| 1. |
- Agalou, Adamantia, et al.
(författare)
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A genome-wide survey of HD-Zip genes in rice and analysis of drought-responsive family members
- 2008
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Ingår i: Plant Molecular Biology. - : Springer Science and Business Media LLC. - 0167-4412 .- 1573-5028. ; 66:1-2, s. 87-103
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Tidskriftsartikel (refereegranskat)abstract
- The homeodomain leucine zipper (HD-Zip) genes encode transcription factors that have diverse functions in plant development and have often been implicated in stress adaptation. The HD-Zip genes are the most abundant group of homeobox (HB) genes in plants and do not occur in other eukaryotes. This paper describes the complete annotation of the HD-Zip families I, II and III from rice and compares these gene families with Arabidopsis in a phylogeny reconstruction. Orthologous pairs of rice and Arabidopsis HD-Zip genes were predicted based on neighbour joining and maximum parsimony (MP) trees with support of conserved intron-exon organization. Additionally, a number of HD-Zip genes appeared to be unique to rice. Searching of EST and cDNA databases and expression analysis using RT-PCR showed that 30 out of 31 predicted rice HD-Zip genes are expressed. Most HD-Zip genes were broadly expressed in mature plants and seedlings, but others showed more organ specific patterns. Like in Arabidopsis and other dicots, a subset of the rice HD-Zip I and II genes was found to be regulated by drought stress. We identified both drought-induced and drought-repressed HD-Zip genes and demonstrate that these genes are differentially regulated in drought-sensitive versus drought-tolerant rice cultivars. The drought-repressed HD-Zip family I gene, Oshox4, was selected for promoter-GUS analysis, showing that drought-responsiveness of Oshox4 is controlled by the promoter and that Oshox4 expression is predominantly vascular-specific. Loss-of-function analysis of Oshox4 revealed no specific phenotype, but overexpression analysis suggested a role for Oshox4 in elongation and maturation processes.
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| 2. |
- Anderson, John B, et al.
(författare)
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Understanding Information Transmission
- 2005
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- This text is written for first or second year students in electrical, computer or information engineering. Chapters are history/innovation in information transmission, mathematical tools (linear system theory, convolution, Fourier transforms), information sources, modulation methods, cryptography, Shannon theory and coding, and information networks. Ample problems and examples are included.
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| 3. |
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| 4. |
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| 5. |
- Bocharova, Irina, et al.
(författare)
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A BEAST for prowling in trees
- 2004
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Ingår i: IEEE Transactions on Information Theory. - 0018-9448. ; 50:6, s. 1295-1302
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Tidskriftsartikel (refereegranskat)abstract
- When searching for convolutional codes and tailbiting codes of high complexity it is of vital importance to use fast algorithms for computing their weight spectra, which corresponds to finding low-weight paths in their code trellises. This can be efficiently done by a combined search in both forward and backward code trees. A bidirectional efficient algorithm for searching such code trees (BEAST) is presented. For large encoder memories, it is shown that BEAST is significantly more efficient than comparable algorithms. BEAST made it possible to rind new convolutional and tailbiting codes that have larger free (minimum) distances than the previously best known codes with the same parameters. Tables of such codes are presented.
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| 6. |
- Bocharova, Irina, et al.
(författare)
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A Closed Form Expression for the Exact Bit Error Probability for Viterbi Decoding of Convolutional Codes
- 2012
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Ingår i: IEEE Transactions on Information Theory. - 0018-9448. ; 58:7, s. 4635-4644
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Tidskriftsartikel (refereegranskat)abstract
- In 1995, Best et al. published a formula for the exact bit error probability for Viterbi decoding of the rate R=1/2, memory m=1 (2-state) convolutional encoder with generator matrix G(D)=(1 1+D) when used to communicate over the binary symmetric channel. Their formula was later extended to the rate R=1/2, memory m=2 (4-state) convolutional encoder with generator matrix G(D)=(1+D^2 1+D+D^2) by Lentmaier et al. In this paper, a different approach to derive the exact bit error probability is described. A general recurrent matrix equation, connecting the average information weight at the current and previous states of a trellis section of the Viterbi decoder, is derived and solved. The general solution of this matrix equation yields a closed form expression for the exact bit error probability. As special cases, the expressions obtained by Best et al. for the 2-state encoder and by Lentmaier et al. for a 4-state encoder are obtained. The closed form expression derived in this paper is evaluated for various realizations of encoders, including rate R=1/2 and R=2/3 encoders, of as many as 16 states. Moreover, it is shown that it is straightforward to extend the approach to communication over the quantized additive white Gaussian noise channel.
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| 7. |
- Bocharova, Irina, et al.
(författare)
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A Greedy Search for Improved QC LDPC Codes with Good Girth Profile and Degree Distribution
- 2012
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Ingår i: IEEE International Symposium on Information Theory Proceedings (ISIT), 2012. - 9781467325806 ; , s. 3083-3087
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Konferensbidrag (refereegranskat)abstract
- Search algorithms for regular and irregular quasi-cyclic LDPC block codes with both good girth profile and good degree distribution are presented. New QC LDPC block codes of various code rates are obtained and their bit error rate performance is compared with that of the corresponding LDPC block codes defined in the IEEE 802.16 WiMAX standard of the same block length and code rate.
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| 8. |
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| 9. |
- Bocharova, Irina, et al.
(författare)
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An improved bound on the list error probability and list distance properties
- 2008
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Ingår i: IEEE Transactions on Information Theory. - 0018-9448. ; 54:1, s. 13-32
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Tidskriftsartikel (refereegranskat)abstract
- List decoding of binary block codes for the additive white Gaussian noise channel is considered. The output of a list decoder is a list of the $L$ most likely codewords, that is, the L signal points closest to the received signal in the Euclidean-metric sense. A decoding error occurs when the transmitted codeword is not on this list. It is shown that the list error probability is fully described by the so-called list configuration matrix, which is the Gram matrix obtained from the signal vectors forming the list. The worst-case list configuration matrix determines the minimum list distance of the code, which is a generalization of the minimum distance to the case of list decoding. Some properties of the list configuration matrix are studied and their connections to the list distance are established. These results are further exploited to obtain a new upper bound on the list error probability, which is tighter than the previously known bounds. This bound is derived by combining the techniques for obtaining the tangential union bound with an improved bound on the error probability for a given list. The results are illustrated by examples.
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| 10. |
- Bocharova, Irina, et al.
(författare)
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An improved bound on the list error probability and list distance properties
- 2006
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Ingår i: 2006 IEEE International Symposium on Information Theory. - 1 4244 0504 1 ; , s. 719-723
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Konferensbidrag (refereegranskat)abstract
- A new upper bound on the list error probability is presented. This bound is derived by combining the techniques for obtaining the tangential union bound with an improved bound on the error probability with respect to a given list. Connections between the list distance and the eigenvalues of the covariance matrix of the code are studied
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