检索结果-南通市图书馆

The seamless model for three-dimensional datum transformation

Science China Earth Sciences 2012年第12期55卷 2099-2108页

作者： li BoFeng SHEN YunZhong li weixiao GNSS Research Centre Department of Spatial SciencesCurtin University of TechnologyGPO Box U1987PerthWA 6845Australia Department of Surveying and Geo-informatics Engineering Tongji UniversityShanghai 200092China Centre for Spatial Information Science and Sustainable Development Tongji UniversityShanghai 200092China

With extensive applications of space geodesy, three-dimensional datum transformation model has been necessarily used to transform the coordinates in the different coordinate *** essence is to predict the coordinates of non-common points in the second coordinate system based on their coordinates in the first coordinate system and the coordinates of common points in two coordinate ***, the computation of seven transformation parameters and the transformation of noncommon points are individually implemented, in which the errors of coordinates are taken into account only in the second system although the coordinates in both two systems are inevitably contaminated by the random ***, the coordinate errors of non-common points are disregarded when they are transformed using the solved transformation *** we propose the seamless (rigorous) datum transformation model to compute the transformation parameters and transform the non-common points integratively, considering the errors of all coordinates in both coordinate *** a result, a nonlinear coordinate transformation model is *** on the Gauss-Newton algorithm and the numerical characteristics of transformation parameters, two linear versions of the established nonlinear model are individually *** the least-squares collocation (prediction) method is employed to trivially solve these linear ***, the simulation experiment is carried out to demonstrate the performance and benefits of the presented *** results show that the presented method can significantly improve the precision of the coordinate transformation, especially when the non-common points are strongly correlated with the common points used to compute the transformation parameters.

关键词： coordinate transformation collocation total least squares Bursa model Gauss-Newton method

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

An Efficient Method for Identifying Lower limb Behavior Intentions Based on Surface Electromyography

引用

Computers, Materials & Continua 2023年第12期77卷 2771-2790页

作者： liuyi ling Yiwen Wang Fan Ding li Jin Bin Feng weixiao li Chengjun Wang Xianhua li School of Artificial Intelligence Anhui University of Science and TechnologyHuainan232001China Institute of Environment-Friendly Materials and Occupational Health Anhui University of Science and TechnologyWuhu241003China School of Electrical&Information Engineering Anhui University of Science and TechnologyHuainan232001China School of Mechanical Engineering Anhui University of Science and TechnologyHuainan232001China

Surface electromyography(sEMG)is widely used for analyzing and controlling lower limb assisted exoskeleton *** intention recognition based on sEMG is of great significance for achieving intelligent prosthetic and exoskeleton *** highly efficient recognition while improving performance has always been a significant *** address this,we propose an sEMG-based method called Enhanced Residual Gate Network(ERGN)for lower-limb behavioral intention *** proposed network combines an attention mechanism and a hard threshold function,while combining the advantages of residual structure,which maps sEMG of multiple acquisition channels to the lower limb motion ***,continuous wavelet transform(CWT)is used to extract signals features from the collected sEMG ***,a hard threshold function serves as the gate function to enhance signals quality,with an attention mechanism incorporated to improve the ERGN’s performance *** results demonstrate that the proposed ERGN achieves extremely high accuracy and efficiency,with an average recognition accuracy of 98.41%and an average recognition time of only 20 ms-outperforming the state-of-the-art research *** research provides support for the application of lower limb assisted exoskeleton robots.

关键词： sEMG movement intention efficient network convolutional neural network

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

In vitro investigation of a new thrombus aspiration and autologous blood reinfusion system

引用

Journal of Interventional Medicine 2019年第1期2卷 12-15页

作者： weixiao li Qiang li Shuiting Zhai Tianxiao li Nick Cheshire Zhidong Zhang Kai liang Department of Vascular and Endovascular Surgery Henan Provincial People's HospitalZhengzhou University People's HospitalChina Department of Medical Imaging Henan Provincial People's HospitalZhengzhou University People's HospitalChina Department of Interventional Radiology Henan Provincial People's HospitalZhengzhou University People's HospitalChina Department of Vascular Surgery Royal Brompton&Harefield NHS Foundation TrustImperial College LondonChina

Purpose: The aim of the study was to evaluate the feasibility of a new venous-thrombus aspiration and autologous blood(auto-blood) reinfusion *** and methods: We constructed the venous model from polyvinyl chloride(PVC) tubes and three-way unions using a fresh clot of chicken blood as the venous thrombus. Eight French and 12 F aspiration catheters were used to aspirate the thrombus in the right–pulmonary-artery model, 8 French and 14 F aspiration catheters were used in the inferior–vena cava model, and 8 French and 10 F aspiration catheters were used in the left-–iliofemoral-vein model. A thrombus filtration and auto-blood reinfusion bottle was used to filter the thrombus and re-infuse auto-blood. We evaluated the thrombus aspiration capability of each catheter by comparing preaspirated with the post-aspirated thrombus volume, and we evaluated the difference in aspiration capability between the two catheters in each model by comparing their thrombus aspiration rates. We used Student’s t-test for statistical ***: Differences between pre-aspirated and post-aspirated thrombus volumes for each catheter were insignificant, as were those between the thrombus aspiration rates of the two catheters in each venous model. Using the thrombus aspiration and auto-blood reinfusion system, each aspiration catheter could fluently aspirate the thrombus out of the venous ***: In this study, we designed a new venous-thrombus aspiration system. This system could be used to aspirate acute venous thrombi and re-infuse autologous blood.

关键词： Deep-venous thrombosis Manual aspiration thrombectomy Percutaneous mechanical thrombectomy Autologous blood reinfusion Aspiration catheter

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A canine model of aortic arch aneurysm created with autologous pericardium

引用

Journal of Interventional Medicine 2022年第3期5卷 133-137页

作者： weixiao li Jun li Qiang li Mingzhe Cui Rutao Xu Shuiting Zhai Cheshire Nick Tianxiao li Jiangbo Chen Wenli Zhao Department of Vascular and Endovascular Surgery Zhengzhou University People's HospitalHenan Provincial Peoples HospitalZhenghouChina Operation Department Zhengzhou University People's HospitalHenan Provincial People's HospitalZhenghouChina Department of Medical Imaging Zhengzhou University People's HospitalHenan Provincial People's HospitalZhenghouChina Department of Vascular Surgery Royal Brompton and Harefield HospitalLondonUK Department of Cerebrovascular Disease Zhengzhou University People's HospitalHenan Provincial People's HospitalZhenghouChina

Background:To establish a canine model of aortic arch aneurysm that is suitable for research on new devices and techniques applied to the aortic *** and methods:Fifteen mongrel dogs underwent *** autologous pericardial patch was sewn on the aortotomy site in the anterior wall of the aortic *** animals were followed up for 3 months *** tomography angiography was used to visualize and measure the aneurysm *** and eosin staining was used to observe the histological characteristics of the aneurysm *** in aneurysm diameter over time were analyzed using analysis of ***:One dog died of hemorrhage during *** dogs survived the surgical *** of them died on the first postoperative day because of ruptures at the suturing *** diameter of the aneurysm model was twice as large as that of the aortic *** was no significant change in the maximum diameter of the aneurysm model during the follow-up ***:We established a controllable and stable aortic arch aneurysm model created with an autologous pericardium *** aneurysm model can be used to research endoleaks after thoracic endovascular aortic repair and new endovascular techniques can be applied to the aortic arch.

关键词： Aortic aneurysm Pericardium patch Ascending aorta Aortic arch Animal model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Application of transmesenteric vein extrahepatic portosystemic shunt in treatment of symptomatic portal hypertension with cavernous transformation of portal vein

引用

Journal of Interventional Medicine 2023年第2期6卷 90-95页

作者： weixiao li Mingzhe Cui Qiang li Kewei Zhang Shuiting Zhai Tianxiao li Cheshire Nick Xiuling li Heng Wang Yadong Zhu Danghui Lu Jiangbo Chen Department of Vascular and Endovascular Surgery Zhengzhou University People's HospitalHenan Provincial People's HospitalZhengzhouHenan ProvinceChina Department of Medical Imaging Zhengzhou University People's HospitalHenan Provincial People's HospitalZhengzhouHenan ProvinceChina Department of Cerebrovascular Disease Zhengzhou University People's HospitalHenan Provincial People's HospitalZhengzhouHenan ProvinceChina Department of Vascular Surgery Royal Brompton and Harefield HospitalLondonUK Department of Gastroenterology Zhengzhou University People's HospitalHenan Provincial People's HospitalZhengzhouHenan ProvinceChina

Purpose:To evaluate the feasibility and efficacy of a transmesenteric vein extrahepatic portosystemic shunt(TmEPS)for the treatment of cavernous transformation of the portal vein(CTPV).Materials and methods:The clinical data of 20 patients with CTPV who underwent TmEPS between December 2020and January 2022 at Henan Provincial People’s Hospital were retrospectively *** superior mesenteric vein(SMV)trunk was patent or partially occluded in these *** extrahepatic portosystemic shunt between the inferior vena cava and the SMV was established using a stent graft through an infraumbilical median longitudinal *** technical success,efficacy,and complication rates were evaluated,and the preand postoperative SMV pressures were ***’clinical outcomes and shunt patency were ***:TmEPS was successfully performed in 20 *** initial puncture success rate of the balloon-assisted puncture technique is 95%.The mean SMV pressure decreased from 29.1±2.9 mmHg to 15.6±3.3 mmHg(plications *** the follow-up period,hepatic encephalopathy occurred in two *** remaining patients remained *** shunts were ***:TmEPS is a feasible,safe,and effective treatment option for patients with CTPV.

关键词： Transmesenteric vein extrahepatic portosystemic shunt Cavernous transformation of portal vein Portal vein thrombosis Portal hypertension liver cirrhosis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

德国广播电视考察印象

引用

中国广播电视学刊 2002年第6期 65-66页

作者：李维肖河北省邯郸市广播电视局

去年,我随河北广播电视代表团赴德国北莱茵-威斯特法伦州,对广播电视业进行了短期采访考察.北莱茵-威斯特法伦州位于德国西部,西与比利时、荷兰接壤,是德国人口稠密的地区.德国最大的广播电视台--西德意志广播电视台设于此州.代表团先... 详细信息

去年,我随河北广播电视代表团赴德国北莱茵-威斯特法伦州,对广播电视业进行了短期采访考察.北莱茵-威斯特法伦州位于德国西部,西与比利时、荷兰接壤,是德国人口稠密的地区.德国最大的广播电视台--西德意志广播电视台设于此州.代表团先后考察了位于门兴格拉德巴赫市的RADIO90.1广播电台和位于亚琛市的西德意志广播电视台(以下简称WDR).对德国广播电视的总体现状、运行机制和社会影响等方面有了初步了解,留下了深刻印象.

关键词：德国广播电视办台体制运营模式

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

顾及2套坐标误差的三维坐标变换方法

引用

同济大学学报（自然科学版） 2011年第8期39卷 1243-1246页

作者：李微晓沈云中李博峰同济大学测量与国土信息工程系上海200092 淮海工学院测绘工程学院江苏连云港222001 现代工程测量国家测绘局重点实验室上海200092

探讨顾及2套坐标误差改正数的三维坐标转换模型,以2套坐标改正数的加权平方和最小为准则导出了转换参数的解算公式;并根据公共点的坐标改正数以及公共点与待转换点间的协方差阵计算待转换点的坐标改正数并对其改正,从而求得近似无缝的... 详细信息

探讨顾及2套坐标误差改正数的三维坐标转换模型,以2套坐标改正数的加权平方和最小为准则导出了转换参数的解算公式;并根据公共点的坐标改正数以及公共点与待转换点间的协方差阵计算待转换点的坐标改正数并对其改正,从而求得近似无缝的坐标转换结果.试验表明:当公共点与转换点坐标相关性较大时,该方法能显著地提高坐标转换精度.

关键词：坐标转换最小二乘配置 Bursa模型转换参数

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

基于物联网技术的智慧长输管道

引用

油气储运 2018年第1期37卷 15-19页

作者：王昆李琳李维校西安石油大学

通过研究国内外物联网技术在长输管道中的应用,结合管道完整性管理系统和云计算、大数据技术构建了长输管道物联网技术架构,实现了管道业务流程从调度控制、生产管理、经营管理完整业务链的整体贯通,进而对管道业务各项技术与管理领域... 详细信息

通过研究国内外物联网技术在长输管道中的应用,结合管道完整性管理系统和云计算、大数据技术构建了长输管道物联网技术架构,实现了管道业务流程从调度控制、生产管理、经营管理完整业务链的整体贯通,进而对管道业务各项技术与管理领域的数据流进行有效协调和衔接。依托智慧型长输管道架构,结合管道生产中实际存在的问题,实例应用结果表明:该架构具有可行性和广阔的发展前景。

关键词：物联网油气管道架构水击数据采集与监视控制系统

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

西藏阿里地区耕地的时空分异特征及其影响因素

引用

农业工程学报 2024年第15期40卷 233-244页

作者：李维肖王兆锋张镱锂宫殿清中国科学院地理科学与资源研究所陆地表层格局与模拟重点实验室北京100101 中国科学院大学北京100049 中国科学院青藏高原地球科学卓越创新中心北京100101

研究西藏阿里地区耕地时空分异特征,为阿里土地利用现状、农业用地规划、耕地可持续发展等提供参考。该研究基于Google Earth高分影像,目视解译获取2005、2013和2020年3期阿里地区耕地数据,运用ArcGIS软件识别耕地时空分异及影响因素。... 详细信息

研究西藏阿里地区耕地时空分异特征,为阿里土地利用现状、农业用地规划、耕地可持续发展等提供参考。该研究基于Google Earth高分影像,目视解译获取2005、2013和2020年3期阿里地区耕地数据,运用ArcGIS软件识别耕地时空分异及影响因素。结果发现:1)阿里地区耕地分散破碎,以普兰县西南部和札达县中部的河谷地带较集中,且以小斑块为主。2)在空间分异上,耕地主要分布于海拔3 500~4 500 m、坡度0~6°、坡向西南方、年均降水量0~25 mm、年均温0~5℃、距道路和河流<200 m的区域。3)在时间分异上,2005—2020年,耕地面积整体呈增长趋势,集聚区呈多区域化。阿里南部地区增加缓慢甚至有下降趋势,北部地区增加明显。总体而言阿里地区耕地以区位条件和水热条件为基础条件,并受人口数量、非农化发展水平、市场需求等影响存在时空分异特征,且不同地区耕地分布和面积变化存在差异。

关键词：遥感耕地时空分异目视解译阿里地区

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

多模型融合的时空特征运动想象脑电解码方法

引用

南京大学学报（自然科学版） 2024年第1期60卷 65-75页

作者：凌六一李卫校冯彬安徽理工大学电气与信息工程学院淮南232001 安徽理工大学人工智能学院淮南232001

运动想象脑电(Motor Imagery Electroencephalogram,MI-EEG)已经应用在脑机接口(Brain Computer Interface,BCI)中,能帮助上下肢功能障碍的患者进行康复训练.然而,现有技术对MI-EEG低效的解码性能和对MI-EEG过度依赖预处理的方式限制了... 详细信息

运动想象脑电(Motor Imagery Electroencephalogram,MI-EEG)已经应用在脑机接口(Brain Computer Interface,BCI)中,能帮助上下肢功能障碍的患者进行康复训练.然而,现有技术对MI-EEG低效的解码性能和对MI-EEG过度依赖预处理的方式限制了BCI的广泛发展.提出了一种多模型融合的时空特征运动想象脑电解码方法(Multi-model Fusion Temporal-spatial Feature Motor Imagery EEG Decoding Method,MMFTSF).MMFTSF使用时空卷积网络提取MI-EEG中浅层信息特征,使用多头概率稀疏自注意力机制关注MI-EEG中最具有价值的信息特征,使用时间卷积网络提取MI-EEG高维时间特征,使用带有softmax分类器的全连接层对MI-EEG进行分类,并利用基于卷积的滑动窗口和空间信息增强模块进一步提升MI-EEG解码性能.在公开的BCI竞赛数据集IV-2a上进行验证.实验结果表明,MMFTSF在数据集上达到89.03%的解码准确度,在MI-EEG分类任务中具有理想的分类性能.

关键词：概率稀疏注意力运动想象卷积神经网络时间卷积网络

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：