11,132 research outputs found
Single machine slack due-window assignment and scheduling of linear time-dependent deteriorating jobs and a deteriorating maintenance activity
In this paper, we consider the slack due-window assignment model and study a
single machine scheduling problem of linear time-dependent deteriorating jobs
and a deteriorating maintenance activity. The cost for each job consists of
four components: earliness, tardiness, window location and window size. The
objective is to schedule the jobs and to assign the maintenance activity and
due-windows such that the total cost among all the jobs is minimized. A
polynomial-time algorithm with the running time not exceeding to
give a solution to this problem is introduced, where is the number of jobs.Comment: Submitted - Under Revie
Long-wavelength fluctuations and static correlations in quasi-2D colloidal suspensions
Dimensionality strongly affects thermal fluctuations and critical dynamics of
equilibrium systems. These influences persist in amorphous systems going
through the nonequilibrium glass transition. Here, we experimentally study the
glass transition of quasi-2D suspensions of spherical and ellipsoidal particles
under different degrees of circular confinement. We show that the strength of
the long-wavelength fluctuations increases logarithmically with system sizes
and displays the signature of the Mermin-Wagner fluctuations. Moreover, using
confinement as a tool, we also measure static structural correlations and
extract a growing static correlation length in 2D supercooled liquids. Finally,
we explore the influence of the Mermin-Wagner fluctuations on the translational
and orientational relaxations of 2D ellipsoidal suspensions, which leads to a
new interpretation of the two-step glass transition and the orientational glass
phase of anisotropic particles. Our study reveals the importance of
long-wavelength fluctuations in 2D supercooled liquids and provides new
insights into the role of dimensionality in the glass transition.Comment: 11 pages, 12 figures, Soft Matter (accepted
Composite Behavioral Modeling for Identity Theft Detection in Online Social Networks
In this work, we aim at building a bridge from poor behavioral data to an
effective, quick-response, and robust behavior model for online identity theft
detection. We concentrate on this issue in online social networks (OSNs) where
users usually have composite behavioral records, consisting of
multi-dimensional low-quality data, e.g., offline check-ins and online user
generated content (UGC). As an insightful result, we find that there is a
complementary effect among different dimensions of records for modeling users'
behavioral patterns. To deeply exploit such a complementary effect, we propose
a joint model to capture both online and offline features of a user's composite
behavior. We evaluate the proposed joint model by comparing with some typical
models on two real-world datasets: Foursquare and Yelp. In the widely-used
setting of theft simulation (simulating thefts via behavioral replacement), the
experimental results show that our model outperforms the existing ones, with
the AUC values in Foursquare and in Yelp, respectively.
Particularly, the recall (True Positive Rate) can reach up to in
Foursquare and in Yelp with the corresponding disturbance rate (False
Positive Rate) below . It is worth mentioning that these performances can
be achieved by examining only one composite behavior (visiting a place and
posting a tip online simultaneously) per authentication, which guarantees the
low response latency of our method. This study would give the cybersecurity
community new insights into whether and how a real-time online identity
authentication can be improved via modeling users' composite behavioral
patterns
Maximally symmetric subspace decomposition of the Schwarzschild black hole
The well-known Schwarzschild black hole was first obtained as a stationary,
spherically symmetric solution of the Einstein's vacuum field equations. But
until thirty years later, efforts were made for the analytic extension from the
exterior area to the interior one . As a contrast to its
maximally extension in the Kruskal coordinates, we provide a comoving
coordinate system from the view of the observers freely falling into the black
hole in the radial direction. We find an interesting fact that the spatial part
in this coordinate system is maximally symmetric , i.e., along the world
lines of these observers, the Schwarzschild black hole can be decomposed into a
family of maximally symmetric subspaces.Comment: Plain LaTex2e File, 8 pages, 1 eps figur
Statistical properties of radiation fields in a compact space
We discuss radiation fields in a compact space of finite size instead of that
in a cavity for investigating the coupled atom-radiation field system.
Representations of group are used to give a formulation for
kinematics of the radiation fields. The explicit geometrical parameter
dependence of statistical properties of radiation fields is obtained. Results
show remarkable differences from that of the black-body radiation system in
free space.Comment: LaTeX2e plain file of 10 pages, 1 eps figur
, , and : molecules or compact pentaquarks?
In a chromomagnetic model, we analyse the properties of the newly observed
, , and states. We estimate the masses
of the and
pentaquark states by considering the isospin breaking effects. Their values are
determined by calculating mass distances from the and
thresholds, respectively. It is found that the isospin
breaking effects on the spectrum are small. From the uncertainty consideration
and the rearrangement decay properties in a simple model, we find that it is
possible to assign the , , and as
, , and pentaquark states, respectively. The
assignment in the molecule picture can be different, in particular for the
. The information from open-charm channels, e.g. , will play an important
role in distinguishing the inner structures of the states. Discussions
and predictions based on the calculations are also given.Comment: 15 pages, 2 figures, 8 tables. Version accepted by PR
Well-Supported versus Approximate Nash Equilibria: Query Complexity of Large Games
We study the randomized query complexity of approximate Nash equilibria (ANE)
in large games. We prove that, for some constant , any randomized
oracle algorithm that computes an -ANE in a binary-action, -player
game must make payoff queries. For the stronger solution
concept of well-supported Nash equilibria (WSNE), Babichenko previously gave an
exponential lower bound for the randomized query complexity of
-WSNE, for some constant ; the same lower bound was shown
to hold for -ANE, but only when .
Our result answers an open problem posed by Hart and Nisan and Babichenko and
is very close to the trivial upper bound of . Our proof relies on a
generic reduction from the problem of finding an -WSNE to the problem
of finding an -ANE, in large games with actions,
which might be of independent interest.Comment: 10 page
Multipartite entanglement, quantum coherence, and quantum criticality in triangular and Sierpi\'nski fractal lattices
We investigate the quantum phase transitions of the transverse-field quantum
Ising model on the triangular lattice and Sierpi\'nski fractal lattices by
employing multipartite entanglement and quantum coherence along with the
quantum renormalization group method. It is shown that the quantum
criticalities of these high-dimensional models closely relate to the behaviors
of the multipartite entanglement and quantum coherence. As the thermodynamic
limit is approached, the first derivatives of multipartite entanglement and
quantum coherence exhibit singular behaviors and the consistent finite-size
scaling behaviors for each lattice are also obtained from the first
derivatives. The multipartite entanglement and quantum coherence are
demonstrated to be good indicators for detecting the quantum phase transitions
in the triangular lattice and Sierpi\'nski fractal lattices. Furthermore, the
factors that determine the relations between the critical exponents and the
correlation length exponents for these models are diverse. For the triangular
lattice, the decisive factor is the spatial dimension, while for the
Sierpi\'nski fractal lattices, it is the Hausdorff dimension.Comment: 12 pages; 12 figure
SilentSense: Silent User Identification via Dynamics of Touch and Movement Behavioral Biometrics
With the increased popularity of smartphones, various security threats and
privacy leakages targeting them are discovered and investigated. In this work,
we present \ourprotocoltight, a framework to authenticate users silently and
transparently by exploiting dynamics mined from the user touch behavior
biometrics and the micro-movement of the device caused by user's screen-touch
actions. We build a "touch-based biometrics" model of the owner by extracting
some principle features, and then verify whether the current user is the owner
or guest/attacker. When using the smartphone, the unique operating dynamics of
the user is detected and learnt by collecting the sensor data and touch events
silently. When users are mobile, the micro-movement of mobile devices caused by
touch is suppressed by that due to the large scale user-movement which will
render the touch-based biometrics ineffective. To address this, we integrate a
movement-based biometrics for each user with previous touch-based biometrics.
We conduct extensive evaluations of our approaches on the Android smartphone,
we show that the user identification accuracy is over 99%
Entanglement concentration for concatenated Greenberger-Horne-Zeiglinger state with feasible linear optics
The concatenated Greenberger-Horne-Zeiglinger (C-GHZ) state which is a new
type of logic-qubit entanglement has attracted a lot of attentions recently. We
present a feasible entanglement concentration protocol (ECP) for logic-qubit
entanglement. This ECP is based on the linear optics, and it does not know the
initial coefficients of the less-entangled C-GHZ state. This protocol can be
extended to arbitrary C-GHZ state. This protocol may be useful in future
quantum information processing tasks.Comment: 18 pages, 4 figure
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