RFID (radio-frequency identification) is the use of a wireless non-contact system that uses radio-frequencyelectromagnetic fields to transfer datafrom a tag attached to an object, for the purposes of automatic identification and tracking [38]. The basic technologies for RFID have been around for a long time. Its root can be traced back to an espionage device designed in 1945 by Leon Theremin of the Soviet Union,whichretransmittedincidentradiowaves modulatedwith audioinformation. After decades of development, RFID systems have gain more and more attention from both the research community and the industry.
标签： Infrastructure RFID as an
上传时间： 2020-06-08
上传用户：shancjb
I wrote this book so that students, hobbyists, and engineers alike can take advantage of the Arduino platform by creating several projects that will teach them about the engineering process. I also wanted to guide the reader through introductory projects so that they could get a firm grasp on the Arduino Language, and how to incorporate several pieces of hardware to make their own projects. This book offers so much information on the Arduino, not just the basic LED projects but it offers different peripherals such as Ultrasonic sensor, the Xbox® controller, Bluetooth, and much more. This book also teaches the non-engineer to follow a process that will help them in future project (not just Arduino projects).
标签： Engineering Practical Arduino
上传时间： 2020-06-09
上传用户：shancjb
The main aim of this book is to present a unified, systematic description of basic and advanced problems, methods and algorithms of the modern con- trol theory considered as a foundation for the design of computer control and management systems. The scope of the book differs considerably from the topics of classical traditional control theory mainly oriented to the needs of automatic control of technical devices and technological proc- esses. Taking into account a variety of new applications, the book presents a compact and uniform description containing traditional analysis and op- timization problems for control systems as well as control problems with non-probabilistic models of uncertainty, problems of learning, intelligent, knowledge-based and operation systems – important for applications in the control of manufacturing processes, in the project management and in the control of computer systems.
上传时间： 2020-06-10
上传用户：shancjb
The PW5300 is a current mode boost DC-DC converter. Its PWM circuitry with built-in 0.2Ω powerMOSFET make this regulator highly power efficient. The internal compensation network alsominimizes as much as 6 external component counts. The non-inverting input of error amplifierconnects to a 0.6V precision reference voltage and internal soft-start function can reduce the inrushcurrent. The PW5300 is available in the SOT23-6L package and provides space-saving PCB for theapplication fields
标签： pw5300
上传时间： 2022-02-11
上传用户：jiabin
解读 5G 八大关键技术 【摘要】5G 不是一次革命，5G 是 4G 的延续，我相信 5G 在核心网部分不会有太 大的变动，5G 的关键技术集中在无线部分。 在进入主题之前，我觉得首先应该弄清楚一个问题：为什么需要 5G？不是因 为通信工程师们突然想改变世界，而炮制了一个 5G。是因为先有了需求，才有了 5G。什么需求？ 未来的网络将会面对：1000 倍的数据容量增长，10 到 100 倍的无线设备连接， 10 到 100 倍的用户速率需求，10 倍长的电池续航时间需求等等。坦白的讲，4G 网络无法满足这些需求，所以 5G 就必须登场。 但是，5G 不是一次革命。5G 是 4G 的延续，我相信 5G 在核心网部分不会有 太大的变动，5G 的关键技术集中在无线部分。虽然 5G 最终将采用何种技术，目前 还没有定论。不过，综合各大高端论坛讨论的焦点，我今天收集了 8 大关键技术。 当然，应该远不止这些。 1.非正交多址接入技术 （Non-Orthogonal Multiple Access,NOMA） 我们知道 3G 采用直接序列码分多址（Direct Sequence CDMA ，DS-CDMA） 技术，手机接收端使用 Rake 接收器，由于其非正交特性，就得使用快速功率控制 （Fast transmission power control ，TPC)来解决手机和小区之间的远-近问题。 而 4G 网络则采用正交频分多址（
标签： 5G
上传时间： 2022-02-25
上传用户：20125101110
mosfet并联使用介绍了并联使用的注意事项，特别注意避开Vgsth zero thermal coefficient以下的正温特性设计
上传时间： 2022-03-01
上传用户：bluedrops
华为AI安全白皮书2018-cn近年来，随着海量数据的积累、计算能力的发展、机器学习方法与系统的持续创新与演进，诸如图像识别、语音识 别、自然语言翻译等人工智能技术得到普遍部署和广泛应用。越来越多公司都将增大在AI的投入，将其作为业务发展 的重心。华为全球产业愿景预测：到2025年，全球将实现1000亿联接，覆盖77%的人口；85%的企业应用将部署到 云上；智能家庭机器人将进入12%的家庭，形成千亿美元的市场。 人工智能技术的发展和广泛的商业应用充分预示着一个万物智能的社会正在快速到来。1956年，麦卡锡、明斯基、 香农等人提出“人工智能”概念。60年后的今天，伴随着谷歌DeepMind开发的围棋程序AlphaGo战胜人类围棋冠 军，人工智能技术开始全面爆发。如今，芯片和传感器的发展使“+智能”成为大势所趋：交通+智能，最懂你的 路；医疗+智能，最懂你的痛；制造+智能，最懂你所需。加州大学伯克利分校的学者们认为人工智能在过去二十年 快速崛起主要归结于如下三点原因[1]：1）海量数据：随着互联网的兴起，数据以语音、视频和文字等形式快速增 长；海量数据为机器学习算法提供了充足的营养，促使人工智能技术快速发展。2）高扩展计算机和软件系统：近 年来深度学习成功主要归功于新一波的CPU集群、GPU和TPU等专用硬件和相关的软件平台。3）已有资源的可获得 性：大量的开源软件协助处理数据和支持AI相关工作，节省了大量的开发时间和费用；同时许多云服务为开发者提供 了随时可获取的计算和存储资源。 在机器人、虚拟助手、自动驾驶、智能交通、智能制造、智慧城市等各个行业，人工智能正朝着历史性时刻迈进。谷 歌、微软、亚马逊等大公司纷纷将AI作为引领未来的核心发展战略。2017年谷歌DeepMind升级版的AlphaGo Zero横 空出世；它不再需要人类棋谱数据，而是进行自我博弈，经过短短3天的自我训练就强势打败了AlphaGo。AlphaGo Zero能够发现新知识并发展出打破常规的新策略，让我们看到了利用人工智能技术改变人类命运的巨大潜能。 我们现在看到的只是一个开始；未来，将会是一个全联接、超智能的世界。人工智能将为人们带来极致的体验，将 积极影响人们的工作和生活，带来经济的繁荣与发展。
上传时间： 2022-03-06
上传用户：
随着光伏发电系统快速发展,以及电动汽车充电桩的普及,传统的剩余电流保护器无法满足实际需求。介绍了一款B型剩余电流保护器,采用磁调制剩余电流互感器和零序电流互感器采集剩余电流。根据GB/T 22794—2017标准要求,可识别1 kHz及以下的正弦交流、带和不带直流分量的脉动直流、平滑直流等剩余电流信号。经信号调理电路将电压信号送到单片机进行采集和判断。通过试验测试,该样机在测试精度和速度上均符合国家标准的相关要求。The rapid development of photovoltaic power generation systems and the popularity of electric vehicle charging piles make the traditional residual current protective devices unable to meet the actual demand.This paper proposed a type B residual current protective device,which uses the magnetically modulated residual current transformer and the zero sequence current transformer to acquire the residual current.According to the requirements of GB/T 22794—2017,the type B residual current protective device can detect sinusoidal AC residual current of 1kHz and below 1kHz,pulsating DC residual current with and without DC component,smooth DC residual current and so on.The signal processing circuit sends the voltage signal to the MCU for acquisition and judgment.Through experimental tests,the device meets the relevant requirements of national standards in terms of test accuracy and speed.
标签： 电流保护器
上传时间： 2022-03-27
上传用户：
温度控制如今已成为当代社会研究的热点之一,而温度检测在现代设备参数检测中也是一项极其重要的技术,应用十分广泛。与传统的测温方法相比,红外测温方法具有时间短、精度高、使用简单方便等优点。本文以环境温度为被测对象,设计了以STC89C52单片机为控制中心的红外测温装置,能够实现对目标温度的实时采集、处理、显示和报警等功能。本设计主要是由STC89C52单片机、红外测温传感器、LCD1602液晶显示器、按键和蜂鸣器等部分组成,采用非接触的方式对目标温度进行实时检测。Temperature control has become one of the hotspots in contemporary social research,and temperature detection is an extremely important technology in modern equipment parameter detection.Compared with traditional method,the infrared temperature measuring method has advantages of short time,high precision and convenient operation,etc.This paper consider environment temperature as research objects and designs an infrared temperature measuring device which employs the STC89C52singlechipas-control center,and it can realize timely collection,processing,display and alarm function of the target temperature.The design is mainly composed of STC89C52 singlechip,infrared temperature sensor,LCD1602monitor,keys and buzzer,etc.This design detects the target temperature by non-contact method.
上传时间： 2022-03-27
上传用户：jiabin
本系统基于STM32单片机设计的非接触式电流检测控制系统,通过OPA548片将所给任意信号放大,由100Ω电阻和INA128芯片进行电流电压转换放大后,利用STM32单片机对获取的电压信号以0.488μs频率采样,利用STM32单片机的FFT库,获得信号的谐波信息。测量电流信号精准,该设计可广泛应用在以STM32单片机为核心控制器件的新型仪表中,性能精准且抗干扰能力强。This system is a non-contact current detection and control system based on STM32 single chip microcomputer. It amplifiesany signal through OPA548 chip, converts and amplifies the current and voltage by 100 Ω resistance and INA128 chip. The obtainedvoltage signal is sampled at the frequency of 0.488 μs by STM 32 single chip microcomputer, and the harmonic information of the signalis obtained by the FFT library of STM 32 single chip microcomputer. The measurement of current signal is accurate. This design can bewidely used in a new instrument with STM 32 single chip microcomputer as its core control device, with accurate performance and stronganti-interference capability.
上传时间： 2022-03-27
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