Owing to their global search capabilities and gradient-free operation,metaheuristic algorithms are widely applied to a wide range of optimization problems.However,their computational demands become prohibitive when ta...Owing to their global search capabilities and gradient-free operation,metaheuristic algorithms are widely applied to a wide range of optimization problems.However,their computational demands become prohibitive when tackling high-dimensional optimization challenges.To effectively address these challenges,this study introduces cooperative metaheuristics integrating dynamic dimension reduction(DR).Building upon particle swarm optimization(PSO)and differential evolution(DE),the proposed cooperative methods C-PSO and C-DE are developed.In the proposed methods,the modified principal components analysis(PCA)is utilized to reduce the dimension of design variables,thereby decreasing computational costs.The dynamic DR strategy implements periodic execution of modified PCA after a fixed number of iterations,resulting in the important dimensions being dynamically identified.Compared with the static one,the dynamic DR strategy can achieve precise identification of important dimensions,thereby enabling accelerated convergence toward optimal solutions.Furthermore,the influence of cumulative contribution rate thresholds on optimization problems with different dimensions is investigated.Metaheuristic algorithms(PSO,DE)and cooperative metaheuristics(C-PSO,C-DE)are examined by 15 benchmark functions and two engineering design problems(speed reducer and composite pressure vessel).Comparative results demonstrate that the cooperative methods achieve significantly superior performance compared to standard methods in both solution accuracy and computational efficiency.Compared to standard metaheuristic algorithms,cooperative metaheuristics achieve a reduction in computational cost of at least 40%.The cooperative metaheuristics can be effectively used to tackle both high-dimensional unconstrained and constrained optimization problems.展开更多
In practical engineering, many uncertain factors in loading or degradation of material properties may vary with time. Stochastic process modeling constitutes a suitable approach for describing these time-dependent unc...In practical engineering, many uncertain factors in loading or degradation of material properties may vary with time. Stochastic process modeling constitutes a suitable approach for describing these time-dependent uncertainties. By adopting this approach, however, the timedependent reliability calculation is a great challenge owing to the complexity and the huge computational burden. This paper presents a new instantaneous response surface method t-IRS for time-dependent reliability analysis. Different from the adaptive extreme response surface approach, the proposed method does not need to build and update surrogate models separately at each time node. It first uses the expansion optimal linear estimation method to discretize the stochastic processes into a set of independent standard normal variables together with some deterministic functions of time. Time is then treated as an independent one-dimensional variable. Next, initial samples are generated by Latin hypercube sampling, and the corresponding response values are calculated and utilized to construct an instantaneous response surrogate model of the Kriging type. The active learning method is applied to update the Kriging surrogate model until satisfactory accuracy is achieved. Finally, the instantaneous response surrogate model is used to compute the time-dependent reliability via Monte Carlo simulation. Four case studies are utilized to demonstrate the effectiveness of the ^-IRS method for time-dependent reliability analysis.展开更多
Objective:To study the effect of inhalant combined with Dingchuan Zhike decoction therapy on the airway remodeling, inflammation and PARC/CCL-18 pathways in patients with cough variant asthma.Methods: A total of 60 pa...Objective:To study the effect of inhalant combined with Dingchuan Zhike decoction therapy on the airway remodeling, inflammation and PARC/CCL-18 pathways in patients with cough variant asthma.Methods: A total of 60 patients with cough variant asthma who were treated in our hospital between January 2014 and May 2016 were collected and divided into the control group (n=30) who received conventional inhalant treatment and the observation group (n=30) who received inhalant combined with Dingchuan Zhike decoction treatment according to single-blind randomized controlled method, and the treatment lasted for 6 months. Before treatment and after 6 months of treatment, high-resolution CT was used to determine the airway remodeling index levels, RIA method was used to detect the peripheral blood airway remodeling index contents, and enzyme-linked immunosorbent assay (ELISA) was used to detect the contents of inflammatory mediators in induced sputum and the PARC/CCL-18 in serum.Results: Before treatment, the differences in the airway remodeling degree as well as the contents of inflammatory mediators and PARC/CCL-18 were not statistically significant between the two groups. After 6 months of treatment, CT airway remodeling indexes LA and TA levels of observation group were higher than those of control group while WA level was lower than that of control group, and peripheral blood airway remodeling indexes CTGF, YKL-39, MMP-9 and TIMP-1 contents were lower tha=n those of control group;inflammatory mediators IL-5, IL-6 and IL-8 contents in induced sputum of observation group were lower than those of control group, and serum PARC/CCL-18 content was lower than that of control group.Conclusion:Inhalant combined with Dingchuan Zhike decoction can inhibit the airway remodeling and reduce the airway inflammation in patients with cough variant asthma.展开更多
基金funded by National Natural Science Foundation of China(Nos.12402142,11832013 and 11572134)Natural Science Foundation of Hubei Province(No.2024AFB235)+1 种基金Hubei Provincial Department of Education Science and Technology Research Project(No.Q20221714)the Opening Foundation of Hubei Key Laboratory of Digital Textile Equipment(Nos.DTL2023019 and DTL2022012).
文摘Owing to their global search capabilities and gradient-free operation,metaheuristic algorithms are widely applied to a wide range of optimization problems.However,their computational demands become prohibitive when tackling high-dimensional optimization challenges.To effectively address these challenges,this study introduces cooperative metaheuristics integrating dynamic dimension reduction(DR).Building upon particle swarm optimization(PSO)and differential evolution(DE),the proposed cooperative methods C-PSO and C-DE are developed.In the proposed methods,the modified principal components analysis(PCA)is utilized to reduce the dimension of design variables,thereby decreasing computational costs.The dynamic DR strategy implements periodic execution of modified PCA after a fixed number of iterations,resulting in the important dimensions being dynamically identified.Compared with the static one,the dynamic DR strategy can achieve precise identification of important dimensions,thereby enabling accelerated convergence toward optimal solutions.Furthermore,the influence of cumulative contribution rate thresholds on optimization problems with different dimensions is investigated.Metaheuristic algorithms(PSO,DE)and cooperative metaheuristics(C-PSO,C-DE)are examined by 15 benchmark functions and two engineering design problems(speed reducer and composite pressure vessel).Comparative results demonstrate that the cooperative methods achieve significantly superior performance compared to standard methods in both solution accuracy and computational efficiency.Compared to standard metaheuristic algorithms,cooperative metaheuristics achieve a reduction in computational cost of at least 40%.The cooperative metaheuristics can be effectively used to tackle both high-dimensional unconstrained and constrained optimization problems.
基金supported by the National Natural Science Foundation of China (Nos.11572134 and 11832013).
文摘In practical engineering, many uncertain factors in loading or degradation of material properties may vary with time. Stochastic process modeling constitutes a suitable approach for describing these time-dependent uncertainties. By adopting this approach, however, the timedependent reliability calculation is a great challenge owing to the complexity and the huge computational burden. This paper presents a new instantaneous response surface method t-IRS for time-dependent reliability analysis. Different from the adaptive extreme response surface approach, the proposed method does not need to build and update surrogate models separately at each time node. It first uses the expansion optimal linear estimation method to discretize the stochastic processes into a set of independent standard normal variables together with some deterministic functions of time. Time is then treated as an independent one-dimensional variable. Next, initial samples are generated by Latin hypercube sampling, and the corresponding response values are calculated and utilized to construct an instantaneous response surrogate model of the Kriging type. The active learning method is applied to update the Kriging surrogate model until satisfactory accuracy is achieved. Finally, the instantaneous response surrogate model is used to compute the time-dependent reliability via Monte Carlo simulation. Four case studies are utilized to demonstrate the effectiveness of the ^-IRS method for time-dependent reliability analysis.
文摘Objective:To study the effect of inhalant combined with Dingchuan Zhike decoction therapy on the airway remodeling, inflammation and PARC/CCL-18 pathways in patients with cough variant asthma.Methods: A total of 60 patients with cough variant asthma who were treated in our hospital between January 2014 and May 2016 were collected and divided into the control group (n=30) who received conventional inhalant treatment and the observation group (n=30) who received inhalant combined with Dingchuan Zhike decoction treatment according to single-blind randomized controlled method, and the treatment lasted for 6 months. Before treatment and after 6 months of treatment, high-resolution CT was used to determine the airway remodeling index levels, RIA method was used to detect the peripheral blood airway remodeling index contents, and enzyme-linked immunosorbent assay (ELISA) was used to detect the contents of inflammatory mediators in induced sputum and the PARC/CCL-18 in serum.Results: Before treatment, the differences in the airway remodeling degree as well as the contents of inflammatory mediators and PARC/CCL-18 were not statistically significant between the two groups. After 6 months of treatment, CT airway remodeling indexes LA and TA levels of observation group were higher than those of control group while WA level was lower than that of control group, and peripheral blood airway remodeling indexes CTGF, YKL-39, MMP-9 and TIMP-1 contents were lower tha=n those of control group;inflammatory mediators IL-5, IL-6 and IL-8 contents in induced sputum of observation group were lower than those of control group, and serum PARC/CCL-18 content was lower than that of control group.Conclusion:Inhalant combined with Dingchuan Zhike decoction can inhibit the airway remodeling and reduce the airway inflammation in patients with cough variant asthma.
