Contributions in Merlin

Facial emotions express our internal states and are fundamental in social interactions. Here we explore whether the repetition of unattended facial emotions builds up a predictive representation of frequently encountered emotions in the visual system. Participants (n = 24) were presented peripherally with facial stimuli expressing emotions while they performed a visual detection task presented in the center of the visual field. Facial stimuli consisted of four faces of different identity, but expressed the same emotion (happy or fearful). Facial stimuli were presented in blocks of oddball sequence (standard emotion: p = 0.9, deviant emotion: p = 0.1). Event-related potentials (ERPs) to the same emotions were compared when the emotions were deviant and standard, respectively. We found visual mismatch negativity (vMMN) responses to unattended deviant emotions in the 170–360 ms post-stimulus range over bilateral occipito-temporal sites. Our results demonstrate that information about the emotional content of unattended faces presented at the periphery of the visual field is rapidly processed and stored in a predictive memory representation by the visual system. We also found evidence that differential processing of deviant fearful faces starts already at 70–120 ms after stimulus onset. This finding shows a ‘negativity bias’ under unattended conditions. Differential processing of fearful deviants were more pronounced in the right hemisphere in the 195–275 ms and 360–390 ms intervals, whereas processing of happy deviants evoked larger differential response in the left hemisphere in the 360–390 ms range, indicating differential hemispheric specialization for automatic processing of positive and negative affect.

In modern economies the information problem is less one of getting information but one of receiving too much information. This abundance of information creates a scarcity of attention and, if information senders can influence their chance of perception, a competition for attention aside the conventional economic competition e.g. for consumer budget. The following two facts are well documented by marketing and psychological research and serve as main building blocks for my model: 1) consumers are not capable of considering the entire set of items if this set is large. 2) information senders can positively influence their chance of perception by sending a relative stronger signal. Using a game theoretic, microfounded approach I investigate how the interdependence of economic and perceptional competition affect the market equilibrium at the positive level. The main results are in an information rich economy traditional economic variables as market prices reflect psychological limitations of consumers which implies that market size and other traditional measures of competition may give misleading measures of competition. In general, whether firms benefit or not from perceptual limitations of consumers depends on how well firms can influence their chance of perception (the toughness of the attention competition) and how much revenue they can extract from consumers (the severity of the economic competition). The more the items are substitutable the more likely firms are to extract additional profits because of limited attention, which implies larger markets to occur under free entry. Using a standard model of circular product differentiation I show that if consumers are inattentive then equilibrium diversity and prices are higher and consumers choose a ”bad” variety more often compared to the hypothetical case of unlimited attention capacities. This shows that if the allocation problem of attention is left to be solved by the market this might result in a very undesirable result. Further, the implications of limited attention for models of informative advertising is discussed. I show that the cause why consumers have limited information (because they receive only little information or because of limited attention) matters for policy implications. Under limited attention the advice originating from models of informative advertising may have no or the wrong effect if limited attention is not taken into account. Moreover, models of informative advertising without limited attention have serious problems matching the pattern of the U.S. advertising data of the last three decades. Finally, I extend the game theoretic literature on uniqueness and stability by some further tools for symmetric games which help to establish certain results of my models but also are of self-interest. In modernen Okonomien ist das Informationsproblem weniger überhaupt an Information zu gelangen sondern eher von Information uberschwemmt zu werden. Dieser Informationsüberschuss generiert eine Knappheit der Aufmerksamkeit und, wenn die Informationssender ihre Wahrnehmungswahrscheinlichkeit beeinflussen können, auch einen Wettbewerb um die Aufmerksamkeit zusätzlich zum konventionellen Wettbewerb um das Budget der Konsumenten. Die folgenden beiden Fakten sind durch die Marketing-Literatur und die Literatur der Wahrnehmungspsychologie gut dokumentiert und dienen als Grundbausteine meines Modells: 1) die Individuen nicht in der Lage sind alle Information zu verarbeiten, die sie sehen. 2) die Informationssender ihre Wahrnehmungschance positiv durch relativ starke eigene Signale beeinflussen können. Mittels einem spieltheoretischen, mikrofundierten Ansatz untersuche ich wie die Interdependenz von ökonomischem und perzeptionellem Wettbewerb das Marktgleichgewicht beeinflusst. Die zentralen Resultate sind in einer informationsreichen Ökonomie reflektieren traditionelle Marktvariablen wie der Preis psychologische Grenzen der Konsumenten, was zur Folge hat, dass traditionelle Masse des Wettbewerbs, wie die Anzahl der Mitstreiter, falsche Vorhersagen generieren. Ob die Firmen von der beschränkten Aufmerksamkeit der Konsumenten profitieren können, hängt im allgemeinen davon ab, wie gut die Firmen ihre Wahrnehmungschance beeinflussen können und wie stark der ökonomische Wettbewerb ausgeprägt ist. Je mehr die Güter substituierbar sind, umso eher können die Firmen, wegen der begrenzten Aufmerksamkeit, zusätzliche Erträge generieren, was dann wiederum unter freiem Marktzugang zu grösseren Märkten führt. Unter Verwendung eines Standard-Modells der zirkulären Produktdifferenzierung zeige ich, dass wenn die Konsumenten begrenzt aufmerksam sind, die gleichgewichtige Diversität sowie die Preise höher sind und Konsumenten tendenziell häufiger eine für sie schlechte Alternative wählen. Falls also das Problem der Aufmerksamkeitsallokation durch einen Marktmechanismus gel¨st wird, führt dies möglicherweise zu einem nicht wünschenswerten Endresultat. Im weiteren diskutiere ich die Implikationen von begrenzter Aufmerksamkeit für Modelle von informativer Werbung. Es wird aufgezeigt, dass die Ursachen begrenzter Information (weil die Konsumenten zu wenig Information erhalten oder weil sie gar nicht alle Information wahrnehmen können) eine entscheidende Rolle spielen für wirtschaftspolitische Massnahmen. Unter beschränkter Aufmerksamkeit können Massnahmen, die aus solchen Modellen ohne spezielle Berücksichtigung der Aufmerksamkeitsschranken abgeleitet wurden, keine oder eine falsche Wirkung entfalten. Ausserdem haben solche Modelle grösste Mühe, das Muster der U.S. Werbedaten der letzten dreissig Jahre zu erklären, falls beschränkte Aufmerksamkeit nicht berücksichtigt wird. Zum Schluss erweitere ich die rein spieltheoretische Literatur zu Eindeutigkeit und Stabilität um einige neue Tools, welche äussert hilfreich sind um gewisse Resultate meiner Modelle nachzuweisen und, als Werkzeuge, von eigenständigem Interesse sind.

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The efficient and high-quality rendering of large vector data sets onto multiresolution 3D landscapes poses a significant problem in three-dimensional (3D) geographic information systems. The advances in technology of remote sensing have led to very complex and high resolution digital elevation models (DEM), which can only be rendered in real time with elaborated level-of-detail (LOD) models, making the combination of 2D vector data and 3D terrain surfaces very challenging.In this work the problems, constraints, requirements and solutions of combining variable level-of-detail DEM triangulations with adaptive vector maps are studied, in the context of interactive 3D geovisualization.The survey shows that the geometry and texture based approaches to render vector data onto 3D landscapes have their issues and therefore a solution based on the shadow volume algorithm, which overcomes the limitations of the other approaches, is provided and discussed more detailed. This one allows a per pixel exact mapping and an easy integration of the vector data into a variable-LOD based interactive visualization, rendering the vector data independent of the underlying 3D terrain model.

Vector maps and network graph data are widely used in visualization applications and GIS-based decision making processes. In order to meet the rising demand for powerful 3D visualizations of massive vector maps, level-of-detail (LOD) models have to be developed and applied. Accurate and efficient vector map generalization is needed to generate the different LODs. Among all generalization operators, line simplification is the one that is most investigated and used. The Douglas-Peucker line simplification algorithm delivers visually pleasing results and preserves the shape of the original line, but introduces topological inconsistencies. The introduction of Epsilon-Voronoi diagrams solves the problem of intersecting polylines, but cannot avoid self-intersections. Therefore, the polylines have to be split into monotone subpolylines. The use of frame buffers and out-of-core systems enables fast interactive visualization. Even the integration of large vector maps in 3D terrain visualization is possible by using the shadow volume approach and texture-based mapping. However, the on-the-fly generation of continuous LODs is still prospects ahead.

In this master thesis, an agent-based simulation software based on a conceptual model of the Swiss woodfuel market has been programmed. The simulation software was implemented in Java. Instead of holding all information about the agents directly as Java objects in memory, an ontology database was used to store the data. The objective of this approach was to get more sophisticated possibilities for the evaluation of the simulations, as on the one hand all the data about the interactions between the agents are available, on the other hand it is possible to read out very specific information with SPARQL-Queries. Additionally, logical consequences should be inferred from the ontology database using a reasoner and specifying inference rules. It could be demonstrated that using an ontology-database in fact improves the possibilities of evaluating the simulation. Moreover, the source code stayed clearer since it only contains methods for the mutation of agent data, but doesn't hold the data itself. However, using the ontology databases decreases the performance of the simulation: simulating 25 years with 1000 agents on a high performance cluster took between two and ten hours, depending on the settings used. This makes the processes of verification and validation even more complex. Hence, with the present version of the simulation program it was not possible to make precise statements about the Swiss woodfuel market. Even though it was demonstrated with the help of an example how the simulation program can be used to make statements about the Swiss woodfuel market, based on a specific question.

The manual translation of Domain Relational Calculus (DRC) queries into equivalent Structured Query Language (SQL) queries is cumbersome. Thus, the automation of this process is desired. This paper describes the implementation of an automatic DRC into SQL translator called DRC2SQL. The program requirements and the program design are described extensively. Further, DRC2SQL is critically discussed. DRC2SQL offers a graphical user interface and is able to translate correctly 14 out of 15 previously defined DRC queries.

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