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101.
To provide responsive information services in a ubiquitous computing environment, service software and system development are indispensable. A component-based ubiquitous information system with a JAIN (Java APIs for Integrated Networks) platform to achieve seamless transmissions and reach-everywhere communications was designed in our research. In this development, numerous ubiquitous service modules were identified: location management, roaming, mobile IP and WAP networking. These component-based network modules were constructed using a component composition language with component specification and interface definition, running on top of a distributed service architecture using a JAIN platform to distribute the ubiquitous information services to mobile users. Two applications, Wireless-Application-Protocol (WAP) Mail and Video-on-Demand (VoD) services, show that the JAIN-like platform with the developed networking components effectively fills the gap for application developers between mobile appliances and various kinds of ubiquitous information services. 相似文献
102.
我国移动通信制造业在2G上晚了十年,未能取得相应的市场份额。但在3G领域,已经逐渐同步业界先进水平。如何改变现有市场格局,我国移动通信业面临全新的机会和重大的挑战,本就我国WCDMA系统产业化现状做了简要论述。 相似文献
103.
104.
Human can handle a deformable object and damp its vibration with recognized skill. However, for an industrial robot, handling a deformable object with acute vibration is often a difficult task. This paper addresses the problem of active damping skill for handling deformable linear objects (DLOs) by using a strategy inspired from human manipulation skills. The strategy is illustrated by several rules, which are explained by a fuzzy and a P controller. A proportional-integral-derivative (PID) controller is also employed to explain the rules as a comparison. The interpretations from controllers are translated into high level commands in a robotic language V+. A standard industrial robot with a force/torque sensor mounted on the wrist was employed to demonstrate the skill. Experimental results showed the fuzzy based damping skill is quite effective and stable even without any previous acknowledge of the deformable linear objects.Category (5) 相似文献
105.
High accuracy path tracking for vehicles in presence of sliding: Application to farm vehicle automatic guidance for agricultural tasks 总被引:1,自引:0,他引:1
Roland Lenain Benoit Thuilot Christophe Cariou Philippe Martinet 《Autonomous Robots》2006,21(1):79-97
When designing an accurate automated guidance system for vehicles, a major problem is sliding and pseudo-sliding effects. This is especially the case in agricultural applications, where five-centimetre accuracy with respect to the desired trajectory is required, although the vehicles are moving on slippery ground. It has been established that RTK GPS was a very suitable sensor to achieve automated guidance with such high precision: several control laws have been designed for vehicles equipped with this sensor, and provide the expected guidance accuracy as long as the vehicles do not slide. In previous work, further control developments have been proposed to take sliding into account: guidance accuracy in slippery environments has been shown to be preserved, except transiently at the beginning/end of curves. In this paper, the design of this control law is first recalled and discussed. A Model Predictive Control method is then applied in order to preserve accuracy of guidance even during these curvature transitions. Finally, the overall control scheme is implemented, and improvements with respect to previous guidance laws are demonstrated through full-scale experiments. 相似文献
106.
Mou Weimin; Biocca Frank; Owen Charles B.; Tang Arthur; Xiao Fan; Lim Lynette 《Canadian Metallurgical Quarterly》2004,10(4):238
In 3 experiments, the authors investigated spatial updating in augmented reality environments. Participants learned locations of virtual objects on the physical floor. They were turned to appropriate facing directions while blindfolded before making pointing judgments (e.g., "Imagine you are facing X. Point to Y"). Experiments manipulated the angular difference between the learning heading and the imagined heading and between the actual heading and the imagined heading. The effect of actual-imagined on pointing latency was observed for naive users but not for users with brief training or instructions concerning the fact that objects can move with body movements. The results indicated that naive users used an environment-stabilized reference frame to access information arrays, but with experience and instruction the nature of the representation changed from an environment stabilized to a body stabilized reference frame. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
107.
介绍了莱钢中小型轧钢生产线打捆机器人自动控制系统的硬件配置、软件结构及其主要控制功能,并对打捆定位和打捆过程作了详细说明。 相似文献
108.
杨宇航 《计算机工程与设计》2004,25(8):1278-1281
论述了采用直接序列扩频技术设计的便携式无线图像传输系统原理,结构,关键技术和安全保密方法等。系统具有通信质量好、性能稳定、安全性高,便于机动等优点,适合于需要经常改变安装位置的情况,是多种情况下图像传输的理想选择。 相似文献
109.
XIAN He-qun FENG Deng-guo 《通讯和计算机》2007,4(3):44-51
Even with attractive computational advantages, mobile agent technology has not developed its full potential due to various security issues. This paper proposes a method called Private Key Consignment to solve the problem of how to protect the data carried by mobile agents. It exploits new functionalities and mechanism provided by the trusted computing technology, and adopts both public key and symmetric key cryptographic means for data and key protection. The most notable feature of this method is that it protects the private key of the agent by consigning it to a tamper proof hardware, thus, enabling convenient and secure use of the private key. It provides a new scheme of mobile agents' data protection. 相似文献
110.
随着网络的迅猛发展,管理网技术的相关研究也越来越得到广泛重视,传统的集中式管理方法在可扩展性、可靠性、灵活性方面存在一定的不足。基于移动代理的分布式网络管理方案可以很好地解决这些问题。网管站派遣移动代理到各被管节点上去收集数据和执行网管操作,这样可以分散网络管理站的工作量和降低网络的流量,并提升网络管理系统的主动性。 相似文献