This paper proposes a methodology for the quantitative robustness evaluation of PID controllers employed in a DC motor. The robustness analysis is performed employing a 2~3 factorial experimental design for a fraction...This paper proposes a methodology for the quantitative robustness evaluation of PID controllers employed in a DC motor. The robustness analysis is performed employing a 2~3 factorial experimental design for a fractional order proportional integral and derivative controller(FOPID), integer order proportional integral and derivative controller(IOPID)and the Skogestad internal model control controller(SIMC). The factors assumed in experiment are the presence of random noise,external disturbances in the system input and variable load. As output variables, the experimental design employs the system step response and the controller action. Practical implementation of FOPID and IOPID controllers uses the MATLAB stateflow toolbox and a NI data acquisition system. Results of the robustness analysis show that the FOPID controller has a better performance and robust stability against the experiment factors.展开更多
Fractional factorial(FF)designs are commonly used for factorial experiments in many fields.When some prior knowledge has shown that some factors are more likely to be significant than others,Li,et al.(2015)proposed a ...Fractional factorial(FF)designs are commonly used for factorial experiments in many fields.When some prior knowledge has shown that some factors are more likely to be significant than others,Li,et al.(2015)proposed a new pattern,called the individual word length pattern(IWLP),which,defined on a column of the design matrix,measures the aliasing of the effect assigned to this column and effects involving other factors.In this paper,the authors first investigate the relationships between the IWLP and other popular criteria for regular FF designs.As we know,fractional factorial split-plot(FFSP)designs are important both in theory and practice.So another contribution of this paper is extending the IWLP criterion from FF designs to FFSP designs.The authors propose the IWLP of a factor from the whole-plot(WP),or sub-plot(SP),denoted by the I_w WLP and Is WLP respectively,in the FFSP design.The authors further propose combined word length patterns C_(w) WLP and Cs WLP,in order to select good designs for different cases.The new criteria C_(w) WLP and Cs WLP apply to the situations that the potential important factors are in WP or SP,respectively.Some examples are presented to illustrate the selected designs based on the criteria established here.展开更多
Fractional factorial split-plot design has been widely used in many fields due to its advantage of saving experimental cost. The general minimum lower order confounding criterion is usually used as one of the attracti...Fractional factorial split-plot design has been widely used in many fields due to its advantage of saving experimental cost. The general minimum lower order confounding criterion is usually used as one of the attractive design criterion for selecting fractional factorial split-plot design. In this paper, we are interested in the theoretical construction methods of the optimal fractional factorial split-plot designs under the general minimum lower order confounding criterion. We present the theoretical construction methods of optimal fractional factorial split-plot designs under general minimum lower order confounding criterion under several conditions.展开更多
Fractional factorial split-plot (FFSP) designs have an important value of investigation for their special structures.There are two types of factors in an FFSP design: the whole-plot (WP) factors and sub-plot (SP) fact...Fractional factorial split-plot (FFSP) designs have an important value of investigation for their special structures.There are two types of factors in an FFSP design: the whole-plot (WP) factors and sub-plot (SP) factors,which can form three types of two-factor interactions:WP2fi,WS2fi and SP2fi.This paper considers FFSP designs with resolution Ⅲ or Ⅳ under the clear effects criterion.It derives the upper and lower bounds on the maximum numbers of clear WP2fis and WS2fis for FFSP designs,and gives some methods for constructing the desired FFSP designs.It further examines the performance of the construction methods.展开更多
It is very powerful for constructing nearly saturated factorial designs to characterize fractional factorial (FF) designs through their consulting designs when the consulting designs are small. Mukerjee and Fang emplo...It is very powerful for constructing nearly saturated factorial designs to characterize fractional factorial (FF) designs through their consulting designs when the consulting designs are small. Mukerjee and Fang employed the projective geometry theory to find the secondary wordlength pattern of a regular symmetrical fractional factorial split-plot (FFSP) design in terms of its complementary subset, but not in a unified form. In this paper, based on the connection between factorial design theory and coding theory, we obtain some general and unified combinatorial identities that relate the secondary wordlength pattern of a regular symmetrical or mixed-level FFSP design to that of its consulting design. According to these identities, we further establish some general and unified rules for identifying minimum secondary aberration, symmetrical or mixed-level, FFSP designs through their consulting designs.展开更多
The issue of optimal blocking for fractional factorial split-plot (FFSP) designs is considered under the two criteria of minimum aberration and maximum estimation capacity. The criteria of minimum secondary aberration...The issue of optimal blocking for fractional factorial split-plot (FFSP) designs is considered under the two criteria of minimum aberration and maximum estimation capacity. The criteria of minimum secondary aberration (MSA) and maximum secondary estimation capacity (MSEC) are developed for discriminating among rival nonisomorphic blcoked FFSP designs. A general rule for identifying MSA or MSEC blocked FFSP designs through their blocked consulting designs is established.展开更多
A fundamental and practical question for fractional factorial designs is the issue of optimal factor assignment. Recently, some new criteria, such as generalized minimum aberration, WV-criterion, NB-criterion and unif...A fundamental and practical question for fractional factorial designs is the issue of optimal factor assignment. Recently, some new criteria, such as generalized minimum aberration, WV-criterion, NB-criterion and uniformity criterion are proposed for comparing and selecting fractions. In this paper, we indicate that these criteria agree quite well for symmetrical fraction factorial designs.展开更多
In accordance with the enhancement for luminous efficiency improving, LED (Light Emitting Diode) has been gradually developed by combining the characteristics of small volume, impact resistance, good reliability, long...In accordance with the enhancement for luminous efficiency improving, LED (Light Emitting Diode) has been gradually developed by combining the characteristics of small volume, impact resistance, good reliability, long life, low power consumption with multiple purposes for energy saving and environmental protection. Therefore, the array LED has been widely applied in human livings nowadays. This study applies the finite element analysis software ANSYS to analyze the thermal behavior of the array power LED work lamp which is modeled by four same-size LED with MCPCB (Metal Core Print Circuit Board) mounted on a base heat-sink. The Flotran heat flow analysis is applied to obtain the natural convection of air coefficient, while the convection value can be confirmed by the iterative method since it is set as the boundary condition for ANSYS thermal analysis to obtain the temperature distribution, accordingly the chip junction temperature and the base heat-sink temperature were followed through experiments in order to check if the simulation results meet the design requirements and coincide with the power LED product design specification. Prior to the optimal design process for chip junction temperature, the most significant parameters were first chosen by the fractional factorial design. The regressive models were respectively setup by the dual response surface method (RSM) and the mixed response surface method. Furthermore, the genetic algorithm combined with response surface method was applied to acquire the optimal design parameters, and the results were obtained from both methods, which are reviewed for comparison. Afterwards, the mixed response surface method is adopted to investigate the effects of interactions among various factors on chip junction temperature. In conclusion, it is found that the thermal conductivity of MCPCB and the height of base heat-sink are the two major significant factors. In addition, the interactive effects between chip size and thermal conductivity of chip adhesion layer are acknowledged as the most significant interaction influenced on the chip junction temperature.展开更多
The mechanisms of adsorption of pesticides(dimethoate, metalaxyl, atrazine, malathion and prometryn) and heavy metals(Cu, Cd, Pb, Zn and Ni) coexisting in sediments, with pesticides as target pollutants, and the i...The mechanisms of adsorption of pesticides(dimethoate, metalaxyl, atrazine, malathion and prometryn) and heavy metals(Cu, Cd, Pb, Zn and Ni) coexisting in sediments, with pesticides as target pollutants, and the influence of their main effects and double-order interaction effects were studied using the experimental design module in the Minitab software package with a 2^10-3 fractional factorial design method at resolution V. The main, double-order interaction, synergistic and antagonistic effect values of pollutant concentrations influencing the adsorption of pesticides were set as dependent variables, while various quantum chemical parameters of pesticides were set as independent variables, and two-dimensional quantitative structure activity relationship(2D-QSAR) models were established by stepwise regression to reveal the adsorption mechanisms of pesticides in a composite contamination system. The main effects of pollutants concentration played the primary role in the adsorption of dimethoate and malathion(the rates of contributions were 53.54% and 56.46%, respectively), while double-order interaction effects were primarily responsible for metalaxyl, atrazine and prometryn adsorption(the rates of contributions were 79.05%, 60.21% and 57.89%, respectively) in the pesticide/heavy metals coexisting sediment system. The synergistic effects of the main effects and double-order interaction effects of pollutants concentration(synergistic effects) played a leading role in adsorption of malathion and prometryn(the rates of contributions were 70.61% and 69.61%, respectively), while an- tagonistic effects of the main effects and double-order interaction effects of pollutants(antagonistic effects) played a dominant role in the adsorption of dimethoate, metalaxyl and atrazine(the rates of contributions were 58.82%, 56.89% and 58.24%, respectively). Moreover, the correlation coefficient value(R2) ranged from 0.986 to 0.999(〉0.8783) in the 2D-QSAR model, while the standard deviation(SD) ranged from 0.006 to 0.066 and the Ftest values were 22.684-199.544, indicating the model has good predictive ability and fit. The 2D-QSAR model revealed a significant correlation(P=0.05) between the main effects of pollutants concentrations on pesticides adsorption(main effect values) and the most positive hydrogen atomic charge(qa+), the highest occupied molecular orbital energy(EHOMO) and the dipole moment(μ). Furthermore, double-order interaction effect values of pollutant concentrations influenced the adsorption of pesticides(double-order interaction effect values), and the most positive atomic charge(q+), qH+, and the lowest unoccupied molecular orbital energy(ELMO) were significantly correlated. The qw, EHOMO and μ of pesticides were found to be significant factors promoting pesticides adsorption, while the q+ and ELVMO of pesticides were significant inhibiting factors(P=0,05). Overall, this study provides a theoretical basis for further realization of combined pollution control of pesticide pollutants in complex environmental systems.展开更多
文摘This paper proposes a methodology for the quantitative robustness evaluation of PID controllers employed in a DC motor. The robustness analysis is performed employing a 2~3 factorial experimental design for a fractional order proportional integral and derivative controller(FOPID), integer order proportional integral and derivative controller(IOPID)and the Skogestad internal model control controller(SIMC). The factors assumed in experiment are the presence of random noise,external disturbances in the system input and variable load. As output variables, the experimental design employs the system step response and the controller action. Practical implementation of FOPID and IOPID controllers uses the MATLAB stateflow toolbox and a NI data acquisition system. Results of the robustness analysis show that the FOPID controller has a better performance and robust stability against the experiment factors.
基金supported by the National Natural Science Foundation of China under Grant Nos.11871033,11971204,12101357,12131001 and 12271270National Ten Thousand Talents Program of China+2 种基金Natural Science Foundation of Tianjin under Grant No.20JCYBJC01050Natural Science Foundation of Shandong under Grant No.ZR2021QA080the 111 Project B20016。
文摘Fractional factorial(FF)designs are commonly used for factorial experiments in many fields.When some prior knowledge has shown that some factors are more likely to be significant than others,Li,et al.(2015)proposed a new pattern,called the individual word length pattern(IWLP),which,defined on a column of the design matrix,measures the aliasing of the effect assigned to this column and effects involving other factors.In this paper,the authors first investigate the relationships between the IWLP and other popular criteria for regular FF designs.As we know,fractional factorial split-plot(FFSP)designs are important both in theory and practice.So another contribution of this paper is extending the IWLP criterion from FF designs to FFSP designs.The authors propose the IWLP of a factor from the whole-plot(WP),or sub-plot(SP),denoted by the I_w WLP and Is WLP respectively,in the FFSP design.The authors further propose combined word length patterns C_(w) WLP and Cs WLP,in order to select good designs for different cases.The new criteria C_(w) WLP and Cs WLP apply to the situations that the potential important factors are in WP or SP,respectively.Some examples are presented to illustrate the selected designs based on the criteria established here.
文摘Fractional factorial split-plot design has been widely used in many fields due to its advantage of saving experimental cost. The general minimum lower order confounding criterion is usually used as one of the attractive design criterion for selecting fractional factorial split-plot design. In this paper, we are interested in the theoretical construction methods of the optimal fractional factorial split-plot designs under the general minimum lower order confounding criterion. We present the theoretical construction methods of optimal fractional factorial split-plot designs under general minimum lower order confounding criterion under several conditions.
基金This work was partially supported by the National Natural Science Foundation of China(Grant Nos.10301015 and 10571093)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20050055038).
文摘Fractional factorial split-plot (FFSP) designs have an important value of investigation for their special structures.There are two types of factors in an FFSP design: the whole-plot (WP) factors and sub-plot (SP) factors,which can form three types of two-factor interactions:WP2fi,WS2fi and SP2fi.This paper considers FFSP designs with resolution Ⅲ or Ⅳ under the clear effects criterion.It derives the upper and lower bounds on the maximum numbers of clear WP2fis and WS2fis for FFSP designs,and gives some methods for constructing the desired FFSP designs.It further examines the performance of the construction methods.
基金supported by the National Natural Science Foundation of China(Grant Nos.10231030&10571093)Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20050055038).
文摘It is very powerful for constructing nearly saturated factorial designs to characterize fractional factorial (FF) designs through their consulting designs when the consulting designs are small. Mukerjee and Fang employed the projective geometry theory to find the secondary wordlength pattern of a regular symmetrical fractional factorial split-plot (FFSP) design in terms of its complementary subset, but not in a unified form. In this paper, based on the connection between factorial design theory and coding theory, we obtain some general and unified combinatorial identities that relate the secondary wordlength pattern of a regular symmetrical or mixed-level FFSP design to that of its consulting design. According to these identities, we further establish some general and unified rules for identifying minimum secondary aberration, symmetrical or mixed-level, FFSP designs through their consulting designs.
基金This work was partially supported by National Natural Science Foundation of China(Grant No.10231030)Chinese Postdoctoral Science Foundation(Grant No.20040350240).
文摘The issue of optimal blocking for fractional factorial split-plot (FFSP) designs is considered under the two criteria of minimum aberration and maximum estimation capacity. The criteria of minimum secondary aberration (MSA) and maximum secondary estimation capacity (MSEC) are developed for discriminating among rival nonisomorphic blcoked FFSP designs. A general rule for identifying MSA or MSEC blocked FFSP designs through their blocked consulting designs is established.
基金Supported by the National Natural Science Foundation of China (No.i0441001), the Key Project of Chinese Ministry of Education (No. i05119), SRF for R0CS(SEM) (No.[2004]176) and the Nature Science Foundation of Hubei Province. Acknowledgements. The authors cordially thank the referees and Editor for their valuable comments.
文摘A fundamental and practical question for fractional factorial designs is the issue of optimal factor assignment. Recently, some new criteria, such as generalized minimum aberration, WV-criterion, NB-criterion and uniformity criterion are proposed for comparing and selecting fractions. In this paper, we indicate that these criteria agree quite well for symmetrical fraction factorial designs.
文摘In accordance with the enhancement for luminous efficiency improving, LED (Light Emitting Diode) has been gradually developed by combining the characteristics of small volume, impact resistance, good reliability, long life, low power consumption with multiple purposes for energy saving and environmental protection. Therefore, the array LED has been widely applied in human livings nowadays. This study applies the finite element analysis software ANSYS to analyze the thermal behavior of the array power LED work lamp which is modeled by four same-size LED with MCPCB (Metal Core Print Circuit Board) mounted on a base heat-sink. The Flotran heat flow analysis is applied to obtain the natural convection of air coefficient, while the convection value can be confirmed by the iterative method since it is set as the boundary condition for ANSYS thermal analysis to obtain the temperature distribution, accordingly the chip junction temperature and the base heat-sink temperature were followed through experiments in order to check if the simulation results meet the design requirements and coincide with the power LED product design specification. Prior to the optimal design process for chip junction temperature, the most significant parameters were first chosen by the fractional factorial design. The regressive models were respectively setup by the dual response surface method (RSM) and the mixed response surface method. Furthermore, the genetic algorithm combined with response surface method was applied to acquire the optimal design parameters, and the results were obtained from both methods, which are reviewed for comparison. Afterwards, the mixed response surface method is adopted to investigate the effects of interactions among various factors on chip junction temperature. In conclusion, it is found that the thermal conductivity of MCPCB and the height of base heat-sink are the two major significant factors. In addition, the interactive effects between chip size and thermal conductivity of chip adhesion layer are acknowledged as the most significant interaction influenced on the chip junction temperature.
文摘The mechanisms of adsorption of pesticides(dimethoate, metalaxyl, atrazine, malathion and prometryn) and heavy metals(Cu, Cd, Pb, Zn and Ni) coexisting in sediments, with pesticides as target pollutants, and the influence of their main effects and double-order interaction effects were studied using the experimental design module in the Minitab software package with a 2^10-3 fractional factorial design method at resolution V. The main, double-order interaction, synergistic and antagonistic effect values of pollutant concentrations influencing the adsorption of pesticides were set as dependent variables, while various quantum chemical parameters of pesticides were set as independent variables, and two-dimensional quantitative structure activity relationship(2D-QSAR) models were established by stepwise regression to reveal the adsorption mechanisms of pesticides in a composite contamination system. The main effects of pollutants concentration played the primary role in the adsorption of dimethoate and malathion(the rates of contributions were 53.54% and 56.46%, respectively), while double-order interaction effects were primarily responsible for metalaxyl, atrazine and prometryn adsorption(the rates of contributions were 79.05%, 60.21% and 57.89%, respectively) in the pesticide/heavy metals coexisting sediment system. The synergistic effects of the main effects and double-order interaction effects of pollutants concentration(synergistic effects) played a leading role in adsorption of malathion and prometryn(the rates of contributions were 70.61% and 69.61%, respectively), while an- tagonistic effects of the main effects and double-order interaction effects of pollutants(antagonistic effects) played a dominant role in the adsorption of dimethoate, metalaxyl and atrazine(the rates of contributions were 58.82%, 56.89% and 58.24%, respectively). Moreover, the correlation coefficient value(R2) ranged from 0.986 to 0.999(〉0.8783) in the 2D-QSAR model, while the standard deviation(SD) ranged from 0.006 to 0.066 and the Ftest values were 22.684-199.544, indicating the model has good predictive ability and fit. The 2D-QSAR model revealed a significant correlation(P=0.05) between the main effects of pollutants concentrations on pesticides adsorption(main effect values) and the most positive hydrogen atomic charge(qa+), the highest occupied molecular orbital energy(EHOMO) and the dipole moment(μ). Furthermore, double-order interaction effect values of pollutant concentrations influenced the adsorption of pesticides(double-order interaction effect values), and the most positive atomic charge(q+), qH+, and the lowest unoccupied molecular orbital energy(ELMO) were significantly correlated. The qw, EHOMO and μ of pesticides were found to be significant factors promoting pesticides adsorption, while the q+ and ELVMO of pesticides were significant inhibiting factors(P=0,05). Overall, this study provides a theoretical basis for further realization of combined pollution control of pesticide pollutants in complex environmental systems.
文摘将克隆自卡波霉素产生菌的4"-O-异戊酰基转移酶基因整合到螺旋霉素产生菌S trep tomy ces sp iramy ceticus F-21的染色体上,构建成一株稳定的生物工程菌W SJ-1-195,它产生的一组以4"-O-异戊酰螺旋霉素为主要成分的多组分基因工程新型抗生素命名为必特螺旋霉素。针对目前没有适合必特螺旋霉素产生菌的合成培养基,所以本文顺序通过部分因子析因设计法、最速上升实验、中心组合实验,并利用统计学软件SA S V 8对实验数据进行分析,确定了必特螺旋霉素合成培养基的组成,为以后对必特螺旋霉素生理生化特性的研究提供基础。经过优化后必特螺旋霉素的发酵效价从173μg/m l提高到1880μg/m l。