基于不重叠路径熵的网络抗毁性评估方法

通过引入熵的概念,提出了基于不重叠路径数的标准稳定熵指标,用于刻画节点间抗毁性随不重叠路径数变化的规律.在此基础上给出了用于全网抗毁性评估的模型.同时指出了评价模型中涉及的节点间不重叠路径数的计算方法.最后通过算例分析以及与最短路径法相比较,论证了基于不重叠路径熵的模型在网络抗毁性评估方面具有更高的准确性与合理性.     

Automatic resource allocation in a distributed camera network

In this paper, we present a hierarchical smart resource coordination and reconfiguration framework for distributed systems. We view the coordination problem as one of context aware resource reconfiguration. The fundamental unit in this hierarchy is a Fault Containment Unit (FCU) that provides run-time fault-tolerance by deciding on the best alternative course of action when a failure occurs. FCUs are composed hierarchically and are responsible for dynamically reconfiguring failing FCUs at lower levels. When such a reconfiguration is not possible, FCUs propagate the failure upward for resolution. We evaluate the effectiveness of our framework in a people tracking application using a network of cameras. The task for our multi-camera network is to allocate pairs of cameras that localize a subject optimally given the current run-time context. The system automatically derives policies for switching between camera pairs that enable robust tracking while being attentive to certain performance measures. Our approach is unique in that we model the dynamics in the scene and the camera network configuration steers the policies to provide robust tracking.     

Prowling autonomous mobile robot with a network camera

This research aimed to develop an autonomous mobile robot that helps various kinds of people. The evasion of obstacles is absolutely imperative so that the robot can act in a human-life environment. Therefore, we developed a robot that moves through doors and avoids obstacles with the help of images taken by a camera set on the robot. This work was presented in part at the 13th International Symposium on Artifical Life and Robotics, Oita, Japan, January 31–February 2, 2008     

TDI-CCD相机动态成像的速度同步控制研究

在介绍时间延迟积分电荷耦合器件(TD I-CCD)的结构与工作原理基础上,通过像移调制传递函数(MTF)分析了TD I-CCD行扫速率与运动像不同步时对相机成像质量的影响。理论和实验仿真表明:在奈奎斯特频率范围内,只要将TD I-CCD推扫成像过程中的同步误差控制在一定的范围内,就可以明显地减少像移对成像质量的影响,最后,给出了2种简便和实用的同步控制方法。     

Intelligent unmanned anti-theft system using network camera

In this paper, we propose the intelligent unmanned anti-theft system using network cameras. To do this, we use two Internet Protocol (IP) cameras, which are installed at the inside and the outside of the restricted area. First of all, the external camera is used to monitor a potential intruder entering the restricted area in real time. To detect the potential intruder from sequential images obtained by external IP camera, we propose the robust algorithm combining the background modeling, the hybrid silhouette, the convex summation, the morphology and the smoothing. Once the intruder is detected by the external camera, the internal camera with pan-tilt mechanism is then activated and starts tracking the intruder and monitoring the prescribed valuables registered with some feature points in the database. To track the intruder, we propose the tracking algorithm using the background elimination and the histogram. And then, we completes the proposed anti-theft system by using the Scale Invariant Feature Transform (SIFT) algorithm in order to monitor whether the intruder steals the prescribed valuables or not. Finally, we have shown the effectiveness and the applicability of the proposed method through experiments.     

Auto-organized visual perception using distributed camera network

Camera networks are complex vision systems difficult to control if the number of sensors is getting higher. With classic approaches, each camera has to be calibrated and synchronized individually. These tasks are often troublesome because of spatial constraints, and mostly due to the amount of information that need to be processed. Cameras generally observe overlapping areas, leading to redundant information that are then acquired, transmitted, stored and then processed. We propose in this paper a method to segment, cluster and codify images acquired by cameras of a network. The images are decomposed sequentially into layers where redundant information are discarded. Without the need of any calibration operation, each sensor contributes to build a global representation of the entire network environment. The information sent by the network is then represented by a reduced and compact amount of data using a codification process. This framework allows structures to be retrieved and also the topology of the network. It can also provide the localization and trajectories of mobile objects. Experiments will present practical results in the case of a network containing 20 cameras observing a common scene.     

新一代协议IPv6自动地址配置的实现

本文分析了 IPv6协议的特点、协议过度方案及在新协议实施时自动地址配置的必要性 .探讨了两种自动地址配置方式的独立性和互补性 ,从系统和工程角度阐述了 DHCPv6系统的实现过程 ,并在 Free BSD4.0系统下实现了系统的三个部分 ,最后讨论了基于 Free BSD系统的改进问题     

基于高清网络摄像机的自动聚焦算法

针对传统的聚焦评价函数运算量大、峰值搜索算法易受干扰且视频质量反复变化的问题,实现一种较传统聚焦评价函数与爬山算法相结合的聚焦算法更好的自动聚焦算法.采用TI公司的TMS320DM368处理器自带的自动聚焦(AF)引擎作为硬件实现的聚焦评价函数;采用的峰值搜索算法将聚焦曲线分为聚焦区和散焦区,在散焦区使用大步长的GM(1,1)模型预测搜索方向,在聚焦区使用小步长的爬山算法搜索峰值.实验结果表明,该算法拥有更好地实时性与准确性,适用于高清网络摄像机的自动聚焦.     

Estimation of the dynamic spinal forces using a recurrent fuzzy neural network.

Estimation of the dynamic spinal forces from kinematics data is very complicated because it involves the handling of the relationship between kinematic variables and electromyography (EMG) signals, as well as the relationship between EMG signals and the forces. A recurrent fuzzy neural network (RFNN) model is proposed to establish the kinematics-EMG-force relationship and model the dynamics of muscular activities. The EMG signals are used as an intermediate output and are fed back to the input layer. Since EMG is a direct reflection of muscular activities, the feedback of this model has a physical meaning. It expresses the dynamics of muscular activities in a straightforward way and takes advantage from the recurrent property. The trained model can then have the forces predicted directly from kinematic variables while bypassing the costly procedure of measuring EMG signals and avoiding the use of a biomechanics model. A learning algorithm is derived for the RFNN model.     

Intrinsically dynamic network communities

Community finding algorithms for networks have recently been extended to dynamic data. Most of these recent methods aim at exhibiting community partitions from successive graph snapshots and thereafter connecting or smoothing these partitions using clever time-dependent features and sampling techniques. These approaches are nonetheless achieving longitudinal rather than dynamic community detection. We assume that communities are fundamentally defined by the repetition of interactions among a set of nodes over time. According to this definition, analyzing the data by considering successive snapshots induces a significant loss of information: we suggest that it blurs essentially dynamic phenomena—such as communities based on repeated inter-temporal interactions, nodes switching from a community to another across time, or the possibility that a community survives while its members are being integrally replaced over a longer time period. We propose a formalism which aims at tackling this issue in the context of time-directed datasets (such as citation networks), and present several illustrations of both empirical and synthetic dynamic networks. We eventually introduce intrinsically dynamic metrics to qualify temporal community structure and emphasize their possible role as an estimator of the quality of the community detection—taking into account the fact that various empirical contexts may call for distinct ‘community’ definitions and detection criteria.     

基于虚拟骨干网的MANET地址自动配置方法

针对MANET的地址自动配置问题,提出了基于虚拟骨干网的IPv6地址自动配置方法。充分利用了虚拟骨干网的分层结构、骨干网和子网分别执行不同的配置算法,消息复杂度和时间复杂度低,非常适合通信资源宝贵的MANET。     

Key observation selection-based effective video synopsis for camera network

Nowadays, tremendous amount of video is captured endlessly from increased numbers of video cameras distributed around the world. Since needless information is abundant in the raw videos, making video browsing and retrieval is inefficient and time consuming. Video synopsis is an effective way to browse and index such video, by producing a short video representation, while keeping the essential activities of the original video. However, video synopsis for single camera is limited in its view scope, while understanding and monitoring overall activity for large scenarios is valuable and demanding. To solve the above issues, we propose a novel video synopsis algorithm for partially overlapping camera network. Our main contributions reside in three aspects: First, our algorithm can generate video synopsis for large scenarios, which can facilitate understanding overall activities. Second, for generating overall activity, we adopt a novel unsupervised graph matching algorithm to associate trajectories across cameras. Third, a novel multiple kernel similarity is adopted in selecting key observations for eliminating content redundancy in video synopsis. We have demonstrated the effectiveness of our approach on real surveillance videos captured by our camera network.     

基于IP Camera的网络视频监控系统的设计

设计了一种基于IP Camera的网络视频监控系统,系统通过各种不同的接入服务,提供了C/S、Web、ClickOnce等多种访问方式,实现了多种平台下对视频终端的监控.系统采用类似于DNS的目录服务,将所有物理节点、逻辑节点均统一编码,并存储到本地配置数据库或文件中,实现了视频终端、客户监控端、视频数据文件等信息的管理和访问.系统在有线和无线两种不同的传输方式下,根据不同的网络传输特点,分别采用了TCP和UDP两种不同的通信方式和通信机制向外部提供视频数据服务,提高了视频流畅性.     

Synchronization of coupled harmonic oscillators in a dynamic proximity network

In this paper, we revisit the synchronization problems for coupled harmonic oscillators in a dynamic proximity network. Unlike many existing algorithms for distributed control of complex dynamical networks that require explicit assumptions on the network connectivity, we show that the coupled harmonic oscillators can always be synchronized, without imposing any network connectivity assumption. Moreover, we also investigate the synchronization with a leader and show that all harmonic oscillators can asymptotically attain the position and velocity of the leader, again without any assumption on connectivity of the followers. Numerical simulation illustrates the theoretical results.     

Security evaluation of a wireless ad-hoc network with dynamic topology

This article reviews the approach to security evaluation of wireless ad-hoc networks (mesh networks, MANET/VANET networks, networks of smart houses, etc.), which is based on the method of principal component analysis.     

Tracklet style transfer and part-level feature description for person reidentification in a camera network

Pattern Analysis and Applications - Reidentifying multiple objects in a camera network are a difficult problem, especially when determining whether the same object appears in a different place at a...     

A dynamic K-winners-take-all neural network

In this paper, a dynamic K-winners-take-all (KWTA) neural network, which can quickly identify the K-winning neurons whose activations are larger than the remaining ones, is proposed and analyzed. For N competitors, the proposed KWTA network is composed of N feedforward hardlimit neurons and three feedback neurons, which are used to determine the dynamic threshold. From theoretical analysis and simulation results, we found that the convergence of the proposed KWTA network, which requires Log(2)(N+1) iterations in average to complete a KWTA process, is independent of K, the number of the desired winners, and faster than that of the existing KWTA networks.     

The effects of a trust mechanism on a dynamic supply chain network

Recognizing trust as the basis for firm cooperation, we investigate how a trust mechanism affects a supply chain network using a dynamic multi-agent and multi-stage model that incorporates three supplier selection rules: a preferred price rule, a preferred trust rule, and a preferred random rule. We use this model to explore the impact of the three rules on supply chain performance and bankruptcy propagation under the conditions of external disruption, bank rate, and new firms entering the market. Our results identify the preferred trust rule as the supplier selection method that can in most cases best improve the total revenue of the whole supply chain network. In terms of firm bankruptcy, on the other hand, it is the preferred random rule that has the least impact and the preferred price rule that has the most.     

基于树型结构的摄像头网络智能监控系统设计

视频监控是安防的重要组成部分,随着摄像头监控网规模的增大,传统的监控系统已经无法胜任基于网络的智能监控任务。大规模摄像头网络要求高性能的处理能力和高效的联合分析智能算法,为了解决这个问题,提出了一种全新的监控系统架构:系统基于树型结构。它充分利用集群计算机的处理能力,高效地运行加载于其上的多种智能算法,便捷地进行多摄像头信息联合分析。系统已在20台高清摄像头组成的网络下实际运行,其稳定的性能证明了设计的合理性。