Junfei Li

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Despite the critical role that middleboxes play in introducing new network functionality, management and innovation of them are still severe challenges for network operators, since traditional middleboxes based on hardware lack service flexibility and scalability. Recently, though new networking technologies, such as network function virtualization (NFV)(More)
An impedance matched surface is able, in principle, to totally absorb the incident sound and yield no reflection, and this is desired in many acoustic applications. Here we demonstrate a design of impedance matched sound absorbing surface with a simple construction. By coupling different resonators and generating a hybrid resonance mode, we designed and(More)
It is very important to choose swift, powerful and compatible suppliers in supply chain management (SCM). According to the credit grade assessment for suppliers in practice and the related theories, a set of index system which assesses a supplier's credit grade is established. Basing on the index system, a multi-layer support vector machines (SVM)(More)
To my wife Ning and daughter Cara v Acknowledgements First, I would like to thank my thesis advisor, Professor Hao Ling for his guidance and mentorship, both academically and personally. Without the numerous interesting and enlightening discussions with him, this work would be impossible. His continued support will be remembered for the many years to come.(More)
Acoustic holographic rendering in complete analogy with optical holography are useful for various applications, ranging from multi-focal lensing, multiplexed sensing and synthesizing three-dimensional complex sound fields. Conventional approaches rely on a large number of active transducers and phase shifting circuits. In this paper we show that by using(More)
Membrane-type acoustic metamaterials are well known for low-frequency sound insulation. In this work, by introducing a flexible piezoelectric patch, we propose sound-insulation metamaterials with the ability of energy harvesting from sound waves. The dual functionality of the metamaterial device has been verified by experimental results, which show an over(More)
As the core content of the regional innovation system, regional innovation capability determines whether a region can obtain competitive advantage. It must be paid special attention to the role played by the regional intellectual capital in improving regional innovation capability. Aiming at related data of the Chongqing city, this paper analyzes(More)
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