首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
介绍一种新型小区防盗系统的设计原理和方法,该系统由计算机、集中控制器、收发器和多个采集器组成。集中控制器、收发器和采集器采用ATmega8单片机作为主控芯片,各个组成部分之间采用灵活的通信方式,不但提高了传输的可靠性,而且降低了整个系统的陈本,在一些智能小区已经得到了较好的应用。  相似文献   

2.
《中国科技信息》2006,(6):35-35
飞利浦半导体公司日前推出了面向主动安全系统的FlexRay2.1系统解决方案。该解决方案包括两个主要部分:TJA1080收发器和包含一个ARM9微控制器并且完整集成FlexRay2.1版本的SJA2510通信控制器。采用FlexRay作为网络总线后,汽车制造商可以在性能和特性方面实现差异化,同时给消费者带来最新的安全应用。  相似文献   

3.
根据LONWorks控制网络的相关资料,采用自由拓朴网络的神经元芯片智能收发器FT3150和双绞线收发器FT-X1设计基于LONWorks网络控制技术的智能节点。应用LONMaker组网工具和基于节点开发的NodeBuilder工具,设计温度控制器功能试验节点的控制软件并完成调试,以实现LONWorks网络型风机盘管温度控制器的功能试验环境。  相似文献   

4.
《科技风》2017,(26)
随着科技的发展和社会的进步,城市居民对生活质量也有了更高的要求。地热作为目前大多数小区集中供暖的主要手段,能够让住户在冬天不感到寒冷。集中供暖会出现温度不合适的情况,过冷过热都会导致用户不舒服,使用科学高效的控制系统,能够精确合理的调节温度和供水压力等参数,保证达到最佳的供暖效果,最好的用户体验。一般来说,小区的集中供暖主要有两大原则,就地控制和集中协调原则。控制算法主要为闭环式PID控制控制器IC选用西门子S7-200系列PLC。本文通过对热力站控制系统的构成和功能简述,介绍了编程软件及程序结构的组成,包括软件编程和硬件结构,最后阐述了可编程控制器的PID指令,实现了对本地监控系统的整体介绍。  相似文献   

5.
文章介绍了一种CAN转IIC通讯系统设计。该系统使用Atmega64作为主控芯片,并使用SJA1000独立CAN总线控制器和TJA1050高速CAN收发器组成CAN接口,系统的主要作用是完成上下层系统的通讯连接。本系统通过实际的验证,通讯正常。  相似文献   

6.
如今的家庭生活越来越离不开安防,设计出具有防盗、防火和防煤气泄露功能的智能小区安防报警系统已显得十分重要。本文设计的智能小区安防系统由三部分组成:报警传感器、单片机控制器和监控中心。系统采用了体积小巧、功能强大、价格便宜的430单片机作为小区住户家庭的第一监视端。与单片机相连接的各种传感器用于收集各种报警信号,并送单片机进行初步处理。单片机实时与远方监控中心通信,通过CAN总线将传感器感受的信号传给主机。这样,监控中心就可以清楚了解小区住户家里的异常情况,以便及时处理。该系统使用方便,价格合理,在实际的工程中有广泛的应用,因而具有良好的应用前景和推广价值。  相似文献   

7.
简要阐述了某高层住宅小区消防给水系统的设计,并对集中高层住宅小区设置区域消防给水系统时设置增压稳压设备的必要性进行了分析。  相似文献   

8.
CAN总线作为一种技术先进、可靠性高、功能完善、成本低的远程网络通信控制方式,已广泛应用于汽车电子、自动控制、电力系统、机电一体化等自动化领域。本文介绍了一种以单片机的为主控制器,利用CAN总线控制器与CAN总线收发器进行CAN总线节点硬件与软件设计的方法。  相似文献   

9.
本文设计了一种符合国家电网、南方电网的新型智能采集器,并对它的原理和实现做了详细阐述。该采集器采用RENESAS公司的uPD78F0526为主控制芯片,兼容DL/T645-1997和DL/T645-2007通信规约,自动适应电能表通信波特率。经过实际安装使用表明,设计的系统具有功耗低、运行稳定、抄读成功率高等特点,完全符合国家电网及南方电网要求。  相似文献   

10.
郑琴  熊麟 《科技风》2013,(16):57
新的地面观测系统是以自动气象站为主,采集器是自动气象站的"心脏",采集器故障,整个自动站基本也就处于瘫痪状态了。本文通过我站在开展自动气象站的业务工作中遇到的一些问题,对采集器的常见故障进行分析并给出采集器故障之后异常记录的处理方法。  相似文献   

11.
This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors.  相似文献   

12.
Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China's projected climate warming could decrease the pest's numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007.  相似文献   

13.
A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction.  相似文献   

14.
Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said.  相似文献   

15.
Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies.  相似文献   

16.
The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means.  相似文献   

17.
Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP.  相似文献   

18.
Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.  相似文献   

19.
Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction.  相似文献   

20.
<正>In Xishuangbanna,one of China’s most biodiverse regions,landscape has changed dramatically during the past three decades due to the conversion of tropical rainforest to rubber plantations.In steep areas,terraces are often constructed before planting rubber trees,which causes two important changes in the soil:the destabilization of soil in the bench terraces and the increased vulnerability of unvegetated riser faces to erosion.Few studies have documented the nature and intensity of erosion on bench terraces.Prof.LIU Wenjie and his colleagues from the Xishuangbanna Tropical Botanical Garden(XTBG)conducted a study in Menglun County(21°5′39″N,101°15′55″E),Xishuangbanna to evaluate the influence  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号