检索结果-内蒙古大学图书馆

International Workshop on Research Issues in Data engineering

作者： H.A. Kuno E.A. Rundensteiner Department of Elect. Engineering and Computer Science Software Systems Research Laboratory University of Michigan Ann Arbor MI USA

Materialized complex object-oriented views are a promising technique for the integration of heterogeneous databases and the development of powerful data warehousing systems. Path query views are virtual classes formed from selection queries that specify a predicate upon the value of an aggregation hierarchy path. The primary difference between previous work regarding OODB indexing and the efficient implementation of materialized path query views addressed in this paper lies in the nature of their usage. For OODB indexing, query usage is the primary purpose of index structures. Because the materialized view data itself can be used to answer queries, the primary use of index structures with regard to materialized path query views is for the incremental maintenance of views in the face of updates. We have developed an augmented inherited multi-index (AIM) strategy that is specifically tailored for the maintenance of materialized path query views. We find that we can improve update performance by augmenting traditional inherited multi-indices with structured representations of the path queries that use them. This enables us to use class hierarchy relationships to prune the number of aggregation paths that must be re-instantiated during update propagation and also to support complex path queries that include cycles.

关键词： Object oriented databases Warehousing Indexing Distributed databases Workflow management software computer science software systems Laboratories Information technology Database systems

来源：评论

学校读者我要写书评

暂无评论

Consistent view removal in transparent schema evolution systems

Consistent view removal in transparent schema evolution syst...

引用

International Workshop on Research Issues in Data engineering

作者： V. Crestana-Taube E.A. Rundensteiner Department of Elect. Engineering and Computer Science Software Systems Research Laboratory University of Michigan Ann Arbor MI USA

We have developed the transparent schema evolution (TSE) system that, simulating schema evolution using object-oriented views, allows for the interoperability of applications with diverse and even changing requirements. TSE relieves users of the risk of making existing application programs obsolete when run against the modified schema, because the old view schema is maintained while a new view schema is generated to capture the changes desired by the user. However TSE may be generating a large number of schema versions (object-oriented view schemata) over time, resulting in an excessive build-up of classes and underlying object instances-some of which may potentially no longer be in use. We propose to solve this problem by developing techniques for effective and consistent schema removal. First, we characterize four potential problems of schema consistency that could be caused by removal of a single virtual class; and then outline our solution approach for each of these problems. Second, we demonstrate that view schema removal is sensitive to the order in which individual classes are processed. Our solution to this problem is the development of a dependency graph model for capturing the class relationships, used as a foundation for selecting among removal sequences. Designed to optimize the performance of the TSE system by effective schema version removal, the proposed techniques will enable more effective interoperability among evolving software applications.

关键词： Application software Object oriented modeling computer science software systems Laboratories Computational modeling Marine vehicles Design optimization software performance Veins

来源：评论

学校读者我要写书评

暂无评论

Extended real-time logic for hybrid systems controller design

Extended real-time logic for hybrid systems controller desig...

引用

IEE Colloquium on Hybrid Control for Real-Time systems

作者： J.G. Hall R. de Lemos High Integrity Systems Engineering Group Department of Computer Science University of York UK Centre for Software Reliability Department of Computing Science University of Newcastle UK

Summary form only given. Hybrid systems are systems which combine both continuous variable and discrete event dynamics. Their complexity has risen to the extent that traditional approaches which dealt separately with the continuous and discrete aspects of such systems have become obsolete. Instead of proposing a novel formal notation for the specification of controllers for hybrid systems we have developed extended real time Logic (ERTL) as a formal notation for the modelling and analysis of relative and absolute timing properties of hybrid systems. ERTL embeds the discrete system model of the real time logic (RTL) of Jahanian and Mok (1986, 1988) into continuous time, and adds the ability to reason about piecewise continuous functions using predicates over real valued variables. While RTL is able to formally describe the behaviour of computational entities in the time domain, ERTL also permits the formal description of the behaviour of physical entities in both value and time domains.

关键词： Discrete time systems

来源：评论

学校读者我要写书评

暂无评论

ERTL: an extension to RTL for the specification, analysis and verification of hybrid systems

ERTL: an extension to RTL for the specification, analysis an...

引用

Euromicro Conference on Real-Time systems

Real time logic (RTL) was introduced as a formalism for reasoning about the relative and absolute timing properties of computational tasks of discrete real-time systems. Extended real time logic (ERTL) is a formalism for the modelling and analysis of relative and absolute timing properties of hybrid systems (systems that combine continuous variables and discrete event dynamics). The extensions provided by ERTL enable the modelling of system behaviour ranging from activities of the physical entities that form part of the environment of a computing system, to the temporal ordering of the computational tasks of the computing system itself thus providing a formal notation that can be used in all stages of software development.

关键词： Real time systems Timing Logic Physics computing systems engineering and theory computer science software reliability Equations Hardware design languages Production systems

来源：评论

学校读者我要写书评

暂无评论

ASPECT-an Architecture SPECification Technique a report on work in progress

ASPECT-an Architecture SPECification Technique a report on w...

引用

International Conference and Workshop on engineering of computer-Based systems

作者： V. Kirova W. Rossak Department of Computer and Information Science Department of Computer and Information Science New Jersey Institute of Technology Newark NJ USA Department of Computer and Information Science Department of Computer and Information Science Software and Systems Engineering Laboratory New Jersey Institute of Technology Newark NJ USA

We discuss ASPECT, a first step towards a generic specification technique for software architectures. We present and discuss an abstract grammar for ASPECT that lists and relates to each other all the architectural elements that form ASPECT's vocabulary. After elaborating on the characteristics of these architectural elements, we illustrate their application in a small example.

关键词： computer architecture software systems systems engineering and theory Laboratories software architecture Information science Open systems Costs Decision support systems Standardization

来源：评论

学校读者我要写书评

暂无评论

Integration of a relational database with multimedia data

Integration of a relational database with multimedia data

引用

IEEE Annual International computer software and Applications Conference (COMPSAC)

作者： S.M. Chung P.S. Mah J.L. Kim Department of Computer Science and Engineering Wright State University Dayton OH USA Software Engineering Division Systems Engineering Research Institute Daejeon South Korea Software R & D Center Hyundai Electronics Industrial Company Limited Seoul South Korea

We propose a method for integrating a preexisting conventional database system with a multimedia server in a multidatabase environment. In the multidatabase environment, changes to the preexisting database system are not allowed because such changes are too expensive. For the integration, high-level semantic description of multimedia data is modeled using the enhanced entity-relationship (EER) model to support content-based retrieval of multimedia data. The EER design is translated into a schema of the preexisting database system and then the translated schema is integrated with the preexisting database schema. The content description can be used to locate pertinent multimedia data, and the identifiers are used to access the multimedia data stored in the multimedia server. However, with only a simple schema representation of the semantic description of multimedia data, high levels of recall and precision of queries may not be obtained because conventional database systems provide only exact matching answers to the query. Thus, we extended the conventional query processing mechanism by providing a modified cooperative query answering mechanism.

关键词： Relational databases Multimedia databases Database systems Information retrieval Videos Data engineering Content based retrieval systems engineering and theory Graphics Sprites (computer)

来源：评论

学校读者我要写书评

暂无评论

Virtual memory versus file interfaces for large, memory-intensive scientific applications 96

Virtual memory versus file interfaces for large, memory-inte...

引用

Proceedings of the 1996 ACM/IEEE conference on Supercomputing

作者： Yoonho Park Ridgway Scott Stuart Sechrest High Performance Computing Center University of Houston Houston TX Software Systems Research Laboratory Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor MI

ISBN: (纸本)9780897918541

Scientific applications often require some strategy for temporary data storage to do the largest possible simulations. The use of virtual memory for temporary data storage has received criticism because of performance problems. However, modern virtual memory found in recent operating systems such as Cenju-3/DE give application writers control over virtual memory policies. We demonstrate that custom virtual memory policies can dramatically reduce virtual memory overhead and allow applications to run out-of-core efficiently. We also demonstrate that the main advantage of virtual memory, namely programming simplicity, is not lost.

关键词： custom policies

来源：评论

学校读者我要写书评

暂无评论

Virtual Memory versus File Interface for Large, Memory-Intensive Scientific Applications

Virtual Memory versus File Interface for Large, Memory-Inten...

引用

Supercomputing Conference

作者： Yoonho Park R. Scott S. Sechrest High performance computing center University of Houston Houston TX USA Software Systems Research Laboratory Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor MI USA

关键词： Memory Operating systems Control systems

来源：评论

学校读者我要写书评

暂无评论

Incorporation of relational modeling method into object-oriented analysis

Incorporation of relational modeling method into object-orie...

引用

IEEE International Conference on Communications (ICC)

作者： Chung-Horng Lung J.E. Urban G.T. Mackulak Software Engineering Analysis Laboratory Nortel Technologies Inc. Ottawa ONT Canada Department of Computer Science Arizona State University Tempe AZ USA Systems Simulation Laboratory Industrial & Management Systems Engineering Arizona State University Tempe AZ USA

It is a generally accepted concept that multiple views are needed in object-oriented analysis or domain analysis techniques. Three commonly adopted models for requirements analysis include object model, functional model and dynamic model. This paper introduces and incorporates the concept of relational modeling into the analysis techniques. Relational modeling mainly deals with two tasks: classification of semantic relations and identification of higher-order system causal relations. Classification of semantic relations supports comparison and evaluation of various relations, which in turn can be used to select suitable methods to process the relations. A higher-order relation depicts the relations between different relations as opposed to the relations between objects often discussed in object modeling. A network of higher-order relations reveals the cause-effect dependency relationships and can facilitate understanding and reasoning of application systems. Furthermore, incorporation of relational modeling techniques can support software reuse in an application domain or across domains.

关键词： Object oriented modeling Application software Lungs computer science Computational modeling Analytical models computer simulation Laboratories Seals software engineering

来源：评论

学校读者我要写书评

暂无评论

A software architectural design method for large-scale distributed information systems

引用

Distributed systems engineering 1996年第3期3.0卷 162-172页

作者： Gomaa, Hassan Menascé, Daniel Kerschberg, Larry Department of Information and Software Systems Engineering George Mason University Fairfax VA 22030-4444 United States Department of Computer Science George Mason University Fairfax VA 22030-4444 United States

This paper describes a software architectural design method for large-scale distributed information systems. The method, which is part of an integrated design and performance evaluation method, addresses the design of client/server software architectures, where the servers need to cooperate with each other to service client requests. The goal of this software architecture is to provide a concurrent message based design that is highly configurable. The method is illustrated by applying it to the design of a complex software system, the Earth Observing System Data and Information System (EOSDIS) Core System.

关键词：

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：