36,426 research outputs found
Understanding Artificial Anasazi
A replication and analysis of the Artificial Anasazi model is presented. It is shown that the success of replicating historical data is based on two parameters that adjust the carrying capacity of the Long House Valley. Compared to population estimates equal to the carrying capacity the specific agent behavior contributes only a modest improvement of the model to fit the archaeological records.Replication, Model Analysis, Model-Based Archaeology, Population Dynamics, Social-Ecological Systems
Evolution of Cooperation when Feedback to Reputation Scores is Voluntary
Reputation systems are used to facilitate interaction between strangers in one-shot social dilemmas, like transactions in e-commerce. The functioning of various reputation systems depend on voluntary feedback derived from the participants in those social dilemmas. In this paper a model is presented under which frequencies of providing feedback to positive and negative experiences in reputation systems explain observed levels of cooperation. The results from simulations show that it is not likely that reputation scores alone will lead to high levels of cooperation.Trust, Reputation, One-Shot Prisoner Dilemma, Voluntary Feedback, Symbols
Short wavelength radio observations of Saturn's rings
Passive radio observations are discussed from 1 mm to 2 cm wavelengths. The interferometric technique was used to observe the brightness of the rings. The reflectivity and disk temperature are also considered. The differences between radio and radar observations are examined and discussed
The Role of Diverse Strategies in Sustainable Knowledge Production
Online communities are becoming increasingly important as platforms for
large-scale human cooperation. These communities allow users seeking and
sharing professional skills to solve problems collaboratively. To investigate
how users cooperate to complete a large number of knowledge-producing tasks, we
analyze StackExchange, one of the largest question and answer systems in the
world. We construct attention networks to model the growth of 110 communities
in the StackExchange system and quantify individual answering strategies using
the linking dynamics of attention networks. We identify two types of users
taking different strategies. One strategy (type A) aims at performing
maintenance by doing simple tasks, while the other strategy (type B) aims
investing time in doing challenging tasks. We find that the number of type A
needs to be twice as big as type B users for a sustainable growth of
communities.Comment: 10 pages, 3 figure
Characterization and computation of canonical tight windows for Gabor frames
Let be a Gabor frame for for given window .
We show that the window that generates the canonically
associated tight Gabor frame minimizes among all windows
generating a normalized tight Gabor frame. We present and prove versions of
this result in the time domain, the frequency domain, the time-frequency
domain, and the Zak transform domain, where in each domain the canonical
is expressed using functional calculus for Gabor frame operators. Furthermore,
we derive a Wiener-Levy type theorem for rationally oversampled Gabor frames.
Finally, a Newton-type method for a fast numerical calculation of \ho is
presented. We analyze the convergence behavior of this method and demonstrate
the efficiency of the proposed algorithm by some numerical examples
Diffusion processes in demographic transitions: a prospect on using multi agent simulation to explore the role of cognitive strategies and social interactions
Multi agent simulation (MAS) is a tool that can be used to explore the dynamics of different systems. Considering that many demographic phenomena have roots in individual choice behaviour and social interactions it is important that this behaviour is being translated in agent rules. Several behaviour theories are relevant in this context, and hence there is a necessity of using a meta-theory of behaviour as a framework for the development of agent rules. The consumat approach provides a basis for such a framework, as is demonstrated with a discussion of modelling the diffusion of contraceptives. These diffusion processes are strongly influenced by social processes and cognitive strategies. Different possible research lines are discussed which might be addressed with a multi-agent approach like the consumats.
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