Entity

Time filter

Source Type

Hengyang, China

Long W.,Central South University | Liang X.-M.,Central South University | Long Z.-Q.,Hengyang Normal College | Qin H.-Y.,Central South University
Kongzhi yu Juece/Control and Decision | Year: 2012

A hybrid evolutionary algorithm based on gradient descends method is proposed to determine the structure of RBF neural network and optimize its parameters. A gradient descend operator is introduced into the evolutionary algorithm. Gradient descend method is carried on search by certain probability for certain elitists of every generation to strengthen the ability of local search. The structure and parameters of RBF network are trained and optimized together by using hybrid evolutionary algorithm. The experimental results show that the RBF neural network has stronger generalization ability. Source


Zhao X.,University of South China | Huang S.,Hengyang Normal College | Liu L.,University of South China | Liu C.,Nuclear Power Institute of China | Zong S.,Nuclear Power Institute of China
Hedongli Gongcheng/Nuclear Power Engineering | Year: 2014

To realize the relative distribution measurement of neutron flux in reactor core, the measurement device for multi-channel neutron flux relative distribution has been developed, based on the radioactive counting of activated detection slice measured by NaI detector. The measurement device is made up of PTMC12 data-acquisition board, industrial PC and MNFDAS software, which can automatically achieve the timing and counting function in both cyclical and non-cyclical models, meanwhile the measuring results can be saved as both graphic and data files. The test shows that the stability of the measurement device is excellent with relative deviation within 1%, which can guarantee the requirement of real-time and long-term stable measurement of relative distribution measurement of neutron flux in reactor. Source


Zhao Y.-H.,University of South China | Liu L.-Y.,University of South China | Huang S.,Hengyang Normal College | Liu C.-X.,Nuclear Power Institute of China | And 2 more authors.
Yuanzineng Kexue Jishu/Atomic Energy Science and Technology | Year: 2014

For the measurement of neutron fluence rate in reactor and reliable assurance of γ count measurement of activated 55Mn-58Ni alloy irradiated foils in reactor, 9-channel amplifier-discriminator was developed. The main technical parameter test and application test show that the gain of each channel amplifier-discriminator is continuously adjustable from 1 to 21, the threshold of each discriminator circuit is continuously adjustable, the maximum count rate and sensitivity of discriminator circuit are high, and the system has stable property and excellent anti-interference. In conclusion, relevant technical parameters can guarantee the real-time and long-term stable measurement of neutron fluence rate relative distribution in reactor, with the technical parameters that gain stability of amplifier is less than 1%, the minimum input pulse width of discriminator circuit is greater than 0.1 μs, and the maximum count rate of discriminator is less than 4×106 s-1. Source


Long W.,Central South University | Liang X.,Central South University | Long Z.,Hengyang Normal College | Li Z.,Central South University
Dianli Zidonghua Shebei/Electric Power Automation Equipment | Year: 2011

The boiler combustion process of coal-fired power plant is a very complicated MIMO system with high nonlinearity and strong coupling. The LSSVM(Least Square Support Vector Machine) is applied to build the boiler combustion model based on the property test data and the nonlinear MPC(Model Predictive Control) is applied to optimize the control of boiler combustion process. The improved ACO(Ant Colony Optimization) is proposed to solve the nonlinear optimization problem of MPC algorithm, which extracts the target individuals dynamically and stochastically to lead the global search of ant colony while carries out the small step search nearby the optimal ant. Case study indicates its effectiveness. Source


Hu J.,University of South China | Hu J.,Hunan Normal University | Ding Y.,Hunan Normal University | Qian S.,Hunan Normal University | Tang X.,Hengyang Normal College
Ultrasonics | Year: 2013

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 °C, 50 °C and 55 °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. © 2012 Elsevier B.V. All rights reserved. Source

Discover hidden collaborations