EDA的发展及其应用

信息产业是21世纪的战略性产业,而EDA技术在其中起着举足轻重的作用。EDA技术的高速发展为各国带来了机遇和挑战。本文较详细地阐述了EDA技术的发展、基本设计方法、高层次的设计和应用,介绍了高速PCB和板级系统仿真技术以及EDA技术在我所的应用情况。     

EDA技术的发展及面向21世纪基于INTERNET环境的EDA

本文介绍现代ＥＤＡ技术的发展及未来基于ＩＮＴＥＲＮＥＴ环境下的ＥＤＡ     

Travel and us: the impact of mode share on sentiment using geo-social media and GIS

Commute stress is a serious health problem that impacts nearly everyone. Considering that microblogged geo-locational information offers new insight into human attitudes, the present research examined the utility of geo-social media data for understanding how different active and inactive travel modes affect feelings of pleasure, or displeasure, in two major US cities: Chicago, Illinois and Washington DC. A popular approach was used to derive a sentiment index (pleasure or valence) for each travel Tweet. Methodologically, exploratory spatial data analysis (ESDA) and global and spatial regression models were used to examine the geography of all travel modes and factors affecting their valence. After adjusting for spatial error associated with socioeconomic, environmental, weather and temporal factors, spatial autoregression models proved superior to the base global model. The results showed that water and pedestrian travel were universally associated with positive valences. Bicycling also favourably influenced valence, albeit only in DC. A noteworthy finding was the negative influence temperature and humidity had on valence. The outcomes from this research should be considered when additional evidence is needed to elevate commuter sentiment values in practice and policy, especially in regards to active transportation.     

基于探索性空间数据分析的安吉县水土流失时空变异规律研究

摘要实时、准确地掌握区域水土流失时空变异规律是制定有效水土保持措施的关键.但目前水土流失时空规律分析鲜有兼顾定量数值特征与空间可视化特征.本研究利用探索性空间分析方法和遥感信息,在景观尺度上,对1994~2003年间浙江安吉县水土流失的时空动态格局进行分析.结果表明,10年间安吉县水土流失强度增加、影响范围扩大、水土流失高风险区面积增加.在500 m×500 m和1 000 m×1 000 m 2种格网尺度上,水土流失空间格局均表现出明显的空间集聚性,但以500 m×500 m尺度上的表现更为显著.这种探索性空间分析方法,从定量的统计学和可视化角度有效地揭示了水土流失的时空变异规律,为相关部门和人员定量评价水土流失,制定有效的水保措施提供了新的方法和手段.     

一种基于软件无线电技术的扩频通信系统

文章介绍了一种基于软件无线电技术的数字扩颊通信系统,包括扩频ASIC芯片的设计,发射机、接收机的设计等。着重描述了采用ESDA技术设计扩频ASIC信片的过程,给出了ASIC芯片的数学模型、仿真结果及系统性能分析。仿真及测试结果表明,该扩频通信系统具有较强的抗干扰能力。