36 research outputs found
Multimedia Fusion for Public Security in Heterogeneous Sensor Networks
Public security is a widespread disastrous phenomenon that constitutes a grave threat. Although information fusion of video sensor networks for public security has been studied extensively, multimedia fusion in heterogeneous sensor networks or its application in public security remains a challenge and central goal in the field of information fusion. In this study, to realize the detection, monitoring, and intelligent alarm of such hazards, we develop a graph-based real-time schema for studying the dynamic structure of heterogeneous sensors for public security. In the proposed schema, data fusion algorithms based on data-driven aspects of fusion are explored to locate the optimal sensing ranges of sensor nodes in a network with heterogeneous targets. In addition, we propose a framework incorporating useful contextual and temporal cues for public security alarm, explore its conceptualizations, benefits, and challenges, and analyze the correlations of the target motion elements in the multimedia sensor stream. The experimental results show that the new method offers a better way of intelligent alarm that cannot be achieved by existing schemes
Slave fermion interpretation of the pseudogap in doped Mott insulators
We apply the recently developed slave fermion approach to study the doped
Mott insulator in the one-band Hubbard and Hubbard-Heisenberg models. Our
results produce several subtle features in the electron spectra and confirm the
key role of antiferromagnetic (AFM) correlations in the appearance of the
pseudogap. Upon hole doping, the electron spectra exhibit a single peak near
the Fermi energy in the local approximation of the Hubbard model where AFM
correlations are not included. When AFM correlations are included through an
explicit mean-field Heisenberg interaction, a second peak emerges at slightly
lower energy and pushes the other peak to higher energy, so that a pseudogap
emerges between the two peaks at small doping. Both peaks grow rapidly with
increasing doping and eventually merge together, where the pseudogap no longer
exists. Detailed analyses of the spectral evolution with doping and the
strength of the Heisenberg interaction confirm that the lower-energy peak comes
from a polaronic mechanism due to the holon-spinon interaction in the
AFM-correlated background and the higher-energy peak arises from the holon
hybridization to form the electron quasiparticles. Thus, the pseudogap arises
from the interplay of the polaronic and hybridization mechanisms. Our results
are in good agreement with previous numerical calculations using the dynamical
mean-field theory and its cluster extensions, but give a clearer picture of the
underlying physics. Our work provides a promising perspective for clarifying
the nature of doped Mott insulators and may serve as a starting point for more
elaborate investigations in the future
A Simple Solvable Model for Heavy Fermion Superconductivity from the Two-Fluid Normal State
We propose an exactly solvable momentum-space Kondo-BCS model to study heavy
fermion superconductivity. The Kondo interaction is local in momentum space,
which can be derived from an Anderson lattice with a Hatsugai-Kohmoto
interaction between -electrons. By increasing the Kondo interaction, the
model exhibits a crossover from a weak-coupling BCS superconductor to a
strong-coupling heavy fermion superconductor featured with a large gap ratio
and a large specific heat jump anomaly. Accordingly, the normal state evolves
from a Fermi liquid above the BCS superconductor to a non-Fermi liquid
two-fluid state above the heavy fermion superconductor. The two-fluid normal
state also leads to two types of Cooper pairs, one between conduction
electrons, the other between composite fermions formed by conduction electrons
and -spins, which is responsible for the strong coupling behaviors of heavy
fermion superconductivity.Comment: 7 pages, 4 figure
Dynamic charge Kondo effect and a slave fermion approach to the Mott transition
Mott transition plays a key role in strongly correlated physics but its
nature is not yet fully understood. Motivated by recent development of
Schwinger boson approach for the Kondo lattice, we propose in this work a novel
slave fermion algorithm to study the Mott transition. Upon local approximation,
our method yields a phase diagram with a zero-temperature continuous (Mott)
metal-insulator transition at finite Coulomb interaction for the
half-filled one-band Hubbard model on a square lattice, and the resistivity
exhibits a critical scaling around the quantum Widom line. We argue that the
Mott transition may be associated with a dynamic charge Kondo effect of local
degenerate doublon and holon states, causing sharp resonances on the
doublon/holon and electron spectra. The transition is pushed to once
intersite antiferromagnetic correlations are included, in agreement with exact
numerical calculations. Our approach captures some essential features of the
Mott transition and offers an alternative angle to view this important problem.
It can be extended to study other correlated electron models with more
complicated local interactions.Comment: 9 pages, 4 figure
Pair density wave, unconventional superconductivity, and non-Fermi liquid quantum critical phase in frustrated Kondo lattice
Motivated by the recent discovery of an intermediate quantum critical phase
between the antiferromagnetic order and the Fermi liquid in the frustrated
Kondo lattice CePdAl, we study here a Kondo-Heisenberg chain with frustrated
- XXZ interactions among local spins using the density matrix
renormalization group method. Our simulations reveal a global phase diagram
with rich ground states including the antiferromagnetic order, the
valence-bond-solid and bond-order-wave orders, the pair density wave state, the
uniform superconducting state, and the Luttinger liquid state. We show that
both the pair density wave and uniform superconductivity belong to the family
of Luther-Emery liquids and may arise from pair instability of an intermediate
quantum critical phase with medium Fermi volume in the presence of strong
quantum fluctuations, while the Luttinger liquid has a large Fermi volume. This
suggests a deep connection between the pair density wave, the unconventional
superconductivity, and the non-Fermi liquid quantum critical phase.Comment: 10 pages, 9 figure
Intelligent Context-Aware and Adaptive Interface for Mobile LBS
Context-aware user interface plays an important role in many human-computer Interaction tasks of location based services. Although spatial models for context-aware systems have been studied extensively, how to locate specific spatial information for users is still not well resolved, which is important in the mobile environment where location based services users are impeded by device limitations. Better context-aware human-computer interaction models of mobile location based services are needed not just to predict performance outcomes, such as whether people will be able to find the information needed to complete a human-computer interaction task, but to understand human processes that interact in spatial query, which will in turn inform the detailed design of better user interfaces in mobile location based services. In this study, a context-aware adaptive model for mobile location based services interface is proposed, which contains three major sections: purpose, adjustment, and adaptation. Based on this model we try to describe the process of user operation and interface adaptation clearly through the dynamic interaction between users and the interface. Then we show how the model applies users’ demands in a complicated environment and suggested the feasibility by the experimental results
Improving Crowded Object Detection via Copy-Paste
Crowdedness caused by overlapping among similar objects is a ubiquitous
challenge in the field of 2D visual object detection. In this paper, we first
underline two main effects of the crowdedness issue: 1) IoU-confidence
correlation disturbances (ICD) and 2) confused de-duplication (CDD). Then we
explore a pathway of cracking these nuts from the perspective of data
augmentation. Primarily, a particular copy-paste scheme is proposed towards
making crowded scenes. Based on this operation, we first design a "consensus
learning" method to further resist the ICD problem and then find out the
pasting process naturally reveals a pseudo "depth" of object in the scene,
which can be potentially used for alleviating CDD dilemma. Both methods are
derived from magical using of the copy-pasting without extra cost for
hand-labeling. Experiments show that our approach can easily improve the
state-of-the-art detector in typical crowded detection task by more than 2%
without any bells and whistles. Moreover, this work can outperform existing
data augmentation strategies in crowded scenario.Comment: Accepted by AAAI202