889 research outputs found
Experiments and Simulations on Day-to-Day Route Choice-Behaviour
The paper reports laboratory experiments on a day-to-day route choice game with two routes. Subjects had to choose between a main road M and a side road S. The capacity was greater for the main road. 18 subjects participated in each session. In equilibrium the number of subjects is 12 on M and 6 on S. Two treatments with 6 sessions each were run at the Laboratory of Experimental Economics at Bonn University using RatImage. Feedback was given in treatment I only about own travel time and in treatment II on travel time for M and S. Money payoffs increase with decreasing time. The main results are as follows. 1. Mean numbers on M and S are very near to the equilibrium. 2. Fluctuations persist until the end of the sessions in both treatments. 3. Fluctuations are smaller under treatment II .The effect is small but significant. 4. The total number of changes is significantly greater in treatment I. 5. Subjects’ road changes and payoffs are negatively correlated in all sessions. 6. A direct response mode reacts with more changes for bad payoffs whereas a contrary response mode shows opposite reactions. Both response modes can be observed. 7. The simulation of an extended payoff sum learning model closely fits the main results of the statistical evaluation of the data.travel behaviour research, information in intelligent transportation systems, day-to-day route choice, laboratory experiments, payoff sum model
Monte Carlo sampling of Wigner functions and surface hopping quantum dynamics
The article addresses the achievable accuracy for a Monte Carlo sampling of Wigner functions in combination with a surface hopping algorithm for non-adiabatic quantum dynamics. The approximation of Wigner functions is realized by an adaption of the Metropolis algorithm for real-valued functions with disconnected support. The integration, which is necessary for computing values of the Wigner function, uses importance sampling with a Gaussian weight function. The numerical experiments agree with theoretical considerations and show an error of 2–3%
Recommended from our members
Testing (beliefs about) social preferences: evidence from an experimental coordination game
We report experimental results on a simple coordination game in which two players can coordinate either on an equal distribution of payoffs or on a Pareto superior but unequal distribution of payoffs. We find that the higher the difference in individual payoffs, the less likely is a successful coordination on the Pareto superior distribution. While this is well in line with the recent models of inequity aversion, our results are best explained not by a preference for equality per se but rather by the belief that the opponent has such a preference
Impact of secondary hard substrate on the distribution and abundance of Aurelia aurita in the western Baltic Sea
Highlights:
• Impacts of wind farms on the occurrence of the moon jelly Aureliaaurita.
• Artificial hard substrate has the potential to increase the abundance of A.aurita.
• In the given example the abundance of A. aurita increases about 20%.
• Distribution patterns indicate cross-border impacts on various sectors.
This study assessed the impact of secondary hard substrate, as being introduced into marine ecosystems by the establishment of wind farm pillars, on the occurrence and distribution of the moon jelly Aurelia aurita in the southwestern Baltic Sea. A two-year data sampling was conducted with removable settlement plates to assess the distribution and population development of the scyphozoan polyps. The data collected from these samples were used to set up a model with Lagrangian particle technique. The results confirm that anthropogenic created hard substrate (e.g. offshore wind farms) has the potential to increase the abundance of the A. aurita population. The distribution of wind farm borne jellyfish along Danish, German and Polish coasts indicates conflicts with further sectors, mainly energy and tourism
Recommended from our members
Commuters route choice behaviour
The paper reports laboratory experiments with a two route choice scenario. In each session 18 subjects had to choose between a main road M and a side road S. The capacity of M was larger. Feedback was given in treatment I only on the subjects' own travel time and in treatment II on travel time for M and S. The main results are as follows:
• Mean numbers on M and S are near to pure equilibrium.
• Fluctuations persist until the end of the sessions.
• The total number of changes is significantly greater in treatment I.
• Subjects' road changes and payoffs are negatively correlated.
• A direct response mode results in more changes for bad payoffs whereas a contrary response mode shows opposite reactions.
• Simulations of an extended payoff sum learning model fits the main results of the statistical evaluation of the data
Are depressive symptoms linked to a reduced pupillary response to novel positive information?:An eye tracking proof-of-concept study
Introduction:Depressive symptoms have been linked to difficulties in revising established negative beliefs in response to novel positive information. Recent predictive processing accounts have suggested that this bias in belief updating may be related to a blunted processing of positive prediction errors at the neural level. In this proof-of-concept study, pupil dilation in response to unexpected positive emotional information was examined as a psychophysiological marker of an attenuated processing of positive prediction errors associated with depressive symptoms.Methods: Participants (N = 34) completed a modified version of the emotional Bias Against Disconfirmatory Evidence (BADE) task in which scenarios initially suggest negative interpretations that are later either confirmed or disconfirmed by additional information. Pupil dilation in response to the confirmatory and disconfirmatory information was recorded. Results: Behavioral results showed that depressive symptoms were related to difficulties in revising negative interpretations despite disconfirmatory positive information. The eye tracking results pointed to a reduced pupil response to unexpected positive information among people with elevated depressive symptoms. Discussion: Altogether, the present study demonstrates that the adapted emotional BADE task can be appropriate for examining psychophysiological aspects such as changes in pupil size along with behavioral responses. Furthermore, the results suggest that depression may be characterized by deviations in both behavioral (i.e., reduced updating of negative beliefs) and psychophysiological (i.e., decreased pupil dilation) responses to unexpected positive information. Future work should focus on a larger sample including clinically depressed patients to further explore these findings.</p
Local Communication Protocols for Learning Complex Swarm Behaviors with Deep Reinforcement Learning
Swarm systems constitute a challenging problem for reinforcement learning
(RL) as the algorithm needs to learn decentralized control policies that can
cope with limited local sensing and communication abilities of the agents.
While it is often difficult to directly define the behavior of the agents,
simple communication protocols can be defined more easily using prior knowledge
about the given task. In this paper, we propose a number of simple
communication protocols that can be exploited by deep reinforcement learning to
find decentralized control policies in a multi-robot swarm environment. The
protocols are based on histograms that encode the local neighborhood relations
of the agents and can also transmit task-specific information, such as the
shortest distance and direction to a desired target. In our framework, we use
an adaptation of Trust Region Policy Optimization to learn complex
collaborative tasks, such as formation building and building a communication
link. We evaluate our findings in a simulated 2D-physics environment, and
compare the implications of different communication protocols.Comment: 13 pages, 4 figures, version 2, accepted at ANTS 201
Socio-cultural norms of body size in Westerners and Polynesians affect heart rate variability and emotion during social interactions
The perception of body size and thus weight-related stigmatization vary between cultures. Both are stronger in Western than in Polynesian societies. Negative emotional experiences alter one’s behavioral, psychological, and physiological reactions in social interactions. This study compared affective and autonomic nervous system responses to social interactions in Germany and American Samoa, two societies with different body-size related norms. German (n = 55) and Samoan (n = 56) volunteers with and without obesity participated in a virtual ball-tossing game that comprised episodes of social inclusion and social exclusion. During the experiment, heart rate was measured and parasympathetic activity (i.e., high-frequency heart rate variability) was analyzed. We found differences in both emotional experience and autonomic cardio-regulation between the two cultures: during social inclusion, Germans but not Samoans showed increased parasympathetic activity. In Germans with obesity, this increase was related to a more negative body image (comprising high rates of weight-related teasing). During social exclusion, Samoans showed parasympathetic withdrawal regardless of obesity status, while Germans with obesity showed a stronger increase in parasympathetic activity than lean Germans. Furthermore, we found fewer obesity-related differences in emotional arousal after social exclusion in Samoans as compared to Germans. Investigating the interplay of socio-cultural, psychological, and biological aspects, our results suggest influences of body size-related socio-cultural norms on parasympathetic cardio-regulation and negative emotions during social interactions
Rolls-Royce Low Noise Highly Variable Cycle Nozzle for Next Generation Supersonic Aircraft
An overview of the work performed by Rolls-Royce under contract NNL08AA29C is presented. The work includes computational fluid dynamic (CFD) analysis for, and design of, a highly variable cycle exhaust model for the Supersonic project (NRA NN06ZEA001N). The CFD analysis shows that the latest design improvements to the clam shell doors have increased flow through the ejector over that achieved with previous designs
- …