检索结果-内蒙古大学图书馆

AIAA Science and Technology Forum and Exposition (AIAA SciTech)

作者： Zahr, Matthew J. Persson, Per-Olof Univ Notre Dame Dept Aerosp & Mech Engn Notre Dame IN 46556 USA Univ Calif Berkeley Dept Math Berkeley CA 94720 USA

ISBN: (数字)9781624105951

ISBN: (纸本)9781624105951

This work extends the method developed in [1, 2] that uses a high-order discontinuous Galerkin discretization and optimization-based r-adaptivity to track discontinuous solutions of conservation laws with the underlying mesh and provide high-order accurate approximations without additional stabilization techniques, e.g., limiting or artificial viscosity, to problems with shocks attached to curved boundaries. Central to the framework is an optimization problem whose solution is a shock-aligned mesh and the correspondingDGapproximation to the flow;in this sense, the framework is an implicit tracking method, which distinguishes it from methods that aim to explicitly mesh the shock surface. The optimization problem is solved using a sequential quadratic programming method that simultaneously converges the mesh and DG solution, which is critical to avoids nonlinear stability issues that would come from computing a DG solution on a unconverged (non-aligned) mesh. In the case of a shock attached to a curved boundary, the mesh coordinates are parametrized in terms of a reduced set of degrees of freedom and a mapping that ensures boundary nodes always conform to the appropriate boundary. We use the proposed method to solve for the inviscid, transonic flow around a NACA0012 airfoil. The framework generates a mesh that successfully tracks the attached shock and provides an accurate flow approximation on a relatively coarse mesh.

关键词： Discontinuous Galerkin Method Compressible Fluid Airfoil sequential quadratic programming Viscosity Computing Rankine Hugoniot Conditions Angle of Attack Poisson's Equation Stiffness Matrices

来源：评论

学校读者我要写书评

暂无评论

Distributed Electric Propulsion and Vehicle Integration with Ducted Fans

Distributed Electric Propulsion and Vehicle Integration with...

引用

AIAA Aviation Forum

作者： Jedamski, Devon Lakshminarayan, Vinod Ahuja, Vineet Alvarez, Eduardo J. Moore, Mark Whisper Aero Inc Crossville TN 38555 USA

ISBN: (数字)9781624107047

ISBN: (纸本)9781624107047

Electric aircraft enable unconventional integrations which has spurred the requirement for advanced computational frameworks to model these inter-disciplinary design problems. This paper employs an internally developed framework spanning evolutionary and gradient based optimization algorithms, ducted fans and open rotors, as well as mean-line 1D models through full 3D RANS. This work demonstrates that electric ducted fans enable improved performance with high levels of distribution, leading to configurations that would not be feasible with conventional gas turbine propulsion nor propellers. Furthermore, the Regional Air Mobility market requires high speed aircraft to improve the customer value proposition and efficiently amortize capital expenditures. Pareto optimal propulsion configurations indicate that ducted fans outperform open rotors in weight and efficiency for these high speed missions at 250 KTAS. Finally, several podded propulsor integrations are studied using GPU enabled RANS to explore the highly coupled airframe-propulsion system and resulting effect on steady level flight input power and inlet distortion.

关键词： Electric Ducted Fan Distributed Electric Propulsion Aircraft Configurations Distributed Propulsion System Regional Air Mobility Variable Pitch Propellers Unsteady Reynolds Averaged Navier Stokes Level Flight sequential quadratic programming Gas Turbine

来源：评论

学校读者我要写书评

暂无评论

Unequally Pulsed Arrays for High Resolution Scanning and Low Side Lobe Level

Unequally Pulsed Arrays for High Resolution Scanning and Low...

引用

IEEE Antennas-and-Propagation-Society International Symposium (APSURSI)

作者： Reyna, Alberto Panduro, Marco A. Univ Autonoma Tamaulipas UAMRR Reynosa Tamaulipas Mexico

ISBN: (纸本)9781479935406

this article reports the unequally pulsed antenna arrays for an optimum scannable energy pattern. The study is based on the synthesis of unequally antenna positions. The synthesis process is carried out by the well-known sequential quadratic programming. Theoretical results show the performance of the unequally pulsed antenna arrays for a high resolution scanning with low side lobe level.

关键词： Time domain antenna arrays unequally pulsed arrays energy pattern sequential quadratic programming

来源：评论

学校读者我要写书评

暂无评论

Multi-effectors Distribution of Flying Wing with Stealthy Optimization 36

Multi-effectors Distribution of Flying Wing with Stealthy Op...

引用

第36届中国控制会议

作者： ZHAO Li CHEN Yong LI Duo Xixian New District Logistics Research Institute of Shaanxi International School of Trade & Commerce College of Aeronautics and Astronautics Engineering Air Force Engineering University

ISBN: (纸本)9781538629185

With regard to the objective of stealthy optimization in control surface deflection, the stealth-based multi-effectors distribution scheme is presented for flying wing in this paper. The radar cross section（RCS） of each control surface is calculated and analyzed. The stealthy efficiency data curves are obtained through comparing the deflection values with the normal state. Taking the objective of optimal stealthy performance into account, the weighted pseudo-inverse is achieved by equivalence transformation. Furthermore, the sequential quadratic programming（SQP） based control allocation is applied to get rid of actuator constraints. To validate the effectiveness of the proposed approach, the simulation on the flying wing indicates that the stealthy generated by control surfaces can be minimized by reasonable deflections.

关键词： multi-effectors distribution stealthy optimization weighted pseudo-inverse sequential quadratic programming

来源：评论

学校读者我要写书评

暂无评论

Hybrid Predictive Control Design with Mixed Inputs based on PSO and its Application for Control of a Batch Reactor

Hybrid Predictive Control Design with Mixed Inputs based on ...

引用

2010 IEEE World Congress on Computational Intelligence

作者： Munoz-Carpintero, Diego A. Saez, Doris Skrjanc, Igor Univ Chile Dept Elect Engn Av Tupper 2007 Santiago Chile Univ Ljubljana Fac Elect Engn Ljubljana Slovenia

ISBN: (纸本)9781424481262

In this work, we propose a combined approach based on Particle Swarm Optimization (PSO) and sequential quadratic programming (SQP) for solving the real-time optimization problem appearing in the hybrid predictive control of systems with continuous and discrete inputs. The conventional PSO for continuous problems is mixed with binary PSO for handling discrete variables, and after iterations of the algorithm have ended, SQP is applied for refining the continuous variables. This new method (PSO+SQP) is favorably compared with a conventional non-linear optimization techniques (based on Branch and Bound and Explicit Enumeration) and PSO. Also, a multi-objective approach is considered as a tuning method for the population size and number of iterations for PSO. All these algorithms are applied for the temperature control of a Batch Reactor.

关键词： batch reactor binary PSO branch and bound chemical reactors continuous inputs control system synthesis discrete inputs explicit enumeration hybrid predictive control design mixed inputs nonlinear optimization particle swarm optimisation particle swarm optimization predictive control quadratic programming real-time optimization problem sequential quadratic programming temperature control temperature control

来源：评论

学校读者我要写书评

暂无评论

Electrical Machine Design by Optimization for E-motor Application: a Drive Cycle Approach

Electrical Machine Design by Optimization for E-motor Applic...

引用

24th International Conference on Electrical Machines (ICEM)

作者： Cardoso, J. F. Chillet, C. Gerbaud, L. Belhaj, L. A. Univ Grenoble Alpes Grenoble Elect Engn Lab G2Elab Grp PSA Carrieres Sous Poissy F-78955 Grenoble France Univ Grenoble Alpes Grenoble Elect Engn Lab G2Elab F-38000 Grenoble France Grp PSA F-78955 Carrieres Sous Poissy France

ISBN: (纸本)9781728199450

w This paper presents a methodology for the design by optimization of an electric machine considering several operating cycles. This is achieved by simplifying the operating cycles using a k-means clustering algorithm. K-means clustering is used to simplify three operating cycles: WLTP, highway and urban. The three simplified cycles are then considered in the design optimization of a permanent magnet synchronous machine with the objective of minimizing the losses of both the electrical machine and the voltage inverter. The machine is represented by a magnetic equivalent circuit model and the voltage inverter losses by an analytical model. Then, the three optima (obtained for each cycle) are characterized and compared in terms of performance over these drive cycles.

关键词： Electric machines electric vehicles design by optimization drive cycle sequential quadratic programming

来源：评论

学校读者我要写书评

暂无评论

Based on the Moving Horizon Estimation of the Nonlinear Parameters Optimization

Based on the Moving Horizon Estimation of the Nonlinear Para...

引用

International Conference on Computer Technology and Development

作者： Wang Jianfang Li Weihua Northwestern Polytech Univ Coll Comp Xian 710129 Peoples R China

ISBN: (纸本)9780769538921

In order to solve error between the system output values and the model estimation values in non-linear system. A new method, the Particle Swarm Optimization & sequential quadratic programming (PSO-SQP), is proposed to realize the on-line optimization to nonlinear complex system. Firstly, the PSO-SQP algorithm is proposed to solve the slow search speed of the PSO and easy convergence to the local minimum points of SQP. Then the method that the unknown parameters and states are estimated by the moving window based on Moving Horizon Estimation (MILE) is also described in the paper. Finally, the two examples are simulated to test those methods. It is validated that this method can cut down iteration times about 40%similar to 60%, the optimization of this algorithm can be about up to 30% on average.

关键词： Particle Swarm Optimization sequential quadratic programming Moving Horizon Estimation Nonlinear Optimization

来源：评论

学校读者我要写书评

暂无评论

Eliminating Magnetic Phase Transitions with Microstructural Optimization in 2D Lattices

Eliminating Magnetic Phase Transitions with Microstructural ...

引用

AIAA SciTech Forum

作者： Eger, Zekeriya Ender Acar, Pinar Virginia Tech Dept Mech Engn Blacksburg VA 24061 USA

ISBN: (数字)9781624107115

ISBN: (纸本)9781624107115

The magnetic phase transition of ferromagnetic materials is an irreversible and undesired phenomenon as the material loses its magnetism permanently when it enters the paramagnetic phase. When the material is not under the influence of external magnetic fields, ambient temperature is the sole underlying reason for the ferromagnetic-paramagnetic phase transition. Regardless of the initial spin combination of the lattice structure, the magnetic spins tend to change their direction if the material is ferromagnetic. With the change in spin directions, the free energy of the system representing the interactions of all spins with neighbor spins also changes. The system favors the state of the magnetization level with minimum free energy. As the temperature increases, the minimum free energy is observed on lower magnetization levels. The uncertainty of the temperature, particularly when close to the phase transition, affects the free energy curve, increasing the possibility of the transition. The goal of this study is to create a lattice design to minimize the resultant uncertainty of the free energy arising from the variations of the measurements of high-temperature values. In order to achieve this goal, the locations of the spins in the lattice coordinate system are set as design variables, and the variance of the free energy of the most probable spin combination is minimized.

关键词： Magnetic Ordering Ferromagnetic Materials External Magnetic Field Magnetic Properties Boltzmann's Constant Aircraft Systems sequential quadratic programming Energy Distribution Numerical Modeling Heat Treatment

来源：评论

学校读者我要写书评

暂无评论

Churn Management Optimization via Partial Least Square (PLS) Model with Controllable Marketing Instruments and Associated Management Costs

Churn Management Optimization via Partial Least Square (PLS)...

引用

18th Americas Conference on Information Systems

作者： Kim, Yong Seog Lee, Hyeseon Utah State Univ Dept Management Informat Syst Logan UT 84322 USA Pohang Univ Sci & Technol Dept Ind & Management Engn Pohang South Korea

ISBN: (纸本)9780615663463

In this paper, we use a partial least square (PLS) optimization method as a prediction model to estimate the churn probabilities of customers and as a control model after configuring optimization objective and constraints with relative management costs of controllable variables. In our experiment, we observe that while the training and test data sets are dramatically different in terms of churner distributions (50% vs. 1.8%), four controllable variables in three marketing strategies played a key role in optimization process. We also observe that the most significant variable for prediction does not necessarily play an important role in optimization model because of the highest management cost. In addition, we show that marketing managers even further maximize financial outcomes of marketing campaigns by selecting customers based on churn probability or management cost.

关键词： Churn management PLS prediction model PLS optimization model Triangulation sequential quadratic programming

来源：评论

学校读者我要写书评

暂无评论

Optimal aircraft landing-approach trajectories: A comparison of two dynamic models

引用

Annual Review in Automatic programming 1985年第PART 2期13卷 139-145页

作者： Pierson, B.L Department of Aerospace Engineering Iowa State University Ames IA 50011 United States

sequential quadratic programming is used to solve a minimum-noise aircraft landing-approach problem for two dynamic models. The "exact" model features the usual point-mass equations of motion for flight in a vertical plane. The other model is based on two simplifying assumptions: 1. (1) small angle of attack and flight path angle and 2. (2) no flight path angle dynamics (lift equals weight). Range is used to replace time as the independent variable. The resulting models are of order three and two, respectively;each model involves two control functions. The primary objective is to compare the solutions for each model with regard to accuracy and computational effort. Numerical results are presented for a variety of boundary conditions and path constraints. © 1986.

关键词： aerospace trajectories bang-bang control modelling Optimal control sequential quadratic programming

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：