Invariant Teacher and Equivariant Student for Unsupervised 3D Human Pose Estimation

We propose a novel method based on teacher-student learning framework for 3D human pose estimation without any 3D annotation or side information. To solve this unsupervised-learning problem, the teacher network adopts pose-dictionary-based modeling for regularization to estimate a physically plausible 3D pose. To handle the decomposition ambiguity in the teacher network, we propose a cycle-consistent architecture promoting a 3D rotation-invariant property to train the teacher network. To further improve the estimation accuracy, the student network adopts a novel graph convolution network for flexibility to directly estimate the 3D coordinates. Another cycle-consistent architecture promoting 3D rotation-equivariant property is adopted to exploit geometry consistency, together with knowledge distillation from the teacher network to improve the pose estimation performance. We conduct extensive experiments on Human3.6M and MPI-INF-3DHP. Our method reduces the 3D joint prediction error by 11.4% compared to state-of-the-art unsupervised methods and also outperforms many weakly-supervised methods that use side information on Human3.6M. Code will be available at https://github.com/sjtuxcx/ITES.Comment: Accepted in AAAI 202

Market Interdependence In The Pacific Basin Region: Internal Drives And External Influences

This paper examines equity market linkages in the Pacific Basin (PB) region and their relations to other mature markets and also assesses the response of these markets to major global events. Results from weekly data for market pairs and for the region as a whole consistently suggest that markets in the PB region are internally interdependent and exhibit significant external relations mainly with the US (rather than Japan). The presence of potent market linkages seems inconsistent with market efficiency provided that implied trading rules yield risk-adjusted excess returns. However, the results further indicate that PB market linkages, both internally within the region and externally with the US, have endured considerable weaknesses particularly since the September 11, 2001 terrorist attack. Such recent weakening of equity market linkages may have strengthened diversification benefits available to US investors from investing in the PB region. We also obtain evidence indicating that three main factors significantly explain the differing degrees of market linkages across countries in the PB region; namely, exchange-rate volatility, equity market volatility and money-market interlink

SNR-based adaptive acquisition method for fast Fourier ptychographic microscopy

Fourier ptychographic microscopy (FPM) is a computational imaging technique with both high resolution and large field-of-view. However, the effective numerical aperture (NA) achievable with a typical LED panel is ambiguous and usually relies on the repeated tests of different illumination NAs. The imaging quality of each raw image usually depends on the visual assessments, which is subjective and inaccurate especially for those dark field images. Moreover, the acquisition process is really time-consuming.In this paper, we propose a SNR-based adaptive acquisition method for quantitative evaluation and adaptive collection of each raw image according to the signal-to-noise ration (SNR) value, to improve the FPM's acquisition efficiency and automatically obtain the maximum achievable NA, reducing the time of collection, storage and subsequent calculation. The widely used EPRY-FPM algorithm is applied without adding any algorithm complexity and computational burden. The performance has been demonstrated in both USAF targets and biological samples with different imaging sensors respectively, which have either Poisson or Gaussian noises model. Further combined with the sparse LEDs strategy, the number of collection images can be shorten to around 25 frames while the former needs 361 images, the reduction ratio can reach over 90%. This method will make FPM more practical and automatic, and can also be used in different configurations of FPM.Comment: 11 pages, 6 figure