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基于两种转换函数的真实波浪参数的统计分析 预览
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作者 韩端锋 崔婷 +3 位作者 昝英飞 袁利毫 丁松 李志刚 《船舶与海洋工程学报:英文版》 CSCD 2019年第3期247-259,共13页
The probability distributions of wave characteristics from three groups of sampled ocean data with different significant wave heights have been analyzed using two transformation functions estimated by non-parametric a... The probability distributions of wave characteristics from three groups of sampled ocean data with different significant wave heights have been analyzed using two transformation functions estimated by non-parametric and parametric methods. The marginal wave characteristic distribution and the joint density of wave properties have been calculated using the two transformations, with the results and accuracy of both transformations presented here. The two transformations deviate slightly between each other for the calculation of the crest and trough height marginal wave distributions, as well as the joint densities of wave amplitude with other wave properties. The transformation methods for the calculation of the wave crest and trough height distributions are shown to provide good agreement with real ocean data. Our work will help in the determination of the most appropriate transformation procedure for the prediction of extreme values. 展开更多
关键词 Wave characteristic DISTRIBUTIONS Transformed Gaussian process Transformed FUNCTION PARAMETRIC METHOD NON-PARAMETRIC METHOD Crossing-density FUNCTION
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基于参数化BIM建筑设计的特点及其应用 预览
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作者 孙夏 《智能建筑与智慧城市》 2019年第6期51-52,共2页
在我国建筑工程的规模和结构日益扩大和复杂的背景下,参数化BIM技术辅助进行建筑设计,可优化资源配置,提高建筑设计方案的精确合理性。论文主要基于参数化BIM建筑设计体系的特点及其在建筑设计中的应用进行探讨。
关键词 建筑设计 BIM 参数化 应用
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基于Inventor的减速器参数化设计系统的研究与开发
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作者 何康康 聂壮壮 高志康 《煤矿机械》 北大核心 2019年第5期177-179,共3页
利用Inventor实体造型、特征技术、参数化技术及二次开发技术,开发了基于Inventor的减速器参数化设计系统。该系统用户界面友好,集成了设计规则、选型方法,设计时只需输入少数基本参数即可实现整机产品修改设计。在避免设计错误的同时,... 利用Inventor实体造型、特征技术、参数化技术及二次开发技术,开发了基于Inventor的减速器参数化设计系统。该系统用户界面友好,集成了设计规则、选型方法,设计时只需输入少数基本参数即可实现整机产品修改设计。在避免设计错误的同时,简化了设计流程,提高了系列产品的设计、选型、报价效率,具有一定的实用价值。 展开更多
关键词 减速器 INVENTOR 参数化 设计系统
Observational evidences of wave excitation and inverse cascade in a distant Earth foreshock region
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作者 Jiansen HE Die DUAN +2 位作者 Xingyu ZHU Limei YAN Linghua WANG 《中国科学:地球科学英文版》 SCIE EI CAS CSCD 2019年第4期619-630,共12页
The foreshock with nascent plasma turbulence is regarded as a fascinating region to understand basic plasma physical processes, e.g., wave-particle interactions as well as wave-wave couplings. Although there have been... The foreshock with nascent plasma turbulence is regarded as a fascinating region to understand basic plasma physical processes, e.g., wave-particle interactions as well as wave-wave couplings. Although there have been plenty of intensive studies on this topic, some key clues about the physical processes still lack observations. A relatively comprehensive case study with some new observations is presented in this work based on the WIND spacecraft observations. In this case, upstream energetic protons were drifting at tens of Alfvén speed with respect to the background plasma protons. When looking at the magnetic wave activities, we find the co-existence of high-frequency(0.1-0.5 Hz) large-amplitude right-hand polarized(RHP) waves and lowfrequency(0.02-0.1 Hz) small-amplitude left-hand polarized(LHP) waves in the spacecraft(SC) frame. The observed anticorrelation between magnetic and velocity fluctuations along with the sunward magnetic field direction indicates that the lowfrequency LHP waves in the SC frame are in fact the sunward upstream RHP Alfvénic waves in the solar wind frame. This new observation corroborates the applicability of theories about plasma non-resonance instability and inverse cascade to the foreshock region, where the downstream high-frequency RHP parent waves are excited by the upstream energetic protons through non-resonance instability and the low-frequency RHP daughter waves are generated by the parent waves due to nonlinear parametric instability. Furthermore, enhanced downstream energetic proton fluxes are inferred to result from scattering of the upstream protons by the nascent turbulent fluctuations. Therefore, some critical clues about the newborn turbulence in the foreshock are provided in this work. 展开更多
关键词 Solar WIND FORESHOCK Wave-particle interaction PARAMETRIC INSTABILITY
参数不确定及有扰动的情况下欠驱动遥控无人潜水器鲁棒性建模、滑模控制及仿真研究 预览
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作者 Mostafa Eslami Cheng Siong Chin Amin Nobakhti 《船舶与海洋工程学报:英文版》 CSCD 2019年第2期213-227,共15页
A dynamic model of a remotely operated vehicle(ROV)is developed.The hydrodynamic damping coefficients are estimated using a semi-predictive approach and computational fluid dynamic software ANSYS-CFX?and WAMIT?.A slid... A dynamic model of a remotely operated vehicle(ROV)is developed.The hydrodynamic damping coefficients are estimated using a semi-predictive approach and computational fluid dynamic software ANSYS-CFX?and WAMIT?.A sliding-mode controller(SMC)is then designed for the ROV model.The controller is subsequently robustified against modeling uncertainties,disturbances,and measurement errors.It is shown that when the system is subjected to bounded uncertainties,the SMC will preserve stability and tracking response.The paper ends with simulation results for a variety of conditions such as disturbances and parametric uncertainties. 展开更多
关键词 Remotely operated VEHICLE Robust modeling Sliding-mode control Simulation Disturbances PARAMETRIC UNCERTAINTIES
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Finite-time stabilization of uncertain delayed-hopfield neural networks with a time-varying leakage delay via non-chattering control
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作者 AOUITI Chaouki LI XiaoDi MIAADI Foued 《中国科学:技术科学英文版》 SCIE EI CAS CSCD 2019年第7期1111-1122,共12页
This article is concerned with the finite-time stabilization(FTSB) of a class of delayed-Hopfield neural networks with a timevarying delay in the leakage term in the presence of parameter uncertainties. To accomplish ... This article is concerned with the finite-time stabilization(FTSB) of a class of delayed-Hopfield neural networks with a timevarying delay in the leakage term in the presence of parameter uncertainties. To accomplish the target of FTSB, two new finitetime controllers are designed for uncertain delayed-Hopfield neural networks with a time-varying delay in the leakage term. By utilizing the finite-time stability theory and the Lyapunov-Krasovskii functional(LKF) approach, some sufficient conditions for the FTSB of these neural networks are established. These conditions, which can be used for the selection of control parameters,are in the form of linear matrix inequalities(LMIs) and can be numerically checked. Additionally, an upper bound of the settling time was estimated. Finally, our theoretical results are further substantiated by two numerical examples with graphical illustrations to demonstrate the effectiveness of the results. 展开更多
关键词 neural networks FINITE-TIME stabilization parametric uncertainties LEAKAGE DELAY LYAPUNOV-KRASOVSKII functional LMI
隐式参数化白车身多目标协同优化设计 预览
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作者 吕天佟 王登峰 王传青 《北京理工大学学报》 EI CAS CSCD 北大核心 2019年第5期447-453,共7页
利用参数化建模软件SFE-CONCEPT建立了某轿车白车身的参数化模型,用仿真方法分析了白车身的静态弯扭刚度、主要低阶模态频率并与试验对比,再将白车身与动力总成、底盘连接后,对整车正碰性能进行仿真分析,并与试验对比,验证了所建参数化... 利用参数化建模软件SFE-CONCEPT建立了某轿车白车身的参数化模型,用仿真方法分析了白车身的静态弯扭刚度、主要低阶模态频率并与试验对比,再将白车身与动力总成、底盘连接后,对整车正碰性能进行仿真分析,并与试验对比,验证了所建参数化白车身的有效性.由于安全性分析属于非线性分析,传统优化方法通常需要人工介入,无法实现优化流程的全自动化.通过编写批处理文件,提取安全性能指标,实现白车身结构轻量化优化流程的自动化.白车身结构轻量化优化后弯曲刚度提升0.15%,扭转刚度降低0.03%,一阶扭转模态频率提高1.30%,一阶弯曲模态频率提高0.09%,碰撞安全性能基本不变的情况下,白车身质量降低24.17kg,减重率高达7.42%,取得了显著的轻量化效果. 展开更多
关键词 白车身 参数化 轻量化 全自动优化
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Stress distribution and fatigue life of nonlinear vibration of an axially moving beam
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作者 DING Hu HUANG LingLu +1 位作者 DOWELL Earl CHEN LiQun 《中国科学:技术科学英文版》 SCIE EI CAS CSCD 2019年第7期1123-1133,共11页
In this paper, the effects of the nonlinear vibration on stress distribution and fatigue life of the axially moving beam are studied.The parametric excitation of the flexible material is created by the pulsating movin... In this paper, the effects of the nonlinear vibration on stress distribution and fatigue life of the axially moving beam are studied.The parametric excitation of the flexible material is created by the pulsating moving speed. Three-to-one internal resonance condition is satisfied. The three-parameter model is adopted in the viscoelastic constitutive relation. The nonlinear vibration of the axially moving beam with parametric and internal resonance are studied by using the direct multiple scales method(MSM)with numerical simulation confirmation. Based on the approximate analytical solution, the distribution of tensile stress and bending stress on the axially moving beam is presented by adopting a V-belt as the prototype. Based on the maximum stable cyclic stress, the limit cycle response of the V-belt is utilized to evaluate the effect of the resonance on the fatigue life. Also, the influences of the internal resonance on the steady-state responses and the fatigue life of the V-belt are revealed. Numerical examples illustrate that large unwanted resonances occur and the second-order mode receives vibration energy from to the firstorder mode. The numerical results demonstrate that the nonlinear vibration significantly reduces the fatigue life of the V-belt.The fatigue life analysis method in this paper can be applied to the excited vibration of other axially moving systems and even static continuum. 展开更多
关键词 AXIALLY MOVING beam nonlinear vibration PARAMETRIC EXCITATION internal RESONANCE stress distribution V-BELT
An Elastic Shell Model for the Human Tricuspid Valve
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作者 Xiao-qin SHEN Qian YANG +2 位作者 Lin-jin LI Li CAI Xiao-shan CAO 《应用数学学报:英文版》 SCIE CSCD 2019年第1期111-128,共18页
The human tricuspid valve, one of the key cardiac structures, plays an important role in the circulatory system. However, there are few mathematical models to accurately simulate it.In this paper, firstly, we consider... The human tricuspid valve, one of the key cardiac structures, plays an important role in the circulatory system. However, there are few mathematical models to accurately simulate it.In this paper, firstly, we consider the tricuspid valve as an elastic shell with a specific shape and establish its novel geometric model. Concretely, the anterior, the posterior and the septal leaflets of the valve are supposed to be portions of the union of two interfacing semi-elliptic cylindrical shells when they are fully open.Next, we use Koiter’s linear shell model to describe the tricuspid valve leaflets in the static case, and provide a numerical scheme for this elastostatics model. Specifically, we discretize the space variable, i.e., the two tangent components of the displacement are discretized by using conforming finite elements(linear triangles) and the normal component of the displacement is discretized by using conforming Hsieh-Clough-Tocher triangles(HCT triangles).Finally, we make numerical experiments for the tricuspid valve and analyze the outcome. The numerical results show that the proposed mathematical model describes well the human tricuspid valve subjected to applied forces. 展开更多
关键词 TRICUSPID valve GEOMETRIC MODEL PARAMETRIC equation Koiter MODEL conforming finite element
Concurrent optimization of structural topology and infill properties with a CBF-based level set method
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作者 Long JIANG Yang GUO +3 位作者 Shikui CHEN Peng WEI Na LEI Xianfeng David GU 《机械工程前沿:英文版》 CSCD 2019年第2期171-189,共19页
In this paper,a parametric level-set-based topology optimization framework is proposed to concurrently optimize the structural topology at the macroscale and the effective infill properties at the micro/meso scale.The... In this paper,a parametric level-set-based topology optimization framework is proposed to concurrently optimize the structural topology at the macroscale and the effective infill properties at the micro/meso scale.The concurrent optimization is achieved by a computational framework combining a new parametric level set approach with mathematical programming.Within the proposed framework,both the structural boundary evolution and the effective infill property optimization can be driven by mathematical programming,which is more advantageous compared with the conventional partial differential equatiodriven level set approach.Moreover,the proposed approach will be more efficient in handling nonlinear problems with multiple constraints.Instead of using radial basis functions(RBF),in this paper,we propose to construct a new type of cardinal basis functions(CBF)for the level set function parameterization.The proposed CBF parameterization ensures an explicit impose of the lower and upper bounds of the design variables.This overcomes the intrinsic disadvantage of the conventional RBF-based parametric level set method,where the lower and upper bounds of the design variables oftentimes have to be set by trial and error;A variational distance regularization method is utilized in this research to regularize the level set function to be a desired distanceregularized shape.With the distance information embedded in the level set model,the wrapping boundary layer and the interior infill region can be naturally defined.The isotropic infill achieved via the mesoscale topology optimization is conformally fit into the wrapping boundary layer using the shape-preserving conformal mapping method,which leads to a hierarchical physical structure with optimized overall topology and effective infill properties.The proposed method is expected to provide a timely solution to the increasing demand for multiscale and multifunctional structure design. 展开更多
关键词 CONCURRENT TOPOLOGY OPTIMIZATION PARAMETRIC level set method cardinal basis function shell-infill structure design confonnal mapping
Control performance comparison between tuned liquid damper and tuned liquid column damper using real-time hybrid simulation 预览
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作者 Zhu Fei Wang Jinting +1 位作者 Jin Feng Lu Liqiao 《地震工程与工程振动:英文版》 SCIE EI CSCD 2019年第3期695-701,共7页
Tuned liquid damper (TLD) and tuned liquid column damper (TLCD) are two types of passive control devices that are widely used in structural control. In this study, a real-time hybrid simulation (RTHS) technique is emp... Tuned liquid damper (TLD) and tuned liquid column damper (TLCD) are two types of passive control devices that are widely used in structural control. In this study, a real-time hybrid simulation (RTHS) technique is employed to investigate the diff erence in control performance between TLD and TLCD. A series of RTHSs is presented with the premise of the same liquid length, mass ratio, and structural parameters. Herein, TLD and TLCD are physically experimented, and controlled structures are numerically simulated. Then, parametric studies are performed to further evaluate the diff erent performance between TLD and TLCD. Experimental results demonstrate that TLD is more eff ective than TLCD under diff erent amplitude excitations. 展开更多
关键词 tuned LIQUID DAMPER tuned LIQUID COLUMN DAMPER REAL-TIME hybrid simulation CONTROL effi ciency structural CONTROL PARAMETRIC study
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The upper bound function of nonadiabatic dynamics in parametric driving quantum systems
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作者 张林 刘军鹏 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第8期31-41,共11页
The adiabatic control is a powerful technique for many practical applications in quantum state engineering,light-driven chemical reactions and geometrical quantum computations.This paper reveals a speed limit of nonad... The adiabatic control is a powerful technique for many practical applications in quantum state engineering,light-driven chemical reactions and geometrical quantum computations.This paper reveals a speed limit of nonadiabatic transition in a general time-dependent parametric quantum system that leads to an upper bound function which lays down an optimal criteria for the adiabatic controls.The upper bound function of transition rate between instantaneous eigenstates of a time-dependent system is determined by the power fluctuations of the system relative to the minimum gap between the instantaneous levels.In a parametric Hilbert space,the driving power corresponds to the quantum work done by the parametric force multiplying the parametric velocity along the parametric driving path.The general two-state time-dependent models are investigated as examples to calculate the bound functions in some general driving schemes with one and two driving parameters.The calculations show that the upper bound function provides a tighter real-time estimation of nonadiabatic transition and is closely dependent on the driving frequencies and the energy gap of the system.The deviations of the real phase from Berry phase on different closed paths are induced by the nonadiabatic transitions and can be efficiently controlled by the upper bound functions.When the upper bound is adiabatically controlled,the Berry phases of the electronic spin exhibit nonlinear step-like behaviors and it is closely related to topological structures of the complicated parametric paths on Bloch sphere. 展开更多
关键词 ADIABATIC dynamics PARAMETRIC driving upper BOUND FUNCTION
New few parameters differential evolution algorithm with application to structural identification
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作者 Rita Greco Ivo Vanzi 《交通运输工程学报(英文版)》 CSCD 2019年第1期1-14,共14页
Differential evolution algorithm(DEA)is a stochastic,population-based global optimization method.In this paper,we propose new schemes for both mutation and crossover operators in order to enhance the performances of t... Differential evolution algorithm(DEA)is a stochastic,population-based global optimization method.In this paper,we propose new schemes for both mutation and crossover operators in order to enhance the performances of the standard DEA.The advantage of these proposed operators is that they are'parameters-less',without a tuning phase of algorithm parameters that is often a disadvantage of DEA.Once the modified differential evolutions are presented,a large comparative analysis is performed with the aim to assess both correctness and efficiency of the proposed operators.Advantages of proposed DEA are used in an important task of modern structural engineering that is mechanical identification under external dynamic loads.This is because of the importance of using a“parametersless”algorithm in identification problems whose characteristics typically vary strongly case by case,needing of a continuous set up of the algorithm proposed.This important advantage of proposed optimizers,in front of other identification algorithms,is used to develop a computer code suitable for the automatic identification of a simple supported beam subject to an impact load,that has been tested both using numerical simulations and real standard tests dynamic.The results point out that this algorithm is an interesting candidate for standard applications in structural identification problems. 展开更多
关键词 DIFFERENTIAL evolution PARAMETRIC IDENTIFICATION STRUCTURAL IDENTIFICATION Optimization
High efficiency second harmonic generation of nanojoule-level femtosecond pulses in the visible based on BiBO
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作者 Mario Galletti Hugo Pires +4 位作者 Victor Hariton Celso Paiva Joao Swen Künzel Marco Galimberti Goncalo Figueira 《高功率激光科学与工程:英文版》 CAS CSCD 2019年第1期82-89,共8页
We demonstrate high efficiency second harmonic generation(SHG)of near infrared femtosecond pulses using a BiB3O6 crystal in a single-pass tight focusing geometry setup.A frequency doubling efficiency of 63%is achieved... We demonstrate high efficiency second harmonic generation(SHG)of near infrared femtosecond pulses using a BiB3O6 crystal in a single-pass tight focusing geometry setup.A frequency doubling efficiency of 63%is achieved,which is,to the best of our knowledge,the highest value ever reported in the femtosecond regime for such low energy(nJ-level)pumping pulses.Theoretical analyses of the pumping scheme focusing waist and the SHG efficiency are performed,by numerically solving the three wave mixing coupled equations in the plane-wave scenario and by running simulations with a commercial full 3D code.Simulations show a good agreement with the experimental data regarding both the efficiency and the pulse spectral profile.The simulated SHG pulse temporal profile presents the characteristic features of the group velocity mismatch broadening in a‘thick’crystal. 展开更多
关键词 nonlinear process SECOND HARMONIC generation PUMPING scheme PARAMETRIC amplification/oscillators high power laser
基于参数化模型的柴油机连杆结构轻量化设计 预览
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作者 张宏远 覃士耘 《内燃机与配件》 2019年第12期21-23,共3页
本文以缸径为110mm柴油机连杆为研究对象,建立连杆结构的参数化模型,将连杆的主要结构参数作为设计变量,以最大许用应力等因素作为约束条件,以连杆重量最小作为目标函数编制优化命令,对连杆结构进行轻量化设计。计算结果表明:优化后的... 本文以缸径为110mm柴油机连杆为研究对象,建立连杆结构的参数化模型,将连杆的主要结构参数作为设计变量,以最大许用应力等因素作为约束条件,以连杆重量最小作为目标函数编制优化命令,对连杆结构进行轻量化设计。计算结果表明:优化后的连杆质量降低了352.31g,变化比例为22.91%。采用参数化模型进行轻量化分析,可以快速准确的获得最优设计值,为连杆结构设计提供依据。 展开更多
关键词 柴油机 连杆 轻量化设计 参数化 ANSYS
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Pendulum systems for harvesting vibration energy from railroad tracks and sleepers during the passage of a high-speed train:A feasibility evaluation 预览
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作者 Franco E.Dotti Mauricio D.Sosa 《力学快报:英文版》 CAS CSCD 2019年第4期229-235,I0005共8页
We evaluate the feasibility of recovering energy from the vibrations of track and sleepers,during passage of a high-speed train,by means of a pendulum harvester.A simple mathematical model of the parametric pendulum i... We evaluate the feasibility of recovering energy from the vibrations of track and sleepers,during passage of a high-speed train,by means of a pendulum harvester.A simple mathematical model of the parametric pendulum is employed to obtain numerical predictions,while measured data of vibration tests during the passage of a Thalys high-speed train are considered as input forcing.Since a sustained rotation is the most energetic motion of a pendulum,the possibility of achieving such state is evaluated,taking into account the influence of initial conditions,damping and other factors.Numerical simulations show that rotating pendulum harvesters with sufficiently low viscous damping could be able to generate a usable average power on the order of 5–6 W per unit.Considering a modular arrangement of devices,such energy is enough to feed variety of rail-side equipment,as wireless sensors or warning light systems.However,a suitable choice of initial conditions could be a difficult task,leading to the need of a control action. 展开更多
关键词 Energy HARVESTING PARAMETRIC PENDULUM RAILROAD safety Train induced vibration
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扶壁挡土墙数字模型参数化设计研究 预览
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作者 左威龙 吕大为 《江苏水利》 2019年第2期52-55,共4页
三维协同设计和数字化设计的年代正在到来,它提振了设计行业的信心和期望。Autodesk Revit是由Autodesk公司推出的三维设计软件,目前在工业与民用建筑领域已经具有了非常完善的建筑、结构参数化设计功能,但在其他行业的参数化设计方面... 三维协同设计和数字化设计的年代正在到来,它提振了设计行业的信心和期望。Autodesk Revit是由Autodesk公司推出的三维设计软件,目前在工业与民用建筑领域已经具有了非常完善的建筑、结构参数化设计功能,但在其他行业的参数化设计方面还有待研究。以水利工程中常用的扶壁挡土墙的参数化建模过程为例,研究了在Revit平台上建立参数化族模型的方法及其应用,为基础设计行业的建筑物构件创建参数化族模型提供参考,以期对水利工程数字化的进步和工程实践有所帮助。 展开更多
关键词 扶壁挡土墙 AUTODESK REVIT 三维模型 参数化
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A Linear Quadratic Controller Design Incorporating a Parametric Sensitivity Constraint
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作者 Mohamed Yagoubi 《国际自动化与计算杂志:英文版》 EI CSCD 2019年第4期553-562,共10页
The purpose of this paper is to propose a synthesis method of parametric sensitivity constrained linear quadratic (SCLQ) controller for an uncertain linear time invariant (LTI) system. System sensitivity to parameter ... The purpose of this paper is to propose a synthesis method of parametric sensitivity constrained linear quadratic (SCLQ) controller for an uncertain linear time invariant (LTI) system. System sensitivity to parameter variation is handled through an additional quadratic trajectory parametric sensitivity term in the standard LQ criterion to be minimized. The main purpose here is to find a suboptimal linear quadratic control taking explicitly into account the parametric uncertainties. The paper main contribution is threefold: 1) A descriptor system approach is used to show that the underlying singular linear-quadratic optimal control problem leads to a non-standard Riccati equation. 2) A solution to the proposed control problem is then given based on a connection to the so-called Lur'e matrix equations. 3) A synthesis method of multiple parametric SCLQ controllers is proposed to cover the whole parametric uncertainty while degrading as less as possible the intrinsic robustness properties of each local linear quadratic controller. Some examples are presented in order to illustrate the effectiveness of the approach. 展开更多
关键词 LINEAR QUADRATIC control PARAMETRIC uncertainties trajectory sensitivity non-standard RICCATI equation Lur'e matrix equations LINEAR time invariant (LMI) particle SWARM optimization
Development cost prediction of general aviation aircraft projects with parametric modeling
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作者 Xiaonan CHEN Jun HUANG Mingxu YI 《中国航空学报:英文版》 SCIE EI CAS CSCD 2019年第6期1465-1471,共7页
The study of the development cost of general aviation aircraft is limited by small samples with many cost-driven factors. This paper investigates a parametric modeling method for prediction of the development cost of ... The study of the development cost of general aviation aircraft is limited by small samples with many cost-driven factors. This paper investigates a parametric modeling method for prediction of the development cost of general aviation aircraft. The proposed technique depends on some principal components, acquired by utilizing P value analysis and gray correlation analysis. According to these principal components, the corresponding linear regression and BP neural network models are established respectively. The feasibility and accuracy of the P value analysis are verified by comparing results of model fitting and prediction. A sensitivity analysis related to model precision and suitability is discussed in detail. Results obtained in this study show that the proposed method not only has a certain degree of versatility, but also provides a preliminary prediction of the development cost of general aviation aircraft. 展开更多
关键词 BP neural network DEVELOPMENT cost General AVIATION AIRCRAFT GRAY correlation ANALYSIS Linear regression P value ANALYSIS PARAMETRIC modeling Preliminary prediction Sensitivity ANALYSIS
A Survey on Algorithms for Computing Comprehensive Gr?bner Systems and Comprehensive Grobner Bases
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作者 LU Dong SUN Yao WANG Dingkang 《系统科学与复杂性学报:英文版》 SCIE EI CSCD 2019年第1期234-255,共22页
Weispfenning in 1992 introduced the concepts of comprehensive Gr?bner system/basis of a parametric polynomial system,and he also presented an algorithm to compute them.Since then, this research field has attracted muc... Weispfenning in 1992 introduced the concepts of comprehensive Gr?bner system/basis of a parametric polynomial system,and he also presented an algorithm to compute them.Since then, this research field has attracted much attention over the past several decades,and many efficient algorithms have been proposed.Moreover,these algorithms have been applied to many different fields, such as parametric polynomial equations solving,geometric theorem proving and discovering,quantifier elimination,and so on.This survey brings together the works published between 1992 and 2018,and we hope that this survey is valuable for this research area. 展开更多
关键词 COMPREHENSIVE Gr?bner basis COMPREHENSIVE Gr?bner SYSTEM DISCOVERING geometric THEOREMS mechanically parametric polynomial SYSTEM QUANTIFIER elimination.
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