The radio spectrum is one of the most precious resources which must be managed to ensure efficient access for the wireless communication services which use it. The allocation and management of spectrum are administered by the regulatory authorities. Traditionally, spectrum allocation is carried out exclusively of its use in large geographic areas and assigning frequency bands to specific users or service providers is proved to be inefficient. Recently, substantial knowledge about dynamic spectrum access scheme has been accumulated to enable efficient spectrum sharing.
标签： Management Spectrum Access and
上传时间： 2020-06-01
上传用户：shancjb
Spread-spectrum communication is a core area within the field of digital communication. Originally used in military networks as countermeasures against the threats of jamming and interception, spread-spectrum systems are now widely used in commercial applications and are part of several wireless and mobile communication standards. Although spread-spectrum communication is a staple topic in textbooks on digital communication, its treatment is usually cursory. This book is designed to provide a more intensive examination of the subject that is suitable for graduate students and practicing engineers with a solid background in the theory of digital communication. As the title indicates, this book stresses principles rather than specific current or planned systems, which are described in manyotherbooks.My goal in this bookis to providea concisebut lucidexplanation of the fundamentals of spread-spectrum systems with an emphasis on theoretical principles.
标签： Spread-Spectrum Communication Systems 2nd
上传时间： 2020-06-01
上传用户：shancjb
Intensive development of digital technologies coincided in time with the beginning of the new era in telecommunications. It made possible to formalize many proce- dures of data exchange and to atomize some operations which made providing of serviceandmakeworkofmanytelecommunicationworkersmucheasier. Somenew telecommunication technologies were born out of the necessity for use of specific configurations of network elements and networks, as well as for a possibility of providing maximum characteristics of efficiency combined with high requirements to the stability of operation, the overcoming of different catastrophic situations and deadlockconditions,such as failuresand ”pending”of the networkandthe like. The thresholdbetweeninformationsystems andtelecommunicationsystems has become practically invisible. It resulted in such a new term as ”infocommunication”
上传时间： 2020-06-01
上传用户：shancjb
The Raspberry Pi has become a computing phenomenon. This single-board miniature computer, first released in February 2012 by the Raspberry Pi Foundation, has grown into a series of nearly a dozen models that have sold a total of more than 10 million units in five years. Inexpensive to buy and to run, Raspberry Pi computers are great for enthusiasts, good for games, and fun for children. Raspberry Pi computers are also terrific in the classroom, enabling you to put on each desk an easily-manageable computer on which students can do everything from learning Internet use and essential office software skills, through grasping programming basics in an easy-to-learn format, to performing full-on programming in Python, Java, C, and other languages. Better yet, you can install all the software needed for those activities automatically alongside the operating system.
标签： Deploying Classroom Raspberry the Pi in
上传时间： 2020-06-06
上传用户：shancjb
This book is the result of works dedicated to specific applications of metaheuristics in smart electrical grids. From electric transmission, distribution networks to electric microgrids, the notion of intelligence refers to the ability to propose acceptable solutions in an increasingly more restrictive environment. Most often, it refers to decision-making assisting tools designed to support all human action.
标签： Metaheuristics Intelligent Electrical Networks for
上传时间： 2020-06-07
上传用户：shancjb
The continuous progress in modern power device technology is increasingly supported by power-specific modeling methodologies and dedicated simulation tools. These enable the detailed analysis of operational principles on the the device and on the system level; in particular, they allow the designer to perform trade- off studies by investigating the operation of competing design variants in a very early stage of the development process. Furthermore, using predictive computer simulation makes it possible to analyze the device and system behavior not only under regularoperatingconditions, but also at the rim of the safe-operatingarea and beyond of it, where destructive processes occur that limit the lifetime of a power system.
标签： POWERHVMOS_Devices_Compact_Modeli ng
上传时间： 2020-06-07
上传用户：shancjb
To a quantum mechanic the whole universe is one godawful big interacting wavefunction ? but to the rest of us, it’s a world full of separate and distinguishable objects that hurt us when we kick them. At a few months of age, human children recognize objects, expect them to be permanent and move continuously, and display surprise when they aren’t or don’t. We associate visual, tactile, and in some cases audible and olfactory sensations with identifiable physical things. We’re hardwired to understand our environment as being composed of separable things with specific properties and locations. We understand the world in terms of what was where when.
上传时间： 2020-06-08
上传用户：shancjb
Artificial Intelligence (AI) has undoubtedly been one of the most important buz- zwords over the past years. The goal in AI is to design algorithms that transform com- puters into “intelligent” agents. By intelligence here we do not necessarily mean an extraordinary level of smartness shown by superhuman; it rather often involves very basic problems that humans solve very frequently in their day-to-day life. This can be as simple as recognizing faces in an image, driving a car, playing a board game, or reading (and understanding) an article in a newspaper. The intelligent behaviour ex- hibited by humans when “reading” is one of the main goals for a subfield of AI called Natural Language Processing (NLP). Natural language 1 is one of the most complex tools used by humans for a wide range of reasons, for instance to communicate with others, to express thoughts, feelings and ideas, to ask questions, or to give instruc- tions. Therefore, it is crucial for computers to possess the ability to use the same tool in order to effectively interact with humans.
标签： Embeddings Processing Language Natural in
上传时间： 2020-06-10
上传用户：shancjb
CHAPTER 1: THE OP AMP CHAPTER 2: OTHER LINEAR CIRCUITS CHAPTER 3: SENSORS CHAPTER 4: RF/IF CIRCUITS CHAPTER 5: FUNDAMENTALS OF SAMPLED DATA SYSTEMS CHAPTER 6: CONVERTERS CHAPTER 7: DATA CONVERTER SUPPORT CIRCUITS CHAPTER 8: ANALOG FILTERS CHAPTER 9: POWER MANAGEMENT CHAPTER 10: PASSIVE COMPONENTS CHAPTER 11: OVERVOLTAGE EFFECTS ON ANALOG INTEGRATED CIRCUITS CHAPTER 12: PRINTED CIRCUIT BOARD (PCB) DESIGN ISSUES CHAPTER 13: DESIGN DEVELOPMENT TOOLS
上传时间： 2021-12-21
上传用户：wangshoupeng199
一天学会用Allegro画电源板Allegro 由于其相对完善、强大的功能，一向被认为是较难学的画板软件之一，主要原因也是因为功能太多， 如果按 500 多页的出版教材来一一学是有点费时的，其实，如果只是用来画简单电源板的话，一两天就可以学会了， 没有很多命令要记，几乎要用的命令都可以从下拉菜单中找到且大部分都已以直观的图标按钮形式分布在软件主界 面上，即你可直接输入命令也可以从菜单中操作，也可从工具栏中点“按钮”，觉得哪种更方便就用哪种。该教程 只说画电源板用到的功能部分，使复杂工具变为简单、易学。如下图是一块用 Allegro 画的单面电源板。 ————本教材主要 for 从用 Altium Designer 和 PADS 转过来的工程师。完成板子的效率比 99SE 高得多。 一、 建原理图 *目的是用于生成网表导入 allegro 中布局。（习惯不需原理图和网表就能画板的工程师请跳到 allegro 篇） 1.1 找个盘比如 D 盘建个项目文件夹，里面再建两个文件夹，一个用于放电路原理图，一个用于放 PCB 文件， 尽量不要中文名。PS：原理图和 PCB 都放在同一个文件夹下也可以的，只是不好找不方便管理。 1.2 打开 Or CAD Capture CIS→File→New→Project，在 name 一栏填电路图名称；在 Create a New Project Using 一栏中选 PC Board Wizard;接下来一栏 Location 是选刚才建的文件夹路径然后点 OK 按钮。
上传时间： 2022-02-06
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