenger capacities influence travel options that can be offered by an airport and by the connecting airlines. If infrastructure, policy or technological measures modify transport options, then the benefits do not only depend on the technology, but also on possibly heterogeneous user preferences such as desired arrival times or on the availability of altern...

Mobiles Ganganalysesystem zur Bewertung der prothetischen Versorgung transfemoraler Amputationen

Thiele, Julius (2019)

Introduction: The loss of parts of the lower limbs means a severe change to anyone affected. With a prosthetic leg, mobility can be largely regained. Compared to the much more complex natural counterpart, even prostheses featuring modern microprocessor-based knee joint systems (MPK) have distinct limitations. Against this backdrop a reasonable selection of the prosthesis components and an accur...

Simulation and modeling of a Helmholtz resonator under grazing turbulent flow

Stein, Lewin (2019)

When gas flows along a surface containing a cavity or gap, this fluid-dynamical process is likely linked with acoustical effects. Primarily, in the transport and energy sector, the phenomenon occurs frequently: gas flows around land and air vehicles or streams inside duct systems and engines. A key challenge for these examples is either to prevent cavity noise before it arises or to reduce exis...

Network breakdown “at the edge of chaos” in multi-agent traffic simulations

Rieser, Marcel ; Nagel, Kai (2008)

Traffic is highly influenced by network structure and human behaviour. Small changes in the human behaviour can lead to huge changes in the load of a traffic network. Current transportation models do not, and most of them cannot, research such random behaviour but always calculate a steady state. In our multi-agent transport simulation, we frequently observe seemingly random "network breakdowns...

Preliminary Results of a Multiagent Traffic Simulation for Berlin

Beuck, Ulrike ; Nagel, Kai ; Rieser, Marcel ; Strippgen, David ; Balmer, Michael (2007)

This paper provides an introduction to multi-agent traffic simulation. Metropolitan regions can consist of several million inhabitants, implying the simulation of several million travelers, which represents a considerable computational challenge. We reports on our recent case study of a real-world Berlin scenario. The paper explains computational techniques necessary to achieve results. It turn...

Mind the Gap – Passenger Arrival Patterns in Multi-agent Simulations

Neumann, Andreas ; Kaddoura, Ihab ; Nagel, Kai (2016)

In most studies mathematical models are developed finding the expected waiting time to be a function of the headway. These models have in common that the proportion of passengers that arrive randomly at a public transport stop is less as headway in-creases. Since there are several factors of influence, such as social demographic or regional aspects, the reliability of public transport service a...

Bicycle traffic and its interaction with motorized traffic in an agent-based transport simulation framework

Ziemke, Dominik ; Metzler, Simon ; Nagel, Kai (2018)

Cycling as an inexpensive, healthy, and efficient mode of transport for everyday traveling is becoming increasingly popular. While many cities are promoting cycling, it is rarely included in transport models and systematic policy evaluation procedures. The purpose of this study is to extend the agent-based transport simulation framework MATSim to be able to model bicycle traffic more realistica...

Autonomous vehicles and their impact on parking search

Bischoff, Joschka ; Maciejewski, Michał ; Schlenther, Tilmann ; Nagel, Kai (2018)

Parking is a major constraint for car users and therefore an important factor in mode choice decisions. In this paper we introduce a model to simulate parking search behavior for cars within a multi-agent transport simulation, including full simulation of all steps of parking search, such as walking to and from the vehicle. This is combined with the capabilities of privately owned autonomous ve...

Effect of vibrations on friction in the context of brake squeal

Nguyen, Thai Minh Tuan (2019)

Brake squeal is a case of friction-induced vibration that has not been fully understood yet due to difficulties in both experimental and theoretical approaches. Both approaches are considered in this research in order to contribute knowledge to this topic. Following the idea of the already existing Dynamic Compression Test Rig (DCTR), which shows that the dynamic stiffness of a pad specimen de...

Comparing traffic flow models with different number of “phases”

Wagner, Peter ; Nagel, Kai (2008)

By comparing microscopic traffic flow models with a different number of phases in the context of a simple scenario, the similarities as well as the differences of the various traffic flow models can be discussed. It turns out that there is a certain range of traffic flow conditions, where it is difficult to discern the space-time patterns produced by the different models. However, there are som...

A Model of Risk-Sensitive Route-Choice Behavior and the Potential Benefit of Route Guidance

Illenberger, Johannes ; Flötteröd, Gunnar ; Nagel, Kai (2011)

In this paper, we present a simulation-based investigation of the potential benefit of route-guidance information in the context of risk-sensitive travelers. We set up a simple two-route scenario where travelers are repeatedly faced with risky route-choice decisions. The risk averseness of the travelers is implicitly controlled through a generic utility function. We vary both the travelers' sen...

An improved framework for large-scale multi-agent simulations of travel behaviour

Raney, Bryan ; Nagel, Kai (2006)

We describe a framework for running large-scale multi-agent simulations of travel behaviour. The framework represents each traveller as an individual ‘agent’ that makes independent decisions about its desired use of the transporta- tion system during a typical day. An agent keeps a record of its decisions in a ‘plan’. A plan contains the agent’s schedule of activities it wants to perform during...

The MATSim Network Flow Model for Traffic Simulation Adapted to Large-Scale Emergency Egress and an Application to the Evacuation of the Indonesian City of Padang in Case of a Tsunami Warning

Lämmel, Gregor ; Klüpfel, Hubert ; Nagel, Kai (2009)

The evacuation of whole cities or even regions is an important problem, as demonstrated by recent events such as evacuation of Houston in the case of Hurricane Rita or the evacuation of coastal cities in the case of Tsunamis. This paper describes a complex evacuation simulation framework for the city of Pandang, with approximately 1,000,000 inhabitants. Padang faces a high risk of being inundat...

Large-Scale Multi-Agent Simulations for Transportation Applications

Balmer, Michael ; Nagel, Kai ; Raney, Bryan (2004)

In many transportation simulation applications including intelligent transportation systems (ITS), behavioral responses of individual travelers are important. This implies that simulating individual travelers directly may be useful. Such a microscopic simulation, consisting of many intelligent particles (= agents), is an example of a multi-agent simulation. For ITS applications, it would be use...

Income-contingent user preferences in policy evaluation: application and discussion based on multi-agent transport simulations

Kickhöfer, Benjamin ; Grether, Dominik ; Nagel, Kai (2011)

Standard economic policy evaluation allows the realization of projects if the aggregated economic benefit outweighs their costs. The use of one single aggregated welfare measure for evaluating and ranking projects has often been criticized for many reasons. A major issue is that differentiated effects on individuals or subgroups of the population are not taken into consideration. This leads to ...

Generating complete all-day activity plans with genetic algorithms

Charypar, David ; Nagel, Kai (2005)

Activity-based demand generation contructs complete all-day activity plans for each member of a population, and derives transportation demand from the fact that consecutive activities at different locations need to be connected by travel. Besides many other advantages, activity-based demand generation also fits well into the paradigm of multi-agent simulation, where each traveler is kept as an ...