31,328 research outputs found
Connecting ICTs to development: The IDRC experience
Book ReviewAlthough the editors speciªcally deny that this book is a historical account, it only narrowly escapes that label. The book does attempt to consolidate some 15 years of International Development Research Centre (IDRC)–sponsored action research on ICT intervention projects undertaken in three main global regions, Latin America and the Caribbean, Africa and Asia. This “Herculean” (the editors’ words) effort does give the book the semblance of an epic, engrossing, all-encompassing exposition of the key concerns, actors, and events relevant to the IDRC’s ICT4D community. The book reports on the work of an IDRC-created thematic grouping identified as “Information and Communications Technologies for Development” (ICT4D), an acronym which has since gained widespread appeal in the academic research community (Heeks, 2006)
Upper Limits from Counting Experiments with Multiple Pipelines
In counting experiments, one can set an upper limit on the rate of a Poisson
process based on a count of the number of events observed due to the process.
In some experiments, one makes several counts of the number of events, using
different instruments, different event detection algorithms, or observations
over multiple time intervals. We demonstrate how to generalize the classical
frequentist upper limit calculation to the case where multiple counts of events
are made over one or more time intervals using several (not necessarily
independent) procedures. We show how different choices of the rank ordering of
possible outcomes in the space of counts correspond to applying different
levels of significance to the various measurements. We propose an ordering that
is matched to the sensitivity of the different measurement procedures and show
that in typical cases it gives stronger upper limits than other choices. As an
example, we show how this method can be applied to searches for
gravitational-wave bursts, where multiple burst-detection algorithms analyse
the same data set, and demonstrate how a single combined upper limit can be set
on the gravitational-wave burst rate.Comment: 26 pages (CQG style), 8 figures. Added study of robustness of limits
Discrete--time ratchets, the Fokker--Planck equation and Parrondo's paradox
Parrondo's games manifest the apparent paradox where losing strategies can be
combined to win and have generated significant multidisciplinary interest in
the literature. Here we review two recent approaches, based on the
Fokker-Planck equation, that rigorously establish the connection between
Parrondo's games and a physical model known as the flashing Brownian ratchet.
This gives rise to a new set of Parrondo's games, of which the original games
are a special case. For the first time, we perform a complete analysis of the
new games via a discrete-time Markov chain (DTMC) analysis, producing winning
rate equations and an exploration of the parameter space where the paradoxical
behaviour occurs.Comment: 17 pages, 5 figure
Advantage of a quantum player over a classical one in 2x2 quantum games
We study a general symmetric, entangled, quantum game. When one
player has access only to classical strategies while the other can use the full
range of quantum strategies, there are ``miracle'' moves available to the
quantum player that can direct the result of the game towards the quantum
player's preferred result regardless of the classical player's strategy. The
advantage pertaining to the quantum player is dependent on the degree of
entanglement. Below a critical level, dependent on the payoffs in the game, the
miracle move is of no advantage.Comment: Revtex, 10 pages, 2 tables, 4 figures; v2 typo corrected in table 2,
cosmetic changes to tables and figures, comment added to section VI E; v3
title changed to published title; minor mathematical errors in published
version correcte
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