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Unique Continuation on Quadratic Curves for Harmonic Functions 被引量:2
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作者 Yufei KE Yu CHEN 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2022年第1期17-32,共16页
The unique continuation on quadratic curves for harmonic functions is dis-cussed in this paper.By using complex extension method,the conditional stability of unique continuation along quadratic curves for harmonic fun... The unique continuation on quadratic curves for harmonic functions is dis-cussed in this paper.By using complex extension method,the conditional stability of unique continuation along quadratic curves for harmonic functions is illustrated.The nu-merical algorithm is provided based on collocation method and Tikhonov regularization.The stability estimates on parabolic and hyperbolic curves for harmonic functions are demonstrated by numerical examples respectively. 展开更多
关键词 Unique continuation quadratic curves Harmonic function
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STUDY ON THE UNIQUENESS OF LIMIT CYCLE OF THE QUADRATIC SYSTEM BY USING THE QUADRATIC CURVE WITHOUT CONTACT(CONTINUED 1)
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作者 徐思林 《Annals of Differential Equations》 1998年第2期252-258,共7页
In this paper, we continue to discuss the uniqueness of limit cycle of the quadratic system by using the quadratic curve without contact and several new criteria for the uniqueness have been obtained.
关键词 quadratic system limit cycle UNIQUENESS quadratic curve without contact
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Existence of Limit Cycles for a Cubic Kolmogorov System with a Hyperbolic Solution 被引量:4
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作者 沈伯骞 刘德明 《Northeastern Mathematical Journal》 CSCD 2000年第1期91-95,共5页
This paper is concerned with a cubic Kolmogorov system with a solution of central quadratic curve which neither contacts with the coordinate axes, nor passes through the origin. The conclusion is that such a system ma... This paper is concerned with a cubic Kolmogorov system with a solution of central quadratic curve which neither contacts with the coordinate axes, nor passes through the origin. The conclusion is that such a system may possess limit cycles. 展开更多
关键词 cubic kolmogorov system central quadratic curve limit cycle
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Parameterization based on maximum curvature minimization model
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作者 BAN Jinjin ZHANG Caiming ZHOU Yuanfeng 《Computer Aided Drafting,Design and Manufacturing》 2013年第1期47-52,共6页
Parameterization is one of the key problems in the construction of a curve to interpolate a set of ordered points. We propose a new local parameterization method based on the curvature model in this paper. The new met... Parameterization is one of the key problems in the construction of a curve to interpolate a set of ordered points. We propose a new local parameterization method based on the curvature model in this paper. The new method determines the knots by mi- nimizing the maximum curvature of quadratic curve. When the knots by the new method are used to construct interpolation curve, the constructed curve have good precision. We also give some comparisons of the new method with existing methods, and our method can perform better in interpolation error, and the interpolated curve is more fairing. 展开更多
关键词 ordered data points quadratic curve CURVATURE PARAMETERIZATION
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Extraction and evolution of grader’s bionic morphological feature line using shape structure behavior function model
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作者 Bin Qi Yubin Lan +3 位作者 Xiaoming Sun He Zhu Yanhao Li Ke Lou 《International Journal of Agricultural and Biological Engineering》 SCIE 2024年第2期74-84,共11页
To improve the innovation of agricultural machinery product styling,this paper proposes a shape structure behavior function(SSBF)model suitable for the industrial design field.The feature line evolution method combini... To improve the innovation of agricultural machinery product styling,this paper proposes a shape structure behavior function(SSBF)model suitable for the industrial design field.The feature line evolution method combining shape grammar and genetic algorithm was used for modelling the of the grader,which not only maintains the product style characteristics but also reflects the typical identification characteristics of the bionic prototype and produces a new product modelling scheme.By conducting cognitive and recognition experiments on product styling features,the ranking of product styling features and the contribution of each component to product styling were determined.The method of combining shape grammar and quadratic Bézier curve was used to express and encode feature lines,and genetic algorithm was used to evolve biomimetic forms to form product feature lines with typical biological morphological features;The extracted form bionic elements were integrated into the grader modelling design,and the interaction evaluation was carried out through the genetic algorithm evolution scheme.The basic form elements were extracted and analyzed,and the deduction rules were formulated and reorganized.The derived feature line geometric data considered the product’s image features and the bio-inspired prototype,which can be used for the follow-up guidance of industrial design schemes. 展开更多
关键词 bionic design shape-structure-behavior-function SSBF biologically inspired design BID shape grammars quadratic Bézier curves
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