De Casteljau algorithm and degree elevation of Bézier and NURBS curves/surfaces are two important techniques in computer aided geometric design. This paper presents the de Casteljau algorithm and degree elevation...De Casteljau algorithm and degree elevation of Bézier and NURBS curves/surfaces are two important techniques in computer aided geometric design. This paper presents the de Casteljau algorithm and degree elevation of toric surface patches, which include tensor product and triangular rational Bézier surfaces as special cases. Some representative examples of toric surface patches with common shapes are illustrated to verify these two algorithms. Moreover, the authors also apply the degree elevation of toric surface patches to isogeometric analysis. And two more examples show the effectiveness of proposed method.展开更多
The optical windows used in aircrafts protect their imaging sensors from environmental effects. Considering the imaging performance, flat surfaces are traditionally used in the design of optical windows. For aircrafts...The optical windows used in aircrafts protect their imaging sensors from environmental effects. Considering the imaging performance, flat surfaces are traditionally used in the design of optical windows. For aircrafts operating at high speeds, the optical windows should be relatively aerodynamic, but a flat optical window may introduce unacceptably high drag to the airframes. The linear scanning infrared sensors used in aircrafts with, respectively, a flat window, a spherical window and a toric window in front of the aircraft sensors are designed and compared. Simulation results show that the optical design using a toric surface has the integrated advantages of field of regard, aerodynamic drag, narcissus effect, and imaging performance, so the optical window with a toric surface is demonstrated to be suited for this application.展开更多
This paper establishes an asymptotic formula with a power-saving error term for the number of rational points of bounded height on the singular cubic surface of P3 Qgiven by the following equation x0（x12+ x22）-x33= ...This paper establishes an asymptotic formula with a power-saving error term for the number of rational points of bounded height on the singular cubic surface of P3 Qgiven by the following equation x0（x12+ x22）-x33= 0 in agreement with the Manin-Peyre conjectures.展开更多
Inspired by the r-refinement method in isogeometric analysis,in this paper,the authors propose a curvature-based r-adaptive isogeometric method for planar multi-sided computational domains parameterized by toric surfa...Inspired by the r-refinement method in isogeometric analysis,in this paper,the authors propose a curvature-based r-adaptive isogeometric method for planar multi-sided computational domains parameterized by toric surface patches.The authors construct three absolute curvature metrics of isogeometric solution surface to characterize its gradient information,which is more straightforward and effective.The proposed method takes the internal weights as optimization variables and the resulting parameterization is analysis-suitable and injectivity-preserving with a theoretical guarantee.Several PDEs are solved over multi-sided computational domains parameterized by toric surface patches to demonstrate the effectiveness and efficiency of the proposed method.展开更多
基金supported by the National Natural Science Foundation of China under Grant Nos.11671068 and 11801053。
文摘De Casteljau algorithm and degree elevation of Bézier and NURBS curves/surfaces are two important techniques in computer aided geometric design. This paper presents the de Casteljau algorithm and degree elevation of toric surface patches, which include tensor product and triangular rational Bézier surfaces as special cases. Some representative examples of toric surface patches with common shapes are illustrated to verify these two algorithms. Moreover, the authors also apply the degree elevation of toric surface patches to isogeometric analysis. And two more examples show the effectiveness of proposed method.
文摘The optical windows used in aircrafts protect their imaging sensors from environmental effects. Considering the imaging performance, flat surfaces are traditionally used in the design of optical windows. For aircrafts operating at high speeds, the optical windows should be relatively aerodynamic, but a flat optical window may introduce unacceptably high drag to the airframes. The linear scanning infrared sensors used in aircrafts with, respectively, a flat window, a spherical window and a toric window in front of the aircraft sensors are designed and compared. Simulation results show that the optical design using a toric surface has the integrated advantages of field of regard, aerodynamic drag, narcissus effect, and imaging performance, so the optical window with a toric surface is demonstrated to be suited for this application.
基金supported by the program PRC 1457-Au For Di P(CNRS-NSFC)supported by National Natural Science Foundation of China(Grant No.11531008)+1 种基金the Ministry of Education of China(Grant No.IRT16R43)the Taishan Scholar Project of Shandong Province
文摘This paper establishes an asymptotic formula with a power-saving error term for the number of rational points of bounded height on the singular cubic surface of P3 Qgiven by the following equation x0（x12+ x22）-x33= 0 in agreement with the Manin-Peyre conjectures.
基金supported by the National Natural Science Foundation of China under Grant Nos.12071057,11671068,and 12001327.
文摘Inspired by the r-refinement method in isogeometric analysis,in this paper,the authors propose a curvature-based r-adaptive isogeometric method for planar multi-sided computational domains parameterized by toric surface patches.The authors construct three absolute curvature metrics of isogeometric solution surface to characterize its gradient information,which is more straightforward and effective.The proposed method takes the internal weights as optimization variables and the resulting parameterization is analysis-suitable and injectivity-preserving with a theoretical guarantee.Several PDEs are solved over multi-sided computational domains parameterized by toric surface patches to demonstrate the effectiveness and efficiency of the proposed method.
