altan derivatives of polycyclic conjugated hydrocarbons were recently introduced and studied in theoretical organic chemistry. we now provide a generalization of the altan concept, applicable to any graph. several earlier noticed topological properties of altan derivatives of polycyclic conjugated hydrocarbons are shown to be the properties of all altan derivatives of all graphs. among these ar...

let g be a (p,q) graph. an injective map f : e(g) → {±1,±2,...,±q} is said to be an edge pair sum labeling if the induced vertex function f*: v (g) → z - {0} defined by f*(v) = σp∈ev f (e) is one-one where ev denotes the set of edges in g that are incident with a vertex v and f*(v (g)) is either of the form {±k1,±k2,...,±kp/2} or {±k1,±k2,...,±k(p-1)/2} u {±k(p+1)/2} according a...

GUPRO (Generic Unit for Program Understanding, http://www.gupro.de) provides an adaptable and extesible workbench for program understanding and software reengineering. GUPRO is strongly based on graph technology, i. e. source code is parsed into graph structures which are accessible by graph algorithms and a general graph query language GReQL. In GUPRO, these base technologies are combined into...

A user-centred design approach in combination with a tool-supported development of abstract prototypes is proposed. Based on task, object and user models an editor for modelling the navigation structure of a user interface as a dialogue graph is demonstrated. This editor is based on the XIML technology and allows simulations considering temporal relations between task and design decisions for t...

GUPRO is an integrated workbench to support program understanding of heterogenous software systems on arbitrary levels of granularity. GUPRO can be adapted to specific needs by an appropriate conceptual model of the target software. GUPRO is based on graph-technology. It heavily relies on graph querying and graph algorithms. Source code is extracted into a graph repository which can be viewed b...

a emph{signed graph} (or, in short, emph{sigraph}) $s=(s^u,sigma)$ consists of an underlying graph $s^u :=g=(v,e)$ and a function $sigma:e(s^u)longrightarrow {+,-}$, called the signature of $s$. a emph{marking} of $s$ is a function $mu:v(s)longrightarrow {+,-}$. the emph{canonical marking} of a signed graph $s$, denoted $mu_sigma$, is given as $$mu_sigma(v) := prod_{vwin e(s)}sigma(vw).$$the li...

In a proper vertex coloring of a graph a subgraph is colorful if its vertices are colored with different colors. It is well-known that in every proper coloring of a k-chromatic graph there is a colorful path Pk on k vertices. If the graph is k-chromatic and triangle-free then in any proper coloring there is also a path Pk which is an induced subgraph. N.R. Aravind conjectured that these results...

A general purpose 2D CAD system was established by Object-Oriented technology. Key technologies for realizing the system were introduced. The methods for forming shape container, manipulating shape container and constructing graph template library were described in detail. Basic shapes, such as line, rectangle, ellipse, polygon, B-Spline curve and textbox, can be grouped to be a shape container...

A local property reconstructor for a graph property is an algorithm which, given oracle access to the adjacency list of a graph that is “close” to having the property, provides oracle access to the adjacency matrix of a “correction” of the graph, i.e. a graph which has the property and is close to the given graph. For this model, we achieve local property reconstructors for the properties of co...