高光谱场景辐亮度模型仿真研究

高光谱遥感的地面场景是高光谱遥感系统中影响因素最复杂多变的部分。首先基于星载高光谱遥感成像的辐射传输过程,对非均匀的朗伯表面的入瞳处大气辐亮度传输模型进行了研究,得到只需要考虑目标与邻近像元反射率,大气传输因子的辐亮度简化模型。之后介绍了大气中光子扩散原理,并采用蒙特卡洛方法对大气点扩散函数进行仿真;联合地表目标像元反射率数据计算得到基于非均匀朗伯面地表的邻近像元反射率;然后总结了大气传输模型软件MODTRAN计算入瞳处辐亮度数据的原理步骤,并利用其反演了朗伯表面的相关大气传输参数。最终利用基于传感器入瞳处的辐亮度数据表征了高光谱地面场景。     

大倾角光学遥感中大气点扩散函数的近似模型

大气对垂直遥感和大倾角遥感影响的主要差别之一体现于邻近象元的影响，对于垂直遥感，点扩散函数是各向同性的，即邻近象元对于目标象元的影响只与它们之间的距离有关，和它们之间的相对方位无关，但是对于大倾角遥感，点扩散函数不仅依赖于邻近象元和目标象元之间的距离，而且还依赖于它们之间的相对方位，在距离相同时，在观测方位上的邻近象元对目标象元的影响最大。本文用传感器，目标象元和邻近元构成的几何关系描述来自邻近象元的漫反射再经大气的一次散射而达到传感器的辐射通量，从而得到大气的点扩散函数的近似解析解，这种解析近似同蒙托卡洛的模拟结果有很好的一致，我们用这种方法得到了ASAS（Advanced Solid-state Array Spectroradiameter)大倾角观测时的大气的点扩散函数，并设计了一个Wiener滤波器去除邻近象元的影响，视觉效果评价和空间相关性分析的结果表明了这种方法的有效性和可行性。     

高性能大气校正算法中遥感数据切分策略研究

高分辨率卫星遥感数据在地物识别等方面具有明显优势,然而其定量化应用中需要精确的大气校正,该过程通常相当耗时。分别研究了大气校正算法串行处理方法及基于通用计算机集群系统的并行处理过程。通过对2012年7月我国华北地区的环境卫星CCD数据进行大气校正,并分析了串、并行过程各个步骤运行时间,表明了对大气校正并行处理的高可行性。针对并行过程中负载不均衡和通讯频繁等问题,设计了基于卫星像元特征的数据切分策略,并对不同并行算法进行了性能分析,表明了本文反演结果的可靠性,以及提出的切分策略能达到更高的加速比。     

卫星遥感数字图像的地面辐射改正研究

讨论了地形、大气以及地理位置对卫片像元土尤辐射三分量(直射、散射、邻坡反射)的影响和这种影响所引起的卫星遥感数据变化。研究了地面光辐射、地形、大气和遥感数据之间的定量关来，并以此为基础，研究了卫星遥感数字图像地面辐射改正的原理和方法。经地面辐射改正后的卫星遥感数据能满足遥感应用基础研究和地面辐射状况研完的需要。     

基于分解思想的导航星座多目标优化

导航星座多目标优化是寻找既能满足设计指标又能使代价最小的理想导航星座。首先,建立了一种由中轨道卫星(MEO)、地球静止轨道卫星(GEO)和倾斜同步轨道卫星(IGSO)组成的混合星座构型模型,并提出一种将星座性能和星座成本作为目标函数的多目标导航星座优化方法,其次,分析了优化目标函数加权几何精度因子WGDOP、可见星数目M和导航星座成本的选择及计算方法,并将基于分解思想的多目标优化算法(MOEA/D)引入导航星座优化中。最后,建立了导航星座多目标优化的数学模型,对基于北斗系统的混合星座进行优化,提出一种新的北斗系统的优化方案。     

地球静止轨道卫星有效载荷可优选凝视型光学遥感器

提出了在地球静止轨道上利用高分辨率固态成像器件按“凝视”模式观测地球的设想,分析了按凝视模式工作时的各种几何关系,并根据目前和近期能达到的固态成像器件的水平,以5 0002像元的CCD器件和1 0002像元的红外焦平面阵列作为探测器,提出了性能分别类似于VHRR和GOES-9成像仪的两种传感器的设计方案,并与之比较。分析结果表明,在静止轨道上按“凝视”模式观测地球是在气象观测和海洋遥感中很有吸引力的方案。     

基于同步实测光谱数据的ASTER影像邻近效应校正研究

2008年6月在甘肃省张掖市开展的天-空-地同步大型遥感实验“黑河综合遥感联合实验”中,用自己设计的装置在兰州大学草地观测站开展了卫星同步邻近效应测量实验,用逆最小二乘算法求算了邻近效应校正系数,并将系数应用于影像真实反射率转换方程,对同步获取的ASTER影像进行了邻近效应校正,校正结果影像质量有所改善。将校正的结果影像与SHDOM方程的邻近效应校正结果影像对比,结果表明,经过邻近效应校正系数校正后影像的反射率、归一化植被指数产生较大差异,像元之间的相关性也明显降低。     

山地TM遥感影像大气辐射校正模型改进及地表反射率反演

基于光学遥感辐射传输理论,着重阐述了地形对天空散射光相互作用及邻近像元的影响,提出了一种改进的山地大气辐射校正模型及地表反射率反演方法;基于IDL编程实现模型算法,选择贵州黎平县丘陵森林覆盖典型研究区,结合Landsat-5TM和1∶50000DEM数据进行了实例验证、评价与分析。研究结果表明,本研究方法能够同时有效消除TM数据的大气与地形影响,提高地表反射率反演精度与数据质量,将进一步推动山地光学遥感数据的定量分析与应用。     

遥感湖泊面积MTMF提取方法及空间尺度效应研究

主要研究遥感湖泊面积亚像元分解提取方法和空间尺度效应,为遥感湖泊面积提取、检验及基于此的局地气候变化分析提供科学的基础数据。在对TM遥感数据进行升尺度处理的基础上,采用混合调制匹配滤波(Mixture Tuned Matched Filtering,MTMF)进行亚像元分解,得到不同空间分辨率的湖泊面积。进而分析不同面积湖泊随遥感空间尺度的变化。结果表明:(1)当通过对高空间分辨率的遥感数据重采样获取多尺度遥感影像进行湖泊面积提取及湖泊空间尺度效应分析时,采用最近邻法比像元聚合重采样法更合理。(2)MTMF亚像元分解法可以用于基于水体光谱特征的遥感湖泊边界提取和面积计算,但边界提取过程中容易将湖泊与河流或其他非湖泊的水体混淆。(3)遥感湖泊面积的提取结果受所用遥感影像空间分辨率的影响较大,影像的空间分辨率越低,湖泊面积提取的偏差越大,尤其对面积较小的湖泊。     

黑河中游试验区不同分辨率LAI数据处理、分析和尺度转换

008年开展的黑河综合遥感联合试验获取了大量野外实测叶面积指数(LAI)数据以及遥感LAI产品。在利用LAI地面点观测数据对遥感影像进行验证或者不同分辨率遥感产品相互比较的过程中存在由于地表异质性引起的尺度效应,导致无法直接进行验证、比较,需要进行尺度转换。以基于泰勒级数展开的尺度转换模型为基础,研究不同源LAI之间的尺度转换方法。包括两部分内容：① 以高分辨率影像为辅助数据将地面实测点尺度的LAI转换到中、低分辨率遥感像元尺度;② 利用高分辨率影像作为亚像元信息对低分辨率LAI产品进行尺度纠正。结果表明,利用泰勒级数展开模型进行尺度转换是一种简单可行的方法,经尺度转换的地面实测点尺度LAI可用作像元尺度数据比较验证的参考。     

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。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。