检索结果-南通市图书馆

非线性多智能体系统的无模型自适应聚类一致性控制

在线全文

学校读者我要写书评

暂无评论

控制与决策 2024年第1期39卷 345-352页

作者：李玉涵崔立志卜旭辉郭金丽河南理工大学电气工程与自动化学院河南焦作454000

针对一类模型未知的离散时间非线性多智能体系统聚类一致性问题,提出一种无模型自适应控制算法.首先,假设系统具有固定拓扑,利用伪偏导数概念得到系统的数据关系模型,在考虑多智能体之间耦合系数条件下给出聚类一致性误差,在此基础上设... 详细信息

针对一类模型未知的离散时间非线性多智能体系统聚类一致性问题,提出一种无模型自适应控制算法.首先,假设系统具有固定拓扑,利用伪偏导数概念得到系统的数据关系模型,在考虑多智能体之间耦合系数条件下给出聚类一致性误差,在此基础上设计一种数据驱动的聚类一致性跟踪控制协议;然后,采用压缩映射方法在理论上分析了跟踪误差的收敛性,结果表明所提出算法不需要智能体模型信息即可完成跟踪任务,是一种数据驱动的控制方法;最后,将结果拓展至随机切换拓扑结构的多智能体系统中,数值仿真结果验证了所提出算法的有效性.

关键词：无模型自适应控制多智能体系统聚类一致性数据驱动

中国新能源汽车产业合作创新网络的空间格局及驱动机制

在线全文

学校读者我要写书评

暂无评论

科技创新发展战略研究 2024年第3期8卷 3-16页

作者：袁源郭进利郭曌华上海理工大学管理学院上海200093 延安大学西安创新学院西安710100 上海交通大学船舶海洋与建筑工程学院上海200240

为了解新能源汽车产业发展的现状和技术创新趋势,基于2012一2021年新能源汽车产业专利合作数据构建城际合作创新网络,利用复杂网络分析方法、空间自相关和冷热点方法解析产业空间格局。此外,构建城市数字经济和环境规制评估指标,使用指... 详细信息

为了解新能源汽车产业发展的现状和技术创新趋势,基于2012一2021年新能源汽车产业专利合作数据构建城际合作创新网络,利用复杂网络分析方法、空间自相关和冷热点方法解析产业空间格局。此外,构建城市数字经济和环境规制评估指标,使用指数随机图模型对网络的驱动因素进行研究。结果表明:(1)北京和南京在城市网络中扮演着关键的辐射带动作用。网络中存在“富者愈富”效应,网络结构逐渐平衡和扁平化。(2)全国冷热点空间分布总体表现为“东热西冷”的空间格局,热点区由东部沿海地区向中部蔓延,冷点区和次冷区逐渐转化为正常区和次热区。(3)数字经济在新能源汽车产业网络形成早期表现出显著正相关;严格的环境规制会阻碍企业参与合作创新网络的意愿和能力;有较高度中心性的城市更倾向于吸引其他城市建立合作关系;较高的外部开放度不利于跨城市合作。(4)较远的地理位置阻碍了合作机会的获取;网络中的聚集效应随着产业的发展越来越不明显;传递效应是驱动新能源汽车产业创新网络形成的重要因素。

关键词：新能源汽车复杂网络合作专利技术创新指数随机图模型

维普期刊数据库博看期刊

Multi-Objective Multi-Variable Large-Size Fan Aerodynamic Optimization by Using Multi-Model Ensemble Optimization Algorithm

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2024年第3期33卷 914-930页

作者： XIONG jin guo Penghua li jingyin School of Energy and Power Engineering Xi’an Jiaotong UniversityXi’an710049China

The constrained multi-objective multi-variable optimization of fans usually needs a great deal of computational fluid dynamics(CFD)calculations and is *** this study,a new multi-model ensemble optimization algorithm is proposed to tackle such an expensive optimization *** multi-variable and multi-objective optimization are conducted with a new flexible multi-objective infill *** addition,the search direction is determined by the multi-model ensemble assisted evolutionary algorithm and the feature extraction by the principal component analysis is used to reduce the dimension of optimization ***,the proposed algorithm and other two optimization algorithms which prevail in fan optimizations were compared by using test *** the same number of objective function evaluations,the proposed algorithm shows a fast convergency rate on finding the optimal objective function ***,this algorithm was used to optimize the rotor and stator blades of a large axial fan,with the efficiencies as the objectives at three flow rates,the high,the design and the low flow ***-two variables were included in the optimization *** results show that compared with the prototype fan,the total pressure efficiencies of the optimized fan at the high,the design and the low flow rate were increased by 3.35%,3.07%and 2.89%,respectively,after CFD simulations for 500 fan candidates with the constraint for the design *** optimization results validate the effectiveness and feasibility of the proposed algorithm.

关键词： multi-objective optimization surrogate-assisted evolutionary algorithm axial fan computational fluid dynamics aerodynamic optimization

Effect of boron addition on microstructure and mechanical properties of an additively manufactured superalloy

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research(International) 2023年第3期30卷 601-609页

作者： Rui Wang Dao-hong Wang Peng Zhang Zhi-qing Yang jing-jing liang jin-guo li Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016LiaoningChina School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026AnhuiChina Jiang Su Feiyue Machine and Pump Group Co. Ltd.Jingjiang 225300JiangsuChina

The effect of boron addition(0.010,0.015,and 0.020 wt.%)on the microstructure and mechanical properties of an additively manufactured superalloy was *** as-built microstructure was investigated by scanning electron microscopy and transmission electron *** results demonstrate that boron precipitates as M_(3)B_(2)boride at the grain *** increase in boron content increases the amount ofγ/γ′eutectic and the size and fraction of M_(3)B_(2)*** creates nanoscale fine borides at grain boundaries,which significantly reinforces grain *** mechanical property analysis indicated that the addition of boron improved the tensile ductility at 760℃and stress rupture properties at 760℃/780 ***,with the excessive addition of boron,the mechanical property was reduced.

关键词： Additive manufacturing Superalloy Boron Grain boundary Stress rupture Tension

Effect of sintering temperature on microstructure and properties of 3D printing polysilazane reinforced Al_(2)O_(3)core

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

中国铸造:英文版 2023年第5期20卷 387-394页

作者： Wen-jun Dong Qiao-lei li Tian-ci Chen Ming-ke Zou jing-jing liang li-rong liu Hui Mei jin-guo li School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China Space Manufacturing Technology(CAS Key Lab) Beijing 100094China Science and Technology on Thermostructural Composite Materials Laboratory School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi'an 710072China

Ceramic cores are the key intermediate components of hollow blades for *** processes,such as hot-press molding and gel film casting,face difficulties in fabricating complex-structured ceramic cores due to the complexity of moulds and long process *** 3D printing provides a new idea for the fabrication of complex-structured ceramic *** effect of sintering temperature on open porosity,bulk density,weight loss rate,shrinkage rate,flexural strength and microstructure of the Al_(2)O_(3)-based ceramic core doped with 10vol.%polysilazane(PSZ)was *** sintering mechanism of PSZ-reinforced ceramic cores was *** show that the optimum sintering temperature of PSZ-reinforced ceramic cores is 1,450°*** this temperature,the open porosity of the ceramic core is 36.60%,bulk density is 2.33 g·cm^(-3),weight loss rate is 22.11%,shrinkage rate along the X,Y,Z directions is 5.72%,5.01%,9.61%,respectively;the flexural strength is 28.794 MPa at 25°C and 13.649 MPa at 1,500°*** of 3D printing PSZ-reinforced ceramic cores can meet the casting requirement of superalloy hollow blades,which is expected to promote the industrial application of 3D printing complex structure ceramic cores.

关键词： investment casting ceramic core 3D printing sintering temperature flexural strength

Deep learning for joint channel estimation and feedback in massive MIMO systems

在线全文

学校读者我要写书评

暂无评论

Digital Communications and Networks 2024年第1期10卷 83-93页

作者： Jiajia guo Tong Chen Shi jin Geoffrey Ye li Xin Wang Xiaolin Hou National Mobile Communications Research Laboratory Southeast UniversityNanjing210096China Department of Electrical and Electronic Engineering Imperial College LondonLondonSW72AZUK DOCOMO Beijing Communications Laboratories Co. LtdBeijingChina

The great potentials of massive Multiple-Input Multiple-Output(MIMO)in Frequency Division Duplex(FDD)mode can be fully exploited when the downlink Channel State Information(CSI)is available at base ***,the accurate CsI is difficult to obtain due to the large amount of feedback overhead caused by massive *** this paper,we propose a deep learning based joint channel estimation and feedback framework,which comprehensively realizes the estimation,compression,and reconstruction of downlink channels in FDD massive MIMO *** networks are constructed to perform estimation and feedback explicitly and *** explicit network adopts a multi-Signal-to-Noise-Ratios(SNRs)technique to obtain a single trained channel estimation subnet that works well with different SNRs and employs a deep residual network to reconstruct the channels,while the implicit network directly compresses pilots and sends them back to reduce network *** module is also designed to generate data-bearing *** results show that the two proposed networks exhibit excellent performance of reconstruction and are robust to different environments and quantization errors.

关键词： Channel estimation CSI feedback Deep learning Massive MIMO FDD

Design strategies of high-performance lead-free electroceramics for energy storage applications

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

Rare Metals 2024年第3期43卷 853-878页

作者： Biao guo Fei jin li li Zi-Zhao Pan Xin-Wei Xu Hong Wang Department of Materials Science and Engineering College of EngineeringSouthern University of Science and TechnologyShenzhen518055China School of Microelectronics and State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an710049China

A greater number of compact and reliable electrostatic capacitors are in demand due to the Internet of Things boom and rapidly growing complex and integrated electronic systems,continuously promoting the development of high-energy-density ceramic-based *** significant successes have been achieved in obtaining high energy densities in lead-based ferroelectric ceramics,the utilization of lead-containing ceramies has been restricted due to environmental and health hazards of ***-free ferroelectric ceramics have garnered tremendous attention and are expected to replace lead-based ceramics in the near ***,the energy density of lead-free ceramics is still lagging behind that of lead-containing ***,severely limiting their *** efforts have been made to enhance the energy storage performance of lead-free ceramics using multi-scale design strategies,and exciting progress has been achieved in the past *** review briefly discusses the energy storage mechanism and fundamental characteristics of a dielectric capacitor,summarizes and compares the state-of-the-art design strategies for high-energy-density lead-free ceramics,and highlights several critical issues and requirements for industrial *** prospects and challenges of lead-free ceramics for energy storage applications are also discussed.

关键词： Dielectric materials Lead-free ceramic Environment friendly Energy storage Design strategy

Comparative Experimental Study on Heat Transfer Characteristics of Building Exterior Surface at High and Low Altitudes

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2024年第3期33卷 1119-1131页

作者： JIA Yonghong guo Shurui li jin guo Lei CHENG Zhu ZHANG Yin YANG Hanyu LONG Enshen Institute for Disaster Management and Reconstruction Sichuan UniversityChengdu610065China MOE Key Laboratory of Deep Earth Science and Engineering College of Architecture and EnvironmentSichuan UniversityChengdu610065China

The external surface heat transfer coefficient of building envelope is one of the important parameters necessary for building energy saving design,but the basic data in high-altitude area are ***,the authors propose a modified measurement method based on the heat balance of a model building,and use the same model building to measure its external surface heat transfer coefficient under outdoor conditions in Chengdu city,China at an altitude of 520 m and Daocheng city at an altitude of 3750 m *** results show that the total heat transfer coefficient(h_(t))of building surface in high-altitude area is reduced by 34.48%.The influence of outdoor wind speed on the convective heat transfer coefficient(h_(c))in high-altitude area is not as significant as that in low-altitude *** fitting relation between convection heat transfer coefficient and outdoor wind speed is also *** the same heating power,the average temperature rise of indoor and outdoor air at highaltitude is 41.9%higher than that at low altitude,and the average temperature rise of inner wall is 25.8%higher than that at low *** shows that high-altitude area can create a more comfortable indoor thermal environment than low-altitude area under the same energy consumption *** is not appropriate to use the heat transfer characteristics of the exterior surface of buildings in low-altitude area for building energy saving design and related heating equipment selection and system terminal matching design in high-altitude area.

关键词： altitude heat transfer characteristics convective heat transfer coefficient(h_(c)) radiative heat transfer coefficient(h_(r)) external building envelope

Three-dimensional pseudo-dynamic reliability analysis of seismic shield tunnel faces combined with sparse polynomial chaos expansion

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2024年第6期31卷 2087-2101页

作者： guo Feng-qi li Shi-wei ZOU jin-Feng School of Civil Engineering Central South UniversityChangsha 410075China

To address the seismic face stability challenges encountered in urban and subsea tunnel construction,an efficient probabilistic analysis framework for shield tunnel faces under seismic conditions is *** on the upper-bound theory of limit analysis,an improved three-dimensional discrete deterministic mechanism,accounting for the heterogeneous nature of soil media,is formulated to evaluate seismic face *** metamodel of failure probabilistic assessments for seismic tunnel faces is constructed by integrating the sparse polynomial chaos expansion method(SPCE)with the modified pseudo-dynamic approach(MPD).The improved deterministic model is validated by comparing with published literature and numerical simulations results,and the SPCE-MPD metamodel is examined with the traditional MCS *** on the SPCE-MPD metamodels,the seismic effects on face failure probability and reliability index are presented and the global sensitivity analysis(GSA)is involved to reflect the influence order of seismic action ***,the proposed approach is tested to be effective by a engineering case of the Chengdu outer ring *** results show that higher uncertainty of seismic response on face stability should be noticed in areas with intense earthquakes and variation of seismic wave velocity has the most profound influence on tunnel face stability.

关键词： reliability analysis shield tunnel face sparse polynomial chaos expansion modified pseudo-dynamic approach seismic stability assessment