97 research outputs found
Multi-Stage Reinforcement Learning for Non-Prehensile Manipulation
Manipulating objects without grasping them enables more complex tasks, known
as non-prehensile manipulation. Most previous methods only learn one
manipulation skill, such as reach or push, and cannot achieve flexible object
manipulation.In this work, we introduce MRLM, a Multi-stage Reinforcement
Learning approach for non-prehensile Manipulation of objects.MRLM divides the
task into multiple stages according to the switching of object poses and
contact points.At each stage, the policy takes the point cloud-based state-goal
fusion representation as input, and proposes a spatially-continuous action that
including the motion of the parallel gripper pose and opening width.To fully
unlock the potential of MRLM, we propose a set of technical contributions
including the state-goal fusion representation, spatially-reachable distance
metric, and automatic buffer compaction.We evaluate MRLM on an Occluded
Grasping task which aims to grasp the object in configurations that are
initially occluded.Compared with the baselines, the proposed technical
contributions improve the success rate by at least 40\% and maximum 100\%, and
avoids falling into local optimum.Our method demonstrates strong generalization
to unseen object with shapes outside the training distribution.Moreover, MRLM
can be transferred to real world with zero-shot transfer, achieving a 95\%
success rate.Code and videos can be found at
https://sites.google.com/view/mrlm
Ser 71 phosphorylation inhibits actin-binding of profilin-1 and its apoptosis-sensitizing activity
The essential actin-binding factor profilin-1 (Pfn1) is a non-classical tumor suppressor with the abilities toboth inhibit cellular proliferation and augment chemotherapy-induced apoptosis. Besides actin, Pfn1 interacts with proteins harboring the poly-L-proline (PLP) motifs. Our recent work demonstrated that both nuclear localization and PLP-binding are required for tumor growth inhibition by Pfn1, and this is at least partially due to Pfn1 association with the PLP-containing ENL protein in the Super Elongation Complex (SEC) and the transcriptional inhibition of pro-cancer genes. In this paper, by identifying a phosphorylation event of Pfn1 at Se
MSA-GCN:Multiscale Adaptive Graph Convolution Network for Gait Emotion Recognition
Gait emotion recognition plays a crucial role in the intelligent system. Most
of the existing methods recognize emotions by focusing on local actions over
time. However, they ignore that the effective distances of different emotions
in the time domain are different, and the local actions during walking are
quite similar. Thus, emotions should be represented by global states instead of
indirect local actions. To address these issues, a novel Multi Scale Adaptive
Graph Convolution Network (MSA-GCN) is presented in this work through
constructing dynamic temporal receptive fields and designing multiscale
information aggregation to recognize emotions. In our model, a adaptive
selective spatial-temporal graph convolution is designed to select the
convolution kernel dynamically to obtain the soft spatio-temporal features of
different emotions. Moreover, a Cross-Scale mapping Fusion Mechanism (CSFM) is
designed to construct an adaptive adjacency matrix to enhance information
interaction and reduce redundancy. Compared with previous state-of-the-art
methods, the proposed method achieves the best performance on two public
datasets, improving the mAP by 2\%. We also conduct extensive ablations studies
to show the effectiveness of different components in our methods
On-Policy Pixel-Level Grasping Across the Gap Between Simulation and Reality
Grasp detection in cluttered scenes is a very challenging task for robots.
Generating synthetic grasping data is a popular way to train and test grasp
methods, as is Dex-net and GraspNet; yet, these methods generate training
grasps on 3D synthetic object models, but evaluate at images or point clouds
with different distributions, which reduces performance on real scenes due to
sparse grasp labels and covariate shift. To solve existing problems, we propose
a novel on-policy grasp detection method, which can train and test on the same
distribution with dense pixel-level grasp labels generated on RGB-D images. A
Parallel-Depth Grasp Generation (PDG-Generation) method is proposed to generate
a parallel depth image through a new imaging model of projecting points in
parallel; then this method generates multiple candidate grasps for each pixel
and obtains robust grasps through flatness detection, force-closure metric and
collision detection. Then, a large comprehensive Pixel-Level Grasp Pose Dataset
(PLGP-Dataset) is constructed and released; distinguished with previous
datasets with off-policy data and sparse grasp samples, this dataset is the
first pixel-level grasp dataset, with the on-policy distribution where grasps
are generated based on depth images. Lastly, we build and test a series of
pixel-level grasp detection networks with a data augmentation process for
imbalance training, which learn grasp poses in a decoupled manner on the input
RGB-D images. Extensive experiments show that our on-policy grasp method can
largely overcome the gap between simulation and reality, and achieves the
state-of-the-art performance. Code and data are provided at
https://github.com/liuchunsense/PLGP-Dataset
Profilin-1 regulates DNA replication forks in a context-dependent fashion by interacting with SNF2H and BOD1L
DNA replication forks are tightly controlled by a large protein network consisting of well-known core regulators and many accessory factors which remain functionally undefined. In this study, we report previously unknown nuclear functions of the actin-binding factor profilin-1 (PFN1) in DNA replication, which occur in a context-dependent fashion and require its binding to poly-L-proline (PLP)-containing proteins instead of actin. In unperturbed cells, PFN1 increases DNA replication initiation and accelerates fork progression by binding and stimulating the PLP-containing nucleosome remodeler SNF2H. Under replication stress, PFN1/SNF2H increases fork stalling and functionally collaborates with fork reversal enzymes to enable the over-resection of unprotected forks. In addition, PFN1 binds and functionally attenuates the PLP-containing fork protector BODL1 to increase the resection of a subset of stressed forks. Accordingly, raising nuclear PFN1 level decreases genome stability and cell survival during replication stress. Thus, PFN1 is a multi-functional regulator of DNA replication with exploitable anticancer potential
Atomic-scale structure and nonlinear optical absorption of two-dimensional GeS
info:eu-repo/semantics/publishedVersio
Cancer-associated exportin-6 upregulation inhibits the transcriptionally repressive and anticancer effects of nuclear profilin-1
Aberrant expression of nuclear transporters and deregulated subcellular localization of their cargo proteins are emerging as drivers and therapeutic targets of cancer. Here, we present evidence that the nuclear exporter exportin-6 and its cargo profilin-1 constitute a functionally important and frequently deregulated axis in cancer. Exportin-6 upregulation occurs in numerous cancer types and is associated with poor patient survival. Reducing exportin-6 level in breast cancer cells triggers antitumor effects by accumulating nuclear profilin-1. Mechanistically, nuclear profilin-1 interacts with eleven-nineteen-leukemia protein (ENL) within the super elongation complex (SEC) and inhibits the ability of the SEC to drive transcription of numerous pro-cancer genes including MYC. XPO6 and MYC are positively correlated across diverse cancer types including breast cancer. Therapeutically, exportin-6 loss sensitizes breast cancer cells to the bromodomain and extra-terminal (BET) inhibitor JQ1. Thus, exportin-6 upregulation is a previously unrecognized cancer driver event by spatially inhibiting nuclear profilin-1 as a tumor suppressor
The comparison of aerodynamic and stability characteristics between conventional and blended wing body aircraft
Aircraft with advanced wing geometry, like the flying wing or blended wing body configuration, seems to be the seed candidate of future aircraft. Compared with conventional aircraft, there are significant aerodynamic performance improvements because of its highly integrated wing and fuselage configuration. On the other hand, due to its tailless configuration, the stability characteristics are not as good as conventional aircraft.
The research aims to compare the aerodynamic and stability characteristics of conventional, flying wing and blended wing body aircraft. Based on the same requirement—250 passenger capability and 7,500 nautical miles range, three different configurations—conventional, flying wing and blended wing body options were provided to make direct comparison.
The research contains four parts. In the first part, the aerodynamic characteristics were compared using empirical equation ESDU datasheet and Vortex-Lattice Method based AVL software. In the second part, combined with the aerodynamic data and output mass data from other team member, the stability characteristics were analysed. The stability comparison contains longitudinal, lateral-directional static stability and dynamic stability. In the third part, several geometry parameters were varied to investigate the influence on the aerodynamic and stability characteristics of blended wing body configuration. In the last part, a special case has been explored in an attempt to improve the static stability by changing geometry parameters. The process shows that the design of blended wing body is really complex since the closely coupling of several parameters
Multi-Scale and Occlusion Aware Network for Vehicle Detection and Segmentation on UAV Aerial Images
With the advantage of high maneuverability, Unmanned Aerial Vehicles (UAVs) have been widely deployed in vehicle monitoring and controlling. However, processing the images captured by UAV for the extracting vehicle information is hindered by some challenges including arbitrary orientations, huge scale variations and partial occlusion. In seeking to address these challenges, we propose a novel Multi-Scale and Occlusion Aware Network (MSOA-Net) for UAV based vehicle segmentation, which consists of two parts including a Multi-Scale Feature Adaptive Fusion Network (MSFAF-Net) and a Regional Attention based Triple Head Network (RATH-Net). In MSFAF-Net, a self-adaptive feature fusion module is proposed, which can adaptively aggregate hierarchical feature maps from multiple levels to help Feature Pyramid Network (FPN) deal with the scale change of vehicles. The RATH-Net with a self-attention mechanism is proposed to guide the location-sensitive sub-networks to enhance the vehicle of interest and suppress background noise caused by occlusions. In this study, we release a large comprehensive UAV based vehicle segmentation dataset (UVSD), which is the first public dataset for UAV based vehicle detection and segmentation. Experiments are conducted on the challenging UVSD dataset. Experimental results show that the proposed method is efficient in detecting and segmenting vehicles, and outperforms the compared state-of-the-art works
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