检索结果-内蒙古大学图书馆

Diffractive optical element design based on vector diffraction theory and improved PSO-SA algorithm

OPTICAL ENGINEERING 2023年第2期62卷 025103-025103页

作者： Yan, Yu Fan, Zhentao Sun, Guofang Tian, Kehan Zhejiang Univ Sci & Technol Hangzhou Peoples R China Jiaxing Yuguang Photoelect Technol Co Ltd Jiaxing Peoples R China Beijing Yuguang Technol Dev Co Beijing Peoples R China

The existence of the beam vector effect requires rigorous electromagnetic computational methods for the optimization of subwavelength diffractive optical elements (DOEs). To design DOEs with high performance, we proposed an optimization strategy combining a global optimization algorithm with the finite difference time domain (FDTD) method. First, scalar initial solutions are obtained by the Gerchberg-Saxton algorithm. Then, regarding the diffraction efficiency, the uniformity error and figure of merit are calculated by FDTD as evaluation functions, and the optimization of the initial solutions is implemented by improved particle swarm optimization and continues with the simulated annealing algorithm. After several numerical simulations, the analysis results confirm the robustness of the algorithm and the reduction of the computational cost. The experimental data demonstrate that the correlation of diffraction energy orders between the simulated design and fabricated sample are above 85%. This method efficiently improves the DOEs design.

关键词： diffraction optical elements finite difference time domain global optimization algorithm beam splitter

来源：评论

学校读者我要写书评

暂无评论

A real time multi-objective optimization Guided-MPC strategy for power-split hybrid electric bus based on velocity prediction

引用

ENERGY 2023年第1期276卷

作者： Yang, Dongpo Liu, Tong Song, Dafeng Zhang, Xuanming Zeng, Xiaohua Jilin Univ State Key Lab Automot Simulat & Control Changchun 130025 Peoples R China

Considering the frequent acceleration and deceleration of bus vehicles, the working conditions are complex, efficiency-oriented power-split hybrid electric bus (PSHEB) typically require frequent shifting to stay in high-efficiency areas, driving comfort and fuel economy may be affected. Therefore, to achieve a good balance be-tween overall efficiency and shifting stability, the study proposes a Real time Multi-objective optimization Guided-MPC strategy (RMGMPC) for PSHEB based on velocity prediction. Firstly, considering the different driving habits of drivers, combining with multi-source data fusion technology, a vehicle speed prediction controller is established;secondly, based on global optimization algorithm and multi-source data fusion tech-nology, a SOC reference generator is designed, which will determine the SOC guidance at predicted vehicle speed time domain online;then, to coordinate fuel efficiency, shifting stability and online optimization control real-time, the novel RMGMPC based on the direct multiple shooting method and sequential quadratic program-ming algorithm for PSHEB is proposed;finally, to avoid experience value of uncertain weight coefficient affecting the MPC, a weighted method of objective function with orientation is proposed. To verify the effectiveness of RMGMPC, the fuel economy reaches 98.41% of the global optimum;the shifting times are improved by 12.5%;Compared with MPC-DP, the calculation time is improved by 93.97%;And HIL test was carried out to further verify the real-time performance of the algorithm. The results manifest the excellent performance of the proposed RMGMPC.

关键词： Power-split hybrid electric bus MPC global optimization algorithm Direct multiple shooting method HIL test

来源：评论

学校读者我要写书评

暂无评论

globally optimal design of refinery hydrogen networks with pressure discretization

引用

CHEMICAL ENGINEERING SCIENCE 2022年 247卷 117021-117021页

作者： Chang, Chenglin Lin, Qucheng Liao, Zuwei Wang, Jingdai Yang, Yongrong Zhejiang Univ Coll Chem & Biol Engn Zhejiang Prov Key Lab Adv Chem Engn Manufacture T Hangzhou 310027 Peoples R China Zhejiang Univ Coll Chem & Biol Engn State Key Lab Chem Engn Hangzhou 310027 Peoples R China

The design of refinery hydrogen networks minimizing the total annualized cost is a computationally hard optimization problem. This is mainly due to the highly nonlinear compression power constraint and the nonconvexities of the problem. To decrease the nonlinearities, we propose in this work a concept of pres -sure discretization, and therein the pressure variables of new makeup compressors make discrete choices among the specified pressures of hydrogen origin and destination units. Based on this concept, the con-straint of compression power is linearized without losing rigors. Then, hydrogen networks design is for-mulated as a mixed integer nonlinear programming model that is applicable to both grass-roots synthesis and retrofit problems. We develop a global optimization algorithm to solve the proposed model to global optimality. Two grass-roots synthesis and three retrofit examples are tested for illustration purposes. The total annualized cost and computing time of our solutions compare favorably to those of literature solutions. (c) 2021 Elsevier Ltd. All rights reserved.

关键词： Hydrogen networks Pressure discretization global optimization algorithm

来源：评论

学校读者我要写书评

暂无评论

Almost perfect quantum state transfer on isotropic and anisotropic Heisenberg spin chains with tailored site dependent exchange couplings

引用

PHYSICS LETTERS A 2022年 449卷

作者： Serra, Pablo Ferron, Alejandro Osenda, Omar Univ Nacl Cordoba Fac Matemat Astron Fis & Computac CONICET Inst Fis Enrique Gaviola Av Medina Allende S-NCiudad UnivCP X5000HUA Cordoba Argentina Univ Nacl Nordeste Inst Modelado & Innovac Tecnol CONICET UNNE Ave Libertad 5400W3404AAS Corrientes Argentina Univ Nacl Nordeste Fac Ciencias Exactas Nat & Agrimensura Ave Libertad 5400W3404AAS Corrientes Argentina

Spin chains with site dependent exchange coefficients can achieve near perfect quantum state transfer for Hamiltonians with nearest neighbors XXZ type interactions without external control. The strength of the interactions is obtained using a global optimization method, which can be employed without assuming a particular relationship between the arrival time and the strength of the interactions. This relationship arises naturally when data collapse techniques are used to analyze the results of the optimization method. The arrival times achievable are competitive with respect to those obtained by other methods, for chains of moderate length. The stability of the resulting spin chains against static perturbations is also studied. The differences in the dynamical behavior between the isotropic and anisotropic spin chains are analyzed for some particular cases.(C) 2022 Elsevier B.V. All rights reserved.

关键词： Quantum spin chains global optimization algorithm Almost perfect quantum state transfer Control

来源：评论

学校读者我要写书评

暂无评论

Transformation rule-based molecular evolution for automatic gasoline molecule design

引用

CHEMICAL ENGINEERING SCIENCE 2022年 263卷

作者： Cai, Guangqing Liu, Zhefu Zhang, Linzhou China Univ Petr Petr Mol Engn Ctr PMEC State Key Lab Heavy Oil Proc Beijing 102249 Peoples R China Chinese Acad Sci Quanzhou Inst Equipment Mfg Computat Intelligence & Ind Big Data Grp Luoshan St 166 Jinjiang City 362216 Fujian Peoples R China

Automatic molecular design on computers is an emerging technology for the determination of optimal fuel molecules. We developed a computer-aided molecular design framework through a transformation rule-based molecular evolution method. The reaction rule was used as the elementary step to change the molecular structure. A molecule can achieve structural variation continuously using a series of reaction rules. The finding of the optimal molecule can be seen as the evolution of structure in the chemical space, which was guided by using a global optimization algorithm to select the best reaction routine. We showed that the optimized molecule is independent of the input initial structure, proving the robustness of the method. We then applied the method to design gasoline molecules for motor and aviation gasoline. The designed molecules can not only serve as competitive candidate components for high-quality gasoline, but also accelerate the synthesis rate of new molecules in the laboratory. (C) 2022 Elsevier Ltd. All rights reserved.

关键词： Molecular design Transformation rule Structural variation global optimization algorithm Gasoline molecule

来源：评论

学校读者我要写书评

暂无评论

A Parameter Search Method For Optimal Efficiency Design Of High Power Millimeter Wave Gyrotron TWT 22

A Parameter Search Method For Optimal Efficiency Design Of H...

引用

22nd International Vacuum Electronics Conference (IVEC)

作者： Zou, Fucheng Yan, Ran Luo, Yong Univ Elect Sci & Technol China Sch Elect Sci & Engn Chengdu 610054 Sichuan Peoples R China

ISBN: (纸本)9781665441056

This paper introduces a method for searching the optimal efficiency parameters of high-power millimeter wave gyrotron based on BP neural network prediction. This method can establish the prediction model through the actual design gyrotron test data, and optimize the prediction model through the global optimization algorithm to obtain the optimal efficiency design parameters. This method can effectively extract accurate and effective information from the test data and feed back to the designers.

关键词： Gyrotron BP neural network global optimization algorithm

来源：评论

学校读者我要写书评

暂无评论

A study on a representative heat source model for simulating laser welding for liquid hydrogen storage containers

引用

MARINE STRUCTURES 2022年 86卷

作者： Pyo, Changmin Kim, Jaewoong Kim, Younghyun Kim, Munsung Korea Inst Ind Technol Gwangju 61012 South Korea Korea Corp Dassault Syst Seoul 06164 South Korea

Laser welding enhances the productivity with high speed, and minimizes thermoelastic distortion with a concentrated heat source for a narrow area over a short period of time. With these strengths various industries such as the automobile, aviation, and shipbuilding adopt that. However welding distortion is still one of principal problems, simulation of distortion and corresponding design are very important for applying that technology. Naturally accurate laser welding heat source model is needed, but there is not representative heat source model which can cover diverse types of models. This study proposes a multi-layered heat source model as a representative model, and develops a welding heat source that complies with welding conditions by comparing it to the bead-on-plate welding experiment on 304L stainless steel, a material used for cryogenic purposes with liquid hydrogen condition. To derive a welding heat source, a parametric study was used as it was able to identify an appropriate solution by changing the parameter values constituting the heat source for finite element analysis, where the physical properties for each temperature were applied. For this process optimization method was applied, and the objective function and constraints were defined based on the value of temperature through simulation, also a global optimization algorithm was adopted. In this study, we suggest a representative model that can be used under most welding conditions;this is a method that can be of great help in future welding distortion analyses and can be used in a design that can tolerate distortion.

关键词： Representative welding heat source model Multi-layered heat source model global optimization algorithm Liquid hydrogen Fiber laser welding

来源：评论

学校读者我要写书评

暂无评论

Heap-based optimizer inspired by corporate rank hierarchy for global optimization

引用

EXPERT SYSTEMS WITH APPLICATIONS 2020年 161卷 113702-113702页

作者： Askari, Qamar Saeed, Mehreen Younas, Irfan GIFT Univ Dept Comp Sci Gujranwala Pakistan Natl Univ Comp & Emerging Sci Dept Comp Sci Lahore Pakistan

In an organization, a group of people working for a common goal may not achieve their goal unless they organize themselves in a hierarchy called Corporate Rank Hierarchy (CRH). This principle motivates us to map the concept of CRH to propose a new algorithm for optimization that logically arranges the search agents in a hierarchy based on their fitness. The proposed algorithm is named as heap-based optimizer (HBO) because it utilizes the heap data structure to map the concept of CRH. The mathematical model of HBO is built on three pillars: the interaction between the subordinates and their immediate boss, the interaction between the colleagues, and self-contribution of the employees. The proposed algorithm is benchmarked with 97 diverse test functions including 29 CEC-BC-2017 functions with very challenging landscapes against 7 highly-cited optimization algorithms including the winner of CEC-BC-2017 (EBO-CMAR). In the first two experiments, the exploitative and explorative behavior of HBO is evaluated by using 24 unimodal and 44 multimodal functions, respectively. It is shown through experiments and Friedman mean rank test that HBO outperforms and secures 1st rank. In the third experiment, we use 29 CEC-BC-2017 benchmark functions. According to Friedman mean rank test HBO attains 2nd position after EBO-CMAR;however, the difference in ranks of HBO and EBO-CMAR is shown to be statistically insignificant by using Bonferroni method based multiple comparison test. Moreover, it is shown through the Friedman test that the overall rank of HBO is 1st for all 97 benchmarks. In the fourth and the last experiment, the applicability on real-world problems is demonstrated by solving 3 constrained mechanical engineering optimization problems. The performance is shown to be superior or equivalent to the other algorithms, which have been used in the literature. The source code of HBO is publicly available at https://***/qamar-askari/HBO. (c) 2020 Elsevier Ltd. All rights rese

关键词： Social optimization algorithm Corporate hierarchy based optimization Nature-inspired meta-heuristic global optimization algorithm

来源：评论

学校读者我要写书评

暂无评论

Comparison of Regional Winter Wheat Mapping Results from Different Similarity Measurement Indicators of NDVI Time Series and Their Optimized Thresholds

引用

REMOTE SENSING 2021年第6期13卷 1162-1162页

作者： Li, Fangjie Ren, Jianqiang Wu, Shangrong Zhao, Hongwei Zhang, Ningdan Chinese Acad Agr Sci Inst Agr Resources & Reg Planning Beijing 100081 Peoples R China Key Lab Agr Remote Sensing Minist Agr & Rural Affairs Beijing 100081 Peoples R China

Generally, there is an inconsistency between the total regional crop area that was obtained from remote sensing technology and the official statistical data on crop areas. When performing scale conversion and data aggregation of remote sensing-based crop mapping results from different administrative scales, it is difficult to obtain accurate crop planting area that match crop area statistics well at the corresponding administrative level. This problem affects the application of remote sensing-based crop mapping results. In order to solve the above problem, taking Fucheng County of Hebei Province in the Huanghuaihai Plain of China as the study area, based on the Sentinel-2 normalized difference vegetation index (NDVI) time series data covering the whole winter wheat growth period, the statistical data of the regional winter wheat planting area were regarded as reference for the winter wheat planting area extracted by remote sensing, and a new method for winter wheat mapping that is based on similarity measurement indicators and their threshold optimizations (WWM-SMITO) was proposed with the support of the shuffled complex evolution-University of Arizona (SCE-UA) global optimization algorithm. The accuracy of the regional winter wheat mapping results was verified, and accuracy comparisons with different similarity indicators were carried out. The results showed that the total area accuracy of the winter wheat area extraction by the proposed method reached over 99.99%, which achieved a consistency that was between the regional remote sensing-based winter wheat planting area and the statistical data on the winter wheat planting area. The crop recognition accuracy also reached a high level, which showed that the proposed method was effective and feasible. Moreover, in the accuracy comparison of crop mapping results based on six different similarity indicators, the winter wheat distribution that was extracted by root mean square error (RMSE) had the best recognition accur

关键词： crop mapping similarity crop area statistical data total amount control global optimization algorithm

来源：评论

学校读者我要写书评

暂无评论

The optimal synchronizability of complex networks with saturated coupling strength

引用

INTERNATIONAL JOURNAL OF MODERN PHYSICS C 2020年第10期31卷

作者： Huang, Chen Lu, Xinbiao Zhou, Jun Qin, Buzhi Hohai Univ Sch Energy & Elect Engn Nanjing 211100 Peoples R China Nanjing Polytech Inst Dept Automat Nanjing 210048 Peoples R China

For networks with fixed network topology, when the total coupling strength between nodes is limited and the coupling strength between nodes is saturated, the global optimization algorithms including genetic algorithm (GA) and particle swarm optimization (PSO) algorithm are used to adjust the coupling strength between nodes to improve the synchronizability of the network, respectively. Simulation results show that in WS small-world network, when the edge betweenness centrality of the edge is large, the coupling strength of the edge after optimization is greater. Furthermore, compared with GA, PSO has better performance.

关键词： Saturation synchronizability global optimization algorithm edge betweenness centrality

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

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

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：