3 research outputs found
Privacy Threats in E-Shopping (Position Paper)
The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-29883-2_14E-shopping has grown considerably in the last years, providing
customers with convenience, merchants with increased sales, and
financial entities with an additional source of income. However, it may
also be the source of serious threats to privacy. In this paper, we review
the e-shopping process, discussing attacks or threats that have been analyzed
in the literature for each of its stages. By showing that there exist
threats to privacy in each of them, we argue our following position: “It is
not enough to protect a single independent stage, as is usually done in
privacy respectful proposals in this context. Rather, a complete solution
is necessary spanning the overall process, dealing also with the required
interconnections between stages.” Our overview also reflects the diverse
types of information that e-shopping manages, and the benefits (e.g.,
such as loyalty programs and fraud prevention) that system providers
extract from them. This also endorses the need for solutions that, while
privacy preserving, do not limit or remove these benefits, if we want
prevent all the participating entities from rejecting it.This work was supported by project S2013/ICE-3095-CM (CIBERDINE) of the Comunidad de Madrid and MINECO TIN2010-19607, TIN2012-30883, TIN2014-54580-R. The work of Seung Geol Choi was supported in part by the Office of Naval Research under Grant Number N0001415WX01232. The work of Moti Yung was done in part while visiting the Simons Institute for Theory of Computing, UC Berkeley. The work of Jesus Diaz was done in part while visiting the Network Security Lab at Columbia University
Anisotropic drop spreading on superhydrophobic grates during drop impact
We study the influence of geometric anisotropy of micro-grate structures on the spreading dynamics of water drops after impact. It is found that the maximal spreading diameter along the parallel direction to grates becomes larger than that along the transverse direction beyond a certain Weber number, while the extent of such an asymmetric spreading increases with the structural pitch of grates and Weber number. By employing grates covered with nanostructures, we exclude the possible influences coming from the Cassie-to-Wenzel transition and the circumferential contact angle variation on the spreading diameter. Then, based on a simplified energy balance model incorporating slip length, we propose that slip length selectively enhances the spreading diameter along the parallel direction, being responsible for the asymmetric drop spreading. We believe that our work will help better understand the role of microstructures in controlling the drop dynamics during impact, which has relevance to various engineering applications
Fermi Level Pinning at Electrical Metal Contacts of Monolayer Molybdenum Dichalcogenides
Electrical
metal contacts to two-dimensional (2D) semiconducting
transition metal dichalcogenides (TMDCs) are found to be the key bottleneck
to the realization of high device performance due to strong Fermi
level pinning and high contact resistances (<i>R</i><sub>c</sub>). Until now, Fermi level pinning of monolayer TMDCs has been
reported only theoretically, although that of bulk TMDCs has been
reported experimentally. Here, we report the experimental study on
Fermi level pinning of monolayer MoS<sub>2</sub> and MoTe<sub>2</sub> by interpreting the thermionic emission results. We also quantitatively
compared our results with the theoretical simulation results of the
monolayer structure as well as the experimental results of the bulk
structure. We measured the pinning factor <i>S</i> to be
0.11 and −0.07 for monolayer MoS<sub>2</sub> and MoTe<sub>2</sub>, respectively, suggesting a much stronger Fermi level pinning effect,
a Schottky barrier height (SBH) lower than that by theoretical prediction,
and interestingly similar pinning energy levels between monolayer
and bulk MoS<sub>2</sub>. Our results further imply that metal work
functions have very little influence on contact properties of 2D-material-based
devices. Moreover, we found that <i>R</i><sub>c</sub> is
exponentially proportional to SBH, and these processing parameters
can be controlled sensitively upon chemical doping into the 2D materials.
These findings provide a practical guideline for depinning Fermi level
at the 2D interfaces so that polarity control of TMDC-based semiconductors
can be achieved efficiently