Ivana Djurdjevic

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This letter presents an algebraic method for constructing regular low-density parity-check (LDPC) codes based on Reed-Solomon codes with two information symbols. The construction method results in a class of LDPC codes in Gallager's original form. Codes in this class are free of cycles of length 4 in their Tanner graphs and have good minimum distances. They(More)
Two algebraic methods for systematic construction of structured regular and irregular low-density parity-check (LDPC) codes with girth of at least six and good minimum distances are presented. These two methods are based on geometry decomposition and a masking technique. Numerical results show that the codes constructed by these methods perform close to the(More)
We have three main goals in this paper. First, we will show the equivalences and relationships among some of the well-known classes of structured low density parity check (LDPC) codes. Second, we consider application of these codes to magnetic recording channel. We will make performance comparisons not only with bit-error-rate (BER) metric but also with(More)
This paper explores the architecture of a first-generation iterative detection read channel solution that delivers up to an 8% increase in drive capacity compared to previous generation electronics. Using low density parity check (LDPC) coding, detected data is continually improved by a detection structure that implements multiple iterations through a set(More)
This article presents a graph-theoretic method for constructing low-density parity-check (LDPC) codes from connected graphs without the requirement of large girth. This method is based on finding a set of paths in a connected graph, which satisfies the constraint that any two paths in the set are either disjoint or cross each other at one and only one(More)
In this study, a new signal model for shingled magnetic recording (SMR) is developed based on the drive waveform analysis with squeezed side tracks. Shingled recording effects are modeled by the data dependent effective write width or erase band, and the readback signals are represented by the weighted sum of the individual target and side track signals(More)
The alternative, vanadium-dependent nitrogenase is employed by Azotobacter vinelandii for the fixation of atmospheric N2 under conditions of molybdenum starvation. While overall similar in architecture and functionality to the common Mo-nitrogenase, the V-dependent enzyme exhibits a series of unique features that on one hand are of high interest for(More)
This paper compares the efficiency of two intelligent methods: expert systems and neural networks, in detecting children’s mathematical gift at the fourth grade of elementary school. The input space for the expert system and the neural network model consisted of 60 variables describing five basic components of a child’s mathematical gift identified in(More)