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钢筋混凝土空心板行模挤压成型机设计计算
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作者 安国社 李树晖 刘满银 《西北轻工业学院学报》 1995年第2期12-18,共7页
本文对钢筋混凝土空心板行模挤压成型机的结构作了设计,并对关键零件螺旋绞刀作了强度校核,使减速、分动器输入为一体,送料用振动下料,结构紧凑合理,减少材料消耗、功率消耗、提高生产率。为空心板成型机设计找到了可靠的理论依据。
关键词 挤压成型机 设计 混凝土空心板 行模
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分布交互三维视景行为-特征建模方法研究 被引量:24
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作者 杨克俭 刘舒燕 陈定方 《计算机辅助设计与图形学学报》 EI CSCD 北大核心 2000年第11期846-850,共5页
分布交互三维视景提出了两个新的问题 :更有效的建模方法和如何解决视景质量与 Internet传输速度的矛盾 ?针对以上两个问题 ,提出了一种更为有效的分布交互三维视景“行为 -特征建模”
关键词 为-特征建 分布处理 三维视景 虚拟现实
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行走人体的多刚力学模型 被引量:1
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作者 林良明 陈大跃 孙志宏 《中国康复医学杂志》 CAS CSCD 1995年第1期31-33,共3页
行走人体的多刚力学模型上海交通大学林良明,陈大跃,孙志宏临床医学证实:步态分析已作为诊断下肢损伤、中枢神经和脑瘫等疾病的一种有效手段。然而目前先进的步态分析系统(如:美国CODA-Ⅲ、英国VICON等)都需用4~6台... 行走人体的多刚力学模型上海交通大学林良明,陈大跃,孙志宏临床医学证实:步态分析已作为诊断下肢损伤、中枢神经和脑瘫等疾病的一种有效手段。然而目前先进的步态分析系统(如:美国CODA-Ⅲ、英国VICON等)都需用4~6台摄像机和坐标发生器来测量人体运动[... 展开更多
关键词 多刚力学 人体 康复医学工程
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Influence of pier height on the safety of trains running on high-speed railway bridges during earthquakes
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作者 NIE Yu-tao GUO Wei +8 位作者 JIANG Li-zhong YU Zhi-wu ZENG Chen WANG Yang HE Xu-en REN Shao-xun HUANG Ren-qiang LIANG Guang-yue LI Chang-qing 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第6期2102-2115,共14页
Sudden earthquakes pose a threat to the running safety of trains on high-speed railway bridges,and the stiffness of piers is one of the factors affecting the dynamic response of train-track-bridge system.In this paper... Sudden earthquakes pose a threat to the running safety of trains on high-speed railway bridges,and the stiffness of piers is one of the factors affecting the dynamic response of train-track-bridge system.In this paper,a experiment of a train running on a high-speed railway bridge is performed based on a dynamic experiment system,and the corresponding numerical model is established.The reliability of the numerical model is verified by experiments.Then,the experiment and numerical data are analyzed to reveal the pier height effects on the running safety of trains on bridges.The results show that when the pier height changes,the frequency of the bridge below the 30 m pier height changes greater;the increase of pier height causes the transverse fundamental frequency of the bridge close to that of the train,and the shaking angle and lateral displacement of the train are the largest for bridge with 50 m pier,which increases the risk of derailment;with the pier height increases from 8 m to 50 m,the derailment coefficient obtained by numerical simulations increases by 75% on average,and the spectral intensity obtained by experiments increases by 120% on average,two indicators exhibit logarithmic variation. 展开更多
关键词 pier height high-speed railway bridge running safety numerical model
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In-situ Micro-CT analysis of deformation behavior in sandwich-structured meta-stable beta Ti−35Nb alloy
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作者 Yu-jing LIU Zi-lin ZHANG +4 位作者 Jin-cheng WANG Xiang WU Xiao-chun LIU Wei-ying HUANG Lai-chang ZHANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第8期2552-2562,共11页
Beta Ti−35Nb sandwich-structured composites with various reinforcing layers were designed and produced using additive manufacturing(AM)to achieve a balance between light weight and high strength.The impact of reinforc... Beta Ti−35Nb sandwich-structured composites with various reinforcing layers were designed and produced using additive manufacturing(AM)to achieve a balance between light weight and high strength.The impact of reinforcing layers on the compressive deformation behavior of porous composites was investigated through micro-computed tomography(Micro-CT)and finite element method(FEM)analyses.The results indicate that the addition of reinforcement layers to sandwich structures can significantly enhance the compressive yield strength and energy absorption capacity of porous metal structures;Micro-CT in-situ observation shows that the strain of the porous structure without the reinforcing layer is concentrated in the middle region,while the strain of the porous structure with the reinforcing layer is uniformly distributed;FEM analysis reveals that the reinforcing layers can alter stress distribution and reduce stress concentration,thereby promoting uniform deformation of the porous structure.The addition of reinforcing layer increases the compressive yield strength of sandwich-structured composite materials by 124%under the condition of limited reduction of porosity,and the yield strength increases from 4.6 to 10.3 MPa. 展开更多
关键词 beta titanium alloy sandwich-structured composite in-situ micro-computed tomography finite element modeling compressive behavior
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基于心理模型的汽车满意度数据可视化系统交互式GUI研究
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作者 杨靖 孙静伟 张丹 《汽车工业研究》 2016年第9期19-24,共6页
"以用户为中心"的思想已成为交互界面设计领域的主流,心理学研究中的"用户心理模型"对于交互式界面研究具有积极地促进作用,良好匹配用户心理模型的界面,能够显著缩小用户在认知界面过程中执行阶段与评估阶段的障碍... "以用户为中心"的思想已成为交互界面设计领域的主流,心理学研究中的"用户心理模型"对于交互式界面研究具有积极地促进作用,良好匹配用户心理模型的界面,能够显著缩小用户在认知界面过程中执行阶段与评估阶段的障碍,从而提升界面的易用性和用户的使用体验。本文通过用户行为观察和用户访谈等研究方法对数据可视化系统的相关汽车企业用户进行实际调研,搭建了有针对性的"用户心理模型",使设计人员深入有效地定位到了汽车企业用户的需求,并据此对可视化系统界面进行了初步设计。 展开更多
关键词 心理 满意度 可视化
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Operational modal identification of suspension bridge based on structural health monitoring system 被引量:7
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作者 李枝军 李爱群 韩晓林 《Journal of Southeast University(English Edition)》 EI CAS 2009年第1期104-107,共4页
An output-only modal identification method by a combination use of the peak-picking method and the cross spectrum methods are presented. Meanwhile, a novel mode shape optimum method of the deck is proposed. The method... An output-only modal identification method by a combination use of the peak-picking method and the cross spectrum methods are presented. Meanwhile, a novel mode shape optimum method of the deck is proposed. The methods are applied to the operational modal identification system of the Runyang Suspension Bridge, which can be used to obtain the modal parameters of the bridge from out-only data sets collected by its structural health monitoring system (SHMS). As an example, the vibration response data of the deck, cable and tower recorded during typhoon Matsa excitation are used to illustrate the program application. Some of the modal frequencies observed from deck vibration responses are also found in the vibration responses of the cable and the tower. The results show that some modal shapes of the deck are strongly coupled with the cable and the tower. By comparing the identification results from the operational modal system with those from field measurements, a good agreement between them is achieved, but some modal frequencies identified from the operational modal identification system (OMIS), such as L1 and L2, obviously decrease compared with those from the field measurements. 展开更多
关键词 suspension bridge operational modal identification structural health monitoring system ambient vibration test
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Modal macro-strain identification from operational macro-strain shape under changing loading conditions 被引量:1
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作者 李舒 徐赵东 +1 位作者 王少杰 吴智深 《Journal of Southeast University(English Edition)》 EI CAS 2016年第2期219-225,共7页
To develop modal macro-strain ( MMS ) identification techniques and improve their applicability in a continuous health monitoring system for civil infrastructures, the concept of operational macro-strain shape (OMS... To develop modal macro-strain ( MMS ) identification techniques and improve their applicability in a continuous health monitoring system for civil infrastructures, the concept of operational macro-strain shape (OMSS) and the corresponding identification method are proposed under unknown ever-changing loading conditions, and the MMS is then obtained. The core of the proposed technique is mainly based on the specific property that the macro-strain transmissibility tends to be independent of external excitations at the poles of the system and converges to a unique value. The proposed method is verified using the experimental data from a three-span continuous beam excited by an impact hammer at different locations. The identified results are also compared with the commonly used methods, such as the peak- picking (PP) method, the stochastic subspace identification (SSI) method, and numerical results, in the case of unknown input forces. Results show that the proposed technique has unique merits in accuracy and robustness due to its combining multiple tests under changing loading conditions, which also reveal the promising application of the distributed strain sensing system in identifying MMS of operational structures, as well as in the structural health monitoring (SHM) field. 展开更多
关键词 macro-stain/distributed strain fiber Bragggrating FBG operational modal analysis OMA operational deflection shape (ODS) TRANSMISSIBILITY
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Application of support vector machine in trip chaining pattern recognition and analysis of explanatory variable effects 被引量:2
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作者 杨硕 邓卫 程龙 《Journal of Southeast University(English Edition)》 EI CAS 2017年第1期106-114,共9页
In order to improve the accuracy of travel demand forecast and considering the distribution of travel behaviors within time dimension, a trip chaining pattern recognition model was established based on activity purpos... In order to improve the accuracy of travel demand forecast and considering the distribution of travel behaviors within time dimension, a trip chaining pattern recognition model was established based on activity purposes by applying three methods: the support vector machine (SVM) model, the radial basis function neural network (RBFNN) model and the multinomial logit (MNL) model. The effect of explanatory factors on trip chaining behaviors and their contribution to model performace were investigated by sensitivity analysis. Results show that the SVM model has a better performance than the RBFNN model and the MNL model due to its higher overall and partial accuracy, indicating its recognition advantage under a smai sample size scenario. It is also proved that the SVM model is capable of estimating the effect of multi-category factors on trip chaining behaviors more accurately. The different contribution of explanatory, factors to trip chaining pattern recognition reflects the importance of refining trip chaining patterns ad exploring factors that are specific to each pattern. It is shown that the SVM technology in travel demand forecast modeling and analysis of explanatory variable effects is practical. 展开更多
关键词 trip chaining patterns support vector machine recognition performance sensitivity analysis
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Dynamical analysis for a malware propagation model in wireless sensor network 被引量:4
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作者 宋礼鹏 张蓉萍 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2016年第2期136-144,共9页
The threat of malware in wireless sensor network has stimulated some activities to model and analyze the malware prevalence.To understand the dynamics of malware propagation in wireless sensor network,we propose a nov... The threat of malware in wireless sensor network has stimulated some activities to model and analyze the malware prevalence.To understand the dynamics of malware propagation in wireless sensor network,we propose a novel epidemic model named as e-SEIR(susceptible-exposed-infectious-recovered)model,which is a set of delayed differential equations,in this paper.The model has taken into account the following two factors:1 Multi-state antivirus measures;2 Temporary immune period.Then,the stability and Hopf bifurcation at the equilibria of linearized model are carefully analyzed by considering the distribution of eigenvalues of characteristic equations.Both mathematical analysis and numerical simulations show that the dynamical features of the proposed model rely on the basic reproduction number R0 and time delayτ.This novel model can help us to better understand and predict the propagation behaviors of malware in wireless sensor networks. 展开更多
关键词 wireless sensor network STABILITY Hopf bifurcation epidemic model time delay
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Capacity model of on-rampmerging section of urban expressway 被引量:3
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作者 曲昭伟 曹宁博 +2 位作者 陈永恒 白乔文 孙磊 《Journal of Southeast University(English Edition)》 EI CAS 2016年第2期226-232,共7页
To establish the empirical capacity model of an on- ramp merging section, the Erlang distribution is first selected to define the time headway distribution, and then the gap acceptance theory is applied to develop the... To establish the empirical capacity model of an on- ramp merging section, the Erlang distribution is first selected to define the time headway distribution, and then the gap acceptance theory is applied to develop the basic capacity model of the on-ramp merging section. Since not all the time headways on the shoulder lane can be made full use of by on- ramp vehicles, a modified capacity model is developed, which takes the usage probability of time headway into consideration. Then, a model of capacity discount coefficient ~: is developed. Finally, based on the modified capacity model and the model of capacity discount coefficient, an empirical merge capacity model which contains the shoulder lane volume, critical gap, and the distance from nose to merging point, is constructed. Results show that, compared with other models, the proposed model is more reasonable since it takes merging section geometry into consideration, and it is easy to apply. The merge capacity varies with the shoulder lane volume, the critical gap, the distance between the nose and the merging point, and the design velocity of the shoulder lane and ramp. 展开更多
关键词 merging section empirical capacity model urbanexpressway gap acceptance
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Influence of casting module on corrosion behavior of Mg-11Gd-3Y alloy 被引量:2
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作者 刘贤斌 单大勇 +2 位作者 宋影伟 陈荣石 韩恩厚 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第4期903-911,共9页
The influences of two kinds of casting modules of metal casting (MC) and expandable pattern casting (EPC) on the corrosion behavior of Mg-11Gd-3Y alloy were studied by electrochemical measurements, scanning electr... The influences of two kinds of casting modules of metal casting (MC) and expandable pattern casting (EPC) on the corrosion behavior of Mg-11Gd-3Y alloy were studied by electrochemical measurements, scanning electron microscopy (SEM) observation, X-ray diffractometry (XRD) and X-ray photoelectron spectroscopy (XPS) analysis. It is found that the quantity of the Mg 24 (Gd, Y) 5 phase in MC is more than that in EPC due to the cooling rate. There is more alloying element dissolved in the matrix compared with MC. For EPC, the galvanic corrosion effect between the matrix and the Mg 24 (Gd, Y) 5 phase decreases and the corrosion resistance increases compared with the MC. The chief corrosion mode for Mg-11Gd-3Y alloy is pitting corrosion because most of the alloying elements are transformed into intermetallic phases. The average corrosion rate of the MC alloy in the immersion test is five times higher than that of EPC alloy and yttrium is present in the product film, which will provide increased protection for Mg-11Gd-3Y alloy. The electrochemical measurements and immersion test show that the EPC process increases the corrosion resistance compared with the MC Mg-11Gd-3Y alloy. 展开更多
关键词 Mg-11Gd-3Y alloy corrosion behavior casting module expandable pattern casting metal casting
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Congregated electron phase and Wagner model applied in titanium distribution behavior in low-titanium slag 被引量:5
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作者 王振阳 张建良 +1 位作者 邢相栋 刘征建 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第5期1640-1647,共8页
For studying the carbon thermal reduction rules of titanium in hot metal and providing a theoretical basis for the blast furnace(BF) hearth protection, the distribution behavior of titanium between low-titanium slag... For studying the carbon thermal reduction rules of titanium in hot metal and providing a theoretical basis for the blast furnace(BF) hearth protection, the distribution behavior of titanium between low-titanium slag system of CaO-SiO2-MgO-Al2O3-TiO2 and hot metal was studied using analytical reagents in a temperature range from 1350 °C to 1600 °C. Through high temperature melting, rapid quenching, chemical analysis and thermodynamic model calculating, the results showed that the increase of reaction temperature, which improved the titanium distribution L(Ti) and lowered the system activity coefficient γsys, leads to the rise of equilibrium constant. Combined with Wagner and congregated electron phase models, the data obtained in distribution experiments were used to fit out the Gibbs free energy formula of titanium carbothermic reduction. Finally, the relations between the contents of Si and Ti in hot metal and the titanium load to reach the minimum w(Ti) for the formation of Ti C were given. 展开更多
关键词 TITANIUM distribution behavior activity coefficient model hearth protection titanium load
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Dynamic recrystallization kinetics of as-cast AZ91D alloy 被引量:18
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作者 徐岩 胡连喜 孙宇 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第6期1683-1689,共7页
The flow behavior and dynamic recrystallization(DRX) behavior of an as-cast AZ91 D alloy were investigated systematically by applying the isothermal compression tests in temperature range of 220-380 ℃ and strain ra... The flow behavior and dynamic recrystallization(DRX) behavior of an as-cast AZ91 D alloy were investigated systematically by applying the isothermal compression tests in temperature range of 220-380 ℃ and strain rate range of 0.001-1 s^-1.The effect of temperature and strain rate on the DRX behavior was discussed.The results indicate that the nucleation and growth of dynamic recrystallized grains easily occur at higher temperatures and lower strain rates.To evaluate the evolution of dynamic recrystallization,the DRX kinetics model was proposed based on the experimental data of true stress-true strain curves.It was revealed that the volume fraction of dynamic recrystallized grains increased with increasing strain in terms of S-curves.A good agreement between the proposed DRX kinetics model and microstructure observation results validates the accuracy of DRX kinetics model for AZ91 D alloy. 展开更多
关键词 AZ91D magnesium alloy compression flow behavior dynamic recrystallization behavior kinetics model
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The System Design of Semiconductor Device Simulator
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作者 杨廉峰 吴金 +2 位作者 夏君 刘其贵 魏同立 《Journal of Southeast University(English Edition)》 EI CAS 1999年第2期24-29,共6页
This paper studies the numerical simulation for semiconductor devices and discusses the software design of the simulation system. Our focus is on the deep submicron device simulation for BJT, MOSFET, heterojunction bi... This paper studies the numerical simulation for semiconductor devices and discusses the software design of the simulation system. Our focus is on the deep submicron device simulation for BJT, MOSFET, heterojunction bipolar transistors (HBT), etc. So the object oriented technology for software design and its realization is used to make the system easy to implement, maintain and extend. Besides the discussion of simulation and software system design, this paper introduces a device simulator SMDS and its parallel extension under local network environment using CORBA technology. 展开更多
关键词 device simulation submicron device object oriented technology parallel simulation
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Co-Design of Monolithically Integrated Photo-Detector and Optical-Receiver
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作者 高鹏 陈弘达 +3 位作者 毛陆虹 贾九春 陈永权 孙增辉 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2004年第2期133-137,共5页
A behavioral model of the photodiode is presented.The model describes the relationship between photocurrent and incident optical power,and it also illustrates the impact of the reverse bias to the variation of the jun... A behavioral model of the photodiode is presented.The model describes the relationship between photocurrent and incident optical power,and it also illustrates the impact of the reverse bias to the variation of the junction capacitance.According to this model,the photodiode and a CMOS receiver circuit are simulated and designed simultaneously under a universal circuit simulation environment. 展开更多
关键词 monolithically integrated CO-DESIGN behavioral model
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Alternate operation characteristics of a solar-ground source heat pump system 被引量:4
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作者 杨卫波 陈振乾 施明恒 《Journal of Southeast University(English Edition)》 EI CAS 2010年第2期327-332,共6页
In order to investigate the alternate operation characteristics of a solar-ground source heat pump system(SGSHPS),various alternate operation modes are put forward and defined.A two-dimensional mathematical model wi... In order to investigate the alternate operation characteristics of a solar-ground source heat pump system(SGSHPS),various alternate operation modes are put forward and defined.A two-dimensional mathematical model with freezing/melting phase changes is developed for the heat transfer analysis of the soil.Based on the numerical solution of the model,the variation trends of underground soil temperature of the SGSHPS operated in various alternate operation modes are discussed.The results indicate that,for the day-night and short-time interval alternate operation modes without solar energy,the operation time fraction of a solar heat source should be confined to from 50% to 58% when operated in an alternate period of 24 h.Meanwhile,the disadvantages of a natural resumption of soil temperature can be overcome effectively by solar energy filling,and an optimal operation effect can be achieved by integrating the mode of solar energy filling with other alternate modes.In addition,the accuracy of the presented model is verified by the experimental data of borehole wall temperatures.The conclusions can provide a reference for the optimization operation of the SGSHPS. 展开更多
关键词 solar-ground source heat pump alternate operation characteristics numerical simulation experimental validation
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Behavioral modeling of RF power amplifiers with time-delay feed-forward neural networks
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作者 翟建锋 周健义 +2 位作者 赵嘉宁 张雷 洪伟 《Journal of Southeast University(English Edition)》 EI CAS 2008年第1期6-9,共4页
A novel behavioral model using three-layer time-delay feed-forward neural networks (TDFFNN)is adopted to model radio frequency (RF)power amplifiers exhibiting memory nonlinearities. In order to extract the paramet... A novel behavioral model using three-layer time-delay feed-forward neural networks (TDFFNN)is adopted to model radio frequency (RF)power amplifiers exhibiting memory nonlinearities. In order to extract the parameters, the back- propagation algorithm is applied to train the proposed neural networks. The proposed model is verified by the typical odd- order-only memory polynomial model in simulation, and the performance is compared with different numbers of taped delay lines(TDLs) and perceptrons of the hidden layer. For validating the TDFFNN model by experiments, a digital test bench is set up to collect input and output data of power amplifiers at a 60 × 10^6 sample/s sampling rate. The 3.75 MHz 16-QAM signal generated in the vector signal generator(VSG) is chosen as the input signal, when measuring the dynamic AM/AM and AM/PM characteristics of power amplifiers. By comparisons and analyses, the presented model provides a good performance in convergence, accuracy and efficiency, which is approved by simulation results and experimental results in the time domain and frequency domain. 展开更多
关键词 behavioral model power amplifier time-delay feed- forward neural network(TDFFNN)
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MATHEMATICAL MODEL OF SELF-REPAIRING FLIGHT CONTROL 被引量:2
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作者 王永 詹训慧 +1 位作者 吴刚 胡寿松 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2003年第2期178-183,共6页
The most prospective method for certain structural failures and damages that cannot employ redundancy is self-repairing techniques, to ensure especially the maximum flight safety. Based on the characters of self-repai... The most prospective method for certain structural failures and damages that cannot employ redundancy is self-repairing techniques, to ensure especially the maximum flight safety. Based on the characters of self-repairing aircraft, this paper states some basic assumptions of the self-repairing aircraft, and puts forward some special new conceptions concerning the self-repairing aircraft: control input, operating input, command input, repair input and operating and control factor as well as their relationships. Thus it provides a simple and reliable mathematical model structure for the research on the self-repairing control of the aircraft. 展开更多
关键词 SELF-REPAIRING flight control mathematical model operating and control factor
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Influence of pavement frictional properties on braking distance 被引量:6
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作者 丛菱 黄晓明 《Journal of Southeast University(English Edition)》 EI CAS 2011年第2期210-212,共3页
In order to study the relationship between pavement friction management criteria and braking distance requirements of road geometric design, an approach for determining the braking distance considering pavement fricti... In order to study the relationship between pavement friction management criteria and braking distance requirements of road geometric design, an approach for determining the braking distance considering pavement frictional properties is proposed. A finite element model (FEM) of a rolling tire under steady state is established based on theoretical hydrodynamics and mechanics principles, in which factors, including tire type, water film thickness, pavement surface properties, and vehicle speed, are considered. With the FEM, braking distances under different operating conditions are calculated. Furthermore, the allowable water film thickness is determined by comparing braking distances calculated with friction management criteria and that required by road geometric design. The results show that the braking distance is affected by the above operating conditions. As a result, it is necessary to maintain consistency between geometric design braking distance requirements and pavement friction management to achieve safe road operations. 展开更多
关键词 pavement frictional properties braking distance operating conditions finite element simulation
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