Combinatorial optimization model for railway engine assignment problem

This paper presents an experimental study for the Hungarian State Railway Company (M\'AV). The engine assignment problem was solved at M\'AV by their experts without using any explicit operations research tool. Furthermore, the operations research model was not known at the company. The goal of our project was to introduce and solve an operations research model for the engine assignment problem on real data sets. For the engine assignment problem we are using a combinatorial optimization model. At this stage of research the single type train that is pulled by a single type engine is modeled and solved for real data. There are two regions in Hungary where the methodology described in this paper can be used and M\'AV started to use it regularly. There is a need to generalize the model for multiple type trains and multiple type engines

Using Comics to Destigmatize Burn-Out and Depression: An Experimental Investigation

Comics bieten ein vielversprechendes, aber bislang kaum genutztes Potenzial für die Kommunikation von Gesundheitsinformationen. Über die Wirkung von Comics bei der Aufklärung über psychische Erkrankungen wie Depressionen oder Burnout ist wenig bekannt. Depressionen werden von Laien oft als Burnout bezeichnet, was zu einer geringeren Stigmatisierung der Betroffenen, aber auch zu einer Verharmlosung depressiver Symptome führen kann. In der vorliegenden Studie (N = 1.201) wurde untersucht, wie das Geschlecht des Fallbeispiels und zusätzliche Sachinformationen in Comics die Stigmatisierung der Rezipierenden gegenüber Betroffenen beeinflussen und welche Rolle kognitive Prozesse dabei spielen. Die Ergebnisse bestätigen die destigmatisierende Wirkung des Burnout-Labels im Vergleich zu einem Depressions-Label. Die beobachteten Effekte sind jedoch von geschlechtsspezifischen Wahrnehmungen und in gewissem Maße von kognitiven Prozessen bei der Bildung stigmatisierender Einstellungen abhängig. Implikationen für die strategische Anti-Stigma- und Gesundheitskommunikation werden diskutiert.Comics are considered a promising, but often neglected medium for health information. However, little is known about the effects of comics providing health information about mental illnesses like depression or burn-out. Depression is often labeled by laypersons as burn-out, which can lead to reduced stigmatization of affected individuals, but likewise to a trivialization of depressive symptoms. The present study (N = 1,201) examined how the depiction of mental illness labels, exemplar's sex, and additional factual information in comics influences recipients' stigma-related perceptions about affected individuals and which role cognitive processes play in this regard. Results confirm the stigma-reducing effect of the burn-out label compared to a depression label. The observed effects, however, rely on sex-specific perceptions and, to some extent, on cognitive processes for the formation of stigmatizing attitudes. Implications for strategic anti-stigma and health communication are discussed

On Sparsification for Computing Treewidth

We investigate whether an n-vertex instance (G,k) of Treewidth, asking whether the graph G has treewidth at most k, can efficiently be made sparse without changing its answer. By giving a special form of OR-cross-composition, we prove that this is unlikely: if there is an e > 0 and a polynomial-time algorithm that reduces n-vertex Treewidth instances to equivalent instances, of an arbitrary problem, with O(n^{2-e}) bits, then NP is in coNP/poly and the polynomial hierarchy collapses to its third level. Our sparsification lower bound has implications for structural parameterizations of Treewidth: parameterizations by measures that do not exceed the vertex count, cannot have kernels with O(k^{2-e}) bits for any e > 0, unless NP is in coNP/poly. Motivated by the question of determining the optimal kernel size for Treewidth parameterized by vertex cover, we improve the O(k^3)-vertex kernel from Bodlaender et al. (STACS 2011) to a kernel with O(k^2) vertices. Our improved kernel is based on a novel form of treewidth-invariant set. We use the q-expansion lemma of Fomin et al. (STACS 2011) to find such sets efficiently in graphs whose vertex count is superquadratic in their vertex cover number.Comment: 21 pages. Full version of the extended abstract presented at IPEC 201

Excess GeV radiation and cosmic ray origin

Recent EGRET observations of the diffuse Galactic gamma-ray emission reveal a spectrum which is incompatible with the assumption that the cosmic ray spectra measured locally hold throughout the Galaxy: the spectrum above 1 GeV, where the emission is supposedly dominated by pi^0-decay, is harder than that derived from the local cosmic ray proton spectrum. We demonstrate that in case of a SNR origin of cosmic ray nucleons part of this gamma-ray excess may be attributed to the dispersion of the spectral indices in these objects. In global averages, as are gamma-ray line-of-sight integrals, this dispersion leads to a positive curvature in the composite spectrum, and hence to modified pi^0-decay gamma-ray spectra.Comment: accepted for publication in Astronomy and Astrophysic

Cluster Editing: Kernelization based on Edge Cuts

Kernelization algorithms for the {\sc cluster editing} problem have been a popular topic in the recent research in parameterized computation. Thus far most kernelization algorithms for this problem are based on the concept of {\it critical cliques}. In this paper, we present new observations and new techniques for the study of kernelization algorithms for the {\sc cluster editing} problem. Our techniques are based on the study of the relationship between {\sc cluster editing} and graph edge-cuts. As an application, we present an ${\cal O}(n^2)$-time algorithm that constructs a $2k$ kernel for the {\it weighted} version of the {\sc cluster editing} problem. Our result meets the best kernel size for the unweighted version for the {\sc cluster editing} problem, and significantly improves the previous best kernel of quadratic size for the weighted version of the problem

Nicht-intendierte Fallbeispiel-Effekte in der Gesundheitskommunikation: Negative Emotionen und Stigmatisierung im Kontext der Pränataldiagnostik

In der Gesundheitskommunikation werden Fallbeispiele eingesetzt, um Aufmerksamkeit für Gesundheitsbotschaften zu fördern und Gesundheitsverhalten zu beeinflussen. Das gesundheitsbezogene Thema der Pränataldiagnostik ist eng mit anderen kontroversen Themen wie Schwangerschaftsabbrüchen verknüpft und insbesondere mit der Genommutation Trisomie 21 assoziiert. In der vorliegenden Studie wird untersucht, inwiefern Fallbeispiele im Kontext der Pränataldiagnostik nicht-intendierte Effekte wie negative Emotionen und generalisierte Stigmatisierung von Menschen mit Trisomie 21 auslösen. In einem 2 x 2 x 3-Online-Experiment lasen 958 Teilnehmende einen randomisiert zugeteilten Medienbericht über Pränataldiagnostik, der durch das Fallbeispiel einer schwangeren Frau gerahmt wurde. Die Fallbeispiele wurden hinsichtlich des Alters, des Familienstandes und der Vorerfahrungen mit Trisomie 21 manipuliert. Darstellungen von älteren und alleinstehenden Frauen sowie die Kombination vermeintlich "ungünstiger" Schwangerschaftsbedingungen riefen vermehrt negative Emotionen hervor. Die generalisierte Stigmatisierung von Menschen mit Trisomie 21 wurde durch das Alter des Fallbeispiels direkt beeinflusst. Ferner zeigte sich ein signifikanter Effekt des Geschlechts der Teilnehmenden auf die negativen emotionalen Reaktionen und die generalisierte Stigmatisierung von Menschen mit Trisomie 21. Implikationen zur Vermeidung nicht-intendierter Fallbeispieleffekte im Kontext der Pränataldiagnostik werden diskutiert.Exemplars are frequently used to increase attention for health messages and to influence health behavior. The topic prenatal diagnosis is closely linked to other controversial topics such as abortion and is particularly associated with the genomic mutation trisomy 21. The present study investigates the extent to which exemplars in the context of prenatal diagnosis trigger unintended effects such as negative emotions and generalized stigmatization of people with trisomy 21. In a 2 x 2 x 3 online experiment, 958 participants read a randomly assigned media report about prenatal diagnosis which featured an exemplar of a pregnant woman. Exemplars were manipulated regarding the exemplar's age, marital status, and previous experience with trisomy 21. Depictions of older and single women, as well as the combination of supposedly unfavorable pregnancy conditions increased recipients' negative emotions. Generalized stigmatization of people with trisomy 21 was directly influenced by the exemplar’s age. Participants' sex had a significant influence on negative emotional reactions and generalized stigmatization towards people with trisomy 21. Implications for the prevention of unintended exemplar effects in the context of prenatal diagnosis are discussed

Neutrinos from active galactic nuclei as a diagnostic tool

Active galactic nuclei (AGN) are known as sources of high energy gamma-rays. The emission probably results from non-thermal radiation of relativistic jets belonging to the AGN. Earlier investigations of these processes have suggested that neutrinos are among the radiation products of the jets and may be used to discriminate between hadrons and leptons as primary particles for the production of the high energy emission. It is shown that the neutrino flux is correlated with the flux of TeV gamma-rays. This allows to distinctly search for neutrino emissions from the jets of AGN by using the TeV gamma-ray light curves to drastically reduce the temporal and spatial parameter space. Given the observed TeV photon fluxes from nearby BL Lacs the neutrino signal from AGN may be detectable with future neutrino observatories as least as sensitive as IceCube.Comment: Accepted for publication in A&A, 10 pages, 27 PS figure

Microcanonical Treatment of Hadronizing the Quark-Gluon Plasma

We recently introduced a completely new way to study ultrarelativistic nuclear scattering by providing a link between the string model approach and a statistical description. A key issue is the microcanonical treatment of hadronizing individual quark matter droplets. In this paper we describe in detail the hadronization of these droplets according to n-body phase space, by using methods of statistical physics, i.e. constructing Markov chains of hadron configurations.Comment: Complete paper enclosed as postscript file (uuencoded