To achieve sparse sampling on a coded ultrasonic signal,the finite rate of innovation(FRI)sparse sampling technique is proposed on a binary frequency-coded(BFC)ultrasonic signal.A framework of FRI-based sparse samplin...To achieve sparse sampling on a coded ultrasonic signal,the finite rate of innovation(FRI)sparse sampling technique is proposed on a binary frequency-coded(BFC)ultrasonic signal.A framework of FRI-based sparse sampling for an ultrasonic signal pulse is presented.Differences between the pulse and the coded ultrasonic signal are analyzed,and a response mathematical model of the coded ultrasonic signal is established.A time-domain transform algorithm,called the high-order moment method,is applied to obtain a pulse stream signal to assist BFC ultrasonic signal sparse sampling.A sampling of the output signal with a uniform interval is then performed after modulating the pulse stream signal by a sampling kernel.FRI-based sparse sampling is performed using a self-made circuit on an aluminum alloy sample.Experimental results show that the sampling rate reduces to 0.5 MHz,which is at least 12.8 MHz in the Nyquist sampling mode.The echo peak amplitude and the time of flight are estimated from the sparse sampling data with maximum errors of 9.324%and 0.031%,respectively.This research can provide a theoretical basis and practical application reference for reducing the sampling rate and data volume in coded ultrasonic testing.展开更多
What is open innovation？ There are different definitions of open innovation, depending, at least, on three parameters： source, ownership, or users of the knowledge linked to innovation. The aim of the paper is to ma...What is open innovation？ There are different definitions of open innovation, depending, at least, on three parameters： source, ownership, or users of the knowledge linked to innovation. The aim of the paper is to make a systematic literature review, to map open innovation studies, and to re-conceptualize the openness according to two dimensions： degree of technology convergence and ontology of openness. In particular, we propose a classification of open innovation, based on the distinction between the originator/developer of the knowledge and the user. Users are a ubiquitous category, because they can be originators, as well as customers of the innovation itself. Therefore, we point out that there are three types of open innovation, whose degree of openness is defined according to an ontological dimension： at users’ level, at an industry level, and among different fields or industries. Firm’s structure affects the propensity to open innovation adoption; and the type of innovation itself. Finally, we identify another literature gap： the relationship between the open innovation model and grand challenge. Even if open innovation seems to be ideally connected to grand challenges and many industries actually adopt this model, there seems to emerge a gap in literature. Therefore, we propose a conceptual model for future researches.展开更多
Professor Yuan Jin from Zhongshan Ophthalmic Center(ZOC) affiliated with Sun Yat-sen University has recently won the "Grand Challenge 2015 Young Scientist" award in "2015 Innovation Challenge Annual Mee...Professor Yuan Jin from Zhongshan Ophthalmic Center(ZOC) affiliated with Sun Yat-sen University has recently won the "Grand Challenge 2015 Young Scientist" award in "2015 Innovation Challenge Annual Meeting" held in Beijing. The meeting is organized by the Ministry of Science and Technology of the People Republic of China(MOST), the Bill & Melinda Gates Foundation in the United States and the US Agency for International Development. The journal Eye Science(ES) is the official publication of ZOC, sponsored by Sun Yat-sen University.展开更多
基金The National Natural Science Foundation of China (No.51375217)。
文摘To achieve sparse sampling on a coded ultrasonic signal,the finite rate of innovation(FRI)sparse sampling technique is proposed on a binary frequency-coded(BFC)ultrasonic signal.A framework of FRI-based sparse sampling for an ultrasonic signal pulse is presented.Differences between the pulse and the coded ultrasonic signal are analyzed,and a response mathematical model of the coded ultrasonic signal is established.A time-domain transform algorithm,called the high-order moment method,is applied to obtain a pulse stream signal to assist BFC ultrasonic signal sparse sampling.A sampling of the output signal with a uniform interval is then performed after modulating the pulse stream signal by a sampling kernel.FRI-based sparse sampling is performed using a self-made circuit on an aluminum alloy sample.Experimental results show that the sampling rate reduces to 0.5 MHz,which is at least 12.8 MHz in the Nyquist sampling mode.The echo peak amplitude and the time of flight are estimated from the sparse sampling data with maximum errors of 9.324%and 0.031%,respectively.This research can provide a theoretical basis and practical application reference for reducing the sampling rate and data volume in coded ultrasonic testing.
文摘What is open innovation？ There are different definitions of open innovation, depending, at least, on three parameters： source, ownership, or users of the knowledge linked to innovation. The aim of the paper is to make a systematic literature review, to map open innovation studies, and to re-conceptualize the openness according to two dimensions： degree of technology convergence and ontology of openness. In particular, we propose a classification of open innovation, based on the distinction between the originator/developer of the knowledge and the user. Users are a ubiquitous category, because they can be originators, as well as customers of the innovation itself. Therefore, we point out that there are three types of open innovation, whose degree of openness is defined according to an ontological dimension： at users’ level, at an industry level, and among different fields or industries. Firm’s structure affects the propensity to open innovation adoption; and the type of innovation itself. Finally, we identify another literature gap： the relationship between the open innovation model and grand challenge. Even if open innovation seems to be ideally connected to grand challenges and many industries actually adopt this model, there seems to emerge a gap in literature. Therefore, we propose a conceptual model for future researches.
文摘Professor Yuan Jin from Zhongshan Ophthalmic Center(ZOC) affiliated with Sun Yat-sen University has recently won the "Grand Challenge 2015 Young Scientist" award in "2015 Innovation Challenge Annual Meeting" held in Beijing. The meeting is organized by the Ministry of Science and Technology of the People Republic of China(MOST), the Bill & Melinda Gates Foundation in the United States and the US Agency for International Development. The journal Eye Science(ES) is the official publication of ZOC, sponsored by Sun Yat-sen University.
