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管理信息系统外文翻译 (2)

管理信息系统外文翻译 (2)
管理信息系统外文翻译 (2)

毕业设计(论文)外文文献翻译

毕业设计(论文)题目

翻译(1)题目管理信息系统

翻译(2)题目数据库管理系统的介绍

学院计算机学院

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班级

学号

Management Information System

It is the MIS(Management Information System ) that we constantly say that the management information system , and is living to emphasize the administration , and emphasizes that it changes into more and more significantly and more and more is universalized in the contemporary community of message . MIS is a fresh branch of learning, and it leaped over several territories, and for instance administers scientific knowledge, system science, operational research, statistic along with calculating machine scientific knowledge. Is living on these the branches of learning base, and takes shape that the message is gathered and the process means, thereby take shape the system that the crossbar mingles.

1. The Management Information System Summary

20 centuries, in the wake of the flourishing development of whole world economy, numerous economists propose the fresh administration theory one by one. Xi Men propose the administration and was dependent on idea to message and decision of strategic importance in the 50’s 20 centuries. The dimension of simultaneous stage is admitted issuing cybernetics, and he thinks that the administration is a control procedure. In 1958, Ger. write the lid: “ the administration shall obtain without delay with the lower cost and exact message, completes the better control “. This particular period, the calculating machine starts being used accountancy work. The data handling term has risen.

In 1970, Walter T.Kennevan give administration that has raised the only a short while ago information system term to get off a definition: “ either the cover of the book shape with the discount, is living appropriately time to director, staff member along with the outside world personnel staff supplies the past and now and message that internal forecasting the approaching relevant business reaches such environment, in order to assist they make a strategic de cision”. Is living in this definition to emphasize, yet does not emphasize using the pattern, and mention the calculating machine application in the way of the message support decision of strategic importance.

In 1985, admonishing information system originator, title Buddhist nun Su Da university administration professor Gordon B.Davis give the management information system relatively integrated definition, in immediate future “ administer the information system is one use calculating machine software and hardware resources along with data bank man - the engine system.

It be able to supply message support business either organization operation, administration or the decision making function. Comprehensive directions of this definition management information system target and meritorious service capacity and component, but also make known the management information system to be living the level that attains at that time.

1.1 The Developing History of MIS

The management information system is living the most primarily phase is

counting the system, the substance which researched is the regular pattern on face between the incremental data, it what may separate into the data being mutually related and more not being mutually related series, afterwards act as the data conversion to message.

The second stage is the data are replaced the system, and it is that the SABRE that the American airline company put up to in the 50’s 20 centuries subscribes to book the bank note system that such type stands for. It possess 1008 bank note booking spots, and may access 600000 traveler keep the minutes and 27000 flight segments record. Its operation is comparatively more complex, and is living whatever one “spot ”wholly to check whether to be the free place up some one flight n umbers. Yet through approximately attending school up to say, it is only a data and replaces the system, for instance it can not let know you with the bank note the selling velocity now when the bank note shall be sell through, thereby takes remedying the step. As a result it also is administer information system rudimentary phase.

The third phase is the status reports system, and it may separate into manufacture state speech and service state and make known and research the systems such as status reports and so on. Its type stands for the production control system that is the IBM corporation to the for instance manufacture state speech system. As is known to all, the calculating machine corporation that the IBM corporation is the largest on the world, in 1964 it given birth to middle-sized calculating machine IBM360 and causes the calculating machine level lift a step, yet form that the manufacture administration work. Yet enormously complicatedly dissolve moreover, the calculating machine overtakes 15000 difference components once more, in addition the plant of IBM extends all over the American various places to every one components once more like works an element, and the order of difference possess difference components and the difference element, and have to point out that what element what plant what installation gives birth to, hence not merely giving birth to complexly, fitting, installation and transportation wholly fully complex. Have to there be a manufacture status reports system that takes the calculating machine in order to guarantee being underway successfully of manufacture along with else segment as the base. Hence the same ages IBM establish the systematic AAS of well-developed administration it be able to carry on 450 professional work operations. In 1968, the corporation establishes the communal once more and manufactures information

system CMIS and runs and succeeds very much, the past needs 15 weeks work, that system merely may be completed in the way of 3 weeks.

It is the data handling system that the status reports system still possess one kind of shape , and that it is used for handles the everyday professional work to make known with manufacture , and stress rests with by the handwork task automation , and lifts the effectiveness with saves the labor power . The data handling system ordinarily can not supply decision of strategic importance message.

Last phase is the support systems make a strategic decision, and it is the information system being used for supplementary making a strategic decision. That system may program and the analysis scheme, and goes over key and the error solve a problem. Its proper better person-machine dialogue means, may with not particularly

the personnel staff who have an intimate knowledge of the calculating machine hold conversation. It ordinarily consists of some pattern so as to come into being decision of strategic importance message, yet emphasize comprehensive administration meritorious service capacity.

1.2 The Application of Management Information System

The management information system is used to the most base work, like dump report form, calculation pay and occurrences in human tubes and so on, and then developing up business financial affairs administrations and inventory control and so on individual event operational control , this pertains to the electron data handling ( EDP Data Processing ) system . When establish the business data bank, thereby possess the calculating machine electric network to attain data sharing queen , the slave system concept is start off , when the implementation the situation as a whole is made program and the design information system ,attained the administration information system phase . In the wake of calculating machine technique progress and the demand adjust the system of people lift further, people emphasize more furthermore administer the information system phase. Progress and people in the wake of the calculating machine technique lift at the demand adjust the system further, people emphasize more furthermore to administer the information system whether back business higher level to lead makes a strategic decision this meritorious service capacity, still more lay special emphasis on the gathering to the external message of business and integrated data storehouse, model library , means storehouse and else artificial intelligence means whether directly to decision of strategic importance person , this is the support system ( DDS ) mission making a strategic decision.

There is the part application that few business start MIS inner place the limit of the world at the early days of being living in the 70’s 20 centuries. Up at the moment, MIS is living, and there be the appropriate

Popularization rate in every state nation in world, and nearly covered that every profession reaches every department.

1.3 The Direction of MIS Development

Close 20 curtains; external grand duke takes charge of having arisen3 kinds of alternations:

A. Paying special attention to the administration being emphasized to

establishing MIS’s s ystem, and causing the administration technique head

for the ageing.

B. The message is the decision of strategic importance foundation, and MIS

supplies the message service in the interest of director at all times.

C. Director causes such management program getting in touch with together

with the concrete professional work maneuver by means of MIS. not merely

big-and-middle-sized business universally establish MIS some small-size

business also not exceptions of self, universally establish the communal

data network, like the electronic mail and electron data exchange and so on,

MIS supplied the well support environment to the application of Intranet’s

technique to speedily developing of INTERNET especially in the past few

years in the interest of the business.

Through international technique development tendency is see, in the 90’s 20 centuries had arisen some kinds of brand-new administration technique.

1. Business Processes Rebuild (BPR)

A business should value correctly time and produce quality, manufacturing cost and technical service and so on several section administrations, grip at the moment organization and the process compose once more,andcompletes that meritorious service capacity integrationist, operation processization and organization form fluctuation. Shall act as the service veer of middle layer management personnel staff the decision of strategic importance of the director service?

2. Intelligentization Decision Support System (IDSS)

The intelligentization decision of strategic importance support system was sufficiently consider demand and the work distinguishing feature of business higher level personnel staff.

3. Lean Production (LP)

Application give birth to on time, comprehensive quality control and parallel project that picked amount is given birth to and so on the technique, the utmost product design cutting down and production cycle, raise produce quality and cuts down the reproduced goods to reserve, and is living in the manufacture promote corps essence, in order to meet the demand that client continuously changes.

4. Agile Manufacture (AM)

One kind of business administration pattern that possess the vision, such distinguishing feature is workers and staff members’ quality is high, and the organization simplifies and the multi-purpose group effectiveness GAO message loading is agile and answers client requires swiftly.

2. The Effect To The Business Administration of MIS Development

The effect to the business administration of the management information system development is administered the change to business and business administration of information system development and come into being and is coming into being the far-reaching effect with.

Decision of strategic importance, particularly strategic decision-making may be assisted by the administration information system, and its good or bad directly affects living and the development up the business. The MIS is impeding the orientation development that the administration means one another unites through quality and ration. This express to utilize the administration in the calculation with the different mathematical model the problem in the quantitative analysis business.

The past administer that the problem is difficult to test, but MIS may unite the administration necessaries, and supply the sufficient data, and simulates to produce the term in the interest of the administration.

In the wake of the development of MIS, much business sit up the decentralized

message concentration to establish the information system ministry of directly under director, and the chief of information system ministry is ordinarily in the interest of assistant manager’s grade. After the authority of business is centralized up high-quality administration personnel staff’s hand, as if causing much sections office work decrease, hence someone prophesy, middle layer management shall vanish. In reality, the reappearance phase employed layer management among the information system queen not merely not to decrease, on the contrary there being the increase a bit.

This is for, although the middle layer management personnel staff getting off exonerate out through loaded down with trivial details daily routine, yet needs them to analyses researching work in the way of even more energy, lift further admonishing the decision of strategic importance level. In the wake of the development of MIS, the business continuously adds to the demand of high technique a talented person, but the scarce thing of capability shall be washed out gradually. This compels people by means of study and cultivating, and continuously lifts individual’s quality. In The wake of the news dispatch and electric network and file transmission system development, business staff member is on duty in many being living incomparably either the home. Having caused that corporation save the expenses enormously, the work efficiency obviously moves upward American Rank Zeros corporation the office system on the net, in the interest of the creativity of raise office personnel staff was produced the advantageous term.

At the moment many countries are fermenting one kind of more well-developed manufacturing industry strategy, and become quickly manufacturing the business. It completely on the basis of the user requirement organization design together with manufacture, may carry on the large-scale cooperation in the interest of identical produce by means of the business that the flow was shifted the distinct districts, and by means of the once more programming to the machinery with to the resources and the reorganization of personnel staff , constituted a fresh affrication system, and causes that manufacturing cost together with lot nearly have nothing to do with. Quickly manufacturing the business establishes a whole completely new strategy dependence relation against consumer, and is able to arouse the structure of production once more revolution.

The management information system is towards the self-adoption and Self-learning orientation development, the decision procedure of imitation man who is be able to be better. Some entrepreneurs of the west vainly hope that consummate MIS is encircles the magic drug to govern the business all kinds of diseases; Yet also someone says, and what it is too many is dependent on the defeat that MIS be able to cause on the administration. It is adaptable each other to comprehend the effect to the business of MIS, and is favor of us to be living in development and the research work, and causes the business organization and administer the better development against MIS of system and administration means , and establish more valid MIS.

The Source Of Article: Russ Basiura, Mike Batongbacal

管理信息系统

管理信息系统就是我们常说的MIS(Management Information System), 在强调管理,强调信息的现代社会中它变得越来越重要、越来越普及。MIS是一门新的学科,它跨越了若干个领域,比如管理科学、系统科学、运筹学、统计学以及计算机科学。在这些学科的基础上,形成信息收集和加工的方法,从而形成一个纵横交织的系统。

1.管理信息系统概述

20世纪,随着全球经济的蓬勃发展,众多经济学家纷纷提出了新的管理理论。20世纪50年代,西蒙提出管理依赖于信息和决策的思想。同时期的维娜发表了控制论,他认为管理是一个控制过程。1958年,盖尔写到:“管理将以较低的成本得到及时的、准确的信息,做到较好的控制”。这个时期,计算机开始用于会计工作。数据处理一词已经出现。

1970年,Walter T.Kennevan给刚刚出现的管理信息系统一词下了一个定义:“以扣头或书面的形式,在合适的时间向经理、职员以及外界人员提供过去的、现在的、预测未来的有关企业内部及其环境的信息,以帮助他们进行决策”。

在这个定义里强调了用信息支持决策,但并没有强调应用模型,没有提到计算机的应用。

1985年,管理信息系统的创始人,名尼苏达大学的管理学教授Gordon B.Davis给了管理信息系统一个较为完整的定义,即“管理信息系统是一个利用计算机软硬件资源以及数据库的人-机系统。它能提供信息支持企业或组织的运行、管理和决策功能。”这个定义全面的说明了管理信息系统的目标、功能和组成,而且反映了管理信息系统在当时达到的水平。

1.1管理信息系统的发展历史

管理信息系统在初级阶段是统计系统,所研究的内容是数量数据间表面的规律,它可以把数据分成较相关和较不相关的组,然后把数据转换为信息。

第二阶段是数据更新系统,其典型代表是美国航空公司于20世纪50年代建成的SABRE预约订票系统。它设有1008个订票点,可以存取600000个旅客记录和27000个飞行段记录。它的操作比较复杂,在任何“点”都可以查到某一航班是

否有空座位。但从概念上来讲,它只是一个数据更新系统,比如它不能告诉你以现在的售票速度何时票将售完,从而采取补救措施。因而它也是管理信息系统的低级阶段。

第三阶段是状态报告系统,它可以分成生产状况报告、服务状态报告和研究状态报告等系统。比如生产状况报告系统,它的典型代表是IBM公司的生产管理系统。众所周知,IBM公司是世界上最大的计算机公司,1964年它生产出中型计算机IBM360,使计算机的水平提高了一个台阶,但同时组织生产的管理工作却大大复杂化了,一台计算机又超过15000个不同的部件,每个部件又有若干个元件,加之IBM的工厂遍及美国各地,不同的订货有不同的部件和不同的元件,必须指出什么工厂什么设备生产什么元件,因此不仅生产复杂,装配、安装和运输都十分复杂。为了保证生产以及其他环节的顺利进行,必须要有一个以计算机为基础的生产状态报告系统。因此同年IBM建立了先进管理系统AAS,它能进行450个业务的操作。1968年,公司又建立了公用制造信息系统CMIS,运行很成功,过去需要15周的工作,该系统只用3周就可以完成。状态报告系统还有一种形式是数据处理系统,它用来处理日常业务和生产报告,重点在于将手工作业自动化,提高效率和节省人力。数据处理系统一般不能提供决策信息。

最后的阶段是决策支持系统,它是用来辅助决策的信息系统。该系统可以计划、分析方案,审查解答和求解的误差。它应有较好的人-机对话方式,可以和不怎么熟悉计算机的人员通话。它一般包括一些模型用以产生决策信息,但不强调全面的管理功能。

1.2管理信息系统的应用

管理信息系统起初应用于最基础的工作,如打印报表、计算工资、人事管等,进而发展到企业财务管理、库存管理等单项业务管理,这属于电子数据处理(EDP,Electroni9c Data Processing) 系统。当建立了企业数据库,有了计算机网络从而达到数据共享后,从系统观点出发,实施全局规划和设计信息系统时,就达到了管理信息系统阶段。随着计算机技术的进步和人们对系统的需求进一步提高,人们更加强调管理信息系统的阶段。随着计算机技术的进步和人们对系统的需求进一步提高,人们更加强调管理信息系统能否支持企业高层领导的决策这一功能,更侧重于企业外部信息的收集、综合数据库、模型库、方法库、和其它人

工智能工具能否直接面向决策者,这是决策支持系统(DDS)的任务。

在20世纪70年代初期,世界范围内有少数企业开始MIS的局部应用。到目前,MIS在世界各国已经有了相当的普及率,几乎覆盖了各个行业及各部门。

1.3管理信息系统的发展方向

近20年间,国外大公司出现了3种变化:

●抓管理着重于建立MIS系统,使管理技术走向成熟。

●信息是决策的依据,MIS随时为经理提供信息服务。

●经理通过MIS使其经营计划和具体的业务活动联系在一起。

由于以上的变化。MIS应用得到了迅速的发展。不仅大中型企业普遍建立了自己的MIS,一些小型企业也不例外,普遍建立了公用数据网络,如电子邮件、电子数据交换等,尤其是近年来INTERNET的飞速发展,INTRANET技术的应用,为企业MIS提供了良好的支持环境。

从国际技术发展趋势看,20世纪90年代出现了几种全新的管理技术

1.企业过程重组(BPR)

一个企业应该重视对时间、产品质量、生产成本和技术服务等几个部分的管理,把目前的机构和过程重新组合,做到功能集成化、运营过程化、机构组织扁平化。

2.智能化决策支持系统(IDDS)

充分考虑了企业高层人员的要求和工作特点,将把中层管理人员的服务转向为经理的决策服务。

3.精量生产(LP)

应用准时生产、全面质量管理、并行工程等技术,最大限度的缩短产品设计和生产周期、提高产品质量、降低再制品库存,并在生产中提倡团队精神,以满足客户不断变化的需求。

4.灵捷制造(AM)

一种有远见的企业管理模式,其特点是职工素质高,组织机构精简、多功能小组效率高、信息存放灵活、响应客户要求迅速。

2.理信息系统的发展对企业管理的影响

管理信息系统的发展对企业和企业管理的变革产生了和正在产生着深远的

影响。管理信息系统可以辅助决策,特别是战略决策,它的好坏直接影响到企业的生存和发展。MIS正在促使管理方法由定性和定量相结合的方向发展。这表现在管理中运用预测和各种数学模型来定量分析企业中的问题。过去管理问题难以进行试验,而MIS则可以结合管理需要,提供充分的数据,为管理模拟创造条件。

随着MIS的发展,许多企业把分散的信息集中起来成立了直属经理的信息系统部,信息系统部的负责人一般为副经理级。企业的权力集中到高级管理人员手中以后,似乎使许多科室的工作减少了,因此有人预言,中层管理将消失。实际上,再现阶段用了信息系统后中层管理不仅没有减少,反而稍有增加。这是因为,虽然中下层管理人员从繁琐的事务性工作中解脱出来,但需要他们用更多的精力去分析研究工作,进一步提高管理决策水平。随着MIS的发展,企业对高技术人才的需求不断增加,而能力不足者将逐步被淘汰。这就迫使人们通过学习、培训,不断提高个人素质。随着通讯、网络和文档传输系统的发展,企业职员可以在远地或家中上班。美国兰克·施乐公司(Rank Zerox)的网上办公系统,已经使该公司大大节省了开支,工作效率明显上升,为提高办公人员的创造性创造了优越的条件。

目前许多国家正在酝酿一种更先进的制造业战略,成为敏捷制造企业。它完全根据用户需求来组织设计与生产,可以通过信息流调动不同地域的企业为同一个产品进行大协作,通过对机器的重新编程和对资源、人员的重新组织,构成了一个新的制造系统,使得生产成本与批量几乎无关。敏捷制造企业与用户建立一个完全崭新的战略依存关系,将会引起产业结构的又一次革命。

管理信息系统正在朝着自适应、自学习的方向发展,也就是能更好的模拟人的决策过程。西方某些企业家梦想完善的MIS是包治企业百病的灵丹妙药;但也有人说,过多的依赖MIS会导致管理上的失败。了解MIS对企业的影响,有利于我们在开发和研究工作中,使企业的组织机构、管理体制和管理方法更好的与MIS的发展相适应,建立更有效的MIS。

文章的出处:《信息管理系统》,作者:Russ Basiura, Mike Batongbacal

A introduction to Database Management System

A database (sometimes spelled data base) is also called an electronic database , referring to any collection of data, or information, that is specially organized for rapid search and retrieval by a computer. Databases are structured to facilitate the storage, retrieval , modification, and deletion of data in conjunction with various data-processing operations .Databases can be stored on magnetic disk or tape, optical disk, or some other secondary storage device.

A database consists of a file or a set of files. The information in these files may be broken down into records, each of which consists of one or more fields. Fields are the basic units of data storage , and each field typically contains information pertaining to one aspect or attribute of the entity described by the database . Using keywords and various sorting commands, users can rapidly search , rearrange, group, and select the fields in many records to retrieve or create reports on particular aggregate of data.

Complex data relationships and linkages may be found in all but the simplest databases .The system software package that handles the difficult tasks associated with creating ,accessing, and maintaining database records is called a database management system(DBMS).The programs in a DBMS package establish an interface between the database itself and the users of the database.. (These users may be applications programmers, managers and others with information needs, and various OS programs.)

A DBMS can organize, process, and present selected data elements form the database. This capability enables decision makers to search, probe, and query database contents in order to extract answers to nonrecurring and unplanned questions that aren’t available in regular reports. These questions might initially be vague and/or poorly defined ,but people can “browse” through the database until they have the needed information. In short, the DBMS will “manage” the stored data items and assemble the needed items from the common database in response to the queries of those who aren’t programmers.

A database management system (DBMS) is composed of three major parts:(1)a storage subsystem that stores and retrieves data in files;(2) a modeling and

manipulation subsystem that provides the means with which to organize the data and to add , delete, maintain, and update the data;(3)and an interface between the DBMS and its users. Several major trends are emerging that enhance the value and usefulness of database management systems;

Managers: who require more up-to-data information to make effective decision Customers: who demand increasingly sophisticated information services and more current information about the status of their orders, invoices, and accounts.

Users: who find that they can develop custom applications with database systems in a fraction of the time it takes to use traditional programming languages.

Organizations : that discover information has a strategic value; they utilize their database systems to gain an edge over their competitors.

The Database Model

A data model describes a way to structure and manipulate the data in a database. The structural part of the model specifies how data should be represented(such as tree, tables, and so on ).The manipulative part of the model specifies the operation with which to add, delete, display, maintain, print, search, select, sort and update the data. Hierarchical Model

The first database management systems used a hierarchical model-that is-they arranged records into a tree structure. Some records are root records and all others have unique parent records. The structure of the tree is designed to reflect the order in which the data will be used that is ,the record at the root of a tree will be accessed first, then records one level below the root ,and so on.

The hierarchical model was developed because hierarchical relationships are commonly found in business applications. As you have known, an organization char often describes a hierarchical relationship: top management is at the highest level, middle management at lower levels, and operational employees at the lowest levels. Note that within a strict hierarchy, each level of management may have many employees or levels of employees beneath it, but each employee has only one manager. Hierarchical data are characterized by this one-to-many relationship among data.

In the hierarchical approach, each relationship must be explicitly defined when the database is created. Each record in a hierarchical database can contain only one key field and only one relationship is allowed between any two fields. This can create a problem because data do not always conform to such a strict hierarchy.

Relational Model

A major breakthrough in database research occurred in 1970 when E. F. Codd proposed a fundamentally different approach to database management called relational model ,which uses a table as its data structure.

The relational database is the most widely used database structure. Data is organized into related tables. Each table is made up of rows called and columns called fields. Each record contains fields of data about some specific item. For example, in a table containing information on employees, a record would contain fields of data such as a person’s last name ,first name ,and street address.

Structured query language(SQL)is a query language for manipulating data in a relational database .It is nonprocedural or declarative, in which the user need only specify an English-like description that specifies the operation and the described record or combination of records. A query optimizer translates the description into a procedure to perform the database manipulation.

Network Model

The network model creates relationships among data through a linked-list structure in which subordinate records can be linked to more than one parent record. This approach combines records with links, which are called pointers. The pointers are addresses that indicate the location of a record. With the network approach, a subordinate record can be linked to a key record and at the same time itself be a key record linked to other sets of subordinate records. The network mode historically has had a performance advantage over other database models. Today , such performance characteristics are only important in high-volume ,high-speed transaction processing such as automatic teller machine networks or airline reservation system.

Both hierarchical and network databases are application specific. If a new application is developed ,maintaining the consistency of databases in different applications can be very difficult. For example, suppose a new pension application is

developed .The data are the same, but a new database must be created.

Object Model

The newest approach to database management uses an object model , in which records are represented by entities called objects that can both store data and provide methods or procedures to perform specific tasks.

The query language used for the object model is the same object-oriented programming language used to develop the database application .This can create problems because there is no simple , uniform query language such as SQL . The object model is relatively new, and only a few examples of object-oriented database exist. It has attracted attention because developers who choose an object-oriented programming language want a database based on an object-oriented model. Distributed Database

Similarly , a distributed database is one in which different parts of the database reside on physically separated computers . One goal of distributed databases is the access of information without regard to where the data might be stored. Keeping in mind that once the users and their data are separated , the communication and networking concepts come into play .

Distributed databases require software that resides partially in the larger computer. This software bridges the gap between personal and large computers and resolves the problems of incompatible data formats. Ideally, it would make the mainframe databases appear to be large libraries of information, with most of the processing accomplished on the personal computer.

A drawback to some distributed systems is that they are often based on what is called a mainframe-entire model , in which the larger host computer is seen as the master and the terminal or personal computer is seen as a slave. There are some advantages to this approach . With databases under centralized control , many of the problems of data integrity that we mentioned earlier are solved . But today’s personal computers, departmental computers, and distributed processing require computers and their applications to communicate with each other on a more equal or peer-to-peer basis. In a database, the client/server model provides the framework for distributing databases.

One way to take advantage of many connected computers running database applications is to distribute the application into cooperating parts that are independent of one anther. A client is an end user or computer program that requests resources across a network. A server is a computer running software that fulfills those requests across a network . When the resources are data in a database ,the client/server model provides the framework for distributing database.

A file serve is software that provides access to files across a network. A dedicated file server is a single computer dedicated to being a file server. This is useful ,for example ,if the files are large and require fast access .In such cases, a minicomputer or mainframe would be used as a file server. A distributed file server spreads the files around on individual computers instead of placing them on one dedicated computer.

Advantages of the latter server include the ability to store and retrieve files on other computers and the elimination of duplicate files on each computer. A major disadvantage , however, is that individual read/write requests are being moved across the network and problems can arise when updating files. Suppose a user requests a record from a file and changes it while another user requests the same record and changes it too. The solution to this problems called record locking, which means that the first request makes others requests wait until the first request is satisfied . Other users may be able to read the record, but they will not be able to change it .

A database server is software that services requests to a database across a network. For example, suppose a user types in a query for data on his or her personal computer . If the application is designed with the client/server model in mind ,the query language part on the personal computer simple sends the query across the network to the database server and requests to be notified when the data are found.

Examples of distributed database systems can be found in the engineering world. Sun’s Network Filing System(NFS),for example, is used in computer-aided engineering applications to distribute data among the hard disks in a network of Sun workstation.

Distributing databases is an evolutionary step because it is logical that data

should exist at the location where they are being used . Departmental computers within a large corporation ,for example, should have data reside locally , yet those data should be accessible by authorized corporate management when they want to consolidate departmental data . DBMS software will protect the security and integrity of the database , and the distributed database will appear to its users as no different from the non-distributed database .

The Source Of Article: WangShan,ShaShiXuan

数据库管理系统的介绍

数据库(database,有时拼作data base)又称为电子数据库,是专门组织起来的一组数据或信息,其目的是为了便于计算机快速查询及检索。数据库的结构是专门设计的,在各种数据处理操作命令的支持下,可以简化数据的存储,检索,修改和删除。数据库可以存储在磁盘,磁带,光盘或其他辅助存储设备上。

数据库由一个或一套文件组成,其中的信息可以分解为记录,每一记录又包含一个或多个字段(或称为域)。字段是数据存取的基本单位。数据库用于描述实体,其中的一个字段通常表示与实体的某一属性相关的信息。通过关键字以及各种分类(排序)命令,用户可以对多条记录的字段进行查询,重新整理,分组或选择,以实体对某一类数据的检索,也可以生成报表。

所有数据库(最简单的除外)中都有复杂的数据关系及其链接。处理与创建,访问以及维护数据库记录有关的复杂任务的系统软件包叫做数据库管理系统(DBMS)。DBMS软件包中的程序在数据库与其用户间建立接口。(这些用户可以是应用程序员,管理员及其他需要信息的人员和各种操作系统程序)。

DBMS可组织,处理和表示从数据库中选出的数据元。该功能使决策者能搜索,探查和查询数据库的内容,从而对在正规报告中没有的,不再出现的且无法预料的问题做出回答。这些问题最初可能是模糊的并且(或者)是定义不恰当的,但是人们可以浏览数据库直到获得所需的信息。简言之,DBMS将“管理”存储的数据项,并从公共数据库中汇集所需的数据项以回答非程序员的询问。

DBMS由3个主要部分组成:(1)存储子系统,用来存储和检索文件中的数据;(2)建模和操作子系统,提供组织数据以及添加,删除,维护,更新数据的方法;(3)用户和DBMS之间的接口。在提高数据库管理系统的价值和有效性方面正在展现以下一些重要发展趋势;

1.管理人员需要最新的信息以做出有效的决策。

2.客户需要越来越复杂的信息服务以及更多的有关其订单,发票和账号的当前信息。

3.用户发现他们可以使用传统的程序设计语言,在很短的一段时间内用数据库系统开发客户应用程序。

4.商业公司发现了信息的战略价值,他们利用数据库系统领先于竞争对手。数据库模型

数据库模型描述了在数据库中结构化和操纵数据的方法,模型的结构部分规

定了数据如何被描述(例如树,表等):模型的操纵部分规定了数据添加,删除,显示,维护,打印,查找,选择,排序和更新等操作。

分层模型

第一个数据库管理系统使用的是分层模型,也就是说,将数据记录排列成树形结构。一些记录时根目录,在其他所有记录都有独立的父记录。树形结构的设计反映了数据被使用的顺序,也就是首先访问处于树根位置的记录,接下来是跟下面的记录,等等。

分层模型的开发是因为分层关系在商业应用中普遍存在,众所周知,一个组织结构图表就描述了一种分层关系:高层管理人员在最高层,中层管理人员在较低的层次,负责具体事务的雇员在最底层。值得注意的是,在一个严格的分层结构体系中,在每个管理层下可能有多个雇员或多个层次的雇员,但每个雇员只有一个管理者。分层结构数据的典型特征是数据之间的一对多关系。

在分层方法中,当数据库建立时,每一关系即被明确地定义。在分层数据库中的每一记录只能包含一个关键字段,任意两个字段之间只能有一种关系。由于数据并不总是遵循这种严格的分层关系,所以这样可能会出现一些问题。

关系模型

在1970年,数据库研究取得了重大突破。E.F.Codd提出了一种截然不同的数据库管理方法,使用表作为数据结构,称之为关系模型.

关系数据库是使用最广的数据结构,数据被组织成关系表,每个表由称作记录的行和称作字段的列组成。每个记录包含了专用项目的字段值。例如,在一个包含雇员信息的表中,一个记录包含了像一个人姓名和地址这样的字段的值。

结构化查询语言(SQL)是一种在关系型数据库中用于处理数据的查询语言。它是非过程化语言或者说是描述性的,用户只须指定一种类似于英语的描述,用来确定操作,记录或描述记录组合。查询优化器将这种描述翻译为过程执行数据库操作。

网状模型

网状模型在数据之间通过链接表结构创建关系,子记录可以链接到多个父记录。这种将记录和链接捆绑到一起的方法叫做指针,他是指向一个记录存储位置的存储地址。使用网状方法,一个子记录可以链接到一个关键记录,同时,它本身也可以作为一个关键记录。链接到其他一系列子记录。在早期,网状模型比其他模型更有性能优势;但是在今天,这种优势的特点只有在自动柜员机网络,航

空预定系统等大容量和高速处理过程中才是最重要的。

分层和网状数据库都是专用程序,如果开发一个新的应用程序,那么在不同的应用程序中保持数据库的一致性是非常困难的。例如开发一个退休金程序,需要访问雇员数据,这一数据同时也被工资单程序访问。虽然数据是相同的,但是也必须建立新的数据库。

对象模型

最新的数据库管理方法是使用对象模型,记录由被称作对象的实体来描述,可以在对象中存储数据,同时提供方法或程序执行特定的任务。

对象模型使用的查询语言与开发数据库程序所使用的面向对象的程序设计语言是相同的,因为没有像SQL这样简单统一的查询语言,所以会产生一些问题。对象模型相对较新,仅有少数几个面向对象的数据库实例。它引起了人们的关注,因为选择面向对象程序设计语言的开发人员希望有一个基于在对象模型基础上的数据库。

分布式数据库

类似的,分布式数据库指的是数据库的各个部分分别存储在物理上相互分开的计算机上。分布式数据库的一个目的是访问数据信息时不必考虑其他位置。注意,一旦用户和数据分开,通信和网络则开始扮演重要角色。

分布式数据库需要部分常驻于大型主机上的软件,这些软件在大型机和个人计算机之间建立桥梁,并解决数据格式不兼容的问题。在理想情况下,大型主机上的数据库看起来像是一个大的信息仓库,而大部分处理则在个人计算机上完成。

分布式数据库系统的一个缺点是它们常以主机中心模型为基础,在这种模型中,大型主机看起来好像是雇主,而终端和个人计算机看起来好像是奴隶。但是这种方法也有许多优点:由于数据库的集中控制,前面提到的数据完整性和安全性的问题就迎刃而解了。当今的个人计算机,部门级计算机和分布式处理都需要计算机之间以及应用程序之间在相等或对等的基础上相互通信,在数据库中客户机/服务器模型为分布式数据库提供了框架结构。

利用相互连接的计算机上运行的数据库应用程序的一种方法是将程序分解为相互独立的部分。客户端是一个最终用户或通过网络申请资源的计算机程序,服务器是一个运行着的计算机软件,存储着那些通过网络传输的申请。当申请的资源是数据库中的数据时,客户机/服务器模型则为分布式数据库提供了框架结

构。

文件服务器指的是一个通过网络提供文件访问的软件,专门的文件服务器是一台被指定为文件服务器的计算机。这是非常有用的,例如,如果文件比较大而且需要快速访问,在这种情况下,一台微型计算机或大型主机将被用作文件服务器。分布式文件服务器将文件分散到不同的计算机上,而不是将它们集中存放到专门的文件服务器上。

后一种文件服务器的优点包括在其他计算机上存储和检索文件的能力,并可以在每一台计算机上消除重复文件。然而,一个重要的缺点是每个读写请求需要在网络上传播,在刷新文件时可能出现问题。假设一个用户申请文件中的一个数据并修改它,同时另外一个用户也申请这个数据并修改它,解决这种问题的方法叫做数据锁定,即第一个申请使其他申请处于等待状态,直到完成第一个申请,其他用户可以读取这个数据,但不能修改。

数据库服务器是一个通过网络为数据库申请提供服务的软件,例如,假设某个用户在他的个人计算机上输入了一个数据查询命令,如果应用程序按照客户机/服务器模型设计,那么个人计算机上的查询语言通过网络传送数据库服务器上,当发现数据时发出通知。

在工程界也有许多分布式数据库的例子,如SUN公司的网络文件系统(NFS)被应用到计算机辅助工程应用程序中,将数据分散到由SUN工作站组成的网络上的不同硬盘之间。

分布式数据库是革命性的进步,因为把数据存放在被使用位置上是很合乎常理的。例如一个大公司不同部门之间的计算机,应该将数据存储在本地,然而,当被授权的管理人员需要整理部门数据时,数据应该能够被访问。数据库信息系统软件将保护数据库的安全性和完整性,对用户而言,分布式数据库和非分布式数据库看起来没有什么差别。

文章的出处:《数据库系统概论》,作者:王珊,萨师煊

外文翻译

Load and Ultimate Moment of Prestressed Concrete Action Under Overload-Cracking Load It has been shown that a variation in the external load acting on a prestressed beam results in a change in the location of the pressure line for beams in the elastic range.This is a fundamental principle of prestressed construction.In a normal prestressed beam,this shift in the location of the pressure line continues at a relatively uniform rate,as the external load is increased,to the point where cracks develop in the tension fiber.After the cracking load has been exceeded,the rate of movement in the pressure line decreases as additional load is applied,and a significant increase in the stress in the prestressing tendon and the resultant concrete force begins to take place.This change in the action of the internal moment continues until all movement of the pressure line ceases.The moment caused by loads that are applied thereafter is offset entirely by a corresponding and proportional change in the internal forces,just as in reinforced-concrete construction.This fact,that the load in the elastic range and the plastic range is carried by actions that are fundamentally different,is very significant and renders strength computations essential for all designs in order to ensure that adequate safety factors exist.This is true even though the stresses in the elastic range may conform to a recognized elastic design criterion. It should be noted that the load deflection curve is close to a straight line up to the cracking load and that the curve becomes progressively more curved as the load is increased above the cracking load.The curvature of the load-deflection curve for loads over the cracking load is due to the change in the basic internal resisting moment action that counteracts the applied loads,as described above,as well as to plastic strains that begin to take place in the steel and the concrete when stressed to high levels. In some structures it may be essential that the flexural members remain crack free even under significant overloads.This may be due to the structures’being exposed to exceptionally corrosive atmospheres during their useful life.In designing prestressed members to be used in special structures of this type,it may be necessary to compute the load that causes cracking of the tensile flange,in order to ensure that adequate safety against cracking is provided by the design.The computation of the moment that will cause cracking is also necessary to ensure compliance with some design criteria. Many tests have demonstrated that the load-deflection curves of prestressed beams are approximately linear up to and slightly in excess of the load that causes the first cracks in the tensile flange.(The linearity is a function of the rate at which the load is applied.)For this reason,normal elastic-design relationships can be used in computing the cracking load by simply determining the load that results in a net tensile stress in the tensile flange(prestress minus the effects of the applied loads)that is equal to the tensile strength of the concrete.It is customary to assume that the flexural tensile strength of the concrete is equal to the modulus of rupture of the

毕业论文外文文献翻译-数据库管理系统的介绍

数据库管理系统的介绍 Raghu Ramakrishnan1 数据库(database,有时拼作data base)又称为电子数据库,是专门组织起来的一组数据或信息,其目的是为了便于计算机快速查询及检索。数据库的结构是专门设计的,在各种数据处理操作命令的支持下,可以简化数据的存储,检索,修改和删除。数据库可以存储在磁盘,磁带,光盘或其他辅助存储设备上。 数据库由一个或一套文件组成,其中的信息可以分解为记录,每一记录又包含一个或多个字段(或称为域)。字段是数据存取的基本单位。数据库用于描述实体,其中的一个字段通常表示与实体的某一属性相关的信息。通过关键字以及各种分类(排序)命令,用户可以对多条记录的字段进行查询,重新整理,分组或选择,以实体对某一类数据的检索,也可以生成报表。 所有数据库(最简单的除外)中都有复杂的数据关系及其链接。处理与创建,访问以及维护数据库记录有关的复杂任务的系统软件包叫做数据库管理系统(DBMS)。DBMS软件包中的程序在数据库与其用户间建立接口。(这些用户可以是应用程序员,管理员及其他需要信息的人员和各种操作系统程序)。 DBMS可组织,处理和表示从数据库中选出的数据元。该功能使决策者能搜索,探查和查询数据库的内容,从而对在正规报告中没有的,不再出现的且无法预料的问题做出回答。这些问题最初可能是模糊的并且(或者)是定义不恰当的,但是人们可以浏览数据库直到获得所需的信息。简言之,DBMS将“管理”存储的数据项,并从公共数据库中汇集所需的数据项以回答非程序员的询问。 DBMS由3个主要部分组成:(1)存储子系统,用来存储和检索文件中的数据;(2)建模和操作子系统,提供组织数据以及添加,删除,维护,更新数据的方法;(3)用户和DBMS之间的接口。在提高数据库管理系统的价值和有效性方面正在展现以下一些重要发展趋势; 1.管理人员需要最新的信息以做出有效的决策。 2.客户需要越来越复杂的信息服务以及更多的有关其订单,发票和账号的当前信息。 3.用户发现他们可以使用传统的程序设计语言,在很短的一段时间内用数据1Database Management Systems( 3th Edition ),Wiley ,2004, 5-12

ASP外文翻译原文

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毕业设计外文翻译原文.

Optimum blank design of an automobile sub-frame Jong-Yop Kim a ,Naksoo Kim a,*,Man-Sung Huh b a Department of Mechanical Engineering,Sogang University,Shinsu-dong 1,Mapo-ku,Seoul 121-742,South Korea b Hwa-shin Corporation,Young-chun,Kyung-buk,770-140,South Korea Received 17July 1998 Abstract A roll-back method is proposed to predict the optimum initial blank shape in the sheet metal forming process.The method takes the difference between the ?nal deformed shape and the target contour shape into account.Based on the method,a computer program composed of a blank design module,an FE-analysis program and a mesh generation module is developed.The roll-back method is applied to the drawing of a square cup with the ˉange of uniform size around its periphery,to con?rm its validity.Good agreement is recognized between the numerical results and the published results for initial blank shape and thickness strain distribution.The optimum blank shapes for two parts of an automobile sub-frame are designed.Both the thickness distribution and the level of punch load are improved with the designed blank.Also,the method is applied to design the weld line in a tailor-welded blank.It is concluded that the roll-back method is an effective and convenient method for an optimum blank shape design.#2000Elsevier Science S.A.All rights reserved. Keywords:Blank design;Sheet metal forming;Finite element method;Roll-back method

外文翻译中文版(完整版)

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外文翻译

华南理工大学广州学院 本科毕业设计(论文)外文翻译 外文原文名Marketing Strategy Adjustment and Marketing Innovation in the Experience Economy Era 中文译名体验经济时代的营销战略调整与营销创新 学院管理学院 专业班级2013级工商管理1班 学生姓名潘嘉谊 学生学号201330090184 指导教师罗玲苑讲师李巍巍 填写日期2017年5月19日

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管理信息系统外文翻译

管理信息系统外文翻译-标准化文件发布号:(9456-EUATWK-MWUB-WUNN-INNUL-DDQTY-KII

英文文献翻译 二〇年月日

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外文翻译原文

204/JOURNAL OF BRIDGE ENGINEERING/AUGUST1999

JOURNAL OF BRIDGE ENGINEERING /AUGUST 1999/205 ends.The stress state in each cylindrical strip was determined from the total potential energy of a nonlinear arch model using the Rayleigh-Ritz method. It was emphasized that the membrane stresses in the com-pression region of the curved models were less than those predicted by linear theory and that there was an accompanying increase in ?ange resultant force.The maximum web bending stress was shown to occur at 0.20h from the compression ?ange for the simple support stiffness condition and 0.24h for the ?xed condition,where h is the height of the analytical panel.It was noted that 0.20h would be the optimum position for longitudinal stiffeners in curved girders,which is the same as for straight girders based on stability requirements.From the ?xed condition cases it was determined that there was no signi?cant change in the membrane stresses (from free to ?xed)but that there was a signi?cant effect on the web bend-ing stresses.Numerical results were generated for the reduc-tion in effective moment required to produce initial yield in the ?anges based on curvature and web slenderness for a panel aspect ratio of 1.0and a web-to-?ange area ratio of 2.0.From the results,a maximum reduction of about 13%was noted for a /R =0.167and about 8%for a /R =0.10(h /t w =150),both of which would correspond to extreme curvature,where a is the length of the analytical panel (modeling the distance be-tween transverse stiffeners)and R is the radius of curvature.To apply the parametric results to developing design criteria for practical curved girders,the de?ections and web bending stresses that would occur for girders with a curvature corre-sponding to the initial imperfection out-of-?atness limit of D /120was used.It was noted that,for a panel with an aspect ratio of 1.0,this would correspond to a curvature of a /R =0.067.The values of moment reduction using this approach were compared with those presented by Basler (Basler and Thurlimann 1961;Vincent 1969).Numerical results based on this limit were generated,and the following web-slenderness requirement was derived: 2 D 36,500a a =1?8.6?34 (1) ? ??? t R R F w ?y where D =unsupported distance between ?anges;and F y =yield stress in psi. An extension of this work was published a year later,when Culver et al.(1973)checked the accuracy of the isolated elas-tically supported cylindrical strips by treating the panel as a unit two-way shell rather than as individual strips.The ?ange/web boundaries were modeled as ?xed,and the boundaries at the transverse stiffeners were modeled as ?xed and simple.Longitudinal stiffeners were modeled with moments of inertias as multiples of the AASHO (Standard 1969)values for straight https://www.wendangku.net/doc/302023637.html,ing analytical results obtained for the slenderness required to limit the plate bending stresses in the curved panel to those of a ?at panel with the maximum allowed out-of-?atness (a /R =0.067)and with D /t w =330,the following equa-tion was developed for curved plate girder web slenderness with one longitudinal stiffener: D 46,000a a =1?2.9 ?2.2 (2) ? ? ? t R f R w ?b where the calculated bending stress,f b ,is in psi.It was further concluded that if longitudinal stiffeners are located in both the tension and compression regions,the reduction in D /t w will not be required.For the case of two stiffeners,web bending in both regions is reduced and the web slenderness could be de-signed as a straight girder panel.Eq.(1)is currently used in the ‘‘Load Factor Design’’portion of the Guide Speci?cations ,and (2)is used in the ‘‘Allowable Stress Design’’portion for girders stiffened with one longitudinal stiffener.This work was continued by Mariani et al.(1973),where the optimum trans-verse stiffener rigidity was determined analytically. During almost the same time,Abdel-Sayed (1973)studied the prebuckling and elastic buckling behavior of curved web panels and proposed approximate conservative equations for estimating the critical load under pure normal loading (stress),pure shear,and combined normal and shear loading.The linear theory of shells was used.The panel was simply supported along all four edges with no torsional rigidity of the ?anges provided.The transverse stiffeners were therefore assumed to be rigid in their directions (no strains could be developed along the edges of the panels).The Galerkin method was used to solve the governing differential equations,and minimum eigenvalues of the critical load were calculated and presented for a wide range of loading conditions (bedding,shear,and combined),aspect ratios,and curvatures.For all cases,it was demonstrated that the critical load is higher for curved panels over the comparable ?at panel and increases with an increase in curvature. In 1980,Daniels et al.summarized the Lehigh University ?ve-year experimental research program on the fatigue behav-ior of horizontally curved bridges and concluded that the slen-derness limits suggested by Culver were too severe.Equations for ‘‘Load Factor Design’’and for ‘‘Allowable Stress Design’’were developed (respectively)as D 36,500a =1?4?192(3)? ?t R F w ?y D 23,000a =1?4 ?170 (4) ? ? t R f w ?b The latter equation is currently used in the ‘‘Allowable Stress Design’’portion of the Guide Speci?cations for girders not stiffened longitudinally. Numerous analytical and experimental works on the subject have also been published by Japanese researchers since the end of the CURT project.Mikami and colleagues presented work in Japanese journals (Mikami et al.1980;Mikami and Furunishi 1981)and later in the ASCE Journal of Engineering Mechanics (Mikami and Furunishi 1984)on the nonlinear be-havior of cylindrical web panels under bending and combined bending and shear.They analyzed the cylindrical panels based on Washizu’s (1975)nonlinear theory of shells.The governing nonlinear differential equations were solved numerically by the ?nite-difference method.Simple support boundary condi-tions were assumed along the curved boundaries (top and bot-tom at the ?ange locations)and both simple and ?xed support conditions were used at the straight (vertical)boundaries.The large displacement behavior was demonstrated by Mi-kami and Furunishi for a range of geometric properties.Nu-merical values of the load,de?ection,membrane stress,bend-ing stress,and torsional stress were obtained,but no equations for design use were presented.Signi?cant conclusions include that:(1)the compressive membrane stress in the circumfer-ential direction decreases with an increase in curvature;(2)the panel under combined bending and shear exhibits a lower level of the circumferential membrane stress as compared with the panel under pure bending,and as a result,the bending moment carried by the web panel is reduced;and (3)the plate bending stress under combined bending and shear is larger than that under pure bending.No formulations or recommendations for direct design use were made. Kuranishi and Hiwatashi (1981,1983)used the ?nite-ele-ment method to demonstrate the elastic ?nite displacement be-havior of curved I-girder webs under bending using models with and without ?ange rigidities.Rotation was not allowed (?xed condition)about the vertical axis at the ends of the panel (transverse stiffener locations).Again,the nonlinear distribu-

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