Context-aware end-to-end QoS diagnosis and quantitative guarantee based on Bayesian network

To support quality of service(QoS)management on current Internet working with best effort, we bring forth a systematic approach for end-to-end QoS diagnosis and quantitative guarantee. For QoS diagnosis, we take contexts of a service into consideration in a comprehensive way that is realized by exploiting causal relationships between a QoS metric and its contexts with the help of Bayesian network(BN)structure learning. Context discretization algorithm and node ordering algorithm are proposed to facilitate BN structure learning. The QoS metric is diagnosed to be causally related to its causal contexts, and the QoS metric can be quantitatively guaranteed by its causal contexts. For quantitative QoS guarantee, those causal relationships are first modeled quantitatively by BN parameter learning. Then, the QoS metric is guaranteed to certain value with a probability given its causal contexts tuned to suitable values, that is, quantitative QoS guarantee is reached. Simulations with three sequential stages:context discretization, QoS diagnosis and quantitative QoS guarantee, on a peer-to-peer(P2P)network, are discussed and our approach is validated to be effective.     

基于卡口上下文和深度置信网络的车辆轨迹预测模型研究

针对车辆轨迹预测中节点序列的时序特性和实际路网中的空间关联性,该文提出一种基于深度置信网络和SoftMax (DBN-SoftMax)轨迹预测方法。首先,考虑到轨迹在节点集合中的强稀疏性和一般特征学习方法对新特征的泛化能力不足,该文利用深度置信网络(DBN)较强的无监督特征学习能力,达到提取轨迹局部空间特性的目的;然后...     

关联情境下物流服务外包商选择的混合型决策分析方法

现实中影响物流服务外包商选择的诸多因素通常具有主客观特性和关联性,针对此问题给出一种关联情境下物流服务外包商选择的混合型决策分析方法.首先,利用二元语义表示模型分别处理和集结专家给出的语言短语形式的因素关联信息和主观评价信息,并通过多因素关联分析确定因素的重要性和归类;然后,分别定义主客观测度因素的正负理想点,利用范数的概念构建规范化评价矩阵;进一步地,借鉴多准则优化妥协解(VIKOR)法的思想,计算每个备选外包商的群效用值和个体遗憾值以及折衷排序值,并根据折衷排序值选择出最理想的外包商.最后,通过一个实例分析说明给出方法的可行性和实用性.     

Privacy Enhanced Mobile Authentication

In this paper, we investigate location- and identity privacy issues related to the access procedures. The investigation includes subscriber identity management, mobility management at the link layer and the security setup (authentication and key agreement) procedures. The paper also presents a Privacy Enhanced Mobile Authentication and Key Agreement (PEMAKA) protocol that illustrates the concepts and demonstrates that future mobile systems can provide both improved access security and enhanced subscriber privacy.     

网络处理器的线程级并行技术研究

线程级并行技术能有效的提高微处理器内核的资源利用率，是目前高性能微处理器研究的重点内容。文章分析了网络处理器的线程级并行技术中存在的几个关键问题，结合网络协议处理的特征提出了一种适合于网络协议处理的混合多线程结构。并将其成功应用于网络协议处理微引擎NRS05的设计中，最大程度的提高了网络处理器的分组吞吐率。     

Context‐Aware Active Services in Ubiquitous Computing Environments

With the advent of ubiquitous computing environments, it has become increasingly important for applications to take full advantage of contextual information, such as the user's location, to offer greater services to the user without any explicit requests. In this paper, we propose context‐aware active services based on context‐aware middleware for URC systems (CAMUS). The CAMUS is a middleware that provides context‐aware applications with a development and execution methodology. Accordingly, the applications based on CAMUS respond in a timely fashion to contextual information. This paper presents the system architecture of CAMUS and illustrates the content recommendation and control service agents with the properties, operations, and tasks for context‐aware active services. To evaluate CAMUS, we apply the proposed active services to a TV application domain. We implement and experiment with a TV content recommendation service agent, a control service agent, and TV tasks based on CAMUS. The implemented content recommendation service agent divides the user's preferences into common and specific models to apply other recommendations and applications easily, including the TV content recommendations.     

A software architecture for GPRS session management

General packet radio service (GPRS) provides efficient access to the integrated services Internet from wireless networks. When the GPRS‐attached mobile station attempts to send or receive data, a packet data protocol (PDP) context shall be established. The GPRS session management (SM) supports the PDP context handling, which consists of PDP context activation, deactivation, and modification procedures. In this paper, we propose an SM software architecture for the serving GPRS support node. Our design goals are to achieve compatibility, modularity, and flexibility. More importantly, our approach can accommodate the design of the SM software architecture for third‐generation wireless networks. Copyright © 2001 John Wiley & Sons, Ltd.     

Research Issues in Ad-Hoc Distributed Personal Networking

This paper discusses the research issues that need to be addressed in order to create a personal distributed environment where people interact with various companion, embedded, or invisible computers not only in their close vicinity but potentially anywhere. These systems are called personal networks (PNs). They constitute a category of distributed systems with very specific characteristics. They are configured in an ad hoc fashion, as the opportunity and the demand arise, to support personal applications. PNs consist of communicating clusters of personal digital devices, devices shared with other people and even infrastructure-based systems. At the heart of a PN is a core Personal Area Network (PAN), which is physically associated with the owner of the PN. Unlike the present PANs that have a geographically limited coverage, the Personal Operating Space, PNs have an unrestricted geographical span, and incorporate devices into the personal environment regardless of their geographic location. In order to do this they need the services of infrastructure-based networks and ad-hoc networks to extend their reach. A PN extends and complements the concept of pervasive computing. We show that PNs introduce new design challenges due to the heterogeneity of the involved technologies, the need for self-organization, the dynamics of the system composition, the application-driven nature, the co-operation with infrastructure-based networks, and the security hazards. We discuss the impact of these problems on network design, assess present and proposed solutions, and identify the research issues. This revised version was published online in August 2006 with corrections to the Cover Date.     

模余代数和Morita-Takeuchi关系

H是Hopf代数,C是H-模余代数.首先利用余积分的概念,诱导C的右H-余模结构,并构造了smash余积余代数C×H,使C×H作为余代数同构于C H.然后,由C的右H-余模结构诱导C的左H0-模结构,令C=C/KerεH0C,则C×H与C有Morita-Takeuchi关系.