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35841.VM内部隔离驱动程序的可靠性架构
[信息传输、软件和信息技术服务业] [2014-11-07]
利用虚拟化技术来整合资源已成为高性能服务器提高资源利用率的重要手段,虚拟化技术的可靠性对于高性能服务器所提供服务的质量至关重要.然而,驱动故障严重影响了虚拟机中操作系统的可靠性,也同样影响到整个服务器的可靠性.为此,提出一种在虚拟机内部通过隔离故障驱动程序来提高虚拟机可靠性的架构,该架构通过监视驱动程序所使用的内存信息来建立驱动可写权限的授权表,并在虚拟机监视器中设置虚拟机内核空间对应影子页表的写保护来捕获虚拟机的写操作,进而结合授权表判断被隔离驱动程序写操作的正确性.目前,该架构能够在无需修改驱动程序的情况下,在虚拟机内部实现对驱动程序的隔离.实验结果表明:该架构可以隔离84.63%的注入故障造成的系统崩溃失效,并且对于驱动性能的影响小于20%,提高了虚拟化环境的可靠性.
关键词：虚拟化；可靠性；驱动隔离
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35842.物联网环境下多智能体决策信息支持技术
[信息传输、软件和信息技术服务业] [2014-11-07]
随着物联网技术的不断发展,传感器网络得到了广泛的应用并成为信息技术领域重要的基础设施.尤其是传感网络提供的实时感知信息,为许多智能应用提供了充分的信息支持和必要的决策依据.然而,由于智能应用的实时感知信息需求通常无法转化为简单的查询请求与传感器底层查询接口准确匹配,因此,基于物联网的智能决策常常无法准确获取到决策相关的实时信息.针对此问题,提出一个基于语义覆盖网的物联网信息资源描述、推理和应用模型,并以多智能体系统决策支持为应用基础,研究了新型物联网环境下的多智能体决策信息支持技术.该技术以基于多智能体系统的团队导向规划的任务分解方法为核心,将复杂任务分解为若干简单子任务,并基于本体推理方法把子任务执行时需要的决策信息转化为精确、完备的传感器信息查询,从而实现从物联网中准确定位具体的传感器并获取相应感知信息的实时决策信息支持机制.
关键词：语义覆盖层；本体；团队导向规划；物联网；多智能体系统
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35843.一种基于DAG动态重构的认知网络服务迁移方法
[信息传输、软件和信息技术服务业] [2014-11-07]
针对认知网络高度动态性带来的服务随机失效问题,提出了一种服务迁移方法以保障认知网络的QoS.首先,采用先迁移、后优化的思想,重新生成关联服务有向无环图(directed acyclic graph,简称DAG),并在此基础上提出DAG动态重构算法,将关联服务转化为层次化DAG服务;其次,计算关键服务迁移路径,并给出可迁移服务死锁避免理论分析,将迁移服务提前迁移到当前网络空闲资源运行,以缩短服务的执行时间.仿真实验测试了3种故障注入类型下网络服务迁移方案的服务性能.实验结果显示,该方法在弹性网络负载与未知故障情况下具有较好的QoS保障效果.
关键词：认知网络；QoS；服务迁移；有向无环图；随机失效
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35844.司机对于汽车导航系统的看法和态度的心理因素影响检查
[交通运输、仓储和邮政业,信息传输、软件和信息技术服务业] [2014-11-07]
To examine drivers' perceptions of and attitudes toward car navigation systems, the present study integrated perceived satisfaction and perceived loca-tional accuracy into a modified technology acceptance model, and investigated hypothesized causal paths proposed by the research model with data collected from an online survey (N = 1,204). Results from the structural equation modeling indicated that perceived satisfaction and locational accuracy played crucial roles in determining perceived ease of use and perceived usefulness of the navigation systems. Implications and limitations are discussed.
关键词：汽车导航系统;技术接受模型;感知满意度;感知位置准确性
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35845.合伙用车系统的动态车辆分配管理
[交通运输、仓储和邮政业,信息传输、软件和信息技术服务业] [2014-11-07]
Carsharing allows members to benefit from private vehicle use without the costs and responsibilities of ownership and provides individuals with access to a fleet of shared-use vehicles in a network of locations on a short-term, as-needed basis. This paper seeks to develop a stochastic optimization framework to address the dynamic vehicle allocation problem for carsharing systems, in which the service operator needs to manage and determine the optimal vehicle allocation in both time and space to maximize profits. A multistage stochastic linear programming model with recourse, which can account for system uncertainties such as car-sharing demand variation, is formulated and solved. Numerical results are discussed and computational insights are presented on the basis of a seven-stage experimental network pilot study.
关键词：合伙用车；信息系统；车辆分配；管理
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35846.人工免疫系统与离散贝塞尔曲线的拟合
[信息传输、软件和信息技术服务业,医药制造业] [2014-11-07]
This chapter deals with the problem of fitting curves to data points, a classical optimization problem in Computer-Aided Geometric Design (CAGD). This issue plays an important role in real problems such as construction of car bodies, ship hulls, airplane fuselage, and other free-form objects. A typical example comes from reverse engineering where free-form shapes are extracted from clouds of scanned data points. In this chapter we address this issue by applying a powerful bio-inspired method called Artificial Immune Systems (AIS). The AIS can be understood as a computational methodology based upon metaphors of the biological immune system. As such, there is not one but several AIS algorithms. In this chapter we focus on the clonal selection algorithm (CSA), which explicitly takes into account the affinity maturation of the immune response. This algorithm is applied to fit Bezier curves to given sets of data points. Some illustrative examples show the good performance of our approach.
关键词：生物免疫系统；克隆算法；离散贝塞尔曲线；仿生学
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35847.一种支持细粒度并行的SDN虚拟化编程框架
[信息传输、软件和信息技术服务业] [2014-11-07]
软件定义网络(software defined network,简称SDN)通过集中式的控制器提高了网络的可编程性,成为近年来网络领域非常热门的话题.以Openflow网络为代表的软件定义网络将逻辑控制与数据转发相隔离,为网络虚拟化技术提供了良好的平台.集中式的抽象与控制使得SDN虚拟化框架的处理效率成为主要瓶颈.现有的SDN虚拟化框架由于缺乏对细粒度并行的支持,为编程人员充分利用多核/众核资源、控制更大规模的网络带来了极大的挑战.为了提高SDN虚拟化框架的处理效率,提出一种新的SDN虚拟化编程框架,通过新颖的API和运行时,在框架内部支持细粒度的并行处理.该框架通过对网络中流和网络资源进行抽象,使开发人员可以直接通过划分流空间来定义不同的虚拟网络,利用无锁的编程方式对共享的网络资源和流进行操作.实验结果表明,该框架在逻辑控制的执行效率方面具有良好的可扩展性,可以创建出更大规模的虚拟网络,并对其进行更为复杂的控制.
关键词：SDN虚拟化；事件编程；细粒度并行；众核处理器
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35848.车辆密度规模程度的建模和描述
[交通运输、仓储和邮政业,信息传输、软件和信息技术服务业] [2014-11-07]
Future vehicular networks shall enable new classes of services and applications for car-to-car and car-to-roadside communication. The underlying vehicular mobility patterns significantly impact the operation and effectiveness of these services, and hence it is essential to model and characterize such patterns. In this paper, we examine the mobility of vehicles as a function of traffic density of more than 800 locations from six major metropolitan regions around the world. The traffic densities are generated from more than 25 million images and processed using background subtraction algorithm. The resulting vehicular density time series and distributions are then analyzed. It is found using the goodness-of-fit test that the vehicular density distribution follows heavy-tail distributions such as Log-gamma, Loglogistic, and Weibull in over 90of these locations. Moreover, a heavy-tail gives rise to long-range dependence and self-similarity, which we studied by estimating the Hurst exponent (H).
关键词：汽车;通信网络;算法;表征;高速公路通信;图像;流动性;建模;交通控制;交通密度
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35849.传感器网络中一种基于单向哈希链的过滤方案
[信息传输、软件和信息技术服务业] [2014-11-07]
已有传感器网络中,过滤机制只能在转发过程中过滤虚假数据而无法过滤重复数据,且无法防范协同攻击.提出了一种基于单向哈希链的过滤方案HFS.在HFS中,节点在部署后将密钥和初始哈希值预分发给部分中间节点存储,每个数据包附带t个MAC和新鲜哈希值,转发节点同时对数据包中检测节点之间相对位置关系的合法性、MAC和哈希值的正确性以及哈希值的新鲜性进行验证.理论分析及仿真实验结果表明,HFS可同时过滤传感器网络中的虚假数据和重复数据,并能有效对抗协同攻击.
关键词：无线传感器网络；虚假数据；重复数据；单向哈希链；协同攻击
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35850.熵加权多视角协同划分模糊聚类算法
[信息传输、软件和信息技术服务业] [2014-11-07]
当前,基于协同学习机制的多视角聚类技术存在如下两点不足:第一,以往构造的用于各视角协同学习的逼近准则物理含义不明确且控制简单;第二,以往算法均默认各视角的重要性程度是相等的,缺少各视角重要性自适应调整的能力.针对上述不足:首先,基于具有良好物理解释性的Havrda-Charvat熵构造了一个全新的异视角空间划分逼近准则,该准则能有效地控制异视角间的空间划分相似程度;其次,基于香农熵理论提出了多视角自适应加权策略,可有效地控制各视角的重要性程度,提高算法的聚类性能;最后,基于FCM框架提出了熵加权多视角协同划分模糊聚类算法(entropy weight-collaborative partition-multi-view fuzzy clustering algorithm,简称EW-CoP-MVFCM).在模拟数据集以及UCI数据集上的实验结果均显示,所提算法较之已有多视角聚类算法在应对多视角聚类任务时具有更好的适应性.
关键词：多视角聚类；协同学习；Havrda-Charvat熵；香农熵；模糊C均值聚类
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