检索结果-内蒙古大学图书馆

20th Annual American Control Conference (ACC)

作者： Imae, J Inoue, K Osaka Prefecture Univ Sakai Osaka 5998531 Japan

ISBN: (纸本)0780372980

A unified approach for numerical solutions of nonlinear optimal control problems is proposed. First, a canonical form of optimal control problems is defined, which includes a variety of control problems, such as time optimal ones, design parameter ones, initial state constrained ones, state discontinuous ones, and so on. Then, based on the algorithms of the Bolza type, the algorithm for numerical solutions of the canonical problems is derived. Lastly, the usefulness of the canonical setting of optimal control problems is demonstrated through some numerical simulations. It should be noted that the canonical problem is considered to be one of the Bolza type problems and so powerful algorithms developed for those problems are available.

关键词： optimal control computational method nonlinear systems discontinuous state trajectory

来源：评论

学校读者我要写书评

暂无评论

Development of a novel method to estimate fluid flow rate in oil wells using electrical submersible pump

引用

JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING 2015年 135卷 466-475页

作者： Ganat, TarekA. Hrairi, Meftah Hawlader, M. N. A. Farj, Osman Int Islamic Univ Malaysia Dept Mech Engn Kuala Lumpur 50728 Malaysia PETRONAS Carigalin Twin Towers Dept Prod Technol Kuala Lumpur 558800 Malaysia

The significant challenge in the oil and gas industry is the simultaneous measurement of commingled gas, oil and water streams, using the three phase test separator or multiphase flow meter (MPFM). A major issue in the application of using either test separator or MPFM in oil fields is the uncertainty of the measurements, due to different process and operations conditions. This paper proposes a new computational method to estimate the electrical submersible pump (ESP) oil wells flow rates. The research idea is to close the wellhead wing valve, to measure the wellhead flowing pressure before and after closing the well head valve, and to record the total shut-in time period. Explicit physics concepts for estimations of the multiphase fluid flow rate in a vertical pipe were employed. The formulas deal with changes of fluid flow parameters along the vertical pipe in the well, as a function of pressure and temperature variations with depth. A Microsoft visual basic program was also developed based on the oil mechanistic and empirical equations that can estimate oil rate for ESP oil wells. The new method was applied on 34 ESP oil wells in a North African oil field and lead to very reliable estimation results, which have about a +/- 10% relative error, and can be applied to all fluid types and under any production conditions. (C) 2015 Elsevier B.V. All rights reserved.

关键词： Flow rate Electrical submersible pump computational method Bubble point pressure Wellhead pressure

来源：评论

学校读者我要写书评

暂无评论

Efficient dynamics analysis of large-deformation flexible beams by using the absolute nodal coordinate transfer matrix method

引用

MULTIBODY SYSTEM DYNAMICS 2014年第4期32卷 535-549页

作者： Rong, Bao Nanchang Mil Acad Nanchang 330103 Peoples R China

This paper describes an efficiently computational method for dynamics simulating of planar multibody system with flexible beams undergoing large deformations by combining the absolute nodal coordinate formulation (ANCF) and the transfer matrix method (TMM). Firstly, according to ANCF and the geometrically nonlinear theory, the two-dimensional shear-deformable beam element and its dynamic equations of motion are presented. Then according to TMM and the dynamic equations of beam elements, by defining the new state vectors and deducing the new transfer equations of elements, an efficient computational method named as ANC-TMM, is presented for dynamics of planar multibody system with flexible beams undergoing large deformations. Compared with the ordinary dynamics methods, the proposed method combines the strengths of TMM and ANCF. It does not need the global dynamic equations of system and has the low order of the system matrix and high computational efficiency. This method can be extended to solve the nonlinear dynamics problems of general flexible multibody systems undergoing large deformations. Formulations as well as a numerical example of a flexible four-bar linkage mechanism are given to validate the method.

关键词： Multibody system Geometric nonlinearity computational method Shear-deformable beam element Large rotation

来源：评论

学校读者我要写书评

暂无评论

A Research On The Ecological Footprint Evaluation And computational methods Of Urban Water Resourse In Beijing

A Research On The Ecological Footprint Evaluation And Comput...

引用

4th International Conference on Technology of Architecture and Structure (ICTAS 2011)

作者： Li, Ying Guo, Tingting Yan, Pan Key Laboratory of Urban Stormwater System and Water Environment Beijing University of Civil Engineering and Architecture Ministry of Education Beijing 100044 China

ISBN: (纸本)9783037852798

Since the water resourse insome towns of Beijing were in a big shortage in the past few years, it becomes a key factor which restricts the sustainable development and theurbanlization of Beijing. Based on the fact, this paper introduces the reserrch situation and development of the ecological footprint of urban water resourse in Beijing. And it puts forward the method for calculating the the ecological footprint of urban water resourse, includeing domestic water, process water and eological water, in Beijing. Furthermore, the computational method of ecological carrying capacity and ecological deficit of urban water resourse in Beijing is proposed, which provides reference for the evaluation of ecological capacity of urban water resourse in Beijing.

关键词： Beijing urban water resourse evaluation of ecological footprint computational method

来源：评论

学校读者我要写书评

暂无评论

computational methods for set-relation-based scalarizing functions

引用

Nihonkai Mathematical Journal 2017年第2期28卷 139-149页

作者： Hui Yu Koichiro Ike Yuto Ogata Yutaka Saito Tamaki Tanaka

In this research, we propose computational methods to evaluate scalarizing functions, which are defined via set-relations. In recent years, many theoretical results of the scalarizing functions for sets have been published. The aim of this paper is to show that each value of the scalarizing functions can be computed and to introduce computational algorithms of them for convex polytopes in a finite dimensional space.

关键词： 46N10 90C29 49J53 ‎54C60‎ computational method scalarizing function set optimization set-relation sublinear scalarization

来源：评论

学校读者我要写书评

暂无评论

A computationally efficient method for tempered fractional differential equations with application

引用

computational & APPLIED MATHEMATICS 2018年第3期37卷 3657-3671页

作者： Moghaddam, Behrouz Parsa Machado, J. A. Tenreiro Babaei, Afshin Islamic Azad Univ Lahijan Branch Dept Math Lahijan Iran Inst Engn Dept Elect Engn Rua Dr Antonio Bernardino de Almeida 431 P-4249015 Porto Portugal Univ Mazandaran Dept Math POB 47416 95447 Babol Sar Iran

This paper investigates the numerical approximation of the tempered fractional integral by using the Sinc-collocation scheme. The algorithm is extended to solve a class of tempered fractional differential equations that converges to the solution with exponential rate. Several numerical examples compare the numerical approximations with the exact solutions. The behavioral responses of the lumped capacitance model with tempered fractional order for transient conduction are investigated. The efficiency and accuracy of the proposed scheme are analyzed in the perspective of the -norm error and convergence order.

关键词： Tempered fractional calculus computational method Sinc-collocation method Convergence order The lumped capacitance model

来源：评论

学校读者我要写书评

暂无评论

Two-step method for radiative transfer calculations in a developing pool fire at the initial stage of its suppression by a water spray

引用

INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER 2018年第PartB期127卷 717-726页

作者： Dombrovsky, Leonid A. Dembele, Siaka Wen, Jennifer X. Sikic, Ivan Kingston Univ Dept Mech & Automot Engn London SW15 3DW England Joint Inst High Temp 17A Krasnokazarmennaya St Moscow 111116 Russia Univ Tyumen 6 Volodarsky St Tyumen 625003 Russia Univ Warwick Sch Engn Coventry CV4 7AL W Midlands England

A procedure based on two-step method is suggested to simplify time-consuming spectral radiative transfer calculations in open flames containing scattering particles. At the first step of the problem solution, the P, approximation is used to calculate the divergence of radiative flux, and it is sufficient to determine the flame parameters. The second step of solution is necessary to obtain the radiation field outside the flame, and this can be made independently using the ray-tracing procedure and the transport source function determined at the first step. Such a splitting of the complete problem results in much simpler algorithm than those used traditionally. It has been proved in previous papers that the combined two-step method is sufficiently accurate in diverse engineering applications. At the same time, the computational time decreases in about two orders of magnitude as compared with direct methods. An axisymmetric pool fire at the initial stage of fire suppression by a water spray is considered as the case problem. It is shown that evaporating small water droplets characterised by a strong scattering of infrared radiation are mainly located in regions near the upper front of the flame and one can observe the scattered radiation. This effect can be used in probe experiments for partial validation of transient computational Fluid Dynamics (CFD) simulations. (C) 2018 The Authors. Published by Elsevier Ltd.

关键词： Radiation Developing pool fire Fire suppression Water droplets computational method

来源：评论

学校读者我要写书评

暂无评论

A CONFORMING POINT INTERPOLATION method (CPIM) BY SHAPE FUNCTION RECONSTRUCTION FOR ELASTICITY PROBLEMS

引用

INTERNATIONAL JOURNAL OF computational methodS 2010年第3期7卷 369-395页

作者： Xu, X. Liu, G. R. Gu, Y. T. Zhang, G. Y. Jilin Univ Coll Math Changchun 130021 Peoples R China Singapore MIT Alliance SMA Singapore 117576 Singapore Queensland Univ Technol Sch Engn Syst Brisbane Qld 4001 Australia Natl Univ Singapore Ctr Adv Computat Engn Sci ACES Dept Mech Engn Singapore 117576 Singapore

A conforming point interpolation method (CPIM) is proposed based on the Galerkin formulation for 2D mechanics problems using triangular background cells. A technique for reconstructing the PIM shape functions is proposed to create a continuous displacement field over the whole problem domain, which guarantees the CPIM passing the standard patch test. We prove theoretically the existence and uniqueness of the CPIM solution, and conduct detailed analyses on the convergence rate;computational efficiency and band width of the stiffness matrix of CPIM. The CPIM does not introduce any additional degrees of freedoms compared to the linear FEM and original PIM;while convergence rate of quadratic CPIM is in between that of linear FEM and quadratic FEM which results in the high computational efficiency. Intensive numerical studies verify the properties of the CPIM.

关键词： Numerical method computational method finite element method meshfree methods point interpolation method convergence rates, computational efficiency, non-conforming

来源：评论

学校读者我要写书评

暂无评论

Synthesis, X-ray diffraction method, spectroscopic characterization (FT-IR, ¹H and ¹³C NMR), antimicrobial activity, Hirshfeld surface analysis and DFT computations of novel sulfonamide derivatives

引用

JOURNAL OF MOLECULAR STRUCTURE 2018年 1161卷 122-137页

作者： Demircioglu, Zeynep Ozdemir, Fethi Ahmet Dayan, Osman Serbetci, Zafer Ozdemir, Namik Sinop Univ Fac Arts & Sci Dept Phys Sinop Turkey Bingol Univ Fac Arts & Sci Dept Mol Biol & Genet Bingol Turkey Canakkale Onsekiz Mart Univ Fac Arts & Sci Dept Chem Canakkale Turkey Bingol Univ Fac Arts & Sci Dept Chem Bingol Turkey Ondokuz Mayis Univ Fac Educ Dept Math & Sci Educ Samsun Turkey

Synthesized compounds of N-(2-aminophenyl)benzenesulfonamide 1 and (Z)-N-(2-((2-nitrobenzylidene)amino)phenyl)benzenesulfonamide 2 were characterized by antimicrobial activity, FT-IR, H-1 and C-13 NMR. Two new Schiff base ligands containing aromatic sulfonamide fragment of (Z)-N-(2-((3-nitrobenzylidene)amino)phenyl)benzenesulfonamide 3 and (Z)-N-(2-((4-nitrobenzylidene)amino)phenyl)benzenesulfonamide 4 were synthesized and investigated by spectroscopic techniques including 1H and 13C NMR, FT-IR, single crystal X-ray diffraction, Hirshfeld surface, theoretical method analyses and by antimicrobial activity. The molecular geometry obtained from the X-ray structure determination was optimized Density Functional Theory (DFT/B3LYP) method with the 6-311++G(d,p) basis set in ground state. From the optimized geometry of the molecules of 3 and 4, the geometric parameters, vibrational wavenumbers and chemical shifts were computed. The optimized geometry results, which were well represented the X-ray data, were shown that the chosen of DFT/B3LYP 6-311G++(d,p) was a successful choice. After a successful optimization, frontier molecular orbitals, chemical activity, non-linear optical properties (NLO), molecular electrostatic mep (MEP), Mulliken population method, natural population analysis (NPA) and natural bond orbital analysis (NBO), which cannot be obtained experimentally, were calculated and investigated. (C) 2018 Published by Elsevier B.V.

关键词： X-ray diffraction method FT-IR and NMR spectroscopy Antimicrobial activity Hirshfeld surfaces computational method

来源：评论

学校读者我要写书评

暂无评论

FINITE DIFFERENCE method FOR SOLVING THE NONLINEAR DYNAMIC EQUATION OF UNDERWATER TOWED SYSTEM

引用

INTERNATIONAL JOURNAL OF computational methodS 2014年第4期11卷 1350060-1-1350060-20页

作者： Yuan, Zhijiang Jin, Liangan Chi, Wei Tian, Hengdou Dalian Naval Acad Dept Nav Dalian 116018 Peoples R China 91439 PLA Dalian 116040 Peoples R China

A wide body of work exists that describes numerical solution for the nonlinear system of underwater towed system. Many researchers usually divide the tow cable with less number elements for the consideration of computational time. However, this type of installation affects the accuracy of the numerical solution. In this paper, a newly finite difference method for solving the nonlinear dynamic equations of the towed system is developed. The mathematical model of tow cable and towed body are both discretized to nonlinear algebraic equations by center finite difference method. A newly discipline for formulating the nonlinear equations and Jacobian matrix of towed system are proposed. We can solve the nonlinear dynamic equation of underwater towed system quickly by using this discipline, when the size of number elements is large.

关键词： computational method finite difference method underwater towed system

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：