7,136 research outputs found
"If You Can't Beat them, Join them": A Usability Approach to Interdependent Privacy in Cloud Apps
Cloud storage services, like Dropbox and Google Drive, have growing
ecosystems of 3rd party apps that are designed to work with users' cloud files.
Such apps often request full access to users' files, including files shared
with collaborators. Hence, whenever a user grants access to a new vendor, she
is inflicting a privacy loss on herself and on her collaborators too. Based on
analyzing a real dataset of 183 Google Drive users and 131 third party apps, we
discover that collaborators inflict a privacy loss which is at least 39% higher
than what users themselves cause. We take a step toward minimizing this loss by
introducing the concept of History-based decisions. Simply put, users are
informed at decision time about the vendors which have been previously granted
access to their data. Thus, they can reduce their privacy loss by not
installing apps from new vendors whenever possible. Next, we realize this
concept by introducing a new privacy indicator, which can be integrated within
the cloud apps' authorization interface. Via a web experiment with 141
participants recruited from CrowdFlower, we show that our privacy indicator can
significantly increase the user's likelihood of choosing the app that minimizes
her privacy loss. Finally, we explore the network effect of History-based
decisions via a simulation on top of large collaboration networks. We
demonstrate that adopting such a decision-making process is capable of reducing
the growth of users' privacy loss by 70% in a Google Drive-based network and by
40% in an author collaboration network. This is despite the fact that we
neither assume that users cooperate nor that they exhibit altruistic behavior.
To our knowledge, our work is the first to provide quantifiable evidence of the
privacy risk that collaborators pose in cloud apps. We are also the first to
mitigate this problem via a usable privacy approach.Comment: Authors' extended version of the paper published at CODASPY 201
Wave mixing of optical pulses and Bose-Einstein condensates
We investigate theoretically the four-wave mixing of optical and matter waves
resulting from the scattering of a short light pulse off an atomic
Bose-Einstein condensate, as recently demonstrated by D. Schneble {\em et al.}
[ Science {\bf 300}, 475 (2003)]. We show that atomic ``pair production'' from
the condensate results in the generation of both forward- and
backward-propagating matter waves. These waves are characterized by different
phase-matching conditions, resulting in different angular distributions and
temporal evolutions.Comment: 4+\epsilon pages, 3 figure
The modern water-saving agricultural technology: Progress and focus
Based on the analysis of water-saving agricultural technology development status and trends in China, and in combination with the development and the needs of modern water-saving agricultural technology, we have put forward a future research emphasis and developing direction of modern watersaving agricultural technology, which include modern biological water-saving technology, unconventional high-efficient and safe-water using technology, water-saving irrigation technology and equipment, dry high-efficient water using technology and new materials regional high-efficient watersaving agriculture comprehensive technology.Key words: Biological water-saving technology, unconventional water resource, water-saving irrigation, dry-land water high-efficient agriculture, technical integration, biotechnology
Holographic recording of laser-induced plasma
We report on a holographic probing technique that allows for measurement of free-electron distribution with fine spatial detail. Plasma is generated by focusing a femtosecond pulse in air. We also demonstrate the capability of the holographic technique of capturing the time evolution of the plasma-generation process
Physical Model of the Immune Response of Bacteria Against Bacteriophage Through the Adaptive CRISPR-Cas Immune System
Bacteria and archaea have evolved an adaptive, heritable immune system that
recognizes and protects against viruses or plasmids. This system, known as the
CRISPR-Cas system, allows the host to recognize and incorporate short foreign
DNA or RNA sequences, called `spacers' into its CRISPR system. Spacers in the
CRISPR system provide a record of the history of bacteria and phage
coevolution. We use a physical model to study the dynamics of this coevolution
as it evolves stochastically over time. We focus on the impact of mutation and
recombination on bacteria and phage evolution and evasion. We discuss the
effect of different spacer deletion mechanisms on the coevolutionary dynamics.
We make predictions about bacteria and phage population growth, spacer
diversity within the CRISPR locus, and spacer protection against the phage
population.Comment: 37 pages, 13 figure
Aharonov-Casher phase and persistent current in a polyacetylene ring
We investigate a polyacetylene ring in an axially symmetric, static electric
field with a modified SSH Hamiltonian of a polyacetylene chain. An effective
gauge potential of the single electron Hamiltonian due to spin-field
interaction is obtained and it results in a Fr\"{o}hlich's type of
superconductivity equivalent to the effect of travelling lattice wave. The
total energy as well as the persistent current density are shown to be a
periodic function of the flux of the gauge field embraced by the polyacetylene
ring.Comment: 12 pages, 5 figure
Advantages of nonclassical pointer states in postselected weak measurements
We investigate, within the weak measurement theory, the advantages of
non-classical pointer states over semi-classical ones for coherent, squeezed
vacuum, and Schr\"{o}inger cat states. These states are utilized as pointer
state for the system operator with property ,
where represents the identity operator. We calculate the ratio
between the signal-to-noise ratio (SNR) of non-postselected and postselected
weak measurements. The latter is used to find the quantum Fisher information
for the above pointer states. The average shifts for those pointer states with
arbitrary interaction strength are investigated in detail. One key result is
that we find the postselected weak measurement scheme for non-classical pointer
states to be superior to semi-classical ones. This can improve the precision of
measurement process.Comment: 8 pages, 5 figure
Hartree-Fock-Bogoliubov Theory of Dipolar Fermi Gases
We construct a fully self-consistent Hartree-Fock-Bogoliubov theory that
describes a spinless Fermi gas with long-range interaction. We apply this
theory to a system of uniform dipolar fermionic polar molecules, which has
attracted much attention recently, due to rapid experimental progress in
achieving such systems. By calculating the anisotropic superfluid order
parameter, and the critical temperature , we show that, "hign "
superfluid can be achieved with a quite modest value of interaction strength
for polar molecules. In addition, we also show that the presence of the Fock
exchange interaction enhances superfluid pairing.Comment: 4.1 pages, 4 figure
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