{"title":"On primitive geometries of rank two","authors":"D. Leemans, B. Rodrigues","doi":"10.26493/2590-9770.1301.165","DOIUrl":"https://doi.org/10.26493/2590-9770.1301.165","url":null,"abstract":"In this paper, we describe a new algorithm to classify primitive coset geometries of rank two for a given group G. This algorithm allows us to classify those geometries for the 12 smallest sporadic simple groups.","PeriodicalId":236892,"journal":{"name":"Art Discret. Appl. Math.","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131750595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"My journey into noncommutative lattices and their theory","authors":"Jonathan Leech","doi":"10.26493/2590-9770.1282.E7A","DOIUrl":"https://doi.org/10.26493/2590-9770.1282.E7A","url":null,"abstract":"This paper describes the motivations leading to a renewed interest in the study of noncommutative lattices, and especially skew lattices, beginning with the initial work of the author. Not only are primary concepts and results recalled, but recognition is given to the individuals involved and their particular contributions. It is the written version of a talk given at the NCS2018 workshop in May, 2018 in Portorož, Slovenia.","PeriodicalId":236892,"journal":{"name":"Art Discret. Appl. Math.","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117324816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The International Congress on Hypergraphs, Graphs and Designs – HyGraDe 2017","authors":"Francesco Belardo","doi":"10.26493/2590-9770.1278.9f3","DOIUrl":"https://doi.org/10.26493/2590-9770.1278.9f3","url":null,"abstract":"This issue of ADAM – The Art of Discrete and Applied Mathematics offers a collection of papers presented at the International Congress on Hypergraphs, Graphs and Designs – HyGraDe 2017, which took place in Sant’Alessio Siculo, Sicily, Italy, June 20 – 24, 2017. HyGraDe 2017 was conceived with the idea of celebrating the 70th birthday of Mario Gionfriddo, a Sicilian mathematician who has devoted his long and successful career to the study of graphs, hypergraphs and designs. The conference HyGraDe 2017 was organized by Francesco Belardo (University of Naples Federico II) and Giovanni Lo Faro (University of Messina), both serving as chair of the Organizing Committee, Luca Giuzzi (University of Brescia), Enzo M. Li Marzi (University of Messina), Lorenzo Milazzo (University of Catania), Salvatore Milici (University of Catania) and Antoinette Tripodi (University of Messina). The Scientific Committee consisted of Marco Buratti (University of Perugia), Giovanni Lo Faro, Guglielmo Lunardon (University of Naples Federico II) and Martin Milanič (University of Primorska). The conference brought together scientists working in different disciplines of Combinatorics. There were 85 participants from 13 different countries, 10 invited talks and 35 contributed talks touching on the latest developments in the corresponding research areas. The invited speakers were Richard Brualdi (University of Winsconsin), Marco Buratti (University of Perugia), Charlie Colbourn (Arizona State University), Klavdjia Kutnar (University of Primorska), Josef Lauri (University of Malta), Curt Lindner (University of Auburn), Dragan Marušič (University of Primorska), Alex Rosa (McMaster University), Zsolt Tuza (Hungarian Academy of Sciences) and Vitaly Voloshin (Troy University). Mario Gionfriddo was the honoured participant at the congress. Among the invited speakers, six of them have been Mario’s co-authors in several scientific papers.","PeriodicalId":236892,"journal":{"name":"Art Discret. Appl. Math.","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127987551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Perfect blocking sets in P3-designs","authors":"Paola Bonacini, M. Gionfriddo, Lucia Marino","doi":"10.26493/2590-9770.1311.cc2","DOIUrl":"https://doi.org/10.26493/2590-9770.1311.cc2","url":null,"abstract":"A well-known problem in Design Theory is the study of the possible existence of blocking sets in Steiner systems. In this paper, we introduce the concept of perfect blocking sets in G-designs and determine all the possible v for which there exist P3-designs having perfect blocking sets.","PeriodicalId":236892,"journal":{"name":"Art Discret. Appl. Math.","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123564670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Parallelism in Steiner systems","authors":"Maria Di Giovanni, M. Gionfriddo, A. Tripodi","doi":"10.26493/2590-9770.1310.6e2","DOIUrl":"https://doi.org/10.26493/2590-9770.1310.6e2","url":null,"abstract":"The authors give a survey about the problem of parallelism in Steiner systems, pointing out some open problems.","PeriodicalId":236892,"journal":{"name":"Art Discret. Appl. Math.","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125199834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Abreu, G. Araujo-Pardo, C. Balbuena, D. Labbate
{"title":"An alternate description of a (q + 1, 8)-cage","authors":"M. Abreu, G. Araujo-Pardo, C. Balbuena, D. Labbate","doi":"10.26493/2590-9770.1219.034","DOIUrl":"https://doi.org/10.26493/2590-9770.1219.034","url":null,"abstract":"Let q ≥ 2 be a prime power. In this note we present an alternate description of the known (q + 1, 8)-cages which has allowed us to construct small (k, g)-graphs for k = q − 1, q and g = 7, 8 in other papers on this same topic.","PeriodicalId":236892,"journal":{"name":"Art Discret. Appl. Math.","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116701601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Mario Gionfriddo and mixed hypergraph coloring","authors":"V. Voloshin","doi":"10.26493/2590-9770.1230.F19","DOIUrl":"https://doi.org/10.26493/2590-9770.1230.F19","url":null,"abstract":"We give a brief description of the explicit and implicit contribution of Mario Gionfriddo to mixed hypergraph coloring.","PeriodicalId":236892,"journal":{"name":"Art Discret. Appl. Math.","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133034200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Mixed hypergraphs and beyond","authors":"Z. Tuza","doi":"10.26493/2590-9770.1234.37B","DOIUrl":"https://doi.org/10.26493/2590-9770.1234.37B","url":null,"abstract":"Some open problems are collected on hypergraphs, graphs, and designs, presented at the HyGraDe conference celebrating Mario Gionfriddo’s 70th birthday.","PeriodicalId":236892,"journal":{"name":"Art Discret. Appl. Math.","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116337432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Francesco Belardo, S. Cioabă, J. Koolen, Jianfeng Wang
{"title":"Open problems in the spectral theory of signed graphs","authors":"Francesco Belardo, S. Cioabă, J. Koolen, Jianfeng Wang","doi":"10.26493/2590-9770.1286.d7b","DOIUrl":"https://doi.org/10.26493/2590-9770.1286.d7b","url":null,"abstract":"Signed graphs are graphs whose edges get a sign $+1$ or $-1$ (the signature). Signed graphs can be studied by means of graph matrices extended to signed graphs in a natural way. Recently, the spectra of signed graphs have attracted much attention from graph spectra specialists. One motivation is that the spectral theory of signed graphs elegantly generalizes the spectral theories of unsigned graphs. On the other hand, unsigned graphs do not disappear completely, since their role can be taken by the special case of balanced signed graphs. \u0000Therefore, spectral problems defined and studied for unsigned graphs can be considered in terms of signed graphs, and sometimes such generalization shows nice properties which cannot be appreciated in terms of (unsigned) graphs. Here, we survey some general results on the adjacency spectra of signed graphs, and we consider some spectral problems which are inspired from the spectral theory of (unsigned) graphs.","PeriodicalId":236892,"journal":{"name":"Art Discret. Appl. Math.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129259683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A graph-theoretic method to define any Boolean operation on partitions","authors":"D. Ellerman","doi":"10.26493/2590-9770.1259.9d5","DOIUrl":"https://doi.org/10.26493/2590-9770.1259.9d5","url":null,"abstract":"The lattice operations of join and meet were defined for set partitions in the nineteenth century, but no new logical operations on partitions were defined and studied during the twentieth century. Yet there is a simple and natural graph-theoretic method presented here to define any n-ary Boolean operation on partitions. An equivalent closure-theoretic method is also defined. In closing, the question is addressed of why it took so long for all Boolean operations to be defined for partitions.","PeriodicalId":236892,"journal":{"name":"Art Discret. Appl. Math.","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121797348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号
