Ha Quy Nguyen

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Frame permutation quantization (FPQ) is a new vector quantization technique using finite frames. In FPQ, a vector is encoded using a permutation source code to quantize its frame expansion. This means that the encoding is a partial ordering of the frame expansion coefficients. Compared to ordinary permutation source coding, FPQ produces a greater number of(More)
The control of electronic and thermal transport through material interfaces is crucial for numerous micro and nanoelectronics applications and quantum devices. Here we report on the engineering of the electro-thermal properties of semiconductor-superconductor (Sm-S) electronic cooler junctions by a nanoscale insulating tunnel barrier introduced between the(More)
Permutation codes are a class of structured vector quantizers with a computationally-simple encoding procedure. In this paper, we provide an extension that preserves the computational simplicity but yields improved operational rate-distortion performance. The new class of vector quantizers has a codebook comprising several permutation codes as subcodes.(More)
Permutation codes are a class of structured vector quantizers with a computationally-simple encoding procedure based on sorting the scalar components. Using a codebook comprising several permutation codes as subcodes preserves the simplicity of encoding while increasing the number of rate–distortion operating points, improving the convex hull of operating(More)
This work is devoted to the study and obtaining of new radioprotective agents based on natural flavonoid genistein and spherical amorphous nanoparticles (SANPs) produced from a mixture of birch bark triterpenoids. The physicochemical characteristics of the nanoparticles were studied by electron microscopy, dynamic light scattering, and UV-VIS spectroscopy.(More)
This report provides an expository summary of the proof of optimal shearlet approximation (compact support case). We only discuss the non-smooth part of the approximation. For further details, the readers are referred to [1], [2] and the references therein. I. COMPACTLY SUPPORTED SHEARLET FRAME A. Some Notations • parabolic scaling matrices: A2j = 2j 0 0(More)
As a generalization of the subspace fitting, the union of subspaces fitting problem consists in finding an union of subspaces in some given family that best fits to the finite data. This report provides a detailed review of the main reference [4] about the existence of such optimal solution. Proofs for a series of unproved statements in the reference are(More)