Enabling Distributed Simulation of OMNeT++ INET Models

Parallel and distributed simulation have been extensively researched for a long time. Nevertheless, many simulation models are still executed sequentially. We attribute this to the fact that many of those models are simply not capable of being executed in parallel since they violate particular constraints. In this paper, we analyze the INET model suite, which enables network simulation in OMNeT++, with regard to parallelizability. We uncovered several issues preventing parallel execution of INET models. We analyzed those issues and developed solutions allowing INET models to be run in parallel. A case study shows the feasibility of our approach. Though there are parts of the model suite that we didn't investigate yet and the performance can still be improved, the results show parallelization speedup for most configurations. The source code of our implementation is available through our web site at code.comsys.rwth-aachen.de.Comment: Published in: A. F\"orster, C. Sommer, T. Steinbach, M. W\"ahlisch (Eds.), Proc. of 1st OMNeT++ Community Summit, Hamburg, Germany, September 2, 2014, arXiv:1409.0093, 201

Comparison of retinal vasodilator and constrictor responses in type 2 diabetes

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93551/1/j.1755-3768.2012.02445.x.pd

Impaired retinal vasodilator responses in prediabetes and type 2 diabetes

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99677/1/aos12129.pd

EXTREME WEATHER EVENTS AND ELECTORAL OUTCOMES A difference-in-differences analysis

Due to anthropogenic climate change, extreme weather events such as floods, droughts, temperature extremes, storms or wildfires will increase in severity and frequency. While the most obvious consequences of extreme weather events are material and human damages, there is also a growing body of literature on the societal and political implications of such events. A strand of this literature has found that particularly extreme weather events of a large scale which occur shortly before elections significantly influence electoral outcomes. However, within this growing body of literature, there are so far only few insights into sub-national elections, medium-sized extreme weather events and the effect of such events on the electoral outcomes of fringe parties. This Master’s thesis addresses these gaps by conducting a difference-indifferences analysis of a sub-national election following a medium-sized flood in Germany. The analysis finds that voters in state-level elections are attentive to national- and state-level responses to an extreme weather event, but do not consistently reward or punish politicians at the correct level of government. In addition, the analysis shows that extreme weather events increase the vote share of fringe parties. Overall, the results of this Master's thesis demonstrate that not just large-scale but also medium-sized extreme weather events constitute an increasingly important explanatory factor for electoral outcomes

A system for improving the quality of real-time services on the internet

Real-time Internet services are becoming more popular every day, and Voice over Internet Protocol (VOIP) is arguably the most popular of these, despite the quality and reliability problems that are so characteristic of VOIP. This thesis proposes to apply a routing technique called Fully Redundant Dispersity Routing to VOIP and shows how this mitigates these problems to deliver a premium service that is more equal to traditional telephony than VOIP is currently.Fully Redundant Dispersity Routing uses the path diversity readily available in the Internet to route complete copies of the data to be communicated over multiple paths. This allows the effect of a failure on a path to be reduced, and possibly even masked completely, by the other paths. Significantly, rather than expecting changes of the Internet that will improve real-time service quality, this approach simply changes the manner in which real-time services use the Internet, leaving the Internet itself to stay the way it is.First, real VOIP traffic in a commercial call centre is measured (1) to establish a baseline of current quality characteristics against which the effects of Fully Redundant Dispersity Routing may be measured, and (2) as a source of realistic path characteristics. Simulations of various Fully Redundant Dispersity Routing systems that adopt the measured VOIP traffic characteristics then (1) show how this routing technique mitigates quality and reliability problems, and (2) quantify the quality deliverable with the VOIP traffic characteristics measured. For example, quantifying quality as a Mean Opinion Score (MOS) estimated from the measurements with the International Telecommunication Union’s E-model, slightly more than 1 in every 23 of the VOIP telephone calls measured in the call centre is likely to be perceived to be of a quality with which humans would be less than very satisfied. Simulations carried out for this thesis show that using just two paths adopting the same measurements, Fully Redundant Dispersity Routing may increase quality to reduce that proportion to slightly less than 1 in every 10 000 VOIP telephone calls

A stochastic model for heart rate fluctuations

Normal human heart rate shows complex fluctuations in time, which is natural, since heart rate is controlled by a large number of different feedback control loops. These unpredictable fluctuations have been shown to display fractal dynamics, long-term correlations, and 1/f noise. These characterizations are statistical and they have been widely studied and used, but much less is known about the detailed time evolution (dynamics) of the heart rate control mechanism. Here we show that a simple one-dimensional Langevin-type stochastic difference equation can accurately model the heart rate fluctuations in a time scale from minutes to hours. The model consists of a deterministic nonlinear part and a stochastic part typical to Gaussian noise, and both parts can be directly determined from the measured heart rate data. Studies of 27 healthy subjects reveal that in most cases the deterministic part has a form typically seen in bistable systems: there are two stable fixed points and one unstable one.Comment: 8 pages in PDF, Revtex style. Added more dat

Role and Regulation of Myeloid Zinc Finger Protein 1 in Cancer

Myeloid zinc finger 1 (MZF1) belongs to the SCAN-Zinc Finger (SCAN-ZF) transcription factor family that has recently been implicated in a number of types of cancer. Although the initial studies concentrated on the role of MZF1 in myeloid differentiation and leukemia, the factor now appears to be involved in the etiology of major solid tumors such as lung, cervical, breast, and colorectal cancer. Here we discuss the regulation of MZF1 that mediated its recruitment and activation in cancer, concentrating on posttranslational modification by phosphorylation, and sumoylation, formation of promyelocytic leukemia nuclear bodies and its association with co-activators and co-repressors

Analysis of Aircraft Noise Data in the Area of the Airport of Hamburg

Outdoor sound propagation can be modeled numerically, but it is difficult to validate the results using measurements. The main objective of this master’s thesis was to quantify meteorological effects on outdoor sound propagation using noise measurements and weather data obtained by the Hamburg airport for air traffic control purposes. 91,000 A320 measurements from the period August 22 - August 23 were recorded. This data is supplemented by weather profiles measured at the Hamburg Weathermast. In addition to the precise modeling of the noise emissions generated at the source, of the aircraft, the modeling of atmospheric effects is also crucial to accurately determine the noise measured on the ground. To analyze the data, we first perform a Principal Component Analysis (PCA) to investigate the correlation of the combined noise, flight, and weather parameters. The Analysis of Variance (ANOVA) method is used to investigate whether there are significant differences in the weighted maximum sound pressure level LAS,max values between different meteorological parameters. In addition, we use the mean decrease in impurity (MDI) and permutation importance of a random forest model to evaluate how weather parameters can be used in the prediction of noise from aircraft overflights. A positive and negative temperature gradient differed on average by 2.13 - 2.61 dB, p-value < 0.05. A measured difference of 1.2 dB on average, p-value 0.00, was found between the upwind and downwind classes. When predicting noise with a Random Forest model, the removal of the weather parameters would lead to a loss of 14.85% accuracy on the training data. Overall, the noise can be predicted with an accuracy of 1 dB at a specific measuring station for the A320 type depending on the state of the source, e.g. the aircraft’s configuration and flight procedures. From the measurement data, it is possible to derive audible differences for humans depending on the weather conditions. However, we can’t yet predict noise for all aircraft types and locations