基于SoC技术的1553B总线软件设计

介绍基于1553B SoC的软件设计,针对GJB289A-97中规定的总线控制器和远程终端的相关要求提出一种基于1553B SoC模块的软件设计实现方法。使得该MBI模块在兼容之前版本的驱动接口情况下,提高可靠性,减少子系统主机的资源开销。     

基于1553B协议的总线控制器和远程终端的FPGA实现

研究了基于MIL-STD-1553B协议的总线控制器和远程终端的FPGA设计及其实现. 在一片FPGA上实现了总线控制器和远程终端2部分功能,给出了设计原理和不同配置模式下的响应流程. 结果表明,基于FPGA 实现1553B协议总线控制器和远程终端功能的方法可行.     

直升机1553B总线测试系统

随着航空事业的不断进步,机载总线测试技术也得到了长足发展,本文针对总线测试系统,结合在直升机多种航空总线工程实践中的应用,根据早期研制及测试经验,总结了1553B型总线测试方法。提出了其发展趋势,对后续直升机1553B总线系统测试提供了经验。     

GPS接收机中1553B总线接口的CPLD设计

传统的GPS用户接收机的接口部分的设计往往比较复杂,针对这种情况,本文着重介绍了一种利用CPLD技术来实现GPS接收机中1553B总线接口的设计方法,同时还对1553B总线协议进行了分析。该系统具有结构简单、体积小、设计灵活、可靠性高等优点。     

基于BU61580的1553B总线远程终端软件设计

BU-61580是DDC公司MIL-STD-1553B系列芯片中功能最强、体积最小的芯片,它提供了微处理器与1553B总线之间完全、灵活的软件接口功能。首先简要介绍了1553B总线RT远程终端,详细介绍了总线接口协议芯片BU-61580,以及在1553B总线RT远程终端软件设计实现方法。     

一种1553B总线数据的实时过滤方法

<正>point在飞行试验中,1553B总线数据的实时采集对于获取鉴定测试数据具有重要的意义。1553B总线数据的实时采集过程中,按照用户预设的条件对采集到的数据进行过滤,才能得到需要的数据。然而,过滤方法得当与否直接影响采集数据的实时性。本文基于DSP和FPGA技术,设计了一种1553B总线数据过滤机制,即快速查表的方法,详细论述了此     

CAN总线监控系统中硬件平台的研究与设计

本文主要是对CAN总线监控系统中硬件平台进行研究与设计,硬件平台包括控制器、电源模块、JTAG仿真调试接口、复位电路、CAN接口模块和TFT-LCD的控制器Mz T24等模块。     

二极管焊接加固工艺改进方法研究

为研究接口模块复位异常导致系统无法启动故障,通过复位机理分析,建立复位二极管断裂故障树,分析故障原因并对分析结果进行试验和故障复现。结果表明:玻壳二极管电装过程中的点红胶工艺,在高低温交替过程中,因玻壳和红胶膨胀系数差异较大,红胶会对玻壳产生温度应力,最终导致玻壳断裂。改进的电装去红胶工艺,经多次高低温循环试验验证,改进措施有效。     

基于PowerPC处理器硬核的1553B总线远置终端的实现

MIL-STD-1553B总线是目前在航空、航天、军事等领域的电子联网系统中广泛应用的一种标准总线。本课题采用新型的嵌入PowerPC405处理器硬核的FPGA片上可编程系统（SOPC）和美国DDC公司1553B协议芯片65170构建1553B总线的远置终端（RT）系统。文中介绍了PowerPC405处理器硬核和Virtex-II Pro系列FPGA芯片的基本特点，系统的软硬件实现方法和设计验证结果。     

1553B总线接口板的设计与实现

文中介绍了1553B数据总线的传输协议和工作方式,设计了基于ISA接口的同时具有BC/RT/MT多个功能的1553B总线接口板,并给出了相应的软、硬件实现方法.     

Students' Reactions to the Introduction of Videoconferencing for Classroom Instruction

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.     

Cooler temperatures inductive to locust outbreaks

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.     

Exploring Multiplexity: Social Network Structures in a Computer-Supported Distance Learning Class

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.     

The Role of Intermediating Institutions in the Diffusion of Electronic Data Interchange (EDI): How Industry Associations Intervened in Denmark, Finland, and Hong Kong

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.     

How Electronic Publishers are Protecting Against Piracy: Doubts About Technical Systems of Protection

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.     

Rough Justice: A Statistical Assessment of ICANN's Uniform Dispute Resolution Policy

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.     

Prevalence of soft neurological signs in Chinese people

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.     

Monoculture Rubber Plantations Have Negative Ef ects on Controlling Splash Erosion

<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     

Chinese Scientists Use Earth Observation Technologies to Study and Protect Wild Camels

<正>Chinese scientists plan to apply Earth Observation technologies to protect the critically endangered wild camels(Camelus ferus).With the help of remote sensing,satellite positioning,geographical information system and wireless sensors networks,they will be able to access the distribution and population of the wild camels and protect their habitats.The project will be carried out by the International Research Center for Wild Camel Conservation,which was jointly established earlier this year by the Institute of Remote Sensing and Digital Earth(RADI)of the Chinese     

More than Skin Deep – Understand Skin Biology by Means of Dermatogenomics

<正>The Paul Gerson Unna Research Group on Dermatogenomics was founded in October 2012 at the Partner Institute for Computational Biology.The ultimate goal of the group is to understand the biology of skin and skin appendages.