While all-optical networks become more and more popular as the basis of the next generation Internet(NGI)infrastructure,such networks raise many critical security issues.High power inter-channel crosstalk attack is on...While all-optical networks become more and more popular as the basis of the next generation Internet(NGI)infrastructure,such networks raise many critical security issues.High power inter-channel crosstalk attack is one of the security issues which have negative effect on information security in optical networks.Optical fiber in optical networks has some nonlinear characteristics,such as self phase modulation(SPM),cross phase modulation(XPM),four-wave mixing(FWM)and stimulated Raman scattering(SRS).They can be used to implement high power inter-channel crosstalk attack by malicious attackers.The mechanism of high power inter-channel crosstalk attack is analyzed.When an attack occurs,attack signal power and fiber nonlinear refractive index are the main factors which affect quality of legitimate signals.The effect of high power inter-channel crosstalk attack on quality of legitimate signals is investigated by building simulation system in VPI software.The results show that interchannel crosstalk caused by high power attack signal leads to quality deterioration of legitimate signals propagated in the same fiber.The higher the power of attack signal is,the greater the fiber nonlinear refractive index is.The closer the channel spacing away from the attack signal is,the more seriously the legitimate signals are affected by attack.We also find that when attack position and power of attack signal are constant,attack signal cannot infinitely spread,while its attack ability shows a fading trend with the extension of propagation distance.展开更多
Image super-resolution is essential for a variety of applications such as medical imaging,surveillance imaging,and satellite imaging,among others.Traditionally,the most popular color image super-resolution is performe...Image super-resolution is essential for a variety of applications such as medical imaging,surveillance imaging,and satellite imaging,among others.Traditionally,the most popular color image super-resolution is performed in each color channel independently.In this paper,we show that the super-resolution quality can be further enhanced by exploiting the cross-channel correlation.Inspired by the High-Quality Linear Interpolation(HQLI)demosaicking algorithm by Malvar et al.,we design an image super-resolution scheme that integrates intra-channel interpolation with cross-channel details by isotropic linear combinations.Despite its simplicity,our super-resolution method achieves the accuracy comparable with the existing fastest state-of-the-art super-resolution algorithm at 20 times faster speed.It is well applicable to applications that adopt traditional interpolations,for improved visual quality at trivial computation cost.Our comparative study verifies the effectiveness and efficiency of the proposed super-resolution algorithm.展开更多
基金the National Natural Science Foundation of China(No.61179002)the National Defence Foundation of China(No.2012JY002-260)
文摘While all-optical networks become more and more popular as the basis of the next generation Internet(NGI)infrastructure,such networks raise many critical security issues.High power inter-channel crosstalk attack is one of the security issues which have negative effect on information security in optical networks.Optical fiber in optical networks has some nonlinear characteristics,such as self phase modulation(SPM),cross phase modulation(XPM),four-wave mixing(FWM)and stimulated Raman scattering(SRS).They can be used to implement high power inter-channel crosstalk attack by malicious attackers.The mechanism of high power inter-channel crosstalk attack is analyzed.When an attack occurs,attack signal power and fiber nonlinear refractive index are the main factors which affect quality of legitimate signals.The effect of high power inter-channel crosstalk attack on quality of legitimate signals is investigated by building simulation system in VPI software.The results show that interchannel crosstalk caused by high power attack signal leads to quality deterioration of legitimate signals propagated in the same fiber.The higher the power of attack signal is,the greater the fiber nonlinear refractive index is.The closer the channel spacing away from the attack signal is,the more seriously the legitimate signals are affected by attack.We also find that when attack position and power of attack signal are constant,attack signal cannot infinitely spread,while its attack ability shows a fading trend with the extension of propagation distance.
基金supported by the National Natural Science Foundation of China under Grant Nos.61472157 and 61872162the Open Project Program of State Key Laboratory of Virtual Reality Technology and Systems,Beihang University,under Grant No.VRLAB2020C05.
文摘Image super-resolution is essential for a variety of applications such as medical imaging,surveillance imaging,and satellite imaging,among others.Traditionally,the most popular color image super-resolution is performed in each color channel independently.In this paper,we show that the super-resolution quality can be further enhanced by exploiting the cross-channel correlation.Inspired by the High-Quality Linear Interpolation(HQLI)demosaicking algorithm by Malvar et al.,we design an image super-resolution scheme that integrates intra-channel interpolation with cross-channel details by isotropic linear combinations.Despite its simplicity,our super-resolution method achieves the accuracy comparable with the existing fastest state-of-the-art super-resolution algorithm at 20 times faster speed.It is well applicable to applications that adopt traditional interpolations,for improved visual quality at trivial computation cost.Our comparative study verifies the effectiveness and efficiency of the proposed super-resolution algorithm.
