Contributions in Merlin

Simulations of swarm behavior have been employed as a generative processes in many musical and artistic realizations. Despite this popularity, the application of swarm simulations as a visual and interactive component for stage performances seems to be very rare. This paper tries to show that swarm simulations can be employed as flexible and fascinating choreographic elements for dance performance. In particular, a swarm's strong spatial presence and it's behavioral flexibility provide a wide range of choreographic possibilities that accentuate or complement the human dancers' activities. This paper places a particular focus on the presentation of several examples of swarm based stage effects that have been realized as collaboration between the authors and choreographers.

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This technical report describes the discourse representation structures (DRS) derived from texts written in version 6.5 of Attempto Controlled English (ACE 6.5). The description is done by an exhaustive set of examples. Among other things, ACE 6.5 supports modal statements, negation as failure, and sentence subordination. These features require an extended form of discourse representation structures. The discourse representation structure itself uses a reified, or ""flat"" notation, meaning that its atomic conditions are built from a small number of predefined predicates that take constants standing for words of the ACE text as their arguments

This new edition of the seminar entitled ""Internet Economics IV"" discusses a number of selected topics, addressing investigations of the use and application of communications technology under economic constraints and technical optimization measures. The technical report has been prepared during the autumn term HS 2008 as the result of the Internet Economics seminar. The seminar deals with the use of Internet technology and additional ways to support and do business. Beside technical details of service provisioning in the Internet, in communication and mobile networks, the seminar discusses and focuses on financial and economical aspects, including upcoming business models, charging, financial clearing processes, and business relations in a multi-provider environment

Peer-to-peer (P2P) systems achieve scalability, fault tolerance, and load balancing with a lower-cost infrastructure, from which collaboration systems, such as Wikipedia, could benefit from. A major challenge in P2P collaboration systems, however, is to maintain article quality after each modification at the presence of malicious peers. Therefore, to allow modifications to take effect will be only possible, if a majority of previous editors approve changes by voting. This determines a challenge in P2P systems, due to the absence of a central authority. Thus, this paper proposes the fully decentralized voting mechanism PeerVote, which enables users to vote on modifications in articles in a P2P collaboration system. Simulations and experiments show the scalability and robustness of PeerVote, even at the presence of malicious peers

People experience relief whenever outcomes are better than they would have been, had an alternative course of action been chosen. Here we investigated the neuronal basis of relief with functional resonance imaging in a choice task in which the outcome of the chosen option and that of the unchosen option were revealed sequentially. We found parametric activation increases in anterior ventrolateral prefrontal cortex with increasing relief (chosen outcomes better than unchosen outcomes). Conversely, anterior ventrolateral prefrontal activation was unrelated to the opposite of relief, increasing regret (chosen outcomes worse than unchosen outcomes). Furthermore, the anterior ventrolateral prefrontal activation was unrelated to primary gains and increased with relief irrespective of whether the chosen outcome was a loss or a gain. These results suggest that the anterior ventrolateral prefrontal cortex encodes a higher-order reward signal that lies at the core of current theories of emotion.

Decision making under risk is central to human behavior. Economic decision theory suggests that value, risk, and risk aversion influence choice behavior. Although previous studies identified neural correlates of decision parameters, the contribution of these correlates to actual choices is unknown. In two different experiments, participants chose between risky and safe options. We identified discrete blood oxygen level-dependent (BOLD) correlates of value and risk in the ventral striatum and anterior cingulate, respectively. Notably, increasing inferior frontal gyrus activity to low risk and safe options correlated with higher risk aversion. Importantly, the combination of these BOLD responses effectively decoded the behavioral choice. Striatal value and cingulate risk responses increased the probability of a risky choice, whereas inferior frontal gyrus responses showed the inverse relationship. These findings suggest that the BOLD correlates of decision factors are appropriate for an ideal observer to detect behavioral choices. More generally, these biological data contribute to the validity of the theoretical decision parameters for actual decisions under risk.

Reward and punishment have opposite affective value but are both processed by the cingulate cortex. However, it is unclear whether the positive and negative affective values of monetary reward and punishment are processed by separate or common subregions of the cingulate cortex. We performed a functional magnetic resonance imaging study using a free-choice task and compared cingulate activations for different levels of monetary gain and loss. Gain-specific activation (increasing activation for increasing gain, but no activation change in relation to loss) occurred mainly in the anterior part of the anterior cingulate and in the posterior cingulate cortex. Conversely, loss-specific activation (increasing activation for increasing loss, but no activation change in relation to gain) occurred between these areas, in the middle and posterior part of the anterior cingulate. Integrated coding of gain and loss (increasing activation throughout the full range, from biggest loss to biggest gain) occurred in the dorsal part of the anterior cingulate, at the border with the medial prefrontal cortex. Finally, unspecific activation increases to both gains and losses (increasing activation to increasing gains and increasing losses, possibly reflecting attention) occurred in dorsal and middle regions of the cingulate cortex. Together, these results suggest separate and common coding of monetary reward and punishment in distinct subregions of the cingulate cortex. Further meta-analysis suggested that the presently found reward- and punishment-specific areas overlapped with those processing positive and negative emotions, respectively.

Delayed rewards lose their value for economic decisions and constitute weaker reinforcers for learning. Temporal discounting of reward value already occurs within a few seconds in animals, which allows investigations of the underlying neurophysiological mechanisms. However, it is difficult to relate these mechanisms to human discounting behavior, which is usually studied over days and months and may engage different brain processes. Our study aimed to bridge the gap by using very short delays and measuring human functional magnetic resonance responses in one of the key reward centers of the brain, the ventral striatum. We used psychometric methods to assess subjective timing and valuation of monetary rewards with delays of 4.0-13.5 s. We demonstrated hyperbolic and exponential decreases of striatal responses to reward predicting stimuli within this time range, irrespective of changes in reward rate. Lower reward magnitudes induced steeper behavioral and striatal discounting. By contrast, striatal responses following the delivery of reward reflected the uncertainty in subjective timing associated with delayed rewards rather than value discounting. These data suggest that delays of a few seconds affect the neural processing of predicted reward value in the ventral striatum and engage the temporal sensitivity of reward responses. Comparisons with electrophysiological animal data suggest that ventral striatal reward discounting may involve dopaminergic and orbitofrontal inputs.