177 research outputs found
3D Path Planning and Obstacle Avoidance Algorithms for Obstacle-Overcoming Robots
This article introduces a multimodal motion planning (MMP) algorithm that
combines three-dimensional (3-D) path planning and a DWA obstacle avoidance
algorithm. The algorithms aim to plan the path and motion of
obstacle-overcoming robots in complex unstructured scenes. A novel A-star
algorithm is proposed to combine the characteristics of unstructured scenes and
a strategy to switch it into a greedy best-first strategy algorithm. Meanwhile,
the algorithm of path planning is integrated with the DWA algorithm so that the
robot can perform local dynamic obstacle avoidance during the movement along
the global planned path. Furthermore, when the proposed global path planning
algorithm combines with the local obstacle avoidance algorithm, the robot can
correct the path after obstacle avoidance and obstacle overcoming. The
simulation experiments in a factory with several complex environments verified
the feasibility and robustness of the algorithms. The algorithms can quickly
generate a reasonable 3-D path for obstacle-overcoming robots and perform
reliable local obstacle avoidance under the premise of considering the
characteristics of the scene and motion obstacles.Comment: 2nd IEEE International Conference on Electronic Communications,
Internet of Things and Big Data Conference 2022 (IEEE ICEIB 2022
Improving Few-shot and Zero-shot Entity Linking with Coarse-to-Fine Lexicon-based Retriever
Few-shot and zero-shot entity linking focus on the tail and emerging
entities, which are more challenging but closer to real-world scenarios. The
mainstream method is the ''retrieve and rerank'' two-stage framework. In this
paper, we propose a coarse-to-fine lexicon-based retriever to retrieve entity
candidates in an effective manner, which operates in two layers. The first
layer retrieves coarse-grained candidates by leveraging entity names, while the
second layer narrows down the search to fine-grained candidates within the
coarse-grained ones. In addition, this second layer utilizes entity
descriptions to effectively disambiguate tail or new entities that share names
with existing popular entities. Experimental results indicate that our approach
can obtain superior performance without requiring extensive finetuning in the
retrieval stage. Notably, our approach ranks the 1st in NLPCC 2023 Shared Task
6 on Chinese Few-shot and Zero-shot Entity Linking.Comment: Accepted to NLPCC202
Multistep modelling of teleseismic receiver functions combined with constraints from seismic tomography: Crustal structure beneath southeast China
With a growing number of modern broad-band seismographic stations in Asia, the conditions have improved to allow higher resolution structural studies on regional scales. Here, we perform a receiver-based study of the lithosphere of southeast China using waveform records of excellent quality from 14 Chinese National Digital Seismic Network and four Global Seismic Network stations. Calculating the theoretical receiver functions (RFs) that match the observed RFs from teleseismic waveforms is an established technique for retrieving information about crustal and upper mantle structure beneath a seismic receiver. RFs, however, are predominantly sensitive to the gradients in the lithospheric elastic parameters, and it is impossible to determine a non-unique distribution of seismic parameters such as absolute shear wave speeds as a function of depth unless other geophysical data are combined with RFs. Thus, we combine RFs with independent information from shear and compressional wave speeds above and below the Mohorovičić discontinuity, available from the existing tomographic studies. We introduce a statistical approach for automatically selecting only mutually coherent RFs from a large set of observed waveforms. Furthermore, an interactive forward modelling software is introduced and applied to observed RFs to define a prior, physically acceptable range of elastic parameters in the lithosphere. This is followed by a grid-search for a simple crustal structure. An initial model for a linearized, iterative inversion is constructed from multiple constraints, including results from the grid-search for shear wave speed, the Moho depth versus vp/vs ratio domain search and tomography. The thickness of the crust constrained by our multistep approach appears to be more variable in comparison with tomographic studies, with the crust thinning significantly towards the east. We observe low values of vp/vs ratios across the entire region, which indicates the presence of a very silicic crust. We do not observe any correlation between the crustal thickness or age of the crust with vp/vs ratios, which argues against a notion that there is a simple relationship between mineralogical composition and crustal thickness and age on a global scale
MMSD2.0: Towards a Reliable Multi-modal Sarcasm Detection System
Multi-modal sarcasm detection has attracted much recent attention.
Nevertheless, the existing benchmark (MMSD) has some shortcomings that hinder
the development of reliable multi-modal sarcasm detection system: (1) There are
some spurious cues in MMSD, leading to the model bias learning; (2) The
negative samples in MMSD are not always reasonable. To solve the aforementioned
issues, we introduce MMSD2.0, a correction dataset that fixes the shortcomings
of MMSD, by removing the spurious cues and re-annotating the unreasonable
samples. Meanwhile, we present a novel framework called multi-view CLIP that is
capable of leveraging multi-grained cues from multiple perspectives (i.e.,
text, image, and text-image interaction view) for multi-modal sarcasm
detection. Extensive experiments show that MMSD2.0 is a valuable benchmark for
building reliable multi-modal sarcasm detection systems and multi-view CLIP can
significantly outperform the previous best baselines.Comment: Accepted by ACL2023 Finding
The band gap and nonlinear optical susceptibility of SrSn1-xVxO3 films
Perovskite-type oxide SrSn1-xVxO3 thin films with different concentrations x = 0.1–0.9 were fabricated by using pulsed-laser deposition, and the effects of V doping on the structure, optical band gap and the third-order optical nonlinearity were systematically investigated. With the increase of x value, the lattice parameters of SrSn1-xVxO3 decrease from 3.997 to 3.862 Å gradually, while the optical band gaps firstly increase and then decrease with boundary at x = 0.3. The third-order nonlinear optical responses were studied via the z-scan technique. The closed-aperture measurements show a negative nonlinear refractive index n2, and the open-aperture measurements demonstrate a saturable absorption β. Both the n2 and β responses vary with the increase of V doping level. The metal-oxygen chemical bond along with the localized V5+Sn2+V5+ complex contribute to the enhancement of optical nonlinearity, and the highest value of third-order susceptibility χ(3) is observed in SrSn0.5V0.5O3 film
Observation of Fungi, Bacteria, and Parasites in Clinical Skin Samples Using Scanning Electron Microscopy
This chapter highlights the description of the clinical manifestation and its pathogen and the host tissue damage observed under the Scanning Electron Microscope, which helps the clinician to understand the pathogen’s superstructure, the change of host subcell structure, and the laboratory workers to understand the clinical characteristics of pathogen-induced human skin lesions, to establish a two-way learning exchange database with vivid image
Biogenic Synthesis and Spatial Distribution of Endogenous Phytohormones and Ginsenosides Provide Insights on Their Intrinsic Relevance in Panax ginseng
Ginseng, the root and rhizome of Panax ginseng C. A. Mey., is a well-known and valuable traditional Chinese medicine. The pharmacological activities of ginseng are mainly attributed to the presence of ginsenosides, which are considered to be critical biomarkers for evaluating ginseng quality. The biosynthesis of triterpenes, which serve defensive functions in plants, is regulated by endogenous phytohormones that play key roles in growth and defense of plant populations. However, the role of major hormones that are closely related to secondary metabolism pathways in P. ginseng is poorly understood. To gain insight into their potential correlation, we performed a spatial synthesis analysis and studied the distribution of endogenous phytohormones and ginsenosides in different tissue regions of the entire P. ginseng plant. Gibberellins are growth hormones that accumulate in the fiber root. In contrast, abscisic acid (ABA), salicylic acid (SA), and jasmonic acid (JA), which are considered stress hormones, were predominantly found in the leaf and leaf peduncle. We observed a tissue-specific distribution of phytohormones consistent with the expression of genes involved in hormone biosynthesis that influenced ginsenoside synthesis and distribution. The aim of this study was to investigate the role of different endogenous phytohormones on triterpene metabolites in ginseng innate immunity
Efficacy of Co-administration of Liuwei Dihuang Pills and Ginkgo Biloba Tablets on Albuminuria in Type 2 Diabetes: A 24-Month, Multicenter, Double-Blind, Placebo-Controlled, Randomized Clinical Trial
Purpose: We investigated the effects of Traditional Chinese Medicine (TCM) on the occurrence and progression of albuminuria in patients with type 2 diabetes.Methods: In this randomized, double-blind, multicenter, controlled trial, we enrolled 600 type 2 diabetes without diabetic nephropathy (DN) or with early-stage DN. Patients were randomly assigned (1:1) to receive Liuwei Dihuang Pills (LWDH) (1.5 g daily) and Ginkgo biloba Tablets (24 mg daily) orally or matching placebos for 24 months. The primary endpoint was the change in urinary albumin/creatinine ratio (UACR) from baseline to 24 months.Results: There were 431 patients having UACR data at baseline and 24 months following-up in both groups. Changes of UACR from baseline to follow-up were not affected in both groups: −1.61(−10.24, 7.17) mg/g in the TCM group and −0.73(−7.47, 6.75) mg/g in the control group. For patients with UACR ≥30 mg/g at baseline, LWDH and Ginkgo biloba significantly reduced the UACR value at 24 months [46.21(34.96, 58.96) vs. 20.78(9.62, 38.85), P < 0.05]. Moreover, the change of UACR from baseline to follow-up in the TCM group was significant higher than that in the control group [−25.50(−42.30, −9.56] vs. −20.61(−36.79, 4.31), P < 0.05].Conclusion: LWDH and Ginkgo biloba may attenuate deterioration of albuminuria in type 2 diabetes patients. These results suggest that TCM is a promising option of renoprotective agents for early stage of DN.Trial registration: The study was registered in the Chinese Clinical Trial Registry. (no. ChiCTR-TRC-07000037, chictr.org
Raffinose degradation-related gene GhAGAL3 was screened out responding to salinity stress through expression patterns of GhAGALs family genes
A-galactosidases (AGALs), the oligosaccharide (RFO) catabolic genes of the raffinose family, play crucial roles in plant growth and development and in adversity stress. They can break down the non-reducing terminal galactose residues of glycolipids and sugar chains. In this study, the whole genome of AGALs was analyzed. Bioinformatics analysis was conducted to analyze members of the AGAL family in Gossypium hirsutum, Gossypium arboreum, Gossypium barbadense, and Gossypium raimondii. Meanwhile, RT-qPCR was carried out to analyze the expression patterns of AGAL family members in different tissues of terrestrial cotton. It was found that a series of environmental factors stimulated the expression of the GhAGAL3 gene. The function of GhAGAL3 was verified through virus-induced gene silencing (VIGS). As a result, GhAGAL3 gene silencing resulted in milder wilting of seedlings than the controls, and a significant increase in the raffinose content in cotton, indicating that GhAGAL3 responded to NaCl stress. The increase in raffinose content improved the tolerance of cotton. Findings in this study lay an important foundation for further research on the role of the GhAGAL3 gene family in the molecular mechanism of abiotic stress resistance in cotton
- …