支持移动设备接入Gnutella网络的代理架构研究

针对当前移动设备无法加入Gnutella网络实现文件共享网络的现状,提出一种移动代理Gnutella网络架构的设计方案。利用移动代理作为移动设备的代理加入Gnutella网络,帮助移动设备实现文件的共享功能。架构能有效地减少移动设备的信息流量,并支持移动设备在Gnutella网络中实现可移动性。     

The impact of incentive mechanisms in multi-channel mobile music distribution

Record labels and telecoms are using the pervasiveness of mobile technologies to create a mobile music market, where customers can have their preferred music at any time and in any place. The idea is to replicate the successful strategy of the Internet-based music market into the mobile scenario. In this paper we first analyze the current mobile music market and we show that this strategy leads to several problems (e.g., excessive download time, cost and protection). As a second contribution, we propose and analyze a multi-channel distribution strategy, where customers can cooperate to music distribution. The approach is based on the cellphone network, the free-of-charge communication technologies provided by cellphones, and on an incentive mechanism that financially compensates users for their cooperation in music distribution. The approach evaluation shows that the employment of an effective incentive mechanism can mitigate the problems of the current mobile music scenario, as it provides benefits to customers, cellphone network providers and music stores.

智能移动设备在电化学检测分析中的应用

智能移动设备近年来发展迅速,市场占有率急剧增长。面向不同研究领域,与多种传感技术相结合的移动检测系统常见诸报道。该文综述了智能移动设备硬件和软件的迅速发展,以及为了满足日益增长的移动分析检测需求所开发的基于智能移动设备的分析检测方法,特别是智能移动设备在电化学检测分析中的应用。     

非完整移动机械臂的鲁棒跟踪控制

针对非完整移动机械臂惯性参数的不确定性,采用滑模控制为其设计了输出跟踪控制器。首先给出了包括驱动电机动态特性的非完整移动机械臂的简化动态模型,然后通过微分同胚和输入变换将其分解为4个低阶子系统,并给出了其输出跟踪的滑模控制器设计方法。仿真实验表明,所设计的鲁棒控制器能很好地跟踪给定轨迹。     

Improving robustness of P2P applications in mobile environments

Mobile P2P networks possess particular characteristics which make accessibility of services deployed on peers a challenge. This has to be taken into account when considering robustness of applications that depend on successfully accessing a set of services. While ensuring robustness is traditionally handled through replication or redundancy, those solutions are not readily applicable to decentralized and dynamic networks. Instead, current solutions are based on efficient P2P structure maintenance or unstructured network search algorithms. A novel and alternative method proposed in this paper is based on the observation that some redundancy may exist between services offered on the network, a fact which could be used to recreate an unavailable service from services accessible to a peer. Instead of adding redundancy to the system, our solution exploits the already existing redundancy to improve robustness of mobile P2P applications. We model the interaction with services as finite-state transducers and propose a heuristic to obtain redundancy between any pair of services. Then, a set of algorithms that uses this inter-service redundancy to recreate the interaction with one service from the other is discussed. The computational cost is polynomial with respect to services’ size, and in practice, the non-redundant functionality and related control need to be implemented locally.

多种移动终端设备管理模式的研究与实现

随着终端的多样化,先前的管理单一设备的技术暴露出种种弊端,探讨了终端设备的特点和管理的技术．在这技术基础上做了改进,使用XML描述各种终端设备信息和性能指标,改进访问速度和增加索引技术,以Web Service方式实现终端设备管理的服务平台．改进后的设备管理技术具有高效、灵活、可扩展性、可重用性等特点,并且在移动证券服务系统中付之实施,取得了良好的效果。     

Directional bias in scrolling tasks: a study of users' scrolling behaviour using a mobile text-entry strategy

Mobile devices with limited interaction controls often employ cyclic scrolling for retrieval tasks. In this paper the scrolling behaviour of users entering text using a tree-key input technique based on two-phase cyclic character scrolling is studied. The results show that users have a tendency to scroll more from left-to-right than from right-to-left. However, users do also use the right-to-left functionality to both speed up their text entry task by choosing the shortest path and to make navigational corrections, suggesting that it is appropriate to provide bidirectional scrolling functionality in user interfaces on constrained mobile devices. In situations where a device architect is constrained to providing only unidirectional scrolling, the results suggest that a right-directional design is preferred over a left-directional design.     

Motor performance of tongue with a computer-integrated system under different levels of background physical exertion

The purpose of this study was to compare the motor performance of tongue, using Tongue Drive System, to hand operation for relatively complex tasks under different levels of background physical exertion. Thirteen young able-bodied adults performed tasks that tested the accuracy and variability in tracking a sinusoidal waveform, and the performance in playing two video games that require accurate and rapid movements with cognitive processing using tongue and hand under two levels of background physical exertion. Results show additional background physical activity did not influence rapid and accurate displacement motor performance, but compromised the slow waveform tracking and shooting performances in both hand and tongue. Slow waveform tracking performance by the tongue was compromised with an additional motor or cognitive task, but with an additional motor task only for the hand.     

Flocking of mobile agents with fuzzy controller

Based on individual local observed information of the swarm, a fuzzy logical controller （FLC） of the attraction/repulsion function is built. Combining with the rate consensus algorithm, the swarming of the separation, cohesion and alignment is achieved. Based on the optimal controller theories, a capability target is used to measure the states of the system. In the computer simulation, it is shown that the aggregation of the multi-agent systems can get consensus following a mobile leader from the individual local perceived information.     

采用分段验证签密的移动代理新方案

密码的应用可使移动代理免受运行主机上恶意软件的攻击,保持其携带信息的机密性并不受撺扰.结合分段验证签密与多方签密,一个采用分段验证签密的移动代理系统新方案被提出,此设计方案具有防止各主机彼此间偷窥与伪造信息的性能.这类移动代理的目标是采集网络多方的敏感数据,这种情况下,对信息提供主机和非信息提供主机的防犯都是重要的.     

Creating human digital memories with the aid of pervasive mobile devices

The abundance of mobile and sensing devices, within our environment, has led to a society in which any object, embedded with sensors, is capable of providing us with information. A human digital memory, created with the data from these pervasive devices, produces a more dynamic and data rich memory. Information such as how you felt, where you were and the context of the environment can be established. This paper presents the DigMem system, which utilizes distributed mobile services, linked data and machine learning to create such memories. Along with the design of the system, a prototype has also been developed, and two case studies have been undertaken, which successfully create memories. As well as demonstrating how memories are created, a key concern in human digital memory research relates to the amount of data that is generated and stored. In particular, searching this set of big data is a key challenge. In response to this, the paper evaluates the use of machine learning algorithms, as an alternative to SPARQL, and treats searching as a classification problem. In particular, supervised machine learning algorithms are used to find information in semantic annotations, based on probabilistic reasoning. Our approach produces good results with 100% sensitivity, 93% specificity, 93% positive predicted value, 100% negative predicted value, and an overall accuracy of 97%.     

可信移动计算与数字版权管理综合方案

针对目前手持终端媒体受到版权侵犯、未授权使用及其非法在移动网络中传播困扰等问题,分析了采用开放移动联盟制订的数字版权管理技术,在解决这些问题时的不足及仍存在的潜在安全风险.创建性提出了一种基于可信移动计算平台之上且更为安全的数字版权管理模式,从而能强化该最新规范架构的安全性能并提升系统的交互性与兼容性.理论分析和实验结果表明,采用这种将两者相结合的策略后所构建的终端系统具备良好的健壮性.     

更新分发环境下移动事务处理的节能策略设计

能量的损耗和事务的一致性是更新分发环境下移动应用所需要考虑的两个主要问题,但传统的节能技术并不支持对移动客户端移动事务的并发控制,而现有的基于数据广播的移动事务处理方法主要针对保持数据一致性而设计,并未考虑事务处理过程中的节能问题.将分布式索引技术应用于移动事务处理,提出一种在更新分发环境下同时实现移动事务并发控制和节能处理的有效方法.实验结果表明使用该方法比未应用索引技术前节能84.5%.     

支持移动客户端的分布式订阅/通知框架

为了实现客户应用移动的透明性,支持在不同的网络连接节点之间的迁移,在扩充订阅,通知分布式框架的基础上,引入订阅消息的重新发送、Fetch 消息的传递和 Replay 消息的传递3个过程,重新构造了应用通知消息的传递路径,实现了缓冲消息按照正确时间顺序重新发送给应用,而且支持应用从多个数据源处订阅消息.该框架具有良好的可适应性.     

基于CPLD的彩色视觉移动机器人路径跟踪系统

路径跟踪是机器人视觉导航控制基本技术之一,为使机器人沿地面彩色引导线自主运动,并能在适时离线执行任务后自动返航,提出了一种用可编程逻辑器件(CPLD)实现的视觉伺服PID控制方法.该方法利用图像特征反馈对其所跟踪的路经进行实时识别跟踪.仿真结果表明,该方法改善了控制算法的实时性,提高了移动机器人的路径跟踪精度与速度.     

Leader–follower formation control of nonholonomic mobile robots with input constraints

The paper deals with leader–follower formations of nonholonomic mobile robots, introducing a formation control strategy alternative to those existing in the literature. Robots’ control inputs are forced to satisfy suitable constraints that restrict the set of leader possible paths and admissible positions of the follower with respect to the leader. A peculiar characteristic of the proposed strategy is that the follower position is not rigidly fixed with respect to the leader but varies in proper circle arcs centered in the leader reference frame.     

On-line extraction of stable visual landmarks for a mobile robot with stereo vision

This paper proposes a method to extract on-line stable visual landmarks from sensory data obtained by stereo vision so as to adapt to changes of environment. Given a two-dimensional obstacle map, the robot first extracts vertical line segments which are distinct and inside planar surfaces not near boundary edges as they are expected to be observed reliably from various viewpoints. However, the extracted feature information such as position and length include uncertainty due to errors of vision and motion. The robot then reduces the uncertainty by matching the planar surface containing the features to the map. These processes are performed on-line in order to adapt to actual changes of lighting and the scene depending on the robot's view. Experimental results in real scenes show the validity of the proposed method.     

Robust tracking control of nonholonomic dynamic systems with application to the bi-steerable mobile robot

A tracking controller for nonholonomic dynamic systems is proposed which allows global tracking of arbitrary reference trajectories and renders the closed loop system robust with respect to bounded disturbances. The controller is based on [Chwa, D. (2004). Sliding-mode tracking control of nonholonomic wheeled mobile robots in polar coordinates. IEEE Transactions on Control Systems Technology, 12(4), 637-644] and shows several generalizations and improvements. The control law for tracking of general nonholonomic systems using inverse kinematic models (IKM) and sliding surfaces is stated. Conditions are proven under which robust tracking is achieved for a specific system. Tracking control is applied to the bi-steerable mobile robot, and simulation results are presented.     

一种引入阈值的Ad Hoc网络分级转发指针的位置管理策略

在移动Ad Hoc网络中,由于网络具有自组织性和节点的频繁移动,也就使得网络的拓扑结构频繁变化。随着节点数目的增加,网络的开销迅速增大,这就直接影响到网络的可扩展性。目前,在移动Ad Hoc网络中越来越多的引入了位置管理的策略,以达到减少网络开销的目的。引入分级转发指针和阈值的思想,提出了一种新的位置管理策略。通过与其他策略的方针比较,证明其在性能上具有更好的可扩展性。