自动白平衡算法的研究与实现

介绍了白平衡基本原理,通过对图像自动白平衡的算法研究,讨论了常用白平衡算法及其特性以及约束条件,给出严格的数学模型以及处理流程,算法步骤;并对各算法的理论基础以及实现作出相应讨论,通过对几种白平衡方法算法优缺点、适用范围,处理结果的比较,分析得出结论。     

基于局域世界的WSN拓扑加权演化模型

 无标度加权网络模型,反映了现实网络的存在形式和动力学特征,是无线传感网络建模和拓扑演化的有效研究工具.本文基于局域世界理论提出一种不均匀成簇的无线传感网络拓扑动态加权演化模型,考虑节点能量,通信流量和距离等因素,对边权重和节点强度进行了定义,同时研究了拓扑生长对边权重分布的影响.实验证明演化所得网络节点度,强度和边权重均服从幂律分布,结合已有理论成果可知,该拓扑不仅继承了无权网络较高的鲁棒性和抗毁性,同时降低了节点发生相继故障的几率,增强了无线传感网络的同步能力.     

基于小世界模型和图论的图像去噪

提出了一种基于图论的偏微分方程(PDE)图像去噪方法。在构造图的拓扑结构过程中,引入了小世界模型,降低图的直径,加快算法的收敛速度。同时,评估了图的权重函数中最优参数的选取。最后,用图的拉普拉斯矩阵和图上的热扩散方程实现图像的去噪。仿真实验结果表明,本文提出的方法能够有效去除高斯噪声,较完整地保持图像中的边缘等细节信息,在去噪性能和算法收敛速率上优于其它的PDE去噪方法。     

控制在小世界网络中的仿真研究

探讨和分析了NS的工作原理和仿真机制,介绍了在小世界网络下利用NS软件进行网络控制系统仿真的方法和设计实现过程。基于网络仿真软件NS的编程通用性强和功能可扩展的特点,利用NS中类C++的语言环境实现了控制系统微分方程的实时求解,最后展示了仿真研究的结果。     

Structured information in sparse-code metric neural networks

Sparse-code networks have retrieval abilities which are strongly dependent on the firing threshold for the neurons. If the connections are spatially uniform, the macroscopic properties of the network can be measured by the overlap between neurons and learned patterns, and by the global activity. However, for nonuniform networks, for instance small-world networks, the neurons can retrieve fragments of patterns without performing global retrieval. Local overlaps are needed to describe the network. We characterize the structure type of the neural states using a parameter that is related to fluctuations of the local overlaps, with distinction between bump and block phases. Simulation of neural dynamics shows a competition between localized (bump), structured (block) and global retrieval. When the network topology randomness increases, the phase-diagram shows a transition from local to global retrieval. Furthermore, the local phase splits into a bump phase for low activity and a block phase for high activity. A theoretical approach solves the asymptotic limit of the model, and confirms the simulation results which predicts the change of stability from bumps to blocks when the storage ratio increases.     

Mathematical programming models for some smallest-world problems

Given a weighted graph G, in the minimum-cost-edge-selection problem (MCES), a minimum weighted set of edges is chosen subject to an upper bound on the diameter of graph G. Similarly, in the minimum-diameter-edge-selection problem (MDES), a set of edges is chosen to minimize the diameter subject to an upper bound on their total weight. These problems are shown to be equivalent and proven to be NP-complete. MCES is then formulated as a 0–1 integer programming problem. The problems MCES and MDES provide models for determining smallest-world networks and for measuring the “small-worldness” of graphs.     

光测力学技术：连接虚拟空间和现实世界的纽带

在轿车的整个开发过程中，零部件、总成和整车产品都必须根据试验结果验证和优化，在轿车开发的过程中测试技术是连接设计师思维空间和现实空间的纽带，现代光学测试技术以数字图象数据处理技术为基础，融汇贯通高速宽带数字采样、数据库和数据自动分析以及计算机智能工程及专家系统等最新技术，巧妙应用于轿车开发过程，在满足计算机虚拟开发工程对测试技术新要求的同时，还可以优化轿车开发程序，提高开发质量，本文以作者多年来在德国轿车开发部门主持的现代测试技术项目的实例介绍采用光测技术解决开发程序中的问题的构想，方法和手段。     

Spatial and Temporal Behaviors in a Modified Evolution Model Based on Small World Network

In this paper, we introduce a new modified evolution model on a small world network. In our model,the spatial and temporal correlations and the spatial-temporal evolve pattern of mutating nodes exhibit some particular behaviors different from those of the original BS evolution model. More importantly, these behaviors will change with φ, the density of short paths in our network.     

WGS-84 坐标系下双机纯角度无源定位及性能分析

为实现切合实际的多运动平台对辐射源的无源定位,提出了基于WGS-84坐标系的双机纯角度交叉定位方法。推导了在各自平台坐标系下的视线(line-of-sight, LOS)到公共的WGS-84坐标系的旋转变换矩阵,然后应用空间两异面直线公垂线线段中点实现纯角度交叉定位;同时,利用一阶Taylor展开法,推导了误差经旋转变换和交叉定位等非线性变换后的协方差矩阵,并将其用于对多个单次定位估计的滤波,以提高算法定位精度。通过仿真,对影响定位精度的主要因素进行了深入分析,对比研究了单次定位和滤波定位性能,结果表明后者可明显改善精度,验证了该方法的有效性,得到的结论可指导实际运用。     

The impact of network structure on innovation efficiency: An agent‐based study in the context of innovation networks

This article investigates the impact of network structure on innovation efficiency by establishing a simulation model of innovation process in the context of innovation networks. The results indicate that short path lengths between vertices are conductive to high efficiency of explorative innovations, dense clusters are conductive to high efficiency of exploitative innovations, and high small‐worldness is conductive to high efficiency of the hybrid of these two innovations. Moreover, we discussed the reason of the results and give some suggestions to innovators and innovation policy makers. © 2014 Wiley Periodicals, Inc. Complexity 21: 111–122, 2015