Xiande Zhang

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We introduce the class of multiply constant-weight codes to improve the reliability of certain physically unclonable function response, and extend classical coding methods to construct multiply constant-weight codes from known \(q\) -ary and constant-weight codes. We derive analogs of Johnson bounds and give constructions showing these bounds to be(More)
Multiply constant-weight codes (MCWCs) have been recently studied to improve the reliability of certain physically unclonable function response. In this paper, we give combinatorial constructions for the MCWCs, which yield several new infinite families of optimal MCWCs. Furthermore, we demonstrate that the Johnson-type upper bounds of the MCWCs are(More)
We demonstrate that certain Johnson-type bounds are asymptotically exact for a variety of classes of codes, namely, constant-composition codes, nonbinary constant-weight codes and multiply constant-weight codes. This was achieved via an interesting application of the theory of decomposition of edge-colored digraphs.
Constant-weight codes (CWCs) play an important role in coding theory. The problem of determining the sizes for optimal ternary CWCs with length <i>n</i>, weight 4, and minimum Hamming distance 5 ((<i>n</i>,5,4)<sub>3</sub> code) has been settled for all positive integers <i>n</i> &#x2264; 10 or <i>n</i> &gt;; 10 and <i>n</i> &#x2261; 1 mod 3 with <i>n</i>(More)
Partitionable skew Room frames of type hn have played an important role in the constructions of 4-frames, (K4 − e)-frames and super-simple (4, 2)-frames. In this paper, we investigate the existence of partitionable skew Room frames of type hn. The necessary conditions for the existence of such a design are that h(n − 1) ≡ 0 (mod 4) and h 5. It is proved(More)
Frameproof codes are used to preserve the security in the context of coalition when fingerprinting digital data. Let M<sub>c,l</sub>(q) be the largest cardinality of a q-ary c-frameproof code of length l and R<sub>c,l</sub>=lim<sub>q&#x2192;&#x221E;</sub> M<sub>c,l</sub>(q)/q<sup>[ l/c]</sup>. It has been determined by Blackburn that R<sub>c,l</sub>=1 when(More)