基于FPGA的实时SAR成像系统的设计与实现     

程雪红  谢佳 《西安文理学院学报》2008,11(2):89-92

根据合成孔径雷达（SAR）成像基本原理,结合当前基于现场可编程门阵列（FPGA）实现数字信号处理的能力,本文对SAR成像系统的FPGA实现方法做了深入探究.该系统设计将SAR成像算法映射到FPGA中进行实现,结合重新时序分布、展开与合并等算法实现技术,同时注重流水线、并行处理等基本设计技巧,极大地提高了SAR成像系统的运算精度和运算速度.通过仿真验证,设计的系统具有实时高性能的特点,可以很好地满足空载实时SAR成像要求.  相似文献   

Migration of surplus agricultural labor in the process of economic transition     

Huang Zu-hui  Lu Bo-xiang  Chen Xin-xin 《浙江大学学报(A卷英文版)》2001,2(2):220-226

This paper on the migration of the surplus farm labor during the economic transition of China focuses on a case study of Zhejiang, China's eastem coastal province, with 45 million population and located in relatively developed area since the reform in 1978. The background and mechanism of Chinese surplus farm labor migration are discussed briefly in the first section. Detailed analysis and development of this topic are based on the Zhejiang case, and consists of two parts: a review of the migration history of surplus agricultural labor in Zhejiang since the 1978 reform: and further analysis and key points are given in the second part. The third sector focuses on challenges and recommendation of policies. Project (70041025) supported by the NSFC.  相似文献   

鲜卑人中白种人来源考     

杨军 《辽宁师范大学学报(社会科学版)》2007,30(6):108-111

公元3世纪,东北西南部即有白种人部族,但他们是"自号鲜卑"并被中原人称为鲜卑的.这部分白种人出自被匈奴征服后被迫南迁的丁零人.匈奴西迁后,他们与匈奴余种一起加入到鲜卑族之中.东部鲜卑中的白种人主要有两个来源:一是公元1世纪随匈奴余种迁入辽东的丁零人,二是公元3世纪随慕容部东迁的丁零人.拓跋鲜卑中的白种人主要是其进入匈奴故地后与之杂居的丁零人.  相似文献   

范氏口传文学家族民歌解读（之一）     

徐永安 《郧阳师范高等专科学校学报》2003,23(4):30-33

在田野调查的基础上，对范氏家族和田畈村的社会背景及其口头学传承状况的研究，从移民活动、家庭传统、社会环境和个人条件等方面，分析了范氏口传学家族形成的原因，丰富了对民间学传承规律研究的内容。同时分析了武当山民歌的内容构成，演变、发展的历史脉络和特点。  相似文献   

乡—城人口迁移对农村人口老龄化的影响——基于“年龄—迁移率”的定量分析   总被引：1，自引：0，他引：1  

王泽强 《黑龙江生态工程职业学院学报》2011,(6):27-33

在我国工业化和城市化快速推进中,农村青壮年人口向城市大规模迁移,其结果会对农村人口结构产生深刻影响。根据"年龄—迁移率"理论,利用2000年第五次人口普查、2005年的1%人口抽查和《中国人口和就业统计年鉴(2009)》等数据,对未来一个时期我国乡—城人口迁移对农村人口年龄结构及农村人口老龄化的影响程度进行测算,结果表明乡—城人口迁移加深了农村人口老龄化程度,这将对农村传统养老制度产生巨大的冲击,进而将会引起农村养老资源供求失衡。应加快推进农村养老制度变革,提高农村社会养老资源供给能力,以弥补农村传统家庭养老资源的流失和供给不足。  相似文献   

Transnationalism,migration and emotions: implications for education     

Michalinos Zembylas 《Globalisation, Societies & Education》2012,10(2):163-179

This article is concerned with the emotional dynamics of transnationalism and migration and the impact on education. This impact is discussed in terms of how the movement of people involves complex emotional processes that have important consequences for educational policy, practice and research. The purpose of the author is to theorise how emotions in the context of an increasingly globalised world are significant in pedagogic terms. It is argued that there is need for more explicit attention on examining what the entanglement of transnationalism, migration and emotions implies for educators, students, parents and their communities.  相似文献