We define binet matrices, which furnish a direct generalization of totally unimodular network matrices and arise from the node-edge incidence matrices of bidirected graphs in the same way as the network matrices do from directed graphs. We develop the necessary theory, give binet representations for interesting sets of matrices, characterize totally… (More)
The need for more realistic network models led to the development of the dynamic network flow theory. In dynamic flow models it takes time for the flow to pass an arc, the flow can be delayed at nodes, and the network parameters, e.g., the arc capacities, can change in time. Surprisingly perhaps, despite being closer to reality, dynamic flow models have… (More)
article(s) in LSE Research Online to facilitate their private study or for non-commercial research. You may not engage in further distribution of the material or use it for any profit-making activities or any commercial gain. You may freely distribute the URL Abstract This paper deals with linear and integer programming problems in which the constraint… (More)
A strongly polynomial time algorithm is described to solve the node-capa-citated routing problem in an undirected ring network.
Conformance testing is based on a test suite. Standardization committees release standard test suites, which consist of hundreds of test cases. The main problem of conformance testing is that we do not have enough time to execute them all. Therefore, test selection is required to maximize the test coverage. In our earlier papers 6,77 we outlined a new… (More)
In this paper we focus on the test selection problem. It is modeled after a real-life problem that arises in telecommunication when one has to check the reliability of an application. We apply different metaheuristics, namely Reactive Tabu Search (RTS), Genetic Algorithms (GA) and Simulated Annealing (SA) to solve the problem. We propose some modifications… (More)
We provide a new class of matrices, called binet matrices (denoted by), which guarantee half-integral vertices for the polytope È Ü Ð Ü ÙÙ Ü. They furnish a direct generalisation of totally unimodular network matrices and arise from the node-edge incidence matrices of bidirected graphs in the same way as the network matrices do from directed graphs. We… (More)