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91.
多时相AVHRR数据的傅立叶分析   总被引:10,自引:0,他引:10  
傅立叶分析(FourierAnalysis)是一种常用的信号处理方法.将中国全年 36旬的NOAA AVHRR的 1km数据采用最大值合成法获得 1 2个月的NDVI时间序列数据,然后运用离散傅立叶变换检测该时间信号的频率分布状况.结果各频率分量与NDVI的累加值及不同周期的季节性变化等生物学特征相关.其中零频率分量为均值NDVI,而 1/1 2频率分量最大程度概括了中国地表覆盖类型的全年季节性变化模式.将提取出的这些生物学特征引入到地表覆盖分类的特征空间中,提高了类别间的可分性.这些研究表明了傅立叶变换是分析多时相AVHRR数据及提取植被的生物学特征的有用工具  相似文献   
92.
Substitution of slate roofing tiles is a conventional operation during building restoration, since tiles are very difficult to restore or clean because of the high degree of alteration they suffer. Criteria for replacement of historical building stones must be based on geological, geotechnical and esthetic parameters, among which color is of great importance. In this sense, this paper constitutes a comprehensive and useful colorimetric study of roofing slates from the Iberian Peninsula, for the purposes of restoration. The color of 50 commercial varieties of roofing slate mined in quarries from the 12 mining districts in the Iberian Peninsula was analyzed with a spectrophotometer device, by considering the CIELAB color space. The results of the study were used to develop a protocol for characterizing the color of roofing slate and to define the color range of roofing slate from the Iberian Peninsula. In addition, the similarities and differences in the color and microstructure of the different commercial varieties of Iberian roofing slate were established and the limit of acceptability of replacement of one type of slate by another was determined. Parameter hab was found to be the most important CIELAB color coordinate as regards the formation of homogeneous color groups, and the specular component excluded (SCE) mode was most sensitive as regards detecting color differences between two samples.  相似文献   
93.
The old urban centres are marks of an historical and architectural heritage that should be protected and safeguarded. For such, it is fundamental to have a complete understanding of the genesis, regarding both building and the urban mesh. This fact is essential to the support of qualified, conscientious and sustainable rehabilitation interventions on the old building stock. The research carried out addresses the issue of the old urban centres from the perspective of the analysis and inventory of buildings features. The cataloguing process of the building typologies is presented in this work as a synthesis of the principal construction forms, with the old city centre of Seixal being used as a case study. The identification of building typologies has supported a seismic and fire vulnerability assessment of the old building stock. The assessment methodologies developed and used are based on the detailed survey and building inspection, therefore the building typology cataloguing is essential in the analysis at such a large scale. Then we discussed the strategy for the conservation actions incorporated in a broader risk management policy.  相似文献   
94.
介绍了多自由度刚性杆系静平衡的分析计算。通过调整初始设计中杆件的长度来优化系统。这对于大型起重机前大梁拉杆系统以及一些相关系统的设计优化有一定的实际参考及应用价值  相似文献   
95.
中日关系新格局与日本对华战略   总被引:4,自引:0,他引:4  
世纪之交,中日两国的实力都处在上升期.在日本以超级经济大国地位加速实现政治大国目标和中国日益崛起的进程中,中日之间“强强型”关系的新格局正在形成.面对新局面,日本逐步调整对华战略,在继续与中国进行多方合作的同时,开始视中国为战略对手,多方面对中国进行牵制与防范.在此情况下,中国也必须重新审视中日关系,采取妥善对策.  相似文献   
96.
José Castro Silva, lecturer in sciences of education, and José Morgado, assistant professor, both work at the Instituto Superior de Psicologica Aplicada in Lisboa, Portugal. In this article, they describe their study of support teachers' beliefs about the academic achievement of school students with special educational needs. The 'support teachers' who were the subject of this study work in mainstream schools where the majority of pupils with special educational needs are educated in mainstream classes run by 'general teachers'. The work of the support teachers is supervised and supported by 'special education team co-ordinators'. The study reported here set out to elicit the support teachers' beliefs about the factors that contribute to success at school for pupils with special educational needs. Results suggest that the support teachers consider that factors including 'school climate', 'curriculum design' and 'teaching approach' contribute significantly to achievements among these pupils. On the other hand, analysis reveals that the support teachers attribute difficulties and lack of achievement significantly to 'out-of-school' contextual variables. These findings are related to a detailed review of the literature and the authors discuss the implications for policy, practice and professional development.  相似文献   
97.
期刊评价标准的合理构建对学术期刊的健康成长具有重要意义,大数据时代的来临将给我国当前学术期刊评价带来巨大影响。在简要阐述我国当前主要学术评价系统、评价标准、基本特征及存在问题的基础上,对大数据给学术期刊评价标准带来的影响进行了细致分析,在此基础上提出大数据背景下学术期刊评价标准可能包含的具体指标及其计算公式。  相似文献   
98.
In this study, the socio-cultural variation in reading comprehension development was examined in 331 fifth graders from schools in Lima, Peru. Reading comprehension was measured using an adaptation of the PIRLS Reading Literacy test. The fifth graders?? reading comprehension results, measured over the course of fifth grade, were related to the development of word decoding, vocabulary, and motivation for reading. Children??s development in these domains was related to their gender, intellectual maturity, home literacy climate, and socio-economic status. Structural Equation Modelling showed that the development of reading comprehension was influenced by the children??s ability to decode words, their vocabulary, and reading motivation. Furthermore, gender and intellectual maturity as well as children??s home literacy climate and socio-economic status appeared to substantially predict reading comprehension development, directly or indirectly. More than half of the variance in reading comprehension by the end of the fifth grade could be explained based on these predictor variables.  相似文献   
99.
Teaching and learning with history and philosophy of science (HPS) has been, and continues to be, supported by science educators. While science education standards documents in many countries also stress the importance of teaching and learning with HPS, the approach still suffers from ineffective implementation in school science teaching. In order to better understand this problem, an analysis of the obstacles of implementing HPS into classrooms was undertaken. The obstacles taken into account were structured in four groups: 1. culture of teaching physics, 2. teachers?? skills, epistemological and didactical attitudes and beliefs, 3. institutional framework of science teaching, and 4. textbooks as fundamental didactical support. Implications for more effective implementation of HPS are presented, taking the social nature of educational systems into account.  相似文献   
100.
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