Effective Hybrid Teaching-learning-based Optimization Algorithm for Balancing Two-sided Assembly Lines with Multiple Constraints

Due to the NP-hardness of the two-sided assembly line balancing （TALB） problem, multiple constraints existing in real applications are less studied, especially when one task is involved with several constraints. In this paper, an effective hybrid algorithm is proposed to address the TALB problem with multiple constraints （TALB-MC）. Considering the discrete attribute of TALB-MC and the continuous attribute of the standard teaching-learning-based optimization （TLBO） algorithm, the random-keys method is hired in task permutation representation, for the purpose of bridging the gap between them. Subsequently, a special mechanism for handling multiple constraints is developed. In the mechanism, the directions constraint of each task is ensured by the direction check and adjustment. The zoning constraints and the synchronism constraints are satisfied by teasing out the hidden correlations among constraints. The positional constraint is allowed to be violated to some extent in decoding and punished in cost fimction. Finally, with the TLBO seeking for the global optimum, the variable neighborhood search （VNS） is further hybridized to extend the local search space. The experimental results show that the proposed hybrid algorithm outperforms the late acceptance hill-climbing algorithm （LAHC） for TALB-MC in most cases, especially for large-size problems with multiple constraints, and demonstrates well balance between the exploration and the exploitation. This research proposes an effective and efficient algorithm for solving TALB-MC problem by hybridizing the TLBO and VNS.

Hyperparameter Tuning for Deep Neural Networks Based Optimization Algorithm

For training the present Neural Network(NN)models,the standard technique is to utilize decaying Learning Rates(LR).While the majority of these techniques commence with a large LR,they will decay multiple times over time.Decaying has been proved to enhance generalization as well as optimization.Other parameters,such as the network’s size,the number of hidden layers,drop-outs to avoid overfitting,batch size,and so on,are solely based on heuristics.This work has proposed Adaptive Teaching Learning Based(ATLB)Heuristic to identify the optimal hyperparameters for diverse networks.Here we consider three architec-tures Recurrent Neural Networks(RNN),Long Short Term Memory(LSTM),Bidirectional Long Short Term Memory(BiLSTM)of Deep Neural Networks for classification.The evaluation of the proposed ATLB is done through the various learning rate schedulers Cyclical Learning Rate(CLR),Hyperbolic Tangent Decay(HTD),and Toggle between Hyperbolic Tangent Decay and Triangular mode with Restarts(T-HTR)techniques.Experimental results have shown the performance improvement on the 20Newsgroup,Reuters Newswire and IMDB dataset.

Policy Optimization Study Based on Evolutionary Learning

In order to achieve an intelligent and automated self-management network,dynamic policy configuration and selection are needed.A certain policy only suits to a certain network environment.If the network environment changes,the certain policy does not suit any more.Thereby,the policy-based management should also have similar "natural selection" process.Useful policy will be retained,and policies which have lost their effectiveness are eliminated.A policy optimization method based on evolutionary learning was proposed.For different shooting times,the priority of policy with high shooting times is improved,while policy with a low rate has lower priority,and long-term no shooting policy will be dormant.Thus the strategy for the survival of the fittest is realized,and the degree of self-learning in policy management is improved.

Battle Royale Optimization with Fuzzy Deep Learning for Arabic Sentiment Classification

Aspect-Based Sentiment Analysis(ABSA)on Arabic corpus has become an active research topic in recent days.ABSA refers to a fine-grained Sentiment Analysis(SA)task that focuses on the extraction of the conferred aspects and the identification of respective sentiment polarity from the provided text.Most of the prevailing Arabic ABSA techniques heavily depend upon dreary feature-engineering and pre-processing tasks and utilize external sources such as lexicons.In literature,concerning the Arabic language text analysis,the authors made use of regular Machine Learning(ML)techniques that rely on a group of rare sources and tools.These sources were used for processing and analyzing the Arabic language content like lexicons.However,an important challenge in this domain is the unavailability of sufficient and reliable resources.In this background,the current study introduces a new Battle Royale Optimization with Fuzzy Deep Learning for Arabic Aspect Based Sentiment Classification(BROFDL-AASC)technique.The aim of the presented BROFDL-AASC model is to detect and classify the sentiments in the Arabic language.In the presented BROFDL-AASC model,data pre-processing is performed at first to convert the input data into a useful format.Besides,the BROFDL-AASC model includes Discriminative Fuzzy-based Restricted Boltzmann Machine(DFRBM)model for the identification and categorization of sentiments.Furthermore,the BRO algorithm is exploited for optimal fine-tuning of the hyperparameters related to the FBRBM model.This scenario establishes the novelty of current study.The performance of the proposed BROFDL-AASC model was validated and the outcomes demonstrate the supremacy of BROFDL-AASC model over other existing models.

Ensemble Based Learning with Accurate Motion Contrast Detection

Recent developments in computer vision applications have enabled detection of significant visual objects in video streams.Studies quoted in literature have detected objects from video streams using Spatiotemporal Particle Swarm Optimization(SPSOM)and Incremental Deep Convolution Neural Networks(IDCNN)for detecting multiple objects.However,the study considered opticalflows resulting in assessing motion contrasts.Existing methods have issue with accuracy and error rates in motion contrast detection.Hence,the overall object detection performance is reduced significantly.Thus,consideration of object motions in videos efficiently is a critical issue to be solved.To overcome the above mentioned problems,this research work proposes a method involving ensemble approaches to and detect objects efficiently from video streams.This work uses a system modeled on swarm optimization and ensemble learning called Spatiotemporal Glowworm Swarm Optimization Model(SGSOM)for detecting multiple significant objects.A steady quality in motion contrasts is maintained in this work by using Chebyshev distance matrix.The proposed system achieves global optimization in its multiple object detection by exploiting spatial/temporal cues and local constraints.Its experimental results show that the proposed system scores 4.8%in Mean Absolute Error(MAE)while achieving 86%in accuracy,81.5%in precision,85%in recall and 81.6%in F-measure and thus proving its utility in detecting multiple objects.

An Overview of Recently Developed Coupled Simulation Optimization Approaches for Reliability Based Minimum Cost Design of Water Retaining Structures

This paper reviews several recently-developed techniques for the minimum-cost optimal design of water-retaining structures (WRSs), which integrate the effects of seepage. These include the incorporation of uncertainty in heterogeneous soil parameter estimates and quantification of reliability. This review is limited to methods based on coupled simulation-optimization (S-O) models. In this context, the design of WRSs is mainly affected by hydraulic design variables such as seepage quantities, which are difficult to determine from closed-form solutions or approximation theories. An S-O model is built by integrating numerical seepage modeling responses to an optimization algorithm based on efficient surrogate models. The surrogate models (meta-models) are trained on simulated data obtained from finite element numerical code solutions. The proposed methodology is applied using several machine learning techniques and optimization solvers to optimize the design of WRS by incorporating different design variables and boundary conditions. Additionally, the effects of several scenarios of flow domain hydraulic conductivity are integrated into the S-O model. Also, reliability based optimum design concepts are incorporated in the S-O model to quantify uncertainty in seepage quantities due to uncertainty in hydraulic conductivity estimates. We can conclude that the S-O model can efficiently optimize WRS designs. The ANN, SVM, and GPR machine learning technique-based surrogate models are efficiently and expeditiously incorporated into the S-O models to imitate the numerical responses of simulations of various problems.

An Experimental Investigation into the Amalgamated Al2O3-40% TiO2 Atmospheric Plasma Spray Coating Process on EN24 Substrate and Parameter Optimization Using TLBO

Surface coating is a critical procedure in the case of maintenance engineering. Ceramic coating of the wear areas is of the best practice which substantially enhances the Mean Time between Failure (MTBF). EN24 is a commercial grade alloy which is used for various industrial applications like sleeves, nuts, bolts, shafts, etc. EN24 is having comparatively low corrosion resistance, and ceramic coating of the wear and corroding areas of such parts is a best followed practice which highly improves the frequent failures. The coating quality mainly depends on the coating thickness, surface roughness and coating hardness which finally decides the operability. This paper describes an experimental investigation to effectively optimize the Atmospheric Plasma Spray process input parameters of Al2O3-40% TiO2 coatings to get the best quality of coating on EN24 alloy steel substrate. The experiments are conducted with an Orthogonal Array (OA) design of experiments (DoE). In the current experiment, critical input parameters are considered and some of the vital output parameters are monitored accordingly and separate mathematical models are generated using regression analysis. The Analytic Hierarchy Process (AHP) method is used to generate weights for the individual objective functions and based on that, a combined objective function is made. An advanced optimization method, Teaching-Learning-Based Optimization algorithm (TLBO), is practically utilized to the combined objective function to optimize the values of input parameters to get the best output parameters. Confirmation tests are also conducted and their output results are compared with predicted values obtained through mathematical models. The dominating effects of Al2O3-40% TiO2 spray parameters on output parameters: surface roughness, coating thickness and coating hardness are discussed in detail. It is concluded that the input parameters variation directly affects the characteristics of output parameters and any number of input as well as output parameters can be easily optimized using the current approach.

Parameter Optimization of Amalgamated Al2O3-40% TiO2 Atmospheric Plasma Spray Coating on SS304 Substrate Using TLBO Algorithm

SS304 is a commercial grade stainless steel which is used for various engineering applications like shafts, guides, jigs, fixtures, etc. Ceramic coating of the wear areas of such parts is a regular practice which significantly enhances the Mean Time Between Failure (MTBF). The final coating quality depends mainly on the coating thickness, surface roughness and hardness which ultimately decides the life. This paper presents an experimental study to effectively optimize the Atmospheric Plasma Spray (APS) process input parameters of Al2O3-40% TiO2 ceramic coatings to get the best quality of coating on commercial SS304 substrate. The experiments are conducted with a three-level L18 Orthogonal Array (OA) Design of Experiments (DoE). Critical input parameters considered are: spray nozzle distance, substrate rotating speed, current of the arc, carrier gas flow and coating powder flow rate. The surface roughness, coating thickness and hardness are considered as the output parameters. Mathematical models are generated using regression analysis for individual output parameters. The Analytic Hierarchy Process (AHP) method is applied to generate weights for the individual objective functions and a combined objective function is generated. An advanced optimization method, Teaching-Learning-Based Optimization algorithm (TLBO), is applied to the combined objective function to optimize the values of input parameters to get the best output parameters and confirmation tests are conducted based on that. The significant effects of spray parameters on surface roughness, coating thickness and coating hardness are studied in detail.

Optimal Deep Belief Network Enabled Cybersecurity Phishing Email Classification

Recently,developments of Internet and cloud technologies have resulted in a considerable rise in utilization of online media for day to day lives.It results in illegal access to users’private data and compromises it.Phishing is a popular attack which tricked the user into accessing malicious data and gaining the data.Proper identification of phishing emails can be treated as an essential process in the domain of cybersecurity.This article focuses on the design of bio-geography based optimization with deep learning for Phishing Email detection and classification(BBODL-PEDC)model.The major intention of the BBODL-PEDC model is to distinguish emails between legitimate and phishing.The BBODL-PEDC model initially performs data pre-processing in three levels namely email cleaning,tokenization,and stop word elimination.Besides,TF-IDF model is applied for the extraction of useful feature vectors.Moreover,optimal deep belief network(DBN)model is used for the email classification and its efficacy can be boosted by the BBO based hyperparameter tuning process.The performance validation of the BBODL-PEDC model can be performed using benchmark dataset and the results are assessed under several dimensions.Extensive comparative studies reported the superior outcomes of the BBODL-PEDC model over the recent approaches.

A heuristic clustering algorithm based on high density-connected partitions

Clustering data with varying densities and complicated structures is important,while many existing clustering algorithms face difficulties for this problem. The reason is that varying densities and complicated structure make single algorithms perform badly for different parts of data. More intensive parts are assumed to have more information probably,an algorithm clustering from high density part is proposed,which begins from a tiny distance to find the highest density-connected partition and form corresponding super cores,then distance is iteratively increased by a global heuristic method to cluster parts with different densities. Mean of silhouette coefficient indicates the cluster performance. Denoising function is implemented to eliminate influence of noise and outliers. Many challenging experiments indicate that the algorithm has good performance on data with widely varying densities and extremely complex structures. It decides the optimal number of clusters automatically.Background knowledge is not needed and parameters tuning is easy. It is robust against noise and outliers.

基于新搜索策略的改进法医调查算法

为解决法医搜索算法的搜索方程存在振荡等问题,构建一种改进的法医调查算法。引入均值机制和莱维飞行策略对分析调查结果进行改进,提高算法的勘探能力;调查方向充分使用当前个体的有效信息,引入自适应动态调整缩放因子及最优个体引导机制,增强算法的探索活力;利用趋优避劣方法对算法的追捕行动进行改进,改善种群个体质量;追捕行动扩展采用单优学习策略解决振荡问题。求解11个标准函数和无线传感网络覆盖问题的结果显示,与对比算法比较,改进算法的优化能力具有显著优势。

基于分组教与学的无人战斗机自适应路径规划

针对无人战斗机(unmanned combat air vehicle,UCAV)处于存在威胁区域的战场中路径规划问题,提出一种基于分组教与学算法的UCAV自适应路径规划方法。通过分析UCAV路径评价指标,提出一种自适应的UCAV路径评价模型,根据作战环境规划出距离短、威胁小的任务路径。针对教与学算法寻优精度低、耗时长的问题,提出一种分组教与学算法,引入动态分组和高斯分布扰动策略,提高算法寻优性能。通过仿真实验,该方案求解的最优路径更短且安全。

不均衡小样本下多特征优化选择的生命体触电故障识别方法

针对现有的剩余电流保护装置无法有效识别触电事故的问题,该文提出了一种不均衡小样本下多特征优化选择的生命体触电故障识别方法。首先通过变分自编码器(VAE)对实验收集到的生命体触电小样本数据进行增殖以实现正负样本均衡;然后在时域上提取能够反映波形动态变化特性的23个特征量,并利用高斯核Fisher判别分析(GKFDA)与最大信息系数(MIC)法从中选择最优表达特征组;最后,提出基于遗忘因子的在线顺序极限学习机(FOS-ELM)算法实现生命体触电行为的鉴别。实验结果表明,所提方法利用不均衡小样本触电数据集就可以训练出一个优秀的分类模型,诊断准确率可达98.75%,诊断时间仅为1.33 ms。其优良的性能结合在线增量式学习分类器设计,使得模型具备新知识学习能力,具有极好的工程应用前景。

基于RegNet-CSAM与ZOA-KELM模型的滚动轴承故障诊断

针对现有深度卷积神经网络对滚动轴承混合故障诊断效果不佳以及模型复杂度过高导致计算成本过大等问题,提出了一种基于RegNet-CSAM与ZOA-KELM模型的滚动轴承故障诊断方法。该模型由RegNet-CSAM网络和ZOA-KELM分类算法组成。首先,将融合了通道和空间特征的注意力机制CSAM与组卷积残差模块结合,提升该结构的表征能力,由此构建的RegNet-CSAM网络,模型复杂度为0.48GF;其次,在分类阶段将斑马优化核极限学习机(ZOA-KELM)替代原来网络中使用的Softmax函数完成最后的分类任务。滚动轴承故障诊断试验结果表明,RegNet网络对滚动轴承混合故障样本容易产生误判,CSAM的融入虽将RegNet网络的分类精度进一步提高,但是仍然存在一定程度的滚动轴承混合故障误判问题;而将ZOA-KELM替代Softmax函数后再对RegNet-CSAM网络输出特征进行分类,能够有效识别出滚动轴承的单一和混合故障,准确率达到了99.92%。所提方法对比其他网络,诊断精度最大提升5.02%,模型复杂度最大缩减32倍。

混合策略改进的风驱动优化算法

为解决风驱动优化算法存在的易陷入局部极值及收敛性差等问题,提出一种混合策略改进的风驱动优化算法。首先,使用Tent混沌映射初始化种群,增加初始个体的多样性;其次,引入柯西变异策略,扩大算法搜索范围,增强算法搜索能力并加速算法收敛;然后,利用反向学习策略生成新的全局最优解,提高算法逃离局部极值能力;最后,针对6个基准测试函数进行仿真实验,结果表明,所提算法收敛速度和精度均优于其他算法。

基于教与学优化的舰载机起飞出动动态调度

本文针对弹射器故障情形下的舰载机起飞出动调度,建立了舰载机起飞出动的多约束分布式流水线调度模型;结合基于扩展随机序解的编码和解码策略、动态调整策略,设计了基于教与学优化的舰载机起飞出动动态调度算法;最后,通过对仿真案例分析、故障预测精度对动态调度的影响分析,及动态调度算法的运行时间分析,结果验证了所设计的算法对舰载机起飞出动动态调度的可行性和有效性。

舱段主动隔振系统作动器配置优化

针对舱段主动隔振系统中作动器配置优化问题,给出一种优化模型和方法,通过数值计算进行方法验证。首先建立了多通道舱段主动隔振系统的动力学模型,然后将作动器配置优化转换为约束0-1非线性规划问题,以系统监测点响应为优化目标函数,作动器启用状态为自变量,最后采用教与学优化(teaching and learning-based optimization,TLBO)算法寻找最优配置。仿真计算结果表明,对于不同的激励,多通道主动隔振系统的最优配置不同,即存在对应给定激励下抑制壳体振动与声辐射的最优配置。

多策略融合的改进狮群算法及其工程优化

狮群算法是近年提出的一种智能优化算法,已经应用于多个领域,然而该算法仍存在搜索效率不足、易落入局部最优等问题.因此,基于狮群算法,提出了多策略融合的改进狮群算法.首先,使用Tent混沌种群的初始化方法,增强种群分布的均匀性的历遍性,提高算法初始解的质量和搜索效率;其次,采用柯西变异机制,在狮群最优位置采用柯西扰动操作,提升算法逃离局部极值的能力;再次,改进母狮位置更新方式和步长公式,提高算法后期的收敛精度;最后,融合精英反向学习,提高解的质量.选取国际通用的13个基准函数和部分CEC2014函数进行实验仿真,结果表明所提算法寻优性能和搜索精度有明显提升;另外通过对两个工程实例进行优化,结果表明改进算法在工程应用中具有优势.

分时电价下任务调度–人员排班组合问题的代理模型求解研究

在分时电价背景下,制造成本和人力成本往往难以取得平衡:晚上电价较低但人员加班费较高,白天人员时薪较低而电价却较高。若将两个问题联合建模,则规模较大,不易求解。在实际应用中,较多采用先进行任务调度,再对人员排班的分阶段建模求解方法,但该求解思路难以保证得到较低成本的解。针对这一问题,提出一种代理模型的方法,以GA算法生成两个子问题的多组较优可行解作为训练样本,利用BP神经网络、深度学习及宽度学习系统分别拟合组合问题的代理模型,并采用BFGS法寻优。随着工件与工序数目的增加,本文所提供的自适应采样算法能有效解决维数灾问题。算例结果表明,新方法能得到明显优于利用遗传算法分阶段求解得到的结果,能为企业节省高达11.91%的电费与人力总成本。

基于北方苍鹰优化核极限学习机的玉米品种鉴别研究

玉米作为我国种植最为广泛的农作物,其产量对于我国粮食安全具有重大意义,由于不同品种具有不同的特性,根据种植条件科学选种能够很大限度上提高产量并且降低生产成本,但不同玉米种子外观极其相似,导致科学选种工作产生了一定难度。该研究基于近红外光谱技术结合核极限学习机(KELM)针对玉米品种分类问题构建鉴别模型,利用甜糯黄玉米、甜妃、昌甜、金色超人、香甜5号五种玉米种子,每种取(13±0.5)g作为一份样品,共计126个样品作为研究对象,对采集的近红外光谱数据进行标准正态变量变换(SNV)处理后采用竞争性自适应重加权采样法(CARS)对数据集进行降维。按照5∶1的比例将样本随机分为训练集和测试集,探讨北方苍鹰优化算法(NGO)对KELM模型性能的影响。分别使用NGO算法、粒子群算法(PSO)和灰狼算法(GWO)对KELM模型的两个重要参正则化参数C和高斯核函数γ进行寻优,选择五折交叉验证识别准确率最高时对应的C和γ作为建模参数,建立KELM分类模型。将各算法寻优后建立的KELM模型性能进行对比。实验发现,通过NGO算法寻优后建立的KELM模型性能高于其他两种算法优化的KELM模型,测试集识别准确率可达100%。在CARS降维的基础上分别建立CARS-NGO-KELM、CARS-PSO-KELM和CARS-GWO-KELM模型,结果表明,在面对降维后的数据时NGO算法仍能表现较好的性能,其测试集准确率和F 1值均达到了100%。为了验证样本数量对模型的影响,使用各品种样品数量同步后的共计90个样品重新训练KELM模型。结果表明,在同步各类样品数量后,各个模型在训练集和测试集上的表现均有提升。该研究在近红外光谱的基础上引入多种优化算法构建核极限学习机模型并将识别准确率提升至100%,实现了对玉米种子快速、无损、准确的品种鉴别,研究结果为玉米品种快速鉴别提供了一种新方法,同时也对监管部门具有一定的指导意义。