检索结果-内蒙古大学图书馆

9th Euro-American Workshop on Information Optics

作者： Katkovnik, Vladimir Migukin, Artem Astola, Jaakko Tampere Univ Technol Dept Signal Proc Tampere Finland

ISBN: (纸本)9781424482276

We present a variational approach to obtain a reconstruction of module and phase of a 3D wave field from intensity-only measurements on two or more sensor planes at different axial positions. The objective functional consists of a data fidelity term and a regularizer. The fidelity term corresponds to the likelihood function derived for the Gaussian noisy observations of the wave field intensities (powers). The wave field reconstruction is framed as a constrained nonlinear optimization with respect to a 2D object wave field and is based on the augmented Lagrangian technique. The main goal is to design an algorithm which is more efficient and accurate than the conventional ones such as the well-known Gerchberg-Saxton algorithms and their multiple modifications. As a further development we discuss a variational approach using a transform domain prior on phase and module of the 2D object wave field.

关键词： 2D object wave field 3D wave field reconstruction Gaussian distribution Gaussian noisy Gerchberg-Saxton algorithm augmented Lagrangian constrained nonlinear optimization image reconstruction intensity-only data likelihood function maximum likelihood estimation optimisation sensor plane variational inverse imaging variational techniques

来源：评论

学校读者我要写书评

暂无评论

A numerical algorithm for solving power-exponent type nonlinear inequalities with applications in calculating stabilizing parameters for LTI systems 16th

A numerical algorithm for solving power-exponent type nonlin...

引用

16th IFAC Symposium on Large Scale Complex Systems - Theory and Applications (LSS)

作者： Chen, Zhihua Guo, Yong Zhang, Kai Xie, Yongchun Beijing Inst Control Engn Beijing 100190 Peoples R China Northwestern Polytech Univ Sch Automat Xian 710072 Peoples R China Sichuan Univ Sch Aeronaut & Astronaut Chengdu 610225 Peoples R China

The paper proposes a numerical algorithm for finding a solution set of a class of power-exponent type nonlinear inequalities. The proposed numerical algorithm applies specifically to the case when the power-exponent is positive irrational number, which can't be effectively solved by using the existing methods. Firstly, by introducing a novel concept of margin variable and using the monotonicity of power-exponent function, this paper converts the problem of solving the nonlinear inequalities into a constrained nonlinear optimization (CNO) problem. Then the obtained CNO problem is solved by using the MATLAB function fmincon. Finally, a numerical algorithm to solve this class of inequalities is obtained. The proposed algorithm can find a solution set of the considered inequalities, not just one or few solutions. Further, the derived algorithm can be easily used to calculate the stabilizing parameter ranges for LTI systems based on the Routh-Hurwitz criterion. Moreover, an example of calculating the stabilizing parameters of a LTI system and an example of solving power-exponent type nonlinear inequalities are provided to show the effectiveness of the proposed algorithm.

关键词： Power-Exponent Function nonlinear Inequalities Solution Set Numerical Algorithm LTI Systems Stabilizing Parameters State Feedback Control constrained nonlinear optimization Margin Variable

来源：评论

学校读者我要写书评

暂无评论

Patient-Specific Optimal Hemodynamic Control with Minimal Myocardial Oxygen Consumption 8

Patient-Specific Optimal Hemodynamic Control with Minimal My...

引用

8th IFAC Conference on nonlinear Model Predictive Control (NMPC)

作者： Kataoka, Yasuyuki Funada, Riku Uemura, Kazunori Peterson, Jon Saku, Keita Sunagawa, Kenji Sampei, Mitsuji Alexander, Joe NTT Res Inc Sunnyvale CA 94040 USA Tokyo Inst Technol Meguro Ku Tokyo 1528550 Japan Natl Cerebral & Cardiovasc Ctr Suita Osaka 5648565 Japan Circulatory Syst Res Fdn Bunkyo Ku Tokyo 1130033 Japan

In treating acute heart failure for each unique patient, the goals of drug therapy encompass multiple clinical considerations: controlling multiple hemodynamic targets such as blood pressure, cardiac output, and left atrial pressure, minimizing myocardial oxygen consumption, and rapidly adapting to the patient-specific pharmacological response. This paper proposes a proof-of-concept study of a practical, clinically feasible control system for treating acute heart failure. The simulation study demonstrates that our controller can achieve these multiple control goals simultaneously based on constrained nonlinear optimization. Copyright (C) 2024 The Authors.

关键词： Hemodynamic Control constrained nonlinear optimization Acute Heart Failure Treatment Biomedical Application

来源：评论

学校读者我要写书评

暂无评论

Identification of Complex nonlinearities Using Cubic Splines with Automatic Discretization 1

引用

35th IMAC Conference and Exposition on Structural Dynamics

作者： Dossogne, T. Noel, J. P. Kerschen, G. Univ Liege Aerosp & Mech Engn Dept Space Struct & Syst Lab 9 Allee Decouverte B52-3 B-4000 Liege Belgium

ISBN: (数字)9783319544045

ISBN: (纸本)9783319544045;9783319544038

One of the major challenges in nonlinear system identification is the selection of appropriate mathematical functions to model the observed nonlinearities. In this context, piecewise polynomials, or splines, offer a simple and flexible representation basis requiring limited prior knowledge. The generally-adopted discretization for splines consists in an even distribution of their control points, termed knots. While this may prove successful for simple nonlinearities, a more advanced strategy is needed for nonlinear restoring forces with strong local variations. The present paper specifically introduces a two-step methodology to select automatically the location of the knots. It proposes to derive an initial model, using nonlinear subspace identification, and incorporating cubic spline basis functions with fixed and equally-spaced abscissas. In a second step, the location of the knots is optimized iteratively by minimizing a least-squares cost function. A single-degree-of-freedom system with a discontinuous stiffness characteristic is considered as a case study.

关键词： nonlinear system identification Frequency-domain subspace algorithm Cubic splines Nonsmooth nonlinearity Automatic splines discretization constrained nonlinear optimization

来源：评论

学校读者我要写书评

暂无评论

Length-preserved natural boundary for intrinsic parameterization

Length-preserved natural boundary for intrinsic parameteriza...

引用

9th International Conference on Computer Aided Design and Computer Graphics

作者： Wang, CCL Chinese Univ Hong Kong Sha Tin 100083 Peoples R China

ISBN: (纸本)0769524737

This paper proposes a fast approach to generate length-preserved natural boundary for intrinsic parameterization. Given a triangular mesh with disk-like topology, we compute an optimal boundary for its parameterization. An optimal boundary is expected to be length-preserved with the length of every triangular edge on the boundary is invariant before and after parameterization;also, the boundary is requested to be natural where the inner angle is close to the angle excess at every boundary vertex on the given mesh. Computation of a length-preserved natural boundary is formulated as a constrained non-linear optimization problem, the procedure of solving which is in general very time-consuming. Here, we speed tip the optimization by adopting the scheme of sequential linearly constrained programming. It is shown at the end of this paper that our length-preserved natural boundary could greatly improve the speed and quality of the original intrinsic parameterization.

关键词： computer graphics constraint handling mesh generation nonlinear programming topology constrained nonlinear optimization disklike topology intrinsic parameterization length-preserved natural boundary optimal boundary sequential linearly constrained progra constraint handling mesh generation nonlinear Programming COMPUTER GRAPHICS Boundary topology parameterization natural triangular mesh constrained optimization

来源：评论

学校读者我要写书评

暂无评论

Optimal Design and Dynamic Analysis of a Hybrid Manipulator for Intra-ocular Surgeries 7

Optimal Design and Dynamic Analysis of a Hybrid Manipulator ...

引用

7th International Conference on Robotics and Mechatronics (ICRoM)

作者： Hayati, Haleh Taefi, Mohammad Khosravi, Mohammad A. Talebi, H. A. Amirkabir Univ Technol Dept Elect Engn Tehran Iran

ISBN: (纸本)9781728166049

This study aims to develop a new robot for vitreo-retinal eye surgery applications, referred to as PERSIS (Precise Robotic System for Intraocular Surgeries). It consists of a linear mechanism coupled to a parallelogram mechanism that has a remote center of motion (RCM) point. The RCM point is employed for manipulating the surgical instrument about this fixed point, where it acts as a pivoting point. Moreover, as the insertion point of the robot is fixed, a gantry mechanism is designed to add three translational Degrees of Freedom (DOF) to the RCM mechanism. According to the above description, the optimal design of the proposed mechanism to achieve superior performance in eye surgery is critical. Therefore, the optimal design of 6DOF mechanism based on the constrained nonlinear optimization is performed according to the requirements of vitreo-retinal surgery and dimensions relevant to the anthropometry of the human head. Moreover, in the eye surgeon robot, due to the accuracy required in routing the surgical instrument, having a relatively accurate description of the robot dynamic equations is necessary. In this paper, a closed-form of equations of motion for PERSIS is generated. Instead of computing the coupled dynamics directly, dynamic equations of the parallelogram and the gantry mechanism are calculated separately and then, dynamic equations of the proposed hybrid mechanism are calculated.

关键词： Eye Surgery Parallelogram mechanism Gantry mechanism Kinematic Analysis constrained nonlinear optimization Hybrid dynamic equations

来源：评论

学校读者我要写书评

暂无评论

Improving a chemical process through use of a designed experiment

引用

Quality Engineering 1990年第2期3卷 215-235页

作者： lawson, John S. Department of Statistics Brigham Young University Provo Utah 84602 United States

Click to increase image sizeClick to decrease image size

关键词： constrained nonlinear optimization Design Parameters Noise Factors Offline Quality Control Parameter Design Performance Statistic Variance Transmission Formula

来源：评论

学校读者我要写书评

暂无评论

Design of the optimal motions of autonomous vehicles in intersections through neural networks

Design of the optimal motions of autonomous vehicles in inte...

引用

15th International-Federation-of-Automatic-Control (IFAC) Symposium on Control in Transportation Systems (CTS)

作者： Nemeth, Balazs Gaspar, Peter Szocs, David Mihaly, Andras Hungarian Acad Sci Syst & Control Lab Inst Comp Sci & Control Budapest Hungary Budapest Univ Technol & Econ Dept Control Transportat & Vehicle Syst Budapest Hungary

The handling of vehicle interactions is a challenge in the research into the traveling of autonomous vehicles. This paper focuses on collision-free motion design of autonomous vehicles to guarantee their minimum traveling time in intersections. First, a decision logic of the order of the vehicles in intersections is proposed. Based on the decision logic a constrained nonlinear optimization method is also proposed, with which the minimum traveling time of the vehicles without their collision is guaranteed. Since the on-line solution of the nonlinear optimization task can be numerically complex, a neural network based approximation of the optimal solution is developed. The efficiency of the method with various intersection scenarios is shown in the CarSim simulation environment. (C) 2018, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.

关键词： autonomous vehicles neural networks intersections constrained nonlinear optimization

来源：评论

学校读者我要写书评

暂无评论

Design and robustness analysis of autonomous vehicles in intersections 10th

Design and robustness analysis of autonomous vehicles in int...

引用

10th IFAC Symposium on Intelligent Autonomous Vehicles IAV

作者： Szilassy, Peter Nemeth, Balazs Gaspar, Peter Budapest Univ Technol & Econ Dept Control Transportat & Vehicle Syst Budapest Hungary Hungarian Acad Sci Inst Comp Sci & Control Syst & Control Lab Budapest Hungary

The paper proposes the design of a neural-network-based control strategy of autonomous vehicles in intersections. The motivation of the neural network approach is to reduce the numerically-intensive computation of the optimization problem in which the motions of autonomous vehicles are formed. In the method the neural network is trained through a preliminary optimal off-line solution. Moreover, a robustness analysis on the neural network based control strategy is proposed. The focus of the analysis is to consider the impact of the position and speed estimation errors on the motion of vehicles. The design and the analysis are illustrated through CarSim simulation examples. (C) 2019, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.

关键词： autonomous vehicles neural networks intersections constrained nonlinear optimization

来源：评论

学校读者我要写书评

暂无评论

Comparison of some Penalty and Barrier Techniques in Direct Search Methods 14

Comparison of some Penalty and Barrier Techniques in Direct ...

引用

14th International Conference on Computational Science and Its Applications (ICCSA)

作者： Correia, A. Matias, J. Mestre, P. Serodio, C. CM UTAD Porto Polytech CIICESI ESTGF IPP Vila Real Portugal CM UTAD Vila Real Portugal CITAB UTAD Vila Real Portugal

ISBN: (纸本)9781479942640

constrained nonlinear optimization problems are in real live situations and in several areas of knowledge. To handle the constrains in these problems Penalty and barrier techniques are widely used. In penalty or barrier methods a sequence of unconstrained problems is constructed and then they are solved using unconstrained optimization methods. These methods attempt to minimize simultaneously both the objective and the constraint violation functions, defining a sequence of new objective functions which include information about the objective function and these violations. There are some real life scenarios where the derivatives are not know or are not accessible, because the involved functions are non smooth, non continuous, non convex and/or with many local minima. Therefore in such problems unconstrained optimization direct search methods must be used. This work presents a comparison of some penalty and barrier techniques in direct search methods.

关键词： optimization methods mathematical programming constrained nonlinear optimization penalty and barrier techniques direct search methods

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：