19 citations · 47 across the 17 of their papers we have counts for
19 papers
Parallel covering a rhombus with equilateral triangles
Jingjing Wang, Yanxun Chang
Suppose that is a rhombus with side length and with an interior angle , where . Let be an equilateral triangle with a side parallel to…
Several problems on reduced spherical polygons of thickness less than π/2
Cen Liu, Yanxun Chang
The present paper aims to solve some problems proposed by Lassak about the reduced spherical polygons. The main result is to show that the regular spherical n-gon has the minimal p…
The area of reduced spherical polygons
Cen Liu, Yanxun Chang, Zhanjun Su
We confirm two conjectures of Lassak on the area of reduced spherical polygons. The area of every reduced spherical non-regular -gon is less than that of the regular spherical $…
Parallel multilevel constructions for constant dimension codes
Shuangqing Liu, Yanxun Chang, Tao Feng
Constant dimension codes (CDCs), as special subspace codes, have received a lot of attention due to their application in random network coding. This paper introduces a family of ne…
Partitionable sets, almost partitionable sets and their applications
Yanxun Chang, Simone Costa, Tao Feng +1
This paper introduces almost partitionable sets to generalize the known concept of partitionable sets. These notions provide a unified frame to construct -cyclic patter…
Triangle decompositions of
Yueting Li, Yanxun Chang, Tao Feng
Denote by the complete graph of order with multiplicity . Let be the graph obtained from by the removal of the edges of two vertex disjoint co…
Leaves for packings with block size four
Yanxun Chang, Peter J. Dukes, Tao Feng
We consider maximum packings of edge-disjoint -cliques in the complete graph . When or , these are simply block designs. In other congruence class…
Strong difference families of special types
Yanxun Chang, Simone Costa, Tao Feng +1
Strong difference families of special types are introduced to produce new relative difference families from the point of view of both asymptotic existences and concrete examples. A…
New bounds on the maximum size of Sperner partition systems
Yanxun Chang, Charles J. Colbourn, Adam Gowty +2
An -Sperner partition system is a collection of partitions of some -set, each into nonempty classes, such that no class of any partition is a subset of a class of any…
Several classes of optimal Ferrers diagram rank-metric codes
Shuangqing Liu, Yanxun Chang, Tao Feng
Four constructions for Ferrers diagram rank-metric (FDRM) codes are presented. The first one makes use of a characterization on generator matrices of a class of systematic maximum…
Constructions for optimal Ferrers diagram rank-metric codes
Shuangqing Liu, Yanxun Chang, Tao Feng
Optimal rank-metric codes in Ferrers diagrams can be used to construct good subspace codes. Such codes consist of matrices having zeros at certain fixed positions. This paper gener…
Group divisible (K_4-e)-packings with any minimum leave
Y. Gao, Y. Chang, T. Feng
A decomposition of , the complete n-partite equipartite graph with a subgraph L (called the leave) removed, into edge disjoint copies of a graph G is called a…
Determination of sizes of optimal three-dimensional optical orthogonal codes of weight three with the AM-OPP restriction
Lidong Wang, Yanxun Chang
In this paper, we further investigate the constructions on three-dimensional optical orthogonal codes with the at most one optical pulse per wavelength/ti…
Semi-cyclic holey group divisible designs with block size three and applications to sampling designs and optical orthogonal codes
Tao Feng, Xiaomiao Wang, Ruizhong Wei
We consider the existence problem for a semi-cyclic holey group divisible design of type (n,m^t) with block size 3, which is denoted by a 3-SCHGDD of type (n,m^t). When t is odd an…
Enumerations of (K_4-e)-designs with small orders
Yanxun Chang, Tao Feng, Giovanni Lo Faro +1
It is established that up to isomorphism,there are only one (K_4-e)-design of order 6, three (K_4-e)-designs of order 10 and two (K_4-e)-designs of order 11. As an application of o…
Combinatorial constructions for optimal two-dimensional optical orthogonal codes with = 2
Tao Feng, Yanxun Chang
In this paper, we are concerned about optimal two-dimensional optical orthogonal codes with = 2. Some combinatorial constructions are presented and many infinite families of op…
Semi-cyclic holey group divisible designs with block size three
Tao Feng, Xiaomiao Wang, Yanxun Chang
In this paper we discuss the existence problem for a semi-cyclic holey group divisible design of type (n,m^t) with block size 3, which is denoted by a 3-SCHGDD of type (n,m^t). Whe…
A Pair of Disjoint 3-GDDs of type g^t u^1
Yanxun Chang, Yeow Meng Chee, Junling Zhou
Pairwise disjoint 3-GDDs can be used to construct some optimal constant-weight codes. We study the existence of a pair of disjoint 3-GDDs of type and establish that its n…
Decompositions of 3-uniform hypergraph K_v^{(3)} into hypergraph K_4^{(3)}+e
Tao Feng, Yanxun Chang
In this paper it is established that a decomposition of a 3-uniform hypergraph K_v^{(3)} into a special kind of hypergraph K_4^{(3)}+e exists if and only if v\equiv 0,1,2 (mod 5) a…