Showing papers on "Connectivity published in 1970"

Parsing of Graph-Representable Pictures

Abstract: A syntax-directed picture analysis system based on a formal picture description scheme is described. The system accepts a description of a set of pictures in terms of a grammar generating strings in a picture description language; the grammar is explicitly used to direct the analysis or parse, and to control the calls on pattern classification routines for primitive picture components. Pictures are represented by directed graphs with labeled edges, where the edges denote elementary picture components and the graph connectivity mirrors the picture component connectivity; blank and don't care “patterns” allow the description of simple relations between visible patterns. The bulk of the paper is concerned with the picture parsing algorithm which is an n-dimensional analog of a classical top-down string parser, and an application of an implemented system to the analysis of spark chamber film. The potential benefits of this approach, as demonstrated by the application, include ease of implementation and modification of picture processing systems, and simplification of the pattern recognition problem by automatically taking advantage of contextual information.

Nonlinear Regression With Linear Constraints: An Extension of the Magnified Diagonal Method

Abstract: A syntax-directed picture analysis system based on a formal picture description scheme is described. The system accepts a description of a set of pictures in terms of a grammar generating strings in a picture description language; the grammar is explicitly used to direct the analysis or parse, and to control the calls on pattern classification routines for primitive picture components. Pictures are represented by directed graphs with labeled edges, where the edges denote elementary picture components and the graph connectivity mirrors the picture component connectivity; blank and don't care “patterns” allow the description of simple relations between visible patterns. The bulk of the paper is concerned with the picture parsing algorithm which is an n-dimensional analog of a classical top-down string parser, and an application of an implemented system to the analysis of spark chamber film. The potential benefits of this approach, as demonstrated by the application, include ease of implementation and modification of picture processing systems, and simplification of the pattern recognition problem by automatically taking advantage of contextual information.

On applications of graph/network theory to problems in communication systems

Abstract: Graph/network theory results are applicable to problems in communications. As a representative example, the node coloring problem in graph theory is applicable to the channel assignment problem in cellular mobile communication systems. The node coloring problem is NP-complete, meaning that optimally solving it is very difficult. Therefore, we use heuristic algorithms for the channel assignment problem. In this case, the graph theory results show the legitimacy of using heuristic techniques. On the other hand, we can directly apply graph theory to communication problems. For example, on contents delivery services in the Internet, we place mirror servers that provide the same contents on the network. Location problems on flow networks are applicable to mirror server allocation problems. In a simple case, we can efficiently solve the problem. In this paper, we concentrate on multi-hop wireless networks and consider the relationship between their problems and the results of graph/network theory.

Graph connectivity algorithm

Abstract: w i t h t h e de te rmina t ion of graph connec t iv i ty and r e l a t e d problems are presented . The a lgor i thms which a r e proposed a r e t e n t a t i v e they accomplish the s t s t e d o b j e c t i v e s bu t , i n some ins t ances , have c e r t a i n shortcomings, a s w i l l become c l e a r . The methods t e n t b t i v e l y adopted f o r ob ta in ing t h e poin t -connec t iv i ty o r l i ne -connec t iv i ty of a graph make use of network flowr a lgor i thms developed by Ford end Fulkerson (1;2) snci Gomory and Hu ( 3 ) . These methods can h l s o y i e l d a d d i t i o n e l informhtion o f i n t e r e s t r e l h t i n g t o connec t iv i ty , such h s i d e n t i f i c a t i o n of ( z ) minimtl d i s connect ing sets of p o i n t s o r l i n e s ; (b ) i mzxirnsl s e t of p o i n t d i s j o i n t o r l i n e d i s j o i n t yhths jo in ing t given p k i r of po in t s ; znd ( c ) , t: s e t of c o n n e c t i v i t y i n c r e t s i n g l i n e s . I n t h e fo l lowing some pre l iminary f ind ings d e a l i n g

Efficient tree-listing algorithm

Abstract: An algorithm, based on the T-triangle method, is given for the generation of all the trees in a nonoriented connected graph. The efficiency of the algorithm is verified by computer results.