基于订货阈值的供应商延期支付策略设计

针对完全信息下以供应商为核心企业的二级供应链库存系统,将全单位延期支付与部分延期支付两种手段相结合,并在考虑延期支付期限与订货量相关的条件下,设计了基于供应商视角和订货阈值的延期支付策略,从而得出此策略能使系统利润达到帕累托最优.最后,通过数值算例对相关结论进行了验证和灵敏度分析.     

一种改进的自适应蚁群聚类算法

提出了一种改进的自适应蚁群聚类算法(improved adaptive ant clustering,IAAC).该算法改进了原来的AM(ant movement)模型,并在此基础上提出了一种网格化的移动策略来改善蚂蚁移动的随机性,使蚂蚁有意识地往模式较多的区域移动,极大地减少了蚂蚁无效的移动,使蚂蚁迅速地找到合适的位...     

基于RS485总线的监控系统研究与设计

PID调节仪表与传感器配合使用,可以实现对钢制品生产线上罩式炉温度的测量与显示。通过相应的执行器,可以实现对相关罩式炉设备的PID调节和控制、报警控制、数据采集和记录。然而对于具备多条生产线,而每条生产线使用多个PID调节仪表的现场环境而言,依次对每个仪表进行操作并不方便。采用Borland C++Builder 6设计了PID调节仪表的在线集中监控系统。,利用Borland C++Builder 6功能强大的图形化控制界面,及SPComm控件在串行口下编程,通过USB转RS485协议转换器,很好地实现了对生产线上各个分区仪表的实时监测与远程控制。     

Source number estimation and separation algorithms of underdetermined blind separation

Recently, sparse component analysis （SCA） has become a hot spot in BSS research. Instead of independent component analysis （ICA）, SCA can be used to solve underdetermined mixture efficiently. Two-step approach （TSA） is one of the typical methods to solve SCA based BSS problems. It estimates the mixing matrix before the separation of the sources. K-means clustering is often used to estimate the mixing matrix. It relies on the prior knowledge of the source number strongly. However, the estimation of the source number is an obstacle. In this paper, a fuzzy clustering method is proposed to estimate the source number and mixing matrix simultaneously. After that, the sources are recovered by the shortest path method （SPM）. Simulations show the availability and robustness of the proposed method.     

Research on the controller of an arc welding process based on a PID neural network

A controller based on a PID neural network （PIDNN） is proposed for an arc welding power source whose output characteristic in responding to a given value is quickly and intelligently controlled in the welding process. The new method syncretizes the PID control strategy and neural network to control the welding process intelligently, so it has the merit of PID control rules and the trait of better information disposal ability of the neural network. The results of simulation show that the controller has the properties of quick response, low overshoot, quick convergence and good stable accuracy, which meet the requirements for control of the welding process.     

基于PI控制律的通用递阶模糊控制器

为解决常规模糊控制器存在的通用性和工程简便性问题,针对动态特性随操作条件变化对象建立自适应递阶模糊控制器,实现闭环模糊增益调度,并引入稳定监督控制使控制系统具有工程稳定性。     

Meta-heuristic algorithms for parameter estimation of semi-parametric linear regression models

Consider the semi-parametric linear regression model Y=β^′X+ε, where ε has an unknown distribution F₀. The semi-parametric MLE of β under this set-up is called the generalized semi-parametric MLE(GSMLE). Although the GSML estimation of the linear regression model is statistically appealing, it has never been attempted due to difficulties with obtaining the GSML estimates of β and F until recent work on linear regression for complete data and for right-censored data by Yu and Wong [2003a. Asymptotic properties of the generalized semi-parametric MLE in linear regression. Statistica Sinica 13, 311-326; 2003b. Semi-parametric MLE in simple linear regression analysis with interval-censored data. Commun. Statist.—Simulation Comput. 32, 147-164; 2003c. The semi-parametric MLE in linear regression with right censored data. J. Statist. Comput. Simul. 73, 833-848]. However, after obtaining all candidates, their algorithm simply does an exhaustive search to find the GSML estimators. In this paper, it is shown that Yu and Wong's algorithm leads to the so-called dimension disaster. Based on their idea, a simulated annealing algorithm for finding semi-parametric MLE is proposed along with techniques to reduce computations. Experimental results show that the new algorithm runs much faster for multiple linear regression models while keeping the nice features of Yu and Wong's original one.     

一种用于嵌入式应用开发的软件体系结构*

研究从软件体系结构和应用开发过程两个角度对嵌入式应用开发作了改进和规范。在软件体系结构上采用了层模式和映像模式相结合的架构。在开发过程的规范和复用上采用了集成开发环境的思想。从改进后在实际应用开发中的结果来看,效果较为理想,值得进一步完善和推广。     

数字化电气信息采集对继电保护可靠性的影响

数字化电气信息采集为数字化变电站乃至智能电网信息化提供直接支撑.针对电子式互感器和合并单元的特点,给出数字化电气信息采集系统的功能模块.从互感器结构、数字传输、数据验证、采样频率和系统配置方面,分析数字化电气信息采集对继电保护可靠性的影响,着重说明了数据同步对差动保护的影响.指出由于存在电子式互感器的稳定性以及网络通讯可依赖性问题,目前数字化变电站继电保护系统在很大程度上仍沿用传统保护的设计思路,有待进行深入研究和突破.