{"title":"Mixed Steiner Triple Systems With Shortest Length","authors":"Tuvi Etzion","doi":"10.1002/jcd.70030","DOIUrl":null,"url":null,"abstract":"<p>A mixed Steiner triple system is a 3-GDD which is viewed as a code with minimum Hamming distance 3. These codes are the minimum weight codewords of a 1-perfect code over a mixed alphabet, when the related codes exist, and provide the connection between 3-GDDs and coding theory. We prove that a 3-GDD of type <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <msup>\n <mn>1</mn>\n \n <mi>n</mi>\n </msup>\n \n <msup>\n <mi>k</mi>\n \n <mn>1</mn>\n </msup>\n \n <msup>\n <mi>ℓ</mi>\n \n <mn>1</mn>\n </msup>\n </mrow>\n </mrow>\n </semantics></math>, where <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>n</mi>\n \n <mo>=</mo>\n \n <mi>k</mi>\n \n <mo>⋅</mo>\n \n <mi>ℓ</mi>\n </mrow>\n </mrow>\n </semantics></math>, with minimum distance 3 exists for every <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>k</mi>\n </mrow>\n </mrow>\n </semantics></math> and <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>ℓ</mi>\n </mrow>\n </mrow>\n </semantics></math> such that <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>n</mi>\n \n <mo>=</mo>\n \n <mi>k</mi>\n \n <mo>⋅</mo>\n \n <mi>ℓ</mi>\n </mrow>\n </mrow>\n </semantics></math>, <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>k</mi>\n \n <mo>≡</mo>\n \n <mn>1</mn>\n </mrow>\n </mrow>\n </semantics></math> or <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mn>3</mn>\n \n <mrow>\n <mo>(</mo>\n \n <mrow>\n <mstyle>\n <mspace></mspace>\n \n <mtext>mod</mtext>\n <mspace></mspace>\n </mstyle>\n <mspace></mspace>\n \n <mn>6</mn>\n </mrow>\n \n <mo>)</mo>\n </mrow>\n </mrow>\n </mrow>\n </semantics></math>, <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>ℓ</mi>\n \n <mo>≡</mo>\n \n <mn>1</mn>\n </mrow>\n </mrow>\n </semantics></math> or <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mn>3</mn>\n \n <mrow>\n <mo>(</mo>\n \n <mrow>\n <mstyle>\n <mspace></mspace>\n \n <mtext>mod</mtext>\n <mspace></mspace>\n </mstyle>\n <mspace></mspace>\n \n <mn>6</mn>\n </mrow>\n \n <mo>)</mo>\n </mrow>\n </mrow>\n </mrow>\n </semantics></math>, and <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>k</mi>\n \n <mo>≥</mo>\n \n <mi>ℓ</mi>\n \n <mo>></mo>\n \n <mn>1</mn>\n </mrow>\n </mrow>\n </semantics></math>. These designs are of the shortest possible length (smallest number of elements) for given <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>k</mi>\n </mrow>\n </mrow>\n </semantics></math> and <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>ℓ</mi>\n </mrow>\n </mrow>\n </semantics></math>. Other constructions for such triple systems are also presented.</p>","PeriodicalId":15389,"journal":{"name":"Journal of Combinatorial Designs","volume":"34 12","pages":"533-544"},"PeriodicalIF":0.8000,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jcd.70030","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Combinatorial Designs","FirstCategoryId":"100","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/jcd.70030","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2026/8/10 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
A mixed Steiner triple system is a 3-GDD which is viewed as a code with minimum Hamming distance 3. These codes are the minimum weight codewords of a 1-perfect code over a mixed alphabet, when the related codes exist, and provide the connection between 3-GDDs and coding theory. We prove that a 3-GDD of type , where , with minimum distance 3 exists for every and such that , or , or , and . These designs are of the shortest possible length (smallest number of elements) for given and . Other constructions for such triple systems are also presented.
期刊介绍:
The Journal of Combinatorial Designs is an international journal devoted to the timely publication of the most influential papers in the area of combinatorial design theory. All topics in design theory, and in which design theory has important applications, are covered, including:
block designs, t-designs, pairwise balanced designs and group divisible designs
Latin squares, quasigroups, and related algebras
computational methods in design theory
construction methods
applications in computer science, experimental design theory, and coding theory
graph decompositions, factorizations, and design-theoretic techniques in graph theory and extremal combinatorics
finite geometry and its relation with design theory.
algebraic aspects of design theory.
Researchers and scientists can depend on the Journal of Combinatorial Designs for the most recent developments in this rapidly growing field, and to provide a forum for both theoretical research and applications. All papers appearing in the Journal of Combinatorial Designs are carefully peer refereed.