76 research outputs found
Asymmetric Lee Distance Codes for DNA-Based Storage
We consider a new family of codes, termed asymmetric Lee distance codes, that
arise in the design and implementation of DNA-based storage systems and systems
with parallel string transmission protocols. The codewords are defined over a
quaternary alphabet, although the results carry over to other alphabet sizes;
furthermore, symbol confusability is dictated by their underlying binary
representation. Our contributions are two-fold. First, we demonstrate that the
new distance represents a linear combination of the Lee and Hamming distance
and derive upper bounds on the size of the codes under this metric based on
linear programming techniques. Second, we propose a number of code
constructions which imply lower bounds
Local Codes with Addition Based Repair
We consider the complexities of repair algorithms for locally repairable
codes and propose a class of codes that repair single node failures using
addition operations only, or codes with addition based repair. We construct two
families of codes with addition based repair. The first family attains distance
one less than the Singleton-like upper bound, while the second family attains
the Singleton-like upper bound
Rates of DNA Sequence Profiles for Practical Values of Read Lengths
A recent study by one of the authors has demonstrated the importance of
profile vectors in DNA-based data storage. We provide exact values and lower
bounds on the number of profile vectors for finite values of alphabet size ,
read length , and word length .Consequently, we demonstrate that for
and , the number of profile vectors is at least
with very close to one.In addition to enumeration
results, we provide a set of efficient encoding and decoding algorithms for
each of two particular families of profile vectors
Locally Encodable and Decodable Codes for Distributed Storage Systems
We consider the locality of encoding and decoding operations in distributed
storage systems (DSS), and propose a new class of codes, called locally
encodable and decodable codes (LEDC), that provides a higher degree of
operational locality compared to currently known codes. For a given locality
structure, we derive an upper bound on the global distance and demonstrate the
existence of an optimal LEDC for sufficiently large field size. In addition, we
also construct two families of optimal LEDC for fields with size linear in code
length.Comment: 7 page
Product Construction of Affine Codes
Binary matrix codes with restricted row and column weights are a desirable
method of coded modulation for power line communication. In this work, we
construct such matrix codes that are obtained as products of affine codes -
cosets of binary linear codes. Additionally, the constructions have the
property that they are systematic. Subsequently, we generalize our construction
to irregular product of affine codes, where the component codes are affine
codes of different rates.Comment: 13 pages, to appear in SIAM Journal on Discrete Mathematic
Verifiable Coded Computation of Multiple Functions
We consider the problem of evaluating distinct multivariate polynomials over
several massive datasets in a distributed computing system with a single master
node and multiple worker nodes. We focus on the general case when each
multivariate polynomial is evaluated over its corresponding dataset and propose
a generalization of the Lagrange Coded Computing framework (Yu et al. 2019) to
perform all computations simultaneously while providing robustness against
stragglers who do not respond in time, adversarial workers who respond with
wrong computation and information-theoretic security of dataset against
colluding workers. Our scheme introduces a small computation overhead which
results in a reduction in download cost and also offers comparable resistance
to stragglers over existing solutions. On top of it, we also propose two
verification schemes to detect the presence of adversaries, which leads to
incorrect results, without involving additional nodes.Comment: 13 pages, 1 figure, 2 table
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