19,274 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
Bit Flipping Moment Balancing Schemes for Insertion, Deletion and Substitution Error Correction
In this paper, two moment balancing schemes, namely a variable index scheme
and a fixed index scheme, for either single insertion/deletion error correction
or multiple substitution error correction are introduced for coded sequences
originally developed for correcting substitution errors only. By judiciously
flipping bits of the original substitution error correcting code word, the
resulting word is able to correct either a reduced number of substitution
errors or a single insertion/deletion error. The number of flips introduced by
the two schemes can be kept small compared to the code length. It shows a
practical value of applying the schemes to a long substitution error correcting
code for a severe channel where substitution errors dominate but
insertion/deletion errors can occur with a low probability. The new schemes can
be more easily implemented in an existing coding system than any previously
published moment balancing templates since no additional parity bits are
required which also means the code rate remains same and the existing
substitution error correcting decoder requires no changes. Moreover, the work
extends the class of Levenshtein codes capable of correcting either single
substitution or single insertion/deletion errors to codes capable of correcting
either multiple substitution errors or single insertion/deletion error
Long-Bone Fracture Detection using Artificial Neural Networks based on Line Features of X-ray Images
Two line-based fracture detection scheme are developed and discussed, namely
Standard line-based fracture detection and Adaptive Differential Parameter
Optimized (ADPO) line-based fracture detection. The purpose for the two
line-based fracture detection schemes is to detect fractured lines from X-ray
images using extracted features based on recognised patterns to differentiate
fractured lines from non-fractured lines. The difference between the two
schemes is the detection of detailed lines. The ADPO scheme optimizes the
parameters of the Probabilistic Hough Transform, such that granule lines within
the fractured regions are detected, whereas the Standard scheme is unable to
detect them. The lines are detected using the Probabilistic Hough Function, in
which the detected lines are a representation of the image edge objects. The
lines are given in the form of points, (x,y), which includes the starting and
ending point. Based on the given line points, 13 features are extracted from
each line, as a summary of line information. These features are used for
fracture and non-fracture classification of the detected lines. The
classification is carried out by the Artificial Neural Network (ANN). There are
two evaluations that are employed to evaluate both the entirety of the system
and the ANN. The Standard Scheme is capable of achieving an average accuracy of
74.25%, whilst the ADPO scheme achieved an average accuracy of 74.4%. The ADPO
scheme is opted for over the Standard scheme, however it can be further
improved with detected contours and its extracted features
On the global dynamics of the inhomogeneous Boltzmann equations without angular cutoff: Hard potentials and Maxwellian molecules
This is the first one of two papers on the global dynamics of the original
Boltzmann equations without angular cutoff on the torus. We address the problem
for the hard potentials and Maxwellian molecules in the present paper. The case
of soft potentials is left to a forthcoming paper. The key to solve the problem
is the energy-entropy method which characterizes the propagation of the
regularity, -theorem and the interplay between the energy and the entropy.
Our main results are as follows:
(i) We present a unified framework to prove the well-posedness for the
original Boltzmann equation for both angular cutoff and without cutoff in
weighted Sobolev spaces with polynomial weights. As a consequence, we obtain an
explicit formula for the asymptotics of the equation from angular cutoff to
non-cutoff.
(ii) We describe the global dynamics of the equation under the almost optimal
assumption on the solution which makes sure that the Boltzmann collision
operator behaves like a fractional Laplace operator for the velocity variable.
More precisely, we obtain the propagation of the regularity for the solution
and a new mechanism for the convergence of the solution to its equilibrium with
quantitative estimates.
(iii) We prove that any global and smooth solution to the equation is stable,
i.e., any perturbed solution will remain close to the reference solution if
initially they are close to each other
Relative Entropy, Mixed Gauge-Gravitational Anomaly and Causality
In this note we explored the holographic relative entropy in the presence of
the 5d Chern-Simons term, which introduces a mixed gauge-gravity anomaly to the
dual CFT. The theory trivially satisfies an entanglement first law. However, to
quadratic order in perturbations of the stress tensor and current density
, there is a mixed contribution to the relative entropy bi-linear in and
, signalling a potential violation of the positivity of the relative
entropy. Miraculously, the term vanishes up to linear order in a derivative
expansion. This prompted a closer inspection on a different consistency check,
that involves time-delay of a graviton propagating in a charged background,
scattered via a coupling supplied by the Chern-Simons term. The analysis
suggests that the time-delay can take either sign, potentially violating
causality for any finite value of the CS coupling.Comment: 21 pages, Details added, typos fixed, references updated; version to
appear in JHE
A Predation Behavior Model Based on Game Theory
This article adopts game theory to build a model for explaining the predation
behavior of animals.We assume that both the prey and the preydator have two
stratigies in this game,the active one and the passive one.By calculating the
outcome and the income of energy in different stratigies, we find the solution
to analyze the different evolution path of both the prey and the predator.A
simulation result approximately represents the correctness of our model.Comment: 5 pages,1 figure,1 tabl
Optimal Scheduling of Multiple Sensors over Lossy and Bandwidth Limited Channels
This work considers the sensor scheduling for multiple dynamic processes. We
consider linear dynamic processes, the state of each process is measured by
a sensor, which transmits their local state estimates over wireless channels to
a remote estimator with certain communication costs. In each time step, only a
portion of the sensors is allowed to transmit data to the remote estimator and
the packet might be lost due to unreliability of the wireless channels. Our
goal is to find a scheduling policy which coordinates the sensors in a
centralized manner to minimize the total expected estimation error of the
remote estimator and the communication costs. We formulate the problem as a
Markov decision process. We develop an algorithm to check whether there exists
a deterministic stationary optimal policy. We show the optimality of monotone
policies, which saves computational effort of finding an optimal policy and
facilitates practical implementation. Nevertheless, obtaining an exact optimal
policy still suffers from curse of dimensionality when the number of processes
are large. We further provide an index-based heuristics to avoid brute force
computation. Numerical examples are presented to illustrate our theoretical
results.Comment: Correct versio
Nonlinearity enhancement in optomechnical system
The nonlinearity is an important feature in the field of optomechanics.
Employing atomic coherence, we put forward a scheme to enhance the nonlinearity
of the cavity optomechanical system. The effective Hamiltonian is derived,
which shows that the nonlinear strength can be enhanced by increasing the
number of atoms at certain range of parameters. We also numerically study the
nonlinearity enhancement beyond the effective Hamiltonian. Furthermore, we
investigate the potential usage of the nonlinearity in performing quantum
nondemolition (QND) measurement of the bosonic modes. Our results show that the
present system exhibits synchronization, and the nonlinear effects provide us
an effective method in performing QND.Comment: 6 pages, 4figure
Radiation tolerance of opto-electronic components proposed for space-based quantum key distribution
Plasma in low earth orbit can damage electronic components and potentially
jeopardise the scientific missions in space. Predicting the accumulated damage
and understanding the components' radiation tolerance are important to mission
planning. In this manuscript we report on the observed radiation tolerance of
single photon detectors and a liquid crystal polarization rotator. We conclude
that an uncooled Si APD could continue to operate from more than a month up to
beyond the lifetime of the satellite depending on the orbit. The polarization
rotator was also unaffected by the exposed dosage.Comment: 4 pages, 2 figures, accepted by Journal of Modern Optic
Robust fermionic-mode entanglement of a nanoelectronic system in non-Markovian environments
A maximal steady-state fermionic entanglement of a nanoelectronic system is
generated in finite temperature non-Markovian environments. The fermionic
entanglement dynamics is presented by connecting the exact solution of the
system with an appropriate definition of fermionic entanglement. We prove that
the two understandings of the dissipationless non-Markovian dynamics, namely
the bound state and the modified Laplace transformation are completely
equivalent. For comparison, the steady-state entanglement is also studied in
the wide-band limit and Born-Markovian approximation. When the environments
have a finite band structure, we find that the system presents various kinds of
relaxation processes. The final states can be: thermal or thermal-like states,
quantum memory states and oscillating quantum memory states. Our study provide
an analytical way to explore the non-Markovian entanglement dynamics of
identical fermions in a realistic setting, i.e., finite temperature reservoirs
with a cutoff spectrum
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