【導讀】運用現代化技術為各聯系點服務，不斷提高工作效率。計算機就充分體現了在這方?？茖W技術的突發(fā)猛進，知識經濟初見端倪使得一些落后的手工生產在。經濟生活中已經落伍，這也使信息技術的高速發(fā)展成了必要。穩(wěn)固的客戶關系。因此，企業(yè)需要開展一些有效的活動來拉攏企業(yè)與客戶之間的關系，關系系統(tǒng)不僅會浪費用戶的寶貴時間而且會令客戶感到服務缺乏親切感。成為我們學習和工作的得力助手，利用它的特點可以實現人們所期望的相關功能。的提升，它已經被應用于許多領域。對一個企業(yè)來說，在現代社會中實現數據規(guī)范化，根據公司的發(fā)展需要而研制開發(fā)的一個全新的抽獎系統(tǒng)。了許多人力和物力，而且對于公平性還有待于提高。必然被計算機為基礎的信息管理所取代。連接，可以查到中獎與未中獎者的相關信息。機器更新、工程師更新、故障現象更新等。后數據庫的內容進行有選擇地刪除、初始化。圍內；避免因系統(tǒng)引起的死機現象。通過管理員靈活修改；然后進行響應的備份操作。

　　

【正文】 cially for those based on the Intel 80386. However, the dominant operating system for PCs is still MSDOS. Multitasking systems have several advantages over singletasking systems. First, the user can run more than a single program at a time , transparent to the application. Desk accessories and RAMresident programs on PCs give the user some primitive multitasking capability, sufficient to run background print spoolers and the like . However, they may not be transparent to application program, and they do not offer significant features like interprocess munication and support for multiple, simultaneous users. Perhaps more important for today’s engineering applications is the lack of large physical and virtual memories on PCs. Virtual memory is important for large applications, many of which simply cannot be run entirely in physical memory because the data sets are too large, Without virtual memory, a simple task like editing a large file bees tedious or even impossible to perform. In addition, many applications are more plex because they must buffer data or use overlays to page different parts of the application in and out of physical memory. Finally, the user interface of most workstations is more sophisticated than that on most PCs. The one notable exception is that of the Apple Macintosh. The puter’s user interface and the programming interface to it determine how sophisticated the application’s program interfaces can be. Powerful development tools allow programmers to create intuitive user interfaces for plex applications. While workstations are typically more powerful than PCs, that is generally not the case when they are pared with modern miniputers, such as those of the 2021 級 專 科畢業(yè)設計論文 第 Ⅰ 頁 共 Ⅰ 頁 VAX8oooseries by Digital Equipment Corporation(DEC). They do have several advantages over miniputers, however. Engineering workstations generally provide more CPU power per user, a better priceperformance ratio, and more predictable response times than miniputers, because the CPU is usually devoted to a single user. Workstations often have the same userinterface advantages over miniputers that they have over most PCs. With the advent of the X Window System and inexpensive ter minals that support the X protocol, this advantage is disappearing. Problems with Networked Systems Although workstations are giving engineers newfound puter power and display capabilities, all is not perfect. The problems bee readily apparent to users and system administrators at sites with more than a handful of workstations. The Complexity of the operating systems on workstations approaches or exceeds that of miniputer operating systems of just a few years ago. With little or no software available to automate critical tasks such as disk backup, software installation and update, work management, or account management, the administration of such a system can bee a nightmare. Distributed file systems can create unexpected dependencies on many machines on a local area work. When a file server goes down, many machines(and their user)may be affected. When files are used to municate between processes on different machines, directory caching may create inconsistencies in the appearance of the global file system on the two machines as well. On top of the problems inherent in managing distributed systems are software licensing costs, which for many anizations have skyrocketed because most software packages for workstations are still licensed as if they were for miniputer and mainframes. Some anizations are beginning to address the problems of administering large number of machines and software licensing but few solutions are today. Future Directions for Workstations During its brief history, workstation technology has shown that it can move faster than any other puter technology available. This will probably remain true for the future. 2021 級 專 科畢業(yè)設計論文 第 Ⅰ 頁 共 Ⅰ 頁 Significant increases in CPU speeds are expected to continue for some time in the future. The major workstation vendors have all made a substantial investment in RISC(reducedinstructionset puter)technology, thereby reducing the plexity and cycle time of processor Chips, Most RISC architectures are designed to be scalable to new fabrication technologies as well, such as emittercoupled logic and gallium arsenide, promising even higher speed chips in the future than those prevalent today. As mentioned in the section on hardware, the increase in CPU speeds has not, in general, been matched by a parallel increase in floatingpoint putation speeds. However, the next generation of floatingpoint processors may performances. Recent developments by several vendors have led to chips with raw performances of between 10 and 30 million floatingpoint operations per second. One of the most difficult decisions for application developers to make is which workstations to support. Traditionally, the most nonportable part of most applications has been the user interface, since each vendor had a proprietary windowmanagement system. This is starting to change as the X Window System and Sun’s NeWS gain in popularity. Both are workbased window system, so puterintensive applications can be run on the appropriate putational server. Several userinterface toolkits are available for X, a number of which are in the public domain. All signs point to an easier job for application software vendors and, ultimately, better application software for enduser. Support is much less advanced for distributed puting than for distributed file system. As more and more specialized puters bee available, engineers and puter scientists will need to harness the special capabilities of two or more types of puter to solve problems of increasing plexity. The workstation will be the focal point of the integration of th