Let V and W be vector spaces over a common field, and let S and T be sets of subspaces of V and W, respectively. A linear function φ : V → W is called a (Grassmann) homomorphism from S to T if φ(S) ∈ T holds for every S ∈ S. Coloring of graphs and hypergraphs and flows in graphs can be reformulated in terms of these homomorphisms. The main results are constructive characterizations of the sets ...

Most approaches for optimizing traffic signal timings deal with the daily traffic. However, there are a few occasional events like football matches or concerts of musicians that lead to exceptional traffic situations. Still, such events occur more or less regularly and place and time are known in advance. Hence, it is possible to anticipate such events with special signal timings. In this paper...

We consider the communication capacity of wireline networks for a two-unicast traffic pattern. The network has two sources and two destinations with each source communicating a message to its own destination, subject to the capacity constraints on the directed edges of the network. We propose a simple outer bound for the problem that we call the Generalized Network Sharing (GNS) bound. We show ...

the problem of finding the minimum cost multi-commodity flow in an undirected and completenetwork is studied when the link costs are piecewise linear and convex. the arc-path model and overflowmodel are presented to formulate the problem. the results suggest that the new overflow model outperformsthe classical arc-path model for this problem. the classical revised simplex, frank and wolf and a ...

The problem of constructing flows associated with first order ordinary differential equations (ODEs) with spatially non-Lipschitz right-hand side is considered. Due to the lack of uniqueness of the solutions, standard flows cannot be defined in this case. For these situations, it is natural to introduce generalized flows which are random fields constructed by assigning a probability measure on ...

We study the facial structure of a polyhedron associated with the single node relaxation of network flow problems with additive variable upper bounds. This type of structure arises, for example, in production planning problems with setup times and in network certain expansion problems. We derive several classes of valid inequalities for this polyhedron and give conditions under which they are f...

In this paper we study a classification of linear systems on Lie groups with respect the conjugacy of the corresponding flows. We also describe stability according to Lyapunov exponents.

Ensuring that the poorer segments of the population have access to financial products and services has taken on increased significance as policymakers have come to understand the broad social ramifications of inclusive financial regimes. Access not only promotes savings but also enables the poor to manage cash flows and to meet basic needs such as health care, food, and housing. In the United S...

the existing works considering the flow-based discount factor in the hub and spoke problems, assume that increasing the amount of flow passing through each edge of network continuously decreases the unit flow transportation cost. although a higher volume of flow allows for using wider links and consequently cheaper transportation, but the unit of flow enjoys more discounts, quite like replacing...

The motivation for writing U.S. Geological Survey Open-File Report 85-95 was to (1) show that the linear regression approach of transferring low-flow statistics (e.g., 7-day, 10-year low flow) from an index station to a partialrecord site was biased and (2) propose an alternative unbiased estimator. Most analysts who use a mathematical technique, use linear regression analysis to relate base-fl...