John Villasenor
University of California, Los Angeles
96 Papers
893 Citations
John Villasenor is an academic researcher from University of California, Los Angeles. The author has contributed to research in topics: Computer science & Image compression. The author has an hindex of 28, co-authored 95 publications. Previous affiliations of John Villasenor include Brookings Institution & University of California.
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Papers
Visibility of wavelet quantization noise
TL;DR: A mathematical model is constructed for DWT noise detection thresholds that is a function of level, orientation, and display visual resolution that allows calculation of a "perceptually lossless" quantization matrix for which all errors are in theory below the visual threshold.
682
Gaussian random number generators
TL;DR: The algorithms underlying various GRNGs are described, their computational requirements are compared, and the quality of the random numbers are examined with emphasis on the behaviour in the tail region of the Gaussian probability density function.
242
Construction of irregular LDPC codes with low error floors
Tao Tian,C. Jones,John Villasenor,Richard D. Wesel +3 more
- 11 May 2003
TL;DR: This work explains the relationship between cycles, stopping sets, and dependent columns of the parity check matrix of low-density parity-check (LDPC) codes and proposes a Viterbi-like algorithm that selectively avoids cycles and increases stopping set size.
223
adaptive mobile multimedia networks
Abeer Alwan,Rajive Bagrodia,Nicholas Bambos,Mario Gerla,Leonard Kleinrock,Joel E. Short,John Villasenor +6 more
TL;DR: Two layers of key importance in multimedia wireless network design are focused on, namely compression algorithms and adaptivity in the voice/video applications layer, and network algorithms at the wireless subnet layer.
200
A hardware Gaussian noise generator using the Wallace method
TL;DR: A hardware Gaussian noise generator based on the Wallace method used for a hardware simulation system that accurately models a true Gaussian probability density function even at high /spl sigma/ values is described.
99