检索结果-内蒙古大学图书馆

Fast Pareto set generation for nonlinear optimal control problems with multiple objectives

STRUCTURAL AND multiDISCIPLINARY optimization 2010年第4期42卷 591-603页

作者： Logist, Filip Houska, Boris Diehl, Moritz Van Impe, Jan Katholieke Univ Leuven Dept Chem Engn BioTeC & Optimizat Engn Ctr OPTEC B-3001 Leuven Belgium Katholieke Univ Leuven Dept Elect Engn SCD & Optimizat Engn Ctr OPTEC B-3001 Leuven Belgium

Many practical engineering problems involve the determination of optimal control trajectories for given multiple and conflicting objectives. These conflicting objectives typically give rise to a set of Pareto optimal solutions. To enhance real-time decision making efficient approaches are required for determining the Pareto set in a fast and accurate way. Hereto, the current paper integrates efficient multiple objective scalarisation strategies (e.g., Normal Boundary Intersection and Normalised Normal Constraint) with fast deterministic approaches for dynamic optimisation (e.g., Single and multiple Shooting). All techniques have been implemented as an easy-to-use add-on module of the automatic control and dynamic optimisation toolkit ACADO (both freely available at http://***). Several algorithmic synergies (e.g., hot-start initialisation strategies) are exploited for an additional speed-up. The features of ACADO multi-objective are discussed and its use is illustrated on different multiple objective optimal control problems arising in several engineering disciplines.

关键词： multiobjective optimization Optimal control Dynamic optimization Normalised Normal Constraint Normal Boundary Intersection

来源：评论

学校读者我要写书评

暂无评论

multi-objective Aerodynamic optimization of Truck Deflector Using Genetic Algorithm and CFD Method

Multi-Objective Aerodynamic Optimization of Truck Deflector ...

引用

Asia-Pacific International Symposium on Aerospace Technology

作者： Zhao Xu Han Tianshi Yang Qiuping NW Polytech Univ Natl Key Lab Aerodynam Design & Res Xian 710072 Peoples R China

ISBN: (纸本)9787561228999

Based on the aerodynamic theory and CFD method, the single/multi-objective aerodynamic optimization design of a truck deflector is completed. During the process, two approaches have been developed separately to improve its performance: (A) a suitable cut transversely on the back yard of the circular deflector;(B) deflector reshaping using B-spline. For single-objective optimization, truck speed is fixed as the precondition, drag is set to be the objective. Moreover, the multi-objective optimization is arranged by Hybrid Genetic Algorithm (HGA), including drag and aerodynamic acoustics. This research indicates that both approaches can improve the local flow status, and provide a better characteristics in reducing drag (4.50%-6.23% and 3.16%-4.03% respectively) and acoustics, which is valuable both in academic research practical application.

关键词： CFD B-spline drag aerodynamic acoustics hybrid genetic algorithm

来源：评论

学校读者我要写书评

暂无评论

A new surface modification approach for CFD-based hull form optimization

引用

JOURNAL OF HYDRODYNAMICS 2010年第5期22卷 503-508页

作者： Kim, Hyunyul Yang, Chi George Mason Univ Dept Computat & Data Sci Fairfax VA 22030 USA

The main focus of this study is on the development of an efficient and effective hull surface modification technique for the CFD-based hull form optimization. Two approaches are utilized. One is based on the radial basis function interpolation, and the other the sectional area curve of the hull. Both local and global modifications of hull forms can be achieved by combining these two approaches. The hull surface modification technique developed in this study is used to vary the hull forms during the optimization process, in which the objective functions associated with the resistance is evaluated by a practical design-oriented CFD tool (SSF), and a multi-objective genetic algorithm is adopted to allow for multi-design speeds. For the purpose of illustration, the KRISO container ship (KCS) is taken as an initial hull to be optimized for reduced drag at given design speeds. Numerical results obtained in this study have shown that the present hull surface modification technique can produce smooth hull forms with reduced drag effectively and efficiently in the CFD-based hull form optimization.

关键词： Hydrodynamic optimization hull surface modification hull form design resistance radial basis function

来源：评论

学校读者我要写书评

暂无评论

Job shop rescheduling by using multi-objective genetic algorithm

Job shop rescheduling by using multi-objective genetic algor...

引用

40th International Conference on Computers and Industrial Engineering, CIE40 2010

作者： Hao, Xinchang Lin, Lin IPS Waseda University 2-7 Hibikino Wakamatsu-ku Kitakyushu 808-0135 Japan Dalian University of Technology Dalian China Fuzzy Logic Systems Institute Kitakyushu Japan

ISBN: (纸本)9781424472956

In current manufacturing systems, production is a very dynamic process with many unexpected events and continuously emerging new requirements. Researchers have developed a wide variety of procedures and heuristics for solving these scheduling problems, called rescheduling. Most proposed approaches are often derived by making simplifying assumptions. As a consequence, the approach is not in accordance with functioning of the real manufacturing system. Such approaches are frequently not suitable and flexible enough to respond efficiently to fast changes in the environment. In this paper, we focus on a practical solution of rescheduling by using mathematical modeling and interactive adaptive-weight evolutionary algorithm. We extend the rescheduling problem to a multi-objective optimization model. We formulate several objectives for corresponding requirement, such as due date, capability, transportation cost, set up cost and available resources etc. We can select the necessary one objective or some objectives for the manufacturing flexibility. However, for traditional approaches of multi-objective optimization problems, researchers focused on the solutions diversity. For the multiobjective rescheduling problem (moJSRS), we have to consider not only the solutions diversity, but also adapting the objectives alternative. We will propose an interactive adaptive-weight evolutionary algorithm with adapting the characteristics of a multi-objective job shop rescheduling problem. Some practical test instances will be demonstrated the effectiveness and efficiency of the proposed algorithm.

关键词： multiobjective optimization

来源：评论

学校读者我要写书评

暂无评论

An Analysis of Algorithmic Components for multiobjective Ant Colony optimization: A Case Study on the Biobjective TSP

An Analysis of Algorithmic Components for Multiobjective Ant...

引用

9th International Conference on Evolution Artificial

作者： Lopez-Ibanez, Manuel Stutzle, Thomas Univ Libre Bruxelles CoDE IRIDIA Brussels Belgium

ISBN: (纸本)9783642141553

In many practical problems, several conflicting criteria exist for evaluating solutions. In recent years, strong research efforts have been made to develop efficient algorithmic techniques for tackling such multiobjective optimization problems. Many of these algorithms are extensions of well-known metaheuristics. In particular, over the last few years, several extensions of ant colony optimization (ACO) algorithms have been proposed for solving multi-objective problems. These extensions often propose multiple answers to algorithmic design questions arising in a multi-objective ACO approach. However, the benefits of each one of these answers are rarely examined against alternative approaches. This article reports results of an empirical research effort aimed at analyzing the components of ACO algorithms for tackling multi-objective combinatorial problems. We use the bi-objective travelling salesman problem as a case study of the effect of algorithmic components and their possible interactions on performance. Examples of design choices are the use of local search, the use of one versus several pheromone matrices, and the use of one or several ant colonies.

关键词： multiobjective optimization Ant Colony optimization Travelling Salesman Problem

来源：评论

学校读者我要写书评

暂无评论

Hull form optimization for reduced resistance and improved seakeeping via practical designed-oriented CFD tools

Hull form optimization for reduced resistance and improved s...

引用

Grand Challenges in Modeling and Simulation Symposium, GCMS 2010, Part of the 2010 Summer Simulation multiconference, SummerSim 2010

作者： Kim, Hyunyul Yang, Chi Noblesse, Francis George Mason University Fairfax VA United States David Taylor Model Basin NSWC-CD West Bethesda MD United States

ISBN: (纸本)9781617387043

A practical designed-oriented computational tool has been further developed for the hull form optimization for reduced resistance and improved seakeeping. The main focus of this study is on the development of an efficient and effective hull surface modification techniques. Two approaches are utilized. One of them is based on the sectional area curve of the hull, and the other the radial basis function interpolation. These two approaches are combined to allow for both local and global modifications of hull forms. In order to optimize hull form for resistance and seakeeping, a multi-objective genetic algorithm is adopted. A practical design-oriented CFD tool and Bales' seakeeping ranking method are used for the evaluation of the objective functions associated with the resistance and seakeeping, respectively, and the hull form modification technique developed in this study is used to vary the hull forms during the optimization process. For the purpose of illustration, a surface combatant ship, the DTMB Model 5415, is taken as an initial hull, and the present multi-objective hydrodynamic optimization tool is used to determine optimal hull forms for reduced drag and improved seakeeping at given design speeds. Numerical results obtained in this study have shown that the present computational tool can be used to develop hull forms exhibiting low resistance and superior seakeeping.

关键词： multiobjective optimization

来源：评论

学校读者我要写书评

暂无评论

A new surface modification approach for CFD-based hull form optimization

A new surface modification approach for CFD-based hull form ...

引用

作者： Kim, Hyunyul Yang, Chi Department of Computational and Data Sciences George Mason University Fairfax VA United States

关键词： Surface treatment

来源：评论

学校读者我要写书评

暂无评论

multi-objective optimization under Positivity Constraints, with a Meteorological Example

Multi-Objective Optimization under Positivity Constraints, w...

引用

2010 IEEE World Congress on Computational Intelligence

作者： Jaimes, Aline Tweedie, Craig Magoc, Tanja Kreinovich, Vladik Ceberio, Martine Univ Texas El Paso Cyber ShARE Ctr El Paso TX 79968 USA

ISBN: (纸本)9781424469208

In many practical situations, we need to optimize several objectives under the positivity constraints. For example, in meteorological and environmental studies, it is important to collect various types of data, such as temperature and wind speed and direction, from weather stations. For maintenance purposes, it is convenient to place instruments that collect different weather data on the same weather station. Thus, we need to find the "best" location for a weather station. The "best" means, for example, that the external influences, such as flux of cars passing on nearby road, have a minimal impact on the measurement results. There are several such criteria, so we face a multi-objective optimization problem. In this paper, we show that traditional approaches for solving such problems - such as the weighted sum approach - are not fully adequate for solving our problem. We show that fuzzy heuristics lead to a more adequate approach - of using a generalized form of Nash bargaining solution. We then prove that under reasonable assumptions of scale-invariance, the generalized Nash bargaining solution is the only adequate solution for the general problem of multi-objective optimization under positivity constraints - and, in particular, for the problem of selecting an optimal location for a weather station.

关键词： Nash bargaining solution environmental factors fuzzy heuristics maintenance meteorology multiobjective optimization optimisation positivity constraints scale-invariance weather data weather station

来源：评论

学校读者我要写书评

暂无评论

multi-objective optimization as decision tool for ship design

Multi-objective optimization as decision tool for ship desig...

引用

11th International Symposium on practical Design of Ships and Other Floating Structures, PRADS 2010

作者： Vasconcellos, J.M. COPPE/UFRJ Federal University of Rio de Janeiro Rio de Janeiro Brazil

ISBN: (纸本)9788528501407

The decision tools for ship and offshore design following the computer ability to treat more complex problems have improved. Currently, optimization uses very time consuming approaches. Genetic algorithms and multi objective problems where the mathematical models used are complex and take computer time to evaluate are very common nowadays. Economic efficiency of shipping investments was and still is the main concern of ship owners but safety, performance and environmental protection have become increasingly important in the ship design decision process. In the last International Marine Design Conference (IMDC 2009-Trondheim) professor Nowacki made a historical overview and indicated some future trends. He established the necessity to treat economy and safety as the leading motivations for innovation in ship design. But environmental protection (damage survival, subdivision, dangerous cargo) should also be considered. Risk-based design procedure indicates the necessity to improve the design and designers have to test many different conceptions. In this scenario optimization may be a good decision design tool. This paper highlights the application of optimization procedures for ship design decision making. A brief overview of the classical optimization procedures is indicated and case studies are used to illustrate. multi objective non linear programming is discussed and the author presents a catamaran preliminary design case study. Finally genetic algorithm (GA) method and Monte Carlo simulation developed to handle uncertainty in the variables and constraints problems are discussed. © 2010 COPPE/UFRJ.

关键词： Genetic algorithms

来源：评论

学校读者我要写书评

暂无评论

On the assignment of students to topics: A Variable Neighborhood Search approach

引用

Socio-Economic Planning Sciences 2010年第1期44卷 25-34页

作者： Geiger, Martin Josef Wenger, Wolf Production and Logistics Management Department University of Hohenheim 70593 Stuttgart Germany

This article presents a study of a practical assignment problem found in teaching within higher education. Here, students are assigned to scientific topics for which written papers must be submitted. Often, preferences across topics exist among other side constraints that should be considered in solving the problem of interest. Characterizing attributes of real-world problems were studied for scientific departments in Economics and Business Administration at German universities by sending out 800 questionnaires, and analyzing the 203 responses. Based on earlier studies, a Variable Neighborhood Search (VNS) approach was formulated to solve the resulting assignment problem. Several neighborhood search operators were tested, and numerical results are reported for a range of problem scenarios taken from real-world cases. It was observed that VNS leads to superior results vs. single operator local search approaches. Furthermore, we were able to show that in the studied problem, the effectiveness of certain neighborhoods was, to a large extent, dependent on the structures of the underlying problem. An extension of the problem was formulated by integrating a second objective function, which simultaneously balances the workload of staff members while maximizing student utility. The VNS approach was implemented in a computer system, available free of charge, providing decision support for selected other institutions within higher education. © 2009 Elsevier Ltd. All rights reserved.

关键词： Lecturer-student assignment problem multi-objective optimization Variable Neighborhood Search

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：