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基于多序列MRI影像组学模型预测脑膜瘤组织学分型的价值

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中国实验诊断学 2024年第3期28卷 278-286页

作者：孔春雨莫展豪程斯文隋赫宛迎春吴帅范晓飞吕忠文吉林大学中日联谊医院放射线科吉林长春130033 吉林大学中日联谊医院超声科吉林长春130033 吉林大学中日联谊医院内分泌科吉林长春130033

目的探究基于常规多序列MRI的影像组学模型在术前预测纤维型和非纤维型脑膜瘤的价值,以助于临床术前准备及预后评估。方法回顾性分析了自2013年3月至2022年12月经手术后病理证实的共317例脑膜瘤患者的临床及多序列MRI(包括T1WI、T2WI、T... 详细信息

目的探究基于常规多序列MRI的影像组学模型在术前预测纤维型和非纤维型脑膜瘤的价值,以助于临床术前准备及预后评估。方法回顾性分析了自2013年3月至2022年12月经手术后病理证实的共317例脑膜瘤患者的临床及多序列MRI(包括T1WI、T2WI、T2WIFLAIR、T1WI增强)资料。手动勾画获得脑膜瘤强化区作为感兴趣区域(EnHROI),并分别将勾画区域向外周各自膨胀3 mm、5 mm得到EnH3mmROI、EnH5mmROI,对每个MRI序列的三种ROI分别提取影像特征,分别采用5折交叉验证法和留一法交叉验证(LOOCV)分别进行特征筛选、模型验证及比较。使用相关系数法和最小绝对收缩和选择算子(least absolute shrinkage and selection operator,LASSO)算法进行特征选择,随后使用支持向量机的机器学习算法(AVM)构建模型,最后评估不同预测模型的效能。结果利用受试者工作特征曲线(receiver-operating characteristic curve,ROC)评估预测脑膜瘤分型的影像组学模型中,基于EnH3mmROI的预测模型均优于基于EnHROI的模型及EnH5mmROI的模型。基于EnHROI模型AUC值为0.801、准确率为0.842;基于EnH3mmROI模型AUC值为0.858、准确率为0.842;基于EnH5mmROI模型AUC值为0.841、准确率为0.868。结论(1)基于EnH3mmROI所建立的影像组学预测模型效能明显优于基于EnHROI及EnH5mmROI所建立的预测模型。(2)基于常规多序列MRI图像建立的术前预测脑膜瘤组织学分型的影像组学模型具有一定的临床价值,有助于临床判断预后以及为治疗计划提供依据。

关键词：脑膜瘤影像组学组织学分型磁共振成像

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稻茬烤烟下部4片烟叶一次性采收成熟度研究

作物杂志 2024年第2期 129-138页

作者：江智敏张仲文章程郑宏斌王卫民李思军侯建林邓小强吴文信朱林邓永晟邓小华浙江中烟工业有限责任公司浙江杭州310008 湖南省烟草公司郴州市公司桂阳县分公司湖南郴州424400 湖南农业大学农学院湖南长沙410128

为明确稻茬烤烟下部烟叶一次性采收适宜成熟度,以云烟87为材料,设计低成熟度、中等成熟度和高成熟度3个处理,在湖南省桂阳烟区开展试验,并采用模糊评价方法对其烤后烟叶质量和经济性状进行综合评价。结果表明,随下部烟叶采收成熟度提高... 详细信息

为明确稻茬烤烟下部烟叶一次性采收适宜成熟度,以云烟87为材料,设计低成熟度、中等成熟度和高成熟度3个处理,在湖南省桂阳烟区开展试验,并采用模糊评价方法对其烤后烟叶质量和经济性状进行综合评价。结果表明,随下部烟叶采收成熟度提高,鲜烟叶的叶绿素相对含量(SPAD值)下降;微带青烟叶比例减少,杂色烟叶比例增加;烟叶结构疏松,油分增加;烟叶单叶重下降,平衡含水率降低;烟叶总糖、还原糖和绿原酸含量下降,烟碱和淀粉含量增加;烟叶产量和产值下降。中等成熟度处理外观质量指数、物理性状指数、化学成分可用性指数、评吸总分、经济性状指数、烟叶质量指数和经济效果综合指数均最高。湖南省桂阳烟区云烟87下部烟叶适宜一次性采收成熟特征为叶片淡绿,主脉淡绿至变白1/3,叶缘微卷曲,叶面无成熟斑,采收指导SPAD值为19.39~26.63。

关键词：稻茬烤烟下部烟叶一次性采收适宜成熟度模糊综合评价

Grouping bi-chi-squared method for pulsar navigation experiment using observations of Rossi X-ray timing explorer

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Chinese Journal of Aeronautics 2023年第1期36卷 386-395页

作者： Haifeng SUN Jianyu SU zhongwen DENG Lirong SHEN Weimin BAO Xiaoping LI Liansheng LI Zhe SU Wencong WANG School of Aerospace Science and Technology Xidian UniversityXi’an 710126China Shaanxi Key Laboratory of Space Extreme Detection Xi’an 710126China Peng cheng Laboratory Shenzhen 518000China Academy of Advanced Interdisciplinary Research Xidian UniversityXi’an 710126China Beijing Institute of Control Engineering Beijing 100190China Institute of Space Electronic Information Technology Xi’an 710100China Shandong Institute of Aerospace Electronic Technology Yantai 264032China

X-ray pulsar-based navigation is a revolutionary technology which is capable of providing the required navigation information in the solar system. Performing as an important pulsar-based navigation technique, the Significance Enhancement of Pulse-profile with Orbit-dynamics(SEPO)can estimate orbital elements by using the distortion of pulse profile. Based on the SEPO technique,we propose a grouping bi-chi-squared technique and adopt the observations of Rossi X-ray Timing Explorer(RXTE) to carry out experimental verification. The pulsar timing is refined to determine spin parameters of the Crab pulsar(PSR B0531+21) during the observation periods, and a short-term dynamic model for RXTE satellite is established by considering the effects of diverse *** results suggest that the position and velocity errors are 16.3 km(3σ) and 13.3 m/s(3σ) with two adjacent observations split by one day(exposure time of 1.5 ks), outperforming those of the POLAR experiment whose results are 19.2 km(3σ) and 432 m/s(3σ). The approach provided is particularly applicable to the estimation of orbital elements via using high-flux observations.

关键词： Model buildings Navigation analysis Navigation testing Pulsars RXTE observations

Observer-based Model Predictive Control Design for Air Supply System of Automotive PEM Fuel Cells

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Observer-based Model Predictive Control Design for Air Suppl...

第三十九届中国控制会议

作者： Weihai Jiang zhongwen Zhu cheng Li Zhang cheng Zichen Zheng School of Electrical and Information Engineering Tianjin University China Automotive Technology and Research Center Co. Ltd

The air supply system control strategy is a significant challenge issue of PEM（Polymer Electrolyte Membrane） fuel cells. In this paper, an observer-based model predictive control scheme is proposed for oxygen excess ratio control to avoid the oxygen starvation without using physical sensor of oxygen excess ratio based on a nonlinear dynamic model. Firstly, a sliding mode PI observer is proposed to estimate the cathode pressure and oxygen excess ratio, and the convergence is also discussed by a constructed Lyapunov function. Then, the observer-based model predictive controller is designed for the oxygen excess ratio control. Finally, the simulation validation is demonstrated to validate the effectiveness of the proposed observer and the control scheme by a high fidelity model.

关键词： Air System PEM Fuel Cells Observer Convergence Model Predictive Control

Research on Control Strategy of Steer-by-wire System for the In-wheel Motor Electric Vehicle Based on Double Fuzzy Control

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Research on Control Strategy of Steer-by-wire System for the...

2020中国汽车工程学会年会暨展览会

作者： Li cheng Wei Qing Zhu zhongwen Wang Xu China Automotive Technology ＆ Research Center Co.Ltd

Aiming at the steer-by-wire control system of in-wheel motor electric vehicle.A control strategy of steer-by-wire system is proposed for *** the steering wheel angle and the velocity as input,and establishing the output torque distribution coefficient of fuzzy control rule *** order to improve the steering stability and sensitivity,The difference between ideal and actual yaw rate is introduced,and the dynamic correction coefficient is obtained by establishing fuzzy controller combine with torque distribution *** simulation and experiment test results show that the control strategy based on yaw rate difference optimization can ensure the stability of vehicle steering and And improve the sensitivity of *** effectively avoids the side slip and tail off dangerous conditions when steering.

关键词： in-wheel driving steer by wire yaw rate fuzzy control

Research on Fuzzy Energy Control Strategy for Four-wheel Hybrid Electric Vehicle

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Research on Fuzzy Energy Control Strategy for Four-wheel Hyb...

2019中国汽车工程学会年会

作者： Li cheng Wang Xu Zhu zhongwen Wei Qing China Automotive Technology ＆ Research Center Co. Ltd.

Aiming at the four-wheel drive hybrid structure,this paper aims at minimizing fuel consumption,takes full account of vehicle status,and designs a control strategy of working mode management and rule-based multi-power source energy *** order to further improve the rationality of energy distribution,the ratio K of the demand torque to the optimal torque and SOC are the two inputs of the fuzzy controller,and engine torque working coefficient y is an output of fuzzy *** fuzzy control system is designed and the fuzzy control rules are established to optimize the engine working torque in real *** simulation results show that the energy management strategy of the fuzzy optimal control accords with the demand of power train,realizes the smooth switching of working mode,reduces the speed error obviously,and improves the fuel economy by 7.81%.

关键词： four-wheel drive hybrid electric vehicle energy management fuzzy control simulation

Observer Based Decoupling Control Research of Fuel Cell Air Supply System

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Observer Based Decoupling Control Research of Fuel Cell Air ...

第40届中国控制会议

作者： Weihai Jiang Boqi Sun cheng Li zhongwen Zhu Xiaowei Li School of Electrical and Information Engineering Tianjin University China Automotive Technology & Research Center Co. Ltd

Accurate control of fuel cell air supply system is critical to fuel cell system output efficiency and life. However, due to air compressor, back pressure valve, pipeline and other auxiliary components of the air system, the system state variables have complex nonlinear coupling and response delay problems, which make the control extremely difficult. In addition, the critical state variables of the system, such as the air flow, cannot be measured, which further increases the difficulty of the air system control. In this paper, a decoupled control architecture based adaptive observer is proposed to improve the control accuracy of transient conditions. First of all, a control-oriented air system model is designed in this paper. And then, an adaptive observer for inlet air flow and cathode pressure is developed based on the model and its stability is proved by using the stability theory method. Finally, An observer-based closed-loop decoupling control algorithm is designed and an experiment is conducted in hardware-in-loop test equipment. The experimental result shows that the observer proposed in this paper can accurately estimate the key variables of the system and ensure the stability, and the control architecture proposed in this paper can realize the precise decoupling control of the air system.

关键词： fuel cell air supply system observer decoupling control

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氢燃料电池汽车整车集成式热管理系统研究

汽车工程 2023年第11期45卷 1991-2000页

作者：朱仲文汪鑫江维海李丞合肥工业大学汽车工程技术研究院合肥230009 汽车零部件先进制造技术教育部重点实验室(重庆理工大学) 重庆400054

有效的热管理对于燃料电池汽车(fuel cell vehicles,FCV)的高效运行至关重要。燃料电池汽车热管理多采用各子系统独立管理方式,然而这种独立的方式并不能很好地利用自身余热从而提高热管理效率和续航里程。对此,本文开发了一种利用燃料... 详细信息

有效的热管理对于燃料电池汽车(fuel cell vehicles,FCV)的高效运行至关重要。燃料电池汽车热管理多采用各子系统独立管理方式,然而这种独立的方式并不能很好地利用自身余热从而提高热管理效率和续航里程。对此,本文开发了一种利用燃料电池余热的整车集成式热管理(vehicle integrated thermal management,VITM)系统,采用热交换器进行一体化的VITM,实现燃料电池的余热回收和各部件高效的热管理,通过六通阀的集成设计实现各回路解耦的灵活管理。并在AMESim仿真平台上开展热管理的仿真研究。结果表明:本文开发的VITM系统能保持燃料电池汽车各部件稳定维持在规定的工作温度范围内;在-10℃的环境温度下,利用燃料电池余热作为热源的热泵空调给动力电池加热,与直接加热模式相比,加热时间缩短55%;给乘员舱加热的时间缩短85%,且能耗比(coefficient of performance,COP)值为4,能耗降低75%。

关键词：燃料电池汽车集成式热管理余热回收

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盒形件冲压拉深成形数值模拟研究

机械制造 2020年第8期58卷 72-77页

作者：许多盛程仲文易湘斌罗文翠苏学众杨赓兰州工业学院机械电子工程学院兰州730050

通过对盒形件冲压拉深成形过程进行数值模拟,得到成形后零件的成形极限图和侧壁厚度分布图,进而研究冲压拉深时压边间隙和凸模圆角半径对盒形件成形质量的影响。研究结果表明,压边间隙为1.08 mm,凸模圆角半径为6 mm时,能够明显改善盒形... 详细信息

通过对盒形件冲压拉深成形过程进行数值模拟,得到成形后零件的成形极限图和侧壁厚度分布图,进而研究冲压拉深时压边间隙和凸模圆角半径对盒形件成形质量的影响。研究结果表明,压边间隙为1.08 mm,凸模圆角半径为6 mm时,能够明显改善盒形件的冲压拉深成形质量。

关键词：盒形件冲压拉深数值模拟