Solar Radiation Estimation Based on a New Combined Approach of Artificial Neural Networks (ANN) and Genetic Algorithms (GA) in South Algeria

When designing solar systems and assessing the effectiveness of their many uses,estimating sun irradiance is a crucial first step.This study examined three approaches(ANN,GA-ANN,and ANFIS)for estimating daily global solar radiation(GSR)in the south of Algeria:Adrar,Ouargla,and Bechar.The proposed hybrid GA-ANN model,based on genetic algorithm-based optimization,was developed to improve the ANN model.The GA-ANN and ANFIS models performed better than the standalone ANN-based model,with GA-ANN being better suited for forecasting in all sites,and it performed the best with the best values in the testing phase of Coefficient of Determination(R=0.9005),Mean Absolute Percentage Error(MAPE=8.40%),and Relative Root Mean Square Error(rRMSE=12.56%).Nevertheless,the ANFIS model outperformed the GA-ANN model in forecasting daily GSR,with the best values of indicators when testing the model being R=0.9374,MAPE=7.78%,and rRMSE=10.54%.Generally,we may conclude that the initial ANN stand-alone model performance when forecasting solar radiation has been improved,and the results obtained after injecting the genetic algorithm into the ANN to optimize its weights were satisfactory.The model can be used to forecast daily GSR in dry climates and other climates and may also be helpful in selecting solar energy system installations and sizes.

Topological optimization of ballistic protective structures through genetic algorithms in a vulnerability-driven environment

Reducing the vulnerability of a platform,i.e.,the risk of being affected by hostile objects,is of paramount importance in the design process of vehicles,especially aircraft.A simple and effective way to decrease vulnerability is to introduce protective structures to intercept and possibly stop threats.However,this type of solution can lead to a significant increase in weight,affecting the performance of the aircraft.For this reason,it is crucial to study possible solutions that allow reducing the vulnerability of the aircraft while containing the increase in structural weight.One possible strategy is to optimize the topology of protective solutions to find the optimal balance between vulnerability and the weight of the added structures.Among the many optimization techniques available in the literature for this purpose,multiobjective genetic algorithms stand out as promising tools.In this context,this work proposes the use of a in-house software for vulnerability calculation to guide the process of topology optimization through multi-objective genetic algorithms,aiming to simultaneously minimize the weight of protective structures and vulnerability.In addition to the use of the in-house software,which itself represents a novelty in the field of topology optimization of structures,the method incorporates a custom mutation function within the genetic algorithm,specifically developed using a graph-based approach to ensure the continuity of the generated structures.The tool developed for this work is capable of generating protections with optimized layouts considering two different types of impacting objects,namely bullets and fragments from detonating objects.The software outputs a set of non-dominated solutions describing different topologies that the user can choose from.

SFGA-CPA: A Novel Screening Correlation Power Analysis Framework Based on Genetic Algorithm

Correlation power analysis(CPA)combined with genetic algorithms(GA)now achieves greater attack efficiency and can recover all subkeys simultaneously.However,two issues in GA-based CPA still need to be addressed:key degeneration and slow evolution within populations.These challenges significantly hinder key recovery efforts.This paper proposes a screening correlation power analysis framework combined with a genetic algorithm,named SFGA-CPA,to address these issues.SFGA-CPA introduces three operations designed to exploit CPA characteris-tics:propagative operation,constrained crossover,and constrained mutation.Firstly,the propagative operation accelerates population evolution by maximizing the number of correct bytes in each individual.Secondly,the constrained crossover and mutation operations effectively address key degeneration by preventing the compromise of correct bytes.Finally,an intelligent search method is proposed to identify optimal parameters,further improving attack efficiency.Experiments were conducted on both simulated environments and real power traces collected from the SAKURA-G platform.In the case of simulation,SFGA-CPA reduces the number of traces by 27.3%and 60%compared to CPA based on multiple screening methods(MS-CPA)and CPA based on simple GA method(SGA-CPA)when the success rate reaches 90%.Moreover,real experimental results on the SAKURA-G platform demonstrate that our approach outperforms other methods.

Appropriate Combination of Crossover Operator and Mutation Operator in Genetic Algorithms for the Travelling Salesman Problem

Genetic algorithms(GAs)are very good metaheuristic algorithms that are suitable for solving NP-hard combinatorial optimization problems.AsimpleGAbeginswith a set of solutions represented by a population of chromosomes and then uses the idea of survival of the fittest in the selection process to select some fitter chromosomes.It uses a crossover operator to create better offspring chromosomes and thus,converges the population.Also,it uses a mutation operator to explore the unexplored areas by the crossover operator,and thus,diversifies the GA search space.A combination of crossover and mutation operators makes the GA search strong enough to reach the optimal solution.However,appropriate selection and combination of crossover operator and mutation operator can lead to a very good GA for solving an optimization problem.In this present paper,we aim to study the benchmark traveling salesman problem(TSP).We developed several genetic algorithms using seven crossover operators and six mutation operators for the TSP and then compared them to some benchmark TSPLIB instances.The experimental studies show the effectiveness of the combination of a comprehensive sequential constructive crossover operator and insertion mutation operator for the problem.The GA using the comprehensive sequential constructive crossover with insertion mutation could find average solutions whose average percentage of excesses from the best-known solutions are between 0.22 and 14.94 for our experimented problem instances.

Generating of Test Data by Harmony Search Against Genetic Algorithms

Many search-based algorithms have been successfully applied in sev-eral software engineering activities.Genetic algorithms(GAs)are the most used in the scientific domains by scholars to solve software testing problems.They imi-tate the theory of natural selection and evolution.The harmony search algorithm(HSA)is one of the most recent search algorithms in the last years.It imitates the behavior of a musician tofind the best harmony.Scholars have estimated the simi-larities and the differences between genetic algorithms and the harmony search algorithm in diverse research domains.The test data generation process represents a critical task in software validation.Unfortunately,there is no work comparing the performance of genetic algorithms and the harmony search algorithm in the test data generation process.This paper studies the similarities and the differences between genetic algorithms and the harmony search algorithm based on the ability and speed offinding the required test data.The current research performs an empirical comparison of the HSA and the GAs,and then the significance of the results is estimated using the t-Test.The study investigates the efficiency of the harmony search algorithm and the genetic algorithms according to(1)the time performance,(2)the significance of the generated test data,and(3)the adequacy of the generated test data to satisfy a given testing criterion.The results showed that the harmony search algorithm is significantly faster than the genetic algo-rithms because the t-Test showed that the p-value of the time values is 0.026<α(αis the significance level=0.05 at 95%confidence level).In contrast,there is no significant difference between the two algorithms in generating the adequate test data because the t-Test showed that the p-value of thefitness values is 0.25>α.

Optimizing Region of Interest Selection for Effective Embedding in Video Steganography Based on Genetic Algorithms

With the widespread use of the internet,there is an increasing need to ensure the security and privacy of transmitted data.This has led to an intensified focus on the study of video steganography,which is a technique that hides data within a video cover to avoid detection.The effectiveness of any steganography method depends on its ability to embed data without altering the original video’s quality while maintaining high efficiency.This paper proposes a new method to video steganography,which involves utilizing a Genetic Algorithm(GA)for identifying the Region of Interest(ROI)in the cover video.The ROI is the area in the video that is the most suitable for data embedding.The secret data is encrypted using the Advanced Encryption Standard(AES),which is a widely accepted encryption standard,before being embedded into the cover video,utilizing up to 10%of the cover video.This process ensures the security and confidentiality of the embedded data.The performance metrics for assessing the proposed method are the Peak Signalto-Noise Ratio(PSNR)and the encoding and decoding time.The results show that the proposed method has a high embedding capacity and efficiency,with a PSNR ranging between 64 and 75 dBs,which indicates that the embedded data is almost indistinguishable from the original video.Additionally,the method can encode and decode data quickly,making it efficient for real-time applications.

基于SPA-GA-SVR模型的土壤水分及温度预测

土壤湿度和温度是影响水文循环和气候变化的重要参数,在农业实践活动和生态平衡中起着重要作用。为及时、准确地监测土壤含水量(Soil Moisture Content,SMC)及温度,提出了一种基于高光谱数据的预测方法。实验数据集来自为期5天的实地测量,所获得的高光谱数据包含大量的噪声及冗余信息,因此首先用Savitzky-Golay卷积平滑对光谱数据进行降噪处理,利用连续投影算法(Successive Projection Algorithm,SPA)提取数据特征波长,然后通过遗传算法(Genetic Algorithm,GA)对支持向量机回归(Support Vector Regression,SVR)的超参数权值和偏置进行优化,构建SPA-GASVR混合算法模型对土壤水分和温度进行预测,并与BP神经网络(Back Propagation Neural Network,BPNN)、SPA-BP、SVR、SPA-SVR、GA-SVR这5种模型的预测性能进行比较。实验结果表明:各模型在土壤湿度低于30%的情况下,表现出的预测能力差异并不显著。但整体上,复合模型相比于单一的神经网络或机器学习模型具有明显的优势,且经过连续投影算法优化的模型进一步的提高其预测能力,最终SPA-GA-SVR算法在各项指标上均优于其他模型,土壤水分预测模型的R^(2)=0.981、RMSE=0.473%,土壤温度预测模型R^(2)=0.963、RMSE=0.883℃。实验证明基于高光谱数据,经过SPA和GA优化的SVR模型能实现对土壤湿度和温度精准的预测。该方法具有一定的应用价值和现实意义,可应用于便携式高光谱仪和无人机上,实现对土壤水分和温度的实时监测,为今后的播种及灌溉提供理论参考。

正交实验结合AHP和GA-BP神经网络优化益黄散醇提工艺

目的 优化益黄散的醇提工艺。方法 采用回流提取法,以乙醇体积分数、液料比、提取时间为考察因素设计正交实验,以橙皮苷、川陈皮素、橘皮素、没食子酸、诃黎勒酸、诃子酸、甘草苷、甘草酸、丁香酚含量和干浸膏得率为指标,采用层次分析法(AHP)进行赋权并计算综合评分。通过验证正交实验和遗传算法(GA)-反向传播神经网络(BP神经网络)所预测的结果确定益黄散最佳醇提工艺参数。结果 正交实验优选的最佳醇提工艺参数为乙醇体积分数60%、液料比14∶1(mL/g)、提取时间90 min、提取2次,验证所得综合评分为79.19分;GA-BP神经网络优选的最佳醇提工艺参数为乙醇体积分数65%、液料比14∶1(mL/g)、提取时间60 min、提取2次,验证所得综合评分为85.30分,高于正交实验所得结果。结论 采用正交实验结合GA-BP神经网络的寻优方法较传统的正交实验寻优方法效果更佳,其优选出的益黄散最佳醇提工艺稳定可靠。

基于AESL-GA的BN球磨机滚动轴承故障诊断方法

针对基于知识的贝叶斯网络(BN)构建方法存在不完全和不精确的缺点,提出一种基于知识引导和数据挖掘的BN结构构建方法。针对单一信号故障诊断结果不精确的问题和故障信息中存在的不确定性问题,将电流信号与振动信号融合建立BN的特征节点,分别提取2种信号的故障特征参数,利用区分度指标法进行特征筛选,将其作为BN结构特征层的节点。将专家知识构建的初始BN结构结合自适应精英结构遗传算法(AESL-GA)进行结构优化,通过自适应限制进化过程中的搜索空间,减少自由参数的数量,提高其全局搜索能力,得到最优BN结构。通过MQY5585溢流型球磨机滚动轴承实测数据和Paderborn University轴承数据集对所提方法进行验证,结果证明了所提方法的有效性。

基于GA-LSTM自适应卡尔曼滤波的路面不平度识别

准确、快速地识别出车辆当前行驶的路面激励信息,是实现智能底盘控制进而保证车辆平顺性的关键。针对传统路面不平度识别算法准确率低、自适应性差等问题,提出了基于遗传算法(genetic algorithm,GA)优化长短期记忆神经网络(long short-term memory networks,LSTM)自适应卡尔曼滤波的路面不平度识别算法。基于2自由度车辆悬架模型,通过灰色关联法选择LSTM神经网络的特征输入变量,并采用GA优化LSTM神经网络的模型参数以准确识别路面等级,并据此实时更新卡尔曼滤波器算法中的噪声矩阵,实现了在复杂路况下对路面不平度的自适应识别。仿真和试验研究表明,所提出的基于GA-LSTM自适应卡尔曼滤波算法能够快速准确的识别路面不平度与路面等级,与传统卡尔曼滤波算法相比,相关系数、均方根误差和最大绝对误差分别提高3.11%、37.5%和51.2%,表明所提算法对复杂工况具有很好的自适应能力。

基于NSGA-Ⅱ遗传算法的Myring流线型量水槽体型优化设计

Myring流线型在水下航行器领域应用较为广泛,而量水槽在渠道中的受阻状态与潜水器潜行时受到的阻力情况具有一定的相似之处,因此本文借鉴潜水器的结构特点进行量水槽体型设计,探究量水槽受阻最小的较优线型。基于FLOW-3D软件,采用最优拉丁超立方设计方法,以流线型的收缩段长度和锐度因子、扩散段长度和离去角为变量设计了40组数值模拟方案,得到对应的水头损失百分比和上游佛汝德数。以数值模拟变量为输入、结果为输出,训练RBF神经网络,结合NSGA-Ⅱ遗传算法获得Patero前沿解,通过TOPSIS评价法筛选出最优解并得出其线形参数:优化模型收缩段长度为45.9 cm、收缩段锐度因子为0.74、扩散段长度为49.2 cm、扩散段离去角为14.63°,并通过等比例缩放得到6组收缩比,在9组流量下进行模型试验分析水力性能。结果表明,优化后线型过流较顺畅,水力性能较优,预测结果和模拟结果误差不超过5%;不同工况下上游佛汝德数均小于0.5,满足测流规范要求,收缩比为0.58~0.66时各项水力性能均较优;基于临界流测流和量纲分析原理得到的测流公式精度较高,平均相对误差为2.09%。本研究证明了将流线型运用于量水槽领域研究以及通过神经网络和遗传算法寻优的可行性,优化后Myring流线型量水槽具有良好的性能和测流精度,在灌区渠道中具有较好的运用前景。

基于VMD-GA-BiLSTM的月降水量预测方法

利用辽宁省气象局提供的地面观测降水资料,构建了具有多元时间特征的降水数据,采用变分模态分解方法(variational mode decomposition,VMD)组合遗传算法(genetic algorithm,GA)对双向长短时记忆神经网络(bidirectional long short-term memory,BiLSTM)进行优化,建立基于VMD-GA-BiLSTM的月降水量预测模型,并与BiLSTM、VMD-BiLSTM和GA-BiLSTM进行实验对比,应用均方根误差(root mean square error,RMSE)、平均绝对误差(mean absolute error,MAE)和R 2决定系数作为模型评价指标。实验结果表明:VMD-GA-BiLSTM模型的R 2决定系数达到0.98,RMSE和MAE表现更低,验证了VMD-GA-BiLSTM模型在时间序列预测方面的优势。

基于GA-BLS方法的手势识别研究

为进一步提升人机交互领域中手势识别的精度和速度,探究肌肉疲劳对手势识别的影响规律,提出了改进的GA-BLS方法,利用遗传算法(genetic algorithms,GA)优化宽度学习(broad learning system,BLS)模型参数,并使用弹性网络回归改进传统的BLS模型。利用所提模型对8种手势下的A型超声信号和肌电信号进行手势识别分析,并与SVM、KNN、RF、LDA等方法进行对比,以验证所研究方法的有效性;将长时间段下的A型超声信号和肌电信号切分成4个数据段,发现随着肌肉疲劳程度的增加,手势识别的准确率均呈现出明显下降的趋势,而且A型超声信号相较于肌电信号具有更好的抗疲劳特性。

基于NSGA-Ⅱ的飞轮-火电联合二次调频最优负荷分配策略

为了在提升飞轮-火电联合二次调频性能的同时控制调频成本、减少飞轮损耗,面向飞轮-火电联合系统,提出一种考虑自动发电控制(AGC)指令及电网频率偏差的基于多目标遗传算法的负荷分配策略。该策略以电网调频偏差、飞轮-火电出力能量和、飞轮损耗为三层最小化目标,考虑火电机组爬坡率及其负荷备用、飞轮荷电状态及其功率等约束条件,基于改进的非支配排序遗传算法(NSGA-Ⅱ),通过AGC功率指令变化速度及频率偏差动态调整飞轮与火电出力权重系数,以频率偏差及其变化方向调整飞轮虚拟下垂、惯性系数,求解飞轮-火电出力比例、飞轮下垂系数和飞轮惯性系数。结合中国宁夏某电厂飞轮储能系统辅助火电机组调频现场AGC指令等历史数据,在双区域两机系统模型上进行仿真实验,结果表明该负荷分配策略有效地减小了火电二次调频偏差和调节时间,提升了调频性能,同时也有效地控制了系统出力能量及飞轮损耗。

基于GA的RBF神经网络气液两相流持液率预测模型优化

为了提高气液两相流持液率预测精度,针对传统径向基函数(RBF)神经网络预测气液两相流持液率网络拓扑结构困难和收敛速度慢等问题,提出一种基于遗传算法(GA)优化径向基函数神经网络的气液两相流持液率预测模型。通过系统聚类算法和灰色关联度分析(GRA)对收集的实验数据进行处理,优选出最优模型特征,同时结合遗传算法确定了RBF神经网络结构参数。基于室内实验数据进行训练,并与常用于持液率预测的反向传播(BP)神经网络、GA-BP神经网络及RBF神经网络进行对比,评估了模型的准确性及可行性。结果表明:GA-RBF神经网络模型均方误差为0.0017,均方根误差为0.0416,平均绝对误差为0.0281,拟合度为0.9483。相较于其他神经网络模型,该预测模型表现出更高的计算精度和更强的泛化能力。

基于GA-BP神经网络的大型客机气流角估计方法

为了解决硬件冗余难以克服的气流角传感器共因故障问题,进一步提高飞机气流角信号的可靠性,研究了基于GABP神经网络的气流角估计方法。通过BP神经网络融合姿态角、加速度、风速等参数来实现不依赖气流角传感器的气流角估计;引入遗传算法对神经网络权值和阈值进行全局优化,提高估计精度;对某大型客机的试飞数据预处理后用于模型的训练和测试。仿真结果表明,训练完成的GA-BP神经网络模型对气流角的估计值贴近实际值,稳定性和精度明显高于BP神经网络。上述方法给飞机增加一个余度的气流角信号,可用于传感器故障时为飞机提供可靠的气流角信号。

基于GA-SVM的钢轨廓形类型在线识别算法研究

针对轨道交通日常运维中钢轨廓形自动化检测识别率不高的情况,提出了一种基于几何描述符和支持向量机(SVM)的高精度钢轨廓形在线识别算法。利用结构光传感器对钢轨廓形数据进行采集,采用几何去噪算法对廓形进行离群点剔除和重采样预处理。通过廓形几何描述符对不同类别钢轨廓形进行特征提取,制作廓形特征数据集用于训练SVM。采用遗传算法(GA)对SVM模型参数进行优化选取。将优化训练后的SVM模型用于钢轨廓形检测并和传统廓形识别方法进行对比。结果表明:提出的采用几何描述符的GA-SVM模型平均准确率达到99.62%,单帧廓形识别用时6.43 ms,能有效提升廓形识别准确率与高速性,满足轨道车辆在线检测的需求,并为轨道自动化检测提供了理论和技术支撑。

基于GA-PSO混合优化SVR的边坡危岩体稳定性评价模型

边坡危岩体稳定性评价是地质灾害防治的重要内容之一。传统的稳定性评价方法在求解复杂非线性问题时存在着精度较低、收敛速度慢等问题,为此,提出了一种基于GA-PSO混合优化支持向量回归(SVR)的边坡危岩体稳定性评价模型。首先,通过采集大量的实测数据和监测数据,建立了边坡危岩体的训练样本集;然后,将SVR算法引入稳定性评价中,利用其非线性映射性能拟合边坡危岩体的稳定性函数。为提高SVR模型的优化能力,将遗传算法(GA)和粒子群优化算法(PSO)相结合,形成了GA-PSO混合优化算法,并用于求解SVR模型中的优化问题。选取了多个现场实际边坡危岩体工程案例进行了算法测试。结果表明:相对于传统方法,GA-PSO混合优化SVR模型能够准确预测边坡危岩体的稳定性,并且具有较高的精度和较快的收敛速度。

车轴滚齿加工工艺参数GA-BP模型NSGA-Ⅱ优化

研究了高速条件下的滚齿工艺参数设置与优化方面的工作,采用新的非支配遗传算法NSGA-Ⅱ设计了相应的优化数学模型,优化达到最低能耗以及最长的刀具使用期限,再以遗传反向传播算法(GABP)神经网络为目标设置预测模型并建立适应度函数,完成迭代优化后获得匹配滚齿工艺的Pareto最优条件。研究结果表明:这里预测模型经过5次循环计算后,均方差为10-5,得到0.000425的最优值,推断上述网络满足良好的稳定性。刀具寿命误差相对后者降低16%,降低了36%的能量损耗,发现GABP算法具备更优收敛能力。Pareto解集获得了比相近加工样本集更优的性能,因此采用多目标优化模型可以确保加工能耗和刀具使用寿命同时达到最佳状态。该研究对提高的滚齿加工工艺参数以及提高机加工效率具有很好的实际应用价值。

基于EGA优化的农用UTV半主动悬架最优控制

针对UTV在恶劣路面行驶引起的车辆振动,以某款农用UTV悬架系统为对象,建立包含俯仰的四自由度(4-DOF)半车半主动悬架动力学模型,并提出一种EGA-LQR复合控制策略,设计满足物理约束的悬架系统自适应最优控制器。利用EGA算法的全局寻优与快速收敛特性,对LQR最优控制器的权重矩阵寻优,输出悬架系统最优控制阻尼力。在Matlab/Simulink中搭建UTV的路面与悬架模型进行时域仿真,仿真分析结果表明,EGA-LQR控制显著减小了车体质心垂向振动加速度、车体俯仰角加速度、前后轮动位移以及前后悬架动行程的均方根值,有效保证了UTV在农田路面下行驶的舒适性与安全性。