In this paper we propose a special computational device which uses light rays for solving the Hamiltonian path problem on a directed graph. The device has a graph-like representation and the light is traversing it by following the routes given by the connections between nodes. In each node the rays are uniquely marked so that they can be easily identified. At the destination node we will search only for particular rays that have passed only once through each node. We show that the proposed device can solve small and medium instances of the problem in reasonable time.
Many theoretical and practical light-based devices have been proposed for dealing with various problems. Optical computation has some advantages, one of them being the fact that it can perform some operations faster than conventional devices. An example is the @math -point discrete Fourier transform computation which can be performed in only unit time @cite_1 @cite_8 .
@cite_1 @cite_8
36503682 2139842859
An all nonionic liquid shampoo which includes an amine oxide, a polyoxyethylene hexitan mono-higher fatty acid ester, and at least one of a higher alkoxy polyoxyethylene ethanol, an alkyl glycoside and a mixture of glycoside, a higher fatty acid lower alkanolamide and polyacrylamide. Optionally, the mixture of higher fatty acid lower alkanolamide and polyacrylamide may be present in the liquid shampoo containing amine oxide, polyoxyethylene hexitan mono-higher fatty acid ester and the higher alkoxy polyoxyethylene ethanol and or alkyl glycoside. Another optional constituent is a polyethylene glycol higher fatty acid ester. The shampoos are essentially free of ions and are desirably completely free of ionic materials with the pH essentially neutral. Optical-computing technology offers new challenges to algorithm designers since it can perform an n-point discrete Fourier transform (DFT) computation in only unit time. Note that the DFT is a nontrivial computation in the parallel random-access machine model, a model of computing commonly used by parallel-algorithm designers. We develop two new models, the DFT–VLSIO (very-large-scale integrated optics) and the DFT–circuit, to capture this characteristic of optical computing. We also provide two paradigms for developing parallel algorithms in these models. Efficient parallel algorithms for many problems, including polynomial and matrix computations, sorting, and string matching, are presented. The sorting and string-matching algorithms are particularly noteworthy. Almost all these algorithms are within a polylog factor of the optical-computing (VLSIO) lower bounds derived by Barakat Reif [Appl. Opt.26, 1015 (1987) and by Tyagi Reif [Proceedings of the Second IEEE Symposium on Parallel and Distributed Processing (Institute of Electrical and Electronics Engineers, New York, 1990) p. 14].