80 research outputs found
Efficient spin-current injection in single-molecule magnet junctions
We study theoretically spin transport through a single-molecule magnet (SMM)
in the sequential and cotunneling regimes, where the SMM is weakly coupled to
one ferromagnetic and one normalmetallic leads. By a master-equation approach,
it is found that the spin polarization injected from the ferromagnetic lead is
amplified and highly polarized spin-current can be generated, due to the
exchange coupling between the transport electron and the anisotropic spin of
the SMM. Moreover, the spin-current polarization can be tuned by the gate or
bias voltage, and thus an efficient spin injection device based on the SMM is
proposed in molecular spintronics.Comment: 4 figure
Holistic Inverse Rendering of Complex Facade via Aerial 3D Scanning
In this work, we use multi-view aerial images to reconstruct the geometry,
lighting, and material of facades using neural signed distance fields (SDFs).
Without the requirement of complex equipment, our method only takes simple RGB
images captured by a drone as inputs to enable physically based and
photorealistic novel-view rendering, relighting, and editing. However, a
real-world facade usually has complex appearances ranging from diffuse rocks
with subtle details to large-area glass windows with specular reflections,
making it hard to attend to everything. As a result, previous methods can
preserve the geometry details but fail to reconstruct smooth glass windows or
verse vise. In order to address this challenge, we introduce three spatial- and
semantic-adaptive optimization strategies, including a semantic regularization
approach based on zero-shot segmentation techniques to improve material
consistency, a frequency-aware geometry regularization to balance surface
smoothness and details in different surfaces, and a visibility probe-based
scheme to enable efficient modeling of the local lighting in large-scale
outdoor environments. In addition, we capture a real-world facade aerial 3D
scanning image set and corresponding point clouds for training and
benchmarking. The experiment demonstrates the superior quality of our method on
facade holistic inverse rendering, novel view synthesis, and scene editing
compared to state-of-the-art baselines
Depth Completion with Multiple Balanced Bases and Confidence for Dense Monocular SLAM
Dense SLAM based on monocular cameras does indeed have immense application
value in the field of AR/VR, especially when it is performed on a mobile
device. In this paper, we propose a novel method that integrates a light-weight
depth completion network into a sparse SLAM system using a multi-basis depth
representation, so that dense mapping can be performed online even on a mobile
phone. Specifically, we present a specifically optimized multi-basis depth
completion network, called BBC-Net, tailored to the characteristics of
traditional sparse SLAM systems. BBC-Net can predict multiple balanced bases
and a confidence map from a monocular image with sparse points generated by
off-the-shelf keypoint-based SLAM systems. The final depth is a linear
combination of predicted depth bases that can be optimized by tuning the
corresponding weights. To seamlessly incorporate the weights into traditional
SLAM optimization and ensure efficiency and robustness, we design a set of
depth weight factors, which makes our network a versatile plug-in module,
facilitating easy integration into various existing sparse SLAM systems and
significantly enhancing global depth consistency through bundle adjustment. To
verify the portability of our method, we integrate BBC-Net into two
representative SLAM systems. The experimental results on various datasets show
that the proposed method achieves better performance in monocular dense mapping
than the state-of-the-art methods. We provide an online demo running on a
mobile phone, which verifies the efficiency and mapping quality of the proposed
method in real-world scenarios
A robust tracking system for low frame rate video
Tracking in low frame rate (LFR) videos is one of the most important problems in the tracking literature. Most existing approaches treat LFR video tracking as an abrupt motion tracking problem. However, in LFR video tracking applications, LFR not only causes abrupt motions, but also large appearance changes of objects because the objects’ poses and the illumination may undergo large changes from one frame to the next. This adds extra difficulties to LFR video tracking. In this paper, we propose a robust and general tracking system for LFR videos. The tracking system consists of four major parts: dominant color-spatial based object representation, bin-ratio based similarity measure, annealed particle swarm optimization (PSO) based searching, and an integral image based parameter calculation. The first two parts are combined to provide a good solution to the appearance changes, and the abrupt motion is effectively captured by the annealed PSO based searching. Moreover, an integral image of model parameters is constructed, which provides a look-up table for parameters calculation. This greatly reduces the computational load. Experimental results demonstrate that the proposed tracking system can effectively tackle the difficulties caused by LFR
Understanding the Reactivity Difference of Isocyanate and Isothiocyanate toward a Ruthenium Silylene Hydride Complex
The detailed reaction mechanisms of the C=O hydrosilylation of isocyanate and the C=S bond cleavage of isothiocyanate mediated by the neutral ruthenium silylene hydride complex Cp{*}(CO)(H)Ru=Si(H){C(SiMe3)(3)} have been investigated with the aid of density functional theory calculations. Through the investigation, the difference in reactivity between isocyanate and isothiocyanate toward the ruthenium silylene hydride complex has been examined and discussed. The different bond strengths and if-accepting abilities of C=O and C=S and the different degrees of affinity of O and S toward the Si center in the silylene ligand contribute to the different reactivities of the isocyanate and isothiocyanate substrates observed experimentally
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