Closed 3-stop Center and Periphery in Graphs Linda EROH Ralucca GERA Steven J.WINTERS A delivery person must leave the central location of the business,deliver packages at a number of addresses,and then return.Natural...Closed 3-stop Center and Periphery in Graphs Linda EROH Ralucca GERA Steven J.WINTERS A delivery person must leave the central location of the business,deliver packages at a number of addresses,and then return.Naturally,he/she wishes to reduce costs by finding the most efficient route.This motivates the following: Given a set of k distinct vertices S = {x_1,x_2,…,x_k} in a simple graph G,the closed k-stop-distance of set S is defined to展开更多
On a Variant of Giuga Numbers Jose Maria GRAU Florian LUCA Antonio M.OLLER-MARCEN In this paper,we characterize the odd positive integers n satisfying the congruence∑_(j=1)^(n-1) j^((n-1)/2) = 0(rood n).We show that ...On a Variant of Giuga Numbers Jose Maria GRAU Florian LUCA Antonio M.OLLER-MARCEN In this paper,we characterize the odd positive integers n satisfying the congruence∑_(j=1)^(n-1) j^((n-1)/2) = 0(rood n).We show that the set of such positive integers has an asymptotic density which turns out to be slightly larger than 3/8.展开更多
＂Chemical Research in Chinese Universities＂, sponsored by Jilin University mandated by the Ministry of Education of R R. China and published by Higher Education Press, is a comprehensive academic journal in the fiel...＂Chemical Research in Chinese Universities＂, sponsored by Jilin University mandated by the Ministry of Education of R R. China and published by Higher Education Press, is a comprehensive academic journal in the field of chemistry. The journal contains original papers, research notes, letters and reviews written by faculty members, scientific researchers, postgraduates and graduate students of universities and colleges, and scientific institutes all over China and the world, and reports the latest and most creative results of important fundamental research in all aspects of chemistry and of developments with significant consequences across subdisciplines.展开更多
文摘Closed 3-stop Center and Periphery in Graphs Linda EROH Ralucca GERA Steven J.WINTERS A delivery person must leave the central location of the business,deliver packages at a number of addresses,and then return.Naturally,he/she wishes to reduce costs by finding the most efficient route.This motivates the following: Given a set of k distinct vertices S = {x_1,x_2,…,x_k} in a simple graph G,the closed k-stop-distance of set S is defined to
文摘On a Variant of Giuga Numbers Jose Maria GRAU Florian LUCA Antonio M.OLLER-MARCEN In this paper,we characterize the odd positive integers n satisfying the congruence∑_(j=1)^(n-1) j^((n-1)/2) = 0(rood n).We show that the set of such positive integers has an asymptotic density which turns out to be slightly larger than 3/8.
文摘＂Chemical Research in Chinese Universities＂, sponsored by Jilin University mandated by the Ministry of Education of R R. China and published by Higher Education Press, is a comprehensive academic journal in the field of chemistry. The journal contains original papers, research notes, letters and reviews written by faculty members, scientific researchers, postgraduates and graduate students of universities and colleges, and scientific institutes all over China and the world, and reports the latest and most creative results of important fundamental research in all aspects of chemistry and of developments with significant consequences across subdisciplines.
