We study special functions related to Lotka-Volterra equations and negative Volterra equation intro-duced from zero curvature representations . At first we show the relationships between Lotka-Volterra equations intro...We study special functions related to Lotka-Volterra equations and negative Volterra equation intro-duced from zero curvature representations . At first we show the relationships between Lotka-Volterra equations introduced from zero curvature representations and symmetric orthogonal polynomials. Sec-ondarily, we describe the relationships between negative Volterra equations with a special solutions and cylinder functions.展开更多
In this paper,we derive a generalized nonisospectral semi-infinite Lotka-Volterra equation,which possesses a determinant solution.We also give its a Lax pair expressed in terms of symmetric orthogonal polynomials.In a...In this paper,we derive a generalized nonisospectral semi-infinite Lotka-Volterra equation,which possesses a determinant solution.We also give its a Lax pair expressed in terms of symmetric orthogonal polynomials.In addition,if the simplified case of the moment evolution relation is considered,that is,without the convolution term,we also give a generalized nonisospectral finite Lotka-Volterra equation with an explicit determinant solution.Finally,an application of the generalized nonisospectral continuous-time Lotka-Volterra equation in the food chain is investigated by numerical simulation.Our approach is mainly based on Hirota’s bilinear method and determinant techniques.展开更多
By applying the generalized singular value decomposition and the canonical correlation decomposition simultaneously, we derive an analytical expression of the optimal approximate solution ^-X, which is both a least-sq...By applying the generalized singular value decomposition and the canonical correlation decomposition simultaneously, we derive an analytical expression of the optimal approximate solution ^-X, which is both a least-squares symmetric orthogonal anti-symmetric solu- tion of the matrix equation A^TXA = B and a best approximation to a given matrix X^＊. Moreover, a numerical algorithm for finding this optimal approximate solution is described in detail, and a numerical example is presented to show the validity of our algorithm.展开更多
The new beam position monitor（BPM） system of the injector at the upgrade project of the Hefei Light Source（HLS II） has 19 stripline beam position monitors. Most consist of four orthogonally symmetric stripline ele...The new beam position monitor（BPM） system of the injector at the upgrade project of the Hefei Light Source（HLS II） has 19 stripline beam position monitors. Most consist of four orthogonally symmetric stripline electrodes. Differences in electronic gain and mismachining tolerance can cause changes in the beam response of the BPM electrodes. This variation will couple the two measured horizontal positions, resulting in measuring error. To alleviate this effect, a new technique to measure the relative response of the four electrodes has been developed. It is independent of the beam charge, and the related coefficient can be calculated theoretically. The effect of electrode coupling on this technique is analyzed. The calibration data is used to fit the gain for all 19 injector beam position monitors. The results show the standard deviation of the distribution of measured gains is about 5%.展开更多
文摘We study special functions related to Lotka-Volterra equations and negative Volterra equation intro-duced from zero curvature representations . At first we show the relationships between Lotka-Volterra equations introduced from zero curvature representations and symmetric orthogonal polynomials. Sec-ondarily, we describe the relationships between negative Volterra equations with a special solutions and cylinder functions.
基金supported by R&D Program of Beijing Municipal Education Commission (Grant No. KM202310005012)National Natural Science Foundation of China (Grant Nos. 11901022 and 12171461)+1 种基金Beijing Municipal Natural Science Foundation (Grant Nos. 1204027 and 1212007)supported in part by the National Natural Science Foundation of China (Grant Nos. 11931017 and 12071447)
文摘In this paper,we derive a generalized nonisospectral semi-infinite Lotka-Volterra equation,which possesses a determinant solution.We also give its a Lax pair expressed in terms of symmetric orthogonal polynomials.In addition,if the simplified case of the moment evolution relation is considered,that is,without the convolution term,we also give a generalized nonisospectral finite Lotka-Volterra equation with an explicit determinant solution.Finally,an application of the generalized nonisospectral continuous-time Lotka-Volterra equation in the food chain is investigated by numerical simulation.Our approach is mainly based on Hirota’s bilinear method and determinant techniques.
基金The Project supported by Scientific Research Fund of Hunan Provincial Education Department,by National Natural Science Foundation of China (10171031)by Natural Science Fundation of Hunan Province (03JJY6028).
文摘By applying the generalized singular value decomposition and the canonical correlation decomposition simultaneously, we derive an analytical expression of the optimal approximate solution ^-X, which is both a least-squares symmetric orthogonal anti-symmetric solu- tion of the matrix equation A^TXA = B and a best approximation to a given matrix X^＊. Moreover, a numerical algorithm for finding this optimal approximate solution is described in detail, and a numerical example is presented to show the validity of our algorithm.
基金Supported by National Natural Science Foundation of China(11175173,11375178,11105141)
文摘The new beam position monitor（BPM） system of the injector at the upgrade project of the Hefei Light Source（HLS II） has 19 stripline beam position monitors. Most consist of four orthogonally symmetric stripline electrodes. Differences in electronic gain and mismachining tolerance can cause changes in the beam response of the BPM electrodes. This variation will couple the two measured horizontal positions, resulting in measuring error. To alleviate this effect, a new technique to measure the relative response of the four electrodes has been developed. It is independent of the beam charge, and the related coefficient can be calculated theoretically. The effect of electrode coupling on this technique is analyzed. The calibration data is used to fit the gain for all 19 injector beam position monitors. The results show the standard deviation of the distribution of measured gains is about 5%.
