多源基因学习的微种群教与学优化及应用

由于微种群教与学优化算法的种群规模较小, 故其种群多样性很难维持. 为提高微种群教与学优化算法的搜索性能, 提出了一种基于多源基因学习的微种群教与学优化算法(micro-population teaching-learning-based optimization based on multi-source gene learning, MTLBO-MGL). 在MTLBO-MGL算法中, 将教阶段和学阶段根据随机选择策略来对个体进行基因水平上的进化操作; 并从基因层面上对种群多样性进行检测和使用稀疏谱聚类方法对种群的每个维度进行聚类. 然后, 根据多样性检测和聚类结果, 选择不同的进化策略来提高所提算法的搜索性能. 在28个测试函数上, 通过将所提算法与其他4种微种群进化算法作对比, 证明了所提算法的整体性能要显著好于所对比的4种算法. 本文还将所提算法应用于无人机三维路径规划问题, 结果表明MTLBO-MGL算法能够在该问题上取得较好结果.     

TLBO optimized sliding mode controller for multi-area multi-source nonlinear interconnected AGC system

This paper represents design of output feedback sliding mode controller (SMC) for multi area multi-source interconnected power system. After designing output feedback SMC, teaching and learning based optimization (TLBO) technique is utilized to optimize feedback gain and switching vector of the controller. The superiority of the proposed approach is shown by comparing the result with output feedback tuned SMC with differential evolution and particle swarm optimization and state feedback SMC tuned with genetic algorithm for a two area thermal interconnected power system. Further, the proposed approach is extended to multi-area multi-source non linear automatic generation control (AGC) system with/without HVDC link. First area consists up thermal, hydro and gas; second area consists up thermal, hydro and nuclear as generating unit. Additionally, the superiority of proposed approach is shown by sensitivity analysis, which is carried out with wide changes in system parameters.     

Optimization of a plate-fin heat exchanger design through an improved multi-objective teaching-learning based optimization (MO-ITLBO) algorithm

Teaching-learning-based optimization (TLBO) is a recently developed heuristic algorithm based on the natural phenomenon of teaching-learning process. In the present work, multi-objective improved teaching-learning-based optimization (MO-ITLBO) algorithm is introduced and applied for the multi-objective optimization of plate-fin heat exchangers. The basic TLBO algorithm is improved to enhance its exploration and exploitation capacities by introducing the concept of number of teachers, adaptive teaching factor, tutorial training and self-motivated learning. The MO-ITLBO algorithm uses a grid-based approach to adaptively assess the non-dominated solutions maintained in an external archive. Minimizing total annual cost and the total weight of heat exchanger as well as minimization of total pressure drop and maximization of heat exchanger effectiveness for specific heat duty requirement are considered as objective functions. Two application examples are presented to demonstrate the effectiveness and accuracy of the proposed algorithm.     

Concurrent optimal allocation of distributed manufacturing resources using extended Teaching-Learning-Based Optimization

The optimal allocation of distributed manufacturing resources is a challenging task for supply chain deployment in the current competitive and dynamic manufacturing environments, and is characterised by multiple objectives including time, cost, quality and risk that require simultaneous considerations. This paper presents an improved variant of the Teaching-Learning-Based Optimisation (TLBO) algorithm to concurrently evaluate, select and sequence the candidate distributed manufacturing resources allocated to subtasks comprising the supply chain, while dealing with the trade-offs among multiple objectives. Several algorithm-specific improvements are suggested to extend the standard form of TLBO algorithm, which is only well suited for the one-dimensional continuous numerical optimisation problem well, to solve the two-dimensional (i.e. both resource selection and resource sequencing) discrete combinatorial optimisation problem for concurrent allocation of distributed manufacturing resources through a focused trade-off within the constrained set of Pareto optimal solutions. The experimental simulation results showed that the proposed approach can obtain a better manufacturing resource allocation plan than the current standard meta-heuristic algorithms such as Genetic Algorithm, Particle Swarm Optimisation and Harmony Search. Moreover, a near optimal resource allocation plan can be obtained with linear algorithmic complexity as the problem scale increases greatly.     

环链种群结构的多目标教与学优化算法*

针对教与学算法采用贪婪进化机制,易造成种群多样性较差的问题,将环链拓扑结构引入到多目标教与学算法中,并改进了自我学习机制,提出了一种环链种群结构的多目标教与学优化算法。根据多种群进化方式,通过一种环链结构将种群划分为多个邻域,每个邻域代表一个小种群,且相邻种群之间存在重叠。在教与学进化过程中,在每个小种群中设置一名教师,由每一位教师引导各自的种群独立进化,且彼此之间存在进化信息交流。同时,提出一种改进的学习机制来提升局部寻优能力,由此平衡算法的全局搜索和局部寻优。该算法通过与五种对等算法在ZDT和DTLZ系列组成的12个多目标测试问题进行测试,实验结果表明了新算法在收敛性、多样性和稳定性等方面均优于或部分优于其他的对比算法。     

基于自主学习行为的教与学优化算法

针对教与学优化（TLBO）算法收敛精度较低、易于早熟收敛等问题,提出一种基于自主学习行为的教与学优化算法（SLTLBO）。SLTLBO算法为学生构建了更加完善的学习框架,学生在完成常规"教"阶段与"学"阶段的学习行为之外,将进一步对比自己与教师、最差学生的差异,自主完成多样化的学习操作,以提高自己的知识水平,提高算法的收敛精度;同时学生通过高斯搜索的自主学习反思行为跳出局部区域,实现更好的全局搜索。利用10个基准测试函数对SLTLBO算法进行了性能测试,并将SLTLBO算法与粒子群优化（PSO）算法、智能蜂群（ABC）算法以及TLBO算法进行结果比对,实验结果验证了SLTLBO算法的有效性。     

广域电力系统稳定器参数的两阶段协调优化方法

广域电力系统稳定器(Wide Area Power System Stabilizer,WAPSS)对电力系统的区间低频振荡能够起到良好的阻尼作用。同时,WAPSS参数的协调优化设计能够避免因增大某一振荡模式的阻尼而造成其他模式阻尼恶化的问题,提出一种两阶段设计的WAPSS参数协调优化方法。第一阶段基于留数相位补偿原理设计WAPSS超前滞后环节的参数。第二阶段,将整定后的超前滞后环节参数代入WAPSS传递函数以减少决策变量,再以提高低频振荡模式和近虚轴模式的阻尼为多优化目标,利用基于精英替换策略的改进教与学算法(Teaching-Learning-Based Optimization,TLBO)对WAPSS的增益参数进行优化。通过将超前滞后环节参数和增益参数两阶段协调优化,不仅减少了每次迭代计算时间,而且达到了提高电力系统阻尼的目的。最后通过两区四机的仿真算例验证了该方法的有效性。     

基于教与学优化算法的相关反馈图像检索

为提高基于内容的图像检索的检索性能和检索速度,克服低层视觉特征与高层语义概念间的“语义鸿沟”,提出一种基于教与学优化的图像检索相关反馈算法（TLBO-RF）.结合图像检索问题的特殊性和粒子群优化算法的优点,对TLBO算法中个体的更新机制进行了改进,通过将相关图像集的中心作为教师以及引入学员最好学习状态Pbest,使之朝用户感兴趣的相关图像区域快速收敛.将该算法与目前效果最好的两种基于进化算法的相关反馈技术在两套标准图像测试集上进行对比,结果表明本文算法相较于另外两种算法具有明显的优势,不仅提高了图像检索性能,同时也加快了图像检索速度,更好地满足了用户的检索要求.     

一种矩形邻域结构的教学优化算法

为了克服原始教学优化算法在求解复杂多峰函数时全局寻优精度不高和过早收敛的缺点,提出一种矩形邻域结构和个体扰动的教学优化算法.算法将种群空间设计为矩形结构,个体的矩形邻域由矩形厚度和围绕其的矩形区域个体决定,教和学两个阶段都使用邻域最优个体引导搜索,加强了算法勘探新解和开发局部最优解的能力;为了防止算法过早陷入局部最优,增加了基于搜索边界信息引导的个体扰动阶段,使得种群即使在进化的后期仍能保持较好的多样性.对带有偏移和旋转的复杂函数进行仿真测试,结果表明新算法在求解精度和稳定性方面,在绝大多数情况下优于原始教学算法和其他一些近来的优秀改进教学算法.     

Comparative study on optimum design of rolling element bearing

Long fatigue life is the most important objective in the optimum design of rolling element bearing. In the present study the fatigue life of a radial ball bearing is maximized. The nonlinear constrained optimization problem has been solved using particle swarm optimization algorithm and a hybrid PSO and Teaching Learning based Optimization algorithm. The algorithm uses a ranking method of constraint handling and contact stress has been introduced as a new constraint. The results have been compared with the established available results. A constraint violation study has been carried out to prioritize the constraints. A convergence study has been performed to identify the key design variables. Encouraging results in terms of objective function values and CPU time have been reported in this study.