37 research outputs found
Robust Component-based Network Localization with Noisy Range Measurements
Accurate and robust localization is crucial for wireless ad-hoc and sensor
networks. Among the localization techniques, component-based methods advance
themselves for conquering network sparseness and anchor sparseness. But
component-based methods are sensitive to ranging noises, which may cause a huge
accumulated error either in component realization or merging process. This
paper presents three results for robust component-based localization under
ranging noises. (1) For a rigid graph component, a novel method is proposed to
evaluate the graph's possible number of flip ambiguities under noises. In
particular, graph's \emph{MInimal sepaRators that are neaRly cOllineaR
(MIRROR)} is presented as the cause of flip ambiguity, and the number of
MIRRORs indicates the possible number of flip ambiguities under noise. (2) Then
the sensitivity of a graph's local deforming regarding ranging noises is
investigated by perturbation analysis. A novel Ranging Sensitivity Matrix (RSM)
is proposed to estimate the node location perturbations due to ranging noises.
(3) By evaluating component robustness via the flipping and the local deforming
risks, a Robust Component Generation and Realization (RCGR) algorithm is
developed, which generates components based on the robustness metrics. RCGR was
evaluated by simulations, which showed much better noise resistance and
locating accuracy improvements than state-of-the-art of component-based
localization algorithms.Comment: 9 pages, 15 figures, ICCCN 2018, Hangzhou, Chin
ViP3D: End-to-end Visual Trajectory Prediction via 3D Agent Queries
Existing autonomous driving pipelines separate the perception module from the
prediction module. The two modules communicate via hand-picked features such as
agent boxes and trajectories as interfaces. Due to this separation, the
prediction module only receives partial information from the perception module.
Even worse, errors from the perception modules can propagate and accumulate,
adversely affecting the prediction results. In this work, we propose ViP3D, a
visual trajectory prediction pipeline that leverages the rich information from
raw videos to predict future trajectories of agents in a scene. ViP3D employs
sparse agent queries throughout the pipeline, making it fully differentiable
and interpretable. Furthermore, we propose an evaluation metric for this novel
end-to-end visual trajectory prediction task. Extensive experimental results on
the nuScenes dataset show the strong performance of ViP3D over traditional
pipelines and previous end-to-end models.Comment: Project page is at https://tsinghua-mars-lab.github.io/ViP3
Stability of stope structure under different mining methods
The ore body has a great influence on the stability of surrounding rock and mining safety under different mining modes, and the reasonable selection of mining mode depends on other characteristics, such as ore structure surface feature, rock mass mechanical property, and ground stress distribution. Given the insufficient mining research data, this study establishes a 3D model by using the FLAC3D calculation program. Through numerical simulation and other technical means, a preliminary study on plastic and minimum stress changes during horizontal pillar mining, stress changes under different mining modes, and the effect comparison of full filling mining modes is conducted. Results show that the surrounding rock at the corner of pillar 1 is damaged, the plastic zone decreases, and the minimum stress in each working procedure increases slightly. The area of the plastic zone in alternate mining is smaller to that in continuous mining. This study provides a theoretical basis for ore body mining
e-block: a tangible programming tool for children
E-Block is a tangible programming tool for children aged 5 to 9 which gives children a preliminary understanding of programming. Children can write programs to play a maze game by placing the programming blocks in E-Block. The two stages in a general programming process: programming and running are all embodied in E-Block. We realized E-Block by wireless and infrared technology and gave it feedbacks on both screen and programming blocks. The result of a preliminary user study proved that E-Block is attractive to children and easy to learn and use.ACM Special Interest Group on Computer-Human Interaction (SIGCHI); ACM Special Interest Group on Computer Graphics (SIGGRAPH)E-Block is a tangible programming tool for children aged 5 to 9 which gives children a preliminary understanding of programming. Children can write programs to play a maze game by placing the programming blocks in E-Block. The two stages in a general programming process: programming and running are all embodied in E-Block. We realized E-Block by wireless and infrared technology and gave it feedbacks on both screen and programming blocks. The result of a preliminary user study proved that E-Block is attractive to children and easy to learn and use
Long non-coding RNA AL137789.1 promoted malignant biological behaviors and immune escape of pancreatic carcinoma cells
Our pre-investigation has revealed that long non-coding RNA (LncRNA) AL137789.1 has the potential to predict the survival of patients with pancreatic carcinoma (PCa). Accordingly, the mechanism underlying the implication of AL137789.1 in PCa is covered in the current study. The non-tumor and paired tumor tissues were collected. Kaplan–Meier curve was employed to estimate the survival of PCa patients with high or low expression of AL137789.1. The proliferation, migration, invasion, and cell cycle of PCa cells were determined, and the cytotoxicity of CD8+ T cells was evaluated as well. Levels of AL137789.1, E-cadherin, N-cadherin, and Vimentin were quantified. According to the experimental results, AL137789.1 was highly expressed in PCa and related to a poor prognosis of patients. Overexpressed AL137789.1 enhanced the proliferation, migration, and invasion of PCa cells, increased the cell population at G2/M and S phases yet decreased that in G0/G1 phase, and diminished the cytotoxicity of CD8+ T cells. Also, overexpressed AL137789.1 elevated levels of N-cadherin and Vimentin, while lessening E-cadherin levels. However, the silencing of AL137789.1 produced contrary effects. Collectively, lncRNA AL137789.1 plays a tumor-promotive role in PCa by enhancing the progression and immune escape
Microbial extracellular polymeric substances alleviate cadmium toxicity in rice (Oryza sativa L.) by regulating cadmium uptake, subcellular distribution and triggering the expression of stress-related genes
Cadmium (Cd) accumulation in crops causes potential risks to human health. Microbial extracellular polymeric substances (EPS) are a complex mixture of biopolymers that can bind various heavy metals. The present work examined the alleviating effects of EPS on Cd toxicity in rice and its detoxification mechanism. The 100 μM Cd stress hampered the overall plant growth and development, damaged the ultrastructures of both leaf and root cells, and caused severe lipid peroxidation in rice plants. However, applying EPS at a concentration of 100 mg/L during Cd stress resulted in increased biomass, reduced Cd accumulation and transport, and minimized the oxidative damage. EPS application also enhanced Cd retention in the shoot cell walls and root vacuoles, and actively altered the expression of genes involved in cell wall formation, antioxidant defense systems, transcription factors, and hormone metabolism. These findings provide new insights into EPS-mediated mitigation of Cd stress in plants and help us to develop strategies to improve crop yield in Cd-contaminated soils in the future
Visible-Light-Promoted Conversion of Alkyl Benzyl Ether to Alkyl Ester or Alcohol via O‑α-sp<sup>3</sup> C–H Cleavage
A mild and high-yielding
visible-light-promoted conversion of alkyl
benzyl ethers to the alkyl esters or alkyl alcohols was developed.
Mechanistic studies provided evidence for a radical chain reaction
involving the homolytic cleavage of <i>O</i>-α-sp<sup>3</sup> C–H bonds in the substrate as one of the propagation
steps. We propose that α-bromoethers are key intermediates in
the transformation