Constrained nonlinear multivariable control of a fluid catalytic cracking process

In this paper, a nonlinear constrained optimization strategy is proposed and applied to the reactor-regenerator section of a fluid catalytic cracking (FCC) unit. A nonlinear dynamic model of the fluid catalytic cracking process was used for the dynamic analysis of the plant and nonlinear multivariable control system. The model realistically simulates the riser-reactor and the one stage regenerator by assembling the mass and energy balances on the system of reactions. The model results were tested in a real-time application and the results were used to provide the initial values for the nonlinear control system design. A dynamic parameter update algorithm was used to reduce the effect of large modelling errors by regularly updating the model parameters. The constrained nonlinear optimization algorithm and strategies were tested in real-time on the fluid catalytic cracking reactor-regenerator. The results compared favourably to those from a linear multivariable controller.     

基于多通信方式实现DSP程序在线编程

该文针对基于DSP的野外及外场数字设备更新升级提出了一种基于多通信方式的DSP程序在线编程的新方法.该方法同时具备有线、无线多种通信能力,可以根据具体环境灵活选择.使用可扩展通信协议栈,支持对通信接口和通信协议的扩展.程序更新基于DSP/BIOS实时操作系统,根据预设算法,更新指定存储区的可执行程序,实现对原程序替换和升级.实践表明,把该方法应用于系统的目标程序在线编程,程序功能稳定可靠,使DSP程序的更新脱离了仿真器,满足了现场更新的时效性、可扩展性和便携性要求.     

基于多跳蜂窝网的组位置管理策略

提出了一种成组进行位置管理的策略,分析了彼此临近的移动台组成一个自组织网的基本网络模型,提出了向中继点注册,由中继点进行信令压缩,组成组控制信令,成批向网络报告位置的位置更新的策略;采用M/M/n/n模型具体比较了批处理方案与传统方案的性能,说明作者的方案不仅减少了移动台的发射功率,还大量节省了频率资源,增加了系统的吞吐能力。     

使用控制模型中可变属性之间影响的安全分析

在使用控制模型中,可变属性之间的更新影响有助于应用系统的表达,但同时也引发一系列安全问题.首先采用属性间影响图描述可变属性之间的影响关系,并给出相应的影响规则,主要解决在属性影响下可变属性的更新问题;然后分析基于更新时序的可变属性之间的影响关系,提出相应的影响规则,以解决可变属性之间影响的安全问题.     

Purchase Contract Management for Fashion Products

This paper develops a tow-stage purchase contract for fashion products to manage the buyer's cost. In addition to require a commitment, the purchase contract allows the buyer to adjust the commitment at a later stage. We model the buyer's problem and obtain explicit formulae to describe the buyer's optimal behavior. We analyze the effect of parameters on the buyer's cost and prove that such contract can decrease the buyer's cost numerically.     

基于MAP的多态自适应NEMO模型

为实现对移动网络(NEMO)的高效支持,提出了基于MAP的多态自适应NEMO模型,根据节点组成情况将NEMO分为三种状态:稳态、亚稳态、活跃态,结合移动IPv6、MAP及前缀绑定更新实现对三态的自适应支持,并设计多态NEMO通信优化算法对NEMO与外界的通信过程进行优化,提高了NEMO的整体通信效率。     

A class of variational strain‐localization finite elements

We present a class of finite elements for capturing sub‐grid localization processes such as shear bands and void sheets. The elements take the form of a double surface and deform in accordance with an arbitrary constitutive law. In particular they allow for the development of displacement and velocity jumps across volume element boundaries. The thickness of the localized zone is set by an additional field variable which is determined variationally. The localization elements are inserted, and become active, only when localized deformations become energetically favourable. The implementation presented in this work is three‐dimensional and allows for finite deformations. The versatility and predictive ability of the method are demonstrated through a simple shear test and the simulation of the dynamic impact of a pre‐notched C300 steel sample by a steel projectile. Copyright © 2004 John Wiley & Sons, Ltd.     

Hierarchical Group Location Tracking for Transportation Systems in Wireless Personal Communication Networks

A hierarchical group location tracking (HGLT) based on grouplocation tracking and hierarchical location update is proposed toreduce the location management cost for terrestrialtransportation systems (TSs) in personal communication networks. A global group location update (GGLU) and a local group locationupdate (LGLU) are performed to provide an accurate position for auser. The GGLU informs a virtual visitor location register of thecurrently camped-on location area and the LGLU informs the servingmobile switching center of the currently camped-on cell. Althoughthe LGLU is done each time a TS moves into a new cell, it causessmall increment in the signaling cost due to localized updates andgroup updates compared with the previous group location trackingscheme. The proposed scheme significantly reduces the paging costbecause the scheme pages only a camped-on cell using the LGLUinformation. Compared with the previous schemes, the HGLT reducesthe location management cost, and it is more efficient as thecost for paging a cell increases.     

基于提升框架的传统小波研究

提升框架的核心思想是通过有限步预测和更新来构造小波滤波器。由于传统小波的多相矩阵可以分解为多个矩阵的乘积,本文从原理上说明了这些矩阵可以看作是预测算子和更新算子,并给出了具体例子。在例子中,把小波分解变换与重建交换表示成提升框架的形式,说明了提升框架对传统离散小波变换具有包容性。     

个人通信位置管理的计时双位置算法

提出了一种新的位置管理算法——计时双位置算法，从理论上导出了TTLA算法的总代价函数，给出了传统IS-41和双位置算法(TLA)的统～数学框架。通过性能分析可知，TTLA算法能根据用户的呼叫移动比，在IS-41和TLA两者之间进行选择，综合性能好，且在某些情况下，性能要超过另两种算法。