186 research outputs found
Energy-Efficient Non-Orthogonal Transmission under Reliability and Finite Blocklength Constraints
This paper investigates an energy-efficient non-orthogonal transmission
design problem for two downlink receivers that have strict reliability and
finite blocklength (latency) constraints. The Shannon capacity formula widely
used in traditional designs needs the assumption of infinite blocklength and
thus is no longer appropriate. We adopt the newly finite blocklength coding
capacity formula for explicitly specifying the trade-off between reliability
and code blocklength. However, conventional successive interference
cancellation (SIC) may become infeasible due to heterogeneous blocklengths. We
thus consider several scenarios with different channel conditions and
with/without SIC. By carefully examining the problem structure, we present in
closed-form the optimal power and code blocklength for energy-efficient
transmissions. Simulation results provide interesting insights into conditions
for which non-orthogonal transmission is more energy efficient than the
orthogonal transmission such as TDMA.Comment: accepted by IEEE GlobeCom workshop on URLLC, 201
U.S.–China trade war and corporate reallocation:Evidence from Chinese listed companies
This paper applies a difference-in-differences framework to explore the economic consequences of the recent U.S.–China trade war. The average abnormal returns of Chinese listed firms during a period centered on President Trump's announcement on 22 March 2018 are taken as a proxy for the firms' exposure to the potential trade war. Firms more negatively exposed are found, surprisingly, to report higher total revenues in the post-announcement period. The results indicate that the Chinese firms tend to reallocate their business from overseas to the domestic market. Such within-firm reallocation is found to be more pronounced among private firms, exporting firms and non-FDI firms. Besides, firms with higher negative exposure increase total investment and financing but decrease foreign investment after the trade war
MLF-DET: Multi-Level Fusion for Cross-Modal 3D Object Detection
In this paper, we propose a novel and effective Multi-Level Fusion network,
named as MLF-DET, for high-performance cross-modal 3D object DETection, which
integrates both the feature-level fusion and decision-level fusion to fully
utilize the information in the image. For the feature-level fusion, we present
the Multi-scale Voxel Image fusion (MVI) module, which densely aligns
multi-scale voxel features with image features. For the decision-level fusion,
we propose the lightweight Feature-cued Confidence Rectification (FCR) module
which further exploits image semantics to rectify the confidence of detection
candidates. Besides, we design an effective data augmentation strategy termed
Occlusion-aware GT Sampling (OGS) to reserve more sampled objects in the
training scenes, so as to reduce overfitting. Extensive experiments on the
KITTI dataset demonstrate the effectiveness of our method. Notably, on the
extremely competitive KITTI car 3D object detection benchmark, our method
reaches 82.89% moderate AP and achieves state-of-the-art performance without
bells and whistles
Developing Dipole-scheme Heterojunction Photocatalysts
The high recombination rate of photogenerated carriers is the bottleneck of
photocatalysis, severely limiting the photocatalytic efficiency. Here, we
develop a dipole-scheme (D-scheme for short) photocatalytic model and materials
realization. The D-scheme heterojunction not only can effectively separate
electrons and holes by a large polarization field, but also boosts
photocatalytic redox reactions with large driving photovoltages and without any
carrier loss. By means of first-principles and GW calculations, we propose a
D-scheme heterojunction prototype with two real polar materials, PtSeTe/LiGaS2.
This D-scheme photocatalyst exhibits a high capability of the photogenerated
carrier separation and near-infrared light absorption. Moreover, our
calculations of the Gibbs free energy imply a high ability of the hydrogen and
oxygen evolution reaction by a large driving force. The proposed D-scheme
photocatalytic model is generalized and paves a valuable route of significantly
improving the photocatalytic efficiency.Comment: 10 pages, 5 figure
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