BA-BGP:一种基于备份AS通告的域间路由协议

BGP协议通过触发全局、反应式收敛应对网络拓扑和策略变化,然而由于其收敛时间过长、收敛过程中大量AS经历不可达、环路,造成大量转发中断,难以支持VoIP、远程医疗等关键业务的应用。本文提出了一种基于备份AS通告的新型域间路由协议BA-BGP,在不影响BGP协议动态性的基础上,通过在更新报文中增加备份AS属性,使AS节点可以获取到达目标的备份AS地址,当节点面临瞬时失效时可将报文封装转发到与备份AS关联的路径,从而降低了转发中断。大量模拟实验证明,通过采用具有互联网特征的拓扑以及广泛采用的BGP策略,BA-BGP有效降低了链路失效引起的瞬时失效率与转发中断时间,增强了网络可靠性。     

TIPC透明进程间通信协议研究和应用

针对雷达、声呐领域高性能信号处理平台的研发需求,提出并实现了在并行信号处理机系统中利用TIPC透明进程间通信协议实现通信接口的方法。分析了TIPC相比其它通信协议的优点,阐述了TIPC的基本实现原理,对TIPC的实现难点和重点进行了详细讨论,将TIPC和TCP传输协议的通信性能进行了实际测试比较。最后,提出了基于TIPC增强并行信号处理系统通信可靠性的方法。     

基于空间相关性的H.264快速自适应模式选择算法

为了减小H.264编码器的复杂度,提出了一种帧间预测模式快速自适应选择算法。该算法首先利用运动补偿后残差宏块的统计信息,将需要计算率失真代价函数的候选模式减少为一个模式组中包含的模式子集;然后根据相邻的左块和上块的模式,从所选择的模式子集中选出出现概率最高的两种模式来计算并比较率失真代价函数,选出代价最小的模式作为最佳模式。实验表明,本算法平均可以节省编码时间约65%,同时PSNR下降约为?0.24dB,有利于实时应用。     

Business relationships in internet-based electronic markets: the role of goodwill trust and transaction costs

Abstract.  Transaction costs and goodwill trust, which differentiate between transactional and collaborative relationships, were found in existing research to play a significant role in the way organizations use internet technologies to manage their relationships with customers and suppliers within electronic markets (EM). However, a thorough investigation of role that the two dimensions play together in shaping the use of EM is lacking from the mainstream literature. This research addresses transaction costs and goodwill trust together to clarify the transformations that internet use has brought on the nature of interorganizational relationships that develop between EM players. The research finds the use of EM in collaborative relationships is governed by trade-offs between different outcomes that different EM functionalities have on organizational objectives. Organizations assess these trade-offs, and select those functionalities that best serve to achieve their collaborative relational objectives. In contrast, no trade-offs are find in the transactional model, as the use of EM here is driven principally by transaction cost reductions.     

惯性平台内、外框架结构系统的动力响应分析

应用有限元数值计算方法,对某型号惯性平台内、外框架结构系统进行了动力响应分析,得到了结构系统在承受正弦周期载荷时的响应曲线、谐振频率、谐振频率点的振型及最大振幅,建立了平台内、外框架结构系统(外框架→内框架→台体)各部分响应的传递关系。通过分析计算,对如何提高结构系统的动态性能提出了方法和建议,为今后型号的改进和设计奠定了基础。     

OFDM系统在多径衰落信道下的时钟同步

为消除时钟同步误差对正交频分复用（OFDM）系统的影响，提出了一种可工作在多径衰落信道下的时钟同步方法.该方法分为时钟频偏估计和时钟频偏补偿两个步骤，在估计时钟频偏时，利用了相邻符号的相邻导频之间的相关性；在补偿时钟频偏时，采用了数字内插环路，这使得时钟同步模块可在全数字接收机中实现.该方法的一个好处是，当存在载波频偏时仍可正常工作，这说明时钟同步可在载波同步之前完成.结果表明，该方法具有足够大的时钟频偏捕捉范围，可用于IEEE802.11a系统和DVB-T系统的接收机中.     

Enumeration and Evaluation of Small Orthogonal Latin Hypercube Designs for Polynomial Regression Models

In this paper, we construct and evaluate all nonisomorphic Latin hypercube designs with n≤16 runs, the use of which guarantee that the estimates of the first‐order effects are uncorrelated with each other and also uncorrelated with the estimates of the second‐order effects, in polynomial regression models. The produced designs are evaluated using well‐known and popular criteria, and optimal designs are presented in every case studied. An effort to construct nonisomorphic small Latin hypercubes in which only the estimates of the first‐order effects are required to be uncorrelated with each other has also been made, and new designs are presented. All the constructed designs, besides their stand‐alone properties, are useful for the construction of bigger orthogonal Latin hypercubes with desirable properties, using well‐known techniques proposed in the literature. Copyright © 2015 John Wiley & Sons, Ltd.     

Growing Oxide Nanowires and Nanowire Networks by Solid State Contact Diffusion into Solution‐Processed Thin Films

New techniques to directly grow metal oxide nanowire networks without the need for initial nanoparticle seed deposition or postsynthesis nanowire casting will bridge the gap between bottom‐up formation and top‐down processing for many electronic, photonic, energy storage, and conversion technologies. Whether etched top‐down, or grown from catalyst nanoparticles bottom‐up, nanowire growth relies on heterogeneous material seeds. Converting surface oxide films, ubiquitous in the microelectronics industry, to nanowires and nanowire networks by the incorporation of extra species through interdiffusion can provide an alternative deposition method. It is shown that solution‐processed thin films of oxides can be converted and recrystallized into nanowires and networks of nanowires by solid‐state interdiffusion of ionic species from a mechanically contacted donor substrate. NaVO₃ nanowire networks on smooth Si/SiO₂ and granular fluorine‐doped tin oxide surfaces can be formed by low‐temperature annealing of a Na diffusion species‐containing donor glass to a solution‐processed V₂O₅ thin film, where recrystallization drives nanowire growth according to the crystal habit of the new oxide phase. This technique illustrates a new method for the direct formation of complex metal oxide nanowires on technologically relevant substrates, from smooth semiconductors, to transparent conducting materials and interdigitated device structures.     

Filter bank‐based multiple access in next‐generation satellite uplinks: A DVB‐RCS2‐based experimental study

In the context of the on‐going evolution of satellite communications (SatCom) systems to their next generation, and in the direction of their integration with fifth generation (5G) terrestrial networks, it is of interest to study in depth the applicability in realistic SatCom of waveforms that have shown promise to meet the 5G requirements. This paper presents a comparative study, based on total degradation (TD) over a range of output back‐off (OBO) values, on out‐of‐band emission and spectral efficiency, of frequency division multiple access (FDMA) schemes employing offset quadrature amplitude modulation‐based filter bank multi‐carrier (FBMC /OQAM), classical orthogonal FDMA (OFDMA), and their single‐carrier counterparts to illustrate the potential gains from the integration of the FBMC waveforms in the satellite context and standards. The air interface simulated follows the digital video broadcasting (DVB) family of standards for the satellite uplink, considering both time and frequency synchronization impairments and two typical input constellations. Our results confirm the superiority of the single‐carrier (SC) schemes in such a nonlinear environment. The SC‐FBMC waveform is shown to be the most practical candidate since it is shown to attain a TD performance similar to that of SC‐OFDM at absolutely no cost in spectral efficiency.     

High order sliding mode observer‐based backstepping fault‐tolerant control for induction motor

This paper presents a robust fault tolerant control for an induction motor in presence of inter‐turn short‐circuit fault. The control strategy is based on Backstepping approach and high order sliding mode observer. That ensures a high‐performance control and a good dynamic in presence of inter‐turn short‐circuit fault. The stability of the Backstepping control is proved by Lyapunov theory. A high order sliding mode observer is used for rotor flux estimation. The performances of the fault tolerant control scheme will be examined via numerical simulation and validated through hardware implementation using MATLAB/Simulink with dSpace signal card. The analysis' results show the robustness of the proposed method for the tolerance of the inter‐turn short‐circuit fault.