Asymptotic Behavior of Strategies in the Repeated Prisoner's Dilemma Game in the Presence of Errors

We examine the asymptotic behavior of a finite, but error-prone population, whose agents can choose one of ALLD (always defect), ALLC (always cooperate), or Pavlov (repeats the previous action if the opponent cooperated and changes action otherwise) to play the repeated Prisoner's Dilemma. A novelty of the study is that it allows for three types of errors that affect agents' strategies in distinct ways: (a) implementation errors, (b) perception errors of one's own action, and (c) perception errors of the opponent's action. We also derive numerical results based on the payoff matrix used in the tournaments of Axelrod (1984). Strategies' payoffs are monitored as the likelihood of committing errors increases from zero to one, which enables us to provide a taxonomy of best response strategies. We find that for some range of error levels, a unique best response (i.e. a dominant strategy) exists. In all other, the population composition can vary based on the proportion of each strategist's type and/or the payoffs of the matrix. Overall, our results indicate that the emergence of cooperation is considerably weak at most error levels

Review of presentations at the 6th European Lupus Meeting 3-5 March 2005.

The 6th European Lupus Meeting was held at the Royal College of Physicians of London and was attended by 450 delegates. The conference brought together leading speakers from Europe and North America who reviewed current knowledge and exciting new developments in both clinical and basic science aspects of systemic lupus erythematosus. This review summarizes the major points covered in each session

High throughput spatial convolution filters on FPGAs

Digital signal processing (DSP) on field- programmable gate arrays (FPGAs) has long been appealing because of the inherent parallelism in these computations that can be easily exploited to accelerate such algorithms. FPGAs have evolved significantly to further enhance the mapping of these algorithms, included additional hard blocks, such as the DSP blocks found in modern FPGAs. Although these DSP blocks can offer more efficient mapping of DSP computations, they are primarily designed for 1-D filter structures. We present a study on spatial convolutional filter implementations on FPGAs, optimizing around the structure of the DSP blocks to offer high throughput while maintaining the coefficient flexibility that other published architectures usually sacrifice. We show that it is possible to implement large filters for large 4K resolution image frames at frame rates of 30–60 FPS, while maintaining functional flexibility

Annus Mirabilis - a guide to the 6th European Lupus meeting 3-5 March 2005

This article has no abstract