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.
標簽： Communications Wireless Mobile and
上傳時間： 2020-05-30
上傳用戶：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.
標簽： Communications Introduction Mobile Media New An to
上傳時間： 2020-05-30
上傳用戶：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.
標簽： Opportunities Consumption Technology Mobile
上傳時間： 2020-05-30
上傳用戶：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).
標簽： Telecommunications Networks
上傳時間： 2020-06-01
上傳用戶：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.
標簽： Evolution WCDMA UMTS HSPA LTE for and
上傳時間： 2020-06-01
上傳用戶：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.
標簽： Communications Management Wireless Resource
上傳時間： 2020-06-01
上傳用戶：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.
標簽： Infrastructure Construction Design RFID and an of
上傳時間： 2020-06-08
上傳用戶：shancjb
STM32L475開發板PDF原理圖+AD集成3D封裝庫+主要器件技術手冊，集成封裝庫型號列表如下：Library Component Count : 44Name Description----------------------------------------------------------------------------------------------------ANT-2.4G ANT,2.4G,PCB天線ATK-TEST-1*4-2.54mm 測試點ATK_MODULE 單排母,1*6,2.54mmBEEP 3.3V有源蜂鳴器BUTTON_DIP3 撥動開關SS-12F44C-0402-SMD C-0603-SMD C-CAP-SMD-220uF/10V C-CEP-220uF/16V D-1N4148 Header-1*3-2.54mm 單排針-2.54mmHeader-2*10-2.54mm 雙排針-2.54mmHeader-2*2-2.54mm 雙排針-2.54mmHeader-2*3-2.54mm 雙排針-2.54mmHeader-2*4-2.54mm 雙排座-2.54mmIR-LED 1206紅外發射管（側）IR-LF0038GKLL-1 紅外接收管SMDJ-MICRO-USB-5S Micro USB 5.9有柱腳長1.25加長針L-0420-4.7uH 電感,4.7uH,3ALCD-TFT-H13TS38A LCD,TFT,1.3'240*240,禹龍LED-0603-RED 發光二極管-紅色LED-RGB-1615-0603 RGB,共陽,1615,0603MIC-6022 MICMotor-SMD 電機,SMDPhone-3-M 耳機座,三節R-0402-SMD 貼片電阻R-0805-SMD 貼片電阻RT9193-3.3S-KEY-SMD-324225 KEY,SMD,324225S8050-SMD SD-MICRO-TF SD,MICRO,TFU-AHT10 Sensor,溫濕度傳感器U-AP3216C Sensor.光照/距離U-AP6181 WIFI Module,SDIOU-ES8388 AUDIO,2-ch DAC,2-ch ADCU-ICM-20608 三軸陀螺儀/三軸加速度計,U-L9110S 電機驅動,800mAU-RT9013-3.3 LDO,500mAU-STM32F103C8T6 U-STM32L475VET6 MCU,LQFP100,512K FLASH,128K RAMU-W25Q128 SPI FLASH,16MY-12M-SMD 晶振 - 12M貼片Y-3215-32.768K XTAL,3215,32.768KY-3215-8M XTAL,3215,8MHz
上傳時間： 2021-12-15
上傳用戶：
配電網中,各種配電終端的電流、電壓、有功功率及無功功率等模擬量的采集是配電網自動化的重要環節。這些模擬量的采集也是各種儀器和家用電器的必要功能。因此,設計了基于嵌入式STM32F103單片機的交流電壓、交流電流及有功功率的采集系統,通過電壓互感器TV1005M和電流互感器TA1005M分別檢測交流電壓和交流電流值;屏幕或者手機APP和WiFi模塊互聯后,可以實時顯示交流電壓、交流電流、功率及電量值;通過設定閾值功率,可以實現對電流的監控和對電路的保護。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.
上傳時間： 2022-03-27
上傳用戶：shjgzh
資源較大，分為三個部分，已全部上傳：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 本書個面介紹了嵌入式 Linux系統開發過程中，從底層系統支持到上層GUI應用的方方面面，內容涵蓋nux操作系統的安裝及相關工具的使用、配置，嵌入式編程所需要的基礎知識（交叉編譯工具的選項設置Makefile語法、ARM匯編指令等），硬件部件的使用及編程（囊括了常見硬件，比如UART、C、LCD等）U-Bo°、Linux內核的分析、配置和移植，根文件系統的構造（包括移植 busybox、glibc、制作映象文件等）內核調試技術（比如添加kgdb補丁、棧回溯等），驅動程序編寫及移植（LED、按鍵、擴展串口、網卡、硬盤、SD卡、LCD和USB等），GUI系統的移植（包含兩個GUI系統：基于 Qtopia和基于Ⅹ），應用程序調試技術木書從最簡單的點亮一個LED開始，由淺入深地講解，使讀者最終可以配置、移植、裁剪內核，編寫驅動程序，移植GU系統，掌握整個嵌入式 Linux系統的開發方法本書出淺入深，循序漸進，適合剛接觸嵌入式Linx的初學者學習，也可作為大、中專院校嵌入式相關專業木科生、研究生的教材。
上傳時間： 2022-04-03
上傳用戶：bluedrops
