402 research outputs found
Sturm 3-ball global attractors 3: Examples of Thom-Smale complexes
Examples complete our trilogy on the geometric and combinatorial
characterization of global Sturm attractors which consist of a
single closed 3-ball. The underlying scalar PDE is parabolic, on the unit interval with Neumann boundary
conditions. Equilibria are assumed to be hyperbolic. Geometrically, we
study the resulting Thom-Smale dynamic complex with cells defined by the fast
unstable manifolds of the equilibria. The Thom-Smale complex turns out to be a
regular cell complex. In the first two papers we characterized 3-ball Sturm
attractors as 3-cell templates . The
characterization involves bipolar orientations and hemisphere decompositions
which are closely related to the geometry of the fast unstable manifolds. An
equivalent combinatorial description was given in terms of the Sturm
permutation, alias the meander properties of the shooting curve for the
equilibrium ODE boundary value problem. It involves the relative positioning of
extreme 2-dimensionally unstable equilibria at the Neumann boundaries and
, respectively, and the overlapping reach of polar serpents in the
shooting meander. In the present paper we apply these descriptions to
explicitly enumerate all 3-ball Sturm attractors with at most 13
equilibria. We also give complete lists of all possibilities to obtain solid
tetrahedra, cubes, and octahedra as 3-ball Sturm attractors with 15 and 27
equilibria, respectively. For the remaining Platonic 3-balls, icosahedra and
dodecahedra, we indicate a reduction to mere planar considerations as discussed
in our previous trilogy on planar Sturm attractors.Comment: 73+(ii) pages, 40 figures, 14 table; see also parts 1 and 2 under
arxiv:1611.02003 and arxiv:1704.0034
To Notify or Not to Notify?:Do Organizations Comply with U.S. Data Breach Notification Laws? An Empirical Study
Data Breach Notification Laws (DBNLs) oblige organizations to notify personal data breaches. In theory, DBNLs mitigate damage after a data breach and incentivize companies to invest in information security. The regulatory enforcement of the DBNL is based on deterrence, because penalties are imposed, varying from 750,000 between states. It is uncertain whether DBNLs are deterrent enough to prevent organizations from concealing data breaches, especially because organizations suffer reputational costs from a notification. This study empirically tests compliance, by relating the adoption and characteristics of different U.S. DBNLs to actual observed data breach notifications based on the privacy breach clearinghouse dataset (2005-2012). After the adoption of the law, a 50% increase of notifications is observed. But, the absolute number of notifications is low, merely 0.05% of the U.S. companies notified. This indicates low compliance, possibly caused by high costs of notifying and low costs of concealing a notification. Unexpectedly, higher sanctions did not have an effect, but limited commensurability of the different sanctioning regimes prohibits a permanent statement. This paper recommends enhancing DBNLs by increasing both the benefits of notifying and deterrence. Benefits are increased by incorporating rewards for good behavior by assisting companies in mitigating damage and continuously reward companies that are compliant by sharing knowledge about threats. Deterrence is increased by higher penalties and more stringent enforcement
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