57,002 research outputs found
Illinois Technograph v. 057, iss. 3 Dec. 1942
published or submitted for publicatio
Structure and Dynamics of Information Pathways in Online Media
Diffusion of information, spread of rumors and infectious diseases are all
instances of stochastic processes that occur over the edges of an underlying
network. Many times networks over which contagions spread are unobserved, and
such networks are often dynamic and change over time. In this paper, we
investigate the problem of inferring dynamic networks based on information
diffusion data. We assume there is an unobserved dynamic network that changes
over time, while we observe the results of a dynamic process spreading over the
edges of the network. The task then is to infer the edges and the dynamics of
the underlying network.
We develop an on-line algorithm that relies on stochastic convex optimization
to efficiently solve the dynamic network inference problem. We apply our
algorithm to information diffusion among 3.3 million mainstream media and blog
sites and experiment with more than 179 million different pieces of information
spreading over the network in a one year period. We study the evolution of
information pathways in the online media space and find interesting insights.
Information pathways for general recurrent topics are more stable across time
than for on-going news events. Clusters of news media sites and blogs often
emerge and vanish in matter of days for on-going news events. Major social
movements and events involving civil population, such as the Libyan's civil war
or Syria's uprise, lead to an increased amount of information pathways among
blogs as well as in the overall increase in the network centrality of blogs and
social media sites.Comment: To Appear at the 6th International Conference on Web Search and Data
Mining (WSDM '13
Detecting a signal in the noise : Monitoring the global spread of novel psychoactive substances using media and other open source information
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. Date of Acceptance: 16/02/2015To determine the feasibility and utility of using media reports and other open-source information collected by the Global Public Health Intelligence Network (GPHIN), an event-based surveillance system operated by the Public Health Agency of Canada, to rapidly detect clusters of adverse drug events associated with ânovel psychoactive substancesâ (NPS) at the international levelPeer reviewedFinal Published versio
Imaging black holes: past, present and future
This paper briefly reviews past, current, and future efforts to image black
holes in the radio regime. Black holes seem like mystical objects, but they are
an integral part of current astrophysics and are at the center of attempts to
unify quantum physics and general relativity. Yet, nobody has ever seen a black
hole. What do they look like? Initially, this question seemed more of an
academic nature. However, this has changed over the past two decades.
Observations and theoretical considerations suggest that the supermassive black
hole, Sgr A*, in the center of our Milky Way is surrounded by a compact, foggy
emission region radiating at and above 230 GHz. It has been predicted that the
event horizon of Sgr A* should cast its shadow onto that emission region, which
could be detectable with a global VLBI array of radio telescopes. In contrast
to earlier pictures of black holes, that dark feature is not supposed to be due
to a hole in the accretion flow, but would represent a true negative image of
the event horizon. Currently, the global Event Horizon Telescope consortium is
attempting to make such an image. In the future those images could be improved
by adding more telescopes to the array, in particular at high sites in Africa.
Ultimately, a space array at THz frequencies, the Event Horizon Imager, could
produce much more detailed images of black holes. In combination with numerical
simulations and precise measurements of the orbits of stars - ideally also of
pulsars - these images will allow us to study black holes with unprecedented
precision.Comment: 10 pages, 3 figures, invited review,
http://iopscience.iop.org/article/10.1088/1742-6596/942/1/01200
Volume 2, Number 1 - May 1956
The Entropy (also published as the Providence College Journal of Physics and Chemistry) was an undergraduate scholarship journal published by the Phi Chi Club of Providence College. (Volume 2, Number 1 - May 1956 - 16 pages in total.
Journalists\u27 Views of the Environment: Issues and Challenges
In advocating the use of an environmental handbook for journalists, the authors report on a survey of reporters and editors regarding salient environmental issues in different regions of the United States and e emphasis placed on environmental reporting in newsrooms
From analogue to digital scholarship: implications for science communication researchers
Digital media have transformed the social practices of science communication. They have extended the number of channels that scientists, media professionals, other stakeholders and citizens use to communicate scientific information. Social media provide opportunities to communicate in more immediate and informal ways, while digital technologies have the potential to make the various processes of research more visible in the public sphere. Some digital media also offer, on occasion, opportunities for interaction and engagement. Similarly, ideas about public engagement are shifting and extending social practices, partially influencing governance strategies, and science communication policies and practices. In this paper I explore this developing context via a personal journey from an analogue to a digital scholar. In so doing, I discuss some of the demands that a globalised digital landscape introduces for science communication researchers and document some of the skills and competencies required to be a digital scholar of science communication
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