Signal transduction in living systems is inevitably disturbed by stochastic factors, such as the internal molecular noise, random openings and closings of voltage-gated membrane channels, thermal fluctuations of membrane potential etc. Many investigations have been done to explore the effects of stochastic factors on calcium signals (Ullah & Jung, 2006; Falcke, 2004; Li et al., 2005; Dupont et ...

We present a model-theoretic property of finite structures, that can be seen to be a finitary analogue of the well-studied downward Löwenheim-Skolem property from classical model theory. We call this property the L-equivalent bounded substructure property, denoted L-EBSP, where L is either FO or MSO. Intuitively, L-EBSP states that a large finite structure contains a small “logically similar” s...

General equilibrium theory has been proposed for resource allocation in computational markets. The basic procedure is that agents submit bids and that a resource (re)allocation is performed when a set of prices (one for each commodity) is found such that supply meets demand for each commodity. For successful implementation of large markets based on general equilibrium theory, e cient algorithms...

In this paper, we study the conflict-free coloring of graphs induced by neighborhoods. A coloring of a graph is conflict-free if every vertex has a uniquely colored vertex in its neighborhood. The conflict-free coloring problem is to color the vertices of a graph using the minimum number of colors such that the coloring is conflict-free. We consider both closed neighborhoods, where the neighbor...

Vertex Separation Minimization Problem (VSMP) consists of finding a layout of a graph G = (V,E) which minimizes the maximum vertex cut or separation of a layout. It is an NPcomplete problem in general for which metaheuristic techniques can be applied to find near optimal solution. VSMP has applications in VLSI design, graph drawing and computer language compiler design. VSMP is polynomially sol...

This paper introduces the notion of involution module, the first generalization of the modular decomposition of 2-structure which has a unique linear-sized decomposition tree. We derive an O(n) decomposition algorithm and we take advantage of the involution modular decomposition tree to state several algorithmic results. Cographs are the graphs that are totally decomposable w.r.t modular decomp...

The Gallai graph and the anti-Gallai graph of a graph G are edge disjoint spanning subgraphs of the line graph L(G). The vertices in the Gallai graph are adjacent if two of the end vertices of the corresponding edges in G coincide and the other two end vertices are nonadjacent in G. The anti-Gallai graph of G is the complement of its Gallai graph in L(G). Attributed to Gallai (1967), the study ...

This paper presents a new algebraic multigrid-based method for solving the curl-curl formulation of Maxwell’s equations discretized with edge elements. The ultimate goal of this approach is two-fold. The first is to produce a multiple-coarsening multigrid method with two approximately decoupled hierarchies branching off at the initial coarse level, one resolving the divergence-free error and th...

The class Steiner tree problem (CSP) 18, 19, 29] is a generalization of the well known Steiner tree problem (STP) 17, 35]; one is given a weighted undirected graph in which the nodes are partitioned into g classes of terminals or required nodes. A minimum size tree that includes at least one node from each class is required. CSP is MAX SNP-hard even on a tree 19]. We show that CSP can be reduce...

A gain graph (Γ, g, G) is a graph Γ = (V,E) together with a group G, the gain group, and a homomorphism g, the gain function, from the free group F (E) on the edge set E into G. We think of the edges of G as oriented in an arbitrary but fixed way, so that if e is an edge in one direction, then e−1 is the same edge in the opposite direction; thus g(e−1) = g(e)−1. A gain graph is balanced if for ...