基于DSP的一维云模型控制器的设计

作为智能控制领域的新兴学科,云模型控制理论主要以理论研究和实验仿真为主,其硬件实现成为目前的研究热点。根据云模型控制器的设计理念,结合DSP运算速度快、体积小和功耗低的性能特点,提出了一种基于TMS320F2812的定点一维云模型控制器的硬件设计方法。利用该方法设计的云模型控制器在直流电机的调速系统中得到了验证。通过测试表明系统响应速度快,调节精度高,证明了该设计方法的可行性,为今后云模型控制器的硬件实现提供了参考。     

应用粒子系统构建云雾模型

随着科学技术的发展以及互联网的广泛应用。使用计算机图形学和虚拟现实技术对不规则物体进行模拟现今已经在国防、气象、网络架构等领域得到了广泛的应用。使用粒子系统对云雾等不规则图形进行模拟可以极大地减小模型3D真实度对计算机配置的需求,降低平台架构难度。同时由于粒子系统建立模型的随机性使得建立的模型具有更加自然的视觉效果,更加合理的物理学结构从而能在广泛的领域得到应用。本文应用粒子系统与纹理过程函数相结合的方法对自然景物中的云雾模型进行模拟,在具体的模型绘制过程中应用纹理映射和Billboard技术来实现,从而提出了一种多种建模方式相结合的模拟不规则物体的全新方法。     

单幅航空影像中云阴影的自动去除

云阴影的存在严重影响了高分辨率航空遥感影像的视觉效果和影像质量.为去除云阴影,提出了一种无需人工参与的自动处理方法.首先采用光谱特征阈值法初步检测云阴影,再结合形态学方法进行后处理,提取完整的云阴影区域;阴影去除时,设计了一种利用非阴影区域信息、阴影整体区域信息、阴影像素局部窗口及像素本身信息的综合补偿模型,所需参数均可自动获取,进而实现阴影的自动去除.实验表明,区域级、窗口级和像素级多层次信息的引入,使模型的细节敏感度增强,提升了对比度,能灵活根据复杂的云阴影遮挡情况对阴影进行合理提升,有效解决了部分补偿方法存在的补偿效果不均匀的问题,阴影中地物的色彩与纹理等信息均得到更真实的再现.     

带色彩地面激光雷达点云数据的匀光匀色方法

目前许多地面激光雷达(light detection and ranging,LiDAR)能够获取带有目标色彩信息的点云数据,利用这些数据,可以实现点云模型的精细纹理快速、自动化的生成.但因异站点云数据存在颜色差异,生成的纹理可视化效果并不理想.针对这一问题,根据色彩分量表达与空间坐标的相似性,提出了一种基于色彩坐标转换的点云匀光匀色方法.实验结果表明,异站点云颜色差异得到了较好的修正,生成的纹理效果佳.该方法不仅可用于地面LiDAR数据,对于其他来源的具有颜色信息的地面LiDAR点云数据也可据此进行带色彩点云数据的匀光匀色并生成精细纹理.     

电路与器件的混合模拟方法

以二级牛顿算法为基础提出了电路与器件的混合模拟方法，从而实现了一个有效的混合仿真工具。提出了一种通用的数值器件模型，可以适用于所有器件仿真工具所包含的新器件和由此组成的电路，并在计算机网络上实现了混合模拟的并行计算，大大提高了运算速度。这种方法使人们在新器件设计的同时能够很方便地进行电路级模拟，从而为新器件和新电路的发展和应用提供了强有力的模拟工具。     

真实感人体头部建模方法研究

在虚拟环境中，对人体头部变形曲面提取特征并参数化，建立基于弹簧质点系统的标准几何模型；借助重叠图像拼接技术形成纹理图像；根据纹理图像调整几何模型特征参数，配准图形和图像形成特定的变形几何模型，再把拼接图像纹理映射到变形几何模型上，得到一种真实感人体头部模型。     

初级视皮层机制启发下的特征提取

针对传统计算机视觉方法在纹理细节提取和局部运动感知方面的局限性,借鉴生物视觉系统的强大信息处理机制,提出一种基于三维时空能量模型的初级视皮层(V1)视觉模型。模型首先利用三维Gabor滤波器初步模拟得到简单细胞感受野,接着采用半波整流操作进一步得到简单细胞模型,随后通过能量模型整合简单细胞感受野进行,模拟得到复杂细胞模型。仿真结果表明:所提模型在图像静态纹理特征和简单视频序列运动特征提取上取得了较好的效果。较传统模型而言,模型将计算机视觉与生物视觉有效融合,具有更强的动静态特征表达提取能力,体现了V1细胞强大的信息处理机制,为视觉脑启发计算提供新的思路。     

基于分层时序模型的步态识别算法

以隐马尔可夫模型和动态纹理模型为代表的动态贝叶斯网是描述步态序列的重要方法,但都存在一些不足之处.提出了一种新的动态贝叶斯网——分层时序模型,该方法采用分段线性逼近非线性和用各段的动态纹理模型作为隐状态,将隐马尔可夫模型和动态纹理模型做了结合,充分发挥了其优势.该方法在CMU Mobo步态数据库和CASIA步态数据库B上做了评估,结果充分显示了分层时序模型的高性能.     

一种新的布样仿真算法

提出了一种新的意匠图布样模拟建模方法：在布样的意匠图的基础上,先进行矩阵扩展,然后通过简化后的纹理综合加速算法生成纱线的基本颜色,最后利用一个三维显示模型,产生纱线的三维效果。最后做了一个实例,证明了该方法能够比较好地实现对意匠图的布样模拟。     

基于QoS的一维逆云控制器研究

采用云模型不确定性推理方法设计了一种逆云映射器,并给出了逆云映射器的结构设计方法,分析了其映射特性.据此提出了一种一维逆云智能控制器,将其应用于基于QoS的网络控制系统中,并给出了相关的仿真结果.     

基于Perlin噪声的动态云仿真

用Perlin噪声建模、指数函数对其锐化、HLS颜色模型转换等生成静态云彩图像;然后用静态云彩方法来实现不重复运动云彩的生成算法,该算法可得到任意长度的云图;云彩平滑变形算法能连续平稳改变云彩结构,最后运用VC++和OpenGL开发工具及纹理映射方法将云彩置入虚拟环境中,能在PC机上产生了实时和逼真的动态云效果.     

飞行仿真中三维云场景的渲染

云的建模和渲染是近年来计算机图形学领域的一个研究难点,在飞行视景仿真系统、计算机游戏、三维动画领域中有着广泛的应用.从建模方法、光照模型以及实时渲染3个方面对云景仿真进行研究.提出一种基于粒子系统的静态云建模方法,降低了建模的复杂度.采用云的多重散射光照模型加速了渲染速度,并且结合Impostor技术、Billboard技术实现云场景的实时漫游.仿真结果表明,生成的云层效果真实,具有良好的实时性,可在普通的PC机上流畅运行.     

基于卫星云图的DBSCAN聚类云团分类方法

针对云分类问题提出一种新的云团分类方法.该方法先利用风云二号静止气象卫星实时云图图像资料建立多种云和地表类型的样本库,提取分析已知样本的光谱特征和纹理特征;再使用中值滤波器对云图进行预处理,并采用具有噪声的基于密度的聚类算法对云区聚类;最后对聚类得到的云团光谱特征和纹理特征进行匹配,确定云团所属的云类别.实验结果表明,该方法以云团为单位进行划分,易实现云团分类自动化.     

Contribution of cloud condensate to surface rainfall process

Contribution of cloud condensate to surface rainfall processes is investigated in a life span of tropical convection based on hourly data from a two-dimensional cloud resolving simulation. The model is forced by the large-scale vertical velocity, zonal wind and horizontal advections obtained from tropical ocean global atmosphere coupled ocean-atmosphere response experiment (TOGA COARE). The results show that during the genesis, development, and decay of tropical convection, calculations with water vapor overestimate surface rain rate, and cloud condensate plays an important role in correcting overestimation in surface rain rates. The analysis is carried out in deep convective clouds and anvil clouds during the development of tropical convection. The surface rain rates calculated with water vapor in deep convective clouds and anvil clouds have similar magnitudes, the large surface rain rate appears in deep convective clouds due to the consumption of water hydrometeors whereas the small surface rain rate occurs in anvil clouds because of the gain of ice hydrometeors. Further analysis of the grid data shows that the surface rain rates calculated with water vapor and with cloud condensate are negatively correlated with the correlation coefficient of -0.85, and the surface rain rate calculated with cloud condensate is mainly contributed to the water hydrometeors in the tropical deep convective regime.     

MCloudSim： modeling and simulating distributed clouds

Many distributed clouds which try to integrate the advantages of centralized clouds and distributed systems have been studied in recent years. Traditional cloud simulators focus on large scale data centers with virtualized servers, and cannot meet the needs of distributed cloud simulations. This paper introduces a generalized and extensible simulation framework, named MCloudSim, which is used for modeling and simulating distributed clouds. MCloudSim has the following characteristics： （ 1 ） the overlay protocol in MCloudSim can be freely replaced without affecting the function of other modules; （2） a Petri net workflow theory based task model is proposed to simulate distributed tasks; （3） a distributed cloud can be easily built by assembling and expanding the basic resource entities provided by MCloudSim. Finally, simulation results of scenarios with a 3-tier central-controlled distributed cloud and a P2P based cloud prove that MCloudSim has high efficiency and satisfies performance in supporting large scale experiments and different distributed clouds.     

基于纹理特征的地基云分类识别研究

云是一种重要的天气现象,云观测对当时天气系统的观测具有很强的指导意义,同时云的变化趋势也是预测未来天气的一项重要指标?目前对遥感卫星云图的研究取得了较丰富的成果,但地基云图分类识别研究取得的成果则比较有限,地基云图的研究一直是模式识别中的难点?采用标准气象站地基云图数据,选取了浓积云?积雨云?雨层云等5类常见的云类,并将Gabor小波变换应用于地基云图的纹理特征数据提取,运用实验法选取了Gabor小波变换的最优参数?将地基云图纹理特征数据运用到最短距离和包含BP神经网络的陀螺分类器构造成的地基云图分类系统,从而实现了对地基云图的分类?实验结果表明,该方案不仅能够有效地运用于地基云图分类,而且分类效果也是比较理想的?     

Convex decomposition of concave clouds for the ultra-short-term power prediction of distributed photovoltaic system

Concave clouds will cause miscalculation by the power prediction model based on cloud features for distributed photovoltaic (PV) plant.The algorithm for decomposing concave cloud into convex images is proposed .Adopting minimum polygonal approximation ( MPP) to demonstrate the contour of concave cloud , cloud features are described and the subdivision lines of convex decomposition for the concave clouds are determined by the centroid point scattering model and centroid angle func -tion, which realizes the convex decomposition of concave cloud .The result of MATLAB simulation indicates that the proposed algorithm can accurately detect cloud contour corners and recognize the concave points .The proposed decomposition algorithm has advantages of less time complexity and decomposition part numbers compared to traditional algorithms .So the established model can make the convex decomposition of complex concave clouds completely and quickly , which is available for the existing prediction algorithm for the ultra-short-term power output of distributed PV system based on the cloud features .     

扩展的正态云发生器

正态云模型是一种最基本的云模型,用于定性概念与定量描述之间的不确定性转换.根据实际定性概念的含义,可扩展为三角云、半正态云和正态组合云.将云模型的数字特征期望理解为函数或图形,提出函数云、分形云等扩展云模型.给出各种扩展云模型的云发生器算法,有效地扩大地云模型的应用场合.     

A modeling study of relation between cloud amount and SST over western tropical pacific cloudy regions during TOGA COARE

The relationship between cloud amount and sea surface temperature (SST) over western tropical Pacific cloudy regions during TOGA COARE is investigated based on hourly grid simulation data from a two-dimensional coupled ocean-cloud resolving atmosphere model. The model is forced by the large-scale vertical velocity and zonal wind observed and derived from TOGA COARE for a 50-day period. The cloud amount becomes smaller when the ocean surface gets warmer, which is similar to previous relations obtained from observational analyses. As SST increases, the atmospheric temperature increases whereas the surface sensible heat flux decreases. The atmospheric water vapor is not sensitive to SST whereas the surface evaporation flux decreases as SST increases. These indicate that the oceanic effects do not play an important role in determining atmospheric heat and water vapor budgets. The cold atmosphere produces a larger amount of ice clouds that cover a larger area than the warm atmosphere does. The large amounts of ice clouds lead to cooling of the ocean surface through reflecting large amount of solar radiation back to the space. Thus, the negative correlation between the cloud amount and SST only accounts for the important atmospheric effects on the ocean.     

引力不稳定性在巨分子云聚合形成中的作用

　Two models of molecular cloud in disk galaxies are proposed to investigate the formation of giant molecular clouds (GMCs) under the gravitational instability and random collision using PP(Particle-Particle) simulation. Some conclusions can be drawn: 1) The gravitational instability can make small clouds form large clouds faster than random collision. 2) The differential rotation in the gravitational instability model plays a positive role in the agglomeration of molecular clouds.