Smooth support vector machine （SSVM） changs the normal support vector machine （SVM） into the unconstrained op- timization by using the smooth sigmoid function. The method can be solved under the Broyden-Fletcher-G...Smooth support vector machine （SSVM） changs the normal support vector machine （SVM） into the unconstrained op- timization by using the smooth sigmoid function. The method can be solved under the Broyden-Fletcher-Goldfarb-Shanno （BFGS） algorithm and the Newdon-Armijio （NA） algorithm easily, however the accuracy of sigmoid function is not as good as that of polyno- mial smooth function. Furthermore, the method cannot reduce the influence of outliers or noise in dataset. A fuzzy smooth support vector machine （FSSVM） with fuzzy membership and polynomial smooth functions is introduced into the SVM. The fuzzy member- ship considers the contribution rate of each sample to the optimal separating hyperplane and makes the optimization problem more accurate at the inflection point. Those changes play a positive role on trials. The results of the experiments show that those FSSVMs can obtain a better accuracy and consume the shorter time than SSVM and lagrange support vector machine （LSVM）.展开更多
In the implementation of quality function deployment （QFD）, the determination of the target values of engineering characteristics is a complex decision process with multiple variables and multiple objectives that sh...In the implementation of quality function deployment （QFD）, the determination of the target values of engineering characteristics is a complex decision process with multiple variables and multiple objectives that should trade off, and optimize all kinds of conflicts and constraints. A fuzzy linear programming model （FLP） is proposed. On the basis of the inherent fuzziness of QFD system, triangular fuzzy numbers are used to represent all the relationships and correlations, and then, the functional relationships between the customer needs and engineering characteristics and the functional correlations among the engineering characteristics are determined with the information in the house of quality （HoQ） fully used. The fuzzy linear programming （FLP） model aims to find the optimal target values of the engineering characteristics to maximize the customer satisfaction. Finally, the proposed method is illustrated by a numerical example.展开更多
Fuzzy logic controller adopting unevenly-distributed membership function was presented with the purpose of enhancing performance of the temperature control precision and robustness for the chamber cooling system.Histo...Fuzzy logic controller adopting unevenly-distributed membership function was presented with the purpose of enhancing performance of the temperature control precision and robustness for the chamber cooling system.Histogram equalization and noise detection were performed to modify the evenly-distributed membership functions of error and error change rate into unevenly-distributed membership functions.Then,the experimental results with evenly and unevenly distributed membership functions were compared under the same outside environment conditions.The experimental results show that the steady-state error is reduced around 40% and the noise disturbance is rejected successfully even though noise range is 60% of the control precision range.The control precision is improved by reducing the steady-state error and the robustness is enhanced by rejecting noise disturbance through the fuzzy logic controller with unevenly-distributed membership function.Moreover,the system energy efficiency and lifetime of electronic expansion valve(EEV) installed in chamber cooling system are improved by adopting the unevenly-distributed membership function.展开更多
The problem of track control is studied for a class of strict-feedback stochastic nonlinear systems in which unknown virtual control gain function is the main feature. First, the so-called stochastic LaSalle theory is...The problem of track control is studied for a class of strict-feedback stochastic nonlinear systems in which unknown virtual control gain function is the main feature. First, the so-called stochastic LaSalle theory is extended to some extent, and accordingly, the results of global ultimate boundedness for stochastic nonlinear systems are developed. Next, a new design scheme of fuzzy adaptive control is proposed. The advantage of it is that it does not require priori knowledge of virtual control gain function sign, which is usually demanded in many designs. At the same time, the track performance of closed-loop systems is improved by adaptive modifying the estimated error upper bound. By theoretical analysis, the signals of closed-loop systems are globally ultimately bounded in probability and the track error converges to a small residual set around the origin in 4th-power expectation.展开更多
The subjection function of the fuzzy quantity is bell like,which is on the base of the theory;but during the course of the control,each fuzzy grade should be predigested into a triangle of W=4.
For discrete-time T-S fuzzy systems, the stability and controller design method are in-vestigated based on parameter-dependent Lyapunov function (PDLF). T-S fuzzy systems di?er fromnon-fuzzy systems with polytopic des...For discrete-time T-S fuzzy systems, the stability and controller design method are in-vestigated based on parameter-dependent Lyapunov function (PDLF). T-S fuzzy systems di?er fromnon-fuzzy systems with polytopic description or multi-model description in that the weighting coef-ficients have respective meanings. They, however, have stability aspect in common. By adopting astability condition for polytopic systems obtained via PDLF, and combining the properties of T-Sfuzzy systems, new results are given in this paper. An example shows that by applying the newresults, the stability conditions that can be distinguished are less conservative.展开更多
The thermal power boiler-turbine system is a complex system with high nonlinearity,time-delay and strong coupling.It is difi cult to obtain an excellent dynamic response by means of traditional PI/PID control when the...The thermal power boiler-turbine system is a complex system with high nonlinearity,time-delay and strong coupling.It is difi cult to obtain an excellent dynamic response by means of traditional PI/PID control when the power system load changes in a wide range.So far many advanced control strategies have been presented to solve the above problem,but most of these strategies are dependent on an accurate object model.展开更多
Euphemisms are widely employed in every aspect of social life. The analysis is made on the realization of interpersonal function of euphemism as a fuzzy language on the basis of discussion on the relationship between ...Euphemisms are widely employed in every aspect of social life. The analysis is made on the realization of interpersonal function of euphemism as a fuzzy language on the basis of discussion on the relationship between euphemism and fuzzy linguistics. It is hoped that the analysis can enrich and perfect the current research on euphemism so that the readers can have a general picture of euphemism and employ euphemisms more precisely and properly in communication. By so doing,the communication can be smoother and the objective of communication can be better achieved.展开更多
大豆分离蛋白(Soy Protein Isolate,SPI)功能特性决定应用领域,加工过程中NaOH添加量影响SPI功能特性。文章究利用Matlab模拟,采用传统比例积分微分(proportional integral derivative,PID)和模糊自适应控制(Adaptive Fuzzy Control,AFC...大豆分离蛋白(Soy Protein Isolate,SPI)功能特性决定应用领域,加工过程中NaOH添加量影响SPI功能特性。文章究利用Matlab模拟,采用传统比例积分微分(proportional integral derivative,PID)和模糊自适应控制(Adaptive Fuzzy Control,AFC)方法调控NaOH,中和大豆凝乳,并分析其对SPI结构和功能特性的影响。结果表明,pH值为7时,常规PID控制方法NaOH超调量为1.86%,调节时间为47.1 s;模糊自适应控制方法无超调量,调节时间为35.8 s。模糊自适应控制下,SPI傅里叶红外光谱吸收峰更稳定,紫外吸收特性更佳,二级结构向有序转变,表面疏水性较高,且溶解性、起泡性、泡沫稳定性、乳化性和乳化稳定性均优于常规PID控制方法。展开更多
基金supported by the National Natural Science Foundation of China (60974082)
文摘Smooth support vector machine （SSVM） changs the normal support vector machine （SVM） into the unconstrained op- timization by using the smooth sigmoid function. The method can be solved under the Broyden-Fletcher-Goldfarb-Shanno （BFGS） algorithm and the Newdon-Armijio （NA） algorithm easily, however the accuracy of sigmoid function is not as good as that of polyno- mial smooth function. Furthermore, the method cannot reduce the influence of outliers or noise in dataset. A fuzzy smooth support vector machine （FSSVM） with fuzzy membership and polynomial smooth functions is introduced into the SVM. The fuzzy member- ship considers the contribution rate of each sample to the optimal separating hyperplane and makes the optimization problem more accurate at the inflection point. Those changes play a positive role on trials. The results of the experiments show that those FSSVMs can obtain a better accuracy and consume the shorter time than SSVM and lagrange support vector machine （LSVM）.
基金supported by the National Natural Science Foundation of China (70571041).
文摘In the implementation of quality function deployment （QFD）, the determination of the target values of engineering characteristics is a complex decision process with multiple variables and multiple objectives that should trade off, and optimize all kinds of conflicts and constraints. A fuzzy linear programming model （FLP） is proposed. On the basis of the inherent fuzziness of QFD system, triangular fuzzy numbers are used to represent all the relationships and correlations, and then, the functional relationships between the customer needs and engineering characteristics and the functional correlations among the engineering characteristics are determined with the information in the house of quality （HoQ） fully used. The fuzzy linear programming （FLP） model aims to find the optimal target values of the engineering characteristics to maximize the customer satisfaction. Finally, the proposed method is illustrated by a numerical example.
文摘Fuzzy logic controller adopting unevenly-distributed membership function was presented with the purpose of enhancing performance of the temperature control precision and robustness for the chamber cooling system.Histogram equalization and noise detection were performed to modify the evenly-distributed membership functions of error and error change rate into unevenly-distributed membership functions.Then,the experimental results with evenly and unevenly distributed membership functions were compared under the same outside environment conditions.The experimental results show that the steady-state error is reduced around 40% and the noise disturbance is rejected successfully even though noise range is 60% of the control precision range.The control precision is improved by reducing the steady-state error and the robustness is enhanced by rejecting noise disturbance through the fuzzy logic controller with unevenly-distributed membership function.Moreover,the system energy efficiency and lifetime of electronic expansion valve(EEV) installed in chamber cooling system are improved by adopting the unevenly-distributed membership function.
基金Supported by National Natural Science Foundation of P. R. China (60572070, 60325311, 60534010) Natural Science Foundation of Liaoning Province (20022030)
文摘The problem of track control is studied for a class of strict-feedback stochastic nonlinear systems in which unknown virtual control gain function is the main feature. First, the so-called stochastic LaSalle theory is extended to some extent, and accordingly, the results of global ultimate boundedness for stochastic nonlinear systems are developed. Next, a new design scheme of fuzzy adaptive control is proposed. The advantage of it is that it does not require priori knowledge of virtual control gain function sign, which is usually demanded in many designs. At the same time, the track performance of closed-loop systems is improved by adaptive modifying the estimated error upper bound. By theoretical analysis, the signals of closed-loop systems are globally ultimately bounded in probability and the track error converges to a small residual set around the origin in 4th-power expectation.
文摘The subjection function of the fuzzy quantity is bell like,which is on the base of the theory;but during the course of the control,each fuzzy grade should be predigested into a triangle of W=4.
文摘For discrete-time T-S fuzzy systems, the stability and controller design method are in-vestigated based on parameter-dependent Lyapunov function (PDLF). T-S fuzzy systems di?er fromnon-fuzzy systems with polytopic description or multi-model description in that the weighting coef-ficients have respective meanings. They, however, have stability aspect in common. By adopting astability condition for polytopic systems obtained via PDLF, and combining the properties of T-Sfuzzy systems, new results are given in this paper. An example shows that by applying the newresults, the stability conditions that can be distinguished are less conservative.
文摘The thermal power boiler-turbine system is a complex system with high nonlinearity,time-delay and strong coupling.It is difi cult to obtain an excellent dynamic response by means of traditional PI/PID control when the power system load changes in a wide range.So far many advanced control strategies have been presented to solve the above problem,but most of these strategies are dependent on an accurate object model.
文摘Euphemisms are widely employed in every aspect of social life. The analysis is made on the realization of interpersonal function of euphemism as a fuzzy language on the basis of discussion on the relationship between euphemism and fuzzy linguistics. It is hoped that the analysis can enrich and perfect the current research on euphemism so that the readers can have a general picture of euphemism and employ euphemisms more precisely and properly in communication. By so doing,the communication can be smoother and the objective of communication can be better achieved.
文摘大豆分离蛋白(Soy Protein Isolate,SPI)功能特性决定应用领域,加工过程中NaOH添加量影响SPI功能特性。文章究利用Matlab模拟,采用传统比例积分微分(proportional integral derivative,PID)和模糊自适应控制(Adaptive Fuzzy Control,AFC)方法调控NaOH,中和大豆凝乳,并分析其对SPI结构和功能特性的影响。结果表明,pH值为7时,常规PID控制方法NaOH超调量为1.86%,调节时间为47.1 s;模糊自适应控制方法无超调量,调节时间为35.8 s。模糊自适应控制下,SPI傅里叶红外光谱吸收峰更稳定,紫外吸收特性更佳,二级结构向有序转变,表面疏水性较高,且溶解性、起泡性、泡沫稳定性、乳化性和乳化稳定性均优于常规PID控制方法。
