990 research outputs found
How to Bootstrap Anonymous Communication
We ask whether it is possible to anonymously communicate a large amount of
data using only public (non-anonymous) communication together with a small
anonymous channel. We think this is a central question in the theory of
anonymous communication and to the best of our knowledge this is the first
formal study in this direction. To solve this problem, we introduce the concept
of anonymous steganography: think of a leaker Lea who wants to leak a large
document to Joe the journalist. Using anonymous steganography Lea can embed
this document in innocent looking communication on some popular website (such
as cat videos on YouTube or funny memes on 9GAG). Then Lea provides Joe with a
short key which, when applied to the entire website, recovers the document
while hiding the identity of Lea among the large number of users of the
website. Our contributions include:
- Introducing and formally defining anonymous steganography,
- A construction showing that anonymous steganography is possible (which uses
recent results in circuits obfuscation),
- A lower bound on the number of bits which are needed to bootstrap anonymous
communication.Comment: 15 page
Crowdsourcing and Scholarly Culture: Understanding Expertise in an Age of Popularism
The increasing volume of digital material available to the humanities creates clear potential for crowdsourcing. However, tasks in the digital humanities typically do not satisfy the standard requirement for decomposition into microtasks each of which must require little expertise on behalf of the worker and little context of the broader task. Instead, humanities tasks require scholarly knowledge to perform and even where sub-tasks can be extracted, these often involve broader context of the document or corpus from which they are extracted. That is the tasks are macrotasks, resisting simple decomposition. Building on a case study from musicology, the In Concert project, we will explore both the barriers to crowdsourcing in the creation of digital corpora and also examples where elements of automatic processing or less-expert work are possible in a broader matrix that also includes expert microtasks and macrotasks. Crucially we will see that the macrotask–microtask distinction is nuanced: it is often possible to create a partial decomposition into less-expert microtasks with residual expert macrotasks, and crucially do this in ways that preserve scholarly values
Characterizing Online Vandalism: A Rational Choice Perspective
What factors influence the decision to vandalize? Although the harm is clear,
the benefit to the vandal is less clear. In many cases, the thing being damaged
may itself be something the vandal uses or enjoys. Vandalism holds
communicative value: perhaps to the vandal themselves, to some audience at whom
the vandalism is aimed, and to the general public. Viewing vandals as rational
community participants despite their antinormative behavior offers the
possibility of engaging with or countering their choices in novel ways.
Rational choice theory (RCT) as applied in value expectancy theory (VET) offers
a strategy for characterizing behaviors in a framework of rational choices, and
begins with the supposition that subject to some weighting of personal
preferences and constraints, individuals maximize their own utility by
committing acts of vandalism. This study applies the framework of RCT and VET
to gain insight into vandals' preferences and constraints. Using a
mixed-methods analysis of Wikipedia, I combine social computing and
criminological perspectives on vandalism to propose an ontology of vandalism
for online content communities. I use this ontology to categorize 141 instances
of vandalism and find that the character of vandalistic acts varies by vandals'
relative identifiability, policy history with Wikipedia, and the effort
required to vandalize
Making Text Annotation Fun with a Clicker Game
In this paper we present WordClicker, a clicker game for text annotation. We believe the mechanics of 'Ville type Free-To-Play (F2P) games in general, and clicker games in particular, is particularly suited for GWAPs (Games-With-A-Purpose). WordClicker was developed as one component of a suite of GWAPs meant to cover all aspects of language interpretation, from tokenization to anaphoric interpretation. As such, WordClicker is intended to have a dual function as part of this suite of GWAPs: both for parts-of-speech annotation and for teaching players about parts of speech so that they can go on and play GWAPs for more complex syntactic annotation. Therefore, game-based language learning platforms also had a strong influence on its design
Phylo: A Citizen Science Approach for Improving Multiple Sequence Alignment
BACKGROUND: Comparative genomics, or the study of the relationships of genome structure and function across different species, offers a powerful tool for studying evolution, annotating genomes, and understanding the causes of various genetic disorders. However, aligning multiple sequences of DNA, an essential intermediate step for most types of analyses, is a difficult computational task. In parallel, citizen science, an approach that takes advantage of the fact that the human brain is exquisitely tuned to solving specific types of problems, is becoming increasingly popular. There, instances of hard computational problems are dispatched to a crowd of non-expert human game players and solutions are sent back to a central server. METHODOLOGY/PRINCIPAL FINDINGS: We introduce Phylo, a human-based computing framework applying "crowd sourcing" techniques to solve the Multiple Sequence Alignment (MSA) problem. The key idea of Phylo is to convert the MSA problem into a casual game that can be played by ordinary web users with a minimal prior knowledge of the biological context. We applied this strategy to improve the alignment of the promoters of disease-related genes from up to 44 vertebrate species. Since the launch in November 2010, we received more than 350,000 solutions submitted from more than 12,000 registered users. Our results show that solutions submitted contributed to improving the accuracy of up to 70% of the alignment blocks considered. CONCLUSIONS/SIGNIFICANCE: We demonstrate that, combined with classical algorithms, crowd computing techniques can be successfully used to help improving the accuracy of MSA. More importantly, we show that an NP-hard computational problem can be embedded in casual game that can be easily played by people without significant scientific training. This suggests that citizen science approaches can be used to exploit the billions of "human-brain peta-flops" of computation that are spent every day playing games. Phylo is available at: http://phylo.cs.mcgill.ca
Search for W' bosons decaying to an electron and a neutrino with the D0 detector
This Letter describes the search for a new heavy charged gauge boson W'
decaying into an electron and a neutrino. The data were collected with the D0
detector at the Fermilab Tevatron proton-antiproton Collider at a
center-of-mass energy of 1.96 TeV, and correspond to an integrated luminosity
of about 1 inverse femtobarn. Lacking any significant excess in the data in
comparison with known processes, an upper limit is set on the production cross
section times branching fraction, and a W' boson with mass below 1.00 TeV can
be excluded at the 95% C.L., assuming standard-model-like couplings to
fermions. This result significantly improves upon previous limits, and is the
most stringent to date.Comment: submitted to Phys. Rev. Let
A global experiment on motivating social distancing during the COVID-19 pandemic
Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e., a controlling message) compared with no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared with the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing. Controlled motivation was associated with more defiance and less long-term behavioral intention to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges
Astrophysical Origins of Ultrahigh Energy Cosmic Rays
In the first part of this review we discuss the basic observational features
at the end of the cosmic ray energy spectrum. We also present there the main
characteristics of each of the experiments involved in the detection of these
particles. We then briefly discuss the status of the chemical composition and
the distribution of arrival directions of cosmic rays. After that, we examine
the energy losses during propagation, introducing the Greisen-Zaptsepin-Kuzmin
(GZK) cutoff, and discuss the level of confidence with which each experiment
have detected particles beyond the GZK energy limit. In the second part of the
review, we discuss astrophysical environments able to accelerate particles up
to such high energies, including active galactic nuclei, large scale galactic
wind termination shocks, relativistic jets and hot-spots of Fanaroff-Riley
radiogalaxies, pulsars, magnetars, quasar remnants, starbursts, colliding
galaxies, and gamma ray burst fireballs. In the third part of the review we
provide a brief summary of scenarios which try to explain the super-GZK events
with the help of new physics beyond the standard model. In the last section, we
give an overview on neutrino telescopes and existing limits on the energy
spectrum and discuss some of the prospects for a new (multi-particle)
astronomy. Finally, we outline how extraterrestrial neutrino fluxes can be used
to probe new physics beyond the electroweak scale.Comment: Higher resolution version of Fig. 7 is available at
http://www.angelfire.com/id/dtorres/down3.html. Solicited review article
prepared for Reports on Progress in Physics, final versio
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