Flow pack facets of the single node fixed-charge flow polytope
نویسندگان
چکیده
منابع مشابه
Flow pack facets of the single node fixed-charge flow polytope
i∈N yi ≤ b, yi ≤ uixi ∀i ∈ N}, where variable yi is the flow on arc i with capacity ui, xi is a binary variable that indicates whether arc i is open or closed, and N = N ∪N. The single node fixed–charge flow model is interesting not only because it is a relaxation of the fixed–charge network flow problem, but also because it is possible to derive relaxations of the form S of a general MBIP prob...
متن کاملPath Cover and Path Pack Inequalities for the Capacitated Fixed-Charge Network Flow Problem
Capacitated fixed-charge network flows are used to model a variety of problems in telecommunication, facility location, production planning and supply chain management. In this paper, we investigate capacitated path substructures and derive strong and easy-to-compute path cover and path pack inequalities. These inequalities are based on an explicit characterization of the submodular inequalitie...
متن کاملFacets with fixed defect of the stable set polytope
The stable set polytope of a graph is the convex hull of the 01 vectors corresponding to stable sets of vertices. To any nontrivial facet ∑n i=1 aixi ≤ b of this polytope we associate an integer δ, called the defect of the facet, by δ = ∑n i=1 ai − 2b. We show that for any fixed δ there is a finite collection of graphs (called “basis”) such that any graph with a facet of defect δ contains a sub...
متن کاملthe effects of changing roughness on the flow structure in the bends
flow in natural river bends is a complex and turbulent phenomenon which affects the scour and sedimentations and causes an irregular bed topography on the bed. for the reason, the flow hydralics and the parameters which affect the flow to be studied and understand. in this study the effect of bed and wall roughness using the software fluent discussed in a sharp 90-degree flume bend with 40.3cm ...
The Circuit Polytope: Facets
Given an undirected graph G = (V;E) and a cost vector c 2 IRE , the weighted girth problem is to nd a circuit in G having minimum total cost. This problem is in general NP-hard since the traveling salesman problem can be reduced to it. A promising approach to hard combinatorial optimization problems is given by the so-called cutting plane methods. These involve linear programming techniques bas...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Operations Research Letters
سال: 2001
ISSN: 0167-6377
DOI: 10.1016/s0167-6377(01)00100-6