329 research outputs found
Self-mapping degrees of 3-manifolds
For each closed oriented 3-manifold M in Thurston's picture, the set of degrees of self-maps on M is given.MathematicsSCI(E)2ARTICLE1247-2694
Semi-supervised Deep Multi-view Stereo
Significant progress has been witnessed in learning-based Multi-view Stereo
(MVS) under supervised and unsupervised settings. To combine their respective
merits in accuracy and completeness, meantime reducing the demand for expensive
labeled data, this paper explores the problem of learning-based MVS in a
semi-supervised setting that only a tiny part of the MVS data is attached with
dense depth ground truth. However, due to huge variation of scenarios and
flexible settings in views, it may break the basic assumption in classic
semi-supervised learning, that unlabeled data and labeled data share the same
label space and data distribution, named as semi-supervised distribution-gap
ambiguity in the MVS problem. To handle these issues, we propose a novel
semi-supervised distribution-augmented MVS framework, namely SDA-MVS. For the
simple case that the basic assumption works in MVS data, consistency
regularization encourages the model predictions to be consistent between
original sample and randomly augmented sample. For further troublesome case
that the basic assumption is conflicted in MVS data, we propose a novel style
consistency loss to alleviate the negative effect caused by the distribution
gap. The visual style of unlabeled sample is transferred to labeled sample to
shrink the gap, and the model prediction of generated sample is further
supervised with the label in original labeled sample. The experimental results
in semi-supervised settings of multiple MVS datasets show the superior
performance of the proposed method. With the same settings in backbone network,
our proposed SDA-MVS outperforms its fully-supervised and unsupervised
baselines.Comment: This paper is accepted in ACMMM-2023. The code is released at:
https://github.com/ToughStoneX/Semi-MV
Diffusion Probabilistic Model Based Accurate and High-Degree-of-Freedom Metasurface Inverse Design
Conventional meta-atom designs rely heavily on researchers' prior knowledge
and trial-and-error searches using full-wave simulations, resulting in
time-consuming and inefficient processes. Inverse design methods based on
optimization algorithms, such as evolutionary algorithms, and topological
optimizations, have been introduced to design metamaterials. However, none of
these algorithms are general enough to fulfill multi-objective tasks. Recently,
deep learning methods represented by Generative Adversarial Networks (GANs)
have been applied to inverse design of metamaterials, which can directly
generate high-degree-of-freedom meta-atoms based on S-parameter requirements.
However, the adversarial training process of GANs makes the network unstable
and results in high modeling costs. This paper proposes a novel metamaterial
inverse design method based on the diffusion probability theory. By learning
the Markov process that transforms the original structure into a Gaussian
distribution, the proposed method can gradually remove the noise starting from
the Gaussian distribution and generate new high-degree-of-freedom meta-atoms
that meet S-parameter conditions, which avoids the model instability introduced
by the adversarial training process of GANs and ensures more accurate and
high-quality generation results. Experiments have proven that our method is
superior to representative methods of GANs in terms of model convergence speed,
generation accuracy, and quality
A New Dynamic Path Planning Approach for Unmanned Aerial Vehicles
Dynamic path planning is one of the key procedures for unmanned aerial vehicles (UAV) to successfully fulfill the diversified missions. In this paper, we propose a new algorithm for path planning based on ant colony optimization (ACO) and artificial potential field. In the proposed algorithm, both dynamic threats and static obstacles are taken into account to generate an artificial field representing the environment for collision free path planning. To enhance the path searching efficiency, a coordinate transformation is applied to move the origin of the map to the starting point of the path and in line with the source-destination direction. Cost functions are established to represent the dynamically changing threats, and the cost value is considered as a scalar value of mobile threats which are vectors actually. In the process of searching for an optimal moving direction for UAV, the cost values of path, mobile threats, and total cost are optimized using ant optimization algorithm. The experimental results demonstrated the performance of the new proposed algorithm, which showed that a smoother planning path with the lowest cost for UAVs can be obtained through our algorithm.
(PDF) A New Dynamic Path Planning Approach for Unmanned Aerial Vehicles. Available from: https://www.researchgate.net/publication/328765418_A_New_Dynamic_Path_Planning_Approach_for_Unmanned_Aerial_Vehicles [accessed Nov 20 2018]
Genetic Relationships of Ethnic Minorities in Southwest China Revealed by Microsatellite Markers
Population migrations in Southwest and South China have played an important role in the formation of East Asian populations and led to a high degree of cultural diversity among ethnic minorities living in these areas. To explore the genetic relationships of these ethnic minorities, we systematically surveyed the variation of 10 autosomal STR markers of 1,538 individuals from 30 populations of 25 ethnic minorities, of which the majority were chosen from Southwest China, especially Yunnan Province. With genotyped data of the markers, we constructed phylogenies of these populations with both DA and DC measures and performed a principal component analysis, as well as a clustering analysis by structure. Results showed that we successfully recovered the genetic structure of analyzed populations formed by historical migrations. Aggregation patterns of these populations accord well with their linguistic affiliations, suggesting that deciphering of genetic relationships does in fact offer clues for study of ethnic differentiation
- …