电流感测电阻的挑战:开放式金属元件电阻与金属带状线贴片电阻

为了操作安全或对电流进行控制,现在的电子产品越来越多地使用各种电流感测装置.电流感测常用于以下两方面:1)过电流保护,监测流过发动机或电源输出线的电流,如果负载过大就降低电压;2)多相负载平衡,监测每条有电流的线上的安培数值,并对实时响应产生影响.使用电流感测电阻能够提供简单的电流感测信号,对电流变化作出线性响应,从而能够保证电路在很大温度范围内可靠工作.     

The bombsight war: Norden vs. Sperry

A retrospective is provided of the invention of two major bombsights during World War II: the well-known Norden bombsight and the less famous but superior Sperry bombsight. The author describes their invention and compares the two. He explains why the Norden became so famous during World War II that it was even featured in popular movies while the Sperry was comparatively little known in spite of its advantages     

Project Management Research - The Challenge and Opportunity

This publication contains reprint articles for which IEEE does not hold copyright. You may purchase this article from the Ask*IEEE Document Delivery Service at http://www.ieee.org/services/askieee/     

科学传播的挑战：“欧洲研究区域”

本文通过2005年在欧洲32个国家进行的公众民意调查结果显示,反映了当今欧洲公民认知科学和技术的方法。文章还将此次调查与美国和中国近来开展的类似调查进行了比较。在此背景下,文章提出了当前欧洲科学传播面临的挑战和困难。文中还就欧洲委员会(EC)近期为了推进整体传播,以及科学传播所开展的活动进行了介绍。欧洲委员会研究理事会正积极参与到将欧洲委员会资助的研究项目成果传播给媒体和一般公众的活动当中。为了使得研究工作的目标和结果能够通过有效的信息流获得公开,研究项目协调人和团队领导人得到了各种支持和帮助。文中还提到了欧洲委员会用以加强对研究成果进行传播的具体措施,如在布鲁塞尔召开的“2005欧洲研究传播”会议。     

Android vs. IOS: a comparative analysis over mobile operator infrastructures based on crowdsourced mobile dataset

User equipment (UE)’s operating system (OS) and category types are important factors that are affecting the end-user performance in a given mobile network operator (MNO)’s infrastructure. For this reason, fair and statistically accurate observed network performance differences of UE’s OSs based on category types, MNOs or locations can be of interest for mobile telecommunication ecosystem players. This paper’s focus is on performance comparisons of UE OSs (including Android, IOS (iPhone Operating System) and Windows phones) over different UE categories, MNOs and locations based on previously collected end-to-end nationwide crowd-sourced data measurements in Turkey. The analysis results performed in this paper uses statistical comparisons of unpaired observations due to imbalance between number of observations between all OSs and yield insight on how the mobile OS types’ network performances differ using some important Key Performance Indicators (KPIs) such as downlink (DL) speed, latency, jitter and packet loss (PL). The outcome of the analysis indicate that Android devices perform better in terms of DL speed among all MNOs, whereas IOS devices are better in terms of latency values. On the other hand depending on the UE category, the performances of MNOs may vary when IOS and Android OSs are compared based on different KPIs. Additionally, IOS has shown better performance than Android in large geographical areas of Turkey. Finally, the business aspects of performing the proposed statistical OS comparisons from the perspectives of OS developers, MNOs, device manufacturers, and end-users are highlighted.

     

AI as a friend or assistant: The mediating role of perceived usefulness in social AI vs. functional AI

Advents of new technology have transformed how we currently view and use artificial intelligence (AI). Originally, AI was first developed to assist humans to complete tasks, but AI now takes on more social roles, such as functioning as a companion. However, little is known about how individuals view these different types of AI. Thus, the present study conducted an online experiment to explore people’s perceptions about social AI vs. functional AI. Primary results suggest that individuals have more positive attitudes toward functional AI than social AI. Perceived usefulness of AI is found to have a mediation effect, suggesting functional AI, compared to social AI, leads to stronger perceived usefulness, which consequently fosters more positive attitudes and stronger perceived realism of AI. The results collectively suggest meaningful implications for human-AI communication and human–machine communication research.     

移动电话挑战嵌入式Linux

正当移动电话制造商(OEM)拥抱Linux作为下一代智能电话的平台的时候,开发和布置这样的设备还在面临着技术上的挑战,特别是OEM们必须保证电话具有电源管理,快速引导,集成的无线接口,先进的多媒体功能,吸引人的小尺寸GUI以及各种PIM应用-而且所有的这些全部集成和运行在一个适度的手机储存空间里面.这也是嵌入式Linux开发者所面临的挑战,不同于PC,电话设计并不是建立在一个标准的系统上面.文章详细阐述了基于Linux的移动电话开发的各种技术问题,涉及到关键的Linux技术和支持电话开发开源项目的可用性和成熟性.另外,文章还讨论了移动运营商提出的技术和经济层面的问题.     

数字中频与FPGA

数字中频 所谓中频,顾名思义,是指一种中间频率的信号形式.中频是相对于基带信号和射频信号来讲的,中频可以有一级或多级,它是基带和射频之间过渡的桥梁.     

Superconductivity: fact vs. fancy

The two-part special report discusses the recently developed high-temperature superconducting ceramics. The first part describes promising processing advances and examines concerns about critical current density and brittleness. Both problems present a serious roadblock to practical use of these materials. The second part investigates the more interesting and feasible applications, which appear to be several years away. An accompanying box insert on theory explains what is known about superconductivity in these ceramics     

Careers: Mom vs. Bomb

This paper discusses the development of a robot that has the ability to detect, inspect, and neutralize bombs. Its success is proved by saving lives in the warzone. Since 2003, more than 330 explosive ordnance disposal (EOD) robots have been shipped to Iraq and Afghanistan, costing roughly US $150000 each. The robots are tested to gauge their effectiveness and speed in a variety of environments and terrains. Efforts are underway to develop better navigation tools and appendages that allow the robots to manipulate explosives with more dexterity     

字符串匹配算法的实现:CPU vs.GPU vs.FPGA

针对字符串匹配算法在各平台实现的性能问题,将算法在CPU、GPU及FPGA上做了测试对比。GPU具有计算单元多的特点,使得GPU对计算密集型应用有较大的效率提升;而FPGA具有级强的灵活性、可编程性及大量的逻辑运算单元,在处理字符串匹配时的处理速度快。通过对3种实现方式在Snort规则库下做的分析,其结果表明,FPGA的处理速度最快,相比GPU的处理速度提升了10倍。而CPU的串行处理速度最慢,且FPGA的资源消耗最多,GPU次之,CPU的资源消耗最少,且实现最简单。     

DVB-C与IPTV的博弈--正确认识IPTV

本文介绍了IPTV的技术特点,阐述了DVB-C与IPTV各自的优、缺点,分析了IPTV带给广电DVB-C的压力以及机遇,论述了这两种数字电视在竞争中的处境,并就广电行业如何正确看待IPTV、发展DVB-C进行了有益的探索。     

Technically speaking: Tired vs. Wired

Discusses the terminology that has emerged to describe the impact of excessive information on people in today's wired world.