On the existence of minimal end-separators
نویسنده
چکیده
2. We recall the two following concepts: 2.1. An infinite subset S of V(G) is concentrated if there is a ray R such that, for any finite set F of vertices, only finitely many elements of S do not belong to the component of G-F containing a subray of R. 2.2. A set of vertices of G is dkpersed in G if it has no concentrated subset. Note that any subset of vertices of a tree T which is dispersed in some subtree of T, is also dispersed in T.
منابع مشابه
On minimal vertex separators of dually chordal graphs: Properties and characterizations
Many works related to dually chordal graphs, their cliques and neighborhoods were published [1, 6]. We will undertake a similar study by considering minimal vertex separators and their properties instead. We find a necessary and sufficient condition for every minimal vertex separator to be contained in the closed neighborhood of a vertex and two major characterizations of dually chordal graphs ...
متن کاملMinimal separators in P4-sparse graphs
In this paper, we determine the minimal separators of P4-sparse graphs and establish bounds on their number. Specifically, we show that a P4-sparse graph G on n vertices and m edges has fewer than 2n/3 minimal separators of total description size at most 4m/3. The bound on the number of minimal separators is tight and is also tight for the class of cographs, a well known subclass of the P4-spar...
متن کاملA Novel Approach to Obtaining the Optimum Pressure and Stages of Separators
Nowadays, the increasing demand for energy in the world is one of the main concerns for energy supply. In fact, the required energy can be obtained by increasing the production rate of fossil fuels such as oil and natural gas. However, improving the efficiency of the equipment and facilities might have a significant impact on production from hydrocarbon resources. With respect to this subject, ...
متن کاملEnhanced wettability and electrolyte uptake of coated commercial polypropylene separators with inorganic nanopowders for application in lithium-ion battery
In this research, inorganic material type and content influence on coating of commercially available polypropylene (PP) separator were studied for improving its performance and safety as lithium ion battery separator. Heat-resistant nanopowders of Al2O3, SiO2 and ZrO2 were coated using polyvinylidene fluoride (PVDF) binder. Coating effects on the separators morphology, wettability, high tempera...
متن کاملتحقیقی در وضعیت باکتریولوژی جدا کننده های ارتدنسی
Normal 0 false false false EN-US X-NONE AR-SA In this practical study, various types of orthodontic separators were analyzed in order to indentify microbial population on them. Due to high amount of time and energy needed on this issue, only 12 patients were selected. The results showed that elastic separators and Brass wire separators involved the...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Discrete Mathematics
دوره 85 شماره
صفحات -
تاریخ انتشار 1990