Novel Technique for All-Optical Clock Extraction Using Fiber Bragg Gratings

We demonstrate a simple passive technique, using phase shifted fibre Bragg gratings, for extraction of optical clock signals from RZ optical data signals . The generation of an optical clock signal at 12.5 GHz from a 12.5 Gbs RZ optical data stream is experimentally demonstrated with simulation of optical clock extraction at 10 GHz fro m 40 Gbs OTDM data streams .     

AI and OR in management of operations: history and trends

The last decade has seen a considerable growth in the use of Artificial Intelligence (AI) for operations management with the aim of finding solutions to problems that are increasing in complexity and scale. This paper begins by setting the context for the survey through a historical perspective of OR and AI. An extensive survey of applications of AI techniques for operations management, covering a total of over 1200 papers published from 1995 to 2004 is then presented. The survey utilizes Elsevier's ScienceDirect database as a source. Hence, the survey may not cover all the relevant journals but includes a sufficiently wide range of publications to make it representative of the research in the field. The papers are categorized into four areas of operations management: (a) design, (b) scheduling, (c) process planning and control and (d) quality, maintenance and fault diagnosis. Each of the four areas is categorized in terms of the AI techniques used: genetic algorithms, case-based reasoning, knowledge-based systems, fuzzy logic and hybrid techniques. The trends over the last decade are identified, discussed with respect to expected trends and directions for future work suggested.     

On bimeasurings II

We answer some questions posed in [L. Grunenfelder, M. Mastnak, On bimeasurings, J. Pure Appl. Algebra 204 (2006) 258-269] concerning the universal bimeasuring bialgebra via a construction of suitable subcoalgebras of the universal measuring coalgebra.     

A perturbation-based heuristic for the capacitated multisource Weber problem

This paper proposes a perturbation-based heuristic for the capacitated multisource Weber problem. This procedure is based on an effective use of borderline customers. Several implementations are considered and the two most appropriate are then computationally enhanced by using a reduced neighbourhood when solving the transportation problem. Computational results are presented using data sets from the literature, originally used for the uncapacitated case, with encouraging results.     

Regularization of singular systems of linear algebraic equations by shifts

Regularization of singular systems of linear algebraic equations by shifts is examined. New equivalent conditions for the shift regularizability of such systems are derived.     

Impact of two mass scale oscillations on the analysis of atmospheric and reactor neutrino data

We study the stability of the results of the three-neutrino oscillation analysis of atmospheric and reactor neutrino data under departures of the one dominant mass scale approximation. In order to do so we perform the analysis of atmospheric and reactor neutrino data in terms of three-neutrino oscillations where the effect of both mass differences is explicitly considered. We study the allowed parameter space resulting from this analysis as a function of the mass splitting hierarchy parameter which parameterizes the departure from the one dominant mass scale approximation. We consider schemes with both direct and inverted mass ordering. Our results show that in the analysis of the atmospheric data the derived range of the largest mass splitting, , is stable, while the allowed ranges of mixing angles and are wider than those obtained in the one dominant mass scale approximation. Inclusion of the CHOOZ reactor data in the analysis results in the reduction of the parameter space in particular for the mixing angles. As a consequence the final allowed ranges of the parameters from the combined analysis are only slightly broader than when obtained in the one dominant mass scale approximation. Received: 31 May 2002 / Revised version: 10 July 2002 / Published online: 31 October 2002     

Photothermal techniques applied to the determination of the water vapor diffusion coefficient and thermal diffusivity of edible films.

Water vapor diffusion coefficient (WVDC) and thermal diffusivity (alpha) were determined in gelatin-starch films through photothermal techniques. The effect of different variables in the elaboration of these films, such as starch and glycerol concentrations and pH, were evaluated through the response surface methodology. The results indicated that an increase in the glycerol concentration and pH favored the WVDC of the films. On the other hand, alpha was influenced principally by the starch content and pH of the film-forming solution. The minimum alpha value was 4.5 x 10(-4) cm2/s, which is compared with alpha values reported for commercial synthetic polymers.     

Schemes of effective magnetic AND and XOR logic elements

Schemes and calculated characteristics of effective logic elements with two inputs for classical ground-state computations are reported. These elements have a high threshold (0.48) and perform a desired logical operation in a wide range of input signals.