182 research outputs found
Coloring vertices of a graph or finding a Meyniel obstruction
A Meyniel obstruction is an odd cycle with at least five vertices and at most
one chord. A graph is Meyniel if and only if it has no Meyniel obstruction as
an induced subgraph. Here we give a O(n^2) algorithm that, for any graph, finds
either a clique and coloring of the same size or a Meyniel obstruction. We also
give a O(n^3) algorithm that, for any graph, finds either aneasily recognizable
strong stable set or a Meyniel obstruction
The travelling preacher, projection, and a lower bound for the stability number of a graph
AbstractThe coflow min–max equality is given a travelling preacher interpretation, and is applied to give a lower bound on the maximum size of a set of vertices, no two of which are joined by an edge
Machine Learning-Based Side-Channel Analysis on the Advanced Encryption Standard
Hardware security is essential in keeping sensitive information private. Because of this, it’s imperative that we evaluate the ability of cryptosystems to withstand cutting edge attacks. Doing so encourages the development of countermeasures and new methods of data protection as needed. In this thesis, we present our findings of an evaluation of the Advanced Encryption Standard, particularly unmasked and masked AES-128, implemented in software on an STM32F415 microcontroller unit (MCU), against machine learning-based side-channel analysis (MLSCA). 12 machine learning classifiers were used in combination with a side-channel leakage model in the context of four scenarios: profiling one device and key and attacking the same device with the same key, profiling one device and key and attacking a different device with the same key, profiling one device and key and attacking the same device with a different key, and profiling one device and key and attacking a different device with a different key. We found that unmasked AES-128 can be very vulnerable to this form of attack and that masking can be applied as a countermeasure to successfully prevent attacks in 2 out of the 4 tested scenarios. In addition to providing our experimental results on the following pages, we also plan to release a public GitHub repository with all of our collected side-channel data along with sample analysis code shortly after the time of writing this. We hope that doing so will allow for complete reproducibility of our results and encourage future research without the need for purchasing hardware equipment
Modified Dark Matter: Relating Dark Energy, Dark Matter and Baryonic Matter
Modified dark matter (MDM) is a phenomenological model of dark matter,
inspired by gravitational thermodynamics. For an accelerating Universe with
positive cosmological constant (), such phenomenological
considerations lead to the emergence of a critical acceleration parameter
related to . Such a critical acceleration is an effective
phenomenological manifestation of MDM, and it is found in correlations between
dark matter and baryonic matter in galaxy rotation curves. The resulting MDM
mass profiles, which are sensitive to , are consistent with
observational data at both the galactic and cluster scales. In particular, the
same critical acceleration appears both in the galactic and cluster data fits
based on MDM. Furthermore, using some robust qualitative arguments, MDM appears
to work well on cosmological scales, even though quantitative studies are still
lacking. Finally, we comment on certain non-local aspects of the quanta of
modified dark matter, which may lead to novel non-particle phenomenology and
which may explain why, so far, dark matter detection experiments have failed to
detect dark matter particles
Privacy policies: Are they meeting users\u27 needs?
This paper examines the web site privacy policies of 200 web sites, 100 of the most popular as well as 100 random web sites. It examines the extent at which these privacy policies comprehensively define a company\u27s data collection and dissemination policies. Such policies are important in creating trust between a company and its customers
Testing Modified Dark Matter with Galaxy Clusters: Does Dark Matter know about the Cosmological Constant?
We discuss the possibility that the cold dark matter mass profiles contain
information on the cosmological constant, and that such information constrains
the nature of cold dark matter (CDM). We call this approach Modified Dark
Matter (MDM). In particular, we examine the ability of MDM to explain the
observed mass profiles of 13 galaxy clusters. Using general arguments from
gravitational thermodynamics, we provide a theoretical justification for our
MDM mass profile and successfully compare it to the NFW mass profiles both on
cluster and galactic scales. Our results suggest that indeed the CDM mass
profiles contain information about the cosmological constant in a non-trivial
way
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