Application of metaheuristics-based clustering algorithm to item assignment in a synchronized zone order picking system

Warehousing management policy is a crucial issue in logistic management. It must be managed effectively and efficiently to reduce the production cost as well as the customer satisfaction. Synchronized zoning system is a warehousing management policy which aims to increase the warehouse utilization and customer satisfaction by reducing the customer waiting time. This policy divides a warehouse into several zones where each zone has its own picker who can work simultaneously. Herein, item assignment plays an important role since it influences the order processing performance. This study proposes an application of metaheuristic algorithms, namely particle swarm optimization (PSO) and genetic algorithm (GA), for item assignment in synchronized zoning system. The original PSO and GA algorithms are modified so that it is suitable for solving item assignment problem. The datasets with different sizes are used for method validation. Results obtained by PSO and GA are then compared with the result of an existing algorithm. The experimental results showed that PSO and GA can perform better than the existing algorithm. These results also show that PSO has better performance than GA, especially for bigger problems. It proves that item assignment policy obtained by PSO and GA has higher utilization rates than the existing algorithm.     

基于多周循环步进式插值扫描轨迹的工业CT柔性检测技术研究

为了在一次CT检测过程中同时实现被检工件的精细检测与内部缺陷快速发现的两种检测需求，提出了一种新型CT检测方案。该方案将一种改进的圆形CT投影扫描轨迹与不完全投影插值算法有效融合，实现了投影采集与最优图像实时重建的同步进行。为验证该技术的可行性，设计了相应的扇束CT仿真平台及试验模体，仿真试验结果表明，该检测技术在CT扫描过程中可及时发现被检工件的内部缺陷，扫描结束后可获得工件的精细CT图像，有效满足了工业CT用户在多种检测目的之间自由切换的柔性检测需求。     

道路交通网络中的关键节点识别方法研究

在现实世界中，大量复杂系统都可以通过抽象的节点和连边构成的网络来加以刻画。作为城市交通系统的重要组成部分，道路交通网络是一个典型的复杂系统，与人们的生活密切相关。道路交通网络中的关键节点识别问题是复杂网络领域研究中的一个经典难题。传统的度中心性算法和PageRank算法在复杂网络的关键节点的识别中具有较好的应用，考虑到道路交通网络中关键节点的特殊性和彼此关联性，在度中心性算法的基础上引入贪心算法的思想，提出了一个基于贪心策略的度中心性关键节点识别方法；同时，在PageRank算法的基础上引入贪心算法的思想，提出了一种基于贪心策略的PageRank关键节点识别方法，从而使道路交通网络中关键节点识别的结果更合理，在交通道路维护保养、规划设计，以及犯罪分子潜逃阻断等领域都有重要的应用价值。通过公开数据集与经典的关键节点识别方法做比较，验证了算法的有效性。     

A hybrid approach based on an improved gravitational search algorithm and orthogonal crossover for optimal shape design of concrete gravity dams

A hybrid approach based on an improved gravitational search algorithm (IGSA) and orthogonal crossover (OC) is proposed to efficiently find the optimal shape of concrete gravity dams. The proposed hybrid approach is called IGSA-OC. The hybrid of IGSA and the OC operator can improve the global exploration ability of the IGSA method, and increase its convergence rate. To find the optimal shape of concrete gravity dams, the interaction effects of dam–water–foundation rock subjected to earthquake loading are considered in this study. The computational cost of the optimal shape of concrete gravity dams subjected earthquake loads is usually high. Due to this problem, the weighted least squares support vector machine (WLS-SVM) regression as an efficient metamodel is utilized to considerably predict dynamic responses of gravity dams by spending low computational cost. To testify the robustness and efficiency of the proposed IGSA-OC, first, four well-known benchmark functions in literatures are optimized using the proposed IGSA-OC, and provides comparisons with the standard gravitational search algorithm (GSA) and the other modified GSA methods. Then, the optimal shape of concrete gravity dams is found using IGSA-OC. The solutions obtained by the IGSA-OC are compared with those of the standard GSA, IGSA and particle swarm optimization (PSO). The numerical results demonstrate that the proposed IGSA-OC significantly outperforms the standard GSA, IGSA and PSO.     

EvoSeedRNSAII: An improved evolutionary algorithm for generating detectors in the real-valued Negative Selection Algorithms

In the previous work, a detector generation algorithm, named as the EvoSeedRNSA, is proposed. A genetic algorithm is adopted in the EvoSeedRNSA to evolve the random seeds to generate an approximately optimal detector set. This paper proposes an improved EvoSeedRNSA, named as the EvoSeedRNSAII, to generate a more efficient detector set. A multi-group random seed encoding scheme is designed to represent the individuals and different detector generation sequences are discussed. The experiments demonstrate that the EvoSeedRNSAII has a better performance than the EvoSeedRNSA.     

Solving the integrated scheduling of production and rail transportation problem by Keshtel algorithm

Nowadays, scheduling of production cannot be done in isolation from scheduling of transportation since a coordinated solution to the integrated problem may improve the performance of the whole supply chain. In this paper, because of the widely used of rail transportation in supply chain, we develop the integrated scheduling of production and rail transportation. The problem is to determine both production schedule and rail transportation allocation of orders to optimize customer service at minimum total cost. In addition, we utilize some procedures and heuristics to encode the model in order to address it by two capable metaheuristics: Genetic algorithm (GA), and recently developed one, Keshtel algorithm (KA). Latter is firstly used for a mathematical model in supply chain literature. Besides, Taguchi experimental design method is utilized to set and estimate the proper values of the algorithms’ parameters to improve their performance. For the purpose of performance evaluation of the proposed algorithms, various problem sizes are employed and the computational results of the algorithms are compared with each other. Finally, we investigate the impacts of the rise in the problem size on the performance of our algorithms.     

A label field fusion model with a variation of information estimator for image segmentation

This paper proposes a new and reliable segmentation approach based on a fusion framework for combining multiple region-based segmentation maps (with any number of regions) to provide a final improved (i.e., accurate and consistent) segmentation result. The core of this new combination model is based on a consensus (cost) function derived from the recent information Theory based variation of information criterion, proposed by Meila, and allowing to quantify the amount of information that is lost or gained in changing from one clustering to another. In this case, the resulting consensus energy-based segmentation fusion model can be efficiently optimized by exploiting an iterative steepest local energy descent strategy combined with a connectivity constraint. This new framework of segmentation combination, relying on the fusion of inaccurate, quickly and roughly calculated, spatial clustering results, emerges as an appealing alternative to the use of complex segmentation models existing nowadays. Experiments on the Berkeley Segmentation Dataset show that the proposed fusion framework compares favorably to previous techniques in terms of reliability scores.     

Physics‐based search and optimization: Inspirations from nature

This paper presents a review of recently developed physics‐based search and optimization algorithms that have been inspired by natural phenomena. They include Big Bang–Big Crunch, black hole search, galaxy‐based search, artificial physics optimization, electromagnetism optimization, charged system search, colliding bodies optimization, and particle collision algorithm.     

一种基于敏感分量融合的液压泵退化特征提取方法

液压泵退化特征提取是实现故障预测的关键环节。在液压泵性能退化过程中，其振动信号复杂度高、非线性强，难以有效地提取退化特征，为此，本文提出一种基于敏感分量融合的退化特征提取方法。采用改进局部特征尺度分解（ILCD）方法对振动信号进行分解，并利用贝叶斯信息准则与所构建的敏感因子，对内禀尺度分量进行筛选，以减少干扰分量的影响，得到敏感分量，有效抓取特征信息；在此基础上，引入离散余弦变换代替传统复合谱分析中的傅里叶变换，提出离散余弦变换-复合谱（DCS）算法，以解决信息遗漏问题，并利用DCS对敏感分量进行融合，提取复合谱熵作为退化特征，以提高对退化过程的表征能力；最后，通过对液压泵性能退化试验实测振动信号的应用分析，验证了该方法的有效性。     

Evolving flexible beta basis function neural tree using extended genetic programming & Hybrid Artificial Bee Colony

In this paper, a new hybrid learning algorithm is introduced to evolve the flexible beta basis function neural tree (FBBFNT). The structure is developed using the Extended Genetic Programming (EGP) and the Beta parameters and connected weights are optimized by the Hybrid Artificial Bee Colony algorithm. This hybridization is essentially based on replacing the random Artificial Bee Colony (ABC) position with the guided Opposite-based Particle Swarm Optimization (OPSO) position. Such modification can minimize the delay which might be lead by the random position, in reaching the global solution. The performance of the proposed model is evaluated for benchmark problems drawn from time series prediction area and is compared with those of related methods.