外文翻译----高级数据库应用

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1、 毕业设计（论文） 外文翻译 题 目 高级数据库应用 专 业 信息与计算科学 班 级 学 生 指导教师 信息与计算科学毕业设计 1 Advanced Database Applications The 1990s have seen significant changes in the computer industry. In database systems, we have seen the widespread acceptance of RDBMSs for traditional business applications, such as order processing, in

2、ventory control, banking, and airline reservations. However, existing RDBMSs have proven inadequate for applications whose needs are quite different from those of traditional business database applications. These applications include: computer-aided design (CAD)； computer-aided manufacturing (CAM)；

3、computer-aided software engineering (CASE)； office information systems (OIS) and multimedia systems； digital publishing； eographic information systems (GIS)； interactive and dynamic Web sites. Computer-aided design (CAD) A CAD database stores data relating to mechanical and electrical design coverin

4、g, for example, buildings, aircraft, and integrated circuit chips. Designs of this type have some common characteristics: Design data is characterized by a large number of types, each with a small number of instances. Conventional databases are typically the opposite. For example, the DreamHome data

5、base consists of only a dozen or so relations, although relations such as PropertyForRent, Client, and Viewing may contain thousands of tuples. Designs may be very large, perhaps consisting of millions of parts, often with many interdependent subsystem designs. The design is not static but evolves t

6、hrough time. When a design change occurs, its implications must be propagated through all design representations. The dynamic nature of design may mean that some actions cannot be foreseen at the beginning. Updates are fat-reaching because of topological or functional relationships, tolerances, and

7、so on. One change is likely to affect a large number of design objects. Often, many design alternatives are being considered for each component, and the correct version for each part must be maintained. This involves some form of version control and 2 configuration management. There may be hundreds

8、of staff involved with the design, and they may work in parallel on multiple versions of a large design. Even so, the end-product must be consistent and coordinated. This is sometimes referred to as cooperative engineering. Computer-aided manufacturing （ CAM） A CAM database stores similar data to a

9、CAD system, in addition to addition to data relating to discrete production (such as cars on an assembly line) and continuous production (such as chemical synthesis). For example, in chemical manufacturing there will be applications that monitor information about the state of the system, such as rea

10、ctor Bessel temperatures, flow rates, and yields. There will also be applications that control various physical processes, such as opening valves, applying more heat to reactor vessels, and increasing the flow of cooling systems. These applications are often organized in a hierarchy, with a top-leve

11、l application monitoring the entire factory and lower=level applications monitoring individual manufacturing processes. These applications must respond in real time and be capable of adjusting processes to maintain optimum performance within tight tolerances. The applications use a combination of st

12、andard algorithms and custom rules to respond to different conditions. Operators may modify these rules occasionally to optimize performance based on complex historical data that the system has to maintain. In this example, the system has to maintain large volumes of data that is hierarchical in nat

13、ure and maintain complex relationships between the data. It must also be able to rapidly navigate the data to review and respond to changes. Computer-aided software engineering (CASE) A CASE database stores data relating to stages of the software development lifecycle: planning, requirements collect

14、ion and analysis, design, implementation, testing, maintenance, and documentation. As with CAD, designs may be extremely large, and cooperative engineering is the norm. For example, software configuration management tools allow concurrent sharing of project design, code, and documentation. They also

15、 track the dependencies between these components and assist with change management. Project management tools facilitate the coordination of various project management activities, such as the scheduling of potentially highly complex interdependent tasks, cost estimation, and progress monitoring. Network management systems Network management systems coordinate the delivery of communication services across a