Integer equal flows
نویسندگان
چکیده
The integer equal flow problem is an NP-hard network flow problem, in which all arcs in given sets R1, . . . , R` must carry equal flow. We show that this problem is effectively inapproximable, even if the cardinality of each set Rk is two. When ` is fixed, it is solvable in polynomial time. © 2009 Elsevier B.V. All rights reserved.
منابع مشابه
Integer Network Synthesis Problem for Hop Constrained Flows
Hop constraint is associated with modern communication network flows. We consider the problem of designing an optimal undirected network with integer-valued edge-capacities that meets a given set of single-commodity, hop-constrained network flow value requirements. We present a strongly polynomial, combinatorial algorithm for the problem with value of hop-parameter equal to three when values of...
متن کاملEffects of integrating physical and financial flows through a closed-loop supply chain network under uncertain demand and return
The impact of financial challenges on the profit of a supply chain, have caused the researcher to model the supply chain network by considering the operational and financial dimensions. Also, the establishment of a closed loop supply chain (CLSC) network has a high effect on economic profit. So, the purpose of this study is to design a stochastic closed loop supply chain network by considering ...
متن کاملVector Flows in Graphs and Integer Flows in Signed Graphs
My research focuses on the flow problems consisting of two parts, vector flows in graphs and integer flows in signed graphs. The concept of integer flows was first introduced by Tutte (1949) as a refinement of map coloring. In fact, integer flows is the dual concept of map coloring for planar graphs. This is often referred as duality theorem. Tutte proposed three celebrated flow conjectures whi...
متن کاملOptimisation models for re-routing air traffic flows in Europe
This paper focuses on the usability of optimisation models to support the re-routing of air traffic flows in Europe. It discusses different modelling approaches and proposes three integer programming models, with different levels of detail, aimed at re-routing air traffic flows. The models are tested on a set of test data based on the actual traffic crossing the whole French upper airspace. The...
متن کاملClassification of Conformally Indecomposable Integral Flows on Signed Graphs
A conformally indecomposable flow f on a signed graph Σ is a nonzero integral flow that cannot be decomposed into f = f1 + f2, where f1, f2 are nonzero integral flows having the same sign (both ≥ 0 or both ≤ 0) at every edge. This paper is to classify at integer scale conformally indecomposable flows into characteristic vectors of Eulerian cycle-trees — a class of signed graphs having a kind of...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Oper. Res. Lett.
دوره 37 شماره
صفحات -
تاریخ انتشار 2009