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Effects of electroacupuncture at lower he-sea points on interleukin-1β and high mobility group box 1 in model rats with ulcerative colitis 被引量:4
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作者 张泓 易细芹 +2 位作者 凌希 吴金峰 艾坤 《World Journal of Acupuncture-Moxibustion》 CSCD 2015年第4期25-31,共7页
Objective To comparatively observe the effect of electroacupuncture at digestive system-related lower he-sea points on the expressions of serum interleukin-1β(IL-1 β), tumor necrosis factor-α(TNF-α) of colon t... Objective To comparatively observe the effect of electroacupuncture at digestive system-related lower he-sea points on the expressions of serum interleukin-1β(IL-1 β), tumor necrosis factor-α(TNF-α) of colon tissues and high mobility group box 1 protein(HMGB 1) of ulcerative colitis(UC) model rats, and to explore whether there is relative specificity of electroacupuncture at Shàngjùxū(上巨虚 ST 37), one of lower he-sea points of large intestine, in treatment of bowel diseases. Method A total of 60 SD rats were randomly divided into control group, model group, ST 37 group, Zúsānl?(足三里 ST 36) group, Xiàjùxū(下巨虚 ST 39) group and Yánglíngquán(阳陵泉 GB 34) group. There were ten rats in each group; five were males, and five were females. UC models were established by clysis with 2, 4, 6-trinitrobenzene sulfonic acid/alcohol solution. After modeling, treatment was conducted for ten days, specimens were collected, colonic ulcers and inflammation were inspected visually and scored. The content of serum IL-1β and the expressions of TNF-α and HMGB 1 in colon were detected through ELISA. Results 1 Compared with control group, the scores of colonic ulcers and inflammation, the content of serum IL-1β and the expressions of TNF-α(except ST 37 group) and HMGB 1 were all higher(P〈0.05, P〈0.01); 2 compared with model group, the scores of colonic ulcers in ST 36 group and ST 37 group were lower obviously(P〈0.05, P〈0.01); the expressions of IL-1β, TNF-α and HMGB 1 in the four treatment groups were lower obviously(P〈0.01); 3 compared with ST 37 group, the expressions of IL-1β, TNF-α and HMGB 1 in other three treatment groups were higher obviously(P〈0.05, P〈0.01); and the scores of colonic ulcers in ST 39 group and GB 34 group were higher obviously(P〈0.05). Conclusion 1 The score of colonic ulcers can be reduced through electroacupuncture at ST 37, ST 36, ST 39 and GB 34, which can also reduce the content of serum IL-1β and the expressions of TNF-α and HMGB 1, and effectively inhibit inflammatory response of colon caused by UC; 2 the effect trend of the four acupoints in treatment of UC is: ST 37ST 36ST 39GB 34, and electroacupuncture at ST 37 has the best effect with relative specificity. 展开更多
关键词 ELECTROACUPUNCTURE lower he-sea points ulcerative colitis(UC) model rats interleukin-1β(IL-1β) tumor necrosis factor-α high mobility group box 1 protein(HMGB 1) curing viscera diseases by he-sea points
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基于Point Transformer方法的鱼类三维点云模型分类
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作者 胡少秋 段瑞 +3 位作者 张东旭 鲍江辉 吕华飞 段明 《水生生物学报》 北大核心 2025年第2期146-155,共10页
为实现对不同鱼类的精准分类,研究共采集110尾真实鱼类的三维模型,对获取的3D模型进行基于预处理、旋转增强和下采样等操作后,获取了1650尾实验样本。然后基于Point Transformer网络和2个三维分类的对比网络进行数据集的分类训练和验证... 为实现对不同鱼类的精准分类,研究共采集110尾真实鱼类的三维模型,对获取的3D模型进行基于预处理、旋转增强和下采样等操作后,获取了1650尾实验样本。然后基于Point Transformer网络和2个三维分类的对比网络进行数据集的分类训练和验证。结果表明,利用本实验的目标方法Point Transformer获得了比2个对比网络更好的分类结果,整体的分类准确率能够达到91.9%。同时对所使用的三维分类网络进行有效性评估,3个模型对于5种真实鱼类模型的分类是有意义的,其中Point Transformer的模型ROC曲线准确率最高,AUC面积最大,对于三维鱼类数据集的分类最为有效。研究提供了一种可以实现对鱼类三维模型进行精准分类的方法,为以后的智能化渔业资源监测提供一种新的技术手段。 展开更多
关键词 点云处理 point Transformer 三维模型 鱼类分类
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Effect of electroacupuncture at“ Zúsānlǐ”(足三里 ST 36) and other lower he-sea points on the expression of TNF-α and NF-κB of acute gastric mucosal lesion rats 被引量:5
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作者 AI Kun WU Jin-feng +3 位作者 QI Fang ZHANG Hong YI Xi-qin LING Xi 《World Journal of Acupuncture-Moxibustion》 CSCD 2016年第4期26-32,共7页
Objective To contrastively observe the effect of electroacupuncture at lower he-sea points of stomach, large intestine, small intestine and gallbladder of acute gastric mucosal lesion(AGML) model rats on the express... Objective To contrastively observe the effect of electroacupuncture at lower he-sea points of stomach, large intestine, small intestine and gallbladder of acute gastric mucosal lesion(AGML) model rats on the expression of serum high mobility group protein B 1(HMGB 1), tumor necrosis factor-α(TNF-α) and nuclear factor-κB(NF-κB) of gastric tissue, and to explore whether the lower he-sea points of stomach have relative specificity in treatment of stomach diseases. Methods Seventy healthy SD rats were randomly divided into seven groups, including control group, model group, "Zúsānlǐ"(足三里 ST 36) group, "Shàngjùxū"(上巨虚 ST 37) group, "Xiàjùxū"(下巨虚 ST 39) group, "Yánglíngquán"(阳陵泉 GB 34) group and "Chéngjīn"(承筋 BL 56) group, with five male rats and five female rats in each group. Acute gastric mucosal lesion model was established by applying WRS method. After successful modeling and treatment for ten days, sampling was conducted, gastric mucosal lesion was observed visually and scored, the levels of serum HMGB 1 and gastric tissue TNF-α were detected by ELISA method, and the expression of NF-κB was detected by immunohistochemical method. Results①Compared with the model group, the levels of Ulcers and inflammation(UI) in gastric mucosal and serum HMGB1, and the expression of gastric tissue TNF-α and NF-κB in the four lower he-sea points groups reduced(P〈0.01 or P〈0.05);② compared with ST 36 group, the levels of gastric mucosal UI and serum HMGB1, and the expression of gastric mucosal TNF-α and NF-κB in other treatment groups increased significantly, and the difference was statistically significant(P〈0.01 or P〈0.05). Conclusion①Electroacupuncture at relevant lower he-sea points can inhibit the body's immune response, relieve inflammatory reaction and reduce mucosal lesion by regulating HMGB 1, TNF-α and NF-κB, so as to realize the intervention and treatment on AGML rats;② the total intervention effect in ST 36 group is superior to that in other groups, indicating partially that there is a relative specificity between ST 36 and stomach. 展开更多
关键词 ELECTROACUPUNCTURE lower he-sea points AGML rats HMGB1 TNF-α NF-κB he-sea points for treatment of diseases in the six fu organs
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Optimizing electronic structure through point defect engineering for enhanced electrocatalytic energy conversion
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作者 Wei Ma Jiahao Yao +6 位作者 Fang Xie Xinqi Wang Hao Wan Xiangjian Shen Lili Zhang Menggai Jiao Zhen Zhou 《Green Energy & Environment》 SCIE EI CAS 2025年第1期109-131,共23页
Point defect engineering endows catalysts with novel physical and chemical properties,elevating their electrocatalytic efficiency.The introduction of defects emerges as a promising strategy,effectively modifying the e... Point defect engineering endows catalysts with novel physical and chemical properties,elevating their electrocatalytic efficiency.The introduction of defects emerges as a promising strategy,effectively modifying the electronic structure of active sites.This optimization influences the adsorption energy of intermediates,thereby mitigating reaction energy barriers,altering paths,enhancing selectivity,and ultimately improving the catalytic efficiency of electrocatalysts.To elucidate the impact of defects on the electrocatalytic process,we comprehensively outline the roles of various point defects,their synthetic methodologies,and characterization techniques.Importantly,we consolidate insights into the relationship between point defects and catalytic activity for hydrogen/oxygen evolution and CO_(2)/O_(2)/N_(2) reduction reactions by integrating mechanisms from diverse reactions.This underscores the pivotal role of point defects in enhancing catalytic performance.At last,the principal challenges and prospects associated with point defects in current electrocatalysts are proposed,emphasizing their role in advancing the efficiency of electrochemical energy storage and conversion materials. 展开更多
关键词 point defect engineering DOPING VACANCY ELECTROCATALYSIS Electronic structure
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Sensitivity Analysis of Structural Dynamic Behavior Based on the Sparse Polynomial Chaos Expansion and Material Point Method
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作者 Wenpeng Li Zhenghe Liu +4 位作者 Yujing Ma Zhuxuan Meng Ji Ma Weisong Liu Vinh Phu Nguyen 《Computer Modeling in Engineering & Sciences》 2025年第2期1515-1543,共29页
This paper presents a framework for constructing surrogate models for sensitivity analysis of structural dynamics behavior.Physical models involving deformation,such as collisions,vibrations,and penetration,are devel-... This paper presents a framework for constructing surrogate models for sensitivity analysis of structural dynamics behavior.Physical models involving deformation,such as collisions,vibrations,and penetration,are devel-oped using the material point method.To reduce the computational cost of Monte Carlo simulations,response surface models are created as surrogate models for the material point system to approximate its dynamic behavior.An adaptive randomized greedy algorithm is employed to construct a sparse polynomial chaos expansion model with a fixed order,effectively balancing the accuracy and computational efficiency of the surrogate model.Based on the sparse polynomial chaos expansion,sensitivity analysis is conducted using the global finite difference and Sobol methods.Several examples of structural dynamics are provided to demonstrate the effectiveness of the proposed method in addressing structural dynamics problems. 展开更多
关键词 Structural dynamics DEFORMATION material point method sparse polynomial chaos expansion adaptive randomized greedy algorithm sensitivity analysis
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基于注意力权重PointNet++的电力走廊点云语义分割研究
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作者 鲍万轲 姜媛媛 《东北电力技术》 2025年第1期30-34,52,共6页
传统的电力走廊点云数据的分割会出现精度低、数据局部特征捕获存在局限性等问题,为此提出了一种基于注意力权重的PointNet++网络场景分割模型。将深度学习中的PointNet++算法用于电力走廊场景分割中,再引入了空间注意力机制,帮助模型... 传统的电力走廊点云数据的分割会出现精度低、数据局部特征捕获存在局限性等问题,为此提出了一种基于注意力权重的PointNet++网络场景分割模型。将深度学习中的PointNet++算法用于电力走廊场景分割中,再引入了空间注意力机制,帮助模型更有效地关注重要的空间区域。为此采用自制的数据集,并基于PointNet++网络模型的经典结构,在每个点集抽取(set abstraction,SA)模块中的多层感知机(multi layer perceptron,MLP)加入倒置瓶颈设计,提高对点云数据的处理效率和准确性。研究结果表明,与传统的PointNet++网络相比,改进的PointNet++网络平均交并比(mean intersection over union,mIoU)高出6.3%,加入空间注意力机制的改进模型在自制数据集上表现出更好的分割效果,尤其是在边界划分方面提升明显,验证了该方法在点云语义分割上的有效性。 展开更多
关键词 点云语义分割 输电通道 pointNet++ 注意力机制
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位置自适应卷积PointNet++的点云数据分类方法
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作者 闫晓奇 彭逸清 任小玲 《计算机与现代化》 2025年第1期44-49,共6页
针对复杂场景中点云数据分类精度低问题,提出一种基于位置自适应卷积的PointNet++深度神经网络模型。由于位置自适应卷积具有较强捕捉细粒度局部特征能力,能充分获取三维点云的空间变化和几何结构特征信息,故本文在PointNet++基础上,首... 针对复杂场景中点云数据分类精度低问题,提出一种基于位置自适应卷积的PointNet++深度神经网络模型。由于位置自适应卷积具有较强捕捉细粒度局部特征能力,能充分获取三维点云的空间变化和几何结构特征信息,故本文在PointNet++基础上,首先通过最远点采样获取关键点,其次根据关键点使用K最近邻方法(KNN)实现分组,然后由位置自适应卷积代替原方法中的MLP提取每组的局部特征,最终完成点云分类。在2个公开的点云数据集S3DIS、Semantic3D上对本文方法进行多次对比实验,实验结果表明,本文方法在室内数据集S3DIS上的总体精度和mIoU较PointNet++网络分别提高约2.7个百分点和3.2个百分点,在室外数据集Semantic3D上的总体精度和mIoU PointNet++分别高出约2.5个百分点和2.1个百分点。 展开更多
关键词 点云分类 位置自适应卷积 pointNet++ 深度学习 局部特征
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基于PointNet的钢板毛坯垛点云分割
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作者 林振杨 《机电工程技术》 2025年第1期152-156,共5页
钢板毛坯垛拆垛工序中,钢板毛坯分层厚度的估计是推钢机准确且安全执行推钢动作的关键;当前不少企业此道生产工序仍主要靠操作员人工观察的方式估算钢板厚度及与传送辊道的相对高度,其估算不准易导致碰撞,造成输送设备损坏生产中断。提... 钢板毛坯垛拆垛工序中,钢板毛坯分层厚度的估计是推钢机准确且安全执行推钢动作的关键;当前不少企业此道生产工序仍主要靠操作员人工观察的方式估算钢板厚度及与传送辊道的相对高度,其估算不准易导致碰撞,造成输送设备损坏生产中断。提出一种钢板毛坯垛智能分层方法,该方法结合现场工况环境采用激光雷达,对钢板毛坯垛进行三维点云成像,然后对采集的点云数据,用PointNet神经网络框架进行特征识别、分层分割与提取,最后对分割的不同层根据标定值,换算成真实厚度。根据现场实验结果表明,PointNet对钢板毛坯垛分割的识别率达到了87.4%,厚度估算误差低于1.2cm,根据钢厂钢板毛坯规格表(3种规格150、160、180cm)可以准确估计出钢板毛坯厚度的规格,识别速度15帧/s,满足现场工况要求。 展开更多
关键词 钢板毛坯垛 点云分割 特征识别 pointNet
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基于轻量化PointNet网络的林果园喷雾作业靶标实时识别方法 被引量:1
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作者 刘慧 杜志鹏 +2 位作者 杨锋 张钰 沈跃 《农业工程学报》 EI CAS CSCD 北大核心 2024年第8期144-151,共8页
为了进一步提高喷雾机器人靶标检测的精准性、实时性和应用部署的实用性,该研究提出一种基于轻量化PointNet网络的林果园喷雾作业靶标实时识别方法。首先通过区域提取降采样、地面分割和改进DBSCAN聚类等点云预处理方法提取原始点云中... 为了进一步提高喷雾机器人靶标检测的精准性、实时性和应用部署的实用性,该研究提出一种基于轻量化PointNet网络的林果园喷雾作业靶标实时识别方法。首先通过区域提取降采样、地面分割和改进DBSCAN聚类等点云预处理方法提取原始点云中的靶标;然后通过移动最小二乘上采样将靶标点云转化为满足点云识别网络输入要求的点云数据;最终通过在PointNet网络中引入残差模块和改进循环剪枝算法轻量化PointNet网络,完成林果树靶标的实时识别。试验结果表明,在ModelNet40数据集上,轻量化PointNet网络可达89.7%的准确率;在实际苗圃环境的试验中,该研究方法对靶标的识别准确率可达92.49%,同时误识率与拒识率分别为13.4%和6.47%,相较PointNet网络识别准确率提升了4.38个百分点,误识率和拒识率分别降低了7.2和4.07个百分点;轻量化PointNet网络识别准确率仅比PointNet++网络低1.14个百分点,误识率和拒识率分别高了0.9和1.12个百分点。但是轻量化PointNet网络的模型参数量较PointNet网络和PointNet++网络的模型参数量显著减少,仅为PointNet网络的11.5%,PointNet++网络的27.02%;运算量相较PointNet网络、PointNet++网络分别减少13.3和76.79个百分点。该研究提出的轻量化PointNet网络具有较高的实时性、精确性和鲁棒性,能够满足林果园喷雾作业的靶标识别需求,可为林果园喷雾作业靶标实时识别提供参考。 展开更多
关键词 喷雾 机器人 林果园 点云预处理 轻量化pointNet网络 循环剪枝
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Effect of electroacupuncture at Lower He-Sea points including Yanglingquan(GB 34)on nuclear factor-κB and interleukin-1βin guinea pigs with acute cholecystitis 被引量:1
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作者 Ni Wei Zhang Jian 《Journal of Acupuncture and Tuina Science》 CSCD 2020年第4期247-255,共9页
Objective:To observe the effect of electroacupuncture(EA)at Lower He-Sea points on the expression levels of interleukin-1β(IL-1β)in the serum and gallbladder tissues,and nuclear factor-κB(NF-κB)in gallbladder tiss... Objective:To observe the effect of electroacupuncture(EA)at Lower He-Sea points on the expression levels of interleukin-1β(IL-1β)in the serum and gallbladder tissues,and nuclear factor-κB(NF-κB)in gallbladder tissues of the guinea pigs with acute cholecystitis(AC),and to explore whether Yanglingquan(GB 34),the Lower He-Sea point pertaining to Dan Fu(gallbladder),is relatively specific for the Dan Fu(gallbladder)disorders.Methods:Eighty-two healthy guinea pigs were randomly divided into 6 groups according to the random number table method,a blank group,a model group,a Yanglingquan(GB 34)group,a Zusanli(ST 36)group,a Shangjuxu(ST 37)group,and a Xiajuxu(ST 39)group,with 12 guinea pigs in the blank group while 14 in the other groups,respectively,half males and half females in each group.Except for the blank group,guinea pigs in the other groups were injected with E.coli into the gallbladder to establish AC models.Guinea pigs in the blank group were fed routinely without special treatment;those in the model group were daily tied up for 30 min without EA treatment;those in the 4 groups receiving EA treatment were acupunctured at the corresponding Lower He-Sea points after daily binding and stimulated with the SDZ-V EA instrument.After successful modeling and treatment for 5 d,blood was collected from the abdominal aorta of the guinea pigs,and the gallbladder tissues in each group were isolated for hematoxylin-eosin(HE)staining to observe the morphological changes.Enzyme-linked immunosorbent assay(ELISA)was used to detect the serum IL-1βlevel,and immunohistochemistry(IHC)was used to detect the expression levels of NF-κB and IL-1βin gallbladder.Results:On the 3rd day after modeling,the guinea pigs in the five groups with modeling were mentally depressed with decreased appetite,significantly reduced activities,slouch,lassitude,slack and matted fur,and loose stools;two guinea pigs were selected from each group(one male and one female,not included in the final statistics)to isolate the gallbladder after sacrifice;macroscopic observation showed that the gallbladder wall was differently thickened;the bile color was dark green and opaque with particles suspended or accumulated;light microscope observation showed that the submucosal blood vessels of the gallbladder were congested,along with mucosal edema,ulceration,necrosis,shedding,and a large number of inflammatory cells infiltrating in the lamina propria,indicating that the AC model was successfully prepared.Compared with the model group,the gallbladder tissue injuries of the four groups receiving EA treatment were all differently repaired,the serum IL-1βlevels were reduced(P<0.01 or P<0.05),and the IL-1βlevels in the gallbladder tissues were reduced(P<0.01 or P<0.05).Compared with the model group,the NF-κB expression level in the Yanglingquan(GB 34)group was significantly reduced(P<0.01),but was not statistical different in the Zusanli(ST 36)group,Shangjuxu(ST 37)group and Xiajuxu(ST 39)group(all P>0.05).Compared with the Yanglingquan(GB 34)group,the gallbladder tissues of the Zusanli(ST 36)group,Shangjuxu(ST 37)group and Xiajuxu(ST 39)group were more severely damaged,and the expression levels of serum IL-1β,the NF-κB and IL-1βin the gallbladder tissues were increased(P<0.01 or P<0.05).Intervention effect of Yanglingquan(GB 34)on AC guinea pigs was superior to that of Zusanli(ST 36),Shangjuxu(ST 37)and Xiajuxu(ST 39).Conclusion:EA at the Lower He-Sea points of the stomach,large intestine,small intestine and gallbladder can produce curative effects on AC guinea pigs and reduced the inflammatory symptoms.Intervention effect of Yanglingquan(GB 34)on AC guinea pigs is superior to that of Zusanli(ST 36),Shangjuxu(ST 37)and Xiajuxu(ST 39).The mechanism of EA at Yanglingquan(GB 34)in treating AC may be regulating IL-1βand NF-κB to control the inflammatory response and improve the gallbladder tissue damage. 展开更多
关键词 Acupuncture Therapy ELECTROACUPUNCTURE point Yanglingquan(GB 34) point Lower he-sea Interleukin-1 beta NF-kappa B Cholecystitis Acute Guinea Pigs
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基于K F-PointNet++的油菜植株点云分割算法
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作者 黄友锐 苏静 +1 位作者 韩涛 崔涛 《湖北民族大学学报(自然科学版)》 CAS 2024年第4期451-457,469,共8页
针对传统的点云分割算法精度低、鲁棒性差的问题,提出了基于K近邻算法和特征融合的深度点云网络(point clouds network++based on K-nearest neighbor algorithm and feature fusion,K F-PointNet++)三维点云分割算法。该算法首先采用了... 针对传统的点云分割算法精度低、鲁棒性差的问题,提出了基于K近邻算法和特征融合的深度点云网络(point clouds network++based on K-nearest neighbor algorithm and feature fusion,K F-PointNet++)三维点云分割算法。该算法首先采用了K近邻(K-nearest neighbors,K NN)算法对点云进行分组;其次,将点云网络(point clouds network,PointNet)中的局部特征与中心点全局特征进行拼接,增强算法对几何细节和全局上下文信息的捕捉能力,从而提高算法的分割精度和鲁棒性,实现了对油菜点云器官的精准分割。使用自制的油菜点云数据集进行实验,结果表明,K F-PointNet++算法在油菜点云分割中的总体精度(overall accuracy,OA)可达97.1%,平均交并比(mean intersection over union,mIoU)为86.4%。该算法在分割性能方面明显优于PointNet、深度点云网络(PointNet++)和核点卷积(kernal point convolution,KPConv),可以为油菜表型研究提供可靠基础。 展开更多
关键词 点云分割 深度学习 特征拼接 表型 器官 K NN 油菜
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基于PointNet++的邻域特征增强点云语义分割方法
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作者 李松 张安思 +1 位作者 伍婕 张保 《激光杂志》 CAS 北大核心 2024年第7期174-179,共6页
随着智能驾驶、机器人导航等以点云为基础的应用蓬勃发展,点云语义分割逐渐成为研究热点。然而,现有的点云语义分割方法存在局部特征提取不充分、特征融合不完整的缺陷。针对这些不足,提出了对应的解决方案。对于局部特征提取不充分的现... 随着智能驾驶、机器人导航等以点云为基础的应用蓬勃发展,点云语义分割逐渐成为研究热点。然而,现有的点云语义分割方法存在局部特征提取不充分、特征融合不完整的缺陷。针对这些不足,提出了对应的解决方案。对于局部特征提取不充分的现象,通过嵌入邻域点的坐标、方向、距离等相关信息去关联邻域点的显式特征。对于特征融合不完整的现象,提出了一种最大池化与自注意力池化相结合的混合池化方法。网络架构基于PointNet++,并结合提出的局部特征提取和融合方法,在S3DIS数据集上的实验结果表明,与基线方法PointNet++相比,各评价指标都有不同程度的提高,证实了新方法的有效性和优越性。 展开更多
关键词 三维点云 语义分割 特征提取 深度学习
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基于Point Transformer v2的点云枝叶分离方法研究
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作者 马津 陈一平 +3 位作者 韩汀 王朝磊 张小海 张吴明 《航天返回与遥感》 CSCD 北大核心 2024年第3期62-72,共11页
准确高效的点云枝叶分离对精确计算森林树木的垂直参数至关重要。然而,当前的研究方法计算成本高,且依赖先验知识导致泛化能力不足。针对以上问题,文章提出利用基于点特征的Transformer网络进行自动化的森林场景三维点云的枝叶分离研究... 准确高效的点云枝叶分离对精确计算森林树木的垂直参数至关重要。然而,当前的研究方法计算成本高,且依赖先验知识导致泛化能力不足。针对以上问题,文章提出利用基于点特征的Transformer网络进行自动化的森林场景三维点云的枝叶分离研究。该方法使用Point Transformer v2网络,首先利用网格编码模块提取可学习的局部结构关系,保留点云的几何拓扑结构;其次使用分组注意力实现多通道联合学习,降低特征的冗余度,提高计算的效率;最后构建了基于点的Transformer网络实现高精度森林树木三维点云语义分割,降低了对于先验知识的需求。使用地基激光扫描仪获取的加拿大和芬兰7个不同树种样地的三维点云数据,进行枝叶分离实验和精度评价。实验结果表明,网络整体精度(OA)为94.42%,mIoU为78.89%,能够适应不同树种、不同点云密度的森林场景的枝叶分离。 展开更多
关键词 三维点云 深度学习 枝叶分离 point TRANSFORMER V2
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基于改进PointNet++的船体分段合拢面构件智能识别算法研究
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作者 李瑞 赵怡荣 +2 位作者 霍世霖 汪骥 史卫东 《中国舰船研究》 CSCD 北大核心 2024年第6期173-179,共7页
[目的]三维扫描仪获得的船体分段合拢面点云数据,具有精度高、数据量大的优势,能够很好地反映分段合拢面的建造状况。由于现有的PointNet++网络无法处理大容量点云数据,因此提出一种基于改进PointNet++的船体分段合拢面构件智能识别算法... [目的]三维扫描仪获得的船体分段合拢面点云数据,具有精度高、数据量大的优势,能够很好地反映分段合拢面的建造状况。由于现有的PointNet++网络无法处理大容量点云数据,因此提出一种基于改进PointNet++的船体分段合拢面构件智能识别算法,实现针对大容量船体分段合拢面点云数据构件的智能识别。[方法]基于超体素生长理论对船体分段合拢面点云数据进行分割及简化,构建船体分段合拢面点云数据集,并使用该数据集训练基于深度学习理论改进的PointNet++网络。[结果]网络模型在船体分段合拢面点云数据训练集和测试集上的收敛结果趋于稳定,在测试集上识别准确率达到90.012%。[结论]该方法具有良好的识别能力,能够完成船体分段合拢面构件的智能识别。 展开更多
关键词 船舶建造 人工智能 船体分段合拢面 点云数据 超体素生长 pointNet++ 智能识别
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基于PointNet++进行附属设施语义分割的隧道收敛变形分析 被引量:1
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作者 卞政 石波 +3 位作者 吴凡 王静 赵凯 杨兴宜 《铁道科学与工程学报》 EI CAS CSCD 北大核心 2024年第11期4827-4839,共13页
随着城市轨道交通日趋广泛,隧道结构变形引起的地铁安全事故凸显,亟需对运营期隧道进行变形检测。隧道衬砌作为隧道变形分析的研究对象,衬砌内表面存在的大量附属设施影响隧道收敛变形分析精度。为了提高变形分析精度,解决点云处理环节... 随着城市轨道交通日趋广泛,隧道结构变形引起的地铁安全事故凸显,亟需对运营期隧道进行变形检测。隧道衬砌作为隧道变形分析的研究对象,衬砌内表面存在的大量附属设施影响隧道收敛变形分析精度。为了提高变形分析精度,解决点云处理环节中存在的自动化程度低的问题,提出基于PointNet++点云语义分割的隧道收敛变形分析方法。首先利用深度学习方法进行点云语义分割,对隧道衬砌附属设施进行自动滤除。然后对隧道衬砌进行断面提取,利用随机抽样一致性算法(Random Sample Consensus,RANSAC)对隧道断面点云进行采样,分析隧道收敛变形程度,从Z+F PROFILER 9012A激光断面扫描仪获取山东省济南市地铁盾构隧道点云实测数据上并进行应用。研究结果表明:所提出的处理方法可以有效地将大规模隧道衬砌与连接紧密的附属设施分离出来,隧道附属设施总体分类精度达到96%,滤波结果较好地保留了隧道衬砌原始形态特征。在对隧道整体和局部收敛变形分析的重复性验证中,测试区间内隧道整体变形精度往返测长半轴平均偏差为1.04 mm,短半轴平均偏差为0.9 mm,测试区间内隧道局部收敛变形往返测标准差最小为0.773 mm,最大为0.938 mm,可以满足隧道收敛变形分析的精度需求。研究结果可以有效提升处理大规模隧道数据的自动化程度,具有良好的有效性与可靠性,对运营期地铁隧道收敛变形检测或监测有较好的实践应用意义。 展开更多
关键词 轨道交通隧道 激光点云 收敛变形分析 点云深度学习 随机抽样一致性
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Diagnosis of indirectly driven double shell targets with point-projection hard x-ray radiography 被引量:1
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作者 Chao Tian Minghai Yu +17 位作者 Lianqiang Shan Fengjuan Wu Bi Bi Qiangqiang Zhang Yuchi Wu Tiankui Zhang Feng Zhang Dongxiao Liu Weiwu Wang Zongqiang Yuan Siqian Yang Lei Yang Zhigang Deng Jian Teng Weimin Zhou Zongqing Zhao Yuqiu Gu Baohan Zhang 《Matter and Radiation at Extremes》 SCIE EI CSCD 2024年第2期50-62,共13页
We present an application of short-pulse laser-generated hard x rays for the diagnosis of indirectly driven double shell targets. Coneinserted double shell targets were imploded through an indirect drive approach on t... We present an application of short-pulse laser-generated hard x rays for the diagnosis of indirectly driven double shell targets. Coneinserted double shell targets were imploded through an indirect drive approach on the upgraded SG-II laser facility. Then, based on thepoint-projection hard x-ray radiography technique, time-resolved radiography of the double shell targets, including that of their near-peakcompression, were obtained. The backlighter source was created by the interactions of a high-intensity short pulsed laser with a metalmicrowire target. Images of the target near peak compression were obtained with an Au microwire. In addition, radiation hydrodynamicsimulations were performed, and the target evolution obtained agrees well with the experimental results. Using the radiographic images, arealdensities of the targets were evaluated. 展开更多
关键词 double PROJECTION point
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Point Cloud Classification Using Content-Based Transformer via Clustering in Feature Space 被引量:2
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作者 Yahui Liu Bin Tian +2 位作者 Yisheng Lv Lingxi Li Fei-Yue Wang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第1期231-239,共9页
Recently, there have been some attempts of Transformer in 3D point cloud classification. In order to reduce computations, most existing methods focus on local spatial attention,but ignore their content and fail to est... Recently, there have been some attempts of Transformer in 3D point cloud classification. In order to reduce computations, most existing methods focus on local spatial attention,but ignore their content and fail to establish relationships between distant but relevant points. To overcome the limitation of local spatial attention, we propose a point content-based Transformer architecture, called PointConT for short. It exploits the locality of points in the feature space(content-based), which clusters the sampled points with similar features into the same class and computes the self-attention within each class, thus enabling an effective trade-off between capturing long-range dependencies and computational complexity. We further introduce an inception feature aggregator for point cloud classification, which uses parallel structures to aggregate high-frequency and low-frequency information in each branch separately. Extensive experiments show that our PointConT model achieves a remarkable performance on point cloud shape classification. Especially, our method exhibits 90.3% Top-1 accuracy on the hardest setting of ScanObjectN N. Source code of this paper is available at https://github.com/yahuiliu99/PointC onT. 展开更多
关键词 Content-based Transformer deep learning feature aggregator local attention point cloud classification
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Material point method simulation of hydro-mechanical behaviour in twophase porous geomaterials: A state-of-the-art review 被引量:2
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作者 Xiangcou Zheng Shuying Wang +1 位作者 Feng Yang Junsheng Yang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期2341-2350,共10页
The material point method(MPM)has been gaining increasing popularity as an appropriate approach to the solution of coupled hydro-mechanical problems involving large deformation.In this paper,we survey the current stat... The material point method(MPM)has been gaining increasing popularity as an appropriate approach to the solution of coupled hydro-mechanical problems involving large deformation.In this paper,we survey the current state-of-the-art in the MPM simulation of hydro-mechanical behaviour in two-phase porous geomaterials.The review covers the recent advances and developments in the MPM and their extensions to capture the coupled hydro-mechanical problems involving large deformations.The focus of this review is aiming at providing a clear picture of what has or has not been developed or implemented for simulating two-phase coupled large deformation problems,which will provide some direct reference for both practitioners and researchers. 展开更多
关键词 Coupled problems Hydro-mechanical behaviour Large deformation Material point Method(MPM)
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Two-Staged Method for Ice Channel Identification Based on Image Segmentation and Corner Point Regression 被引量:1
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作者 DONG Wen-bo ZHOU Li +2 位作者 DING Shi-feng WANG Ai-ming CAI Jin-yan 《China Ocean Engineering》 SCIE EI CSCD 2024年第2期313-325,共13页
Identification of the ice channel is the basic technology for developing intelligent ships in ice-covered waters,which is important to ensure the safety and economy of navigation.In the Arctic,merchant ships with low ... Identification of the ice channel is the basic technology for developing intelligent ships in ice-covered waters,which is important to ensure the safety and economy of navigation.In the Arctic,merchant ships with low ice class often navigate in channels opened up by icebreakers.Navigation in the ice channel often depends on good maneuverability skills and abundant experience from the captain to a large extent.The ship may get stuck if steered into ice fields off the channel.Under this circumstance,it is very important to study how to identify the boundary lines of ice channels with a reliable method.In this paper,a two-staged ice channel identification method is developed based on image segmentation and corner point regression.The first stage employs the image segmentation method to extract channel regions.In the second stage,an intelligent corner regression network is proposed to extract the channel boundary lines from the channel region.A non-intelligent angle-based filtering and clustering method is proposed and compared with corner point regression network.The training and evaluation of the segmentation method and corner regression network are carried out on the synthetic and real ice channel dataset.The evaluation results show that the accuracy of the method using the corner point regression network in the second stage is achieved as high as 73.33%on the synthetic ice channel dataset and 70.66%on the real ice channel dataset,and the processing speed can reach up to 14.58frames per second. 展开更多
关键词 ice channel ship navigation IDENTIFICATION image segmentation corner point regression
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Mobility and dynamic erosion process of granular flow:insights from numerical investigation using material point method 被引量:1
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作者 YU Fangwei SU Lijun +1 位作者 LI Xinpo ZHAO Yu 《Journal of Mountain Science》 SCIE CSCD 2024年第8期2713-2738,共26页
In order to understand the dynamics of granular flow on an erodible base soil,in this paper,a series of material point method-based granular column collapse tests were conducted to investigate numerically the mobility... In order to understand the dynamics of granular flow on an erodible base soil,in this paper,a series of material point method-based granular column collapse tests were conducted to investigate numerically the mobility and dynamic erosion process of granular flow subjected to the complex settings,i.e.,the aspect ratio,granular mass,friction and dilatancy resistance,gravity and presence of water.A set of power scaling laws were proposed to describe the final deposit characteristics of granular flow by the relations of the normalized run-out distance and the normalized final height of granular flow against the aspect ratio,being greatly affected by the complex geological settings,e.g.,granular mass,the friction and dilatancy resistance of granular soil,and presence of water in granular flow.An index of the coefficient of friction of granular soil was defined as a ratio of the target coefficient of friction over the initial coefficient of friction to quantify the scaling extent of friction change(i.e.,friction strengthening or weakening).There is a characteristic aspect ratio of granular column corresponding to the maximum mobility of granular flow with the minimum index of the apparent coefficient of friction.The index of the repose coefficient of friction of granular flow decreased gradually with the increase in aspect ratio because higher potential energy of granular column at a larger aspect ratio causes a larger kinetic energy of granular soil to weaken the friction of granular soil as a kind of velocity-related friction weakening.An increase in granular mass reduces gradually the indexes of the apparent and repose coefficients of friction of granular soil to enhance the mobility of granular flow.The mobility of granular flow increases gradually with the decrease in friction angle or increase in dilatancy angle of granular soil.However,the increase of gravity accelerates granular flow but showing the same final deposit profile without any dependence on gravity.The mobility of granular flow increases gradually by lowering the indexes of the apparent and repose coefficients of friction of granular flow while changing the surroundings,in turn,the dry soil,submerged soil and saturated soil,implying a gradually increased excessive mobility of granular flow with the friction weakening of granular soil.Presence of water in granular flow may be a potential catalyzer to yield a long run-out granular flow,as revealed in comparison of water-absent and water-present granular flows.In addition,the dynamic erosion and entrainment of based soil induced by granular flow subjected to the complex geological settings,i.e.,the aspect ratio,granular mass,gravity,friction and dilatancy resistance,and presence of water,were comprehensively investigated as well. 展开更多
关键词 Column collapse Granular flow Granular soil Material point method MOBILITY Numerical tests
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