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1.
主动数据库的模型及实现途径   总被引:7,自引:0,他引:7  
毕利 《计算机工程》2000,26(9):102-103,160
介绍了主动数据库系统的模型,ECA规则和事件模型及实现途径,并讨论了在关系模式下主动数据库系统的基本框架和事件机制的优化策略。  相似文献   

2.
论述了多用户交互的特性,提出了一个多用户交互模型(E*Fb*Ft)nCAn。针对该模型的特点,建立起ECA规则模型,讨论了交互事件、回调事件和复合事件。分析了将(E*Fb*Ft)nCAn模型转换为主动机制系统中的事件、规则的方法。用例表明基于主动机制的(E*Fb*Ft)nCAn模型是有效的。  相似文献   

3.
一种分布式实时系统软件体系结构   总被引:3,自引:0,他引:3  
针对分布式实时系统的软件体系结构进行了深入研究,试图为应用开发者提供一个开发分布式实时系统的通用框架,首先提出由事件总线和数据访问总线组成具有开放结构的分布式实时系统的参考模型,然后详细讨论了事件总线和数据访问总线的组成成分,工作原理和工作过程,最后,研究了支持平台的单一映象编程模型,实时QoS的支持,提供主动服务机制,灵活开放的系统结构等技术特点。  相似文献   

4.
一种基于策略的软件自适应框架   总被引:1,自引:0,他引:1  
普适计算成为一种新的应用模式,普适计算运行环境的复杂性对软件自适应提出了新的挑战.提出一种基于策略的软件自适应框架,该框架采用基于上下文的自适应策略模型及上下文驱动的事件机制实现软件运行的自适应能力,该框架屏蔽了软件运行环境的复杂性,具有较强的可扩展性.  相似文献   

5.
李雅峰  沙晓光  李会杰 《微计算机信息》2007,23(22):198-199,227
本文在讨论了故障和容错机制与故障注入模型相关的几个问题之后,提出了一种形式化的故障注入模型框架,并给出了其应用算法。  相似文献   

6.
基于构件技术的应用框架元模型的研究   总被引:44,自引:2,他引:44       下载免费PDF全文
从应用框架构造和组成的角度,使用UML(unified modeling language,统一建模语言)符号体系,提出了框架元模型,给出了框架内部组成元素的语义,特别是对扩展点的表示和实现机制进行了详细的讨论.最后以电信综合营业系统框架为例,给出了框架元模型的一个实例,并给出了应用框架的复用方法.  相似文献   

7.
吴立国  王青  马波 《计算机工程与应用》2006,42(11):119-123,168
文章提出了一种新型远程作业管理系统框架。该框架基于JMX架构,融合了基于企业权限映射模型的安全机制、JSF(JavaServerFace)的可视化框架等多项技术,有效地改进了传统的作业管理系统的可扩展性差、安全机制不足和缺乏统一、完善的系统管理三点不足。并基于该框架实现了国家863项目“远程作业管理系统”,实现了灵活的系统组件动态配置,基于企业权限映射模型的高安全和可视化管理界面,比较了实现系统和传统系统的优点,讨论了其中涉及到的关键技术。  相似文献   

8.
实时主动数据库中的事件   总被引:12,自引:0,他引:12  
主动数据库系统一般采用触发器机制实现系统的主动能力,而事件则是触发器机制中的重要部分。本文讨论实时主动数据库系统ARTs-I中事件的概念、结构与说明以及事件探测与复合事件的处理;提出了一种支持实时应用的S-A触发器模型;将定量限制与时间事件统一起来,使定时机制与主动数据库更紧密地结合为一体。  相似文献   

9.
事件抽取旨在把含有事件信息的非结构化文本以结构化的形式予以呈现。现有的基于监督学习的事件抽取方法往往受限于数据稀疏和分布不平衡问题,具有较低的召回率。针对这一问题,该文提出一种利用框架语义优化事件抽取的方法,引入框架类型作为泛化特征,在此基础上进行框架类型和事件类型的映射,然后结合框架类型识别模型和事件类型识别模型进行协作判定,以此优化事件抽取的召回性能。实验结果显示,针对触发词(事件类型)识别任务,相较于仅使用事件类型识别模型,该文提出的框架语义辅助的事件类型识别模型能够提高抽取召回率6.44%(5.74%),提高F值1.45%(0.83%)。  相似文献   

10.
全面分析了车辆异常行为的识别及交通流参数采集处理方法,提出构建具备二级报警机制的交通事件自动识别系统框架模型.该系统可充分利用高速公路目前已有的监测设备作为系统数据采集的前端设备,提高交通事件检测的准确性和可靠性,减少二次事故的发生.  相似文献   

11.
郭涛  曲宝胜  郭勇 《电脑学习》2011,(2):113-116
本文简单介绍了自然语言处理发展的现状,讨论了自然语言处理模型,将其分为三大类:分析模型、统计模型及混合模型。具体介绍了分析模型原理及存在的问题,重点讨论了各种统计模型的特点及局限性,最后简单介绍了混合模型,并指出目前自然语言处理技术中存在的问题。  相似文献   

12.
分布式Web组件模型分析   总被引:1,自引:1,他引:0  
着重分析了组件模型的规范和CORBA、DCOM两种工业标准的组件模型。并探讨了组件模型的体系结构和分布工计算等问题。  相似文献   

13.
Recently, many fuzzy time series models have already been used to solve nonlinear and complexity issues. However, first-order fuzzy time series models have proven to be insufficient for solving these problems. For this reason, many researchers proposed high-order fuzzy time series models and focused on three main issues: fuzzification, fuzzy logical relationships, and defuzzification. This paper presents a novel high-order fuzzy time series model which overcomes the drawback mentioned above. First, it uses entropy-based partitioning to more accurately define the linguistic intervals in the fuzzification procedure. Second, it applies an artificial neural network to compute the complicated fuzzy logical relationships. Third, it uses the adaptive expectation model to adjust the forecasting during the defuzzification procedure. To evaluate the proposed model, we used datasets from both the Taiwanese stock index from 2000 to 2003 and from the student enrollment records of the University of Alabama. The results of our study show that the proposed model is able to obtain an accurate forecast without encountering conventional fuzzy time series issues.  相似文献   

14.
The paper discusses the development of a prototype solid modeling system based on the extended octree modeling approach and its applications in 3-D NC machining simulation and automatic verification. Along with a simple hierarchical data structure, the extended octree model uses the face boundary information (i) to represent complex objects, (ii) to improve object representational accuracy, and (iii) to accelerate the model updating procedures in a graphic simulation process. The improved representational accuracy makes it possible to carry out automatic NC program verification by generating the machined model of the part through the simulation and comparing it with the designed model of the part. The paper also addresses the issues of model conversions from CSG and B-Rep schemes to the corresponding extended octree models and the issues of carrying out Boolean operations on those extended octree models. A prototype system has been implemented and is integrated with AutoCAD AME solid modeler for object modeling and for NC simulation purpose.  相似文献   

15.
This paper discusses the issues involved in evaluating a software bidding model. We found it difficult to assess the appropriateness of any model evaluation activities without a baseline or standard against which to assess them. This paper describes our attempt to construct such a baseline. We reviewed evaluation criteria used to assess cost models and an evaluation framework that was intended to assess the quality of requirements models. We developed an extended evaluation framework and an associated evaluation process that will be used to evaluate our bidding model. Furthermore, we suggest the evaluation framework might be suitable for evaluating other models derived from expert-opinion based influence diagrams.  相似文献   

16.
网络应用系统或数据库管理系统安全管理中一个重要问题就是访问控制,本文对传统的自主访问控制模型、强制访问控制模型和基于角色的访问控制模型等几种主流模型进行了介绍,并在最后详细分析和介绍了RBAC96模型.  相似文献   

17.
Nowadays a large number of user-adaptive systems has been developed. Commonly, the effort to build user models is repeated across applications and domains, due to the lack of interoperability and synchronization among user-adaptive systems. There is a strong need for the next generation of user models to be interoperable, i.e. to be able to exchange user model portions and to use the information that has been exchanged to enrich the user experience. This paper presents an overview of the well-established literature dealing with user model interoperability, discussing the most representative work which has provided valuable solutions to face interoperability issues. Based on a detailed decomposition and a deep analysis of the selected work, we have isolated a set of dimensions characterizing the user model interoperability process along which the work has been classified. Starting from this analysis, the paper presents some open issues and possible future deployments in the area.  相似文献   

18.
描述了访问控制和逻辑的关系,并将访问控制授权判决问题归约成逻辑蕴涵问题;总结了基于逻辑的访问控制的基本逻辑问题,即逻辑基础、可判定性和安全性分析;分析了一些访问控制模型的基本逻辑问题,包括基于身份的访问控制模型、基于信任管理的访问控制模型和基于属性的访问控制模型;指出了结构化属性描述能力和安全性分析是基于逻辑的访问控制需要进一步研究的问题.  相似文献   

19.
为深入了解基于深度学习的单图像超分辨率重建(SISR)的发展,把握当前研究的热点和方向,针对现有基于深度学习的单图像超分辨率重建模型进行了梳理。介绍了相关深度学习算法和基于深度学习的模型以及评价指标,并通过实验对比分析现有模型的性能,其目的在于从本质上了解基于深度学习的单图像超分辨率重建模型的优势;对单图像超分辨率重建的关键问题进行了总结,并对未来的发展趋势进行了展望。  相似文献   

20.
Because of the increasing complexity of the problems faced by decision makers and the nature of decision support systems, decision models are becoming more and more crucial to their success. In this paper, a general framework for model management, which can integrate model management and data management and handle issues in model management such as model creation, model modification and model use is proposed.  相似文献   

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