Dynamic frequency planning for professional wireless microphone systems

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Optimal Opinion Control: The Campaign Problem

Opinion dynamics is nowadays a very common field of research. In this article we formulate and then study a novel, namely strategic perspective on such dynamics: There are the usual normal agents that update their opinions, for instance according the well-known bounded confidence mechanism. But, additionally, there is at least one strategic agent. That agent uses opinions as freely selectable strategies to get control on the dynamics: The strategic agent of our benchmark problem tries, during a campaign of a certain length, to influence the ongoing dynamics among normal agents with strategically placed opinions (one per period) in such a way, that, by the end of the campaign, as much as possible normals end up with opinions in a certain interval of the opinion space. Structurally, such a problem is an optimal control problem. That type of problem is ubiquitous. Resorting to advanced and partly non-standard methods for computing optimal controls, we solve some instances of the campaign problem. But even for a very small number of normal agents, just one strategic agent, and a ten-period campaign length, the problem turns out to be extremely difficult. Explicitly we discuss moral and political concerns that immediately arise, if someone starts to analyze the possibilities of an optimal opinion control.Comment: 47 pages, 12 figures, and 11 table

Hidden costs and benefits in two-tier welfare states

We apply a monopoly trade union model and analyze employment, wage and budgetary effects of (i) an inflow of migrant workers and (ii) an increase in the labor market participation rate of migrants. Per assumption, natives and migrants solely differ with respect to the level of benefit claims in a two- tier welfare system. Furthermore, the labor effects are studied under two types of union behavior. Analyzing the ceteris paribus labor market effects, we identify hidden costs and benefits of intensified integration that emerge from the design of the welfare program. We support previous findings in case of an inflow of migrant workers. More interesting, though, it is shown that a larger share of migrants in the workforce increases (decreases) the employment level, if the union represents (does not represent) migrant workers

Recognizable Graph Languages for Checking Invariants

We generalize the order-theoretic variant of the Myhill-Nerode theorem to graph languages, and characterize the recognizable graph languages as the class of languages for which the Myhill-Nerode quasi order is a well quasi order. In the second part of the paper we restrict our attention to graphs of bounded interface size, and use Myhill-Nerode quasi orders to verify that, for such bounded graphs, a recognizable graph property is an invariant of a graph transformation system. A recognizable graph property is a recognizable graph language, given as an automaton functor. Finally, we present an algorithm to approximate the Myhill-Nerode ordering

Health professionals' views on maternity care for women with physical disabilities: a qualitative study

Background: During pregnancy, childbirth and puerperium, women receive care from a range of health professionals, particularly midwives. To assess the current situation of maternity care for women with physical disabilities in Austria, this study investigated the perceptions and experiences of health professionals who have provided care for women with disabilities during pregnancy, childbirth and postpartum. Methods: The viewpoints of the participating health professionals were evaluated by means of semistructured interviews followed by an inductive qualitative content analysis of the interview transcripts, as proposed by Mayring. Results: Four main categories emerged from the inductive content analysis: (i) structural conditions and accessibility, (ii) interprofessional teamwork and cooperation, (iii) action competence, and (iv) diversity-sensitive attitudes. According to the participating health professionals, the structural conditions were frequently not suitable for providing targeted group-oriented care services. Additionally, a shortage of time and staff resources also limited the necessary flexibility of treatment measures in the care of mothers with physical disabilities. The importance of interprofessional teamwork for providing adequate care was highlighted. The health professionals regarded interprofessionalism as an instrument of quality assurance and team meetings as an elementary component of high-quality care. On the other hand, the interviewees perceived a lack of action competence that was attributed to a low number of cases and a corresponding lack of experience and routine. Regarding diversity-sensitive attitudes, it became apparent that the topic of mothers with physical disabilities in care posed challenges to health professionals that influenced their natural handling of the interactions. Conclusion: The awareness of one’s own attitudes towards diversity, in the perinatal context in particular, influences professional security and sovereignty as well as the quality of care of women with disabilities. There is a need for optimization in the support and care of women with physical disabilities during pregnancy, childbirth and puerperium

Klar und dunkel: Zu Stilformen im Werk von Peter Szondi und Jean Bollack

The article focuses on questions of form and style in the essays of Peter Szondi and Jean Bollack. Style in literary criticism reveals itself as a methodological mode for rendering the individuality of literary texts. This argument takes into account the relationship of analysis and persona of the critic, as well as the notions of clarity and darkness in writing about literature, with Szondi and Bollack representing two distinct poles on the scale between clarity and darkness. As it turns out, obscuritas can be a means of being precise, clarity a means of engaging the reader in providing for more precision

Selection and allocation functions of teacher education systems - Development and test of a model based on Open Systems Theory

Starting from several conceptual and methodological shortcomings of current research on the relation of teacher education and student achievement (Study 1), this thesis aims at developing an alternative, organizational perspective on teacher education based on Open Systems Theory. The resulting model of teacher education as an open system focuses on the selection and sorting of student teachers, as well as on the allocation of trained teachers to schools in the education system. This focus allows addressing the connection between student teachers, organizational features of teacher education, and the context of teacher education. At the same time it allows investigating the inherent selection and non-random allocation problem of research on the relation of teacher education and student achievement. The model includes characterizations of teacher education’s selection and allocation functions as arrangement of structural elements governing the selection and allocation processes. Their characterization and the model are validated further by means of an interview study with experts in the fields of teacher education, education systems, and comparative education (Studies 2 and 3). The model is tested by means of two international comparative studies implementing a multigroup structural equation modeling approach. In case of the selection function, its structural arrangements in the teacher education systems of Singapore, Poland, and the USA are compared with regard to their impact on the motivational orientation of student teachers and their relation to their use of learning opportunities (Study 4). While the results show no differences in the relation between the motivational orientation of student teachers and their use of learning opportunities, there are differences in the motivational orientation of and the use of learning opportunities by student teachers across the three structural arrangements. In case of the allocation function, its structural arrangement in the teacher education systems of Singapore and Finland are compared with regard to associated differences in the degree of positive matching (Study 5). The results of this study show differences in the degree of positive matching across the two structural arrangements. Despite some methodological limitations, which are mainly due to characteristics and availability of adequate data, the results of both international comparisons allow deriving several policy recommendations. Eventually, these recommendations and the potential use of the model in further research are discussed

Interactions between eye movement systems in cats and humans

Eye movements can be broadly classified into target-selecting and gaze-stabilizing eye movements. How do the different systems interact under natural conditions? Here we investigate interactions between the optokinetic and the target-selecting system in cats and humans. We use combinations of natural and grating stimuli. The natural stimuli are movies and pictures taken from the cat's own point of view with a head-mounted camera while it moved about freely in an outdoor environment. We superimpose linear global motion on the stimuli and use measurements of optokinetic nystagmus as a probe to study the interaction between the different systems responsible for controlling eye movements. Cats display higher precision stabilizing eye movements in response to natural pictures as compared to drifting gratings. In contrast, humans perform similarly under these two conditions. This suggests an interaction of the optokinetic and the pursuit system. In cats, the natural movies elicit very weak optokinetic responses. In humans, by contrast, the natural movie stimuli elicit effectively stabilizing eye movements. In both species, we find a unimodal distribution of saccades for all stimulus velocities. This suggests an early interaction of target-selecting and gaze-stabilizing saccades. Thus, we argue for a more integrated view in humans of the different eye movement system

Model-agnostic Feature Importance and Effects with Dependent Features -- A Conditional Subgroup Approach

Partial dependence plots and permutation feature importance are popular model-agnostic interpretation methods. Both methods are based on predicting artificially created data points. When features are dependent, both methods extrapolate to feature areas with low data density. The extrapolation can cause misleading interpretations. To overcome extrapolation, we propose conditional variants of partial dependence plots and permutation feature importance. Our approach is based on perturbations in subgroups. The subgroups partition the feature space to make the feature distribution within a group more homogeneous and between the groups more heterogeneous. The interpretable subgroups enable additional local, nuanced interpretations of the feature dependence structure as well as the feature effects and importance values within the subgroups. We also introduce a data fidelity measure that captures the degree of extrapolation when data is transformed with a certain perturbation. In simulations and benchmarks on real data we show that our conditional interpretation methods reduce extrapolation. In an application we show that these methods provide more nuanced and richer explanations