This paper constructs a model of the particle swarm algorithm, compares and analyzes the performance of the particle swarm algorithm under the two parameters of
and
in detail, and solves the ...constrained optimization problem by the particle swarm algorithm. On the basis of the local optimal value to find the global optimal value, the particle swarm algorithm is improved with reference to the particle’s motion state and behavior. Based on the particle swarm algorithm, a digital enterprise management system is constructed to plan enterprise management operations and optimize efficiency. Finally, we compare the performance of different algorithms in enterprise management risk prediction, analyze the correlation between the management system and enterprise management efficiency, and compare the management efficiency of different enterprises to explore the effect of the particle swarm algorithm in digital enterprise management. The results show that the predictive classification effect of the particle swarm algorithm model reaches more than 95% correct rate, and the management system of the particle swarm algorithm presents significance at 1% and 5% significance level for enterprise management efficiency, respectively.
This paper first investigates the implementation process of the particle swarm algorithm by introducing the weight factor
to make the algorithm population iterative, using the particles to perform a ...local search and make them stay near the optimal solution of the algorithm to find the best. Then, we discuss the improvement of the particle swarm optimization algorithm by adding inertia weight
and shrinkage factor to improve the performance of the algorithm and analyze the convergence of the optimization algorithm to determine the convergence conditions and the state of the system. Finally, the improved particle swarm algorithm was used to evaluate the development status of vocational education, analyze its problems, and propose countermeasures for high-quality development. In terms of problems, 68% believe that there is a misalignment in management. 69% believe that the internal management system of the school is not perfect. 66% believe that the school does not have enough funds for the cultivation of talents. As for the learning atmosphere, 294 people think the learning atmosphere is weak, and 487 people think the learning atmosphere is average. The study of this paper is important for the development and optimization of vocational education.
The naïve empirical Bayes method has been widely used as an ad hoc tool in fitting linear mixed-effect models, which is much computationally efficient than the maximum likelihood estimation method. ...However, the shrinkage effect of the empirical Bayes method causes bias in the estimates of the fixed effects. Bias-correction has been proposed for the mixed-effects model when only one covariate is present. In this paper, we derive the shrinkage factor of the empirical Bayes predictors of the random effects and the variance-covariance matrix of the corrected estimates when the model has more than one covariate. The empirical Bayes estimates and test statistics are then corrected using the derived factor. Theoretical derivations, simulation studies and a real data application demonstrate the validity of the proposed method in that the corrected estimates are unbiased and the corrected tests have correct p-values.
Display omitted
•Mixed-effects model can improve statistical power; however, EBE will give biased estimates due to shrinkage.•mSCEBE can correct for the bias of EBE to produce unbiased estimates and p-values in mixed-effects models.•mSCEBE is applicable to the general situation that multiple covariates have effects on multiple random effect parameters.
This study is concerned with the problem of estimating the reliability function of the parameters of the two-parameter Burr XII distribution when the data are complete. Concepts such as the ...likelihood estimator, bias, bias ratio, and mean square error are defined. The purpose of this research is investigate the properties of the double-stage shrinkage estimators (DSSEs) of the reliability function of Burr XII distribution and obtain the equations of bias, mean square error, and bias ratio. The relative efficiency of the Burr XII distribution of the proposed estimators is also investigated by deriving their equations. Numerical results show performance of our estimators to be better than those of the classical pooled estimators based on the relative efficiency criteria. In particular, our proposed DSSEs have better performance than the classical estimator and single-stage shrinkage estimators.
Staining of mast cells (MCs), including porcine ones, is critically dependent upon the fixation and staining technique. In the pig, mucosal and submucosal MCs do not stain or stain only faintly after ...formalin fixation. Some fixation methods are particularly recommended for MC staining, for example the fixation with Carnoy or lead salts. Zinc salt fixation (ZSF) has been reported to work excellently for the preservation of fixation-sensitive antigens. The aim of this study was to establish a reliable histological method for counting of MCs in the porcine intestinum. For this purpose, different tissue fixation and staining methods that also allow potential subsequent immunohistochemical investigations were evaluated in the porcine mucosa, as well as submucosa of small and large intestine. Tissues were fixed in Carnoy, lead acetate, lead nitrate, Zamboni and ZSF and stained subsequently with either polychromatic methylene blue, alcian blue or toluidine blue. For the first time our study reveals that ZSF, a heavy metal fixative, preserves metachromatic staining of porcine MCs. Zamboni fixation was not suitable for histochemical visualization of MCs in the pig intestine. All other tested fixatives were suitable. Alcian blue and toluidine blue co-stained intestinal goblet cells which made a prima facie identification of MCs difficult. The polychromatic methylene blue proved to be the optimal staining. In order to compare MC counting results of the different fixation methods, tissue shrinkage was taken into account. As even the same fixation caused shrinkage-differences between tissue from small and large intestine, different factors for each single fixation and intestinal localization had to be calculated. Tissue shrinkage varied between 19% and 57%, the highest tissue shrinkage was found after fixation with ZSF in the large intestine, the lowest one in the small intestine after lead acetate fixation. Our study emphasizes that MC counting results from data using different fixation techniques can only be compared if the respective study-immanent shrinkage factor has been determined and quantification results are adjusted accordingly.
As an advanced technique, compressed sensing has been used for rapid magnetic resonance imaging in recent years, Two-step Iterative Shrinkage Thresholding Algorithm (TwIST) is a popular algorithm ...based on Iterative Thresholding Shrinkage Algorithm (ISTA) for fast MR image reconstruction. However TwIST algorithms cannot dynamically adjust shrinkage factor according to the degree of convergence. So it is difficult to balance speed and efficiency. In this paper, we proposed an algorithm which can dynamically adjust the shrinkage factor to rebalance the fidelity item and regular item during TwIST iterative process. The shrinkage factor adjusting is judged by the previous reconstructed results throughout the iteration cycle. It can greatly accelerate the iterative convergence while ensuring convergence accuracy. We used MR images with 2 body parts and different sampling rates to simulate, the results proved that the proposed algorithm have a faster convergence rate and better reconstruction performance. We also used 60 MR images of different body parts for further simulation, and the results proved the universal superiority of the proposed algorithm.
The research results of cutting speed effect on cutting force and chip shrinkage when turning missile parts made of titanium alloy BT6 (Russian State Standard GOST 19807-91, Ti (86.485 – 91.2%, Al ...(5.3 – 6.8%), V (3.5 – 5.3%) are given in the paper. The influence of cutting speeds on cutting force and chip shrinkage when turning parts made of titanium alloy BT6 (Russian State Standard GOST 19807-91) were experimentally determined. In accordance with test results, the following conclusions were made: cutting speed increase more than 30 m/min is inappropriate as cutting force values do not decrease; it is not recommended to use light feeds and high cutting speeds due to fire safety; increasing cutting speed more than 40 m/min demands either increasing the thickness of material to be removed or the feed rate, otherwise, choosing another plan approach angle φ.
In this paper, we propose two novel source localization methods; one is the shrinkage estimator with the minimum mean squared error criterion, and the other is the shrinkage estimator with the ...minimum bias criterion. The mean squared error performance of the two-step weighted least squares deteriorates in the large noise variance regimes. In order to improve the two-step weighted least squares in the large noise variance regimes, the shrinkage factor is multiplied by the two-step weighted least squares estimator, and then the novel estimator is determined such that the mean squared error and squared bias are minimized. Simulation results show that the mean squared error performances of the proposed methods are better than those of the two-step weighted least squares method as well as the minimax estimator in a regime with large measurement noise variances.
PDF
