A Supermodel Framework Supporting Validated Upgrading of Reactive Systems

A software product is typically upgraded many times over its lifetime. Reactive systems are no exception, undergoing evolutionary version changes to add features and fix bugs. Evolving these stateful systems, such as email clients, software agents, smart cell phones, and personal digital assistants, is complicated by the fact that new versions of the software must deal correctly with legacy instances. Users of earlier versions have invested significant resources in creating the state of the legacy instance, and usually require that this state be upgraded appropriately when the new system version is activated. However, validating the correctness of this upgrading behavior is particularly difficult, whether through testing or automated reasoning techniques like theorem proving or model checking, because legacy states are typically unreachable to the new version of the software. This paper explores this problem and requirements for its solution. It then presents a simple and widely applicable upgrade framework, based upon the idea of a supermodel that allows upgrade behavior to be validated using mainstream approaches. Finally, it also gives techniques for simplifying the validation problem.     

Optimal design of a welded I-section frame using four conceptually different optimization algorithms

The purpose of this study is to investigate the suitability of four conceptually different optimization algorithms for specifically the optimal design of welded I-section frames. The cost function to be minimized is the volume of the frame. Constraints on lateral-torsional buckling as well as local buckling of the beam and column webs and flanges are taken into consideration. The algorithms evaluated include a genetic algorithm, a novel leap-frog gradient method without line searches, as well as an orthogonal search method requiring no gradients and the differential evolution technique. Received September 26, 2001 RID="*" ID="*"Part of this paper was presented at the World Congress on Structural and Multidisciplinary Optimization, June 4–8 2001, Dalian, China     

王照与胡适

王照与胡适的交往,缘于同梁漱溟的争论,反映出他们思想上的殊途同归之处:胡氏是充分的西化论者,强调世界文化的同一性,主张学习西方的物质文明和精神文明,主张一步一步的渐进改革。王氏也强调物质文明的重要性,又从"世上那有捷径可走"的直观的进化论出发,在改革的途径上与胡氏达成了共识。     

呼唤网络领域的安全保障

分析Internet在网络安全方面失控原因 ,提出在网络安全方面实施安全保障的战略构思和策略     

Hydration Characteristics of Sodium Sulfate Slag Cement System

The hydration characteristics by thermal analysis ( DTA ) were determined, and an isothermal calorimeter (IC) was used to study the pastes . The experimental results indicate: (1) The main hydration products of SSC are C-S-H( I ) gel with a low Ca/Si ratio, crystalline Thomsonite-type and AFt-type phases containing certain alkali cations; (2) No phases of the AFm-type and high alkaline Ca( OH)2 in SSC system could benefit the hydrated cements to improve its strength and durability; (3) Crystalline Thomsonite-type and AFt-type phases containing Na will greatly reduce free alkali and alleviate the harmness of alkali aggregate reaction ( AAR) in SSC system; (4) Similar to ordinary Portland cement( OPC), the hydration process of SSC could be classified into five stages : initial, induction, acceleration, deceleration and decay; (5) Regardless of the activator used, the apparent activation energy is higher with the increased slag in cement system, and the rising temperature could promote the hydration of SSC.     

基于ERP的财务管理系统的研究与实现

针对现行财务管理系统存在的问题,设计开发出一套新型的基于ERP的财务管理系统,介绍了系统的功能与实现过程。最后对如何有效实施提出了建议。该系统使财务会计与管理会计通过集成达到了财务管理的一体化,提高了财务管理的效率,为企业决策提供了可靠的财务依据。     

汽车电子商务与企业ERP的整合

作为汽车企业信息系统主体的制造资源计划MRP-Ⅱ/ERP系统应该与电子商务有机结合起来,充分利用互联网络技术,将供需链管理、客户关系管理、电子商务、办公业务等功能全面集成,形成资源共享、数据共享,适应网络经济的充分柔性的汽车企业管理信息系统.     

模板法电化学共沉积Ni-Mo合金纳米线的研究

使用多孔阳极氧化铝模板, 电沉积制备了Ni-Mo合金纳米线. 用扫描电镜（SEM）和表面能谱（XPS）表征沉积物形貌和组成, 用伏安法研究了Ni-Mo合金纳米线的沉积条件及催化性能. 结果表明, Ni-Mo合金纳米线的直径在20～30 nm之间. Ni-Mo共沉积的伏安图上在-1.4 V（vs Ag/AgCl）左右出现一个扩散电流平台. 光电子能谱（XPS）表明, Ni-Mo合金纳米线的共沉积电位出现在-1.4 V以后, 大于这个电位钼以低价氧化物存在. Mo-Ni离子浓度比大于2时扩散电流平台消失. 柠檬酸盐浓度达到2～3倍镍盐浓度时, 扩散电流平台趋于稳定. 在较优条件下电沉积的Ni-Mo合金纳米线显示较高的析氢催化活性.     

企业资源计划系统的应用

介绍了企业资源计划系统(ERP-Enterprise Resource Planning)的功能、特点、管理思想及应用阶段,说明了企业实施ERP系统存在的风险,最后分析了ERP系统成功的标志。为企业成功实施ERP项目提供了很好的借鉴。     

企业实施ERP项目的培训管理

在现今我国实现“以信息化带动工业化,以工业化促进信息化”的战略部署中,大力推进ERP在企业中的有效应用,是促进企业管理创新的突破口,而企业要想保证ERP项目的有效实施,必须首先抓好ERP项目培训管理。本文分析了ERP项目培训管理的要点,提出了ERP项目培训中应注意的问题。