On a Covering Property of Maximal

نویسنده

  • Niall Graham
چکیده

In the lattice of subsets of an n-set X , every maximal Sperner family S may be partitioned into disjoint subfamilies A and B, such that the union of the upset of A with the downset of B yields the entire lattice: U(A) [ D(B) = 2 X . The result generalizes to certain posets.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

A modified NSGA-II solution for a new multi-objective hub maximal covering problem under uncertain shipments

Hubs are centers for collection, rearrangement, and redistribution of commodities in transportation networks. In this paper, non-linear multi-objective formulations for single and multiple allocation hub maximal covering problems as well as the linearized versions are proposed. The formulations substantially mitigate complexity of the existing models due to the fewer number of constraints and v...

متن کامل

General form of a cooperative gradual maximal covering location problem

Cooperative and gradual covering are two new methods for developing covering location models. In this paper, a cooperative maximal covering location–allocation model is developed (CMCLAP). In addition, both cooperative and gradual covering concepts are applied to the maximal covering location simultaneously (CGMCLP). Then, we develop an integrated form of a cooperative gradual maximal covering ...

متن کامل

A New Heuristic Solution Method for Maximal Covering Location-Allocation Problem with M/M/1 Queueing System

We consider the queueing maximal covering location-allocation problem (QM-CLAP) with an M/M/1 queueing system. We propose a new solution procedure based on decomposition of the problem into smaller sub-problems. We solve the resulting sub-problems both with a branch and bound algorithm and with the meta-heuristic GRASP. We also solve the entire model with GRASP. Computational results for these ...

متن کامل

Maximal covering location-allocation problem with M/M/k queuing system and side constraints

  We consider the maximal covering location-allocation problem with multiple servers. The objective is to maximize the population covered, subject to constraints on the number of service centers, total number of servers in all centers, and the average waiting time at each center. Each center operates as an M/M/k queuing system with variable number of servers. The total costs of establishing cen...

متن کامل

Presenting a three-objective model in location-allocation problems using combinational interval full-ranking and maximal covering with backup model

Covering models have found many applications in a wide variety of real-world problems; nevertheless, some assumptions of covering models are not realistic enough. Accordingly, a general approach would not be able to answer the needs of encountering varied aspects of real-world considerations. Assumptions like the unavailability of servers, uncertainty, and evaluating more factors at the same ti...

متن کامل

Mathematical Model for Bi-objective Maximal Hub Covering Problem with Periodic Variations of Parameters

The problem of maximal hub covering as a challenging problem in operation research. Transportation programming seeks to find an optimal location of a set of hubs to reach maximum flow in a network. Since the main structure's parameters of the problem such as origin-destination flows, costs and travel time, change periodically in the real world applications, new issues arise in handling it. In t...

متن کامل

ذخیره 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 نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2007