59,990 research outputs found
Ground State Solutions of Kirchhoff-type Fractional Dirichlet Problem with -Laplacian
We consider the Kirchhoff-type -Laplacian Dirichlet problem containing the
left and right fractional derivative operators. By using the Nehari method in
critical point theory, we obtain the existence theorem of ground state
solutions for such Dirichlet problem.Comment: 13 pages. arXiv admin note: text overlap with arXiv:1607.0158
Infinitely Many Weak Solutions for Fractional Dirichlet Problem with -Laplacian
We focus on the study of -Laplacian Dirichlet problem containing the left
and right fractional derivative operators. By using the genus properties in
critical point theory, we establish some new criteria to guarantee the
existence of infinitely many weak solutions for the considered problem.Comment: 14 page
Existence and Multiplicity of Nontrivial Weak Solutions for Kirchhoff-type Fractional -Laplacian Equation
We discuss the Kirchhoff-type -Laplacian Dirichlet problem containing the
left and right fractional derivative operators. By using the mountain pass
theorem and the genus properties in critical point theory, we get some new
results on the existence and multiplicity of nontrivial weak solutions for such
Dirichlet problem.Comment: 18 pages. arXiv admin note: text overlap with arXiv:1605.0923
Sensitivity of parameter estimation near the exceptional point of a non-Hermitian system
The exceptional points of non-Hermitian systems, where different energy
eigenstates merge into an identical one, have many intriguing properties that
have no counterparts in Hermitian systems. In particular, the
dependence of the energy level splitting on a perturbative parameter
near an -th order exceptional point stimulates the idea of metrology with
arbitrarily high sensitivity, since the susceptibility
diverges at the exceptional point. Here we
theoretically study the sensitivity of parameter estimation near the
exceptional points, using the exact formalism of quantum Fisher information.
The quantum Fisher information formalism allows the highest sensitivity to be
determined without specifying a specific measurement approach. We find that the
exceptional point bears no dramatic enhancement of the sensitivity. Instead,
the coalescence of the eigenstates exactly counteracts the eigenvalue
susceptibility divergence and makes the sensitivity a smooth function of the
perturbative parameter.Comment: 25 pages, 4 figure
Optimal Control of DERs in ADN under Spatial and Temporal Correlated Uncertainties
The control schemes of distributed energy resources (DERs) in active
distribution networks (ADNs) are largely influenced by uncertainties. The
uncertainties of DERs are complicated, containing spatial and temporal
correlation, which makes it challenging to design proper control schemes,
especially when there exist temporal-correlated units such as energy units
(EUs). This paper provides an Ito process model to describe the characteristics
of stochastic resources and EUs in a unified way, which makes it easy to
evaluate the impacts of stochastic resources on temporal-correlated units.
Based the moment form of the Ito process model, a moment optimization (MO)
approach is provided to transform the stochastic control (SC) problem into an
optimization problem with respect to the first-order and second-order moments
of the system variables. The scale of MO is comparable to that of the
corresponding deterministic control problem, which means that the computational
efficiency of MO is much smaller than that of traditional approaches. Case
studies also show that the proposed approach outperforms existing approaches in
both the performance and computational efficiency, which means that the
proposed approach has attractive potential for use in large-scale applications.Comment: 9 pages, 5 figure
Trivariate monomial complete intersections and plane partitions
We consider the homogeneous components U_r of the map on R = k[x,y,z]/(x^A,
y^B, z^C) that multiplies by x + y + z. We prove a relationship between the
Smith normal forms of submatrices of an arbitrary Toeplitz matrix using Schur
polynomials, and use this to give a relationship between Smith normal form
entries of U_r. We also give a bijective proof of an identity proven by J. Li
and F. Zanello equating the determinant of the middle homogeneous component U_r
when (A, B, C) = (a + b, a + c, b + c) to the number of plane partitions in an
a by b by c box. Finally, we prove that, for certain vector subspaces of R,
similar identities hold relating determinants to symmetry classes of plane
partitions, in particular classes 3, 6, and 8.Comment: 21 pages, 15 figure
Learning to Navigate in Indoor Environments: from Memorizing to Reasoning
Autonomous navigation is an essential capability of smart mobility for mobile
robots. Traditional methods must have the environment map to plan a
collision-free path in workspace. Deep reinforcement learning (DRL) is a
promising technique to realize the autonomous navigation task without a map,
with which deep neural network can fit the mapping from observation to
reasonable action through explorations. It should not only memorize the trained
target, but more importantly, the planner can reason out the unseen goal. We
proposed a new motion planner based on deep reinforcement learning that can
arrive at new targets that have not been trained before in the indoor
environment with RGB image and odometry only. The model has a structure of
stacked Long Short-Term memory (LSTM). Finally, experiments were implemented in
both simulated and real environments. The source code is available:
https://github.com/marooncn/navbot
Quantification of the underlying mechanisms and relationship among cancer, metastasis and differentiation/development
Recurrence and metastasis have been regarded as two of the greatest obstacles
for curing cancer. Cancer stem cell (CSC) have been found. They contribute to
cancer development with the distinct feature of recurrence and resistance to
the popular treatments such as drugs and chemotherapy. In addition, recent
discoveries suggest that the epithelial mesenchymal transition (EMT) is an
essential process in normal embryogenesis and tissue repair, which is a
required step in cancer metastasis. Although there are many indications showing
the connections between metastasis and stem cell, researches often studied them
separately or at most bi-laterally, not in an integrated way. In this study, we
aim at exploring the global mechanisms and interrelationship among cancer,
development and metastasis which are currently poorly understood. To start, we
constructed a core gene regulatory network motif which contain specific genes
and microRNAs of CSC, EMT and cancer. We uncovered seven distinct states
emerged from the underlying landscape. They are identified as Normal,
Premalignant, Cancer, stem cell (SC), cancer stem cell (CSC), Lesion and
Hyperlasia state. Given the biological definition of each state, we also
discussed the metastasis ability of each state. We show how and which types of
cells can be transformed to a cancer state and the connections among cancer,
CSC and EMT. The barrier height and flux of the kinetic paths are explored to
quantify how and which cells switch stochastically between the states. Our
landscape model provides a quantitative way which reveals the global mechanisms
of cancer, development and metastasis.Comment: 6 figures,9 page
Intrinsic ferromagnetism and quantum anomalous Hall effect in CoBr2 monolayer
The electronic, magnetic, and topological properties of CoBr2 monolayer are
studied in the frame-work of the density-functional theory (DFT) combined with
tight-binding (TB) modeling in terms of Wannier basis. Our DFT investigation
and Monte Carlo simulation show that there exists intrinsic two-dimensional
ferromagnetism in the CoBr2 monolayer thanks to large out-of-plane
magnetocrystalline anisotropic energy. Our further study shows that the
spin-orbits coupling makes it become a topologically nontrivial insulator with
quantum anomalous Hall effect and topological Chern number C=4, and its edge
states can be manipulated by changing the width of its nanoribbons and applying
strains. The CoBr2 monolayer can be exfoliated from the layered CoBr2 bulk
material because its exfoliation energy is between those of graphene and MoS2
monolayer and it is dynamically stable. These results make us believe that the
CoBr2 monolayer can make a promising spintronic material for future
high-performance devices
A physical mechanism of heterogeneity in stem cell, cancer and cancer stem cell
Heterogeneity is ubiquitous in stem cells (SC), cancer cells (CS), and cancer
stem cells (CSC). SC and CSC heterogeneity is manifested as diverse
sub-populations with self-renewing and unique regeneration capacity. Moreover,
the CSC progeny possesses multiple plasticity and cancerous characteristics.
Many studies have demonstrated that cancer heterogeneity is one of the greatest
obstacle for therapy. This leads to the incomplete anti-cancer therapies and
transitory efficacy. Furthermore, numerous micro-metastasis leads to the wide
spread of the tumor cells across the body which is the beginning of metastasis.
The epigenetic processes (DNA methylation or histone remodification etc.) can
provide a source for certain heterogeneity. In this study, we develop a
mathematical model to quantify the heterogeneity of SC, CSC and cancer taking
both genetic and epigenetic effects into consideration. We uncovered the roles
and physical mechanisms of heterogeneity from the three aspects (SC, CSC and
cancer). In the adiabatic regime (relatively fast regulatory binding and
effective coupling among genes), seven native states (SC, CSC, Cancer,
Premalignant, Normal, Lesion and Hyperplasia) emerge. In non-adiabatic regime
(relatively slow regulatory binding and effective weak coupling among genes),
multiple meta-stable SC, CS, CSC and differentiated states emerged which can
explain the origin of heterogeneity. In other words, the slow regulatory
binding mimicking the epigenetics can give rise to heterogeneity. Elucidating
the origin of heterogeneity and dynamical interrelationship between
intra-tumoral cells has clear clinical significance in helping to understand
the cellular basis of treatment response, therapeutic resistance, and tumor
relapse.Comment: 7 pages, 2 figure
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