Experimental analysis of the accessibility of drawings with few segments

The visual complexity of a graph drawing is defined as the number of geometric objects needed to represent all its edges. In particular, one object may represent multiple edges, e.g., one needs only one line segment to draw two collinear incident edges. We study the question if drawings with few segments have a better aesthetic appeal and help the user to asses the underlying graph. We design an experiment that investigates two different graph types (trees and sparse graphs), three different layout algorithms for trees, and two different layout algorithms for sparse graphs. We asked the users to give an aesthetic ranking on the layouts and to perform a furthest-pair or shortest-path task on the drawings.Comment: Appears in the Proceedings of the 25th International Symposium on Graph Drawing and Network Visualization (GD 2017

A relativistic diffusion model for hadron production in asymmetric heavy-ion collisions

Charged-hadron production in asymmetric heavy-ion collisions at relativistic energies is investigated to enhance our understanding of the non-perturbative regime of Quantum Chromodynamics. We extend the three source Relativistic Diffusion model, a nonequilibrium-statistical model, by substituting the underlying phenomenological distributions with microscopic distributions based on the parton model. The mid-rapidity source is computed through gluon-gluon interactions using $k_T$-factorization within the framework of gluon saturation, while the two fragmentation sources are determined by quark-gluon interactions using hybrid-factorization and the parton distribution functions. The concept of the fragmentation sources is grounded in the phenomenon of baryon stopping but requires an extension through a diffusion process in rapidity space allowing to explain charged-hadron production. The final hadronisation stage is modeled based on parton-hadron duality. We calculate the pseudorapidity distributions for deuteron-gold (d-Au) at {$\sqrt{s_{NN}}=200$ GeV} and proton-lead (p-Pb) at {$\sqrt{s_{NN}}=5.02$ and $8.16$ TeV} numerically from solutions of the corresponding Fokker-Planck equation and compare them with experimental data from RHIC and LHC. In order to address non-analytical integrals and to utilize the numerical procedures required for the computations, a novel and self-developed \Cpp program is utilized. The centrality-dependent distributions of produced charged hadrons obtained from the model calculations exhibit good agreement with the experimental data. The model calculations also highlight the significance of the fragmentation sources in comprehending the centrality dependence of produced hadrons, with particular emphasis on their pronounced influence in ultra-peripheral collisions

Towards Inclusive Gender in Transitional Justice: Gaps, Blind-Spots and Opportunities

While gender perspectives have become a burgeoning focus of analysis in transitional justice, the dominant conceptualization of 'gender' in such processes is effectively an exclusive one. As a result, careful consideration for the roles of masculinities and for the experiences of sexual and gender minorities remains strikingly absent. To engage with these blind-spots, in this article I initiate a move towards a more inclusive understanding of gender in transitional justice, which includes masculinities and queer perspectives. I also indicate how a move from the macro- to the micro-level of TJ implies opportunities and challenges for more inclusive understandings of gender

Male survivors are not ’emasculated’ but experience ‘displacement from gendered personhood’

Taking Northern Uganda as a case study, Philipp Schulz explores the intersecting harms experienced by male survivors of sexual violence, and argues that these harms can potentially be mitigated. He suggests that improved understanding – and language – can aid recovery

Queueing-Theoretic End-to-End Latency Modeling of Future Wireless Networks

The fifth generation (5G) of mobile communication networks is envisioned to enable a variety of novel applications. These applications demand requirements from the network, which are diverse and challenging. Consequently, the mobile network has to be not only capable to meet the demands of one of these applications, but also be flexible enough that it can be tailored to different needs of various services. Among these new applications, there are use cases that require low latency as well as an ultra-high reliability, e.g., to ensure unobstructed production in factory automation or road safety for (autonomous) transportation. In these domains, the requirements are crucial, since violating them may lead to financial or even human damage. Hence, an ultra-low probability of failure is necessary. Based on this, two major questions arise that are the motivation for this thesis. First, how can ultra-low failure probabilities be evaluated, since experiments or simulations would require a tremendous number of runs and, thus, turn out to be infeasible. Second, given a network that can be configured differently for different applications through the concept of network slicing, which performance can be expected by different parameters and what is their optimal choice, particularly in the presence of other applications. In this thesis, both questions shall be answered by appropriate mathematical modeling of the radio interface and the radio access network. Thereby the aim is to find the distribution of the (end-to-end) latency, allowing to extract stochastic measures such as the mean, the variance, but also ultra-high percentiles at the distribution tail. The percentile analysis eventually leads to the desired evaluation of worst-case scenarios at ultra-low probabilities. Therefore, the mathematical tool of queuing theory is utilized to study video streaming performance and one or multiple (low-latency) applications. One of the key contributions is the development of a numeric algorithm to obtain the latency of general queuing systems for homogeneous as well as for prioritized heterogeneous traffic. This provides the foundation for analyzing and improving end-to-end latency for applications with known traffic distributions in arbitrary network topologies and consisting of one or multiple network slices.Es wird erwartet, dass die fünfte Mobilfunkgeneration (5G) eine Reihe neuartiger Anwendungen ermöglichen wird. Allerdings stellen diese Anwendungen sowohl sehr unterschiedliche als auch überaus herausfordernde Anforderungen an das Netzwerk. Folglich muss das mobile Netz nicht nur die Voraussetzungen einer einzelnen Anwendungen erfüllen, sondern auch flexibel genug sein, um an die Vorgaben unterschiedlicher Dienste angepasst werden zu können. Ein Teil der neuen Anwendungen erfordert hochzuverlässige Kommunikation mit niedriger Latenz, um beispielsweise unterbrechungsfreie Produktion in der Fabrikautomatisierung oder Sicherheit im (autonomen) Straßenverkehr zu gewährleisten. In diesen Bereichen ist die Erfüllung der gestellten Anforderungen besonders kritisch, da eine Verletzung finanzielle oder sogar personelle Schäden nach sich ziehen könnte. Eine extrem niedrige Ausfallwahrscheinlichkeit ist daher von größter Wichtigkeit. Daraus ergeben sich zwei wesentliche Fragestellungen, welche diese Arbeit motivieren. Erstens, wie können extrem niedrige Ausfallwahrscheinlichkeiten evaluiert werden. Ihr Nachweis durch Experimente oder Simulationen würde eine extrem große Anzahl an Durchläufen benötigen und sich daher als nicht realisierbar herausstellen. Zweitens, welche Performanz ist für ein gegebenes Netzwerk durch unterschiedliche Konfigurationen zu erwarten und wie kann die optimale Konfiguration gewählt werden. Diese Frage ist insbesondere dann interessant, wenn mehrere Anwendungen gleichzeitig bedient werden und durch sogenanntes Slicing für jeden Dienst unterschiedliche Konfigurationen möglich sind. In dieser Arbeit werden beide Fragen durch geeignete mathematische Modellierung der Funkschnittstelle sowie des Funkzugangsnetzes (Radio Access Network) adressiert. Mithilfe der Warteschlangentheorie soll die stochastische Verteilung der (Ende-zu-Ende-) Latenz bestimmt werden. Dies liefert unterschiedliche stochastische Metriken, wie den Erwartungswert, die Varianz und insbesondere extrem hohe Perzentile am oberen Rand der Verteilung. Letztere geben schließlich Aufschluss über die gesuchten schlimmsten Fälle, die mit sehr geringer Wahrscheinlichkeit eintreten können. In der Arbeit werden Videostreaming und ein oder mehrere niedriglatente Anwendungen untersucht. Zu den wichtigsten Beiträgen zählt dabei die Entwicklung einer numerischen Methode, um die Latenz in allgemeinen Warteschlangensystemen für homogenen sowie für priorisierten heterogenen Datenverkehr zu bestimmen. Dies legt die Grundlage für die Analyse und Verbesserung von Ende-zu-Ende-Latenz für Anwendungen mit bekannten Verkehrsverteilungen in beliebigen Netzwerktopologien mit ein oder mehreren Slices

Male Survivors of Wartime Sexual Violence

Although wartime sexual violence against men occurs more frequently than is commonly assumed, its dynamics are remarkably underexplored, and male survivors’ experiences remain particularly overlooked. This reality is poignant in northern Uganda, where sexual violence against men during the early stages of the conflict was geographically widespread, yet now accounts of those incidents are not just silenced and neglected locally but also widely absent from analyses of the war. Based on rare empirical data, this book seeks to remedy this marginalization and to illuminate the seldom-heard voices of male sexual violence survivors in northern Uganda, bringing to light their experiences of gendered harms, agency, and justice. “Schulz offers a nuanced frame for understanding the dynamic and varied lived experiences of male survivors. Essential reading for anyone who wants to better comprehend conflict-related sexual violence as well as political violence more generally.” MARIA ERIKSSON BAAZ, author of Sexual Violence as a Weapon of War? Perceptions, Prescriptions, Problems in the Congo and Beyond “This extraordinary book opens new conceptual pathways in and beyond the field of transitional justice. A rich exploration of justice as a survivor-led praxis and a generous methodological offering for conducting ethical research.” ERIN BAINES, author of Buried in the Heart: Women, Complex Victimhood and the War in Northern Uganda “In his ethnographically nuanced study, Schulz charts a more grounded approach to international justice. The Ugandan men who have survived wartime rape have a lot to teach us—about constructing non-oppressive masculinities, creating mutual support, and building gender-aware sustainable peace.” CYNTHIA ENLOE, author of The Big Push: Exposing and Challenging the Persistence of Patriarch