66 research outputs found
The Fake News Spreading Plague: Was it Preventable?
In 2010, a paper entitled "From Obscurity to Prominence in Minutes: Political
Speech and Real-time search" won the Best Paper Prize of the Web Science 2010
Conference. Among its findings were the discovery and documentation of what was
termed a "Twitter-bomb", an organized effort to spread misinformation about the
democratic candidate Martha Coakley through anonymous Twitter accounts. In this
paper, after summarizing the details of that event, we outline the recipe of
how social networks are used to spread misinformation. One of the most
important steps in such a recipe is the "infiltration" of a community of users
who are already engaged in conversations about a topic, to use them as organic
spreaders of misinformation in their extended subnetworks. Then, we take this
misinformation spreading recipe and indicate how it was successfully used to
spread fake news during the 2016 U.S. Presidential Election. The main
differences between the scenarios are the use of Facebook instead of Twitter,
and the respective motivations (in 2010: political influence; in 2016:
financial benefit through online advertising). After situating these events in
the broader context of exploiting the Web, we seize this opportunity to address
limitations of the reach of research findings and to start a conversation about
how communities of researchers can increase their impact on real-world societal
issues
Renal oncocytoma mimicking renal carcinoma
Renal Oncocytomas are rare benign renal masses. They can be easily mistaken for Renal Cell Cancers and patients usually undergo a radical nephrectomy. We present a case of a female patient who was admitted with a large mass originating from the right kidney. The results from the CT (stellate scar) and the angiography (spoke-wheel pattern) were consistent with Renal Oncocytoma, but still a radical nephrectomy was performed. This decision was made due to the inability of the current diagnostic procedures to safely differentiate Renal Oncocytomas from Renal Cell Cancer
Parallel Algorithms For Graph Problems
In this thesis we examine three problems in graph theory and propose efficient parallel algorithms for solving them. We also introduce a number of parallel algorithmic techniques
Investigating Rumor Propagation with TwitterTrails
Social media have become part of modern news reporting, used by journalists
to spread information and find sources, or as a news source by individuals. The
quest for prominence and recognition on social media sites like Twitter can
sometimes eclipse accuracy and lead to the spread of false information. As a
way to study and react to this trend, we introduce {\sc TwitterTrails}, an
interactive, web-based tool ({\tt twittertrails.com}) that allows users to
investigate the origin and propagation characteristics of a rumor and its
refutation, if any, on Twitter. Visualizations of burst activity, propagation
timeline, retweet and co-retweeted networks help its users trace the spread of
a story. Within minutes {\sc TwitterTrails} will collect relevant tweets and
automatically answer several important questions regarding a rumor: its
originator, burst characteristics, propagators and main actors according to the
audience. In addition, it will compute and report the rumor's level of
visibility and, as an example of the power of crowdsourcing, the audience's
skepticism towards it which correlates with the rumor's credibility. We
envision {\sc TwitterTrails} as valuable tool for individual use, but we
especially for amateur and professional journalists investigating recent and
breaking stories. Further, its expanding collection of investigated rumors can
be used to answer questions regarding the amount and success of misinformation
on Twitter.Comment: 10 pages, 8 figures, under revie
System and Method for Parallel Error Diffusion Dithering
A system is disclosed for error diffusion dithering. The system includes an input for receiving an input matrix representative of image data, and a plurality of processors. The plurality of processors processes the input matrix and provides output data. Each of the processors is in communication with at least a portion of the input matrix. At least one processor processes a portion of the input matrix defined at least in part by a substantially diagonal edge within the image matrix
Connected Components in O(lg3/2|V|) Parallel Time for the CREW PRAM
Computing the connected components of an undirected graph G = (V,E) on |V| = n vertices and |E| = m edges is a fundamental computational problem. The best known parallel algorithm for the CREW PRAM model runs on O(lg2n) time using n2/lg2n processors [CLC82,HCS79]. For the CRCW PRAM model in which concurrent writing is permitted, the best known algorithm runs in O(lg n) time using almost (n+m)/lg n processors [SV82,CV86,AS87]. Unfortunately, simulating this algorithm on the weaker CREW model increases its running time to O(lg2n) [CDR86, KR90,Vis83]. We present here an efficient and simple algorithm that runs in O(lg 3/2n) time using n+m CREW processors
Optimal Parallel and Sequential Algorithms for the Vertex Updating Problem of a Minimum Spanning Tree
We present a set of rules that can be used to give optimal solutions to the vertex updating problem for a minimum spanning tree: Update a given MST when a new vertex z is introducted, along with weighted edges that connect z with the vertices of the graph. These rules lead to simple parallel algorithms that run in O(lg n) parallel time using n/lg n EREW PRAMs. They can also be used to derive simple linear-time sequential algorithms for the same problem. Furthermore, we show how our solution can be used to solve the multiple vertex updating problem
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