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1.
随着移动计算的不断普厦,针对移动终端的安全问题日益受到重视。传统的访问控制技术能够解决机密性和完整性问题,但没有充分考虑可用性要求。移动终端同个人计算机相比更容易耗尽系统资源,受到拒绝服务攻击。本文提出一种应用于移动终端的访问控制框架,扩充DTE机制,保证数据机密性和完整性,并允许关键应用预留动态资源(如CPU时间、物理内存页面等),系统对预留的资源进行统一的调度和管理,防止关键应用与其它程序竞争系统资源时产生冲突,保证系统对关键应用的响应,提高系统的可用性。 相似文献
2.
Heterogeneity in mobile computing devices and application scenarios complicates the development of collaborative software systems. Heterogeneity includes disparate computing and communication capabilities, differences in users needs and interests, and semantic conflicts across different domains and representations. In this paper, we describe a software framework that supports mobile collaboration by managing several aspects of heterogeneity. Adopting graph as a common data structure for the application state representation enables us to develop a generic solution for handling the heterogeneities. The effect external forces, such as resource constraints and diverging user interests, can be quantified and controlled as relational and attribute heterogeneity of state graphs. When mapping the distributed replicas of the application state, the external forces inflict a loss of graph information, resulting in many-to-one correspondences of graph elements. A key requirement for meaningful collaboration is maintaining a consistent shared state across the collaborating sites. Our framework makes the best of maximizing the state consistency, while accommodating the external force constraints, primarily the efficient use of scarce system resources. Furthermore, we describe the mobility aspects of our framework, mainly its extension to peer-to-peer scenarios and situations of intermittent connectivity. We describe an implementation of our framework applied to the interoperation of shared graphics editors across multiple platforms, where users are able to share 2D and 3D virtual environments represented as XML documents. We also present performance results, namely resource efficiency and latency, which demonstrate its feasibility for mobile scenarios. 相似文献
3.
The Mobile Agent (MA) technology is gainingimportance in the distributed management of networks andservices for heterogeneous environments. MA-basedmanagement systems could represent an interestingalternative to traditional tools built upon theclient/server model, either SNMP- or CMIP-based. Twomain requirements currently limit the acceptance of MAsolutions for management: the need of interoperabilityand the request for security. Without security,management systems cannot suit global untrustedenvironments, such as the Internet; withoutinteroperability, they cannot interact with existingtools and legacy systems. The paper describes an MA-basedmanagement system with security and interoperability asthe two main design objectives. It is an open managementframework that grants interoperability by providing compliance with CORBA, the most diffusedstandard in the area of object-oriented components. Inaddition, it is based on a thorough security model andprovides a wide range of tools and mechanisms to build and enforce flexible securitypolicies. 相似文献
4.
在移动分布式数据库系统中采用三层结构,提出了DMVOCC-DA-2PLV(Distributed Multiversion Optimistic Concurrency Control—Dynamic Adjustment of Serialization Order-Two-Phase Local Validation)协议处理移动分布式实时事务。移动实时事务处理分两阶段进行。第一阶段在移动主机(MHs)上处理,并进行局部部分有效性检查性确认,使用向后有效性确认机制,与在服务器提交事务进行有效性确认。及早地检测数据冲突,节省了处理和通信资源。第二阶段在服务器处理,通过局部部分有效性确认的事务,提交到服务器进行局部最终有效性确认。协议消除了移动只读事务和移动更新事务的冲突,使用多版本动态调整串行次序技术,避免了不必要的事务重启动。如果移动只读事务所有读数据项通过局部部分向后有效性确认,则可提交,大大降低了移动只读事务的响应时间。在全局有效性确认中对分布更新事务进行检查,以保证分布串行性。通过模拟仿真,对DMVOCC-DA-2PV协议进行了性能测试,并与DTO-2PC和DHP-2PL进行了比较。实验结果表明DMVOCC-DA-2PV并发控制协议要优于其它协议。 相似文献
5.
Autonomous systems are an emerging AI technology functioning without human intervention underpinned by the latest advances in intelligence,cognition,computer,and systems sciences.This paper explores the intelligent and mathematical foundations of autonomous systems.It focuses on structural and behavioral properties that constitute the intelligent power of autonomous systems.It explains how system intelligence aggregates from reflexive,imperative,adaptive intelligence to autonomous and cognitive intelligence.A hierarchical intelligence model(HIM)is introduced to elaborate the evolution of human and system intelligence as an inductive process.The properties of system autonomy are formally analyzed towards a wide range of applications in computational intelligence and systems engineering.Emerging paradigms of autonomous systems including brain-inspired systems,cognitive robots,and autonomous knowledge learning systems are described.Advances in autonomous systems will pave a way towards highly intelligent machines for augmenting human capabilities. 相似文献
6.
随着无线通信网络的更新换代和手机、PDA等移动设备的快速发展.移动设备对访问web的需求与日俱增.因而对移动应用系统的需求也就越来越多.在众多可用的移动开发平台中,12ME是其中比较主要的技术,而且变得越来越流行.面对业务和功能日新月异的移动应用系统.提出一个易于建模、实现和维护的基于12ME的移动应用系统开发框架.并在实际项目实践中取得了良好的效果. 相似文献
7.
提出了一种基于信度推理网络的移动代理系统黄页服务模型,为自主迁移的移动代理提供迁移决策支持。与现有的移动代理系统黄页服务模型相比,该模型较好地解决了信息局部性和信息更新的问题,其结构具有良好的可扩展性和灵活性,能更好地适应Internet动态的网络环境。 相似文献
8.
Accountability and responsibility are key concepts in the academic and societal debate on Autonomous Weapon Systems, but these notions are often used as high-level overarching constructs and are not operationalised to be useful in practice. “Meaningful Human Control” is often mentioned as a requirement for the deployment of Autonomous Weapon Systems, but a common definition of what this notion means in practice, and a clear understanding of its relation with responsibility and accountability is also lacking. In this paper, we present a definition of these concepts and describe the relations between accountability, responsibility, control and oversight in order to show how these notions are distinct but also connected. We focus on accountability as a particular form of responsibility—the obligation to explain one’s action to a forum—and we present three ways in which the introduction of Autonomous Weapon Systems may create “accountability gaps”. We propose a Framework for Comprehensive Human Oversight based on an engineering, socio-technical and governance perspective on control. Our main claim is that combining the control mechanisms at technical, socio-technical and governance levels will lead to comprehensive human oversight over Autonomous Weapon Systems which may ensure solid controllability and accountability for the behaviour of Autonomous Weapon Systems. Finally, we give an overview of the military control instruments that are currently used in the Netherlands and show the applicability of the comprehensive human oversight Framework to Autonomous Weapon Systems. Our analysis reveals two main gaps in the current control mechanisms as applied to Autonomous Weapon Systems. We have identified three first options as future work for the design of a control mechanism, one in the technological layer, one in the socio-technical layer and one the governance layer, in order to achieve comprehensive human oversight and ensure accountability over Autonomous Weapon Systems. 相似文献
9.
在现代控制系统中,网络控制系统可以用最小成本实现柔性系统,该柔性系统可以完成包括功能可重新配置的许多任务;网络控制系统采用公用的总线结构,使得系统具有更加有效的灵活功能、更好的资源共享、降低系统的维护成本,网络控制系统的最大问题是由于网络而产生的时延和数据包的丢失;研究了基于网络控制原理的水下自主航行器制导系统,详细分析了水下自主航行器网络控制系统的稳定性问题和基于时间触发的TTCAN高层协议;论文旨在通过对水下自主航行器网络控制系统结构的研究,指出其结构的意义和进一步的研究领域. 相似文献
10.
自治移动云可以为本地区域内的移动用户提供临时的存储服务。在节点空间有限的情况下,保持数据的持久性是自治移动云存储服务的一个主要挑战。提出了一种有限空间下的自治移动云存储协议,称为SLAMS(space limited storage protocol for autonomous mobile cloud),其基本思想是通过移动节点之间周期性的信息交互,维护每个数据块在网络中的K个副本,将数据块副本按需存储在空闲空间较大的节点中。给出了SLAMS协议中的副本维护机制、数据结构和算法、SLAMS协议的详细设计。仿真实验结果表明,相对于现有的自治移动云存储协议Phoenix,SLAMS协议在节点空间有限的情况下,具有较低的数据丢失率,最大可降低50%左右;具有较短的收敛时间,最高可降低95%;具有较少的数据块存储开销,最高可降低约90%;而且SLAMS协议中数据块维持K个副本的概率明显提高,最大可提高40%左右。 相似文献
11.
Linear logic can be used as a meta-logic to specify a range of object-level proof systems. In particular, we show that by
providing different polarizations within a focused proof system for linear logic, one can account for natural deduction (normal and non-normal), sequent proofs (with and without cut), and
tableaux proofs. Armed with just a few, simple variations to the linear logic encodings, more proof systems can be accommodated,
including proof system using generalized elimination and generalized introduction rules. In general, most of these proof systems
are developed for both classical and intuitionistic logics. By using simple results about linear logic, we can also give simple
and modular proofs of the soundness and relative completeness of all the proof systems we consider. 相似文献
13.
描述了一种动态、可定制的构件自主化的实现手段及运行平台,试图通过对实现自主构件的方法和手段的探索,为开发具有自主性的基于Internet的软件系统提供一定的实践基础和经验.在实现自主构件时,采取了改装已有普通构件的方式,将软件Agent技术和构件技术结合起来,通过为构件定制行为规则和规划来控制和调度构件的行为,使得构件能够根据环境的状态调整自己的行为.同时,通过集成可以解释和执行声明式规则的规则引擎,使得可以在不修改构件源代码和重新部署构件的情况下,动态定制和实现构件的自主性行为能力. 相似文献
14.
This paper presents a connection mechanism for autonomous self-assembly in mobile robots. Using this connection mechanism, mobile robots can be autonomously connected and disconnected. The purpose of self-assembly in mobile robotics is to add a new capability to mobile robots, thus, improving their performance to best fit the terrain conditions. Construction of a reconnectable joint is of primary concern in such systems. In this paper, first the geometric conditions and force equations of a general docking mechanism are studied. Then, we discuss the design details of our connection mechanism and present some experimental results that show that the proposed mechanism overcomes significant alignment errors and is considerably power efficient. 相似文献
15.
针对以往自主移动机器人体系结构在实时处理方面的不足,提出了一种基于多智能体的混合式体系结构,统一规划了机器人系统的软硬件结构,在该体系结构中设计并实现了协调Agent和推理Agent两种智能体,针对紧急事件进行了更实时的Agent实现,有效的提高的自主移动机器人在突发事件时的实时性,提出了使用多样化的信息组织形式,增强了系统的自适应能力和易扩展性。本文的实验结果表明在紧急状态下,系统的反应时间有效缩短,增加了系统的智能性和实时性。 相似文献
16.
This paper presents a novel navigation method for Autonomous Mobile Vehicle in unknown environments. The proposed navigator consists of an Obstacle Avoider (OA), a Goal Seeker (GS), a Navigation Supervisor (NS) and an Environment Evaluator (EE). The fuzzy actions inferred by the OA and the GS are weighted by the NS using the local and global environmental information and fused through fuzzy set operation to produce a command action, from which the final crisp action is determined by defuzzification. The EE tunes the supports of the fuzzy sets for the OA and the NS; therefore, the capability of the navigation method is enhanced. Simulation shows that the navigator is able to perform successful navigation task in various unknown or partially known environments, and it has satisfactory ability in tackling moving obstacles. More importantly, it has smooth action and exceptionally good robustness to sensor noise. 相似文献
17.
提出了一种基于策略的移动设备安全应用框架,该框架采用XML描述访问控制策略,并结合身份认证、信任连接等安全机制实现对设备自身资源以及设备对网络服务的安全访问,使得用户对移动设备的使用处于安全控制之下。 相似文献
18.
Due to the success of Napster, Gnutella and Freenet, peer to peer (P2P) computing has suddenly emerged at the forefront of Internet computing. And a lot of problems including security, reliability and rooting are urgent to be solved.Unfortunately, traditional techniques are not directly applicable to P2P systems. This paper presents a new framework called MAPPS for designing P2P applications based on JXTA and mobile agents. The MAPPS framework is structured as three layers:the MAPPS infiastmcture based on mobile agents, MAPPS services and MAPPS applications. In this way, MAPPS not only follows the ootstanding architecture of JXTA, but also enhances the mobility and flexibility of P2P systems. Using MAPPS,developers of new P2P systems can design and implement P2P systems more efficiently. 相似文献
19.
在研究移动机器人自身特点及网络控制特性的基础上,提出一种基于组件的移动机器人程序框架,减少了编写移动机器人应用程序时的复杂性并提高了代码的复用性。通过构建统一的网络平台和控制平台,制定一组规范的模块抽象类和接口,实现组件的动态加载和连接。通过优先值控制,灵活地调整对机器人的控制方式和网络控制模式。结合中科院智能机器人平台AIM,说明如何使用Java和XML构建该框架。 相似文献
20.
Exploratory activities seem to be intrinsically rewarding for children and crucial for their cognitive development. Can a machine be endowed with such an intrinsic motivation system? This is the question we study in this paper, presenting a number of computational systems that try to capture this drive towards novel or curious situations. After discussing related research coming from developmental psychology, neuroscience, developmental robotics, and active learning, this paper presents the mechanism of Intelligent Adaptive Curiosity, an intrinsic motivation system which pushes a robot towards situations in which it maximizes its learning progress. This drive makes the robot focus on situations which are neither too predictable nor too unpredictable, thus permitting autonomous mental development. The complexity of the robot's activities autonomously increases and complex developmental sequences self-organize without being constructed in a supervised manner. Two experiments are presented illustrating the stage-like organization emerging with this mechanism. In one of them, a physical robot is placed on a baby play mat with objects that it can learn to manipulate. Experimental results show that the robot first spends time in situations which are easy to learn, then shifts its attention progressively to situations of increasing difficulty, avoiding situations in which nothing can be learned. Finally, these various results are discussed in relation to more complex forms of behavioral organization and data coming from developmental psychology 相似文献
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