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Ashish Jagmohan, Irvington US

Ashish Jagmohan, Irvington, NY US

Patent application numberDescriptionPublished
20080288929METHOD AND APPARATUS FOR RUN-TIME STATISTICS DEPENDENT PROGRAM EXECUTION USING SOURCE-CODING - Disclosed are a method and system for optimized, dynamic data-dependent program execution. The disclosed system comprises a statistics computer which computes statistics of the incoming data at the current time instant, where the said statistics include the probability distribution of the incoming data, the probability distribution over program modules induced by the incoming data, the probability distribution induced over program outputs by the incoming data, and the time-complexity of each program module for the incoming data, wherein the said statistics are computed on as a function of current and past data, and previously computed statistics; a plurality of alternative execution path orders designed prior to run-time by the use of an appropriate source code; a source code selector which selects one of the execution path orders as a function of the statistics computed by the statistics computer; a complexity measurement which measures the time-complexity of the currently selected execution path-order.11-20-2008
20080320363METHOD AND APPARATUS FOR RATELESS SOURCE CODING WITH/WITHOUT DECODER SIDE INFORMATION - A method of and system for rateless source coding are disclosed. The method comprises the steps of providing a set of low-density parity check (LDPC) codes, each of which accepts a range of data input lengths and a range of target compression rates; identifying a data input having a data input length; and identifying a desired compression rate. The method comprises the further steps of selecting one of said LDPC codes based on said data input length and desired compression rate; encoding the data input, using the selected LDPC code, to generate a sequence of data values; and puncturing some of said encoded data values to achieve the desired compression rate. Preferably, the encoding step includes the steps of generating a syndrome and a parity sequence from the data input, puncturing the generated parity sequence, and mixing a remaining portion of the data input with the punctuated parity sequence.12-25-2008
20090030922Method and Apparatus for Constructing Efficient Slepian-Wolf Codes With Mismatched Decoding - Disclosed is a method for constructing Slepian-Wolf codes, wherein the designed Slepian-Wolf codes are robust to mismatched decoding. The disclosed method for constructing Slepian-Wolf codes includes the steps of: choosing representative probability distributions from a set of possible probability distributions; choosing a probability distribution as a decoding metric; converting the chosen decoding metric to a cyclic-symmetric channel; computing the initial message value given the cyclic-symmetric channel; computing a set of probability distributions of the initial message given the initial message values and the representative probability distributions; optimizing the degree distribution given the set of probability distributions of the initial message; optimizing the decoding metric.01-29-2009
20090122868METHOD AND SYSTEM FOR EFFICIENT VIDEO COMPRESSION WITH LOW-COMPLEXITY ENCODER - Disclosed are a method and system for video compression, wherein the video encoder has low computational complexity and high compression efficiency. The disclosed system comprises a video encoder and a video decoder, wherein the method for encoding includes the steps of converting a source frame into a space-frequency representation; estimating conditional statistics of at least one vector of space-frequency coefficients; estimating encoding rates based on the said conditional statistics; and applying Slepian-Wolf codes with the said computed encoding rates. The preferred method for decoding includes the steps of; generating a side-information vector of frequency coefficients based on previously decoded source data, encoder statistics, and previous reconstructions of the source frequency vector; and performing Slepian-Wolf decoding of at least one source frequency vector based on the generated side-information, the Slepian-Wolf code bits and the encoder statistics.05-14-2009
20090323798METHOD AND SYSTEM FOR LOW-COMPLEXITY SLEPIAN-WOLF RATE ESTIMATION IN WYNER-ZIV VIDEO ENCODING - A method and system for low-complexity Slepian-Wolf rate estimator in a hybrid Wyner-Ziv video encoder determines the minimum Slepian-Wolf code rate required to allow correct decoding. The Slepian-Wolf estimator does not assume ideality of source and side-information statistics and does not require the presence of a feedback channel from the decoder to the encoder in order to determine the correct Slepian-Wolf coding rate. Instead, it adapts to the statistical properties of the video steam. The Slepian-Wolf estimator provides very efficient compression performance while avoiding Slepian-Wolf decoding failures.12-31-2009
20100095116Method and System for Secure Collaboration Using Slepian-Wolf Codes - A method and system provide for secure sharing of arbitrary data between users with limited mutual trust. A user can encode its information by using a Slepian-Wolf code at a rate which enables a second user to correctly decode only if the side-information it has satisfies a conditional entropy constraint. The key advantages are as follows. Firstly, it is very flexible, in that it enables secure sharing for general data including multimedia data. Secondly, by appropriate Slepian-Wolf code selection, it enables compression in conjunction with security. Thirdly, it can be used for the case where the data model is imperfectly known and trust is to be built up incrementally.04-15-2010
20110246703CONSTRAINED CODING TO REDUCE FLOATING GATE COUPLING IN NON-VOLATILE MEMORIES - Constrained coding to reduce floating gate coupling in non-volatile memories including a method for storing data. The method includes receiving write data to be written to a flash memory device, selecting a codeword in response to the write data, and writing the codeword to the flash memory device. The codeword is selected to reduce floating gate coupling in the flash memory device by preventing specified symbol patterns from occurring in the codeword.10-06-2011

Patent applications by Ashish Jagmohan, Irvington, NY US