证券宽带卫星通信系统关键技术应用

本文主要阐述用于传送证券交易数据的宽带卫星系统(Linkstar)的关键技术。介绍了在带宽分配管理技术、网络安全性技术应用、TCP加速技术、服务质量保证(QOS)及VLAN虚拟专网技术应用等方面所做的应用研究。     

分数槽在正弦波交流永磁伺服电动机中的应用

介绍分数槽绕组在正弦波交流永磁伺服电动机中的应用及实例.     

基于ECN的单播流与多播流间带宽共享算法

An ECN-based implementing bandwidth-sharing algorithm for unicast and multicast flows is presented.The algorithm uses a bandwidth allocation strategy to give an incentive to multicast flows in bandwidth allocation according to algorithm of the number of receivers, and to assure the unicast flows get their bandwidth shares fairly.Provided best-effort networks, an ECN-based congestion control algorithm is used to implement differentiated service in bandwidth allocation between unicast flows and multicast flows. In implementation, we solve the problems such asreceiver‘s number estimation, the RTT estimation and compromise between convergence and stability.The simulation results show that the algorithm can implement bandwidth sharing for TCP flows and multicast flows. Atthe same time, the algorithm not only allocates more bandwidth to multicast flows, but promises TCP flows to get their fair bandwidth share.     

Low cost pre-stored video transmission across networks

This paper proposes a simple, practical and low-cost dynamic segmentation and bandwidth allocation scheme, called middle point, to transmit pre-stored video from source to playback destination across networks. The proposed scheme is based on two concepts, playback tunnel and bandwidth tunnel, to determine the segmentation boundary and transmission bandwidth with the objective of reducing transmission cost while guaranteeing the playback buffer neither underflows nor overflows. The performance of the proposed scheme is evaluated by a set of real-life MPEG video traces and also compared with the well-known optimal smoothing scheme. The obtained results show that the proposed scheme can be easily implemented with low complexity and low transmission cost.     

基于广义细胞自动机的网络带宽优化

Nowadays,bandwidth allocation schemes in a TCP/IP or ATM network are congestion avoidance oriented.Few scheme has taken global optimization into account,for global optimization problem can not be easily solved by conventional mathematical method due to the complexity and large-scale of massive information system,such as Internet.We present a novel bandwidth allocation scheme based on generalized cellular automaton (GCA).Firstly we introduce how to map network topology into GCA model,then we propose how cells and macro cells interact in our solution.Our simulation results show the scheme leads to global optimization rapidly.     

一种基于度量的Web服务质量机制

提出了一种简单、准确和高效的带宽调节算法，该算法对每一个服务请求设置一个带宽标准，同时根据对服务请求的分类和Web服务器系统的有效带宽，来分配及调节每一个服务请求的实际带宽，构成一种基于度量的Web服务质量机制，使Web服务器系统能为不同类型的客户请求提供有区分的和有服务质量的Web服务。     

网格环境下保证服务质量的带宽代理的研究

提出了一种提供服务质量保证的带宽代理模型，在模拟的网格实验环境下实现了CSAPFBA算法，并根据实验结果分析了CSAPFBA算法的性能。     

An Introduction to Multivariate Statistical Analysis

A permutation test is proposed for examining the significance of effects in unreplicated factorial experiments. The procedure tests each effect with a separate sampling distribution using a test statistic that is equivalent to the optimal invariant decision rule of Birnbaum. The proposed test is more flexible than other methods proposed for the same situation because it requires no a priori assumptions regarding the underlying distribution of the data nor does it impose any practical restriction on the number of potentially significant effects present.     

Elementary Statistics

Fractional two-level factorial designs are often used in the early stages of an investigation to screen for important factors. Traditionally, 2 ^n-k fractional factorial designs of resolution III, IV, or V have been used for this purpose. When the investigator is able to specify the set of nonnegligible factorial effects, it is sometimes possible to obtain an orthogonal design with fewer runs than a standard textbook design by searching within a wider class of designs called parallel-flats designs. The run sizes in this class of designs do not necessarily need to be powers of 2. We discuss an algorithm for constructing orthogonal parallel-flats designs to meet user specifications. Several examples illustrate the use of the algorithm.     

An optimal deployable bandwidth aggregation system

The explosive increase in data demand coupled with the rapid deployment of various wireless access technologies have led to the increase of number of multi-homed or multi-interface enabled devices. Fully exploiting these interfaces has motivated researchers to propose numerous solutions that aggregate their available bandwidths to increase overall throughput and satisfy the end-user’s growing data demand. These solutions, however, do not utilize their interfaces to the maximum without network support, and more importantly, have faced a steep deployment barrier. In this paper, we propose an optimal deployable bandwidth aggregation system (DBAS) for multi-interface enabled devices. We present the DBAS architecture that does not introduce any intermediate hardware, modify current operating systems, modify socket implementations, nor require changes to current applications or legacy servers. The DBAS architecture is designed to automatically estimate the characteristics of applications and dynamically schedule various connections and/or packets to different interfaces. We also formulate our optimal scheduler as a mixed integer programming problem yielding an efficient solution. We evaluate DBAS via implementation on the Windows OS and further verify our results with simulations on NS2. Our evaluation shows that, with current Internet characteristics, DBAS reaches the throughput upper bound with no modifications to legacy servers. It also highlights the significant enhancements in the response time introduced by DBAS, which directly enhances the user experience.