An efficient cycle slip detection method is proposed for high precision positioning and navigation results with global positioning system （GPS）,which is based on the assumption of a high sampling interval, measureme...An efficient cycle slip detection method is proposed for high precision positioning and navigation results with global positioning system （GPS）,which is based on the assumption of a high sampling interval, measurement errors are so small that they can be ignored in the temporal single difference observables. And ambiguities are ordinarily equal to zero,but could be the number of cycles that have ＂slipped＂ if loss-of-lock has occurred.Therefore,cycle slips are estimated as parameters of time-relative positioning observation equations.Because the temporal single difference observables are taken at different epochs and different stations with a single GPS receiver,if time-relative positioning observation equations are linearized as that of conventional relative positioning,the design matrix will be rank defective.To obtain a stable linearization scheme,time-relative positioning observation equations are further analyzed,and the concept of virtual measurement is applied.A sample of data collected on a vehicle test shows that a cycle slip detection approach based on time-relative positioning theory can detect slips at the value of one cycle.The results also indicate if two satellites are so near to each other that they have the same equivalent to satellite-receiver geometry,cycle slip detection will be difficult and may get wrong results.Cycle slips of different satellites also affect detection by satellite-receiver geometry.展开更多
Let M be an n dimensional complete Riemannian manifold satisfying the doublingvolume property and an on-diagonal heat kernel estimate. The necessary-sufficientcondition for the Sobolev inequality ‖f‖q ≤ Cn,,v,p,q(...Let M be an n dimensional complete Riemannian manifold satisfying the doublingvolume property and an on-diagonal heat kernel estimate. The necessary-sufficientcondition for the Sobolev inequality ‖f‖q ≤ Cn,,v,p,q(‖▽f‖p+‖fp) (2≤p＜q＜∞) is given.展开更多
Dislocation dynamics simulations are performed to investigate the effect of template shape on the nanoimprinting of metal layers. To this end, metal thin films are imprinted by a rigid template made of an array of equ...Dislocation dynamics simulations are performed to investigate the effect of template shape on the nanoimprinting of metal layers. To this end, metal thin films are imprinted by a rigid template made of an array of equispaced indenters of various shapes, i.e., rectangular, wedge, and circular. The geometry of the indenters is chosen such that the contact area is approximately the same at the final imprinting depth. Results show that, for all template shapes, the final patterns strongly depend on the dislocation activity, and that each imprint differs from the neighboring ones. Large material pile ups appear between the imprints, such that polishing of the metal layer is suggested for application of the patterns in electronics. Rectangular indenters require the lowest imprinting force and achieve the deepest retained imprints.展开更多
The authors prove a Schwarz lemma for harmonic mappings between the unit balls in real Euclidean spaces. Roughly speaking, this result says that under a harmonic mapping between the unit balls in real Euclidean spaces...The authors prove a Schwarz lemma for harmonic mappings between the unit balls in real Euclidean spaces. Roughly speaking, this result says that under a harmonic mapping between the unit balls in real Euclidean spaces, the image of a smaller ball centered at origin can be controlled. This extends the related result proved by Chen in complex plane.展开更多
文摘An efficient cycle slip detection method is proposed for high precision positioning and navigation results with global positioning system （GPS）,which is based on the assumption of a high sampling interval, measurement errors are so small that they can be ignored in the temporal single difference observables. And ambiguities are ordinarily equal to zero,but could be the number of cycles that have ＂slipped＂ if loss-of-lock has occurred.Therefore,cycle slips are estimated as parameters of time-relative positioning observation equations.Because the temporal single difference observables are taken at different epochs and different stations with a single GPS receiver,if time-relative positioning observation equations are linearized as that of conventional relative positioning,the design matrix will be rank defective.To obtain a stable linearization scheme,time-relative positioning observation equations are further analyzed,and the concept of virtual measurement is applied.A sample of data collected on a vehicle test shows that a cycle slip detection approach based on time-relative positioning theory can detect slips at the value of one cycle.The results also indicate if two satellites are so near to each other that they have the same equivalent to satellite-receiver geometry,cycle slip detection will be difficult and may get wrong results.Cycle slips of different satellites also affect detection by satellite-receiver geometry.
基金Project supported by the National Natural Science Foundation of China (No.10271107) the 973 Project of the Ministry of Science and Technology of China (No.G1999075105) the Zhejiang Provincial Natural Science Foundation of China (No.RC97017).
文摘Let M be an n dimensional complete Riemannian manifold satisfying the doublingvolume property and an on-diagonal heat kernel estimate. The necessary-sufficientcondition for the Sobolev inequality ‖f‖q ≤ Cn,,v,p,q(‖▽f‖p+‖fp) (2≤p＜q＜∞) is given.
基金Project (No VENI 08120) supported by the Dutch National Scientific Foundation NWO and Dutch Technology Foundation STW
文摘Dislocation dynamics simulations are performed to investigate the effect of template shape on the nanoimprinting of metal layers. To this end, metal thin films are imprinted by a rigid template made of an array of equispaced indenters of various shapes, i.e., rectangular, wedge, and circular. The geometry of the indenters is chosen such that the contact area is approximately the same at the final imprinting depth. Results show that, for all template shapes, the final patterns strongly depend on the dislocation activity, and that each imprint differs from the neighboring ones. Large material pile ups appear between the imprints, such that polishing of the metal layer is suggested for application of the patterns in electronics. Rectangular indenters require the lowest imprinting force and achieve the deepest retained imprints.
基金supported by the National Natural Science Foundation of China(Nos.11201199,11671361)
文摘The authors prove a Schwarz lemma for harmonic mappings between the unit balls in real Euclidean spaces. Roughly speaking, this result says that under a harmonic mapping between the unit balls in real Euclidean spaces, the image of a smaller ball centered at origin can be controlled. This extends the related result proved by Chen in complex plane.
