132 research outputs found

    Learning a Disentangled Embedding for Monocular 3D Shape Retrieval and Pose Estimation

    Full text link
    We propose a novel approach to jointly perform 3D shape retrieval and pose estimation from monocular images.In order to make the method robust to real-world image variations, e.g. complex textures and backgrounds, we learn an embedding space from 3D data that only includes the relevant information, namely the shape and pose. Our approach explicitly disentangles a shape vector and a pose vector, which alleviates both pose bias for 3D shape retrieval and categorical bias for pose estimation. We then train a CNN to map the images to this embedding space, and then retrieve the closest 3D shape from the database and estimate the 6D pose of the object. Our method achieves 10.3 median error for pose estimation and 0.592 top-1-accuracy for category agnostic 3D object retrieval on the Pascal3D+ dataset, outperforming the previous state-of-the-art methods on both tasks

    An Empirical Study of IPO Underpricing in China: The IPO Systems Evolution and Determinants with Quantile Regression

    Get PDF
    This paper interprets and analyses the phenomenon of IPO underpricing in China with considering four transitions in Chinese IPO regulation systems. Firstly, one-way ANOVA is applied using 3,343 Chinese IPOs from 1993 to 2018 to test the IPO system transitions’ influence on IPO underpricing level. The empirical result indicates that the transitions in IPO system have profound impacts on the improvement of IPO underpricing phenomenon in Chinese primary market. Secondly, OLS and quantile regressions are conducted to find out key factors can influence the magnitude of IPO underpricing using 2,142 IPOs between 2006 and 2018. According to the comprehensive regressions results, 5 variables including issuing price, issuing size, time interval, over-subscription ratio, and agency cost ratio are significant determinants of IPO underpricing. However, both initial turnover rate and underwriter reputation do not show significant effect on the magnitude of underpricing. Most of these findings are consistent with information asymmetry theory and Chinese capital market characteristics

    The effect of sad mood on early sensory event-related potentials to task-irrelevant faces

    Get PDF
    It has been shown that the perceiver's mood affects the perception of emotional faces, but it is not known how mood affects preattentive brain responses to emotional facial expressions. To examine the question, we experimentally induced sad and neutral mood in healthy adults before presenting them with task-irrelevant pictures of faces while an electroencephalography was recorded. Sad, happy, and neutral faces were presented to the participants in an ignore oddball condition. Differential responses (emotional – neutral) for the P1, N170, and P2 amplitudes were extracted and compared between neutral and sad mood conditions. Emotional facial expressions modulated all the components, and an interaction effect of expression by mood was found for P1: an emotional modulation to happy faces, which was found in neutral mood condition, disappeared in sad mood condition. For N170 and P2, we found larger response amplitudes for both emotional faces, regardless of the mood. The results add to the previous behavioral findings showing that mood already affects low-level cortical feature encoding of task-irrelevant faces.publishedVersionPeer reviewe

    Microglial refinement of A-fibre projections in the postnatal spinal cord dorsal horn is required for normal maturation of dynamic touch

    Get PDF
    Sensory systems are shaped in postnatal life by the refinement of synaptic connections. In the dorsal horn of the spinal cord, sensory circuits undergo postnatal activity dependent reorganisation, including the retraction of primary afferent A-fibres from superficial to deeper laminae which is accompanied by decreases in cutaneous sensitivity. Here we show that microglia, the resident immune cells in the CNS, phagocytose A-fibre terminals in superficial laminae in the first weeks of life. Genetic perturbation of microglial engulfment at that time prevents the normal process of A-fibre retraction, resulting in increased sensitivity of dorsal horn cells to dynamic tactile cutaneous stimulation, and behavioural hypersensitivity to dynamic touch. Thus, functional microglia are necessary for normal postnatal development of dorsal horn sensory circuits. In the absence of microglial engulfment, superfluous A-fibre projections remain in the dorsal horn and the balance of sensory connectivity is disrupted, leading to lifelong hypersensitivity to dynamic touch

    Pose guided person image generation

    Get PDF
    This paper proposes the novel Pose Guided Person Generation Network (PG2^2) that allows to synthesize person images in arbitrary poses, based on an image of that person and a novel pose. Our generation framework PG2^2 utilizes the pose information explicitly and consists of two key stages: pose integration and image refinement. In the first stage the condition image and the target pose are fed into a U-Net-like network to generate an initial but coarse image of the person with the target pose. The second stage then refines the initial and blurry result by training a U-Net-like generator in an adversarial way. Extensive experimental results on both 128×\times64 re-identification images and 256×\times256 fashion photos show that our model generates high-quality person images with convincing details.Comment: Xu Jia and Qianru Sun contribute equally. Accepted in Proceedings of 31st Conference on Neural Information Processing Systems (NIPS 2017

    Quantifying the impact of grain for green program on ecosystem service management: a case study of Exibei region, China

    Get PDF
    Evaluating the impact of an ecological restoration program on ecosystem services is crucial, given the role of such a program in boosting sustainable ecosystem management. This study examines the impact of one of the large-scale ecological restoration programs in China, the Grain for Green Program (GGP), on ecosystem service management in the Exibei region of China. This region is studied, as it is a key source water area with rich biodiversity and has been experiencing GGP for 20 years. To achieve the stated goal the changes of land use and ecosystem services value (ESV) and the ecosystem services scarcity value (ESSV) in the Exibei region were quantified and assessed based on remote sensing images from 1990, 1995, 2000, 2005, 2010, 2015 and field survey data. The results indicated that the expansion of construction land and the increase of water body were the dominant land use changes throughout the study period. Farmland, forestland and grassland decreased by 2.61%, 0.47% and 1.41% after the GGP, respectively. The ESV of the entire Exibei region increased slightly in response to land use change during 1990-2015, with an annual loss of 0.08% before the implementation of GGP and an annual growth of 0.03% after the implementation of GGP. Moreover, forestland was the dominant contributor to ESSV after the implementation of the GGP. Its annual growth rate was four times higher than before the commencement of GGP. The results of this study contribute to the protection of the Exibei region ecosystem, and more importantly, the future management of the ecosystem service in the hilly regions of southern China
    corecore