8,404 research outputs found
Invariance Matters: Exemplar Memory for Domain Adaptive Person Re-identification
This paper considers the domain adaptive person re-identification (re-ID)
problem: learning a re-ID model from a labeled source domain and an unlabeled
target domain. Conventional methods are mainly to reduce feature distribution
gap between the source and target domains. However, these studies largely
neglect the intra-domain variations in the target domain, which contain
critical factors influencing the testing performance on the target domain. In
this work, we comprehensively investigate into the intra-domain variations of
the target domain and propose to generalize the re-ID model w.r.t three types
of the underlying invariance, i.e., exemplar-invariance, camera-invariance and
neighborhood-invariance. To achieve this goal, an exemplar memory is introduced
to store features of the target domain and accommodate the three invariance
properties. The memory allows us to enforce the invariance constraints over
global training batch without significantly increasing computation cost.
Experiment demonstrates that the three invariance properties and the proposed
memory are indispensable towards an effective domain adaptation system. Results
on three re-ID domains show that our domain adaptation accuracy outperforms the
state of the art by a large margin. Code is available at:
https://github.com/zhunzhong07/ECNComment: To appear in CVPR 201
Bose metal in exactly solvable model with infinite-range Hatsugai-Kohmoto interaction
In a conventional boson system, the ground state can either be an insulator
or a superfluid (SF) due to the duality between particle number and phase. This
paper reveals that the long-sought Bose metal (BM) state can be realized in an
exactly solvable interacting bosonic model, i.e. the Bose-Hatsugai-Kohmoto
(BHK) model, which acts as the nontrivial extension of Bose-Hubbard (BH) model.
By tuning the parameters such as bandwidth , chemical potential , and
interaction strength , a BM state without any symmetry-breaking can be
accessed for a generic ratio, while a Mott insulator (MI) with integer
boson density is observed at small . The quantum phase transition between
the MI and BM states belongs to the universality class of the Lifshitz
transition, which is further confirmed by analyzing the momentum-distribution
function, the Drude weight, and the superfluid density. Additionally, our
investigation at finite temperature reveals similarities between the BM state
and the Fermi liquid, such as a linear- dependent heat capacity () and a saturated charge susceptibility ( constant) as
approaches zero. Comparing the BM state with the SF state in the standard
BH model, we find that the key feature of the BM state is a compressible total
wavefunction accompanied by an incompressible zero-momentum component. Given
that the BM state prevails over the SF state at any finite in the BHK
model, our work suggests the possibility of realizing the BM state with on-site
repulsion interactions in momentum space.Comment: 10 pages, 8 figure
Shubnikov-de Haas effect in the Falicov-Kimball model: strong correlation meets quantum oscillation
We present a comprehensive investigation of quantum oscillations (QOs) in the
strongly-correlated Falicov-Kimball model (FKM). The FKM is a particularly
suitable platform for probing the non-Fermi liquid state devoid of
quasiparticles, affording exact Monte Carlo simulation across all parameter
spaces. In the high-correlation regime, we report the presence of prominent QOs
in magnetoresistance and electron density at low temperatures within the phase
separation state. The frequency behavior of these oscillations uncovers a
transition in the Fermi surface as electron density diminishes, switching from
hole-like to electron-like. Both types of Fermi surfaces are found to conform
to the Onsager relation, establishing a connection between QOs frequency and
Fermi surface area. Upon exploring the temperature dependence of QOs amplitude,
we discern a strong alignment with the Lifshitz-Kosevich (LK) theory, provided
the effective mass is suitably renormalized. Notwithstanding, the substantial
enhancement of the overall effective mass results in a notable suppression of
the QOs amplitude within the examined temperature scope, a finding inconsistent
with Fermi liquid predictions. For the most part, the effective mass diminishes
as the temperature increases, but an unusual increase is observed at the
proximity of the second-order phase transition instigated by thermal effects.
As the transition ensues, the regular QOs disappear, replaced by irregular ones
in the non-Fermi liquid state under a high magnetic field. We also uncover
significant QOs in the insulating charge density wave state under weak
interactions (), a phenomenon we elucidate through analytical
calculations. Our findings shed light on the critical role of quasiparticles in
the manifestation of QOs, enabling further understanding of their function in
this context.Comment: 10 pages, 9 figure
Application of Random Matrix Theory to Biological Networks
We show that spectral fluctuation of interaction matrices of yeast a core
protein interaction network and a metabolic network follows the description of
the Gaussian orthogonal ensemble (GOE) of random matrix theory (RMT).
Furthermore, we demonstrate that while the global biological networks evaluated
belong to GOE, removal of interactions between constituents transitions the
networks to systems of isolated modules described by the Poisson statistics of
RMT. Our results indicate that although biological networks are very different
from other complex systems at the molecular level, they display the same
statistical properties at large scale. The transition point provides a new
objective approach for the identification of functional modules.Comment: 3 pages, 2 figure
Risk Identification And Analysis Of Precast Concrete Structure Based On Work Breakdown Structure-Risk Breakdown Structure
Because the prefabricated building started late in China, and subject to management and technical restrictions, the safety problems during the construction of the prefabricated building have not been solved effectively. In view of the problems of complex environments in precast concrete structure and many influencing factors which makes the construction risks are difficult to identify. The work breakdown structure (WBS) - risk breakdown structure (RBS) method is introduced to solve the problem. By means of analyzing the investigation data of the prefabricated building accidents, its risks during construction are identified and coupled. Then the judgment matrix is obtained and the corresponding risk factors can be established. In the meanwhile, the fault tree analysis method has been being used to analyze the sensitivity of three kinds of accidents, such as falling, striking by object and electrocution. The sensitive coefficients of risk factors are calculated and sorted. The result shows that the main risk factors of falling accident are verticality deviation of component installation, deviation of component position and unsecured mechanics. The main risk factors of striking by object/equipment are insufficient strength of components supporting, overturning components and unreasonable of suspension point. The main risk factors of electrocution are improper welding operation and short circuit. Finally, corresponding control measures are put forward according to the risk accidents. The research results provided a good theoretical basis for the risk identification of prefabricated building construction
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