{"title":"长度较小的不同代码","authors":"Sascha Kurz","doi":"10.1016/j.exco.2024.100139","DOIUrl":null,"url":null,"abstract":"<div><p>A code <span><math><mrow><mi>C</mi><mo>⊆</mo><msup><mrow><mrow><mo>{</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>,</mo><mn>2</mn><mo>}</mo></mrow></mrow><mrow><mi>n</mi></mrow></msup></mrow></math></span> of length <span><math><mi>n</mi></math></span> is called trifferent if for any three distinct elements of <span><math><mi>C</mi></math></span> there exists a coordinate in which they all differ. By <span><math><mrow><mi>T</mi><mrow><mo>(</mo><mi>n</mi><mo>)</mo></mrow></mrow></math></span> we denote the maximum cardinality of trifferent codes with length <span><math><mi>n</mi></math></span>. The values <span><math><mrow><mi>T</mi><mrow><mo>(</mo><mn>5</mn><mo>)</mo></mrow><mo>=</mo><mn>10</mn></mrow></math></span> and <span><math><mrow><mi>T</mi><mrow><mo>(</mo><mn>6</mn><mo>)</mo></mrow><mo>=</mo><mn>13</mn></mrow></math></span> were recently determined (Fiore et al., 2022). Here we determine <span><math><mrow><mi>T</mi><mrow><mo>(</mo><mn>7</mn><mo>)</mo></mrow><mo>=</mo><mn>16</mn></mrow></math></span>, <span><math><mrow><mi>T</mi><mrow><mo>(</mo><mn>8</mn><mo>)</mo></mrow><mo>=</mo><mn>20</mn></mrow></math></span>, and <span><math><mrow><mi>T</mi><mrow><mo>(</mo><mn>9</mn><mo>)</mo></mrow><mo>=</mo><mn>27</mn></mrow></math></span>. For the latter case <span><math><mrow><mi>n</mi><mo>=</mo><mn>9</mn></mrow></math></span> there also exist linear codes attaining the maximum possible cardinality 27.</p></div>","PeriodicalId":100517,"journal":{"name":"Examples and Counterexamples","volume":"5 ","pages":"Article 100139"},"PeriodicalIF":0.0000,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666657X24000053/pdfft?md5=6d4ca67bb2a4151b63492ee97290bf7c&pid=1-s2.0-S2666657X24000053-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Trifferent codes with small lengths\",\"authors\":\"Sascha Kurz\",\"doi\":\"10.1016/j.exco.2024.100139\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>A code <span><math><mrow><mi>C</mi><mo>⊆</mo><msup><mrow><mrow><mo>{</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>,</mo><mn>2</mn><mo>}</mo></mrow></mrow><mrow><mi>n</mi></mrow></msup></mrow></math></span> of length <span><math><mi>n</mi></math></span> is called trifferent if for any three distinct elements of <span><math><mi>C</mi></math></span> there exists a coordinate in which they all differ. By <span><math><mrow><mi>T</mi><mrow><mo>(</mo><mi>n</mi><mo>)</mo></mrow></mrow></math></span> we denote the maximum cardinality of trifferent codes with length <span><math><mi>n</mi></math></span>. The values <span><math><mrow><mi>T</mi><mrow><mo>(</mo><mn>5</mn><mo>)</mo></mrow><mo>=</mo><mn>10</mn></mrow></math></span> and <span><math><mrow><mi>T</mi><mrow><mo>(</mo><mn>6</mn><mo>)</mo></mrow><mo>=</mo><mn>13</mn></mrow></math></span> were recently determined (Fiore et al., 2022). Here we determine <span><math><mrow><mi>T</mi><mrow><mo>(</mo><mn>7</mn><mo>)</mo></mrow><mo>=</mo><mn>16</mn></mrow></math></span>, <span><math><mrow><mi>T</mi><mrow><mo>(</mo><mn>8</mn><mo>)</mo></mrow><mo>=</mo><mn>20</mn></mrow></math></span>, and <span><math><mrow><mi>T</mi><mrow><mo>(</mo><mn>9</mn><mo>)</mo></mrow><mo>=</mo><mn>27</mn></mrow></math></span>. For the latter case <span><math><mrow><mi>n</mi><mo>=</mo><mn>9</mn></mrow></math></span> there also exist linear codes attaining the maximum possible cardinality 27.</p></div>\",\"PeriodicalId\":100517,\"journal\":{\"name\":\"Examples and Counterexamples\",\"volume\":\"5 \",\"pages\":\"Article 100139\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-02-07\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S2666657X24000053/pdfft?md5=6d4ca67bb2a4151b63492ee97290bf7c&pid=1-s2.0-S2666657X24000053-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Examples and Counterexamples\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2666657X24000053\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Examples and Counterexamples","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2666657X24000053","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
摘要
长度为 n 的代码 C⊆{0,1,2}n,如果 C 的任意三个不同元素都存在一个坐标,且它们都不同,则称为三不同代码。T(5)=10 和 T(6)=13 的值是最近确定的(Fiore 等人,2022 年)。在此,我们确定了 T(7)=16、T(8)=20 和 T(9)=27。对于后一种情况 n=9,也存在达到最大可能心数 27 的线性编码。
A code of length is called trifferent if for any three distinct elements of there exists a coordinate in which they all differ. By we denote the maximum cardinality of trifferent codes with length . The values and were recently determined (Fiore et al., 2022). Here we determine , , and . For the latter case there also exist linear codes attaining the maximum possible cardinality 27.