The first gem of wisdom I ever acquired about consulting, obtained many years ago from a former schoolmate, was to ensure that everything is plugged in: no continuity, no data. Wires carry voltages and currents from one place to another. Their behavior is reasonably simple and predictable—at least for sufficiently low data rates and short lengths—and they can be seen, grabbed, traced, and tugged.
標簽： RF Engineering
上傳時間： 2020-06-01
上傳用戶：shancjb
This paper presents a Hidden Markov Model (HMM)-based speech enhancement method, aiming at reducing non-stationary noise from speech signals. The system is based on the assumption that the speech and the noise are additive and uncorrelated. Cepstral features are used to extract statistical information from both the speech and the noise. A-priori statistical information is collected from long training sequences into ergodic hidden Markov models. Given the ergodic models for the speech and the noise, a compensated speech-noise model is created by means of parallel model combination, using a log-normal approximation. During the compensation, the mean of every mixture in the speech and noise model is stored. The stored means are then used in the enhancement process to create the most likely speech and noise power spectral distributions using the forward algorithm combined with mixture probability. The distributions are used to generate a Wiener filter for every observation. The paper includes a performance evaluation of the speech enhancer for stationary as well as non-stationary noise environment.
標簽： Telecommunications Processing Signal for
上傳時間： 2020-06-01
上傳用戶：shancjb
Telecommunications is today widely understood to mean the electrical means of communicating over a distance. The first form of telecommunications was that of the Telegraph, which was invented quite independently in 1837 by two scientists, Wheatstone and Morse. Telegraphy was on a point-to-point unidirectional basis and relied on trained operators to interpret between the spoken or written word and the special signals sent over the telegraph wire. However, the use of telegraphy did greatly enhance the operations of railways and, of course, the dissemination of news and personal messages between towns.
標簽： Telecommunications Understanding Networks
上傳時間： 2020-06-01
上傳用戶：shancjb
This is a book on wireless communication. That usually means communica- tion by radio, though ultrasound and infrared light are also used occasion- ally. The term “wireless” has come to mean nonbroadcast communication, usually between individuals who very often use portable or mobile equip- ment. The term is rather vague, of course, and there are certainly borderline applications that are called wireless without falling exactly into the above definition.
標簽： Communication Technology Wireless
上傳時間： 2020-06-01
上傳用戶：shancjb
This chapter provides extensive coverage of existing mobile wireless technologies. Much of the emphasis is on the highly anticipated 3G cellular networks and widely deployed wireless local area networks (LANs), as the next-generation smart phones are likely to offer at least these two types of connectivity. Other wireless technologies that either have already been commercialized or are undergoing active research and standardization are introduced as well. Because standardization plays a crucial role in developing a new technology and a market, throughout the discussion standards organizations and industry forums or consortiums of some technologies are introduced. In addition, the last section of this chapter presents a list of standards in the wireless arena.
標簽： Networking Wireless Complete
上傳時間： 2020-06-01
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Nowadays sensors are part of everyday life in a wide variety of fields: scientific applications, medical instrumentation, industrial field, ...and, last but not least, popular mass production and low-cost goods, like smartphones and other mobile devices. Markets and business behind the field of sensors are quite impressive. A common trend for consumer applications is miniaturization which requires, on one side, a lot of research, development efforts, and resources but, on the other hand, allows costs and final application size reduction. In this scenario scientific community and industries are very active to drive innovation.
標簽： Magnetometers Lorentz Force MEMS
上傳時間： 2020-06-06
上傳用戶：shancjb
The purpose of this book is to present detailed fundamental information on a global positioning system (GPS) receiver. Although GPS receivers are popu- larly used in every-day life, their operation principles cannot be easily found in one book. Most other types of receivers process the input signals to obtain the necessary information easily, such as in amplitude modulation (AM) and frequency modulation (FM) radios. In a GPS receiver the signal is processed to obtain the required information, which in turn is used to calculate the user position. Therefore, at least two areas of discipline, receiver technology and navigation scheme, are employed in a GPS receiver. This book covers both areas.
標簽： Fundamentals_of_Global_Positionin g_System_Receivers
上傳時間： 2020-06-09
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The basic topic of this book is solving problems from system and control theory using convex optimization. We show that a wide variety of problems arising in system and control theory can be reduced to a handful of standard convex and quasiconvex optimization problems that involve matrix inequalities. For a few special cases there are “analytic solutions” to these problems, but our main point is that they can be solved numerically in all cases. These standard problems can be solved in polynomial- time (by, e.g., the ellipsoid algorithm of Shor, Nemirovskii, and Yudin), and so are tractable, at least in a theoretical sense. Recently developed interior-point methods for these standard problems have been found to be extremely efficient in practice. Therefore, we consider the original problems from system and control theory as solved.
標簽： Linear_Matrix_Inequalities_in_Sys tem
上傳時間： 2020-06-10
上傳用戶：shancjb
This book will discuss the topic of Control Systems, which is an interdisciplinary engineering topic. Methods considered here will consist of both "Classical" control methods, and "Modern" control methods. Also, discretely sampled systems (digital/computer systems) will be considered in parallel with the more common analog methods. This book will not focus on any single engineering discipline (electrical, mechanical, chemical, etc.), although readers should have a solid foundation in the fundamentals of at least one discipline.
上傳時間： 2020-06-10
上傳用戶：shancjb
Inventors have long dreamed of creating machines that think. This desire dates back to at least the time of ancient Greece. The mythical figures Pygmalion, Daedalus, and Hephaestus may all be interpreted as legendary inventors, and Galatea, Talos, and Pandora may all be regarded as artificial life ( , Ovid and Martin 2004 Sparkes 1996 Tandy 1997 ; , ; , ).
上傳時間： 2020-06-10
上傳用戶：shancjb
