5,256 research outputs found
An introductory educational board game for use in early computer science education
Early computer science education should be necessary in high school curricula, but often it becomes inextricably linked to the act of programming instead of the study of the principles of computation. In order to divest computer science from programming a new teaching medium is needed, and early research into games as teaching tools shows some positive results when used properly. In order to find a better way to teach early computer science concepts I have designed and implemented a board game which illustrates and defines a few necessary computer science terms and mechanics. I had reasonable success in the classroom, with mixed results from two completely different groups of students. The game seems effective, but my methods of teaching and lesson plan surrounding the game weakened the gains I recorded. I plan on reworking the base rules and developing new expansions which would increase the playability of the game and simplify the methods for delivery of the computer science material covered during a game sessio
Modeling Internet-Scale Policies for Cleaning up Malware
An emerging consensus among policy makers is that interventions undertaken by
Internet Service Providers are the best way to counter the rising incidence of
malware. However, assessing the suitability of countermeasures at this scale is
hard. In this paper, we use an agent-based model, called ASIM, to investigate
the impact of policy interventions at the Autonomous System level of the
Internet. For instance, we find that coordinated intervention by the
0.2%-biggest ASes is more effective than uncoordinated efforts adopted by 30%
of all ASes. Furthermore, countermeasures that block malicious transit traffic
appear more effective than ones that block outgoing traffic. The model allows
us to quantify and compare positive externalities created by different
countermeasures. Our results give an initial indication of the types and levels
of intervention that are most cost-effective at large scale.Comment: 22 pages, 9 Figures, Presented at the Tenth Workshop on the Economics
of Information Security, Jun 201
Herding Vulnerable Cats: A Statistical Approach to Disentangle Joint Responsibility for Web Security in Shared Hosting
Hosting providers play a key role in fighting web compromise, but their
ability to prevent abuse is constrained by the security practices of their own
customers. {\em Shared} hosting, offers a unique perspective since customers
operate under restricted privileges and providers retain more control over
configurations. We present the first empirical analysis of the distribution of
web security features and software patching practices in shared hosting
providers, the influence of providers on these security practices, and their
impact on web compromise rates. We construct provider-level features on the
global market for shared hosting -- containing 1,259 providers -- by gathering
indicators from 442,684 domains. Exploratory factor analysis of 15 indicators
identifies four main latent factors that capture security efforts: content
security, webmaster security, web infrastructure security and web application
security. We confirm, via a fixed-effect regression model, that providers exert
significant influence over the latter two factors, which are both related to
the software stack in their hosting environment. Finally, by means of GLM
regression analysis of these factors on phishing and malware abuse, we show
that the four security and software patching factors explain between 10\% and
19\% of the variance in abuse at providers, after controlling for size. For
web-application security for instance, we found that when a provider moves from
the bottom 10\% to the best-performing 10\%, it would experience 4 times fewer
phishing incidents. We show that providers have influence over patch
levels--even higher in the stack, where CMSes can run as client-side
software--and that this influence is tied to a substantial reduction in abuse
levels
A search for rapidly pulsating hot subdwarf stars in the GALEX survey
NASA's Galaxy Evolution Explorer (GALEX) provided near- and far-UV
observations for approximately 77 percent of the sky over a ten-year period;
however, the data reduction pipeline initially only released single NUV and FUV
images to the community. The recently released Python module gPhoton changes
this, allowing calibrated time-series aperture photometry to be extracted
easily from the raw GALEX data set. Here we use gPhoton to generate light
curves for all hot subdwarf B (sdB) stars that were observed by GALEX, with the
intention of identifying short-period, p-mode pulsations. We find that the
spacecraft's short visit durations, uneven gaps between visits, and dither
pattern make the detection of hot subdwarf pulsations difficult. Nonetheless,
we detect UV variations in four previously known pulsating targets and report
their UV pulsation amplitudes and frequencies. Additionally, we find that
several other sdB targets not previously known to vary show promising signals
in their periodograms. Using optical follow-up photometry with the Skynet
Robotic Telescope Network, we confirm p-mode pulsations in one of these
targets, LAMOST J082517.99+113106.3, and report it as the most recent addition
to the sdBVr class of variable stars.Comment: 11 Pages, 8 Figures, Accepted for publication in the Astrophysical
Journa
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