3,565 research outputs found
Gate-Tunable Tunneling Resistance in Graphene/Topological Insulator Vertical Junctions
Graphene-based vertical heterostructures, particularly stacks incorporated
with other layered materials, are promising for nanoelectronics. The stacking
of two model Dirac materials, graphene and topological insulator, can
considerably enlarge the family of van der Waals heterostructures. Despite well
understanding of the two individual materials, the electron transport
properties of a combined vertical heterojunction are still unknown. Here we
show the experimental realization of a vertical heterojunction between Bi2Se3
nanoplate and monolayer graphene. At low temperatures, the electron transport
through the vertical heterojunction is dominated by the tunneling process,
which can be effectively tuned by gate voltage to alter the density of states
near the Fermi surface. In the presence of a magnetic field, quantum
oscillations are observed due to the quantized Landau levels in both graphene
and the two-dimensional surface states of Bi2Se3. Furthermore, we observe an
exotic gate-tunable tunneling resistance under high magnetic field, which
displays resistance maxima when the underlying graphene becomes a quantum Hall
insulator
Privacy Preserving Utility Mining: A Survey
In big data era, the collected data usually contains rich information and
hidden knowledge. Utility-oriented pattern mining and analytics have shown a
powerful ability to explore these ubiquitous data, which may be collected from
various fields and applications, such as market basket analysis, retail,
click-stream analysis, medical analysis, and bioinformatics. However, analysis
of these data with sensitive private information raises privacy concerns. To
achieve better trade-off between utility maximizing and privacy preserving,
Privacy-Preserving Utility Mining (PPUM) has become a critical issue in recent
years. In this paper, we provide a comprehensive overview of PPUM. We first
present the background of utility mining, privacy-preserving data mining and
PPUM, then introduce the related preliminaries and problem formulation of PPUM,
as well as some key evaluation criteria for PPUM. In particular, we present and
discuss the current state-of-the-art PPUM algorithms, as well as their
advantages and deficiencies in detail. Finally, we highlight and discuss some
technical challenges and open directions for future research on PPUM.Comment: 2018 IEEE International Conference on Big Data, 10 page
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