Automatic adaptation of mobile applications to different user devices using modular mobile agents

Wearable, handheld, and embedded or standalone intelligent devices are becoming quite common and can support a diverse range of applications. In order to simplify development of applications which can adapt to a variety of mobile devices, we propose an adaptation framework which includes three techniques: follow‐me, context‐aware adaptation, and remote control scheme. For the first, we construct a personal agent capable of carrying its owner's applications. Second, we design a personal agent capable of carrying applications with an adaptable hierarchical structure. Then, applications can be adapted approximately to the context of evices by using an attribute‐based component decision algorithm. Finally, to achieve a remote control scheme, we distribute the computational load of applications on the resource‐restricted mobile devices. An application is divided into two parts that can be executed on a user device and a server separately. In short, this framework facilitates the development of widespread applications for ubiquitous computing environments. Furthermore, it enables the applications to follow their owners and automatically adapt to different devices. Copyright © 2005 John Wiley & Sons, Ltd.     

五机架轧制规范优化与自适应的研究

对改造后系统控制精度和效果进行了分析,运用模糊数学和模糊模式识别方法对轧制规范进行了优化和自适应修正,在轧制过程中取得了较好效果,提高了设定控制精度。     

Proportional-integral based fuzzy sliding mode control of the milling head

A-axis (that is, the milling head) is an essential assembly in the five-axis CNC machine tools, positioning precision of which directly affects the machining accuracy and surface qualities of the processed parts. Considering the influence of nonlinear friction and uncertain cutting force on the control precision of the A-axis, a novel fuzzy sliding mode control (FSMC) based on the proportional-integral (PI) control is designed according to the parameters adaptation. Main idea of the control scheme is employing the fuzzy systems to approximate the unknown nonlinear functions and adopting the PI control to eliminate the input chattering. Simulation analyses and experimental results illustrate that the designed control strategy is robust to the uncertain load and the parameters perturbation.     

一种自适应模糊系统(英)

采用模糊计算与神经计算相结合的方法，本文提出一种自适应模糊系统模型——AFS．AFS采用前向神经网络来实现模糊推理规则，运用模糊一致矩阵方法实现动态自适应以及最大关联隶属原则执行模糊决策．最后通过若干实例以说明AFS的性能．     

SIGTRAN中的QoS保障措施

下一代网络是基于分组交换的网络。SIGTRAN作为下一代网络中专门用于传输信令的传输层协议,对信令传输的可靠性、时延等问题起着至关重要的作用。QoS问题是IP网络中的关键问题,也是下一代网络中需要重点考虑的问题。SIGTRAN协议在设计的时候就考虑到了许多保证QoS的措施,从而保证了下一代网络中信令消息的传输性能。文中简要介绍了SIGTRAN协议的体系结构,给出了SIGTRAN中的QoS定义,分析了SIGTRAN中的各种QoS保障措施,最后对这些QoS保障措施进行了总结。     

Subdivision Surface Tesselation on the Fly using a versatile Mesh Data Structure

Subdivision surfaces have become a standard technique for freeform shape modeling. They are intuitive to use and permit designers to flexibly add detail. But with larger control meshes, efficient adaptive rendering techniques are indispensable for interactive visualization and shape modeling. In this paper, we present a realization of tesselation-on-the-fly for Loop subdivision surfaces as part of a framework for interactive visualization.     

A unified interaction scheme for information sources

Commonly, for retrieving the desired information from an information source (knowledge base or information base), the user has to use the query language that is provided by the system. This is a big barrier for many ordinary users and the resulting interaction style is rather inflexible. In this paper we give the theoretical foundations of an interaction scheme that allows users to retrieve the objects of interest without having to be familiar with the conceptual schema of the source or with the supported query language. Specifically, we describe an interaction manager that provides a quite flexible interaction scheme by unifying several well-known interaction schemes. Furthermore, we show how this scheme can be applied to taxonomy-based sources by providing all needed algorithms and reporting their computational complexity.     

高速无线局域网DCF机制下的链路自适应算法研究

随着高速无线局域网物理层的制定,动态选择物理层传输模式的链路自适应被认为是一种有效提高系统吞吐量的方法。本文给出了两种基于IEEE802．11a DCF机制下的链路自适应算法,并对它们进行了理论分析与数值仿真,结论表明,基于MPDU的链路自适应算法优于基于MSDU的算法。在分析MPDU算法的基础上,我们给出了一种简单的通过查表来来选择最适合物理层传输模式的方法,并深入地讨论了此物理层传输模式表的建立过程。     

一种基于缓存的SVC流媒体质量自适应算法

新型视频编码标准H.264/AVC的扩展SVC(可扩展视频编码)技术为未来异构环境下的流媒体传输提供了一种新的解决方案。针对基于SVC的流媒体系统中的核心问题——质量自适应,提出了一种新的算法。该算法分为预缓存和基于缓存的动态质量自适应两个阶段,不但能够自适应网络带宽的动态变化,而且避免了频繁的质量切换,使得用户能够在动态的网络环境下获得尽可能好的主观观看体验。实现了一套SVC流媒体原型系统,并在此基础上验证了算法的有效性。     

VXMLR系统存储模式的自适应调整

XML管理系统的查询处理效率很大程度上取决于系统中XML数据的存储模式．在用户查询已知或可预测的情况下,根据用户查询设计存储模式可以改善系统的查询处理效率．该文介绍VXMLR系统存储模式的自适应调整机制,根据历史查询信息,VXMLR系统对其存储模式进行自适应调整,从而提高查询处理效率,其基本思路是：首先根据历史查询,推导出适当的映射规则,得到XML文档在关系数据库中的存储模式;然后,在给定的空间约束下,根据历史查询使用背包问题求解算法选择关系表进行垂直分割或冗余存储相关数据,使查询所访问的无关数据尽可能少,VXMLR系统提供四种存储模式调整策略,其中两种策略可以实现自适应的存储模式调整,实验结果表明文中提出的方法是有效的。