A Bayesian analysis of experiments with small numbers of events

Within the framework of Bayesian statistics we derive a distribution for the posterior degree of belief both for the difference and ratio of small numbers of events, when the background mean in each case is known with finite precision.     

Kalman filtering of traffic fluctuations for real-time network management

Discrete- time stochastic models of sequential traffic records in telephone networks are considered. They appear to be well suited for a use of the Kaiman filter. A version of the filtering algorithm is adopted to deal with traffic fluctuations. The overall approach is tested against the real data gathered by the supervisor of the French toll network. The adaptive traffic estimator is inserted into a simulator of a testbed network operated in the urban zone of Paris. The traffic estimations provided by the filter are used to decide an overflow hierarchy.     

A fuzzy control approach for adaptive traffic routing

The application of fuzzy control to adaptive traffic routing in telephone networks is investigated. The authors use, on one hand, the properties of fuzzy control techniques and adaptive routing, on the other hand, to derive a routing system that is robust and efficient. They analyze the impact of various availability indicators on performance, which indicates that the choice of a suitable indicator must be made to characterize circuit group availability. When used in the fuzzy control framework the indicator used appears clearly to improve the performance of the routing algorithm as compared to existing routing systems. On the other hand, the use of this indicator in a classical way appears to be of poor utility. The study compares the performance of methods usually applied to adaptive traffic routing and the fuzzy control approach and shows that the fuzzy control approach could provide an effective framework for robust control of traffic routing in communications networks. Research studies still need to be carried out to develop fuzzy adaptive routing on different network structures and to evaluate its impact on performance     

Serum beta-carotene deficiency in HIV-infected children

Representative levels of serum micronutrients specifically, beta-carotene and vitamins A and E, were studied in symptomatic human immunodeficiency virus (HIV)-infected children. The nutritional status of 23 symptomatic African-American and Hispanic HIV-infected children were compared with an appropriate control group comprised of 36 uninfected children matched for age and sex, using body mass index. Serum beta-carotene and vitamin A and E levels were randomly determined on 15 of the infected children. Beta-carotene concentration was 4.9-fold reduced in symptomatic HIV-infected children when compared with the control group. There was a 6.5-fold decrease in the serum level for children without acquired immunodeficiency syndrome (AIDS) and a 13-fold reduction in children with AIDS. No differences in the mean values for serum vitamins A and E were observed in the groups studied. Although the nutritional status of the symptomatic HIV-infected children was not different from that of the control population, their serum beta-carotene levels were profoundly deficient. This finding may have immunologic and clinical implications for children with rapidly progressing HIV disease.     

Inference about long run canonical correlations

This article proposes methods for testing the null hypothesis that a number of so‐called long run canonical correlations (LRCCs) are zero. Two test statistics are proposed and their limiting distributions are derived under the null hypothesis. The finite sample properties of the tests are illustrated via a number of simulation studies that reveal the asymptotic theory provides a good guidance to behaviour in moderate or large sized samples. It is shown that the statistics provide a natural way for testing the asymptotic independence of two standardized sums. The usefulness of the tests is illustrated via the following examples: inference about cointegrating vector in a particular cointegration model; inference about break points in a cointegration model; moment estimation; parameter estimation in Generalized Method of Moments estimation.     

Does financial development lower energy intensity?

The growth-induced effects of financial development have been well-established in the empirical literature, as well as the significance of financial development to energy demand behavior. However, the empirical evidence on the relationship between financial development and energy intensity remains sparse in the literature. Given the multifaceted nature of the effects of financial development, the proposed relationship seems a complex one and warrants an empirical investigation. Using the case of Ghana, this study provides an empirical answer to the question: does financial development lower energy intensity? To provide solid grounds for either rejection or acceptance of the null hypothesis, this study performed several robustness checks. Generally, the evidence revealed that financial development lowers energy intensity. Further, the results revealed that the price of energy, trade liberalization and industry structure play significant roles. These results have important implications for the design of macro energy efficiency policies and the creation of a ‘Green Bank’.