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关键词： 可拓学   可拓基元   拓展分析   可拓变换   优度评价   形式化方法   自适应软件  

摘要： 可拓学的核心是建立灵活变通地应对不确定变化和灵感涌现的适应性模型。讨论引入可拓理论去描述、分析和评价软件系统的自适应性质、范围和程度的可能性。用基元描述软件实体,将软件系统构造成基元网,利用拓展分析、可拓变换和优度评价等定性与定量相结合的方法揭示了自适应软件系统的动态性质,并形成了一种自适应软件形式化方法。

关键词： Direct digital manufacturing   Heterogeneous object modeling   Multi-scale feature fabrication   Multi-material additive manufacturing   Hierarchically structured objects   Flow-based computation  

摘要： Structural hierarchy and material organization in design are traditionally achieved by combining discrete homogeneous parts into functional assemblies where the shape or surface is the determining factor in achieving function. In contrast, biological structures express higher levels of functionality on a finer scale through volumetric cellular constructs that are heterogeneous and complex. Despite recent advancements in additive manufacturing of functionally graded materials, the limitations associated with computational design and digital fabrication of heterogeneous materials and structures frame and limit further progress. Conventional computer-aided design tools typically contain geometric and topologic data of virtual constructs, but lack robust means to integrate material composition properties within virtual models. We present a seamless computational workflow for the design and direct digital fabrication of multi-material and multi-scale structured objects. The workflow encodes for and integrates domain-specific meta-data relating to local, regional and global feature resolution of heterogeneous material organizations. We focus on water-based materials and demonstrate our approach by additively manufacturing diverse constructs associating shape-informing variable flow rates and material properties to mesh-free geometric primitives. The proposed workflow enables virtual-to-physical control of constructs where structural, mechanical and optical gradients are achieved through a seamless design-to-fabrication tool with localized control. An enabling technology combining a robotic arm and a multisyringe multi nozzle deposition system is presented. Proposed methodology is implemented and full-scale demonstrations are included. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： Smart Manufacturing Systems   formal method   Supply Chain Operations Reference model   Systems Integration for Manufacturing Applications reference architecture  

摘要： Smart Manufacturing Systems need to be agile to adapt to new situations by using detailed, precise, and appropriate data for intelligent decision-making. The intricacy of the relationship of strategic goals with operational performance across the many levels of a manufacturing system inhibits the realization of Smart Manufacturing Systems. This article proposes a method for identifying what aspects of a manufacturing system should be addressed to respond to changing strategic goals. The method uses standard modeling techniques in specifying a manufacturing system and the relationship between strategic goals and operational performance metrics. Two existing reference models related to manufacturing operations are represented formally and harmonized to support the proposed method. The method is illustrated for a single scenario using agility as a strategic goal.

关键词： allocation of function   flight deck design   reduced crewing   operational event sequence diagrams   task analysis  

摘要： Function Allocation methods are important for the appropriate allocation of tasks between humans and automated systems. It is proposed that Operational Event Sequence Diagrams (OESDs) provide a simple yet rigorous basis upon which allocation of work can be assessed. This is illustrated with respect to a design concept for a passenger aircraft flown by just a single pilot where the objective is to replace or supplement functions normally undertaken by the second pilot with advanced automation. A scenario-based analysis (take off) was used in which there would normally be considerable demands and interactions with the second pilot. The OESD analyses indicate those tasks that would be suitable for allocation to automated assistance on the flight deck and those tasks that are now redundant in this new configuration (something that other formal Function Allocation approaches cannot identify). Furthermore, OESDs are demonstrated to be an easy to apply and flexible approach to the allocation of function in prospective *** Summary: OESDs provide a simple yet rigorous basis upon which allocation of work can be assessed. The technique can deal with the flexible, dynamic allocation of work and the deletion of functions no longer required. This is illustrated using a novel design concept for a single-crew commercial aircraft.

关键词： UML   多媒体资源   项目管理   系统建模  

摘要： 多媒体资源项目管理系统具有系统性和科学性特点,适应了大规模资源建设项目管理的实际需求。设计了UML的用例图、类图、序列图和状态图,为系统开发提供理论基础,同时提高了系统开发人员和用户之间的沟通效率。

关键词： 单片机   汇编语言   结构化程序   设计方案   验证解析  

摘要： 随着我国科研竞争实力的不断提升,涉及单片机技术开始得到大范围推广沿用。须知此类设备型号类别繁杂,特别是在编程规则方面,主张使用多汇编语言,至此相关程序通用、移植,以及维护性能条件等,都产生本质性的变化结果。因此,笔者决定联合现阶段我国结构化程序设计理念,进行既有单片机汇编语言的结构化程序设计方案系统化制定实施,希望能够借此为相关工作人员,提供相对可观的指导性建议。

关键词： 模型检验   路由协议验证   形式化方法   SPIN   CBMC  

摘要： 模型检验可验证路由协议的收敛性,环路问题,包交付失败,由于协议描述的歧义导致的问题,安全性缺陷等.实验一建立关注链路状态数据库同步的OSPF模型,设置攻击者路由器伪造消息,找到攻击成功的反例;实验二建立关注节点加入、失效和相应处理的Chord模型,寻找协议缺陷.两个模型都用显式模型检验工具SPIN和有界模型检验工具CBMC实现验证,实验结果表明SPIN解决此类问题更有优势.

关键词： 硬实时系统   工作流建模   元模型   统一建模语言  

摘要： 针对硬实时系统工作流描述在活动间数据交互的关系、时间约束等方面的不足,研究硬实时系统的工作流建模技术。定义硬实时约束的工作流元模型,给出元模型的组成元素及其相互关系,对具有硬实时约束的相关元素进行说明;在此基础上,使用UML的profile机制,通过对UML建模元素的扩展定义一种硬实时约束的工作流描述语言,称为HRTWDL(hard real-time constrained workflow description language);结合应用案例对HRT-WDL的使用进行说明。

关键词： 统一建模语言   UML   面向对象Petri网   网络协议  

摘要： 网络协议的形式化描述与验证技术是整个协议设计与实现的基础,目前所采用的形式化描述与验证技术各有优势,本文综合了UML(the Unified Modeling Language)和面向对象Petri网各自的优势,提出了UML和面向对象Petri网相结合的建模方法。并以停等协议为例进行说明。

关键词： 信息网络   信息中心网络   形式化方法   身份认证   授权  

摘要： 信息中心网络(information-centric networking,ICN)已经成为下一代网络架构研究的新热点。针对NetInf(network of information)架构下,由于无效的数据注册,NRS在发布阶段容易受伪装和内容投毒攻击,提出在发布和检索之前增加一个注册阶段,并集成认证和授权方案;该阶段在主机访问Net Inf系统之前,对其进行身份认证并采用基于能力的访问策略来解决未经授权的访问问题。通过形式化方法验证,该方法提高了Net Inf框架的安全性。