Tencent and Facebook Data Validate Metcalfe’s Law

In 1980s, Robert Metcalfe, the inventor of Ethernet, proposed a formulation of network value in terms of the network size (the number of nodes of the network), which was later named as Metcalfe’s law. ...     

浅析调度交换机远程集中维护系统的应用

本文针对调度交换机远程集中控制系统的硬件系统、软件系统设计、输入与输入系统进行了分析,并以实例探析了调度交换机远程集中维护系统的调试和实践应用,以供参考.     

贝叶斯电流分解：利用单个传感器感知家用电器电流

通过单个传感器对家庭中各个电器的用电行为进行感知是普适计算中的一个重要应用,其关键问题是电流分解,即在给定总电流波形情况下计算各个电器的实际电流.此问题现有2类求解方法：稳态估计方法和线性分解方法.前一类方法基于电器稳态耗电假设,使用稳态波形估计电器的工作电流.虽然该类方法能避免电器间的相互干扰,但是其结果不能反映总电流的实时变化.后一类方法通过模型约束或数据约束对电流波形进行线性降维,之后将总电流分解到各个低维线性空间中.虽然其分解结果能够反映总电流的实时变化,但是相似电器会降低分解结果的精度.从贝叶斯统计的角度将上述方法的关键假设松弛为位置向量先验分布与噪音先验分布,并提出了基于这2个分布的贝叶斯电流分解方法.利用真实用电数据,构造了多组仿真实验对此方法进行评测.实验结果表明:提出方法分解精度高于原有2类方法,其感知结果既能够反映总电流及各个电器电流的实时变化,又能够降低相似电器对分解结果的干扰.     

A Functional Sensing Model and a Case Study in Household Electricity Usage Sensing

Sensing is a fundamental process to acquire information in the physical world for computation. Existing models treat a sensing process as an indivisible whole, such that sampling and reconstructing of signals are designed to be highly associated with each other in a unified procedure. These strongly coupled sensing systems are efficient, but usually lack reusability and upgradeability. We propose a functional sensing model called SDR （Sampling-Design-Reconstruction） to decouple a sensing process into two modules： sampling protocol and reconstruction algorithm. The core of this decoupling is a design space, which is a common data structure constructed using functions of the sensing target as prior knowledge, to seamlessly bridge the sampling protocol and reconstruction household electricity usage sensing systems can be successfully algorithm together. We demonstrate that existing types of decoupled by introducing corresponding design spaces.