基于树状MAP的移动IPv6无缝实时切换策略研究

提出了一种移动IPv6切换策略,基于分级移动IPv6和快速移动IPv6构造树状MAP框架,设计逐跳绑定更新机制对快速移动IPv6进行改进,实现移动节点的无缝(快速平滑)切换。同时,根据资源预留协议扩展策略功能,提出提前预留方式,增强对实时数据流的支持能力。     

Delay-aware cross-layer optimization method for FANET

An asynchronous distributed cross-layer optimization (ADCO) method was proposed to solve the problem of jointly considering real-time routing,rate allocation and power control in FANET (flying ad hoc network).And a delay-constrained cross-layer optimization framework was designed to formally represent proposed problem.Then Lagrangian relaxation and dual decomposition methods was used to divide joint optimization problem into several sub-problems.ADCO allowed each relay node to perform the optimization operation for different sub-problems with local information,and the relay nodes could update the dual variables based on asynchronous update mechanism.The simulation results show that the proposed algorithm can improve the network performance effectively in terms of energy efficiency,packet timeout ratio and network throughput.     

基于分层代理的MIP方案研究

通过对移动蜂窝网络模型的分析,提出了一种基于IPv6协议的分层网络移动IP切换方案,利用网络层快速切换以及层管理域的适当选取,有效地减少了微移动中的切换时延;在域间切换中,引入对端通信节点与网络外部代理的直达路径,降低了三角路由对切换过程的影响。     

An empirical process central limit theorem for dependent non-identically distributed random variables

This paper establishes a central limit theorem (CLT) for empirical processes indexed by smooth functions. The underlying random variables may be temporally dependent and non-identically distributed. In particular, the CLT holds for near epoch dependent (i.e., functions of mixing processes) triangular arrays, which include strong mixing arrays, among others. The results apply to classes of functions that have series expansions. The proof of the CLT is particularly simple; no chaining argument is required. The results can be used to establish the asymptotic normality of semiparametric estimators in time series contexts. An example is provided.     

Calculating rate constants with updated Hessians using variational transition state theory with multidimensional tunneling

Variational transition state theory with multidimensional tunneling (VTST/MT) has been used for calculating the rate constants of reactions. The updated Hessians have been used to reduce the computational costs for both geometry optimization and trajectory following procedures. In this paper, updated Hessians are used to reduce the computational costs while calculating the rate constants applying VTST/MT. Although we found that directly applying the updated Hessians will not generate good vibrational frequencies along the minimum energy path (MEP), however, we can either re-compute the full Hessian matrices at fixed intervals or calculate the Block Hessians, which is constructed by numerical one-side difference for the Hessian elements in the "critical" region and Bofill updating scheme for the rest of the Hessian elements. Due to the numerical instability of the Bofill update method near the saddle point region, we have suggested a simple strategy in which we follow the MEP until certain percentage of the classical barrier height from the barrier top with full Hessians computed and then performing rate constant calculation with the extended MEP using Block Hessians. This strategy results a mean unsigned percentage deviation (MUPD) around 10% with full Hessians computed till the point with 80% classical barrier height for four studied reactions. This proposed strategy is attractive not only it can be implemented as an automatic procedure but also speeds up the VTST/MT calculation via embarrassingly parallelization to a personal computer cluster.     

基于LabVIEW7.0的某实时监控软件设计与实时性分析

针对某试飞课题,在NI LabVIEW7.0平台下进行了某试飞科目实时监控软件系统开发。飞行试验中,实验分析了影响该系统试飞参数时间历程图实时刷新的原因,提出了在飞行试验实时监控中,采用优化VI及对Chart控件二次编程的方法解决Chart曲线图实时刷新的问题。在此充分挖掘LabVIEW中Chart控件的属性进行二次编程,解决试飞参数时间历程图实时刷新、显示问题,具有很高的实用价值。     

EPON系统远端设备升级方案浅析

分析了以太网无源光网络(EPON)系统对远端ONU设备进行远程升级过程中存在的弊端,结合IEEE 802.3ah标准中下行报文的特点,创新地提出利用基于IEEE 802.3ah标准的下行报文替代传统操作管理维护协议(OAM)报文对远端设备进行升级的改进方案,改进后的升级方案可使升级过程更为快速、稳定.     

动态环境下嵌套移动网络的快速路由优化

针对嵌套移动网络在快速移动场景下,频繁切换带来的较长通信恢复收敛时间和网络内部节点通信的次路由优化问题,提出了一种使用树信息选项的快速路由优化方案.该方案通过使用树信息选项对RA消息进行扩展和新增本地绑定(LBU)机制,减少了在快速变化环境中由于切换造成的通信中断时间,并且能在移动网络内部节点交互业务增多时,保证路由的...     

Scaled memoryless symmetric rank one method for large-scale optimization

This paper concerns the memoryless quasi-Newton method, that is precisely the quasi-Newton method for which the approximation to the inverse of Hessian, at each step, is updated from the identity matrix. Hence its search direction can be computed without the storage of matrices. In this paper, a scaled memoryless symmetric rank one (SR1) method for solving large-scale unconstrained optimization problems is developed. The basic idea is to incorporate the SR1 update within the framework of the memoryless quasi-Newton method. However, it is well-known that the SR1 update may not preserve positive definiteness even when updated from a positive definite matrix. Therefore we propose the memoryless SR1 method, which is updated from a positive scaled of the identity, where the scaling factor is derived in such a way that positive definiteness of the updating matrices are preserved and at the same time improves the condition of the scaled memoryless SR1 update. Under very mild conditions it is shown that, for strictly convex objective functions, the method is globally convergent with a linear rate of convergence. Numerical results show that the optimally scaled memoryless SR1 method is very encouraging.     

基于RapidIO的FPGA远程更新系统设计与实现

现场可编程逻辑门阵列(FPGA)在航电系统领域广泛应用,但是采用JTAG方式更新FPGA程序,效率低下,易受设备环境限制而缺乏灵活性,已经难以满足工程应用的需求。提出了一种实现FPGA程序远程更新的方案,该方案采用RapidIO总线,以软件异构的方式,构建在线更新实时通信链路。通过以太网下发镜像升级文件,经SRIO交换网络传送至FPGA节点,写入FLASH配置空间,实现FPGA程序的远程更新。经过测试,验证了设计的正确性和可行性,并有效地提高了FPGA程序更新的速度。