3 research outputs found
Multiscale Latent-Guided Entropy Model for LiDAR Point Cloud Compression
The non-uniform distribution and extremely sparse nature of the LiDAR point
cloud (LPC) bring significant challenges to its high-efficient compression.
This paper proposes a novel end-to-end, fully-factorized deep framework that
encodes the original LPC into an octree structure and hierarchically decomposes
the octree entropy model in layers. The proposed framework utilizes a
hierarchical latent variable as side information to encapsulate the sibling and
ancestor dependence, which provides sufficient context information for the
modelling of point cloud distribution while enabling the parallel encoding and
decoding of octree nodes in the same layer. Besides, we propose a residual
coding framework for the compression of the latent variable, which explores the
spatial correlation of each layer by progressive downsampling, and model the
corresponding residual with a fully-factorized entropy model. Furthermore, we
propose soft addition and subtraction for residual coding to improve network
flexibility. The comprehensive experiment results on the LiDAR benchmark
SemanticKITTI and MPEG-specified dataset Ford demonstrates that our proposed
framework achieves state-of-the-art performance among all the previous LPC
frameworks. Besides, our end-to-end, fully-factorized framework is proved by
experiment to be high-parallelized and time-efficient and saves more than 99.8%
of decoding time compared to previous state-of-the-art methods on LPC
compression
D-DPCC: Deep Dynamic Point Cloud Compression via 3D Motion Prediction
The non-uniformly distributed nature of the 3D dynamic point cloud (DPC)
brings significant challenges to its high-efficient inter-frame compression.
This paper proposes a novel 3D sparse convolution-based Deep Dynamic Point
Cloud Compression (D-DPCC) network to compensate and compress the DPC geometry
with 3D motion estimation and motion compensation in the feature space. In the
proposed D-DPCC network, we design a {\it Multi-scale Motion Fusion} (MMF)
module to accurately estimate the 3D optical flow between the feature
representations of adjacent point cloud frames. Specifically, we utilize a 3D
sparse convolution-based encoder to obtain the latent representation for motion
estimation in the feature space and introduce the proposed MMF module for fused
3D motion embedding. Besides, for motion compensation, we propose a 3D {\it
Adaptively Weighted Interpolation} (3DAWI) algorithm with a penalty coefficient
to adaptively decrease the impact of distant neighbors. We compress the motion
embedding and the residual with a lossy autoencoder-based network. To our
knowledge, this paper is the first work proposing an end-to-end deep dynamic
point cloud compression framework. The experimental result shows that the
proposed D-DPCC framework achieves an average 76\% BD-Rate (Bjontegaard Delta
Rate) gains against state-of-the-art Video-based Point Cloud Compression
(V-PCC) v13 in inter mode
The New PI3K/mTOR Inhibitor GNE-477 Inhibits the Malignant Behavior of Human Glioblastoma Cells
The most common primary central nervous system tumor in adults is glioblastoma multiforme (GBM). The high invasiveness of GBM cells is an important factor leading to inevitable tumor recurrence and a poor prognosis of patients. GNE-477, a novel PI3K/mTOR inhibitor, has been reported to exert antiproliferative effects on other cancer cells. However, researchers have not clearly determined whether GNE-477 produces antitumor effects on GBM. In the present study, GNE-477 significantly inhibited the proliferation, migration and invasion of U87 and U251 cells. In addition, GNE-477 also induced apoptosis of GBM cells, arresting the cell cycle in G0/G1 phase. More importantly, GNE-477 also reduced the levels of AKT and mTOR phosphorylation in the AKT/mTOR signaling pathway in a concentration-dependent manner. An increase in AKT activity induced by SC79 rescued the GNE-477-mediated inhibition of GBM cell proliferation and apoptosis. The antitumor effects of GNE-477 and the regulatory effects on related molecules were further confirme