For the given bipartite graphs G 1 , . . . , G n , the bipartite Ramsey number BR ( G 1 , . . . , G n ) is the least positive integer b such that any complete bipartite graph K b,b having edges coloured with 1 , 2 , . . . , n , contains a copy of some G i ( 1 ≤ i ≤ n ), where all the edges of G i have colour i . For the given bipartite graphs G 1 , . . . , G n and a positive integer m , the m -bipartite Ramsey number BR m ( G 1 , . . . , G n ) is defined as the least positive integer b ( b ≥ m ) such that any complete bipartite graph K m,b having edges coloured with 1 , 2 , . . . , n , contains a copy of some G i ( 1 ≤ i ≤ n ), where all the edges of G i have colour i . The values of BR m ( G 1 , G 2 ) (for each m ), BR m ( K 3 , 3 , K 3 , 3 ) and BR m ( K 2 , 2 , K 5 , 5 ) (for particular values of m ) have already been determined in several articles, where G 1 = K 2 , 2 and G 2 ∈ { K 3 , 3 , K 4 , 4 } . In this article, the value of BR m ( K 2 , 2 , K 6 , 6 ) is computed for each m ∈ { 2 , 3 , . . . , 8 } .
对于给定的二部图g1,…, G n,二部拉姆齐数BR (g1),…, G n)是最小的正整数b,使得任何完全二部图K b,b的边有1,2,…, n,包含一个G i(1≤i≤n)的副本,其中G i的所有边的颜色都是i。对于给定的二部图g1,…, G n和正整数m, m -二部拉姆齐数BR m (g1,…), G n)被定义为最小正整数b (b≥m),使得任何完全二部图K m,b的边有1,2,…, n,包含一个G i(1≤i≤n)的副本,其中G i的所有边的颜色都是i。BR m (g1, g2)(对于每个m), BR m (k3,3, k3,3)和BR m (k2,2, k5,5)(对于m的特定值)的值已经在几篇文章中确定,其中g1 = k2,2并且g2∈{k3,3, k4,4}。在本文中,对于每个m∈{2,3,…,计算BR m (k2,2, k6,6)的值。, 8}。
{"title":"The m-Bipartite Ramsey Number of the K{2,2} Versus K{6,6}","authors":"Yaser Rowshan","doi":"10.47443/cm.2022.011","DOIUrl":"https://doi.org/10.47443/cm.2022.011","url":null,"abstract":"For the given bipartite graphs G 1 , . . . , G n , the bipartite Ramsey number BR ( G 1 , . . . , G n ) is the least positive integer b such that any complete bipartite graph K b,b having edges coloured with 1 , 2 , . . . , n , contains a copy of some G i ( 1 ≤ i ≤ n ), where all the edges of G i have colour i . For the given bipartite graphs G 1 , . . . , G n and a positive integer m , the m -bipartite Ramsey number BR m ( G 1 , . . . , G n ) is defined as the least positive integer b ( b ≥ m ) such that any complete bipartite graph K m,b having edges coloured with 1 , 2 , . . . , n , contains a copy of some G i ( 1 ≤ i ≤ n ), where all the edges of G i have colour i . The values of BR m ( G 1 , G 2 ) (for each m ), BR m ( K 3 , 3 , K 3 , 3 ) and BR m ( K 2 , 2 , K 5 , 5 ) (for particular values of m ) have already been determined in several articles, where G 1 = K 2 , 2 and G 2 ∈ { K 3 , 3 , K 4 , 4 } . In this article, the value of BR m ( K 2 , 2 , K 6 , 6 ) is computed for each m ∈ { 2 , 3 , . . . , 8 } .","PeriodicalId":48938,"journal":{"name":"Contributions To Discrete Mathematics","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76539049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Relating Energy and Sombor Energy","authors":"","doi":"10.47443/cm.2021.0054","DOIUrl":"https://doi.org/10.47443/cm.2021.0054","url":null,"abstract":"","PeriodicalId":48938,"journal":{"name":"Contributions To Discrete Mathematics","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2021-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73128553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this article, the notion of weakly irreducible filters in strong quasi-ordered residuated systems is introduced and analyzed. It is shown that any weakly irreducible filter is a prime (and therefore, irreducible) filter. It is also proved that if the lattice F(A) of all filters in a strong quasi-ordered residuated system A is distributive, then any irreducible filter in A is weakly irreducible in A.
{"title":"Weakly Irreducible Filter in Strong Quasi-Ordered Residuated Systems","authors":"D. Romano","doi":"10.47443/cm.2021.0032","DOIUrl":"https://doi.org/10.47443/cm.2021.0032","url":null,"abstract":"In this article, the notion of weakly irreducible filters in strong quasi-ordered residuated systems is introduced and analyzed. It is shown that any weakly irreducible filter is a prime (and therefore, irreducible) filter. It is also proved that if the lattice F(A) of all filters in a strong quasi-ordered residuated system A is distributive, then any irreducible filter in A is weakly irreducible in A.","PeriodicalId":48938,"journal":{"name":"Contributions To Discrete Mathematics","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2021-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76178784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
where d(u) and d(u, v) are the degree of the vertex u and the distance between the vertices u and v in G, respectively. This new index is useful in predicting physico-chemical properties with high accuracy compared to some classic topological indices. Mathematical relations between the Harary-Albertson index and other classic topological indices are established. The extremal values of the Harary-Albertson index for trees of given order are also determined.
{"title":"Harary-Albertson index of graphs","authors":"Zhen Lin","doi":"10.47443/cm.2021.0051","DOIUrl":"https://doi.org/10.47443/cm.2021.0051","url":null,"abstract":"where d(u) and d(u, v) are the degree of the vertex u and the distance between the vertices u and v in G, respectively. This new index is useful in predicting physico-chemical properties with high accuracy compared to some classic topological indices. Mathematical relations between the Harary-Albertson index and other classic topological indices are established. The extremal values of the Harary-Albertson index for trees of given order are also determined.","PeriodicalId":48938,"journal":{"name":"Contributions To Discrete Mathematics","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2021-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80276925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract A graph is said to be Hamiltonian (respectively, traceable) if it has a Hamiltonian cycle (respectively, Hamiltonian path), where a Hamiltonian cycle (respectively, Hamiltonian path) is a cycle (respectively, path) containing all the vertices of the graph. In this short note, sufficient conditions involving the clique number for the Hamiltonian and traceable graphs are presented.
{"title":"The Clique Number and Some Hamiltonian Properties of Graphs","authors":"Rao Li","doi":"10.47443/cm.2021.0038","DOIUrl":"https://doi.org/10.47443/cm.2021.0038","url":null,"abstract":"Abstract A graph is said to be Hamiltonian (respectively, traceable) if it has a Hamiltonian cycle (respectively, Hamiltonian path), where a Hamiltonian cycle (respectively, Hamiltonian path) is a cycle (respectively, path) containing all the vertices of the graph. In this short note, sufficient conditions involving the clique number for the Hamiltonian and traceable graphs are presented.","PeriodicalId":48938,"journal":{"name":"Contributions To Discrete Mathematics","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2021-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77976419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anestis G. Hatzimichailidis, G. Souliotis, B. Papadopoulos
In this paper we introduce fuzzy implications stemming from a class of strong negations, which are generated via conical sections. The strong negations form a structural element in the production of fuzzy implications
{"title":"Fuzzy implications based on strong negations","authors":"Anestis G. Hatzimichailidis, G. Souliotis, B. Papadopoulos","doi":"10.47443/cm.2021.0040","DOIUrl":"https://doi.org/10.47443/cm.2021.0040","url":null,"abstract":"In this paper we introduce fuzzy implications stemming from a class of strong negations, which are generated via conical sections. The strong negations form a structural element in the production of fuzzy implications","PeriodicalId":48938,"journal":{"name":"Contributions To Discrete Mathematics","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2021-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80346753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In this short note, an alternative proof of a harmonic mean inequality involving Nielsen’s beta function is provided. This inequality was first posed as a conjecture by Nantomah [Bull. Int. Math. Virtual Inst. 9 (2019) 263–269] and subsequently proved by Matejı́čka [Probl. Anal. Issues Anal. 8(26) (2019) 105–111]. The present proof is more compact and relatively simple.
在这个简短的笔记中,提供了涉及Nielsen的beta函数的调和平均不等式的另一种证明。这个不等式最初是由Nantomah [Bull]提出的一个猜想。Int。数学。虚拟研究所,9(2019)263-269],随后由matejyi æ ka [Probl.]证明。分析的议题通报。8(26)(2019)105-111]。现在的证明更紧凑,也相对简单。
{"title":"An alternative proof of a harmonic mean inequality for Nielsen’s beta function","authors":"K. Nantomah","doi":"10.47443/cm.2021.0028","DOIUrl":"https://doi.org/10.47443/cm.2021.0028","url":null,"abstract":"Abstract In this short note, an alternative proof of a harmonic mean inequality involving Nielsen’s beta function is provided. This inequality was first posed as a conjecture by Nantomah [Bull. Int. Math. Virtual Inst. 9 (2019) 263–269] and subsequently proved by Matejı́čka [Probl. Anal. Issues Anal. 8(26) (2019) 105–111]. The present proof is more compact and relatively simple.","PeriodicalId":48938,"journal":{"name":"Contributions To Discrete Mathematics","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2021-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77351521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
There are misprints in the paper [1]. On the fourth line in the section of Introduction on Page 54, the “Define G1(n, k) := Kk ∨K k+1 where k ≥ 2 and G2(n, k) := Kk ∨K k+2 where k ≥ 1” should be “Define G1(n, k) := Kn−k−1 ∨K k+1 where k ≥ 2 and G2(n, k) := Kn−k−2 ∨K k+2 where k ≥ 1”. Because of the above changes, the following changes should be made, accordingly. • At the end of Proof of Theorem 1.1 on Page 55, “G is G1(n, k)” should be changed into “G is Kk ∨K k+1”. • At the end of Proof of Theorem 1.2 on Page 56, “G is G2(n, k)” should be changed into “G is Kk ∨K k+2”.
{"title":"Corrigendum to “Combinations of some spectral invariants and Hamiltonian properties of\u0000graphs, Contrib. Math. 1 (2020) 54–56”","authors":"Rao Li","doi":"10.47443/cm.2021.n2","DOIUrl":"https://doi.org/10.47443/cm.2021.n2","url":null,"abstract":"There are misprints in the paper [1]. On the fourth line in the section of Introduction on Page 54, the “Define G1(n, k) := Kk ∨K k+1 where k ≥ 2 and G2(n, k) := Kk ∨K k+2 where k ≥ 1” should be “Define G1(n, k) := Kn−k−1 ∨K k+1 where k ≥ 2 and G2(n, k) := Kn−k−2 ∨K k+2 where k ≥ 1”. Because of the above changes, the following changes should be made, accordingly. • At the end of Proof of Theorem 1.1 on Page 55, “G is G1(n, k)” should be changed into “G is Kk ∨K k+1”. • At the end of Proof of Theorem 1.2 on Page 56, “G is G2(n, k)” should be changed into “G is Kk ∨K k+2”.","PeriodicalId":48938,"journal":{"name":"Contributions To Discrete Mathematics","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2021-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80768009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}