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文中介绍了基于UML面向对象的需求分析方法在电力遥测信息系统中的应用,针对电力遥测系统功能行为描述不清、在遥测需求变化时,不能及时响应和追踪等问题,采用原型法、螺旋模型和嵌入式系统快速面向对象过程模型相结合的需求分析方法,使用了UML统一建模语言,创建了用例图、活动图和状态转换图,使用户操作流程、系统子功能模块以及设备节点的信息视图化,提高了系统分析效率。在需求分析阶段使用概念测试,总结出了概念测试用例,有利于及时发现和纠正需求定义中的错误,减少了后期需求变更的维护成本。基于UML的需求分析方法最终生成了需求规格说明书,建立了需求基线,为项目系统的设计奠定了基础。 相似文献
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《电子技术与软件工程》2016,(17)
在"互联网+"时代,企业网站是企业在互联网上的"门面",它具有树立企业形象,提高企业竞争力、展示企业产品及企业优势等战略意义。而作为网站建设需求分析人员,掌握一套科学、合理、高效的需求建模方法,有利于提高网站需求分析的效率与效果。本文以企业网站系统为载体,详细论述了基于UML用例图的需求建模过程,并形成企业网站系统需求用例模型。 相似文献
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《电子技术与软件工程》2017,(17)
将结构化思维方法面向整体、循序渐进、逐步求精的认知结构与软件需求分析和描述相结合,分层次由上至下、逐步细化地对软件需求进行描述,定义软件需求类型和需求元素,构建软件需求结构化的层次结构和模型,建立需求分析的模板,支持软件需求的分析和编写,并结合显示软件的需求分析和描述过程进行了应用实践,验证了结构化思维与软件需求分析相结合开展软件需求分析的有效性。 相似文献
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随着高校留学生数量的增多,大量的学生信息给高校教务管理工作带来了巨大挑战。基于目前广泛应用于高校教务管理系统的B/S结构,采用网络化设计方法,通过对需求进行分析,提出了基于B/S模式的留学生信息管理系统模型。在需求分析中,进行了用户需求分析,功能性需求分析,并对系统中的数据库和功能模块进行了详细设计。通过测试分析可知,该系统的所有功能都实现了预期目标。 相似文献
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数据库建模是数据库应用系统开发的关键步骤。在传统的结构化系统设计中,将需求分析阶段得到的ER图转化为关系数据库模型,而ER图仅仅着眼于数据。为了提高开发效率。采用面向对象的系统分析和设计方法,用系统分析阶段所获得的UML类图为基础进行数据库的逻辑结构设计,把类图转化为关系数据库模型。UML类图不但对数据建模,而且能对行为建模,这些行为在物理数据库中被设计成触发器和存储过程。在此以已开发的教务管理信息系统的数据库建模为例,讨论基于UML类图的数据库建模的方法与过程,该系统主要实现学生学籍管理和成绩管理。 相似文献
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P.C. de Mello M.L. Carneiro E.A. Tannuri F. Kassab R.P. Marques J.C. Adamowski K. Nishimoto 《Mechatronics》2013,23(1):94-107
This paper presents the new active absorption wave basin, named Hydrodynamic Calibrator (HC), constructed at the University of São Paulo (USP), in the Laboratory facilities of the Numerical Offshore Tank (TPN). The square (14 m × 14 m) tank is able to generate and absorb waves from 0.5 Hz to 2.0 Hz, by means of 148 active hinged flap wave makers. An independent mechanical system drives each flap by means of a 1HP servo-motor and a ball-screw based transmission system. A customized ultrasonic wave probe is installed in each flap, and is responsible for measuring wave elevation in the flap. A complex automation architecture was implemented, with three Programmable Logic Computers (PLCs), and a low-level software is responsible for all the interlocks and maintenance functions of the tank. Furthermore, all the control algorithms for the generation and absorption are implemented using higher level software (MATLAB®/Simulink block diagrams). These algorithms calculate the motions of the wave makers both to generate and absorb the required wave field by taking into account the layout of the flaps and the limits of wave generation. The experimental transfer function that relates the flap amplitude to the wave elevation amplitude is used for the calculation of the motion of each flap. This paper describes the main features of the tank, followed by a detailed presentation of the whole automation system. It includes the measuring devices, signal conditioning, PLC and network architecture, real-time and synchronizing software and motor control loop. Finally, a validation of the whole automation system is presented, by means of the experimental analysis of the transfer function of the waves generated and the calculation of all the delays introduced by the automation system. 相似文献
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针对红外遥控器整机手工测试速度慢,容易误测的缺点,根据对红外遥控器的测试要求,设计了一种能够配合流水线作业的快速红外遥控器测试装置,给出该装置的结构设计、控制电路设计和测试流程图。样机试验表明,该测试装置能够实现对不同型号红外遥控器各种技术指标的快速、精确测试和筛选,有效改进遥控器生产线的测试手段,提高生产效率。 相似文献
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Unified modeling language (UML) sequence diagrams combined with the UML profile for modeling and analysis of real-time and embedded (MARTE) systems are used to represent systems?? requirements. To enhance formal analysis abilities, sequence diagrams annotated with MARTE stereotypes are mapped into timed colored Petri nets with inhibitor arcs (TCPNIA). The mapping rules for the fragments of sequence diagrams and MARTE stereotypes are proposed respectively. They are proposed both in graphical and formal forms. The soundness of mapping rules is analyzed. The data related issues are handled through colored properties in TCPNIA models, guard functions and operational functions. A mapping rule for state invariant is proposed based on data related information. Through state invariant, complicated control relations can be expressed. Formal definitions for morphing and substitution in TCPNIA models are given. They provide modular and hierarchical modeling methods for TCPINA models. To show the applicability and feasibility of our method, an application example in vehicular ad hoc networks (VANETs) domain is studied. 相似文献
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随着对汽车安全性以及舒适性要求的提高,汽车厂商对于负载模拟系统的动态响应和控制精度也有了更高的要求。在电机控制系统中,参数的突变会引起试验台的稳定性降低并且伴有震荡产生。为克服震荡,文中使用伺服控制液压马达模拟EPS的方向盘系统以及负载系统代替原有的电机控制。通过Simulink仿真得到的系统阶跃响应图和Bode图分析发现,该试验台液压系统闭环稳定,且在一定程度上克服了震荡现象,具有可借鉴性。 相似文献
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系统重用技术作为数字化工程的一部分,具有减少重复劳动的特点。为数字化工程实现缩短设计周期,降低开发成本和提高产品质量提供了重要支持。面向对象系统中的类模型、状态模型和交互模型在系统重用方面起着重要作用,为了提取被重用系统中的结构和功能信息,以类图、状态图和序列图为例,研究其数据在系统存储文件.sbs包中的组织结构,并且采用VC工具对一组实例图中的信息进行提取。结果表明,通过该存储文件获得的信息完全符合原设计意图,这为管理重用信息提供了数据支持。 相似文献
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针对提高校园卡系统准确性和可靠性测试的要求,提出了Object-Z与Markov链结合的测试用例自动生成算法.使用Object-Z对系统进行形式化规约,生成测试场景和操作顺序图;将操作顺序图转换为Markov链使用模型;根据测试场景和Markov链使用模型生成数量相对合理的测试用例.该方法无需对系统进行运行,在需求分析与测试阶段就能对系统的功能进行测试.生成的校园卡系统测试用例证明该方法是有效的,并且在提高测试覆盖率的同时,使用Markov链也能保证对系统的可靠性测试. 相似文献
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Venkatesh K. MengChu Zhou Caudill R.J. 《Industrial Electronics, IEEE Transactions on》1994,41(6):611-619
Design methods for sequence controllers play a very important role in advancing industrial automation. The increasing complexity and varying needs of modern discrete manufacturing systems have challenged the traditional design methods such as the use of ladder logic diagrams (LLDs) for programmable logic controllers. The methodologies based on research results in computer science have recently received growing attention by academic researchers and industrial engineers in order to design flexible, reusable, and maintainable control software. Particularly, Petri nets are emerging as a very important tool to provide an integrated solution for modeling, analysis, simulation, and control of industrial automated systems. This paper identifies certain criteria to compare LLDs and Petri nets in designing sequence controllers and responding to the changing control requirements. The comparison is performed through a practical system after introducing “real-time Petri nets” for discrete-event control purposes. The results reported in this paper will help: (a) further establish Petri net based techniques for discrete-event control of industrial automated systems; and (b) effectively convince industrial practitioners and researchers that it is worthy and timely to consider and promote the applications of Petri nets to their particular discrete-event control problems 相似文献
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针对家用中央空调的特点,介绍了一种以富士通MB89P133A单片机为核心,集显示和控制功能于一体的中央空调室内显示控制面板的设计方法。给出了系统结构、部分电路原理图及软件流程图。 相似文献
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A data transmission filter design method is introduced. The method yields filters that are optimal in the sense that for given pole locations the intersymbol interference error is minimum. The prescribed loss requirements in the stopband are met and the eye diagrams are wide open.<> 相似文献