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KNOT PLACEMENT FOR B-SPLINE CURVE APPROXIMATION VIA l_(∞,1)-NORM AND DIFFERENTIAL EVOLUTION ALGORITHM

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Journal of Computational Mathematics 2022年第4期40卷 589-606页

作者： Jiaqi Luo Hongmei Kang Zhouwang yang School of Mathematical Sciences Soochow UniversitySuzhou 215008China School of Mathematical Sciences University of Science and Technology of ChinaHefei 230026China

In this paper,we consider the knot placement problem in B-spline curve approximation.A novel two-stage framework is proposed for addressing this *** the first step,the l_(∞,1)-norm model is introduced for the sparse selection of candidate knots from an initial knot *** this step,the knot number is *** the second step,knot positions are formulated into a nonlinear optimization problem and optimized by a global optimization algorithm—the differential evolution algorithm(DE).The candidate knots selected in the first step are served for initial values of the DE *** the candidate knots provide a good guess of knot positions,the DE algorithm can quickly *** advantage of the proposed algorithm is that the knot number and knot positions are determined *** with the current existing algorithms,the proposed algorithm finds approximations with smaller fitting error when the knot number is fixed in ***,the proposed algorithm is robust to noisy data and can handle with few data *** illustrate with some examples and applications.

关键词： B-spline curve approximation Knot placement l_(∞,1)-norm Differential Evolution algorithm

IMAGE SUPER-RESOLUTION RECONSTRUCTION BY HUBER REGULARIZATION AND TAILORED FINITE POINT METHOD

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Journal of Computational Mathematics 2024年第2期42卷 313-336页

作者： wenli yang Zhongyi Huang wei Zhu School of Mathematics China University of Mining and TechnologyXuzhou 221116China Department of Mathematics Tsinghua UniversityBeijing 100084China Department of Mathematics University of AlabamaTuscaloosaAL 35487USA

In this paper,we propose using the tailored finite point method(TFPM)to solve the resulting parabolic or elliptic equations when minimizing the Huber regularization based image super-resolution model using the augmented Lagrangian method(ALM).The Hu-ber regularization based image super-resolution model can ameliorate the staircase for restored *** employs the method of weighted residuals with collocation tech-nique,which helps get more accurate approximate solutions to the equations and reserve more details in restored *** compare the new schemes with the Marquina-Osher model,the image super-resolution convolutional neural network(SRCNN)and the classical interpolation methods:bilinear interpolation,nearest-neighbor interpolation and bicubic *** experiments are presented to demonstrate that with the new schemes the quality of the super-resolution images has been *** these,the existence of the minimizer of the Huber regularization based image super-resolution model and the convergence of the proposed algorithm are also established in this paper.

关键词： Image super-resolution Variational model Augmented Lagrangian methods Tailored finite point method

Spatiotemporal pattern of climate change in the China-Myanmar Economic Corridor from 1901 to 2018

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Journal of Mountain Science 2024年第1期21卷 131-145页

作者： yang Xiaoliu LI Yungang GAO Lu Institute of Geography Fujian Normal UniversityFuzhou 350117China School of Geographical Sciences Fujian Normal UniversityFuzhou 350117China Institute of International Rivers and Eco-Security Yunnan UniversityKunming 650500China Fujian Provincial Engineering Research Center for Monitoring and Accessing Terrestrial Disasters Fujian Normal UniversityFuzhou 350117China Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education Fujian Normal UniversityFuzhou 350117China

The China-Myanmar Economic Corridor(CMEC) is an important part of China's Belt and Road Initiative and an important area for global ecology and biodiversity. In this study, the annual and seasonal spatiotemporal patterns of temperature and precipitation in the CMEC over the past century were investigated using linear tendency estimation, the Mann-Kendall mutation test, the T-test, and wavelet analysis based on the monthly mean climatic data from 1901 to 2018 released by the Climatic Research Unit(CRU) of the University of East Anglia, UK. The results show that the CMEC demonstrated a trend of warming and drying over the past 100 years, and the rate of change in Myanmar was stronger than that in Yunnan Province of China. The warming rate was 0.039 ℃/10a. Precipitation decreased at a rate of -6.1 mm/10a. From the perspective of spatial distribution, temperature was high in the central and southern, low in the north of the CMEC, and the high-temperature centers were mainly distributed in the southern plain and river valley. Precipitation decreased from west to east and from south to north of the CMEC. From the perspective of the rate of change, warming was stronger in central and northern CMEC than in southern and northeastern CMEC. The rate of precipitation decline was stronger in the central and western regions than in the eastern region. This study provides a scientific reference for the CMEC to address climate change and ensure sustainable social and economic development and ecological security.

关键词： China-Myanmar Economic Corridor CRU Air temperature Precipitation Spatiotemporal pattern

Rational Design of Biological Crystals with Enhanced Physical Properties by Hydrogen Bonding Interactions

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Research 2023年第3期2023卷 659-668页

作者： Hui Yuan Bin Xue Dingyi yang Sigal Rencus-Lazar Yi Cao Ehud Gazit Dan Tan Rusen yang School of Advanced Materials and Nanotechnology Xidian UniversityXi’an 710126China The Shmunis School of Biomedicine and Cancer Research George S.Wise Faculty of Life SciencesDepartment of Materials Science and EngineeringThe Iby and Aladar Fleischman Faculty of EngineeringTel Aviv UniversityTel Aviv 6997801Israel National Laboratory of Solid State Microstructure Department of PhysicsNanjing UniversityNanjing 210093JiangsuChina

Hydrogen bonds are non-covalent interactions and essential for assembling supermolecules into ordered structures in biological systems,endowing crystals with fascinating physical properties,and inspiring the construction of eco-friendly electromechanical ***,the interplay between hydrogen bonding and the physical properties is not fully understood at the molecular ***,we demonstrate that the physical property of biological crystals with double-layer structures could be enhanced by rationally controlling hydrogen bonding interactions between amino and carboxyl *** hydrogen bonding interactions result in various thermal,mechanical,electronic,and piezoelectric *** particular,the weak interaction between O and H atoms contributes to low mechanical strength that permits important ion displacement under stress,giving rise to a strong piezoelectric *** study not only reveals the correlation between the hydrogen bonding and physical properties in double-layer structures of biological crystals but also demonstrates the potential of these crystals as functional biomaterials for high-performance energy-harvesting *** calculations and experimental verifications in this work provide new insights into the rational design of biomaterials with desirable physical properties for bioelectrical devices by modulating intermolecular interactions.

关键词： bonding rational biomaterials

Multiobjective trajectory optimization of intelligent electro-hydraulic shovel

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Frontiers of Mechanical Engineering 2022年第4期17卷 67-90页

作者： Rujun FAN Yunhua LI Liman yang School of Automation Science and Electrical Engineer Beihang UniversityBeijing 100191China

Multiobjective trajectory planning is still face challenges due to certain practical requirements and mul-tiple contradicting objectives optimized *** this paper,a multiobjective trajectory optimization approach that sets energy consumption,execution time,and excavation volume as the objective functions is presented for the electro-hydraulic shovel(EHS).The proposed cubic polynomial S-curve is employed to plan the crowd and hoist speed of ***,a novel hybrid constrained multiobjective evolutionary algorithm based on decomposition is proposed to deal with this constrained multiobjective optimization *** normalization of objectives is introduced to minimize the unfavorable effect of orders of magnitude.A novel hybrid constraint handling approach based onε-constraint and the adaptive penalty function method is utilized to discover infeasible solution information and improve population ***,the entropy weight technique for order preference by similarity to an ideal solution method is used to select the most satisfied solution from the Pareto optimal *** performance of the proposed strategy is validated and analyzed by a series of simulation and experimental *** show that the proposed approach can provide the high-quality Pareto optimal solutions and outperforms other trajectory optimization schemes investigated in this article.

关键词： trajectory planning electro-hydraulic shovel cubic polynomial S-curve multiobjective optimization entropy weight technique

Explicit G2-constrained Merging of a Pair of Bezier Curves by Control Point Optimization

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自动化学报 2014年第7期40卷 1505-1508页

作者： LU Li-Zheng QIU Yu-yang School of Statistics and Mathematics Zhejiang Gongshang University Hangzhou 310018 China

This paper presents a simple and explicit method for G~2-constrained merging of a pair of Bezier curves by minimizing the l_2 distance defined in terms of control points. After expressing the l_2 distance as a quadratic function of two parameters, the optimally merged curve can be explicitly obtained, which is achieved by control point optimization such that the l_2 distance is minimized. The existence of the unique solution is shown by proving that the l_2 distance is convex. The proposed method is explicit and efficient since it is non-iterative and expressed by known control points. Numerical examples demonstrate the effectiveness of the new method.

关键词：贝塞尔曲线控制点合并 G2 优化二次函数距离最小化

Scaling of interaction lengths for hypersonic shock wave/turbulent boundary layer interactions

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Chinese Journal of Aeronautics 2021年第5期34卷 504-509页

作者： Yuting HONG Zhufei LI Jiming yang Department of Modern Mechanics University of Science and Technology of ChinaHefei 230027China

The interaction length induced by Shock wave/Turbulent Boundary-Layer Interactions(SwTBLIs)in the hypersonic flow was investigated using a scaling analysis,in which the interaction length normalized by the displacement thickness of boundary layer was correlated with a corrected non-dimensional separation criterion across the interaction after accounting for the wall temperature effects.A large number of hypersonic SwTBLIs were compiled to examine the scaling analysis over a wide range of Mach numbers,Reynolds numbers,and wall *** results indicate that the hypersonic SwTBLIs with low Reynolds numbers collapse on the supersonic SwTBLIs,while the hypersonic cases with high Reynolds numbers show a more rapid growth of the interaction length than that with low Reynolds ***,two scaling relationships are identified according to different Reynolds numbers for the hypersonic *** scaling analysis provides valuable guidelines for engineering prediction of the interaction length,and thus,enriches the knowledge of hypersonic SwTBLIs.

关键词： Hypersonic flow Interaction length Scaling laws Separation criterion Shock wave/turbulent boundary layer interactions

Advances in research on solid-state fermented feed and its utilization:The pioneer of private customization for intestinal microorganisms

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Animal Nutrition 2021年第4期7卷 905-916页

作者： Lijie yang Xiangfang Zeng Shiyan Qiao State Key Laboratory of Animal Nutrition College of Animal Science and TechnologyChina Agricultural UniversityYuanmingyuan West Road 2Haidian DistrictBeijingChina Beijing Biofeed Additives Key Laboratory BeijingChina

with sustainable development of biotechnology,increasing attention has been placed on utilization of solid-state fermented feed(SFF).Solid-state fermented feed has been a candidate strategy to alleviate the contradiction between supply and demand of feed resources,ensure food hygiene safety,promoting energy conservation,and emission *** production of SFF,a variety of organic acids,enzymes,vitamins,peptides,and other unknown growth factors are produced,which could affect performance of ***-state fermented feed produced by different fermentation techniques has great instability on different physiological stages of different animals,which hinders the application and standardized production of ***,we summarize the current advances in the role of the characteristics of SFF prepared by different manufacturing technique and its research progress in animal experiments on growth performance,gastrointestinal ecology,and immune system,so as to provide references for further acquiring a relatively perfect set of SFF production and evaluation systems.

关键词： Solid-state fermented feed Manufacturing technique Growth performance Gastrointestinal ecology Immune system

A Method of Obtaining Deformation Information by Tracing Deformation from Sections for 3D FE Simulation

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Journal of Materials Science & Technology 2003年第z1期19卷 65-68页

作者： Mei ZHAN He yang Yuli LIU College of Materials Science and Engineering Northwestern Polytechnical University Xi′an 710072 China College of Materials Science and Engineering Northwestern Polytechnical University Xi′an 710072 China College of Materials Science and Engineering Northwestern Polytechnical University Xi′an 710072 China

with the development of computer technology and finite element method, the priority research area of plasticforming has focused on 3D FE simulation of forming processes for components with complicated geometrical *** processes have complex deforming mechanism, and different sections have different deforming ***, for making a simple, convenient, and practical analysis of its deforming law, how to obtain deformationinformation of key sections from the results of 3D FE simulation has become one of problems urgently to be ***, a method of obtaining deformation information by tracing deformation from sections for 3D FE simulation hasbeen proposed. From the deformation information got by this method, the deformation law of key locations and thewhole deforming body can be obtained. This method can also help to compare the result from FE simulation withthat from physical modeling. Key procedures of this method have been presented in detail, and it has been testedby applying to 3D FE simulation of precision forging of the blade with a damper platform. The result shows thatthe method is practicable and reliable, and it can also be applied to 3D FE simulation of plastic forming processes ofother components.

关键词： Plastic forming, 3D FE simulation, Deformation information