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1.
In the last decade, the research of the usability of mobile phones has been a newly evolving area with few established methodologies and realistic practices that ensure capturing usability in evaluation. Thus, there exists growing demand to explore appropriate evaluation methodologies that evaluate the usability of mobile phones quickly as well as comprehensively. This study aims to develop a task-based usability checklist based on heuristic evaluations in views of mobile phone user interface (UI) practitioners. A hierarchical structure of UI design elements and usability principles related to mobile phones were developed and then utilized to develop the checklist. To demonstrate the practical effectiveness of the proposed checklist, comparative experiments were conducted on the usability checklist and usability testing. The majority of usability problems found by usability testing and additional problems were discovered by the proposed checklist. It is expected that the usability checklist proposed in this study could be used quickly and efficiently by usability practitioners to evaluate the mobile phone UI in the middle of the mobile phone development process.  相似文献   

2.
通过对各种SIM卡技术的对比,说明了SIM卡不仅用于解决用户入网鉴权和加密问题,还在向着双面应用、非预置个人化信息、更小更薄、存储容量更大等方向发展。SIM卡技术的演进,推动着手机终端的发展,随着智能手机的普及,手机终端除具备通信功能外,还将具有银行卡、门禁卡、公交卡等多种个人化应用。  相似文献   

3.
通过手机SIM卡实现增值服务开创了移动电子商务应用的一个新领域,文章介绍了基于SIM卡的移动通信信息服务系统的总体构架及系统功能,同时,就该系统在安全方面采用的先进技术进行了讨论。  相似文献   

4.
This article presents the results from research in which 3 different remote control interfaces were compared to assess the impact of interface structure on the performance of the operator for remotely controlled mobile inspection robots. The primary control interface of a mobile robot consists of a head-mounted display, data gloves for gripper control, joystick for movement control of the robot platform, and a motion tracking system for measuring head orientation and hand position. In order to compare different control interfaces, an additional system, based on a Liquid Crystal Display monitor and joystick, was prepared. Results of this study show that the use of virtual reality techniques in the interfaces of mobile inspection robots increases operator productivity, the level of spatial presence, and distance evaluation while facilitating the execution of tasks, as well as improving and speeding up their execution and reducing the operator’s time needed to adapt to the control interface. The latter is achieved with the increased level of intuitive control while ensuring comfort.  相似文献   

5.
Containment Control in Mobile Networks   总被引:2,自引:0,他引:2  
In this paper, the problem of driving a collection of mobile robots to a given target destination is studied. In particular, we are interested in achieving this transfer in an orderly manner so as to ensure that the agents remain in the convex polytope spanned by the leader-agents, while the remaining agents, only employ local interaction rules. To this aim we exploit the theory of partial difference equations and propose hybrid control schemes based on stop-go rules for the leader-agents. Non-Zenoness, liveness and convergence of the resulting system are also analyzed.  相似文献   

6.
移动Ad-hoc网络安全   总被引:13,自引:0,他引:13  
移动Ad-hoc网络是一种不依赖任何固定的基础设施的新型的无线网络。在网络中,节点之间的通信完全依赖无线链路,网络拓扑随着节点的移动频繁变化。移动Ad-hoc网络不同于有线网络的特性对于保证其安全性提出了新的挑战。本文在探讨移动Ad-hoc网络的安全需求的基础上,着重分析了移动Ad-hoc网络易于遭受的攻击,并集中了讨论移动Ad-hoc网络的路由安全、密钥管理等关键问题。  相似文献   

7.
Mobile IP网络中主动分布式移动网络管理系统   总被引:2,自引:0,他引:2  
由于无线移动网络带宽低、延迟高以及移动性强的特点,传统的SNMP集中式网管也由于自身的缺陷无法,接有效地对无线移动网络进行管理.为此,我们提出了一个Mobile IP网络中主动分布式移动网络管理系统的结构框架即将新型分布式网络体系结构一主动网络融合于移动网络管理.本文详细描述了系统工作流程、管理过程以及功能结构,并在一个宽带无线IP网络中进行了原型实验,实验结果证明系统高效、分布、灵活和可扩展.  相似文献   

8.
栅栏覆盖是传感器网络研究中的热点问题,现有有关栅栏覆盖研究大多针对静态兴趣区域的栅栏覆盖,而对于实际应用中如海洋污染、森林火灾、部队行军等的栅栏覆盖应用不适用;该文主要针对动态对象研究移动传感器网络的有效栅栏覆盖;抽象了问题模型并提出了栅栏覆盖评价指标,然后结合凸优化理论提出了一种分布式的移动栅栏覆盖算法;通过3个不同场景分别测试了算法在400*600m的区域中随机部署有50个移动传感器节点对于不同动态对象构建一条封闭栅栏带所花费的时间以及栅栏带动态形成时的移动距离;测试结果算法能够快速有效实现动态区域的栅栏覆盖。  相似文献   

9.
The use of applications on mobile devices has reached historic levels. Using the System Usability Scale (SUS), data were collected on the usability of applications used on two kinds of mobile platforms—phones and tablets—across two general classes of operating systems, iOS and Android. Over 4 experiments, 3,575 users rated the usability of 10 applications that had been selected based on their popularity, as well as 5 additional applications that users had identified as using frequently. The average SUS rating for the top 10 apps across all platforms was 77.7, with a nearly 20-point spread (67.7–87.4) between the highest and lowest rated apps. Overall, applications on phone platforms were judged to be more usable than applications on the tablet platforms. Practitioners can use the information in this article to make better design decisions and benchmark their progress against a known universe of apps for their specific mobile platform.  相似文献   

10.
11.
Scalable Routing in Cyclic Mobile Networks   总被引:1,自引:0,他引:1  
The nonexistence of an end-to-end path poses a challenge in adapting traditional routing algorithms to delay-tolerant networks (DTNs). Previous works have covered centralized routing approaches based on deterministic mobility, ferry-based routing with deterministic or semideterministic mobility, flooding-based approaches for networks with general mobility, and probability-based routing for semideterministic mobility models. Unfortunately, none of these methods can guarantee both scalability and delivery. In this paper, we extend the investigation of scalable deterministic routing in DTNs with repetitive mobility based on our previous works. Instead of routing with global contact knowledge, we propose a routing algorithm that routes on contact information compressed by three combined methods. We address the challenge of efficient information aggregation and compression in the time-space domain while maintaining critical information for efficient routing. Then, we extend it to handle a moderate level of uncertainty in contact prediction. Analytical studies and simulation results show that the performance of our proposed routing algorithm, DTN Hierarchical Routing (DHR), is comparable to that of the optimal time-space Dijkstra algorithm in terms of delay and hop count. At the same time, the per-node storage overhead is substantially reduced and becomes scalable.  相似文献   

12.
论文将讨论在IPv6环境中,一个移动网络中同时存在多个路由器的条件下,比较单路由器条件所需要进行的优化工作。论文将提出两种方案,并且针对每种方案的优劣进行讨论。实现这项工作的意义在于可以有效地减少移动路由器和本地代理以及对等节点之间报文交互的数量或是降低本地代理和对等节点的缓冲绑定(CachedBinding)中所存储记录的数量,最终将有助于节约系统资源和提高搜索效率。  相似文献   

13.
The growing number of mobile subscribers has attracted firms to invent newer strategies to reach prospective customers in innovative but nonintrusive ways. While customer mobility creates an opportunity to reach them at desired times and locations, in practice, real-time ad deliveries are difficult due to the size of the ad-delivery decision problem. This research aims at analyzing and developing a decision policy for delivering ads on mobile devices such as cell phones. We look at the ad delivery problem from the perspective of an advertising firm, which delivers ads on behalf of its clients (merchants) to mobile customer using a wireless carrier's infrastructure. We formulate the mobile ad delivery problem as a Markov decision process (MDP) model. The ad delivery policy depends on the customer's desire and willingness to receive ads, their real-time locations, historical mobility patterns, available network capacity, and fee structure agreed upon for ad deliveries. We also develop a fast heuristic to solve larger size problems. We test our heuristic against an upper bound we developed and analyze performance using simulation.  相似文献   

14.
严伟  倪明选 《软件学报》2005,16(9):1647-1660
选播是一种新型的"1对一些中的多个"通信模式,是任播和组播通信的通用形式.有了选播的支持,客户端可以与多个服务器建立联系以此增加可靠性,可以被分布式服务用来在移动自组网络中给多个服务器分发重要信息.不仅描述了选播面临的主要问题和最近几年提出的选播机制,而且讨论了借助其他相关技术进行可能的优化方案和实际应用的部署.  相似文献   

15.
介绍了在两种典型的无线移动环境下的组播路由协议——移动IP网络和AdHoc网络,比较了它们的特性和性能。在无线移动环境下实现组播路由协议是一件很复杂的工作,比起固定网络下的组播实现,它的路由模式、转发算法、可靠性、安全性等的实现都更为困难。最后对该领域的前景进行了展望。  相似文献   

16.
One of the most critical roles security researchers have is keeping up with new technologies and considering the security implications that go along with them-essentially, ensuring that security is "baked in" to new ideas from the earliest possible moment. Because of this, researchers have had significant interest in the field of mobile ad hoc networks (Manets). Such networks are frequently viewed as a key communications technology enabler for network-centric warfare and disaster relief operations, and as the technology matures, Manets are increasingly reaching many other applications in areas such as intelligent transportation systems and fault-tolerant mobile sensor grids.  相似文献   

17.
Abstract. In this paper we deal with competitive local on-line algorithms for non-preemptive channel allocation in mobile networks. The signal interferences in a network are modeled using an interference graph G . We prove that the greedy on-line algorithm is Δ -competitive, where Δ is the maximum degree of G . We employ the ``classify and randomly select" paradigm [5], [17], and give a 5 -competitive randomized algorithm for the case of planar interference graphs, a 2 -competitive randomized algorithm for trees, and a (2c) -competitive randomized algorithm for graphs of arboricity c . We also show that the problem of call control in mobile networks with multiple available frequencies reduces to the problem of call control in mobile networks with a single frequency. Using this reduction, we present on-line algorithms for general networks with a single frequency. We give a local on-line algorithm which is (α (δ +1 + α )/(1/2+α ) 2 )-competitive, where α is the independence number of G , and δ is the average degree of G . The above results hold in the case when the duration of each request is infinite, and the benefit the algorithm gains by accepting each request is equal to one. They are extended to handle requests of arbitrary durations, and arbitrary benefits.  相似文献   

18.
移动IP与移动AdH oc网络(MANET)结合可以充分扩大网络的覆盖范围,然而在这种集成环境下两个节点间的应用程序进行通讯目前还存在着问题,如名字唯一分配、域间域名解析、IP地址不固定造成的通讯中断等等。本文提出一种新的体系框架综合考虑名字唯一分配、地址自动配置、域名解析与移动IP机制,解决了上述问题。  相似文献   

19.
在过去的十几年中,移动视频网络飞速发展,逐渐成为人们生活中所不可或缺的一部分.随着用户需求的不断变化,移动视频网络也在不断发展与革新.本文以移动视频网络架构的演变为标准,将其演进过程分为服务器/客户端架构、覆盖网架构、面向内容网络架构三个阶段,并详细阐述了每个阶段移动视频网络发展的驱动力和它的关键技术.最后,本文对三个阶段的移动视频网络做了全面的对比分析,并且展望了移动视频网络未来的发展趋势.  相似文献   

20.
为了满足移动多媒体传输的需要,提出了一种新的移动模型——multimedia communication mobility model (MCM),该移动模型充分考虑了实际环境中存在障碍物和多媒体业务的特殊要求。利用MCM设计了针对多媒体业务的路由算法,并给出了算法的详细描述。由于该算法考虑到了现实障碍物的影响。并借鉴了无线自组网基本路由协议,因此其不仅能获得满足业务要求的路由。而且能避免链路中断的影响,以便通过及时开启备用节点来提供备用路由。与目前已经提出的路由算法相比。该协议更适合于移动多媒体业务的需求。  相似文献   

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