Integral problem for Schrödinger-type equations with the general elliptic part

2021 ◽  
Vol 209 (2) ◽  
pp. 1523-1536
Author(s):  
V. B. Shakhmurov
2014 ◽  
Vol 613 ◽  
pp. 269-278
Author(s):  
Zhen Xian Fu ◽  
Yu Rong Lin ◽  
Yang Liu ◽  
Xing Lin Chen

To facilitate the calibration of a precision inertial navigation platform, the drifting of the platform under vibratory testing environment is analyzed, and a simplified drift model is developed which features the accumulative rather than instantaneous impact of the vibration on the platform drifting. When applied to error parameter calibration for the platform, the proposed model entails much less computing load in drifting prediction, and removes the requirement of strict real-time synchronization between the vibration generating device and the drift-predicting programs. The form of vibration can be assumed to be elliptic, a relatively general one which allows the shaker to vibrate sinuoidally in two directions perpendicular to each other and with phase difference of 90 degree. Under certain circumstances, the elliptic vibration can be simplified to a linear or circular one, as is typical in practice. Simulations of the platform drifting error under linear, circular and general elliptic vibration shows that the accumulative model can well serve as an alternative to the conventional one in such test environments, and the merits of the proposed model become more prominent when the frequency of vibration gets higher.


2016 ◽  
Vol 8 (6) ◽  
pp. 1050-1071 ◽  
Author(s):  
Tianliang Hou ◽  
Li Li

AbstractIn this paper, we investigate the error estimates of mixed finite element methods for optimal control problems governed by general elliptic equations. The state and co-state are approximated by the lowest order Raviart-Thomas mixed finite element spaces and the control variable is approximated by piecewise constant functions. We derive L2 and H–1-error estimates both for the control variable and the state variables. Finally, a numerical example is given to demonstrate the theoretical results.


1933 ◽  
Vol 29 (2) ◽  
pp. 235-244
Author(s):  
W. G. Welchman

1. The work of this paper was undertaken with a view to finding out what ruled surfaces can be determined by incidences, i.e. generated by the lines which meet a certain set of spaces which I shall call a base. Such ruled surfaces I shall call incidence scrolls. In [3] the lines which meet three lines generate a quadric surface. In [4] it is easy to show that a base consisting of a line and three planes gives the general rational quartic scroll, while the lines which meet five planes in [4] give the general elliptic quintic scroll. One might be tempted to think that at least all the rational normal scrolls could be obtained as incidence scrolls by taking for base a suitable number of spaces containing directrix curves, but unfortunately there is a residual surface except in the case of the rational scrolls of general type and of those with a directrix line.


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