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1.
Multimedia synchronization is the essential technology for the integration of multimedia in distributed multimedia systems.The multimedia synchronization model has been recognized by many researchers as a premise of the implementation of multimedia synchronization.In distributed multimedia systems,the characteristic of multimedia synchronization is dynamic,and the key medium has the priority in multimedia synchronization.The previously proposed multimedia synchronization models cannot meet these requirements.So a new multimedia dynamic synchronization model-DSPN,based on the timed Petri-net has been designed in this paper.This model can not only let the distributed multimedia system keep multimedia synchronization in a more precise and effective manner according to the runtime situation of the system,but also allow the user to interact with the presentation of multimedia.  相似文献   

2.
Up to now, AI technology is dominated by the Physical Symbolic System(PSS), in which symbolic information is used as the medium for reasoning, In these approaches, information other than symbols, such as image, graphics, and even video should first be represented by symbols, and after reasoning, the symbolic result is again changed into its original media form. In this paper, we will propose a new form of reasoning method called multimedia reasoning (MR), a kind of reasoning that is based on the different media such as text, image, video, audio and so on. By introducing the concept of multimedia transformation theory (MTT), it presents a conceptual framework for multimedia reasoning, In the end, it discusses the importance and potentials in applications.  相似文献   

3.
In this paper, the projective lag synchronization of a new hyperchaotic system with certain/uncertain parameters is addressed. Based on Lyapunov stability theory, a generic and simple controller is designed for the projective lag synchronization. Furthermore, with LaSalle s invariance principle, an adaptive method is proposed to identify the unknown parameters of the new hyperchaotic system based on the projective lag synchronization. Finally, numerical simulations are given to support the analytical approach.  相似文献   

4.
Synchronization is an important issue in multimedia systems which integrate a variety of temporally related media objects.One part of synchronization is the representation of temporal information.Wish the emerging interactive multimedia,deterministic temporal models are replaced by nondeterministic ones with more expressiveness.This paper classifies temporal models by their expressiveness,and evealuates relevant nondeterministic temporal relations in multimedia data.Additionally,an interval-based nondeterministic model based on a complete temporal operator set is proposed providing high-leval abstractions and a high degree of expressiveness for interactive multimedia systems.  相似文献   

5.
The paper proposes a new text similarity computing method based on concept similarity in Chinese text processing. The new method converts text to words vector space model at first, and then splits words into a set of concepts. Through computing the inner products between concepts, it obtains the similarity between words. The new method computes the similarity of text based on the similarity of words at last. The contributions of the paper include: 1) propose a new computing formula between words; 2) propose a new text similarity computing method based on words similarity; 3) successfully use the method in the application of similarity computing of WEB news; and 4) prove the validity of the method through extensive experiments.  相似文献   

6.
This paper proposes a new method of constructing generalized concept lattice and producing rules from it in the generalized rough approximate space based on generalized similar relation which is more extensive than equivalent relation.Finally,a simple algorithm is presented to extract rules based on interesting measure.  相似文献   

7.
A new mixed method for relative error model order reduction is proposed. In the proposed method the frequency domain balanced stochastic truncation method is improved by applying the generalized singular perturbation method to the frequency domain balanced system in the reduction procedure. The frequency domain balanced stochastic truncation method, which was proposed in [15] and [17] by the author, is based on two recently developed methods, namely frequency domain balanced truncation within a desired frequency bound and inner-outer factorization techniques. The proposed method in ttiis paper is a carry over of the frequency-domain balanced stochastic truncation and is of interest for practical model order reduction because in this context it shows to keep the accuracy of the approximation as high as possible without sacrificing the computational efficiency and important system properties. It is shown that some important properties of the frequency domain stochastic balanced reduction technique are extended to the proposed reduction method by using the concept and properties of the reciprocal systems. Numerical results show the accuracy, simplicity and flexibility enhancement of the method.  相似文献   

8.
Logic Petri nets (LPNs) are suitable to describe and analyze batch processing functions and passing value indeterminacy in cooperative systems. To investigate the dynamic properties of LPNs directly, a new method for analyzing LPNs is proposed based on marking reachability graphs in this paper. Enabled conditions of transitions are obtained and a marking reachability graph is constructed. All reach- able markings can be obtained based on the graph; the fairness and reversibility of LPNs are analyzed. Moreover, the computing complexity of the enabled conditions and reachable markings can be reduced by this method. The advantages of the proposed method are illustrated by examples and analysis.  相似文献   

9.
This paper presents a new optimized decentralized controller design method for solving the tracking and disturbance rejection problems for large-scale linear time-invariant systems, using only low-order decentralized controllers. To illustrate the type of results which can be obtained using the new optimized decentralized control design method, the control of a large flexible space structure is studied and compared with the standard centralized LQR-observer controller. The order of the resultant decentralized controller is much smaller than that of the standard centralized LQR-observer controller. The proposed controller also has certain fail-safe properties and, in addition, it can be five orders of magnitude more robust than the standard LQR-observer controller based on their real stability radii. The new decentralized controller design method is applied to a large flexible space structure system with 5 inputs and 5 outputs and of order 24.  相似文献   

10.
This paper investigates cluster synchronization of a class of multi-agent systems with a directed bipartite graph topology,and presents a number of new results by using the neighbor’s rules for the following two cases:I)there is competition among the agents of diferent clusters,and II)there are both competition and cooperation among the agents.Firstly,for case I),a linear control protocol is designed for cluster synchronization of multi-agent systems,and a method is presented to determine the final state with the initial conditions based on state-space decomposition.Secondly,we study case II),and design a control protocol based on the information of neighbors and that of two-hop neighbors(that is,neighbors’neighbors).Finally,two examples are studied by using our presented results.The study of illustrative examples with simulations shows that our results as well as designed control protocols work very well in studying the cluster synchronization of this class of multi-agent systems.  相似文献   

11.
基于时间Petri网的多媒体同步模型   总被引:1,自引:1,他引:1  
多媒体同步是多媒体应用的一个重要需求,这已为众多研究人员所共识。多媒体同步的一个主要问题是多媒体同步时间需求的描述和建模。本文在克服当前多媒体同步模型局限性的基础上,提出了一个新的基于时间Petri网的多媒体同步模型--MSTP模型,它能使多媒体系统依据实际运行时的延迟和多媒体动脉同步类型。以更准确、高效的方式来保持多媒体同步。  相似文献   

12.
扩展时间流Petri网多媒体同步模型   总被引:5,自引:0,他引:5  
多媒体同步的一个主要问题是多媒体同步时间要求的描述与建模。文中基于时间流Petri网模型(TSPN),通过分析TSPN模型的不足之处,提出了一种新的多媒体同步模型--扩展时间流Petri网模型(STSPN),STSPN不但可以完全、准确地描述媒体流内和流间的时间行为,而且通过引入容许阻塞时间、问题算法等对TSPN进行扩展,可以有铲地克服网络随机延迟、阻塞和丢包等因素的不良影响,提高了模型的建模能力  相似文献   

13.
一种扩展的基于Petri网的多媒体同步模型   总被引:1,自引:0,他引:1  
多媒体应用的一个主要问题是对多媒体同步时间的描述和建模。文章通过引入全局时钟和对输入事件进行优先级分类,同时借鉴了TSPN的动态同步语义以及DTPN的用户交互思想,使模型可以准确描述多媒体同步时间要求,有效克服网络随机延迟和阻塞等影响。  相似文献   

14.
Web 2.0 applications allow rich media contents to be exposed and shared by users. Nevertheless, usually, a multimedia is provided as an unicum, made by synchronized media items. Sound tracks, video sequences, captions, cannot be customized “on-the-fly” by users. Managing multimedia in a deep way would meet the expectations of nowadays Web prosumers (i.e. producers and consumers), and it would widen the audience. Describing and synchronizing each medium, as well as specifying different alternative contents for it, are the keystones of multimedia customization and of audience widening. This paper presents a multimedia collaborative system, which provides support to the arrangement of medium into a multi-views composed multimedia. Each prosumer can add medium by juxtaposition or by defining it as an alternative (audio, video, textual) version of an existing one. The implementation of such a system is based on SMIL 3.0 specification but implements a new and compact syntax to let users manipulate the original multimedia synchronization and their alternatives. The proposed approach has been put to test in two different scenarios.  相似文献   

15.
流媒体同步机制的研究*   总被引:14,自引:0,他引:14  
多媒体同步是多媒体应用中的一个关键问题,介绍了较流行的几种多媒体同步方法,并对这些方法进行了简单的比较,在此基础上提出了一种基于流媒体传输技术和RTP/RTCP协议的同步模型,该模型有机地结合了分层同步法和时间戳同步法,实现了媒体间不同粒度的同步。  相似文献   

16.
张爱军  王石 《微机发展》2006,16(4):49-51
文中旨在研究基于MPEG-4技术的面向对象多媒体同步。所采用的方法是在分析现有多媒体同步模型的基础上,结合MPEG-4系统同步机制和高级同步模型(FlexTime),设计面向对象的多媒体同步模型,以实现MPEG-4中各媒体对象间同步。由此方法设计的层结构同步模型是一种有效可行的多媒体间同步的实现方法。和其它的多媒体间同步方法相比,这种方法在基于对象的多媒体的传输过程中携带较少的时间信息来完成对象间的同步,并且增强了基于对象内容交互的灵活性。  相似文献   

17.
多媒体信息的同步是分布式多媒体信息系统的关键技术。本文在对国外几个典型多媒体同步模型进行分析、比较的基础上,提出一个新的多媒体同步要模型。该模型不但可以充分、准确、形式化地描述和规模多媒体信息流的时间行为,而且还考虑到了分布式环境中多媒体信息的时间特性(如抖动),并且有人机交互功能。  相似文献   

18.
As network technology provides the capability to handle multimedia traffic and the demand of multimedia services increases, protocols are required for effective communication of multimedia data in a distributed environment. Synchronization is one of the key issues in a multimedia system. Most of the current approaches do not support an integrated solution to the problem of synchronization. In this paper we propose a mechanism for synchronization of multimedia data in distributed environment where the accuracy of the protocol can be tailored to the application. The system model supports live and video-on-demand service. We present a scheme where the specification of the temporal requirements provided by the application can be directly mapped to obtain the information necessary to enforce the synchronization required. We present two examples of specifying the temporal requirements and process of obtaining the information and present performance results of our simulation studies.  相似文献   

19.
基于同步有向图的同步测试序列生成方法   总被引:3,自引:0,他引:3  
使用多测试单元的测试系统可以对多端口协议实现进行一致性测试,但是在进行这种一致性测试时,测试系统各个端口之间可能会出现同步问题,现在,解决同步问题常用的办法是在测试单元相应端口之间增加同步连接,然后通过此同步连接相互发送同步消息来进行同步,多端口协议和其它类型的分布式系统可以用有限状态机模型来描述,目前,同步问题被分为双端口同步问题,多端口同步问题,紧同步问题等多种类型,该文考虑两种有限状态机测试问题,第一种是面向端口的测试,不考虑有限状态机测试单元之间的通信问题,第二种面向组的测试,有限状态机中的各个端口被分成互不相关的多个组,属于不同组中的测试单元之间互不通信,该文提出了一种基于同步有向图的同步测试序列生成方法,这种生成方法适用于Pair同步,Port同步和组同步问题,并且,这种方法也可以用来判断如何在非同步测试序列中增加同步通信,将非同步测试序列转化为同步测试序列。  相似文献   

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