Design of Data Acquisition System for Vehicle Based on CAN Bus

To the question that a meter is correspond with a set of lead and a sensor,this paper presents a design of data acquisition system for vehicle based on CAN bus.In this way,the combinatorial instrument is only connected by a bus unit.Author introduces the data acquisition structure chart and the CAN interface,analyzes the software by program flow chart,and shows it's application for vehicle virtual instrument.A method of calculating vehicle speed,engine rotate speed and the course of development mileage are also given.     

Research on Cooperative Design Network Security Based on IP-VPN

As the important method and instrument of agile manufacture,the technology of distributed collaborative design and manufacturing has become the hotspot of manufacturing. The basic concept and key technologies of IP_VPN are introduced in this paper,and a collaborative design network model based on IP_VPN is presented. Distributed collaborative design is a multi_user,multitask involved system, which is consisted of lots of collaborative processs,so the network security is the key of distributed collaborative design. We research on the security of collaborative design network based on IP_VPN, hence get a conclusion:we can construct an economical?practical and secure collaborative design network system by the application of data encryption,user authentication and access control based on the role,etc.     

Opportunities and Challenges in Chinese Housing Industry

This article studies the opportunities and challenges in housing industry in China and proposes its development tendency.     

地下热水的来源与补给机制分析——以重庆北温泉为例

地下热水的来源研究对地下热水资源量评价和可持续开发利用有重要意义。选取重庆市北温泉作为研究对象,采用水化学分析、D、O同位素以及实时在线监测对其热水来源进行了研究。研究认为：重庆市北温泉泉水为中-低温浅层中性地热水,水化学类型为SO4-Ca型,地下热水的δ 18O值为-8.48‰～-7.09‰,δD值为-55.46‰～-53.26‰,其补给来源为雨水,补给高程为海拔641～1 206 m的岩溶出露区。安装马歇尔槽和CDTP300高分辨率实时在线监测发现：1)地下热水水文地球化学特征在长时间内稳定,体现了稳定的水-岩作用过程;2)北温泉的流量与研究区降雨量呈现出以半年为单位的滞后,雨季偏低,旱季偏高;当场降雨后20 d左右,温泉水的水温和电导率微降,水量增加。地下热水的来源为大气降水,其补给除了长时间长距离的含水层稳定补给外,热水上升过程中受地表水和浅层地下水的补给。     

Requirement Model Based on UML 2.0 for Equipment MIS

This paper introduces the modeling of Unified Modeling Language with use case diagram and active diagram based on Rational Unified Process for Equipment Managemet Information System. It discusses the modeling mechanism and character of UML and develops the Computer Equipment management Information System Based Web using Rational Rose of UML CASE Tool. First, it is describe the authors how to analyze the structure of organize and build the model of structure organize. Second, they abstract the workflow of main operation in organize and build workflow model by active diagram. Finally, they abstract actor, use case with case diagram and finish the requirement model.     

MPEG Layer Ⅲ Decoder Design Based on DSP

The design of MP3 decode system based on DSP is introduced. TLV320AIC23, a high performance and stereo codec chip, is selected as a D/A converter in the system. Two McBSPs ofDSP are connected to TLV320AIC23, one of them acts as configuration interface, the other ,the audio digital interface. Configuration interfacemode is SPI. The MP3 audio bitstreamtransmissionbetween the PC and DSP isrealized through the USB1.1 interface. So it is convenientto access MP3 audio bitstream. A large capacitymemory device, Compact Flash Card , is a storage media accessing MP3 bitstream.a programmable logical device, CPLD, controls reading, writing and chip selection of USB and Compact Flash Card. Some experiments show the systemcan well accomplish MP3 decodingand playing.     

Energy Efficiency Analysis of Heating System in the Birdhouse

In this paper the problem of energy consumption and environment in the birdhouse is introduced and the reconstructive measures aiming at energy savings are recommended. The measures include the limitation of temperature region, reconstruction of the building envelop and using the sunny board at the south side of the birdhouse roof. Finally, the energy efficiency of the reconstructive project is estimated.     

The Algorithm of Searching out the Least and Most Loops by Making Use of Direction Factor

Based upon the conception of the least loop,the most loop and direction factor presented by the author firstly,the algorithm of searching out the least and most loops has been designed.By building the adjoining matrix, confirming the start-point of searching,vectorizing the searching sides,calculating the direction factor of adjoining sides,we can search out the next side of the least loop or the most loop rapidly.With a valid searching side being confirmed at every searching and the searching scope being reduced by forming degenerate graph,the time compexity of the algorithm is much less. In the research of the automatic calculating system of construction quantities, the problem of houses partition and out-wall partition had been solved succesfully by utilizing this searching algorithm.