关键词： 光谱学   功能性近红外光谱   中值滤波   数学形态学   运动伪迹  

摘要： 功能性近红外光谱技术(fNIRS)作为一种新兴的神经成像技术得到了广泛关注,然而fNIRS信号中运动伪迹的存在会使信号的处理结果产生偏差。提出了一种定向中值滤波和数学形态学相结合的算法——tMedMor算法,并采用该算法对fNIRS信号中的三种运动伪迹(包括尖峰、基线突变和缓慢漂移)进行去除;然后用仿真数据和实验数据进行了验证,并将所提算法与常用的几种算法进行对比,结果表明:tMedMor算法在均方误差、信噪比、皮尔逊相关系数的平方、峰峰误差方面具有良好的表现,说明该算法可以作为一种新方法用于fNIRS信号的预处理阶段。

关键词： 模糊数据算法   超声驱动器   振动   控制  

摘要： 传统超声驱动器振动自动控制模型由于外界环境的扰动,无法对超声驱动器振动进行动态监测,存在着控制力度较小的问题,为此,提出基于模糊数学算法的超声驱动器振动自动控制模型构建研究。获取超声驱动器振动轨迹集合,利用模糊数学算法处理超声驱动器振动轨迹集合,得到驱动器振动轨迹特征,避免了外界环境的干扰,以振动轨迹特征为基础,模拟超声驱动器振动,计算振动控制力因子,实现了超声驱动器振动自动控制模型的运行。仿真对比测试结果显示:与传统模型相比较,构建模型的振动控制力因子较大、控制效果较好,表明构建模型的控制力度较大,适合大力推广使用。

关键词： Delays   Receivers   Forward error correction   Encoding   Decoding   Wireless communication   End-to-end latency   in-order delivery delay   forward error correction code (FEC)   partially observable Markov decision process (POMDP)   delayed feedback  

摘要： In this paper, we consider the packet-level forward error correction (FEC) code design, without feedback or with delayed feedback, for achieving the minimum end-to-end latency, i.e., the latency between the time that packet is generated at the source and its in-order delivery to the application layer of the destination. We first show that the minimum-latency FEC design problem can be modeled as a partially observable Markov decision process (POMDP), and hence the optimal code construction can be obtained by solving the corresponding POMDP. However, solving the POMDP optimally is in general difficult unless its state and action space is very small. To this end, we propose an efficient heuristic algorithm, namely the majority vote policy, for obtaining a high quality approximate solution. We also derive the tight lower and upper bounds of the optimal state values of this POMDP, based on which a more sophisticated D-step search algorithm can be implemented for obtaining near-optimal solutions. The simulation results show that the proposed code designs via solving the POMDP, either with the majority vote policy or the D-step search algorithm, strictly outperform the existing schemes, for both cases, without or with only delayed feedback.

关键词： Energy-conservation   flow shop scheduling (FSS)   fuzzy mathematical programming   outsourcing option   self-adaptive artificial fish swarm algorithm (SAAFSA)  

摘要： Flow shop scheduling (FSS) problem constitutes a major part of production planning in every manufacturing organization. It aims at determining the optimal sequence of processing jobs on available machines within a given customer order. In this article, a novel biobjective mixed-integer linear programming (MILP) model is proposed for FSS with an outsourcing option and just-in-time delivery in order to simultaneously minimize the total cost of the production system and total energy consumption. Each job is considered to be either scheduled in-house or to be outsourced to one of the possible subcontractors. To efficiently solve the problem, a hybrid technique is proposed based on an interactive fuzzy solution technique and a self-adaptive artificial fish swarm algorithm (SAAFSA). The proposedmodel is treated as a single objectiveMILP using a multiobjective fuzzy mathematical programming technique based on the e-constraint, and SAAFSA is then applied to provide Pareto optimal solutions. The obtained results demonstrate the usefulness of the suggested methodology and high efficiency of the algorithm in comparison with CPLEX solver in different problem instances. Finally, a sensitivity analysis is implemented on the main parameters to study the behavior of the objectives according to the real-world conditions.

关键词： Vehicle routing problem   Cross-docking   Scheduling   Splitting orders   Multi-product   Multi-objective meta-heuristics  

摘要： This paper addresses a vehicle routing problem with cross-docking (VRPCD) that considers truck scheduling, splitting pickup and delivery orders with time-windows at supplier and retailer locations, while optimizing two conflicting objectives (i.e., cost efficiency and responsiveness). The objectives are to minimize the total operational cost and the sum of the maximum earliness and tardiness. A new bi-objective mixed-integer linear programming model is presented and a multi-objective meta-heuristic evolutionary algorithm is proposed for solving the problem. Numerical results indicate the effectiveness of our proposed algorithm comparing with two multi-objective meta-heuristic algorithms (i.e., non-dominated sorting genetic algorithm (NSGA-II) and Pareto archived evolution strategy (PAES)). Also, we report findings from a hypothetical case study in a retail chain in Houston, Texas.

关键词： Semi-automated assembly line   Assembly line balancing problem   Energy efficient manufacturing   Improved whale optimization algorithm  

摘要： In this study, a new extension of the semi-automated assembly line designing problem is presented. The main difference between this paper and existing work is that the energy consumption, smoothness index and total cost are all taken into consideration. The tasks can be performed by more than one format in the semi-automated assembly line, which means the operation time and energy consumption of tasks depend on the allocated stations. To obtain the trade-off among three objectives. First, a mathematical model with constraints is provided. Then, an improved whale optimization algorithm (IWOA) is presented, the chaotic maps, variable neighborhood search (VNS) and mutation are adopted to enhance the algorithm performance. In order to demonstrate the effectiveness of the algorithm and employed mechanisms, numerical comparison experiments are accordingly conducted. The results show that the specific designed algorithm outperforms five other well-known algorithms in solving the energy-oriented semi-automated assembly line designing problem. At last, the managerial insights are provided based on the sensitivity analysis. And a real case derives from car floor assembly system is used for validation of the proposed model and algorithm.

关键词： 数学方法   计算机算法   应用  

摘要： 随着我国科学技术的不断发展,信息技术在人们的生活中得到了广泛的运用。而计算机算法的基础是数学方法,很多计算机应用都需要借助数学方法来完成,数学方法可以很大程度上提高计算机的运行效率,并且对计算机编程内容进行优化,使得计算机算法程序更加简洁。因此,我们对数学方法在计算机算法中的应用进行研究是十分必要的。

关键词： 算法设计   标准推理   建模   人工智能  

摘要： 研究基于数学算法的设计,从理解模拟某种认知关系的框架的形式和计算性质的角度。阐述对标准推理统计论证的建模,从逻辑人工智能和分析认识论两方面得出结果。

关键词： 橡胶衬套   Bouc-Wen模型   参数辨识  

摘要： 文中以某汽车副车架的橡胶衬套为研究对象,采用理论与试验相结合的方法,对汽车橡胶衬套进行数学建模及参数辨识研究。首先建立了台架试验系统,在不同频率、幅值激励下通过试验获得橡胶衬套动力学特性数据,然后根据数据的迟滞非线性特性,建立橡胶衬套Bouc-Wen数学模型,并以最小二乘法对模型参数进行初步辨识,最后基于遗传算法对获得的参数值进行修正,并运用数值仿真方法对橡胶衬套的Bouc-Wen模型重构力-位移曲线,结果与试验结果吻合较好,误差在5%以内,验证了参数辨识方法的正确性和有效性。

关键词： 低空无线信道   数学建模   BP算法   信道参数提取   参数处理算法   仿真实验  

摘要： 为了保证低空无线信道功率谱的稳定性,提出基于BP算法的低空无线信道数学建模方法。采用BP算法获取低空无线信道的观测空间,设计信道参数提取流程,完成无线信道参数的提取。根据信道参数处理算法的具体实现步骤,采用迭代计算的方式将处理后的信道参数保存,完成低空无线信道参数处理算法的设计。通过分析低空无线信道数学模型的建立过程,实现基于BP算法的低空无线信道的数学建模。仿真实验结果表明,基于BP算法的低空无线信道数学建模方法与基于EM算法的低空无线信道数学建模方法相比,低空无线信道的功率谱更稳定,具有较好的应用效果。