引入莱维飞行与动态权重的改进灰狼算法

针对求解复杂优化问题时,灰狼（GWO）算法存在全局搜索能力不足、容易陷入局部最优值等问题,提出一种引入莱维飞行与动态权重策略的改进灰狼算法（LGWO）。基于Singer混沌映射初始化灰狼个体位置,增加种群多样性;收敛因子采用新的非线性更新策略,在种群迭代全期平衡全局搜索与局部搜索能力;在种群位置更新公式引入莱维飞行与动态权重策略,增加种群跳出局部最优值的概率,提升寻优准确度。通过8个基准函数的测试,并与其他优化算法和改进算法进行对比,LGWO取得了最优的收敛速度与预测精度,并验证了LGWO算法优化高维复杂问题的有效性。     

一种改进的鲸鱼优化算法

针对鲸鱼优化算法（whale optimization algorithm ,WOA）容易陷入局部最优和收敛精度低的问题进行了研究,提出一种改进的鲸鱼优化算法（IWOA）。该算法通过准反向学习方法来初始化种群,提高种群的多样性;然后将线性收敛因子修改为非线性收敛因子,有利于平衡全局搜索和局部开发能力;另外,通过增加自适应权重改进鲸鱼优化算法的局部搜索能力,提高收敛精度;最后,通过随机差分变异策略及时调整鲸鱼优化算法,避免陷入局部最优。实验选取九个基准函数,所有算法均迭代30次,结果表明：改进的鲸鱼优化与原鲸鱼优化算法以及五种改进的鲸鱼优化算法相比,其均值和标准差均优于其他算法,收敛曲线也优于其他大多数算法。说明改进的鲸鱼优化算法收敛精度和算法稳定性最佳,收敛速度较其他大多数改进的鲸鱼优化算法明显加快。     

基于混合策略改进的鲸鱼优化算法

针对标准WOA算法初始种群分布不均、收敛速度较慢、全局搜索能力弱且易陷入局部最优等问题,提出一种混合策略改进的鲸鱼优化算法。采用Sobol序列初始化种群以使初始解在解空间分布更均匀;通过非线性时变因子和惯性权重平衡并提高全局搜索及局部开发能力,并结合随机性学习策略增加迭代过程中种群的多样性;引入柯西变异提升算法跳出局部最优的能力。通过对12个基准函数和一个水资源需求预测模型的参数估计进行优化实验,结果表明,基于混合策略改进的鲸鱼优化算法在寻优精度及收敛速度上均有明显提升。     

混合策略改进的鲸鱼优化算法

针对标准鲸鱼优化算法易出现搜索速度慢、寻优精度低及早熟收敛等问题,提出一种混合策略改进的鲸鱼优化算法。首先采用混沌映射生成初始种群增加种群多样性,为算法全局搜索奠定基础;然后引入非线性策略改进收敛因子和惯性权重,平衡算法的全局探索与局部开发能力并加快收敛速度;最后根据群体适应度方差设定阈值进行变异操作,避免算法出现早熟收敛的现象。通过对12个典型基准函数进行三方面的性能测试,实验结果表明,改进算法在搜索速度、收敛精度等方面有显著提高,且摆脱陷入局部最优解的能力强。     

一种基于动态惯性权重的鸟群优化算法

鸟群算法（BSA）作为一种新型的元启发式群智能算法,存在易陷入局部最优、收敛速度慢和求解精度低等问题。针对原鸟群算法在求解最优化问题中的不足,提出一种基于动态惯性权重的鸟群优化算法(DBSA)。该算法通过引入非线性动态惯性权重修正鸟群飞行间隔,平衡种群全局搜索与局部搜索能力;在模拟鸟群生产者觅食的过程中引入莱维飞行,替换原算法中生产者的觅食策略提高算法活力和有效性。实验表明改进后的鸟群算法有效提高了算法的收敛速度和寻优精度。     

多策略融合的改进萤火虫算法

针对传统萤火虫算法（FA）中存在的易陷入局部最优及收敛速度慢等问题,把莱维飞行和精英参与的交叉算子及精英反向学习机制融入到萤火虫优化算法中,提出了一种多策略融合的改进萤火虫算法——LEEFA。首先,在传统萤火虫算法的基础上引入莱维飞行,从而提升算法的全局搜索能力;其次,提出精英参与的交叉算子以提升算法的收敛速度和精度,并增强算法迭代过程中解的多样性和质量;最后,结合精英反向学习机制进行最优解的搜索,从而提高FA跳出局部最优的能力和收敛性能,并实现对于解搜索空间的迅速勘探。为验证所提出的算法的有效性,在基准测试函数上进行了仿真实验,结果表明相较于粒子群优化（PSO）算法、传统FA、莱维飞行萤火虫算法（LFFA）、基于莱维飞行和变异算子的萤火虫算法（LMFA）和自适应对数螺旋-莱维飞行萤火虫优化算法（ADIFA）等算法,所提算法在收敛速度和精度上均表现得更为优异。     

基于混合策略改进的鲸鱼优化算法

针对传统鲸鱼优化算法收敛速度慢、易陷入局部最优等问题,提出一种基于混合策略改进的鲸鱼优化算法。首先,引入非线性调整策略改进收敛因子,平衡算法的全局探索与局部开发能力并加快算法收敛速度;然后,将自适应权重系数引入鲸鱼位置更新式中,从而提高算法的寻优精度;最后,结合人工蜂群算法的limit阈值思想,使算法能够有效跳出局部最优,改善算法早熟收敛现象。通过对14个基准测试函数在不同维度上的仿真实验表明,改进算法具有较高的寻优精度和较快的收敛速度。     

融合莱维飞行与黄金正弦的蚁狮优化算法

针对蚁狮优化算法较易陷入局部最优停滞、收敛精度低以及收敛速度较慢等问题,将莱维飞行机制和黄金正弦算法融合到蚁狮优化算法中,提出了融合莱维飞行与黄金正弦的蚁狮优化算法（LGSALO）。该算法利用 Levy 飞行的变异机制对寻优过程中位置更新方式进行变异操作,可以改善种群多样性,使得算法跳出局部最优,提高全局寻优能力,并在一定程度上避免了算法的过早收敛;同时引入黄金正弦算法改进精英蚁狮的寻优方式,协调算法的全局探索与局部开发能力。实验仿真结果表明,该改进算法的寻优性能良好,开发能力强。     

基于混合策略改进的麻雀搜索算法

为克服基本麻雀搜索算法(Sparrow Search Algorithm, SSA)存在的迭代过程中种群多样性减少、易陷入局部最优停滞、早熟收敛等不足,提出一种基于混合策略改进的麻雀搜索优化算法(EGSSA)。首先,迭代时利用精英反向学习机制在个体求解过程中计算精英反向解,提升算法寻优过程中种群丰富性和种群质量,为提高算法全局寻优能力以及收敛精度奠定基础;其次,将黄金正弦策略用以改进发现者位置更新方式,协调算法局部开发和全局搜索能力,并且提高算法的收敛能力;最后,在加入者的更新中采用了莱维飞行随机步长,以使新加入者所搜索的范围更为全面,一定程度避免算法陷入“早熟收敛”。选取12个基准测试函数进行仿真实验,分别与4种元启发式算法以及3种改进麻雀搜索算法进行比较,实验结果以及Wilcoxon秩和检验均表明,EGSSA算法具有更好的全局探索能力和稳定性以及较强跳出局部极值的能力。     

混合策略改进鲸鱼优化算法

针对标准鲸鱼优化算法（whale optimization algorithm,WOA）易陷入局部最优解、收敛精度低、收敛速度慢等问题,提出一种利用混合策略改进的鲸鱼优化算法（multi-strategy improved whale optimization algorithm,MSIWOA）。首先采取精英反向策略初始化种群,提高初始种群质量;其次,采取卡方分布的逆累积分布函数更新收敛因子以实现全局探索和局部开发的平衡;然后利用改进氏族拓扑结构强化种群的全局探索能力,并提高算法收敛速度;最后采取Circle映射产生混沌解,结合贪婪策略保留较优解,以帮助种群跳出局部最优解。通过对10个基准测试函数以及CEC2019测试函数进行仿真实验,结果表明,MSIWOA在收敛精度和收敛速度上均有较明显的提升。     

Formulation and parameter selection of multi-objective deterministic particle swarm for simulation-based optimization

Global derivative-free deterministic algorithms are particularly suitable for simulation-based optimization, where often the existence of multiple local optima cannot be excluded a priori, the derivatives of the objective functions are not available, and the evaluation of the objectives is computationally expensive, thus a statistical analysis of the optimization outcomes is not practicable. Among these algorithms, particle swarm optimization (PSO) is advantageous for the ease of implementation and the capability of providing good approximate solutions to the optimization problem at a reasonable computational cost. PSO has been introduced for single-objective problems and several extension to multi-objective optimization are available in the literature. The objective of the present work is the systematic assessment and selection of the most promising formulation and setup parameters of multi-objective deterministic particle swarm optimization (MODPSO) for simulation-based problems. A comparative study of six formulations (varying the definition of cognitive and social attractors) and three setting parameters (number of particles, initialization method, and coefficient set) is performed using 66 analytical test problems. The number of objective functions range from two to three and the number of variables from two to eight, as often encountered in simulation-based engineering problems. The desired Pareto fronts are convex, concave, continuous, and discontinuous. A full-factorial combination of formulations and parameters is investigated, leading to more than 60,000 optimization runs, and assessed by three performance metrics. The most promising MODPSO formulation/parameter is identified and applied to the hull-form optimization of a high-speed catamaran in realistic ocean conditions. Its performance is finally compared with four stochastic algorithms, namely three versions of multi-objective PSO and the genetic algorithm NSGA-II.     

Real-time dynamic optimization of batch systems

In this paper a methodology for designing and implementing a real-time optimizing controller for batch processes is proposed. The controller is used to optimize a user-defined cost function subject to a parameterization of the input trajectories, a nominal model of the process and general state and input constraints. An interior point method with penalty function is used to incorporate constraints into a modified cost functional, and a Lyapunov based extremum seeking approach is used to compute the trajectory parameters. The technique is applicable to general nonlinear systems. A precise statement of the numerical implementation of the optimization routine is provided. It is shown how one can take into account the effect of sampling and discretization of the parameter update law in practical situations. A simulation example demonstrates the applicability of the technique.     

Multiobjective optimization of trusses using genetic algorithms

In this paper we propose the use of the genetic algorithm (GA) as a tool to solve multiobjective optimization problems in structures. Using the concept of min–max optimum, a new GA-based multiobjective optimization technique is proposed and two truss design problems are solved using it. The results produced by this new approach are compared to those produced by other mathematical programming techniques and GA-based approaches, proving that this technique generates better trade-offs and that the genetic algorithm can be used as a reliable numerical optimization tool.     

An integrated approach to topology,sizing, and shape optimization

Topology optimization has become very popular in industrial applications, and most FEM codes have implemented certain capabilities of topology optimization. However, most codes do not allow simultaneous treatment of sizing and shape optimization during the topology optimization phase. This poses a limitation on the design space and therefore prevents finding possible better designs since the interaction of sizing and shape variables with topology modification is excluded. In this paper, an integrated approach is developed to provide the user with the freedom of combining sizing, shape, and topology optimization in a single process.     

Effects of dominant wolves in grey wolf optimization algorithm

Bio-inspired computation is one of the emerging soft computing techniques of the past decade. Although they do not guarantee optimality, the underlying reasons that make such algorithms become popular are indeed simplicity in implementation and being open to various improvements. Grey Wolf Optimizer (GWO), which derives inspiration from the hierarchical order and hunting behaviours of grey wolves in nature, is one of the new generation bio-inspired metaheuristics. GWO is first introduced to solve global optimization and mechanical design problems. Next, it has been applied to a variety of problems. As reported in numerous publications, GWO is shown to be a promising algorithm, however, the effects of characteristic mechanisms of GWO on solution quality has not been sufficiently discussed in the related literature. Accordingly, the present study analyses the effects of dominant wolves, which clearly have crucial effects on search capability of GWO and introduces new extensions, which are based on the variations of dominant wolves. In the first extension, three dominant wolves in GWO are evaluated first. Thus, an implicit local search without an additional computational cost is conducted at the beginning of each iteration. Only after repositioning of wolf council of higher-ranks, the rest of the pack is allowed to reposition. Secondarily, dominant wolves are exposed to learning curves so that the hierarchy amongst the leading wolves is established throughout generations. In the final modification, the procedures of the previous extensions are adopted simultaneously. The performances of all developed algorithms are tested on both constrained and unconstrained optimization problems including combinatorial problems such as uncapacitated facility location problem and 0-1 knapsack problem, which have numerous possible real-life applications. The proposed modifications are compared to the standard GWO, some other metaheuristic algorithms taken from the literature and Particle Swarm Optimization, which can be considered as a fundamental algorithm commonly employed in comparative studies. Finally, proposed algorithms are implemented on real-life cases of which the data are taken from the related publications. Statistically verified results point out significant improvements achieved by proposed modifications. In this regard, the results of the present study demonstrate that the dominant wolves have crucial effects on the performance of GWO.     

多元插值全局优化算法及其应用

本文介绍一种多元插值逼近和动态搜索轨迹相结合的全局优化算法.该算法大大减少了目标函数计算次数,寻优收敛速度快,算法稳定,且可获得全局极小,有效地解决了大规模非线性复杂动态系统的参数优化问题.一个具有8个控制参数的电力系统优化控制问题,采用该算法仅访问目标函数78次,便可求得最优控制器参数。     

云搜索优化算法

本文将云的生成、动态运动、降雨和再生成等自然现象与智能优化算法的思想融合,建立了一种新的智能优化算法-云搜索优化算法(CSO)。生成与移动的云可以弥漫于整个搜索空间,这使得新算法具有较强的全局搜索能力;收缩与扩张的云团在形态上会有千奇百态的变化,这使得算法具有较强的局部搜索能力;降雨后产生新的云团可以保持云团的多样性,这也是使搜索避免陷入局优的有效手段。实验表明,基于这三点建立的新算法具有优异的性能,benchmark函数最优值的计算结果以及与已有智能优化算法的比较展现了新算法精确的、稳定的全局求解能力。     

Value Creation in a Network: The Role of Pricing and Revenue Optimization and Enterprise Profit OptimizationTM

The Internet has created a virtual upheaval in the structural features of the supply and demand chains for most businesses. New agents and marketplaces have surfaced. The potential to create value and enhance profitable opportunities has attracted both buyers and sellers to the Internet. Yet, the Internet has proven to be more complex than originally thought. With information comes complexity: the more the information in real time, the greater the difficulty in interpretation and absorption. How can the value-creating potential of the Internet still be realized, its complexity notwithstanding? This paper argues that with the emergence of innovative tools, the expectations of the Internet as a medium for enhanced profit opportunities can still be realized. Creating value on a continuing basis is central to sustaining profitable opportunities. This paper provides an overview of the value creation process in electronic networks, the emergence of the Internet as a viable business communication and collaboration medium, the proclamation by many that the future of the Internet resides in “embedded intelligence”, and the perspectives of pragmatists who point out the other facet of the Internet—its complexity. The paper then reviews some recent new tools that have emerged to address this complexity. In particular, the promise of Pricing and Revenue Optimization (PRO) and Enterprise Profit Optimization^TM (EPO) tools is discussed. The paper suggests that as buyers and sellers adopt EPO, the market will see the emergence of a truly intelligent network—a virtual network—of private and semi-public profitable communities.     

粒子群算法在组合优化问题上的研究与发展

粒子群优化算法是一种新兴的基于群智能搜索的优化技术。该算法简单、易实现、参数少,具有较强的全局优化能力,可有效应用于科学与工程实践中。介绍了算法的基本原理和算法在组合优化上一些改进方法的主要应用形式。最后,对粒子群算法作了一些深入分析并在此基础上对粒子群算法应用于组合优化问题做了一些总结。     

SEO技术研究

为了利用搜索引擎优化SEO（Search Engine Optimization）技术给网站带来高质量的流量并将其转化为商业利益,理解搜索引擎的算法和排名原理十分必要。通过对网站的结构优化、关键词优化、单页优化、防止被搜索引擎惩罚和挽救被惩罚网站等技术的研究,达到提高网站排名,实现网站的价值目的。