检索结果-内蒙古大学图书馆

Optimal analysis of material ratio for artificial rock by 3D printing technique

GEOMECHANICS AND GEOENGINEERING-AN INTERNATIONAL JOURNAL 2022年第1期17卷 260-268页

作者： Wu, Tingting Zhao, Hong Xu, Quan Zhao, Yixin China Univ Petr Coll Mech & Transportat Engn Beijing Peoples R China China Univ Petr State Key Lab Heavy Oil Proc Beijing Peoples R China China Univ Min & Technol Dept Min Xuzhou Jiangsu Peoples R China

Rock cores are important for rock properties research because they are linked to significant oil and gas drilling and production technology around the world. The goal of synthesising rock cores in the laboratory is to simulate the main factors of properties of reservoir rocks such as permeability, porosity and pore radius that can be used for tests in extreme conditions in replacement the high cost of obtaining natural cores. The reproduction of artificial rock cores in the laboratory also enables researchers to obtain samples with predetermined characteristics to better understand the relationship between their physical characteristics. In this paper, low-permeability and high-porosity artificial rock cores were made by 3D printing technology. The behaviour of the main petrophysical characteristics of these samples was investigated, such as setting time, rheology, permeability, porosity and compressive strength. The results were compared with natural samples and showed a high similarity to the petrophysical behaviour. By optimising the ratio of 3D printing materials, the physical properties of the samples were closer to the natural carbonate rocks. It provides a new technique and method to the development of special reservoir physical simulation experiments.

关键词： Artificial rock core 3D printing technology rock physical properties orthogonal test sqp algorithm

来源：评论

学校读者我要写书评

暂无评论

Optimal trajectory generation for manipulator with strong nonlinear constraints and multiple boundary conditions

Optimal trajectory generation for manipulator with strong no...

引用

IEEE International Conference on Robotics and Biomimetics (ROBIO 2004)

作者： Xu, CQ Ming, AG Shimojo, M Univ Electrocommun Dept Mech Engn & Intelligent Syst Tokyo Japan

ISBN: (纸本)0780386418

Up to now, the research work about optimal trajectory generation mainly focuses on such motion planning with boundary conditions of specified initial and final configurations. Multiple boundary conditions are seldom taken into account. This paper explores the motion planning method for hyper dynamic manipulation with multiple boundary conditions of initial, final and middle configurations and strong nonlinear constraints derived from active torque limitation and joint stop, and B-spline based optimal torque trajectory generation method is proposed by authors. By transforming the torque limitation constraints into a series of linear limitations for the coefficients of B-spline, and by using sqp optimization algorithm, optimal solutions are obtained with high convergence. Numerical experiments show the proposed method has superior numerical stability and high optimization accuracy in dealing with the optimal motion planning problem with strong nonlinear constraints and multiple boundary conditions.

关键词： B-spline motion planning multiple boundary condition nonlinear constraint sqp algorithm

来源：评论

学校读者我要写书评

暂无评论

Mathematical modeling and optimization of industrial scale ELUXYL simulated moving bed (SMB)

引用

SEPARATION AND PURIFICATION TECHNOLOGY 2020年 248卷 116961-116961页

作者： Shahmoradi, Ali Khosravi-Nikou, Mohammad Reza Aghajani, Masoud Shariati, Ahmad Saadi, Shahram Petr Univ Technol Ahwaz Fac Petr Dept Gas Engn Ahvaz Iran BouAli Sina Petrochem Co Mahshahr Iran

In this work, a detailed study on the modeling, simulation and optimization of the industrial-scale Eluxyl simulated moving bed (SMB) process are presented. Commercial SPX3000 (Ba-faujasite type zeolite) was used as an adsorbent, and para-diethylbenzene applied as a desorbent for separating para-xylene from other C-8 aromatics isomers. In the first step, the xylenes and para-diethylbenzene adsorption equilibrium on the commercial adsorbent were measured at operating conditions (175 degrees C, 9 bar) experimentally. The density of particle and porosities were determined from commercial plant operation and adsorbent analysis. Furthermore, mass transfer coefficients, including internal (diffusion in the pore) and external (diffusion in the liquid film) resistance, have been investigated in details. A common mathematical model encompassing the SMB strategy, node model, extended Langmuir isotherm, and rate expression were constructed to implement a numerical simulation of the industrial-scale Eluxyl SMB process with and without considering backwash stream. The accuracy of the mathematical model was validated by the industrial data. Besides, a dynamic optimization framework with Sequential Quadratic Programming (sqp) optimization algorithm was used for obtaining optimal conditions. Two separate single objective optimizations by considering minimum desorbent consumption and maximum SMB unit productivity as objectives were firstly designated. By comparing the results, it was concluded that minimizing desorbent consumption was more favorable to be selected as an objective function, which could achieve 6.35% increase in productivity and 7.28% decrease in desorbent consumption. Finally, two-level optimization was planned for reaching maximum feed throughput with minimum desorbent consumption. The results showed that productivity could be increased by 13.75%, and para-diethylbenzene consumption could be reduced by 10.81% at the optimal condition.

关键词： Para-xylene Simulated Moving Bed Eluxyl Modeling Optimization sqp algorithm

来源：评论

学校读者我要写书评

暂无评论

Optimal Design and Cogging Torque Minimization of a Permanent Magnet Motor for an Electric Vehicle

引用

TEHNICKI VJESNIK-TECHNICAL GAZETTE 2023年第2期30卷 538-544页

作者： Msaddek, Hejra Mansouri, Ali Trabelsi, Hafedh Engn Sch Sfax CES Lab Sfax 3038 Tunisia Univ Gafsa Higher Inst Appl Sci & technol TEMI Lab Gafsa 2100 Tunisia

With the increase of electric vehicle mobility, the integration of an electric motor inside the vehicle wheel is an interesting architecture for electric vehicles. This solution has the advantage of a great compactness of the motor and the elimination of mechanical transmission. This paper deals with the analytical modeling and the optimal dimension's finding of an in-wheel motor. An optimization procedure, based on Sequential Quadratic Programming sqp, is performed. The main objectives are the minimization of the machine weight and the maximization of its efficiency. While respecting constraints, an optimal machine with a weight of 11.61 kg and an efficiency of 93% is reached. To verify the satisfaction of the design requirements and the motor performances, finite element analysis (FEA), was applied. The comparison of induction results shows a good accuracy with a maximum error of 14%. The output torque and the air gap flux density are assessed. A maximum output torque of 90 Nm is achieved, and the slotting effect is noticed. Then the cogging torque of the machine is investigated;different rotor structures were studied. It is concluded, from results, that the topology with circular segmented magnets has the lowest cogging torque which does not exceed 7 Nm.

关键词： analytical model cogging torque finite element analysis optimization problem permanent magnet motor sqp algorithm

来源：评论

学校读者我要写书评

暂无评论

Benzene Reduction Process Simulation and Optimization in Catalytic Cracking Gasoline Distillation

引用

PROCESSES 2023年第1期11卷 151页

作者： Wang, Zijian Ke, Ming Song, Zhaozheng Li, Jiahan Sun, Jinru China Univ Petr Sch Sci Beijing 102249 Peoples R China

For countries where catalytic cracking gasoline is the primary source, the proposed technology consists in separating a benzene-rich fraction from catalytic cracking gasoline in order to be processed further together with reforming gasoline in a unit dedicated to aromatics extraction. In this way, two benefits are obtained: a benzene-rich fraction as raw material for extraction and the leftover fraction that satisfies the benzene content standards as a qualified product. It is established to use the divided wall distillation model, single-column distillation model, and double-column distillation model. Sensitivity analysis and sqp optimization are used to identify the ideal operating conditions and gasoline yield. Economic research shows that the divided wall and single-column distillation models have more potential for growth. It offers theoretical direction for businesses to design and optimize the pertinent process.

关键词： gasoline benzene divided wall column conventional column sqp algorithm

来源：评论

学校读者我要写书评

暂无评论

OPTIMAL CONTROL OF MULTIPLE-TIME DELAYED SYSTEMS BASED ON THE CONTROL PARAMETERIZATION METHOD

引用

The ANZIAM Journal 2012年第1期53卷 68-86页

作者： W. H. GUI X. Y. SHEN N. CHEN C. H. YANG L. Y. WANG School of Information Science and Engineering Central South University Changsha 410083 PR China (email: gwh@*** shxy-0501@*** ningchen@*** ychh@***) School of Electrical Engineering and Renewable Energy China Three Gorges University Yichang 443002 PR China (email: wly@***)

In this paper we study optimal control computation based on the control parameterization method for a class of optimal control problems involving nonlinear systems with multiple time delays subject to continuous state inequality constraints. Both the state and the control are allowed to have different time delays, and they are uncorrelated in this system. The control of the dynamical system is approximated by a piecewise constant function whose heights are taken as decision vectors. The formulae for computing the gradients of the cost and constraint functions are then derived. Based on this, a computational method for finding the optimal control is developed by utilizing the Sequential Quadratic Programming (sqp) algorithm with an active set strategy. The computational method is applied to an industrial problem arising in the purification process of zinc hydrometallurgy. Numerical simulation shows that the amount of zinc powder that is needed can be decreased significantly, thus avoiding wastage of resources.

关键词： multiple-time delayed system control parameterization continuous state inequality constraints sqp algorithm

来源：评论

学校读者我要写书评

暂无评论

Comparison of LPM,GPM and RPM for Optimization of Low-Thrust Earth-Mars Rendezvous Trajectories

Comparison of LPM,GPM and RPM for Optimization of Low-Thrust...

引用

2014中国制导、导航与控制学术会议

作者： Yukai Wang Yongsheng Zhu Xiuqiang Jiang Shuang Li College of Astronautics Nanjing University of Aeronautics and AstronauticsNanjing 210016China Shanghai Engineering Center for MicrosatellitesShanghai 201203China

ISBN: (纸本)9781479946983

The performance comparison is performed among Legendre (LPM),Gauss (GPM),and Radau (RPM) pseudospectral methods,which are utilized to optimize the low-thrust Earth-Mars rendezvous *** order to provide a fair comparison condition,a shape-based approach is implemented to provide equivalent initial guesses for all the next accurate optimization,and the sqp algorithm is used to solve the resulting nonlinear programming problem for each of the *** behavior and performance of the three pseudospectral methods are compared on the mission of Earth-Mars Rendezvous in 2013.

关键词： Earth Mars quadratic programming trajectory optimisation (aerospace) GPM Gauss pseudospectral methods LPM Legendre pseudospectral methods RPM Radau pseudospectral methods sqp algorithm low-thrust Earth-Mars rendezvous trajectory optimization nonlinear programming problem sequential quadratic programming algorithm shape-based approach Approximation methods Optimal control Optimization Polynomials Space vehicles Trajectory Vectors

来源：评论

学校读者我要写书评

暂无评论

The Optimum Design of Gear Transmission Based on MATLAB

The Optimum Design of Gear Transmission Based on MATLAB

引用

2010 International Conference on Measuring Technology and Mechatronics Automation(ICMTMA 2010)(2010年检测技术与机电自动化国际会议)

作者： Xiaofang Yang Jianhua Li Zongde Fang Cheng Wang School of Mechatronics Northwestern Polytechnical University Xi'an 710072 China

ISBN: (纸本)9781424450015

Gear mechanism is the most popular transmission mechanism, however, conventional design methods are complex and inaccurate. The optimum design solves the abovementioned problems effectively by means of applying to gear design. In numerous of optimization software,MATLAB holds obvious predominance on program and numerical calculation. Taking single gear transmission as an example, the math model of gear is founded, systematically, on the base of analyzing the foundation of goal function, the selection of design variables and the confirmation of restrictive conditions. The results solved by sqp algorithm prove out that the optimum design, by MATLAB, is effective, reliable and simple.

关键词： MATLAB gear transmission optimization design concrete example sqp algorithm

来源：评论

学校读者我要写书评

暂无评论

A Modified Sequence Quadratic Programming Method for Nonlinear Programming

A Modified Sequence Quadratic Programming Method for Nonline...

引用

The Fourth International Joint Conference on Computational Science and Optimization(第四届计算科学与优化国际大会 CSO 2011)

作者： Guohua Chen Zhijun Luo Lirong Wang The Department of Mathematics & Applied Mathematics Hunan University of Humanities Science and Tec Loudi Technician College Hunan Loudi.417000P.R.China

Sequence quadratic programming method is one of the most useful methods for solving constrained optimization problem. In this paper, a new modified sqp method is proposed to solve the nonlinear programming. This algorithm starts from an arbitrary initial point and adjusts penalty parameter automatically. A descent direction is obtained by solving only one variant constrained subproblem. In order to avoid Marotos effect, a high-order revised direction is obtained by solving a line system. Furthermore, under mild conditions, the global and local superlinear convergence properties are obtained.

关键词： Nonlinear programming sqp algorithm Global convergence Superlinear convergence

来源：评论

学校读者我要写书评

暂无评论

Application of the LPPL model in the identification and measurement of structural bubbles in the Chinese stock market

引用

NORTH AMERICAN JOURNAL OF ECONOMICS AND FINANCE 2024年 70卷

作者： Ji, Hongyun Zhang, Han Univ Shanghai Sci & Technol Business Sch Dept Finance 516 Jungong Rd Shanghai 200093 Peoples R China ICBC AXA Asset Management Co Equ Investment Dept 27F Mirae Asset Bldg 166 Lujiazui Ring Rd Shanghai 200120 Peoples R China

This study proposes innovative methods for determining the starting point and estimating the parameters of the LPPL model for predicting stock market bubbles. These methods address the challenges in determining the starting point of irregularly staged bubbles and the issues of multiple local optima or no solutions in previous prediction algorithms. The proposed LPPL model, incorporating innovative algorithms, is applied to the Chinese A-share market from 2018 to 2021. The starting points of structural bubbles are determined using the difference and grid search methods, and the sequential quadratic programming (sqp) algorithm is used to estimate the parameters of the LPPL model. The study measures and warns about structural bubbles in the A-share market. The results demonstrate that the LPPL model with the innovative algorithm can accurately measure staged and structural bubbles in the A-share market and provide reasonably accurate warnings of bubble bursts, which have been confirmed by the market multiple times.

关键词： Chinese stock market Structural bubble LPPL model sqp algorithm

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：