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1.
.NET环境下的移动代理迁移机制   总被引:1,自引:0,他引:1  
The migration mechanism is one of the most important techniques for the mobile agent techniques. In this paper, migration mechanism for the mobile agent based on Microsoft .NET developing environment is researched. First, the two serialized techniques provided by .NET platform are analyzed and compared,and Binary serialization techniques are adopted to implement the data state migration of the mobile agent. Then, the Web serviceapproach is introduced to realize the code state migration of the mobile agent and the corresponding Web service is constructed. At last, the whole migration process of the mobile agent is described.  相似文献   

2.
基于时序逻辑的移动计算的形式方法分析   总被引:1,自引:0,他引:1  
魏峻 《计算机科学》2000,27(6):22-27
At present,mobile computing is widely considered as a new computing paradigm supported by advanced computational technologies.One of main characteristics of this paradigm is the ability to dynamically change the binding for hardware and/or software components,that is mobility. Although there are many languages appeared to announce supporting mobile computing,the requirements and features of this paradigm are still scarcely recognized.So a lot of research is being expanded on formal models and methods for mobile computing. In this paper,we analyze a temporal logic based formalism for mobile computing——Mobile Unity. At first,we summarize the features of mobile computing,and generalize that mobile systems should be decoupled,strongly-autonomous,context-dependent and owning new requirements for location-transparency.Then we introduce Mobile Unity,its extensions for U NITY from syntax to computational semantics,specially analyze the correspondence between the language structures of Mobile Unity and the abstraction of mobile features,such as location,mobility,transient interactions etc.At the end,we conclude its some deficiency for supporting mobile computing.  相似文献   

3.
基于JavaCard的移动代理系统安全性研究   总被引:1,自引:0,他引:1  
With wide and increasing range applications of mobile agent technology, the security problem has gotten more and more focus. This paper discusses the security problems that the mobile agent system faces with at presentand the existing protesting schemes for it. Then a solving method based on JavaCard is proposed to protect mobile a-gents. And a feasible solving method is also provided to solve the security problems of JavaCard itself.  相似文献   

4.
张全新  宋瀚涛 《计算机科学》2003,30(10):133-135
Introduce method and technology of combination of the TCP/IP protocol based on IPv6 and the cellular wireless communication network. Analyze the cut-in point and key technology of the combination from the view of frame, system structure and the realization of protocols. The 3G cellular wireless communication is a hotspot today and the mobile IP technology is one of the developing directions for the Internet's future. We put forward a new idea and method for the mobile communication technology from the practical view.  相似文献   

5.
Knowledge is essential for the competitiveness of individuals as well as organizations.Thus the application of the latest methodologies and technologies are utilized to support knowledge acquisition,warehousing,distribution,and transfer.Means and methods of web 2.0 are useful to support this procedure.Especially,highly complex and very dynamic knowledge domains have to be accessible and applicable in the framework of learning network communities,including the stakeholders of training and education.Mechatronics for example is such an interdisciplinary,dynamic field of research and application.Based on intelligence,software,and hardware it is requiring special approaches for developing a courseware based learning and knowledge transfer environment.After defining the specifics of mechatronics education and postgraduate training in the context of e-education,the concepts of the development and utilization of mechatronic courseware can be deduced from e-learning 2.0 and mobile learning facilities,possibilities,and abilities.Mechatronic courseware will be developed by using authoring software and embedding the material into learning management systems with respect to general methods and rules of modern system and software development.As an example,the courseware is used for vocational training and further education especially in cooperation networks of educational institutions and SME.  相似文献   

6.
7.
When traditional Intrusion Detection System(IDS)is used to detect and analyze the great flow data transfer in high-speed network,it usually causes the computation bottleneck.This paper presents a new Mobile Agent Distributed IDS(MADIDS) system based on the mobile agents.This system is specifically designed to process the great flow data transfer in high-speed network.In MADIDS,the agents that are set at each node process the data transfer by distributed computation architecture.Meanwhile by using the reconfiguration quality of the mobile agents,the load balance of distributed computation can be dynamically implemented to gain the high-performance computing ability.This ability makes the detecting and analyzing of high-speed network possible.MADIDS can effectively solve the detection and analysis performance bottleneck caused by the great flow data transfer in high-speed network.It enhances the performance of IDS in high-speed network.In this paper,we construct the infrastructure and theoretical model of MADIDS,and the deficiencies of MADIDS and future research work are also indicated.  相似文献   

8.
Nowadays E-learning as a form of learning depending on networks and computer devices has been expanding by leaps and bounds. As a special kind of E-learning, M-learning (mobile learning) aims at the use of mobile devices anywhere at anytime by anybody. In this paper, the technologies to develop a M-learning system are deeply analyzed according to the layer model at first. Then, from the view of application, the standardization in M-learning is researched in order to accelerate the development and popularization of M-learning. Finally, quality estimation of M-learning system is discussed from the view of QoE (quality of experiences). The experience form end-user is the sole effective norm to judge the result of M-learning technology. It is no doubt that technologies, standardization and evaluation will play very important parts in the course of M-leaming development.  相似文献   

9.
In the ages of current network technology, as a new technology, the emergence of mobile agent shows us a wider and wider application prospect in the fields of network technology, such as Network Management,Intelligence Information Retrieval and Electronic Commence and so on. The security is the essence of mobile agent technology. In this paper we analyze the security issues and survey some representative approaches to solve the problem in mobile agent systems. We focus on the issues about the agent's security and propose a master-slave designpattern based security model for mobile agent called SMAP(Secure Mobile Agent Platform). In the end we give anapplication example to show how to use these.  相似文献   

10.
基于CORBA的移动Agent技术研究   总被引:11,自引:3,他引:8  
In the first,a common conceptual model for mobile agent is introduced.According to this model,the related CORBA object services are discussed and a mobile agent faclicity interface definition is given.  相似文献   

11.
“Grid” computing has emerged as an important new research field. With years of efforts, grid researchers have successfully developed grid technologies including security solutions,resource management protocols, information query protocols, and data management services. How-ever, as the ultimate goal of grid computing is to design an infrastructure which supports dynarnic,cross-organizational resource sharing, there is a need of solutions for efficient and transparent task re-scheduling in the grid. In this research, a new grid middleware is proposed, called G-JavaMPI. This middleware adds the parallel computing capability of Java to the grid with the support of a Grid-enabled message passing interface (MPI) for inter-process communication between Java processes executed at dif-ferent grid points. A special feature of the proposed G-JavaMPI is the support of Java process migration with post-migration message redirection. With these supports, it is possible to migrate executing Java process from site to site for continuous computation, if some site is scheduled to be turned down for system reconfiguration. Moreover, the proposed G-JavaMPI middleware is very portable since it requires no modification of underlying OS, Java virtual machine, and MPI package. Preliminary performance tests have been conducted. The proposed mechanisms have shown good migration efficiency in a simulated grid environment.  相似文献   

12.
Mobile platform is now widely seen as a promising multimedia service with a favorable user group and market prospect. To study the influence of mobile terminal models on the quality of scene roaming, a parameter setting platform of mobile terminal models is established to select the parameter selection and performance index on different mobile platforms in this paper. This test platform is established based on model optimality principle, analyzing the performance curve of mobile terminals in different scene models and then deducing the external parameter of model establishment. Simulation results prove that the established test platform is able to analyze the parameter and performance matching list of a mobile terminal model.  相似文献   

13.
In mobile network, quality of service (Qos) is difficultly guaranteed for the particularity of mobile network. If the system knows, prior to the mobile subscriber movement, the exact trajectory it will follow, the Qos can be guaranteed. Thus, location prediction is the key issue to provide quality of service to mobile subscriber. In the present paper, RBF Network of Neural Network techniques were used to predict the mobile user's next location based on his current location as well as time. The software Matlab 6.5 was used to confirm the parameters of RBF network, and to same training data, makes the detailed contrast with resilient propagation BP and BP in learning time and steps of learning. Experiment results show that predicted locations with RBF are more effective and accurate than resilient BP.  相似文献   

14.
基于移动帧的在线小波去噪   总被引:8,自引:0,他引:8  
夏睿  孟科  钱锋  王振雷 《自动化学报》2007,33(9):897-901
In this paper, shortcoming of traditional wavelet denoising in real-time signal processing is discussed, requirements of online denoising are considered, and a moving window is introduced into traditional wavelet transform. Using the moving window, an online wavelet denoising approach is proposed. Some problems of online denoising, such as border distortion and pseudo-Gibbs phenomena, are discussed. To solve these problems, window extension and window cycle spinning are also proposed. Different approaches are tested by the signal widely used in denoising domain. Both the visual results and the quantitative measures are presented to highlight the availability of the new approach.  相似文献   

15.
An obstacle avoidance scheme of a two-wheeled mobile robot is shown by selecting an appropriate Lya- punov function. When considering the obstacle, the Lyapunov function may have some local minima. A method which erases the local minima is proposed by using a function which covers the minima with a plane surface. The effectiveness of the proposed method is verified by numerical simulations.  相似文献   

16.
The thesis sets forth for the policy maker a way of achieving the aim of building model data warehouse based on relation model distributed database by using Mobile Agent technology. According to the design principal of data warehouse and the standard technology,author puts forward forming metadatas by tree pattern or forests strctur-e,giving the definition of metadata. Model and the general principal of combining metadatas to form data warehouse and showing a picture tool of data warehouse designing system. It creates a Mobile Agent orieinal form that can realize the constrction of data warehouse based on relation model distributed database.  相似文献   

17.
In the mobile computing environment, we propose a novel watermarking algorithm based on integer wavelet through pixel-wise masking with simple human visual system (HVS). Then the correlation between the watermarking sequence and the marked DWT coefficients coded with difference refinement is discussed. Finally,watermarking detection algorithm is presented for scalable coding.  相似文献   

18.
移动Agent系统构建研究   总被引:1,自引:0,他引:1  
贾志勇  谢立 《计算机科学》2003,30(10):31-34
Mobile agent technology has strong adaptability to the status of network and executing environment, and provides a flexible and uniform framework for Web and distributed applications.Mobile agent system, as the foundation of agent computing, should provide the basic supports like executing support, agent migration, andcommunication, as well the extensive supports like naming service, security, fault tolerance, interoperation,application development and management tools. Based on the analysis of current mobile agent system, this article discusses these supports deeply, and also points out the main challenges to the development of mobile agent system.  相似文献   

19.
Mobile Internet Protocol is a recommended Internet protocol designed to support the mobility of a user (host). Host mobility is becoming important because of the recent blossoming of laptop computers and the high desire to have continuous network connectivity anywhere the host happens to be. The development of Mobile IP makes this possible. The traditional Mobile IP specification forces all packets forwarded to the MN (mobile node), to be routed via HA (home agent), which often leads to Triangular routing, which in turn causes data transmission delay and wastes network resources. This paper discusses means of resolving the triangle routing problem, it introduces some of the recent route optimization schemes that have been used to solve that problem.  相似文献   

20.
TCP Issues in Mobile Ad Hoc Networks: Challenges and Solutions   总被引:10,自引:0,他引:10       下载免费PDF全文
Mobile ad hoc networks (MANETs) are a kind of very complex distributed communication systems with wireless mobile nodes that can be freely and dynamically self-organized into arbitrary and temporary network topologies. MANETs inherit several limitations of wireless networks, meanwhile make new challenges arising from the specificity of MANETs, such as route failures, hidden terminals and exposed terminals. When TCP is applied in a MANET environment, a number of tough problems have to be dealt with. In this paper, a comprehensive survey on this dynamic field is given. Specifically, for the first time all factors impairing TCP performance are identified based on network protocol hierarchy, i.e., lossy wireless channel at the physical layer; excessive contention and unfair access at the MAC layer; frail routing protocol at the network layer, the MAC layer and the network layer related mobile node; unfit congestion window size at the transport layer and the transport layer related asymmetric path. How these factors degrade TCP performance is clearly explained. Then, based on how to alleviate the impact of each of these factors listed above, the existing solutions are collected as comprehensively as possible and classified into a number of categories, and their advantages and limitations are discussed. Based on the limitations of these solutions, a set of open problems for designing more robust solutions is suggested.  相似文献   

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