Performance modeling,real-time dispatching and simulation of wafer fabrication systems using timed extended object-oriented Petri nets

Semiconductor wafer fabrication system (SWFS) is the most complex and capital-intensive phase in the entire semiconductor manufacturing cycle. With characteristics of re-entrant processing routes, equipment uncertainty, product diversity and improving technologies, great challenges are presented in SWFS’s modeling, scheduling and simulation. To implement efficient production control, this paper provides a timed extended object-oriented Petri nets (TEOPNs) approach to performance modeling, real-timed dispatching and simulation of SWFSs. The TEOPNs models are constructed in a hierarchy to accord with the real-world SWFS’s organization, and a new type of signal place is added into the TEOPNs to respond the dynamic states of all processing facilities. A novel autonomy and coordination-based real-time dispatching mechanism (A&C-RDM) is developed in this paper, which executes under the support of the TEOPNs-based hybrid real-time dispatching control system (HRDCS). Owning to the ability of gathering dynamic real-time information of all production facilities and WIP products, the HRDCS can make adaptive dispatching decisions according to the local and global real-time processing status. Two sets of key elements of real-time dispatching, i.e. the state thresholds and dispatching rules, are defined in the HRDCS so that the A&C-RDM can integrate different types of dispatching rules. A set of simulation experiments prove the efficiency of the proposed modeling and dispatching algorithm. In summary, the proposed TEOPNs, HRDCS and A&C-RDM form the cornerstones of a real-time dispatching simulation prototype of SWFS, and the work described in this paper carries out an advanced integrated “modeling–dispatching–simulation” methodology.     

Finite-time weighted average consensus with respect to a monotonic function and its application

The consensus state is an important and fundamental quantity for consensus problems of multi-agent systems, which indicates where all the dynamical agents reach. In this paper, weighted average consensus with respect to a monotonic function, which means that the trajectories of the monotonic function along the state of each agent reach the weighted average of their initial values, is studied for a group of kinematic agents with time-varying topology. By constructing a continuous nonlinear distributed protocol, such a consensus problem can be solved in finite time even though the time-varying topology involves unconnected graphs. Then the distributed protocol is employed to compute the maximum-likelihood estimation of unknown parameters over sensor networks. Compared with the existing results, the estimate scheme proposed here may reduce the costs of data communication, storage memory, book-keeping and computational overheads.     

Sweeping Points

Given a set of points in the plane, and a sweep-line as a tool, what is best way to move the points to a target point using a sequence of sweeps? In a sweep, the sweep-line is placed at a start position somewhere in the plane, then moved orthogonally and continuously to another parallel end position, and then lifted from the plane. The cost of a sequence of sweeps is the total length of the sweeps. Another parameter of interest is the number of sweeps. Four variants are discussed, depending on whether the target is a hole or a pile, and whether the target is specified or freely selected by the algorithm. Here we present a ratio 4/π≈1.27 approximation algorithm in the length measure, which performs at most four sweeps. We also prove that, for the two constrained variants, there are sets of n points for which any sequence of minimum cost requires 3n/2?O(1) sweeps.     

基于ATMEGA16语音录放系统的设计与实现

介绍了具有较强通用性的语音告警系统。系统通过单片机ATMEGA16控制语音芯片ISD1790,实现了在不同情况下提供不同的语音提示告警,且提示语音可以自行录入。最后通过D类音频功率放大器TPA3101D2,实现了高音质大音量语音输出。     

OMT在企业物流分析中的应用

文章介绍了面向对象的模型化技术（ＯＭＴ）的基本概念,分析了它的实现过程,即对象模型、动态模型、和过程模型的建立,并以一个具体的实例说明其在企业物流分析中的应用。     

一个实用的面向中小型企业的产品数据管理系统

介绍了一个面向中小型企业的产品数据管理系统SMPDM。它是一个建立在PDM基本框架之上,集产品结构与配置管理、图档管理、工艺卡片管理及编码管理为一体的实用系统。它实施简单,见效快,是管理中小型企业产品数据的良好工具。     

80C51原始IP核内部RAM的扩展方案

80C51系列单片机是一类经典的8位微处理器,其设计方法和体系结构一直是其他各类单片机设计的参考典范,自从20世纪80年代面世以后,得到了极大的发展与应用。直到今天,市场上还有一大部分单片机应用成品将其作为处理核心。基于80C51系列单片机无知识产权保护、市场应用广泛等优点,对其进行功能拓展,既有利于经济上节约成本,也有利于成果的推广使用。