The maximum size of unrestricted binary three-error-correcting codes has been known up to the length of the binary Golay code, with two exceptions. Specifically, denoting the maximum size of an unrestricted binary cod...
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The maximum size of unrestricted binary three-error-correcting codes has been known up to the length of the binary Golay code, with two exceptions. Specifically, denoting the maximum size of an unrestricted binary code of length n and minimum distance d by A(n,d), it has been known that 64A(18,8)68 and 128A(19,8)131. In the current computer-aided study, it is shown that A(18,8)=64 and A(19,8)=128, so an optimal code is obtained even after shortening the extended binary Golay code six times.
We consider the problem of finding bounds and exact values of A(5)(n, d) - the maximum size of a code of length n and minimum distance d over an alphabet of 5 elements. Using a wide variety of constructions and method...
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We consider the problem of finding bounds and exact values of A(5)(n, d) - the maximum size of a code of length n and minimum distance d over an alphabet of 5 elements. Using a wide variety of constructions and methods, a table of bounds on A(5)(n, d) for n less than or equal to 11 is obtained. (C) 2001 Elsevier Science B.V. All rights reserved.
We investigate the properties of a family of polytopes that naturally arise in connection with a problem in distributed data storage, namely service rate region polytopes. The service rate region of a distributed code...
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We investigate the properties of a family of polytopes that naturally arise in connection with a problem in distributed data storage, namely service rate region polytopes. The service rate region of a distributed coded system describes the data access requests that the underlying system can support. In this paper, we study the polytope structure of the service rate region with the primary goal of describing its geometric shape and properties. We achieve this by introducing various structural parameters of the service rate region and establishing upper and lower bounds for them. The techniques we apply in this paper range from coding theory to optimization. One of our main results shows that every rational point of the service rate region has a so-called rational allocation, answering an open question in the research area.
Asynchronous circuit design is a promising technology for large-scale multi-core systems. As a family of asynchronous circuits, Quasi-delay-insensitive (QDI) circuits have been widely used to build chip-level long int...
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Asynchronous circuit design is a promising technology for large-scale multi-core systems. As a family of asynchronous circuits, Quasi-delay-insensitive (QDI) circuits have been widely used to build chip-level long interconnects due to their tolerance to delay variations. However, QDI interconnects are vulnerable to faults. Traditional fault-tolerant techniques for synchronous circuits cannot be easily used to protect QDI interconnects. This paper focuses on protecting QDI interconnects from transient faults. The first contribution of this paper is a fault-tolerant delay-insensitive redundant check code named DIRC. Using DIRC in 4-phase 1-of-n QDI pipelines, all 1-bit and some multi-bit transient faults are tolerated. The DIRC and basic pipeline stages are mutually exchangeable. Arbitrary basic stages can be replaced by DIRC ones to strengthen fault-tolerance. This feature permits designers to use DIRC flexibly according to the practical design requirement. The second contribution is a redundant technique protecting the acknowledge wires (RPA). Experimental results indicate that DIRC pipelines have moderate area and speed overheads. Compared with unprotected basic pipelines, the average speed decrease of DIRC pipelines is less than 50%, with the 128-bit 1-of-2 DIRC pipeline only 28% slower. In severe environments with multi-bit transient faults, the fault-tolerance capability of DIRC pipelines increases thousands-fold. (C) 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license.
We derive an upper bound on the size of a block code with prescribed burst-error-correcting capability combining those two ideas underlying the generalized Singleton and sphere-packing bounds. The two ideas are punctu...
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We derive an upper bound on the size of a block code with prescribed burst-error-correcting capability combining those two ideas underlying the generalized Singleton and sphere-packing bounds. The two ideas are puncturing and sphere-packing. We use the burst metric defined by Gabidulin [1], which is suitable for burst error correction and detection. It is demonstrated that the proposed bound improves previously known ones for finite code-length, when minimum distance is greater than 3, as well as in the asymptotic forms.
This paper focuses on a biometric cryptosystem implementation and evaluation based on a number of fingerprint texture descriptors. The texture descriptors, namely, the Gabor filter-based Fingercode, a local binary pat...
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This paper focuses on a biometric cryptosystem implementation and evaluation based on a number of fingerprint texture descriptors. The texture descriptors, namely, the Gabor filter-based Fingercode, a local binary pattern (LBP), and a local direction pattern (LDP), and their various combinations are considered. These fingerprint texture descriptors are binarized using a biometric discretization method and used in a fuzzy commitment scheme (FCS). We constructed the biometric cryptosystems, which achieve a good performance, by fusing discretized fingerprint texture descriptors and using effective error-correcting codes. We tested the proposed system on a FVC2000 DB2a fingerprint database, and the results demonstrate that the new system significantly improves the performance of the FCS for texture-based fingerprints. (C) 2012 Elsevier Ltd. All rights reserved.
作者:
MAZUMDER, PDept. of Electr. Eng. & Comput. Sci.
Michigan Univ. Ann Arbor MI USA Abstract Authors References Cited By Keywords Metrics Similar Download Citation Email Print Request Permissions
As VLSI technology is inching forward to the ultimate limits of physical dimensions, memory manufacturers are striving to integrate more memory cells in a chip by employing innovative three-dimensional cell topographi...
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As VLSI technology is inching forward to the ultimate limits of physical dimensions, memory manufacturers are striving to integrate more memory cells in a chip by employing innovative three-dimensional cell topographies. Most of the current-generation multimegabit dynamic random-access memory (DRAM) chips use three-dimensional storage capacitors where the charge is stored on a vertically integrated trench-type structure. It has been experimentally verified that these memory cells have poor reliability, because they are highly vulnerable to alpha particles, which frequently create plasma shorts between two adjoining trench capacitors on the same word line, resulting in uncorrectable double-bit soft errors. The conventional on-chip error-correcting codes (ECCs) cannot correct such double-bit/word-line soft errors. The paper presents a systematic study of soft-error related problems and it discusses the methodologies to correct single-bit and double-bit memory-cell upsets by using on-chip ECC circuits. Conventional double-error-correcting (DEC) codes used in digital communications are known to be inadequate for this application. By modifying the product code, an effective coding scheme has been designed in this paper that can be integrated within a DRAM chip to correct double-bit errors. The paper demonstrates that the reliability of a memory chip can be improved by several million times by integrating the proposed circuit. The area and timing overhead have been calculated and compared with the memory chips without any ECC and chips with single-error-correcting (SEC) codes. The ability of the circuit to correct soft errors in the presence of multiple-bit errors has also been analyzed by combinatorial enumeration.
An edit refers to a single insertion, deletion, or substitution. This paper aims to construct binary codes that can correct two edits. To do this, a necessary and sufficient condition for a code to be two-edit correct...
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An edit refers to a single insertion, deletion, or substitution. This paper aims to construct binary codes that can correct two edits. To do this, a necessary and sufficient condition for a code to be two-edit correctable is provided, showing that a code is a two-edit correctingcode if and only if it can correct two deletions, up to two substitutions, and one deletion and up to one substitution, separately. This criterion allows for the construction of two-edit correctingcodes leveraging these three types of errorcorrectingcodes. In the field of constructing codes for correcting two deletions, we present a construction with 4 log n + O(log log n) redundant bits that can be viewed as a subcode proposed by Guruswami and Hastad, and provide an alternative proof. Moreover, our two-deletion correctingcodes can also correct up to two substitutions after making a slight modification. In the field of constructing codes for correcting one deletion and up to one substitution, we present a construction with 4logn+O(log log n) redundant bits, which outperforms the best previously known results 6 log n + O(1) . Leveraging these codes, we obtain a construction of two-edit correctingcodes with 6 log n + O(log log n) redundant bits. This outperforms the best previously known result, which requires at least 8 log n redundant bits. Moreover, we also consider the list-decoding problem under the two-edit channel and construct a two-edit list-decodable code with a list size of two employing 4 log n + O(log log n) redundant bits.
A partial-sum query obtains the summation over a set of specified cells of a data cube. We establish a connection between the covering problem in the theory of error-correcting codes and the partial-sum problem and us...
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A partial-sum query obtains the summation over a set of specified cells of a data cube. We establish a connection between the covering problem in the theory of error-correcting codes and the partial-sum problem and use this connection to devise algorithms for the partial-sum problem with efficient space-time-trade-offs. For example,using our algorithms, with 44 percent additional storage, the query response time can be improved by about 12 percent;by roughly doubling the storage requirement, the query response time can be improved by about 34 percent.
This paper studies t- interleaving on two-dimensional tori. Interleaving has applications in distributed data storage and burst error correction, and is closely related to Lee metric codes. A t- interleaving of a grap...
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This paper studies t- interleaving on two-dimensional tori. Interleaving has applications in distributed data storage and burst error correction, and is closely related to Lee metric codes. A t- interleaving of a graph is defined as a vertex coloring in which any connected subgraph of t or fewer vertices has a distinct color at every vertex. We say that a torus can be perfectly t- interleaved if its t- interleaving number ( the minimum number of colors needed for a t- interleaving) meets the sphere- packing lower bound, [t(2)/2]. We show that a torus is perfectly t-interleavable if and only if its dimensions are both multiples of t(2)+ 1/2 ( if t is odd) or t ( if t is even). The next natural question is how much bigger the t- interleaving number is for those tori that are not perfectly t-interleavable, and the most important contribution of this paper is to. nd an optimal interleaving for all *** large tori, proving that when a torus is large enough in both dimensions, its t- interleaving number is at most just one more than the sphere- packing lower bound. We also obtain bounds on t- interleaving numbers for the cases where one or both dimensions are not large, thus completing a general characterization of t- interleaving numbers for two-dimensional tori. Each of our upper bounds is accompanied by an efficient t-interleaving scheme that constructively achieves the bound.
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