设备可靠性评测仿真系统

设备可靠性评测仿真系统是为了智能管理仓库内设备和提高设备整体可靠性。针对仓库内设备可靠性评测,先进行设备模型化,提取有效因素对设备分类汇总,以建立设备聚类模型和设备管理学习模型,并与基于可靠度的设备维护模型相结合,完整实现对设备调度和维护的决策,并制定有效的维护计划。本系统创建的结构对设备可靠性评测和设备管理具有一定研究意义。     

统计聚类模型研究综述

聚类分析在工程领域如生物序列分析、图像分割、文本分析等广泛应用。聚类方法涉及广泛,而基于概率统计理论的方法是其中的一大类。从最基本的FCM模型出发,阐述了势函数(Potential)、山脉(Mountain)函数聚类方法、信息熵方法,分析比较了这些方法的适用范围和优缺点,介绍了当今流行的核聚类、谱聚类和高斯混合模型聚类方法及其求解过程,并分析了它们的优缺点、计算复杂性等指标。最后,介绍了一些崭新的聚类模型的研究方向。     

Multiscale fuzzy system identification

One of the biggest challenges in constructing empirical models is the presence of measurement errors in the data. These errors (or noise) can have a drastic effect on the accuracy and prediction of estimated models, and thus need to be removed for improved models accuracy. Multiscale representation of data has shown great noise-removal ability when used in data filtering. In this paper, this advantage of multiscale representation is exploited to improve the accuracy of the nonlinear Takagi–Sugeno (TS) fuzzy models by developing a multiscale fuzzy (MSF) system identification algorithm. The developed algorithm relies on constructing multiple TS fuzzy models at multiple scales using the scaled signal approximations of the input–output data, and then selecting the optimum multiscale model that maximizes the signal-to-noise ratio of the model prediction. The developed algorithm is shown to outperform the time domain fuzzy model, NARMAX model, and fuzzy model estimated from pre-filtered data using an Exponentially weighted Moving Average (EWMA) filter through a simulated shell and tube heat exchanger modeling example. The reason for this improvement is that the developed MSF modeling algorithm improves the model accuracy by integrating modeling and data filtering using a filter bank, from which the optimum filter (for modeling purposes) is selected.     

考虑商品间适应度的在线零售商分仓选品优化研究

随着在线零售业的快速发展, 线上订单数量日益庞大, 分仓选品对于高效服务线上订单愈发重要. 现有研究多从降低拆单率的角度优化选品方案, 忽略了拆单造成的额外运输距离差异. 鉴于此, 首先, 构建以最小化拆单率和运输距离为目标的分仓选品问题模型, 提出综合衡量订单商品分布与客户地理分布的商品间适应度指标; 然后, 结合谱聚类方法设计基于固定-优化框架的两阶段分仓选品算法. 数值实验表明: 与直接求解分仓选品模型相比, 所提出算法的固定阶段能够有效缩小搜索空间, 在保证求解质量的前提下能够提升求解效率; 与现有文献算法相比, 所提出算法能够显著降低运输距离和拆单率, 为企业优化分仓选品方案提供决策支持.     

R*-树结点多目标遗传分裂算法

R*-树可有效地提高散乱点云、网格曲面等数据的处理效率.为提高R*-树结点空间利用率,将结点分裂过程视为多目标优化问题,采用遗传多目标优化求解结点分裂的近似全局最优解集;以结点最小外接矩形的重叠度和体积作为评价标准选取最佳分裂方案,实现R*-树的结点最优分裂.实例结果证明,该算法可实现各类复杂几何对象的R*-树结点分裂问题,并有效地降低R*-树结点分裂的参数依赖性,提高R*-树空间数据的查询效率.     

The OptdesX design optimization software

This paper describes the OptdesX design optimization software. The software provides a design environment for optimization of engineering problems. The software supports interactive variable and function selection, optimization with continuous and discrete algorithms, design space graphics, tolerance analysis, and control of noise in numerical derivatives, as well as numerous other features. The software is described and illustrated in terms of a small example problem. The software is available on Unix platforms only. Received December 30, 2000     

Nonlinear discrete-time models: state-space vs. I/O representations

This paper compares state-space and input–output realizations for nonlinear discrete-time dynamic models. For linear models, these two realizations are essentially equivalent and their structures are closely related, but these statements do not hold for nonlinear models. We illustrate this point with simple, realistic examples for which only one of the two realizations exists or for which both exist but their structures are profoundly different. Overall, the main point of this paper is the importance of the choice of realization in the development of nonlinear dynamic models.     

Ternary butterfly subdivision

This paper presents an interpolating ternary butterfly subdivision scheme for triangular meshes based on a 1–9 splitting operator. The regular rules are derived from a C² interpolating subdivision curve, and the irregular rules are established through the Fourier analysis of the regular case. By analyzing the eigenstructures and characteristic maps, we show that the subdivision surfaces generated by this scheme is C¹ continuous up to valence 100. In addition, the curvature of regular region is bounded. Finally we demonstrate the visual quality of our subdivision scheme with several examples.     

Visual–Motor Coordination Using a Quantum Clustering Based Neural Control Scheme

Visual–Motor Coordination is a problem considered analogous to the hand-eye coordination in biological systems. In this work we propose a novel approach to this problem using Quantum Clustering and an extended Kohonen's Self-Organizing Feature Map (K-SOFM). This facilities the use of the method in varying workspaces by considering the joint angles of the robot arm. Unlike previous work, where a fixed topology for the input space is considered, the proposed approach determines a topology as the workspace varies. Quantum Clustering is a method which constructs a scale-space probability function and uses the Schroedinger equation and its lowest eigenstate to obtain a potential whose minimum gives the cluster centers. It transforms the input space into a Hilbert space, where it searches for its minimum. The motivation of this work is to identify the implicit relationship existing between the end-effector positions and the joint angles through Quantum Clustering and Neural Network methods to fine-tune the system to correctly identify the mapping.     

异构监测传感器网络寿命最大化模型及其求解

对于有两类无线传感器节点组成的异构监测网络,给出了考虑连通覆盖约束条件的求解网络寿命的最优化模型;根据KKT条件,最优解处的不等式约束可以转化为等式约束,得到了模型的最优解,该最优解对于实时调整传感器网络的感知/发射半径具有很强的指导意义.数值结果表明,网络最大寿命值随传感器的感知/发射半径的增加而减小;同时传感器发射半径的调整,可以提高网络寿命.     

Human–Robot Cooperation Using Multi-Agent-Systems

In this paper a new intelligent robot control scheme is presented which enables a cooperative work of humans and robots through direct contact interaction in a partially known environment. Because of the high flexibility and adaptability, the human–robot cooperation is expected to have a wide range of applications in uncertain environments, not only in future construction and manufacturing industries but also in service branches. A multi-agent control architecture gives an appropriate frame for the flexibility of the human–robot-team. Robots are considered as intelligent autonomous assistants of humans which can mutually interact on a symbolic level and a physical level. This interaction is achieved through the exchange of information between humans and robots, the interpretation of the transmitted information, the coordination of the activities and the cooperation between independent system components. Equipped with sensing modalities for the perception of the environment, the robot system KAMRO (Karlsruhe Autonomous Mobile Robot) is introduced to demonstrate the principles of the cooperation among humans and robot agents. Experiments were conducted to prove the effectiveness of our concept.     

基于电力设备采购质量提升的供应商选择与管理

设备质量是电网安全稳定的物质基础,提高电网装备水平,推动电网装备迈向中高端,持之以恒提升电网本质安全水平,是当前和今后一个时期工作的重中之重,而只有把好电网设备入网质量关,即从采购质量入手,才能从本质上提高设备质量。近年来,国网公司在招标前开展供应商资质能力核实,通过对供应商的资质、业绩等信息及现场实际生产情况核实确认,初步掌握了潜在供应商是否具备生产合格产品的资质和能力。但仍存在设备运行期间发生重大故障等情况。因此,为有效防控和杜绝产品技术风险,推动现有电力企业由规模扩张型向质量效益型转变,强化电网全过程质量管控,从源头入手提高设备质量,建立基于PSO-ELM的供应商选择机制,推动电网设备向中高端迈进、提升电网本质安全与可靠水平。     

Creative destruction of computing systems: analysis and modeling

The paper analyzes the problem of rational replacement of computing systems. Such systems, especially high-performance computers, are expensive, but quickly become obsolete. A system analysis of the replacement problem is provided and the relevant modeling problems are identified and studied. The obtained results give certain rules for calculating the optimal lifetime of computing systems, which are based on the given rates of technological change in the related computer industry. Two simulation examples estimate the optimal lifetime of PCs and high-performance computers in the current US economy. The results are in good agreement with other recommendations and existing business practice.     

Explicit solutions for multivariate, discrete-time control problems under uncertainty

We consider discrete time control problems, where only the support sets of the initial condition and of the disturbances are known. We study the applicability of the DP method and, as a counterpart of the LQ problem of the stochastic setting, we present a problem that admits an explicit analytic solution. In particular, we characterize a property of compatibility between the system dynamics and the norms of the spaces, that is crucial to obtain the analytic solution also in the general multidimensional case.