Through the refractive index engineering of the subwavelength grating, an ultra-compact multimode interference based diplexer is proposed and demonstrated. It is 43.4 μm in length, only ~30% of its conventional count...
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Length-variant pooling according to conducted sample number excludes endeavor to expand image dimension from image formation process of ghost imaging, leaving bit-length growth alone. Experiment confirms positive corr...
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We present a method for the spatial resolution of ghost imaging to approach its theoretical limit based on parameter optimization of compressive sensing This method shows robustness against additive noise in bucket de...
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We orthonormalize the reference patterns those are generated by a pseudo-thermal source and calculate new bucket detector responses. The obtained image quality by new orthonormal references and bucket signals is impro...
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Structural contrast function prevails cross-correlation and mutual information on image alignment of ghost imaging, both accuracy (pixel shift) and robustness (error curve kurtosis), especially in under-sampling condi...
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Low-rank constraint improves image quality of ghost imaging, for both correlation and compressive sensing approaches. Image by correlation plus low-rank constraint can even surpass that by compressive sensing when und...
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In ghost imaging with pseudo-thermal light, Wiener filter improves reconstructed image quality with the estimation of point spread function and a noise factor, which is well-fitted as proportional relation to noise am...
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In harsh channel conditions, the quality of the synthetic speech at low bit rate would be affected severely. In order to improve the robustness of the vocoder and make it more resilient to errors in random channel, un...
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ISBN:
(纸本)9781509038237;9781509038220
In harsh channel conditions, the quality of the synthetic speech at low bit rate would be affected severely. In order to improve the robustness of the vocoder and make it more resilient to errors in random channel, unequal error protection（UEP） channel coding is usually adopted. However, when the errors cannot be corrected in some cases, UEP channel coding will not improve the quality of the synthetic speech. More seriously, the quality of the synthetic speech may deteriorate rapidly. In order to improve the user’s feeling in such case, a detection method of unbearable bit error rate（BER） is proposed in the paper. This method can increase the error resilience capability of the vocoder in random channel. When the error bits cannot be corrected, the vocoder will output comfortable noise to improve the user’s feeling. This method is used for a 2.4 kbps vocoder based on MELP, and the test results show that it works effectively.
A typical magnetic-resonance scheme employs a static bias magnetic field and an orthogonal driving magnetic field oscillating at the Larmor frequency, at which the atomic polarization precesses around the static magne...
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A typical magnetic-resonance scheme employs a static bias magnetic field and an orthogonal driving magnetic field oscillating at the Larmor frequency, at which the atomic polarization precesses around the static magnetic field. Here we demonstrate both theoretically and experimentally the variations of the resonance condition and the spin precession dynamics resulting from the parametric modulation of the bias field. We show that the driving magnetic field with the frequency detuned by different harmonics of the parametric modulation frequency can lead to resonance as well. Also, a series of frequency sidebands centered at the driving frequency and spaced by the parametric modulation frequency can be observed in the precession of the atomic polarization. We further show that the resonant amplitudes of the sidebands can be controlled by varying the ratio between the amplitude and the frequency of the parametric modulation. These effects could be used in different atomic magnetometry applications.
We consider the noisy thermal amplifier channel, where signal modes are amplified together with environmental thermal modes. We focus on the secret-key capacity of this channel, which is the maximum amount of secret b...
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