{"title":"顶点覆盖的偏长码与硬度","authors":"","doi":"10.1145/3568031.3568037","DOIUrl":null,"url":null,"abstract":"5.1 Biased Long Code While the biased long code can be viewed as an encoding scheme, it is more con venient to take a combinatorial view and treat it as a weighted Kneser graph. Valid codewords correspond to certain large (in fact the largest) independent sets in this graph. Definition 5.1 For a bias parameter p ∈ (0, 1) and alphabet Σ, the vertex set of weighted Kneser graph Gp[Σ] is P(Σ), the family of all subsets of Σ. The weight of a vertex A ⊆ Σ is μp(A) = p|A|(1 − p)|Σ|−|A|. The edge set is { (A, B) | A, B ⊆ Σ, A ∩ B = φ}. For a family F ⊆ P(Σ), let μp(F ) denote its weight under μp.","PeriodicalId":377190,"journal":{"name":"Circuits, Packets, and Protocols","volume":"45 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"The Biased Long Code and Hardness of Vertex Cover\",\"authors\":\"\",\"doi\":\"10.1145/3568031.3568037\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"5.1 Biased Long Code While the biased long code can be viewed as an encoding scheme, it is more con venient to take a combinatorial view and treat it as a weighted Kneser graph. Valid codewords correspond to certain large (in fact the largest) independent sets in this graph. Definition 5.1 For a bias parameter p ∈ (0, 1) and alphabet Σ, the vertex set of weighted Kneser graph Gp[Σ] is P(Σ), the family of all subsets of Σ. The weight of a vertex A ⊆ Σ is μp(A) = p|A|(1 − p)|Σ|−|A|. The edge set is { (A, B) | A, B ⊆ Σ, A ∩ B = φ}. For a family F ⊆ P(Σ), let μp(F ) denote its weight under μp.\",\"PeriodicalId\":377190,\"journal\":{\"name\":\"Circuits, Packets, and Protocols\",\"volume\":\"45 1\",\"pages\":\"0\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1900-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Circuits, Packets, and Protocols\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1145/3568031.3568037\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Circuits, Packets, and Protocols","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1145/3568031.3568037","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
虽然偏长码可以看作是一种编码方案,但从组合的角度来看,将其视为加权的Kneser图更为方便。有效码字对应于此图中某些较大的(实际上是最大的)独立集。定义5.1对于偏差参数p∈(0,1),字母Σ,加权Kneser图Gp[Σ]的顶点集为p (Σ),即Σ的所有子集的族。一个顶点的重量⊆Σμp (a) = p | |(1−p) |Σ|−| |。边集为{(A, B) | A, B≤Σ, A∩B = φ}。对于一个族F (Σ),设μp(F)为其在μp下的权值。
5.1 Biased Long Code While the biased long code can be viewed as an encoding scheme, it is more con venient to take a combinatorial view and treat it as a weighted Kneser graph. Valid codewords correspond to certain large (in fact the largest) independent sets in this graph. Definition 5.1 For a bias parameter p ∈ (0, 1) and alphabet Σ, the vertex set of weighted Kneser graph Gp[Σ] is P(Σ), the family of all subsets of Σ. The weight of a vertex A ⊆ Σ is μp(A) = p|A|(1 − p)|Σ|−|A|. The edge set is { (A, B) | A, B ⊆ Σ, A ∩ B = φ}. For a family F ⊆ P(Σ), let μp(F ) denote its weight under μp.