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9,272 research outputs found

Mobslinger: The Fastest Mobile in the West.

Author: Chehimi Fadi
Clemson Helen
Coulton Paul
Edwards Reuben
Publication venue
Publication date: 01/06/2006
Field of study

Whilst there is a number of location sensing games emerging for mobile phones, from both commercial and academic sectors, there are few examples of social proximity based games that are effectively position independent. Bluetooth would seem an obvious choice for proximity based games, although the majority of games produced to-date simply uses it to provide a quasi peer to peer connection between users of multiplayer games. This is no-doubt due to the fact that proximity can often be implied from other location sensing technologies and that Bluetooth is often perceived as difficult to employ. In this paper we will show that Bluetooth can provide exciting game scenarios that can enable spontaneous stimulated social interaction using only proximity information. We illustrate this through the design rationale and subsequent implementation of ‘mobslinger’ which is a wild west, quick draw, ‘shoot-em-up’ game using mobile phones

Lancaster E-Prints

Interacting Dark Energy -- constraints and degeneracies

Author: Clemson Timothy
Koyama Kazuya
Maartens Roy
Väliviita Jussi
Zhao Gong-Bo
Publication venue: 'American Physical Society (APS)'
Publication date: 01/01/2012
Field of study

In standard cosmologies, dark energy interacts only gravitationally with dark matter. There could be a non-gravitational interaction in the dark sector, leading to changes in the effective DE equation of state, in the redshift dependence of the DM density and in structure formation. We use CMB, BAO and SNIa data to constrain a model where the energy transfer in the dark sector is proportional to the DE density. There are two subclasses, defined by the vanishing of momentum transfer either in the DM or the DE frame. We conduct a Markov-Chain Monte-Carlo analysis to obtain best-fit parameters. The background evolution allows large interaction strengths, and the constraints from CMB anisotropies are weak. The growth of DM density perturbations is much more sensitive to the interaction, and can deviate strongly from the standard case. However, the deviations are degenerate with galaxy bias and thus more difficult to constrain. Interestingly, the ISW signature is suppressed since the non-standard background evolution can compensate for high growth rates. We also discuss the partial degeneracy between interacting DE and modified gravity, and how this can be broken.Comment: 12 pages, 18 figures. Clarification on instabilities. Accepted by PR

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