Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles
Nowadays, incredible growth of the energy consumption has changed the global attention to the pro... more Nowadays, incredible growth of the energy consumption has changed the global attention to the production and utilization of the heavy crude oils such as bitumen resources around the globe. Amongst the bitumen properties, density is an important parameter which improves bitumen recovery efficiency and transportation quality. For easy production of bitumen, n-alkanes are usually injected into the reservoir to reduce its viscosity and density; however, there are few numbers of models focusing on proper estimation/prediction of diluted bitumen mixture density in literature. In present work, a new method was proposed to accurately prognosticate the bitumen/n-tetradecane mixture density as a function of thermodynamic conditions using Gene Expression Programming (GEP) for the first time as a function of solvent composition, pressure and temperature. Consequently, the proposed model here predicts the mixture density with the average Absolute Relative Deviation (AARD%) of 0.3016% and R-squar...
ABSTRACT In this paper, I will give a brief introduction to the theory of low-density parity-chec... more ABSTRACT In this paper, I will give a brief introduction to the theory of low-density parity-check codes, and their decoding. I will emphasize the case of correcting erasures as it is still the best understood and most accessible case. At the end of the paper, I will also describe more recent developments.
ABSTRACT In this paper, I will give a brief introduction to the theory of low-density parity-chec... more ABSTRACT In this paper, I will give a brief introduction to the theory of low-density parity-check codes, and their decoding. I will emphasize the case of correcting erasures as it is still the best understood and most accessible case. At the end of the paper, I will also describe more recent developments.
2000 IEEE International Symposium on Information Theory (Cat. No.00CH37060), 2000
Abstract Multiple antennas can greatly increase the data rate and reliability of a wireless commu... more Abstract Multiple antennas can greatly increase the data rate and reliability of a wireless communication link in a fading environment, but the practical success of using multiple antennas depends crucially on our ability to design high-rate space-time constellations ...
2000 IEEE Wireless Communications and Networking Conference. Conference Record (Cat. No.00TH8540), 2000
We construct signal constellations for differential transmission with multiple basestation antenn... more We construct signal constellations for differential transmission with multiple basestation antennas. The signals are derived using the theory of fixed-point-free groups and are especially suitable for mobile cellular applications because they do not require the handset to have more than one antenna or to know the time-varying propagation environment. Yet we achieve full transmitter diversity and excellent performance gains over
2000 IEEE International Symposium on Information Theory (Cat. No.00CH37060), 2000
Abstract Multiple antennas can greatly increase the data rate and reliability of a wireless commu... more Abstract Multiple antennas can greatly increase the data rate and reliability of a wireless communication link in a fading environment, but the practical success of using multiple antennas depends crucially on our ability to design high-rate space-time constellations ...
The polynomial time algorithm of Lenstra, Lenstra, and Lovász [15] for factoring integer polynomi... more The polynomial time algorithm of Lenstra, Lenstra, and Lovász [15] for factoring integer polynomials and variants thereof have been widely used to show that various computational problems in number theory have polynomial time solutions. Among them is the problem of factoring polynomials over algebraic number fields, which is used itself as a major subroutine for several other algorithms. Although a theoretical breakthrough, algorithms based on factorization of polynomials are notoriously slow and hard to implement, with running times ranging between $O(n^12)$ and $O(n^18)$ depending on which variant of the lattice basis reduction is used. Here, n is an upper bound for the maximum of the degrees and the bit-lengths of the coefficients of the polynomials involved. On the other hand, in many situations one does not need the full power of factorization, so one may ask whether there exist faster algorithms in these cases. In this paper we develop more efficient Monte Carlo algorithms to ...
We design sequences of low-density parity check codes that provably perform at rates extremely cl... more We design sequences of low-density parity check codes that provably perform at rates extremely close to the Shannon capacity. The codes are built from highly irregular bipartite graphs with carefully chosen degree patterns on both sides. Our theoretical analysis of the codes is based on [1]. Additionally, based on the assumption that the underlying communication channel is symmetric, we prove that the probability densities at the message nodes of the graph satisfy a certain symmetry. This enables us to derive a succinct description of the density evolution for the case of a belief propagation decoder. Furthermore, we prove a stability condition which implies an upper bound on the fraction of errors that a belief propagation decoder can correct when applied to a code induced from a bipartite graph with a given degree distribution. Our codes are found by optimizing the degree structure of the underlying graphs. We develop several strategies to perform this optimization. We also...
We design sequences of low-density parity check codes that provably perform at rates extremely cl... more We design sequences of low-density parity check codes that provably perform at rates extremely close to the Shannon capacity. The codes are built from highly irregular bipartite graphs with carefully chosen degree patterns on both sides. Our theoretical analysis of the codes is based on [1]. Additionally, based on the assumption that the underlying communication channel is symmetric, we prove that the probability densities at the message nodes of the graph satisfy a certain symmetry. This enables us to derive a succinct description of the density evolution for the case of a belief propagation decoder. Furthermore, we prove a stability condition which implies an upper bound on the fraction of errors that a belief propagation decoder can correct when applied to a code induced from a bipartite graph with a given degree distribution. Our codes are found by optimizing the degree structure of the underlying graphs. We develop several strategies to perform this optimization. We also...
Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles
Nowadays, incredible growth of the energy consumption has changed the global attention to the pro... more Nowadays, incredible growth of the energy consumption has changed the global attention to the production and utilization of the heavy crude oils such as bitumen resources around the globe. Amongst the bitumen properties, density is an important parameter which improves bitumen recovery efficiency and transportation quality. For easy production of bitumen, n-alkanes are usually injected into the reservoir to reduce its viscosity and density; however, there are few numbers of models focusing on proper estimation/prediction of diluted bitumen mixture density in literature. In present work, a new method was proposed to accurately prognosticate the bitumen/n-tetradecane mixture density as a function of thermodynamic conditions using Gene Expression Programming (GEP) for the first time as a function of solvent composition, pressure and temperature. Consequently, the proposed model here predicts the mixture density with the average Absolute Relative Deviation (AARD%) of 0.3016% and R-squar...
ABSTRACT In this paper, I will give a brief introduction to the theory of low-density parity-chec... more ABSTRACT In this paper, I will give a brief introduction to the theory of low-density parity-check codes, and their decoding. I will emphasize the case of correcting erasures as it is still the best understood and most accessible case. At the end of the paper, I will also describe more recent developments.
ABSTRACT In this paper, I will give a brief introduction to the theory of low-density parity-chec... more ABSTRACT In this paper, I will give a brief introduction to the theory of low-density parity-check codes, and their decoding. I will emphasize the case of correcting erasures as it is still the best understood and most accessible case. At the end of the paper, I will also describe more recent developments.
2000 IEEE International Symposium on Information Theory (Cat. No.00CH37060), 2000
Abstract Multiple antennas can greatly increase the data rate and reliability of a wireless commu... more Abstract Multiple antennas can greatly increase the data rate and reliability of a wireless communication link in a fading environment, but the practical success of using multiple antennas depends crucially on our ability to design high-rate space-time constellations ...
2000 IEEE Wireless Communications and Networking Conference. Conference Record (Cat. No.00TH8540), 2000
We construct signal constellations for differential transmission with multiple basestation antenn... more We construct signal constellations for differential transmission with multiple basestation antennas. The signals are derived using the theory of fixed-point-free groups and are especially suitable for mobile cellular applications because they do not require the handset to have more than one antenna or to know the time-varying propagation environment. Yet we achieve full transmitter diversity and excellent performance gains over
2000 IEEE International Symposium on Information Theory (Cat. No.00CH37060), 2000
Abstract Multiple antennas can greatly increase the data rate and reliability of a wireless commu... more Abstract Multiple antennas can greatly increase the data rate and reliability of a wireless communication link in a fading environment, but the practical success of using multiple antennas depends crucially on our ability to design high-rate space-time constellations ...
The polynomial time algorithm of Lenstra, Lenstra, and Lovász [15] for factoring integer polynomi... more The polynomial time algorithm of Lenstra, Lenstra, and Lovász [15] for factoring integer polynomials and variants thereof have been widely used to show that various computational problems in number theory have polynomial time solutions. Among them is the problem of factoring polynomials over algebraic number fields, which is used itself as a major subroutine for several other algorithms. Although a theoretical breakthrough, algorithms based on factorization of polynomials are notoriously slow and hard to implement, with running times ranging between $O(n^12)$ and $O(n^18)$ depending on which variant of the lattice basis reduction is used. Here, n is an upper bound for the maximum of the degrees and the bit-lengths of the coefficients of the polynomials involved. On the other hand, in many situations one does not need the full power of factorization, so one may ask whether there exist faster algorithms in these cases. In this paper we develop more efficient Monte Carlo algorithms to ...
We design sequences of low-density parity check codes that provably perform at rates extremely cl... more We design sequences of low-density parity check codes that provably perform at rates extremely close to the Shannon capacity. The codes are built from highly irregular bipartite graphs with carefully chosen degree patterns on both sides. Our theoretical analysis of the codes is based on [1]. Additionally, based on the assumption that the underlying communication channel is symmetric, we prove that the probability densities at the message nodes of the graph satisfy a certain symmetry. This enables us to derive a succinct description of the density evolution for the case of a belief propagation decoder. Furthermore, we prove a stability condition which implies an upper bound on the fraction of errors that a belief propagation decoder can correct when applied to a code induced from a bipartite graph with a given degree distribution. Our codes are found by optimizing the degree structure of the underlying graphs. We develop several strategies to perform this optimization. We also...
We design sequences of low-density parity check codes that provably perform at rates extremely cl... more We design sequences of low-density parity check codes that provably perform at rates extremely close to the Shannon capacity. The codes are built from highly irregular bipartite graphs with carefully chosen degree patterns on both sides. Our theoretical analysis of the codes is based on [1]. Additionally, based on the assumption that the underlying communication channel is symmetric, we prove that the probability densities at the message nodes of the graph satisfy a certain symmetry. This enables us to derive a succinct description of the density evolution for the case of a belief propagation decoder. Furthermore, we prove a stability condition which implies an upper bound on the fraction of errors that a belief propagation decoder can correct when applied to a code induced from a bipartite graph with a given degree distribution. Our codes are found by optimizing the degree structure of the underlying graphs. We develop several strategies to perform this optimization. We also...
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