The Experts below are selected from a list of 402546 Experts worldwide ranked by ideXlab platform
Dan Popescu - One of the best experts on this subject based on the ideXlab platform.
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Information Capacity of a random signature multiple-input multiple-output channel
IEEE Transactions on Communications, 2000Co-Authors: Predrag B. Rapajic, Dan PopescuAbstract:A closed-form expression for Information Capacity of the random\nsignature multiple input multiple-output channel is given. A direct\ncalculation of the Capacity is provided additional to the proof\ninvolving the Capacity of minimum mean-square-error systems provided by\nVerdu and Shamai (see IEEE Trans. Inform. Theory, vol.45, p.622-40,\n1999)
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Derivation of the closed form Information Capacity equation of the random signature multiple-input multiple-output Gaussian channel
Proceedings of the 1999 IEEE Information Theory and Communications Workshop (Cat. No. 99EX253), 1999Co-Authors: Predrag B. Rapajic, Dan PopescuAbstract:A closed form expression for the Shannon Capacity of the random signature (RS) multiple-input multiple-output (MIMO) fading channel with mutual interference is found. It is shown that the Capacity of a RS-MIMO fading channel is equal to the Shannon Capacity of the orthogonal Gaussian channel with no interference if the dimensionality of the received signal is large.
Mohammad Ishtiyaq Qureshi - One of the best experts on this subject based on the ideXlab platform.
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on the partition bound for undirected unicast network Information Capacity
arXiv: Information Theory, 2020Co-Authors: Mohammad Ishtiyaq Qureshi, Satyajit ThakorAbstract:One of the important unsolved problems in Information theory is the conjecture that network coding has no rate benefit over routing in undirected unicast networks. Three known bounds on the symmetric rate in undirected unicast Information networks are the sparsest cut, the LP bound and the partition bound. In this paper, we present three results on the partition bound. We show that the decision version problem of computing the partition bound is NP-complete. We give complete proofs of optimal routing schemes for two classes of networks that attain the partition bound. Recently, the conjecture was proved for a new class of networks and it was shown that all the network instances for which the conjecture is proved previously are elements of this class. We show the existence of a network for which the partition bound is tight, achievable by routing and is not an element of this new class of networks.
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undirected unicast network Capacity a partition bound
International Symposium on Information Theory, 2019Co-Authors: Satyajit Thakor, Mohammad Ishtiyaq QureshiAbstract:In this paper, we present a new technique to obtain upper bounds on undirected unicast network Information Capacity. Using this technique, we characterize an upper bound, called partition bound, on the symmetric rate of Information flow in undirected unicast networks and give an algorithm to compute it. Two classes of networks are presented for which the bound is tight and the Capacity is achievable by routing thus confirming the undirected unicast conjecture for these classes of networks. We also show that the bound can be loose in general and present an approach to tighten it.
Predrag B. Rapajic - One of the best experts on this subject based on the ideXlab platform.
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Information Capacity of a random signature multiple-input multiple-output channel
IEEE Transactions on Communications, 2000Co-Authors: Predrag B. Rapajic, Dan PopescuAbstract:A closed-form expression for Information Capacity of the random\nsignature multiple input multiple-output channel is given. A direct\ncalculation of the Capacity is provided additional to the proof\ninvolving the Capacity of minimum mean-square-error systems provided by\nVerdu and Shamai (see IEEE Trans. Inform. Theory, vol.45, p.622-40,\n1999)
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Derivation of the closed form Information Capacity equation of the random signature multiple-input multiple-output Gaussian channel
Proceedings of the 1999 IEEE Information Theory and Communications Workshop (Cat. No. 99EX253), 1999Co-Authors: Predrag B. Rapajic, Dan PopescuAbstract:A closed form expression for the Shannon Capacity of the random signature (RS) multiple-input multiple-output (MIMO) fading channel with mutual interference is found. It is shown that the Capacity of a RS-MIMO fading channel is equal to the Shannon Capacity of the orthogonal Gaussian channel with no interference if the dimensionality of the received signal is large.
Chueh Loo Poh - One of the best experts on this subject based on the ideXlab platform.
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high Capacity dna data storage with variable length oligonucleotides using repeat accumulate code and hybrid mapping
Journal of Biological Engineering, 2019Co-Authors: Yixin Wang, Jingyun Zhang, Erry Gunawan, Yong Liang Guan, Chueh Loo PohAbstract:With the inherent high density and durable preservation, DNA has been recently recognized as a distinguished medium to store enormous data over millennia. To overcome the limitations existing in a recently reported high-Capacity DNA data storage while achieving a competitive Information Capacity, we are inspired to explore a new coding system that facilitates the practical implementation of DNA data storage with high Capacity. In this work, we devised and implemented a DNA data storage scheme with variable-length oligonucleotides (oligos), where a hybrid DNA mapping scheme that converts digital data to DNA records is introduced. The encoded DNA oligos stores 1.98 bits per nucleotide (bits/nt) on average (approaching the upper bound of 2 bits/nt), while conforming to the biochemical constraints. Beyond that, an oligo-level repeat-accumulate coding scheme is employed for addressing data loss and corruption in the biochemical processes. With a wet-lab experiment, an error-free retrieval of 379.1 KB data with a minimum coverage of 10x is achieved, validating the error resilience of the proposed coding scheme. Along with that, the theoretical analysis shows that the proposed scheme exhibits a net Information density (user bits per nucleotide) of 1.67 bits/nt while achieving 91% of the Information Capacity. To advance towards practical implementations of DNA storage, we proposed and tested a DNA data storage system enabling high potential mapping (bits to nucleotide conversion) scheme and low redundancy but highly efficient error correction code design. The advancement reported would move us closer to achieving a practical high-Capacity DNA data storage system.
Izabela Sachajdakiewicz - One of the best experts on this subject based on the ideXlab platform.
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Simple yet effective: Historical proximity variables improve the species distribution models for invasive giant hogweed (Heracleum mantegazzianum s.l.) in Poland.
PloS one, 2017Co-Authors: Piotr Medrzycki, Ingeborga Jarzyna, Artur Obidziński, Barbara Tokarska-guzik, Zofia Sotek, Piotr Pabjanek, Adam Pytlarczyk, Izabela SachajdakiewiczAbstract:Species distribution models are scarcely applicable to invasive species because of their breaking of the models’ assumptions. So far, few mechanistic, semi-mechanistic or statistical solutions like dispersal constraints or propagule limitation have been applied. We evaluated a novel quasi-semi-mechanistic approach for regional scale models, using historical proximity variables (HPV) representing a state of the population in a given moment in the past. Our aim was to test the effects of addition of HPV sets of different minimal recentness, Information Capacity and the total number of variables on the quality of the species distribution model for Heracleum mantegazzianum on 116000 km2 in Poland. As environmental predictors, we used fragments of 103 1×1 km, world- wide, free-access rasters from WorldGrids.org. Single and ensemble models were computed using BIOMOD2 package 3.1.47 working in R environment 3.1.0. The addition of HPV improved the quality of single and ensemble models from poor to good and excellent. The quality was the highest for the variants with HPVs based on the distance from the most recent past occurrences. It was mostly affected by the algorithm type, but all HPV traits (minimal recentness, Information Capacity, model type or the number of the time periods) were significantly important determinants. The addition of HPVs improved the quality of current projections, raising the occurrence probability in regions where the species had occurred before. We conclude that HPV addition enables semi-realistic estimation of the rate of spread and can be applied to the short-term forecasting of invasive or declining species, which also break equal-dispersal probability assumptions.