Richard Van Slyke

Backtracking Algorithms for Network Reliability Analysis

Backtracking algorithms are applied to determine various reliability measures for networks. These algorithms are useful in analyzing the reliability of many data communication networks. We consider an undirected network where each node and each arc may be in one of two states: operative or inoperative. These states are independent random events. In addition to the more usual measure of network reliability, the probability that a specified pair of nodes can communicate, we consider more global measures such as the probability that all nodes can communicate and all operative nodes can communicate.

Programming under Uncertainty and Stochastic Optimal Control

Abstract : The theory of programming under uncertainty is extended to the case when the decision variables are elements of a Banach space. This approach leads to a very natural application of the computational techniques of mathematical programming to stochastic optimal control problems. It is shown that there exists an equivalent deterministic mathematical program whose set of feasible solutions is a convex set and whose objective function can be expressed as a convex function of the initial decision variables. In the second part, a duality theory is developed for this class of problems and some of the relations to the maximum principle for stochastic linear control problems are given.

Packet radio system: network considerations

The Packet Radio System considered as a network is characterized by devices, terminals, repeaters and stations, linked together by broadcast radio channels.

A distributed, scaleable simplex method

We present a simple, scaleable, distributed simplex implementation for large linear programs. It is designed for coarse-grained computation, particularly, readily available networks of workstations. Scalability is achieved by using the standard form of the simplex rather than the revised method. Virtually all serious implementations are based on the revised method because it is much faster for sparse LPs, which are most common. However, there are advantages to the standard method as well. First, the standard method is effective for dense problems. Although dense problems are uncommon in general, they occur frequently in some important applications such as wavelet decomposition, digital filter design, text categorization, and image processing. Second, the standard method can be easily and effectively extended to a coarse grained, distributed algorithm. Such an implementation is presented here. The effectiveness of the approach is supported by experiment and analysis.

Reliability of computer-communication networks

A major consideration in the original design and in the expansion of any computer-communication network is the provision of a network which will be relatively invulnerable to failures of its components. This paper considers the reliability analysis of such networks. Two indices of reliability for a network are introduced. Methods for the calculation of these indices are illustrated by carrying out a detailed reliability analysis of the ARPA Computer Network. This analysis includes sensitivity calculations to protect against inaccuracies of measured system parameters and the evaluation of possible improvements in reliability through modification of network configuration.

Cutting plane algorithms and state space constrained linear optimal control problems

In this paper an algorithm is proposed for solving continuous linear optimal control systems with state space constraints by solving a sequence of linear optimal control systems without state space constraints. The convergence of the algorithm is proved by a method similar to cutting plane algorithm for convex programs in Banach Spaces. It is also shown how to solve the problem by using mathematical programming algorithm on the discretized problem. A numerical example is solved by discretization and mathematical programming.

Simulation of Centralized Computer Communications Systems

In this concise paper we described the simulation approach for a general centralized computer communication system with emphasis on efficiency and versatility. The simulation program consists of three modules representing different levels in a hierarchy. The lowest level models the polled multidrop line connecting remote terminals to the concentrator. The second level models the trunk lines and the concentrator which interfaces the multidrop lines of lower speed to one or more higher speed trunk lines connected to a central computer. The highest level models the central computer which communicates with remote terminals via the trunks. A hybrid simulation approach is used to ease program development and to shorten computer running time. When feasible, empirical distributions, analytical formulas, or analytical models are used to eliminate simulation steps and simplify simulation procedures. The techniques developed are illustrated by application to the NASDAQ system.

Artificial intelligence applications to communication network design with bulk facilities

This paper presents a heuristic sytem for a special problem in communication network design with bulk facilities, called the TI problem. We apply AI to this problem. The knowledge acquired from an expert team is represented procedurally. Our work shows the promise of applying AI methodologies in solving network optimization problems.

Educating the telecommunications manager

Abstract Given the complexity, scope, and magnitude of technological and regulatory changes in the telecommunications industry, management education programs must offer training beyond the traditional management curriculum. Courses in technology, regulation, and telecommunications economics are an essential part of a curriculum for telecommunications managers. Polytechnic University, in conjunction with Center for Advanced Technology in Telecommunications (CATT), has developed an MS in Telecommunications Management Program which combines technical and managerial training in an executive-education format course extending over a two-year period. Students are sponsored by their corporations and are employed in companies that provide telecommunications equipment and/or services and companies whose use of telecommunications makes it a strategic resource.