Fourth Generation (4G) wireless communication systems aim to allow peak data rates in the range of 1 Gbps for nomadic access and 100 Mbps for vehicular mobil- ity. 4G aims to support current and emergent multimedia services, such as mobile TV, Social networks and gaming, high-definition television and video telecon- ference, multimedia messaging service, using the All-over IP concept and with improved quality of service.
标签： Transmission Techniques Systems for 4G
上传时间： 2020-06-01
上传用户：shancjb
Recent advances in wireless communication technologies have had a transforma- tive impact on society and have directly contributed to several economic and Social aspects of daily life. Increasingly, the untethered exchange of information between devices is becoming a prime requirement for further progress, which is placing an ever greater demand on wireless bandwidth. The ultra wideband (UWB) system marks a major milestone in this progress. Since 2002, when the FCC allowed the unlicensed use of low-power, UWB radio signals in the 3.1–10.6GHz frequency band, there has been significant synergistic advance in this technology at the cir- cuits, architectural and communication systems levels. This technology allows for devices to communicate wirelessly, while coexisting with other users by ensuring that its power density is sufficiently low so that it is perceived as noise to other users.
上传时间： 2020-06-01
上传用户：shancjb
Five years have passed since the first edition of this book was published.Over the five years,the world has witnessed a technological revolution headlined by an array of exciting consumer and industrial products such as the Nintendo Wii, Apple iPod/iPad, sensor-rich smart phones, phones with cameras,new operating systems for mobile phones and apps,e-books,WiFi,voice- over-IP calls, Social networking, 3D animated movies, and cloud computing, to name the major ones that affect everyday living
标签： Foundations MEMS of
上传时间： 2020-06-06
上传用户：shancjb
This is a practical book, to be sure, but it is also a book about hope and posi- tive change. I am quite sincere. The delivery of electricity is deeply rooted in the principle of universal access; when clean, reliable energy is available it contributes to poverty alleviation, improved Social conditions, and enhanced economic development. In the developed world, we know this to be true. The digital fabric of our lives is a testimony to the importance of energy security. Across the globe, we have seen the vital contributions that electrification has brought to the development of economies and an enhanced quality of life. Nonetheless, this supreme engineering achievement has languished, and we are deeply challenged.
标签： Strategies Analytics Data Big
上传时间： 2020-06-07
上传用户：shancjb
Today, electric power transmission systems should face many demanding chal- lenges, which include balancing between reliability, economics, environmental, and other Social objectives to optimize the grid assets and satisfy the growing electrical demand. Moreover, the operational environment of transmission systems is becoming increasingly rigorous due to continually evolving functions of interconnected power networks from operation jurisdiction to control responsibly – coupled with the rising demand and expectation for reliability.
标签： Monitoring Protection Wide Area
上传时间： 2020-06-07
上传用户：shancjb
Although doing science is at the heart of discovery, the effort would have very limited consequence in the long term without writingscience. As a Social enterprise that depends on collaboration, scientific inquiry requires its practi- tioners to write on a regular basis. From time to time, some members of the scientific community have been critical of the overall quality of writing by re- searchers.
标签： Goldbort_Writing Science for
上传时间： 2020-06-09
上传用户：shancjb
Computer science as an academic discipline began in the 1960’s. Emphasis was on programming languages, compilers, operating systems, and the mathematical theory that supported these areas. Courses in theoretical computer science covered finite automata, regular expressions, context-free languages, and computability. In the 1970’s, the study of algorithms was added as an important component of theory. The emphasis was on making computers useful. Today, a fundamental change is taking place and the focus is more on a wealth of applications. There are many reasons for this change. The merging of computing and communications has played an important role. The enhanced ability to observe, collect, and store data in the natural sciences, in commerce, and in other fields calls for a change in our understanding of data and how to handle it in the modern setting. The emergence of the web and Social networks as central aspects of daily life presents both opportunities and challenges for theory.
标签： Foundations Science Data of
上传时间： 2020-06-10
上传用户：shancjb
历时四年，在继好评如潮的《你好，放大器》之后，西安交通大学电气工程学院杨建国老师携模电系列丛书《新概念模拟电路》再度归来！全书共五册，近50万字，一样的风趣幽默，一样的Social化语言，深入浅出地将枯燥深奥的模电知识讲得简单易学。《新概念模拟电路》丛书包含了《晶体管》、《负反馈和运算放大器》、《运放电路的频率特性和滤波器》、《信号处理电路》以及《源电路·信号和电源》，绝大部分内容都是杨教授亲自实验或仿真总结之后才写出来的，非常有价值。杨教授表示，"尽管全书囊括众多模电知识点，但它绝不会是一本有着欺世盗名名字却包罗万象的大杂烩。"
标签： 模拟电路
上传时间： 2022-03-22
上传用户：zhanglei193
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
