软件定义网络中基于负载均衡的多控制器部署算法

随着软件定义网络规模扩大,控制层与数据层解耦带来了诸如控制器部署等新问题。该文提出基于负载均衡的多控制器部署算法(Multi-Controller Deployment Algorithm Based on Load Balance, MCDALB)。算法首先根据网络拓扑结构及其负载情况,确定控制器数量K;然后根据控制器容量限制,提出一种近似比为2的多控制器负载均衡算法,将网络划分成K个控制区域;最后根据区域内所有交换机到控制器距离总和最小原则,在控制区域部署控制器。为了验证算法的性能,选取实际网络拓扑进行实验。实验结果表明,与AL, WL算法相比,该算法在满足控制器负载近似比为2的同时,网络最大延时差距不超过0.65 ms。     

Windows9X提速技巧

本文主要从软件和硬件等方面介绍了在windows9x操作系统下提高运行速度的几种方法.     

数字信号频谱编码传输中基于一阶保持的软同步方法

该文提出了一种应用于数字信号频谱编码传输中的完全利用软件来实现的同步方法,并对该方法进行了详细的理论描述,提出了实现同步的步骤和方法。并且与传统的载波同步相比较,阐述了这种用软件来实现同步的优点。     

基于单片机系统的红外遥控器应用

文章介绍红外遥控器与单片机的硬件接口,并从原理出发给出软件解码的方法。通过软件 程序对红外遥控器发射的脉冲波形检测得出信号码,从而为软件解码提供依据。     

Measuring C program coverage based on binary decision diagrams

Test coverage analysis is a structural testing technique, which helps to evaluate the sufficiency of software testing. This letter presents two test generation algorithms based on binary decision diagrams to produce tests for the Multiple-Condition Criterion(M-CC) and the Modified Condition/Decision Criterion(MC/DC), and describes the design of the C program Coverage Measurement Tool (CCMT), which can record dynamic behaviors of C programs and quantify test coverage.     

COMBINATORIAL DESIGN APPROACHES FOR AUTOMATIC TEST GENERATION

The n-way combination testing is a specification-based testing criterion, which requires that for a system consisted of a few parameters, every combination of valid values of arbitrary n(n ≥ 2) parameters be covered by at least one test. This letter proposed two different test generation algorithms based on combinatorial design for the n-way coverage criterion. The automatic test generators are implemented and some valuable empirical results are obtained.     

Flexible Digital Receiver Architecture with Optimized Components

Future wireless communication systems require increased flexibility, lower power consumption, smaller size and decreasing costs for the terminals and therewith for the components. By replacing analogue by digital signal processing the degree of integration and the flexibility of a terminal with respect to multi-mode capability can be improved.In a highly integrated implementation the most critical components are the A/D-converter and the digital filter stages due to high speed and low power requirements. In this contribution a novel concept for a flexible, digital receiver with highly optimized components will be presented. The concept is based on down-conversion of the broadband receive signal to a low intermediate frequency. The main modules of the receiver are a properly designed ΔΣ-modulator for A/D-conversion, and novel digital filtering stages. It will be demonstrated, that the use of cascaded low-order wave digital lattice filters results in a number of advantages and makes a very efficient realization in VLSI-technology feasible.     

送电线路终勘测量制表软件的开发及应用

充分利用线路测量CAD成图系统所形成的数据资源,实现送电线路终勘测量制表自动化,完全替代手工作业方式,大大提高内业工效及成果质量。结合工程实践介绍有关软件的开发及处理过程。     

非线性励磁控制器改善华中电网稳定性的仿真分析

在华中电网中,由于湖北网与江西网之间的弱联系,当葛凤线（５００ｋＶ）发生三相短路故障时,系统会出现增幅的低频振荡。为寻找解决方案,华中网局与清华大学电机系采用电力部电科院《电力系统分析综合程序》,利用其用户自定义功能建立非线性最优励磁控制器模型,并进行了仿真计算。计算结果表明,在主要电厂的相关机组上装设非线性最优励磁控制器,能够解决上述低频振荡的问题和改善系统的暂态稳定性水平。     

GPS测量控制网纳入独立坐标系的方法

介绍了独立坐标系的建立方法,并以ＧＰＳｕｒｖｅｙ软件为例说明了ＧＰＳ测量控制网纳入独立坐标系的具体方法,最后给出了应用实例。