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 saw...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.展开更多
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...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.展开更多
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 implem...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.展开更多
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...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.展开更多
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 role...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.展开更多
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 examp...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.展开更多
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 in...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.展开更多
基金Doctoral Foundation of Ministry of Education of China (No. 20040056008)
文摘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.
文摘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.
文摘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.
文摘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.
文摘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.
文摘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.
文摘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.
