7,836 research outputs found
Deterministic Dense Coding and Faithful Teleportation with Multipartite Graph States
We proposed novel schemes to perform the deterministic dense coding and
faithful teleportation with multipartite graph states. We also find the
sufficient and necessary condition of a viable graph state for the proposed
scheme. That is, for the associated graph, the reduced adjacency matrix of the
Tanner-type subgraph between senders and receivers should be invertible.Comment: 10 pages, 1 figure;v2. discussions improve
Reconstructing Theory from Ricci Dark Energy
In this letter, we regard the theory as an effective description for
the acceleration of the universe and reconstruct the function from the
Ricci dark energy, which respects holographic principle of quantum gravity. By
using different parameter in RDE, we show the behaviors of
reconstructed and find they are much different in the future.Comment: 16 pages, 7 figure
Ricci Dark Energy in braneworld models with a Gauss-Bonnet term in the bulk
We investigate the Ricci Dark Energy (RDE) in the braneworld models with a
Gauss-Bonnet term in the Bulk. We solve the generalized Friedmann equation on
the brane analytically and find that the universe will finally enter into a
pure de Sitter spacetime in stead of the big rip that appears in the usual 4D
Ricci dark energy model with parameter . We also consider the
Hubble horizon as the IR cutoff in holographic dark energy model and find it
can not accelerate the universe as in the usual case without interacting.Comment: 7 pages, 2 figure
Corrigendum to “Advanced esthesioneuroblastoma with hyperostosis of the anterior skull base” [Formos J Surg 2015;48:181–184]
Federated Deep Reinforcement Learning for THz-Beam Search with Limited CSI
Terahertz (THz) communication with ultra-wide available spectrum is a
promising technique that can achieve the stringent requirement of high data
rate in the next-generation wireless networks, yet its severe propagation
attenuation significantly hinders its implementation in practice. Finding beam
directions for a large-scale antenna array to effectively overcome severe
propagation attenuation of THz signals is a pressing need. This paper proposes
a novel approach of federated deep reinforcement learning (FDRL) to swiftly
perform THz-beam search for multiple base stations (BSs) coordinated by an edge
server in a cellular network. All the BSs conduct deep deterministic policy
gradient (DDPG)-based DRL to obtain THz beamforming policy with limited channel
state information (CSI). They update their DDPG models with hidden information
in order to mitigate inter-cell interference. We demonstrate that the cell
network can achieve higher throughput as more THz CSI and hidden neurons of
DDPG are adopted. We also show that FDRL with partial model update is able to
nearly achieve the same performance of FDRL with full model update, which
indicates an effective means to reduce communication load between the edge
server and the BSs by partial model uploading. Moreover, the proposed FDRL
outperforms conventional non-learning-based and existing non-FDRL benchmark
optimization methods
An Evolutionary Method for Financial Forecasting in Microscopic High-Speed Trading Environment
The advancement of information technology in financial applications nowadays have led to fast market-driven events that prompt flash decision-making and actions issued by computer algorithms. As a result, today’s markets experience intense activity in the highly dynamic environment where trading systems respond to others at a much faster pace than before. This new breed of technology involves the implementation of high-speed trading strategies which generate significant portion of activity in the financial markets and present researchers with a wealth of information not available in traditional low-speed trading environments. In this study, we aim at developing feasible computational intelligence methodologies, particularly genetic algorithms (GA), to shed light on high-speed trading research using price data of stocks on the microscopic level. Our empirical results show that the proposed GA-based system is able to improve the accuracy of the prediction significantly for price movement, and we expect this GA-based methodology to advance the current state of research for high-speed trading and other relevant financial applications
On the Ricci dark energy model
We study the Ricci dark energy model (RDE) which was introduced as an
alternative to the holographic dark energy model. We point out that an
accelerating phase of the RDE is that of a constant dark energy model. This
implies that the RDE may not be a new model of explaining the present
accelerating universe.Comment: 8 page
3D LiDAR Aided GNSS NLOS Mitigation for Reliable GNSS-RTK Positioning in Urban Canyons
GNSS and LiDAR odometry are complementary as they provide absolute and
relative positioning, respectively. Their integration in a loosely-coupled
manner is straightforward but is challenged in urban canyons due to the GNSS
signal reflections. Recent proposed 3D LiDAR-aided (3DLA) GNSS methods employ
the point cloud map to identify the non-line-of-sight (NLOS) reception of GNSS
signals. This facilitates the GNSS receiver to obtain improved urban
positioning but not achieve a sub-meter level. GNSS real-time kinematics (RTK)
uses carrier phase measurements to obtain decimeter-level positioning. In urban
areas, the GNSS RTK is not only challenged by multipath and NLOS-affected
measurement but also suffers from signal blockage by the building. The latter
will impose a challenge in solving the ambiguity within the carrier phase
measurements. In the other words, the model observability of the ambiguity
resolution (AR) is greatly decreased. This paper proposes to generate virtual
satellite (VS) measurements using the selected LiDAR landmarks from the
accumulated 3D point cloud maps (PCM). These LiDAR-PCM-made VS measurements are
tightly-coupled with GNSS pseudorange and carrier phase measurements. Thus, the
VS measurements can provide complementary constraints, meaning providing
low-elevation-angle measurements in the across-street directions. The
implementation is done using factor graph optimization to solve an accurate
float solution of the ambiguity before it is fed into LAMBDA. The effectiveness
of the proposed method has been validated by the evaluation conducted on our
recently open-sourced challenging dataset, UrbanNav. The result shows the fix
rate of the proposed 3DLA GNSS RTK is about 30% while the conventional GNSS-RTK
only achieves about 14%. In addition, the proposed method achieves sub-meter
positioning accuracy in most of the data collected in challenging urban areas
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