检索结果-内蒙古大学图书馆

optimization of Time-Open Constrained Lambert Rendezvous Using Interval Analysis

JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2013年第1期36卷 175-184页

作者： Chen, Tong van Kampen, E. Yu, H. Chu, Q. P. Beihang Univ Sch Astronaut Dept Guidance Nav & Control Beijing 100191 Peoples R China Delft Univ Technol Fac Aerosp Engn Sect Control & Simulat NL-2600 GB Delft Netherlands

By defining a parking time and a transfer time, a time-open constrained Lambert rendezvous problem is proposed in this paper. The purpose of optimization is to minimize the velocity increment for the orbital rendezvous. The interval branch and bound optimization algorithm is introduced for solving a rendezvous optimization problem with strong nonlinearity and nonconvexity. A numerical example is undertaken to validate the interval optimization algorithm. The results indicate that although the global optimal solution for the time-open constrained Lambert rendezvous problem can't be found by using only the interval algorithm in the restricted hardware environment because of the inevitable influence of interval dependency and the complex calculation for the cost function, the interval algorithm can narrow the search space and split the feasible space into many small subspaces. Combining the gradient-based optimization method, an improved interval algorithm is used to find the minimal velocity increment for orbital rendezvous, which is better than the optimal solution using the genetic algorithm.

关键词： Orbital Rendezvous optimization algorithm Genetic algorithm Orbital Maneuvers Lambert's Problem Orbital Elements Branch and Bound algorithm Apogee Altitude Numerical Analysis Right Ascension

来源：评论

学校读者我要写书评

暂无评论

Power optimization of Solar-Powered Aircraft with Specified Closed Ground Tracks

引用

JOURNAL OF AIRCRAFT 2013年第1期50卷 232-238页

作者： Spangelo, Sara C. Gilbert, Elmer G. Univ Michigan Ann Arbor MI 48109 USA

This paper considers the optimization of flight trajectories for solar-powered aircraft. This work is unique relative to past work because flight path is constrained to repeatedly traverse a specified closed ground path. Constraints of this form are of interest in a variety of missions where the goal is to loiter near a fixed point on the ground. The performance index to be maximized is the average input power to the battery over each cycle of the ground path. It is advantageous to allow the periodic flight path to have altitude variations because during both ascent and descent there are opportunities to increase the angle of sun exposure to the aircraft solar array. A novel procedure for solving the related optimization problem is described that addresses the implementation of a difficult state constraint: the flight path must belong to the surface of the vertical cylinder whose base is the closed ground path. Results for a wide collection of optimization examples are described, which lead to an important conclusion. By allowing aircraft speed and altitude to vary iris possible to obtain an average input battery power greater than the optimal power for constant speed and constant altitude.

关键词： Solar Powered Aircraft Flight Trajectory Aircraft Speed Level Flight Aerodynamic Coefficients Solar Power optimization algorithm Aircraft Trajectory Aircraft Altitude Flight Data

来源：评论

学校读者我要写书评

暂无评论

Chosen Numerical algorithms for Interval Finite Element Analysis

引用

Procedia Engineering 2014年 96卷 400-409页

作者： Milan Sága Milan Vaško Peter Pecháč Department of applied mechanics Faculty of Mechanical Engineering University of ŽilinaUniverzitná 1 Žilina 01026 Slovakia

Our paper presents chosen computational algorithms for solution of finite element models with structural uncertainties. An application of the chosen approaches will be presented–the first one, a simple combination of only inf-values or only sup-values; the second one presents full combination of all inf-sup values; the third one uses the optimizing process as a tool for finding out an inf-sup solution and last one is the Monte Carlo method as a comparison tool.

关键词： Uncertain mechanical parameters Monte Carlo method Interval arithmetic optimization algorithm

来源：评论

学校读者我要写书评

暂无评论

Heuristic optimization algorithm for Task Assignment in Collaborative Project Based on CITIS

Heuristic Optimization Algorithm for Task Assignment in Coll...

引用

International Asia Conference on Informatics in Control, Automation and Robotics

作者： Zhao Xingwen Jiang Lili Xi Xiaoying Li Muzhi Guangdong Univ Technol Fac Electromech Engn Guangzhou Guangdong Peoples R China

ISBN: (纸本)9780769535197

In CITIS (Contractor Integrated Technical Information Service) collaborative manufacturing project, how the prime contractor reasonably chooses cooperative enterprises and assigns tasks among them will directly effects on gaining benefit from the project. To solve this problem, in this paper, a new heuristic optimization algorithm is proposed for tasks assignment, which objectives are minimizing costs and reducing the number of enterprises selected based on the minimization of project time. Finally, the algorithm is varied through an example, and the evaluation for it is given.

关键词： CITIS collaborative manufacturing task assignment optimization algorithm

来源：评论

学校读者我要写书评

暂无评论

Multi-Objective optimization for Multiphase Orbital Rendezvous Missions

引用

JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2013年第2期36卷 622-629页

作者： Zhang, Jin Parks, Geoffrey Natl Univ Def Technol Coll Aerosp Sci & Engn Changsha 410073 Hunan Peoples R China Univ Cambridge Dept Engn Cambridge CB2 1PZ England

A multi-objective optimization approach was proposed for multiphase orbital rendezvous missions and validated by application to a representative numerical problem. By comparing the Pareto fronts obtained using the proposed method, the relationships between the three objectives considered are revealed, and the influences of other mission parameters, such as the sensors' field of view, can also be analyzed effectively. For multiphase orbital rendezvous missions, the tradeoff relationships between the total velocity increment and the trajectory robustness index as well as between the total velocity increment and the time of flight are obvious and clear. However, the tradeoff relationship between the time of flight and the trajectory robustness index is weak, especially for the four- and five-phase missions examined. The proposed approach could be used to reorganize a stable rendezvous profile for an engineering rendezvous mission, when there is a failure that prevents the completion of the nominal mission.

关键词： Orbital Rendezvous Multi Objective Genetic algorithm Orbital Maneuvers Propellant Orbital Inclination Right Ascension Earth optimization algorithm Nonlinear Programming Charge Coupled Device

来源：评论

学校读者我要写书评

暂无评论

ASSIMILATION OF FIELD MEASURED LAI INTO CROP GROWTH MODEL BASED ON SCE-UA optimization algorithm

ASSIMILATION OF FIELD MEASURED LAI INTO CROP GROWTH MODEL BA...

引用

IEEE International Geoscience and Remote Sensing Symposium

作者： Ren, Jianqiang Yu, Fushui Du, Yunyan Qin, Jun Chen, Zhongxin Minist Agr Key Lab Resources Remote Sensing & Digital Agr Beijing 100081 Peoples R China Chinese Acad Agr Sci Inst Agr Resources & Reg Planning Beijing 100081 Peoples R China Chinese Acad Sci Inst Geog Sci & Natural Resources Res State Key Lab Resources & Environm Informat Syst Beijing 100101 Peoples R China Chinese Acad Sci Inst Tibetan Plateau Res Beijing 100085 Peoples R China

ISBN: (纸本)9781424433940

Assimilating external data into crop growth model to Improve accuracy of crop growth monitoring and yield estimation has been being a research focus in recent years In this paper, the shuffled complex evolution (SCE-UA) global optimization algorithm was used to assimilate field measured LAI into EPIC model to simulate yield, sowing date and nitrogen fertilizer application amount of summer maize in Huanghuaihai Plain in China. The results showed that RMSE between simulated yield and field measured yield of summer maize was 0.84 t ha(-1) and the R-2 was only 0 033 without external data assimilation. While the performances of EPIC model of simulating yield, sowing date and nitrogen fertilizer application amount of summer maize was better through assimilating field measured LAI into the EPIC model. The RMSE of between simulated yield and field measured yield of summer maize was 0.60 t ha(-1) and the R-2 was 0.5301. The relative error between simulated sowing date and real sowing date of summer maize was 2 28% On the simulation of nitrogen fertilizer application rate, the relative error was -6 00% compared with local statistical data These above accuracy could meet the need of crop growth monitoring and yield estimation at regional scale. It proved that assimilating field measured LAI Into crop growth model based on SCE-UA optimization algorithm to monitor crop growth and estimate crop yield was feasible

关键词： Crop growth model EPIC Data assimilation optimization algorithm LAI Yield estimation

来源：评论

学校读者我要写书评

暂无评论

optimization-based key frame extraction for motion capture animation

引用

VISUAL COMPUTER 2013年第1期29卷 85-95页

作者： Liu, Xian-mei Hao, Ai-min Zhao, Dan Beihang Univ State Key Lab Virtual Real Technol & Syst Beijing 100083 Peoples R China NE Petr Univ Sch Comp & Informat Technol Daqing 163318 Peoples R China

In this paper, we present a new solution for extracting key frames from motion capture data using an optimization algorithm to obtain compact and sparse key frame data that can represent the original dense human body motion capture animation. The use of the genetic algorithm helps determine the optimal solution with global exploration capability while the use of a probabilistic simplex method helps expedite the speed of convergence. By finding the chromosome that maximizes the fitness function, the algorithm provides the optimal number of key frames as well as the low reconstruction error with an ordinary interpolation technique. The reconstruction error is computed between the original motion and the reconstruction one by the weighted differences of joint positions and velocities. The resulting set of key frames is obtained by iterative application of the algorithm with initial populations generated randomly and intelligently. We also present experiments which demonstrate that the method can effectively extract key frames with a high compression ratio and reconstruct all other non key frames with high quality.

关键词： Computer animation Motion capture Key frame extraction optimization algorithm

来源：评论

学校读者我要写书评

暂无评论

Fisheries Ecosystem Management Based on optimization algorithm

Fisheries Ecosystem Management Based on Optimization Algorit...

引用

International Conference on Environmental Science and Information Application Technology (ESIAT 2009)

作者： Sun, Lin Xiao, Hongjun Yang, Dequan Li, Shouju Dalian Univ Technol Sch Management Dalian Peoples R China Dalian Univ Technol Dept Engn Mech Dalian Peoples R China

ISBN: (纸本)9780769536828

The pressure on marine renewable resources has rapidly increased over past decades. The resulting scarcity has led to a variety of different control and surveillance instruments. The dynamics of fish stocks are an important consideration in determining appropriate fishery management policy. Equally crucial are the dynamics of fishing effort. A variety of growth curves have been applied to model both unpredated, intraspecific population dynamics and more general biological growth. Fishing effort dynamics are determined by the difference in profits and opportunity costs. Several management alternatives are evaluated at equilibrium. Performance variables such as equilibrium catch, social profits, consumer surplus, social benefits, direct fishery employment and income of individual crew are used in the evaluation.

关键词： equilibrium catch fisheries ecosystem management optimization algorithm sustainable development

来源：评论

学校读者我要写书评

暂无评论

Robust state estimator design for uncertain linear systems using optimization techniques

引用

NEURAL COMPUTING & APPLICATIONS 2013年第5期23卷 1395-1406页

作者： Sheikhan, Mansour Bagheri, Mohammad Mahdi Islamic Azad Univ Dept Elect Engn Fac Engn South Tehran Branch Tehran Iran

The estimation of state variables of dynamic systems in noisy environments has been an active research field in recent decades. In this way, Kalman filtering approach may not be robust in the presence of modeling uncertainties. So, several methods have been proposed to design robust estimators for the systems with uncertain parameters. In this paper, an optimized filter is proposed for this problem considering an uncertain discrete-time linear system. After converting the subject to an optimization problem, three algorithms are used for optimizing the state estimator parameters: particle swarm optimization (PSO) algorithm, modified genetic algorithm (MGA) and learning automata (LA). Experimental results show that, in comparison with the standard Kalman filter and some related researches, using the proposed optimization methods results in robust performance in the presence of uncertainties. However, MGA-based estimation method shows better performance in the range of uncertain parameter than other optimization methods.

关键词： State estimator Uncertain system optimization algorithm Particle swarm optimization Modified genetic algorithm Learning automata

来源：评论

学校读者我要写书评

暂无评论

Heuristic shape optimization of gas ducting in process and power plants

引用

CHEMICAL ENGINEERING RESEARCH & DESIGN 2013年第6期91卷 999-1008页

作者： Avvari, Ramesh Jayanti, Sreenivas Indian Inst Technol Dept Chem Engn Madras 600036 Tamil Nadu India Indian Inst Technol Dept Appl Mech Madras 600036 Tamil Nadu India

Sudden changes in the flow direction are quite common but are inevitable in the lay-out in gas ducting in process and power plants. While it is well known that such changes lead to high pressure drops and flow separation, the scope for optimization is limited by constraints such as on-site fabrication and lay-out limitations. In the present paper, we present an efficient, computational fluid dynamics (CFD)-based shape optimization method which results in lesser pressure drop and more streamlined flow while adhering to site-specific constraints in terms of the extent of changes that can be made. The method is based on velocity defect in the plane of the bend: if, at a particular streamwise location, the average velocity in one half of cross section is above (or below) the cross sectional average velocity by, say, 10% or more, then the width of the duct locally is increased (or decreased), if it is possible to do so within the lay-out restrictions. An iterative application of this criterion using a commercial CFD code is shown to lead to better design of the bend. The optimized solution is validated with experimental results. (c) 2013 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

关键词： Shape optimization Bends Power plant ducting Computational fluid dynamics optimization algorithm Pressure drop reduction

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：