冬小麦红边参数变化规律及其营养诊断

研究了冬小麦冠层光谱红边参数随作物生育期的变化规律,并进行了红边参数与各组分间的相关分析,发现可利用用红边位置反演叶片可溶性糖和叶绿素含量,利用红边振幅反演叶片全氮含量,利用红谷反演叶面积指数。建立了基于红边参数的各组分的统计回归模型,可为生产上利用遥感手段大面积、无破坏、及时评价冬小麦生长状态及营养诊断提供重要依据。     

叶绿素指数与最大羧化速率相关性研究

以陆地生态系统碳循环机理为基础建立的生态模型是估算区域和全球陆地生态系统GPP时空变化特征的有效手段。叶片最大羧化速率(V_(cmax))是生态系统机理模型中不可或缺的参数,准确模拟V_(cmax)对于GPP模拟具有重要意义,然而,传统方法获取大范围V_(cmax)耗时耗力。利用MERIS遥感数据以及站点实测V_(cmax)数据,分析不同站点3种叶绿素指数,即MCARI、TCARI和MTCI分别与冠层V_(cmax)的关系,以及同一站点不同时间序列MTCI与冠层V_(cmax)的相关性。结果表明:叶绿素指数与冠层V_(cmax)之间相关性显著。其中3种叶绿素指数中,MTCI与冠层V_(cmax)关系最为显著;不同站点,MTCI与冠层V_(cmax)相关性随着植被类型的差异而不同。研究结果为利用遥感数据估算具有时空变化特征的V_(cmax)提供了可能。     

机载高光谱数据提取冬小麦冠层叶绿素含量的模型分析及验证

遥感提取叶绿素含量的方法是精准农业的重要研究方向之一,但是如何用冠层光谱数据有效地提取叶绿素含量仍然是一个难点。本文用光谱指数TCARI和OSAVI的组合建立提取冬小麦冠层叶绿素含量的关系式,并使用实验田获取的冬小麦冠层光谱以及与之同步的机载高光谱传感器OMIS数据进行了验证。通过误差分析讨论了该方法用于遥感高光谱数据时需要注意的问题,表明大气校正的精度,传感器的信噪比以及波段中心的漂移是模型反演精度的主要制约因素。     

新疆棉花LAI和叶绿素密度的高光谱估算研究

利用非成像高光谱仪,对棉花(2品种4水平种植密度)冠层5个关键生育时期进行光谱测定,分析棉花反射光谱及微分光谱生育期的变化规律,并对棉花冠层叶面积指数(LAI)、叶绿素密度(CH.D)与光谱数据进行回归分析,结果表明,用归一化差值植被指数(NDVI)与LAI建立的对数模型能够较好地估测棉花冠层的LAI(r=0.9123**,n=20);近红外729 nm波段处一阶微分光谱数值与CH.D高度相关(r=0.9372**,n=20),用此波段建立的CH.D估算模型,精度达84.3%,标准差为0.234g.m-2,RMSE=0.1569。研究表明,可以用高光谱数据对新疆棉花冠层LAI和CH.D进行遥感估算。     

基于时序定量遥感的冬小麦长势监测与估产研究

遥感技术是高效、客观监测农作物生长状态的重要手段,对农业生产管理具有重要意义。以安徽龙亢农场为研究区,收集了中高分辨率多源卫星遥感数据并进行了定量化处理,构建了冬小麦叶绿素密度、叶面积指数的遥感反演模型,生产了长时序冬小麦植被参数卫星遥感产品。通过监测冬小麦叶绿素密度、叶面积指数的时序变化规律,分析了不同品种冬小麦的长势情况,发现高产量小麦在越冬期长势显著优于低产量小麦。在此基础上,构建了基于归一化植被指数（NDVI）的冬小麦估产模型,结果表明：利用小麦抽穗期和乳熟期的累计NDVI值可以实现产量的精确估算,据此绘制了龙亢农场2017年冬小麦产量遥感估算地图,产量分布与实际种植情况吻合良好。实现了基于时序卫星定量遥感数据的冬小麦长势监测和产量预测,为区域范围内农作物长势监测提供了一种有效途径。     

基于时序定量遥感的冬小麦长势监测与估产研究

遥感技术是高效、客观监测农作物生长状态的重要手段，对农业生产管理具有重要意义。以安徽龙亢农场为研究区，收集了中高分辨率多源卫星遥感数据并进行了定量化处理，构建了冬小麦叶绿素密度、叶面积指数的遥感反演模型，生产了长时序冬小麦植被参数卫星遥感产品。通过监测冬小麦叶绿素密度、叶面积指数的时序变化规律，分析了不同品种冬小麦的长势情况，发现高产量小麦在越冬期长势显著优于低产量小麦。在此基础上，构建了基于归一化植被指数（NDVI）的冬小麦估产模型，结果表明：利用小麦抽穗期和乳熟期的累计NDVI值可以实现产量的精确估算，据此绘制了龙亢农场2017年冬小麦产量遥感估算地图，产量分布与实际种植情况吻合良好。实现了基于时序卫星定量遥感数据的冬小麦长势监测和产量预测，为区域范围内农作物长势监测提供了一种有效途径。     

玉米冠层最佳水分指数优选

针对基于植被指数反演不同生长期、不同冠层结构特征下玉米冠层含水量的序列性研究较少,冠层含水量反演较低等问题,优选不同生长期玉米冠层含水量反演最佳植被指数,完成玉米冠层含水量高精度提取。初步选择4种可靠性强的水分指数:归一化植被指数、归一化水体指数1、归一化水体指数2、水协迫指数,分别基于PROSAIL辐射传输模型、三期实测冠层含水量及同步Landsat-8OLI数据,模拟分析4种植被指数与冠层含水量的关系,优选不同生长期玉米最佳水分指数,实现玉米冠层含水量快速精确反演。实例验证结果表明,水分指数归一化水体指数1可作为植被冠层含水量反演的最佳指数且反演精度随着植被含水量的增加而降低,在玉米生长初期,中误差为0.13kg/m~2,在生长中后期,中误差达到0.582kg/m~2,满足生长初期玉米冠层含水量快速反演需求。研究结果可为植被冠层含水量反演中水分指数选择提供参考,也可为稀疏植被覆盖区土壤水分反演研究提供借鉴。     

基于时序定量遥感的冬小麦长势监测与估产研究

遥感技术是高效、客观监测农作物生长状态的重要手段,对农业生产管理具有重要意义。以安徽龙亢农场为研究区,收集了中高分辨率多源卫星遥感数据并进行了定量化处理,构建了冬小麦叶绿素密度、叶面积指数的遥感反演模型,生产了长时序冬小麦植被参数卫星遥感产品。通过监测冬小麦叶绿素密度、叶面积指数的时序变化规律,分析了不同品种冬小麦的长势情况,发现高产量小麦在越冬期长势显著优于低产量小麦。在此基础上,构建了基于归一化植被指数(NDVI)的冬小麦估产模型,结果表明:利用小麦抽穗期和乳熟期的累计NDVI值可以实现产量的精确估算,据此绘制了龙亢农场2017年冬小麦产量遥感估算地图,产量分布与实际种植情况吻合良好。实现了基于时序卫星定量遥感数据的冬小麦长势监测和产量预测,为区域范围内农作物长势监测提供了一种有效途径。     

基于无人机高光谱数据的多类型混合作物LAI反演及尺度效应分析

叶面积指数(Leaf Area Index,LAI)作为表征不同作物生长状况的基本参数,是农业精细化管理及农田生态系统建模的关键。我国农田作物种植比较离散,受地表空间结构非均一性和反演模型非线性等因素影响,不同尺度遥感数据估算的作物LAI存在一定的差异,即农田作物LAI的遥感反演普遍存在尺度效应问题。以包头遥感综合验证场农业示范区为研究区,利用无人机高光谱数据结合PROSPECT+SAIL模型构建典型农作物区多类型作物的查找表(Look-Up-Table,LUT)反演农田LAI,研究查找表用于玉米、马铃薯、向日葵、瓜地等不同作物LAI反演的适用性和精度;通过无人机高光谱数据聚合获得多尺度遥感数据源,结合Taylor展开理论和计算几何模型,提出了一种既考虑类间差异又考虑类内异质性的尺度转换模型,定量描述多种作物混合的非均一地表LAI反演过程中的尺度效应特征。结果表明:基于分类和参数敏感性分析的LUT方法能很好地应用于包头典型农作物区多类型混合作物LAI反演,总估算精度为相关系数R~2=0.82、均方根误差RMSE=0.43m~2/m~2。随着反演尺度的增加,作物类间差异造成的反演偏差明显高于类内异质性,利用本文所提出的尺度转换模型均能较好纠正低分辨率LAI反演的尺度效应问题。     

基于ETM和图像融合的优势植被冠层叶面积指数和消光系数的遥感反演

叶面积指数和消光系数是表征植被群体冠层结构及光能利用的地球表层下垫面参量,国内外对叶面积指数的遥感反演有较多的研究与应用,但对消光系数的遥感反演尚不多见。我国南方少见单一大面积的均匀植被分布。为更好地匹配叶面积指数和光合有效辐射(用于估算消光系数)的实测数据,反映植被混交和疏密不均的状态,以Landsat ETM作为遥感信息源,通过HSV、Brovey和Gram-Schmidt(GS)3种图像融合方法的比较,选取效果最佳的图像融合方法,将ETM融合成空间分辨率为15 m的多光谱数据。以鄱阳湖源头梅江流域为研究区,在实测优势植被叶面积指数和光合有效辐射的基础上,利用植被指数法经验公式法反演流域的叶面积指数,并根据Beer-Lambert定律,建立了流域优势植被冠层消光系数的反演模型。在此基础上,反演了流域植被冠层叶面积指数和消光系数的空间分布,为SWAT植物生长模式的修正提供输入数据基础。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.