一个基于对象代理模型的多表现地理信息系统

文中提出了一种基于对象代理模型的实现多表现GIS的新方法。通过地理对象的代理对象来定义多表现，因此代理对象可以用来表示对象的视角多样性和角色多样性。通过对象更新迁移可以支持动态分类和系统一致性维护。另外，对象及其代理对象之间的双向指针使得跨类查询变得非常容易，从而可以扩展查询的范围。文中实现了一个基于对象代理模型的多表现GIS原型，性能测试表明该方法比传统的方法更加有效。     

健壮性分析在软件开发中的应用

以迷宫的创建作为软件开发对象,本文探索了ICONIX统一对象建模方法中的健壮性分析在软件开发中的应用,介绍了健壮性分析的概念,运用健壮性分析设计开发了迷宫创建软件,重点探讨了健壮性分析在分析模型与系统设计模型之间的关键链接作用.     

基于组件对象模型的安全性策略

从组件对象模型的角度来看,安全的范围是很广泛的.COM不直接访问安全性协议,而是使用微软的安全性支持提供者接口来实现安全性.在使用COM进行工作时,可以用基于对象和基于角色的两种安全性策略机制,选择不同的安全性策略将大大影响设计组件的方式.     

RBAC模型时间约束的OCL描述

基于角色的访问控制模型以其灵活性、方便性和安全性在许多系统的权限管理中得到普遍应用,而引入时间约束后的角色访问控制更能增强系统的安全性和模型的描述能力。该文使用对象约束语言OCL来描述模型中的时间约束,使模型更加直观和精确。     

基于数据对象的RBAC权限访问控制模型

针对传统的基于角色的权限访问控制模型没有考虑数据对象权限分配的缺点,提出一种基于数据对象的RBAC(role-based access control)模型.该模型基本思想是:用户和角色不直接相连,而是通过数据对象把用户和角色相联系,同时将角色对象分为公有角色和私有角色,使得同一用户的不同数据对象,可以拥有不同的功能访问权限.实验结果表明,该模型有效地实现了数据权限和功能权限的分离,改善了传统RBAC模型权限管理模式.     

基于角色的业务审批模型的设计与实现

以江西省医疗保险系统中的业务审批流程为对象,设计了一种审批权限管理控制模型.采用基于角色的访问控制技术(RBAC),通过引入角色的概念,使得用户审批权限管理条理化,业务审批无纸化.该模型具有高扩展性、易维护的特点,最后给出其在实际系统中的实现.     

角色Use Case:UML的一个更加完全的分析方法

根据角色模型 ,讨论了一个更加完全的 U ML角色 U se Case分析方法 .提倡使用角色的视点定义和分析UML Use Case,使用概念的角色 Use Case模型定义和分析系统的需求 .提出了运用 AOP和角色 U se Case法的求精 (refine)、实现 (realization)和反演 (reflection)的 3R机制与 U ML相结合 ,跨越系统分析和设计之间的鸿沟 .为开发可构造、可扩充的开放式软件系统提供了一些方法和手段 .     

MAS远程教学系统角色建模

为了解决远程教学中缺乏智能性和适应性的问题,给出了Agent角色模型的实例并讨论了实现两种角色模型的方法:角色对象模型和AOP。通过引入角色,实现了整个系统和具体执行Agent之间的隔离,使得系统的组成更稳定,更易于分析和实现。     

基于角色、标记及BLP模型的多级访问控制——B/S架构OA系统应用

本文基于BLP模型的安全性和角色访问模型的简便性,结合两者优点,克服其缺点.根据办公自动化(OA)系统的实际情况设计一种新的模型.BLP模型的读写分离,角色可以授权和回收,角色层次机制,标记等保证信息安全.增强了系统的可用性同时,方便用户使用.并提供了核心Java代码.     

角色建模工具RModeler的设计与实现*

提倡在对象技术中基于角色识别对象及其协调关系,然后展开到类模型、接口模型、实体模型,同时对角色模型的形式化定义和表示方法进行了系统地研究,并在此基础上设计和实现了基于RML的可视化角色建模工具RModeler。RModeler目前完成了代码实现和测试工作,并在实际开发中使用,运行良好。RModeler支持业务过程中采用RML语言的建模,具备将RML模型转换为UML模型的功能,采用业界标准数据描述格式XMI来传递和共享建模信息。     

Role models—implementation‐based approaches to using roles

A role of an entity can be defined as the set of properties that are important for an object in order to behave in a certain way, as expected by a set of other objects. A role model is a software that specifies a style of designing and implementing roles. This paper evaluates roles in the context of modeling dynamic systems by examining its foundations, surveying the recent role models available for academic use and giving implementation examples. Copyright © 2010 John Wiley & Sons, Ltd.     

An object deputy model for realization of flexible and powerful objectbases

In object-oriented databases, data and methods are combined by objects and their classes. Information redundancies are removed by the notions of class hierarchy and inheritance. This contributes the realization of high-performance systems. However, the flexibility of object structures still remains a problem due to its encapsulation feature. In this paper, we introduce an object deputy model which extends conventional object-oriented models with the concepts of deputy objects and deputy classes. A deputy object has its own identifier and may possess its own attributes and methods. It can also have attributes that are computed from values stored within its source object, and can be associated with methods generated from these of the source object. The inheritances are realized by switching operations, which make it possible to realize controllable, selective and dynamic inheritance structures. Schemata of deputy objects are defined by deputy classes which can be derived by an object deputy algebra. An object can have many deputy objects, and several objects can share a single deputy object. Thus, objects can be indirectly divided and combined through their deputy objects. We show that several difficult database problems, such as flexible views, objects with more than one role, object migration, and multiple inheritance become much easier in this model. The data-knowledge coordination model developed for the integration of distributed databases and knowledge-bases can also be realized easily by the object deputy model. Finally, we discuss several advanced database applications of this model, such as geographic databases, virtual office systems, and distant education systems.     

A database model for object dynamics

To effectively model complex applications in which constantly changing situations can be represented, a database system must be able to support the runtime specification of structural and behavioral nuances for objects on an individual or group basis. This paper introduces the role mechanism as an extension of object-oriented databases to support unanticipated behavioral oscillations for objects that may attain many types and share a single object identity. A role refers to the ability to represent object dynamics by seamlessly integrating idiosyncratic behavior, possibly in response to external events, with pre-existing object behavior specified at instance creation time. In this manner, the same object can simultaneously be an instance of different classes which symbolize the different roles that this object assumes. The role concept and its underlying linguistic scheme simplify the design requirements of complex applications that need to create and manipulate dynamic objects. Edited by D. McLeod / Received March 1994 / Accepted January 1996     

An enhanced role model for alleviating the role‐binding anomaly

Roles and role models have received much attention as useful concepts for developing highly reusable and dynamically evolvable systems. Role models belong to the category of collaboration‐based development techniques, but most of the existing approaches to role models do not explicitly incorporate the core principle of collaboration‐based developments as an essential property of their primary design goals. Consequently, the existing approaches still suffer from a problematic phenomenon that the structural and behavioral constraints defined in a role system can be violated during the role‐binding stage. We call such a problematic phenomenon the role‐binding anomaly. In order to alleviate the role‐binding anomaly, we propose an enhanced role model, in which all role instances and core objects can exist by themselves, namely, they can be developed, executed, and tested independently. Roles and core classes can be bound to each other at the instance level. In addition, the role system describes and encapsulates the behavior for dynamic reconfigurations among role instances. The enhanced role model is designed so as to be meaningful with respect to software engineering principles, rather than dynamic evolution. It also facilitates role model implementation using general programming languages (i.e. not supporting dynamic specialization) such as Java. To illustrate how the proposed role model makes such benefits, we develop a set of Java classes necessary for implementing the enhanced role model in the form of a Java package role, and present a simplified automatic teller machine system as an example application. Copyright © 2002 John Wiley & Sons, Ltd.     

基于WEB服务和CORBA的C~3I网络管理系统的研究

C3I网络系统是一个结构非常复杂、实时性强、安全可靠性要求严格的高度分布式处理系统,是未来信息化战场的重要基础设施,对相关的网络管理系统提出了非常严格的要求。本文分析了现有网络管理的体系结构及其技术局限性,研究在C3I网络管理系统中综合应用Web服务和CORBA技术,提出一种新的网络管理模型,使得C3I网络管理系统具有分布、实时、可靠、配置灵活等一系列新特性。     

Generalization to Novel Views: Universal,Class-based,and Model-based Processing

A major problem in object recognition is that a novel image of a given object can be different from all previously seen images. Images can vary considerably due to changes in viewing conditions such as viewing position and illumination. In this paper we distinguish between three types of recognition schemes by the level at which generalization to novel images takes place: universal, class, and model-based. The first is applicable equally to all objects, the second to a class of objects, and the third uses known properties of individual objects. We derive theoretical limitations on each of the three generalization levels. For the universal level, previous results have shown that no invariance can be obtained. Here we show that this limitation holds even when the assumptions made on the objects and the recognition functions are relaxed. We also extend the results to changes of illumination direction. For the class level, previous studies presented specific examples of classes of objects for which functions invariant to viewpoint exist. Here, we distinguish between classes that admit such invariance and classes that do not. We demonstrate that there is a tradeoff between the set of objects that can be discriminated by a given recognition function and the set of images from which the recognition function can recognize these objects. Furthermore, we demonstrate that although functions that are invariant to illumination direction do not exist at the universal level, when the objects are restricted to belong to a given class, an invariant function to illumination direction can be defined. A general conclusion of this study is that class-based processing, that has not been used extensively in the past, is often advantageous for dealing with variations due to viewpoint and illuminant changes.     

企业管理信息系统的面向对象分析

研究了用面向对象技术进行企业信息系统分析的方法，主要研究了系统分析中用户需求模型的建立方法，系统中界面对象、实体对象和控制对象的标识方法及分析模型的建立。这种方法清楚地表现了用户的需求，且分析模型具有环境可适应性和易维护性。     

模糊面向对象数据库中的模糊对象匹配

对象匹配的目标在于区分对象,用以识别多个对象是否代表相同的现实世界实体,其在数据集成和数据清洗等方面发挥着至关重要的作用.为了满足同时处理复杂对象、复杂对象关系以及不确定数据的需求,模糊面向对象数据库的研究近年来受到了研究者的关注.本文识别出模糊面向对象数据库中模糊对象的三种情况:两个模糊对象属于同一个类;两个模糊对象分属于具有子类/超类关系的两个类;两个模糊对象分属于两个完全不同的类.针对不同的模糊对象情况,基于可能性理论和模糊数据的语义测度,给出了计算两个模糊对象等价度和必要度的方法.