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Evaluation of measurement uncertainty of the high-speed variable-slit system based on the Monte Carlo method

Yin ZHANG, Jianwei WU, Kunpeng XING, Zhongpu WEN, Jiubin TAN

《机械工程前沿(英文)》 2020年 第15卷 第4期   页码 517-537 doi: 10.1007/s11465-020-0589-z

摘要: This paper presents a dynamic and static error transfer model and uncertainty evaluation method for a high-speed variable-slit system based on a two-dimensional orthogonal double-layer air-floating guide rail structure. The motion accuracy of the scanning blade is affected by both the moving component it is attached to and the moving component of the following blade during high-speed motion. First, an error transfer model of the high-speed variable-slit system is established, and the influence coefficients are calculated for each source of error associated with the accuracy of the blade motion. Then, the maximum range of each error source is determined by simulation and experiment. Finally, the uncertainty of the blade displacement measurement is evaluated using the Monte Carlo method. The proposed model can evaluate the performance of the complex mechanical system and be used to guide the design.

关键词: air-floating guide rail     error transfer model     driving and following structure     dynamic error     uncertainty evaluation     Monte Carlo method    

Extended model predictive control scheme for smooth path following of autonomous vehicles

《机械工程前沿(英文)》 2022年 第17卷 第1期   页码 4-4 doi: 10.1007/s11465-021-0660-4

摘要: This paper presents an extended model predictive control (MPC) scheme for implementing optimal path following of autonomous vehicles, which has multiple constraints and an integrated model of vehicle and road dynamics. Road curvature and inclination factors are used in the construction of the vehicle dynamic model to describe its lateral and roll dynamics accurately. Sideslip, rollover, and vehicle envelopes are used as multiple constraints in the MPC controller formulation. Then, an extended MPC method solved by differential evolution optimization algorithm is proposed to realize optimal smooth path following based on driving path features. Finally, simulation and real experiments are carried out to evaluate the feasibility and the effectiveness of the extended MPC scheme. Results indicate that the proposed method can obtain the smooth transition to follow the optimal drivable path and satisfy the lateral dynamic stability and environmental constraints, which can improve the path following quality for better ride comfort and road availability of autonomous vehicles.

关键词: autonomous vehicles     vehicle dynamic modeling     model predictive control     path following     optimization algorithm    

Right coronary occlusion following transcatheter aortic valve implantation: two case reports

null

《医学前沿(英文)》 2016年 第10卷 第3期   页码 351-355 doi: 10.1007/s11684-016-0465-8

摘要:

This paper discusses two male patients with severe aortic stenosis, whose right coronary arteries (RCA) were completely occluded during transcatheter aortic valve implantation (TAVI), leading to fatal hemodynamic disorder. Occlusions of RCA complicated by TAVI are rare. In addition, emergency cardiopulmonary bypass (CPB) played a critical role in rescuing our second patient. Both patients were admitted for “severe aortic stenosis,” and TAVIs were performed. The first patient’s blood pressure immediately dropped to 70/40 mmHg after the balloon expansion and did not increase much after the administration of aramine or fluid therapy. He did not receive emergency surgery and died after 1.5 h of resuscitation. The second patient’s blood pressure fluctuated greatly for several minutes after the valve implantation, ranging from 170/100 mmHg to 60/40 mmHg. Angiography revealed a total occlusion of RCA. Thoracic surgery with CPB was performed, and the patient survived.

关键词: aortic stenosis     transcatheter aortic valve implantation     right coronary occlusion     cardiac group    

Universal influenza virus vaccines: what can we learn from the human immune response following exposure

null

《医学前沿(英文)》 2017年 第11卷 第4期   页码 471-479 doi: 10.1007/s11684-017-0602-z

摘要:

Several universal influenza virus vaccine candidates based on eliciting antibodies against the hemagglutinin stalk domain are in development. Typically, these vaccines induce responses that target group 1 or group 2 hemagglutinins with little to no cross-group reactivity and protection. Similarly, the majority of human anti-stalk monoclonal antibodies that have been isolated are directed against group 1 or group 2 hemagglutinins with very few that bind to hemagglutinins of both groups. Here we review what is known about the human humoral immune response to vaccination and infection with H7 subtype influenza viruses on a polyclonal and monoclonal level. It seems that unlike vaccination with H5 hemagglutinin, which induces antibody responses mostly restricted to the group 1 stalk domain, H7 exposure induces both group 2 and cross-group antibody responses. A better understanding of this phenomenon and the underlying mechanisms might help to develop future universal influenza virus vaccine candidates.

关键词: universal influenza virus vaccine     hemagglutinin stalk     H7N9    

ORGANIC CARBON STOCKS IN A SILTY TEXTURED SOIL FOLLOWING REINTEGRATION OF A 20 YEARS OLD × SITE INTO

《农业科学与工程前沿(英文)》 2023年 第10卷 第2期   页码 183-197 doi: 10.15302/J-FASE-2023485

摘要:

● 0.98 Mg·ha−1·yr−1 Corg accumulation under miscanthus over 26 years.

关键词: biobased energy crops     C balance     humus accumulation    

Spatiotemporal evolution and driving factors for GHG emissions of aluminum industry in China

《能源前沿(英文)》 2023年 第17卷 第2期   页码 294-305 doi: 10.1007/s11708-022-0819-7

摘要: China’s aluminum (Al) production has released a huge amount of greenhouse gas (GHG) emissions. As one of the biggest country of primary Al production, China must mitigate its overall GHG emission from its Al industry so that the national carbon neutrality target can be achieved. Under such a background, the study described in this paper conducts a dynamic material flow analysis to reveal the spatiotemporal evolution features of Al flows in China from 2000 to 2020. Decomposition analysis is also performed to uncover the driving factors of GHG emission generated from the Al industry. The major findings include the fact that China’s primary Al production center has transferred to the western region; the primary Al smelting and carbon anode consumption are the most carbon-intensive processes in the Al life cycle; the accumulative GHG emission from electricity accounts for 78.14% of the total GHG emission generated from the Al industry; China’s current Al recycling ratio is low although the corresponding GHG emission can be reduced by 93.73% if all the primary Al can be replaced by secondary Al; and the total GHG emission can be reduced by 88.58% if major primary Al manufacturing firms are transferred from Inner Mongolia to Yunnan. Based upon these findings and considering regional disparity, several policy implications are proposed, including promotion of secondary Al production, support of clean electricity penetration, and relocation of the Al industry.

关键词: aluminum     material flow analysis     GHG (greenhouse gas) emissions     LMDI (logarithmic mean divisa index)    

Appendiceal inflammation affects the length of stay following appendicectomy amongst children: a myth

null

《医学前沿(英文)》 2013年 第7卷 第2期   页码 264-269 doi: 10.1007/s11684-013-0259-1

摘要:

The effect of the severity of appendiceal inflammation on post-operative stay in children following appendicectomy has shown conflicting results. This study was conducted to determine the association between the severity of appendiceal inflammation and post-operative stay amongst children undergoing open appendicectomy. A retrospective cohort study was conducted at a District General Hospital for two years. A total of 204 patients were included in the study with an age range between 3 and 16 years. Females were 54.9% while the rest were male. Mean age was 12.5±3 years. The association of the severity of appendiceal inflammation and post-operative stay was assessed by multivariable Cox Proportional hazards model. Mean post-operative stay was 2.32 days (95% CI 2.14–2.51). Macroscopically perforated appendix, histological inflammation and post-operative complications were significantly associated with post-operative stay on univariable analysis (P<0.05). Whereas, the multivariable analysis showed that the post-operative stay was significantly prolonged only in case of either perforated appendix or post-operative complications while it remained unaffected by the histological inflammation.

关键词: appendiceal inflammation     post-operative stay     paediatrics    

基于驾驶脑的智能驾驶车辆硬件平台架构 Article

李德毅,高洪波

《工程(英文)》 2018年 第4卷 第4期   页码 464-470 doi: 10.1016/j.eng.2018.07.015

摘要:

不同智能驾驶试验平台的传感器型号、数量、安装位置各不相同,导致传感器信息处理模块也各不相同;不同驾驶地图,其提供信息的粒度也没有固定标准,由此构成的智能驾驶系统软件模块的数量、接口各不相同。基于以驾驶脑为核心的智能驾驶车辆软件与硬件架构,决策模块将不直接与传感器信息处理模块发生关联,通过驾驶认知的形式化语言,将驾驶认知形式化,由驾驶脑认知形成决策。驾驶认知的形式化降低了传感器数量、类型、安装位置的变化对整个软件架构的影响,使得软件架构可以在不同传感器配置车辆平台上方便地移植。

关键词: 驾驶脑     智能驾驶     硬件平台架构    

Mechanism of self-excited torsional vibration of locomotive driving system

Jianxin LIU, Huaiyun ZHAO, Wanming ZHAI

《机械工程前沿(英文)》 2010年 第5卷 第4期   页码 465-469 doi: 10.1007/s11465-010-0115-9

摘要: A single wheelset drive model and 2-DOFs torsional vibration model were established to investigate the self-excited torsional vibration of a locomotive driving system. The simulation results indicate that the self-excited torsional vibration occurs when the steady slip velocity is located at the descending slope of the adhesion coefficient curve. The principle of energy conservation was used to analyze the mechanism of the self-excited vibration. The factors affecting on the amplitude of the self-excited vibration are studied.

关键词: locomotive     driving system     self-excited torsional vibration     mechanism     influence factor    

Improved control of hypertension following laparoscopic fundoplication for gastroesophageal reflux disease

null

《医学前沿(英文)》 2017年 第11卷 第1期   页码 68-73 doi: 10.1007/s11684-016-0490-7

摘要:

This study aims to determine whether successful laparoscopic fundoplication for gastroesophageal reflux disease (GERD) can improve the control of hypertension. We conducted an observational study of GERD patients with hypertension. The esophageal and gastroesophageal symptoms of these patients were successfully treated with laparoscopic fundoplication, as measured by the reduced GERD symptoms and proton pump inhibitor consumption. A hypertension control scale was used to classify the use of antihypertensive medications and the quality of blood pressure control before and after anti-reflux surgery. Wilcoxon signed-ranks test was used for the statistical analyses. Seventy GERD patients were included in the analysis and followed up for a mean period of 3.5±1.4 years. Prior to surgery, all participating patients were taking at least one class of antihypertensive medication, and 56 patients (80%) had intermittently high blood pressure. After surgery, the mean number of antihypertensive medication classes per patient was significantly reduced from 1.61±0.77 pre-procedure to 1.27±0.88 post-procedure (P?<?0.001). The blood pressure of 48 of the 56 cases (86%) with preoperative intermittent high blood pressure returned to normal post procedure. A total of 50 patients (71%) recorded improvements on the hypertension control scale, with the overall mean score decreasing from 3.1±1.0 pre-procedure to 1.4±1.0 post-procedure (P?<?0.001). Therefore, successful laparoscopic fundoplication may result in better blood pressure control in some hypertensive GERD patients. This result suggests a possible connection between gastroesophageal reflux and hypertension.

关键词: gastroesophageal reflux disease     hypertension     blood pressure     laparoscopic fundoplication    

APFD:面向移动轨迹大数据的出租车路径推荐方法 Research Article

陈卫彬1,3,陈杨杨1,2,张亚1,2

《信息与电子工程前沿(英文)》 2022年 第23卷 第10期   页码 1511-1521 doi: 10.1631/FITEE.2100476

摘要:

本文研究了连续反馈方法在有限时间内同时实现路径跟踪和沿期望轨道编队运动控制的应用。假设虚拟领导者和跟随者之间的拓扑结构是有方向的。设计了一种称为障碍函数的附件条件,使所有智能体在一个有限的区域内移动。首先,基于障碍函数和反步法,设计了一种新型的连续有限时间路径跟踪控制算法。然后,通过将路径跟踪误差视为扰动,设计了一种新型的连续有限时间编队控制算法。详细研究了所得系统的稳定时间特性,并对所提策略进行仿真验证。

关键词: 有限时间;协同路径跟踪;多智能体系统;障碍函数    

Overexpression of netrin-1 improves neurological outcomes in mice following transient middle cerebral

null

《医学前沿(英文)》 2011年 第5卷 第1期   页码 86-93 doi: 10.1007/s11684-011-0118-x

摘要:

Netrin-1 (NT-1) is one of the axon-guiding molecules that are critical for neuronal development. Because of its structural homology to the endothelial mitogens, NT-1 may have similar effects on vascular network formation. NT-1 was shown to be able to stimulate the proliferation and migration of human cerebral endothelial cells in vitro and also promote focal neovascularization in adult brain in vivo. In the present study, we reported the delivery of NT-1 using an adeno-associated virus (AAV) vector (AAV-NT-1) into mouse brain followed by transient middle cerebral artery occlusion (tMCAO). We found that AAV vectors did not elicit a detectable inflammatory response, cell loss or neuronal damage after brain transduction. The level of NT-1 was increased in the AAV-NT-1-transduced tMCAO mice compared with the control mice. Furthermore, the neurobehavioral outcomes were significantly improved in AAV-NT-1-transduced mice compared with the control animals (P<0.05) 7 days after tMCAO. Our data suggests that NT-1 plays a neuronal function recovery role in ischemic brain and that NT-1 gene transfer might present a valuable approach to treat brain ischemic disorders.

关键词: adeno-associated virus     angiogenesis     gene transfer     ischemia     middle cerebral artery occlusion     netrin-1    

自动驾驶地图有关政策的思考和建议

刘经南,董杨,詹骄,高柯夫

《中国工程科学》 2019年 第21卷 第3期   页码 92-97 doi: 10.15302/J-SSCAE-2019.03.004

摘要:

自动驾驶地图作为实现汽车自动驾驶的关键基础设施,对于推动我国自动驾驶领域的商业化开发至关重要。现阶段,我国受地图测绘、应用和监管等相关法律法规的制度掣肘,在自动驾驶地图的产业化进程方面相对滞后。为此,本文着重分析了我国在自动驾驶地图开发、应用和管理中面临的主要政策法规问题:自动驾驶地图是否需加密的问题、自动驾驶地图部分地理信息表达受限的问题、自动驾驶地图地理信息采集资质和审图流程的问题、自动驾驶地图事故责任和保险问题、自动驾驶地图相关测试规范和测试场景问题。同时结合国内外自动驾驶领域的发展趋势,给出加快我国自动驾驶汽车开发和商业化进程的四点建议:制定自动驾驶地图管理模式、允许自动驾驶地图应用试点及有序开放、适当放开企业权限及优化审核流程、建立国家级自动驾驶地图平台。

关键词: 自动驾驶地图     自动驾驶法规     自动驾驶政策    

一种用于自动驾驶的车辆概率性长期轨迹预测框架 Article

刘金鑫, 罗禹贡, 钟志华, 李克强, 黄荷叶, 熊辉

《工程(英文)》 2022年 第19卷 第12期   页码 228-239 doi: 10.1016/j.eng.2021.12.020

摘要:

在混合动态交通环境中,准确地预测周围车辆长期范围内的运动轨迹是自动驾驶车辆(AV)实现合理行为决策和保障行车安全不可或缺的前提条件之一。本文提出了一种车辆长期轨迹预测的概率框架,由驾驶意图推理模型(DIM)和轨迹预测模型(TPM)组成。DIM基于动态贝叶斯网络进行设计和应用,用于准确推断车辆潜在的驾驶意图。文中所提出的DIM结合了基本的交通规则和车辆多维运动信息。为了进一步提高轨迹预测精度并实现预测不确定性识别,本文开发了基于高斯过程(GP)的TPM,综合考虑了车辆模型的短期预测结果和运动特性。最后,在高速换道场景下进行仿真验证,说明了新方法的有效性。通过与其他先进方法进行对比,展示并验证了该框架在车辆长期轨迹预测任务中的优异性能。

关键词: 自动驾驶     动态贝叶斯网络     驾驶意图识别     高斯过程     车辆轨迹预测    

c-Fos expression in rat brainstem following intake of sucrose or saccharin

Ke Chen, Jianqun Yan, Jinrong Li, Bo Lv, Xiaolin Zhao

《医学前沿(英文)》 2011年 第5卷 第3期   页码 294-301 doi: 10.1007/s11684-011-0144-8

摘要: To examine whether the activation of brainstem neurons during intake of a sweet tastant is due to orosensory signals or post-ingestive factors, we compared the distribution of c-Fos-like immunoreactivity (c-FLI) in the nucleus of the solitary tract (NST) and parabrachial nucleus (PBN) of brainstem following ingestion of 0.25 M sucrose or 0.005 M saccharin solutions. Immunopositive neurons were localized mainly in the middle zone of the PBN and four rostral-caudal subregions of the NST. Intake of sucrose increased the number of FLI neurons in almost every subnucleus of the PBN (F = 7.610, = 0.023), in addition to the caudal NST at the level of the area postrema (F = 10.777, = 0.003) and the NST intermediate zone (F = 7.193, = 0.014). No significant increase in the number of c-Fos positive neurons was detected in response to saccharin ingestion, although there was a trend towards a modest increase in a few select NST and PBN nuclei. These results suggest that the PBN and NST may be involved in sweet taste perception and modulation of sweet tastant intake, but the significantly enhanced intensity of Fos expression induced by sucrose indicates that PBN/NST neuronal activity is driven by the integrated effects of sweet taste sensation and post-ingestive signals.

关键词: c-Fos     parabrachial     the nucleus of the solitary tract     sweet tastant     rat    

标题 作者 时间 类型 操作

Evaluation of measurement uncertainty of the high-speed variable-slit system based on the Monte Carlo method

Yin ZHANG, Jianwei WU, Kunpeng XING, Zhongpu WEN, Jiubin TAN

期刊论文

Extended model predictive control scheme for smooth path following of autonomous vehicles

期刊论文

Right coronary occlusion following transcatheter aortic valve implantation: two case reports

null

期刊论文

Universal influenza virus vaccines: what can we learn from the human immune response following exposure

null

期刊论文

ORGANIC CARBON STOCKS IN A SILTY TEXTURED SOIL FOLLOWING REINTEGRATION OF A 20 YEARS OLD × SITE INTO

期刊论文

Spatiotemporal evolution and driving factors for GHG emissions of aluminum industry in China

期刊论文

Appendiceal inflammation affects the length of stay following appendicectomy amongst children: a myth

null

期刊论文

基于驾驶脑的智能驾驶车辆硬件平台架构

李德毅,高洪波

期刊论文

Mechanism of self-excited torsional vibration of locomotive driving system

Jianxin LIU, Huaiyun ZHAO, Wanming ZHAI

期刊论文

Improved control of hypertension following laparoscopic fundoplication for gastroesophageal reflux disease

null

期刊论文

APFD:面向移动轨迹大数据的出租车路径推荐方法

陈卫彬1,3,陈杨杨1,2,张亚1,2

期刊论文

Overexpression of netrin-1 improves neurological outcomes in mice following transient middle cerebral

null

期刊论文

自动驾驶地图有关政策的思考和建议

刘经南,董杨,詹骄,高柯夫

期刊论文

一种用于自动驾驶的车辆概率性长期轨迹预测框架

刘金鑫, 罗禹贡, 钟志华, 李克强, 黄荷叶, 熊辉

期刊论文

c-Fos expression in rat brainstem following intake of sucrose or saccharin

Ke Chen, Jianqun Yan, Jinrong Li, Bo Lv, Xiaolin Zhao

期刊论文