检索结果-南通市图书馆

Research on Key Issues of Consistency Analysis of Vehicle Steering Characteristics

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2021年第2期34卷 123-134页

作者： yanhua liu Xin Guan Pingping Lu Rui Guo State Key laboratory of Automobile Simulation and Control Jilin UniversityChangchun 200240China

Given the global lack of effective analysis methods for the impact of design parameter tolerance on performance deviation in the vehicle proof-of-concept stage,it is difficult to decompose performance tolerance to design parameter *** study proposes a set of consistency analysis methods for vehicle steering *** process of consistency analysis and control of automotive performance in the conceptual design phase is proposed for the first time.A vehicle dynamics model is constructed,and the multi-objective optimization software Isight is used to optimize the steering performance of the *** analysis is used to optimize the design performance *** tolerance interval of the performance is obtained by comparing the original car performance value with the optimized *** the help of layer-by-layer decomposition theory and interval mathematics,automotive performance tolerance has been decomposed into design parameter *** simulation and real vehicle experiments,the validity of the consistency analysis and control method presented in this paper are *** decomposition from parameter tolerance to performance tolerance can be achieved at the conceptual design stage.

关键词： Interval mathematical theory Layer by layer decomposition theory Consistency of performance Multi-objective optimization

Simulation Research on Dynamic Characteristics of Hydraulic Mount

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2021年第3期34卷 336-344页

作者： yanhua liu Xin Guan Pingping Lu Rui Guo State Key Laboratory of Automobile Simulation and Control Jilin UniversityChangchun 130022China

At present,research on hydraulic mounts has mainly focused on the prediction of the dynamic stiffness and loss *** to the traditional finite element analysis method,the programming method can be used to analyze hydraulic mounts for a rapid and accurate understanding of the influence of the different mounting parameters on the dynamic stiffness and loss *** aims of this study were to investigate the nonlinear dynamic characteristics of a hydraulic mount,and to identify the parameters that affect the dynamic stiffness and loss angle using MATLAB software programs to obtain the influence curves of the parameters,so as to use suitable parameters as the basis for vibration analysis.A nonlinear mechanical model of a hydraulic mount was established according to the basic principles of fluid *** dynamic stiffness and loss angle of the dimensionless expression were proposed.A numerical calculation method for the dynamic performance evaluation index of the hydraulic mount was derived.A one-to-one correspondence was established between the structural parameters and peak frequency of the evaluation *** accuracy and applicability of the mechanical model were verified by the test *** results demonstrated the accuracy of the nonlinear mechanical model of the hydraulic mount,and the vehicle driving comfort was greatly improved by the optimization of the structural parameters.

关键词： Hydraulic mount Vibration analysis Dynamic characteristics Calculation method

Capacitor Voltage Imbalance Mechanism and Balancing Control of MMC When Riding Through PTG Fault

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第2期10卷 778-785页

作者： Zhen He Maozeng Lu Lijun Hang Pingliang Zeng yanhua liu Hangzhou Dianzi University Hangzhou 310018China Shandong University of Technology Zibo 255000China State Grid Hangzhou Power Supply Company State GridHangzhou 310000China

Modular multilevel converter (MMC) based fault ride through (FRT) control is a promising solution to deal with the pole-to-ground (PTG) fault in high voltage direct current (HVDC) system. However, when MMC switches to the FRT control, capacitor voltage imbalance between upper and lower arms will occur, resulting in the deterioration of FRT performance. This letter provides a comprehensive analysis for the imbalance issue from the perspective of fundamental frequency circulating current (FFCC). It is found the imbalance during FRT stage will not expand continuously, but converge to a certain value gradually. The specific imbalance degree is closely associated with the amplitude of FFCC. In order to solve the imbalance issue, an open-loop balancing control is proposed. By introducing a fundamental frequency feedforward item to the inherent circulating current control, the proposed method can not only balance the capacitor voltages, but also minimize the amplitude of FFCC, and consequently the power loss of MMC during FRT process can be reduced. Finally, simulation results of PSCAD/ EMTDC verify the validity of theoretical analysis.

关键词： Balancing control capacitor voltage imbalance FFCC FRT control HVDC system PTG fault

IGED:Towards Intelligent DDoS Detection Model Using Improved Generalized Entropy and DNN

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

Computers, Materials & Continua 2024年第8期80卷 1851-1866页

作者： yanhua liu Yuting Han HuiChen Baokang Zhao XiaofengWang Ximeng liu College of Computer and Data Science Fuzhou UniversityFuzhou350108China Engineering Research Center of Big Data Intelligence Ministry of EducationFuzhou350108China Fujian Key Laboratory of Network Computing and Intelligent Information Processing Fuzhou UniversityFuzhou350108China College of Computer National University of Defense TechnologyChangsha410073China

As the scale of the networks continually expands,the detection of distributed denial of service(DDoS)attacks has become increasingly *** propose an intelligent detection model named IGED by using improved generalized entropy and deep neural network(DNN).The initial detection is based on improved generalized entropy to filter out as much normal traffic as possible,thereby reducing data *** the fine detection is based on DNN to perform precise DDoS detection on the filtered suspicious traffic,enhancing the neural network’s generalization *** results show that the proposed method can efficiently distinguish normal traffic from DDoS *** with the benchmark methods,our method reaches 99.9%on low-rate DDoS(LDDoS),flooded DDoS and CICDDoS2019 datasets in terms of both accuracy and efficiency in identifying attack flows while reducing the time by 17%,31%and 8%.

关键词： DDoS real-time improved generalized entropy DNN

A Blockchain-Based Authentication Protocol for WLAN Mesh Security Access

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

Computers, Materials & Continua 2019年第1期58卷 45-59页

作者： Xin Jiang Mingzhe liu Chen Yang yanhua liu Ruili Wang State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologySichuanChina Institute of Natural and Mathematical Sciences Massey UniversityAucklandNew Zealand

In order to deploy a secure WLAN mesh network,authentication of both users and APs is needed,and a secure authentication mechanism should be ***,some additional configurations of trusted third party agencies are still needed on-site to deploy a secure authentication *** paper proposes a new block chain-based authentication protocol for WLAN mesh security access,to reduce the deployment costs and resolve the issues of requiring key delivery and central server during IEEE 802.11X *** method takes the user’s authentication request as a transaction,considers all the authentication records in the mesh network as the public ledger and realizes the effective monitoring of the malicious ***,this paper analyzes the security of the protocol in detail,and proves that the new method can solve the dependence of the authentication node on PKI and CA.

关键词： WLAN mesh block chain authentication protocol public ledger

Orderly adaptation to climate change： A roadmap for the post-Paris Agreement Era

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

Science China Earth Sciences 2018年第1期61卷 119-122页

作者： WU ShaoHong PAN Tao liu yanhua GAO JiangBo HE XiaoJia Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China College of Resources and Environment University of Chinese Academy of Sciences Beijing 100190 China The Administrative Center for China's Agenda 21 Beijing 100038 China

Mitigation and adaptation are two complementary strategies for addressing climate ***,adaptation has received far less attention than *** response to observed and future climate change,the currently adopted measures for adaptation are ***,constraints,costs and other limitations to adaptation have not been fully recognized(Field et al.,2014).

关键词： adaptation mitigation currently constraints addressing limitations warming costs sector insufficient

Global trends and development of energy services industry in China

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Population,Resources and Environment 2016年第3期16卷 153-158页

作者： Wentao Wang yanhua liu The Administrative Centre for China's Agenda 21 Counselors' Office of the State Council

Energy service is an effective way to promote energy conservation by market mechanisms,including energy saving services,energy procurement,supply of many varieties of energy,supply of renewable energy technologies,energy-related consulting services,risk management,*** is a major energy consumer but energy is in short supply,and the efficiency of energy use is ***'s energy service industry has expanded rapidly,in terms of both the number of new Energy Service Companies entering the market and amount of capital invested in Energy Performance Contracting projects,but the energy service sector in China is still at an early stage of *** countries began early in developing the energy service sector and their energy service market is mature,and the experience of developed countries shows that energy services play a significant role in advancing energy saving and emission *** the new situation,China needs combine energy services experience of developed countries,and take following measures to accelerate China's energy services rapid and healthy development,including the long-term aspects of policy planning,energy-saving core technology,finance and capital investment,public sector reductions,personnel training,and so on.

关键词： energy services industry energy saving USA energy performance contracting

Geopolitics of global climate change and energy security

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Population,Resources and Environment 2015年第2期13卷 119-126页

作者： Wentao Wang yanhua liu The Administrative Centre for China's Agenda 21 Counselors' Office of the State Council

Currently,the problem of climate change is already far beyond the category of scientific research,and it affects the economic operation mode,interests pattern,and geographical relationships and becomes the focus of global *** the transition period of the international economic and social development and the critical transformation period of the world geopolitical pattern reorganization,China's industrialization is still at the intermediate stage,and tackling with climate change is also China's internal demand under this development *** more influence of climate change on national competitiveness,climate change and geopolitics present complex multiple relations,and climate change in the era of geopolitical landscape gradually affected the national strategy and *** article offered some relevant suggestions based on evaluating the new geopolitical characteristics of climate change:(1)weighing of interests and properly handling the complex relations among major powers during international climate negotiations;(2)strengthening risk judgments and actively cooperating with the United States and the European Union on energy and climate change;(3)relying on the"One Belt(Silk Road Economic Belt)and One Road(twenty-first century Maritime Silk Road)"to ensure China's energy security and actively participating in the global energy governance;(4)strengthening the"south-south cooperation"mechanism innovation and increasing the investment.

关键词： climate change energy geopolitics global governance national development strategy

Comparative Study of Structure and Property Changes in Corrosive Media for Self-cleaning Superhydrophobic Magnesium Alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2019年第2期34卷 410-416页

作者：史雪婷 ZHU Yali liu yanhua 冯利邦 School of Materials Science and Engineering Lanzhou Jiaotong University

Magnesium alloys with superhydrophobicity are constructed by controlling rough surface structure and grafting long hydrophobic alkyl chains. Changes of morphology, phase structure, chemical composition as well as wettability, corrosion resistance of superhydrophobic magnesium alloy upon immersing in corrosive media are investigated comparatively. Meanwhile, the contaminating particles on as-prepared superhydrophobic surfaces can be taken away easily by rolling water droplets. Therefore, the results show that as-prepared superhydrophobic magnesium alloys exhibit enhanced corrosion resistance and self-healing performance. Finally, anti-corrosion and self-cleaning mechanisms are deduced. It can be concluded that it is an effective strategy of preparing superhydrophobic surfaces for improving the corrosion resistance and selfcleaning performance of magnesium alloys.

关键词： magnesium alloy superhydrophobicity anti-corrosion self-cleaning