共查询到20条相似文献,搜索用时 526 毫秒
1.
通过建立MRPII系统对象模型、动态模型和功能模型,分析了MRPII管理软件包的组织结构,为软件包开发的程序设计与实现提供基础研究了MRPI系统各主要构成模块及彼此之间的相互作用,抽象出系统的基本对象类、对象的合法变化序列,以及系统中数值之间的函数关系通过分析MRPI系统事件追踪图和数据流图,建立系统的三种模型从而从一个全新的角度来分析研究MRPII系统 相似文献
2.
汪虹 《安庆师范学院学报(自然科学版)》1998,4(3):66-68
从实时监控系统设计角度出发,对一种基于MCS-51单片机的容错多任务实时操作系统MROS51作一讨论,阐述了MROS51的设计思想、层次结构和系统功能,给出了关键数据结构和主要实现方法,并对MROS51的实时性和容错性软件技术作了介绍。该系统已成功地用于中波发射机微机监控系统中。 相似文献
3.
介绍了DS1609 双端口RAM 的性能特点,以时序分析的方法,提出了DS1609 双端口RAM 与51 系列单片机接口的方案. 在多CPU 微处理系统中应用DS1609 双端口RAM,由于其二端口异步操作的特点,不仅简化了系统程序工作要求,而且提高了系统运行的可靠性. 相似文献
4.
一种新的分析和检查需求模型 总被引:1,自引:0,他引:1
由于SCR是较实用的定义软件系统需求的方法,以此方法为基础,提出一个形式化的分析和检查需求的模型。此分析和检查模型主要根据综合知识表示模型的一些基本原理,使用状态转换规则、语义计算规则和属性来形式化地描述SCR中表格符号的语义,并通过执行规则来自动分析由SCR定义的需求。为便于理解,给出了一个简单的实例来介绍如何分析和检查基于SCR的需求的一致性和完整性。 相似文献
5.
文章讨论了求解大型稀疏最小二乘问题的MSOR方法,考虑了2-BMSOR和3-BMSOR方法的收敛区域,并且基于‖A2A-11‖2给出了最佳2-BMSOR松弛参数和相应的收敛谱半径 相似文献
6.
FMS调度研究的现状与发展 总被引:2,自引:0,他引:2
原清海 《上海交通大学学报》1998,32(5):124-127
FMS的高效率和柔性很大程度上取决于FMS调度的水平.对FMS调度问题进行了系统总结,划分了其类型,并对现有的调度规则和评价指标作了评述.从方法学的角度,对已有的FMS调度方法进行了分析和比较,认为目前广泛应用的基于知识的FMS智能调度系统大多是结构不良的,存在三个明显的缺点:常识知识难以形式化、基于符号逻辑的推理效率不高以及系统不通用.提出了人机协同控制的FMS调度方法.以期提出一个框架来引导将来沿此方面的工作. 相似文献
7.
水稻花发育相关MADS-box基因的克隆 总被引:1,自引:1,他引:0
以水稻幼穗总RNA为模板,利用3′-RACE克隆了8个接近于全长的水稻MADS-box 基因的cDNA.在GenBank 的数据库中查询表明,其中2个FDRMADS1,FDRMADS2分别与已报道的水稻MADS-box 基因Os-MADS5和OsMADS45有极高的同源性,另外6个为新的尚未见报道的水稻MADS-box 基因.系统进化树分析表明FDRMADS1,FDRMADS2和FDRMADS4可能与C组基因的功能相关;FDRMADS3,FDRMADS6和FDR-MADS7可能与A 组基因的功能相关 相似文献
8.
提出了一种采用数字信号处理器(DSP)的标准清晰度电视(SDTV)实时复用器的实现方案。系统以TI通用定点DSP TMS320C50为主处理器,配合少量呵编程逻辑器件(PLD),在硬件和软件设计上充分利用DSP的特点,实现了将音频、视频和辅助数据实时复用成符合MPEG2系统层传输规范的码流。系统还具有RS编码功能和E2接口,具备加扰扩展功能。由于系统规范主要由DSP软件实现,因而能通过修改软件以适 相似文献
9.
介绍了一种新的面向对象的形式化规范说明技术VDM++它是VDM的一种扩充,并且通过一个实例说明如何应用VDM++技术对面向对象系统进行形式化规范说明。 相似文献
10.
结合形式化方法的UML系统开发 总被引:1,自引:3,他引:1
介绍并讨论了在系统开发过程中使用UML(Unified Modeling Language)与其他形式化方法得到的一种精化模型,而且这一模型也同样支持形式化的分析和验证. 相似文献
11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness. 相似文献
12.
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly. 相似文献
13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。 相似文献
14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death. 相似文献
15.
Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula- 相似文献
16.
Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re- 相似文献
17.
Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that 相似文献
18.
《上海师范大学学报(自然科学版)》2014,(5):550
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with 相似文献
19.
20.
《吉林大学学报(理学版)》2014,(5):1105
<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has 相似文献