毕设三项文档之-外文翻译

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毕设外文翻译是什么意思(两篇)

毕设外文翻译是什么意思(两篇)

引言概述:在现代高等教育中,毕业设计(或称为毕业论文、学士论文等)是学生完成学业的重要环节。

而对于一些特定的专业,例如翻译专业,有时候还需要完成外文翻译这一项任务。

本文将探讨毕设外文翻译的意义和目的,以及为什么对翻译专业的学生而言这一任务极其重要。

正文内容:1.提高翻译能力和技巧外文翻译是一项对翻译专业学生而言十分重要的任务,通过进行外文翻译,学生们可以通过实践提高自己的翻译能力和技巧。

在这个过程中,他们可以学习如何处理不同类型的外文文本,熟悉不同领域的专业术语,并掌握一些常用的翻译技巧和策略。

2.扩展语言和文化知识毕设外文翻译要求学生们对翻译语言的相关知识和背景有一定的了解。

在进行翻译时,学生们需要遵循目标语言的语法规则,并确保所翻译的内容准确、清晰地传达源语言的意义。

通过这一过程,学生们可以进一步扩展自己的语言和文化知识,提高自己的跨文化沟通能力。

3.提供实践机会毕设外文翻译为学生们提供了一个实践的机会,让他们能够将在课堂上所学到的理论知识应用于实际操作中。

通过实践,学生们可以对所学知识的理解更加深入,同时也可以发现并解决实际翻译过程中的问题和挑战。

这对于学生们将来从事翻译工作时具备更好的实践能力和经验具有重要意义。

4.培养翻译专业素养毕设外文翻译要求学生们具备良好的翻译专业素养。

在进行翻译过程中,学生们需要保持专业的态度和责任心,严谨地对待每一个翻译任务。

他们需要学会如何进行翻译质量的评估和控制,以确保最终翻译稿的准确性和流畅性。

这一系列的要求和实践,可以帮助学生们培养出色的翻译专业素养。

5.提升自我学习和研究能力毕设外文翻译要求学生们进行广泛的文献阅读和研究,以便更好地理解所翻译的内容,并找到适当的翻译方法和策略。

在这个过程中,学生们需要培养自己的自主学习和研究能力,提高对学术和专业领域的敏感性,并能够独立思考和解决问题。

这将对学生们未来的学术研究和进一步的职业发展产生积极的影响。

总结:引言概述:毕业设计外文翻译(Thesis Translation)是指在毕业设计过程中,对相关外文文献进行翻译,并将其应用于研究中,以提供理论支持和参考。

毕业设计外文文献翻译

毕业设计外文文献翻译

毕业设计(论文)外文资料翻译系别:专业:班级:姓名:学号:外文出处:附件: 1. 原文; 2. 译文2013年03月附件一:A Rapidly Deployable Manipulator SystemChristiaan J.J. Paredis, H. Benjamin Brown, Pradeep K. KhoslaAbstract:A rapidly deployable manipulator system combines the flexibility of reconfigurable modular hardware with modular programming tools, allowing the user to rapidly create a manipulator which is custom-tailored for a given task. This article describes two main aspects of such a system, namely, the Reconfigurable Modular Manipulator System (RMMS)hardware and the corresponding control software.1 IntroductionRobot manipulators can be easily reprogrammed to perform different tasks, yet the range of tasks that can be performed by a manipulator is limited by mechanicalstructure.Forexample, a manipulator well-suited for precise movement across the top of a table would probably no be capable of lifting heavy objects in the vertical direction. Therefore, to perform a given task,one needs to choose a manipulator with an appropriate mechanical structure.We propose the concept of a rapidly deployable manipulator system to address the above mentioned shortcomings of fixed configuration manipulators. As is illustrated in Figure 1, a rapidly deployable manipulator system consists of software and hardware that allow the user to rapidly build and program a manipulator which is customtailored for a given task.The central building block of a rapidly deployable system is a Reconfigurable Modular Manipulator System (RMMS). The RMMS utilizes a stock of interchangeable link and joint modules of various sizes and performance specifications. One such module is shown in Figure 2. By combining these general purpose modules, a wide range of special purpose manipulators can be assembled. Recently, there has been considerable interest in the idea of modular manipulators [2, 4, 5, 7, 9, 10, 14], for research applications as well as for industrial applications. However, most of these systems lack the property of reconfigurability, which is key to the concept of rapidly deployable systems. The RMMS is particularly easy toreconfigure thanks to its integrated quick-coupling connectors described in Section 3.Effective use of the RMMS requires, Task Based Design software. This software takes as input descriptions of the task and of the available manipulator modules; it generates as output a modular assembly configuration optimally suited to perform the given task. Several different approaches have been used successfully to solve simpli-fied instances of this complicated problem.A third important building block of a rapidly deployable manipulator system is a framework for the generation of control software. To reduce the complexity of softwaregeneration for real-time sensor-based control systems, a software paradigm called software assembly has been proposed in the Advanced Manipulators Laboratory at CMU.This paradigm combines the concept of reusable and reconfigurable software components, as is supported by the Chimera real-time operating system [15], with a graphical user interface and a visual programming language, implemented in OnikaA lthough the software assembly paradigm provides thesoftware infrastructure for rapidly programming manipulator systems, it does not solve the programming problem itself. Explicit programming of sensor-based manipulator systems is cumbersome due to the extensive amount of detail which must be specified for the robot to perform the task. The software synthesis problem for sensor-based robots can be simplified dramatically, by providing robust robotic skills, that is, encapsulated strategies for accomplishing common tasks in the robots task domain [11]. Such robotic skills can then be used at the task level planning stage without having to consider any of the low-level detailsAs an example of the use of a rapidly deployable system,consider a manipulator in a nuclear environment where it must inspect material and space for radioactive contamination, or assemble and repair equipment. In such an environment, widely varied kinematic (e.g., workspace) and dynamic (e.g., speed, payload) performance is required, and these requirements may not be known a priori. Instead of preparing a large set of different manipulators to accomplish these tasks—an expensive solution—one can use a rapidly deployable manipulator system. Consider the following scenario: as soon as a specific task is identified, the task based design software determinesthe task. This optimal configuration is thenassembled from the RMMS modules by a human or, in the future, possibly by anothermanipulator. The resulting manipulator is rapidly programmed by using the software assembly paradigm and our library of robotic skills. Finally,the manipulator is deployed to perform its task.Although such a scenario is still futuristic, the development of the reconfigurable modular manipulator system, described in this paper, is a major step forward towards our goal of a rapidly deployable manipulator system.Our approach could form the basis for the next generation of autonomous manipulators, in which the traditional notion of sensor-based autonomy is extended to configuration-based autonomy. Indeed, although a deployed system can have all the sensory and planning information it needs, it may still not be able to accomplish its task because the task is beyond the system’s physical capabilities. A rapidly deployable system, on the other hand, could adapt its physical capabilities based on task specifications and, with advanced sensing, control, and planning strategies, accomplish the task autonomously.2 Design of self-contained hardware modulesIn most industrial manipulators, the controller is a separate unit housing the sensor interfaces, power amplifiers, and control processors for all the joints of the manipulator.A large number of wires is necessary to connect this control unit with the sensors, actuators and brakes located in each of the joints of the manipulator. The large number of electrical connections and the non-extensible nature of such a system layout make it infeasible for modular manipulators. The solution we propose is to distribute the control hardware to each individual module of the manipulator. These modules then become self-contained units which include sensors, an actuator, a brake, a transmission, a sensor interface, a motor amplifier, and a communication interface, as is illustrated in Figure 3. As a result, only six wires are requiredfor power distribution and data communication.2.1 Mechanical designThe goal of the RMMS project is to have a wide variety of hardware modules available. So far, we have built four kinds of modules: the manipulator base, a link module, three pivot joint modules (one of which is shown in Figure 2), and one rotate joint module. The base module and the link module have no degrees-of-freedom; the joint modules have onedegree-of-freedom each. The mechanical design of the joint modules compactly fits aDC-motor, a fail-safe brake, a tachometer, a harmonic drive and a resolver.The pivot and rotate joint modules use different outside housings to provide the right-angle or in-line configuration respectively, but are identical internally. Figure 4 shows in cross-section the internal structure of a pivot joint. Each joint module includes a DC torque motor and 100:1 harmonic-drive speed reducer, and is rated at a maximum speed of 1.5rad/s and maximum torque of 270Nm. Each module has a mass of approximately 10.7kg. A single, compact, X-type bearing connects the two joint halves and provides the needed overturning rigidity. A hollow motor shaft passes through all the rotary components, and provides achannel for passage of cabling with minimal flexing.2.2 Electronic designThe custom-designed on-board electronics are also designed according to the principle of modularity. Each RMMS module contains a motherboard which provides the basic functionality and onto which daughtercards can be stacked to add module specific functionality.The motherboard consists of a Siemens 80C166 microcontroller, 64K of ROM, 64K of RAM, an SMC COM20020 universal local area network controller with an RS-485 driver, and an RS-232 driver. The function of the motherboard is to establish communication with the host interface via an RS-485 bus and to perform the lowlevel control of the module, as is explained in more detail in Section 4. The RS-232 serial bus driver allows for simple diagnostics and software prototyping.A stacking connector permits the addition of an indefinite number of daughtercards with various functions, such as sensor interfaces, motor controllers, RAM expansion etc. In our current implementation, only modules with actuators include a daughtercard. This card contains a 16 bit resolver to digital converter, a 12 bit A/D converter to interface with the tachometer, and a 12 bit D/A converter to control the motor amplifier; we have used an ofthe-shelf motor amplifier (Galil Motion Control model SSA-8/80) to drive the DC-motor. For modules with more than one degree-of-freedom, for instance a wrist module, more than one such daughtercard can be stacked onto the same motherboard.3 Integrated quick-coupling connectorsTo make a modular manipulator be reconfigurable, it is necessary that the modules can be easily connected with each other. We have developed a quick-coupling mechanism with which a secure mechanical connection between modules can be achieved by simply turning a ring handtight; no tools are required. As shown in Figure 5, keyed flanges provide precise registration of the two modules. Turning of the locking collar on the male end produces two distinct motions: first the fingers of the locking ring rotate (with the collar) about 22.5 degrees and capture the fingers on the flanges; second, the collar rotates relative to the locking ring, while a cam mechanism forces the fingers inward to securely grip the mating flanges. A ball- transfer mechanism between the collar and locking ring automatically produces this sequence of motions.At the same time the mechanical connection is made,pneumatic and electronic connections are also established. Inside the locking ring is a modular connector that has 30 male electrical pins plus a pneumatic coupler in the middle. These correspond to matching female components on the mating connector. Sets of pins are wired in parallel to carry the 72V-25A power for motors and brakes, and 48V–6A power for the electronics. Additional pins carry signals for two RS-485 serial communication busses and four video busses. A plastic guide collar plus six alignment pins prevent damage to the connector pins and assure proper alignment. The plastic block holding the female pins can rotate in the housing to accommodate the eight different possible connection orientations (8@45 degrees). The relative orientation is automatically registered by means of an infrared LED in the female connector and eight photodetectors in the male connector.4 ARMbus communication systemEach of the modules of the RMMS communicates with a VME-based host interface over a local area network called the ARMbus; each module is a node of the network. The communication is done in a serial fashion over an RS-485 bus which runs through the length of the manipulator. We use the ARCNET protocol [1] implemented on a dedicated IC (SMC COM20020). ARCNET is a deterministic token-passing network scheme which avoids network collisions and guarantees each node its time to access the network. Blocks ofinformation called packets may be sent from any node on the network to any one of the other nodes, or to all nodes simultaneously (broadcast). Each node may send one packet each time it gets the token. The maximum network throughput is 5Mb/s.The first node of the network resides on the host interface card, as is depicted in Figure 6. In addition to a VME address decoder, this card contains essentially the same hardware one can find on a module motherboard. The communication between the VME side of the card and the ARCNET side occurs through dual-port RAM.There are two kinds of data passed over the local area network. During the manipulator initialization phase, the modules connect to the network one by one, starting at the base and ending at the end-effector. On joining the network, each module sends a data-packet to the host interface containing its serial number and its relative orientation with respect to the previous module. This information allows us to automatically determine the current manipulator configuration.During the operation phase, the host interface communicates with each of the nodes at 400Hz. The data that is exchanged depends on the control mode—centralized or distributed. In centralized control mode, the torques for all the joints are computed on the VME-based real-time processing unit (RTPU), assembled into a data-packet by the microcontroller on the host interface card and broadcast over the ARMbus to all the nodes of the network. Each node extracts its torque value from the packet and replies by sending a data-packet containing the resolver and tachometer readings. In distributed control mode, on the other hand, the host computer broadcasts the desired joint values and feed-forward torques. Locally, in each module, the control loop can then be closed at a frequency much higher than 400Hz. The modules still send sensor readings back to the host interface to be used in the computation of the subsequent feed-forward torque.5 Modular and reconfigurable control softwareThe control software for the RMMS has been developed using the Chimera real-time operating system, which supports reconfigurable and reusable software components [15]. The software components used to control the RMMS are listed in Table 1. The trjjline, dls, and grav_comp components require the knowledge of certain configuration dependent parametersof the RMMS, such as the number of degrees-of-freedom, the Denavit-Hartenberg parameters etc. During the initialization phase, the RMMS interface establishes contact with each of the hardware modules to determine automatically which modules are being used and in which order and orientation they have been assembled. For each module, a data file with a parametric model is read. By combining this information for all the modules, kinematic and dynamic models of the entire manipulator are built.After the initialization, the rmms software component operates in a distributed control mode in which the microcontrollers of each of the RMMS modules perform PID control locally at 1900Hz. The communication between the modules and the host interface is at 400Hz, which can differ from the cycle frequency of the rmms software component. Since we use a triple buffer mechanism [16] for the communication through the dual-port RAM on the ARMbus host interface, no synchronization or handshaking is necessary.Because closed form inverse kinematics do not exist for all possible RMMS configurations, we use a damped least-squares kinematic controller to do the inverse kinematics computation numerically..6 Seamless integration of simulationTo assist the user in evaluating whether an RMMS con- figuration can successfully complete a given task, we have built a simulator. The simulator is based on the TeleGrip robot simulation software from Deneb Inc., and runs on an SGI Crimson which is connected with the real-time processing unit through a Bit3 VME-to-VME adaptor, as is shown in Figure 6.A graphical user interface allows the user to assemble simulated RMMS configurations very much like assembling the real hardware. Completed configurations can be tested and programmed using the TeleGrip functions for robot devices. The configurations can also be interfaced with the Chimera real-time softwarerunning on the same RTPUs used to control the actual hardware. As a result, it is possible to evaluate not only the movements of the manipulator but also the realtime CPU usage and load balancing. Figure 7 shows an RMMS simulation compared with the actual task execution.7 SummaryWe have developed a Reconfigurable Modular Manipulator System which currently consists of six hardware modules, with a total of four degrees-of-freedom. These modules can be assembled in a large number of different configurations to tailor the kinematic and dynamic properties of the manipulator to the task at hand. The control software for the RMMS automatically adapts to the assembly configuration by building kinematic and dynamic models of the manipulator; this is totally transparent to the user. To assist the user in evaluating whether a manipulator configuration is well suited for a given task, we have also built a simulator.AcknowledgmentThis research was funded in part by DOE under grant DE-F902-89ER14042, by Sandia National Laboratories under contract AL-3020, by the Department of Electrical and Computer Engineering, and by The Robotics Institute, Carnegie Mellon University.The authors would also like to thank Randy Casciola, Mark DeLouis, Eric Hoffman, and Jim Moody for their valuable contributions to the design of the RMMS system.附件二:可迅速布置的机械手系统作者:Christiaan J.J. Paredis, H. Benjamin Brown, Pradeep K. Khosla摘要:一个迅速可部署的机械手系统,可以使再组合的标准化的硬件的灵活性用标准化的编程工具结合,允许用户迅速建立为一项规定的任务来通常地控制机械手。

本科毕业设计(论文)外文翻译基本规范

本科毕业设计(论文)外文翻译基本规范

本科毕业设计(论文)外文翻译基本规范一、要求1、与毕业论文分开单独成文。

2、两篇文献。

二、基本格式1、文献应以英、美等国家公开发表的文献为主(Journals from English speaking countries)。

2、毕业论文翻译是相对独立的,其中应该包括题目、作者(可以不翻译)、译文的出处(杂志的名称)(5号宋体、写在文稿左上角)、关键词、摘要、前言、正文、总结等几个部分。

3、文献翻译的字体、字号、序号等应与毕业论文格式要求完全一致。

4、文中所有的图表、致谢及参考文献均可以略去,但在文献翻译的末页标注:图表、致谢及参考文献已略去(见原文)。

(空一行,字体同正文)5、原文中出现的专用名词及人名、地名、参考文献可不翻译,并同原文一样在正文中标明出处。

二、毕业论文(设计)外文翻译(一)毕业论文(设计)外文翻译的内容要求外文翻译内容必须与所选课题相关,外文原文不少于6000个印刷符号。

译文末尾要用外文注明外文原文出处。

原文出处:期刊类文献书写方法:[序号]作者(不超过3人,多者用等或et al表示).题(篇)名[J].刊名(版本),出版年,卷次(期次):起止页次.原文出处:图书类文献书写方法:[序号]作者.书名[M].版本.出版地:出版者,出版年.起止页次.原文出处:论文集类文献书写方法:[序号]作者.篇名[A].编著者.论文集名[C]. 出版地:出版者,出版年.起止页次。

要求有外文原文复印件。

(二)毕业论文(设计)外文翻译的撰写与装订的格式规范第一部分:封面1.封面格式:见“毕业论文(设计)外文翻译封面”。

普通A4纸打印即可。

第二部分:外文翻译主题1.标题一级标题,三号字,宋体,顶格,加粗二级标题,四号字,宋体,顶格,加粗三级标题,小四号字,宋体,顶格,加粗2.正文小四号字,宋体。

第三部分:版面要求论文开本大小:210mm×297mm(A4纸)版芯要求:左边距:25mm,右边距:25mm,上边距:30mm,下边距:25mm,页眉边距:23mm,页脚边距:18mm字符间距:标准行距:1.25倍页眉页角:页眉的奇数页书写—浙江师范大学学士学位论文外文翻译。

本科毕业设计(论文)外文翻译基本规范

本科毕业设计(论文)外文翻译基本规范

本科毕业设计(论文)外文翻译基本规范一、要求1、与毕业论文分开单独成文。

2、两篇文献。

二、基本格式1、文献应以英、美等国家公开发表的文献为主(Journals from English speaking countries)。

2、毕业论文翻译是相对独立的,其中应该包括题目、作者(可以不翻译)、译文的出处(杂志的名称)(5号宋体、写在文稿左上角)、关键词、摘要、前言、正文、总结等几个部分。

3、文献翻译的字体、字号、序号等应与毕业论文格式要求完全一致。

4、文中所有的图表、致谢及参考文献均可以略去,但在文献翻译的末页标注:图表、致谢及参考文献已略去(见原文)。

(空一行,字体同正文)5、原文中出现的专用名词及人名、地名、参考文献可不翻译,并同原文一样在正文中标明出处。

二、毕业论文(设计)外文翻译(一)毕业论文(设计)外文翻译的内容要求外文翻译内容必须与所选课题相关,外文原文不少于6000个印刷符号。

译文末尾要用外文注明外文原文出处。

原文出处:期刊类文献书写方法:[序号]作者(不超过3人,多者用等或et al表示).题(篇)名[J].刊名(版本),出版年,卷次(期次):起止页次.原文出处:图书类文献书写方法:[序号]作者.书名[M].版本.出版地:出版者,出版年.起止页次.原文出处:论文集类文献书写方法:[序号]作者.篇名[A].编著者.论文集名[C]. 出版地:出版者,出版年.起止页次。

要求有外文原文复印件。

(二)毕业论文(设计)外文翻译的撰写与装订的格式规范第一部分:封面1.封面格式:见“毕业论文(设计)外文翻译封面”。

普通A4纸打印即可。

第二部分:外文翻译主题1.标题一级标题,三号字,宋体,顶格,加粗二级标题,四号字,宋体,顶格,加粗三级标题,小四号字,宋体,顶格,加粗2.正文小四号字,宋体。

第三部分:版面要求论文开本大小:210mm×297mm(A4纸)版芯要求:左边距:25mm,右边距:25mm,上边距:30mm,下边距:25mm,页眉边距:23mm,页脚边距:18mm字符间距:标准行距:1.25倍页眉页角:页眉的奇数页书写—浙江师范大学学士学位论文外文翻译。

毕业设计外文文献翻译(原文+译文)

毕业设计外文文献翻译(原文+译文)

Environmental problems caused by Istanbul subway excavation and suggestionsfor remediation伊斯坦布尔地铁开挖引起的环境问题及补救建议Ibrahim Ocak Abstract:Many environmental problems caused by subway excavations have inevitably become an important point in city life. These problems can be categorized as transporting and stocking of excavated material, traffic jams, noise, vibrations, piles of dust mud and lack of supplies. Although these problems cause many difficulties,the most pressing for a big city like Istanbul is excava tion,since other listed difficulties result from it. Moreover, these problems are environmentally and regionally restricted to the period over which construction projects are underway and disappear when construction is finished. Currently, in Istanbul, there are nine subway construction projects in operation, covering approximately 73 km in length; over 200 km to be constructed in the near future. The amount of material excavated from ongoing construction projects covers approximately 12 million m3. In this study, problems—primarily, the problem with excavation waste(EW)—caused by subway excavation are analyzed and suggestions for remediation are offered.摘要:许多地铁开挖引起的环境问题不可避免地成为城市生活的重要部分。

毕业设计(论文)外文参考资料及译文

毕业设计(论文)外文参考资料及译文

英文原文:Java is a simple, object-oriented, distributed, interpreted, robust security, structure-neutral, portable, high performance, multithreaded dynamic language. The main advantage of Java language, Java applications across hardware platforms and operating systems for transplant - this is because the JVM is installed on each platform can understand the same byte code. Java language and platform scalability is very strong. At the low end, Java language is the first open standards technology support enterprise one, support the use of XML and Web service can not stride business lines to share information and applications Cheng Xu.There are three versions of Java platform, which makes software developers, service providers and equipment manufacturers can target specific market development:1. Java SE form applications. Java SE includes support for Java Web services development classes, and for the Java Platform, Enterprise Edition (Java EE) to provide a basis. Most Java developers use Java SE 5, also known as Java 5.0 or "Tiger".2. Java EE formerly known as J2EE. Enterprise Edition to help develop and deploy portable, robust, scalable and secure server-side Java applications. Java SE Java EE is built on the foundation, which provides Web services, component model, management and communication API, can be used to achieve enterprise-class service-oriented architecture and Web 2.0 applications.3. Java ME formerly known as J2ME. Java ME devices in mobile and embedded applications running on a robust and flexible environment. Java ME includes flexible user interfaces, robust security model, and many built-in network protocols and networking that can be dynamically downloaded and extensive support for offline applications. Java ME-based application specification only write once and can be used in many devices and can use the native features of each device.Java language is simple. Java language syntax and the C language and C ++ language is very close, Java discarded the C++, rarely used, hard to understand the characteristics, such as operator overloading, multiple inheritance, the mandatory automatic type conversion. Java language does not use pointers, and provides automated waste collection. Java is an object-oriented language. Java language provides classes, interfaces and inheritance of the original language, for simplicity, only supports single inheritance between classes, but support multiple inheritance between interfaces and support classes and interfaces to achieve between the mechanism (keyword implements) . Java language fully supports dynamic binding, and C ++ language used only for dynamic binding of virtual functions. In short, Java language is a pure object-oriented programming language. Java language is distributed. Java language support for Internet application development, Java's RMI (remote method activation) mechanism is also an important means of developing distributed applications. Java language is robust. Java's strong type system, exception handling, automated waste collection is an important guarantee robust Java programs. Java language is safe. Java is often used in network environment, this, Java provides a security mechanism to prevent malicious code attacks.Java language is portable. This portability comes from the architecture neutrality. Java system itself is highly portable. Java language is multi-threaded. In the Java language, the thread is a special object, it must Thread class or the son (Sun) class to create. Java language support simultaneous execution of multiple threads, and provide synchronization mechanisms between threads (keyword synchronized).Java language features make Java an excellent application of unparalleled robustness and reliability, which also reduced application maintenance costs. Java on the full support of object technology and Java Platform API embedded applications to reduce development time and reduce costs. Java's compile once, run everywhere feature can make it anywhere available to provide an open architecture and multi-platform, low-cost way of transmitting information between. Hibernate Hibernate is a lightweight JDBC object package. It is an independent object persistence framework, and the App Server, and EJB is no necessary link. Hibernate can use JDBC can be used in any occasion, such as Java application, database access code, DAO interface implementation class, or even access the database inside a BMP code. In this sense, Hibernate, and EB is not a category of things that did not exist either-or relationship.Hibernate and JDBC is a closely related framework, the Hibernate and JDBC driver compatibility, and databases have some relationship, but the Java program and use it, and the App Server does not have any relationship, there was no compatibility issues. 1614Hibernate provides two Cache, first-level cache is a Session-level cache, which cache belongs to the scope of services. This level of cache by the hibernate managed without the need for intervention under normal circumstances; second-level cache is SessionFactory-level cache, it belongs to the process of range or scope of the cache cluster. This level of cache can be configured and changed, and can be dynamically loaded and unloaded. Hibernate query results also provide a query cache, it depends on the second level cache.When an application called Session's save (), update (), saveOrUpdate (), get () or load (), and the query interface call list (), iterate () or filter () method, if the Session cache does not exist a corresponding object, Hibernate will put the object to the first level cache. When cleaning the cache, Hibernate objects according to the state of the cache changes to synchronize update the database. Session for the application provides two methods of managing the cache: evict (Object obj): removed from the cache parameters of the specified persistent object. clear (): Empty the cache of all persistent objects.Hibernate second-level cache strategy general process is as follows:1) The condition when a query is always issued a select * from table_name where .... (Select all fields) such as SQL statement to query the database, an access to all of the data object.2) all the data objects to be placed under the ID to the second level cache.3) When the Hibernate object-based ID to access the data, the first check from the Session a cache; finding out, if the configuration of the secondary cache, then the secondary cache from the investigation; finding out, and then query the database, the results in accordance with the ID into the cache.4) remove, update and increase the time data, while updating the cache. Hibernate second against the conditions of the Query Cache.Hibernate object-relational mapping for the delay and non-delay object initialization. Non-lazy when reading an object and the object will be all read out together with other objects. This sometimes results in hundreds (if not thousands of words) select statement when reading the object implementation. This problem sometimes occurs when using the two-way relationship, often leading to the databases to be read during the initialization phase out. Of course, you can take the trouble to examine each object and other objects of Guanxi, and to the most expensive of the Shan Chu, but in the last, we may therefore lose Le ORM tool this Xiangzai obtained Bian Li.A cache and secondary cache of comparison: the first level cache second level cache data stored in the form of interrelated persistent objects the object of bulk data cache range of the scope of services, each transaction has a separate first-level cache process range or scope of the cluster, the cache is the same process or cluster to share on all matters within the concurrent access policies because each transaction has a separate first-level cache, concurrency problem does not occur without the need to provide concurrent access policy will be a number of matters simultaneous access to the same second-level cache data, it is necessary to provide appropriate concurrent access policies, to ensure that a particular transaction isolation level data expiration policies did not provide data expiration policies. Object in a cache will never expire, unless the application explicitly clear the cache or clear a specific object must provide data expiration policies, such as memory cache based on the maximum number of objects, allowing objects in the cache of the most a long time, and allowing the object in the cache the longest idle time of physical memory and hard disk memory storage medium. First of all bulk data objects stored in the memory-based cache, when the number of objects in memory to data expiration policy specified limit, the remaining objects will be written on the hard disk cache. Caching software implementation of the Hibernate Session is included in the realization of the cache provided by third parties, Hibernate provides only a cache adapter (CacheProvider). Used to plug into a particular cache in Hibernate. Way cache enabled applications by as long as the Session interface implementation save, update, delete, data loading and query the database operations, Hibernate will enable first-level cache, the data in the database in the form of an object copied to the cache For batch updates and bulk delete operations, if you do not want to enable first-level cache, you can bypass the Hibernate API, JDBC API directly to perform that operation. Users can type in a single class or a single set of second-level cache size on the configuration. If the instance of the class are frequently read but rarely modified, you can consider using a second-level cache. Only for a class or set of second-level cache is configured, Hibernate will run when an instance of it to the second-level cache. User management means the first level cache of physical media for the memory cache, because the memory capacity is limited, must pass the appropriate search strategies and retrieval methods to limit the number of objects loaded. Session of the evit () method can explicitly clear the cache a specific object, but this method is not recommended. Second-level cache memory andthe physical media can be a hard disk, so the second-level cache can store large amounts of data, data expiration policy maxElementsInMemory property values can control the number of objects in memory. Second-level cache management mainly includes two aspects: Select to use the second-level cache of persistent classes, set the appropriate concurrency strategy: Select the cache adapter, set the appropriate data expiration policies.One obvious solution is to use Hibernate's lazy loading mechanism provided. This initialization strategy is only invoked in an object-to-many or many to many relationship between its relationship only when read out of the object. This process is transparent to the developer, and only had a few requests for database operations, it will be more obvious performance have open. This will be by using the DAO pattern abstracts the persistence time of a major problem. Persistence mechanisms in order to completely abstract out all of the database logic, including open or closed session, can not appear in the application layer. The most common is the realization of the simple interface of some DAO implementation class to encapsulate the database logic completely. A fast but clumsy solution is to give up DAO mode, the database connection logic to add the application layer. This may be an effective small applications, but in large systems, this is a serious design flaw, preventing the system scalability.Struts2Struts2 is actually not a stranger to the Web frameworks, Struts2 is Webwork design ideas as the core, absorb Struts1 advantages, so that the Struts2 is the product of the integration Struts1 and Webwork.MVC Description: Struts2 WebWork is compatible with the MVC framework Struts1 and since, that the MVC framework on the MVC framework will have to make a brief, limited to a brief, if want to learn more about MVC can view the related knowledge document, or to find a Struts1 books, I believe the above is not rare on the length of MVC. Closer to home, in fact, Java the present situation of these frameworks, its ultimate goal is to contact coupling, whether Spring, Hibernate or the MVC framework, are designed to increase contact with coupling reuse. MVC contact with the coupling between View and Model. MVC consists of three basic parts: Model, View and Controller, these three parts work together to minimize the coupling to increase the scalability of the program and maintainability. Various parts of the implementation technology can be summarized as follows:1) Model: JavaBean, EJB's EntityBean2) View: JSP, Struts in TagLib3) Controller: Struts the ActionServlet, ActionTo sum up the advantages of MVC mainly about aspects:1) corresponds to multiple views can be a model. By MVC design pattern, a model that corresponds to multiple views, you can copy the code and the code to reduce the maintenance amount, if model changes, but also easy to maintain2) model the data returned and display logic separate. Model data can be applied to any display technology, for example, use the JSP page, Velocity templates, or directly from Excel documents, etc.3) The application is separated into three layers, reducing the coupling between the layers, providing application scalability4) The concept of layers is also very effective, because it put the different models and different views together, to complete a different request. Therefore, the control layer can be said to include the concept of user requests permission5) MVC more software engineering management. Perform their duties in different layers, each layer has the same characteristics of the components is beneficial tool by engineering and production management of program codeStruts2 Introduction: Struts2 Struts1 development appears to come from, but in fact Struts1 Struts2 and design ideas in the framework of the above is very different, Struts2 WebWork's design is based on the core, why not follow the Struts1 Struts2 design ideas After all, Struts1 in the current enterprise applications market is still very big in the, Struts1 some shortcomings:1) support the performance of a single layer2) coupled with the Servlet API serious, this could be the Execute method from the Action Statement which you can see them3) The code depends Struts1 API, there are invasive, this can be written when the Action class and look out FormBean, Action Struts in Action class must implement The reason for Struts2 WebWork's design for the core point is the recent upward trend of WebWork and play WebWork not Struts1 above those shortcomings, more MVC design ideas, and more conducive to reuse the code. Based on the above description can be read out, Struts2 architecture and architecture Struts1 very different, Struts1 is to use the ActionServlet as its central processor, Struts2 is using an interceptor (FilterDispatcher) as its central processor, so One benefit is to make Action class and Servlet API was isolated.Struts2 simple process flow is as follows:1) browser sends a request2) the processor to find the corresponding file under struts.xml the Action class to process the request3) WebWork interceptor chain applications automatically request common functions, such as: WorkFlow, Validation functions4) If Struts.xml Method configuration file parameters, then call the corresponding Action Method parameters in the Method class method, or call the Execute method to deal with common user request5) Action class method returns the results of the corresponding response to the browserStruts2 and Struts1 contrast:1) Action class impleme achieve the time to achieve any classes and interfaces, while providing a ActionSupport class Struts2, however, not required.2) Struts1 the Action class is the singleton pattern, must be designed into the thread-safe, Struts2 was generated for each request for an instance3) Struts1 the Action class dependence and the Servlet API, execute the method from its signature can be seen, execute method has two parameters Servlet HttpServletRequest and HttpServletResponse, Struts2 is not dependent on the ServletAPI4) Struts1 depends on the Servlet API the Web elements, therefore, of Action Struts1 when testing is difficult, it needs with other testing tools, Struts2 in Action can be as testing a number of other classes as Service Model layer test5) Struts1 of Action and the View through the ActionForm or its sub-class of data transmission, although there LazyValidationForm this ActionForm appearance, but still can not like the other levels as a simple POJO data transfer, and Struts2 would like expect change becomes a reality6) Struts1 binding of the JSTL, the preparation of convenience for the page, Struts2 integrates ONGL, you can use JSTL, Therefore, Struts2 is more powerful expression language underCompared with Struts2 WebWork: Struts2 actually WebWork2.3, however, Struts2 WebWork, or with a little difference:1) Struts2 IOC no longer support the built-in containers, use Spring's IOC container2) Struts2 Ajax for Webwork features some of the label to use Dojo to be replacedServletServlet is a server-side Java application, platform and protocol independent features that can generate dynamic Web pages. Customer requests to play it (Web browser or other HTTP client) and server response (HTTP server, database or application) of the middle layer. Servlet Web server is located inside the server-side Java applications started from the command line with the traditional application of different Java, Servlet loaded by the Web server, the Web server must include the Java Virtual Machine to support Servlet.HTTP Servlet using a HTML form to send and receive data. To create an HTTP Servlet, need to extend the HttpServlet class, the class is a special way to handle HTML forms GenericServlet a subclass. HTML form is <FORM> and </ FORM> tag definition. Form typically includes input fields (such as text input fields, check boxes, radio buttons and selection lists) and a button for submitting data. When submitting information, they also specify which server should implement the Servlet (or other program). HttpServlet class contains the init (), destroy (), service () and other methods. Where init () and destroy () method is inherited.init () method: In the Servlet life period, only run once init () method. It is executed when the server load Servlet. You can configure the server to start the server or the client's first visit to Servlet fashion into the Servlet. No matter how many clients to access Servlet, will not repeat the init (). The default init () method is usually to meet the requirements, but can also use custom init () method to overwrite it, typically the management server-side resources. For example, you may write a custom init () to be used only once a load GIF images, GIF images and improve the Servlet returns with the performance of multiple clients request. Another example is to initialize the database connection. The default init () method sets the Servlet initialization parameters, and use it's ServletConfig object parameter to start the configuration, all covered by init () method of the Servlet should call super.init () to ensure that stillperform these tasks. In the call to service () method before, make sure you have completed the init () method.service () method: service () method is the core of Servlet. Whenever a client requests a HttpServlet object, the object of the service () method must be called, and passed to this method a "request" (ServletRequest) objects and a "response" (ServletResponse) object as a parameter. Already exists in the HttpServlet service () method. The default service function is invoked with the HTTP request method to do the corresponding functions. For example, if the HTTP request method is GET, the default on the call to doGet (). Servlet Servlet support should do HTTP method override function. Because HttpServlet.service () method checks whether the request method calls the appropriate treatment, unnecessary coverage service () method. Just do cover the corresponding method on it.Servlet response to the following types: an output stream, the browser based on its content type (such as text / HTML) to explain; an HTTP error response, redirect to another URL, servlet, JSP.doGet () method: When a client through the HTML form to send a HTTP GET request or when a direct request for a URL, doGet () method is called. Parameters associated with the GET request to the URL of the back, and send together with this request. When the server does not modify the data, you should use doGet () method. doPost () method: When a client through the HTML form to send a HTTP POST request, doPost () method is called. Parameters associated with the POST request as a separate HTTP request from the browser to the server. When the need to modify the server-side data, you should use the doPost () method.destroy () method: destroy () method is only executed once, that is, stop and uninstall the server to execute the method of Servlet. Typically, the Servlet as part of the process server to shut down. The default destroy () method is usually to meet the requirements, but can also cover it, and typically manage server-side resources. For example, if the Servlet will be accumulated in the run-time statistics, you can write a destroy () method is used in Servlet will not load the statistics saved in the file. Another example is to close the database connection.When the server uninstall Servlet, it will in all service () method call is completed, or at a specified time interval after the call to destroy () method. Running a Servlet service () method may have other threads, so make sure the call destroy () method, the thread has terminated or completed.GetServletConfig () method: GetServletConfig () method returns a ServletConfig object, which used to return the initialization parameters and ServletContext. ServletContext interface provides information about servlet environment. GetServletInfo () method: GetServletInfo () method is an alternative method, which provides information on the servlet, such as author, version, copyright.When the server calls sevlet of Service (), doGet () and doPost () of these three methods are needed "request" and "response" object as a parameter. "Request" object to provide the requested information, and the "response" object to provide a response message will be returned to the browser as a communications channel.javax.servlet packages in the relevant classes for the ServletResponse andServletRequest, while the javax.servlet.http package of related classes for the HttpServletRequest and HttpServletResponse. Servlet communication with the server through these objects and ultimately communicate with the client. Servlet through call "request" object approach informed the client environment, server environment, information and all information provided by the client. Servlet can call the "response" object methods to send response, the response is ready to send back to clientJSPJavaServerPages (JSP) technology provides a simple and fast way to create a display content dynamically generated Web pages. Leading from the industry, Sun has developed technology related to JSP specification that defines how the server and the interaction between the JSP page, the page also describes the format and syntax.JSP pages use XML tags and scriptlets (a way to use script code written in Java), encapsulates the logic of generating page content. It labels in various formats (HTML or XML) to respond directly passed back to the page. In this way, JSP pages to achieve a logical page design and display their separation.JSP technology is part of the Java family of technologies. JSP pages are compiled into a servlet, and may call JavaBeans components (beans) or EnterpriseJavaBeans components (enterprise beans), so that server-side processing. Therefore, JSP technology in building scalable web-based applications play an important role.JSP page is not confined to any particular platform or web server. JSP specification in the industry with a wide range of adaptability.JSP technology is the result of collaboration with industry, its design is an open, industry standards, and support the vast majority of servers, browsers and related tools. The use of reusable components and tags replaced on the page itself relies heavily on scripting languages, JSP technology has greatly accelerated the pace of development. Support the realization of all the JSP to Java programming language-based scripting language, it has inherent adaptability to support complex operations.JqueryjQuery is the second prototype followed by a good Javascrīpt framework. Its purpose is: to write less code, do more.It is lightweight js library (compressed only 21k), which is less than the other js library which, it is compatible CSS3, is also compatible with all browsers (IE 6.0 +, FF 1.5 +, Safari 2.0 +, Opera 9.0 +).jQuery is a fast, simple javaScript library, allowing users to more easily dealwith HTML documents, events, to achieve animation effects, and provide easy AJAX for interactive web site.jQuery also has a larger advantage is that it is all documented, and various applications are very detailed, as well as many mature plug-ins available.jQuery's html page to allow users to maintain separate code and html content, that is, no need to insert in the html inside a pile of js to call the command, and you can just define id.jQuery is the second prototype followed by a good Javascrīpt framework. On theprototype I use small, simple and understood. However, after using the jquery immediately attracted by her elegance. Some people use such a metaphor to compare the prototype and jquery: prototype like Java, and jquery like a ruby. In fact I prefer java (less contact with Ruby Bale), but a simple jquery does have considerable practical appeal ah! I put the project in the framework jquery as its the only class package. Use the meantime there is also a little bit of experience, in fact, these ideas, in the jquery documentation above may also be speaking, but still it down to stop notes.译文:Java是一种简单的,面向对象的,分布式的,解释型的,健壮安全的,结构中立的,可移植的,性能优异、多线程的动态语言。

毕业设计(论文)外文原文及译文

毕业设计(论文)外文原文及译文

毕业设计(论文)外文原文及译文一、外文原文MCUA microcontroller (or MCU) is a computer-on-a-chip. It is a type of microcontroller emphasizing self-sufficiency and cost-effectiveness, in contrast to a general-purpose microprocessor (the kind used in a PC).With the development of technology and control systems in a wide range of applications, as well as equipment to small and intelligent development, as one of the single-chip high-tech for its small size, powerful, low cost, and other advantages of the use of flexible, show a strong vitality. It is generally better compared to the integrated circuit of anti-interference ability, the environmental temperature and humidity have better adaptability, can be stable under the conditions in the industrial. And single-chip widely used in a variety of instruments and meters, so that intelligent instrumentation and improves their measurement speed and measurement accuracy, to strengthen control functions. In short,with the advent of the information age, traditional single- chip inherent structural weaknesses, so that it show a lot of drawbacks. The speed, scale, performance indicators, such as users increasingly difficult to meet the needs of the development of single-chip chipset, upgrades are faced with new challenges.The Description of AT89S52The AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller with 8K bytes of In-System Programmable Flash memory. The device is manufactured using Atmel's high-density nonvolatile memory technology and is compatible with the industry-standard 80C51 instruction set and pinout. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with In-System Programmable Flash on a monolithic chip, the Atmel AT89S52 is a powerful microcontroller which provides a highly-flexible and cost-effective solution to many embedded control applications.The AT89S52 provides the following standard features: 8K bytes ofFlash, 256 bytes of RAM, 32 I/O lines, Watchdog timer, two data pointers, three 16-bit timer/counters, a six-vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator, and clock circuitry. In addition, the AT89S52 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port, and interrupt system to continue functioning. The Power-down mode saves the RAM contents but freezes the oscillator, disabling all other chip functions until the next interrupt or hardware reset.Features• Compatible with MCS-51® Products• 8K Bytes of In-System Programmable (ISP) Flash Memory– Endurance: 1000 Write/Erase Cycles• 4.0V to 5.5V Operating Range• Fully Static Operation: 0 Hz to 33 MHz• Three-level Program Memory Lock• 256 x 8-bit Internal RAM• 32 Programmable I/O Lines• Three 16-bit Timer/Counters• Eight Interrupt Sources• Full Duplex UART Serial Channel• Low-power Idle and Power-down Modes• Interrupt Recovery from Power-down Mode• Watchdog Timer• Dual Data Pointer• Power-off FlagPin DescriptionVCCSupply voltage.GNDGround.Port 0Port 0 is an 8-bit open drain bidirectional I/O port. As an output port, each pin can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as high-impedance inputs.Port 0 can also be configured to be the multiplexed low-order address/data bus during accesses to external program and data memory. In this mode, P0 has internal pullups.Port 0 also receives the code bytes during Flash programming and outputs the code bytes during program verification. External pullups are required during program verification.Port 1Port 1 is an 8-bit bidirectional I/O port with internal pullups. The Port 1 output buffers can sink/source four TTL inputs. When 1s are written to Port 1 pins, they are pulled high by the internal pullups and can be used as inputs. As inputs, Port 1 pins that are externally being pulled low will source current (IIL) because of the internal pullups.In addition, P1.0 and P1.1 can be configured to be the timer/counter 2 external count input (P1.0/T2) and the timer/counter 2 trigger input (P1.1/T2EX), respectively.Port 1 also receives the low-order address bytes during Flash programming and verification.Port 2Port 2 is an 8-bit bidirectional I/O port with internal pullups. The Port 2 output buffers can sink/source four TTL inputs. When 1s are written to Port 2 pins, they are pulled high by the internal pullups and can be used as inputs. As inputs, Port 2 pins that are externally being pulled low will source current (IIL) because of the internal pullups.Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that use 16-bit addresses (MOVX @ DPTR). In this application, Port 2 uses strong internal pull-ups when emitting 1s. During accesses to external data memory that use 8-bit addresses (MOVX @ RI), Port 2 emits the contents of the P2 Special Function Register.Port 2 also receives the high-order address bits and some control signals during Flash programming and verification.Port 3Port 3 is an 8-bit bidirectional I/O port with internal pullups. The Port 3 output buffers can sink/source four TTL inputs. When 1s are written to Port 3 pins, they are pulled high by the internal pullups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled low will source current (IIL) because of the pullups.Port 3 also serves the functions of various special features of the AT89S52, as shown in the following table.Port 3 also receives some control signals for Flash programming and verification.RSTReset input. A high on this pin for two machine cycles while the oscillator is running resets the device. This pin drives High for 96 oscillator periods after the Watchdog times out. The DISRTO bit in SFR AUXR (address 8EH) can be used to disable this feature. In the default state of bit DISRTO, the RESET HIGH out feature is enabled.ALE/PROGAddress Latch Enable (ALE) is an output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming.In normal operation, ALE is emitted at a constant rate of 1/6 the oscillator frequency and may be used for external timing or clocking purposes. Note, however, that one ALE pulse is skipped during each access to external data memory.If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode.PSENProgram Store Enable (PSEN) is the read strobe to external program memory. When the AT89S52 is executing code from external program memory, PSENis activated twice each machine cycle, except that two PSEN activations are skipped during each access to external data memory.EA/VPPExternal Access Enable. EA must be strapped to GND in order to enable the device to fetch code from external program memory locations starting at 0000H up to FFFFH. Note, however, that if lock bit 1 is programmed, EA will be internally latched on reset. EA should be strapped to VCC for internal program executions.This pin also receives the 12-volt programming enable voltage (VPP) during Flash programming.XTAL1Input to the inverting oscillator amplifier and input to the internal clock operating circuit.XTAL2Output from the inverting oscillator amplifier.Special Function RegistersNote that not all of the addresses are occupied, and unoccupied addresses may not be implemented on the chip. Read accesses to these addresses will in general return random data, and write accesses will have an indeterminate effect.User software should not write 1s to these unlisted locations, since they may be used in future products to invoke new features. In that case, the reset or inactive values of the new bits will always be 0.Timer 2 Registers:Control and status bits are contained in registers T2CON and T2MOD for Timer 2. The register pair (RCAP2H, RCAP2L) are the Capture/Reload registers for Timer 2 in 16-bit capture mode or 16-bit auto-reload mode.Interrupt Registers:The individual interrupt enable bits are in the IE register. Two priorities can be set for each of the six interrupt sources in the IP register.Dual Data Pointer Registers: To facilitate accessing both internal and external data memory, two banks of 16-bit Data Pointer Registers areprovided: DP0 at SFR address locations 82H-83H and DP1 at 84H-85H. Bit DPS = 0 in SFR AUXR1 selects DP0 and DPS = 1 selects DP1. The user should always initialize the DPS bit to the appropriate value before accessing the respective Data Pointer Register.Power Off Flag:The Power Off Flag (POF) is located at bit 4 (PCON.4) in the PCON SFR. POF is set to “1” during power up. It can be set and rest under software control and is not affected by reset.Memory OrganizationMCS-51 devices have a separate address space for Program and Data Memory. Up to 64K bytes each of external Program and Data Memory can be addressed.Program MemoryIf the EA pin is connected to GND, all program fetches are directed to external memory. On the AT89S52, if EA is connected to VCC, program fetches to addresses 0000H through 1FFFH are directed to internal memory and fetches to addresses 2000H through FFFFH are to external memory.Data MemoryThe AT89S52 implements 256 bytes of on-chip RAM. The upper 128 bytes occupy a parallel address space to the Special Function Registers. This means that the upper 128 bytes have the same addresses as the SFR space but are physically separate from SFR space.When an instruction accesses an internal location above address 7FH, the address mode used in the instruction specifies whether the CPU accesses the upper 128 bytes of RAM or the SFR space. Instructions which use direct addressing access of the SFR space. For example, the following direct addressing instruction accesses the SFR at location 0A0H (which is P2).MOV 0A0H, #dataInstructions that use indirect addressing access the upper 128 bytes of RAM. For example, the following indirect addressing instruction, where R0 contains 0A0H, accesses the data byte at address 0A0H, rather than P2 (whose address is 0A0H).MOV @R0, #dataNote that stack operations are examples of indirect addressing, so the upper 128 bytes of data RAM are available as stack space.Timer 0 and 1Timer 0 and Timer 1 in the AT89S52 operate the same way as Timer 0 and Timer 1 in the AT89C51 and AT89C52.Timer 2Timer 2 is a 16-bit Timer/Counter that can operate as either a timer or an event counter. The type of operation is selected by bit C/T2 in the SFR T2CON (shown in Table 2). Timer 2 has three operating modes: capture, auto-reload (up or down counting), and baud rate generator. The modes are selected by bits in T2CON.Timer 2 consists of two 8-bit registers, TH2 and TL2. In the Timer function, the TL2 register is incremented every machine cycle. Since a machine cycle consists of 12 oscillator periods, the count rate is 1/12 of the oscillator frequency.In the Counter function, the register is incremented in response to a1-to-0 transition at its corresponding external input pin, T2. In this function, the external input is sampled during S5P2 of every machine cycle. When the samples show a high in one cycle and a low in the next cycle, the count is incremented. The new count value appears in the register during S3P1 of the cycle following the one in which the transition was detected. Since two machine cycles (24 oscillator periods) are required to recognize a 1-to-0 transition, the maximum count rate is 1/24 of the oscillator frequency. To ensure that a given level is sampled at least once before it changes, the level should be held for at least one full machine cycle.InterruptsThe AT89S52 has a total of six interrupt vectors: two external interrupts (INT0 and INT1), three timer interrupts (Timers 0, 1, and 2), and the serial port interrupt. These interrupts are all shown in Figure 10.Each of these interrupt sources can be individually enabled or disabledby setting or clearing a bit in Special Function Register IE. IE also contains a global disable bit, EA, which disables all interrupts at once.Note that Table 5 shows that bit position IE.6 is unimplemented. In the AT89S52, bit position IE.5 is also unimplemented. User software should not write 1s to these bit positions, since they may be used in future AT89 products. Timer 2 interrupt is generated by the logical OR of bits TF2 and EXF2 in register T2CON. Neither of these flags is cleared by hardware when the service routine is vectored to. In fact, the service routine may have to determine whether it was TF2 or EXF2 that generated the interrupt, and that bit will have to be cleared in software.The Timer 0 and Timer 1 flags, TF0 and TF1, are set at S5P2 of the cycle in which the timers overflow. The values are then polled by the circuitry in the next cycle. However, the Timer 2 flag, TF2, is set at S2P2 and is polled in the same cycle in which the timer overflows.二、译文单片机单片机即微型计算机,是把中央处理器、存储器、定时/计数器、输入输出接口都集成在一块集成电路芯片上的微型计算机。

毕业设计(论文)外文资料翻译(学生用)

毕业设计(论文)外文资料翻译(学生用)

毕业设计外文资料翻译学院:信息科学与工程学院专业:软件工程姓名: XXXXX学号: XXXXXXXXX外文出处: Think In Java (用外文写)附件: 1.外文资料翻译译文;2.外文原文。

附件1:外文资料翻译译文网络编程历史上的网络编程都倾向于困难、复杂,而且极易出错。

程序员必须掌握与网络有关的大量细节,有时甚至要对硬件有深刻的认识。

一般地,我们需要理解连网协议中不同的“层”(Layer)。

而且对于每个连网库,一般都包含了数量众多的函数,分别涉及信息块的连接、打包和拆包;这些块的来回运输;以及握手等等。

这是一项令人痛苦的工作。

但是,连网本身的概念并不是很难。

我们想获得位于其他地方某台机器上的信息,并把它们移到这儿;或者相反。

这与读写文件非常相似,只是文件存在于远程机器上,而且远程机器有权决定如何处理我们请求或者发送的数据。

Java最出色的一个地方就是它的“无痛苦连网”概念。

有关连网的基层细节已被尽可能地提取出去,并隐藏在JVM以及Java的本机安装系统里进行控制。

我们使用的编程模型是一个文件的模型;事实上,网络连接(一个“套接字”)已被封装到系统对象里,所以可象对其他数据流那样采用同样的方法调用。

除此以外,在我们处理另一个连网问题——同时控制多个网络连接——的时候,Java内建的多线程机制也是十分方便的。

本章将用一系列易懂的例子解释Java的连网支持。

15.1 机器的标识当然,为了分辨来自别处的一台机器,以及为了保证自己连接的是希望的那台机器,必须有一种机制能独一无二地标识出网络内的每台机器。

早期网络只解决了如何在本地网络环境中为机器提供唯一的名字。

但Java面向的是整个因特网,这要求用一种机制对来自世界各地的机器进行标识。

为达到这个目的,我们采用了IP(互联网地址)的概念。

IP以两种形式存在着:(1) 大家最熟悉的DNS(域名服务)形式。

我自己的域名是。

所以假定我在自己的域内有一台名为Opus的计算机,它的域名就可以是。

毕业设计外文翻译

毕业设计外文翻译

毕业设计外文翻译Newly compiled on November 23, 2020Title:ADDRESSING PROCESS PLANNING AND VERIFICATION ISSUES WITH MTCONNECTAuthor:Vijayaraghavan, Athulan, UC BerkeleyDornfeld, David, UC BerkeleyPublication Date:06-01-2009Series:Precision Manufacturing GroupPermalink:Keywords:Process planning verification, machine tool interoperability, MTConnect Abstract:Robust interoperability methods are needed in manufacturing systems to implement computeraided process planning algorithms and to verify their effectiveness. In this paper wediscuss applying MTConnect, an open-source standard for data exchange in manufacturingsystems, in addressing two specific issues in process planning and verification. We use data froman MTConnect-compliant machine tool to estimate the cycle time required for machining complexparts in that machine. MTConnect data is also used in verifying the conformance of toolpaths tothe required part features by comparing the features created by the actual tool positions to therequired part features using CAD tools. We demonstrate the capabilities of MTConnect in easilyenabling process planning and verification in an industrial environment.Copyright Information:All rights reserved unless otherwise indicated. Contact the author or original publisher for anynecessary permissions. eScholarship is not the copyright owner for deposited works. Learn moreADDRESSING PROCESS PLANNING AND VERIFICATION ISSUESWITH MTCONNECTAthulan Vijayaraghavan, Lucie Huet, and David DornfeldDepartment of Mechanical EngineeringUniversity of CaliforniaBerkeley, CA 94720-1740William SobelArtisanal SoftwareOakland, CA 94611Bill Blomquist and Mark ConleyRemmele Engineering Inc.Big Lake, MNKEYWORDSProcess planning verification, machine tool interoperability, MTConnect.ABSTRACTRobust interoperability methods are needed in manufacturing systems to implement computeraided process planning algorithms and to verifytheir effectiveness. In this paper we discuss applying MTConnect, an open-source standardfor data exchange in manufacturing systems, in addressing two specific issues in processplanning and verification. We use data from an MTConnect-compliant machine tool to estimatethe cycle time required for machining complex parts in that machine. MTConnect data is also used in verifying the conformance of toolpaths to the required part features by comparing the features created by the actual tool positions tothe required part features using CAD tools. We demonstrate the capabilities of MTConnect in easily enabling process planning and verificationin an industrial environment.INTRODUCTIONAutomated process planning methods are acritical component in the design and planning of manufacturing processes for complex parts. Thisis especially the case with high speed machining, as the complex interactions betweenthe tool and the workpiece necessitates careful selection of the process parameters and the toolpath design. However, to improve the effectiveness of these methods, they need to be integrated tightly with machines and systems in industrial environments. To enable this, we need robust interoperability standards for data exchange between the different entities in manufacturing systems.In this paper, we discuss using MTConnect – an open source standard for data exchange in manufacturing systems – to address issues in process planning and verification in machining.We discuss two examples of using MTConnect for better process planning: in estimating the cycle time for high speed machining, and in verifying the effectiveness of toolpath planning for machining complex features. As MTConnect standardizes the exchange of manufacturing process data, process planning applications can be developed independent of the specific equipment used (Vijayaraghavan, 2008). This allowed us to develop the process planning applications and implement them in an industrial setting with minimal overhead. The experiments discussed in this paper were developed at UC Berkeley and implemented at Remmele Engineering Inc.The next section presents a brief introduction to MTConnect, highlighting its applicability in manufacturing process monitoring. We then discuss two applications of MTConnect – in computing cycle time estimates and in verifying toolpath planning effectiveness. MTCONNECTMTConnect is an open software standard for data exchange and communication between manufacturing equipment (MTConnect, 2008a). The MTConnect protocol defines a common language and structure for communication in manufacturing equipment, and enables interoperability by allowing access to manufacturing data using standardized interfaces. MTConnect does not define methods for data transmission or use, and is not intended to replace the functionality of existing products and/or data standards. It enhances the data acquisition capabiltiies of devices and applications, moving towards a plug-and-play environment that can reduce the cost of integration. MTConnect is built upon prevalent standards in the manufacturing and software industry, which maximizes the number of tools available for its implementation and provides a high level of interoperability with other standards and tools in these industries.MTConnect is an XML-based standard andmessages are encoded using XML (eXtensibleMarkup Language), which has been usedextensively as a portable way of specifying data interchange formats (W3C, 2008). A machinereadable XML schema defines the format ofMTConnect messages and how the data itemswithin those messages are represented. At thetime of publication, the latest version of the MTConnect standard defining the schema is (MTConnect, 2008b).The MTConnect protocol includes the following information about a device:Identity of a deviceIdentity of all the independent components ofthe deviceDesign characteristics of the deviceData occurring in real or near real-time by thedevice that can be utilized by other devices or applications. The types of data that can beaddressed includes:Physical and actual device design dataMeasurement or calibration dataNear-real time data from the deviceFigure 1 shows an example of a data gatheringsetup using MTConnect. Data is gathered innear-time from a machine tool and from thermal sensors attached to it. The data stored by the MTConnect protocol for this setup is shown inTable 1. Specialized adaptors are used to parsethe data from the machine tool and from thesensor devices into a format that can beunderstood by the MTConnect agent, which inturn organizes the data into the MTConnect XML schema. Software tools can be developed which operate on the XML data from the agent. Sincethe XML schema is standardized, the softwaretools can be blind to the specific configuration ofthe equipment from where the data is gathered. FIGURE 1: MTCONNECT SETUP.TABLE 1:MTCONNECT PROTOCOL INFORMATION FOR MACHINE TOOL IN FIGURE 1.Device identity “3-Axis Milling Machine”Devicecomponents1 X Axis; 1 Y Axis; 1 Z Axis;2 Thermal SensorsDevice designcharacteristicsX Axis Travel: 6”Y Axis Travel: 6”Z Axis Travel: 12”Max Spindle RPM: 24000Data occurringin deviceTool position: (0,0,0);Spindle RPM: 1000Alarm Status: OFFTemp Sensor 1: 90oFTemp Sensor 2: 120oFAn added benefit of XML is that it is a hierarchical representation, and this is exploited by designing the hierarchy of the MTConnect schema to resemble that of a conventional machine tool. The schema itself functions as a metaphor for the machine tool and makes the parsing and encoding of messages intuitive. Data items are grouped based on their logical organization, and not on their physical organization. For example, Figure 2 shows the XML schema associated with the setup shown in Figure 1. Although the temperature sensors operate independant of the machine tool (with its own adaptor), the data from the sensors are associated with specific components of the machine tool, and hence the temperature data is a member of the hierarchy of the machine tool. The next section discusses applying MTConnect in estimating cycle time in high-speed machining.ACCURATE CYCLE TIME ESTIMATESIn high speed machining processes there can be discrepancies between the actual feedrates during cutting and the required (or commanded) feedrates. These discrepancies are dependenton the design of the controller used in the machine tool and the toolpath geometry. While there have been innovative controller designs that minimize the feedrate discrepancy (Sencer,2008), most machine tools used in conventional industrial facilities have commercial off-the-shelf controllers that demonstrate some discrepancies in the feedrates, especially when machining complex geometries at high speeds. There is a need for simple tools to estimate the discrepancy in these machining conditions. Apart from influencing the surface quality of the machined parts, feedrate variation can lead to inaccurate estimates of the cycle time during machining. Accurate estimates of the cycle time is a critical requirement in planning for complex machining operations in manufacturing facilities. The cycle time is needed for both scheduling the part in a job shop, as well as for costing the part. Inaccurate cycle time estimates (especiallywhen the feed is overestimated) can lead to uncompetitive estimates for the cost of the part and unrealistic estimates for the cycle time. Related Workde Souza and Coelho (2007) presented a comprehensive set of experiments to demonstrate feedrate limitations during the machining of freeform surfaces. They identified the causes of feedrate variation as dynamic limitations of the machine, block processing time FIGURE 2: MTCONNECT HIERARCHY.for the CNC, and the feature size in the toolpaths. Significant discrepancies were observed between the actual and commanded feeds when machining with linear interpolation (G01). The authors used a custom monitoring and data logging system to capture the feedrate variation in the CNC controller during machining. Sencer et al. (2008) presented feed scheduling algorithms to minimize the machining time for 5- axis contour machining of sculptured surfaces. The algorithm optimized the profile of the feedrate for minimum machining time, while observing constrains on the smoothness of the feedrate, acceleration and jerk of the machine tool drives. This follows earlier work in minimizing the machining time in 3-axis milling using similar feed scheduling techniques(Altintas, 2003). While these methods are very effective in improving the cycle time of complex machining operations, they can be difficult toapply in conventional factory environments asthey require specialized control systems. The methods we discuss in this paper do notaddress the optimization of cycle time during machining. Instead, we provide simple tools to estimate the discrepancy in feedrates during machining and use this in estimating the cycletime for arbitrary parts.MethodologyDuring G01 linear interpolation the chief determinant of the maximum feedrateachievable is the spacing between adjacentpoints (G01 step size). We focus on G01 interpolation as this is used extensively when machining simultaneously in 3 or more axes.The cycle time for this machine tool to machinean arbitrary part (using linear interpolation) is estimated based on the maximum feedachievable by the machine tool at a given path spacing. MTConnect is a key enabler in this process as it standardizes both data collectionas well as the analysis.The maximum feedrate achievable is estimated using a standardized test G-code program. This program consists of machining a simple shapewith progressively varying G01 path spacings.The program is executed on an MTConnectcompliant machine tool, and the position andfeed data from the machine tool is logged innear-real time. The feedrate during cutting at the different spacings is then analyzed, and amachine tool “calibration” curve is developed, which identifies the maximum feedrate possibleat a given path spacing.FIGURE 3: METHODOLOGY FOR ESTIMATING CYCLE TIME.Conventionally, the cycle time for a giventoolpath is estimated by summing the time takenfor the machine tool to process each block of Gcode, which is calculated as the distancetravelled in that block divided by the feedrate ofthe block. For a given arbitrary part G-code to be executed on a machine tool, the cycle time is estimated using the calibration curve as follows. For each G01 block executed in the program, the size of the step is calculated (this is the distance between the points the machine tool is interpolating) and the maximum feedrate possible at this step size is looked up from the calibration curve. If the maximum feedrate is smaller than the commanded feedrate, this line of the G-code is modified to machine at the (lower) actual feedrate, if the maximum feedrate is greater, then the line is left unmodified. This is performed for all G01 lines in the program, and finally, the cycle time of the modified G-code program is estimated the conventional way. This methodology is shown in Figure 3. The next section discusses an example applying this methodology on a machine tool.ResultsWe implemented the cycle time estimation method on a 3-axis machine tool with a conventional controller. The calibration curve of this machine tool was computed by machining a simple circular feature at the following linear spacings: ”, ”, ”, ”,”, ”, ”, ”, ”. Weconfirmed that the radius of the circle (that is, the curvature in the toolpath) had no effect on the feedrate achieved by testing with circular features of radius ”, ”, and ”, andobserving the same maximum feedrate in all cases. Table 2 shows the maximum achievable feedrate at each path spacing when using a circle of radius 1”. We can see from the table that the maximum feedrate achievable is a linear function of the path spacing. Using a linear fit, the calibration curve for this machine tool can be estimated. Figure 4 plots the calibration curve for this machine tool. The relationship between the feedrate and the path spacing is linear asthe block processing time of the machine tool controller is constant at all feedrates. The block processing time determines the maximumfederate achievable for a given spacing as it isthe time the machine tool takes to interpolateone block of G-code. As the path spacing (or interpolatory distance) linearly increases, thespeed at which it can be interpolated alsoincreases linearly. The relationship for the datain Figure 4 is:MAX FEED (in/min) = 14847 * SPACING (in)TABLE 2: MAXIMUM ACHIEVABLE FEEDRATE AT VARYING PATH SPACINGSpacing Maximum Feedrate”””””””””We also noticed that the maximum feedrate for agiven spacing was unaffected by thecommanded feedrate, as long as it was lesserthan the commanded feedrate. This means thatit was adequate to compute the calibration curveby commanding the maximum possible feedratein the machine tool.FIGURE 4: CALIBRATION CURVE FOR MACHINE TOOL.Using this calibration curve, we estimated thecycle time for machining an arbitrary feature inthis machine tool. The feature we used was a3D spiral with a smoothly varying path spacing,which is shown in Figure 5. The spiral path isdescribed exclusively using G01 steps andinvolves simultaneous 3-axis interpolation. Thepath spacing of the G-code blocks for thefeature is shown in Figure 6.FIGURE 5: 3D SPIRAL FEATURE.FIGURE 6: PATH SPACING VARIATION WITH GCODE LINE FOR SPIRAL FEATURE.Figure 7 shows the predicted feedrate based onthe calibration curve for machining the spiralshape at 100 inches/min, compared to the actualfeedrate during machining. We can see that the feedrate predicted by the calibration curvematches very closely with the actual feedrate.We can also observe the linear relationship between path spacing and maximum feedrate by comparing figures 6 and 7.FIGURE 7: PREDICTED FEEDRATE COMPARED TO MEASURED FEEDRATE FOR SPIRAL FEATURE AT 100 IN/MIN.FIGURE 8: ACTUAL CYCLE TIME TO MACHINE SPIRAL FEATURE AT DIFFERENT FEEDRATES. The cycle time for machining the spiral atdifferent commanded feedrates was alsoestimated using the calibration curve. Figure 8 shows the actual cycle time taken to machinethe spiral feature at different feedrates. Noticehere that the trend is non-linear – an increase infeed does not yield a proportional decrease incycle time – implying that there is somefeedrate discrepancy at high feeds. Figure 9 compares the theoretical cycle time to machineat different feedrates to the actual cycle time andthe model predicted cycle time. We can see thatthe model predictions match the cycle times very closely (within 1%). Significant discrepancies are seen between the theoretical cycle time and the actual cycle time when machining at high feed rates. These discrepancies can be explained bythe difference between the block processingtime for the controller, and the time spent oneach block of G-Code during machining. At high feedrates, the time spent at each block is shorterthan the block processing time, so the controller slows down the interpolation resulting in a discrepancy in the cycle time.These results demonstrated the effectiveness of using the calibration curve to estimate feed, and ultimately apply in estimating the cycle time.This method can be extrapolated to multi-axis machining by measuring the feedrate variationfor linear interpolation in specific axes. We canalso specifically correlate feed in one axis to the path spacing instead of the overall feedrate. FIGURE 9: ACTUAL OBSERVED CYCLE TIMESAND PREDICTED CYCLE TIMES COMPARED TO THE NORMALIZED THEORETICAL CYCLE TIMES FOR MACHINING SPIRAL FEATURE AT DIFFERENT FEEDRATES.TOOL POSITION VERIFICATIONMTConnect data can also be used in verifying toolpath planning for the machining of complex parts. Toolpaths for machining complex featuresare usually designed using specialized CAM algorithms, and traditionally the effectiveness ofthe toolpaths in creating the required partfeatures are either verified using computer simulations of the toolpath, or by surfacemetrology of the machined part. The formerapproach is not very accurate, as the toolpath commanded to the machine tool may not matchthe actual toolpath travelled during machining.The latter approach, while accurate, tends to betime consuming and expensive, and requires the analysis and processing of 3D metrology data(which can be complex). Moreover, errors in the features of a machined part are not solely due to toolpath errors, and using metrology data fortoolpath verification may obfuscate toolpatherrors with process dynamics errors. In aprevious work we discussed a simple way toverify toolpath planning by overlaying the actualtool positions against the CAM generated tool positions (Vijayaraghavan, 2008). We nowdiscuss a more intuitive method to verify the effectiveness of machining toolpaths, wheredata from MTConnect-compliant machine toolsis used to create a solid model of the machined features to compare with the desired features.Related WorkThe manufacturing community has focussed extensively on developing process planning algorithms for the machining of complex parts.Elber (1995) in one of the earliest works in thefield, discussed algorithms for toolpathgeneration for 3- and 5-axis machining. Wrightet al. (2004) discussed toolpath generationalgorithms for the finish machining of freeform surfaces; the algorithms were based on thegeometric properties of the surface features. Vijayaraghavan et al. (2009) discussed methodsto vary the spacing of raster toolpaths and tooptimize the orientation of workpieces infreeform surface machining. The efficiency ofthese methods were validated primarily bymetrology and testing of the machined part. MethodologyTo verify toolpath planning effectiveness, we logthe actual cutting tool positions during machiningfrom an MTConnect-compliant machine tool,and use the positions to generate a solid modelof the machined part. The discrepancy infeatures traced by the actual toolpath relative tothe required part features can be computed by comparing these two solid models. The solidmodel of the machined part from the toolpositions can be obtained as follows:Create a 3D model of the toolCreate a 3D model of the stock materialCompute the swept volume of the tool as ittraces the tool positions (using logged data)Subtract the swept volume of the tool from thestock materialThe remaining volume of material is a solidmodel of the actual machined part.The two models can then be compared using 3D boolean difference (or subtraction) operations.ResultsWe implemented this verification scheme bylogging the cutter positions from an MTConnectcompliant 5-axis machine tool. The procedure toobtain the solid model using the tool positionswas implemented in Vericut. The two modelswere compared using a boolean diff operation in Vericut, which identified the regions in the actual machined part that were different from therequired solid model. An example applying thismethod for a feature is shown in Figure 10.FIGURE 10: A – SOLID MODEL OF REQUIRED PART; B – SOLID MODEL OF PART FROM TOOL POSITIONS SHOWING DISCREPANCIES BETWEEN ACTUAL PART FEATURES AND REQUIRED PART FEATURES. SHADED REGIONSDENOTE ~” DIFFERENCE IN MATERIAL REMOVAL.DISCUSSION AND CONCLUSIONS MTConnect makes it very easy to standardize data capture from disparate sources anddevelop common planning and verification applications. The importance of standardization cannot be overstated here – while it has always been possible to get process data from machine tools, this can be generally cumbersome andtime consuming because different machine tools require different methods of accessing data.Data analysis was also challenging to standardize as the data came in differentformats and custom subroutines were needed to process and analyze data from differentmachine tools. With MTConnect the data gathering and analysis process is standardized resulting in significant cost and time savings. This allowed us to develop the verification tools independent of the machine tools they were applied in. This also allowed us to rapidly deploy these tools in an industrial environment without any overheads (especially from the machine tool sitting idle). The toolpath verification was performed with minimal user intervention on a machine which was being actively used in a factory. The only setup needed was to initially configure the machine tool to output MTConnect-compliant data; since this is a onetime activity, it has an almost negligible impacton the long term utilization of the machine tool. Successful implementations of data capture and analysis applications over MTConnect requires a robust characterization of the data capture rates and the latency in the streaming information. Current implementations of MTConnect are over ethernet, and a data rate of about 10~100Hzwas observed in normal conditions (with no network congestion). While this is adequate for geometric analysis (such as the examples in this paper), it is not adequate for real-time process monitoring applications, such as sensor data logging. More work is needed in developing theMTConnect software libraries so that acceptable data rates and latencies can be achieved.One of the benefits of MTConnect is that it can act as a bridge between academic research and industrial practice. Researchers can developtools that operate on standardized data, whichare no longer encumbered by specific data formats and requirements. The tools can then be easily applied in industrial settings, as the framework required to implement the tools in a specific machine or system is already in place. Greater use of interoperability standards by the academic community in manufacturing research will lead to faster dissemination of research results and closer collaboration with industry. ACKNOWLEDGEMENTSWe thank the reviewers for their valuable comments. MTConnect is supported by AMT –The Association for Manufacturing Technology. We thank Armando Fox from the RAD Lab at UC Berkeley, and Paul Warndorf from AMT for their input. Research at UC Berkeley is supported by the Machine Tool Technology Research Foundation and the industrial affiliates of the Laboratory for Manufacturing and Sustainability. To learn more about the lab’s REFERENCESAltintas, Y., and Erkormaz, K., 2003, “Feedrate Optimization for Spline Interpolation In High Speed Machine Tools”, CIRP Annals –Manufacturing Technology, 52(1), pp. 297-302. de Souza, A. F., and Coelho, R. T., 2007, “Experimental Inv estigation of Feedrate Limitations on High Speed Milling Aimed at Industrial Applications”, Int. J. of Afv. Manuf. Tech, 32(11), pp. 1104–1114.Elber, G., 1995, “Freeform Surface Region Optimization for 3-Axis and 5-Axis Milling”, Computer-Aided Design, 27(6), pp. 465–470. MTConnectTM, 2008b, MTConnectTM Standard, Sencer, B., Altintas, Y., and Croft, E., 2008, “Feed Optimization for Five-axis CNC Machine Tools with Drive Constraints”, Int. J. of Mach.Tools and Manuf., 48(7), pp. 733–745. Vijayaraghavan, A., Sobel, W., Fox, A., Warndorf, P., Dornfeld, D. A., 2008, “Improving Machine Tool Interoperability with Standardized Interface Protocols”, Proceedings of ISFA. Vijayaraghavan, A., Hoover, A., Hartnett, J., and Dornfeld, D. A., 2009, “Improving Endmilli ng Surface Finish by Workpiece Rotation and Adaptive Toolpath Spacing”, Int. J. of Mach. Tools and Manuf., 49(1), pp. 89–98.World Wide Web Consortium (W3C), 2008, “Extensible Markup Language (XML),”Wright, P. K., Dornfeld, D. A., Sundararajan, V., and Misra, D., 2004, “Tool Path Generation for Finish Machining of Freeform Surfaces in the Cybercut Process Planning Pipeline”, Trans. of NAMRI/SME, 32, 159–166.毕业设计外文翻译网址。

毕业设计论文外文翻译(中英文).doc

毕业设计论文外文翻译(中英文).doc

译文交通拥堵和城市交通系统的可持续发展摘要:城市化和机动化的快速增长,通常有助于城市交通系统的发展,是经济性,环境性和社会可持续性的体现,但其结果是交通量无情增加,导致交通拥挤。

道路拥挤定价已经提出了很多次,作为一个经济措施缓解城市交通拥挤,但还没有见过在实践中广泛使用,因为道路收费的一些潜在的影响仍然不明。

本文首先回顾可持续运输系统的概念,它应该满足集体经济发展,环境保护和社会正义的目标。

然后,根据可持续交通系统的特点,使拥挤收费能够促进经济增长,环境保护和社会正义。

研究结果表明,交通拥堵收费是一个切实有效的方式,可以促进城市交通系统的可持续发展。

一、介绍城市交通是一个在世界各地的大城市迫切关注的话题。

随着中国的城市化和机动化的快速发展,交通拥堵已成为一个越来越严重的问题,造成较大的时间延迟,增加能源消耗和空气污染,减少了道路网络的可靠性。

在许多城市,交通挤塞情况被看作是经济发展的障碍。

我们可以使用多种方法来解决交通挤塞,包括新的基础设施建设,改善基础设施的维护和操作,并利用现有的基础设施,通过需求管理策略,包括定价机制,更有效地减少运输密度。

交通拥堵收费在很久以前就已提出,作为一种有效的措施,来缓解的交通挤塞情况。

交通拥堵收费的原则与目标是通过对选择在高峰拥挤时段的设施的使用实施附加收费,以纾缓拥堵情况。

转移非高峰期一些出行路线,远离拥挤的设施或高占用车辆,或完全阻止一些出行,交通拥堵收费计划将在节省时间和降低经营成本的基础上,改善空气中的质量,减少能源消耗和改善过境生产力。

此计划在世界很多国家和地方都有成功的应用。

继在20世纪70年代初和80年代中期挪威与新加坡实行收费环,在2003年2月伦敦金融城推出了面积收费;直至现在,它都是已经开始实施拥挤收费的大都市圈中一个最知名的例子。

然而,交通拥堵收费由于理论和政治的原因未能在实践中广泛使用。

道路收费的一些潜在的影响尚不清楚,和城市发展的拥塞定价可持续性,需要进一步研究。

毕业设计(论文)外文资料翻译

毕业设计(论文)外文资料翻译

毕业设计(论文)外文资料翻译学院:艺术学院专业:环境设计姓名:学号:外文出处: The Swedish Country House附件: 1.外文资料翻译译文;2.外文原文附件1:外文资料翻译译文室内装饰简述一室内装饰设计要素1 空间要素空间的合理化并给人们以美的感受是设计基本的任务。

要勇于探索时代、技术赋于空间的新形象,不要拘泥于过去形成的空间形象。

2 色彩要求室内色彩除对视觉环境产生影响外,还直接影响人们的情绪、心理。

科学的用色有利于工作,有助于健康。

色彩处理得当既能符合功能要求又能取得美的效果。

室内色彩除了必须遵守一般的色彩规律外,还随着时代审美观的变化而有所不同。

3 光影要求人类喜爱大自然的美景,常常把阳光直接引入室内,以消除室内的黑暗感和封闭感,特别是顶光和柔和的散射光,使室内空间更为亲切自然。

光影的变换,使室内更加丰富多彩,给人以多种感受。

4 装饰要素室内整体空间中不可缺少的建筑构件、如柱子、墙面等,结合功能需要加以装饰,可共同构成完美的室内环境。

充分利用不同装饰材料的质地特征,可以获得千变完化和不同风格的室内艺术效果,同时还能体现地区的历史文化特征。

5 陈设要素室内家具、地毯、窗帘等,均为生活必需品,其造型往往具有陈设特征,大多数起着装饰作用。

实用和装饰二者应互相协调,求的功能和形式统一而有变化,使室内空间舒适得体,富有个性。

6 绿化要素室内设计中绿化以成为改善室内环境的重要手段。

室内移花栽木,利用绿化和小品以沟通室内外环境、扩大室内空间感及美化空间均起着积极作用。

二室内装饰设计的基本原则1 室内装饰设计要满足使用功能要求室内设计是以创造良好的室内空间环境为宗旨,使室内环境合理化、舒适化、科学化;要考虑人们的活动规律处理好空间关系,空间尺寸,空间比例;合理配置陈设与家具,妥善解决室内通风,采光与照明,注意室内色调的总体效果。

2 室内装饰设计要满足精神功能要求室内设计的精神就是要影响人们的情感,乃至影响人们的意志和行动,所以要研究人们的认识特征和规律;研究人的情感与意志;研究人和环境的相互作用。

毕业设计外文资料翻译——翻译译文

毕业设计外文资料翻译——翻译译文

毕业设计外文资料翻译(二)外文出处:Jules Houde 《Sustainable development slowed down by bad construction practices and natural and technological disasters》2、外文资料翻译译文混凝土结构的耐久性即使是工程师认为的最耐久和最合理的混凝土材料,在一定的条件下,混凝土也会由于开裂、钢筋锈蚀、化学侵蚀等一系列不利因素的影响而易受伤害。

近年来报道了各种关于混凝土结构耐久性不合格的例子。

尤其令人震惊的是混凝土的结构过早恶化的迹象越来越多。

每年为了维护混凝土的耐久性,其成本不断增加。

根据最近在国内和国际中的调查揭示,这些成本在八十年代间翻了一番,并将会在九十年代变成三倍。

越来越多的混凝土结构耐久性不合格的案例使从事混凝土行业的商家措手不及。

混凝土结构不仅代表了社会的巨大投资,也代表了如果耐久性问题不及时解决可能遇到的成本,更代表着,混凝土作为主要建筑材料,其耐久性问题可能导致的全球不公平竞争以及行业信誉等等问题。

因此,国际混凝土行业受到了强烈要求制定和实施合理的措施以解决当前耐久性问题的双重的挑战,即:找到有效措施来解决现有结构剩余寿命过早恶化的威胁。

纳入新的结构知识、经验和新的研究结果,以便监测结构耐久性,从而确保未来混凝土结构所需的服务性能。

所有参与规划、设计和施工过程的人,应该具有获得对可能恶化的过程和决定性影响参数的最低理解的可能性。

这种基本知识能力是要在正确的时间做出正确的决定,以确保混凝土结构耐久性要求的前提。

加固保护混凝土中的钢筋受到碱性的钝化层(pH值大于12.5)保护而阻止了锈蚀。

这种钝化层阻碍钢溶解。

因此,即使所有其它条件都满足(主要是氧气和水分),钢筋受到锈蚀也都是不可能的。

混凝土的碳化作用或是氯离子的活动可以降低局部面积或更大面积的pH值。

当加固层的pH值低于9或是氯化物含量超过一个临界值时,钝化层和防腐保护层就会失效,钢筋受腐蚀是可能的。

毕业设计(论文)外文翻译(原文)

毕业设计(论文)外文翻译(原文)

毕业设计(论文)——外文翻译(原文)NEW APPLICATION OF DA TABASERelational databases have been in use for over two decades. A large portion of the applications of relational databases have been in the commercial world, supporting such tasks as transaction processing for banks and stock exchanges, sales and reservations for a variety of businesses, and inventory and payroll for almost of all companies. We study several new applications, which have become increasingly important in recent years.First. Decision-support systemAs the online availability of data has grown, businesses have begun to exploit the available data to make better decisions about increase sales. We can extract much information for decision support by using simple SQL queries. Recently however, people have felt the need for better decision support based on data analysis and data mining, or knowledge discovery, using data from a variety of sources.Database applications can be broadly classified into transaction processing and decision support. Transaction-processing systems are widely used today, and companies have accumulated a vast amount of information generated by these systems.The term data mining refers loosely to finding relevant information, or “discovering knowledge,”from a large volume of data. Like knowledge discovery in artificial intelligence, data mining attempts to discover statistical rules and patterns automatically from data. However, data mining differs from machine learning in that it deals with large volumes of data, stored primarily on disk.Knowledge discovered from a database can be represented by a set of rules. We can discover rules from database using one of two models:In the first model, the user is involved directly in the process of knowledge discovery.In the second model, the system is responsible for automatically discovering knowledge from the database, by detecting patterns and correlations in the data.Work on automatic discovery of rules has been influenced strongly by work in the artificial-intelligence community on machine learning. The main differences lie in the volume of data handled in databases, and in the need to access disk. Specialized data-mining algorithms have been developed to handle large volumes of disk-resident data efficiently.The manner in which rules are discovered depends on the class of data-mining application. We illustrate rule discovery using two application classes: classification and associations.Second. Spatial and Geographic DatabasesSpatial databases store information related to spatial locations, and provide support for efficient querying and indexing based on spatial locations. Two types of spatial databases are particularly important:Design databases, or computer-aided-design (CAD) databases, are spatial databases used to store design information about how objects---such as buildings, cars or aircraft---are constructed. Other important examples of computer-aided-design databases are integrated-circuit and electronic-device layouts.Geographic databases are spatial databases used to store geographic information, such as maps. Geographic databases are often called geographic information systems.Geographic data are spatial in nature, but differ from design data in certain ways. Maps and satellite images are typical examples of geographic data. Maps may provide not only location information -suchas boundaries, rivers and roads---but also much more detailed information associated with locations, such as elevation, soil type, land usage, and annual rainfall.Geographic data can be categorized into two types: raster data (such data consist a bit maps or pixel maps, in two or more dimensions.), vector data (vector data are constructed from basic geographic objects). Map data are often represented in vector format.Third. Multimedia DatabasesRecently, there has been much interest in databases that store multimedia data, such as images, audio, and video. Today multimedia data typically are stored outside the database, in files systems. When the number of multimedia objects is relatively small, features provided by databases are usually not important. Database functionality becomes important when the number of multimedia objects stored is large. Issues such as transactional updates, querying facilities, and indexing then become important. Multimedia objects often have descriptive attributes, such as those indicating when they were created, who created them, and to what category they belong. One approach to building a database for such multimedia objects is to use database for storing the descriptive attributes, and for keeping track of the files in which the multimedia objects are stored.However, storing multimedia outside the database makes it harder to provide database functionality, such as indexing on the basis of actual multimedia data content. It can also lead to inconsistencies, such a file that is noted in the database, but whose contents are missing, or vice versa. It is therefore desirable to store the data themselves in the database.Forth. Mobility and Personal DatabasesLarge-scale commercial databases have traditionally been stored in central computing facilities. In the case of distributed database applications, there has usually been strong central database and network administration. Two technology trends have combined to create applications in which this assumption of central control and administration is not entirely correct:1.The increasingly widespread use of personal computers, and, more important, of laptop or “notebook” computers.2.The development of a relatively low-cost wireless digital communication infrastructure, base on wireless local-area networks, cellular digital packet networks, and other technologies.Wireless computing creates a situation where machines no longer have fixed locations and network addresses. This complicates query processing, since it becomes difficult to determine the optimal location at which to materialize the result of a query. In some cases, the location of the user is a parameter of the query. A example is a traveler’s information system that provides data on hotels, roadside services, and the like to motorists. Queries about services that are ahead on the current route must be processed based on knowledge of the user’s location, direction of motion, and speed.Energy (battery power) is a scarce resource for mobile computers. This limitation influences many aspects of system design. Among the more interesting consequences of the need for energy efficiency is the use of scheduled data broadcasts to reduce the need for mobile system to transmit queries. Increasingly amounts of data may reside on machines administered by users, rather than by database administrators. Furthermore, these machines may, at times, be disconnected from the network.SummaryDecision-support systems are gaining importance, as companies realize the value of the on-line data collected by their on-line transaction-processing systems. Proposed extensions to SQL, such as the cube operation, help to support generation of summary data. Data mining seeks to discoverknowledge automatically, in the form of statistical rules and patterns from large databases. Data visualization systems help humans to discover such knowledge visually.Spatial databases are finding increasing use today to store computer-aided design data as well as geographic data. Design data are stored primarily as vector data; geographic data consist of a combination of vector and raster data.Multimedia databases are growing in importance. Issues such as similarity-based retrieval and delivery of data at guaranteed rates are topics of current research.Mobile computing systems have become common, leading to interest in database systems that can run on such systems. Query processing in such systems may involve lookups on server database.毕业设计(论文)——外文翻译(译文)数据库的新应用我们使用关系数据库已经有20多年了,关系数据库应用中有很大一部分都用于商业领域支持诸如银行和证券交易所的事务处理、各种业务的销售和预约,以及几乎所有公司都需要的财产目录和工资单管理。

毕业设计外文资料翻译译文

毕业设计外文资料翻译译文

附件1:外文资料翻译译文包装对食品发展的影响一个消费者对某个产品的第一印象来说包装是至关重要的,包括沟通的可取性,可接受性,健康饮食形象等。

食品能够提供广泛的产品和包装组合,传达自己加工的形象感知给消费者,例如新鲜包装/准备,冷藏,冷冻,超高温无菌,消毒(灭菌),烘干产品。

食物的最重要的质量属性之一,是它的味道,其影响人类的感官知觉,即味觉和嗅觉。

味道可以很大程度作退化的处理和/或扩展存储。

其他质量属性,也可能受到影响,包括颜色,质地和营养成分。

食品质量不仅取决于原材料,添加剂,加工和包装的方法,而且其预期的货架寿命(保质期)过程中遇到的分布和储存条件的质量。

越来越多的竞争当中,食品生产商,零售商和供应商;和质量审核供应商有显着提高食品质量以及急剧增加包装食品的选择。

这些改进也得益于严格的冷藏链中的温度控制和越来越挑剔的消费者。

保质期的一个定义是:在食品加工和包装组合下,在食品的容器和条件,在销售点分布在特定系统的时间能保持令人满意的食味品质。

保质期,可以用来作为一个新鲜的概念,促进营销的工具。

延期或保质期长的产品,还提供产品的使用时间,方便以及减少浪费食物的风险,消费者和/或零售商。

包装产品的质量和保质期的主题是在第3章中详细讨论。

包装为消费者提供有关产品的重要信息,在许多情况下,使用的包装和/或产品,包括事实信息如重量,体积,配料,制造商的细节,营养价值,烹饪和开放的指示,除了法律准则的最小尺寸的文字和数字,有定义的各类产品。

消费者寻求更详细的产品信息,同时,许多标签已经成为多语种。

标签的可读性是为视障人士的问题,这很可能成为一个对越来越多的老年人口越来越重要的问题。

食物的选择和包装创新的一个主要驱动力是为了方便消费者的需求。

这里有许多方便的现代包装所提供的属性,这些措施包括易于接入和开放,处置和处理,产品的知名度,再密封性能,微波加热性,延长保质期等。

在英国和其他发达经济体显示出生率下降和快速增长的一个相对富裕的老人人口趋势,伴随着更加苛刻的年轻消费者,他们将要求和期望改进包装的功能,如方便包揭开(百货配送研究所,IGD)。

毕设外文翻译电子版

毕设外文翻译电子版

7.1 INTRODUCTIONAfter lathes, milling machines are the most widely used for manufacturing applications. In milling, the workpiece is fed into a rotating milling cutter, which is a multi-point tool as shown in Fig. 7.1, unlike a lathe, which uses a single point cutting tool. The tool used in milling is called the milling cutter.Fig. 7.1Schematic diagram of a milling operationThe milling process is characterised by:(i)Interrupted cutting Each of the cutting edges removes materialfor only a part of the rotation of the milling cutter. As a result, the cutting edge has time to cool before it again removes material.Thus the milling operation is much more cooler compared to the turning operation. This allows for a much larger material rates.(ii)Small size of chips Though the size of the chips is small, in view of the multiple cutting edges in contact a large amount of material is removed and as a result the component is generally completed ina single pass unlike the turning process which requires a largenumber of cuts for finishing.(iii)Variation in chip thickness This contributes to the non-steady state cyclic conditions of varying cutting forces during the contact of the cutting edge with the chip thickness varying from zero to maximum size or vice versa. This cyclic variation of the force can excite any of the natural frequencies of the machine tool system and is harmful to the tool life and surface finish generatedA milling machine is one of the most versatile machine tools. It is adaptable for quantity production as well as in job shops and tool rooms. The versatility of milling is because of the large variety of accessories and tools available with milling machines. The typical tolerance expected from the process is about ±0.050 mm.7.2 TYPES OF MILLING MACHINESTo satisfy various requirements milling machines come in a number of sizes and varieties. In view of the large material removal ratesmilling machines come with a very rigid spindle and large power. The varieties of milling machines available are:(i) Knee and Column type(a) horizontal(b) vertical(c) universal(d) turret typeThese are the general purpose milling machines, which have a high degree of flexibility and are employed for all types of works including batch manufacturing. A large variety of attachments to improve the flexibility are available for this class of milling machines.(ii) Production (Bed) type(a) simplex(b) duplex(c) triplexThese machines are generally meant for regular production involving large batch sizes. The flexibility is relatively less in these machines which is suitable for productivity enhancement.(iii) Plano millersThese machines are used only for very large workpieces involving table travels in meters.(iv) Special type(a) Rotary table(b) Drum type(c) Copy milling (Die sinking machines)(d) Key way milling machines(e) Spline shaft milling machinesThese machines provide special facilities to suit specific applications that are not catered to by the other classes of milling machines.7.2.1 Knee and Column Milling MachinesThe knee(升降台) and column type is the most commonly used machine in view of its flexibility and easier setup. A typical machine construction is shown in Fig. 7.2 for the horizontal axis. The knee houses the feed mechanism and mounts the saddle and table. The table basically has the T-slots running along the X-axis for the purpose of work holding. The table moves along the X-axis on the saddle while the saddle moves along the Y-axis on the guide ways provided on the knee.The feed is provided either manually with a hand wheel or connected for automatic by the lead screw, which in turn is coupled to the main spindle drive. The knee can move up and down (Z-axis) on a dovetail provided on the column.Fig. 7.2 Horizontal knee and column type milling machineThe massive column at the back of the machine houses all the power train including the motor and the spindle gearbox. The power for feeding the table lead screw is taken from the main motor through a separate feed gearbox. Sometimes a separate feed motor is provided for the feed gearbox as well.While the longitudinal and traverse motions are provided with automatic motion, the raising of the knee is generally made manually.The spindle is located at the top end of the column. The arbour used to mount the milling cutters is mounted in the spindle and is provided with a support on the other end to take care of the heavy cutting forces by means of an overarm with bearing. As shown in Fig.7.2 the overarm extends from the column with a rigid design. The spindle nose has the standard Morse taper of the suitable sizedepending upon the machine size.The milling cutters are mounted on the arbour at any desired position, the rest of the length being filled by standard hardened collars of varying widths to fix the position of the cutter. The arbour is clamped in the spindle with the help of a draw bar and then fixed with nuts.Milling machines are generally specified on the following basis:(i) Size of the table, which specifies the actual working area on the table and relates to the maximum size of the workpiece that can be accommodated.(ii) Amount of table travel, which gives the maximum axis movement that is possible.(iii) Horse power of the spindle, which actually specifies the power of the spindle motor used. Smaller machines may come with 1 to 3 hp while the production machines may go from 10 to 50 hp.Another type of knee and column milling machine is the vertical axis type. Its construction is very similar to the horizontal axis type, except for the spindle type and location.The vertical axis milling machine is relatively more flexible (Fig. 7.4) and suitable for machining complex cavities such as die cavities in tool rooms. The vertical head is provided with a swiveling facility in horizontal direction whereby the cutter axis can be swivelled. This isuseful for tool rooms where more complex milling operations are carried out.The spindle is located in the vertical direction and is suitable for using the shank mounted milling cutters such as end mills, In view of the location of the tool, the setting up of the workpiece and observing the machining operation is more convenient.Fig, 7.3 Vertical knee and column type milling machineFig.7.4 Some of the milling operations normally carried out on vertical axis machinesThe universal machine has the table which can be swivelled in a horizontal plane at about 45o to either the left or right. This makes the universal machine suitable for milling spur and helical gears as well as worm gears and cams.7.2.2 Bed Type Milling MachineIn production milling machines it is desirable to increase the metal removal rates. If it is done on conventional machines by increasingthe depth of cut, there is possibility of chatter. Hence another varietyof milling machines named as bed type machines are used which are made more rugged and are capable of removing more material. The ruggedness is obtained as a consequence of the reduction in versatility.The table in the case of bed type machines is directly mounted on the bed and is provided with only longitudinal motion.The spindle moves along with the column to provide the cutting action. Simplex machines (Fig. 7.5) are the ones with only one spindle head while duplex machines have two spindles (Fig. 7.6). The two spindles are located on either side of a heavy workpiece and remove material from both sides simultaneously.Fig. 7.5 Simplex bed type milling machineFig. 7.6 Duplex bed type milling machine7.3 MILLING CUTTERSThere are a large variety of milling cutters available to suit specific requirements. The versatility of the milling machine is contributed toa great extent by the variety of milling cutters that are available.7.3.1 Types of Milling CuttersMilling cutters are classified into various types based on a variety of methods.(i) Based on construction:(a) Solid(b) Inserted tooth typeBased on mounting:(a) Arbor mounted(b) Shank mounted(c) Nose mountedBase on rotation:(a) Right hand rotation (counter clockwise)(b) Left hand rotation (clockwise)Based on helix:(a) Right hand helix(b) Left hand helixMilling cutters are generally made of high speed steel or cemented carbides. The cemented carbide cutters can be of a brazed tip variety or with indexable tips. The indexable variety is more common since it is normally less expensive to replace the worn out cutting edges than to regrind them.Plain milling cutters These are also called slab milling cutters and are basically cylindrical with the cutting teeth on the periphery as shown in Fig. 7.7. These are generally used for machining flat surfaces.Fig. 7.7 Arbor mounted milling cutters for general purposeLight duty slab milling cutters generally have a face width, which is small of the order of 25 mm. They generally have straight teeth and large number of teeth.Heavy duty slab milling cutters come with a smaller number of teeth to allow for more chip space. This allows taking deeper cuts and consequently high material removal rates.Helical milling cutters have a very small number of teeth but a large helix angle. This type of cutter cuts with a shearing action, which can produce a very fine finish. The large helix angle allows the cutter to absorb most of the end load and therefore the cutter enters and leaves the workpiece very smoothly.Side and face milling cutters These have the cutting edges not only onthe face like the slab milling cutters, but also on both the sides. As aresult, these cutters become more versatile since they can be used for side milling as well as for slot milling.Staggered tooth side milling cutters are a variation where the teeth are arranged in an alternate helix pattern. This type is generally used for milling deep slots, since the staggering of teeth provides for greater chip space.Another variation of the side and face cutter is the half side milling cutter, which has cutting edges only on one side. This arrangement provides a positive rake angle and is useful for machining on only one side. These have a much smoother cutting action and a long tool life. The power consumed is also less for these cutters.Fig. 7.8Special forms of arbor mounted milling cuttersSlitting saws The other common form of milling cutters in the arbor mounted category is the slitting saw. This is very similar to a saw blade inappearance as well as function. Most of these have teeth around the circumference while some have side teeth as well. The thickness of these cutters is generally very small and is used for cutting off operations or for deep slots.Special form cutters In addition to the general type of milling cutters described above, there are a large number of special form milling cutters available which are used for machining specific profiles.Angular milling cutters are made in single or double angle cutters for milling any angle such as 30, 45 or 60o Form relieved cutters are made of various shapes such as circular, corner rounding, convex or concave shapes.T-slot milling cutters are used for milling T-slots such as those in the milling machine table. The central slot is to be milled first using an end mill before using the T-slot milling cutter. Woodruff key seat milling cutters are used for milling as the name suggests, woodruff key seats Some other special form cutters are dovetail milling cutters and gear milling cutters.End mills These are shank mounted as shown in Fig. 7.9 and are generally used in vertical axis milling machines. They are used for milling slots, key ways and pockets where other type of milling cutters cannot be used. A depth of cut of almost half the diameter can be taken with the end mills.The end mills have the cutting edge running through the length of the cutting portion as well as on the face radially up to a certain length. The helix angle of the cutting edge promotes smooth and efficient cutting even at high cutting speeds and feed rates. High cutting speeds(转速?) are generally recommended for this type of milling cutters.Fig. 7.9 Shank mounted milling cutters and various types of end mills There are a large variety of end mills. One of the distinctions is based on the method of holding, i.e., the end mill shank can be straight or tapered. The straight shank is used on end mills of small size and held in the milling machine spindle with the help of a suitable collet. The tapered shank can be directly mounted in the spindle with the help of the selfholding taper. If the taper is small compared to the spindle taper, then an adopter accommodating both the tapers is used.The end teeth of the end mills may be terminated at a distance from the cutter center or may proceed till the center (Fig. 7.9 f). Those with the cutting edge up to the center are called slot drills or end cutting end mills since they have the ability to cut into the solid material (Fig. 7.9 g). The other type of end mills which have a larger number of teeth cannot cut into solid material and hence require a pilot hole drilled before a pocket is machined.The cutting edge along the side of an end mill is generally straight and sometimes can be tapered by grinding on a tool and cutter grinder such that the draft required for mould and die cavities can be automatically generated.。

毕业设计(论文)外文资料翻译

毕业设计(论文)外文资料翻译

1、外文原文(复印件)2、外文资料翻译译文节能智能照明控制系统Sherif Matta and Syed Masud Mahmud, SeniorMember, IEEE Wayne State University, Detroit,Michigan 48202Sherif.Matta@,smahmud@摘要节约能源已成为当今最具挑战性的问题之一。

最浪费能源的来自低效利用的电能消耗的人工光源设备(灯具或灯泡)。

本文提出了一种通过把人工照明的强度控制到令人满意的水平,来节约电能,并且有详细设计步骤的系统。

在白天使用照明设备时,尽可能的节约。

当记录超过预设的照明方案时,引入改善日光采集和控制的调光系统。

设计原理是,如果它可以通过利用日光这样的一种方式,去控制百叶窗或窗帘。

否则,它使用的是人工建筑内部的光源。

光通量是通过控制百叶窗帘的开启角度来控制,同时,人工光源的强度的控制,通过控制脉冲宽度来调制(PWM)对直流灯的发电量或剪切AC灯泡的AC波。

该系统采用控制器区域网络(CAN),作为传感器和致动器通信用的介质。

该系统是模块化的,可用来跨越大型建筑物。

该设计的优点是,它为用户提供了一个单点操作,而这个正是用户所希望的光的亮度。

该控制器的功能是确定一种方法来满足所需的最小能量消耗光的量。

考虑的主要问题之一是系统组件的易于安装和低成本。

该系统显示出了显著节省的能源量,和在实际中实施的可行性。

关键词:智能光控系统,节能,光通量,百叶帘控制,控制器区域网络(CAN),光强度的控制一简介多年来,随着建筑物的数量和建筑物房间内的数量急剧增加,能源的浪费、低效光控制和照明分布难以管理。

此外,依靠用户对光的手动控制,来节省能源是不实际的。

很多技术和传感器最近已经向管理过多的能量消耗转变,例如在一定区域内的检测活动采用运动检测。

当有人进入房间时,自动转向灯为他们提供了便利。

他们通过在最后人员离开房间后不久关闭转向灯来减少照明能源的使用。

毕业设计外文翻译

毕业设计外文翻译

机电工程学院机电工程学院毕业设计外文资料翻译设计题目: 升降横移立体车库的设计译文题目: 鲁棒性的多层停车场车辆火学生姓名:黄幸福学号: 201215010616专业班级:机制P1203指导教师:巴文兰正文:外文资料译文附件:外文资料原文鲁棒性的多层停车场车辆火灾摘要:最近的研究在结构受火都集中在个别结构成员,子框架构成,或整个结构,暴露于火的鲁棒性问题的可能损失列得到了更少的关注。

本文关心的现实的造型是一个多层停车场车辆火灾场景发生在一个内部列,重点是给定的地板系统的鲁棒性和延性的响应柱屈曲后屈曲。

为了解决这个问题,一个详细的传热分析,根据拟议的火灾场景进行,以获得实际的温度分布的结构。

为后续的结构分析,以不同的造型,混合两结构模型的建立,即详细的平板模型和简化的计算模型。

动态的分析,以跟踪潜在的动态影响,其中的非弹性的联合响应被认为是详细的鲁棒性评估的目的。

基于所进行的非线性分析,三个主要的故障模式,特别是单跨故障,双跨故障,剪切破坏,被确定,这可能会引发逐步崩溃。

最后,动态效果随着火灾下柱屈曲的意义进行评估,如发现实际的延性需求下降两个理想的极端情况之间,即“静态列损失'和'柱突然损失。

关键词:数值模拟; 多层停车场; 火; 鲁棒性; 延性; 逐步崩溃.1、前言在未受保护的钢/复合停车场开发的车辆火灾会导致附近的结构元素(连接,梁和列)的严重加热。

这可能导致显著减少局部承载能力的一个或两个列,随后失去全球稳定的结构,相应的机制可以被称为“火诱导进步的崩溃”。

在过去的几十年里,公众对建筑物安全的不稳定和崩溃的认识已显著上升。

1968点的伦敦罗南公寓楼倒塌事件引发了全世界对这一崩溃机制的关注。

世界贸易中心2001服务失败带来的连续倒塌后脱颖而出的问题,即使认为这些故障是完全不相称的启动事件。

虽然已经有更少的整体破坏,直接引起车辆火灾(即在其他极端负载条件的情况下),这是评价汽车公园在局部火灾影响柱和眼前的地板区域固有的鲁棒性的一个相当多的利益。

毕业设计外文翻译资料

毕业设计外文翻译资料

外文翻译资料院校:xx大学土木工程系专业:土木工程层次:本科形式:函授年级:2008级姓名:xx指导:xxPRESCRIPTIVE METHOD FOR RESIDENTIAL COLD-FORMEDSTEEL FRAMINGSecond EditionPrepared forThe U.S. Department of Housingand Urban DevelopmentOffice of Policy Development and ResearchWashington, DCCo-Sponsored byThe American Iron and Steel InstituteWashington, DCandThe National Association of Home BuildersWashington, DCbyNAHB Research Center, Inc.400 Prince George's BoulevardUpper Marlboro, MD 20774-8731August 1997CONTENTS5.0 STEEL FLOOR FRAMING (21)5.1 Floor Construction (21)5.2 Floor to Foundation or Bearing Wall Connection (21)5.3 Allowable Joist Spans (21)5.4 Joist Bracing (21)5.5 Floor Cantilevers (22)5.6 Splicing (22)5.7 Framing of Floor Openings (22)5.8 Floor Trusses (22)5.0 STEEL FLOOR FRAMING5.1 Floor ConstructionCold-formed steel framing members shall comply with the provisions of Section 2.0. Steel floors shall be constructed in accordance with this section and Figure 5.1.5.1.1 Applicability LimitsThe applicability limits of Section 1.3 and Table 1.1 shall apply.5.1.2 In-Line Framing.Load bearing steel floor framing, wall framing, and ceiling/roof framing shall be constructedin-line with the vertical load bearing members (i.e. studs) located below. A maximum tolerance of 3/4 inch (19 mm) between the centerlines of the in-line members shall be permitted in accordance with Figure 1.2.5.2 Floor to Foundation or Bearing Wall ConnectionCold-formed steel floor framing shall be anchored to foundations, wood sills, or load bearing walls in accordance with Table 5.1 and Figures 5.1 through 5.10. Fastening of steel joists to other framing members shall be in accordance with Table 5.2.5.3 Allowable Joist SpansThe clear span of cold-formed steel floor joists shall not exceed the limits set forth in Table 5.3 for single spans and Table 5.4 for multiple spans. When continuous joist members are used for multiple spans, the interior bearing supports shall be located within two feet (0.6 m) of mid-span of the steel joists, and the individual spans shall not exceed the applicable spans in the table. Floor joists shall have a bearing support length of not less than 1.5 inches (38 mm) for exterior wall supports and 3.5 inches (89 mm) for interior wall supports. Bearing stiffeners shall be installed at each joist bearing location in accordance with Section 2.9. The thickness of joist tracks shall be a minimum of 33 mils (0.84 mm) thick except when used as part of floor header or trimmer in accordance with Section 5.7.5.4 Joist BracingThe top flanges of floor joists shall be laterally braced by the application of floor fastened to the joists in accordance with Table 5.2. Floor joists with spans that exceed 12 feet (3.7 m) shall have the bottom flanges laterally braced in accordance with one of the following:1. Gypsum board installed with minimum#6 screws in accordance withtheapplicable building code, or2. Continuous steel strapping installed in accordance with Figure 5.1 and 5.2.Steel straps shall be at least 1-1/2 inches (38 mm) in width and 33 mils(0.84 mm) in thickness. Straps shall be fastened to the bottom flange ofeach joist with at least one #8 screw and shall be fastened to blocking withat least two #8 screws. Blocking or bridging (X-bracing) shall be installedbetween joists at a maximum spacing of 12 feet (3.7m) measured along thecontinuous strapping (perpendicular to the joist run). Blocking orbridging shall also be located at the termination of all straps.5.5 Floor CantileversFloor cantilevers for the second floor of a two-story building or the first floor of a one-story building shall not exceed 24 inches (610 mm) as illustrated in Figure 5.1. Cantilevers shall support interior floor loading only. Cantilevers, not exceeding 24 inches (610 mm) and supporting one floor and roof (first floor of a two story building), shall be permitted provided that all cantilevered joists are doubled (nested or back-to-back). The doubled cantilevered joists shall extend a minimum of 6 feet (1.8 m) toward the inside and shall be fastened with a minimum of two #8 screws spaced at 24 inches (610 mm) on center through the webs (for back-to-back) or flanges (for nested joists). Approved design is required for cantilevered areas supporting uniform live loads greater than 40 psf (1.92 kN/m2).5.6 SplicingJoists and other structural members shall not be spliced without an approved design. Splicing of tracks shall conform with Figure 5.11.5.7 Framing of Floor OpeningsOpenings in floors shall be framed with header and trimmer joists. Header joist spans shall not exceed 8 feet (2.4 m) in length. Header and trimmer joists shall be fabricated from joist and track sections, which shall be of a minimum size and thickness as the adjacent floor joists and shall be installed in accordance with Figures 5.1, 5.12, and 5.13. Each header joist shall be connected to trimmer joists with a minimum of four 2 inch x 2 inch (51 mm x 51 mm) clip angles. Each clip angle shall be fastened to both the header and trimmer joists with four #8 screws evenly spaced on each leg of the clip angle. The clip angles shall have a thickness not less than that of the floor joist.5.8 Floor TrussesCold-formed steel floor trusses shall be designed, braced, and installed in accordance with an approved design. Truss members shall not be notched, cut, or altered in any manner unless by an approved design. All trusses shall be aligned with load carrying members (i.e. studs) in the wall. Refer to AISI publication RG-9518 [17] “Design Guide For Cold-Formed Steel Trusses” for additional guidance.Table 5.1For SI: 1 inch = 25.4 mm, 1 psf = 0.0479 kN/m2, 1 mph = 1.61 km/hr, 1 foot = 0.3m. 1Use the highest of the wind speed and exposure or the seismic requirements for a given site.2All screw sizes shown are minimumTable 5.2Floor Fastening Schedule1For SI: 1 inch = 25.4 mm1All screw sizes shown are minimum.2 Head styles shall be bugle-head, flat-head, or similar with a minimum head diameter of 0.29 inch(7 mm).Allowable Spans For Cold-Formed Steel Floor Joists1,2,3,4Single Span33 ksi SteelFor SI: 1 inch = 25.4 mm, 1 psf = 0.0479 kN/m2, 1 foot = 0.3m.1Table provides the maximum clear span in feet and inches.2Bearing stiffeners shall be installed at all support points and concentrated loads. 3Deflection criteria: L/480 for live loads; L/240 for total loads.4Floor dead load = 10 psf (0.479 kN/m2)5 For actual size refer to Table 2.1.Allowable Spans For Cold-Formed Steel Floor Joists1,2,3,4,5,6Multiple Spans33 ksi SteelFor SI: 1 inch = 25.4 mm, 1 psf = 0.0479 kN/m2, 1 foot = 0.3m.1 Table provides the maximum clear span in feet and inches to either side of the interior support.2Interior bearing supports for multiple span joists shall consist of structural (bearing) walls or beams.3Bearing stiffeners shall be installed at all support points and concentrated loads.4Deflection criteria: L/480 for live loads; L/240 for total loads.5Floor dead load = 10 psf (0.479 kN/m2)6Interior supports shall be located within two feet (610 mm) of mid span provided that each of the resulting spans does not exceed the appropriate maximum span shown in the table above.7For actual size refer to Table 2.1.冷弯型钢框架结构设计方法第二版为美国住房发展政策开发部门和华盛顿研究中心所准备由美国华盛顿钢铁研究所联合主办国家建筑协会,华盛顿NAHB研究中心,乔治王子的大道400号Marlboro.MD 20774-87311997.8目录5.0 钢楼板结构 (21)5.1 楼板结构 (21)5.2 楼板与基础或承重墙连接 (21)5.3安装托梁的允许间距 (21)5.4托梁支撑 (21)5.5 悬臂楼板 (22)5.6 接合 (22)5.7开洞楼板框架 (22)5.8 楼板桁架 (22)5.0钢楼板结构5.1 建筑楼板冷弯钢结构应该符合2.0部分提供的要求。

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本科生毕业设计 (论文)
外文翻译
原文标题
Worlds Collide:
Exploring the Use of Social Media Technologies for
Online Learning
译文标题
世界的碰撞:
探索社交媒体技术在在线学习的应用
作者所在系别计算机科学与工程系作者所在专业计算机科学与技术作者所在班级
作者姓名
作者学号
指导教师姓名
指导教师职称讲师
完成时间2013年2月
北华航天工业学院教务处制
注:1. 指导教师对译文进行评阅时应注意以下几个方面:①翻译的外文文献与毕业设计(论文)的主题是否高度相关,并作为外文参考文献列入毕业设计(论文)的参考文献;②翻译的外文文献字数是否达到规定数量(3 000字以上);③译文语言是否准确、通顺、具有参考价值。

2. 外文原文应以附件的方式置于译文之后。

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