Generation of unpredictable time series by a Neural Network

A perceptron that learns the opposite of its own output is used to generate a time series. We analyse properties of the weight vector and the generated sequence, like the cycle length and the probability distribution of generated sequences. A remarkable suppression of the autocorrelation function is explained, and connections to the Bernasconi model are discussed. If a continuous transfer function is used, the system displays chaotic and intermittent behaviour, with the product of the learning rate and amplification as a control parameter.Comment: 11 pages, 14 figures; slightly expanded and clarified, mistakes corrected; accepted for publication in PR

Competitive Priorities and Competitive Advantage in Jordanian Manufacturing

The purpose of this research was to explore and predict the relationship between the competitive priorities (quality, cost, flexibility and delivery) and the competitive advantage of firms in the Jordanian Industrial Sector. A population of 88 Jordanian manufacturing firms, registered on the Amman Stock Exchange, was targeted using a cross-sectional survey employing a questionnaire method of data collection. The results of the data analysis indicate a significant relationship between competitive priorities and competitive advantage. The research suggests that recognising and nurturing this relationship provides the master key for a firm to survive in a turbulent environment. Therefore, operational and marketing strategies should place emphasis on competitive priorities such as quality, cost, flexibility and delivery to achieve, develop and maintain competitive advantage. This study is one of the first to examine the relationship between the competitive priorities of Jordanian manufacturing firms and their competitive advantage

Cluster Dynamics for Randomly Frustrated Systems with Finite Connectivity

In simulations of some infinite range spin glass systems with finite connectivity, it is found that for any resonable computational time, the saturatedenergy per spin that is achieved by a cluster algorithm is lowered in comparison to that achieved by Metropolis dynamics.The gap between the average energies obtained from these two dynamics is robust with respect to variations of the annealing schedule. For some probability distribution of the interactions the ground state energy is calculated analytically within the replica symmetry assumptionand is found to be saturated by a cluster algorithm.Comment: Revtex, 4 pages with 3 figure

Predicting the fatigue life of polycarbonate

In this study a constitutive modelling approach is used to predict the fatigue life of polycarbonate. After a thorough investigation on the heating effects, accurate lifetime predictions are made under isothermal as well as non-isothermal conditions. Moreover, it is shown that cyclic fatigue has an accelerated effect on the ageing behaviour

Sentinel Node Procedure for Breast Cancer: training, safety, reliability and follow-up aspects

In the recent years the surgical treatment of breast cancer has changed towards a less invasive and less mutilating procedure. Breast conserving therapy and the introduction of the sentinel node (SN) procedure are the two most important changes. The introduction of a new technique is a time consuming procedure. First it should be developed and evaluated in a local situation. If the new technique is believed to be better than the standard treatment, the technique should be come available if possible after a randomised controlled trial for all patients concerned. In CHAPTER 2 the introduction of the SN procedure in three participating hospitals (a large teaching hospital, a cancer centre and a university hospital) is described. Special attention was made on the role of a co-ordinator to assure standardisation and quality control in this multicenter study. The role of the co-ordinator was two folded; firstly the supervision of the implementation in the several involved departments and secondly to refine the procedure upon the collected data. During our study we adjusted several aspects of the procedure: the concentration of the colloid in the radioactive solution, the injection of the blue dye intracutaneously after disappointing results of the peritumoral injection and, in cases of a preceding lumpectomy, a cranial injection to the scar because of failure of the caudal injections. With these corrections the results became excellent. In the end the results of the procedure (sensitivity and false negativity) were the same for the three participating hospitals

Spin Models on Thin Graphs

We discuss the utility of analytical and numerical investigation of spin models, in particular spin glasses, on ordinary ``thin'' random graphs (in effect Feynman diagrams) using methods borrowed from the ``fat'' graphs of two dimensional gravity. We highlight the similarity with Bethe lattice calculations and the advantages of the thin graph approach both analytically and numerically for investigating mean field results.Comment: Contribution to Parallel Session at Lattice95, 4 pages. Dodgy compressed ps file replaced with uuencoded LaTex original + ps figure