作者机构:
[余志武; 陈令坤; 蒋丽忠; 龙卫国] School of Civil Engineering and Architecture, Central South Univ, Changsha, Hunan 410075, China;[李黎] The Third Railway Survey and Design Institute Group Corporation, Tianjin 300142, China;[龙卫国] School of Mathematics and Physics, Univ of South China, Hengyang, Hunan 421001, China
通讯机构:
School of Civil Engineering and Architecture, Central South Univ, China
期刊:
International Journal of Applied Mathematics & Statistics,2013年39(9):47-53 ISSN:0973-1377
通讯作者:
Geng, X.(gengxianya@sina.com)
作者机构:
[Xianya Geng] Department of Mathematics and Physics, Anhui University of Science and Technology, Anhui 232001, Huainan, China;[Zhenghua Xu] School of Mathematics and Physics, Nanhua University, Hunan 421001, Hengyang, China;[Jinshan Xie] School of Mathematics and Computer Science, Longyan University, Fujian 364012, Longyan, China
通讯机构:
[Geng, X.] D;Department of Mathematics and Physics, , Anhui 232001, Huainan, China
期刊:
International Journal of Modelling, Identification and Control,2013年19(2):134-141 ISSN:1746-6172
通讯作者:
Ma, M.(mjunm9@yahoo.com.cn)
作者机构:
[Ma, Manjun; Tao, Jicheng; Han, Yazhou] Department of Mathematics, College of Sciences, China Jiliang University, Hangzhou, Zhejiang, 310018, China;[Zeng, Huadong] School of Mathematics and Physics, University of South China, Hengyang, Hunan Province, China
通讯机构:
Department of Mathematics, College of Sciences, China Jiliang University, China
会议名称:
2012 International Conference on Modelling, Identification and Control, ICMIC 2012
会议时间:
June 24, 2012 - June 26, 2012
会议地点:
Wuhan, China
会议主办单位:
(1) Department of Mathematics, College of Sciences, China Jiliang University, Hangzhou, Zhejiang, 310018, China; (2) School of Mathematics and Physics, University of South China, Hengyang, Hunan Province, China
关键词:
model permanence;stage-structured system;predator-prey model;Beddington-DeAngelis functional response;modelling;predator extinction;biological significance.
作者机构:
[尹岚] University of South China Department of Mathematics and Physics, Hengyang 421001, China;[李达] China Southern Power Grid, Guangzhou 510000, China;[沈辉] Sun Yat-sen University Solar Energy Research Institute, Guangzhou 510000, China;[黄岳文] China Electronics Technology Group Corporation, Changsha 410081, China
通讯机构:
[Li, D.] C;China Southern Power Grid, Guangzhou 510000, China
摘要:
In this paper, a five-neuron model with discrete delays is considered, where the time delays are regarded as parameters. Its dynamics is studied in terms of local analysis and Hopf bifurcation analysis. By analyzing the associated characteristic transcendental equation, it is found that Hopf bifurcation occurs when these delays pass through a sequence of critical value. Some explicit formulae for determining the stability and the direction of the Hopf bifurcation periodic solutions bifurcating from Hopf bifurcations are obtained by using the normal form theory and center manifold theory. Finally, numerical simulations supporting the theoretical analysis are presented.
作者机构:
[蒋丽忠; 龙卫国; 陈令坤] School of Civil Engineering and Architecture, Central South University, Changsha 410075, China;[龙卫国] School of Mathematics and Physics, University of South China, Hunan, Hengyang 421001, China
通讯机构:
School of Civil Engineering and Architecture, Central South University, China
期刊:
International Journal of Applied Mathematics & Statistics,2013年48(18):347-355 ISSN:0973-1377
作者机构:
[Heping Hu] School of Mathematics and Physics, University of south China, Hengyang, 421001, Hunan, China;[Xuecheng Zhao] Mechanical and Electrical Engineering Department, Shaoyang Vocational and Technical College, Shaoyang, 422000, Hunan, China;[Yuhong Zhao] School of Electric Engineering, University of south China, Hengyang, 421001, Hunan, China
摘要:
It is difficult to merge wind power into grid, owing to wind power's uncertainty and prediction inaccuracy. Wind speed is an important factor affecting wind power, so the accuracy of wind speed prediction has a major impact on the wind power prediction. The support vector machine (SVM) has been successfully applied in the short-term wind speed forecasting field, but its learning and generalization ability depend on proper setting of its parameters. In order to improve forecasting accuracy, aiming at the disadvantages like man-made blindness in the parameters selection of SVM, in this paper, the chaos theory was applied to the particles swarm optimization (PSO) algorithm in order to cope with the problems such as low search speed and local optima. Finally, we used it to optimize the support vector machines of short-term wind speed forecasting model. Through the analysis of the forecasting results, it is shown that the proposed method could reduce modeling error and forecasting error of SVM model effectively and has better performance than general methods.
期刊:
International Journal of Applied Mathematics & Statistics,2013年41(11):246-254 ISSN:0973-1377
通讯作者:
Zhao, Y.
作者机构:
[Zhao, Yuhong; Hong, Zhennan] School of Electric Engineering, University of south China, Hengyang, 421001, Hunan, China;[Hu, Heping] School of Mathematics and Physics, University of south China, Hengyang, 421001, Hunan, China
通讯机构:
[Zhao, Y.] S;School of Electric Engineering, , Hengyang, 421001, Hunan, China
摘要:
The control problem in ultrasound therapy is to destroy the tumor tissue while not harming the intervening healthy tissue with a desired temperature elevation. The objective of this research is to present a robust and feasible method to control the temperature distribution and the temperature elevation in treatment region within the prescribed time, which can improve the curative effect and decrease the treatment time for heating large tumor (>= 2.0 cm in diameter). An adaptive self-tuning-regulator (STR) controller has been introduced into this control method by adding a time factor with a recursive algorithm, and the speed of sound and absorption coefficient of the medium is considered as a function of temperature during heating. The presented control method is tested for a self-focused concave spherical transducer (0.5 MHz, 9 cm aperture, 8.0 cm focal length) through numerical simulations with three control temperatures of 43 degrees C, 50 degrees C and 55 degrees C. The results suggest that this control system has adaptive ability for variable parameters and has a rapid response to the temperature and acoustic power output in the prescribed time for the hyperthermia interest. There is no overshoot during temperature elevation and no oscillation after reaching the desired temperatures. It is found that the same results can be obtained for different frequencies and temperature elevations. This method can obtain an ellipsoid-shaped ablation region, which is meaningful for the treatment of large tumor. (C) 2012 Elsevier B.V. All rights reserved.
期刊:
The Journal of Information and Computational Science,2012年9(13):3707-3714 ISSN:1548-7741
通讯作者:
Zou, Q.(qzoucs@gmail.com)
作者机构:
[Zou, Qiang] School of Computer, Southwest University, Chongqing 400715, China;[Zhu, Hui] School of Mathematics and Physics, University of South China, Hengyang, Hunan 421001, China
通讯机构:
School of Computer, Southwest University, China
作者:
Hu, P.*;Lu, J. Q.;Wu, S. X.;Lv, Q. B.;Li, S. W.
期刊:
IEEE Electron Device Letters,2012年33(6):890-892 ISSN:0741-3106
通讯作者:
Hu, P.
作者机构:
[Lv, Q. B.; Lu, J. Q.; Wu, S. X.; Li, S. W.; Hu, P.] Sun Yat Sen Univ, Sch Phys Engn, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Guangdong, Peoples R China.;[Hu, P.] Nanhua Univ, Coll Math & Phys, Hengyang 421001, Peoples R China.
通讯机构:
[Hu, P.] S;Sun Yat Sen Univ, Sch Phys Engn, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Guangdong, Peoples R China.
作者机构:
[彭延峰; 郭燕春; 彭志华; 宁艳桃] School of Mathematics and Physics, University of South China, Hengyang 421001, China;[彭景翠] School of Physics and Microelectronics Science, Hunan University, Changsha 410082, China
通讯机构:
School of Mathematics and Physics, University of South China, China
作者机构:
[杜丹] Department of Mathematics and Physics, University of South China, Hengyang, China;[曹锦佳; 王振华; 龚学余; 扬文超; 郑平卫] Department of Nuclear Science and Technology, University of South China, Hengyang, China
通讯机构:
Department of Mathematics and Physics, University of South China, China
作者:
Yu, Jun*;Dong, J. Q.;Li, X. X.;Du, D.;Gong, X. Y.
期刊:
Journal of Plasma Physics,2012年78(6):651-655 ISSN:0022-3778
通讯作者:
Yu, Jun
作者机构:
[Du, D.; Yu, Jun] Univ S China, Sch Math & Phys, Hengyang 421001, Hunan, Peoples R China.;[Dong, J. Q.] Zhejiang Univ, Inst Fus Theory & Simulat, Dept Phys, Hangzhou 310027, Zhejiang, Peoples R China.;[Dong, J. Q.] SW Inst Phys, Chengdu, Peoples R China.;[Li, X. X.; Gong, X. Y.] Univ S China, Sch Nucl Sci & Technol, Hengyang 421001, Hunan, Peoples R China.
通讯机构:
[Yu, Jun] U;Univ S China, Sch Math & Phys, Hengyang 421001, Hunan, Peoples R China.
摘要:
Excitation of the geodesic acoustic mode continuum by drift wave turbulence is studied using the wave kinetic approach. For a model profile of weak non-uniform ion temperature, the forms of growth rate and radial structure of geodesic acoustic modes are obtained analytically. The growth rate is analyzed for several conditions for present-day tokamaks and compared with that for uniform ion temperature, as well as that given by the coherent mode approach for non-uniform ion temperature.
作者:
Du, Dan*;Gong, Xueyu;Wang, Zhenhua;Yu, Jun;Zheng, Pingwei
期刊:
Journal of Plasma Physics,2012年78(6):595-599 ISSN:0022-3778
通讯作者:
Du, Dan
作者机构:
[Du, Dan; Yu, Jun] Univ S China, Dept Math & Phys, Hengyang City, Hunan, Peoples R China.;[Wang, Zhenhua; Gong, Xueyu] Univ S China, Dept Nucl Sci & Technol, Hengyang City, Hunan, Peoples R China.;[Zheng, Pingwei] Univ S China, Dept Environm Protect & Safety Engn, Hengyang City, Hunan, Peoples R China.
通讯机构:
[Du, Dan] U;Univ S China, Dept Math & Phys, Hengyang City, Hunan, Peoples R China.
摘要:
A well-optimized design of an ion cyclotron resonance heating (ICRH) antenna is very important for steady-state plasma heating with high radio frequency (RF) power of several tens of megawatts. However, a sharp decrease in the coupling RF power because of impedance mismatch of ICRH system is an issue that must be resolved for present-day fusion reactors and International Thermonuclear Experimental Reactor. This paper has theoretically analyzed the ICRH antenna's impedance matching for ELMy plasmas on experimental advanced superconducting tokamak (EAST) by the transmission line theory. The results indicate that judicious choice of the optimal feeder location is found useful for adjustable capacitors' tolerance to the variations of the antenna input impedance during edge-localized mode (ELM) discharge, which is expected to be good for the design of ICRH antenna system and for real-time feedback control during ELM discharge on EAST.