MEASUREMENT OF TEMPERATURE AND HUMIDITY USING
SHT11/71 INTELLIGENT SENSOR
Assist. Prof. Grisha Spasov, PhD, BSc Nikolay Kakanakov Department of Computer Systems, Technical University – branch Plovdiv, 25, “Tzanko
Djustabanov” Str., 4000 Plovdiv, Bulgaria, +359 32 659 576, e-mail: gvs@tu-plovdiv.bg,
kakanak@tu-plovdiv.bg
Keywords: temperature and humidity measurements, intelligent sensors, distributed automation and control
The paper discusses the advantages of intelligent sensors. It presents an SHT11/71 temperature and humidity combined sensor from Sensirion. This sensor is ideal for developing distributed embedded systems for monitoring environmental parameters.
An example application using this sensor is added to present SHT11/71 in real working condition. The application is distributed system for monitoring temperature and humidity. It uses a microcontroller with integrated web server to organize the communication and management of sensors. This application is realized and tested.
1. INTRODUCTION
Measurement and control of temperature and relative humidity has significant appliance in industry, science, healthcare agriculture and controlling technological processes. These two environmental parameters strongly influence each other and it is critical in some application to measure them in parallel. Using modern technologies it is possible to combine temperature measurement element, humidity measurement element, amplifier, ADC, digital interface, calibration memory and CRC calculation logic in a single chip with very small size [1,3].
Using intelligent sensors of this kind can shorten the development time and cost. Integrating ADC and amplifier into sensor’s chip allow developers to optimize sensor elements for accuracy and long-term stability. And that is not all – integrating digital interface logic simplifies connectivity and management of sensors. These advantages can reduce whole time-to-market time and even price [1,3].
In presented paper we use SHT11/71 intelligent sensor from Sensirion as an example and present its advantages and measurement procedures. An example application is also presented to demonstrate its work in real conditions. This application is realized and tested.
2. INTELIGENT SENSORS – SHT11/71
SHT11/71 is a single chip relative humidity and temperature multi sensor module comprising a calibrated digital output. The device includes a capacitive polymer sensing element for relative humidity and a bandgap temperature sensor. Both are seamlessly coupled to a 14bit ADC and a serial interface circuit on the same chip. This results in high signal quality, a fast response time and insensitivity to external disturbances (EMC). Each SHT11/71 is individually calibrated and calibration coefficients are programmed into the OTP memory. The 2-wire serial interface and internal voltage regulation allow easy and fast system integration [1].
The SHT11/71 is shown on fig. 1 [1].
Combining temperature and humidity sensing elements in single unit enables precise determination of dewpoint, without incurring errors due to temperature gradients between elements. The signal amplification near the sensor allows the polymer layers to be optimized not for signal strengths, but rather for long-term stability. Performing analog-to-digital conversion “in place” makes the signal extremely insensitive to noise. A checksum generated by the chip itself is used for additional reliability. The calibration data loaded on the chip memory guarantees that humidity sensors have identical specifications and thus they are 100% replaceable [1].
Some of the advanced functions of the SHT11/71 are available trough the status register. Some of them are: internal heating element; regulation of measurement resolution to optimize for precision or for fast response; End-Of-Battery (EOB) detection (low voltage detection). Status register size is 8 bits but only four of them are used [1].
SHT11/71 can be connected directly to any microcontroller by means of the digital 2-wire interface. This interface is optimized for sensor readout and power consumption and is not compatible with I2C interfaces [1]. (See fig. 2)
Two wires are used to transfer serial clock (SCK) and data (DATA). The SCK is used to synchronize the communication between a microcontroller and the SHT11/71. Since the interface consists of fully static logic there is no minimum frequency. The DATA tristate pin is used to transfer data in and out of the module. It changes after the falling edge and is valid on the rising edge of the SCK. During the transmission the DATA line must remain stable while SCK is high [1].
Signals over the two lines during an example transmission are shown on fig. 3 [1].
3. MEASUREMENT OF TEMPERATURE AND RELATIVE HUMIDITY
A measurement using SHT11/71 is a two-step procedure. First, it is necessary to send command for measurement to the sensor and get the data through the digital interface. Second, it is necessary to convert data from sensor to real physical values and to calculate the temperature compensation of the humidity data [1].
3.1 Sending a command and receiving data
To initiate a transmission, a “transmission start” sequence has to be issued. It consists of a lowering of the DATA line while SCK is high, followed by a low pulse on SCK and raising DATA again while SCK is still high [1].
The subsequent command consists of three address bits (only .000. is currently supported) and five command bits. The SHT11/71 indicates the proper reception of a command by pulling the DATA pin low (ACK bit) after the falling edge of the 8th SCK clock. The DATA line is released (and goes high) after the falling edge of the 9th SCK clock. Two bytes of measurement data and one byte of CRC checksum are transmitted. The μC must acknowledge each byte by pulling the DATA line low. All values are MSB first, right justified. Possible commands are: “get temperature”, “get humidity”, “change measurement resolution”, “get status register value”, “set status register value” [1].
Communication terminates after the acknowledge bit of the CRC data. If CRC-8 checksum is not used the controller may terminate the communication after the measurement data LSB by keeping ACK high. The device automatically returns to sleep mode after the measurement and communication have ended. [1]
3.2 Converting Output to Physical Values
To compensate for non-linearity of humidity sensing element and to obtain the full accuracy it is recommended to convert the readout with the following formula [1,3]:
RH linear = c1 + c2 + c3.SO RH2.
Coefficients c1, c2 and c3 depend only on measurement resolution. For 12bit resolution: c1= – 4, c2= 0.0405 and c3= – 2.8*10-6. For 8bit resolution: c1= – 4, c2= 0.648 and c3= – 7.2*10-4.
For temperatures significantly different from 25°C the temperature coefficient of the humidity sensor should be considered [1,3]:
RH true = (T°C – 25).(t1 + t2 + SO RH) + RH linear ,
where t1 = 0.01 and t2 = 0.00008 for 14bit and t2 = 0.00128 for 8bit resolution [1].
The bandgap PTAT (Proportional To Absolute Temperature) temperature sensor is very linear by design. Use the following formula to convert from digital readout to temperature [1,3]:
Temperature = d1 + d2.SO T.
Since humidity and temperature are both measured on the same monolithic chip, the SHT11/71 allows superb dewpoint measurement.
4. DISTRIBUTED SYSTEM FOR MONITORING TEMPERATURE AND HUMIDITY
On the figure 4 below a functional scheme of distributed system for monitoring temperature and humidity, based on IPC@Chip is shown [2,4].
The functions of the system are separated between the four main blocks, as follows [2,5]:
?The internet browser assures that the system has a familiar user interface.
The visualization of the monitored parameters is placed here.
?The integrated Web server in conjunction with the CGI deals with the control of the remote processes and the transfer of dynamic HTML pages to the client. The real-time operating system (RTOS) of the IPC@Chip manages with the Web server’s tasks, TCP/IP communication, local peripherals, user tasks and interconnection between them.
?Users’ applications and tasks, running on the controller, are used for automation purposes. In our case, this is the sensor driving and management of the SMS communication.
The software of this system consists of several blocks. One block is for temperature and humidity measurement, one – for communication with the GSM gateway and sending SMS and one is for generating dynamic HTML documents with the data from the sensor.
Before every measurement a software restarting of the sensor’s interface take place. After that an initialization command is sent and controller waits 11ms. After this procedure a real measurement can start. The measurement block consists of two identical parts, one – for temperature measurement and one – for humidity measurement. The microcontroller sends a command to the sensor to get data. After getting data μC normalizes and stores it in the operating memory. The two identical parts are executed sequentially and are repeated together. Between every two iterations of this cycle the task “sleeps” for about one minute to free the processor for tasks with low priority (like FTP, Web, Telnet).
The communication between the controller and the sensor is trough 2-line interface (data and synchronization). A C-library based on the software interrupts of the RTOS is made for this communication. This library has the following functions:?shttransstart() – starts a transmission;
?shtreset() – for restarting of the sensor;
?shtinit() – initializes the sensor interface;
?shtsend() – sends a command;
?shtrecv() – receives data from sensor.
These functions are used to control the sensor’s work trough the 2-wire interface and to get temperature and humidity data. This data is stored in the controller memory and then converted using formulas for non-linearity and temperature compensation.
To see the results of the measurement the client sends a HTTP request to the web server and the server sends a HTML document as a reply. CGI is the instrument that connects the web server with the internal data on the controller. It runs as a task and do not use data received from the client, but rather uses data from the measurement block. This transfer of data is carried out with a block of shared memory. The measurement block writes data in this memory and the CGI task reads and use this data. It generates a short HTML document containing the temperature and humidity values from the last measurement.
Example web document sent as a reply from the integrated web server with the results is shown on figure 5.
For controlling the parallel execution of these tasks a small program is written. This program read initialization data from files on the controller memory, installs and uninstalls the CGI processes, declares a semaphore from RTOS and frees it, releases the unused memory and stops the unneeded tasks. The other purpose of this program is to allow adding a security to the project using identification and authorization [2].
5. CONCLUSIONS AND FUTURE WORK
Intelligent sensors with their advantages like combining temperature and humidity sensing elements, integrating ADC, amplifiers and serial interface make development of measurement systems easier. These advantages also decrease development time and cost and the size of the product. One application where these sensors find place are distributed measurement and monitoring systems like meteorological stations, HVAC systems, automotive temperature control and many others.
The SHT11/71 has an address of 3bits, which in present sensors cannot be changed from “000”. This address can be used for future applications like sensor networks and adhoc sensor networks which are leading tendencies in automation and control technologies.
6. REFERENCES
[1] https://www.doczj.com/doc/7312425557.html,/sensors/humidity/ – SHT71 datasheets and info.
[2] Spasov G., Kakanakov N. – CGI-based applications for distributed embedded systems for monitoring temperature and humidity, CompSysTech’04, 17-18 June 2004, Rousse, Bulgaria
[3] https://www.doczj.com/doc/7312425557.html,/sensors/ – measurement technology.
[4] https://www.doczj.com/doc/7312425557.html, – IPC@Chip info and applications.
[5] Djiev, S. – Communication Networks in controlling systems, Automation and Informatics, No.2, pp 13-17, 2003.
华北电力大学科技学院 毕业设计（论文）附件 外文文献翻译 学号：121912020115姓名：彭钰钊 所在系别：动力工程系专业班级：测控技术与仪器12K1指导教师：李冰 原文标题：Infrared Remote Control System Abstract 2016 年 4 月 19 日
红外遥控系统 摘要 红外数据通信技术是目前在世界范围内被广泛使用的一种无线连接技术，被众多的硬件和软件平台所支持。红外收发器产品具有成本低，小型化，传输速率快，点对点安全传输，不受电磁干扰等特点，可以实现信息在不同产品之间快速、方便、安全地交换与传送，在短距离无线传输方面拥有十分明显的优势。红外遥控收发系统的设计在具有很高的实用价值，目前红外收发器产品在可携式产品中的应用潜力很大。全世界约有1亿5千万台设备采用红外技术，在电子产品和工业设备、医疗设备等领域广泛使用。绝大多数笔记本电脑和手机都配置红外收发器接口。随着红外数据传输技术更加成熟、成本下降，红外收发器在短距离通讯领域必将得到更广泛的应用。 本系统的设计目的是用红外线作为传输媒质来传输用户的操作信息并由接收电路解调出原始信号，主要用到编码芯片和解码芯片对信号进行调制与解调，其中编码芯片用的是台湾生产的PT2262，解码芯片是PT2272。主要工作原理是：利用编码键盘可以为PT2262提供的输入信息，PT2262对输入的信息进行编码并加载到38KHZ的载波上并调制红外发射二极管并辐射到空间，然后再由接收系统接收到发射的信号并解调出原始信息，由PT2272对原信号进行解码以驱动相应的电路完成用户的操作要求。 关键字：红外线；编码；解码；LM386；红外收发器。 1 绪论
中等分辨率制备分离的 快速色谱技术 W. Clark Still,* Michael K a h n , and Abhijit Mitra Departm(7nt o/ Chemistry, Columbia Uniuersity,1Veu York, Neu; York 10027 ReceiLied January 26, 1978 我们希望找到一种简单的吸附色谱技术用于有机化合物的常规净化。这种技术是适于传统的有机物大规模制备分离，该技术需使用长柱色谱法。尽管这种技术得到的效果非常好，但是其需要消耗大量的时间，并且由于频带拖尾经常出现低复原率。当分离的样本剂量大于1或者2g时，这些问题显得更加突出。近年来，几种制备系统已经进行了改进，能将分离时间减少到1-3h，并允许各成分的分辨率ΔR f≥（使用薄层色谱分析进行分析）。在这些方法中，在我们的实验室中，媒介压力色谱法1和短柱色谱法2是最成功的。最近，我们发现一种可以将分离速度大幅度提升的技术，可用于反应产物的常规提纯，我们将这种技术称为急骤色谱法。虽然这种技术的分辨率只是中等（ΔR f≥），而且构建这个系统花费非常低，并且能在10-15min内分离重量在的样本。4 急骤色谱法是以空气压力驱动的混合介质压力以及短柱色谱法为基础，专门针对快速分离，介质压力以及短柱色谱已经进行了优化。优化实验是在一组标准条件5下进行的，优化实验使用苯甲醇作为样本，放在一个20mm*5in.的硅胶柱60内，使用Tracor 970紫外检测器监测圆柱的输出。分辨率通过持续时间（r）和峰宽（w,w/2）的比率进行测定的（Figure 1），结果如图2-4所示，图2-4分别放映分辨率随着硅胶颗粒大小、洗脱液流速和样本大小的变化。
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文献信息： 文献标题：Challenges and opportunities affecting the future of human resource management（影响人力资源管理未来的挑战和机遇） 国外作者：Dianna L. Stone，Diana L. Deadrick 文献出处：《Human Resource Management Review》, 2015, 25(2):139-145 字数统计：英文3725单词，21193字符；中文6933汉字 外文文献： Challenges and opportunities affecting the future of human resource management Abstract Today, the field of Human Resource Management (HR) is experiencing numerous pressures for change. Shifts in the economy, globalization, domestic diversity, and technology have created new demands for organizations, and propelled the field in some completely new directions. However, we believe that these challenges also create numerous opportunities for HR and organizations as a whole. Thus, the primary purposes of this article are to examine some of the challenges and opportunities that should influence the future of HR. We also consider implications for future research and practice in the field. Keywords: Future of human resource management, Globalization, Knowledge economy Diversity, Technology 1.Change from a manufacturing to a service or knowledge economy One of the major challenges influencing the future of HR processes is the change from a manufacturing to a service or knowledgebased economy. This new economy is characterized by a decline in manufacturing and a growth in service or knowledge as the core of the economic base. A service economy can be defined as a system based on buying and selling of services or providing something for others (Oxford
文献翻译 原文 Combining JSP and Servlets The technology of JSP and Servlet is the most important technology which use Java technology to exploit request of server, and it is also the standard which exploit business application .Java developers prefer to use it for a variety of reasons, one of which is already familiar with the Java language for the development of this technology are easy to learn Java to the other is "a preparation, run everywhere" to bring the concept of Web applications, To achieve a "one-prepared everywhere realized." And more importantly, if followed some of the principles of good design, it can be said of separating and content to create high-quality, reusable, easy to maintain and modify the application. For example, if the document in HTML embedded Java code too much (script), will lead the developed application is extremely complex, difficult to read, it is not easy reuse, but also for future maintenance and modification will also cause difficulties. In fact, CSDN the JSP / Servlet forum, can often see some questions, the code is very long, can logic is not very clear, a large number of HTML and Java code mixed together. This is the random development of the defects. Early dynamic pages mainly CGI (Common Gateway Interface, public Gateway Interface) technology, you can use different languages of the CGI programs, such as VB, C / C + + or Delphi, and so on. Though the technology of CGI is developed and powerful, because of difficulties in programming, and low efficiency, modify complex shortcomings, it is gradually being replaced by the trend. Of all the new technology, JSP / Servlet with more efficient and easy to program, more powerful, more secure and has a good portability, they have been many people believe that the future is the most dynamic site of the future development of technology. Similar to CGI, Servlet support request / response model. When a customer submit a request to the server, the server presented the request Servlet, Servlet responsible for handling requests and generate a response, and then gave the server, and then from the server sent to
五分钟搞定5000字－外文文献翻译 在科研过程中阅读翻译外文文献是一个非常重要的环节，许多领域高水平的文献都是外文文献，借鉴一些外文文献翻译的经验是非常必要的。由于特殊原因我翻译外文文献的机会比较多，慢慢地就发现了外文文献翻译过程中的三大利器：Google“翻译”频道、金山词霸（完整版本）和CNKI“翻译助手"。 具体操作过程如下： 1.先打开金山词霸自动取词功能，然后阅读文献； 2.遇到无法理解的长句时，可以交给Google处理，处理后的结果猛一看，不堪入目，可是经过大脑的再处理后句子的意思基本就明了了； 3.如果通过Google仍然无法理解，感觉就是不同，那肯定是对其中某个“常用单词”理解有误，因为某些单词看似很简单，但是在文献中有特殊的意思，这时就可以通过CNKI的“翻译助手”来查询相关单词的意思，由于CNKI的单词意思都是来源与大量的文献，所以它的吻合率很高。 另外，在翻译过程中最好以“段落”或者“长句”作为翻译的基本单位，这样才不会造成“只见树木，不见森林”的误导。 注： 1、Google翻译：https://www.doczj.com/doc/7312425557.html,/language_tools google，众所周知，谷歌里面的英文文献和资料还算是比较详实的。我利用它是这样的。一方面可以用它查询英文论文，当然这方面的帖子很多，大家可以搜索，在此不赘述。回到我自己说的翻译上来。下面给大家举个例子来说明如何用吧 比如说“电磁感应透明效应”这个词汇你不知道他怎么翻译， 首先你可以在CNKI里查中文的，根据它们的关键词中英文对照来做，一般比较准确。
在此主要是说在google里怎么知道这个翻译意思。大家应该都有词典吧，按中国人的办法，把一个一个词分着查出来，敲到google里，你的这种翻译一般不太准，当然你需要验证是否准确了，这下看着吧，把你的那支离破碎的翻译在google里搜索，你能看到许多相关的文献或资料，大家都不是笨蛋，看看，也就能找到最精确的翻译了，纯西式的！我就是这么用的。 2、CNKI翻译：https://www.doczj.com/doc/7312425557.html, CNKI翻译助手，这个网站不需要介绍太多，可能有些人也知道的。主要说说它的有点，你进去看看就能发现：搜索的肯定是专业词汇，而且它翻译结果下面有文章与之对应（因为它是CNKI检索提供的，它的翻译是从文献里抽出来的），很实用的一个网站。估计别的写文章的人不是傻子吧，它们的东西我们可以直接拿来用，当然省事了。网址告诉大家，有兴趣的进去看看，你们就会发现其乐无穷！还是很值得用的。https://www.doczj.com/doc/7312425557.html, 3、网路版金山词霸（不到1M）：https://www.doczj.com/doc/7312425557.html,/6946901637944806 翻译时的速度： 这里我谈的是电子版和打印版的翻译速度，按个人翻译速度看，打印版的快些，因为看电子版本一是费眼睛，二是如果我们用电脑，可能还经常时不时玩点游戏，或者整点别的，导致最终SPPEED变慢，再之电脑上一些词典（金山词霸等）在专业翻译方面也不是特别好，所以翻译效果不佳。在此本人建议大家购买清华大学编写的好像是国防工业出版社的那本《英汉科学技术词典》，基本上挺好用。再加上网站如：google CNKI翻译助手，这样我们的翻译速度会提高不少。 具体翻译时的一些技巧（主要是写论文和看论文方面） 大家大概都应预先清楚明白自己专业方向的国内牛人，在这里我强烈建议大家仔
Optimum blank design of an automobile sub-frame Jong-Yop Kim a ,Naksoo Kim a,*,Man-Sung Huh b a Department of Mechanical Engineering,Sogang University,Shinsu-dong 1,Mapo-ku,Seoul 121-742,South Korea b Hwa-shin Corporation,Young-chun,Kyung-buk,770-140,South Korea Received 17July 1998 Abstract A roll-back method is proposed to predict the optimum initial blank shape in the sheet metal forming process.The method takes the difference between the ?nal deformed shape and the target contour shape into account.Based on the method,a computer program composed of a blank design module,an FE-analysis program and a mesh generation module is developed.The roll-back method is applied to the drawing of a square cup with the ˉange of uniform size around its periphery,to con?rm its validity.Good agreement is recognized between the numerical results and the published results for initial blank shape and thickness strain distribution.The optimum blank shapes for two parts of an automobile sub-frame are designed.Both the thickness distribution and the level of punch load are improved with the designed blank.Also,the method is applied to design the weld line in a tailor-welded blank.It is concluded that the roll-back method is an effective and convenient method for an optimum blank shape design.#2000Elsevier Science S.A.All rights reserved. Keywords:Blank design;Sheet metal forming;Finite element method;Roll-back method
XXX学院 毕业设计(论文)外文资料翻译 学院：计算机与软件工程学院 专业：计算机科学技术(软件工程方向) 姓名： 学号： 外文出处：GoyKakus.THE RESEARCH OFCUSTOMER RELATIONSHIP MANAGEMENT STRATEGY [J]. International Journal of Management Research & Review, 2017, 1(9): 624-635. 附件： 1.外文资料翻译译文；2.外文原文。 注：请将该封面与附件装订成册。
附件1：外文资料翻译译文 客户关系管理战略研究 Goy Kakus 摘要 客户关系管理解决方案，通过为你提供客户业务数据来帮助你提供客户想要的服务或产品,提供更好的客户服务、交叉销售和更有效的销售,达成交易,保留现有客户并更好地理解你的客户是谁。本文探讨了客户关系管理模型在获得、保持与发展策略方面的优势。然而,我们对其定义和意义还存在一些困惑。本文通过考察关系营销和其他学科方面的相关文献，解释了客户关系管理的概念基础,从而对客户关系管理的知识作出了贡献。 关键词:客户关系管理模型, 客户关系管理的博弈改变者与关键策略 引言 CRM 是客户关系管理的简称。它的特征在于公司与客户的沟通,无论是销售还是服务相关的。客户关系管理这一术语经常用来解释企业客户关系,客户关系管理系统也以同样的方式被用来处理商业联系, 赢得客户,达成合同和赢得销售。 客户关系管理通常被考虑作为一个业务策略，从而使企业能够: *了解客户 *通过更好的客户体验留住客户 *吸引新客户 *赢得新客户和达成合同 *提高盈利 *减少客户管理成本 *通过服务台等工具软件,电子邮件组织者和不同类型的企业应用程序，企业业务经常寻求个性化的在线体验。 设计精良的客户关系管理包括以下特征: 1．客户关系管理是一种以顾客为中心并以客户投入为基础的服务响应，一对一的解决客户的必需品, 买家和卖家服务中心直接在线互动,帮助客户解决他
我国第三方物流中存在的问题、原因及战略选择 熊卫 【摘要】我国物流业发展刚刚起步，第三方物流的理论和实践等方面都比较薄弱。本文指出我国第三方物流存在的问题在于国内外第三方物流企业差距、物流效率不高、缺乏系统性管理、物流平台构筑滞后、物流管理观念落后等。分析了产生上述问题的原因，并提出了精益物流、中小型第三方物流企业价值链联盟、大型第三方物流企业虚拟化战略等三种可供选择的第三方物流企业发展战略。 【关键词】第三方物流；精益物流战略；价值链联盟；虚拟化战略 1引言 长期以来，我国国内企业对采购、运输、仓储、代理、包装、加工、配送等环节控制能力不强，在“采购黑洞”、“物流陷井”中造成的损失浪费难以计算。因此，对第三方物流的研究，对于促进我国经济整体效益的提高有着非常重要的理论和实践意义。本文试图对我国策三方物流存在的问题及原因进行分析探讨，并提出第三方物流几种可行的战略选择。 2我国第三方物流业存在的主要问题 (一)我国策三方物流企业与国外第三方物流企业的差距较大，具体表现在以下几个方面： 1、规模经济及资本差距明显。由于国外的大型第三方物流企业从全球经营的战略出发，其规模和资本优势是毫无疑问的，尤其初创时期的我国策三方物流业，本身的规模就很小，国外巨头雄厚的资本令国内企业相形见绌。 2、我国策三方物流业企业提供的物流服务水准及质量控制远不如国外同行。当国内一些企业还在把物流理解成“卡车加仓库“的时候，国外的物流企业早已完成了一系列标准化的改造。同时，国外的物流组织能力非常强大，例如德国一家第三方物流公司，公司各方面的物流专家遍布欧洲各地。如果有客户的货物需要经达不同的国家，那么欧洲各地的这些专家就在网上设计出一个最佳的物流解决方案。这种提供解决方案的能力就是这第三方物流公司的核心能力，而不像国内公司号称拥有多少条船，多少辆车。 3、我国加入WTO后物流产业的门槛降低。在物流服务业方面：我国承诺所有的服务行业，在经过合理过渡期后，取消大部分外国股权限制，不限制外国服务供应商进入
翻译文献：INVESTIGATION ON DYNAMIC PERFORMANCE OF SLIDE UNIT IN MODULAR MACHINE TOOL （对组合机床滑台动态性能的调查报告） 文献作者：Peter Dransfield, 出处：Peter Dransfield, Hydraulic Control System-Design and Analysis of TheirDynamics, Springer-Verlag, 1981 翻译页数：p139—144 英文译文： 对组合机床滑台动态性能的调查报告 【摘要】这一张纸处理调查利用有束缚力的曲线图和状态空间分析法对组合机床滑台的滑动影响和运动平稳性问题进行分析与研究，从而建立了滑台的液压驱动系统一自调背压调速系统的动态数学模型。通过计算机数字仿真系统，分析了滑台产生滑动影响和运动不平稳的原因及主要影响因素。从那些中可以得出那样的结论，如果能合理地设计液压缸和自调背压调压阀的结构尺寸. 本文中所使用的符号如下： s1-流源，即调速阀出口流量； S el—滑台滑动摩擦力 R一滑台等效粘性摩擦系数： I1—滑台与油缸的质量 12—自调背压阀阀心质量 C1、c2—油缸无杆腔及有杆腔的液容； C2—自调背压阀弹簧柔度； R1, R2自调背压阀阻尼孔液阻， R9—自调背压阀阀口液阻 S e2—自调背压阀弹簧的初始预紧力； I4, I5—管路的等效液感 C5、C6—管路的等效液容： R5, R7-管路的等效液阻； V3, V4—油缸无杆腔及有杆腔内容积； P3, P4—油缸无杆腔及有杆腔的压力 F—滑台承受负载， V—滑台运动速度。本文采用功率键合图和状态空间分折法建立系统的运动数学模型，滑台的动态特性可以能得到显著改善。
Project Budget Monitor and Control Author：Yin Guo-li Nationality：American Derivation：Management Science and Engineering.Montreal: Mar 20, 2010 . With the marketing competitiveness growing, it is more and more critical in budget control of each project. This paper discusses that in the construction phase, how can a project manager be successful in budget control. There are many methods discussed in this paper, it reveals that to be successful, the project manager must concern all this methods. 1. INTRODUCTION The survey shows that most projects encounter cost over-runs (Williams Ackermann, Eden, 2002,pl92). According to Wright (1997)'s research, a good rule of thumb is to add a minimum of 50% to the first estimate of the budget (Gardiner and Stewart, 1998, p251). It indicates that project is very complex and full of challenge. Many unexpected issues will lead the project cost over-runs. Therefore, many technologies and methods are developed for successful monitoring and control to lead the project to success. In this article, we will discuss in the construction phase, how can a project manager to be successful budget control. 2. THE CONCEPT AND THE PURPOSE OF PROJECT CONTROL AND MONITOR Erel and Raz (2000) state that the project control cycle consists of measuring the status of the project, comparing to the plan, analysis of the deviations, and implementing any appropriate corrective actions. When a project reach the construction phase, monitor and control is critical to deliver the project success. Project monitoring exists to establish the need to take corrective action, whilst there is still time to take action. Through monitoring the activities, the project team can analyze the deviations and decide what to do and actually do it. The purpose of monitor and control is to support the implementation of corrective actions, ensure projects stay on target or get project back on target once it has gone off target。
外文文献原稿和译文 原稿 JSP JSP (JavaServer Pages) is initiated by Sun Microsystems, Inc., with many companies to participate in the establishment of a dynamic web page technical standards. JSP technology somewhat similar to ASP technology, it is in the traditional HTML web page document (*. htm, *. html) to insert the Java programming paragraph (Scriptlet) and JSP tag (tag), thus JSP documents (*. jsp). Using JSP development of the Web application is cross-platform that can run on Linux, is also available for other operating systems. JSP technology to use the Java programming language prepared by the category of XML tags and scriptlets, to produce dynamic pages package processing logic. Page also visit by tags and scriptlets exist in the services side of the resources of logic. JSP page logic and web page design and display separation, support reusable component-based design, Web-based application development is rapid and easy. Web server in the face of visits JSP page request, the first implementation of the procedures of, and then together with the results of the implementation of JSP documents in HTML code with the return to the customer. Insert the Java programming operation of the database can be re-oriented websites, in order to achieve the establishment of dynamic pages needed to function. JSP and Java Servlet, is in the implementation of the server, usually returned to the client is an HTML text, as long as the client browser will be able to visit. JSP pages from HTML code and Java code embedded in one of the components. The server was in the pages of client requests after the Java code and then will generate the HTML pages to return to the client browser. Java Servlet JSP is the technical foundation and large-scale Web application development needs of Java Servlet and JSP support to
外文文献翻译 1 中文翻译 1.1钢筋混凝土 素混凝土是由水泥、水、细骨料、粗骨料（碎石或；卵石）、空气，通常还有其他外加剂等经过凝固硬化而成。将可塑的混凝土拌合物注入到模板内，并将其捣实，然后进行养护，以加速水泥与水的水化反应，最后获得硬化的混凝土。其最终制成品具有较高的抗压强度和较低的抗拉强度。其抗拉强度约为抗压强度的十分之一。因此，截面的受拉区必须配置抗拉钢筋和抗剪钢筋以增加钢筋混凝土构件中较弱的受拉区的强度。 由于钢筋混凝土截面在均质性上与标准的木材或钢的截面存在着差异，因此，需要对结构设计的基本原理进行修改。将钢筋混凝土这种非均质截面的两种组成部分按一定比例适当布置，可以最好的利用这两种材料。这一要求是可以达到的。因混凝土由配料搅拌成湿拌合物，经过振捣并凝固硬化，可以做成任何一种需要的形状。如果拌制混凝土的各种材料配合比恰当，则混凝土制成品的强度较高，经久耐用，配置钢筋后，可以作为任何结构体系的主要构件。 浇筑混凝土所需要的技术取决于即将浇筑的构件类型，诸如：柱、梁、墙、板、基础，大体积混凝土水坝或者继续延长已浇筑完毕并且已经凝固的混凝土等。对于梁、柱、墙等构件，当模板清理干净后应该在其上涂油，钢筋表面的锈及其他有害物质也应该被清除干净。浇筑基础前，应将坑底土夯实并用水浸湿6英寸，以免土壤从新浇的混凝土中吸收水分。一般情况下，除使用混凝土泵浇筑外，混凝土都应在水平方向分层浇筑，并使用插入式或表面式高频电动振捣器捣实。必须记住，过分的振捣将导致骨料离析和混凝土泌浆等现象，因而是有害的。 水泥的水化作用发生在有水分存在，而且气温在50°F以上的条件下。为了保证水泥的水化作用得以进行，必须具备上述条件。如果干燥过快则会出现表面裂缝，这将有损与混凝土的强度，同时也会影响到水泥水化作用的充分进行。 设计钢筋混凝土构件时显然需要处理大量的参数，诸如宽度、高度等几何尺寸，配筋的面积，钢筋的应变和混凝土的应变，钢筋的应力等等。因此，在选择混凝土截面时需要进行试算并作调整，根据施工现场条件、混凝土原材料的供应情况、业主提出的特殊要求、对建筑和净空高度的要求、所用的设计规范以及建筑物周围环
204/JOURNAL OF BRIDGE ENGINEERING/AUGUST1999
JOURNAL OF BRIDGE ENGINEERING /AUGUST 1999/205 ends.The stress state in each cylindrical strip was determined from the total potential energy of a nonlinear arch model using the Rayleigh-Ritz method. It was emphasized that the membrane stresses in the com-pression region of the curved models were less than those predicted by linear theory and that there was an accompanying increase in ?ange resultant force.The maximum web bending stress was shown to occur at 0.20h from the compression ?ange for the simple support stiffness condition and 0.24h for the ?xed condition,where h is the height of the analytical panel.It was noted that 0.20h would be the optimum position for longitudinal stiffeners in curved girders,which is the same as for straight girders based on stability requirements.From the ?xed condition cases it was determined that there was no signi?cant change in the membrane stresses (from free to ?xed)but that there was a signi?cant effect on the web bend-ing stresses.Numerical results were generated for the reduc-tion in effective moment required to produce initial yield in the ?anges based on curvature and web slenderness for a panel aspect ratio of 1.0and a web-to-?ange area ratio of 2.0.From the results,a maximum reduction of about 13%was noted for a /R =0.167and about 8%for a /R =0.10(h /t w =150),both of which would correspond to extreme curvature,where a is the length of the analytical panel (modeling the distance be-tween transverse stiffeners)and R is the radius of curvature.To apply the parametric results to developing design criteria for practical curved girders,the de?ections and web bending stresses that would occur for girders with a curvature corre-sponding to the initial imperfection out-of-?atness limit of D /120was used.It was noted that,for a panel with an aspect ratio of 1.0,this would correspond to a curvature of a /R =0.067.The values of moment reduction using this approach were compared with those presented by Basler (Basler and Thurlimann 1961;Vincent 1969).Numerical results based on this limit were generated,and the following web-slenderness requirement was derived: 2 D 36,500a a =1?8.6?34 (1) ? ??? t R R F w ?y where D =unsupported distance between ?anges;and F y =yield stress in psi. An extension of this work was published a year later,when Culver et al.(1973)checked the accuracy of the isolated elas-tically supported cylindrical strips by treating the panel as a unit two-way shell rather than as individual strips.The ?ange/web boundaries were modeled as ?xed,and the boundaries at the transverse stiffeners were modeled as ?xed and simple.Longitudinal stiffeners were modeled with moments of inertias as multiples of the AASHO (Standard 1969)values for straight https://www.doczj.com/doc/7312425557.html,ing analytical results obtained for the slenderness required to limit the plate bending stresses in the curved panel to those of a ?at panel with the maximum allowed out-of-?atness (a /R =0.067)and with D /t w =330,the following equa-tion was developed for curved plate girder web slenderness with one longitudinal stiffener: D 46,000a a =1?2.9 ?2.2 (2) ? ? ? t R f R w ?b where the calculated bending stress,f b ,is in psi.It was further concluded that if longitudinal stiffeners are located in both the tension and compression regions,the reduction in D /t w will not be required.For the case of two stiffeners,web bending in both regions is reduced and the web slenderness could be de-signed as a straight girder panel.Eq.(1)is currently used in the ‘‘Load Factor Design’’portion of the Guide Speci?cations ,and (2)is used in the ‘‘Allowable Stress Design’’portion for girders stiffened with one longitudinal stiffener.This work was continued by Mariani et al.(1973),where the optimum trans-verse stiffener rigidity was determined analytically. During almost the same time,Abdel-Sayed (1973)studied the prebuckling and elastic buckling behavior of curved web panels and proposed approximate conservative equations for estimating the critical load under pure normal loading (stress),pure shear,and combined normal and shear loading.The linear theory of shells was used.The panel was simply supported along all four edges with no torsional rigidity of the ?anges provided.The transverse stiffeners were therefore assumed to be rigid in their directions (no strains could be developed along the edges of the panels).The Galerkin method was used to solve the governing differential equations,and minimum eigenvalues of the critical load were calculated and presented for a wide range of loading conditions (bedding,shear,and combined),aspect ratios,and curvatures.For all cases,it was demonstrated that the critical load is higher for curved panels over the comparable ?at panel and increases with an increase in curvature. In 1980,Daniels et al.summarized the Lehigh University ?ve-year experimental research program on the fatigue behav-ior of horizontally curved bridges and concluded that the slen-derness limits suggested by Culver were too severe.Equations for ‘‘Load Factor Design’’and for ‘‘Allowable Stress Design’’were developed (respectively)as D 36,500a =1?4?192(3)? ?t R F w ?y D 23,000a =1?4 ?170 (4) ? ? t R f w ?b The latter equation is currently used in the ‘‘Allowable Stress Design’’portion of the Guide Speci?cations for girders not stiffened longitudinally. Numerous analytical and experimental works on the subject have also been published by Japanese researchers since the end of the CURT project.Mikami and colleagues presented work in Japanese journals (Mikami et al.1980;Mikami and Furunishi 1981)and later in the ASCE Journal of Engineering Mechanics (Mikami and Furunishi 1984)on the nonlinear be-havior of cylindrical web panels under bending and combined bending and shear.They analyzed the cylindrical panels based on Washizu’s (1975)nonlinear theory of shells.The governing nonlinear differential equations were solved numerically by the ?nite-difference method.Simple support boundary condi-tions were assumed along the curved boundaries (top and bot-tom at the ?ange locations)and both simple and ?xed support conditions were used at the straight (vertical)boundaries.The large displacement behavior was demonstrated by Mi-kami and Furunishi for a range of geometric properties.Nu-merical values of the load,de?ection,membrane stress,bend-ing stress,and torsional stress were obtained,but no equations for design use were presented.Signi?cant conclusions include that:(1)the compressive membrane stress in the circumfer-ential direction decreases with an increase in curvature;(2)the panel under combined bending and shear exhibits a lower level of the circumferential membrane stress as compared with the panel under pure bending,and as a result,the bending moment carried by the web panel is reduced;and (3)the plate bending stress under combined bending and shear is larger than that under pure bending.No formulations or recommendations for direct design use were made. Kuranishi and Hiwatashi (1981,1983)used the ?nite-ele-ment method to demonstrate the elastic ?nite displacement be-havior of curved I-girder webs under bending using models with and without ?ange rigidities.Rotation was not allowed (?xed condition)about the vertical axis at the ends of the panel (transverse stiffener locations).Again,the nonlinear distribu-