26,223 research outputs found
Stabilizer quantum codes from -affine variety codes and a new Steane-like enlargement
New stabilizer codes with parameters better than the ones available in the
literature are provided in this work, in particular quantum codes with
parameters and that are records.
These codes are constructed with a new generalization of the Steane's
enlargement procedure and by considering orthogonal subfield-subcodes --with
respect to the Euclidean and Hermitian inner product-- of a new family of
linear codes, the -affine variety codes
New Quantum Codes from Evaluation and Matrix-Product Codes
Stabilizer codes obtained via CSS code construction and Steane's enlargement
of subfield-subcodes and matrix-product codes coming from generalized
Reed-Muller, hyperbolic and affine variety codes are studied. Stabilizer codes
with good quantum parameters are supplied, in particular, some binary codes of
lengths 127 and 128 improve the parameters of the codes in
http://www.codetables.de. Moreover, non-binary codes are presented either with
parameters better than or equal to the quantum codes obtained from BCH codes by
La Guardia or with lengths that can not be reached by them
Classical and Quantum Evaluation Codesat the Trace Roots
We introduce a new class of evaluation linear codes by evaluating polynomials at the roots of a suitable trace function. We give conditions for self-orthogonality of these codes and their subfield-subcodes with respect to the Hermitian inner product. They allow us to construct stabilizer quantum codes over several finite fields which substantially improve the codes in the literature. For the binary case, we obtain records at http://codetables.de/. Moreover, we obtain several classical linear codes over the field F 4 which are records at http://codetables.de/
Convolutional Goppa Codes
We define Convolutional Goppa Codes over algebraic curves and construct their
corresponding dual codes. Examples over the projective line and over elliptic
curves are described, obtaining in particular some Maximum-Distance Separable
(MDS) convolutional codes.Comment: 8 pages, submitted to IEEE Trans. Inform. Theor
An Introduction to Algebraic Geometry codes
We present an introduction to the theory of algebraic geometry codes.
Starting from evaluation codes and codes from order and weight functions,
special attention is given to one-point codes and, in particular, to the family
of Castle codes
Board mechanisms and Malaysian Family Companies' Performance
Many overseas studies discussed the topic of corporate governance and performance in family companies, however, few studies have been conducted in Malaysia. The objective of this paper is to examine the board mechanisms and family companies’ performance using three performance indicators (Tobin’s Q, Earnings Per Share & Operating Cash Flow). The sample size is 189 family companies listed on Bursa Malaysia from 2003 to 2007. The findings from this study reveal that some of the board mechanisms influence family companies’ performance. This study evidenced that family companies with a large board size, low directors’ expertise and duality leadership contribute to higher family companies’ performance. However, this study found that the academic qualification of directors does not influence firm performance. Therefore, generally, regulators and investors need to be sensitive to the fact that family companies do have differences in corporate governance practices compared to non-family companies
Hipergráfok = Hypergraphs
A projekt cĂ©lkitűzĂ©seit sikerĂĽlt megvalĂłsĂtani. A nĂ©gy Ă©v során több mint száz kiválĂł eredmĂ©ny szĂĽletett, amibĹ‘l eddig 84 dolgozat jelent meg a tĂ©ma legkiválĂłbb folyĂłirataiban, mint Combinatorica, Journal of Combinatorial Theory, Journal of Graph Theory, Random Graphs and Structures, stb. Számos rĂ©gĂłta fennállĂł sejtĂ©st bebizonyĂtottunk, egĂ©sz rĂ©gi nyitott problĂ©mát megoldottunk hipergráfokkal kapcsolatban illetve kapcsolĂłdĂł terĂĽleteken. A problĂ©mák nĂ©melyike sok Ă©ve, olykor több Ă©vtizede nyitott volt. Nem egy közvetlen kutatási eredmĂ©ny, de szintĂ©n bizonyos Ă©rtĂ©kmĂ©rĹ‘, hogy a rĂ©sztvevĹ‘k egyike a NorvĂ©g Királyi AkadĂ©mia tagja lett Ă©s elnyerte a Steele dĂjat. | We managed to reach the goals of the project. We achieved more than one hundred excellent results, 84 of them appeared already in the most prestigious journals of the subject, like Combinatorica, Journal of Combinatorial Theory, Journal of Graph Theory, Random Graphs and Structures, etc. We proved several long standing conjectures, solved quite old open problems in the area of hypergraphs and related subjects. Some of the problems were open for many years, sometimes for decades. It is not a direct research result but kind of an evaluation too that a member of the team became a member of the Norvegian Royal Academy and won Steele Prize
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