电力线载波通信用的数字调解器

就单载波传输与多载波传输的原理、实现方法 ,对电力线载波通信用数字调解器的组成与方案展开讨论 ,详细阐述了单载波与多载波的回波抵消技术。最后对数字电力线载波通信的发展趋势作简要的分析。

Demodulation System for Fiber Bragg Grating Sensors Using Digital Filtering Technique

A discrimination measurement method and demodulation technique for fiber Bragg grating (FBG) sensors were presented using digital filtering technique. The system can control a tunable fiber Fabry-Perot filter with sawtooth wave voltage generated by digital clock to interrogate FBG sensors. Using the analogue digital converter (ADC), the reflected FBG signals were sampled with synchronous digital clock. With the aid of digital matched filtering technique, the sampled FBG signals were processed to obtain the maximum signal-to-noise ratio (SNR) and the Bragg wavelength shift from the FBG signals was recovered. The results demonstrate that this system has a scanning range of 1 520 nm-1 575 nm,and the wavelength detection accuracy is less than 2 pm with 1.5 Hz scanning frequency.

Study of Software Radio Receiver Development Platform

The Paper introduces an IF software radio receiver development Platform based on high-speed monolithic A/D Converter AD6640, Progranunable Digital Down-converter AD6620 and high-speed DSP chip TMSC320C6701. The implementation method is described as well as AD6620 parameter setting analysis. It also presents a flow chart of the on-line programming with the help of PC. The algorithm for demodulation AM signal is discussed.

Barter Trade Exchange to the Rescue of the Tourism and Travel Industry

South Africa＇s tourism and travel industry is a key sector in its economy as well as a significant job creator. The recent global economic turmoil is threatening the tourism industry; at the same time, global experts claim that tourism may be a key to overcoming economic difficulties and play a vital role in the green new deal. The purpose of the study is to introduce a new strategic option that has become increasingly attractive for troubled businesses-barter. While the study focuses on the advantages of this concept＇s recent refinements for South Africa＇s tourism and travel industry, its findings are also applicable to other countries. A survey of small and medium-sized enterprises （SME） from Europe and Turkey, as well as graduate students at an Israeli university, demonstrate the gap between familiarity with barter processes and their advantages and the actual scale of barter transactions in the supply chain, in order to enhance the economic performance of their tourism enterprises as well as the entire economy, providing evidence for the potential of adapting old proven concepts to the modem digital world.

Research on the impact of computer technology on art and design

With the rapid development of digital technology in the new century, modem technology used to provide aid for teaching is widely used. The pattern of education had been great changed in due to input digital technology .There are many tremendous changes such as the information collected and stored, the teaching process and performance, all aspects of the learner receives ways and means, especially the traditional art education be affected at the most significant way. In the traditional art teaching process, educators and learners mainly in the unarmed way of painting and design which tend to form on the art of teaching content recapitulate and mechanical reproduction of art materials for teaching situation. The art of teaching behaviors had become no creativity and creative fun. Modem art education needs innovation; needs to reflect the flavor of the era of technology. Therefore, the new model for art teaching with the perfect combination of the help of modem digital computer technology is becoming the most urgent needs.

Investigating the Implications of Virtualization for Digital Forensics

Research in virtualization technology has gained significant developments in recent years, which brings not only opportunities to the forensic community, but challenges as well. This paper discusses the potential roles of virtualization in digital forensics, examines the recent progresses which use the virtualization techniques to support modem computer forensics. The influences on digital forensics caused by virtualization technology are identified. Tools and methods in common digital forensic practices are analyzed, and experiences of our practice and reflections in this field are shared.

Research on General Permutation Encryption Module Based on Chaos Theory

Replacement and substitution encryption are two basic types of encryption historically. The classical encryption algorithm has been compromised now, but they still can play special role for modem cryptnlogy. For example, in digital image encryption system, substitution can disrupt the original order of the images and eliminate the correlation of image information which not only can realize security of images, but also can resist intentional attack and destruction of clipping and noise. And transposition transformation is introduced into the design of block ciphers. The substitution has the feature of high efficiency and resistance, which makes it meet the specific requirements of encryption. So substitution cypher can be applied to modern encryption system.

Al-digital demodulation system of interferometric fiber optic sensors using an improved PGC algorithm based on fundamental frequency mixing

We present an all-digital demodulation system of interferometric fiber optic sensor based on an improved arctangent-differential-self-multiplying(arctan-DSM)algorithm.The total harmonic distortion(THD)and the light intensity disturbance(LID)are also suppressed,the same as those in the traditional arctan-DSM algorithm.Moreover,the lowest sampling frequency is also reduced by introducing anti-aliasing filter,so the occupation of the system memory is reduced.The simulations show that the improved algorithm can correctly demodulate cosine signal and chirp signal with lower sampling frequency.