The multi-objective optimal control with X-Q adaptive controller

This paper proposes a new type of nonlinear controllers and a large phase angle allowance design method based on the multi-objective optimal control system. With the proposed method, the performance of the system becomes better than that of the original system. Then, an example of the radar servo system is designed with a large phase angle allowance multi-objective optimal design method. Finally, the performance based on computer simulation demonstrates that the multi-objective optimal system is superior to linear optimal systems.

AMTS:Adaptive Multi-Objective Task Scheduling Strategy in Cloud Computing

Task scheduling in cloud computing environments is a multi-objective optimization problem, which is NP hard. It is also a challenging problem to find an appropriate trade-off among resource utilization, energy consumption and Quality of Service(QoS) requirements under the changing environment and diverse tasks. Considering both processing time and transmission time, a PSO-based Adaptive Multi-objective Task Scheduling(AMTS) Strategy is proposed in this paper. First, the task scheduling problem is formulated. Then, a task scheduling policy is advanced to get the optimal resource utilization, task completion time, average cost and average energy consumption. In order to maintain the particle diversity, the adaptive acceleration coefficient is adopted. Experimental results show that the improved PSO algorithm can obtain quasi-optimal solutions for the cloud task scheduling problem.

基于改进PSO-Elman的液晶显示器颜色特性化

液晶显示器颜色特性化可以实现同一幅图像在不同设备上的准确显示。为解决液晶显示器颜色特性化存在模型建立复杂、模型鲁棒性差导致特性化精度较低的问题,提出基于改进PSO-Elman神经网络的方法建立RGB颜色空间到CIEXYZ颜色空间的转换模型(ACOPSO-Elman)。首先根据粒子种群规模和粒子位置关系构造惯性权重与学习因子的自适应调节函数提高PSO算法的全局寻优能力和收敛速度,并在寻优过程中添加混沌优化(CO),防止粒子陷入局部最优解,将改进的粒子群算法用于Elman模型参数寻优,解决了Elman模型参数较难选取的问题。通过仿真验证并与BP、Elman神经网络模型比较表明,ACOPSO-Elman模型特性化的平均色差为1.9247ΔE^(*)_(ab),最大色差为5.1252ΔE^(*)_(ab),在特性化精度上取得了较好的效果。

PSO Based Multi-Objective Approach for Controlling PID Controller

CSTR(Continuous stirred tank reactor)is employed in process control and chemical industries to improve response characteristics and system efficiency.It has a highly nonlinear characteristic that includes complexities in its control and design.Dynamic performance is compassionate to change in system parameterswhich need more effort for planning a significant controller for CSTR.The reactor temperature changes in either direction from the defined reference value.It is important to note that the intensity of chemical actions inside the CSTR is dependent on the various levels of temperature,and deviation from reference values may cause degradation of biomass quality.Design and implementation of an appropriate adaptive controller for such a nonlinear system are essential.In this paper,a conventional Proportional Integral Derivative(PID)controller is designed.The conventional techniques to deal with constraints suffer severe limitations like it has fixed controller parameters.Hence,A novel method is applied for computing the PID controller parameters using a swarm algorithm that overcomes the conventional controller’s limitation.In the proposed technique,PID parameters are tuned by Particle Swarm Optimization(PSO).It is not easy to choose the suitable objective function to design a PID controller using PSO to get an optimal response.In this article,a multi-objective function is proposed for PSO based controller design of CSTR.

Optimization of buckling load for laminated composite plates using adaptive Kriging-improved PSO:A novel hybrid intelligent method

An effective hybrid optimization method is proposed by integrating an adaptive Kriging(A-Kriging)into an improved partial swarm optimization algorithm(IPSO)to give a so-called A-Kriging-IPSO for maximizing the buckling load of laminated composite plates(LCPs)under uniaxial and biaxial compressions.In this method,a novel iterative adaptive Kriging model,which is structured using two training sample sets as active and adaptive points,is utilized to directly predict the buckling load of the LCPs and to improve the efficiency of the optimization process.The active points are selected from the initial data set while the adaptive points are generated using the radial random-based convex samples.The cell-based smoothed discrete shear gap method(CS-DSG3)is employed to analyze the buckling behavior of the LCPs to provide the response of adaptive and input data sets.The buckling load of the LCPs is maximized by utilizing the IPSO algorithm.To demonstrate the efficiency and accuracy of the proposed methodology,the LCPs with different layers(2,3,4,and 10 layers),boundary conditions,aspect ratios and load patterns(biaxial and uniaxial loads)are investigated.The results obtained by proposed method are in good agreement with the literature results,but with less computational burden.By applying adaptive radial Kriging model,the accurate optimal resultsebased predictions of the buckling load are obtained for the studied LCPs.

基于PSO-SA算法的源项反演方法研究

针对大气污染事故突发时,事故发生点无法确定或人员不能接近的情况,研究了基于环境监测数据源项反演以获取事故源项数据的技术,设计实现了一种基于粒子群-模拟退火源项反演方法。采用自适应方法调整惯性权重系数,与高斯烟羽扩散模型结合,对事故源项数据进行反演。实验结果显示:在所选监测点监测数据的反演实验中,基于粒子群-模拟退火算法(PSO-SA)结合了两种算法的优势,能够获得与期望值较为符合的反演结果。进一步分析了监测点数据误差及监测点数量对反演结果的影响,并将文中方法与粒子群算法(PSO)进行对比,同等条件下,较粒子群算法精度提高了8%,能够快速实现对大气污染源强和位置的准确估计。

基于AM-PSO-BP神经网络的打印路径规划

为提高弧焊焊接效果,提出一种基于AM-PSO-BP神经网络的弧焊打印路径规划方法。方法采用基于自适应方差的自适应变异操作(AM)消除粒子群优化算法(PSO)后期迭代效率低的问题,然后利用AM-PSO算法优化BP(back propagation)神经网络的权重和阈值,实现BP神经网络参数的优化;最后将AM-PSO-BP神经网络算法对弧焊打印工艺参数进行预测,获取更准确的弧焊打印工艺参数。仿真结果表明:所提方法可精确预测弧焊打印工艺参数,在该工艺参数下,弧焊打印的六边形柱体、圆柱体、正方体预测值与实测值相差较小,且在误差允许范围内,具有较高的准确性。以上方法可为精确弧焊打印提供依据。

基于CEEMDAN-VMD-PSO-LSTM模型的桥梁挠度预测

针对桥梁运行阶段的健康状态监测,构建了CEEMDAN-VMD-PSO-LSTM模型对桥梁挠度进行预测。该模型主要分为二次模态分解平稳化、粒子群优化(PSO)算法和长短期记忆(LSTM)网络预测三大模块,共有5个步骤:①利用自适应噪声完备集合经验模态分解(CEEMDAN)算法对桥梁原始挠度序列进行初次模态分解,分解为若干本征模态分解函数(IMF);②使用样本熵(SampEn/SE)计算各IMF分量的复杂度,并通过K-means聚类为高频、中频和低频3个IMF分量;③通过变分模态分解(VMD)算法对高频IMF分量进行二次模态分解;④分别对各个IMF分量通过PSO算法得出LSTM最优超参数组合;⑤将各最优超参数分别代入LSTM模型进行训练,并将各预测结果融合为最终的预测结果。结果表明:该预测方法具有最高的预测精度,为智慧桥梁的安全监测监控提供了新的技术方法。

Dynamic Multi-objective Optimization of Chemical Processes Using Modified BareBones MOPSO Algorithm

Dynamic multi-objective optimization is a complex and difficult research topic of process systems engineering. In this paper,a modified multi-objective bare-bones particle swarm optimization( MOBBPSO) algorithm is proposed that takes advantage of a few parameters of bare-bones algorithm. To avoid premature convergence,Gaussian mutation is introduced; and an adaptive sampling distribution strategy is also used to improve the exploratory capability. Moreover, a circular crowded sorting approach is adopted to improve the uniformity of the population distribution.Finally, by combining the algorithm with control vector parameterization,an approach is proposed to solve the dynamic optimization problems of chemical processes. It is proved that the new algorithm performs better compared with other classic multiobjective optimization algorithms through the results of solving three dynamic optimization problems.

Distribution Network Expansion Planning Based on Multi-objective PSO Algorithm

This paper presents a novel approach for electrical distribution network expansion planning using multi-objective particle swarm optimization (PSO). The optimization objectives are: investment and operation cost, energy losses cost, and power congestion cost. A two-phase multi-objective PSO algorithm is employed to solve this optimization problem, which can accelerate the convergence and guarantee the diversity of Pareto-optimal front set as well. The feasibility and effectiveness of both the proposed multi-objective planning approach and the improved multi-objective PSO have been verified by the 18-node typical system.

基于GWO与PSO融合优化算法的雾计算资源分配研究

针对雾计算资源分配问题,文章通过结合灰狼优化算法(GWO)较好的全局搜索能力以及粒子群优化算法(PSO)良好的算法收敛能力而提出了一种新的资源分配思路。此外优化算法权重取值对算法性能的影响较大,文章引入一种自适应权重策略来调节算法的权重,以优化算法对于节点资源分配准确度和效率。实验结果表明,该文提出的算法在雾计算资源分配问题上具有更好的性能,为任务提供更为高效、快速的资源调度策略。

基于PSO-BP神经网络的临时支架支撑力自适应控制

为了使临时支架的支撑力更好地与矿压相适应,提高支架的支护能力,以双联自移式临时支架为研究对象,提出了基于粒子群优化(PSO)-BP神经网络的临时支架支撑力自适应控制方法。利用PSO算法的全局搜索能力及快速收敛特性对BP神经网络的初始权值进行优化,提高BP神经网络的收敛速度;再通过优化后的BP神经网络实现PID参数在线自调整,构建PSO-BP神经网络优化PID控制器,使临时支架的支撑力更快速、准确地达到预定值,实现临时支架支撑力自适应控制,避免因支护力和顶板压力不匹配而对顶板造成破坏。用单位阶跃信号模拟临时支护支架的期望初撑力进行实验验证,结果表明,与BP神经网络优化PID控制器及传统PID控制器相比,PSO-BP神经网络优化PID控制器可以更快、更准确地达到预期的初撑力,调整时间仅为0.5 s且基本不存在超调。根据实际地质条件仿真模拟开挖支护过程中支架受到的顶板压力,研究3种控制器的支撑力自适应控制效果,结果表明,在PSO-BP神经网络优化PID控制器的控制下,系统误差仅为0.02 MPa,误差最小,控制效果最好。

基于改进PSO-BP神经网络的教学质量评价模型

教学质量评价是教学研究中的重点之一,但已有的数学评价模型不适合解决非线性问题,神经网络模型收敛速度慢、准确率不高。针对以上问题,文中提出一种基于改进PSO(Particle Swarm Optimization)-BP(Back Propagation)神经网络的教学质量评价模型。通过引入动量和自适应学习率优化BP神经网络,采用惯性权重线性递减、学习因子异步变化,并引入速度收缩因子和自适应变异策略来优化PSO算法;再使用PSO粒子群优化算法计算BP神经网络的初始连接权重和阈值,从而提升模型的全局寻优能力和收敛速度、精度。为验证模型效果,使用评价体系指标层的10个指标数据作为模型的输入,评价结果作为输出,进行模型对比实验。实验结果表明,所提模型的准确率达到96.33%,比一般BP神经网络模型提高4.68%,比自适应BP神经网络模型提高4.07%,比PSO-BP神经网络模型提高1.2%,且收敛曲线平稳,整体性能优于其他模型,说明运用该模型能够有效地对教学质量进行评价。

基于动量自适应学习率PSO-BP神经网络的钻速预测模型研究

机械钻速(rate of penetration,ROP)是钻井作业优化和减少成本的关键因素,钻井时有效地预测ROP是提升钻进效率的关键。由于井下钻进时复杂多变的情况和地层的非均质性,通过传统的ROP方程和回归分析方法来预测钻速受到了一定的限制。为了实现对钻速的高精度预测,对现有BP (back propagation)神经网络进行优化,提出了一种新的神经网络模型,即动态自适应学习率的粒子群优化BP神经网络,利用录井数据建立目标井预测模型来对钻速进行预测。在训练过程中对BP神经网络进行优化,利用启发式算法,即附加动量法和自适应学习率,将两种方法结合起来形成动态自适应学习率的BP改进算法,提高了BP神经网络的训练速度和拟合精度,获得了更好的泛化性能。将BP神经网络与遗传优化算法(genetic algorithm,GA)和粒子群优化算法(particle swarm optimization,PSO)结合,得到优化后的动态自适应学习率BP神经网络。研究利用XX8-1-2井的录井数据进行实验,对比BP神经网络、PSO-BP神经网络、GA-BP神经网络3种不同的改进后神经网络的预测结果。实验结果表明:优化后的PSO-BP神经网络的预测性能最好,具有更高的效率和可靠性,能够有效的利用工程数据,在有一定数据采集量的区域提供较为准确的ROP预测。

Multiple-target tracking with adaptive sampling intervals for phased-array radar

A novel adaptive sampling interval algorithm for multitarget tracking is presented. This algorithm which is based on interacting multiple models incorporates the grey relational grade （GRG） into the particle swarm optimization （PSO）. Firstly, the desired tracking accuracy is set for each target. Secondly, sampling intervals are selected as particles, and then the advantage of the GRG is taken as the measurement function for resource management. Meanwhile, the fitness value of the PSO is used to measure the difference between desired tracking accuracy and estimated tracking accuracy. Finally, it is suggested that the radar should track the target whose prediction value of the next sampling interval is the smallest. Simulations show that the proposed method improves both the tracking accuracy and tracking efficiency of the phased-array radar.

基于改进PSO的无线传感器网络数据自适应聚类算法

为解决无线传感器网络数据类项过于繁杂的问题,将相似信息参量整合成独立的簇类对象集合,提出基于改进PSO的无线传感器网络数据自适应聚类算法。按照改进PSO算法的作用机制,确定欧氏距离指标的计算数值,实现对网络数据的处理。在无线传感器网络体系中定义聚类排序原则,结合相关数据样本求解自适应期望熵,完成无线传感器网络数据自适应聚类算法研究。实验结果表明,在改进PSO算法作用下,无线传感器网络数据经过整合后的簇类对象集合数量由20个减少到6个,能够解决无线传感器网络数据类项过于繁杂的问题,满足按需整合相似信息参量的实际应用需求。

Double adaptive selection strategy for MOEA/D

Since most parameter control methods are based on prior knowledge, it is difficult for them to solve various problems.In this paper, an adaptive selection method used for operators and parameters is proposed and named double adaptive selection(DAS) strategy. Firstly, some experiments about the operator search ability are given and the performance of operators with different donate vectors is analyzed. Then, DAS is presented by inducing the upper confidence bound strategy, which chooses suitable combination of operators and donates sets to optimize solutions without prior knowledge. Finally, the DAS is used under the framework of the multi-objective evolutionary algorithm based on decomposition, and the multi-objective evolutionary algorithm based on DAS(MOEA/D-DAS) is compared to state-of-the-art MOEAs. Simulation results validate that the MOEA/D-DAS could select the suitable combination of operators and donate sets to optimize problems and the proposed algorithm has better convergence and distribution.

Multi-objective workflow scheduling in cloud system based on cooperative multi-swarm optimization algorithm

In order to improve the performance of multi-objective workflow scheduling in cloud system, a multi-swarm multiobjective optimization algorithm(MSMOOA) is proposed to satisfy multiple conflicting objectives. Inspired by division of the same species into multiple swarms for different objectives and information sharing among these swarms in nature, each physical machine in the data center is considered a swarm and employs improved multi-objective particle swarm optimization to find out non-dominated solutions with one objective in MSMOOA. The particles in each swarm are divided into two classes and adopt different strategies to evolve cooperatively. One class of particles can communicate with several swarms simultaneously to promote the information sharing among swarms and the other class of particles can only exchange information with the particles located in the same swarm. Furthermore, in order to avoid the influence by the elastic available resources, a manager server is adopted in the cloud data center to collect the available resources for scheduling. The quality of the proposed method with other related approaches is evaluated by using hybrid and parallel workflow applications. The experiment results highlight the better performance of the MSMOOA than that of compared algorithms.

Multi-objective reconfigurable production line scheduling for smart home appliances

In a typical discrete manufacturing process,a new type of reconfigurable production line is introduced,which aims to help small-and mid-size enterprises to improve machine utilization and reduce production cost.In order to effectively handle the production scheduling problem for the manufacturing system,an improved multi-objective particle swarm optimization algorithm based on Brownian motion(MOPSO-BM)is proposed.Since the existing MOPSO algorithms are easily stuck in the local optimum,the global search ability of the proposed method is enhanced based on the random motion mechanism of the BM.To further strengthen the global search capacity,a strategy of fitting the inertia weight with the piecewise Gaussian cumulative distribution function(GCDF)is included,which helps to maintain an excellent convergence rate of the algorithm.Based on the commonly used indicators generational distance(GD)and hypervolume(HV),we compare the MOPSO-BM with several other latest algorithms on the benchmark functions,and it shows a better overall performance.Furthermore,for a real reconfigurable production line of smart home appliances,three algorithms,namely non-dominated sorting genetic algorithm-II(NSGA-II),decomposition-based MOPSO(dMOPSO)and MOPSO-BM,are applied to tackle the scheduling problem.It is demonstrated that MOPSO-BM outperforms the others in terms of convergence rate and quality of solutions.

Edge Detection of COVID-19 CT Image Based on GF_SSR, Improved Multiscale Morphology, and Adaptive Threshold

Edge detection is an effective method for image segmentation and feature extraction.Therefore,extracting weak edges with the inhomogeneous gray of Corona Virus Disease 2019(COVID-19)CT images is extremely important.Multiscale morphology has been widely used in the edge detection of medical images due to its excellent boundary detection accuracy.In this paper,we propose a weak edge detection method based on Gaussian filtering and singlescale Retinex(GF_SSR),and improved multiscale morphology and adaptive threshold binarization(IMSM_ATB).As all the CT images have noise,we propose to remove image noise by Gaussian filtering.The edge of CT images is enhanced using the SSR algorithm.In addition,based on the extracted edge of CT images using improved Multiscale morphology,a particle swarm optimization(PSO)algorithm is introduced to binarize the image by automatically getting the optimal threshold.To evaluate our method,we use images from three datasets,namely COVID-19,Kaggle-COVID-19,and COVID-Chestxray,respectively.The average values of results are worthy of reference,with the Shannon information entropy of 1.8539,the Precision of 0.9992,the Recall of 0.8224,the F-Score of 1.9158,running time of 11.3000.Finally,three types of lesion images in the COVID-19 dataset are selected to evaluate the visual effects of the proposed algorithm.Compared with the other four algorithms,the proposed algorithm effectively detects the weak edge of the lesion and provides help for image segmentation and feature extraction.