LED 一般是恒流操作的，如何改变 LED 的亮度呢？答案就是 PWM 控制。在一定的
频率的方波中，调整高电平和低电平的占空比，即可实现。比如我们用低电平点亮一个 LED
灯，我们假设把一个频率周期分为 10 个时间等份，如果方波中的高低电平占空比是 9：1，
这是就是一个比较暗的亮度，如果方波中高低电平占空比是 10：0，这时 ...
Reconstruction- and example-based super-resolution
(SR) methods are promising for restoring a high-resolution
(HR) image from low-resolution (LR) image(s). Under large
magnification, reconstruction-based methods usually fail
to hallucinate visual details while example-based methods
sometimes introdu ...
The idea of writing this book entitled “Cognitive Networked Sensing and Big Data”
started with the plan to write a briefing book on wireless distributed computing
and cognitive sensing. During our research on large-scale cognitive radio network
(and its experimental testbed), we realized that big ...
This book describes how global mobile communication was made. It is written for those who
want or need to know how this was achieved e.g.:
† Young professionals who want to build their career on GSM and UMTS and need to
understand the basics
† Strategic and technical planners who want to drive the ...
The ever-increasing demand for private and sensitive data transmission over wireless net-
works has made security a crucial concern in the current and future large-scale, dynamic,
and heterogeneous wireless communication systems. To address this challenge, computer
scientists and engineers have trie ...
Quality of Service ( QoS ) has always been in a world of its own, but as the technology
has been refi ned and has evolved in recent years, QOS usage has increased to the point
where it is now considered a necessary part of network design and operation. As with
most technologies, large - scale deploy ...
It was only a few years ago that “ubiquitous connectivity” was recognized as the future of
wireless communication systems. In the era of ubiquitous connectivity, it was expected that
the broadband mobile Internet experience would be pervasive, and seamless connectivity on
a global scale would be n ...
