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Design of Superconducting Shim Coils for a 400 MHz NMR Using nonlinear optimization algorithm

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 2012年第3期22卷 4900505-4900505页

作者： Ni, Zhipeng Li, Lankai Hu, Geli Wen, Cong Hu, Xinning Liu, Feng Wang, Qiuliang Chinese Acad Sci Inst Elect Engn Key Labo Appl Superconduct Beijing Peoples R China Univ Queensland Sch Informat Technol & Elect Engn Brisbane Qld 4072 Australia

A set of superconducting shim coils for a 400 MHz nuclear magnetic resonance spectrometer was designed, analyzed and constructed. A nonlinear optimization algorithm was employed for the calculation of the optimal conductor shapes and positions of superconducting shim coils. In the optimization, a number of system parameters, including field errors, axial size of coils and spherical harmonics have been constrained to acceptable levels. The results have the property of combining best field quality and also controlling the desired harmonics terms strength. The proposed methodology can also be used to design superconducting and resistive shim coils for other homogeneous magnet systems.

关键词： NMR nonlinear optimization algorithm sensitivity spherical harmonic superconducting shimming

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A nonlinear optimization algorithm FOR EVALUATING THE PERFORMANCE OF MICROWAVE IMAGER COMBINED ACTIVE/PASSIVE 37

A NONLINEAR OPTIMIZATION ALGORITHM FOR EVALUATING THE PERFOR...

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IEEE International Geoscience & Remote Sensing Symposium

作者： Zhang, Lan-jie Wang, Zhen-zhan Zhang, Ruan-yu Yin, Xiao-bin Chinese Acad Sci Natl Space Sci Ctr Key Lab Microwave Remote Sensing Beijing 100190 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China Beijing Aerosp Hongtu Informat Technol Inc Co Beijing 100081 Peoples R China

ISBN: (纸本)9781509049516

The Microwave Imager Combined Active/Passive (MICAP) is a suit of active/passive instrument package, which has been proposed for demonstrating the capability of remote sensing the sea surface salinity (SSS), sea surface temperature (SST) and wind speed (WS). In this paper, a nonlinear optimization algorithm for simultaneous retrieval of the above parameters is described. The sensitivity of active/passive microwave observations to SSS is analyzed using the nonlinear optimization algorithm. The results show that the root mean square (RMS) error on the retrieved SSS estimated by using the nonlinear optimization algorithm is enough to meet the requirement of Ocean Salinity Satellite. This is submitted for the special session of "New Developments of Chinese Oceanographic and Meteorological Satellites "

关键词： MICAP nonlinear optimization algorithm SSS RMS error

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nonlinear marine predator algorithm for robust identification of fractional hammerstein nonlinear model under impulsive noise with application to heat exchanger system

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COMMUNICATIONS IN nonlinear SCIENCE AND NUMERICAL SIMULATION 2025年 146卷

作者： Khan, Zeshan Aslam Khan, Taimoor Ali Waqar, Muhammad Chaudhary, Naveed Ishtiaq Raja, Muhammad Asif Zahoor Shu, Chi-Min Natl Yunlin Univ Sci & Technol Int Grad Inst Artificial Intelligence 123 Univ RdSect 3 Touliu 64002 Yunlin Taiwan Natl Yunlin Univ Sci & Technol Future Technol Res Ctr 123 Univ RdSect 3 Touliu 64002 Yunlin Taiwan Natl Yunlin Univ Sci & Technol Dept Safety Hlth & Environm Engn 123 Univ Rd Sect 3 Touliu 64002 Yunlin Taiwan

Identification of stiff nonlinear systems is considered as one of the challenging tasks and research community is providing promising solution for identification of these systems. Researchers have concluded that integration of fractional calculus provides better insight and understanding of complex systems by keeping the previous history. In this study, nonlinear marine predator optimization algorithm (NMPA) is used for the identification of fractional Hammerstein control autoregressive system (FHCAR) with Gaussian as well as impulsive noise. Further, a practical example of heat exchanger system modeled with FHCAR structure, is considered to analyze the knacks of NMPA in terms of convergence, robustness and stability. Grunwald-Letnikov's concept of fractional calculus derivative is used to transform standard Hammerstein control autoregressive system into FHCAR system. Mean square error-based fitness function is used to examine the performance of NMPA for identification of 4th order nonlinear FHCAR system for all three case studies i.e., FHCAR with Gaussian noise, FHCAR with impulsive noise and heat exchanger system identification. The performance of NMPA is observed in terms of fast convergence, accuracy, stability, robustness and accuracy in estimation of correct parameters of the system for multiple noise scenarios and the superiority is endorsed through comparison with the recent counterparts i.e., Gazelle optimization algorithm, Runge Kutta optimization method, Whale optimization algorithm, Harris Hawks optimization algorithm and African vulture optimization algorithm.

关键词： Fractional calculus Heat exchanger system nonlinear dynamical system nonlinear optimization algorithm

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Research on the Microscopic Aging Characteristics of Asphalt Binder Based on Atomic Force Microscopy

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POLYMERS 2025年第8期17卷 1000-1000页

作者： Li, Wenhui Hao, Peiwen Liu, Guofeng Li, Zhigang Le, Chen Wang, Chun Ma, Wenduo Li, Shaohui Changan Univ Sch Highway Xian 710064 Peoples R China Yunnan Ningyong Expressway Co Ltd Lijiang 674300 Peoples R China Xian Univ Sci & Technol Sch Civil & Architectural Engn Xian 710064 Peoples R China

To deeply analyze the difference between styrene-butadiene-styrene (SBS)-modified asphalt and base asphalt in ultraviolet (UV) aging performance, an atomic force microscope was used to carry out an accurate analysis of the bee structural characteristic parameters of two kinds of asphalt experiencing different UV aging time duration. With the advantages of the Levenberg-Marquardt (LM) algorithm and universal global optimization (UGO) algorithm, the relationship between the microscopic characteristic value and the performance index of asphalt under UV aging was constructed. The results show that the physical parameters of the bee structure of asphalt are closely related to the macroscopic properties of asphalt materials. Because the number of bee structures of SBS-modified asphalt is significantly more than that of base asphalt, and in the process of UV aging, the absolute height and area of the bee structure fluctuate less, and the adhesion force fluctuates with aging time. The decreasing trend makes SBS-modified asphalt significantly better than base asphalt in anti-UV aging performance. Under different UV aging time durations, the penetration and aging index (AI) of the two kinds of asphalt showed an excellent linear relationship with the microscopic indexes measured by atomic force microscope (AFM). Through the nonlinear optimization algorithm, the prediction equations of the morphology height and adhesion force of the two kinds of asphalt under different aging stages were successfully derived. The research results can provide theoretical support for the optimization and improvement of the UV aging performance of SBS-modified asphalt.

关键词： road engineering UV aging AFM microstructure nonlinear optimization algorithm aging performance prediction

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Hydraulic performance optimization of meshed district heating network with multiple heat sources

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ENERGY 2017年 126卷 603-621页

作者： Wang, Yaran You, Shijun Zhang, Huan Zheng, Wandong Zheng, Xuejing Miao, Qingwei Tianjin Univ Sch Environm Sci & Engn Yaguan Rd 135 Tianjin 300350 Peoples R China

Operational optimization is the key to energy reduction of the district heating (DH) system. Poor hydraulic performances of the DH network will largely increase the energy consumption. However, for most meshed DH networks with multiple heat sources, the optimal hydraulic conditions are usually not achieved. In this paper, the hydraulic performance optimization problem of meshed DH network with multiple heat sources was proposed. In order to solve the problem, the General Reduced Gradient (GRG) algorithm was adopted to minimize the total pump power through optimizing the pump frequencies and substation valve openings of the DH network. The hydraulic performances of the GRG algorithm based optimal control (OC) strategy were compared with the traditional constant pressure difference control (CPDC) and the constant speed control (CSC) strategies. Results shows that in comparison with the CPDC and CSC strategy, the total pump power can be reduced by 20% and 65% respectively, when applying the OC strategy. And the hydraulic intersection point of the DH network was changeable to reallocate the serving areas of heat sources and optimize the total pump power. Besides, increasing the pump efficiency without considering the hydraulic constraints of the DH network may not lead to optimal conditions. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： Meshed district heating network Multiple heat sources Hydraulic performance optimization nonlinear optimization algorithm Energy reduction

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Extrinsic calibration of non-overlapping multi-camera system with high precision using circular encoded point ruler

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OPTICS AND LASERS IN ENGINEERING 2024年 174卷

作者： Li, Yecheng Ja, Wei Chen, Pengfei Wang, Xinze Xu, Mingyue Xie, Zexiao Ocean Univ China Coll Engn Qingdao 266100 Peoples R China Key Lab Ocean Engn Shandong Prov Qingdao 266100 Peoples R China

In the field of visual metrology, achieving coordinate system unification among non -overlapping multi -camera systems in wide field -of -view scenarios poses significant challenges due to the absence of overlapping fields of view. This paper presents a novel calibration method for such multi -camera systems utilizing a ruler equipped with double -layer circular encoded landmarks. The fabrication of the ruler is simple, and its length covers the entire multi -camera measurement system, rendering the calibration process convenient. To calibrate the cameras, the ruler is positioned in front of the target cameras, and images of the ruler are captured by the multi -cameras. By establishing the initial transformation relationships between the non -overlapping cameras and the ruler's coordinate system, the proposed method efficiently determines the inter -camera transformations. Subsequently, by moving the ruler to different positions and capturing corresponding images, the distances between the encoded center points on the ruler and other encoded points, as captured by the non -overlapping cameras, are kept constant. An optimization -based objective function is formulated to minimize the three-dimensional distances between the measured encoded center points, thereby refining the initial transformation relationships. Combining the coplanarity constraint of the coding center points with the extrinsic results obtained through distance optimization, a secondary optimization was conducted to obtain the final transformation parameters. Experimental results demonstrate the simplicity and versatility of this method, which does not rely on complex constraints. Moreover, it exhibits high calibration accuracy, with maximum distance errors between ruler points and a fitting standard plane error both below 0.275 mm and 0.132 mm, respectively. Following multiple experimental iterations, the average disparity between the radius of the standard cylinder measured via line laser scanning

关键词： Multi-camera Non-overlapping field of view nonlinear optimization algorithm Particle swarm optimization Global calibration Circular encoded point ruler

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Optimal Motion Generation for Autonomous Vehicle in Maze-like Environment

Optimal Motion Generation for Autonomous Vehicle in Maze-lik...

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14th International IEEE Conference on Intelligent Transportation Systems (ITSC)

作者： Han, Long Do, Quoc Huy Guo, Chunzhao Mita, Seiichi Toyota Technol Inst Res Ctr Smart Vehicles Tempaku Ku 2-12-1 Nagoya Aichi 4688511 Japan

ISBN: (纸本)9781457721977

In car-like autonomous vehicle systems, it is an essential task of generating the motion commands according to a given path/strategy. Quite a few theories and techniques have been proposed for the generation of the motion commands in autonomous vehicles, such as pure pursuit, Stanley's nonlinear feedback, chained-form control of kinematic model and the linearized optimal control of dynamic model. Here a non-linear optimization algorithm based on the vehicle's kinematic model and the actuators' model is proposed, which combines the control system dynamic behaviors and gives out the control sequences directly. It starts with modeling the local kinematic behavior and actuators' dynamics. Then online optimization algorithm is applied to the objective function of minimizing the energy cost, execution time and tracking error with some trade-off weights among them. The experiments showed that it worked well for vehicles running in maze-like environment.

关键词： Actuators Equations Kinematics Mathematical model optimization Vehicle dynamics Vehicles car-like autonomous vehicle systems kinematic model linearized optimal control maze-like environment motion commands motion control nonlinear optimization algorithm o

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A Medium and Long Term Orderly Charging Load Planning Method for Electric Vehicles in Residential Areas

A Medium and Long Term Orderly Charging Load Planning Method...

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58th IEEE/IAS Industrial and Commercial Power Systems Technical Conference Asia (IEEE I and CPS Asia)

作者： Liao, Xuezhong Hua, Yuanpeng Wang, Shiqian Han, Ding Bai, Hongkun Wang, Yuanyuan State Grid Henan Econ Res Inst Zhengzhou Peoples R China

ISBN: (数字)9781665450669

ISBN: (纸本)9781665450669

The orderly charging load forecasting for Electric Vehicles (EVs) in urban residential areas(RAs) is of significance for planning the charging facilities and analyzing the load carrying capacity of distribution network as well as its expansion and reconstruction. In this paper, a mid-and long-term load forecasting method for EVs orderly charging in RAs is proposed based on the number and charging probability of EVs. nonlinear programming is used to solve the optimization objective function of orderly charging, and the typical daily load characteristics in urban RAs are used to forecast the orderly charging load of EVs and the overall load in the station area on working days and at weekends in the past three years and the target year. Simulation results show that orderly charging can improve the capability of distribution network in residential areas to accommodate EVs and postpone its upgrade and reconstruction time.

关键词： electric vehicles residential areas orderly charging hierarchical optimization nonlinear optimization algorithm

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Detection and localization of improvised explosive devices based on 3-axis magnetic sensor array system

Detection and localization of improvised explosive devices b...

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2010 Symposium on Security Detection and Information Processing

作者： Liu, Renhao Wang, Hua Beijing Univ Aeronaut & Astronaut Sch Astronaut Beijing 100191 Peoples R China

The detection and localization of improvised explosive devices(IEDs) on the roadside is a new subject encountered in the struggle against terrorism. A novel detection and localization method was proposed for IEDs based on magnetic signals. Since most of the IEDs have the ferromagnetic properties, the magnetic field produced around the body by the IED can be detected by 3-axis fluxgate sensor array system. With these detected sensor data, the detection and localization of the IED can be computed by an appropriate method based on magnetic dipole model and nonlinear optimization algorithm. This paper studied respectively the properties of explosives and roads as target and environment to be detected. First, the gradient of total magnetic field was directly reconstructed from the magnetic field and the data of sensor array. In order to reduce the effects of the Earth's magnetic field, the total gradient contraction was used to detect the IEDs. Second, the localization and magnetic moment parameters were searched in the rough by adopting the particle swarm optimization (PSO) algorithm and the precision ones were found by using steepest descent method. Simulation results show that the method mentioned achieves good effects, the maximum detection range of the sensor array can reach to 12m for a 15Am(2) target and the mean errors of localization and magnetic moment estimation are less than 0.16m and 1Am(2) respectively. Since the method need not know the IED's magnetic moment in advance, it is adapt to battlefield environment. In addition, this detection method can be directly applied to solve the problem of detecting and localizing underwater IEDs. (C) 2010 Published by Elsevier Ltd.

关键词： Explosive device detection Magnetic detection Magnetic localization Magnetic dipole model nonlinear optimization algorithm

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Towards clinical application of 7T TOF angiography

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Journal of Cardiovascular Magnetic Resonance 2012年第Suppl 1期14卷 1-2页

作者： Schmitter, Sebastian Auerbach, Edward J Adriany, Gregor Ugurbil, Kamil Van de Moortele, Pierre-Francois Center for Magnetic Resonance Research University of Minnesota Minneapolis MN United States

[...] significant challenges have to be overcome before using 7T TOF in clinical applications: I RF induced specific absorption rate (SAR) substantially increases at UHF, preventing the use of standard RF pulses (venous Saturation (SAT), Magnetization Transfer (MT)) to improve TOF contrast. Estimation of the spatial receive profile variations removed from both datasets for better visibility of smaller vessels. [figure omitted; refer to PDF] Conclusions We demonstrate, with appropriate RF pulse design, substantial gains in contrast and B1+ homogeneity for TOF angiography at 7T.

关键词： Magnetization Transfer nonlinear optimization algorithm Specific Absorption Rate Specific Absorption Rate Limit Ultra High Field

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