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毕业论文(设计)外文文献翻译及原文

毕业论文(设计)外文文献翻译及原文

金融体制、融资约束与投资——来自OECD的实证分析R.SemenovDepartment of Economics,University of Nijmegen,Nijmegen(荷兰内梅亨大学,经济学院)这篇论文考查了OECD的11个国家中现金流量对企业投资的影响.我们发现不同国家之间投资对企业内部可获取资金的敏感性具有显著差异,并且银企之间具有明显的紧密关系的国家的敏感性比银企之间具有公平关系的国家的低.同时,我们发现融资约束与整体金融发展指标不存在关系.我们的结论与资本市场信息和激励问题对企业投资具有重要作用这种观点一致,并且紧密的银企关系会减少这些问题从而增加企业获取外部融资的渠道。

一、引言各个国家的企业在显著不同的金融体制下运行。

金融发展水平的差别(例如,相对GDP的信用额度和相对GDP的相应股票市场的资本化程度),在所有者和管理者关系、企业和债权人的模式中,企业控制的市场活动水平可以很好地被记录.在完美资本市场,对于具有正的净现值投资机会的企业将一直获得资金。

然而,经济理论表明市场摩擦,诸如信息不对称和激励问题会使获得外部资本更加昂贵,并且具有盈利投资机会的企业不一定能够获取所需资本.这表明融资要素,例如内部产生资金数量、新债务和权益的可得性,共同决定了企业的投资决策.现今已经有大量考查外部资金可得性对投资决策的影响的实证资料(可参考,例如Fazzari(1998)、 Hoshi(1991)、 Chapman(1996)、Samuel(1998)).大多数研究结果表明金融变量例如现金流量有助于解释企业的投资水平。

这项研究结果解释表明企业投资受限于外部资金的可得性。

很多模型强调运行正常的金融中介和金融市场有助于改善信息不对称和交易成本,减缓不对称问题,从而促使储蓄资金投着长期和高回报的项目,并且提高资源的有效配置(参看Levine(1997)的评论文章)。

因而我们预期用于更加发达的金融体制的国家的企业将更容易获得外部融资.几位学者已经指出建立企业和金融中介机构可进一步缓解金融市场摩擦。

外文文献译文(样例)

外文文献译文(样例)

MSE协议攻击1引言2004年,CacheLogic公司(现名Velocix)根据一项六个月的调查指出,BitTorrent(以下简称BT)流量约占Internet总流量的33%[1]。

尽量各项调查得出的结论之间存在一定差异,但不可否认的是,BT的应用已经越来越广泛。

BT的大规模应用给网络性能带来了一定的负面影响。

因此,一些ISP已经开始对BT 进行限速。

为了应对这一情况,BT客户端的开发者设计了MSE协议,其主要目的是对数据流提供混淆功能,其次提供一定的保密和认证功能[2]。

BT客户端的开发者并没有基于已知的公有协议(例如IPSec),而是完全重新设计了MSE协议。

本文描述了MSE协议的大量漏洞,利用这些漏洞可以完全恢复出密钥和导致种子指纹的泄露。

我们把这种攻击应用到不同平台下的各种客户端。

结果显示,MSE协议具有大量漏洞,且协议本身有许多细节之处仍待完善。

2BitTorrent协议BitTorrent协议的设计目的是在网络上高效地传输大型文件。

当需要分发大型文件时,将之分解为文件块,并由多个节点提供下载,以减轻网络中单个节点的成本和负载。

当使用BitTorrent协议下载文件时,几乎将同时开始上传文件块。

BT网络由四个部分组成:下载者、做种者、Web服务器和Tracker服务器。

在使用BT协议共享某个文件之前,必须先创建一个种子文件。

这个种子文件包含了需要下载的共享文件中各个文件块的信息,包括Tracker信息、共享的文件块总数、所有文件块的哈希值等基本信息。

当下载完成后,可以利用这些哈希值来验证文件的完整性。

此外,文件中还包含一个用其它部分的元数据计算得到的哈希值InfoHash。

InfoHash值可以用来确定某个特定的种子文件。

除了将种子文件分发给用户下载外,还必须将文件信息报告给Tracker服务器。

Tracker服务器的工作是跟踪记录所有做种者的信息,并保持下载者之间的相互通信。

当用户使用BT协议下载文件时,首先从Web服务器上下载种子文件。

Spring相关的外文文献和翻译(毕设论文必备)

Spring相关的外文文献和翻译(毕设论文必备)

附录1 外文原文Introducing the Spring FrameworkThe Spring Framework: a popular open source application framework that addresses many of the issues outlined in this book. This chapter will introduce the basic ideas of Spring and dis-cuss the central “bean factory”lightweight Inversion-of-Control (IoC) container in detail.Spring makes it particularly easy to implement lightweight, yet extensible, J2EE archi-tectures. It provides an out-of-the-box implementation of the fundamental architectural building blocks we recommend. Spring provides a consistent way of structuring your applications, and provides numerous middle tier features that can make J2EE development significantly easier and more flexible than in traditional approaches.The basic motivations for Spring are:To address areas not well served by other frameworks. There are numerous good solutions to specific areas of J2EE infrastructure: web frameworks, persistence solutions, remoting tools, and so on. However, integrating these tools into a comprehensive architecture can involve significant effort, and can become a burden. Spring aims to provide an end-to-end solution, integrating spe-cialized frameworks into a coherent overall infrastructure. Spring also addresses some areas that other frameworks don’t. For example, few frameworks address generic transaction management, data access object implementation, and gluing all those things together into an application, while still allowing for best-of-breed choice in each area. Hence we term Spring an application framework, rather than a web framework, IoC or AOP framework, or even middle tier framework.To allow for easy adoption. A framework should be cleanly layered, allowing the use of indi-vidual features without imposing a whole world view on the application. Many Spring features, such as the JDBC abstraction layer or Hibernate integration, can be used in a library style or as part of the Spring end-to-end solution.To deliver ease of use. As we’ve noted, J2EE out of the box is relatively hard to use to solve many common problems. A good infrastructure framework should make simple tasks simple to achieve, without forcing tradeoffs for future complex requirements (like distributed transactions) on the application developer. It should allow developers to leverage J2EE services such as JTA where appropriate, but to avoid dependence on them in cases when they are unnecessarily complex.To make it easier to apply best practices. Spring aims to reduce the cost of adhering to best practices such as programming to interfaces, rather than classes, almost to zero. However, it leaves the choice of architectural style to the developer.Non-invasiveness. Application objects should have minimal dependence on the framework. If leveraging a specific Spring feature, an object should depend only on that particular feature, whether by implementing a callback interface or using the framework as a class library. IoC and AOP are the key enabling technologies for avoiding framework dependence.Consistent configuration. A good infrastructure framework should keep application configuration flexible and consistent, avoiding the need for custom singletons and factories. A single style should be applicable to all configuration needs, from the middle tier to web controllers.Ease of testing. Testing either whole applications or individual application classes in unit tests should be as easy as possible. Replacing resources or application objects with mock objects should be straightforward.To allow for extensibility. Because Spring is itself based on interfaces, rather than classes, it is easy to extend or customize it. Many Spring components use strategy interfaces, allowing easy customization.A Layered Application FrameworkChapter 6 introduced the Spring Framework as a lightweight container, competing with IoC containers such as PicoContainer. While the Spring lightweight container for JavaBeans is a core concept, this is just the foundation for a solution forall middleware layers.Basic Building Blockspring is a full-featured application framework that can be leveraged at many levels. It consists of multi-ple sub-frameworks that are fairly independent but still integrate closely into a one-stop shop, if desired. The key areas are:Bean factory. The Spring lightweight IoC container, capable of configuring and wiring up Java-Beans and most plain Java objects, removing the need for custom singletons and ad hoc configura-tion. Various out-of-the-box implementations include an XML-based bean factory. The lightweight IoC container and its Dependency Injection capabilities will be the main focus of this chapter.Application context. A Spring application context extends the bean factory concept by adding support for message sources and resource loading, and providing hooks into existing environ-ments. Various out-of-the-box implementations include standalone application contexts and an XML-based web application context.AOP framework. The Spring AOP framework provides AOP support for method interception on any class managed by a Spring lightweight container. It supports easy proxying of beans in a bean factory, seamlessly weaving in interceptors and other advice at runtime. Chapter 8 dis-cusses the Spring AOP framework in detail. The main use of the Spring AOP framework is to provide declarative enterprise services for POJOs.Auto-proxying. Spring provides a higher level of abstraction over the AOP framework and low-level services, which offers similar ease-of-use to .NET within a J2EE context. In particular, the provision of declarative enterprise services can be driven by source-level metadata.Transaction management. Spring provides a generic transaction management infrastructure, with pluggable transaction strategies (such as JTA and JDBC) and various means for demarcat-ing transactions in applications. Chapter 9 discusses its rationale and the power and flexibility that it offers.DAO abstraction. Spring defines a set of generic data access exceptions that canbe used for cre-ating generic DAO interfaces that throw meaningful exceptions independent of the underlying persistence mechanism. Chapter 10 illustrates the Spring support for DAOs in more detail, examining JDBC, JDO, and Hibernate as implementation strategies.JDBC support. Spring offers two levels of JDBC abstraction that significantly ease the effort of writing JDBC-based DAOs: the org.springframework.jdbc.core package (a template/callback approach) and the org.springframework.jdbc.object package (modeling RDBMS operations as reusable objects). Using the Spring JDBC packages can deliver much greater pro-ductivity and eliminate the potential for common errors such as leaked connections, compared with direct use of JDBC. The Spring JDBC abstraction integrates with the transaction and DAO abstractions.Integration with O/R mapping tools. Spring provides support classes for O/R Mapping tools like Hibernate, JDO, and iBATIS Database Layer to simplify resource setup, acquisition, and release, and to integrate with the overall transaction and DAO abstractions. These integration packages allow applications to dispense with custom ThreadLocal sessions and native transac-tion handling, regardless of the underlyingO/R mapping approach they work with.Web MVC framework. Spring provides a clean implementation of web MVC, consistent with the JavaBean configuration approach. The Spring web framework enables web controllers to be configured within an IoC container, eliminating the need to write any custom code to access business layer services. It provides a generic DispatcherServlet and out-of-the-box controller classes for command and form handling. Request-to-controller mapping, view resolution, locale resolution and other important services are all pluggable, making the framework highly extensi-ble. The web framework is designed to work not only with JSP, but with any view technology, such as Velocity—without the need for additional bridges. Chapter 13 discusses web tier design and the Spring web MVC framework in detail.Remoting support. Spring provides a thin abstraction layer for accessing remoteservices without hard-coded lookups, and for exposing Spring-managed application beans as remote services. Out-of-the-box support is included for RMI, Caucho’s Hessian and Burlap web service protocols, and WSDL Web Services via JAX-RPC. Chapter 11 discusses lightweight remoting.While Spring addresses areas as diverse as transaction management and web MVC, it uses a consistent approach everywhere. Once you have learned the basic configuration style, you will be able to apply it in many areas. Resources, middle tier objects, and web components are all set up using the same bean configuration mechanism. You can combine your entire configuration in one single bean definition file or split it by application modules or layers; the choice is up to you as the application developer. There is no need for diverse configuration files in a variety of formats, spread out across the application.Spring on J2EEAlthough many parts of Spring can be used in any kind of Java environment, it is primarily a J2EE application framework. For example, there are convenience classes for linking JNDI resources into a bean factory, such as JDBC DataSources and EJBs, and integration with JTA for distributed transaction management. In most cases, application objects do not need to work with J2EE APIs directly, improving reusability and meaning that there is no need to write verbose, hard-to-test, JNDI lookups.Thus Spring allows application code to seamlessly integrate into a J2EE environment without being unnecessarily tied to it. You can build upon J2EE services where it makes sense for your application, and choose lighter-weight solutions if there are no complex requirements. For example, you need to use JTA as transaction strategy only if you face distributed transaction requirements. For a single database, there are alternative strategies that do not depend on a J2EE container. Switching between those transac-tion strategies is merely a matter of configuration; Spring’s consistent abstraction avoids any need to change application code.Spring offers support for accessing EJBs. This is an important feature (andrelevant even in a book on “J2EE without EJB”) because the use of dynamic proxies as codeless client-side business delegates means that Spring can make using a local stateless session EJB an implementation-level, rather than a fundamen-tal architectural, choice. Thus if you want to use EJB, you can within a consistent architecture; however, you do not need to make EJB the cornerstone of your architecture. This Spring feature can make devel-oping EJB applications significantly faster, because there is no need to write custom code in service loca-tors or business delegates. Testing EJB client code is also much easier, because it only depends on the EJB’s Business Methods interface (which is not EJB-specific), not on JNDI or the EJB API.Spring also provides support for implementing EJBs, in the form of convenience superclasses for EJB implementation classes, which load a Spring lightweight container based on an environment variable specified in the ejb-jar.xml deployment descriptor. This is a powerful and convenient way of imple-menting SLSBs or MDBs that are facades for fine-grained POJOs: a best practice if you do choose to implement an EJB application. Using this Spring feature does not conflict with EJB in any way—it merely simplifies following good practice.Introducing the Spring FrameworkThe main aim of Spring is to make J2EE easier to use and promote good programming practice. It does not reinvent the wheel; thus you’ll find no logging packages in Spring, no connection pools, no distributed transaction coordinator. All these features are provided by other open source projects—such as Jakarta Commons Logging (which Spring uses for all its log output), Jakarta Commons DBCP (which can be used as local DataSource), and ObjectWeb JOTM (which can be used as transaction manager)—or by your J2EE application server. For the same reason, Spring doesn’t provide an O/R mapping layer: There are good solutions for this problem area, such as Hibernate and JDO.Spring does aim to make existing technologies easier to use. For example, although Spring is not in the business of low-level transaction coordination, it does provide an abstraction layer over JTA or any other transaction strategy. Spring is alsopopular as middle tier infrastructure for Hibernate, because it provides solutions to many common issues like SessionFactory setup, ThreadLocal sessions, and exception handling. With the Spring HibernateTemplate class, implementation methods of Hibernate DAOs can be reduced to one-liners while properly participating in transactions.The Spring Framework does not aim to replace J2EE middle tier services as a whole. It is an application framework that makes accessing low-level J2EE container ser-vices easier. Furthermore, it offers lightweight alternatives for certain J2EE services in some scenarios, such as a JDBC-based transaction strategy instead of JTA when just working with a single database. Essentially, Spring enables you to write appli-cations that scale down as well as up.Spring for Web ApplicationsA typical usage of Spring in a J2EE environment is to serve as backbone for the logical middle tier of a J2EE web application. Spring provides a web application context concept, a powerful lightweight IoC container that seamlessly adapts to a web environment: It can be accessed from any kind of web tier, whether Struts, WebWork, Tapestry, JSF, Spring web MVC, or a custom solution.The following code shows a typical example of such a web application context. In a typical Spring web app, an applicationContext.xml file will reside in theWEB-INF directory, containing bean defini-tions according to the “spring-beans”DTD. In such a bean definition XML file, business objects and resources are defined, for example, a “myDataSource”bean, a “myInventoryManager”bean, and a “myProductManager”bean. Spring takes care of their configuration, their wiring up, and their lifecycle.<beans><bean id=”myDataSource”class=”org.springframework.jdbc. datasource.DriverManagerDataSource”><property name=”driverClassName”> <value>com.mysql.jdbc.Driver</value></property> <property name=”url”><value>jdbc:mysql:myds</value></property></bean><bean id=”myInventoryManager”class=”ebusiness.DefaultInventoryManager”> <property name=”dataSource”><ref bean=”myDataSource”/> </property></bean><bean id=”myProductManager”class=”ebusiness.DefaultProductManager”><property name=”inventoryManager”><ref bean=”myInventoryManager”/> </property><property name=”retrieveCurrentStock”> <value>true</value></property></bean></beans>By default, all such beans have “singleton”scope: one instance per context. The “myInventoryManager”bean will automatically be wired up with the defined DataSource, while “myProductManager”will in turn receive a reference to the “myInventoryManager”bean. Those objects (traditionally called “beans”in Spring terminology) need to expose only the corresponding bean properties or constructor arguments (as you’ll see later in this chapter); they do not have to perform any custom lookups.A root web application context will be loaded by a ContextLoaderListener that is defined in web.xml as follows:<web-app><listener> <listener-class>org.springframework.web.context.ContextLoaderListener </listener-class></listener>...</web-app>After initialization of the web app, the root web application context will beavailable as a ServletContext attribute to the whole web application, in the usual manner. It can be retrieved from there easily via fetching the corresponding attribute, or via a convenience method in org.springframework.web.context.support.WebApplicationContextUtils. This means that the application context will be available in any web resource with access to the ServletContext, like a Servlet, Filter, JSP, or Struts Action, as follows:WebApplicationContext wac = WebApplicationContextUtils.getWebApplicationContext(servletContext);The Spring web MVC framework allows web controllers to be defined as JavaBeans in child application contexts, one per dispatcher servlet. Such controllers can express dependencies on beans in the root application context via simple bean references. Therefore, typical Spring web MVC applications never need to perform a manual lookup of an application context or bean factory, or do any other form of lookup.Neither do other client objects that are managed by an application context themselves: They can receive collaborating objects as bean references.The Core Bean FactoryIn the previous section, we have seen a typical usage of the Spring IoC container in a web environment: The provided convenience classes allow for seamless integration without having to worry about low-level container details. Nevertheless, it does help to look at the inner workings to understand how Spring manages the container. Therefore, we will now look at the Spring bean container in more detail, starting at the lowest building block: the bean factory. Later, we’ll continue with resource setup and details on the application context concept.One of the main incentives for a lightweight container is to dispense with the multitude of custom facto-ries and singletons often found in J2EE applications. The Spring bean factory provides one consistent way to set up any number of application objects, whether coarse-grained components or fine-grained busi-ness objects. Applying reflection and Dependency Injection, the bean factory can host components that do not need to be aware of Spring at all. Hence we call Spring a non-invasiveapplication framework.Fundamental InterfacesThe fundamental lightweight container interface isorg.springframework.beans.factory.Bean Factory. This is a simple interface, which is easy to implement directly in the unlikely case that none of the implementations provided with Spring suffices. The BeanFactory interface offers two getBean() methods for looking up bean instances by String name, with the option to check for a required type (and throw an exception if there is a type mismatch).public interface BeanFactory {Object getBean(String name) throws BeansException;Object getBean(String name, Class requiredType) throws BeansException;boolean containsBean(String name);boolean isSingleton(String name) throws NoSuchBeanDefinitionException;String[] getAliases(String name) throws NoSuchBeanDefinitionException;}The isSingleton() method allows calling code to check whether the specified name represents a sin-gleton or prototype bean definition. In the case of a singleton bean, all calls to the getBean() method will return the same object instance. In the case of a prototype bean, each call to getBean() returns an inde-pendent object instance, configured identically.The getAliases() method will return alias names defined for the given bean name, if any. This mecha-nism is used to provide more descriptive alternative names for beans than are permitted in certain bean factory storage representations, such as XML id attributes.The methods in most BeanFactory implementations are aware of a hierarchy that the implementation may be part of. If a bean is not found in the current factory, the parent factory will be asked, up until the root factory. From the point of view of a caller, all factories in such a hierarchy will appear to be merged into one. Bean definitions in ancestor contexts are visible to descendant contexts, but not the reverse.All exceptions thrown by the BeanFactory interface and sub-interfaces extend org.springframework. beans.BeansException, and are unchecked. This reflects the fact that low-level configuration prob-lems are not usually recoverable: Hence, application developers can choose to write code to recover from such failures if they wish to, but should not be forced to write code in the majority of cases where config-uration failure is fatal.Most implementations of the BeanFactory interface do not merely provide a registry of objects by name; they provide rich support for configuring those objects using IoC. For example, they manage dependen-cies between managed objects, as well as simple properties. In the next section, we’ll look at how such configuration can be expressed in a simple and intuitive XML structure.The sub-interface org.springframework.beans.factory.ListableBeanFactory supports listing beans in a factory. It provides methods to retrieve the number of beans defined, the names of all beans, and the names of beans that are instances of a given type:public interface ListableBeanFactory extends BeanFactory {int getBeanDefinitionCount();String[] getBeanDefinitionNames();String[] getBeanDefinitionNames(Class type);boolean containsBeanDefinition(String name);Map getBeansOfType(Class type, boolean includePrototypes,boolean includeFactoryBeans) throws BeansException}The ability to obtain such information about the objects managed by a ListableBeanFactory can be used to implement objects that work with a set of other objects known only at runtime.In contrast to the BeanFactory interface, the methods in ListableBeanFactory apply to the current factory instance and do not take account of a hierarchy that the factory may be part of. The org.spring framework.beans.factory.BeanFactoryUtils class provides analogous methods that traverse an entire factory hierarchy.There are various ways to leverage a Spring bean factory, ranging from simple bean configuration to J2EE resource integration and AOP proxy generation. The bean factory is the central, consistent way of setting up any kind of application objects in Spring, whether DAOs, business objects, or web controllers. Note that application objects seldom need to work with the BeanFactory interface directly, but are usu-ally configured and wired by a factory without the need for any Spring-specific code.For standalone usage, the Spring distribution provides a tiny spring-core.jar file that can be embed-ded in any kind of application. Its only third-party dependency beyond J2SE 1.3 (plus JAXP for XML parsing) is the Jakarta Commons Logging API.The bean factory is the core of Spring and the foundation for many other services that the framework offers. Nevertheless, the bean factory can easily be usedstan-dalone if no other Spring services are required.附录2 中文译文Spring框架介绍Spring框架:这是一个流行的开源应用框架,它可以解决很多问题。

预应力混凝土Prestressed-Concrete大学毕业论文外文文献翻译及原文

预应力混凝土Prestressed-Concrete大学毕业论文外文文献翻译及原文

毕业设计(论文)外文文献翻译文献、资料中文题目:预应力混凝土文献、资料英文题目:Prestressed Concrete文献、资料来源:文献、资料发表(出版)日期:院(部):专业:班级:姓名:学号:指导教师:翻译日期: 2017.02.14毕业设计(论文)外文资料翻译外文出处:The Concrete structure附件:1、外文原文;2、外文资料翻译译文。

1、外文资料原文Prestressed ConcreteConcrete is strong in compression, but weak in tension: Its tensile strength varies from 8 to 14 percent of its compressive strength. Due tosuch a Iow tensile capacity, fiexural cracks develop at early stages ofloading. In order to reduce or prevent such cracks from developing, aconcentric or eccentric force is imposed in the longitudinal direction of the structural element. This force prevents the cracks from developing by eliminating or considerably reducing the tensile stresses at thecritical midspan and support sections at service load, thereby raising the bending, shear, and torsional capacities of the sections. The sections are then able to behave elastically, and almost the full capacity of the concrete in compression can be efficiently utilized across the entire depth of the concrete sections when all loads act on the structure.Such an imposed longitudinal force is called a prestressing force,i.e., a compressive force that prestresses the sections along the span ofthe structural elementprior to the application of the transverse gravitydead and live loads or transient horizontal live loads. The type ofprestressing force involved, together with its magnitude, are determined mainly on the basis of the type of system to be constructed and the span length and slenderness desired.~ Since the prestressing force is applied longitudinally along or parallel to the axis of the member, the prestressing principle involved is commonly known as linear prestressing.Circular prestressing, used in liquid containment tanks, pipes,and pressure reactor vessels, essentially follows the same basic principles as does linear prestressing. The circumferential hoop, or "hugging" stress on the cylindrical or spherical structure, neutralizes the tensile stresses at the outer fibers of the curvilinear surface caused by the internal contained pressure.Figure 1.2.1 illustrates, in a basic fashion, the prestressing action in both types of structural systems and the resulting stress response. In(a), the individual concrete blocks act together as a beam due to the large compressive prestressing force P. Although it might appear that the blocks will slip and vertically simulate shear slip failure, in fact they will not because of the longitudinal force P. Similarly, the wooden staves in (c) might appear to be capable of separating as a result of the high internal radial pressure exerted on them. But again, because of the compressive prestress imposed by the metal bands as a form of circular prestressing, they will remain in place.From the preceding discussion, it is plain that permanent stresses in the prestressed structural member are created before the full dead and live loads are applied in order to eliminate or considerably reduce the net tensile stresses caused by these loads. With reinforced concrete,it is assumed that the tensile strength of the concrete is negligible and disregarded. This is because the tensile forces resulting from the bending moments are resisted bythe bond created in the reinforcement process. Cracking and deflection are therefore essentially irrecoverable in reinforced concrete once the member has reached its limit state at service load.The reinforcement in the reinforced concrete member does not exert any force of its own on the member, contrary to the action of prestressing steel. The steel required to produce the prestressing force in the prestressed member actively preloads the member, permitting a relatively high controlled recovery of cracking and deflection. Once the flexural tensile strength of the concrete is exceeded, the prestressed member starts to act like a reinforced concrete element.Prestressed members are shallower in depth than their reinforced concrete counterparts for the same span and loading conditions. In general, the depth of a prestressed concrete member is usually about 65 to 80 percent of the depth of the equivalent reinforced concrete member. Hence, the prestressed member requires less concrete, and,about 20 to 35 percent of the amount of reinforcement. Unfortunately, this saving in material weight is balanced by the higher cost of the higher quality materials needed in prestressing. Also, regardless of the system used, prestressing operations themselves result in an added cost: Formwork is more complex, since the geometry of prestressed sections is usually composed of. flanged sections with thin-webs.In spite of these additional costs, if a large enough number of precast units are manufactured, the difference between at least the initial costs of prestressed and reinforced concrete systems is usually not very large.~ And the indirect long-term savings are quite substantial, because less maintenance is needed; a longer working life is possible due to better quality control of the concrete, and lighter foundations are achieved due to the smaller cumulative weight of the superstructure.Once the beam span of reinforced concrete exceeds 70 to 90 feet (21.3 to 27.4m), the dead weight of the beam becomes excessive, resulting in heavier members and, consequently, greater long-term deflection and cracking. Thus, for larger spans, prestressed concrete becomes mandatory since arches are expensive to construct and do not perform as well due to the severe long-term shrinkage and creep they undergo.~ Very large spans such as segmental bridges or cable-stayed bridges can only be constructed through the use of prestressing.Prestressd concrete is not a new concept, dating back to 1872, when P. H. Jackson, an engineer from California, patented a prestressing system that used a tie rod to construct beams or arches from individual blocks [see Figure 1.2.1 (a)]. After a long lapse of time during which little progress was made because of the unavailability of high-strength steel to overcome prestress losses, R. E. Dill of Alexandria, Nebraska, recognized the effect of the shrinkage and creep (transverse material flow) of concrete on the loss of prestress. He subsequently developed the idea that successive post-tensioning of unbonded rods would compensate for the time-dependent loss of stress in the rods due to the decrease in the length of the member because of creep and shrinkage. In the early 1920s,W. H. Hewett of Minneapolis developed the principles of circular prestressing. He hoop-stressed horizontal reinforcement around walls of concrete tanks through the use of turnbuckles to prevent cracking due to internalliquid pressure, thereby achieving watertightness. Thereafter, prestressing of tanks and pipes developed at an accelerated pace in the United States, with thousands of tanks for water, liquid, and gas storage built and much mileage of prestressed pressure pipe laid in the two to three decades that followed.Linear prestressing continued to develop in Europe and in France, in particular through the ingenuity of Eugene Freyssinet, who proposed in 1926--1928 methods to overcome prestress losses through the use of high-strength and high-ductility steels. In 1940, he introduced thenow well-known and well-accepted Freyssinet system.P. W. Abeles of England introduced and developed the concept of partial prestressing between the 1930s and 1960s. F. Leonhardt of Germany, V. Mikhailov of Russia, and T. Y. Lin of the United States also contributed a great deal to the art and science of the design of prestressed concrete. Lin's load-balancing method deserves particular mention in this regard, as it considerably simplified the design process, particularly in continuous structures. These twentieth-century developments have led to the extensive use of prestressing throughoutthe world, and in the United States in particular.Today, prestressed concrete is used in buildings, underground structures, TV towers, floating storage and offshore structures, power stations, nuclear reactor vessels, and numerous types of bridge systems including segn~ental and cable-stayed bridges, they demonstrate the versatility of the prestressing concept and its all-encompassing application. The success in the development and construction of all these structures has been due in no small measures to the advances in the technology of materials, particularly prestressing steel, and the accumulated knowledge in estimating the short-and long-term losses in the prestressing forces.~2、外文资料翻译译文预应力混凝土混凝土的力学特性是抗压不抗拉:它的抗拉强度是抗压强度的8%一14%。

土木工程建筑外文翻译外文文献英文文献公路建设造价的未来

土木工程建筑外文翻译外文文献英文文献公路建设造价的未来

本科生毕业设计(论文)外文翻译题目Ⅰ:Estimating Future Highway Construction Costs2009年 2 月 19 日Estimating Future Highway Construction CostsC. G. Wilmot, M.ASCE,1 and G. Cheng, P.E.2Abstract: The objective of this research was to develop a model that estimates future highway construction costs in Louisiana. The model describes overall highway construction cost in terms of a highway construction cost index. The index is a composite measure of the cost of construction labor, materials, and equipment; the characteristics of contracts; and the environment in which contracts are let. Future construction costs are described in terms of predicted index values based on forecasts of the price of construction labor, materials, and equipment and the expected contract characteristics and contract environments. The contract characteristics and contract environments that are under the control of highway agency officials, can be manipulated to reflect future cost-cutting policies. Application of the model in forecasting to highway construction costs in Louisiana shows that the model closely replicates past construction costs for the period 1984–1997. When applied to forecasting future highway construction costs, the model predicts that highway construction costs in Louisiana will double between 1998 and 2015. Applying cost-cutting policies and assuming input costs are 20% less than anticipated, the model estimates highway construction costs will increase by 75% between 1998 and 2015.Key words: Highway construction; Costs; Estimation.IntroductionState Departments of Transportation are required to prepare highway construction programs that describe their planned construction activity in the short term. There is usually considerable interest in the program from local authorities, politicians, and interest groups. Draft programs are typically presented to the public and to various agencies at the local, regional, state, and federal level for comment and review. Ultimately, a program will be approved by the state legislature and will become the formal program of construction of the state Department of Transportation until a new program is developed in the next cycle a few years later.Because individual projects are of considerable importance to politicians and individual interest groups, it is common that progress on a construction program is closely monitored. Any deviation is likely to be queried, and the Secretary of the state Department of Transportation or a senior official in the department will often have to defend the situation publicly or in the state legislature. This can lead to perceptions of incompetence and erosion of support from the legislature and the public.To prepare reliable highway construction programs, road authorities must have accurate estimates of future funding and project costs. While future funding is obviously never known witha great deal of certainty, it is often the estimation of project costs that cause upsets in the execution of construction programs.Inaccurate cost estimation is one source of error, but another, the escalation in cost of a project over time, is another source disruption to the program that is usually not anticipated and catered for. Typically, when projects are costed, their costs are estimated in terms of the current cost of the project, and this estimate is not adjusted for the year in which the project is scheduled for implementation. These cost increases can be significant and are, of course, cumulative across projects; also, they rise at an increasing rate each year into the future. Estimating future highway construction is the focus of this paper. The model developed in this study was developed with data from the Louisiana Department of Transportation and Development ~DOTD! and is therefore particular to that state. However, the methodology employed could be employed in other areas. Measuring Project CostsWhen construction in the field lags behind planned construction in the construction program, it is usually because the projects that have been constructed have cost more than anticipated. This is not random variation of actual costs about estimated costs, because, clearly, underestimates would cancel out overestimates over time in such a situation. Rather, it is evidence of a consistent underestimateof all projects collectively. The benefit of this is that it can be measured at the overall level, which is much easier to measure than at the individual project level.In the past, change in overall construction costs has been measured in terms of construction indices. These indices are weighted averages of the cost of a set of representative pay items over time. They have been used to display cost trends in the past. However, there is no reason why cost indices must be restricted to displaying past trends; they can also portray future overall costs, provided the representative pay items on which the index is based can be forecast. A predictive construction cost index was adopted in this study to describe the change in overall construction costs in the future. The formulation of the index is described later in the paper.Past Increases in Construction CostsWhen the change in overall construction costs in the past is observed(as measured by popular construction cost indices), it is apparent that they change significantly from year to year and that the changes can sometimes be quite erratic. The common assumption that construction costs change with the rate of inflation can lead to poor estimates of future construction cost. To illustrate, the Federal Highway Administration‘s Composite Bid Price Index, an index of overall highway construction costs, is plotted in Fig.1 together with the Consumer Price Index (CPI), a common expression of general inflation. The FHWA CBPI for the entire nation and for Louisiana alone is plotted in the diagram. All indices have been normalized to a value of 100 in 1987 for comparison purposes. From the diagram, it is clear that highway construction costs change erratically and even display different short and long-term trends from to those of the CPI. It is also apparent that construction cost changes are different in Louisiana from those in the nation as a whole. While not shown here, review of the FHWA CBPI from other states shows that many of them show a deviation from national values.Past Methods of Forecasting Highway Construction CostForecasting future highway construction costs has been achieved in basically three ways in the past. First, unit rates of construction such as dollars per mile by highway type have been used to estimate construction costs in the short term. However, this method has generally been found to be unreliable, because site conditions such as topography, in situ soil, land prices, environment, and traffic loads vary sufficiently from location to location to make average prices inaccurate estimates of the price of individual projects or even of all projects in a particular year.Second, extrapolation of past trends, or time-series analysis, has been used to forecast future overall construction costs (Koppula 1981; Hartgen et al. 1997). Typically, construction costs have been collapsed in these analyses to a single overall expression of constructioncost such as the FHWA CBPI or the Engineering News Record’s Building Construction Index ~ENR BCI! or Construction Cost Index ~ENR CCI!. However, these types of models are usually only used for short-term forecasting due to their reliance on the notion that past conditions are maintained in the future.Third,models have been established that describe construction costs as a function of factors believed to influence construction costs. The relationship between construction costs and these factors have been established from past records of construction costs. Typically,the models established in this manner have been used to estimate the cost of individual contracts. These models, with their relational structure, are the only models expected to provide reliable long-term estimates. The model developed in this study is of this type. Proposed Construction Cost ModelIt is clear that there are numerous factors that affect construction costs. However, it is striking that most construction cost models developed in the past have used only a few of the many influential factors identified above. One reason for this is that information is generally not available on many factors in data sets used to estimate models. Another reason is that information on the qualitative conditions surrounding each contract is difficult to obtain. These are problems that prevail in most circumstances and are difficult to overcome.To mitigate against the effect of an incomplete set of factors, two strategies can be employed. First, it may be possible to represent some of the absent factors by surrogate variables that are in the data set. For example, as mentioned earlier, annual bid volume has been used in the past as an inverse measure of the level of competition prevailing in the construction industry at that time (Herbsman 1986). Similarly, the number of plan changes each year can serve as a measure of design quality. Second, if the modeling of construction cost is changed from estimating the cost of individual projects to estimating overall construction costs each year, the modeling task is simplified. This is because it is no longer necessary to try to model individual projects in which conditions inflate the price in one case and deflate it in another, since such conditions would tend to cancel themselves out among projects in the same year. For example, firms that reduce their bid prices in an effort to win a particular contract could be balanced out within the same fiscal year by those that increase their prices because they already have enough work and are not particularly interested in winning the contract.Similarly, those firms with expertise in the type of construction required will be balanced out by those with low levels of expertise in that area. Thus, it is generally more tolerable to operate with fewer relevant factors when modeling at the aggregate or overall level than when modeling at the disaggregate level.The objective of this study is to establish a model, estimated on historical quantitative data, that incorporates as many relevant variables as possible and is capable of estimating the future overall cost of highway construction on an annual basis. The model is intended to assess the impact of alternative future conditions on highway construction costs and assist officials of the Louisiana DOTD to identify management policies that will help limit the increase in highway construction costs in the state.It was also the perception of those interviewed that contracts let in the fourth quarter of the fiscal year tended to result in higher bid prices. This was because there was a tendency for projects to accumulate in the fourth quarter due to various delays, and the increased volume of projects resulted in decreased competition among contractors.Model StructureThe model developed to predict overall highway construction costs in this study is based on five submodels of price estimation. Each submodel estimates the price of a pay item representative of cost model a dominant construction area. Dominant construction areas were identified from past expenditure in different areas of highway construction. From the Louisiana DOTD data for the period1984–1997, it was found that more than 50% of all highway construction expenditure occurred in the areas of asphalt concrete surfaces, Portland cement concrete surfaces, excavation and embankment, structural steel, structural concrete, and reinforcing steel. Interestingly, these construction areas are identical to those used to estimate the FHWA CBPI. The structural steel construction area was not included in the model developed in this study, because more than 98% of expenditure in this construction area was bid as a lump sum in each contract with no record of the amount of steel included in the bid. This made comparison of the cost of structural steel among contracts impossible. The other five construction areas included in the model were all represented by pay items whose prices were expressed in terms of rates, which permitted comparison among contracts.A schematic representation of the overall model with its five submodels is shown in Fig. 2. Each submodel estimates the price of a representative pay item from each of the five dominant construction areas. The contribution of each submodel to the overall model is accomplished by combining the prices of the representative pay items in an index similar to that of the FHWA CBPI. In this case, because the formulation is slightly different from the FHWA CBPI and is constructed specifically to reflect past and future overall construction costs in Louisiana, it is named the Louisiana Highway Construction Index and is defined asValidationModel performance is ideally validated using data not used in the estimation of the model. In this case no such data was available. Dividing the existing data set into two portions to estimate the model on one portionand use the other for validation was not practical, given the limited sample size in some of the submodels. For example, the concrete pavement submodel has a total of only 212 observations, and estimating the submodel on the highly variable data on fewer observations would reduce the accuracy of the estimates. Thus, the performance of the model was assessed by observing how well it reproduced observed construction costs.Using the same data as that on which the model was calibrated, the estimated and observed LHCI values for the period 1984–1997 are shown in Fig. 3. The 95% confidence limit of the observed LHCI is also shown in the figure to illustrate that the estimated LHCI values are, for the most part, contained within the 95% confidence limit of the observed LHCI values. The chisquared test of the similarity of the estimated and observed LHCI values indicates that a significant difference could not be observed at the 99% level of significance.Investigating the behavior of the construction cost index in Fig. 3 reveals interesting reasons behind the observed behavior. Reviewing the data and observing its impact on the forecasts through the model allows an analyst to determine the primary causes of change in construction costs during certain periods in the past. For example, the main cause of the decrease in construction costs observed in the period 1984–1986 can be traced back to a decline in labor and petroleum costs during that period. The rapid increase in construction costs from 1995 to 1996 was primarily due to a combination of rising petroleum costs and an increased proportion of smaller contracts. The drop in construction costs observed immediately following this event (i.e., in 1997) was mainly the consequence of an increase in the average size of projects from those let in 1996, very few projects being let in the fourth quarter, and a decrease in the average duration of projects.ConclusionsThis study has shown that the literature indicates that a comprehensive set of factors contributes to the cost of highway construction. In this study, the most influential factors were found to be the cost of the material, labor, and equipment used in constructing the facility. However, characteristics of individual contracts and the contracting environment in which contracts are let also affect construction costs. In particular, contract size, duration, location, and the quarter in which the contract is let were found to have a significant impact on contract cost. Bid volume, bid volume variance, number of plan changes, and changes in construction practice, standards, or specifications also make a significant impact on contract costs. Other factors are expected to have an impact on construction costs but were not included in this analysis because no data on their values were available.The model developed in this study reproduces past overall construction costs reasonably accurately at the aggregate level. Predicted overall construction costs are not significantly different from observed costs at the 99% level of significance. This accuracy is largely the result of the aggregate level at which construction costs are measured in this study; at the individual contract level, the submodels capture only between 42 and 72% of the variation in the data. It is suspected that much of this variation is due to unobserved, essentially subjective factors that influence the bid prices in individual contracts. However, some of these idiosyncratic variations at the individual contract level average out in the aggregation process.This model can be used by highway officials in Louisiana to test alternative contract management strategies. Increasing contract sizes, reducing the duration of contracts, reducing bid volume and bid volume variance, reducing the number of plan changes, and reducing the proportion of contracts let in the fourth quarter all serve to reduce overall construction costs. Highway officials can assess the impact of strategies they believe are achievable by applying the model. Most importantly, though, the model can assist in estimating future construction costs and providing the means to produce more reliable construction programs.ReferenceAssociate Professor, Louisiana Transportation Research Center and Dept. of Civil and Environmental Engineering, Louisiana State Univ., Baton Rouge, LA 70803-6405.Civil Engineer, GEC, Inc., 9357 Interline Ave., Baton Rouge, LA 70809.C. G. Wilmot, M.ASCE, and G. Cheng, P.E.Estimating Future Highway Construction Costs.JOURNAL OF CONSTRUCTION ENGINEERING AND MANAGEMENT © ASCE / MAY/JUNE 2003:272—279 Huyn P.N., Geneserth M.R. and Letsinger R. (1993). ‗Automated concurrent engineering in design‘. World Computing, Vol. 26 (1), pp 74–76.ISO (1994). ISO 10303-1 Part 1: Overview and fundamental principles, International Organization for Standardization, Geneva, Switzerland.Kalay Y.E., Khemluni L. and Choi J.W. (1998). ‗An integrated model to support distributed collaborative des ign of buildings‘. Automation in Construction, Vol. 7 (2–3), pp 177–188.Lee H.K., Lee Y.S., Kim K.H. and Kim J.J. (2007). ‗A cost-based information model for an interior design in a large-scale housing project‘, ICCIT 07, 2007 International Conference on Convergence InformationTechnology, Poster Sessions: Session 4.Luiten G.T.B. and Tolman F.P. (1997). ‗Automating communication, in civil engineering‘. Journal of Construction Engineering and Management, Vol. 123 (2), pp 113-120.公路建设造价的未来C. G. Wilmot, M.ASCE,1 and G. Cheng, P.E.21联合教授,路易斯安娜运输研究中心和国家环境工程局,路易斯安娜国立大学2注册工程师摘要;本文的目标是建立一个用来估算路易斯安娜未来公路建设所需的工程费用的模型。

外文文献及翻译;其中参考文献一般不少于10篇,其中至少参考一篇外文...

外文文献及翻译;其中参考文献一般不少于10篇,其中至少参考一篇外文...

河北大学本科生毕业论文(设计)撰写规范一、毕业论文(设计)撰写结构要求1、题目:应简洁、明确、有概括性,字数不宜超过20个字。

2、摘要:要有高度的概括力,语言精练、明确。

同时有中、英文对照,中文摘要约300—400汉字;英文摘要约200—300个实词。

3、关键词:从论文标题或正文中挑选3~5个最能表达主要内容的词作为关键词,同时有中、英文对照,分别附于中、英文摘要后。

4、目录:写出目录,标明页码。

5、正文:(1)毕业论文正文:包括前言、本论、结论三个部分。

前言(引言)是论文的开头部分,主要说明论文写作的目的、现实意义、对所研究问题的认识,并提出论文的中心论点等。

前言要写得简明扼要,篇幅不要太长。

本论是毕业论文的主体,包括研究内容与方法、实验材料、实验结果与分析(讨论)等。

在本部分要运用各方面的研究方法和实验结果,分析问题,论证观点,尽量反映出自己的科研能力和学术水平。

结论是毕业论文的收尾部分,是围绕本论所作的结束语。

其基本的要点就是总结全文,加深题意。

6、谢辞:简述自己通过做毕业论文(设计)的体会,并应对指导教师和协助完成论文(设计)的有关人员表示谢意。

7、参考文献:在毕业论文(设计说明书)末尾要列出在论文(设计)中参考过的专著、论文及其他资料,所列参考文献应按文中参考或引证的先后顺序排列。

8、注释:在论文(设计说明书)写作过程中,有些问题需要在正文之外加以阐述和说明。

9、附录:对于一些不宜放在正文中,但有参考价值的内容,可编入附录中。

例如,公式的推演、编写的算法、语言程序等。

10.根据《河北省教育厅关于开展普通高等学校2006届本专科毕业生毕业设计(论文)检查的通知》(冀高教[2006]5号)文件的精神,“毕业设计(论文)相关的外文文献的中文翻译一般不少于2000字,文献综述一般不少于1000字”。

二、毕业论文(设计)撰写格式要求1、毕业论文一律打印,采取A4纸张,页边距一律采取:上、下2.5cm,左3cm,右1.5cm,行间距取多倍行距(设置值为1.25);字符间距为默认值(缩放100%,间距:标准),封面采用教务处统一规定的封面。

(完整版)PLC毕业设计的外文文献(及翻译)

(完整版)PLC毕业设计的外文文献(及翻译)

PLC technique discussion and future developmentT.J.byersElectronic Test Equipment-principles and ApplicationsPrinceton University .AmericaAlong with the development of the ages, the technique that is nowadays is also gradually perfect, the competition plays more strong; the operation that list depends the artificial has already can't satisfied with the current manufacturing industry foreground, also can't guarantee the request of the higher quantity and high new the image of the technique business enterprise.The people see in produce practice, automate brought the tremendous convenience and the product quantities for people up of assurance, also eased the personnel's labor strength, reduce the establishment on the personnel. The target control of the hard realization in many complicated production lines, whole and excellent turn, the best decision etc, well-trained operation work, technical personnel or expert, governor but can judge and operate easily, can acquire the satisfied result. The research target of the artificial intelligence makes use of the calculator exactly to carry out, imitate these intelligences behavior, moderating the work through person's brain and calculators, with the mode that person's machine combine, for resolve the very complicated problem to look for the best path.We come in sight of the control that links after the electric appliances in various situation, that is already the that time generation past, now of after use in the mold a perhaps simple equipments of grass-roots control that the electric appliances can do for the low level only; And the PLC emergence also became the epoch-making topic, adding the vivid software control through a very and stable hardware, making the automation head for the new high tide.The PLC biggest characteristics lie in: The electrical engineering teacher already no longer electric hardware up too many calculations of cost, as long as order the importation that the button switch or the importation of the sensors order to link the PLC up can solve problem, pass to output to order the conjunction contact machine or control the start equipments of the big power after the electric appliances, but the exportation equipmentsdirect conjunction of the small power can.PLC internal containment have the CPU of the CPU, and take to have an I/ O for expand of exterior to connect a people's address and saving machine three big pieces to constitute, CPU core is from an or many is tired to add the machine to constitute, mathematics that they have the logic operation ability, and can read the procedure save the contents of the machine to drive the homologous saving machine and I/ Os to connect after pass the calculation; The I/ O add inner part is tired the input and output system of the machine and exterior link, and deposit the related data into the procedure saving machine or data saving machine; The saving machine can deposit the data that the I/ O input in the saving machine, and in work adjusting to become tired to add the machine and I/ Os to connect, saving machine separately saving machine RAM of the procedure saving machine ROM and dates, the ROM can do deposit of the data permanence in the saving machine, but RAM only for the CPU computes the temporary calculation usage of hour of buffer space.The PLC anti- interference is very and excellent, our root need not concern its service life and the work situation bad, these all problems have already no longer become the topic that we fail, but stay to our is a concern to come to internal resources of make use of the PLC to strengthen the control ability of the equipments for us, make our equipments more gentle.PLC language is not we imagine of edit collected materials the language or language of Cs to carry on weaving the distance, but the trapezoid diagram that the adoption is original after the electric appliances to control, make the electrical engineering teacher while weaving to write the procedure very easy comprehended the PLC language, and a lot of non- electricity professional also very quickly know and go deep into to the PLC.Is PLC one of the advantage above and only, this is also one part that the people comprehend more and easily, in a lot of equipments, the people have already no longer hoped to see too many control buttons, they damage not only and easily and produce the artificial error easiest, small is not a main error perhaps you can still accept; But lead even is a fatal error greatly is what we can't is tolerant of. New technique always for bringing more safe and convenient operation for us, make we a lot of problems for face on sweep but light, do you understand the HMI? Says the HMI here you basically not clear what it is, also have no interest understanding, change one inside text explains it into the touch to hold orman-machine interface you knew, it combines with the PLC to our larger space.HMI the control not only is reduced the control press button, increase the vivid of the control, more main of it is can sequence of, and at can the change data input to output the feedback with data, control in the temperature curve of imitate but also can keep the manifestation of view to come out. And can write the function help procedure through a plait to provide the help of various what lies in one's power, the one who make operate reduces the otiose error. Currently the HMI factory is also more and more, the function is also more and more strong, the price is also more and more low, and the noodles of the usage are wide more and more. The HMI foreground can say that think to be good.At a lot of situations, the list is a smooth movement that can't guarantee the equipments by the control of the single machine, but pass the information exchanges of the equipments and equipments to attain the result that we want. For example fore pack and the examination of the empress work preface, we will arrive wrapping information feedback to examine the place, and examine the information of the place to also want the feedback to packing. Pass the information share thus to make both the chain connect, becoming a total body, the match of your that thus make is more close, at each other attain to reflect the result that mutually flick.The PLC correspondence has already come more body now its value, at the PLC and correspondence between Places, can pass the communication of the information and the share of the data’s to guarantee that of the equipments moderates mutually, the result that arrive already to repair with each other. Data conversion the adoption RS232 between PLC connect to come to the transmission data, but the RS232 pick up a people and can guarantee 10 meters only of deliver the distance, if in the distance of 1000 meters we can pass the RS485 to carry on the correspondence, the longer distance can pass the MODEL only to carry on deliver.The PLC data transmission is just to be called a form to it in a piece of and continuous address that the data of the inner part delivers the other party, we, the PLC of the other party passes to read data in the watch to carry on the operation. If the data that data in the watch is a to establish generally, that is just the general data transmission, for example today of oil price rise, I want to deliver the price of the oil price to lose the oil ally on board, that is the share of the data; But take data in the watch for an instruction procedure that controls the PLC, that had the difficulty very much, for example you have to control one pedestal robot to pressthe action work that you imagine, you will draw up for it the form that a procedure combine with the data sends out to pass by.The form that information transport contain single work, the half a work and the difference of a workers .The meaning of the single work also is to say both, a can send out only, but a can receive only, for example a spy he can receive the designation of the superior only, but can't give the superior reply; A work of half is also 2 and can send out similar to accept the data, but can't send out and accept at the same time, for example when you make a phone call is to can't answer the phone, the other party also; But whole pair works is both can send out and accept the data, and can send out and accept at the same time. Be like the Internet is a typical example.The process that information transport also has synchronous and different step cent: The data line and the clock lines are synchronous when synchronous meaning lie in sending out the data, is also the data signal and the clock signals to be carry on by the CPU to send out at the same time, this needs to all want the specialized clock signal each other to carry on the transmission and connect to send, and is constrained, the characteristics of this kind of method lies in its speed very quick, but correspond work time of take up the CPU and also want to be long oppositely, at the same time the technique difficulty also very big. Its request lies in canting have an error margins in a dates deliver, otherwise the whole piece according to compare the occurrence mistake, this on the hardware is a bigger difficulty. Applied more and more extensive in some appropriative equipments, be like the appropriative medical treatment equipments, the numerical signal equipments...etc., in compare the one data deliver, its result is very good.And the different step is an application the most extensive, this receive benefit in it of technique difficulty is opposite and want to be small, at the same time not need to prepare the specialized clock signal, its characteristics to lie in, its data is partition, the long-lost send out and accept, be the CPU is too busy of time can grind to a stop sex to work, also reduced the difficulty on the hardware, the data throw to lose at the same time opposite want to be little, we can pass the examination of the data to observe whether the data that we send out has the mistake or not, be like strange accidentally the method, tired addition and eight efficacies method etc, can use to helps whether the data that we examine to send out have or not themistake occurrence, pass the feedback to carry on the discriminator.A line of transmission of the information contains a string of and combines the cent of: The usual PLC is 8 machines, certainly also having 16 machines. We can be at the time of sending out the data a send out to the other party, also can be 88 send out the data to the other party, and 8 differentiations are also the as that we say to send out the data and combine sends out the data. A speed is more and slowly, but as long as 2 or three lines can solve problem, and can use the telephone line to carry on the long range control. But combine the ocular transmission speed is very quick of, it is a string of ocular of 25600%, occupy the advantage in the short distance, the in view of the fact TTL electricity is even, being limited by the scope of one meter generally, it combine unwell used for the data transmission of the long pull, thus the cost is too expensive.Under a lot of circumstances we are total to like to adopt the string to combine the conversion chip to carry on deliver, under this kind of circumstance not need us to carry on to deposited the machine to establish too and complicatedly, but carry on the data exchanges through the data transmission instruction directly, but is not a very viable way in the correspondence, because the PLC of the other party must has been wait for your data exportation at the time of sending out the data, it can't do other works.When you are reading the book, you hear someone knock on door, you stop to start up of affair, open the door and combine to continue with the one who knock on door a dialogue, the telephone of this time rang, you signal hint to connect a telephone, after connecting the telephone through, return overdo come together knock on door to have a conversation, after dialogue complete, you continue again to see your book, this kind of circumstance we are called the interruption to it, it has the authority, also having sex of have the initiative, the PLC had such function .Its characteristics lie in us and may meet the urgently abrupt affairs in the operation process of the equipments, we want to stop to start immediately up of work, the whereabouts manages the more important affair, this kind of circumstance is we usually meet of, PLC while carry out urgent mission, total will keep the current appearance first, for example the address of the procedure, CPU of tired add the machine data etc., be like to stick down which the book that we see is when we open the door the page or simply make a mark, because we treat and would still need to continue immediately after book of see the behind.The CPU always does the affair that should do according to our will, but your mistake of give it an affair, it also would be same to do, this we must notice.The interruption is not only a, sometimes existing jointly with the hour several inside break, break off to have the preferred Class, they will carry out the interruption of the higher Class according to person's request. This kind of breaks off the medium interruption to also became to break off the set. The Class that certainly breaks off is relevant according to various resources of CPU with internal PLC; also following a heap of capacity size of also relevant fasten.The contents that break off has a lot of kinds, for example the exterior break off, correspondence in of send out and accept the interruption and settle and the clock that count break off, still have the WDT to reset the interruption etc., they enriched the CPU to respond to the category while handle various business. Speak thus perhaps you can't comprehend the internal structure and operation orders of the interruption completely also, we do a very small example to explain.Each equipment always will not forget a button, it also is at we meet the urgent circumstance use of that is nasty to stop the button. When we meet the Human body trouble and surprised circumstances we as long as press it, the machine stops all operations immediately, and wait for processing the over surprised empress recover the operation again. Nasty stop the internal I/ O of the internal CPU of the button conjunction PLC to connect up, be to press button an exterior to trigger signal for CPU, the CPU carries on to the I/ O to examine again, being to confirm to have the exterior to trigger the signal, CPU protection the spot breaks off procedure counts the machine turn the homologous exterior I/ O automatically in the procedure to go to also, be exterior interruption procedure processing complete, the procedure counts the machine to return the main procedure to continue to work. Have 1:00 can what to explain is we generally would nasty stop the button of exterior break off to rise to the tallest Class, thus guarantee the safety.When we are work a work piece, giving the PLC a signal, counting PLC inner part the machine add 1 to compute us for a day of workload, a count the machine and can solve problem in brief, certainly they also can keep the data under the condition of dropping the electricity, urging the data not to throw to lose, this is also what we hope earnestly.The PLC still has the function that the high class counts the machine, being us while accept some dates of high speed, the high speed that here say is the data of the in all aspects tiny second class, for example the bar code scanner is scanning the data continuously, calculating high-speed signal of the data processor DSP etc., we will adopt the high class to count the machine to help we carry on count. It at the PLC carries out the procedure once discover that the high class counts the machine to should of interruption, will let go of the work on the hand immediately. The trapezoid diagram procedure that passes by to weave the distance again explains the high class for us to carry out procedure to count machine would automatic performance to should of work, thus rise the Class that the high class counts the machine to high one Class.You heard too many this phrases perhaps:" crash", the meaning that is mostly is a workload of CPU to lead greatly, the internal resources shortage etc. the circumstance can't result in procedure circulate. The PLC also has the similar circumstance, there is a watchdog WDT in the inner part of PLC, we can establish time that a procedure of WDT circulate, being to appear the procedure to jump to turn the mistake in the procedure movement process or the procedure is busy, movement time of the procedure exceeds WDT constitution time, the CPU turn but the WDT reset the appearance. The procedure restarts the movement, but will not carry on the breakage to the interruption.The PLC development has already entered for network ages of correspondence from the mode of the one, and together other works control the net plank and I/ O card planks to carry on the share easily. A state software can pass all se hardwires link, more animation picture of keep the view to carries on the control, and cans pass the Internet to carry on the control in the foreign land, the blast-off that is like the absolute being boat No.5 is to adopt this kind of way to make airship go up the sky.The development of the higher layer needs our continuous effort to obtain. The PLC emergence has already affected a few persons fully, we also obtained more knowledge and precepts from the top one experience of the generation, coming to the continuous development PLC technique, push it toward higher wave tide.可编程控制器技术讨论与未来发展T.J.拜尔斯(电子测试设备原理及应用普林斯顿大学)随着时代的发展,当今的技术也日趋完善、竞争愈演愈烈;单靠人工的操作已不能满足于目前的制造业前景,也无法保证更高质量的要求和高新技术企业的形象。

内部控制外文文献及翻译

内部控制外文文献及翻译

中文4500字本科生毕业设计(论文)外文原文及译文所在系管理系学生姓名郭淼专业会计学班级学号指导教师2013年6月外文文献原文及译文Internal ControlEmergence and development of the theory of the evolution of the internal controlInternal control in Western countries have a long history of development, according to the internal control characteristics at different stages of development, the development of internal control can be divided into four stages, namely the internal containment phase, the internal control system phase, the internal control structure phase, overall internal control framework stage.Internal check stages: infancy internal controlBefore the 1940s, people used to use the concept of internal check. This is the embryonic stage of internal control. "Keshi Accounting Dictionary" definition of internal check is "to provide effective organization and mode of operation, business process design errors and prevent illegal activities occur. Whose main characteristic is any individual or department alone can not control any part of one or the right way to conduct business on the division of responsibility for the organization, each business through the normal functioning of other individuals or departments for cross-examination or cross-control. designing effective internal check to ensure that all businesses can complete correctly after a specified handler in the process of these provisions, the internal containment function is always an integral part. "The late 1940s, the internal containment theory become important management methods and concepts. Internal check on a "troubleshooting a variety of measures" for the purpose of separation of duties and account reconciliation as a means to money and accounting matters and accounts as the main control object primary control measures. Its characteristics are account reconciliation and segregation of duties as the main content and thus cross-examination or cross-control. In general, the implementation of internal check function can be roughly divided into the following four categories: physical containment; mechanical containment; institutional containment; bookkeeping contain. The basic idea is to contain the internal "security is the result of checks and balances," which is based on two assumptions: First: two or more persons1西安交通大学城市学院本科毕业设计(论文)or departments making the same mistake unconsciously chance is very small; Second: Two or more the possibility of a person or department consciously partnership possibility of fraud is much lower than a single person or department fraud. Practice has proved that these assumptions are reasonable, internal check mechanism for organizations to control, segregation of duties control is the foundation of the modern theory of internal control.Internal control system phases:generating of internal controlThe late1940s to the early1970s, based on the idea of internal check, resulting in the concept of the internal control system, which is the stage in the modern sense of internal control generated. Industrial Revolution has greatly promoted the major change relations of production, joint-stock company has gradually become the main form of business organization of Western countries, in order to meet the requirements of prevailing socio-economic relations,to protect the economic interests of investors and creditors, the Western countries have legal requirements in the form of strengthen the corporate financial and accounting information as well as internal management of this economic activity.In 1934, the "securities and exchange act" issued by the U.S. government for the first time puts forward the concept of "internal accounting control", the implementation of general and special authorization book records, trading records, and compared different remedial measures such as transaction assets. In 1949, the American institute of certified public accountants (AICPA) belongs to the audit procedures of the committee (CPA) in the essential element of internal control: the system coordination, and its importance to management department and the independence of certified public accountants' report, the first official put forward the definition of internal control: "the design of the internal control includes the organization and enterprise to take all of the methods and measures to coordinate with each other. All of these methods and measures used to protect the property of the enterprise, to check the accuracy of accounting information, improve the efficiency of management, promote enterprise stick to established management guidelines." The definition from the formulation and perfecting the inner control of the organization, plan, method and measures such as rules and regulations to implement internal control, break through the limitation of control related to the financial and accounting department directly, the four objectives of internal control, namely the enterprise in commercial2外文文献原文及译文activities to protect assets, check the veracity and reliability of financial data, improve the work efficiency, and promote to management regulations. The definition of positive significance is to help management authorities to strengthen its management, but the scope of limitation is too broad. In 1958, the commission issued no. 29 audit procedures bulletin "independent auditors evaluate the scope of internal control", according to the requirements of the audit responsibility, internal control can be divided into two aspects, namely, the internal accounting control and internal management control. The former is mainly related to the first two of the internal control goal, the latter mainly relates to the internal control after two goals. This is the origin of the internal control system of "dichotomy". Because the concept of management control is vague and fuzzy, in the actual business line between internal control and internal accounting control is difficult to draw. In order to clear the relations between the two, in 1972 the American institute of certified public accountants in the auditing standards announcement no. 1, this paper expounds the internal management control and internal accounting control: the definition of "internal management control including, but not limited to organization plan, and the administrative department of the authorized approval of economic business decision-making steps on the relevant procedures and records. This authorization of items approved activities is the responsibility of management, it is directly related to the management department to perform the organization's business objectives, is the starting point of the economic business accounting control." At the same time, the important content of internal accounting control degree and protect assets, to ensure that the financial records credibility related institutions plans, procedures and records. After a series of changes and redefine the meaning of the internal control is more clear than before and the specification, increasingly broad scope, and introduces the concept of internal audit, has received recognition around the world and references, the internal control system is made.The internal control structure stage: development of the internal controlTheory of internal control structure formed in the 90 s to the 1980 s, this phase of western accounting audit of internal control research focus gradually from the general meaning to specific content to deepen. During this period, the system management theory has become the new management idea, it says: no physical objects in the world are composed of elements of3西安交通大学城市学院本科毕业设计(论文)system, due to the factors, there exists a complicated nonlinear relationship between system must have elements do not have new features, therefore, should be based on the whole the relationship between elements. System management theory will enterprise as a organic system composed of subsystems on management, pay attention to the coordination between the subsystems and the interaction with the environment. In the modern company system and system management theory, under the concept of early already cannot satisfy the need of internal control systems. In 1988, the American institute of certified public accountants issued "auditing standards announcement no. 55", in the announcement, for the first time with the word "internal control structure" to replace the original "internal control", and points out that: "the enterprise's internal control structure including provide for specific target reasonable assurance of the company set up all kinds of policies and procedures". The announcement that the internal control structure consists of control environment, accounting system (accounting system), the control program "three components, the internal control as a organic whole composed of these three elements, raised to the attention of the internal control environment.The control environment, reflecting the board of directors, managers, owners, and other personnel to control the attitude and behavior. Specific include: management philosophy and operating style, organizational structure, the function of the board of directors and the audit committee, personnel policies and procedures, the way to determine the authority and responsibility, managers control method used in the monitoring and inspection work, including business planning, budgeting, forecasting, profit plans, responsibility accounting and internal audit, etc.Accounting systems, regulations of various economic business confirmation, the collection, classification, analysis, registration and preparing method. An effective accounting system includes the following content: identification and registration of all legitimate economic business; Classifying the various economic business appropriate, as the basis of preparation of statements; Measuring the value of economic business to make its currency's value can be recorded in the financial statements; Determine the economic business events, to ensure that it recorded in the proper accounting period; Describe properly in the financial statements of4外文文献原文及译文economic business and related content.The control program, refers to the management policies and procedures, to ensure to achieve certain purpose. It includes economic business and activity approval; Clear division of the responsibility of each employee; Adequate vouchers and bills setting and records; The contact of assets and records control; The business of independent audit, etc. Internal structure of control system management theory as the main control thought, attaches great importance to the environmental factors as an important part of internal control, the control environment, accounting system and control program three elements into the category of internal control; No longer distinguish between accounting control and management control, and uniform in elements describe the internal control, think the two are inseparable and contact each other.Overall internal control framework stages: stage of internal controlAfter entering the 1990 s, the study of internal control into a new stage. With the improvement of the corporate governance institutions, the development of electronic information technology, in order to adapt to the new economic and organizational form, using the new management thinking, "internal control structure" for the development of "internal control to control the overall framework". In 1992, the famous research institutions internal control "by organization committee" (COSO) issued a landmark project - "internal control - the whole framework", also known as the COSO report, made the unification of the internal control system framework. In 1994, the report on the supplement, the international community and various professional bodies widely acknowledged, has wide applicability. The COSO report is a historical breakthrough in the research of internal control theory, it will first put forward the concept of internal control system of the internal control by the original planar structure for the development of space frame model, represents the highest level of the studies on the internal control in the world.The COSO report defines internal control as: "designed by enterprise management, to achieve the effect and efficiency of the business, reliable financial reporting and legal compliance goals to provide reasonable assurance, by the board of directors, managers and other staff to5西安交通大学城市学院本科毕业设计(论文)implement a process." By defining it can be seen that the COSO report that internal control is a process, will be affected by different personnel; At the same time, the internal control is a in order to achieve business objectives the group provides reasonable guarantee the design and implementation of the program. The COSO report put forward three goals and the five elements of internal control. The three major target is a target business objectives, information and compliance. Among them, the management goal is to ensure business efficiency and effectiveness of the internal control; Information goal is refers to the internal control to ensure the reliability of the enterprise financial report; Compliance goal refers to the internal controls should abide by corresponding laws and regulations and the rules and regulations of the enterprise.COSO report that internal control consists of five elements contact each other and form an integral system, which is composed of five elements: control environment, risk assessment, control activities, information and communication, monitoring and review.Control Environment: It refers to the control staff to fulfill its obligation to carry out business activities in which the atmosphere. Including staff of honesty and ethics, staff competence, board of directors or audit committee, management philosophy and management style, organizational structure, rights and responsibilities granted to the way human resources policies and implementation.Risk assessment: It refers to the management to identify and take appropriate action to manage operations, financial reporting, internal or external risks affecting compliance objectives, including risk identification and risk analysis. Risk identification including external factors (such as technological development, competition, changes in the economy) and internal factors (such as the quality of the staff, the company nature of activities, information systems handling characteristics) to be checked. Risk analysis involves a significant degree of risk estimates to assess the likelihood of the risk occurring, consider how to manage risk.Control activities: it refers to companies to develop and implement policies and procedures, and 6外文文献原文及译文to take the necessary measures against the risks identified in order to ensure the unit's objectives are achieved. In practice, control activities in various forms, usually following categories: performance evaluation, information processing, physical controls, segregation of duties.Information and communication: it refers to enable staff to perform their duties, to provide staff with the exchange and dissemination of information as well as information required in the implementation, management and control operations process, companies must identify, capture, exchange of external and internal information. External information, including market share, regulatory requirements and customer complaints and other information. The method of internal information including accounting system that records created by the regulatory authorities and reporting of business and economic matters, maintenance of assets, liabilities and owners' equity and recorded. Communication is so that employees understand their responsibilities to maintain control over financial reporting. There are ways to communicate policy manuals, financial reporting manuals, reference books, as well as examples such as verbal communication or management.Monitoring: It refers to the evaluation of internal controls operation of the quality of the process, namely the reform of internal control, operation and improvement activities evaluated. Including internal and external audits, external exchanges.Five elements of internal control system is actually wide-ranging, interrelated influence each other. Control environment is the basis for the implementation of other control elements; control activities must be based on the risks faced by companies may have a detailed understanding and assessment basis; while risk assessment and control activities within the enterprise must use effective communication of information; Finally, effective monitoring the implementation of internal control is a means to protect the quality. Three goals and five elements for the formation and development of the internal control system theory laid the foundation, which fully reflects the guiding ideology of the modern enterprise management idea that security is the result of systems management. COSO report emphasizes the integration framework and internal control system composed of five elements, the framework for the7西安交通大学城市学院本科毕业设计(论文)establishment of an internal control system, operation and maintenance of the foundation.In summary,because of social, economic and environmental change management, internal control functions along with the changes, in order to guide the evolution of the internal control theory. As can be seen from the history of the development of internal control theory, often derived from the internal control organizational change management requirements, from an agricultural economy to an industrial economy, innovation management methods and tools for the development of the power to bring internal controls.From the internal containment center,controlled by the internal organization of the mutual relations between the internal control of various subsystems and went to COSO as the representative to the prevention and management loopholes to prevent the goal, through the organization of control and information systems,to achieve the overall system optimization of modern internal sense of control theory, from Admiral time, corresponding to the two economic revolution.Therefore, in the analysis of foreign internal control theory and Its Evolution, requires a combination of prevailing socio-economic environment and business organization and management requirements, so as to understand the nature of a deeper internal control theory of development.8外文文献原文及译文译文:内部控制Ge.McVay一、内部控制理论的产生与发展演进内部控制在西方国家已经有比较长的发展历史,根据内部控制在不同发展阶段的特征,可以将内部控制的发展分为四个阶段,即内部牵制阶段、内部控制制度阶段、内部控制结构阶段、内部控制整体框架阶段。

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矿产资源开发利用方案编写内容要求及审查大纲
矿产资源开发利用方案编写内容要求及《矿产资源开发利用方案》审查大纲一、概述
㈠矿区位置、隶属关系和企业性质。

如为改扩建矿山, 应说明矿山现状、
特点及存在的主要问题。

㈡编制依据
(1简述项目前期工作进展情况及与有关方面对项目的意向性协议情况。

(2 列出开发利用方案编制所依据的主要基础性资料的名称。

如经储量管理部门认定的矿区地质勘探报告、选矿试验报告、加工利用试验报告、工程地质初评资料、矿区水文资料和供水资料等。

对改、扩建矿山应有生产实际资料, 如矿山总平面现状图、矿床开拓系统图、采场现状图和主要采选设备清单等。

二、矿产品需求现状和预测
㈠该矿产在国内需求情况和市场供应情况
1、矿产品现状及加工利用趋向。

2、国内近、远期的需求量及主要销向预测。

㈡产品价格分析
1、国内矿产品价格现状。

2、矿产品价格稳定性及变化趋势。

三、矿产资源概况
㈠矿区总体概况
1、矿区总体规划情况。

2、矿区矿产资源概况。

3、该设计与矿区总体开发的关系。

㈡该设计项目的资源概况
1、矿床地质及构造特征。

2、矿床开采技术条件及水文地质条件。

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