Nonintrusive measurements of the telephone channel

Algorithms for a system which performs in-service nonintrusive measurements of telephone line parameters such as echo path delay, echo attenuation, speech and noise levels are presented. It forms the theoretical background of a hardware implementation of the ITU-T P.561 recommendations for nonintrusive assessment of quality of a telephone network for voice transmissions. The type of input signal to the echo path, whether it is speech, fax, or data, has to be determined during the measurement procedure. In the system, the relevant parameters are estimated by means of frequency-domain block-processing algorithms and the estimation process is controlled by algorithms monitoring the signal flow. The complexity of the echo path estimation algorithm is determined and compared to a standard procedure based on the adaptive normalized least mean square (NMLS) algorithm. Simulations showing the performance of the system in single-and double-talk situations are presented. Examples of results from the hardware real-time implementation operating on an international connection are also shown     

On cost-aware monitoring for self-adaptive load sharing

Monitoring is an essential part of any self-adaptive management loop. While providing the necessary information for making management decisions, monitoring itself incurs a cost in terms of the system and network resources committed to this management task. Thus, one can pose a generic question: what is the right amount of monitoring that maximizes its utility for management? This question turns out to be difficult to answer in general. In this paper we focus on quantifying the utility of monitoring for self-adaptive load sharing, where a stream of jobs arrives at a collection of n identical servers. We propose a novel model, that we dubbed an Extended Supermarket Model (ESM) to study the tradeoff between the usefulness of the monitoring information and the cost of obtaining it. We show that for each service request rate, there exists an optimal number of servers that should be monitored to obtain minimal average service time at an optimal cost. Using these findings, we present self-adaptive load-sharing algorithms both for centralized and fully distributed settings and evaluate these algorithms using simulations and a real testbed. Our results show that in realistic scenarios, where monitoring cost is not negligible, the self-adaptive load balancing is clearly superior to any cost-oblivious load-sharing mechanisms. We also demonstrate that in a fully distributed setting, where no dedicated monitoring component is employed, our self-adaptive heuristics perform very well with respect to the current common practice.     

基于SAGA-FCM算法的非侵入式负荷监测方法

针对现有的非侵入式负荷监测(NILM)方法对小功率设备识别准确率不够,以及监测数据量过大时,准确率下降严重等问题,提出一种新颖的非侵入负荷监测方法。该方法以模糊C均值聚类算法(FCM)为基础,采用差量特征提取法提取任意时刻的特征变化值,引入模拟退火算法(SA)和遗传算法(GA)对聚类过程进行优化,实现了多类型电器负荷的聚类识别。实验数据表明,随着监测数据量的增加,该方法最终目标函数始终小且稳定,具有较好的稳定性和可靠性,适用于NILM大数据监测环境,采用谐波特征后识别准确率有一定的提升。     

配电网智能负荷监测与互供系统

针对配电变压器的运行特点以及运行中出现的问题,利用嵌入式系统技术,提出了配电网智能负荷监测及互供系统的构建方法,减少实际运行中由于变压器轻载或过载造成的变压器损耗,增加了变压器的寿命,减少了由于变压器故障或线路故障造成的停电事故,对于智能电网的构建也具有重要的推进作用。     

基于Labview的电力电子负载的动态监测

基于NI公司的Labview软件开发平台，借助于Flash软件优越的动画显示功能，针对相控电力电子电路常用负载——灯泡负载和直流电动机负载，以三相整流电路为例完成了随着控制角α的变化，电力电子负载动态监测软件的开发。该软件经调试，界面友好、美观、使用方便，特别是其灯光、声音和旋转的动画显示效果佳。对电力电子技术的教学和研究工作有指导意义。     

Nonintrusive Iris Image Extraction for Iris Recognition-Based Biometric Identification

This paper proposes a new approach to obtain iris images without requiring the person to look directly into the camera. Most biometric identification methods using iris recognition assume that the eye image of the person is available, and are only concerned with the extraction of the iris from the eye image. These methods require the person to look directly into the camera, which is a rather uncomfortable process. In this paper, a robust approach is proposed to initially locate eye regions within facial images taken from a distance. Then the iris image is extracted from the detected regions. Hence, a nonintrusive and more comfortable iris imaging approach has been implemented.     

基于ZigBee的油井载荷监测系统设计

阐明了在油井作业过程中油杆载荷测量的必要性,并针对一般油田地区环境的特殊性,提出了采用基于ZigBee技术的无线监控系统,既解决了复杂的现场布线、地理环境干扰、组网困难、扩展性差等问题,又实现了低功耗、低成本的远程无线监控,这对油井抽油杆的故障判断和油田的高效生产管理有着重要意义。     

可自动化监测的配变多路负荷管理系统

随着用电量的快速增长,供电质量成为人们日益关注的焦点.而目前对配变的监测自动化程度不高,由于负荷没有得到预测,事故没有得到及时报告,因此造成停电时间长等不利于居民生活的后果,该系统能科学、准确地对配变进行实时监控,有效降低线损,为负荷预测、线损分析提供准确的数据,有效地提高了配变多路负荷的自动化监测水平.     

住宅用电非侵入式电力负荷监测与识别

在住宅用电的非侵入式负荷监测与识别过程中,对负荷的投切时间检测与负荷类型的准确识别是重要的研究部分,本文提出了一种住宅用电非侵入式电力负荷监测与识别算法.首先,提出了一种基于短期环比变点检测算法,能够准确的检测出负荷的投切时间,进而对负荷的稳态特征进行高精度的提取;其次,利用融合莱维飞行与黄金正弦的蚁狮优化(LGSA?LO)支持向量机算法,实现家用电力负荷识别.实验结果表明,本文所提出的变点检测算法和负荷识别方法在实际应用过程中具备较高的准确率.     

多路电压互感器二次压降及负荷在线监测方法

介绍了目前计量用电压互感器现场检定的现状及存在的问题,提出并阐述了一种多路计量用电压互感器在线监测的方法。利用该方法可以对多路电压互感器同时进行在线误差测试,解决了对互感器进行离线检定时工作量大、实时性差的问题,减少了设备反复接线的麻烦,缩短了检验时间,提高了工作效率。     

为电器马达提供动力

马达类型 近一个世纪以来,感应马达一直是电器行业的动力提供部件.在新型的变频驱动器中,也有许多使用感应马达.但有部分新的电器开始采用更高效、更紧凑轻巧的马达系统.     

Nonintrusive TCP connection admission control for bandwidthmanagement of an Internet access link

We describe our approach to monitoring and managing the bandwidth of an Internet edge link with a view toward certain quality of service objectives for the services it carries. Such a link could be, for example, a campus's Internet access link or a small ISP's backbone access link. We use SNMP polls and packet snooping to obtain traffic statistics, and TCP admission control for bandwidth management. Our implementation is completely nonintrusive: we use Ethernet packet capture in the promiscuous mode for traffic analysis, and IP masquerading for blocking new TCP connections. This approach has been implemented by us in a software system for traffic management. We first justify our approach with a simple analytical model. We give an overview of our software implementation, and discuss some implementation issues. Then we provide measurement results that show the effectiveness of the techniques     

基于小波神经网络的大数据在线负载异常监测技术研究

为了提高大数据负载监测的有效性和准确性,采用神经网络算法对大数据负载进行监测。根据相邻时间段的负载数量变化建立负载预测模型,结合负载变化情况判定当前负载状态。对负载变化明显的时间段,采用神经网络算法对负载情况进行正向和反向运算。根据得到的结果与阈值相比较,超出阈值的负载判定为异常负载,将其从大数据平台剔除,确保大数据平台在线负载连接的真实性和有效性。仿真结果显示,基于神经网络的大数据负载方法在准确性和运行效率上均表现良好。     

新一代数字视听家电--光盘录像机(VDR)

一种新型数字视听家电产品——光盘录像机(VDR)已率先在中国诞生并开始上市,使我国激烈竞争的影碟机行业再掀波澜。 光盘录像机的英文名称是Video Digital Recorder,缩写为VDR,其芯片采用了先进的0.18 μm的加工技术。我国厦新、万利达生产的VDR,采用了美国视讯科技有限公司的技术方案。 VDR系统主要由图象基色(Chromakey)控制系统和录制系统组成。Chromakey的功能是从硬盘驱动器(HDD)和摄像机产生现成的(ready-made)活动图象。     

无刷直流电机直驱抽油机系统控制器设计

为改善传统抽油机系统高速驱动、多级传动带来的效率低、因数低、维护费用高、噪声大等缺点,设计了基于MC33035和MC33039的无刷直流电动机直驱抽油机系统控制器,采用低速运行的外转子永磁电机直接驱动抽油机来实现抽油杆的往复运动.     

无刷直流电机直驱抽油机系统控制器设计

为改善传统抽油机系统高速驱动、多级传动带来的效率低、因数低、维护费用高、噪声大等缺点,设计了基于MC33035@MC33039无刷直流电动机直驱抽油机系统控制器,采用低速运行的外转子永磁电机直接驱动抽油机来实现抽油杆的往复运动．     

Internet facsimile as an Internet office appliance

The Internet's emergence as a worldwide digital infrastructure has dramatically encouraged a market for communications-oriented appliances, such as mobile phones, personal assistants, network-enabled games, interactive television, Internet telephony, and Internet facsimile. The marketplace is developing rapidly, along with specialized Internet-based “linking” services to connect these devices. Generally two different technical approaches are being explored for these services. One uses classic Internet technology, such as e-mail or the World Wide Web; the other incorporates unique standards, often derived from earlier non-Internet specifications. This article explores efforts to create Internet facsimile appliances, contrasting them with devices for Internet telephony. Efforts at Internet facsimile have produced two different sets of standards. Store-and-forward Internet facsimile is specialized as a profile of classic Internet mail. Real-time Internet facsimile uses a specialized protocol     

智能电话远程家电控制系统的设计

提出了通过远程电话实现智能家电控制系统的一种实现方案。介绍了家电和电话之间的控制接口电路，讨论了系统结构及硬件、软件设计。测试结果表明设计的系统能完成预定的功能。     

光电成像制导技术发展及在导弹中的应用

光电成像制导技术是精确制导武器的核心技术之一,世界各国尤其是美国等军事大国致力发展并不断将其应用于导弹武器中.红外、雷达、激光等成像制导技术是当今发展的重点,并在巡航导弹、反导防空导弹、弹道导弹等武器系统中广泛应用.报告分析国外该领域的发展和在导弹武器中的应用,得出导弹制导系统应用光电成像技术,将可有效提高导弹命中精度和作战效能,提出我国应加快发展光电成像制导技术,并将其应用到导弹武器中,以提高其综合作战能力.     

用于家电机器的UWB高速接口

1引言众所周知,UWB是美国的一种使用超宽频带的军用无线通信技术。自从2002年2月被美国联邦通信委员会(FCC)解禁以来,一直受到业界的极大重视。但是,作为民用的无线通信技术,似乎一直未见到它的具体用途。但近来的情况有了变化。日本的索尼、松下电器等公司已全部行动起来,把UWB用作数字家电机器的高速接口。包括零件制造厂商在内的约40家公司组成了“UWB研究开发企业联盟”,正进行面向实用化的环境准备。在电波利用条件方面,日本总务省也以罕见的速度进行着面向“国内解禁”的审议。这样,UWB已迅速向数字家电制造厂商比较集中的日本…