One of the very first books published on the social impact of the mobile phone was Timo Kopomaa’s The City in Your Pocket: Birth of the Mobile Information Society. The book, published in 2000, was based on research that Kopomaa had under- taken for Nokia and Sonera as part of his doctoral studies in the Centre for Urban and Regional Studies at the Helsinki University of Technology. The first line he writes in the book is peculiar: ‘Mobile communication is not a serious matter’. By this, we assume he is referring to a view of the world that would regard the mobile phone as little more than an unremarkable fact of everyday life – a simple play- thing for the young, or a productivity tool for the business executive and busy parent.
标签： Communications Wireless Mobile and
上传时间： 2020-05-30
上传用户：shancjb
Do you have a mobile phone? We think you probably do, one way or another. We would also guess that you might use it for many diff erent things in the course of your everyday life—as a telephone certainly, but also as an address book, as a clock or watch, as a camera, or now as a connection to your computer, email and the internet. Th ere will be a range of people you use it to contact (or not), and various strategies you use to take calls—or send texts, or take photos, or receive emails, or search online (or not, in diff erent situations). Th ere are also likely to be a range of social relation- ships in your life that your mobile phone helps to maintain—or disrupts, or inter- venes in, or makes possible, or complicates, or just plain helps to handle.
标签： Communications Introduction Mobile Media New An to
上传时间： 2020-05-30
上传用户：shancjb
The growth of mobile technologies is remarkable. At a recent Mobile World Congress Conference, Eric Schmidt, CEO of Google predicted that within three years, smart phones will surpass Personal Com- puter sales. The number of mobile phones used worldwide has exceeded 4.6 billion with continued growth expected in the future. In fact, in the United States alone, the numbers of mobile phone users comprise over 80% of the population.
标签： Opportunities Consumption Technology Mobile
上传时间： 2020-05-30
上传用户：shancjb
Rapid progress in information and communications technology (ICT) induces improved and new telecommunications services and contributes greatly to society in general and to vendors and network and service providers. In addition to existing services such as telephony or leased line services, spread of the Internet, the Internet Protocol (IP) phone, and new communications services like IPTV are making great progress with the development of digital subscriber lines (DSL) and high - speed communications technologies like fi ber to the home (FTTH).
标签： Telecommunications Networks
上传时间： 2020-06-01
上传用户：shancjb
Second-generation telecommunication systems, such as the Global System for Mobile Communications (GSM), enabled voice traffic to go wireless: the number of mobile phones exceeds the number of landline phones and the mobile phone penetration is approaching 100% in several markets. The data-handling capabilities of second-generation systems are limited, however, and third-generation systems are needed to provide the high bit-rate services that enable high-quality images and video to be transmitted and received, and to provide access to the Web with higher data rates.
标签： Evolution WCDMA UMTS HSPA LTE for and
上传时间： 2020-06-01
上传用户：shancjb
Wirelesscommunications,especiallyinitsmobileform,hasbroughtusthefreedomofmobility andhaschangedthelifestylesofmodernpeople.Waitingatafixedlocationtoreceiveormakea phone call, or sitting in front of a personal computer to send an e-mail or download a video program, has become an old story. Nowadays it is commonplace for people to talk over a cell phonewhilewalkingonthestreet,ortodownloadandwatchamoviewhiletravelingonatrain. Thisisthebenefitmadeavailabletousbythesuccessfulevolutionofwirelesscommunications over three generations, with the fourth generation being under way.
标签： Communications Management Wireless Resource
上传时间： 2020-06-01
上传用户：shancjb
The next avatar of the Internet will revolutionize our world. In time, it will provide us a universal remote control, enabling us to monitor and control physical objects located anywhere on the planet, using a smart phone. It will make the universe around us programmable, allowing us to script the behav- ior of physical objects with electronic commands. This book is about such an emerging new version of the Internet.
标签： Infrastructure Construction Design RFID and an of
上传时间： 2020-06-08
上传用户：shancjb
STM32L475开发板PDF原理图+AD集成3D封装库+主要器件技术手册，集成封装库型号列表如下：Library Component Count : 44Name Description----------------------------------------------------------------------------------------------------ANT-2.4G ANT,2.4G,PCB天线ATK-TEST-1*4-2.54mm 测试点ATK_MODULE 单排母,1*6,2.54mmBEEP 3.3V有源蜂鸣器BUTTON_DIP3 拨动开关SS-12F44C-0402-SMD C-0603-SMD C-CAP-SMD-220uF/10V C-CEP-220uF/16V D-1N4148 Header-1*3-2.54mm 单排针-2.54mmHeader-2*10-2.54mm 双排针-2.54mmHeader-2*2-2.54mm 双排针-2.54mmHeader-2*3-2.54mm 双排针-2.54mmHeader-2*4-2.54mm 双排座-2.54mmIR-LED 1206红外发射管（侧）IR-LF0038GKLL-1 红外接收管SMDJ-MICRO-USB-5S Micro USB 5.9有柱脚长1.25加长针L-0420-4.7uH 电感,4.7uH,3ALCD-TFT-H13TS38A LCD,TFT,1.3'240*240,禹龙LED-0603-RED 发光二极管-红色LED-RGB-1615-0603 RGB,共阳,1615,0603MIC-6022 MICMotor-SMD 电机,SMDPhone-3-M 耳机座,三节R-0402-SMD 贴片电阻R-0805-SMD 贴片电阻RT9193-3.3S-KEY-SMD-324225 KEY,SMD,324225S8050-SMD SD-MICRO-TF SD,MICRO,TFU-AHT10 Sensor,温湿度传感器U-AP3216C Sensor.光照/距离U-AP6181 WIFI Module,SDIOU-ES8388 AUDIO,2-ch DAC,2-ch ADCU-ICM-20608 三轴陀螺仪/三轴加速度计,U-L9110S 电机驱动,800mAU-RT9013-3.3 LDO,500mAU-STM32F103C8T6 U-STM32L475VET6 MCU,LQFP100,512K FLASH,128K RAMU-W25Q128 SPI FLASH,16MY-12M-SMD 晶振 - 12M贴片Y-3215-32.768K XTAL,3215,32.768KY-3215-8M XTAL,3215,8MHz
上传时间： 2021-12-15
上传用户：
配电网中,各种配电终端的电流、电压、有功功率及无功功率等模拟量的采集是配电网自动化的重要环节。这些模拟量的采集也是各种仪器和家用电器的必要功能。因此,设计了基于嵌入式STM32F103单片机的交流电压、交流电流及有功功率的采集系统,通过电压互感器TV1005M和电流互感器TA1005M分别检测交流电压和交流电流值;屏幕或者手机APP和WiFi模块互联后,可以实时显示交流电压、交流电流、功率及电量值;通过设定阈值功率,可以实现对电流的监控和对电路的保护。In the distribution network,the collection of analog,such as current,voltage,active power,and reactive power at various distribution terminals is a very important part of distribution network automation. These analog acquisitions are also for various instruments and household appliances. Very important technology. Therefore,an AC voltage,AC current and active power acquisition system based on embedded STM32 F103 machine is designed,and AC voltage and AC current values are detected by voltage transformer TV1005 M and current Transformer TA1005 M respectively;After the screen or mobile phone APP and WiFi modules are interconnected,AC voltage,AC current,power,and power values can be displayed in real time;By setting the threshold power,the current can be monitored and the circuit can be protected.
上传时间： 2022-03-27
上传用户：shjgzh
资源较大，分为三个部分，已全部上传：第一部分：https://dl.21ic.com/download/linux-427595.html 第二部分：https://dl.21ic.com/download/linux-427596.html 第三部分：https://dl.21ic.com/download/linux-427598.html 本书个面介绍了嵌入式 Linux系统开发过程中，从底层系统支持到上层GUI应用的方方面面，内容涵盖nux操作系统的安装及相关工具的使用、配置，嵌入式编程所需要的基础知识（交叉编译工具的选项设置Makefile语法、ARM汇编指令等），硬件部件的使用及编程（囊括了常见硬件，比如UART、C、LCD等）U-Bo°、Linux内核的分析、配置和移植，根文件系统的构造（包括移植 busybox、glibc、制作映象文件等）内核调试技术（比如添加kgdb补丁、栈回溯等），驱动程序编写及移植（LED、按键、扩展串口、网卡、硬盘、SD卡、LCD和USB等），GUI系统的移植（包含两个GUI系统：基于 Qtopia和基于Ⅹ），应用程序调试技术木书从最简单的点亮一个LED开始，由浅入深地讲解，使读者最终可以配置、移植、裁剪内核，编写驱动程序，移植GU系统，掌握整个嵌入式 Linux系统的开发方法本书出浅入深，循序渐进，适合刚接触嵌入式Linx的初学者学习，也可作为大、中专院校嵌入式相关专业木科生、研究生的教材。
上传时间： 2022-04-03
上传用户：bluedrops
