The number of vertices of degree 5 in a contraction-critically 5-connected graph

The number of vertices of degree 5 in a contraction-critically 5-connected graph

An edge of a k-connected graph is said to be k-contractible if its contraction yields a k-connected graph. A non-complete k-connected graph possessing no k-contractible edges is called contraction-critical k-connected. Let G be a contraction-critical 7-connected graph with n vertices, and V7 the set of vertices of degree 7 in G. In this paper, we prove that |V7| ≥ n 22 , which improves the resu...

connected cototal domination number of a graph

a dominating set $d subseteq v$ of a graph $g = (v,e)$ is said to be a connected cototal dominating set if $langle d rangle$ is connected and $langle v-d rangle neq phi$, contains no isolated vertices. a connected cototal dominating set is said to be minimal if no proper subset of $d$ is connected cototal dominating set. the connected cototal domination number $gamma_{ccl}(g)$ of $g$ is the min...

Removable edges in a 5-connected graph and a construction method of 5-connected graphs

An edge e of a k-connected graph G is said to be a removable edge if G a e is still k-connected, where Ga e denotes the graph obtained from G by deleting e to get G− e and, for any end vertex of e with degree k− 1 in G− e, say x, deleting x and then adding edges between any pair of non-adjacent vertices in NG−e(x). Xu and Guo [28] proved that a 5-connected graph G has no removable edge if and o...

Triangles in contraction critical 5-connected graphs

a swot analysis of the english program of a bilingual school in iran

با توجه به جایگاه زبان انگلیسی به عنوان زبانی بین المللی و با در نظر گرفتن این واقعیت که دولت ها و مسئولان آموزش و پرورش در سراسر جهان در حال حاضر احساس نیاز به ایجاد موقعیتی برای کودکان جهت یاد گیری زبان انگلیسی درسنین پایین در مدارس دو زبانه می کنند، تحقیق حاضر با استفاده از مدل swot (قوت ها، ضعف ها، فرصتها و تهدیدها) سعی در ارزیابی مدرسه ای دو زبانه در ایران را دارد. جهت انجام این تحقیق در م...